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Biomedical subjects

R Saxena

Publications and source records attributed to R Saxena.

At least 91 records · Page 5Linked to original sources
PubMed2000

Biliary cystadenocarcinoma with two types of tumour cells.

We report a rare case of biliary cystadenocarcinoma that occurred in the left hepatic lobe of a 62-year-old man and measured 20 cm in its greatest dimension. The neoplastic epithelium consisted of two types of cells: (1) cells with clear cytoplasm containing abundant mucin, and (2) cells with eosinophilic cytoplasm, which in some areas formed nodules with hepatocytoid features (polygonal cell shape, large nuclei with prominent nucleoli, and pseudoglandular structures). Histochemical stains revealed the presence of cytoplasmic mucin in the hepatocytoid areas, whereas immunohistochemical stains clearly showed a biliary phenotype (diffuse positive staining for "biliary type" cytokeratins, rare foci of positive staining with antibody to human hepatocytes (HEP-PAR1), absence of staining for alpha-fetoprotein, and no evidence of canalicular pattern of staining with polyclonal antibody to carcinoembryonic antigen). These findings indicate that areas reminiscent of hepatocellular carcinoma may occur in biliary cystadenocarcinomas. Histochemical and immunohistochemical stains are useful in reaching a definitive diagnosis in such cases.

Bile Duct Neoplasms↗
PubMed2000

Foreign body reaction to a metal clip causing a benign bile duct stricture 16 years after open cholecystectomy: report of a case.

We present herein a case where a benign bile duct stricture developed 16 years after an open cholecystectomy and without any prior symptoms. The patient was thought to have a Klatskin tumor both pre- and intraoperatively and was treated with a resection of the mass and bile duct confluence, while hepaticojejunostomies were also performed to both ducts separately. A pathologic examination of the specimen revealed extensive fibrosis, chronic inflammation, and a nonnecrotizing granulomata. Any hilar mass presenting after upper abdominal surgery should therefore be considered to be potentially a benign bile duct stricture, even with a long symptom-free interval.

Bile Duct Diseases↗
PubMed2000

HCV RNA levels in hepatocellular carcinomas and adjacent non-tumorous livers.

To determine the antiviral effects of drugs targeted to hepatitis C virus (HCV) in chronic hepatitis patients, an accurate quantitative method with high sensitivity is needed. Reverse transcription nested polymerase chain reaction (RT-PCR) is the most sensitive method for the detection of HCV sequences in clinical specimens. However, this method is not quantitative. For this purpose, a quantitative competitive assay was developed that combines RT and PCR followed by image analysis to quantify HCV RNA. This assay targets the highly conserved 5' non-coding region of HCV and is based on the co-amplification of wild type HCV RNA with known amounts of mutant synthetic RNA. The mutant internal control used in these experiments differs from the wild type RNA by two nucleotide substitutions, which introduces an internal restriction enzyme site. In this report, this method was used to determine the levels of positive strand RNA in 11 HCV positive hepatocellular carcinomas (HCC) and compared these with adjacent non-tumorous liver tissue. To confirm that the difference in viral titers is not related to variations in the amount of RNA used in the assay, glyceraldehyde 3-phosphate dehydrogenase (GAPDH) mRNA was also assessed by competitive RT-PCR in all tissue extracts. Using this competitive assay it was determined that HCV RNA levels in the liver and tumor samples ranged from 10(3) to 10(6) molecules per microg of total RNA which is similar to previous reports. Interestingly, the amount of HCV in all the non-tumorous liver specimens were found to be significantly higher (P<0.05) than the surrounding tumors, while the GAPDH mRNA levels were found to be similar in both liver and tumor. Competitive RT-PCR is a sensitive, accurate and reliable method to determine HCV titers in clinical specimens. Using this method it was determined that malignant tumor cells harbor less HCV as compared with the surrounding non-tumorous liver cells.

Carcinoma, Hepatocellular↗
PubMed2000

Recurrent type I membranoproliferative glomerulonephritis in a renal allograft: successful treatment with plasmapheresis.

Recurrent disease is increasingly recognized as a cause of renal allograft dysfunction and failure. We describe a patient with type I membranoproliferative glomerulonephritis not associated with hepatitis C. The glomerular disease recurred in the renal allograft within 1 month of transplantation, leading to acute allograft dysfunction and nephrotic syndrome. Aggressive treatment with prednisone and plasmapheresis resulted in improvement in kidney function, improvement of the light microscopic picture, and removal of immune complexes from the glomerular subendothelial space.

Adult↗
PubMed2000

Expression of p53 and PCNA in cholangiocarcinoma and primary sclerosing cholangitis.

The aim of this study was to identify the pattern and significance of expression of p53 and PCNA in cholangiocarcinoma and primary sclerosing cholangitis. Histological sections from 18 patients with cholangiocarcinoma (3 of the cases were associated with primary sclerosing cholangitis), 10 patients with primary sclerosing cholangitis without cholangiocarcinoma, and 7 patients with cirrhosis without cholangiocarcinoma or primary sclerosing cholangitis were stained immunohistochemically for p53 and PCNA. Samples from 17 patients with cholangiocarcinoma (94%) stained positively for p53. Among these 17 cases, nontumorous bile duct epithelium was positive in 7 (including 3 cases with primary sclerosing cholangitis and 2 with carcinoma in situ), and were positive proliferating bile ductules in 4 cases. The single p53-negative cholangiocarcinoma did not show p53 positivity in either the bile duct epithelium or the proliferating bile ductules. Bile ductal and ductular cells in all 10 patients with primary sclerosing cholangitis without cholangiocarcinoma and in the 7 controls were not reactive for p53. All 18 samples from patients with cholangiocarcinoma (100%) were positive for PCNA protein. Bile duct epithelium was positive for PCNA in nine cases (90%) of primary sclerosing cholangitis without cholangiocarcinoma and in six (85%) controls. Our study showed a high rate of p53 expression (94%) in cholangiocarcinoma. The adjacent uninvolved bile duct epithelium was also immunoreactive for p53 in 7 of 17 patients (41%). These findings suggest an early p53 mutation in bile ductal cells in cholangiocarcinogenesis. Expression of p53 may potentially be used to identify or screen, by bile duct brushings, cases of primary sclerosing cholangitis suspected of harboring cholangiocarcinoma. Expression of PCNA was a universal feature in cholangiocarcinoma.

Bile Duct Neoplasms↗
PubMed2000

Acquired haemophilia - a study of ten cases.

Clinico-haematological features in 10 patients with acquired Haemophilia are presented. Three patients had FVIII inhibitors following pregnancy while in six the cause for development of inhibitors could not be determined. One patient had acquired von Willebrand's disease. Lupus anticoagulant coexisted with Factor VIII inhibitors in three patients. All patients presented with sudden onset of bleeding without any past or family history of a bleeding disorder. Factor VIII inhibitor levels ranged from 8 to 512 Bethesda units in the nine patients. Immunosuppressive therapy was given to 8 patients, consisting of CVP regimen or corticosteroids with endoxan or cyclosporin. Seven patients had clinical and laboratory responses and one patient did not respond. One patient had severe postpartum bleeding with acute shock which was controlled with FEIBA. Diagnosis and management of idiopathic acquired Haemophilia, thus, continues to be a major challenge, and among acquired Haemophilia, postpartum Haemophilia has good prognosis.

Adrenal Cortex Hormones↗
PubMed2000

Classifying choledochal cysts using hepatobiliary scintigraphy.

PURPOSE: This retrospective study was designed to classify choledochal cysts on the basis of the findings of hepatobiliary scintigraphy. METHODS: Twenty-one patients with choledochal cysts (15 female, 6 male; mean age, 20 years) proved on the findings of endoscopic retrograde cholangiopancreatography (ERCP) or surgery and histopathologic analysis were included in the study. Two nuclear medicine physicians, blinded with regard to cholangiographic and operative details, were asked to review and to classify the type of choledochal cyst seen on the hepatobiliary scan. Later, scintigraphic results were compared with ERCP and surgical findings for a reference standard. RESULTS: The findings of hepatobiliary scintigraphy correlated with ERCP and surgical findings in 18 of 21 cases (86%). Scintiscans correctly identified all type 1 cysts (12/12). The sensitivity of scintigraphy in diagnosing type 4 cysts was 66% (6 of 9 cases). It underestimated the intrahepatic extent of disease in type 4a biliary cysts (37%). CONCLUSION: This study illustrates the utility of hepatobiliary scintigraphy in diagnosing type 1 and 4 choledochal cysts.

Adult↗
PubMed2000

Study of the first contact management profile of cases of infectious keratitis: a hospital-based study.

PURPOSE: To study the management pattern and examine the role of cultures and antibiotic sensitivity testing in infectious keratitis. METHODS: A retrospective analysis of the demographic, clinical, and microbiological data was performed in 100 consecutive patients with infectious keratitis. The main parameters evaluated were nature of first contact with the health care services, investigations undertaken, treatment initiated, and the time interval between presentation to the first medical contact and to our center. Finally, the reports of culture and antibiotic sensitivity testing undertaken at our center were evaluated. RESULTS: In 70% of cases, ophthalmologists in independent practice were the first medical contact. Direct microscopy of the corneal scraping was undertaken in only 6% of cases, whereas culture and sensitivity studies had not been performed in any of the patients. Forty-six percent of the patients were prescribed 0.3% ciprofloxacin eyedrops in an inadequate dosage. Broad-spectrum fortified antibiotics eye drops had not been prescribed in any of the cases. At our center, positive cultures were obtained in 73.86% of cases and the most common organism isolated was coagulase-negative Staphylococcus (33.84%), followed by Pseudomonas aeruginosa (15.38%). A large number of the isolates demonstrated resistance to the recommended antibiotic therapy. CONCLUSIONS: Failure to implement standard management protocol for infectious keratitis at first contact is a major factor contributing to ocular morbidity in India.

Adult↗
PubMed2000

Intraoperative enteroscopy for diagnosis of a bleeding jejunal lymphangioma.

A patient with recurrent gastrointestinal bleeding from a jejunal lymphangioma is described. Multiple preoperative diagnostic studies, including sonde enteroscopy, failed to reveal a bleeding source. A bleeding lymphangioma was subsequently detected by intraoperative enteroscopy of the small bowel. Intraoperative enteroscopy was a useful diagnostic technique in this patient with otherwise unexplained gastrointestinal bleeding.

Endoscopy, Gastrointestinal↗
PubMed2000

Optical mapping of BAC clones from the human Y chromosome DAZ locus.

The accurate mapping of clones derived from genomic regions containing complex arrangements of repeated elements presents special problems for DNA sequencers. Recent advances in the automation of optical mapping have enabled us to map a set of 16 BAC clones derived from the DAZ locus of the human Y chromosome long arm, a locus in which the entire DAZ gene as well as subsections within the gene copies have been duplicated. High-resolution optical mapping employing seven enzymes places these clones into two contigs representing four distinct copies of the DAZ gene and highlights a number of differences between individual copies of DAZ.

Chromosome Mapping↗
PubMed2000

Experimental investigation of the steady flow downstream of the St. Jude bileaflet heart valve: a comparison between laser Doppler velocimetry and particle image velocimetry techniques.

This study investigates turbulent flow, based on high Reynolds number, downstream of a prosthetic heart valve using both laser Doppler velocimetry (LDV) and particle image velocimetry (PIV). Until now, LDV has been the more commonly used tool in investigating the flow characteristics associated with mechanical heart valves. The LDV technique allows point by point velocity measurements and provides enough statistical information to quantify turbulent structure. The main drawback of this technique is the time consuming nature of the data acquisition process in order to assess an entire flow field area. Another technique now used in fluid dynamics studies is the PIV measurement technique. This technique allows spatial and temporal measurement of the entire flow field. Using this technique, the instantaneous and average velocity flow fields can be investigated for different positions. This paper presents a comparison of PIV two-dimensional measurements to LDV measurements, performed under steady flow conditions, for a measurement plane parallel to the leaflets of a St. Jude Medical (SJM) bileaflet valve. Comparisons of mean velocity obtained by the two techniques are in good agreement except for where there is instability in the flow. For second moment quantities the comparisons were less agreeable. This suggests that the PIV technique has sufficient temporal and spatial resolution to estimate mean velocity depending on the degree of instability in the flow and also provides sufficient images needed to duplicate mean flow but not for higher moment turbulence quantities such as maximum turbulent shear stress.

Biomedical Engineering↗
PubMed2000

A beta-thalassaemia allele with 3 base substitution in codons 4/5 & 6 (ACT CCT GAG-> ACA TCT TAG) detected by denaturing gradient gel electrophoresis & sequencing.

We report the analysis of a beta-thalassaemia gene involving three bases in codons 4/5 and 6 (ACT CCT GAG-> ACA TCT TAG) in a confirmed carrier whose child had beta-thalassaemia major. The fragment of the gene carrying the mutation was detected by denaturing gradient gel electrophoresis (DGGE) using GC clamped primers, followed by direct sequencing. DGGE analysis indicated that one gene was the wild type (normal) while the sequence changes observed were all in the other gene causing beta-thalassaemia major in the child. This confirms a single case report from Lucknow (UP) and adds to the beta-thalassaemia mutations identified in the beta-globin gene in India and will help in the thalassaemia control programme.

Adult↗
PubMed2000

Prothrombotic factors in nephrotic syndrome.

Nephrotic syndrome is a hypercoagulable state with variable prevalence of clinical thrombosis. The role of platelet aggregation, fibrinogen and antithrombin III and protein S levels in the pathogenesis of hypercoagulable state in these patients is controversial. Since no study on Indians is available, the clinical and laboratory profile of 22 patients of nephrotic syndrome (age 18-35 years with an MF ratio of 4:3), have been studied. The coagulation profile revealed a prolonged APTT in 12 patients (54.5%), and a prolonged TT in four (18.1%). In the rest APTT and TT were normal. PT was raised in two patients. Fibrinogen, an acute phase reactant was raised in five patients (22.7%). Antithrombin III levels were reduced in 19 patients (86.4%), normal in one and raised in two patients. Free Protein S levels were high in 12(54.5%), normal in seven and decreased in three patients. Platelet aggregation with adrenaline and adenosine diphosphate was raised in 6 patients. Ultrasonographically detected deep vein thrombosis was seen in one patient only (4.5%) who had ATIII levels of 48%. This low incidence can be explained by elevated protein S levels which was found to be raised in 12(54.5%) cases, protein S being an anticoagulant factor. This low level of clinical thrombosis in Indian patients of nephrotic syndrome may be an ethnic variable factor. It is thus concluded that although patients with nephrotic syndrome have a hypercoagulable state, clinical thrombosis is rarely seen in Indian patients with nephrotic syndrome.

Adolescent↗
PubMed1999

A novel polymorphism in the MCP-1 gene regulatory region that influences MCP-1 expression.

Two novel polymorphisms in the distal regulatory region of the MCP-1 gene were identified by directly sequencing PCR amplified genomic DNA. These polymorphisms are located at positions -2518 (G or A) and -2076 (A or T) relative to the major transcriptional start site of the gene. To examine the effect of these polymorphisms on MCP-1 transcription, polymorphic variants of the MCP-1 distal regulatory region were placed upstream of a luciferase reporter gene and transfected into A172 cells. IL-1beta-induced luciferase activity was significantly greater from cells transfected with constructs containing G at position -2518. The polymorphism at -2076 did not affect MCP-1 transcription. IL-1beta-treated peripheral blood mononuclear cells from individuals heterozygous or homozygous for G at -2518 produced more MCP-1 than cells from individuals homozygous for A at -2518. These data identify a polymorphism in the MCP-1 distal regulatory region that affects the level of MCP-1 expression in response to an inflammatory stimulus.

Alleles↗