bluuebunny/crossref_metadata_2025 huggingface dataset:
Microvascularisation of the Lips in the Fetus and Neonate
Authors: Wolfram-Gabel R. , Sick H.
Published: April 2003

The differences observed in the microvascularisation of the lips in the perinatal period correspond to the differences in the histological structures of the cutaneous, glabra, intermediate cutaneous, villous, intermediate mucosal and mucosal parts. A basic pattern is found in each part: on the surface, a papillary or mucosal network, at a deeper level, reticular or submucosal networks and their pedicles. The vascular changes correspond to the transition of tissue (mucocutaneous junction) and are indicative of the functional aspect. The same histological and microcirculatory structures were found in all the preparations, irrespective of the subject’s age. Knowledge of the microvascularisation makes it possible to interpret magnetic resonance imaging of the lip better and finds its application in the surgery of the lips.
A Single Low Dose of RGTA®, a New Healing Agent, Hastens Wound Maturation and Enhances Bone Deposition in Rat Craniotomy Defects
Authors: Colombier M.L. , Lafont J. , Blanquaert F. , Caruelle J.P. , Barritault D. , Saffar J.L.
Published: April 2003

RGTA®, a new family of dextran-derived healing agents, promotes the repair of various tissues, including bone. In this study, we examined whether a dose of RGTA lower than in our previous studies could still modify the healing pattern in craniotomy defects. In 24 rats, two defects (3 mm diameter) were drilled on either side of the calvaria sagittal suture. The right defect was filled with a piece of collagen soaked with RGTA in phosphate-buffered saline (PBS; 4 μg/ml), and the left one with collagen soaked in PBS only. After 7, 14 and 21 days, the calvaria were removed and processed for histometry. On day 7, in contrast with the control defects, the treated sites were inflammation-free and centripetal bone plates had started to grow. By day 14, the bone filling was significantly enhanced in the treated defects (+ 290%, p < 0.05), and isolated bone nodules had formed within the fibrous connective tissue (= fibrous hammock) joining the defect edges. The hammock had already differentiated by day 7 in all the RGTA-treated defects, and it was significantly thicker on days 14 (+ 190%, p < 0.05) and 21 (+ 139%, p < 0.05). The colonization of the hammock by mast cells was increased in the treated sites (+ 320%, p < 0.05 on day 21). On day 7, most of the bony edges of the treated defects had been resorbed by osteoclasts, while the process only started in the controls. These data indicate that a low dose of RGTA modified the cascade of events occurring at the initial stages of repair, so that the tissular maturation of the treated defects was more rapid. In fact the use of RGTA in the wounds provoked a shift from a fibrous repair as seen in the controls, to a bone reconstruction favoring defect closure.
Involvement of Sulfated Proteoglycans in Embryonic Brain Expansion at Earliest Stages of Development in Rat Embryos
Authors: Alonso M.I. , Gato A. , Moro J.A. , Martin P. , Barbosa E.
Published: April 2003

The expansive force generated by the positive pressure of the neural tube fluid confined inside the brain vesicles has been shown to be a key factor during the earliest stages of brain morphogenesis and development of chick embryos. In a previous study, we demonstrated the existence of an intracavity extracellular matrix rich in condroitin sulfate in this species, which could be involved in the regulation of the expansive process. In this report, scanning electron microscopy and immunohistochemistry show that, after neurulation, a similar extracellular matrix rich in chondroitin sulfate is present inside the brain vesicles of rat embryos during early enlargement of the brain anlage. In vitro treatment of rat embryos with β-D-xyloside (a chemical compound which disrupts chondroitin sulfate synthesis) shows that changes in intralumen chondroitin sulfate concentration are accompanied by significant changes in brain anlage growth. These results support the hypothesis that intracerebral chondroitin sulfate plays a relevant role in the regulation of the expansive process of the brain anlage of rat embryos, and could represent a general mechanism in the early brain development of avian and mammalian embryos.
Signaling Mechanisms Regulating Self-Renewal and Differentiation of Pluripotent Embryonic Stem Cells
Authors: Burdon Tom , Chambers Ian , Stracey Craig , Niwa Hitoshi , Smith Austin
Published: April 2003

An ability to propagate pluripotent embryonic cells in culture is the foundation both for defined germline modification in experimental rodents and for future possibilities for broad-based cellular transplantation therapies in humans. Yet, the molecular basis of the self-renewing pluripotent phenotype remains ill-defined. The relationship between factors that influence embryonic stem cell propagation in vitro and mechanisms of stem cell regulation operative in the embryo is also uncertain. In this article we discuss the role of intracellular signalling pathways in the maintenance of pluripotency and induction of differentiation in embryonic stem cell cultures and the mammalian embryo.
Induction of Cellular Differentiation by Retinoic Acid in vitro
Authors: Rohwedel Jürgen , Guan Kaomei , Wobus Anna M.
Published: April 2003

Cellular differentiation by the vitamin A derivative retinoic acid (RA) has been studied with undifferentiated pluripotent embryonic carcinoma (EC) and embryonic stem (ES) cells in vitro. Both cellular systems are suitable to study differentiation of various cell types, because they recapitulate early stages of mouse embryogenesis. In vivo, RA was identified as a morphogenic and teratogenic compound and furthermore as a signalling molecule influencing gene expression in a complex manner via a family of RA receptors. Here, we summarize in vitro studies with ES and EC cells in comparison to in vivo studies that have contributed to our understanding how RA influences differentiation and regulates gene expression. We demonstrate that modulation of ES cell differentiation in vitro by RA depends on the concentration and developmental stage of application which is comparable to its stage-dependent influence on embryonic development in vivo.
Effects of Muscle Contraction on the Load-Strain Properties of Frog Aponeurosis and Tendon
Authors: Lieber Richard L. , Leonard Margot E. , Brown-Maupin Cynthia G.
Published: April 2003

The mechanical properties of the frog semitendinosus (ST) tendon and aponeurosis were measured during passive tensile loading to a force equal to ST maximum tetanic tension and during active isometric muscle contraction. During active contraction, both the tendon and aponeurosis regions initially strained at rates exceeding 400%/s while near the end of the muscle contraction, strain rates were nearly zero. At this point, the strain in the tendon region was equal to that observed during slow passive loading to the same tension level. However, for the aponeurosis, even near the zero strain rate, strain at the end of the active contraction was significantly below that observed during slow passive loading (p < 0.001). Specifically, when aponeurosis strain rate was almost zero, aponeurosis strain was 13.8 ± 3% (means ± SEM, n = 10), which was significantly below that measured during passive loading (23.7 ± 5%) suggesting that active contraction actually altered aponeurosis material properties. These data demonstrate that, while the tendon and aponeurosis regions have different passive biomechanical properties and both demonstrate viscosity typical of other connective tissues, the aponeurosis region of the frog ST actually changed its intrinsic properties during muscle contraction. Thus, extrapolation of biomechanical data obtained at nonphysiological strain rates or under conditions where the muscle-tendon junction has been interrupted should be made with caution.
Changes in Gastroduodenal 5-Hydroxytryptamine-Containing Cells Induced by Dehydroleucodine
Authors: Penissi Alicia , Mariani Laura , Souto Marta , Guzmán Jorge , Piezzi Ramón
Published: April 2003

In previous work, we demonstrated that dehydroleucodine (DhL), a lactone isolated from Artemisia douglasiana Besser, prevents gastroduodenal damage induced by absolute ethanol (EtOH). The present study examined the effects of DhL – applied alone or before EtOH – on gastroduodenal cells containing 5-hydroxytryptamine (5-HT), to clarify the mechanism of action of the drug. Mice were divided into four groups: (I) control; (II) DhL; (III) EtOH, and (IV) DhL + EtOH. Stomachs and duodena were studied by immunohistochemistry and image analysis. EtOH decreased the immunopositive cell number and the area occupied by these cells. This effect was prevented by DhL. DhL alone did not affect the gastric immunopositive cell number and area. Duodena treated only with DhL exhibited a reduction of immunopositive cell number, but no change in area was observed. We propose that the drug probably inhibits the release of the inflammatory mediator 5-HT from endocrine cells, acting as a ‘cell stabilizer’ in response to injury.
Developmental Morphological and Histological Studies on Structures of the Human Fetal Elbow Joint
Authors: Mahasen Laila M. Aboul , Sadek Sohair A.
Published: April 2003

In the present work, morphological changes in the developing human elbow joint were studied at different prenatal ages (8, 12, 16, 20, 29 and 40 weeks) and were compared with the same structures in the adult joint. The elbow joint had gone through its most important developmental changes during the 20th week of prenatal life, probably due to the direct dynamic effect of the newly developed fetal movement. During later prenatal development, the articular surfaces of the lower end of humerus and the upper ends of radius and ulna developed their characteristic congruencies, so that the highly curved convexities always articulate with the highly curved concavities. That process progressed postnatally and even till adult age. In full-term infants it was found that the lower end of humerus had acquired its adult shape, while the shape of the upper ends of radius and ulna were still not fully developed. They continued development in postnatal life even till adult age. In the present work, histological prenatal studies were done on longitudinal sections from the back of the capsule and synovial tissue, early (8 weeks) and late in full term, and the results were also compared with the same structures in adults. It was found that at all ages, the capsules were formed of cellular and fibrous elements, but at early prenatal age (8 weeks), this cellular condensation was more massive and prominent while in full-term infants, it became generally more fibrous, but was still different compared to adults. Basic cellular structures of the synovial tissue changed very little during the late prenatal developmental stage, as it did not become more fibrous than cellular during these periods, but differences in vascularity became more obvious. The cartilaginous content of the articular surface at 8 weeks was highly cellular with very little intercellular matrix. In contrast to that of full term, this cartilage became fully chondrogenous with a notable decrease in cellular density and massive increase in matrix content.
Anatomy of the Intrahepatic Ramification of the Portal Vein in the Right Hemiliver
Authors: Ortale José Roberto , Naves de Freitas Azevedo Cristiano Humberto , Mello de Castro Clésio
Published: April 2003

The ramification of the portal vein in the right hemiliver was studied by anatomic dissection in 36 formalin-fixed human livers. In 28/36 (77.8%) cases, the portal vein bifurcated into a right branch and a left branch and the right branch bifurcated into anterior and posterior segmental branches. The anterior segmental branch terminated in the anterosuperior subsegment (S8) in two types: bifurcated when it divided into anterior P8 and posterior P8 branches towards the respective regions of S8 (24/28 cases) and monopodal when it had a single pedicle (4/28 cases). The maximum anteroinferior subsegmental branch (P5 maximum) originated either from the anterior segmental branch (16/28 cases) or from the anterior P8 branch (12/28 cases). The posterior segmental branch vascularized the posteroinferior (S6) and the posterosuperior (S7) subsegments, and was terminated in three types: fan-shaped (16/28), bifurcated (9/28) and tripodal (3/28). In 4/36 (11.1%) cases the portal vein bifurcated into a right branch and a left branch but the posterior segmental branch was not present. In 4/36 (11.1%) the right branch of the portal vein was not present. These anatomical variations are explained separately and finally all cases are considered as a whole.
Regeneration of Mouse Lip Epidermis after Cryo Treatment
Authors: Osawa T. , Abe M. , Wang Y. , Nozaka Y.
Published: April 2003

The processes of degeneration and the regeneration of the lip epidermal cells was observed by electron microscopy, focussing on the substance and the structure of the lamina lucida, on which regenerating cells migrated. After the repetitive freezing and thawing treatment, epidermal cells degenerated and detached from the dermis. The separation occurred between the epidermal cells and the basement membrane, leaving a small amount of cell debris on the lamina densa. After the separation of the epidermis, there were some thick parts in the lamina densa which appeared to be the part below hemidesmosomes. Regenerating epidermal cells migrated from the nondegenerated area along the cellular surface of the old lamina densa. They migrated over the cell debris which was gradually phagocitized, and formed new hemidesmosomes with the old lamina densa. Regenerating epidermal cells did not make close contact with the old lamina densa during their migration, but there was a clear space in between, indicating that some of the materials and the structure of the lamina lucida of the old basement membrane was preserved. By immunoelectron microscopy using anti-HSPG (heparan sulfate proteoglycan) antibody, it became clear that after the epidermal separation, HSPG was preserved in the basement membrane to some extent, especially in the thick parts of the lamina densa located below. The immunoelectron micrographs support the view that hemidesmosomes may reform at the previous locations at the old lamina densa.
Ultrastructural Characterization of the Rabbit Mandibular Condyle following Experimental Induction of Anterior Disk Displacement
Authors: Sharawy Mohamed , Ali Ayman M. , Choi Won-Seok , Larke Vera
Published: April 2003

Previous studies in our laboratory have shown that surgical induction of anterior disk displacement (ADD) in the rabbit craniomandibular joint (CMJ) leads to cellular and extracellular alterations consistent with osteoarthritis. Similar findings were also reported in human ADD as well as osteoarthritis of other joints. The purpose of this study was to further characterize these histopathological findings at the ultrastructural level. The right joint of 15 rabbits was exposed surgically and all discal attachments were severed except for the posterior attachment. The disk was then repositioned anteriorly and sutured to the zygomatic arch. The left joint served as a sham-operated control. Ten additional joints were used as nonoperated controls. Mandibular condyles were excised 2 weeks following surgery and processed for transmission electron microscopy. Experimental condyles showed neovascularization, fibrillation and vacuolation of the extracellular matrix and an increase in the number of apoptotic cells compared to controls. In addition, chondrocytes in osteoarthritic cartilage showed an increase in the amounts of rough endoplasmic reticulum and Golgi complex suggesting an increase in protein synthesis. The presence of thick collagen fibers in osteoarthritic cartilage supports our previous immunohistochemical results of the presence of type I collagen instead of normally existing type II collagen. It was concluded that surgical induction of ADD in the rabbit CMJ leads to ultrastructural changes in the mandibular condylar cartilage consistent with degenerative alterations known to occur in osteoarthritis.
Unilateral Masticatory Function Changes the Proteoglycan Content of Mandibular Condylar Cartilage in Rabbit
Authors: Poikela Aila , Kantomaa Tuomo , Pirttiniemi Pertti , Tuukkanen Juha , Pietilä Kati
Published: April 2003

Unilateral masticatory function was induced in 10-day-old rabbits by grinding the right side molars out of occlusion under general anesthesia. The grinding procedure was repeated twice a week thereafter. They were killed at the ages of 25 and 35 days. Rabbits of the same age with uninterfered occlusions served as controls. The changes in articular cartilage of the mandibular condyle were studied biochemically and histochemically. There was a significant decrease in the proteoglycan content of the condylar cartilage in both groups of animals subjected to molar grinding compared to the animals with untouched occlusions. Especially the amount of aggregating proteoglycans was reduced. The condylar cartilage matrix synthesis is sensitive to loading produced by masticatory function during growth. The mechanical properties of the articular cartilage after a period of unilateral mastication will be impaired and it is possible that this makes the joint cartilage more susceptible to pathological events.
Bioartificial Skin
Authors: Machens H.-G. , Berger A.C. , Mailaender P.
Published: April 2003

The loss of skin has been one of the oldest, yet most frequent and costly problems in our health care system. To restore functional and esthetic integrity in patients with unstable or hypertrophic scars, in burn patients and after skin loss for hereditary, traumatic or oncological reasons, an armamentarium of reconstructive surgical procedures including autogenous, allogenous and xenogenous tissue transfer as well as implantation of alloplastic materials has been favored. For several decades there has been increasing interest focused on ‘tissue engineering’ of dermal, epidermal and full thickness skin substitutes by both biological and synthetic matrices. At our institution (Hannover Medical School), a collagen/glycosaminoglycan dermal regeneration matrix has been used for immediate dermal coverage after escharectomy in burn injuries as well as for dermal replacement in chronically unstable scars. This article gives an overview on the current state of the art in bioartificial skin as well as our personal experience with the collagen/glycosaminoglycan matrix for dermal replacement in different clinical situations.
Interspecies Variation in Axon-Myelin Relationships
Authors: Fraher J.P. , O’Sullivan A.W.
Published: April 2003

The primary objective of this paper was to determine the extent and nature of interspecies differences in axon calibre and myelin sheath thickness and in the various relationships between these. Morphometric analysis of the axon perimeter-myelin sheath thickness relationship was performed on an equivalent nerve fibre population in a mammal, the rat, a bird, the chicken, an amphibian, the frog, a bony fish, the trout, and a cartilaginous fish, the dogfish. The abducent nerve was studied. It is especially suitable for this purpose because its fibres are closely similar in type and in peripheral distribution across the species studied. The relationship differed substantially between species. Differences were present in its setting, as described by the positions of the scatterplots, in the g ratio and in the regression and correlation data relating the parameters. Both parameters were markedly larger in the fish species than in all of the others. In addition, in rat, chicken, frog and trout, where large and small fibre classes could be differentiated clearly, the setting of the relationship between the two parameters was different for the two classes. In the main, variation in each of the parameters was greater between than within species. The larger fibres in the fish species were closely similar in axon perimeter and sheath thickness despite their long evolutionary separation. From this study and from others in the series, it may be concluded that there is no fixed or constant relationship between axon calibre and the thickness of the surrounding myelin sheath. Each nerve tends to have its own particular relationship and this differs between species.
Quantitative Three-Dimensional Analysis of Chondrocytic Kinetic Responses to Short-Term Stapling of the Rat Proximal Tibial Growth Plate
Authors: Farnum Cornelia E. , Nixon Alan , Lee Andrea O. , Kwan Donna T. , Belanger Lia , Wilsman Norman J.
Published: April 2003

Although it has been demonstrated clinically that controlled compression across a growth plate will slow the rate of endochondral ossification and thus can be used to correct angular limb deformities, the cellular-based mechanism by which altered growth is achieved is poorly understood. This study used short-term uniaxial stapling of the rat proximal tibial growth plate as an experimental system to study chondrocytic responses in the growth plate that account quantitatively for the decreased rate of growth. Growth plates were labeled with oxytetracycline to measure bone growth, and with bromodeoxyuridine to analyze proliferative cell kinetics. Multiple indicators of chondrocytic activity, measured by stereological parameters, were analyzed using growth rate as the primary dependent variable. The unique feature of this analysis was the creation of three-dimensional reconstructions that allowed analysis of data in all directions with distance from the staple. A significant observation was that for the entire operated limb after both 3 and 6 days, all chondrocytic kinetic parameters were affected, indicating that proliferative and hypertrophic responses both act to decrease growth rate in response to stapling. This contradicted our hypothesis that proliferative and hypertrophic responses could occur independently, and that small changes in rate would be attributed primarily to the former and large changes to the latter. The data from this study also demonstrate that volume regulation during hypertrophy can be affected by a primarily mechanical perturbation. Because changes in hypertrophic cell number and volume throughout the growth plate that occur by day 3 remain similar at day 6, the initial modulation of chondrocytic volume and shape may represent the limit of the response while maintaining a growth plate capable of continued growth.
Carbohydrate-Mediated Sperm-Egg Interaction and Species Specificity: A Clue from the Unio elongatulus Model
Authors: Focarelli R. , La Sala G.B. , Balasini M. , Rosati F.
Published: April 2003

As a first step fertilization requires that sperm bind to the extracellular coat of the egg. It is generally accepted that binding is mediated by complex carbohydrates on the egg coat, recognized by carbohydrate-binding proteins on the sperm surface. In the mollusc bivalve Unio elongatulus, the main functional epitope of the carbohydrate ligand has been determined, and it shares several characteristics with other sugar structures involved in the fertilization process in different animal models. A polyclonal antibody against the Unio epitope reacts with the human ZP3 glycoprotein and the Unio ligand binds human spermatozoa in an in vitro assay. These findings are discussed in the light of the species specificity of sperm-egg binding at fertilization.
Carbohydrate-Mediated Formation of the Oviductal Sperm Reservoir in Mammals
Authors: Suarez Susan S.
Published: April 2003

Mammalian sperm are trapped in a reservoir in the oviduct until ovulation is imminent. Then, they are gradually released, such that a few meet the oocytes as they enter the ampulla of the oviduct. In the three eutherian species studied to date, sperm are trapped in the reservoir by carbohydrate-mediated binding to the oviductal mucosa. Evidence indicates that a molecule on the surface of the plasma membrane overlying the acrosome binds to a carbohydrate moiety on the surface of the oviduct. While sperm remain bound, they appear to be protected from degradation. When sperm become capacitated, they lose binding affinity for the oviductal mucosa. The mechanism initiating capacitation in the reservoir is unknown; however, it must be tied to the hormonal signalling of ovulation. Hyperactivated motility may assist sperm in pulling off from the mucosal surface as binding affinity declines. The function of the reservoir appears to be to prevent polyspermy and ensure fertilization by providing a small number of sperm in the proper physiological condition for fertilization at the time the oocytes enter the oviduct.
Use of Botulinum Toxin in the Treatment of Achalasia
Authors: Schiano Thomas D. , Parkman Henry P. , Miller Larry S. , Dabezies Marta A. , Cohen Sidney , Fisher Robert S.
Published: April 2003

Achalasia is a chronic esophageal motor disorder characterized by failure of the lower esophageal sphincter (LES) to relax during swallowing, aperistalsis of the esophageal body, and, often, an elevated resting LES pressure. Pneumatic dilation and Heller cardiomyotomy have been the time-honored, accepted treatments, but each may carry significant morbidity. Recently, intrasphincteric injection of botulinum toxin has been shown to be an effective treatment for achalasia, probably by reducing the excitatory cholinergic tone of the LES. Subjective and objective improvement have been reported in many patients with few reported adverse reactions. Clinical improvement generally lasts 2–6 months with patients often requiring repeat treatment. Although studies directly comparing botulinum toxin injection with pneumatic dilation and surgical myotomy are needed, botulinum toxin injection has rapidly become another therapeutic option in the treatment of achalasia.
Antimicrobial Treatment of Intra-Abdominal Infections
Authors: Elsakr Raif , Johnson David A. , Younes Ziad , Oldfield III Edward C.
Published: April 2003

There have been several recent changes that influence the management of intra-abdominal infections. These changes include important developments in antibiotic resistance such as increases in pneumococcal resistance, emergence of multi-drug-resistant enterococcal isolates, and decreasing sensitivity of anaerobes and gram-negative rods. In addition there are new antibiotics such as piperacillin/tazobactam, and new antibiotic dosing regimens such as single daily dosing of aminoglycosides. In this article, we will review the therapeutic approach to intra-abdominal infections with special emphasis on the various forms of peritonitis, cholecystitis, cholangitis, and diverticulitis. Several new concepts about the treatment of enterococcus, the management of bacterial and fungal peritonitis, and the prevention of spontaneous bacterial peritonitis will also be reviewed. Specific recommendations for the management of the different infections including antibiotic doses and costs will be provided. Finally the role of invasive procedures in the management of some of the infections will be explored.
Management of Bile Duct Stones in the Era of Laparoscopic Cholecystectomy
Authors: Gross Glenn W.W.
Published: April 2003

The development of laparoscopic cholecystectomy has transformed many aspects of gallstone disease management, particularly the care of patients with known or suspected bile duct stones. New obstacles to operative access to the bile duct have stressed the importance of accurate clinical prediction and detection of bile duct stones and led to increased reliance on nonsurgical approaches, especially pre- or postoperative endoscopic retrograde cholangiopancreatography and sphincterotomy, as well as spurring the development of new techniques such as laparoscopic common bile duct exploration. This work reviews the key features and rational usage of the endoscopic, laparoscopic and open surgical procedures, as well as other adjunct techniques, employed in the treatment of bile duct stones, emphasizing current options in the approach to this problem in the perilaparoscopic cholecystectomy setting. Management of bile duct stones in other special clinical circumstances and the potential future role of emerging technologies are also discussed.
Upper Respiratory Tract Complications of Gastroesophageal Reflux in Adult and Pediatric-Age Patients
Authors: Euler Arthur R.
Published: April 2003

Upper airway complications of gastroesophageal reflux occur much less frequently than those aborad to the upper esophageal sphincter; however, laryngitis, laryngeal and/or tracheal stenosis, globus syndrome, oropharyngeal dysphagia, otitis media, sinusitis, and rhinitis can all be associated with significant morbidity and occasional mortality in both adult and pediatric patients. Sudden infant death and apparent life-threatening events, both found only in pediatric patients, are even less frequently associated with gastroesophageal reflux. Today, excellent diagnostic methods are available, such as proximal 24-hour pH probe evaluations or scintigraphy, making proper diagnosis much easier than previously. Although today’s medical and surgical methods do not affect the underlying pathophysiology, they are frequently very effective in controlling signs and symptoms, allowing the patients to return to resume their normal life-styles and livelihoods.
Bile Acid Diarrhea
Authors: Potter Gregory D.
Published: April 2003

Bile acids normally undergo enterohepatic circulation. When this circulation is interrupted, bile acids enter the colon in increased concentrations. Here, they produce Cl– secretion by a calcium- and cyclic AMP-dependent mechanism, resulting in diarrhea. Cholestasis may lead to serum bile acid concentrations high enough to produce colonic secretion by serosal surface effects. When resection or disease interferes with ileal function, the resulting diarrhea can be clearly attributed to bile acid malabsorption. In other states, such as postcholecystectomy diarrhea and idiopathic bile acid diarrhea, the role of bile acids is less well defined. 23-75Selena-25-homotaurocholic acid provides a way of tracing the metabolism of bile acids and their enterohepatic circulation in vivo. Metabolized similarly to natural bile acids, its circulation is easily traced by scintigraphy. Barium x-rays, serum concentrations of bile acids or bile acid intermediates, and tests of vitamin B12 absorption provide indirect measures of ileal function. Careful history and examination combined with one of many the available tests of ileal function allow a diagnosis. A therapeutic trial with a bile acid binding resin confirms the impression and treats the diarrhea.
Hepatobiliary Diseases in Patients with AIDS: Focus on AIDS Cholangiopathy and Gallbladder Disease
Authors: Wilcox C. Mel , Mönkemüller Klaus E.
Published: April 2003

Diseases of the biliary tree and gallbladder are being described with increasing frequency among patients with the acquired immunodeficiency syndrome (AIDS). Despite the profound immunosuppressive therapy transplant recipients receive, these patients do not appear to be affected by these disorders; thus, human immunodeficiency virus (HIV)-infected patients appear to be uniquely susceptible. Most HIV-infected patients that develop cholangiopathy have severe immunodeficiency with CD4 lymphocyte counts <200/mm3. The objective of this review is to summarize the available literature on AIDS-cholangiopathy, focusing on its diagnosis and classification and to suggest an approach for its evaluation and its management.
In vitro Model of the Pathogenesis of Celiac Disease
Authors: Oberhuber Georg , Schwarzenhofer Maria , Vogelsang Harald
Published: April 2003

The in vitro challenge of duodenal mucosa with gliadin is a useful model to reproduce the immunological features of celiac disease (CD) and allows the study of early pathogenetic events in this disease. With this model it was shown that antigens such as ICAM-1 and HLA-DR are upregulated as early as 1–2 h after gliadin challenge in patients with CD. After 24 h the lamina propria contained CD4+ T cells expressing the IL-2 receptor α-chain, which is a sign of activation. Intraepithelial lymphocytes increased in number and showed proliferative activity. After in vitro stimulation with gliadin, endomysial antibodies were found in the supernatant of the cultured mucosa from patients with CD following a gluten-free diet. This supported the notion that endomysial antibodies are at least in part produced locally. The model was also successfully used to identify toxic constituents of gliadin. Presently, organ culture is not commonly used for diagnostic purposes.
Minimally Invasive Surgical Techniques for the Treatment of Gastroesophageal Reflux Disease
Authors: Klingler P.J. , Bammer T. , Wetscher G.J. , Glaser K.S. , Seelig M.H. , Floch N.R. , Branton S.A. , Hinder R.A.
Published: April 2003

Open antireflux surgery produces good long-term control of disease, but new interest in the surgical management of gastroesophageal reflux disease has been stimulated by the introduction of minimally invasive techniques to perform standard antireflux procedures. In the past some scepticism existed among gastroenterologists who quoted the poor surgical results they had seen. These bad results, however, were largely due to inappropriate surgery in poorly worked-up patients or antireflux surgery performed by inexperienced surgeons. Since the introduction of minimally invasive surgery for gastroesophageal reflux disease, excellent results have been reported with over 5 years of follow-up. The most common and successfully used laparoscopically antireflux procedures are reviewed and results analyzed.
Gastrointestinal and Hepatic Manifestations of Human Ehrlichiosis: 8 Cases and a Review of the Literature
Authors: Nutt Angela , Raufman Jean-Pierre
Published: April 2003

Background: Ehrlichiosis has emerged as an increasingly recognized tick-borne rickettsial disease. It can affect multiple organs including the gastrointestinal tract and liver. Signs and symptoms include abdominal pain, nausea, vomiting, diarrhea, jaundice, and hepatosplenomegaly. Patients commonly have elevated liver transaminases early in the course of illness as well as leukopenia and thrombocytopenia. If not diagnosed and treated in a timely fashion, ehrlichiosis can progress to multiorgan failure. Methods: Between 1992 and 1998, 8 patients meeting the CDC criteria for ehrlichiosis were diagnosed and treated at the John L. McClellan Memorial Veterans Hospital and University Hospital in Little Rock, Ark. These cases and English-language articles relating to gastrointestinal and hepatic manifestations of ehrlichiosis, identified by searching Medline and manually reviewing bibliographies of retrieved articles, are reviewed. Results: Seven of the eight patients had elevated transaminases on presentation which increased rapidly initially and slowly returned to normal. Three of our patients had hyperbilirubinemia. One of the eight patients presented with hepatomegaly. Three had hyperbilirubinemia with a peak bilirubin of 13.8 mg/dl. Two patients (25%) had a rash on presentation. All 8 patients were treated with and responded to doxycycline. One developed multiorgan failure but eventually recovered with intensive medical care and doxycycline. Conclusion: To avoid treatment delay and serious complications, in the appropriate clinical setting ehrlichiosis should be considered as a cause of elevated liver transaminases.
Clinical Features of Celiac Disease Today
Authors: Collin Pekka , Kaukinen Katri , Mäki Markku
Published: April 2003

The clinical spectrum of celiac disease has widened over the past decades. The condition is no longer a severe malabsorption syndrome. Instead, a typical celiac disease patient today has merely mild abdominal symptoms. Malabsorption can be subclinical or absent, and there is usually only moderate, if any, loss of weight. Simultaneously, the current prevalence has increased from 1:1,000 to 1:300 inhabitants, or even higher. Clinically silent celiac disease cases are being detected in increasing numbers since the introduction and widespread use of serologic screening tests. Symptoms of celiac disease can appear outside the intestine, a typical example being dermatitis herpetiformis. Gluten intolerance is no longer limited to overt villous atrophy. Inflammation without villous damage may be observed in genetically susceptible individuals. The term latent celiac disease is applied in situations where the patient has normal villous architecture while on a gluten-containing diet, but later develops small bowel villous atrophy compatible with celiac disease.
A Comparison of the Effect of Three Sedatives on Esophageal Sphincters in Cats
Authors: Croffie Joseph M. , Ellett Marsha L. , Lou Quinyan , Fitzgerald Joseph F.
Published: April 2003

Background/Aims: Children 5 years old and younger often require sedation for esophageal motility studies (EMS). At our institution, an intramuscular cocktail of meperidine, promethazine and chlorpromazine (MPC) has been used as the standard sedative for young children undergoing EMS. Administering the intramuscular sedative may, however, be more traumatic to the child than the procedure. Moreover, its effect on esophageal motility is not known and prolonged sedation is common. The aim of this study was to determine the effects of MPC and two orally-administered sedatives on esophageal sphincter function, using the cat model, with a goal to identify a potentially suitable orally-administered sedative for use in young children requiring sedation for EMS. Methods: We measured upper (UESP) and lower (LESP) esophageal sphincter pressures in 25 cats initially without sedation, and then following sedation with midazolam, chloral hydrate and MPC. The results were compared. Results: All three sedatives significantly decreased LESP compared to the control (p<0.05). Midazolam decreased LESP the most; however, the difference from the other sedatives did not reach statistical significance. All three sedatives decreased UESP, compared to control, but the differences were not statistically significant. Of the two oral sedatives, chloral hydrate had the least effect on the esophageal sphincters although its effect was not statistically different from that of midazolam. Conclusions: Ethically appropriate studies are needed to determine which oral sedative would be most beneficial for use in sedating children undergoing esophageal motility studies. Until studies can be done, the choice between chloral hydrate and midazolam should be based on the experience and comfort of the attending physician with regard to the potential side effects of the medications.
Therapeutic Options in Patients with Barrett’s Esophagus
Authors: Lim Kie N. , Waring Patrick J. , Saidi Roxan
Published: April 2003

The rising incidence of esophageal adenocarcinoma has focused attention on the only known risk factor: Barrett’s esophagus. Practice guidelines for the diagnosis, surveillance and management of Barrett’s esophagus were published recently. Although the ultimate goal in the management of this premalignant condition would be the permanent elimination of Barrett’s mucosa, current therapeutic options are limited or still in the investigational stages. This review summarizes current medical and surgical treatment options and introduces endoscopic ablative modalities currently under investigation.
Congenital Esophageal Stenosis: Clinical and Endoscopic Features in Adults
Authors: Younes Ziad , Johnson David A.
Published: April 2003

Background: Congenital esophageal stenosis (CES) is an uncommon anomaly that reportedly rarely goes undiagnosed until adulthood. One variant of CES includes patients with multiple cartilaginous rings described usually in the mid-distal esophagus. Methods: Ten patients with CES seen over the past 7 years were interviewed and their clinical and endoscopic records reviewed. Results: Eight patients were male and age at time of diagnosis ranged from 21 to 75 years. Meat impaction was the presenting symptom in 8 patients and 3 patients reported a relapsing history. Intermittent solid food dysphagia over extended duration (10–40 years) was reported in all patients with an estimated onset of symptoms at a mean age of 27 years (11–52 years). Endoscopically, all patients had segmental esophageal stenosis (length 2–8 cm, mean = 4.7 cm) due to ‘trachea-like’ multiple submucosal rings. Pseudodiverticulosis and distal reflux esophagitis were evident in 1 patient. Nine of 10 patients had no macroscopic esophagitis. Dilatation was performed by balloon insufflation (18 mm in 5 patients, 15 mm in 3 patients, 12 mm followed by 15 mm in a patient with a tight stricture) and by Savary dilators in 1 patient, without any complications. No patient had recurrent meat impaction on follow-up (1–7 years, mean = 3 years) after education about the condition. Conclusion: (1) We suspect CES is an under-recognized cause for intermittent, long-standing dysphagia in adults. (2) Food impaction is a frequent initial presentation. Recognition of CES is critical for appropriate patient education and planning.
Inflammation and Intestinal Metaplasia of the Gastric Cardia: Helicobacter pylori, Gastroesophageal Reflux Disease, or Both
Authors: Goldblum John R.
Published: April 2003

The gastric cardia is a microscopic zone that is normally found in the most proximal portion of the stomach, although cardiac-type mucosa may arise in the distal esophagus as a metaplastic phenomenon secondary to gastroesophageal reflux disease (GERD). Inflammation of the native gastric cardia is strongly associated with Helicobacter pylori infection, although there may be a second form of ‘carditis’ in which metaplastic cardiac-type mucosa becomes inflamed secondary to GERD. Intestinal metaplasia of the cardia may be difficult to recognize because of the difficulty in accurately identifying the esophagogastric junction by endoscopy and the histologic similarities of intestinal metaplasia in the proximal stomach and distal esophagus. However, cytokeratin 7 and 20 immunoreactivity patterns appear to be useful in distinguishing between these forms of intestinal metaplasia. The preponderance of data suggests that intestinal metaplasia of the cardia is associated with H. pylori infection as opposed to GERD, and preliminary data suggest a lower risk of progression to dysplasia and adenocarcinoma when compared to intestinal metaplasia of the distal esophagus.
Epidermal Growth Factor Receptor Expression in Skin Does Not Predict Dementia in the Elderly
Authors: Styren Scot D. , Styren Gisele C. , DeKosky Steven T.
Published: April 2003

We have previously reported that epidermal growth factor receptor (EGFR) was expressed on vascular endothelial cells from postmortem specimens of demented but not cognitively normal subjects. In the present study, we examined skin biopsies from 35 living patients who were either normal or had a clinical diagnosis of probable Alzheimer’s disease. In this living cohort, there was no correlation between the presence of vascular EGFR expression and clinically determined cognitive status. While a variety of factors may be responsible for these findings, endothelial EGFR expression cannot be used to confirm a premortem clinical diagnosis of dementia.
Alanyl-Aminopeptidase Activity Decrease in Cerebrospinal Fluid of Alzheimer Patients
Authors: Iribar Maria C. , Montes Juan , Gonzalez Maldonado Rafael , Peinado José M.
Published: April 2003

We analyzed the amino acid concentrations and aminopeptidase activities in plasma and the cerebrospinal fluid (CSF) of Alzheimer patients. Correlations were calculated between these parameters and the degree of cognitive impairment, duration of the disease and age. In comparison with a control group, no changes were found in the levels of amino acids in CSF or plasma of Alzheimer patients. Alanyl-aminopeptidase activity was significantly lower in the CSF of Alzheimer patients, whereas no differences in CSF were detected as regards the remaining aminopeptidases. The plasma/CSF ratio for aminopeptidase activities was higher in AD patients than in controls, although the difference was only significant for alanyl-aminopeptidase. Amino acid ratios did not show this general tendency. The correlations between plasma aspartate and glutamate concentrations and the stage of the disease, measured with the Mini Mental State Examination, were studied. Changes in aminopeptidase activities and their role in protein dysfunction underlying Alzheimer disease are discussed.
Psychiatric Complications of Dementia: Impact on Caregivers
Authors: Victoroff Jeff , Mack Wendy J. , Nielson Kristy A.
Published: April 2003

This study was designed to determine the relationship between psychiatric features of dementia and their impact on caregivers. 35 patient-caregiver pairs were evaluated at two university-affiliated dementia clinics, using standard instruments to rate patient psychiatric features and caregiver burden and depression. There were highly significant correlations between patient agitation and both caregiver burden (r = 0.59, p = 0.0002) and depression (r = 61, p = 0.0001). These associations remained significant after adjusting for multiple demographic and dementia variables. There was no significant association between patient delusions, hallucinations, or depression and caregiver burden or depression. Agitation, particularly physical aggression, may impact caregivers even more than does the cognitive status of the demented patient.
Platelet Monoamine Oxidase B Activity in Dementia
Authors: Götz M.E. , Fischer P. , Gsell W. , Riederer P. , Streifler M. , Simanyi M. , Müller F. , Danielczyk W.
Published: April 2003

Platelet monoamine oxidase B (MAO-B) activity has been found to increase significantly in demented patients. For the first time, a 4-year follow-up of platelet MAO-B activity and Mini-Mental State (MMS) was performed in patients with probable dementia of the Alzheimer type (DAT) and age-matched controls. MAO-B activity of DAT patients increased significantly 2 years after the beginning of the study as compared with controls and remained significantly higher for the entire period of the examinations (p < 0.0001). The decrease of the MMS scores did not correlate with the time course of the increase of platelet MAO-B activity (Spearman rank correlation test). The decline of the MMS scores of DAT patients preceded the elevation of MAO-B activity. Since degenerative processes in brain areas which are responsible for cognitive function and are reflected by the MMS scores rather affect cerebral cholinergic than monoaminergic neurotransmitter systems, degeneration of the latter at late stages of DAT might be reflected by increased platelet MAO-B activity.