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Biomedical subjects

P S Kamath

Publications and source records attributed to P S Kamath.

At least 19 recordsLinked to original sources
PubMed2001

Regional and systemic hemodynamic disturbances in cirrhosis.

In cirrhosis of the liver there is an imbalance between factors mediating vasodilatation such as nitric oxide and factors mediating vasoconstriction such as endothelins. These imbalances result in portal hypertension, hepatorenal syndrome, portopulmonary hypertension, hepatopulmonary syndrome, as well as alterations in cerebral blood flow.

Animals↗
PubMed2001

Development of hepatic veno-occlusive disease after Mylotarg infusion for relapsed acute myeloid leukemia.

Mylotarg (gemtuzumab zogamicin) is a conjugated monoclonal antibody that has recently become available for use in patients with relapsing or refractory acute myeloid leukemia. Reversible hepatotoxicity is common after administration. We describe the first report of hepatic veno-occlusive disease (HVOD) developing after Mylotarg infusion in a patient who underwent hematopoietic stem cell transplantation 8 months earlier. Certain antineoplastic agents have been implicated as a cause of HVOD, but the disease is most commonly seen within 30 days after hematopoietic stem cell transplantation. The possible association between Mylotarg infusion and HVOD is discussed.

Aged↗
PubMed2001

Charcoal hemofiltration for hepatic veno-occlusive disease after hematopoietic stem cell transplantation.

Hepatic veno-occlusive disease (HVOD) after hematopoietic stem cell transplantation (HSCT) results in considerable morbidity and mortality. No therapy has been shown to be uniformly effective. Several studies have highlighted the pivotal role of endothelial injury and the hemostatic system in the pathogenesis of HVOD. Charcoal hemofiltration has been shown to be effective for adsorbing circulating bilirubin and other protein-bound toxins and for supporting patients in hepatic failure. We describe two adult patients with severe, biopsy-proven HVOD (peak bilirubin levels, more than 50 mg/dl in both cases) after HSCT who were successfully treated with charcoal hemofiltration after other treatments failed (including defibrotide in one patient). Both patients were heavily treated before they underwent either autologous (melphalan and total body irradiation conditioning) or allogeneic (cyclophosphamide and total body irradiation conditioning) HSCT. Additional studies are warranted to confirm this preliminary observation and investigate the mechanism of action.

Adult↗
PubMed2001

A model to predict survival in patients with end-stage liver disease.

A recent mandate emphasizes severity of liver disease to determine priorities in allocating organs for liver transplantation and necessitates a disease severity index based on generalizable, verifiable, and easily obtained variables. The aim of the study was to examine the generalizability of a model previously created to estimate survival of patients undergoing the transjugular intrahepatic portosystemic shunt (TIPS) procedure in patient groups with a broader range of disease severity and etiology. The Model for End-Stage Liver Disease (MELD) consists of serum bilirubin and creatinine levels, International Normalized Ratio (INR) for prothrombin time, and etiology of liver disease. The model's validity was tested in 4 independent data sets, including (1) patients hospitalized for hepatic decompensation (referred to as "hospitalized" patients), (2) ambulatory patients with noncholestatic cirrhosis, (3) patients with primary biliary cirrhosis (PBC), and (4) unselected patients from the 1980s with cirrhosis (referred to as "historical" patients). In these patients, the model's ability to classify patients according to their risk of death was examined using the concordance (c)-statistic. The MELD scale performed well in predicting death within 3 months with a c-statistic of (1) 0.87 for hospitalized patients, (2) 0.80 for noncholestatic ambulatory patients, (3) 0.87 for PBC patients, and (4) 0.78 for historical cirrhotic patients. Individual complications of portal hypertension had minimal impact on the model's prediction (range of improvement in c-statistic: <.01 for spontaneous bacterial peritonitis and variceal hemorrhage to ascites: 0.01-0.03). The MELD scale is a reliable measure of mortality risk in patients with end-stage liver disease and suitable for use as a disease severity index to determine organ allocation priorities.

Hospitalization↗
PubMed2000

Identification of a locus for autosomal dominant polycystic liver disease, on chromosome 19p13.2-13.1.

Polycystic liver disease (PCLD) is characterized by the growth of fluid-filled cysts of biliary epithelial origin in the liver. Although the disease is often asymptomatic, it can, when severe, lead to complications requiring surgical therapy. PCLD is most often associated with autosomal dominant polycystic kidney disease (ADPKD); however, families with an isolated polycystic liver phenotype without kidney involvement have been described. The clinical presentation and histological features of polycystic liver disease in the presence or absence of ADPKD are indistinguishable, raising the possibility that the pathogenetic mechanisms in the diseases are interrelated. We ascertained two large families with polycystic liver disease without kidney cysts and performed a genomewide scan for genetic linkage. A causative gene, PCLD, was mapped to chromosome 19p13.2-13.1, with a maximum LOD score of 10.3. Haplotype analysis refined the PCLD interval to 12.5 cM flanked by D19S586/D19S583 and D19S593/D19S579. The discovery of genetic linkage will facilitate diagnosis and study of this underdiagnosed disease entity. Identification of PCLD will be instrumental to an understanding of the pathogenesis of cyst formation in the liver in isolated PCLD and in ADPKD.

Adult↗
PubMed2000

Gastric mucosal responses to intrahepatic portosystemic shunting in patients with cirrhosis.

BACKGROUND & AIMS: The response of gastric mucosal lesions in cirrhotic patients with portal hypertension, namely, portal hypertensive gastropathy (PHG) and gastric vascular ectasia (GVE), to transjugular intrahepatic portosystemic shunts (TIPS) is not known. METHODS: Clinical and laboratory evaluation, upper gastrointestinal endoscopy, and Doppler ultrasonography were performed before placement of TIPS and 6 weeks, 3 months, and 6 months after TIPS in 54 patients. Thirty patients had mild PHG, 10 had severe PHG, and 14 had GVE. RESULTS: Approximately 75% of the patients with severe PHG responded to TIPS as shown by improvement in endoscopic findings and by a decrease in transfusion requirements; 89% of patients with mild PHG had endoscopic resolution. Patients with GVE had neither endoscopic resolution nor a decrease in transfusion requirements after TIPS. There was no difference in mortality between the 2 groups. CONCLUSIONS: The results support the position that severe PHG and GVE may be different lesions. Mild and severe PHG respond to TIPS. Because GVE does not respond to TIPS, we recommend that TIPS be avoided for the treatment of gastrointestinal bleeding associated with GVE.

Aged↗
PubMed2000

A model to predict poor survival in patients undergoing transjugular intrahepatic portosystemic shunts.

Transjugular intrahepatic portosystemic shunts (TIPS) may worsen liver function and decrease survival in some patients. The Child-Pugh classification has several drawbacks when used to determine survival in such patients. The survival of 231 patients at 4 medical centers within the United States who underwent elective TIPS was studied to develop statistical models to (1) predict patient survival and (2) identify those patients whose liver-related mortality post-TIPS would be 3 months or less. Among these elective TIPS patients, 173 had the procedure for prevention of variceal rebleeding and 58 for treatment of refractory ascites. Death related to liver disease occurred in 110 patients, 70 within 3 months. Cox proportional-hazards regression identified serum concentrations of bilirubin and creatinine, international normalized ratio for prothrombin time (INR), and the cause of the underlying liver disease as predictors of survival in patients undergoing elective TIPS, either for prevention of variceal rebleeding or for treatment of refractory ascites. These variables can be used to calculate a risk score (R) for patients undergoing elective TIPS. Patients with R > 1.8 had a median survival of 3 months or less. This model was superior to both the Child-Pugh classification, as well as the Child-Pugh score, in predicting survival. Using logistic regression and the same variables, we also developed a nomogram that indicates which patients survive less than 3 months. Finally, the model was validated among an independent set of 71 patients from the Netherlands. This Mayo TIPS model may predict early death following elective TIPS for either prevention of variceal rebleeding or for treatment of refractory ascites.

Adult↗
PubMed2000

Hepatic localization of endothelin-1 in patients with idiopathic portal hypertension and cirrhosis of the liver.

Endothelin-1 (ET-1) may mediate increased resistance to hepatic sinusoidal blood flow. We evaluated the hepatic distribution of ET-1 in patients with idiopathic portal hypertension (IPH), in which liver architecture may be normal, and in patients with cirrhosis, in which distortion of hepatic sinusoidal architecture is prominent. Immunohistochemistry and in situ hybridization were used to localize ET-1 in hepatic tissue of patients with IPH and cirrhosis. ET-1 was measured in plasma from a peripheral vein, the hepatic vein, and the portal vein of patients with cirrhosis of the liver and controls. On immunohistochemistry and in situ hybridization, ET-1 was localized to periportal hepatocytes and sinusoidal cells in patients with IPH and cirrhosis. Minimal positive staining for ET-1 was observed in control livers. Plasma ET-1 levels were significantly greater in patients with cirrhosis than in controls. In patients with cirrhosis, ET-1 was greater in the hepatic vein compared with the portal vein. However, the level of plasma ET-1 in patients with cirrhosis did not correlate with either the presence of ascites or portacaval pressure gradient. We conclude that in IPH, ET-1 is localized to sites in which it can modulate intrahepatic resistance. In late stages of cirrhosis, ET-1 may not modulate resistance. We speculate that vascular resistance in late stages of cirrhosis probably results from distortion of hepatic architecture.

Blood Pressure↗
PubMed2000

Differentiation of typhoid fever from fulminant hepatic failure in patients presenting with jaundice and encephalopathy.

OBJECTIVE: To determine the clinical and laboratory features that allow the early diagnosis of typhoid fever in patients who present with jaundice and encephalopathy. PATIENTS AND METHODS: This 12-month prospective study, conducted in Bangalore, India, between 1990 and 1991, evaluated the clinical and laboratory features of all patients (N=47) who presented with encephalopathy within 8 weeks of onset of jaundice. Ciprofloxacin and dexamethasone were used to treat 11 patients diagnosed on blood culture as having typhoid fever. The other 36 patients were presumed to have fulminant hepatic failure with a viral cause and were treated with supportive measures (bioartificial liver support and transplantation were not available). RESULTS: In patients with jaundice and encephalopathy, a liver span of greater than 9 cm on physical examination, thrombocytopenia, elevated alkaline phosphatase level, aspartate aminotransferase level greater than alanine aminotransferase level, and only mild prolongation of the prothrombin time suggested a diagnosis of typhoid fever. All 11 patients diagnosed as having typhoid fever had an excellent response to treatment with ciprofloxacin and dexamethasone with no mortality and with normalization of the liver test results in 2 weeks. On the other hand, 30 of the 36 patients with nontyphoid fulminant hepatic failure died. CONCLUSIONS: In patients presenting with jaundice and encephalopathy, physical examination and simple laboratory tests can help make an early diagnosis of typhoid fever. We believe that patients with a presumptive diagnosis of typhoid fever should be treated with ciprofloxacin and dexamethasone, even before the results of blood cultures are available.

Adult↗
PubMed2000

Managing the complications of cirrhosis.

The 3 major and potentially fatal complications of cirrhosis of the liver result from portal hypertension and include variceal bleeding, ascites, and encephalopathy. The cause of other complications, eg, thyroid dysfunction and hepatopulmonary syndrome, is uncertain. Several recent advances have occurred in the treatment of varices. However, treatment of ascites is still primarily confined to achieving a negative sodium balance, and therapy for encephalopathy centers on the use of lactulose. Although effective therapy may be available for most complications of cirrhosis, a major complication indicates a poor long-term prognosis. Liver transplantation is the only effective long-term treatment of complications due to cirrhosis.

Adrenergic beta-Antagonists↗
PubMed1999

Endothelin-1 modulates intrahepatic resistance in a rat model of noncirrhotic portal hypertension.

Factors that increase resistance to blood flow through the hepatic sinusoids when portal hypertension occurs in the absence of significant hepatic fibrosis are not completely understood. Experiments were designed to test the hypothesis that endothelin-1 (ET-1) is one of the humoral factors that increases sinusoidal vascular resistance in a bile duct- ligated noncirrhotic portal hypertensive (BDL) rat. The effect of ET-1 and nitric oxide (NO) on contractility of rings of portal vein taken from BDL rats was tested. The effect of ET-1 and NO on intrahepatic resistance in an isolated perfused liver was studied, and localization of ET-1 in the liver was identified by immunohistochemistry. Portal vein rings in BDL rats showed increased maximal tension in response to ET-1, as well as a shift of the dose-response curve to the left as compared with sham-operated animals. Removal of the endothelium further increased contractility. In isolated perfused liver studies, ET-1 increased portal resistance in both sham operated and BDL rats. The endothelin Type A receptor antagonist BQ 123 lowered the high portal resistance in BDL rats to levels comparable with sham operated animals. Infusion of L-arginine lowered resistance to a much smaller extent. In livers from BDL rats, ET-1 was localized in periportal and pericentral hepatocytes and hepatic sinusoidal cells. We conclude that in a BDL model of portal hypertension where distortion of hepatic architecture by fibrosis is minimal, increased resistance to portal blood flow may be mediated by ET-1.

Animals↗
PubMed1999

Hepatic hydrothorax: pathogenesis, diagnosis, and management.

Hepatic hydrothorax is defined as a pleural effusion in a patient with cirrhosis of the liver and no cardiopulmonary disease. The estimated prevalence of this often debilitating complication in patients with liver cirrhosis is 4% to 10%. Its pathophysiology involves movement of ascitic fluid from the peritoneal cavity into the pleural space through diaphragmatic defects. As a result patients are at increased risk of respiratory infection. Initial management consists of sodium restriction, diuretics, and thoracentesis. A transjugular intrahepatic portosystemic shunt may be required. Because most patients with hepatic hydrothorax have end-stage liver disease, a liver transplant should be considered if these options fail.

Algorithms↗
PubMed1999

Utilization of the Mayo risk score in patients with primary biliary cirrhosis receiving ursodeoxycholic acid.

BACKGROUND/AIMS: Ursodeoxycholic acid (UDCA) is an effective therapy for most patients with primary biliary cirrhosis (PBC). During the management of these treated patients, a number of clinically important issues arose including which patients might be candidates for combined therapy, which patients require endoscopy for variceal bleeding, and how survival can be predicted during treatment. Our aims were: 1) to identify factors associated with a suboptimal response to UDCA in patients with PBC; 2) to define a simple, non-invasive method to predict those PBC patients most apt to have esophageal varices; and 3) to determine the reliability of the Mayo survival model in predicting the course of UDCA treated patients. METHODS: We analyzed the prospectively collected data of 180 patients, who we continue to follow, with PBC who participated in a randomized, placebo-controlled trial of UDCA. RESULTS: After six months of UDCA therapy, patients with serum alkaline phosphatase levels less than twice normal (p < 0.04), and/or a Mayo risk score < 4.5 (p < 0.04) were more likely to respond favorably to treatment over a two year period. The Mayo risk score was the single risk factor independently predictive of development of varices (p < 0.01); 93% of patients who developed varices had a Mayo risk score > or = 4. The Mayo survival model, recalculated after 6 months on UDCA therapy accurately predicted patient survival. CONCLUSIONS: Suboptimal responders to UDCA can be identified by assessment of serum alkaline phosphatase levels, and/or Mayo risk score. A Mayo risk score above 4 helps in selecting patients for endoscopic surveillance for varices and the Mayo survival model accurately predicts the clinical course in patients with PBC receiving UDCA.

Adult↗