bluuebunny/crossref_metadata_2025 huggingface dataset:
Visual Perception and Memory: A New View of Medial Temporal Lobe Function in Primates and Rodents
Authors: Murray Elisabeth A. , Bussey Timothy J. , Saksida Lisa M.
Published: March 2007

The prevailing view of medial temporal lobe (MTL) function has two principal elements: first, that the MTL subserves memory but not perception, and second, that the many anatomically distinctive parts of the MTL function together in the service of declarative memory. Recent neuropsychological studies have, however, challenged both opinions. First, studies in rodents, nonhuman primates, and humans suggest that the perirhinal cortex represents information about objects for both mnemonic and perceptual purposes. Second, the idea that MTL components contribute to declarative memory in similar ways has also been contradicted. Whereas the perirhinal cortex plays an essential role in familiarity-based object recognition, the hippocampus contributes little, if at all, to this function. In both primates and rodents, the hippocampus contributes to the memory and perception of places and paths, whereas the perirhinal cortex does so for objects and the contents of scenes.
Anatomical and Physiological Plasticity of Dendritic Spines
Authors: Alvarez Veronica A. , Sabatini Bernardo L.
Published: March 2007

In excitatory neurons, most glutamatergic synapses are made on the heads of dendritic spines, each of which houses the postsynaptic terminal of a single glutamatergic synapse. We review recent studies demonstrating in vivo that spines are motile and plastic structures whose morphology and lifespan are influenced, even in adult animals, by changes in sensory input. However, most spines that appear in adult animals are transient, and the addition of stable spines and synapses is rare. In vitro studies have shown that patterns of neuronal activity known to induce synaptic plasticity can also trigger changes in spine morphology. Therefore, it is tempting to speculate that the plastic changes of spine morphology reflect the dynamic state of its associated synapse and are responsible to some extent for neuronal circuitry remodeling. Nevertheless, morphological changes are not required for all forms of synaptic plasticity, and whether changes in the spine shape and size significantly impact synaptic signals is unclear.
Ventral Tegmental Area Neurons in Learned Appetitive Behavior and Positive Reinforcement
Authors: Fields Howard L. , Hjelmstad Gregory O. , Margolis Elyssa B. , Nicola Saleem M.
Published: March 2007

Ventral tegmental area (VTA) neuron firing precedes behaviors elicited by reward-predictive sensory cues and scales with the magnitude and unpredictability of received rewards. These patterns are consistent with roles in the performance of learned appetitive behaviors and in positive reinforcement, respectively. The VTA includes subpopulations of neurons with different afferent connections, neurotransmitter content, and projection targets. Because the VTA and substantia nigra pars compacta are the sole sources of striatal and limbic forebrain dopamine, measurements of dopamine release and manipulations of dopamine function have provided critical evidence supporting a VTA contribution to these functions. However, the VTA also sends GABAergic and glutamatergic projections to the nucleus accumbens and prefrontal cortex. Furthermore, VTA-mediated but dopamine-independent positive reinforcement has been demonstrated. Consequently, identifying the neurotransmitter content and projection target of VTA neurons recorded in vivo will be critical for determining their contribution to learned appetitive behaviors.
Neuron-Glial Interactions in Blood-Brain Barrier Formation
Authors: Banerjee Swati , Bhat Manzoor A.
Published: March 2007

The blood brain barrier (BBB) evolved to preserve the microenvironment of the highly excitable neuronal cells to allow for action potential generation and propagation. Intricate molecular interactions between two main cell types, the neurons and the glial cells, form the underlying basis of the critical functioning of the nervous system across species. In invertebrates, interactions between neurons and glial cells are central in establishing a functional BBB. However, in vertebrates, the BBB formation and function is coordinated by interactions between neurons, glial cells, and endothelial cells. Here we review the neuron-glial interaction–based blood barriers in invertebrates and vertebrates and provide an evolutionary perspective as to how a glial-barrier system in invertebrates evolved into an endothelial barrier system. We also summarize the clinical relevance of the BBB as this protective barrier becomes disadvantageous in the pharmacological treatment of various neurological disorders.
Thrombin inhibits migration of human hepatic myofibroblasts
Authors: Gillibert-Duplantier Jennifer , Neaud Véronique , Blanc Jean-Frédéric , Bioulac-Sage Paulette , Rosenbaum Jean
Published: March 2007

Several lines of data recently pointed out a role of the serine proteinase thrombin in liver fibrogenesis, but its mechanism of action is unknown. The aim of this study was to evaluate the effect of thrombin on the migration of human liver myofibroblasts. We show here that thrombin inhibits both basal migration and platelet-derived growth factor (PDGF)-BB-induced migration of myofibroblasts. By using a thrombin antagonist, a protease-activated receptor (PAR)-1 mimetic peptide, and a PAR-1 antibody, we show that this effect is dependent on the catalytic activity of thrombin and on PAR-1 activation. Thrombin's effect on basal migration was dependent on cyclooxygenase 2 (COX-2) activation because it was blocked by the COX-2 inhibitors NS-398 and nimesulide, and pharmacological studies showed that it was relayed through prostaglandin E2and its EP2receptor. On the other hand, thrombin-induced inhibition of PDGF-BB-induced migration was not dependent on COX-2. We show that thrombin inhibits PDGF-induced Akt-1 phosphorylation. This effect was consecutive to inhibition of PDGF-β receptor activation through active dephosphorylation. Thus thrombin, through two distinct mechanisms, inhibits both basal- and PDGF-BB-induced migration of human hepatic liver myofibroblasts. The fine tuning of myofibroblast migration may be one of the mechanisms used by thrombin to regulate liver fibrogenesis.
Cellular regulation of basal tone in internal anal sphincter smooth muscle by RhoA/ROCK
Authors: Patel Chirag A. , Rattan Satish
Published: March 2007

Sustained contractions of smooth muscle cells (SMC) maintain basal tone in the internal anal sphincter (IAS). To examine the molecular bases for the myogenic tone in the IAS, the present studies focused on the role of RhoA/ROCK in the SMC isolated from the IAS vs. the adjoining phasic tissues of the rectal smooth muscle (RSM) and anococcygeus smooth muscle (ASM) of rat. We also compared cellular distribution of RhoA/ROCK, levels of RhoA-GTP, RhoA-Rho guanine nucleotide dissociation inhibitor (GDI) complex formation, levels of pThr696-MYPT1, and SMC relaxation caused by RhoA inhibition. Levels of RhoA/ROCK were higher at the cell membrane in the IAS SMC compared with those from the RSM and ASM. C3 exoenzyme (RhoA inhibitor) and Y 27632 (ROCK inhibitor) caused a concentration-dependent relaxation of the IAS SMC. In addition, active ROCK-II (primary isoform of ROCK in SMC) caused further shortening in the IAS SMC. C3 exoenzyme increased RhoA-RhoGDI binding and reduced the levels of RhoA-GTP and pThr696-MYPT1. ROCK inhibitor attenuated PKC-induced contractions in IAS SMC. Conversely, a PKC inhibitor (Gö 6850, which causes partial relaxation of the SMC) had no significant effect on ROCK-II-induced contractions. Further experiments showed the highest levels of RhoA, active form of RhoA (RhoA-GTP), ROCK-II, 20-kDa myosin regulatory light chain (MLC20), phospho-MYPT1, and phospho-MLC20in the IAS vs. RSM and ASM SMC. However, the trend was the reverse with the levels of inactive RhoA (GDP-RhoA-RhoGDI complex) and MYPT1. We conclude that RhoA/ROCK play a critical role in maintenance of spontaneous tone in the IAS SMC via inhibition of myosin light chain phosphatase.
Tissue oxygen monitoring in rodent models of shock
Authors: Dyson Alex , Stidwill Ray , Taylor Val , Singer Mervyn
Published: March 2007

Tissue Po2 (tPo2) reflects the balance between local O2 supply and demand and, thus, could be a useful monitoring modality. However, the consistency and amplitude of the tPo2 response in different organs during different cardiorespiratory insults is unknown. Therefore, we investigated the effects of endotoxemia, hemorrhage, and hypoxemia on tPo2 measured in deep and peripheral organ beds. We compared arterial pressure, blood gas and lactate levels, descending aortic and renal blood flow, and tPo2 in skeletal muscle, bladder epithelium, liver, and renal cortex during 1) LPS infusion (10 mg/kg), 2) sequential removal of 10% of circulating blood volume, and 3) reductions in inspired O2 concentration in an anesthetized Wistar rat model with values measured in sham-operated animals. Different patterns were seen in each of the shock states, with condition-specific variations in the degree of acidemia, lactatemia, and tissue O2 responses between organs. Endotoxemia resulted in a rise in bladder tPo2 and an early fall in liver tPo2 but no significant change in muscle and renal cortical tPo2. Progressive hemorrhage, however, produced proportional declines in liver, muscle, and bladder tPo2, but renal cortical tPo2 was maintained until profound blood loss had occurred. By contrast, progressive hypoxemia resulted in proportional decreases in tPo2 in all organ beds. This study highlights the heterogeneity of responses in different organ beds during different shock states that are likely related to local changes in O2 supply and utilization. Whole body monitoring is not generally reflective of these changes.
Evaluation of a noninvasive continuous cardiac output monitoring system based on thoracic bioreactance
Authors: Keren Hanan , Burkhoff Daniel , Squara Pierre
Published: March 2007

Noninvasive cardiac output (CO) measurement can be useful in many clinical settings where invasive monitoring is not desired. Bioimpedance (intrabeat measurement of changes in transthoracic voltage amplitude in response to an injected high-frequency current) has been explored for this purpose but is limited in some clinical settings because of inherently low signal-to-noise ratio. Since changes in fluid content also induce changes in thoracic capacitive and inductive properties, we tested whether a noninvasive CO measurement could be obtained through measurement of the relative phase shift of an injected current (i.e., bioreactance). We constructed a prototype device that applies a 75-kHz current and determines the relative phase shift (dΦ/d t) of the recorded transthoracic voltage. CO was related to the product of peak dΦ/d t, heart rate, and ventricular ejection time. The preclinical study was done in nine open-chest pigs put on right heart bypass so that CO could be varied at known values. This was followed by a feasibility study in 27 postoperative patients who had a Swan-Ganz catheter (SGC). The measurements of noninvasive CO measurement and cardiopulmonary bypass pump correlated to each other ( r = 0.84) despite the large variation in CO and temperatures. Similarly, in patients, mean CO values were 5.18 and 5.17 l/min as measured by SGC and the noninvasive CO measurement system, respectively, and were highly correlated over the range of values studied ( r = 0.90). Preclinical and clinical data demonstrate the feasibility of using blood flow-related phase shifts of transthoracic electric signals to perform noninvasive continuous CO monitoring.
Left ventricular volume measurement in mice by conductance catheter: evaluation and optimization of calibration
Authors: Nielsen Jan Møller , Kristiansen Steen B. , Ringgaard Steffen , Nielsen Torsten Toftegaard , Flyvbjerg Allan , Redington Andrew N. , Bøtker Hans Erik
Published: March 2007

The conductance catheter (CC) allows thorough evaluation of cardiac function because it simultaneously provides measurements of pressure and volume. Calibration of the volume signal remains challenging. With different calibration techniques, in vivo left ventricular volumes (VCC) were measured in mice ( n = 52) with a Millar CC (SPR-839) and compared with MRI-derived volumes (VMRI). Significant correlations between VCC and VMRI [end-diastolic volume (EDV): R2 = 0.85, P < 0.01; end-systolic volume (ESV): R2 = 0.88, P < 0.01] were found when injection of hypertonic saline in the pulmonary artery was used to calibrate for parallel conductance and volume conversion was done by individual cylinder calibration. However, a significant underestimation was observed [EDV = −17.3 μl (−22.7 to −11.9 μl); ESV = −8.8 μl (−12.5 to −5.1 μl)]. Intravenous injection of the hypertonic saline bolus was inferior to injection into the pulmonary artery as a calibration method. Calibration with an independent measurement of stroke volume decreased the agreement with VMRI. Correction for an increase in blood conductivity during the in vivo experiments improved estimation of EDV. The dual-frequency method for estimation of parallel conductance failed to produce VCC that correlated with VMRI. We conclude that selection of the calibration procedure for the CC has significant implications for the accuracy and precision of volume estimation and pressure-volume loop-derived variables like myocardial contractility. Although VCC may be underestimated compared with MRI, optimized calibration techniques enable reliable volume estimation with the CC in mice.
High-intensity exercise elicits the mobilization of senescent T lymphocytes into the peripheral blood compartment in human subjects
Authors: Simpson Richard J. , Florida-James Geraint D. , Cosgrove Cormac , Whyte Greg P. , Macrae Scott , Pircher Hanspeter , Guy Keith
Published: March 2007

Clonal expansion of T lymphocytes in response to antigenic stimulation is a fundamental process of adaptive immunity. As a consequence of clonal expansion, some T lymphocytes acquire a senescent phenotype, fail to replicate in response to further antigenic stimulation, and express the killer cell lectin-like receptor G1 (KLRG1) and/or CD57. Physical exercise elicits a mobilization of large numbers of T lymphocytes into the bloodstream from peripheral lymphoid compartments, but the frequency of senescent cells in the mobilized population is not known. Eight male runners (age: 29 ± 9 yr; maximal O2uptake 62 ± 6 ml·kg−1·min−1) performed an intensive treadmill-running protocol at 80% maximal O2uptake to volitional exhaustion. Blood lymphocytes isolated before, immediately after, and 1 h after exercise were assessed for cell surface expression of KLRG1, CD57, CD28, CD45RA, CD45RO, CD62L, and lymphocyte subset markers (CD3, CD4, CD8, CD56) by flow cytometry. The percentage of all CD3+T lymphocytes expressing KLRG1 and CD57 increased with exercise ( P < 0.01). The change in T-lymphocyte KLRG1 expression was attributed to both CD4+and CD8 bright T cells, with the relative change being greater for the CD8 bright population ( P < 0.01). Mobilized T-lymphocyte populations expressing KLRG1 and CD57 appeared to extravasate the peripheral blood compartment after 1 h of recovery. In conclusion, T lymphocytes with a senescent phenotype are mobilized and subsequently removed from the bloodstream in response to acute high-intensity exercise. This suggests that T lymphocytes contained within the peripheral lymphoid compartments that are mobilized by exercise are likely to be at a more advanced stage of biological aging and have a reduced capacity for clonal expansion than blood-resident T cells.
Why Do They Do It?
Authors: Treloar Susan A. , Morley Katherine I. , Taylor Sandra D. , Hall Wayne D.
Published: March 2007

Objective:This exploratory, pilot study aimed to investigate motivations and reflections of participants who had provided epidemiological information, blood samples and access to clinical records and data in a large genetic epidemiological study of endometriosis, a common multifactorial disorder affecting women. We also aimed to explore understanding of complex genetic or multifactorial conditions in general. Methods:In-depth interviews were conducted with 16 endometriosis study participants with diverse characteristics. Results:Interviewees generally described their participation in the genetic study using altruistic frameworks of reference. Themes that emerged included unquestioning willingness and consent to participate, little concern about privacy issues, desire for more information from the researchers about the condition rather than scientific progress, the benefits of research participation to family communication, and differing ideas about genetic influences on endometriosis. Specific features of endometriosis also influenced reflections on research participation experience. Conclusions:As increasing numbers of individuals and families in the community become involved in genetic epidemiological studies of common diseases, more extensive research will be needed to better understand their expectations with a view to improving researchers’ communications with study participants.
Cancer Genetic Counseling in Public Health Care Hospitals: The Experience of Three Brazilian Services
Authors: Palmero Edenir Inez , Kalakun Luciane , Schüler-Faccini Lavinia , Giugliani Roberto , Regla Vargas Fernando , Rocha José Cláudio C. , Ashton-Prolla Patricia
Published: March 2007

In Brazil, genetic counseling is usually available in university-affiliated medical genetics services located in tertiary centers that provide cancer diagnosis and treatment. The present study aims to describe the structure and characteristics of three cancer genetic services in Brazilian public health care hospitals and discuss alternatives for the identification and prevention of hereditary cancer syndromes in developing countries. The three services presented here are similar in their structure, routine procedures for cancer risk estimation and criteria for the indication of genetic testing. They all demand that genetic counseling be an essential part of the cancer risk evaluation process, before and after cancer predisposition testing. However, when high-risk patients are identified, all services describe difficulties in the access and continuity of genetic and medical services to the patient and his/her at-risk relatives. The services differ in the type of population served, reflecting distinct referral guidelines. This study emphasizes the importance of the creation of new cancer genetic services in other Brazilian regions and the necessity for establishing a collaborative network to facilitate the diagnosis and research of cancer genetic syndromes.
Preoperative Imaging Staging of Rectal Cancer
Authors: Karantanas A.H. , Yarmenitis S. , Papanikolaou N. , Gourtsoyiannis N.
Published: March 2007

Carcinomas of the rectum are associated with a significant local and distant recurrence rate. Not all patients are appropriate candidates for preoperative radiation therapy. Preoperative identification of those most likely to benefit from neoadjuvant therapy is important. There is no general consensus on the role of endorectal ultrasonography, computed tomography (CT), and magnetic resonance imaging (MRI) in staging patients with rectal cancer. Although the tumor stage is an important prognostic factor, preoperative assessment is associated with prediction of the circumferential resection margin. Newer developments such as coils, sequences and gradients in MRI, evolution of multidetector CT and new contrast media, allow for an algorithm selection aiming at the best diagnostic options for patients. The present review will discuss the current role of the various imaging modalities in staging carcinomas of the rectum.
Laparoscopic Approach to Colonic Cancer: Critical Appraisal of the Literature
Authors: Fingerhut Abe , Ata Toufik , Chouillard Elie , Alexakis Nicholas , Veyrie Nicolas
Published: March 2007

Background/Aims: As laparoscopic colectomy finds its place in the surgical armamentarium, the literature concerning the safety, efficacy, and oncological rational for treatment of colonic cancer is also enriched. A review and critical appraisal of the literature on this subject was the aim of this paper. Methods: A systematic research and a hand search were conducted to gain access to all controlled studies involving laparoscopic colectomy using the Medline, Embase, HealthSTAR, Cumulative Index for Nursing and Allied Health Literature, CancerLit data bases and the Cochrane Central Register of Controlled Trials for the years 1991–2006. Results: Over 40 controlled randomized trials and ten systematic reviews and/or meta-analyses were found. Several of the completed controlled randomized trials have published either short- or long-term results; only partial and short-term results are available in rectal cancer. The principal conclusions are that the laparoscopic approach affords better short-term outcomes including surgical site morbidity, but with increased operative times and direct costs. Among the proven long-term outcomes, cancer recurrence and survival do not seem to be worse. Whether conversion, a source of increased operative time and costs, is responsible for poorer outcomes or whether specific settings associated with poorer outcomes are among the causes of conversion remains to be shown. However, there are still concerns as regards specific laparoscopic-related complications. Conclusion: There seems to no real safety problems in performing laparoscopic colectomy for cancer; improvement in operative times, conversion rates, and complications should make laparoscopy the best cost-effective approach to colectomy.
Role of Total Mesorectal Excision and of Circumferential Resection Margin in Local Recurrence and Survival of Patients with Rectal Carcinoma
Authors: Tzardi Maria
Published: March 2007

Rectal cancer is a common disease with poor prognosis because of local recurrence and metastases. Local recurrence arises mainly as a result of incomplete surgical resection. Evaluation of completeness of the mesorectum provides significant information about prognosis. Total mesorectal excision (TME) has become the surgical treatment of choice for rectal cancer because adopting the principles of TME achieves very low local recurrence rates. The adoption of the TME principles along with the estimation of the circumferential resection margin on the non-peritonealized surface of the resected rectal specimen are the most important predictors of local recurrence.
Assessment of Quality Guidelines Implementation Using a Continuous Quality Improvement Programme
Authors: Richards Nick , Ayala Juan Antonio , Cesare Salvatore , Chazot Charles , Di Benedetto Attilio , Gassia Jean-Paul , Merello Jose-Ignacio , Rentero Ramon , Scatizzi Laura , Marcelli Daniele
Published: March 2007

Background: Data from the Dialysis Outcomes and Practice Patterns Study (DOPPS) study suggest that the level of implementation of the European Best Practice Guidelines (EBPG) is at best partial. The main aim of this study is to describe the level of implementation of the EBPG in the European Fresenius Medical Care (FME) clinic network. Methods: Data presented in this investigation were gained through the FME database EuCliD® (European Clinical Database). Patient data from 4 countries (Great Britain, France, Italy, Spain) were selected from the EuCliD® database. The parameters chosen were haemodialysis adequacy, biocompatibility, anaemia control and serum phosphate control, which are surrogate indicators for quality of care. They were compared, by country, between the first quarter (Q1) 2002 and the fourth quarter (Q4) 2005. Results: During Q1 2002 and Q4 2005, respectively, a total of 7,067 and 9,232 patients were treated in FME clinics located in France, Italy, Spain and the UK. This study confirms variations in haemodialysis practices between countries as already described by the DOPPS study. A large proportion of patients in each country achieved the targets recommended by the EBPG in Q4 2005 and this represented a significant improvement over the results achieved in Q1 2002. Conclusions: Differences in practices between countries still exist. The FME CQI programme allows some of these differences to be overcome leading to an improvement in the quality of the treatment delivered.
A Prospective Study to Compare Subcutaneously Buried Peritoneal Dialysis Catheter Technique with Conventional Technique
Authors: Wu Chia-Chun , Su Pei-Fang , Chiang Shou-Shang
Published: March 2007

Aims: To reduce peritoneal dialysis-related infections, Moncrief-Popovich (MP) designed a special catheter and implantation technique. Herein we report our experience of patients treated with the MP and conventional approach. Methods: A total of 214 patients were divided into three groups according to catheter type and implantation technique: group A received a MP catheter (MPC) via MP technique (n = 27); group B received Tenckhoff catheters via MP technique (n = 32), and group C received Tenckhoff catheters via conventional technique (n = 155). Data were collected for infection and catheter survival. Results: The catheter survival and peritonitis rate was similar in our study groups. Age was found to be the significant factor associated with peritonitis rate. Conclusions: Although the MP technique was not associated with a lower peritonitis rate in our practice, the possible benefit of less healthcare costs is still considerable.
The Impact of Living Donor Kidney Transplantation on Markers of Cardiovascular Risk in Chronic Kidney Disease Patients
Authors: Bignelli Alexandre T. , Barberato Silvio H. , Aveles Paulo , Abensur Hugo , Pecoits-Filho Roberto
Published: March 2007

Background: Kidney transplant (Tx) patients present a reduced cardiovascular (CV) mortality in comparison to the dialysis population, but in comparison to the general population, it is still several-fold higher. Methods: We studied risk factors for CV disease in a group of 38 patients (50% males, median age 36 years) who underwent a living donor Tx at the baseline and after 3 ± 1 and 9 ± 2 months. Results: The prevalence of overweight increased from 26 to 54% after Tx (p < 0.001). The mean systolic blood pressure decreased significantly after the Tx (148 ± 27.6 vs. 126 ± 12.7 mm Hg). There was a significant increase in LDL (97 ± 30 vs. 114 ± 35) and hematocrit (33.8 ± 4.4 to 42 ± 5.7%) levels and a significant reduction in fibrinogen levels (394 ± 91 vs. 366 ± 100 mg/dl) after 9 months as compared to the baseline. Obesity and dislipidemia were significantly correlated with inflammation. Significant changes in left ventricle mass index (293 ± 116 vs. 241 ± 96) were observed after the Tx. Patients with a low glomerular filtration rate (GFR) in the follow-up evaluation presented higher LDL (128 ± 7 vs. 99 ± 7 mg/dl; p < 0.05) and higher fibrinogen levels (399 ± 21 vs. 332 ± 22 mg/dl; p < 0.05) compared to patients with a high GFR. Conclusion: Most of the risk factors analyzed (particularly the uremia-related) improved after the renal Tx, which could justify the positive impact of Tx on the development of CV disease. Inflammation and dyslipidemia were related to renal dysfunction after the Tx, suggesting that complete restoration of renal function may have an impact on reducing CV mortality in CKD patients treated with renal Tx.
A True ‘Advanced Imaging Assisted’ Skull-Mounted Stereotactic System
Authors: Carol Mark
Published: March 2007

A stereotactic system has been designed based upon a series of interlocking discs secured to the skull with self-tapping screws. Unlike previous skull-mounted systems, this system is a true, advanced imaging based stereotactic device with the capabilities and accuracy of more traditional, frame based devices. It has been used in a range of applications, from simple biopsies to interstitial radiation implant procedures. Well tolerated by the patient, it allows reaccess to the intracranial target without rescanning. It is convenient for the physician to utilize, both mechanically and timewise, is adaptable to MRI, DSA, and conventional X-ray techniques without modification, and is affordable.
Microsurgical Selective Procedures in Peripheral Nerves and the Posterior Root-Spinal Cord Junction for Spasticity
Authors: Sindou Marc , Abdennebi Benaïssa , Sharkey Paul
Published: March 2007

This review deals with the long-term results of selective peripheral neurotomy (SPN) of the tibial nerve and selective posterior rhizotomy (SPR) in 123 cases of severe spastic syndromes in the limbs. The microtechniques and peroperative electrostimu-lation for identification of the nervous structures responsible for the spastic components give to these methods an advantage of a substantial reduction of the harmful spasticity, without suppressing the useful muscle tone and impairing the residual motor and sensory functions. The results were effective, with a 1- to 13-year follow-up, in 89% of 47 SPN of the tibial nerve for spastic foot, in 92% of 53 SPR for paraplegia and in 87% of 23 SPR for hemiplegia.
Characteristics of the Tonic Stretch Reflex in Spastic Spinal Cord and Head-Injured Patients
Authors: Gildenberg Philip L. , Campos Robert J. , Dimitrijevic Milan R.
Published: March 2007

Spasticity is a known sequelae of spinal cord injury and head injury. We sought to examine whether there were any significant differences in the characterstics or underlying mechanisms of spasticity in these two groups in the chronic period which may be related to the level of injury of the neuraxis.The response to vibration applied to the muscle, or the tonic vibratory reflex, has been shown to be related to the degree of spasticity, and was therefore studied along with phasic reflexes and passive movements. These studies were carried out on cooperative, stabilized patients who were otherwise healthy, 5 with head injuries, and 5 with spinal cord injuries. The patients were examined in a supine position while surface EMG recordings were made of quadriceps and triceps surae muscles bilaterally. Tendon jerk responses, passive and volitional movements, and responses to a powerful vibratory stimulator were measured. In both head injury and spinal cord injury patient groups, a large EMG response was elicited by passive maneuvers, and tendon jerks were exaggerated. The tonic vibratory response, previously shown to be dependent upon brain influence, was present in both groups. These observations suggest that similar suprasegmental mechanisms may be responsible for hypertonia in both head-injured and spinal cord-injured patients.
Somatosensory-Evoked Potentials in the Ventrolateral Thalamus
Authors: Birk P. , Struppler A. , Riescher H. , Keidel M.
Published: March 2007

Electrical and physiological stimulation in the periphery evokes potentials which can be recorded in the target region during stereotactic surgery. This procedure, combined with intracerebral stimulation, is commonly used as a method to verify the localization of the tip of the probe. We recorded evoked potentials following electrical stimulation of a peripheral nerve during stereotactic operations of patients with parkinsonian tremor and spasmodic torticollis, in order to qualify the functional modalities of the fiber system which might be interrupted by a lesion in the target area. Therefore, mixed nerves (median nerve at the wrist, ulnar and median nerve in the brachial sulcus) were stimulated with a bipolar surface electrode contralateral to the operated side. In contrast, skin nerves were stimulated by a loop electrode around the tips of fingers 2–5 on the same side. The evoked potentials recorded in the target region were generally biphasic with an initially positive deflection at a latency of about 14 ms following median nerve stimulation at the wirst. No significant potential was recorded when the skin afferents were stimulated. The recording sites were plotted by computer with reference to the third ventricle and transferred to the stereotactic atlas using special software.
Focus Irradiation in Epilepsy. Experimental Study in the Cat
Authors: Salorio Barcia , Vanaclocha V. , Cerda M. , Roldan P.
Published: March 2007

An experimental model of chronic epilepsy has been developed in cats by means of placing cobalt oxide powder epidurally on the left frontal lobe. Radiosurgery of the epileptic focus with a total dose of 10 Gy was performed in a group of 6 animals, and behaviour and EEG observed.
Deafferentation Pain and Stimulation of the Thalamic Sensory Relay Nucleus: Clinical and Experimental Study
Authors: Tsubokawa Takashi , Katayama Yoichi , Yamamoto Takamitsu , Hirayama Teruyasu
Published: March 2007

This report summarizes our clinical experience in which the effects of both thalamic sensory relay nucleus (TSRN) and periaqueductal gray (PAG) stimulation were tested in the same series of patients with various forms of pain. The clinical data indicated that neurogenic pain due to deafferentation at the level of the peripheral nerves or the spinal cord was often controlled by TSRN stimulation but not by PAG stimulation. We also review the results of our experimental investigations in cats which were undertaken in an attempt to clarify the neurophysiologic basis of such differential clinical effects of TSRN and PAG stimulation. It appeared that abnormal hyperactivity within the trigeminal medullary dorsal horn following retrogasserian rhizotomy was far more frequently inhibited by TSRN stimulation than by PAG stimulation.
Pain Relief following Stimulation of the Pontomesencephalic Parabrachial Region in Humans: Brain Sites for Nonopiate-Mediated Pain Control
Authors: Katayama Yoichi , Tsubokawa Takashi , Hirayama Teruyasu , Yamamoto Takamitsu
Published: March 2007

It has been demonstrated that stimulation of the pontomesencephalic parabrachial region (PBR) by microinjection of cholinergic drugs or electricity in the cat produces potent pain suppression which is not antagonized by the opiate antagonist, naloxone. We report the application of electrical PBR stimulation in 2 patients whose pain was resistant to conventional methods of treatment including morphine administration. Intermittent use of low-frequency PBR stimulation was found to relieve pain in these patients. The present results appear to suggest that PBR stimulation, unlike periaqueductal gray stimulation, may be useful for the control of morphine-resistant pain in humans.
An Experimental Model of Deafferented Pain in the Cat
Authors: Namba Shimpei , Shimizu Yoji , Wani Takao , Fujiwara Noriaki
Published: March 2007

Deafferentation hyperactivity, produced unilaterally in the neurons of the subnucleus caudalis of the spinal trigeminal nucleus (STNcd) in cats by left Gasserian ganglionectomy, was studied neurochemically and electrophysiologically. Analysis of neuronal activities on both sides of the STNcd was done 11–63 days after the denervation. On the denervated side, 37 (57%) of the 65 neurons identified showed deafferentation hyperactivity. Continuous and spontaneous firing of these hyperactive neurons were inhibited neither by the intraventricular administration of morphine or enkephalinamide nor by the electrical stimulation of periaqueductal gray. In contrast, the facilitation of the pain perceptive neuronal activities in the STNcd of the nondenervated side was remarkably inhibited, both by the administration of the same drugs and by periaqueductal gray stimulation. The deafferentation hyperactivity produced in this experiment in the STNcd of the denervated side might have a close physiological relationship to the deafferented pain of clinical patients.
Stimulation of the Basal Nucleus of Meynert in Senile Dementia of Alzheimer’s Type
Authors: Turnbull I.M. , McGeer P.L. , Beattie L. , Calne D. , Pate B.
Published: March 2007

The basal nuclei of Meynert are the principal sources of cholinerigic innervation of the cerebral cortex. It has been hypothesized that the depressed cortical glucose metabolic activity in senile dementia of Alzheimer’s type (SDAT) may result primarily from diminished activity and loss of these cells. The present study was designed to test the hypothesis that electrical stimulation of the basal nuclei would bring about clinical improvement and increase cortical glucose metabolic activity in SDAT. An electrode was implanted in September 1984 into the left basal nucleus of a 74-year-old man with SDAT. Repetitive cycles of stimulation for 9 months since have had no definite effect clinically but a follow-up positron emission tomography scan shows that cortical glucose metabolic activity was preserved in the ipsilateral temporal and parietal lobes while it declined elsewhere in the cortex.
Problems with Retrogasserian Glycerol in the Treatment of Trigeminal Neuralgia
Authors: Sweet William H. , Poletti Charles E.
Published: March 2007

Following glycerol injections for trigeminal neuralgia. Hakanson, Lunsford, Apfelbaum, Beek and Lobosky and Dieckmann, among others, report that few patients have sensory loss and dysesthesia and a high percentage have sustained gratifying relief. Such was not our experience or that of Laitinen, Price, Siegfried, or Takusagawa, among others. Our own disappointing results reinitial failures to achieve relief, significant sensory loss including corneal anesthesia and some dysesthesias in 77 patients are described.
Therapeutic Protocol in the Treatment of Trigeminal Neuralgia
Authors: Esposito S. , Delitala A. , Bruni P. , Hernandez R. , Callovini G.M.
Published: March 2007

The ideal treatment of trigeminal neuralgia is still an open question. A recent large series reporting the results from the three available percutaneous techniques has been reviewed. Fifty consecutive cases, treated from January 1984 to January 1985, are reported. Microcompression was performed as the first approach in all cases. The other techniques were adopted only in case of failure of microcompression.
Spinal Cord Stimulation in the Treatment of Spasmodic Torticollis
Authors: Waltz Joseph M. , Scozzari Carmen A. , Hunt David P.
Published: March 2007

This report presents our observations in 63 patients undergoing chronic spinal cord stimulation for treatment of spasmodic torticollis. In this series there were 23 patients (36.5%) who demonstrated marked improvement, characterized by no evidence of torticollis. full range of motility of the head and neck and no pain. Moderate improvement was found in 20 patients (31.8%) who showed minimal residual torticollis, but had full motility and no pain. There were 5 patients (7.9%) considered mildly improved who demonstrated decrease in their torticollic position, spasms and pain, but retained some element of torticollis and/or some limitation of motility. Correlations were made demonstrating the effect on the results of age, sex, electrode array, the configuration of the applied field and the parameters of stimulation.
The Place of Stereotactic Depth Electrode Recording in Epilepsy
Authors: Olivier André , Gloor Peter , Andermann L. Frederick , Quesney Felipe
Published: March 2007

A series of 70 patients studied with stereotactically implanted depth electrodes is analyzed. Indications and grouping fall into three main categories: (A) the bitemporal series (52 patients), where there is ambiguity as to the lateralization of the focus; (B) the unilateral series (6 patients), where the main problem is one of Iocalization within one hemisphere, and (C) the generalized and/or multifocal series (12 patients), where a primary focus is suspected. The best indication is represented by the group of ‘bitemporal cases'' which turned out to have a well-lateralized onset with intracerebral recording.
Surgery for Epilepsy Selective Partial Microsurgical Callosotomy for Intractable Multiform Seizures: Criteria for Clinical Selection and Results
Authors: Marino Jr. Raul
Published: March 2007

A series of 35 patients have been submitted to microsurgical callosotomy since February 1978, their age ranging from 6 to 42 years. The surgical procedure consisted either of a frontal parasagittal trephination or a Iarger frontoparietal rectangular craniotomy to allow the investigation of the surgical areas of the hemispheres with electrocorticography under local anesthesia. This allowed us to better follow the electrographic abnormalities and plan the extent of the callosal section suited to each case, in particular rostral and genual section, section of the trunk only or subtotal section sparing the splenium. In 2 cases, cortical resection was associated with the split. The callosal fibers which were divided by careful section under the resected portion provided a critical postoperative control of the extent of the lesion. Results and selection criteria will also be analyzed.
Absence Attacks Controlled by Thalamic Stimulation
Authors: Andy O.J. , Jurko M.
Published: March 2007

Thalamic electrical stimulation in 3 patients alleviated chronic pain, absence attacks and spontaneously occurring delta and theta EEG discharges. It is suggested that diencephalic discharges may activate and/or lower the threshold for pain at the level of the diencephalon.
Correlation between Stereo-EEG, CT-Scan and Stereotactic Biopsy Data in Epileptic Patients with Low-Grade Gliomas
Authors: Munari C. , Musolino A. , Daumas-Duport C. , Missir O. , Brunet P. , Giallonardo A.T. , Chodkiewicz J.P. , Bancaud J.
Published: March 2007

Stereo-EEG activity, which was recorded precisely from the same location as stereotactic biopsies, was studied on 11 patients with low-grade glioma and severe partial epilepsy. The volume of the lesions varied from 6 to 72 cm3 (mean 23 cm3). A very depressed activity was recorded in all the 25 specimens of solid tumor and in more than half of infiltrated white matter. The background activity was still conserved in all ‘normal’ fragments, while itis never found in solid tumor; sometimes it could be found in the infiltrating tumors of white or gray matter. High voltage theta and delta activity was recorded in neither ‘normal’ nor solid tumors. We emphasize the importance of considering the stage of evolution when we evaluate the significance of the stereo-EEG activity.
Use of Intraoperative Stimulation in the Selection of Target Sites for CT-Guided Stereotactic Biopsies
Authors: Bullard Dennis E. , Makachinas Thad T. , Nashold Jr. Blaine S.
Published: March 2007

We have utilized intraoperative stimulation to establish the functional nature of tissue to be biopsied in 20 patients undergoing CT-guided stereotactic biopsies. We have performed from 1–4 stimulations at 2–100 Hz using a monopolar and/or bipolar electrode at the intended target sites. Thresholds for motor and sensory response have been obtained. Stimulation results have ranged from sensory changes to tonic/clonic motor activity of the contralateral body and face.
Long-Term Erythropoietin Therapy Does Not Affect Metalloproteinases and Their Inhibitor Levels, Oxidative Stress and Inflammation in Hemodialyzed Patients
Authors: Pawlak Krystyna , Pawlak Dariusz , Mysliwiec Michal
Published: March 2007

Background: Matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) play an important role in the atherosclerosis. Recombinant human erythropoietin (EPO) has become widely used to treat anemic hemodialyzed (HD) patients; however, an increased mortality has been reported for HD patients with cardiovascular disease when randomly assigned to normal hematocrit by EPO. Therefore, we conducted a study examining the effect of EPO on MMPs/TIMPs system, oxidative stress and inflammation in these patients. Methods: Assessment of MMP-2, MMP-9, TIMP-1 and TIMP-2 were performed in 20 stable HD patients and 15 healthy controls. Additionally, the effects of EPO on malondialdehyde (MDA) – a marker of SOX and C-reactive protein (CRP) levels – as a marker of inflammation were also investigated. Of the 20 patients, 10 were receiving EPO therapy [HD-EPO(+)] for 12 months or more and 10 were not receiving EPO therapy [HD-EPO(–)]. Both groups were not receiving iron supplementation. Results: All parameters, with the exception of MMP-9, were lower in the healthy subjects compared with the HD subjects, irrespective of EPO administration. There was no difference in MMPs/TIMPs system, MDA and C-reactive levels between HD-EPO(+) and HD-EPO(–) patients. Conclusion:Erythropoietin therapy did not influence MMPs/TIMPs system, inflammation, or SOX in a low-risk HD patient population, in the absence of concomitant iron supplementation and mean Hg levels within target.
Treatment of Malignant Pain of the Head and Neck
Authors: Miles John
Published: March 2007

The treatment of pain due to malignancy in the head and neck is difficult, and the pain doctor must take a special responsibility in selecting the appropriate treatment. Specialized and often combined surgical procedures may still offer the best chance of relief, particularly when tumours involve the paranasal sinuses and the petrous bone. Peripheral and central destructive procedures can prove effective, and perhaps thalamotomy is deserving of greater usage. Chronic intrathecal analgesic administration can undoubtedly prove effective, and while the unwanted features may yet have to be established, it provides a welcome additional option in the management of pain in this difficult area.
Depth Electrode Recording in Patients Undergoing Corpus Callosotomy f or Intractable Epilepsy
Authors: Roberts D.W. , Allen C.D. , Allen A.H. , Reeves A.G.
Published: March 2007

6 patients undergoing anterior corpus callosotomy for intractable epilepsy have been studied with depth electroencephalography (EEG). Recording before, during and after surgery has confirmed the ability of depth EEG to demonstrate and identify lateralized, focal and often multifocal disturbances. Callosal section has an immediate and lasting effect on clinical seizures and is accompanied by EEG changes with loss of generalization and synchrony following commissurotomy. Depth electrodes within the corpus callosal radiations variably reflect preoperative epileptiform activity recorded from the temporal and frontal regions and postoperatively confirm loss of a potential route of propagation through the commissure.
Diencephalic Seizures
Authors: Andy O.J. , Jurko M.
Published: March 2007

Intractable complex partial and diencephalic seizures in 1 patient are being treated effectively by intermittent daily electrical stimulation in the right thalamus in conjunction with phenytoin, 200 mg/day, Electrical stimulation in the right thalamus was found to suppress spike and sharp wave discharge activity temporarily in the right thalamus and in the left parietal and right scalp leads. It was postulated that beneficial effects from electrical stimulation were due to electrically ‘jamming a low-threshold discharge system’.
Discovery of the First Human Stereotactic Instrument
Authors: Olivier A. , Bertrand G. , Picard C.
Published: March 2007

It has been uncovered that the first human stereotactic instrument was designed around 1918, but was never put to human use. It was designed after the Horsley-Clarke animal apparatus by an engineer, Aubrey Mussen. The history surrounding that historical event is revealed in a series of letters between the engineer and his son some years later.
Thalamic Stimulation for Chronic Pain
Authors: Andy O.J.
Published: March 2007

Electrical stimulation of the thalamus was found to be effective for the treatment of chronic intractable pain of various etiologies. Diencephalic recordings re-vealed spontaneous focal electrical discharge patterns with relatively low activation thresholds. Localization of the optimum thalamic discharge site is used as a guide for the electrode implant to be used for chronic stimulation. The thalamic sites which most frequently displayed the low threshold spontaneous focal discharge activity were the CM-Pf complex and related intralaminar nuclear structures. Generation of diencephalic pain-reverberating circuits was discussed in relation to explaining the pain syndromes herein described. The applied electrical stimulation is thought to electrophysiologically ‘jam’ the low threshold discharging systems and thereby alleviate pain.