Search PubMed⌕ Search

Biomedical subjects

Pratima Sharma

Publications and source records attributed to Pratima Sharma.

14 recordsLinked to original sources
PubMed2025

Predictors of response to terlipressin therapy in hepatorenal syndrome: Metabolomic and proteomic analysis from the CONFIRM trial.

BACKGROUND: Terlipressin is the only FDA-approved vasoconstrictor for hepatorenal syndrome (HRS). The CONFIRM study is the largest trial of terlipressin versus placebo. Novel predictors of HRS response are required to enrich patient selection and optimize outcomes. METHODS: Samples at treatment initiation were tested using (a) liquid chromatography-mass spectrometry of 1594 plasma/1420 urine metabolites (Metabolon Inc.), (b) aptamer-based array of 7289 plasma proteins (SomaScan), and (c) 14 plasma/urine pre-specified assays. The CONFIRM trial's original definition of HRS response [2 serum creatinine (SCr) <1.5&#xa0;mg/dL separated by >2&#xa0;h] was used as the primary outcome. RESULTS: In all, 115 patients [79 terlipressin-treated (TT) and 36 placebo-treated (PT)] provided samples. Baseline characteristics, outcomes, and 2:1 TT:PT allocation were preserved from the original 300-patient trial. A total of 36 out of 116 (31.0%) patients achieved HRS reversal. HRS reversal was associated with lower SCr (p=0.001), cystatin C (p=0.005), angiopoietin-2 (p=0.04), and beta-2 microglobulin (p=0.006). In metabolite analysis, PT had the most significant differences in HRS reversal [n=26 plasma, n=50 urine, including lower urine levels of those centered on sulfated secondary bile acids (microbiome-derived), N-acetylated amino acids, catechols (both uremic toxins), and phosphocholines (cell membrane integrity)], with fewer in TT (n=1 plasma, n=2 urine), and in all patients (n=3 plasma, n=7 urine). There were no significant aptamers associated with HRS reversal after false-discovery correction. CONCLUSIONS: SCr, cystatin C, angiopoietin-2, and beta-2 microglobulin were associated with HRS reversal. Protein and metabolite signals centered on microbiome function and uremic toxins appeared more robust in PT patients, likely selecting a subgroup that may recover without terlipressin. Use of novel biomarkers may enrich for terlipressin response.

Humans↗
PubMed2006

Evidence that the MAPK-docking site in MAPKK Dpbs2p is essential for its function.

In eukaryotes, mitogen-activated protein kinase (MAPK) pathways are very important signal transduction modules that regulate various cellular processes. Although eukaryotic cells possess a number of MAP kinase pathways, normally the MAPKKs selectively activate their cognate MAPK. Recent studies suggest that the MAPK-docking site in MAPKK facilitates this specific recognition and activation. However, the role of the docking site under in vivo conditions has not been demonstrated. In yeast external high osmolarity activates HOG (high osmolarity glycerol) MAPK pathway that consists of MAPKKK (Ste11p or Ssk2p/Ssk22p), MAPKK (Pbs2p), and MAPK (Hog1p). Previously, we have isolated a Pbs2p homologue (Dpbs2p) from osmo-tolerant and salt-tolerant yeast Debaryomyces hansenii that complemented pbs2 mutation in Saccharomyces cerevisiae. Here we show, for the first time, the presence of a MAPK-docking domain in Dpbs2p that is essential for its function in vivo. Mutation in this motif completely abolished its binding to Hog1p in vitro.

Binding Sites↗
PubMed2006

Liver transplantation in the MELD era: a single-center experience.

Model for Endstage Liver Disease (MELD) score has been used to allocate organs since February 2002. This policy allocates organs to candidates with regard to severity of their underlying liver disease except in the case of hepatocellular carcinoma (HCC) patients. The purpose of this study was to determine the impact of MELD on waiting times, dropout rates, and transplantation rates in all patients awaiting liver transplantation at our center. The records of all patients listed for liver transplantation between May 28, 1999, and February 27, 2004, at the Mayo Clinic, Scottsdale, Arizona, were reviewed. Candidates were grouped by two time periods as pre-MELD or post-MELD based on date of MELD implementation (February 27, 2002). The incidence of deceased donor liver transplantation (DDLT), waiting time to DDLT, dropout rate from the waiting list because of clinical deterioration or death, and survival while waiting for or after DDLT were determined for each group. Three hundred fifty-one patients were listed for liver transplantation (195 pre-MELD, 156 post-MELD) during the study period. HCC patients had an improved rate of transplantation after MELD (pre-MELD, 1.39 persons per year; post-MELD, 3.48 persons per year). In all groups, with the exception of hepatitis C virus, the transplantation rates were the same for both categories. The hepatitis C virus group also had improved transplantation rates in the post-MELD period. HCC candidates under the new allocation policy have an increased incidence of DDLT in our institution. However, this has not disadvantaged patients with non-HCC diagnoses. Thus, the new MELD-based allocation policy has benefited all candidates by allowing more timely transplants.

Arizona↗
PubMed2006

Viral hepatitis and liver transplantation.

Hepatitis C is the one of the most common indications for liver transplantation. Infection of the allograft after transplantation is universal, and recurrent hepatitis C progresses at an accelerated rate. Antiviral therapy in selected patients on the transplant waiting list may reduce the rate of hepatitis C virus reinfection. Preemptive antiviral therapy after transplantation has been disappointing. However, treatment of established histological disease with a combination of pegylated interferon and ribavirin is associated with sustained virologic response rates of 25 to 40%. Significant advances have been made in the prevention of hepatitis B reinfection after transplantation. Results are now excellent, with graft infection rates less than 10%. The challenges for the future include designing strategies to optimize the use of antiviral agents to prevent the need for transplantation and to avoid antiviral resistance and to determine the dose and duration of hepatitis B immunoglobulin needed in the era of multiple nucleoside analogs.

Antiviral Agents↗
PubMed2005

Debaryomyces hansenii, a highly osmo-tolerant and halo-tolerant yeast, maintains activated Dhog1p in the cytoplasm during its growth under severe osmotic stress.

The HOG pathway is an important mitogen-activated protein kinase (MAPK) signal transduction pathway in Saccharomyces cerevisiae that mediates adaptation of cells to hyper-osmotic stress. Activation of this pathway causes rapid but transient, phosphorylation of the MAPK Hog1p. Phosphorylated Hog1p is rapidly transported to the nucleus that results in the transcription of target genes. The HOG pathway appears to be ubiquitous in yeast. Components of HOG pathway have also been identified in Debaryomyces hansenii, a highly osmotolerant and halotolerant yeast. We have studied activation of HOG pathway in D. hansenii under different stress conditions. Our experiments demonstrated that the pathway is activated by high osmolarity, oxidative and UV stress but not by heat stress. We have provided evidence, for the first time, that D. hansenii maintains phosphorylated Dhog1p in the cytoplasm during its growth under severe osmotic stress.

Cytoplasm↗
PubMed2005

Evidence that C-terminal non-kinase domain of Pbs2p has a role in high osmolarity-induced nuclear localization of Hog1p.

Mitogen-activated protein kinase (MAPK) cascade is a ubiquitous signaling module that transmits extracellular stimuli through the cytoplasm to the nucleus. In baker's yeast external high osmolarity activates high osmolarity glycerol (HOG) MAPK pathway which consists of two upstream branches (SHO1 and SLN1) and common downstream elements Pbs2p MAPKK and Hog1p MAPK. Activation of this pathway causes rapid nuclear accumulation of Hog1p, essentially leading to the expression of target genes. Previously we have isolated a PBS2 homologue (DPBS2) from osmo-tolerant and salt-tolerant yeast Debaryomyces hansenii that partially complemented pbs2 mutation in Saccharomyces cerevisiae. Here we show that by replacing C-terminal region of Dpbs2p with the homologous region of Pbs2p we could abrogate partial complementation exhibited by Dpbs2p and this was achieved due to increase in nuclear translocation of Hog1p. Thus, our result showed that in HOG pathway, MAPKK has important role in nuclear translocation of Hog1p.

Active Transport, Cell Nucleus↗
PubMed2004

Hepatitis C virus infection with hepatocellular carcinoma: not a controversial indication for liver transplantation.

BACKGROUND: The association of hepatocellular carcinoma (HCC) and chronic hepatitis C virus (HCV) infection has been identified as a potential contraindication for orthotopic liver transplantation (LT) because of lower survival rate compared with other indications. AIM: Evaluate the outcome of patients with and without HCC and cirrhosis with and without chronic HCV infection undergoing transplantation. Determine the postLT HCC recurrence rate and frequency of de novo postLT HCC. PATIENTS AND METHODS: United Network for Organ Sharing (UNOS) data was collected from January 1998 to December 2002. Cohort included 17,968 patients (11,552 M; 6,416 F) with a mean age of 51 (18-87) years. Four groups were established: HCV (n = 7,079), HCC (n = 611), HCV+HCC (n = 1,078), and no HCV/no HCC (n = 9,200). The overall survival rate was calculated at 24 and 48 months postLT. RESULTS: Patient survival at 24 months and 48 months was 84% and 75% for HCV, 84% and 68% for HCC, 78% and 72% for HCV+HCC, and 85% and 80% for no HCV/no HCC, respectively. Survival at 48 months among the two groups was not significantly different (NS). Further analysis of these groups revealed a statistically significant advantage in survival at 48 months postLT for the no HCV/no HCC group when compared with the HCV group.(P < 0.05) The reported rate of postLT HCC recurrence and de novo postLT HCC was 3.3% and 0.05%, respectively. CONCLUSION: In this large cohort of U.S. patients, HCC does not have an impact on the survival of LT patients infected with HCV.

Adolescent↗
PubMed2004

Treatment of recurrent hepatitis C infection after liver transplantation with combination of pegylated interferon alpha2b and ribavirin: an open-label series.

BACKGROUND: Hepatitis C virus (HCV) recurrence after orthotopic liver transplantation (OLT) is universal. We aimed to evaluate the efficacy and safety of pegylated interferon (PEG-IFN) and ribavirin (RIB) in the treatment of post-OLT HCV recurrence. METHODS: Thirty-seven patients with recurrent HCV after OLT were screened and began treatment. Nineteen patients have completed therapy. PEG-IFN was started at a dose of 0.5 microg/kg per week and titrated toward a maximum dose of 1.5 microg/kg per week. RIB was started at a dose of 400 mg per day and titrated toward a maximum of 1000 mg per day, as tolerated. Therapy continued for 1 year after HCV replication was undetectable by reverse transcriptase-polymerase chain reaction and was discontinued if there was no virologic clearance at 48 weeks. RESULTS: Twelve patients (63%) completed the combination regimen. Therapy was discontinued in seven (37%) patients. Seven patients (37%) had undetectable viral load at the end of treatment. Of those, five patients (26%) had sustained viral response 6 months after discontinuation of therapy. Five patients (26%) had no virologic response. Necro-inflammatory score declined from 5.22 to 2.89 (P=0.05) in nonresponders versus 6.8 to 2.6 (P<0.01) in responders. Fibrosis stage did not change in either group. Genotype 1-infected patients had a lower likelihood of attaining end of treatment or sustained viral response (P<0.05 for both). CONCLUSIONS: Post-OLT HCV recurrence can be safely treated with PEG-IFN and RIB. Bone marrow toxicity, depression, and rejection are limiting factors that require aggressive management. There was short-term histologic benefit to the use of this regimen, even in those patients without viral clearance.

Antiviral Agents↗
PubMed2004

Liver transplantation for hepatocellular carcinoma: the MELD impact.

The new allocation policy of the United Network of Organ Sharing (UNOS) based on the model for end-stage liver disease (MELD) gives candidates with stage T1 or stage T2 hepatocellular carcinoma (HCC) a priority MELD score beyond their degree of hepatic decompensation. The aim of this study was to determine the impact of the new allocation policy on HCC candidates before and after the institution of MELD. The UNOS database was reviewed for all HCC candidates listed between July 1999 and July 2002. The candidates were grouped by two time periods, based on the date of implementation of new allocation policy of February 27, 2002. Pre-MELD candidates were listed for deceased donor liver transplantation (DDLT) before February 27,2002, and post-MELD candidates were listed after February 27, 2002. Candidates were compared by incidence of DDLT, time to DDLT, and dropout rate from the waiting list because of clinical deterioration or death, and survival while waiting and after DDLT. Incidence rates calculated for pre-MELD and post-MELD periods were expressed in person years. During the study, 2,074 HCC candidates were listed for DDLT in the UNOS database. The DDLT incidence rate was 0.439 transplant/person years pre-MELD and 1.454 transplant/person years post-MELD (P < 0.001). The time to DDLT was 2.28 years pre-MELD and 0.69 years post-MELD (P < 0.001). The 5-month dropout rate was 16.5% pre-MELD and 8.5% post-MELD (P < 0.001). The 5-month waiting-list survival was 90.3% pre-MELD and 95.7% post-MELD (P < 0.001). The 5-month survival after DDLT was similar for both time periods. The new allocation policy has led to an increased incidence rate of DDLT in HCC candidates. Furthermore, the 5-month dropout rate has decreased significantly. In addition, 5-month survival while waiting has increased in the post-MELD period. Thus, the new MELD-based allocation policy has benefited HCC candidates.

Carcinoma, Hepatocellular↗
PubMed2004

Hepatic steatosis in hepatitis C virus genotype 3 infection: does it correlate with body mass index, fibrosis, and HCV risk factors?

Hepatic steatosis is a recognized feature of hepatitis C viral infection, particularly in genotype 3. The demographics and the associations contributing to moderate to severe steatosis in genotype 3 are not very well studied. The aim of this study is to determine the demographics and association of steatosis with fibrosis, obesity, diabetes, lipid levels, and risk factors among patients with hepatitis C virus (HCV) genotype 3. Two hundred ninety-three consecutive HCV patients (genotype 1, n = 218; genotype 2, n = 43; genotype 3, n = 32) at our institution were studied retrospectively. Demographic information such as height, weight, genotype, risk factors, serum cholesterol and triglyceride, and liver biopsy was collected. Steatosis was graded using the Brunt classification. HCV genotype 3-infected patients were younger (P < 0.04) and had lower serum cholesterol levels (P < 0.02) compared to nongenotype 3 patients. Moderate to severe steatosis was more prevalent in HCV genotype 3 patients (P < 0.001) with intravenous drug abuse as a risk factor (P = 0.04). Genotype 3 was the independent predictor of steatosis in all patients. There was no statistical association between grade of steatosis and body mass index, fibrosis, necroinflammation, or hyperlipidemia when only HCV genotype 3 patients were included in the multivariate logistic model. Hepatic steatosis is a feature of genotype 3. Patients with HCV genotype 3 are younger and have lower serum cholesterol levels. Genotype 3 is the independent predictor for steatosis in HCV patients. HCV genotype 3 patients with moderate to severe steatosis are more likely to have intravenous drug use as a risk factor.

Arizona↗
PubMed2004

Hepatitis C virus recurrence in living donor liver transplant recipients.

Recurrence of hepatitis C virus (HCV) after liver transplantation (LT) is a universal phenomenon. Recent reports have suggested an earlier and more aggressive recurrence in the living donor liver transplant (LDLT) population. The aim of this study was to compare the histological recurrence of HCV after LDLT versus deceased donor transplantation (DDT). Twenty-nine patients underwent LT for HCV-related end-stage liver disease at our institution between April 2001 and March 2003 (42 months). Twenty patients underwent DDT, and nine patients LDLT. Laboratory data were collected on a weekly to biweekly basis and HCV PCR was performed before LT and 3-4 months and yearly post-LT. Liver biopsies were performed as needed and per institutional protocol at 7 days, at 4 months, and yearly thereafter. All biopsies were evaluated by a single pathologist and scored for rejection (Banff score) and chronic hepatitis (Ishak score system). The predominant genotype in the DDT and LDLT groups was genotype 1 (DDT = 70%, LDLT = 79%). HCV RNA titers pre-LT and 3-4 months after LT did not differ. The incidence of rejection was higher in the DDT group (P < 0.05). There was a trend toward improved Ishak stage and grade in the LDLT group at 4 and 12 months post-LT, however, this trend did not reach statistical significance. No histological difference in the recurrence or severity rate was observed at 4 or 12 months post-LT in the DDT group vs. the LDLT group.

Adult↗
PubMed2003

Outcome of liver transplantation for familial amyloidotic polyneuropathy.

Familial amyloidotic polyneuropathy (FAP) is an autosomal dominant disorder caused by mutation in the transthyretin gene. The most common mutation is substitution of valine for methionine at position 30 (MET30). Liver transplantation (LT) is the preferred treatment. After LT, although many patients show stabilization or improvement in the disease, adverse outcomes have been reported in those who have malnutrition, long-standing disease, and non-MET (NMET) mutations at position 30. Our aim is to compare survival and outcome of symptoms associated with FAP after LT in patients with MET30 and NMET30 mutations. Medical records of all patients who underwent LT for amyloidosis at our institution were reviewed to obtain demographic information and clinical features, such as severity of neuropathy, diarrhea, orthostatic hypotension, and posterior wall or ventricle septal thickness before and after LT. Fifteen patients underwent LT for amyloidosis at our institution between 1990 and 2000 (MET30, n = 5; NMET30, n = 7; hereditary amyloidosis, n = 2; primary amyloidosis, AL type, n = 1). Patients with hereditary and primary amyloidosis were excluded from analysis. One- and 3-year survival rates after LT in MET30 patients were 100%. Before LT, five of five patients had sensorimotor neuropathy; five of five patients had diarrhea, and four of five patients had orthostatic hypotension. After LT, improvement or stabilization of neuropathy was seen in two of five patients; of diarrheal symptoms, in three of five patients; and of orthostatic hypotension, in three of four patients. One- and 3-year survival rates after LT in NMET30 patients were 100% and 85.7%, respectively. Before LT, six of seven patients had sensorimotor neuropathy, six of seven patients had diarrhea, and five of seven patients had orthostatic hypotension. After LT in this group, improvement or stabilization of neuropathy was seen in two of six patients; of diarrhea, in six of six patients; and of orthostatic hypotension, in five of five patients. Before LT, posterior wall and/or ventricle septal thickness was increased in two of five MET patients and seven of seven NMET patients. Five of seven NMET30 patients (71.4%) who received a combined liver and heart transplant had stabilization, and two patients in the NMET group and one patient in the MET group had progression of heart disease. Outcomes for LT for patients with FAP with MET or NMET mutations were similar. Earlier LT for patients with FAP with MET30 or NMET30 mutation would improve outcomes after LT.

Adult↗