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Biomedical subjects

L Podesta

Publications and source records attributed to L Podesta.

At least 19 recordsLinked to original sources

Common medical problems in sports.

This article reviews the most common medical problems encountered in the day-to-day care of athletes at all levels of competition. Common medical conditions affecting the pulmonary, gastrointestinal, urological, and endocrine systems are reviewed, as well as common infectious diseases. Review of environmental factors affecting athletes, including sleep disorders, travel, and exposure to the environment during athletic competition, are discussed.

Athletic Injuries

Intragraft cytokine gene expression in human liver allografts.

Cytokines are thought to play an important role in the inflammatory and immune responses of allograft rejection. We evaluated the pattern of cytokine gene expression in 36 liver biopsy specimens obtained from 20 recipients of primary orthotopic liver allografts. Specific mRNA expression was identified by a polymerase chain reaction (PCR) using oligonucleotide primers specific for human interleukin (IL)-1 beta, IL-2, IL-4, IL-6, IL-10 Interferon (IFN) gamma, tumor necrosis factor (TNF)-alpha and beta-actin. We detected IL-1 beta, IL-6 and IFN-gamma cytokine message most consistently in patients with rejecting liver allografts. TNF-alpha and IL-2 were also observed in rejecting livers, but only during the early phases of the reaction. IL-4 was expressed in the majority of liver allograft biopsy specimens, regardless of the presence or absence of clinical or pathological evidence of rejection. Sequential biopsy specimens in rejecting allografts showed decreased cytokine expression after the induction of a positive response to immunosuppressive therapy. The analysis of biopsy specimens from stable liver grafts showed a predominance in the expression of IL-10. These results may reflect a differential production of inflammatory and regulatory cytokines in response to liver allograft rejection in transplant recipients. They suggest that three cytokines, IL-1 beta, IL-6 and IFN-gamma, may play an important role as markers for liver allograft rejection. Conversely, IL-10 expression was noted in patients with stable graft function. This pattern of expression may correlate with host immune responses that allow for prolonged, rejection-free survival of the graft.

Biomarkers

Failure of liver transplantation to diminish cardiac deposits of amylopectin and leukocyte inclusions in type IV glycogen storage disease.

Orthotopic liver transplantation has been used to treat glycogen storage disease type IV. Most long-term surviving patients who have undergone liver transplantation have been free of neuromuscular and cardiac morbidity, and regression of cardiac amylopectin infiltration has been reported after liver transplantation. Leukocyte inclusions in glycogen storage disease type IV have also been reported. We present the case of a child who underwent orthotopic liver transplantation for glycogen storage disease type IV. In contrast to previous reports, at autopsy 2 1/2 years after transplantation, there was massive amylopectin deposits in his heart. Further, peripheral leukocytes never showed loss of amylopectin inclusions after transplantation. Orthotopic liver transplantation for type IV glycogen storage disease may not, in all cases, result in improvement in other affected organs. Consideration of multiorgan transplantation appears warranted.

Amylopectin

Portal vein patency in candidates for liver transplantation: MR angiographic analysis.

PURPOSE: To assess the accuracy of magnetic resonance (MR) angiography for evaluating portal vein patency in candidates for liver transplantation. MATERIALS AND METHODS: MR angiography was performed in the main portal vein and proximal confluence of the portal vein in 102 candidates for liver transplantation (64 male patients and 38 female patients aged 8 months to 74 years; mean age, 47 years). The MR angiographic results were compared with the surgical and histologic findings in the explanted liver and excised main portal vein. RESULTS: MR angiography depicted 10 portal vein clots, all of which were confirmed at transplantation. Ninety-two portal veins were patent at MR angiography, a finding that was confirmed at transplantation. One tiny chronic clot in a small, intrahepatic branch of the portal vein was not seen at MR angiography or transplantation. It was identified at histologic analysis of the explanted liver. CONCLUSION: MR angiography is accurate in the evaluation of portal vein patency.

Adolescent

Early clinical experience with a hybrid bioartificial liver.

BACKGROUND: Severe liver failure is associated with high mortality. Orthotopic liver transplantation (OLT) is the only effective therapeutic modality; there is a need for a 'bridge' system to support patients until an organ becomes available. METHODS: A bioartificial liver (BAL) was used to treat 10 patients with severe liver failure. A plasmapheresis system was used to pump patient plasma through a module with porcine hepatocytes. Each treatment lasted 6-7 h. RESULTS: All patients tolerated the procedure(s) well. Eight patients underwent OLT following BAL treatment(s). There were two late deaths after recovery from liver failure. Five patients with increased intracranial pressure (ICP) and decerebration had ICP normalization, increased cerebral perfusion pressure and full neurologic recovery after OLT. There was improvement in the level of encephalopathy and a significant decrease in serum ammonia after BAL treatment(s). CONCLUSIONS: BAL treatment is safe and beneficial and can be successfully used as a 'bridge' to transplantation.

Adult

A bioartificial liver to treat severe acute liver failure.

OBJECTIVE: To test the safety and efficacy of a bioartificial liver support system in patients with severe acute liver failure. SUMMARY BACKGROUND DATA: The authors developed a bioartificial liver using porcine hepatocytes. The system was tested in vitro and shown to have differentiated liver functions (cytochrome P450 activity, synthesis of liver-specific proteins, bilirubin synthesis, and conjugation). When tested in vivo in experimental animals with liver failure, it gave substantial metabolic and hemodynamic support. METHODS: Seven patients with severe acute liver failure received a double lumen catheter in the saphenous vein; blood was removed, plasma was separated and perfused through a cartridge containing 4 to 6 x 10(9) porcine hepatocytes, and plasma and blood cells were reconstituted and reinfused. Each treatment lasted 6 to 7 hours. RESULTS: All patients tolerated the procedure(s) well, with neurologic improvement, decreased intracranial pressure (23.0 +/- 2.3 to 7.8 +/- 1.7 mm Hg; p < 0.005) associated with an increase in cerebral perfusion pressure, decreased plasma ammonia (163.3 +/- 21.3 to 112.2 +/- 9.8 microMoles/L; p < 0.01), and increased encephalopathy index (0.60 +/- 0.17 to 1.24 +/- 0.22; p < 0.03). All patients survived, had a liver transplant, and were discharged from the hospital. CONCLUSIONS: This bioartificial liver is safe and serves as an effective "bridge" to liver transplant in some patients.

Adolescent

Late surgical complications of choledochal cystoenterostomy.

Choledochal cyst is a rare congenital abnormality of the biliary tract characterized by dilatation and stasis. Cyst excision is now preferred to internal drainage because of the predilection for development of cancer in the unresected cyst wall. We report on four patients who required reoperations for complications of prior cystoenteric drainage from 14 to 21 years after the original operations. Gastrointestinal bleeding from cyst ulceration as occurred in one patient is heretofore unreported. This reoperative experience emphasizes the importance of cyst excision as primary therapy and underscores these principles: 1) The spectrum of complications, including infection, pancreatitis, cancer, and bleeding may occur with or without intracyst and ductal stones; 2) Radical operative procedures may be required for treatment of the complications; 3) Despite these, cholangiocarcinoma has a dismal prognosis; 4) Patients whose cysts remain unexcised require meticulous lifelong scrutiny and strong consideration for planned reoperation at the time of the first complication.

Adult

Hepatocellular adenoma in glycogen storage disease type IV.

The development of hepatocellular adenoma has been recognized in association with glycogen storage disease type I and, less often, with glycogen storage disease type III, but, to our knowledge, it has not been reported in glycogen storage disease type IV. We had the opportunity to study an 11-month-old male infant who underwent orthotopic liver transplantation for cirrhosis that developed in the setting of glycogen storage disease type IV. A clinically unsuspected hepatocellular adenoma was present in the explanted liver. Glycogen storage disease type IV should be considered as a potential precursor to the development of hepatocellular adenoma. Recognition of this association is important, both in terms of the differential diagnosis of tumors that occur in this setting and also to anticipate potential complications of this benign neoplasm.

Adenoma, Liver Cell

Control of cerebral oedema by total hepatectomy and extracorporeal liver support in fulminant hepatic failure.

Keeping a patient with fulminant hepatic failure (FHF) alive until a donor liver is available for transplantation can be a problem. We describe an 18-year-old woman with paracetamol-induced FHF, who was treated by total hepatectomy, hypothermia, plasma exchange, and extracorporeal liver support. The patient was anhepatic for 14 h. The liver-support system consisted of plasma separation and perfusion through a charcoal filter and a hollow-fibre module seeded with matrix-attached porcine hepatocytes. With artificial liver treatment there was reversal of severe neurological dysfunction, normalisation of intracranial pressure, and decreased serum ammonia. The patient underwent emergency transplantation with an ABO-incompatible liver, followed by transplantation with a compatible organ eight days later. The patient has fully recovered and is neurologically intact.

Adolescent

Epstein-Barr virus infection in liver transplantation patients: correlation of histopathology and semiquantitative Epstein-Barr virus-DNA recovery using polymerase chain reaction.

Epstein-Barr virus (EBV) infection may complicate orthotopic liver transplantation, and can lead to hepatitis with subsequent graft failure and to benign and malignant lymphoproliferative disorders. Early diagnosis allows for prevention or treatment of complications. Histopathologic features of EBV infection in the liver vary and may be difficult to recognize. To delineate the morphologic features that allow for recognition we studied 61 biopsy specimens from 37 patients, correlating the results of EBV-DNA demonstration after polymerase chain reaction with histopathology of formalin-fixed, hematoxylin-eosin-stained liver biopsy specimens. DNA was extracted from fresh liver biopsy samples, and polymerase chain reaction was carried out with EBV primers (capsid protein gp220) using standard techniques and 25-cycle amplification. Epstein-Barr virus-related sequences after polymerase chain reaction were detected by DNA blot assay. Histopathologic features were classified into three categories on the basis of the semiobjective determination of the number and distribution of immunoblasts and other immature lymphocytes in portal tracts and sinusoids: highly suggestive (three biopsy specimens), indeterminant (one biopsy specimen), and negative (57 biopsy specimens). Only the three highly suggestive biopsy specimens had high levels of EBV-DNA. We conclude that the histopathologic features of EBV infection after orthotopic liver transplantation can be relied on to establish the diagnosis.

Biopsy

Pediatric liver transplantation.

The excellent survival rates that have been achieved by pediatric liver transplantation today can be attributed to a multitude of factors. Refinements in immunosuppressive regimens, new immunosuppressive agents, improvements in surgical technique, and a better understanding of the unique issues that pertain to patient care have resulted in not only excellent survival rates, but also improvements in quality of life. The future promises even more progress in the directions of tolerance induction, expansion of the donor organ pool, and genetic manipulation allowing cellular transplantation for correction of inborn errors of metabolism.

Adolescent

Distal humeral epiphyseal separation in a young athlete: a case report.

Elbow pain in the young throwing athlete can have numerous etiologies. Skeletally immature athletes commonly sustain epiphyseal injuries secondary to trauma and/or repetitive activity. The case of a 7-year-old Little League pitcher with the diagnosis of distal humeral epiphyseal separation is presented along with a review of the current literature.

Baseball

Immunodepletion in xenotransplantation.

Xenograft transplantation is perhaps the most immunologically difficult problem in transplantation today. An overwhelming hyperacute rejection reaction (HAR) occurs within minutes of organ implantation. Preformed antibodies are thought to initiate this process. We used a pig-to-dog renal xenograft transplant model and investigated methods of decreasing the severity of hyperacute rejection. Female pigs weighing 15-20 kg were used as donors. Recipients were mongrel dogs weighing 15-25 kg. Experimental dogs were all given a number of treatments of IgG depletion using an antibody removal system (Dupont-Excorim). This machine immunoadsorbs plasma against a column containing immobilized staphylococcal protein A, which is known to bind the IgG Fc receptor. An 84% reduction in the IgG levels and a 71% reduction in IgM levels was achieved. Postoperative assessment was made of urine output, time to onset of HAR, and histopathological examination of the rejected kidneys. Although cross-matches between donor lymphocytes and recipient sera remained strongly positive in the treated dogs, there was a two- to fourfold reduction in the titers. The time to onset of HAR was prolonged in the experimental group, and the urine output was increased slightly. The histopathologic changes in the experimental group generally showed signs of HAR, but of less intensity than in the nonimmunodepleted control group.

Animals

Rationale and protocol for postoperative anterior cruciate ligament rehabilitation.

A rehabilitation program for postoperative anterior cruciate ligament (ACL) reconstruction permits adequate tissue healing time and allows early protected muscular conditioning. The program is based on kinematic, biomechanical, and kinesiologic factors as they pertain to ACL function. The program is divided into five phases. The early phases, zero to 12 weeks, are intended to control translational forces across the ACL and to allow necessary time for ligament revascularization and soft-tissue healing. During this period, isometric and isotonic training of the hamstrings and quadriceps muscle groups in a restricted active arc of motion is permitted. Passive motion is encouraged, and progressive weight bearing is allowed. Conditioning of the upper body as well as the nonsurgical lower limb is stressed. During the advanced phases, 12-31 weeks, isotonic muscle training continues throughout a full range of motion. Greater strength, coordination, and endurance to achieve dynamic stability of the knee, preparing the patient for unrestricted activity, are stressed. Approximately 52 weeks of active rehabilitation after ACL reconstruction surgery are usually required to return to a preinjury level of function.

Biomechanical Phenomena