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P K Garg

Publications and source records attributed to P K Garg.

At least 19 recordsLinked to original sources
PubMed2001

[7alpha-18F]fluoro-17alpha-methyl-5alpha-dihydrotestosterone: a ligand for androgen receptor-mediated imaging of prostate cancer.

We have synthesized a 18F-labeled androgen, [7alpha-18F]fluoro-17alpha-methyl-5alpha-dihydrotestosterone, in a no-carrier-added radiosynthesis by exchange of 18F- (tetrabutylammonium fluoride) with the 7beta-tosyloxy of 17alpha-methyl-5alpha-dihydrotestosterone. The nonradioactive steroid binds with high affinity and specificity to the androgen receptor and binds poorly, if at all, to other steroid receptors and plasma sex hormone binding globulin. The 7alpha-18F-androgen concentrates markedly in the prostate of rats by an androgen receptor-dependent mechanism. It is likely that [7alpha-18F]fluoro-17alpha-methyl-5alpha-dihydrotestosterone will be an excellent positron emission tomography imaging agent for prostate cancer.

Animals↗
PubMed2001

Auditory P300 event-related potentials and number connection test for evaluation of subclinical hepatic encephalopathy in patients with cirrhosis of the liver: a follow-up study.

BACKGROUND AND AIMS: The P300 event-related potentials (P3ERP) have been recently advocated for detection of cognitive disturbances in early encephalopathy. However, no systematic follow-up study has been conducted to understand the clinical significance of subclinical hepatic encephalopathy (SHE) detected by this or other methods. The present study was therefore undertaken to examine the diagnostic usefulness of auditory P3ERP in the detection of SHE, to compare it with that of the number connection test (NCT), and to investigate the clinical outcome of patients with SHE in terms of progression to overt encephalopathy. METHODS: P300 event-related potential latencies were measured and the NCT time was recorded in 81 non-encephalopathic cirrhotic patients (Aged 43.8 +/- 11 years, 23 alcoholic and 58 non-alcoholics) attending the outpatient department at our tertiary care hospital (All India Institute of Medical Sciences Hospital). Cut-off values for abnormality in the tests were developed from age-, sex- and education-matched controls. Patients were followed up at regular intervals for the development of overt encephalopathy, and the identifiable precipitating factors were noted. The P3ERP latencies (363 +/- 34 msec vs 349 +/- 23 msec), as well as NCT time (54.6 +/- 30.6 s vs 39.5 +/- 15.8 s) were significantly prolonged (P< 0.01) in patients with liver cirrhosis when compared with the non-cirrhotic controls. RESULTS: The P3ERP defects were seen in 24.6% of cirrhotic patients, while NCT time was prolonged in 19.7% of the patients. Nearly 43% of the patients with SHE progressed to overt encephalopathy within a mean duration of 5 months, while only 3.9% of the non-SHE patients did so. Of the patients who developed overt encephalopathy, 64.2% had P3ERP latency prolongations while 35.7% had abnormal NCT. CONCLUSIONS: The results of the present study suggest that P3ERP and NCT are valid tools for the screening of SHE in cirrhotic patients as there is a greater likelihood of overt encephalopathy development in patients with an abnormality detected by these tests than in patients with no such abnormality.

Adolescent↗
PubMed2001

Incidence, spectrum and antibiotic sensitivity pattern of bacterial infections among patients with acute pancreatitis.

BACKGROUND AND AIM: Secondary infection of pancreatic necrotic tissue and peripancreatic fluid is a serious complication of acute pancreatitis resulting in significant morbidity and mortality. The aim of this study was to find out the spectrum of bacterial infections, and their antibiotic sensitivity pattern in patients with acute pancreatitis. METHODS: All consecutive patients with acute pancreatitis were studied prospectively. Detailed investigations were carried out to identify bacterial infections and their antibiotic sensitivities in patients with suspected infection. These investigations included cultures of various body fluids, throat swabs, indwelling cannula and catheter tips. Pancreatic tissue was obtained by using needle aspiration or at surgery for Gram's stain, culture and sensitivity. All cultures were repeated until the presence of infection was confirmed or excluded. RESULTS: A total of 169 patients with acute pancreatitis were studied during the period between January 1997 and June 2000 (mean age 41.3 years; 116 males and 53 females). Of the 169 patients, 63 had infections at various sites. A total of 80 cultures were positive, and 12 different bacterial isolates were cultured from samples taken from these 63 patients. Polymicrobial infection was seen in 32% of patients. Twenty-four patients had a confirmed pancreatic infection. Blood cultures had a growth of organisms in 19 patients, with evidence of ongoing or worsening pancreatitis, thus raising a strong suspicion of infected necrosis in them. The commonest organisms were Escherichia coli from 20 cultures and Pseudomonas aeruginosa from 18 cultures. The antibiotic sensitivity pattern showed that most bacteria were sensitive to third generation cephalosporins and quinolones; notably among them were cefotaxime, ceftazidime, and ciprofloxacin. CONCLUSION: Bacterial infections were seen in 37% of patients with acute pancreatitis. The commonest organisms were Pseudomonas aeruginosa and Escherichia coli. Most bacterial isolates were sensitive to third generation cephalosporins and quinolones.

Adolescent↗
PubMed2001

Utility of P300 auditory event related potential in detecting cognitive dysfunction in patients with cirrhosis of the liver.

The P300 event related potential (P3ERP) latency has recently been advocated for detection of cognitive disturbances in early encephalopathy associated with chronic liver disease. The present study was undertaken to assess the magnitude of cognitive dysfunction, a marker of subclinical hepatic encephalopathy (SHE), in India, using this widely recommended test. One hundred and one patients with cirrhosis of the liver (17 females, 84 males; Age 43.3 +/- 11 years, 33 alcoholic, 49 viral induced, 19 cryptogenic) attending our tertiary care hospital were studied. P300 responses were elicited by the standard 'auditory odd ball paradigm'. A value of mean+2SD of the latency obtained in 40 age matched controls was established as a cut off to define latency prolongation in patients. The mean P3ERP latency of cirrhotics (363.6 +/- 32.1 msec) was significantly longer (p<0.05) than those of controls (347.8 +/- 24.8 msec). No difference was found in the latencies of cirrhotics with or without alcoholic aetiology of liver disease. 21 (20.8%) cirrhotics were found to have SHE i.e. latency prolongation beyond the cutoff value. A higher proportion of patients in advanced stage of liver disease had prolongation in latencies (p<0.02) compared to less severe cases. Till the time a gold standard is derived for detection of SHE, P3ERP latencies seem to be a reasonable method for detection as well as follow up of patients. Since SHE is considered as a preclinical stage of overt encephalopathy, it would be worthwhile screening cirrhotics for cognitive disturbances using P3ERP latencies and administering prompt therapeutic action.

Adult↗
PubMed2000

Equilibrium modeling of 5-HT(2A) receptors with [18F]deuteroaltanserin and PET: feasibility of a constant infusion paradigm.

[(18)F]Altanserin has emerged as a promising positron emission tomography (PET) ligand for serotonin-2A (5-HT(2A)) receptors. The deuterium substitution of both of the 2'-hydrogens of altanserin ([(18)F]deuteroaltanserin) yields a metabolically more stable radiotracer with higher ratios of parent tracer to radiometabolites and increased specific brain uptake than [(18)F]altanserin. The slower metabolism of the deuterated analog might preclude the possibility of achieving stable plasma and brain activities with a bolus plus constant infusion within a reasonable time frame for an (18)F-labeled tracer (T(1/2) 110 min). Thus, the purpose of this study was to test the feasibility in human subjects of a constant infusion paradigm for equilibrium modeling of [(18)F]deuteroaltanserin with PET. Seven healthy male subjects were injected with [(18)F]deuteroaltanserin as a bolus plus constant infusion lasting 10 h postinjection. PET acquisitions and venous blood sampling were performed throughout the infusion period. Linear regression analysis revealed that time-activity curves for both specific brain uptake and plasma [(18)F]deuteroaltanserin concentration stabilized after about 5 h. This permitted equilibrium modeling and estimation of V(')(3) (ratio of specific uptake to total plasma parent concentration) and the binding potential V(3) (ratio of specific uptake to free plasma parent concentration). Cortical/cerebellar ratios were increased by 26% relative to those we previously observed with [(18)F]altanserin using similar methodology in a somewhat older subject sample. These results demonstrate feasibility of equilibrium imaging with [(18)F]deuteroaltanserin and suggest that it may be superior to [(18)F]altanserin as a PET radioligand.

Adolescent↗
PubMed2000

Stimulation of gallbladder by intravenous infusion of amino acid: a new method to obtain duodenal bile for bile analyses.

Bile analysis is performed on duodenal bile obtained after stimulation of the gallbladder (GB) with cholecystokinin or its analog. Rapid amino acids (AA) infusion contracts the GB. Our objective was to assess qualitatively the adequacy of duodenal bile obtained following AA infusion. We prospectively studied 15 patients each with non ulcer dyspepsia (NUD) and gallstones (GS), and 17 patients with acute idiopathic pancreatitis (AIP). Duodenal bile was obtained after duodenal intubation and stimulation of GB by rapid AA infusion. The GB contractile response to AA infusion was assessed by functional ultrasonography. Bile was analyzed for lipids, nucleation time, cholesterol saturation index (CSI), and biliary crystals. Adequate duodenal bile could be collected in all but one patient with AIP and one with GS. The mean +/- SD percent ejection fraction of GB following AA infusion in patients with NUD, GS and AIP was 53.41 +/- 16.23, 52.06 +/- 16.07, and 43.37 +/- 14.16, respectively. Biliary microscopy showed the presence of cholesterol monohydrate crystals (CMC) in 7 of 16 patients with AIP, 12 of 14 patients with GS, and 1 of 15 patients with NUD. Mean CSIs in patients with NUD, GS, CMC-positive AIP, and CMC-negative AIP were 0.78, 1.97, 1.85, and 1.00, respectively. Nucleation time in patients with NUD and gallstones was 21.1 and 8.42 days. respectively. In conclusion, qualitatively adequate bile can be obtained for chemical and microscopic examination following rapid intravenous infusion of AA to stimulate the GB.

Acute Disease↗
PubMed2000

Typhoid carriers among patients with gallstones are at increased risk for carcinoma of the gallbladder.

OBJECTIVE: The aim of this study was to identify risk factors for carcinoma of the gallbladder (CaGB) among patients with gallstones (GS) with special reference to role of chronic Salmonella typhi carrier state. METHODS: A prospective case-control study was conducted in a tertiary care center in India. Cases were defined as consecutive patients with CaGB and GS, whereas controls were patients with GS alone. All were assessed clinically and their demographic data, diet, and smoking history recorded. Patients were detected to be typhoid carriers on the basis of Vi serology by enzyme linked immunosorbent assay. Cases (n = 37) and controls (n = 80) were compared by univariate and logistic regression analysis. RESULTS: The mean age of the cases and the controls were 53.4 +/- 11 yr and 43.5 +/- 14 yr, respectively. Among the cases, six (16%) patients were detected to be typhoid carriers, in contrast to two (2.5%) among controls (p = 0.01). Compared to controls, cases were more often older (p = 0.0002), of a lower socioeconomic status (p = 0.0005), and smokers (p = 0.0002). Stepwise logistic regression analysis identified typhoid carrier state (OR = 14; CI 2-92), age > or =47 yr (OR = 5; CI 2-14) and smoking (OR = 11; CI 2-71) as the three independent risk factors for development of CaGB among patients with GS. CONCLUSION: Chronic typhoid carrier state was the most important risk factor among patients with CaGB and gallstones.

Adult↗
PubMed2000

PET quantification of 5-HT2A receptors in the human brain: a constant infusion paradigm with [18F]altanserin.

UNLABELLED: [18F]altanserin has been used to label serotonin 5-HT2A receptors, which are believed to be important in the pathophysiology of schizophrenia and depression. The purpose of this study was to test the feasibility of a constant infusion paradigm for equilibrium modeling of [18F]altanserin with PET. Kinetic modeling with [18F]altanserin may be hampered by the presence of lipophilic radiometabolites observed in plasma after intravenous administration. METHODS: Eight healthy volunteers were injected with [18F]altanserin as a bolus (208+/-9 MBq [5.62+/-0.25 mCi]) plus constant infusion (65+/-3 MBq/h [1.76+/-0.08 mCi/h]) ranging from 555 to 626 min (615+/-24 min) after injection. PET acquisitions (10-20 min) and venous blood sampling were performed every 30-60 min throughout the infusion period. RESULTS: Linear regression analysis revealed that time-activity curves for both brain activity and plasma [18F]altanserin and metabolite concentrations stabilized after about 6 h. This permitted equilibrium modeling and estimation of V3' (ratio of specific uptake [cortical-cerebellar] to total plasma parent concentration after 6 h). Values of V3' ranged from 1.57+/-0.38 for anterior cingulate cortex to 1.02+/-0.39 for frontal cortex. The binding potential V3 (ratio of specific uptake to free plasma parent concentration after 6 h, using group mean f1) was also calculated and ranged from 169+/-41 for anterior cingulate cortex to 110+/-42 for frontal cortex. From 6 h onward, the rate of change for V3' and V3 was only 1.11+/-1.69 %/h. CONCLUSION: These results demonstrate the feasibility of equilibrium imaging with [18F]altanserin over more than 5 radioactive half-lives and suggest a method to overcome difficulties associated with lipophilic radiolabeled metabolites. The stability in V3 and V3' once equilibrium is achieved suggests that a single PET acquisition obtained at 6 h may provide a reasonable measure of 5-HT2A receptor density.

Adult↗
PubMed1999

A complete remote-control system for reliable preparation of [18F]altanserin.

A complete remote control system was constructed for production of the PET 5-HT2A ligand [18F]altanserin by nitro-for-fluoro exchange. Comparing with published methods, the key features include (1) conducting azeotropic distillation and nucleophilic displacement in an open vessel heated by a commercial microwave oven; (2) purifying the product by a single HPLC procedure and (3) removing HPLC solvent by solid phase extraction. The preparation took 114 min with 23% yield and high quality.

Calibration↗
PubMed1999

Role of anti-Helicobacter pylori treatment in H. pylori-positive and cytoprotective drugs in H. pylori-negative, non-ulcer dyspepsia: results of a randomized, double-blind, controlled trial in Asian Indians.

BACKGROUND: The efficacy of anti-Helicobacter pylori treatment and cytoprotective drugs in H. pylori-positive and -negative non-ulcer dyspepsia (NUD), respectively, is debatable. METHODS: In a randomized study, the efficacy of anti-H. pylori treatment versus sucralphate was tested in patients with NUD. One hundred and twelve patients with NUD, 62 positive and 50 negative for H. pylori were studied. Of 62 patients positive for H. pylori, 32 were treated with triple therapy (colloidal bismuth subcitrate, tetracycline and metronidazole) for 2 weeks and the remaining 30 were treated with sucralphate (1 g, q.i.d.) for 4 weeks. Of 50 patients negative for H. pylori, 25 each were treated with either sucralphate (1 g, q.i.d.) or ranitidine (150 mg, b.d.) for 4 weeks. RESULTS: In patients with NUD and H. pylori infection, triple therapy eradicated H. pylori in 88% and was superior to sucralphate in producing symptom relief (81 vs 33%, P = 0.0003) and histological improvement in gastritis (73 vs 30%, P = 0.003). In the H. pylori-negative group, sucralphate was superior to ranitidine with regard to symptom relief (68 vs 36%, P = 0.04) and improvement in gastritis (44 vs 12%, P = 0.09). The symptomatic improvement persisted until 12 weeks after the start of treatment in triple therapy group only. CONCLUSIONS: In patients with NUD associated with H. pylori, triple therapy was better than sucralphate in terms of symptomatic and histological improvement. However, sucralphate was superior to ranitidine in providing symptom relief in patients with H. pylori-negative NUD.

Adult↗
PubMed1999

Comparison of endoscopic variceal sclerotherapy with sequential endoscopic band ligation plus low-dose sclerotherapy for secondary prophylaxis of variceal hemorrhage: a prospective randomized study.

BACKGROUND: Endoscopic variceal sclerotherapy and band ligation both have certain limitations such as, respectively, esophageal complications and early recurrence of varices. METHODS: From February 1994 to March 1996, all consecutive patients with portal hypertension due to either cirrhosis or noncirrhotic portal fibrosis and a history of variceal bleeding were included in a prospective study and randomly assigned to receive either endoscopic variceal sclerotherapy alone or endoscopic variceal band ligation plus low-dose endoscopic variceal sclerotherapy. RESULTS: Of 69 patients, 34 were randomly assigned to receive endoscopic variceal sclerotherapy alone; 35 received endoscopic variceal band ligation plus endoscopic variceal sclerotherapy. Complete variceal eradication rates (85% vs. 80%) and the number of endoscopic sessions required for eradication (6.61 +/- 2.94 vs. 7.85 +/- 3.31) were similar in the endoscopic variceal sclerotherapy and endoscopic variceal band ligation plus endoscopic variceal sclerotherapy groups, respectively. The mean volume of sclerosant required in the combined group (54.94 +/- 33.74 mL) was significantly less than that in the endoscopic variceal sclerotherapy group (81.91 +/- 34.80 mL). The complication and recurrent bleeding rates were significantly higher in the endoscopic variceal sclerotherapy group than those in the combined group (20% and 16% vs. 3% and 3%, respectively). CONCLUSIONS: Both endoscopic variceal sclerotherapy and endoscopic variceal band ligation plus endoscopic variceal sclerotherapy were comparable in eradicating varices but the combined technique was associated with significantly lower complication and recurrent bleeding rates.

Adult↗
PubMed1998

A prospective study on the incidence of hepatitis B & C infections amongst patients with lymphoproliferative disorders.

Fifty one patients with acute lymphoblastic leukaemia (ALL) and non-Hodgkins lymphoma (NHL) undergoing chemotherapy were studied prospectively to determine the incidence, aetiology and natural course of hepatitis. Of 51 patients (31 NHL and 20 ALL), 22 developed hepatitis. Hepatitis B (IgM anti HBc positive) was the cause in 11 patients (50%), hepatitis C in 4 patients, and septicaemia and cytotoxic drugs in 3 patients each. Malignant infiltration of the liver was the cause in the remaining 1 patient. Hepatitis was predominantly (75%) anicteric. Mean duration of hepatitis was 21 days. Of 51 patients, 21 acquired hepatitis B and/or C virus infection. They had received 6.4 (+/- 3.4) units of packed red cells and 5.3 (+/- 11) units of platelet concentrate as compared to 3.4 (+/- 4.8) units of red cells and 5.3 (+/- 12.1) units of platelet concentrate received by those who did not acquire virus infection (P < 0.05 for packed red cells). Only transient stoppage of chemotherapy was necessary following development of hepatitis and most of the patients who developed hepatitis could complete their chemotherapy schedule. None of the patients who developed viral B or C infection cleared the infection. We conclude that there was a high incidence of hepatitis B and C infection amongst patients with lymphoproliferative disorders with an increased carrier rate. Transfusion was a major risk factor for such infections.

Acute Disease↗
PubMed1997

Increased incidence of biliary sludge and normal gall bladder contractility in patients with high spinal cord injury.

BACKGROUND: Patients with spinal cord injury (SCI) have an increased prevalence of gallstones. AIMS: To study prospectively the incidence of gallstones and gall bladder contractility in patients with SCI. PATIENTS AND METHODS: Thirty six consecutive patients with SCI were studied: 18 patients with SCI above thoracic 10 neuronal segment (> T10) and 18 patients with SCI below T10 (< T10). An equal number each of disease controls (multiple fractures) and healthy controls were also studied. All patients and controls underwent serial ultrasonography to detect development of gallstones and ultrasonographic measurement of gall bladder contractility. RESULTS: A significantly higher number (9/18) of patients with SCI > T10 developed biliary sludge compared with patients with SCI < T10 (2/18), disease controls (2/18), and healthy controls (1/18) (p < 0.05). No patient developed gallstones. The gall bladder fasting volume was significantly decreased in patients with SCI > T10 (20.56 ml; 95% confidence intervals (CI) 19.74 to 21.38) compared with that in patients with SCI < T10 (27.33 ml, 95% CI 26.17 to 28.49; p < 0.05), disease controls (27.92 ml, 95% CI 26.69 to 29.15; p < 0.05), and healthy controls (28.35 ml, 95% CI 27.25 to 29.45; p < 0.05). Gall bladder contractility was normal in patients with SCI as shown by normal gall bladder residual volume and emptying time. CONCLUSIONS: Patients with SCI above T10 have an increased incidence of biliary sludge and a decreased gall bladder fasting volume. Gall bladder contractility is, however, normal.

Adult↗
PubMed1997

Primary epithelioid haemangioendothelioma of the liver: case report and review of the literature.

A 31 year old female patient presented with a one and a half year history of pain in the upper abdomen. The pain was mild, constant, dull aching, and increased with change in posture or sudden movements. There was no definite relation to meals. She also had a lump in the right upper quadrant, which had been gradually increasing in size over three months. She had mild anorexia and reported a 5 kg weight loss over one year. She had no history of intake of oral contraceptive drugs, exposure to vinyl chloride, thorotrast or any other industrial toxin. Ultrasonography of the abdomen revealed multiple space occupying lesions of altered echotexture in both lobes of the liver. The portal venous system and hepatic vascular system were normal. Computed tomography of the abdomen confirmed the ultrasound findings. Histopathology was diagnostic for primary epithelioid haemangioendothelioma; the first such case reported from India. The patient has been put on a waiting list for a liver transplant.

Adult↗