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Biomedical subjects

R R Selby

Publications and source records attributed to R R Selby.

At least 19 recordsLinked to original sources
PubMed2006

A comparison of sirolimus vs. calcineurin inhibitor-based immunosuppressive therapies in liver transplantation.

BACKGROUND: Sirolimus is a potent immunosuppressive agent whose role in liver transplantation has not been well-described. AIM: To evaluate the efficacy and side-effects of sirolimus-based immunosuppression in liver transplant patients. METHODS: Retrospective analysis of 185 patients who underwent orthotopic liver transplantation. Patients were divided into three groups: group SA, sirolimus alone (n = 28); group SC, sirolimus with calcineurin inhibitors (n =56) and group CNI, calcineurin inhibitors without sirolimus (n = 101). RESULTS: One-year patient and graft survival rates were 86.5% and 82.1% in group SA, 94.6% and 92.9% in group SC, and 83.2% and 75.2% in group CNI (P = N.S.). The rates of acute cellular rejection at 12 months were comparable among the three groups. At the time of transplantation, serum creatinine levels were significantly higher in group SA, but mean creatinine among the three groups at 1 month was similar. More patients in group SA required dialysis before orthotopic liver transplantation (group SA, 25%; group SC, 9%; group CNI, 5%; P = 0.008), but at 1 year, post-orthotopic liver transplantation dialysis rates were similar. CONCLUSIONS: Sirolimus given alone or in conjunction with calcineurin inhibitors appears to be an effective primary immunosuppressant regimen for orthotopic liver transplantation patients. Further studies to evaluate the efficacy and side-effect profile of sirolimus in liver transplant patients are warranted.

Blood Cell Count↗
PubMed2006

Risk factors for graft survival after liver transplantation from donation after cardiac death donors: an analysis of OPTN/UNOS data.

Due to increasing use of allografts from donation after cardiac death (DCD) donors, we evaluated DCD liver transplants and impact of recipient and donor factors on graft survival. Liver transplants from DCD donors reported to UNOS were analyzed against donation after brain death (DBD) donor liver transplants performed between 1996 and 2003. We defined a recipient cumulative relative risk (RCRR) using significant risk factors identified from a Cox regression analysis: age; medical condition at transplantation; regraft status; dialysis received and serum creatinine. Graft survival from DCD donors (71% at 1 year and 60% at 3 years) were significantly inferior to DBD donors (80% at 1 year and 72% at 3 years, p < 0.001). Low-risk recipients (RCRR < or = 1.5) with low-risk DCD livers (DWIT < 30 min and CIT < 10 h, n = 226) achieved graft survival rates (81% and 67% at 1 and 3 years, respectively) not significantly different from recipients with DBD allografts (80% and 72% at 1 and 3 years, respectively, log-rank p = 0.23). Liver allografts from DCD donors may be used to increase the cadaveric donor pool, with favorable graft survival rates achieved when low-risk grafts are transplanted in a low-risk setting. Whether transplantation of these organs in low-risk recipients provides a survival benefit compared to the waiting list is unknown.

Cadaver↗
PubMed2001

Liver transplantation in cystic fibrosis.

Liver disease is the second most common cause of death in patients with cystic fibrosis (CF). Improvement in surgical techniques, medical management, and imaging modalities has broadened the range of options for treatment of these patients. Medical management with ursodeoxycholic acid and nutritional support may help decelerate the progression of liver disease. A timely evaluation of CF patients with liver involvement for transplantation is important. Such evaluation should not be delayed until signs of hepatic decompensation occur. Combined lung-liver transplant can be considered for patients with advanced pulmonary disease. Pretransplant management of portal hypertension with a portosystemic shunt procedure is an option for patients with well-preserved synthetic liver function. Improvement in lung function after liver transplantation and no significant risk of pulmonary infection with immunosuppressive therapy have been reported. Review of individual center experiences have shown satisfactory survival and improved quality of life for CF patients undergoing liver transplant.

Cystic Fibrosis↗
PubMed2001

Role of promoter methylation in increased methionine adenosyltransferase 2A expression in human liver cancer.

Methionine adenosyltransferase (MAT), an essential enzyme that catalyzes the formation of S-adenosylmethionine (SAM), is encoded by two genes, MAT1A (liver-specific) and MAT2A (non-liver-specific). We showed a switch from MAT1A to MAT2A expression in human liver cancer, which facilitates cancer cell growth. The present work examined the role of methylation in MAT2A transcriptional regulation. We found that the human MAT2A promoter is hypomethylated in hepatocellular carcinoma, in which the gene is upregulated transcriptionally, but hypermethylated in normal liver, in which the gene is minimally expressed. Luciferase activities driven by in vitro methylated MAT2A promoter constructs were 75-95% lower than activities driven by unmethylated constructs. SAM treatment of Hep G2 cells reduced MAT2A endogenous expression by 75%, hypermethylated the MAT2A promoter, and reduced luciferase activities driven by MAT2A promoter constructs by 65-75% while not affecting MAT1A's promoter activity. Treatment of adult rat and human hepatocytes with trichostatin A, an inhibitor of histone deacetylase, upregulated MAT2A expression by more than fourfold. Collectively, these results suggest that MAT2A expression is regulated by promoter methylation and histone acetylation.

Animals↗
PubMed2000

Does an infected peripancreatic fluid collection or abscess mandate operation?

OBJECTIVE: To assess the treatment of peripancreatic fluid collections or abscess with percutaneous catheter drainage (PCD). SUMMARY BACKGROUND DATA: Surgical intervention has been the mainstay of treatment for infected peripancreatic fluid collections and abscesses. Increasingly, PCD has been used, with mixed results reported in the literature. METHODS: A retrospective chart review of 1993 to 1997 was performed on 82 patients at a tertiary care public teaching hospital who had computed tomography-guided aspiration for suspected infected pancreatic fluid collection or abscess. Culture results, need for subsequent surgical intervention, length of stay, and death rate were assessed. RESULTS: One hundred thirty-five aspirations were performed in 82 patients (57 male patients, 25 female patients) with a mean age of 40 years (range 17-68). The etiologies were alcohol (41), gallstones (32), and other (9). The mean number of Ranson's criteria was four (range 0-9). All patients received antibiotics. Forty-eight patients had evidence of pancreatic necrosis on computed tomography scan. Cultures were negative in 40 patients and positive in 42. Twenty-five of the 42 culture-positive patients had PCD as primary therapy, and 6 required subsequent surgery. Eleven patients had primary surgical therapy, and five required subsequent surgery. Six patients were treated with only antibiotics. The death rates were 12% for culture-positive patients and 8% for the entire 82 patients. CONCLUSIONS: Historically, patients with positive peripancreatic aspirate culture have required operation. This series reports an evolving strategy of reliance on catheter drainage. PCD should be considered as the initial therapy for culture-positive patients, with surgical intervention reserved for patients in whom treatment fails.

AIDS-Related Opportunistic Infections↗
PubMed2000

Management of duodenal perforation after endoscopic retrograde cholangiopancreatography and sphincterotomy.

OBJECTIVE: To evaluate the authors' experience with periduodenal perforations to define a systematic management approach. SUMMARY BACKGROUND DATA: Traditionally, traumatic and atraumatic duodenal perforations have been managed surgically; however, in the last decade, management has shifted toward a more selective approach. Some authors advocate routine nonsurgical management, but the reported death rate of medical treatment failures is almost 50%. Others advocate mandatory surgical exploration. Those who favor a selective approach have not elaborated distinct management guidelines. METHODS: A retrospective chart review at the authors' medical center from June 1993 to June 1998 identified 14 instances of periduodenal perforation related to endoscopic retrograde cholangiopancreatography (ERCP), a rate of 1.0%. Charts were reviewed for the following parameters: ERCP findings, clinical presentation of perforation, diagnostic methods, time to diagnosis, radiographic extent and location of duodenal leak, methods of management, surgical procedures, complications, length of stay, and outcome. RESULTS: Fourteen patients had a periduodenal perforation. Eight patients were initially managed conservatively. Five of the eight patients recovered without incident. Three patients failed nonsurgical management and required extensive procedures with long hospital stays and one death. Six patients were managed initially by surgery, with one death. Each injury was evaluated for location and radiographic extent of leak and classified into types I through IV. CONCLUSIONS: Clinical and radiographic features of ERCP-related periduodenal perforations can be used to stratify patients into surgical or nonsurgical cohorts. A selective management scheme is proposed based on the features of each type.

Adult↗
PubMed1999

Surgical management of biliary gallstone disease during pregnancy.

BACKGROUND: Biliopancreatic gallstone disorders (BPD) manifesting during pregnancy are relatively rare. The management of these conditions remains controversial. Although perioperative problems and fetal loss have been reported, recent publications have advocated an early surgical approach. PATIENTS AND METHODS: Thirty-two pregnant women underwent operation for BPD between January 1993 and December 1997. The mean age was 29 years and ranged from 18 to 41 years. RESULTS: Twelve patients underwent a laparoscopic cholecystectomy (LC), and 20 open cholecystectomies (OC), including two conversions from laparoscopic. Seven of the OC patients required additional open CBD exploration and intraoperative choledochoscopy for CBD stones. No maternal mortality was observed. A single fetal demise (3%) occurred for a patient with gallstone pancreatitis who underwent open cholecystectomy during her 14th week of gestation. CONCLUSIONS: Early involvement of the obstetric team, with preoperative and postoperative fetal monitoring, and adequate management of anesthetic and tocolytic agents make cholecystectomy a safe procedure at any stage of pregnancy.

Acute Disease↗
PubMed1999

Current management of recurrent pyogenic cholangitis.

Recurrent pyogenic cholangitis (RPC) is a chronic disease with multiple exacerbations requiring repeated biliary dilatation and stone removal. Even after adequate biliary drainage, most patients will have progression of intrahepatic disease. Management of patients with RPC is a multidisciplinary challenge for endoscopists, interventional radiologists, and surgeons because of the frequency and inaccessibility of strictures and stones. Complete stone clearance at any one operation is difficult. Hepaticojejunostomy with a subcutaneous afferent limb is a safe and effective way to provide access to the biliary tree for the management of patients with RPC. In our experience, trans-stomal cholangioscopic stricture dilatation followed by stone removal remains the basis of therapy in patients with RPC. By diligent surveillance, we should be able to eliminate or decrease the number of stones and prevent cholangitis and its sequelae.

Adult↗
PubMed1998

Does transjugular intrahepatic portosystemic shunt (TIPS) resolve thrombocytopenia associated with cirrhosis?

Thrombocytopenia is frequently present in patients with cirrhosis. The effect of portal decompression on thrombocytopenia using a variety of shunt procedures has been contradictory. Transjugular intrahepatic portosystemic shunt (TIPS) has been proposed as a less invasive procedure for portal decompression, mainly for control of variceal bleeding or intractable ascites. Its effect on thrombocytopenia has not been defined yet. The aim of this review is to define the effect of TIPS on patients with cirrhosis and thrombocytopenia. Sixty-two patients who underwent TIPS at the University of Pittsburgh and survived without transplant for more than two months were included. Platelet count was determined prior to TIPS as well as at one-week, one-month, and three-month intervals after TIPS. The prevalence of thrombocytopenia prior to TIPS was 49%. TIPS had no effect on thrombocytopenia even when the portosystemic gradient was reduced to less than 12 mm Hg. In conclusion, portal decompression after TIPS did not affect the degree of thrombocytopenia.

Adult↗
PubMed1998

Adrenal cortical carcinoma associated with a splenic vein tumor thrombus.

A unique case is reported of a left adrenal cortical carcinoma with a splenic vein tumor thrombus. En bloc radical nephroadrenalectomy, distal pancreatectomy, splenectomy and splenic vein tumor thrombectomy were performed. Reconstruction of the proximal portal vein was required, incorporating a segment of the left renal vein (harvested from the surgical specimen) as a free interposition graft, bridging the defect between the superior mesenteric vein and portal vein. To our knowledge, this is the first reported case of an adrenal cortical carcinoma associated with a splenic vein tumor thrombus. In addition, the described technique used to reconstruct the proximal portion of the portal vein has not been previously reported.

Adrenal Cortex Neoplasms↗
PubMed1995

Alternative procedure for failed reconstruction of a right replaced hepatic artery in liver transplantation.

A right replaced hepatic artery (RRHA) arising from the superior mesenteric artery (SMA) is the most frequent variation of the hepatic arterial supply requiring backtable reconstruction. There are several widely used techniques for backtable reconstruction of the RRHA to a single conduit. If these reconstructions fail, due to technical reasons or size discrepancies, an alternative method of rearterialization is needed. We describe six cases in which an RRHA was anastomosed to the donor's gastroduodenal artery (GDA) stump utilizing a loupe magnification technique. In four cases the reconstruction was performed at the time of the backtable procedure and in two after reperfusion and failure of the original RRHA to splenic artery (SA) reconstruction. In all cases, the anastomoses remained patent. All patients had Doppler sonography and two had subsequent arteriograms that verified anastomotic patency. This method of reconstruction is more demanding technically but obviates the awkward 90-degree twist of the hepatic artery when an RRHA is anastomosed to the SA stump.

Hepatic Artery↗
PubMed1994

Needle-localized thoracoscopic resections of small indeterminate pulmonary nodules in transplant patients.

Indeterminate pulmonary nodules (IPN) in transplant patients create a diagnostic and therapeutic challenge. Patients who are transplant candidates or have already undergone organ transplantation require diagnostic clarification of IPN which may represent oncologic and/or infectious disease processes. Between December 1991 and January 1993, we performed 43 needle-localized thoracoscopic resections (NLTR) on 40 patients for IPN considered too small for less invasive diagnostic techniques. Four of these patients were candidates for orthotopic liver transplantation (OLT) and required exclusion of either extrahepatic malignancy or pulmonary infection before proceeding with transplantation. The 5th patient had undergone OLT for an unresectable hepatocellular carcinoma, and NLTR confirmed the presence of pulmonary metastatic disease. Of the 4 OLT candidates, 2 had pathologically confirmed metastases from their primary hepatic malignancy and did not undergo transplantation. The remaining 2 OLT candidates had benign pulmonary processes (hamartoma, hyaline plaque) and underwent successful OLT. In all patients, the IPN was successfully identified with NLTR. There were no complications. NLTR is a reliable and well-tolerated method to diagnose IPN in transplant patients.

Biopsy, Needle↗
PubMed1993

The 11-year Pittsburgh experience with liver transplantation for hepatocellular carcinoma: 1981-1991.

Experience with liver transplantation over a period of 11 years at the University of Pittsburgh is presented. The application of liver transplantation to cases of hepatocellular carcinoma has changed considerably over this 11-year period with the sequential introduction of adjuvant and, more recently, neoadjuvant chemotherapy. Results with the combination of chemotherapy plus surgery appear to be better than results with either agent alone. Moreover, the early results with neoadjuvant therapy appear to be better than those achieved with adjuvant therapy. As a result of this experience, conceptual changes in the approach to the problem of hepatic cancer and the role of both chemotherapy and liver transplantation in its management have changed at the University of Pittsburgh. These changes are identified and discussed.

Adenoma, Bile Duct↗
PubMed1991

The spectrum of portal vein thrombosis in liver transplantation.

Thrombosis of the portal vein with or without patency of its tributaries used to be a contraindication to orthotopic liver transplantation (OLTX) until quite recently. Rapid progress in the surgical technique of OLTX in the last few years has demonstrated that most patients with portal vein thrombosis can be safely and successfully transplanted. Presented here is a series of 34 patients with portal vein thrombosis transplanted at the University of Pittsburgh since 1984. The various techniques used to treat various forms of thrombosis are described. The survival rate for this series was 67.6% (23 of 34 patients). Survival was best for patients who underwent phlebothrombectomy or placement of a jump graft from the superior mesenteric vein. The survival rate also correlated with the amount of blood required for transfusion during surgery. Overall it is concluded that a vast majority of the patients with thrombosis of the portal system can be technically transplanted and that their survival rate is comparable to that of patients with patent portal vein.

Anastomosis, Surgical↗
PubMed1991

The liver transplant waiting list--a single-center analysis.

At this transplant center 1340 patients were entered on the liver transplant waiting list during the first 25 months (October 1987 to November 1989) after the initiation of the UNOS allocation system for liver grafts. Of these 972 (72.5%) of the patients received a graft, 120 (9.0%) died waiting for a graft, 109 (8.1%) remained on the active list as of the study endpoint of December 15, 1989, 123 (9.2%) were withdrawn from candidacy, and 16 (1.2%) received a transplant at another center. A total of 1201 patients were candidates for a first graft. Of the 812 primary candidates who received a graft, 64.8% received their graft within one month of entry on the waiting list. Of the 109 primary candidates who died before a graft could be found, 79.0% died within a month of entry onto the waiting list. At time of transplantation, 135 (16.6%) primary recipients of a graft were UNOS class 1, 326 (40.1%) were UNOS class 2, 190 (23.4%) were UNOS class 3, and 161 (19.8%) were UNOS class 4. Actuarial survival rates (percentage) at 6 months for recipients in UNOS class 1, class 2, class 3, and class 4 were 88.7 +/- 2.9, 82.6 +/- 2.1, 78.4 +/- 3.2, and 68.4 +/- 3.9, respectively (P less than 0.001). At the time of death of recipients who failed to get a graft, 6 (5.5%) were UNOS class 1, 14 (12.8%) were UNOS class 2, 23 (21.1%) were UNOS class 3, and 66 (60.6%) were UNOS class 4. These results indicate that a high proportion of liver transplant candidates are in urgent need of a graft and that the UNOS system succeeds in giving these patients high priority. However patient mortality on the waiting list and after transplantation would lessen significantly if more patients with end-stage liver disease were referred to the transplant center in a timely manner before their condition reaches the point where the probability of survival is diminished.

ABO Blood-Group System↗