Biomedical subjects

B A Solomon

Publications and source records attributed to B A Solomon.

58 records · Page 4Linked to original sources

PubMedDate not supplied

Islet transplantation using an immunoprotective membrane in dogs that have undergone a pancreatectomy.

The use of a selectively permeable membrane to transplant nonsyngeneic tissue without accompanying immunosuppressive therapy has been investigated using two approaches. The first hybrid artificial pancreas is implanted as a vascular shunt in which blood circulates through the lumen of a tubular membrane. The islet tissue is distributed within a chamber surrounding the membrane enclosed by an acrylic housing. Studies with diabetic dogs that have had pancreatectomies have demonstrated that these devices could replace exogenous insulin therapy for at least 6 months in five animals. This report presents data on two of these dogs, demonstrating viability and function of the transplanted tissue after 1 year. As an alternative to the vascular device, islets sealed within cylindrical permselective membrane chambers have been implanted in the peritoneum. Preliminary data from three dogs indicate that the nonvascular implants can also regulate fasting glucose levels in the diabetic dog model.

Animals↗

PubMedDate not supplied

Transient cutaneous vesicles in a teenager: the final piece to a puzzle.

Cicatricial pemphigoid is a chronic blistering disease that predominantly affects the mucous membranes. It has a peak occurrence in the seventh decade. Pediatric cicatricial pemphigoid is a rare entity, with fewer than 20 cases reported. We report an 18-year-old man who was recently diagnosed with cicatricial pemphigoid after six years of diagnostic uncertainty.

Adolescent↗

PubMedDate not supplied

Percutaneous placement of an intercostal central venous catheter for chronic hyperalimentation guided by transhepatic venography.

BACKGROUND AND METHODS: Increased utilization of central venous catheters for hyperalimentation has caused a rise in the incidence of central venous complications including occlusions and stenoses. When this occurs, the continued use of these catheters becomes more difficult. We describe a technique for catheter placement in a patient requiring access for total parenteral nutrition who had extensive central venous occlusion involving both internal jugular veins, both subclavian veins, and the infrorenal inferior vena cava (IVC). RESULTS: A percutaneous transhepatic venous catheter had been placed in a patient with inferior vena caval, subclavian, and internal jugular venous occlusions. The Hickman catheter functioned well until the patient developed fungal sepsis and a large fibrin sheath around the catheter tip creating the need for a new access site. Placement of an intercostal venous catheter was performed using transhepatic venography to map patent collateral veins and microcatheters to access an intercostal route for Hickman placement. CONCLUSIONS: Patients who require long-term central venous access often develop stenotic and occlusive complications in the central venous circulation. Individualized, unique and innovative routes to the central venous circulation must often be utilized to maintain venous access in these patients. Transhepatic venous mapping and microcatheter techniques aid in the finding of alternative sites in these patients with difficult access problems.

Catheterization, Central Venous↗

PubMedDate not supplied

Functional recovery of porcine hepatocytes after hypothermic or cryogenic preservation for liver support systems.

The provision of an immediate supply of isolated porcine hepatocytes for artificial liver support requires preservation techniques that will allow maintenance of cell viability and detoxification functions. By means of a simple and cost-effective cryopreservation system, porcine hepatocytes can be available for both local and distant medical treatment facilities. Additionally, cryopreservation provides an adequate period for quality control testing to be completed prior to use of any specific cell lot. We are reporting a dual approach, namely the preservation of porcine hepatocytes, at 4 degrees C and at -196 degrees C in liquid nitrogen (LN2). Using a combination of cryoprotectant agents with Chee's modified Eagle's culture media (CEM), collagenase isolated hepatocytes stored at 4 degrees C for 24 h maintained 80% of the initial diazepam metabolism measured in freshly isolated cells and nearly 100% of initial function was preserved in hepatocytes stored up to 6 mo at -196 degrees C. University of Wisconsin solution (UW) was also tested and while adequate for 4 degrees C storage, it certainly did not match the performance of the CEM formulations for preservation of metabolic function of cells stored in liquid nitrogen. Based on our results of viability and detoxification function the combination of CEM with DMSO, polyethylene glycol and serum provided optimal protection for LN2 frozen cells. Other findings in these studies underlined the importance of the gradual introduction of DMSO in the prefreezing process, the period of osmotic equilibration, and the rapid postthaw withdrawal of this agent to minimize cytotoxic effects at these critical stages. Our freezing methodology provides the foundation for further technological developments in the cryopreservation of the large numbers of cells (billions) that are necessary for extracorporeal liver assist devices.

Animals↗