Biomedical subjects

S Ghosh

Publications and source records attributed to S Ghosh.

At least 217 records · Page 12Linked to original sources

PubMed2001

Infliximab therapy for Crohn's disease in the presence of chronic hepatitis C infection.

Treatment of Crohn's disease with infliximab is an important drug therapy for patients with refractory and fistulating disease. There are concerns over its use in a proportion of Crohn's patients with concurrent hepatitis C infection, since there are theoretical risks of accelerated hepatic decompensation due to the immunomodulatory impact of infliximab. We report a patient with both Crohn's disease and ongoing active hepatitis C infection who underwent infliximab therapy, with no worsening of his liver function or PCR status.

Adult↗

PubMed2001

Gut luminal neutrophil migration is influenced by the anatomical site of Crohn's disease.

BACKGROUND: Clinical differences between small- and large-bowel Crohn's disease have been demonstrated. Neutrophil migration and degranulation are important effector mechanisms in gut damage. Granulocyte elastase, a neutrophil-bound enzyme, interleukin 8 and 1beta can be detected in whole-gut lavage fluid. We aimed to assess differences between large- and small-bowel Crohn's disease. METHODS: A total of 167 patients with active inflammatory bowel disease (118 Crohn's disease, 49 ulcerative colitis) underwent whole-gut lavage with a polyethylene glycol electrolyte solution. Granulocyte elastase was assayed using an enzyme substrate reaction, IL-8 and IL-1beta by ELISA. RESULTS: Twenty-seven of 36 patients with isolated colonic Crohn's disease had detectable granulocyte elastase (median 0.259 pKat/l, range < 0.039-2.742 microKat/l), whereas 3 of 15 with small-bowel involvement alone had detectable granulocyte elastase (median < 0.039 microKat/l, range < 0.039-0.266 microKat/l; P < 0.0001). Granulocyte elastase levels were significantly higher in patients with ileocolonic disease and post-ileocaecal resection compared with small-bowel disease alone. IL-8 (P< 0.0001) and IL-1beta (P < 0.04) levels differed between colonic and ileal distributions. No variations were seen in ulcerative colitis. CONCLUSIONS: Neutrophil migration to the gut lumen in Crohn's disease is a feature of colonic disease irrespective of associated ileal lesions. This suggests that bacterial-derived chemo-attractants may play a role. High levels of IL-8 in colonic disease are consistent with this hypothesis.

Adult↗

PubMed2001

Is neutropenia required for effective maintenance of remission during azathioprine therapy in inflammatory bowel disease?

BACKGROUND: Azathioprine is an effective treatment for maintaining remission in inflammatory bowel disease (IBD). It is a matter of debate as to whether neutropenia is required during azathioprine therapy to achieve more effective disease remission. We evaluated whether neutropenia during azathioprine therapy reduced relapse rates in IBD patients. PATIENTS AND METHODS: This retrospective study was based on a total of 173 IBD (96 Crohn's disease (CD), 77 ulcerative colitis (UC)) patients who were stable on azathioprine for a minimum of 6 months. Median duration of follow-up was 4.0 years (range 0.6-21 years). The lowest neutrophil counts during treatment for these patients were recorded. Relapse rates per year of follow-up were compared in non-neutropenic patients (neutrophil count > 2.5 x 10(9), n = 129) and neutropenic patients (neutrophil count < or = 2.5 x 10(9), n = 44) groups, and survival curves for cumulative remission rates compared by log-rank test. RESULTS: Mean relapse rate per year of follow-up for the non-neutropenic group was 0.19/year (SD = 0.37/year) compared with the neutropenic group 0.28/year (SD = 0.43/year) (P = NS). Analysis was performed on UC and CD subgroups, and relapse rates were not significantly different. The cumulative remission per cent determined by Kaplan-Meier survival analysis showed no difference between non-neutropenic and neutropenic groups by log-rank analysis, for UC and CD as well as for all IBD patients. CONCLUSION: Neutropenia < or = 2.5 x 10(9) while on azathioprine does not reduce the relapse rates of IBD patients who were established on azathioprine therapy compared with neutrophil counts > 2.5 x 10(9).

Adolescent↗

PubMed2001

Effective maintenance of inflammatory bowel disease remission by azathioprine does not require concurrent 5-aminosalicylate therapy.

OBJECTIVES: To assess the effect of 5-aminosalicylate treatment in conjunction with azathioprine on remission maintenance in inflammatory bowel disease patients. METHOD: This retrospective study was based on a total of 186 inflammatory bowel disease patients (104 with Crohn's disease; 82 with ulcerative colitis), who were stable on azathioprine for a minimum of 6 months. The median duration of follow-up was 4.3 years (range 0.6-15.5 years). Relapse rates per year of follow-up were compared in an azathioprine + 5-aminosalicylate group (n = 103) and an azathioprine alone group (n = 83); survival curves for cumulative remission rates were compared by log-rank test. Discontinuation of azathioprine in both groups was also recorded, as was the incidence of malignancy. RESULTS: In ulcerative colitis patients (n = 82), mean relapse rates for the azathioprine + 5-aminosalicylate group were 0.21/year compared with 0.19/year for the azathioprine alone group (P = not significant). In Crohn's disease patients (n = 104), mean relapse rates for the azathioprine + 5-aminosalicylate group were 0.27/year compared with 0.3/year for the azathioprine alone group (P = not significant). The cumulative remission percentage (determined from time to first relapse) was used in Kaplan-Meier survival analysis and showed no difference between the azathioprine + 5-aminosalicylate group and the azathioprine alone group by log-rank analysis, for ulcerative colitis and Crohn's disease as well as for all inflammatory bowel disease patients. Concurrent use of 5-aminosalicylates was no more frequent in patients who discontinued azathioprine due to adverse events. The only malignancy recorded was Waldenström's macroglobulinaemia after 7 years of azathioprine therapy. CONCLUSION: Concurrent use of 5-aminosalicylate drugs did not reduce the relapse rates of inflammatory bowel disease patients who were established on azathioprine therapy. The use of 5-aminosalicylate drugs did not lead to any increase in discontinuation of azathioprine due to adverse events.

Adolescent↗

PubMed2001

Cross-sectional and prospective studies of nutritional indices after percutaneous gastrostomy.

OBJECTIVE: Formal monitoring of nutritional status may be lacking in many patients after gastrostomy. We aimed to study nutritional assessment and its problems in patients after gastrostomy in a cross-sectional study, assess prospectively the changes in nutritional status of patients at 1 month and 6 months after gastrostomy placement, and determine the prognostic value of nutritional indices assessed at the time of gastrostomy placement. DESIGN: We used cross-sectional and prospective cohorts. The subjects were institutional and community patients receiving percutaneous gastrostomy in a teaching hospital. METHOD: We studied patients living in the community and in long-term care institutions after gastrostomy. In the cross-sectional study, we observed all individuals who received a percutaneous gastrostomy from the Gastrointestinal Unit, Western General Hospital, Edinburgh from January 1994 to December 1996. In the prospective study, we observed consecutive referrals of patients to the Gastrointestinal Unit for percutaneous gastrostomy from March 1997 to June 1998. Nutritional status was assessed using: weight (kg), height or stature estimated from knee-height (m), mid-upper arm circumference and triceps skinfold thickness. Body mass index, arm-muscle circumference and corrected arm-muscle area were calculated. A blood sample was taken to assess micronutrient status. RESULTS: In the cross-sectional study, 215 patients were identified who had received a percutaneous gastrostomy during the 3-year period 1994-1996. The weight and height measurements obtained in patients after gastrostomy were not as successful as upper-arm anthropometry. Of the 55 who were alive, traceable and agreed to take part in the study, 8% were under-nourished by corrected arm-muscle area at a median of 16 months after gastrostomy placement, whilst 57% had biochemical evidence of macro- or micronutrient deficiency. In the prospective study, 54 out of 87 patients referred for percutaneous gastrostomy agreed to participate. Using corrected arm-muscle area, 14% of patients were under-nourished at the time of gastrostomy placement. Changes in nutritional status at 1 month and 6 months post gastrostomy were mixed across the patient groups. Patients with a depleted corrected arm-muscle area 21.6 cm2 (log-rank test 9.05; P = 0.003, relative risk 4.7). All patients in whom corrected arm-muscle area had increased at the 1-month follow-up survived to 6 months post gastrostomy. CONCLUSIONS: Assessment of nutritional status may be difficult in gastrostomy-fed patients. Upper-arm anthropometry is more often successful than other assessment methods and gives prognostic information.

Adult↗

PubMed2001

Increasing incidence of both juvenile-onset Crohn's disease and ulcerative colitis in Scotland.

OBJECTIVE: A previous study reported a three-fold rise in the incidence of juvenile-onset Crohn's disease in Scottish children and a marginal fall in ulcerative colitis between 1968 and 1983. The present study aimed to document the incidence of juvenile-onset inflammatory bowel disease between 1981 and 1995 and examine temporal trends between 1968 and 1995 in Scotland. SETTING: Scotland (latitude 55-60 degrees N) has a total area of 77 837 km2 (30 405 square miles) and includes four urban centres each with a population of over 100,000. PARTICIPANTS: The Scottish hospital discharges linked database was used to identify 1002 patients less than 19 years old who were coded as having inflammatory bowel disease between 1981 and 1997. All case notes were reviewed and diagnoses verified. Incident cases were defined as those with symptom onset before or at 16 years of age between 1 January 1981 and 31 December 1995. RESULTS: During the 15 year period 1981-1995, 438 incident cases of Crohn's disease and 227 of ulcerative colitis were identified, giving standardized incidences of 2.5 cases and 1.3 cases per 100,000 population per year for Crohn's disease and ulcerative colitis respectively. On 31 December 1995 there were 150 children < or = 16 years of age with Crohn's disease and 101 with ulcerative colitis, giving crude prevalences of 13.7 cases per 100,000 population for Crohn's disease and 9.2 for ulcerative colitis. The continuing rise in Crohn's disease incidence between 1981 and 1995 fits that predicted by linear trend analysis of the 1968-1983 data. The incidence of Crohn's disease in the 12-16 age range almost doubled between 1981 and 1995 and was greater for males than females. Ulcerative colitis incidence was thought to show a slight fall in the 1968-1983 data, but this is reversed in the 1981-1995 data. CONCLUSION: The incidence of juvenile-onset Crohn's disease continues to rise in Scotland and the prevalence has increased by 30% since 1983. Unlike the previous report from Scotland, the incidence of juvenile-onset ulcerative colitis also is apparently rising. Whether this represents a real rise in incidence, or merely the inclusion of milder cases which were not previously hospitalized remains uncertain.

Adolescent↗

PubMed2001

Linkage disequilibrium between microsatellite markers extends beyond 1 cM on chromosome 20 in Finns.

Linkage disequilibrium (LD) is a proven tool for evaluating population structure and localizing genes for monogenic disorders. LD-based methods may also help localize genes for complex traits. We evaluated marker-marker LD using 43 microsatellite markers spanning chromosome 20 with an average density of 2.3 cM. We studied 837 individuals affected with type 2 diabetes and 386 mostly unaffected spouse controls. A test of homogeneity between the affected individuals and their spouses showed no difference, allowing the 1223 individuals to be analyzed together. Significant (P < 0.01) LD was observed using a likelihood ratio test in all (11/11) marker pairs within 1 cM, 78% (25/32) of pairs 1-3 cM apart, and 39% (7/18) of pairs 3-4 cM apart, but for only 12 of 842 pairs more than 4 cM apart. We used the human genome project working draft sequence to estimate kilobase (kb) intermarker distances, and observed highly significant LD (P < 10(-10)) for all six marker pairs up to 350 kb apart, although the correlation of LD with cM is slightly better than the correlation with megabases. These data suggest that microsatellites present at 1-cM density are sufficient to observe marker-marker LD in the Finnish population.

Alleles↗

PubMed2001

4-[3-Bromo-4-hydroxyphenyl)amino]-6,7-dimethoxyquinazolin-1-ium chloride methanol solvate and 4-[(3-hydroxyphenyl)amino]-6,7-dimethoxy-1-quinazolinium chloride.

The title compounds, C16H15BrN3(O3)(+).Cl(-).CH4O (WHI-P154) and C16H16N3(O3)(+).Cl(-) (WHI-P180), are potent inhibitors [WHI-P154 with IC50 = 5.6 microM and WHI-P180 with IC50 = 4.0 microM for epidermal growth factor receptor (EGFR) kinase inhibition] of the EGFR tyrosine kinase as well as Janus Kinase 3. The molecular structures of these compounds are very similar except for the dihedral angle between the anilino and quinazoline moieties which is 1.10 (5) degrees for WHI-P154, and 45.66 (6) and 25.29 (7) degrees for the two molecules of WHI-P180 in the asymmetric unit. The nitrogen at the N3 position is protonated in both structures and participates in hydrogen bonding with the chlorine anions.

Animals↗

PubMed2001

Vitamin B12 deficiency in untreated celiac disease.

OBJECTIVES: Iron and folate malabsorption are common in untreated celiac disease as the proximal small intestine is predominantly affected. Vitamin B12 deficiency is thought to be uncommon, as the terminal ileum is relatively spared. This study aims to investigate the prevalence of vitamin B12, deficiency in patients with untreated celiac disease. METHODS: Prospective study of 39 consecutive biopsy-proven celiac disease patients (32 women, seven men; median age 48 yr, range 22-77 yr) between September 1997 and February 1999. The full blood count, serum vitamin B12, red blood cell folate, and celiac autoantibodies (IgA antigliadin and IgA antiendomysium antibodies) were measured before and after a median of 4 months (range 2-13 months) of treatment with a gluten-free diet. In vitamin B12-deficient patients, intrinsic factor antibodies and a Schilling test, part 1, were performed. RESULTS: A total of 16 (41%) patients were vitamin B12 deficient (<220 ng/L) and 16 (41%) patients (11 women and live men) were anemic. Concomitant folate deficiency was present in only 5/16 (31%) of the vitamin B12 patients. The Schilling test, performed in 10 of the vitamin B12-deficient patients, showed five low and five normal results. Although only five patients received parenteral vitamin B12, at follow-up the vitamin B12 results had normalized in all patients. Acral paraesthesia at presentation in three vitamin B12-deficient patients resolved after vitamin B12 replacement. CONCLUSIONS: Vitamin B12 deficiency is common in untreated celiac disease, and concentrations should be measured routinely before hematinic replacement. Vitamin B12 concentrations normalize on a gluten-free diet alone, but symptomatic patients may require supplementation.

Adult↗

PubMed2001

How Giardia swim and divide.

To determine how binuclear giardia swim, we used video microscopy to observe trophozoites of Giardia intestinalis, which were labeled with an amino-specific Alexa Fluor dye that highlighted the flagella and adherence disc. Giardia swam forward by means of the synchronous beating of anterior, posterolateral, and ventral flagella in the plane of the ventral disc, while caudal flagella swam in a plane perpendicular to the disc. Giardia turned in the plane of the disc by means of a rudder-like motion of its tail, which was constant rather than beating. To determine how giardia divide, we used three-dimensional confocal microscopy, the same surface label, nuclear stains, and antitubulin antibodies. Giardia divided with mirror-image symmetry in the plane of the adherence disc, so that the right nucleus of the mother became the left nucleus of the daughter. Pairs of nuclei were tethered together by microtubules which surrounded nuclei and prevented mother or daughter giardia from receiving two copies of the same nucleus. New adherence discs formed upon a spiral backbone of microtubules, which had a clockwise rotation when viewed from the ventral surface. These dynamic observations of the parasite begin to reveal how giardia swim and divide.

Animals↗

PubMed2001

Attenuation of virulence and changes in morphology in Candida albicans by disruption of the N-acetylglucosamine catabolic pathway.

A Candida albicans mutant with mutations in the N-acetylglucosamine (GlcNAc) catabolic pathway gene cluster, including the GlcNAc-6-phosphate deacetylase (DAC1), glucosamine-6-phosphate deaminase (NAG1), and GlcNAc kinase (HXK1) genes, was not able to grow on amino sugars, exhibited highly attenuated virulence in a murine systemic candidiasis model, and was less adherent to human buccal epithelial cells in vitro. No germ tubes were formed by the mutant after induction with GlcNAc, but the mutant exhibited hyperfilamentation under stress-induced filamentation conditions. In addition, the GlcNAc catabolic pathway played a vital role in determining the colony phenotype. Our results imply that this pathway is very important because of its diverse links with pathways involved in virulence and morphogenesis of the organism.

Acetylglucosamine↗

PubMed2001

Immunomodulatory role of interleukin-10 in visceral leishmaniasis: defective activation of protein kinase C-mediated signal transduction events.

Leishmania donovani, an intracellular protozoan parasite, challenges host defense mechanisms by impairing the signal transduction of macrophages. In this study we investigated whether interleukin-10 (IL-10)-mediated alteration of signaling events in a murine model of visceral leishmaniasis is associated with macrophage deactivation. Primary in vitro cultures of macrophages infected with leishmanial parasites markedly elevated the endogenous release of IL-10. Treatment with either L. donovani or recombinant IL-10 (rIL-10) inhibited both the activity and expression of the Ca2+-dependent protein kinase C (PKC) isoform. However, preincubation with neutralizing anti-IL-10 monoclonal antibody (MAb) restored the PKC activity in the parasitized macrophage. Furthermore, we observed that coincubation of macrophages with rIL-10 and L. donovani increased the intracellular parasite burden, which was abrogated by anti-IL-10 MAb. Consistent with these observations, generation of superoxide (O2-) and nitric oxide and the release of murine tumor necrosis factor-alpha were attenuated in response to L. donovani or rIL-10 treatment. On the other hand, preincubation of the infected macrophages with neutralizing anti-IL-10 MAb significantly blocked the inhibition of nitric oxide and murine tumor necrosis factor-alpha release by the infected macrophages. These findings imply that infection with L. donovani induces endogenous secretion of murine IL-10, which in turn facilitates the intracellular survival of the protozoan and orchestrates several immunomodulatory roles via selective impairment of PKC-mediated signal transduction.

Adjuvants, Immunologic↗

PubMed2001

Intermediate subunit of the Gal/GalNAc lectin of Entamoeba histolytica is a member of a gene family containing multiple CXXC sequence motifs.

Killing by Entamoeba histolytica requires parasite adherence to host galactose- and N-acetyl-D-galactosamine (Gal/GalNAc)-containing cell surface receptors. A 260-kDa heterodimeric E. histolytica Gal/GalNAc lectin composed of heavy (Hgl) and light (Lgl) subunits has been previously described. Here we present the cloning and characterization of Igl, a 150-kDa intermediate subunit of the Gal/GalNAc lectin. Igl, Hgl, and Lgl colocalized on the surface membrane of trophozoites. Two unlinked copies of genes encoding Igl shared 81% amino acid sequence identity (GenBank accession no. AF337950 and AF337951). They encoded cysteine-rich proteins with amino- and carboxy-terminal hydrophobic signal sequences characteristic of glycosylphosphatidylinositol (GPI)-anchored membrane proteins. The igl genes lacked carbohydrate recognition domains but were members of a large family of amebic genes containing CXXC and CXC motifs. These data indicate that Igl is part of the parasite's multimolecular Gal/GalNAc adhesin required for host interaction.

Amino Acid Motifs↗

PubMed2001