Patent Publication Number: US-7906481-B2

Title: Specific TNF-A inhibitors for treating spinal disorders mediated by nucleous pulposus

Description:
This application is a continuation-in-part of U.S. patent application Ser. No. 11/521,093, filed on Sep. 14, 2006 now U.S. Pat. No. 7,708,995, which is a continuation-in-part of U.S. patent application Ser. No. 10/225,237, filed on Aug. 22, 2002, now U.S. Pat. No. 7,115,557, which is a continuation in part of Ser. No. 09/826,893 filed on Apr. 6, 2001, now abandoned, which is a continuation-in-part of U.S. patent application Ser. No. 09/743,852 filed on Jan. 17, 2001, now U.S. Pat. No. 6,649,589, which was a National Stage filing under 35 U.S.C. §371 of International Application No. PCT/SE99/01671 filed on Sep. 23, 1999 which was published in English on Apr. 6, 2000 and claims benefit of Swedish Application Nos. 9803276-6 and 9803710-4 filed respectively on Sep. 25, 1998 and Oct. 29, 1998. These applications are herein incorporated by reference in their entirety for all purposes. 
    
    
     TECHNICAL FIELD 
     The present invention relates to a method for treating nerve root injury and other nerve and spinal disorders in a mammal or a vertebrate by administering a TNF-alpha inhibitor. The invention also relates to the use of a TNF-alpha inhibitor in the preparation of pharmaceutical compositions for the treatment of nerve root injury and other nerve and spinal disorders. 
     The object of the present invention is to obtain an improved possibility to treat nerve disorders, such as nerve root injury induced by disc herniation (e.g., by intervertebral disc herniation), which may turn up, for example, as a radiating pain in the arm or leg (sciatica), as low back pain or as whiplash associated disorder, by blocking disk related cytokines. 
     The present invention also relates to the use of a TNF-alpha inhibitor in the preparation of pharmaceutical compositions for the treatment of nerve disorders, such as nerve root injury (e.g., induced by intervertebral disc herniation), as well as a method for treating nerve root injury. 
     Another object of the present invention is to treat nerve root injury induced by nerve and spinal disorders such as disk herniation, which may turn up as radiating pain into the arm or leg (sciatica), low back pain, and whiplash associated disorder, by blocking disk related cytokines. 
     The methods and pharmaceutical compositions described herein can be used to treat nerve and spinal disorders such as nerve root injuries, a nerve disorder caused by or associated with a herniated disc(s), a nerve disorder involving pain, a nucleus pulposus-induced nerve injury, a spinal cord compression and sciatica. 
     BACKGROUND OF THE INVENTION 
     It is established that conditions such as sciatica and low back pain are due to activation and irritation of intraspinal nervous structures by disk derived substances (45, 48, 49). One key substance for inducing such irritation is Tumor Necrosis Factor alpha (TNF or TNF-alpha). TNF is a proinflammatory cytokine that may sensitize a nerve root in a way that when it is simultaneously deformed mechanically, ectopic nerve may be elicited locally and interpreted by the brain as pain in the corresponding dermatome. TNF may also induce a nutritional deficit in the nerve root by increasing the vascular permeability leading to intraneural edema, and by initiating intravascular coagulation by activation of adhesion molecules at the surface of the endothelial cells (48). Both these mechanisms may subsequently lead to a reduced blood flow with a reduced supply of nutrients and elimination of metabolic waist products. This reduction in nutrition may also induce sciatic pain per se. TNF may also induce low back pain due to local irritation of sensory nerve endings at the surface of the intervertebral disk. This may occur when the nucleus pulposus herniates out into the spinal canal and TNF produced and released from the disk cells may reach the nerve endings. 
     Disk herniation is a troublesome disorder, which can cause pronounced pain and muscle dysfunction, and thereby loss of ability to work. A herniation may occur in any disk in the spine but herniations in the lumbar and the cervical spine are most common. A disk herniation in the cervical spine may induce radiating pain and muscle dysfunction in the arm, which is generally referred to as cervical rhizopathy. Herniation in the lumbar spine may induce radiating pain and muscle dysfunction in the leg. The radiating pain in the leg is generally referred to as sciatica. Disk herniation will cause trouble to a varying degree, and the pain may last for one or two months or in severe cases up to 6 months. The arm or leg pain that can occur as a result of disk herniation can be very intense and may thus affect the individual patient&#39;s whole life situation during the sickness period. 
     U.S. Pat. No. 5,703,092 discloses the use of hydroxamic acid compounds and carbocyclic acids as metalloproteinase and TNF inhibitors, for the treatment of arthritis and other related inflammatory diseases. No use of these compounds for the treatment of nerve root injuries is disclosed or suggested. 
     U.S. Pat. No. 4,925,833 discloses the use of tetracyclines to enhance bone protein synthesis and treatment of osteoporosis. 
     U.S. Pat. No. 4,666,897 discloses inhibition of mammalian collagenolytic enzymes by administering tetracyclines. The collagenolytic activity is manifested by excessive bone resorption, periodontal disease, rheumatoid arthritis, ulceration of cornea, or resorption of skin or other connective tissue collagen. 
     However, neither this nor U.S. Pat. No. 4,925,833 disclose nerve root injury or the treatment thereof. 
     It has also been disclosed that selective inhibition may be efficient in reducing sciatic pain (32). 
     Low back pain affects approximately 80% of the population during their lifetime in most countries. Except for being extremely common, it is also one of the most costly disorders for the society. In Sweden alone, low back pain was estimated to cost $320,000,000 in 1997. The major part of the cost relates to indirect costs such as sick-compensation and reduced productivity, and only a minor part is related to direct costs such as medical care and pharmacological substances. 
     In a minority of the cases (5%), there may be a known cause for the pain such as intra spinal tumors, rheumatic diseases, infections and more. In these cases the treatment may be specifically aimed at the cause. However, in the majority of the cases of low back pain, the cause remains unknown. At present there is no direct way to treat low back pain with an unknown cause and existing treatment modalities only aim at symptomatic relief. 
     Low Back Pain and Sciatica 
     It is necessary to make a distinction between low back pain and one specific condition that is often linked to low back pain called “sciatica”. Sciatica refers to radiating pain into the leg according to the dermatomal innervation area of a specific spinal nerve root. The pain in sciatica is distinctly different from that of low back pain. In sciatica, the pain is sharp and intense, often described as “toothache-like”, and radiates down into the lower extremities, below the level of the knee. The experience of the pain is closely related to the dermatomal innervation of one or more lumbar spinal nerve roots. Sciatica is also frequently related to neurological dysfunction in that specific nerve and may be seen as sensory dysfunction, reduced reflexes and reduced muscular strength. The sciatic pain thus seem to be a neuropathic pain, i.e. pain due to nerve injury, induced by sensitized axons in a spinal nerve root at the lumbar spinal level. The pain experienced by the patient as low back pain is more dull and is diffusely located in the lower back. There is never any radiating pain into the leg. 
     Sciatica is the result of nerve injury, and the cause of sciatica has an anatomical correlate. Since 1934, sciatica is intimately linked to the presence of a herniated intervertebral disc. However, although most patients with sciatica will display a herniated disc at radiological examination, it is surprising that approximately 30% of an adult population at the age of 40-50 years of age with no present or previous sciatica also have disc herniations when assessed by magnetic resonance tomography, so called “silent” disc herniations (8, 9, 10, 75). The presence of silent disc herniations is intriguing to the spine research community and seems to contradict the relationship between disc herniations and sciatica. 
     Scientific Knowledge of the Pathophysiologic Mechanisms Behind Low Back Pain 
     It is well known that the outer part of the annulus fibrosus of the intervertebral disc and the posterior longitudinal ligament are innervated by C-fibers. Although there are no nerve fibers in the deeper part of the annulus fibrosus or the nucleus pulposus in normal discs, nerves may reach these parts in degenerated discs through annular tears. 
     Silent Disc Herniations 
     As presented earlier, it is known that approximately one-third of a normal adult population who never suffered from sciatica have radiological visible disc herniations. Since the presence of a disc herniation is so intimately linked to the symptom of sciatica this is surprising, and at present there is no valid explanation for this phenomenon. However, “silent” in this regard only implies that the disc herniations did not produce sciatica. One may assume though that they produce other symptoms. 
     Whiplash and Whiplash Associated Disorders (WAD) 
     About 10% to 20% of the occupants of a stricken vehicle in rear-end car collisions suffer from whiplash injury. The injury may also occur as a result of other types of accidents, such as train accidents, and sudden retardations. This injury is defined as a non-contact acceleration-deceleration injury to the head-neck system. It is most often caused by a rear-end car collision and there is no direct impact on the neck. 
     Presenting symptoms usually include neckpain, headaches, disequilibrium, blurred vision, parenthesize, changes in cognition, fatigue, insomnia and hypersensitivity to light and sound. Dizziness described in a variety of terms such as imbalance, light-headedness and vertigo also occurs frequently and these symptoms may be associated with long-term disability. 
     Although neurologic and orthopedic examinations do not reveal abnormalities in the majority of patients, the characteristics of dizziness due to whiplash can be elucidated by means of ElectroNystagmoGraphic (ENG) evaluation. This examination is a method that is suitable for proving pathology in the oculo-vestibular system of whiplash-patients. 
     Until recently, the reason for the extent of injury was poorly understood. In addition, due to the legal and insurance issues, the veracity of complaints of neck pain and other symptoms by people who suffer from whiplash is commonly viewed as suspect. 
     Whiplash injuries can be quite complex and may include a variety of related problems, such as joint dysfunction, and faulty movement patterns, chronic pain and cognitive and higher center dysfunction. 
     When the cervical spine (neck) is subject to a whiplash injury, there is usually a combination of factors that contribute to the pain. These factors must be addressed individually, while maintaining a “holistic” view of the patient. 
     The most significant factors may include one or more of the following: joint dysfunction, muscle dysfunction, and faulty movement patterns. 
     Joint Dysfunction 
     This occurs when one of the joints in the spine or limbs loses its normal joint play (resiliency and shock absorption). It is detected through motion palpation, a procedure in which the doctor gently moves the joint in different directions and assesses its joint play. When a joint develops dysfunction, its normal range of movement may be affected and it can become painful. In addition, joint dysfunction can lead to a muscle imbalance and muscle pain and a vicious cycle. The loss of joint play can cause abnormal signals to the nervous system (there are an abundance of nerve receptors in the joint). The muscles related to that joint can subsequently become tense or, conversely, underactive. The resulting muscle imbalance can place increased stress on the joint, aggravating the joint dysfunction that already exists. 
     Muscle Dysfunction 
     When joint dysfunction develops, muscles are affected. Some muscles respond by becoming tense and overactive, while others respond by becoming inhibited and underactive. In either case, these muscles can develop trigger points. Trigger points are areas of congestion within the muscle where sensitizing compounds accumulate. These sensitizing compounds can irritate the nerve endings within the muscle and produce pain. This pain can occur in the muscle itself or can be referred pain (perceived in other areas of the body). Muscle related mechanisms may also give rise to abnormal signaling to the nervous system. This event can subsequently cause disruption of the ability of the nervous system to properly regulate muscles in other parts of the body, leading to the development of faulty movement patterns. 
     Faulty Movement Patterns 
     It is thought that the intense barrage of pain signals from a traumatic injury to the cervical spine can change the way the nervous system controls the coordinated function of muscles. The disruption of coordinated, stable movement is known as faulty movement patterns. Faulty movement patterns cause increased strain in the muscles and joints, leading to pain. They can involve the neck itself or can arise from dysfunction in other areas of the body such as the foot or pelvis. Instability is also considered part of faulty movement patterns. There are 2 types of instability that can occur in whiplash: passive instability—the ligaments of the neck are loosened, and dynamic instability—the nervous system disruption causes a disturbance in the body&#39;s natural muscular response to common, everyday forces. As a result of instability, even mild, innocuous activities can become painful. 
     SUMMARY OF THE INVENTION 
     It has been found that the use of a TNF-alpha inhibitor, such as a substance selected from the group consisting of metalloproteinase inhibitors excluding methylprednisolone, tetracyclines including chemically modified tetracyclines, quinolones, corticosteroids, thalidomide, lazaroids, pentoxifylline, hydroxamic acid derivatives, carbocyclic acids, napthopyrans, soluble cytokine receptors, monoclonal antibodies towards TNF-alpha, amrinone, pimobendan, vesnarinone, phosphodiesterase inhibitors, lactoferrin and lactoferrin derived analogs, and melatonin are suitable for treatment of spinal disorders and nerve root injury caused by the liberation of TNF-alpha and compounds triggered by the liberation of or presence of TNF-alpha by inhibiting spinal disc TNF-alpha. 
     These substances are thus suitable for treatment of nerve root injury, and for treatment of sciatica, low back pain (LBP), and whiplash associated disorder (WAD). The substances can be used to treat nerve and spinal disorders such as nerve root injuries, a nerve disorder caused by or associated with a herniated disc(s), a nerve disorder involving pain, a nucleus pulposus-induced nerve injury, a spinal cord compression and sciatica. 
     TNF is one of many pro-inflammatory substances with similar action, and it is considered as a “major player” in inflammatory events. However, TNF may also in part acts through other pro-inflammatory cytokines such as for instance IL-1, IL-6, FAS, and IFN-gamma. 
     It is an object of the invention to provide novel and improved methods for inhibiting the action of TNF-alpha for treating disorders in a subject by administering a TNF-alpha inhibitor comprising the step of administering to said subject a therapeutically effective dosage of said TNF-alpha inhibitor, wherein said TNF-alpha inhibitor is a monoclonal antibody selected from CDP-571 (HUMICADE™) D2E7, and CDP-870. 
     It is an object of the invention to provide novel and improved methods for inhibiting the action of TNF-alpha for treating disorders in a subject by administering a TNF-alpha inhibitor comprising the step of administering to said subject a therapeutically effective dosage of a soluble cytokine receptor, such as etanercept. 
     Alternatively the TNF-alpha inhibitor used in the above method can be lactoferrin, CT3, ITF-2357, PD-168787, CLX-1100, M-PGA, NCS-700, PMS-601, RDP-58, TNF-484A, PCM-4, CBP-1011, SR-31747, AGT-1, Solimastat, CH-3697, NR58-3.14.3, RIP-3, Sch-23863 and SH-636. 
     The subject which can be treated by these methods include any vertebrate, preferably mammals, and of those, most preferably humans. 
     It is a more specific object of the invention to provide a novel pharmaceutical composition for treating nerve disorders in a subject comprising a therapeutically effective amount of a TNF-alpha inhibitor that is a monoclonal antibody selected from the group consisting of CDP-571 (HUMICADE™), D2E7, and CDP-870, and a pharmaceutically acceptable carrier, wherein said pharmaceutical composition inhibits nerve injury when administered to said subject. The pharmaceutical composition may comprise a therapeutically effective amount of a TNF-alpha inhibitor that is a soluble cytokine receptor, such as etanercept. The pharmaceutical composition alternatively can comprise one or more of these agents, or can comprise, alone or in combination, any of the agents discussed herein. 
     In another embodiment, the methods and pharmaceutical compositions described herein can be used to treat such nerve disorders as spinal disorders, nerve root injuries, a nerve disorder caused by or associated with a herniated disc(s), a nerve disorder involving pain, a nucleus pulposus-induced nerve injury, a spinal cord compression and sciatica. 
     Nerve disorders treatable with the method and the pharmaceutical composition according to the invention are, for example, nerve disorders due to a reduced nerve reduction velocity, spinal disorders, nerve root injuries, nerve disorders caused by disc herniation, sciatica, cervical rhizopathy, low back pain, whiplash associated disorder, nerve disorders involving pain, nucleus pulposus-induced nerve injuries, and spinal cord compressions. 
     The subject which can be treated by these methods include any vertebrate, preferably mammals, and of those, most preferably humans. 
     With the foregoing and other objects, advantages and features of the invention that will become hereinafter apparent, the nature of the invention may be more clearly understood by reference to the following detailed description of the preferred embodiments of the invention and to the appended claims. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     It has now surprisingly been shown possible to be able to treat nerve root injuries, or at least alleviate the symptoms of nerve root injuries by using a pharmaceutical composition comprising a therapeutically active amount of a TNF-alpha inhibitor. TNF-alpha inhibitors, include but are not limited to, metalloproteinase (MMP) inhibitors (excluding methylprednisolone), tetracyclines, chemically modified tetracyclines, quinolones, corticosteroids, thalidomide, lazaroids, pentoxifylline, hydroxamic acid derivatives, napthopyrans, soluble cytokine receptors, monoclonal antibodies towards TNF-alpha, amrinone, pimobendan, vesnarinone, phosphodiesterase inhibitors, lactoferrin and lactoferrin derived analogous, and melatonin in the form of bases or addition salts together with a pharmaceutically acceptable carrier. 
     By “therapeutically active amount” and “therapeutically effective dosage” are intended to be an amount that will lead to a desired therapeutic effect, i.e., an amount that will lead to an improvement of the patient&#39;s condition. In one preferred example, an amount sufficient to ameliorate or treat a condition associated with a nerve disorder. In some embodiments, the therapeutically effective amount is a dosage normally used when using such compounds for other therapeutic uses. Many of these drugs are commercially known registered drugs. 
     By “mammal” is meant to include but is not limited to primate, human, canine, porcine, equine, murine, feline, caprine, ovine, bovine, lupine, camelid, cervidae, rodent, avian and ichthyes. By animal is meant to include any vertebrate animal wherein there is a potential for nerve root injury. 
     As used herein, the term “antibody” is meant to refer to complete, intact antibodies, and Fab fragments, scFv, and F(ab) 2  fragments thereof. Complete, intact antibodies include monoclonal antibodies such as murine monoclonal antibodies (mAb), chimeric antibodies, humanized antibodies and human antibodies. The production of antibodies and the protein structures of complete, intact antibodies, Fab fragments, scFv fragments and F(ab) 2  fragments and the organization of the genetic sequences that encode such molecules, are well known and are described, for example, in Harlow et al., ANTIBODIES: A LABORATORY MANUAL, Cold Spring Harbor Laboratory, Cold Spring Harbor, N.Y. (1988) and Harlow et al., USING ANTIBODIES: A LABORATORY MANUAL, Cold Spring Harbor Press, 1999, which are herein incorporated by reference in their entirety. 
     By “epitope” is meant a region on an antigen molecule to which an antibody or an immunogenic fragment thereof binds specifically. The epitope can be a three dimensional epitope formed from residues on different regions of a protein antigen molecule, which, in a naive state, are closely apposed due to protein folding. “Epitope” as used herein can also mean an epitope created by a peptide or hapten portion of TNF-alpha and not a three dimensional epitope. Preferred epitopes are those wherein when bound to an immunogen (antibody, antibody fragment, or immunogenic fusion protein) results in inhibited or blocked TNF-alpha activity. 
     By “TNF-alpha blocking” is meant a compound or composition that blocks, inhibits or prevents the activity of TNF or TNF-alpha. 
     Compounds that possess TNF-alpha inhibitory activity are for example tetracyclines, (e.g., tetracycline, doxycycline, lymecycline, oxytetracycline, minocycline), and chemically modified tetracyclines (e.g., dedimethylamino-tetracycline), hydroxamic acid compounds, carbocyclic acids and derivatives, thalidomide, lazaroids, pentoxifylline, napthopyrans, soluble cytokine receptors, monoclonal antibodies towards INF-alpha, amrinone, pimobendan, vesnarinone, phosphodiesterase inhibitors, lactoferrin and lactoferrin derived analogs, melatonin, norfloxacine, ofloxacine, ciprofloxacine, gatifloxacine, pefloxacine, lomefloxacine, temafloxacine, TTP and p38 kinase inhibitors. These compounds can be present as bases or in the form of addition salts, whichever possesses the best or preferred pharmaceutical effect, and best property to be brought into a suitable pharmaceutical composition. A more complete list is given below. 
     Further, the active component can comprise a substance inhibiting a compound triggered by the release of TNF-alpha, such as interferon-gamma, interleukin-1, and nitrogen oxide (NO). 
     Aminoguanidine has been shown to inhibit the release of nitrogen oxide (NO) at nerve root injuries by inhibiting inducible nitrogen oxide synthetase, and aminoguanidine is thus one compound that inhibits a compound trigged by the release of TNF-alpha. 
     As stated above, there are several different types of cytokine blocking substances and pharmacological preparations that may be used according to the invention, and examples of those substances may be grouped in different subclasses: 
                                SPECIFIC TNF-A BLOCKING SUBSTANCES                     Monoclonal Antibodies   infliximab, CDP-571, (HUMICADE ™),           D2E7, CDP-870       Antibody Fragments   CDP-870       Soluble Cytokine Receptors   etanercept, lenercept, pegylated TNF-           receptor type I, TBP-1       TNF-receptor antagonists       Antisense oligonucleotides   ISIS-104838                 NON-SPECIFIC TNF-A BLOCKING SUBSTANCES                     MMP-inhibitors   (or TACE-inhibitors, i.e. TNF Alpha           Converting Enzyme-inhibitors), AG3340           (Prinomastat), Batimastat and Marimastat       Tetracyclines   Doxycycline, Lymecycline,           Oxitetracycline, Tetracycline, Minocycline           and synthetic tetracycline derivatives, such           as CMT (i.e., Chemically Modified           Tetracyclines such as KB-R7785; TIMP1           and 2, adTIMP2)       Quinolones   Norfloxacin, Levofloxacin, Enoxacin,           Sparfloxacin, Temafloxacin, Moxifloxacin,           Gatifloxacin, Gemifloxacin, Grepafloxacin,           Trovafloxacin, Ofloxacin, Ciprofloxacin,           Pefloxacin, Lomefloxacin and           Temafloxacin       Thalidomide derivatives   Selective Cytokine inhibitors (SelCID),           such as thalidomide derivatives such as           CC-1088, CDC-501, and CDC-801           (ROQUININEX ®)       Lazaroids   non-glucocorticoid 21-aminosteroids such           as U-74389G (16-desmethyl tirilazad) and           U-74500       Prostaglandins   Iloprost (prostacycline)       Cyclosporins       Pentoxifyllin derivatives       Hydroxamic acid derivatives       Napthopyrans       Phosphodiesterase I, II, III, IV, and V-   CC-1088, Ro 20-1724, rolipram, amrinone,       inhibitors   pimobendan, vesnarinone, SB 207499           (ARIFLO ®)       Melanocortine agonists   HP-228       Other TNF-a blocking agents   Lactoferrin; CT3; ITF-2357; PD- 168787;           CLX-1100; M-PGA; NCS- 700; PMS-601;           RDP-58; TNF-484A; PCM-4; CBP-1011;           SR-31747; AGT- 1; Solimastat; CH-3697;           NR58-3.14.3; RIP-3; Sch-23863; Yissum           project no. 11649; Pharma projects no.           6181, 6019 and 4657; SH-636                    
TNF Inhibitors
 
Specific TNF Inhibitors
 
     Monoclonal antibodies such as: infliximab, CDP-571 (HUMICADE™), D2E7 (Adalimumab), and the antibody fragment CDP-870; Polyclonal antibodies; Soluble cytokine receptors such as: etanercept, lenercept, pegylated TNF receptor type I, and TBP-1; TNF receptor antagonists; Antisense oligonucleotides such as: ISIS-104838 
     Non-Specific TNF Inhibitors 
     5,6-dimethylxanthenone-4-acetic acid (acemannan); AGT-1; ANA 245; AWD 12281; BN 58705; Caspase inhibitors; CBP-1011; CC 1069; CC 1080; CDC 801; CDDO; CH-3697; CLX 1100; CM 101; CT3; CT 2576; CPH 82; CV 1013; Cyclosporin; Compounds used in anti-cancer treatment such as: the binuclear DNA threading transition metal complexes and pharmaceutical compositions comprising them described in WO 99/15535, and methotrexate; Declopramide; DPC 333; DWP 205297; DY 9973; Edodekin alfa; Flt ligand (available from Immunex); Gallium nitrate; HP 228; Hydroxamic acid derivates; IL-12; IL-18; Ilodekacin; Ilomastat; ITF-2357; JTE 607; Lactoferrin; Lactoferrin derived or derivable peptides such as: the peptides described in WO 00/01730; Lazaroids; nonglucocorticoid 21-aminosteroids such as: U-74389G (16-desmethyl tirilazad), and U-74500; LPS agonist Esai; Melancortin agonists such as: HP-228; Mercaptoethylguanidine; Metoclopramide; MMP inhibitors (i.e. matrix metalloproteinase inhibitors or TACE inhibitors, i.e. TNF Alpha Converting Enzyme-inhibitors) such as: Tetracyclines such as: Doxycycline, Lymecycline, Oxitetracycline, Tetracycline, and Minocycline; Synthetic tetracycline derivates (CMT=Chemically Modified Tetracyclines); KB-R7785; TIMP1 and TIMP2; adTIMP2 and adTIMP2; M-PGA; Napthopyrans; NCS-700; Nimesulide; NR58-3.14.3; p38 kinase inhibitors such as: VX-702, VX-740, VX-745 (Pralnacasan), VX-765, VX-850, SB-202190, SB-203580, and Pyridinyl imidazoles; PCM-4; PD-168787; Pentoxifyllin derivates; Pharma projects no. 6181, 6019 and 4657; Phosphodiesterase I, II, III, IV, and V-inhibitors such as: CC-1088, Ro 20-1724, rolipram, amrinone, pimobendan, vesnarinone, and SB 207499; Piclamastat; PMS-601; Prostaglandins such as: Iloprost (prostacyclin); Quinolones (chinolones) such as: Norfloxacin, Levofloxacin, Enoxacin, Sparfloxacin, Temafloxacin, Moxifloxacin, Gatifloxacin, Gemifloxacin, Grepafloxacin, Trovafloxacin, Ofloxacin, Ciprofloxacin, Pefloxacin, Lomefloxacin, and Temafloxacin; RDP-58; RIP-3; Sch-23863; SH-636; Solimastat; SR-31747; Tasonermin; Thalidomide derivates (or SelCID=Selective Cytokin inhibitors, e.g. thalidomide derivate) such as: CC-1088 CDC-501, and CDC-801; TNF alpha proteinase inhibitor available from Immunex; TNF-484A; Tristetraproline (TTP) (available from AstraZeneca); VRCTC 310; Yissum project no. 11649; Zanamivir 
     Inhibitors of Interleukin-1 Alpha and Beta (IL-1α and IL-1β) 
     Specific Inhibitors of IL-1 Alpha and IL-1 Beta 
     Monoclonal antibodies such as: CDP-484; Soluble cytokine receptors; IL-1 type II receptor (decoy RII); Receptor antagonists such as: IL-1ra, anakinra (KINERET®), and ORTHOKIN®; Antisense oligonucleotides 
     Non-Specific Inhibitors of IL-1 Alpha and IL-1 Beta 
     MMP inhibitors (i.e. matrix metalloproteinase inhibitors) such as: Tetracyclines such as: Doxycycline, Trovafloxacin, Lymecycline, Oxitetracycline, Tetracycline, Minocycline, and synthetic tetracycline derivatives, such as CMT, i.e. Chemically Modified Tetracyclines; Prinomastat (AG3340); Batimastat; Marimastat; BB-3644; KB-R7785; TIMP-1, and TIMP-2, adTIMP-1 (adenoviral delivery of TIMP-1), and adTIMP-2 (adenoviral delivery of TIMP-2); 
     Quinolones (chinolones) such as: Norfloxacin, Levofloxacin, Enoxacin, Sparfloxacin, Temafloxacin, Moxifloxacin, Gatifloxacin, Gemifloxacin, Grepafloxacin, Trovafloxacin, Ofloxacin, Ciprofloxacin, Pefloxacin, Lomefloxacin, Temafloxacin; Prostaglandins; Iloprost (prostacyclin); Phosphodiesterase I, II, III, IV, and V-inhibitors; CC-1088, Ro 20-1724, rolipram, amrinone, pimobendan, vesnarinone, SB 207499 
     Inhibitors of Interleukin-6 (IL-6) 
     Specific Inhibitors of IL-6 
     Monoclonal antibodies; Soluble cytokine receptors; Receptor antagonists; Antisense oligonucleotides 
     Non-Specific Inhibitors of IL-6 
     MMP inhibitors (i.e. matrix metalloproteinase inhibitors) such as: Tetracyclines such as: Doxycycline, Lymecycline, Oxitetracycline, Tetracycline, Minocycline, and synthetic tetracycline derivatives, such as CMT, i.e. Chemically Modified Tetracyclines; Prinomastat (AG3340); Batimastat; Marimastat; BB-3644; KB-R7785; TIMP-1, and TIMP-2, adTIMP-1 (adenoviral delivery of TIMP-1), and adTIMP-2 (adenoviral delivery of TIMP-2); 
     Quinolones (chinolones) such as: Norfloxacin, Levofloxacin, Enoxacin, Sparfloxacin, Temafloxacin, Moxifloxacin, Gatifloxacin, Gemifloxacin, Grepafloxacin, Trovafloxacin, Ofloxacin, Ciprofloxacin, Pefloxacin, Lomefloxacin, Temafloxacin; Prostaglandins; Iloprost (prostacyclin); Cyclosporin Pentoxifyllin derivates; Hydroxamic acid derivates; Phosphodiesterase I, II, III, IV, and V-inhibitors; CC-1088, Ro 20-1724, rolipram, amrinone, pimobendan, vesnarinone, SB 207499; Melanin and melancortin agonists; HP-228 
     Inhibitors of Interleukin-8 (IL-8) 
     Specific Inhibitors of IL-8 
     Monoclonal antibodies; Soluble cytokine receptors; Receptor antagonists; Antisense oligonucleotides 
     Non-Specific Inhibitors of IL-8 
     Quinolones (chinolones) such as: Norfloxacin, Levofloxacin, Enoxacin, Sparfloxacin, Temafloxacin, Moxifloxacin, Gatifloxacin, Gemifloxacin, Grepafloxacin, Trovafloxacin, Ofloxacin, Ciprofloxacin, Pefloxacin, Lomefloxacin, Temafloxacin; Thalidomide derivates such as: SelCID, i.e. Selective Cytokine inhibitors such as: CC-1088, CDC-501, CDC-801 and Linomide (Roquininex®); Lazaroids; Cyclosporin; Pentoxifyllin derivates 
     FAS Inhibitors 
     Specific FAS Inhibitors 
     Monoclonal antibodies; Soluble cytokine receptors; Receptor antagonists; Antisense oligonucleotides 
     Non-Specific FAS Inhibitors 
     Inhibitors of FAS Ligands 
     Specific Inhibitors of FAS Ligands 
     Monoclonal antibodies; Soluble cytokine receptors; Receptor antagonists; Antisense oligonucleotides 
     Non-Specific Inhibitors of FAS Ligands 
     Inhibitors of Interferon-Gamma (IFN-Gamma) 
     Specific IFN-Gamma Inhibitors 
     Monoclonal antibodies; Soluble cytokine receptors; Receptor antagonists; Antisense oligonucleotides; 
     Non-Specific IFN-Gamma Inhibitors 
     MMP inhibitors (i.e. matrix metalloproteinase inhibitors) such as: Tetracyclines such as: Doxycycline, Trovafloxacin, Lymecycline, Oxitetracycline, Tetracycline, Minocycline, and synthetic tetracycline derivatives, such as CMT, i.e. Chemically Modified Tetracyclines; Prinomastat (AG3340); Batimastat; Marimastat; BB-3644; KB-R7785; TIMP-1, and TIMP-2, adTIMP-1 (adenoviral delivery of TIMP-1), and adTIMP-2 (adenoviral delivery of TIMP-2); Quinolones (chinolones) such as: Norfloxacin, Levofloxacin, Enoxacin, Sparfloxacin, Temafloxacin, Moxifloxacin, Gatifloxacin, Gemifloxacin, Grepafloxacin, Trovafloxacin, Ofloxacin, Ciprofloxacin, Pefloxacin, Lomefloxacin, Temafloxacin, Rebamipide, and Nalidixic acid; Lazaroids; Pentoxifyllin derivates; Phosphodiesterase I, II, III, IV, and V-inhibitors; CC-1088, Ro 20-1724, rolipram, amrinone, pimobendan, vesnarinone, SB 207499. 
     Also contemplated are the pharmaceutically acceptable bases and salts of the substances listed above. 
     Preferred groups of TNF-alpha blocking substances for use according to the present invention are soluble cytokine receptors, monoclonal antibodies, and tetracyclines or chemically modified tetracyclines. 
     Two preferred substances for use according to the present invention are the monoclonal antibodies, D2E7 and CDP-870. 
     D2E7 is a fully humanized monoclonal antibody directed against human TNF-alpha, which has been developed by Knoll and Cambridge Antibody Technology. A transgenic recombinant version of this antibody is under development by Genzyme Transgenic. The invention contemplates any antibody that binds to the same epitope as D2E7 or that has the same TNF-alpha inhibitory effect as D2E7. Preferably the antibody is primatized®, humanized or human. 
     CDP-870 (or CDP 870) is a humanized antibody fragment with high affinity to TNF-alpha. It has been developed by Celltech Group plc, and was co-developed with Pharmacia Corporation. The invention contemplates any antibody, antibody fragment or immunogen that binds to the same epitope as CDP-870 or that has the same TNF-alpha inhibitory activity as CDP-870. Preferably the antibody, antibody fragment or immunogen has the same or similar TNF-alpha inhibitory activity. Preferably the antibody, antibody fragment or immunogen is primatized, humanized or human. 
     Further, the active component may be a substance inhibiting a compound triggered by the release of TNF-alpha or part of a TNF-alpha cascade that is associated with nerve root injury, such as interferon-gamma (INF-γ), interleukin-1 (IL-1), and nitrogen oxide (NO). 
     It is possible to use either one or two or more substances according to the invention in the treatment, for example, of low back pain (LBP). When two or more substances are used they may be administered either simultaneously or separately. 
     Doxycycline inhibits the action of TNF in a non-specific manner. TNF and other similar bioactive substances are first produced in an inactive form and transported to the cell membrane. Upon activation, the active part of the pro-TNF is cleaved and released. This process is called shedding and may be initiated by one or more enzymes. These enzymes have in common that they are metalloproteinases, i.e. dependent of a metal-ion for their function. Doxycycline and other tetracyclines are known to bind to metal-ions and will thereby inhibit the action of metalloproteinases and subsequently the release of TNF and other pro-inflammatory cytokines in a non-specific manner. A monoclonal anti-TNF antibody, on the other hand, will bind directly to TNF and thereby inhibit TNF in a more specific way than doxycycline. The inhibition may thus be assumed to be more efficient but will be restricted to TNF. However, in the work leading to the present invention, it was found that anti-TNF treatment was more efficient than doxycycline treatment. 
     The substances according to the invention may also be administered in combination with other drugs or compounds, provided that these other drugs or compounds do not eliminate the desired effects according to the present invention, i.e., the effect on TNF-alpha. 
     The invention further relates to a method for inhibiting the symptoms of nerve root injury. 
     The effects of doxycycline, soluble cytokine-receptors, and monoclonal cytokine-antibodies have been studied and representative methods used and results obtained are disclosed below. Although the present invention has been described in detail with reference to examples herein, it is understood that various modifications can be made without departing from the spirit of the invention, and would be readily known to the skilled artisan. 
     The compounds of the invention can be administered in a variety of dosage forms, e.g., orally (per os), in the form of tablets, capsules, sugar or film coated tablets, liquid solutions; rectally, in the form of suppositories; parenterally, e.g., intramuscularly (i.m.), subcutaneous (s.c.), intracerebroventricular (i.c.v.), intrathecal (i.t.), epidurally, transepidermally or by intravenous (i.v.) injection or infusion; by inhalation; or intranasally. 
     The therapeutic regimen for the different clinical syndromes may be adapted to the disease or condition, medical history of the subject as would be know to the skilled artisan or clinician. Factors to be considered but not limiting to the route of administration, the form in which the compound is administered, the age, weight, sex, and condition of the subject involved. 
     For example, the oral route is employed, in general, for all conditions, requiring such compounds. In emergency cases, preference is sometimes given to intravenous injection. For these purposes, the compounds of the invention can be administered, for example, orally at doses ranging from about 20 to about 1500 mg/day. Of course, these dosage regimens may be adjusted to provide the optimal therapeutic response depending on the subject&#39;s condition. 
     The nature of the pharmaceutical composition containing the compounds of the invention in association with pharmaceutically acceptable carriers or diluents will, of course, depend upon the desired route of administration. The composition may be formulated in the conventional manner with the usual ingredients. For example, the compounds of the invention may be administered in the form of aqueous or oily solutions or suspensions, tablets, pills, gelatin capsules (hard or soft ones), syrups, drops or suppositories. 
     For oral administration, the pharmaceutical compositions containing the compounds of the invention are preferably tablets, pills or gelatine capsules, which contain the active substance or substances together with diluents, such as lactose, dextrose, sucrose, mannitol, sorbitol, cellulose; lubricants, e.g., silica, talc, stearic acid, magnesium or calcium stearate, and/or polyethylene glycols; or they may also contain binders, such as starches, gelatine, methyl cellulose, carboxymethylcellulose, gum arabic, tragacanth, polyvinylpyrrolidone; disaggregating agents such as starches, alginic acid, alginates, sodium starch glycolate, microcrystalline cellulose; effervescing agents, such a carbonates and acids; dyestuffs; sweeteners; wetting agents, such as lecithin, polysorbates, laurylsulphates; and in general non-toxic and pharmaceutically inert substances used in the formulation of pharmaceutical compositions. Said pharmaceutical compositions may be manufactured in known manners, e.g., by means of mixing, granulating, tableting, sugar-coating or film-coating processes. Film providing compounds can be selected to provide release in the right place or at the appropriate time in the intestinal tract with regard to absorption and maximum effect. Thus pH-dependent film formers can be used to allow absorption in the intestines as such, whereby different phthalates are normally used or acrylic acid/methacrylic acid derivatives and polymers. 
     The liquid dispersions for oral administration may be, e.g., syrups, emulsions, and suspensions. 
     The syrups may contain as carrier, e.g., saccharose, or saccharose with glycerine and/or mannitol and/or sorbitol. 
     Suspensions and emulsions may contain as Garner, e.g., a natural gum, such as gum arabic, xanthan gum, agar, sodium alginate, pectin, methyl cellulose, carboxymethylcellulose, polyvinyl alcohol. 
     The suspension or solutions for intramuscular injections may contain together with the active compound, a pharmaceutically acceptable carrier, such as e.g., sterile water, olive oil (or other vegetable or nut derived oil), ethyl oleate, glycols, e.g., propylene glycol, and if so desired, a suitable amount of lidocaine hydrochloride. Adjuvants for triggering the injection effect can be added as well. 
     The solutions for intravenous injection or infusion may contain as carrier, e.g., sterile water, or preferably, a sterile isotonic saline solution, as well as adjuvants used in the field of injection of active compounds. Such solutions would also be suitable for i.m. and i.c.v. injection. 
     The suppositories may contain together with the active compounds, a pharmaceutically acceptable carrier, e.g., cocoa-butter polyethylene glycol, a polyethylene sorbitan fatty acid ester surfactant or lecithin. 
     Examples of suitable doses of the active agents contemplated for different administration routes are given below. 
     
       
         
           
               
               
               
               
             
               
                   
                   
               
             
            
               
                   
                 Per os 
                 10-300 
                 mg 
               
               
                   
                 i.m. 
                 25-100 
                 mg 
               
               
                   
                 i.v. 
                 2.5-25 
                 mg 
               
               
                   
                 i.t. 
                 0.1-25 
                 mg (daily--every 3 rd  month) 
               
               
                   
                 inhalation 
                 0.2-40 
                 mg 
               
               
                   
                 transepidermally 
                 10-100 
                 mg 
               
               
                   
                 intranasally 
                 0.1-10 
                 mg 
               
               
                   
                 s.c. 
                 5-10 
                 mg 
               
               
                   
                 i.c.v. 
                 0.1-25 
                 mg (daily--every 3 rd  month) 
               
               
                   
                 epidurally 
                 1-100 
                 mg 
               
               
                   
                   
               
            
           
         
       
     
     These ranges are approximate (e.g., about 1 to about 100) and may vary depending on the specific agent being administered and the nature of the disorder in the subject. Thus, it is further contemplated that any dosage in between for the cited ranges may also be used. 
     Examples of suitable doses for different TNF-alpha inhibitors are given in the table below. 
     
       
         
           
               
               
               
               
             
               
                   
                   
               
               
                   
                   
                 More 
                 Most 
               
               
                   
                 Preferred 
                 preferred 
                 preferred 
               
               
                   
                 dosage 
                 dosage 
                 dosage 
               
               
                   
                   
               
             
            
               
                   
               
            
           
           
               
            
               
                 TNF-alpha blocking substance and administration route 
               
            
           
           
               
               
               
               
            
               
                 Lenercept 
                 5-200 
                  10-100 
                 30-80 
               
               
                 i.v. (all given in mg for 
               
               
                 administration once every 4th 
               
               
                 week) 
               
               
                 TBP-1 
                 5-200 
                  10-100 
                 30-80 
               
               
                 i.v. (all given in mg for 
               
               
                 administration once every 4th 
               
               
                 week) 
               
               
                 CDP-571 (HUMICADE ®) 
                 1-100 
                  5-10 
                  5-10 
               
               
                 i.v. (all given in mg/kg body 
               
               
                 weight for administration as a 
               
               
                 single dose) 
               
               
                 D2E7 
               
               
                 i.v. 
                 0.1-50   
                 0.5-10  
                  1-10 
               
               
                 s.c. 
                 0.1-50   
                 0.5-10  
                  1-10 
               
               
                 (all given in mg/kg body weight 
               
               
                 for administration as a single 
               
               
                 dose) 
               
               
                 Iloprost 
               
               
                 i.v. (all given in μg/kg body 
                 0.1-2000  
                   1-1500 
                  100-1000 
               
               
                 weight/day) 
               
               
                 intranasally (all given in μg/day) 
                 50-250  
                 100-150 
                 100-150 
               
               
                 Thalidomide 
                 100-1200  
                  300-1000 
                 500-800 
               
               
                 (all given in μg/day) 
               
               
                 CC-1088 
                 50-1200 
                 200-800 
                 400-600 
               
               
                 Per os (all given in mg/day) 
               
               
                 CDP-870 
                 1-50  
                  2-10 
                 3-8 
               
               
                 i.v. (all given in mg/kg body 
               
               
                 weight for administration once 
               
               
                 every 4th week) 
               
               
                 HP-228 
                 5-100 
                 10-50 
                 20-40 
               
               
                 i.v. (all given in μg/kg body 
               
               
                 weight) 
               
               
                 ISIS-10483 
               
               
                 Per os 
                 1-100 
                 10-50 
                 20-50 
               
               
                 s.c. 
                 1-100 
                 10-50 
                 20-50 
               
               
                 i.v. (all given in mg) 
                 1-100 
                 10-50 
                 20-50 
               
               
                 ARIFLO ® (SB 207499 
                 10-100  
                 30-60 
                 30-45 
               
               
                 Per os (all given in mg/day) 
               
               
                 KB-R7785 
                 100-500  
                 100-300 
                 150-250 
               
               
                 s.c. (all given in mg/kg body 
               
               
                 weight/day) 
               
               
                 CDC-501 
                 50-1200 
                 200-800 
                 400-600 
               
               
                 Per os (all given in mg/day) 
               
               
                 CDC-801 (ROQUININEX ®) 
                 50-1200 
                 200-800 
                 400-600 
               
               
                 Per os (all given in mg/day) 
               
               
                 Prinomastat, Batimastat, and 
                 1-250 mg 
                  5-100 mg 
                 10-50 mg 
               
               
                 Marimastat 
               
               
                 Per os (all given in mg 
               
               
                 twice/day) 
               
               
                 Linomide 
                 0.1-25   
                  5-20 
                 10-15 
               
               
                 Per os (all given in mg/kg body 
               
               
                 weight/day) 
               
            
           
           
               
            
               
                 IL-1 blocking substance and administration route 
               
            
           
           
               
               
               
               
            
               
                 Anakinra (KINERET ®) 
                 10-200  
                  50-150 
                 100 
               
               
                 s.c. (all given in mg/day) 
               
               
                   
               
            
           
         
       
     
     Incorporation by Reference and Examples 
     Although the present invention has been described in detail with reference to examples below, it is understood that various modifications can be made without departing from the spirit of the invention, and would be readily known to the skilled artisan. All cited patents and publications referred to in this application are herein incorporated by reference in their entirety for all purposes. 
     The application incorporates herein by reference in their entirety International Application No. PCT/SE99/01670 and Swedish Application Nos. 9803276-6 and 9803710-4 for all purposes. 
     EXAMPLES 
     Example 1 
     Study Design (Example 1) 
     The effects of nucleus pulposus and various treatments to block TNF-activity were evaluated in an experimental set-up using immunohistochemistry and nerve conduction velocity recordings. 
     Summary of Background Data (Example 1) 
     A meta-analysis of observed effects induced by nucleus pulposus reveals that these effects might relate to one specific cytokine, Tumor Necrosis Factor alpha (TNF-alpha). 
     Objectives (Example 1) 
     To assess the presence of TNF-alpha in pig nucleus pulposus cells and to see if blockage of TNF-alpha also blocks the nucleus pulposus-induced reduction of nerve root conduction velocity. 
     Methods (Example 1) 
     Series-1: Cultured nucleus pulposus-cells were immunohistologically stained with a monoclonal antibody for TNF-alpha. 
     Series-2: Nucleus pulposus was harvested from lumbar discs and applied to the sacrococcygeal cauda equina in 13 pigs autologously. Four pigs received 100 mg of doxycycline intravenously, 8 pigs had a blocking monoclonal antibody to TNF-alpha applied locally in the nucleus pulposus, and 4 pigs remained non-treated (controls). Three days after the application the nerve root conduction velocity was determined over the application zone by local electrical stimulation. 
     Series-3: Thirteen pigs had autologous nucleus pulposus placed onto their sacrococcygeal cauda equina similar to series-2. Five pigs (body weight 25 kg) received REMICADE® (infliximab) 100 mg i.v. preoperatively, and 8 pigs received ENBREL® (etanercept) 12.5 mg s.c. preoperatively and additionally 12.5 mg s.c. three days after the operation. Seven days after the nucleus pulposus-application the nerve root conduction velocity was determined over the application zone by local electrical stimulation according to series-2. 
     Results (Example 1) 
     Series-1: TNF-alpha was found to be present in the nucleus pulposus-cells. 
     Series-2: The selective antibody to TNF-alpha limited the reduction of nerve conduction velocity. However, treatment with doxycycline significantly blocked the nucleus pulposus-induced reduction of conduction velocity. 
     Series-3: Both drugs (infliximab, and etanercept) blocked the nucleus pulposus induced nerve injury efficiently. Normal average nerve conduction velocities were found after 15 treatment with both of these two drugs. 
     Conclusion (Example 1) 
     For the first time a specific substance, Tumor Necrosis Factor-alpha (TNF-alpha), has been linked to the nucleus pulposus-induced effects of nerve roots after local application. Although the effects of this substance may be synergistic with other similar substances, the data of the present study may be of significant importance for the continued understanding of nucleus pulposus&#39; biologic activity, and might also be of potential use for future treatment strategies of sciatica and other nerve root injury conditions or related conditions. 
     After previously being considered as just a biologically inactive tissue component compressing the spinal nerve root at disc herniation, the nucleus pulposus has recently been found to be highly active, inducing both structural and functional changes in adjacent nerve roots when applied epidurally (28, 42, 43, 47, 49). It has thereby been established that autologous nucleus pulposus may induce axonal changes and a characteristic myelin injury (28, 43, 47, 49), increased vascular permeability (13), vascular coagulation (28, 41), and that membrane-bound structure or substances of the nucleus pulposus-cells are responsible for these effects (28, 42). The effects have also been found to be efficiently blocked by methylprednisolone and cyclosporin A (2, 43). When critically looking at these data, one realizes that there is at least one cytokine that relates to all of these effects, TNF-alpha. 
     To assess if TNF-alpha may be involved in the nucleus pulposus induced nerve root injury, the presence of TNF-alpha in nucleus pulposus-cells was assessed and was studied if the nucleus pulposus-induced effects could be blocked by doxycycline, a soluble TNF-receptor, and a selective monoclonal TNF-alpha antibody, the latter administered both locally in the nucleus pulposus and systemically. 
     Example 2 
     Material and Methods (Example 2) 
     Series-1, Presence of TNF-Alpha in Pig Nucleus Pulposus-Cells: 
     Nucleus pulposus (NP) from a total of 13 lumbar and thoracic discs were obtained from 10 pigs, which were used for other purposes. NP was washed once in Ham&#39;s F12 medium (Gibco BRL, Paisley, Scotland) and then centrifuged and suspended in 5 ml of collagenase solution in Ham&#39;s F12 medium (0.8 mg/ml, Sigma Chemical Co., St Louis, Mo., USA) for 40 minutes, at 37° C. in 25 cm tissue culture flasks. The separated NP-cell pellets were suspended in DMEM/F12 1:1 medium (Gibco BRL, Paisley, Scotland) supplemented with 1% L-glutamine 200 mM (Gibco BRL, Paisley, Scotland), 50 mg/ml gentamycine sulphate (Gibco BRL, Paisley, Scotland) and 10% fetal calf serum (FCS), (Gibco BRL, Paisley, Scotland). The cells were cultured at 37° C. and 5% CO 2  in air for 3-4 weeks and then cultured directly on tissue culture treated glass slides (Becton Dickinson &amp; Co Labware, Franklin Lakes, N.J., USA). After 5 days on the glass slides, the cells were fixed in situ by exposing the slides to acetone for 10 minutes. After blocking irrelevant antigens by application of 3% H 2 O 2  (Sigma Chemical Co., St Louis, Mo., USA) for 30 minutes and Horse Serum (ImmunoPure ABC, peroxidase mouse IgG staining kit nr.32028, Pierce, Rockford, Ill.) for 20 minutes, the primary antibody (Anti-pig TNF-alpha monoclonal purified antibody, Endogen, Cambridge, Mass., USA, Ordering Code MP-390) was applied over night at +40° C., diluted at 1:10, 1:20 and 1:40 dilutions. For control, BSA (bovine serum albumin, Intergen Co, New York, USA) suspended in PBS (phosphate buffered saline, Merck, Darmstadt, Germany) was applied in the same fashion. The next day the cells were washed with 1% BSA in PBS and the secondary antibody (ImmunoPure ABC, peroxidase mouse IgG staining kit Cat. Cat. #32028, Pierce, Rockford, Ill.) was applied for 30 minutes. To enhance this reaction, the cells were exposed to Avidin-Biotin complex for an additional 30 minutes (ImmunoPure ABC, peroxidase mouse IgG staining kit Cat. #32028, Pierce, Rockford, Ill.). The cells were then exposed to 20 mg of DAB (3,3-diaminobenzidine tetrahydrochloride No. D-5905, Sigma Chemical Co., St Louis, Mo., USA) and 0.033 ml of 3% H 2 O 2  in 10 ml of saline for 10 minutes. The cells were washed in PBS, dehydrated in a series of ethanol, mounted and examined by light microscopy by an unbiased observer for the presence of a brown coloration indicating the presence of TNF-alpha. 
     Series-2 Neurophysiologic Evaluation: 
     Thirteen pigs (body weight 25-30 kg) received an intramuscular injection of 20 mg/kg body weight of KETALAR® (ketamine, 50 mg/ml, Parke-Davis, Morris Plains, N.J.) and an intravenous injection of 4 mg/kg body weight of HYPNODIL® (methomidate chloride, 50 mg/ml, AB Leo, Helsingborg, Sweden) and 0.1 mg/kg body weight of STRESNIL® (azaperon, 2 mg/ml, Janssen Pharmaceutica, Beerse, Belgium). Anesthesia was maintained by additional intravenous injections of 2 mg/kg body weight of HYPNODIL® and 0.05 mg/kg body weight of STRESNIL®. The pigs also received an intravenous injection of 0.1 mg/kg of STESOLID NOVUM® (Diazepam, Dumex, Helsingborg, Sweden) after surgery. 
     Nucleus pulposus was harvested from the 5.sup.th lumbar disc through a retro peritoneal approach (49). Approximately 40 mg of the nucleus pulposus was applied to the sacrococcygeal cauda equina through a midline incision and laminectomy of the first coccygeal vertebra. Four pigs did not receive any treatment (no treatment). Four other pigs received an intravenous infusion of 100 mg of doxycycline (Vibramycino, Pfizer Inc., New York, USA) in 100 ml of saline over 1 hour. In 5 pigs, the nucleus pulposus was mixed with 100 μl of a 1.11 mg/mL suspension of the anti-TNF-alpha antibody used in series 1, before application. 
     Three days after the application, the pigs were re-anesthetized by an intramuscular injection of 20 mg/kg body weight of KETALAR® and an intravenous injection of 35 mg/kg body weight 25 of PENTOTHAL® (Thiopental sodium, Abbott lab, Chicago, Ill.). 
     The pigs were ventilated on a respirator. Anesthesia was maintained by an intravenous bolus injection of 100 mg/kg body weight of Chloralose ((a)-D(+)-gluco-chloralose, Merck, Darmstadt, Germany) and by a continuous supply of 30 mg/kg/hour of Chloralose. A laminectomy from the 4 th  sacral to the 3 rd  coccygeal vertebra was performed. The nerve roots were covered with SPONGOSTANE® (Ferrosan, Denmark). Local tissue temperature was continuously monitored and maintained at 37.5-38.0° C. by means of a heating lamp. 
     The cauda equina was stimulated by two E2 subdermal platinum needle electrodes (Grass Instrument Co., Quincy, Mass.) which were connected to a Grass SD9 stimulator (Grass Instrument Co., Quincy, Mass.) and gently placed intermittently on the cauda equina first 10 mm cranial and then 10 mm caudal to the exposed area. To ensure that only impulses from exposed nerve fibers were registered, the nerve root that exited from the spinal canal between the two stimulation sites were cut. An electromyogram (EMG) was registered by two subdermal platinum needle electrodes which were placed into the paraspinal muscles in the tail approximately 10 mm apart. This procedure is reproducible and represents a functional measurement of the motor nerve fibers of the cauda equina nerve roots. The EMG was visualized using a Macintosh IIci computer provided with Superscope software and MacAdios II AID converter (GW Instruments, Sommerville, Mass.) together with a Grass P18 preamplifier (Grass Instrument Co., Quincy, Mass.). The separation distance between the first peaks of the EMG from the two recordings was determined, and the separation distance between the two stimulation sites on the cauda equina was measured with calipers. The nerve conduction velocity between the two stimulation sites could thus be calculated from these two measurements. 
     The person performing the neurophysiologic analyses was unaware of the experimental protocol for the individual animal. After finishing the complete study, the data were arranged in the three experimental groups and statistical differences between the groups were assessed by Student&#39;s t-test. The experimental protocol for this experiment was approved by the local animal research ethics committee. 
     Series-3: 
     Thirteen pigs had autologous nucleus pulposus placed onto their sacrococcygeal cauda equina similar to series-2. Five pigs (bodyweight 25 kg) received the human/murine monoclonal antibody, REMICADE® (infliximab, Immunex Corporation, Seattle, Wash. 98101, USA) 100 mg i.v. preoperatively, and 8 pigs received ENBREL® (etanercept, Centocor B.V., Leiden, the Netherlands) 12.5 mg s.c. preoperatively and additionally 12.5 mg s.c. three days after the operation. Seven days after the nucleus pulposus-application the nerve root conduction velocity was determined over the application zone by local electrical stimulation according to series-2. To blind the study, the neurophysiological evaluation was conducted in parallel to another study and the person performing the analyses did not know from which study and what treatment each specific animal was subjected to. No non-treated animals were included in the series-3 due to the pre-existing knowledge of nerve conduction velocity after seven days of either nucleus pulposus or fat (control) application. The statistical difference between the groups, infliximab, and etanercept, nucleus pulposus without treatment (positive control from previous data) and application of retroperitoneal fat (negative control from previous data) was assessed by using ANOVA and Fisher&#39;s PLSD at 5%. 
     Results (Example 2) 
     Series-1, Presence of TNF-Alpha in Pig Nucleus Pulposus-Cells: 
     Examples of the light microscopic appearance of the stained glass slides. In the sections using BSA in PBS as “primary antibody” (control), no staining was observed, ensuring that there was no labeling and visualization of irrelevant antigens. When the anti-TNF-alpha antibody was applied at 1:40 dilution there was only weak staining. However, the staining increased with diminishing dilutions of the antibody. The staining was seen in the soma of the cells, and it was not possible to differentiate whether TNF-alpha was located in the cytoplasm, on the cell surface bound to the cell-membrane, or both. 
     Series-2 Neurophysiologic Evaluation: 
     Application of non-modified nucleus pulposus and without any treatment induced a reduction in nerve conduction velocity similar to previous studies (Table 1). In contrast, treatment with doxycycline completely blocked this reduction (p&lt;0.01 Student&#39;s t-test). Local application of anti-TNF-alpha-antibody also induced a partial block of this reduction, although not as complete as doxycycline and was not statistically significant as compared to the no treatment-series. 
     Series-3: 
     Treatment with both drugs seemed to prevent the nucleus pulposus-induced reduction of nerve root conduction velocities, since the average nerve conduction velocity for both these treatment groups were close to the average conduction of the fat-application series, as seen in a previous study (Table 2). The average nerve conduction velocity in pigs treated with ENBREL® was statistically different from the average nerve conduction velocity in the series with pigs with no treatment. The average new conduction velocity in the group treated with REMICADE® was also statistically significantly different from the average nerve conduction velocity in the group with no treatment. 
     
       
         
           
               
             
               
                 TABLE 1 
               
             
            
               
                   
               
               
                 Series 2 
               
            
           
           
               
               
               
               
            
               
                   
                 Treatment 
                 n 
                 NCV (m/s +/− SD) 
               
               
                   
                   
               
               
                   
                 Local anti-TNF alpha 
                 5 
                 64 +/− 28 
               
               
                   
                 Doxycycline 
                 4 
                 76 +/− 9  
               
               
                   
                 No treatment 
                 4 
                 46 +/− 12 
               
               
                   
                   
               
            
           
         
       
     
                     TABLE 2                  Series 3                                 Treatment   n   NCV (m/s +/− SD)                       Fat*   5   76 +/− 11           ENBREL ®   8   78 +/− 14           REMICADE ®   5   79 +/− 15           No treatment*   5   45 +/− 19                       *Data included from reference 49.            
Discussion (Example 2)
 
     The data of the present study demonstrated that TNF-alpha may be found in nucleus pulposus-cells of the pig. If TNF-alpha was blocked by a locally applied selective monoclonal antibody, the nucleus pulposus-induced reduction of nerve root conduction velocity was partially blocked, although not statistically significant as compared to the series with non-treated animals. However, if animals were treated systemically with doxycycline, infliximab, and etanercept to inhibit TNF-alpha, the reduction of nerve conduction velocity was significantly prevented. 
     In recent years, it has been verified that local application of autologous nucleus pulposus may injure the adjacent nerve roots. Thus, it has become evident that the nerve root injury seen as disc herniation may not be solely based on mechanical deformation of the nerve root, but may also be induced by unknown “biochemical effects” related to the epidural presence of herniated nucleus pulposus. Although this new research field has generated many experimental studies, the mechanisms and substances involved are not fully known. It has been seen that local application of autologous nucleus pulposus may induce axonal injury (28, 42, 43, 46, 47, 49), a characteristic injury of the myelin sheath (28, 43, 46, 47, 49), a local increase of vascular permeability (13, 41) infra vascular coagulations, reduction of infra neural blood flow (50), and leukotaxis (41). It has been seen that the nucleus pulposus-related effects may be blocked efficiently by methylprednisolone (43) and cyclosporin A (2), and slightly less efficiently by indomethacin (3), and lidocaine (77). Further, it has been understood that the effects are mediated by the nucleus pulposus-cells (42), particularly by substances or structures bound to the cell-membranes (29). When critically considering these data, it becomes evident that at least one specific cytokine could be related to these observed effects, Tumor Necrosis Factor-alpha (TNF-alpha). TNF-alpha may induce nerve injury (34, 36, 52, 57, 73), mainly seen as a characteristic myelin injury that closely resembles the nucleus pulposus-induced myelin-injury (34, 54, 58, 61, 69, 71, 73, 78). TNF-alpha may also induce an increase in vascular permeability (54, 73) and initiate coagulation (22, 39, 70). Further, TNF-alpha may be blocked by steroids (4, 11, 26, 68, 76), and cyclosporin A (15, 62, 74, 76). However, the blocking effect on TNF-alpha is not so pronounced by NSAID (18, 21, 24) and very low or the agonized by lidocaine (5, 37, 53, 67). 
     It was recently observed that local application of nucleus pulposus may induce pain-related behavior in rats, particularly thermal hyperalgesia (27, 46). TNF-alpha has also been found to be related to such pain-behavioristic changes (16, 40, 63, 73), and also to neuropathies in general (35, 61, 63, 64). However there are no studies that have assessed the possible presence of TNF-alpha in the cells of the nucleus pulposus. 
     To assess if TNF-alpha could be related to the observed nucleus pulposus induced reduction in nerve root conduction velocity it was necessary first to analyze if there was TNF-alpha in the nucleus pulposus-cells. The data clearly demonstrated that TNF-alpha was present in these cells. TNF-alpha is produced as a precursor (pro-TNF) that is bound to the membrane, and it is activated by cleavage from the cell-membrane by a zinc-dependent metallo-endopeptidase (i.e., TNF-alpha converting enzyme, TACE) (6, 19, 20, 55, 56). This may thus relate well to experimental findings, where application of only the cell-membranes of autologous nucleus pulposus-cells induced nerve conduction velocity reduction, which indicated that the effects were mediated by a membrane-bound substance. Second, the effects of the TNF-alpha had to be blocked in a controlled manner. We then first chose to add the same selective antibody that was used for immunohistochemistry in series 1, which is known to also block the effects of TNF-alpha, to the nucleus pulposus before application. Also, we chose to treat the pigs with doxycycline, which is known to block TNF-alpha (30, 31, 38, 59, 60). However, due to the low pH of the doxycycline preparation, it was chosen to treat the pigs by intravenous injection instead of local addition to the nucleus pulposus since nucleus pulposus at a low pH has been found to potentiate the effects of the nucleus pulposus (43, 25). 
     Two recently developed drugs for specific TNF-alpha inhibition were also included in the study. Infliximab is a chimeric monoclonal antibody composed of human constant and murine variable regions. Infliximab binds specifically to human TNF-alpha. As opposed to the monoclonal antibody used in series-2 for the 3-day observation period, infliximab was not administered locally in the autotransplanted nucleus pulposus, but instead was administered systemically in a clinically recommended dose (4 mg/kg). 
     Etanercept is a dimeric fusion protein consisting of the Fc portion of human IgG. The drug, etanercept, was administered in a dosage comparable to the recommended dose for pediatric use (0.5 mg/kg, twice a week). 
     The data regarding nerve conduction velocity showed that the reduction was completely blocked by the systemic-treatment and that the nerve conduction velocities in these series were close to the conduction velocity after application of a control substance (retro peritoneal fat) from a previous study (49). Application of the anti-TNF-alpha-antibody to the nucleus pulposus also partially prevented the reduction in nerve conduction velocity. However, the reduction was not as pronounced as that observed for doxycycline, and the velocity in this series was not statistically different to the velocity in the series with untreated animals, given the wide deviation of the data. 
     The local anti-TNF-alpha antibody treatment only partially blocked the nucleus pulposus-induced reduction of nerve conduction velocity and the high standard deviation of the data could probably have at least three different explanations. First, if looking at the specific data within this group, it was found that the nerve conduction velocity was low in 2 animals (mean 37.5 m/s) and high in 3 animals (mean 81.3 m/s). There are thus 2 groups of distinctly different data within the anti-TNF-alpha treatment series. This will account for the high standard deviation and might imply that the blocking effect was sufficient in 3 animals and insufficient in 2 animals. The lack of effects in these animals could be based simply on the amount of antibodies in relation to TNF-alpha molecules not being sufficient, and if a higher dose of the antibody had been used, the TNF-alpha effects would thus have been blocked even in these animals. Such a scenario could then theoretically imply that TNF-alpha alone is responsible for the observed nucleus pulposus-induced effects, and that this could not be verified experimentally due to the amount of antibody being too low. 
     Second, it is also known that tetracyclines such as doxycycline and minocycline may block a number of cytokines and other substances. For instance they may block IL-1 (1, 33, 65), IFN-gamma, NO-synthetase, and metalloproteinases (1, 60, 65). Particularly IL-1 and IFN-gamma are known to act synergistically with TNF-alpha and are known to be more or less neurotoxic (7, 14, 17, 22, 23, 63, 66). These substances, are also blocked by steroids and cyclosporin A which corresponds well with the previous observations on nucleus pulposus-induced nerve root injury which have shown that the nucleus pulposus-induced effects may be blocked by these substances (11, 74). One may therefore also consider the possibility that a selective block of TNF-alpha may not be sufficient to completely block the nucleus pulposus-induced effects on nerve function, and that simultaneous block of other synergistic substances is necessary as well. Thus, this scenario, on the other hand, implies that TNF-alpha is not solely responsible for the nucleus pulposus-induced effects, and that other synergistic substances, which are also blocked by doxycycline, may be necessary. 
     The third explanation could be that the amount of TNF in the nucleus pulposus may well be enough to start the pathophysiologic cascade locally in the nerve root, comprising increased vascular permeability and aggregation and recruitment of systemic leukocytes. However, it is these leukocytes that have the major content of TNF-alpha and that systemic treatment in a sufficient dose is necessary to block the contribution from these leukocytes, and thereby also blocking the events leading to nerve injury. 
     TNF-alpha may have various pathophysiologic effects. It may have direct effects on tissues such as nerve tissue and blood vessels, it may trigger other cells to produce other pathogenic substances and it may trigger release of more TNF-alpha both by inflammatory cells and also by Schwann-cells locally in the nerve tissue (72). There is thus reason to believe that even low amounts of TNF-alpha may be sufficient to initiate these processes and that there is a local recruitment of cytokine producing cells and a subsequent increase in production and release of other cytokines as well as TNF-alpha. TNF-alpha may therefore act as the “ignition key” of the pathophysiologic processes and play an important role for the initiation of the pathophysiologic cascade behind the nucleus pulposus-induced nerve injury. However, the major contribution of TNF-alpha may be derived from recruited, aggregated and maybe even extravasated leukocytes, and that successful pharmacologic block may be achieved only by systemic treatment. 
     In conclusion, although the exact role of TNF-alpha can not be fully understood from the experimental set-up, we may conclude that for the first time a specific substance (TNF-alpha) has been linked to the nucleus pulposus-induced nerve root injury. This new information may be of significant importance for the continued understanding of nucleus pulposus-induced nerve injury as well as raising the question of the potential future clinical use of pharmacological interference with TNF-alpha and related substances, for treatment of sciatica. 
     The presence of TNF-alpha in pig nucleus pulposus-cells was thus immunohistochemically verified. Block of TNF-alpha by a locally applied monoclonal antibody limited the nucleus pulposus-induced reduction of nerve root conduction velocity, whereas intravenous treatment with doxycycline, infliximab, and etanercept significantly blocked this reduction. These data for the first time links one specific substance, TNF-alpha, to the nucleus pulposus-induced nerve injury. 
     Example 3 
     CDP-571 (HUMICADE®) 
     A 43-year old man with radiating pain corresponding to the left 4th lumbar nerve root is diagnosed as having sciatica with nerve root disturbance. He will be treated with 10 mg/kg of CDP-571 (HUMICADE®) intravenously in a single dose. 
     Example 4 
     D2E7 
     A 38-year old female with radiating pain and slight nerve dysfunction corresponding to the 1st sacral nerve on the left side is diagnosed as having a disc herniation with sciatica. She will be treated with an intravenous injection of 5 mg/kg of D2E7. 
     Example 5 
     CDP-870 
     A 41-year old female with dermatomal pain corresponding to the first sacral nerve root on the left side is examined revealing no neurological deficit but a positive straight leg raising test on the left side. She will be treated with an intravenous injection of 5 mg/kg of CDP-870. 
     REFERENCES 
     
         
         1. Amin A R, Attur M G, Thakker G D, Patel P D, Vyas P R, Patel R N, Patel I R, Abramson S B. A novel mechanism of action of tetracyclines: effects on nitric oxide syntheses. Proc Natl Acad Sci USA 1996; 93:14014-9. 
         2. Arai I, Konno S, Otani K, Kikuchi S, Olmarker K. Cyclosporin A blocks the toxic effects of nucleus pulposus on spinal nerve roots. Manuscript 
         3. Arai I, Mao G P, Otani K, Komo S, Kikuchi S, Olmarker K, Indomethacin blocks nucleus pulposus related effects in adjacent nerve roots, Accepted for publication in Eura Spine J. 
         4. Baumgartner R A, Deramo V A, Beaven M A. Constitutive and inducible mechanisms for synthesis and release of cytokines in immune cell lines. J Immunol 1996; 157:4087-93. 
         5. Bidani A, Heming T A. Effects of lidocaine on cytosolic pH regulation and stimulus-induced effector functions in alveolar macrophages. Lung 1997; 175:349-61. 
         6. Black R A, Rauch C T, Kozlosky C J, Peschon J J, Slack J L, Wolfson M F, Castner B J, Stocking K L, Reddy P, Srinivasan S, Nelson N, Boiani N, Schooley K A, Gerhart M, Davis R, Fitzner J N, Johnson R S, Paxton R J, March C J, Cerretti D P. A metalloproteinase disintegrin that releases tumour-necrosis factor-alpha from cells. Nature 1997; 385:729-33. 
         7. Bluthe R M, Dantzer R, Kelley K W. Interleukin-1 mediates behavioural but not metabolic effects of tumor necrosis factor alpha in mice. Eur J Pharmacol 1991; 209:281-3. 
         8. Boden S D, Davis D O, Dina T S, Patronas N J, Wiesel S W. Abnormal magnetic-resonance scans of the lumbar spine in asymptomatic subjects. A prospective investigation. J Bone Joint Surg Am. 1990 March; 72(3):403-8. 
         9. Boos N, Rieder R, Schade V, Spratt K F, Semmer N, Aebi M. 1995 Volvo Award in clinical sciences. The diagnostic accuracy of magnetic resonance imaging, work perception, and psychosocial factors in identifying symptomatic disc herniations. Spine. 1995 Dec. 15; 20(24):2613-25. 
         10. Boos N, Dreier D, Hilfiker E, Schade V, Kreis R, Hora J, Aebi M, Boesch C. Tissue characterization of symptomatic and asymptomatic disc herniations by quantitative magnetic resonance imaging. J Orthop Res. 1997 January; 15(1):141-9. 
         11. Brattsand R, Linden M. Cytokine modulation by glucocorticoids: mechanisms and actions in cellular studies. Aliment Pharmacol Ther 1996; 10:81-90. 
         12. Byrod G, Otani K, Rydevik B, Olmarker K. Acute increase in endoneural vascular permeability induce by epidural application of nucleus pulposus on spinal nerve roots. Manuscript 
         13. Byrod G, Otani K, Brisby H, Rydevik B, Olmarker K, Methylprednisolone reduces the early vascular permeability increase in spinal nerve roots induced by epidural nucleus pulposus application, J Orthop Res 1987; 18:6:983-7. 
         14. Chao C C, Hu S, Ehrlich L, Peterson P K. Interleukin-1 and tumor necrosis factor-alpha synergistically mediate neurotoxicity: involvement of nitric oxide and of N-methyl-D-aspartate receptors. Brain Behav Immun 1995; 9:355-65. 
         15. Dawson J, Hurtenbach U, MacKenzie A. Cyclosporin A inhibits the in vivo production of interleukin-1 beta and tumour necrosis factor alpha, but not interleukin-6, by a T-cell-independent mechanism. Cytokine 1996; 8:882-8. 
         16. DeLeo J A, Colbum R W, Rickman A J. Cytokine and growth factor immunohistochemical spinal profiles in two animal models of mononeuropathy. Brain Res 1997; 759:50-7. 
         17. Gadient R A, Cron K C, Otten U. Interleukin-1 beta and tumor necrosis factor-alpha synergistically stimulate nerve growth factor (NGF) release from cultured rat astrocytes. Neurosci Lett 1990; 117:335-40. 
         18. Garcia-Vicuna R, Diaz-Gonzalez F, Gonzalez-Alvaro 1, del Pozo M A, Moilinedo F, Cabanas C, Gonzalez-Amaro R, Sanchez-Madrid F. Prevention of cytokine-induced changes in leucocyte adhesion receptors by nonsteroidal antiinflammatory drugs from the oxicam family. Arthritis Rheum 1997; 40:143-53. 
         19. Gearing A J, Beckett P, Christodoulou M, Churchill M, Clements J, Davidson A H, Drummond A H, Galloway W A, Gilbert R, Gordon J L, et al. Processing of tumour necrosis factor-alpha precursor by metalloproteinases. Nature 1994; 370:555-7. 
         20. Gazelle E J, Banda M J, Leppert D. Matrix metallo-proteinases in immunity. J Immunol 1996; 156:14. 
         21. Gonzalez E, de la Cruz C, de Nicolas R, Egido J, Herrero-Beaumont G. Long-term effect of nonsteroidal anti-inflammatory drugs on the production of cytokines and other inflammatory mediators by blood cells of patients with osteosis. Agents Actions 1994; 41:171-8. 
         22. Hartung H P, Jung S, Stoll G, Zielasek J, Schmidt B, Archelos J J, Toyka K V. Inflammatory mediators in demyelinating disorders of the CNS and PNS. J Neuroimmunol 1992; 40:197-210. 
         23. Hattori A, Iwasald S, Murase K, Tsujimoto M, Sato M, Hayashi K, Kohno M. Tumor necrosis factor is markedly synergistic with interleukin I and ii3terferon-gamma in stimulating the production of nerve growth factor in fibroblasts. FEBS Lett 1994; 340:177-80. 
         24. Herman J H, Sowder W G, Hess E V. Nonsteroidal antiinflammatory drug modulation of prosthesis pseudomembrane induced bone resorption. J Rheunutol 1994; 21:338-43. 
         25. Iwabuchi M, Rydevik B, Kikuchi S, Olmarker K, Methylprednisolone reduces the early vascular permeability increase in spinal nerves by epidural nucleus pulposus application, Accepted for publication in Spine. 
         26. Iwamoto S, Takeda K. [Possible cytotoxic mechanisms of TNF in vitro]. Hum Cell 1990; 3:107-12. 
         22. Jurd K M, Stephens C J, Black M M, Hunt B J. Endothelial cell activation in cutaneous vasculitis. Clin Exp Dermatol 1996; 21:28-32. 
         27. Kawakami M, Tamaki T, Weinstein J N, Hashizume H, Nishi H, Meller S T. Pathomechanism of pain-related behaviour produced by allografts of intervertebral disc in the rat. Spine 1996; 21:2101-7. 
         28. Kayama S, Konno S, Olmarker K, Yabuki S, Kikuchi S. Incision of the anulus fibrosis induces nerve root morphologic, vascular, and functional changes. An experimental study. Spine 1996; 21:2539-43. 
         29. Kayama S, Olmarker K, Larsson K, Sjogren-Jansson E, Lindahl A, Rydevik B. Cultured, autologous nucleus pulposus cells induce structural and functional changes in spinal nerve roots. Spine, 1998, 23:90:2155-58. 
         30. Kloppenburg M, B.about.an B M, de Rooij-Dijk H H, Miltenburg A M, Daha M R, Breedveld F C, Dijkmans B A, Verweij C. The tetracycline derivative minocycline differentially affects cytokine production by monocytes and T lymphocytes. Antimicrob Agents Chemother 1996; 40:934-40. 
         31. Kloppenburg M, Verweij C L, Miltenburg A M, Verboeven A J, Daha M R, Dijkmans B A, Breeveld F C. The influence of tetracyclines on T cell activation. Clin Exp Immunol 1995; 102:635-41. 
         32. Korhonen K, Karppinen J, Malmivaara A, Paimela L, Kyllonen E, Lindgren K-A, et al. Treatment of sciatica with infliximab, a monoclonal humanised chimaeric antibody against TNF. Trans. International Society for the Study of the Lumbar Spine 2002; Cleveland, Ohio, p. 14 
         33. Lamster I B, Pullman J R, Celenti R S, Grbic J T. The effect of tetracycline fiber therapy on beta-glucuronidase and interleukin-1 beta in crevicular fluid. J Clin Periodontol 1996; 23:816-22. 
         34. Liberski P P, Yanagihara R, Nerurkar V, Gajdusek D C. Further ultrastructural studies of lesions induced in the optic nerve by tumor necrosis factor alpha (TNF-alpha): a comparison with experimental Creutzfeldt-Jakob disease. Acta Neurobiol Exp (Warsz) 1994; 54:209-18. 
         35. Lin X H, Kashima Y, Khan M, Heller K B, Gu X Z, Sadun A A. An immunohistochemical study of TNF-alpha in optic nerves from AIDS patients. Curr Eye Res 1997; 16:1064-8. 
         36. Madigan M C, Sadun A A, Rao N S, Dugel P U, Tenhula W N, Gill P S. Tumor necrosis factor-alpha (TNF-alpha)-induced optic neuropathy in rabbits. Neurol Res 1996; 18:176-84. 
         37. Matsumori A, Ono K, Nishio R, Nose Y, Sasayama S. Amiodarone inhibits production of tumor necrosis factor-alpha by human mononuclear cells: a possible mechanism for its effect in heart failure. Circulation 1997; 96:1386-9. 
         38. Milano S, Arcoleo F, D&#39;Agostino P, Cillari E. Intraperitoneal injection of tetracyclines protects mice from lethal endotoxemia downregulating inducible nitric oxide synthase in various organs and cytokine and nitrate secretion in blood. Antimicrob Agents Chemother 1997; 41:117-21. 
         39. Nawroth P, Handley D, Matsueda G, De Waal R, Gerlach H, Blohm D, Stem D. Tumor necrosis factor/cachectin-induced intra vascular fibrin formation in meth A fibrosarcomas. J Exp Med 1988; 168:637-47. 
         40. Oka T, Wakugawa Y, Hosoi M, Oka K, Hori T. Intracerebroventricular injection of tumor necrosis factor-alpha induces thermal hyperalgesia in rats. Neuroimmunomodulation 1996; 3:135-40. 
         41. Olmarker K, Blomquist J, Stromberg J, Nannmark, U, Thomsen P, Rydevik B. Inflamma-togenic properties of nucleus pulposus. Spine 1995; 20:665-9. 
         42. Olmarker K, Brisby H, Yabuki S, Nordborg C, Rydevik B. The effects of normal, frozen, and hyaluronidase-digested nucleus pulposus on nerve root structure and function. Spine 1997; 22:4715; discussion 476. 
         43. Olmarker K, Byrod G, Comefjord M, Nordborg C, Rydevik B. Effects of methylprednisolone on nucleus pulposus-induced nerve root injury. Spine 1994; 19:1803-8. 
         44. Olmarker K, Iwabuchi M, Larsson K, Rydevik B. Effects of in vitro degenerated nucleus pulposus on nerve root conduction velocity. Manuscript 
         45. Olmarker K, Larsson K, Tumor necrosis factor alpha and nucleus-pulposus-induced nerve root injury, Spine 1998; 23(23): 2538-44. 
         46. Olmarker K, Myers R R. Pathogenesis of sciatic pain: Role of herniated nucleus pulposus and deformation of spinal nerve root and DRG. Pain, 1998, 78:9-105 
         47. Olmarker K, Nordborg C, Larsson K, Rydevik B. Ultrastructural changes in spinal nerve roots induced by autologous nucleus pulposus. Spine 1996; 21:411-4. 
         48. Olmarker K, Rydevik B, Selective inhibition of tumor necrosis factor-alpha prevents nucleus pulposus-induced thrombus formation, intraneural edema, and reduction of nerve conduction velocity: possible implications for future pharmacologic treatment strategies of sciatica, Spine 2001; 26(8):863-9. 
         49. Olmarker K, Rydevik B, Nordborg C. Autologous nucleus pulposus induces neurophysiologic and histologic changes in porcine cauda equina nerve roots [see comments]. Spine 1993; 18:1425-32. 
         50. Otani K, Arai I, Mao G P, Konno S, Olmarker K, Kikuchi S, Nucleus pulposus-induced nerve root injury. The relationship between blood flow and nerve conduction velocity, Neurosurgery 1999; 45: 619-20. 
         51. Otani K, Mao G P, Arai I, Konno S, Olmarker K, Kikuchi S, Nucleus pulposus-induced increase in vascular permeability in the nerve root. Manuscript 
         52. Petrovich M S, Hsu H Y, Gu X, Dugal P, Heller K B, Sadun A A. Pentoxifylline suppression of TNF-alpha mediated axonal degeneration in the rabbit optic nerve. Neurol Res 1997; 19:551-4. 
         53. Pichler W J, Zanni M, von Greyerz S, Schnyder B, Mauri-HeUweg D, Wendland, T. High IL-5 production by human drug-specific T cell clones. Int Arch Allergy Immunol 1997; 1 13:177-80. 
         54. Redford E J, Hall S M, Smith K J. Vascular changes and demyelination induced by the intra neural injection of tumour necrosis factor. Brain 1995; 1 18:869-78. 
         55. Robache-Gallea S, Bruneau J M, Robbe H, Morand V, Capdevila C, Bhatnagar N, Chouaib S, Roman-Roman S. Partial purification and characterization of a tumor necrosis factor-alpha converting activity. Eur J Immunol 1997; 27:1275-82. 
         56. Rosendahl M S, Ko S C, Long D L, Brewer M T, Rosenzweig B, Hedl E, Anderson L, Pyle S M, Moreland J, Meyers M A, Kohno T, Lyons D, Lichenstein H S. Identification and characterization of a pro-tumor necrosis factor-alpha-processing enzyme from the ADAM family of zinc metalloproteases. J Biol Chem 1997; 272:24588-93. 
         57. Said G, Hontebeyrie-Joskowicz M. Nerve lesions induced by macrophage activation. Res Immunol 1992; 143:589-99. 
         58. Sehnaj K W, Raine C S. Tumor necrosis factor mediates myelin and oligodendrocyte damage in vitro. Ann Neurol 1988; 23:339-46. 
         59. Shapira L, Houri Y, Barak V, Halabi A, Soskoine W A, Stabholz A. Human monocyte response to cementum extracts from periodontally diseased teeth: effect of conditioning with tetracycline. J Periodontol 1996; 67:682-7. 
         60. Shapira L, Houri Y, Barak V, Soskolne W A, Halabi A, Stabholz A. Tetracycline inhibits&#39;  Porphyromonas gingivalis  lipopolysaccharide-induced lesions in vivo and TNF .alpha. processing in vitro. J Periodontal Res 1997; 32:183-8. 
         61. Sharief M K, Ingram D A, Swash M. Circulating tumor necrosis factor-alpha correlates with electrodiagnostic abnormalities in Guillain-Barre syndrome. Ann Neurol 1997; 42:68-73. 
         62. Smith C S, Ortega G, Parker L, Shearer W T. Cyclosporin A blocks induction of tumor necrosis factor-alpha in human B lymphocytes. Biochem BioRhys Res Commun 1994; 204:383-90. 
         63. Sonuner C, Schmidt C, George A, Toyka K V. A metalloprotease-inhibitor reduces pain associated behaviour in mice with experimental neuropathy. Neurosci Lett 1997; 237:45-8. 
         64. Sorkin L S, Xiao W H, Wagner R, Myers R R. Tumour necrosis factor-alpha induces ectopic activity in nociceptive primary afferent fibres. Neuroscience 1997; 81:255-62. 
         65. Steinmeyer J, Daufeldt S, Taiwo Y O. Pharmacological effect of tetracyclines on proteoglycanases from interleukin-1-treated articular cartilage. Biochem Pharmacol 1998; 55:93-100. 
         66. Stoll G, Jung S, Jander S, van der Meide P, Hartung H P. Tumor necrosis factor-alpha in immunomediated demyelination and Wallerian degeneration of the rat peripheral nervous system. Neuroimmunol 1993; 45: 175-82. 
         67. Takao Y, Mikawa K, Nishina K, Maekawa N, Obara H. Lidocaine attenuates hyperoxic lung injury in rabbits. Acta Anaesthesiol Scand 1996; 40:318-25. 
         68. Teoh K H, Bradley C A, Galt J, Burrows H. Steroid inhibition of cytokine-mediated vasodilation after warm heart surgery. Circulation 1995; 92:11347-53. 
         69. Tsukamoto T, Ishikawa M, Yamamoto T. Suppressive effects of TNF-alpha on myelin formation in vitro. Acta Neurol Scand 1995; 91:71-5. 
         70. van der Poll T, Jansen P M, Van Zee K J, Welborn M Br, de Jong I, Hack C E, Loetscher H, Lesslauer W, Lowry S F, Moidawer L L. Tumor necrosis factor-alpha induces activation of coagulation and fibrinolysis in baboons through an exclusive effect on the p55 receptor. Blood 1996; 88:922-7. 
         71. Villarroya H, Violleau K, Ben Younes-Chennoufi A, Baumann N. Myelin-induced experimental allergic encephalomyelitis in Lewis rats: tumor necrosis factor alpha levels in serum of cerebrospinal fluid immunohistochemical expression in glial cells and neurophages of optic nerve and spinal cord. J Neuroimmunol 1996; 64:55-61. 
         72. Wagner R, Myers R R. Schwann cells produce tumor necrosis factor alpha: expression in injured non-injured nerves. Neuroscience 1996; 73:625-9. 
         73. Wagner R, Myers R R. Endoneurial injection of TNF-alpha produces neuropathic pain behaviours. Neuroreport 1996; 7:2897-901. 
         74. Wasaki S, Sakaida I, Uchida K, Kiinura T, Kayano K, Okita K. Preventive effect of cyclosporin A on experimentally induced acute liver injury in rats. Liver 1997; 17:107-14. 
         75. Wiesel S W, Tsourmas N, Feffer H L, Citrin C M, Patronas N. A study of computer-assisted tomography. I. The incidence of positive CAT scans in an asymptomatic group of patients. Spine. 1984 September; 9(6):549-51. 
         76. Wershil B K, Furuta G T, Lavigne J A, Choudhury A R, Wang Z S, Galli S J. Dexamethasone cyclosporin A suppress mast cell-leukocyte cytokine cascades by multiple mechanisms. Int Arch Allerg Immunol 1995; 107:323-4. 
         77. Yabuki S, Kawaguchi Y, Olmarker K, Rydevik B. Effects of lidocaine on nucleus pulposus-induced nerve root injury. Spine, 1998, 23:29:2383-89 
         78. Zhu J, Bai X F, Mix E, Link H. Cytokine dichotomy in peripheral nervous system influences the outcome of experimental allergic neuritis: dynamics of mRNA expression for IL-1 beta, IL-6, IL-10, IL-12, TNF-alpha, TNF-beta, and cytolysin. Clin Immunol Immunuopathol 1997; 84:85-94.