PubMed Health⌕ Search

Biomedical subjects

A J Fabrega

Publications and source records attributed to A J Fabrega.

30 records · Page 2Linked to original sources

The morphology and function of rabbit hepatocytes isolated using ethylenediaminetetraacetate.

The enzyme digestion technique using collagenase is used in most studies that describe hepatocyte isolation, including those in which hepatocytes are isolated for transplantation. The use of collagenase, however, has several drawbacks. We describe the use of a highly concentrated ethylenediaminetetraacetate solution for isolation of hepatocytes followed by purification using a Percoll gradient in the rabbit model. Isolated hepatocytes were then preserved at 4 degrees C for up to three days in either University of Wisconsin solution or Dulbecco's modified eagle's medium. Morphological studies of hepatocytes at 24 hr and 72 hr in either medium were performed using Papanicolaou and PAS stains of cytopreparations for the presence of glycogen. Similarly, functional studies of the preserved hepatocytes included LDH release, total tissue water content, and amount of 99m-technetium mebrofenin uptake. The use of EDTA perfusion for hepatocyte isolation was highly reproducible in this model. The cell yield was comparable to that achieved previously using collagenase. The morphologic studies demonstrated pure hepatocytes with well-preserved architecture when preserved for up to three days in UW solution. Functional studies showed a statistically significant lower LDH release and total tissue water content and a higher technetium-99m mebrofenin uptake for hepatocytes preserved in UW solution. We conclude that a pure and viable hepatocyte suspension can be obtained from rabbit livers using concentrated EDTA solutions. These hepatocytes can be well preserved at 4 degrees C for up to 72 hr in UW solution, based on morphologic and functional criteria.

Adenosine↗

Spontaneous rupture of a normal bladder.

We have reported a case of spontaneous rupture of a normal urinary bladder. Patients with this rare condition characteristically have a recent history of heavy alcohol intake, sudden onset of abdominal pain coincidental with bloody urine, generalized peritonitis, and abnormal renal chemistry. A high index of suspicion will lead to early diagnosis and treatment, minimizing the mortality attributed to this condition.

Adult↗

Problems in the long-term renal allograft recipient.

Despite great improvement in patient and graft survival, the long-term morbidity and mortality in renal transplant recipients are still significant. Cardiovascular disease accounts for much of the mortality in long-term survivors; screening before the transplant procedure and adequate control of hypertension should help improve patient survival. Many of the gastrointestinal complications are due to overimmunosuppression and sepsis. Adequate management must include withdrawal of all immunosuppressive medications in order to save the patient's life. Liver disease is usually of viral origin; patients with chronic active hepatitis or cirrhosis should remain on dialysis. Chronic rejection is the major cause of graft loss in long-term survivors; it is unresponsive to antirejection treatment and its progression may be mediated by nonimmunologic mechanisms. Correctable problems such as renal artery stenosis and ureteral obstruction should be ruled out before a late deterioration in graft function is disregarded as chronic rejection. Post-transplant diabetes, osteonecrosis, cataracts, and nephrotoxicity are directly related to the various immunosuppressive drugs currently used. The lowest dose compatible with graft acceptance should help reduce the incidence of these nonfatal but significant complications. Recurrence of disease is a common histologic finding in many transplant recipients but, except for a few diseases such as HUS, FSGS, and oxalosis, it usually does not lead to graft failure. Successful transplantation restores fertility in many uremic patients. Adequate counseling on contraception is imperative in order to avoid unwanted pregnancies and to delay parenthood for at least 1 year. Current immunosuppressive agents are not teratogenic, no dose adjustments are necessary, and an ill-advised decrease in medication may precipitate a rejection episode. Premature delivery is the major problem in these patients and can be avoided by maintaining adequate graft function and controlling hypertension and infections. It is evident from this review that most of the long-term morbidity and mortality seen in renal allograft recipients are due to overimmunosuppression with sepsis or to side effects of the individual drugs, steroids being a common denominator in almost all cases. New immunosuppressive protocols must aim not only to improve patient and graft survival but also to avoid the many complications that limit the full rehabilitation of these patients.

Graft Survival↗

Pancreas-kidney transplantation for intensivists: perioperative care and complications.

Simultaneous pancreas-kidney transplantation is a therapeutic option for type I diabetics with end-stage renal disease. It aims to correct the uremic state, to normalize glucose hemeostasis, and to ameliorate diabetic complications. Careful donor-recipient selection and meticulous intra-operative and postoperative care will substantially impact recipient morbidity. An understanding of the technical aspects of the surgical procedure and its metabolic and immunological consequences is necessary to successfully manage a pancreas-kidney transplant recipient, many of whom are nursed in intensive care units. A successful outcome is predicted in early recognition of technical complications and aggressive management of rejection to achieve the current 1-year graft survival rates of 75% for pancreas transplants and 84% for kidney transplants.

Adult↗

Transplantation of hepatocytes: an in-vitro and in-vivo study in canines.

We isolated and transplanted hepatocytes in the canine, large animal model to evaluate hepatocyte yield and purity as well as the optimal site for hepatocyte engraftment (i.e., the spleen or the portal bed). We obtained viable, pure, single hepatocyte suspensions that were readily preserved at 4 degrees C in University of Wisconsin (UW) solution for up to 3 days. Both intrasplenic and portal vein injection were well tolerated, with minimal recipient morbidity and mortality when 1-2 x 10(9) hepatocytes were injected into immunosuppressed allogeneic hosts. We noted the embolization of hepatocytes into the parenchyma of the native liver within 7 days of intrasplenic transplantation that produced a mild reversible derangement of liver function and histology. These results warrant consideration prior to clinical trials of hepatocyte transplantation in man.

Adenosine↗