PubMed Health⌕ Search

Biomedical subjects

S Florman

Publications and source records attributed to S Florman.

13 recordsLinked to original sources

Conversion of stable liver transplant recipients from a twice-daily Prograf-based regimen to a once-daily modified release tacrolimus-based regimen.

INTRODUCTION: Modified release (MR) tacrolimus is an extended release formulation administered once daily. The purpose of this pharmacokinetic (PK) study was to evaluate tacrolimus exposure in stable liver transplant recipients converted from Prograf twice a day to MR tacrolimus once daily. METHODS: This was an open-label, multicenter study with a single sequence, four-period crossover design. Eligible patients were 18 to 65 years of age, >6 months posttransplant with stable renal and hepatic function and receiving stable doses of Prograf twice a day for >2 weeks prior to enrollment. Patients received Prograf twice a day on days 1 to 14 and 29 to 42. Patients were converted to the same milligram-for-milligram daily dose of MR once daily on days 15 to 28 and 43 to 56. Twenty-four-hour PK profiles were obtained on days 14, 28, 42, and 56. Laboratory and safety parameters were also evaluated. RESULTS: Of 70 patients, 62 completed all four PK profiles. The AUC0-24 of tacrolimus was comparable for Prograf twice a day (days 14 and 42) and MR tacrolimus once daily (days 28 and 56). The 90% confidence intervals for MR tacrolimus versus Prograf at steady state (days 28 and 56 vs days 14 and 42) was 0.85 to 0.92 for AUC0-24. MR tacrolimus was well tolerated with a safety profile comparable to that of Prograf. AUC0-24 was highly correlated to Cmin for Prograf (day 14, r = .93; Day 42, r = .89) and for MR tacrolimus (day 28, r = .93; day 56, r = .92). Renal and liver function remained stable. One patient experienced acute rejection. CONCLUSION: The steady-state tacrolimus exposure of MR tacrolimus once daily is equivalent to Prograf twice a day after a milligram-for-milligram conversion in stable liver transplant recipients.

Area Under Curve↗

Identification of ultrastructural changes in liver allografts of patients experiencing primary nonfunction.

BACKGROUND: Primary nonfunction (PNF) after liver transplantation is fatal without timely retransplantation. PNF has been associated with many risk factors, but the etiology remains unknown in most cases. Using electron microscopy, we examined the hepatic ultrastructure of donor allografts in patients experiencing PNF and compared the findings with a well-matched group of other donor allografts. MATERIALS AND METHODS: Archival paraffin-embedded pre- and post-reperfusion donor liver biopsies were examined by electron microscopy in 10 patients with PNF and in 10 controls, matched by donor age +/- 5 years, gender, cold ischemic time +/- 1 hour, and donor cause of death. Mitochondria, endoplasmic reticulum, sinusoidal endothelial cells, and the glycogen content of the cells were assessed. The donors' serum peak transaminases, bilirubin and sodium levels, as well as the recipient age and serum creatinine were compared. RESULTS: There were no significant differences in recipient age at the time of transplantation, peak recipient serum creatinine, donor peak serum transaminase, sodium or bilirubin levels. In all cases, the endoplasmic reticulum and sinusoidal endothelial cells were ultrastructurally normal. Hepatocytes had variable degrees of glycogen pooling. Hepatic steatosis and intramitochondrial inclusions cells were present in 5/10 PNF compared to 0/10 controls patients on preperfusion liver biopsy (P = .17). CONCLUSION: Liver allografts from patients suffering from PNF can have mitochondrial ultrastructural changes on preperfusion biopsies.

Adult↗

Noninvasive preoperative evaluation of biliary anatomy in right-lobe living donors with mangafodipir trisodium-enhanced MR cholangiography.

BACKGROUND: Accurate preoperative radiologic imaging is essential to assess the vascular and biliary anatomy of right-lobe living donors and to ensure their safety. Volumetric magnetic resonance cholangiography (MRCP) using Mangafodipir trisodium (Mn-DPDP) contrast has been recently proposed to evaluate the biliary anatomy of living donor candidates. METHODS: During their preoperative evaluation, 18 right-lobe (RL) living donors underwent 3D Mn-DPDP-enhanced MRCP in addition to the standard thin- and thick-slab MRCP imaging. Immediately prior to hepatectomy all 18 RL donors underwent intraoperative cholangiography (IOC) via the cystic duct. We compared the efficacy of these different radiologic techniques to actual intraoperative IOC findings. RESULTS: Sixty-eight intrahepatic bile ducts were identified on IOC, 67(98.5%) by Mn-DPDP-enhanced 3D MRCP, 41 (60%) by thick-slab SSFSE imaging, and 35 (51%) by thin-slice SSFSE imaging. Mn-DPDP-enhanced 3D MRCP detected 100% (n = 5) of the anomalous origins of the right bile duct, and thick-slab MRCP detected 20% (n = 1) and thin-slab MRCP detected 0%. Anterior and posterior right intrahepatic bile ducts were identified by MnDPDP-enhanced 3D MRCP 100% of the time, by thick-slab SSFSE imaging 35% of the time, and by thin-slice SSFSE imaging only 12% of the time. CONCLUSIONS: Mn-DPDP-enhanced 3D MRCP imaging was highly sensitive and specific in identifying variants of the intrahepatic bile ducts. This technique should be included in the standard protocol of preoperative radiologic evaluation of RL living donor candidates.

Cholangiography↗

Clinical presentations of soft-tissue infections and surgical site infections.

Skin and soft-tissue infections that usually follow minor traumatic events or surgical procedures are caused by a wide spectrum of bacteria. Less frequently, the infections occur spontaneously, which often is clinically confusing and leads to delays in diagnosis. Most of the infections are self-limited and easily treated with local measures and/or antibiotics. Others are life-threatening, requiring prompt diagnosis and aggressive surgical debridement in addition to the wise choice of antibiotic agents to limit tissue loss and preserve life. Many survivors experience critical tissue losses that may require changes in lifestyle as well as major reconstructive cosmetic surgery. Involvement of antibiotic-resistant gram-positive microorganisms in these infections only increases the difficulty of their treatment and may have a significant influence on the ultimate outcome.

Anti-Bacterial Agents↗

Graft function and survival depend primarily on host factors in compromised recipient models of orthotopic liver transplantation in the rat.

BACKGROUND: Experimental models of liver transplantation use normal recipients, although most patients undergoing liver transplantation suffer from acute or chronic liver failure. This study was designed to analyze the outcome of orthotopic liver transplantation in compromised rat hosts. METHODS: Recipient animals were either rats with D-galactosamine-induced acute or rats with chronic liver failure secondary to common bile duct ligation. Liver damage was evaluated by monitoring enzymes, bilirubin, ammonia levels, prothrombin, thrombin time, and cytokines. In vivo function of hepatocytes and sinusoidal endothelial cells were evaluated by indocyanine green and hyaluronic acid uptake. Transplantation was performed in normal, acute, and chronic liver failure rats at different time points using either freshly harvested or cold-preserved syngeneic livers. RESULTS: Survival with fresh grafts decreased significantly when transplants were performed 48 hr after the induction of acute liver failure. No rats with acute liver failure survived transplantation with grafts stored for 12 or 24 hr although in chronic failure survival was more 80%. Survival of acute liver failure rats receiving 6 hr preserved grafts was 16.6% compared with 83.3% observed with fresh grafts transplanted at the same time point after D-galactosamine injection. Elevated tumor necrosis factor-alpha and interleukin-1beta levels as well as impaired sinusoidal endothelial cell function were detected in acute liver failure rats with 6 h preserved grafts. CONCLUSION: These results suggest that preoperative status and different host factors have a significant effect on outcome and graft function after liver transplantation in rats.

Animals↗

One hundred nine living donor liver transplants in adults and children: a single-center experience.

OBJECTIVE: To summarize the evolution of a living donor liver transplant program and the authors' experience with 109 cases. SUMMARY BACKGROUND DATA: The authors' institution began to offer living donor liver transplants to children in 1993 and to adults in 1998. METHODS: Donors were healthy, ages 18 to 60 years, related or unrelated, and ABO-compatible (except in one case). Donor evaluation was thorough. Liver biopsy was performed for abnormal lipid profiles or a history of significant alcohol use, a body mass index more than 28, or suspected steatosis. Imaging studies included angiography, computed tomography, endoscopic retrograde cholangiopancreatography, and magnetic resonance imaging. Recipient evaluation and management were the same as for cadaveric transplant. RESULTS: After ABO screening, 136 potential donors were evaluated for 113 recipients; 23 donors withdrew for medical or personal reasons. Four donor surgeries were aborted; 109 transplants were performed. Fifty children (18 years or younger) received 47 left lateral segments and 3 left lobes; 59 adults received 50 right lobes and 9 left lobes. The average donor hospital stay was 6 days. Two donors each required one unit of banked blood. Right lobe donors had three bile leaks from the cut surface of the liver; all resolved. Another right lobe donor had prolonged hyperbilirubinemia. Three donors had small bowel obstructions; two required operation. All donors are alive and well. The most common indications for transplant were biliary atresia in children (56%) and hepatitis C in adults (40%); 35.6% of adults had hepatocellular carcinoma. Biliary reconstructions in all children and 44 adults were with a Roux-en-Y hepaticojejunostomy; 15 adults had duct-to-duct anastomoses. The incidence of major vascular complications was 12% in children and 11.8% in adult recipients. Children had three bile leaks (6%) and six (12%) biliary strictures. Adult patients had 14 (23.7%) bile leaks and 4 (6.8%) biliary strictures. Patient and graft survival rates were 87.6% and 81%, respectively, at 1 year and 75.1% and 69.6% at 5 years. In children, patient and graft survival rates were 89.9% and 85.8%, respectively, at 1 year and 80.9% and 78% at 5 years. In adults, patient and graft survival rates were 85.6% and 77%, respectively, at 1 year. CONCLUSION: Living donor liver transplantation has become an important option for our patients and has dramatically changed our approach to patients with liver failure. The donor surgery is safe and can be done with minimal complications. We expect that living donor liver transplants will represent more than 50% of our transplants within 3 years.

ABO Blood-Group System↗

Utility of CT angiography for evaluation of living kidney donors.

We reviewed our initial experience with helical computed tomography (CT) angiography in the evaluation of living kidney donors which, until now, has necessitated arteriography. Nineteen donors (12 women, 7 men) have had their renal anatomy evaluated solely by CT angiography preoperatively. All scans demonstrated normal collecting systems and single ureters. Five donors (26%) had supernumerary renal arteries. Fourteen donors had single, 4 donors had two, and 1 donor had three renal arteries. Helical CT demonstrated small polar vessels in several donors. Two donors (10%) had supernumerary renal veins. Accuracy of vascular anatomy defined on CT was 90% when confirmed at operation. Anatomically all CT findings were consistent with operative findings except in 1 donor who was found to have a 0.8 cm lesion near the renal hilum. At our institution, the total charges for selective renal arteriography are $3845 and for helical CT with three-dimensional (3-D) reconstruction are $1546. The amount of contrast dye (approximately 100 mL) is equivalent. Patients uniformly reported that the CT scan was a convenient and painless procedure. The accuracy of helical CT angiography is equivalent to arteriography in assessing renal vascular anatomy (with the additional benefit of imaging venous and parenchymal anatomy). Charges for helical CT are 59% less. There is greater patient acceptance and potentially less morbidity associated with the non-invasive nature of helical CT. We believe that CT angiography is the radiologic procedure of choice for the assessment of renal anatomy in potential living kidney donors.

Adult↗

Differential in vivo recovery of sinusoidal endothelial cells, hepatocytes, and Kupffer cells after cold preservation and liver transplantation in rats.

BACKGROUND: The injury resulting from cold preservation/reperfusion primarily affects sinusoidal endothelial cells, while hepatocytes are thought to be less vulnerable; morphological changes and increased cytokine release suggest that Kupffer cells are activated. We evaluated the extent of functional damage to the different cell types in the liver after cold preservation and transplantation. Additionally, we analyzed in vivo the patterns of functional recovery of all three cell types over the first week after transplantation in Lewis rats. METHODS: We evaluated the in vivo uptake of hyaluronic acid, indocyanine green, and radio-labeled sulphur colloid to assess the function of sinusoidal endothelial cells, hepatocytes, and Kupffer cells, respectively. Measurements were performed immediately after transplantation using syngeneic grafts preserved in University of Wisconsin solution for different periods. Functional recovery was monitored in animals receiving grafts preserved for 24 hr over the first postoperative week. RESULTS: We found that hepatocyte were less affected compared with the profoundly damaged endothelial cells. The phagocytic ability of Kupffer cells was, however, also seriously compromised, which suggests a selective down-regulation. Functional recovery occurs in a differential manner during the first postoperative week starting with hepatocytes followed by sinusoidal endothelial cells. Phagocytic function further deteriorates after transplantation before showing improvement. CONCLUSIONS: In viable liver grafts, all cell types recover from preservation/reperfusion injury by the end of the first week after transplantation. The differential time courses of the recovery suggest that successful sinusoidal endothelial cell recovery may depend upon prior hepatocyte regeneration and may involve a paracrine interaction, via cytokines and growth factors.

Alanine Transaminase↗