PubMed Health⌕ Search

Biomedical subjects

A Hossain

Publications and source records attributed to A Hossain.

At least 37 records · Page 2Linked to original sources
PubMed2000

Etiology of sexually transmitted infections among street-based female sex workers in Dhaka, Bangladesh.

An etiological study of sexually transmitted infections (STIs) was conducted among female sex workers (FSWs) in Dhaka, Bangladesh. Endocervical swab and blood samples from 269 street-based FSWs were examined for Neisseria gonorrhoeae, Chlamydia trachomatis, and Trichomonas vaginalis as well as for antibodies to Treponema pallidum and herpes simplex virus 2 (HSV-2). Sociodemographic data and data regarding behavior were also collected. A total of 226 of the 269 FSWs (84%) were positive for the STI pathogens studied. Among the 269 FSWs, 35.5% were positive for N. gonorrhoeae, 25% were positive for C. trachomatis, 45.5% were positive for T. vaginalis, 32.6% were seropositive for T. pallidum, 62.5% were seropositive for HSV-2, and 51% had infections with two or more pathogens.

Animals↗
PubMed2000

Nontropical pyomyositis: analysis of eight patients in an urban center.

Nontropical pyomyositis is rare and usually associated with immunodeficiency virus (HIV) infection. This study assessed manifestations and response to treatment of nontropical pyomyositis in an area with a high prevalence of HIV seropositivity. We undertook a chart review of eight consecutive patients treated for pyomyositis - primary infection of skeletal muscles - from 1988 through 1998. All patients complained of myalgia; four (50%) had fever and six (75%) had leukocytosis. Muscles involved were deltoid, quadriceps, gluteus, and psoas. Six (75%) patients had identifiable risk factors for pyomyositis: HIV seropositivity (two), history of intravenous drug abuse (one), chronic paraplegia and malnutrition (one), diabetes and chronic renal failure (one), and leukemia (one). One patient had had streptococcal pharyngitis previously but was otherwise healthy; another, a 2-year-old, had no evidence of underlying disease. Staphylococcus aureus was the most common organism isolated (50%). Four patients were treated with incision and drainage plus antibiotics; the remaining four patients were treated with intravenous antibiotics only; all recovered. Nontropical pyomyositis, which is often associated with HIV seropositivity or chronic illness, has a favorable outcome. Treatment can be effective even without surgical intervention.

Adult↗
PubMed2000

Serological response to immunization with tetanus toxoid.

A total of two hundred women were immunized with tetanus toxoid vaccine. Two batches of toxoid prepared at the Institute of Public Health (IPH), Dhaka and one batch of imported vaccines, were being used by the EPI in Bangladesh for immunization. Each hundred women were immunized by IPH and imported vaccine. Two human doses were given in one month interval. Blood samples from all the study subjects were collected on the day of 1st dose and one month after second dose. Both the preimmunized sera and the sera after vaccination were tested to determine the antibody titre against tetanus toxoid by the haemagglutination method. The preimmunized sera showed the presence of protective antibody in 50(25%) subjects who had the history of previous immunization. Including these initial antitoxin positive cases the seroconversions found among 95% and 96% of the study population respectively after immunization with IPH and imported toxoids, which were 93.05% and 94.87% when these 50 subjects were excluded. No significant difference (p = 1.0) was observed between the immunity of the subjects after receiving IPH and imported vaccine. Antibody titre of initial tetanus-antitoxin positive cases raised eight folds after getting more doses. The result gave fair indication of the antigenicity of all the toxoids used in the study.

Antigens, Bacterial↗
PubMed1999

Signal transduction-mediated CYP1A1 induction by omeprazole in human HepG2 cells.

Benzimidazole compounds, such as omeprazole and thiabendazole, are a different type of CYP1A1-inducer from Ah receptor-ligands, such as 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and 3-methylcholanthrene. In HepG2 cells, the commonly used tyrosine kinase-inhibitors, herbimycin-A and a series of tyrphostins, inhibited the induction of CYP1A1 produced by treatment with TCDD. Genistein, another type of tyrosine kinase inhibitor, inhibited the induction of CYP 1A1 whether it was produced by omeprazole or TCDD; however, this inhibition was caused by a dual effect of genistein, that is an anti-tyrosine kinase and an anti-topoisomerase I effect. An antagonist of Ah receptor, 3'-methoxy-4'-aminoflavone (1 microM), did not inhibit the induction of CYP1A1 produced in HepG2 cells by omeprazole or alpha-naphthoflavone (50 microM), but this antagonist did inhibit that produced by TCDD. Thus, omeprazole appears to induce CYP1A1 by initiating a protein tyrosine kinase-mediated signal transduction pathway, a different pathway from that initiated by TCDD.

Benzoflavones↗
PubMed1999

Venovenous modified ultrafiltration after cardiopulmonary bypass in children: a prospective randomized study.

BACKGROUND: Cardiopulmonary bypass is associated with the production of both proinflammatory and anti-inflammatory cytokines, the balance of which leads to varying degrees of postoperative systemic inflammation. Arteriovenous modified ultrafiltration effectively reduces total body water and improves postoperative hemodynamic and homeostatic functions. Venovenous modified ultrafiltration is a modification of this technique, which has the potentially added advantage of eliminating the obligatory left-to-right shunt associated with arteriovenous modified ultrafiltration. We tested the hypothesis that venovenous modified ultrafiltration is a safe and effective method of achieving ultrafiltration in children after cardiopulmonary bypass. METHODS: Thirty-eight pediatric patients were randomly assigned to undergo conventional, venovenous (n = 13), or no ultrafiltration venovenous (n = 13), and controls (n = 12). Perioperative, cardiopulmonary, and cytokine (tumor necrosis factor-alpha, interleukin-1beta, interleukin-6, interleukin-8, and interleukin-10) data were collected for statistical analysis. RESULTS: Compared with patients in the conventional ultrafiltration and control groups, patients undergoing venovenous modified ultrafiltration had the greatest volume of ultrafiltrate removed (46. 9 +/- 8.4 mL/kg vs 20.1 +/- 5.0 mL/kg and 0 mL/kg for conventional ultrafiltration and control groups, respectively; P =.0001), least increase in total body water (1.91% +/- 1.49% vs 3.90% +/- 1.86% and 8.24% +/- 3.41%; P =.05), greatest rise in hematocrit (39.7% +/- 1. 7% vs 33.8% +/- 2.1% and 29.6% +/- 2.3%; P =.006), and shortest length of hospital stay (4.41 +/- 0.28 days vs 6.69 +/- 1.47 days and 8.38 +/- 1.11 days; P =.03, P =.03). CONCLUSIONS: Venovenous modified ultrafiltration is a safe and effective method of reducing the increase in total body water and duration of postoperative convalescence after cardiopulmonary bypass.

Cardiopulmonary Bypass↗
PubMed1999

Reproducibility of sputum smear examination for acid-fast bacilli: practical problems met during cross-checking.

SETTING: A TB control programme in Bangladesh with proficiency testing of sputum smears for acid-fast bacilli (AFB) using cross-checking of routine smears. OBJECTIVE: To document factors that may adversely affect repeatability of the AFB smear, and which should be taken into account for interpretation of cross-checking. DESIGN: A number of simple experiments falling within the scope of small routine laboratories in a developing country. RESULTS: Fuchsin staining is not stable, fading quickly in direct sunlight and combinations of high temperature and humidity. Diffuse daylight, immersion oil or xylene did not have the same effect. Contamination of smears by saprophytic mycobacteria may occur during staining or rinsing, with contaminants becoming visible only after restaining and cross-checking. Finally, AFB may be dislodged from smears during soaking in xylene or restaining, especially if the smears are made from thin, liquefied sputum. CONCLUSIONS: These possible interfering factors should be taken into account when organizing proficiency testing and interpreting its results.

Bangladesh↗
PubMed1998

Induction of cytochrome P-450 1A1 by omeprazole in human HepG2 cells is protein tyrosine kinase-dependent and is not inhibited by alpha-naphthoflavone.

Benzimidazole compounds, such as omeprazole and thiabendazole, are a different type of CYP1A1 inducer from Ah receptor-ligands, such as TCDD (2,3,7,8-tetrachlorodibenzo-p-dioxin) and 3-methylcholanthrene. In HepG2 cells, the commonly used tyrosine kinase inhibitors, herbimycin-A and a series of tyrphostins, inhibited the induction of CYP1A1 produced by treatment with TCDD. Genistein, another type of tyrosine kinase inhibitor, inhibited the induction of CYP1A1 whether it was produced by omeprazole or TCDD; however, this inhibition was caused by a dual effect of genistein, that is an anti-tyrosine kinase and an anti-topoisomerase I effect. An antagonist of Ah receptor, alpha-naphthoflavone (0.1-10 microM), and 3'-methoxy-4'-aminoflavone (1 microM), did not inhibit the induction of CYP1A1 produced in HepG2 cells by omeprazole, but both of them did inhibit that produced by TCDD. In one of a number of human lung tumor cell lines, S6T, the inducibility of CYP1A1 was high by TCDD, whereas the inducibility by omeprazole was low. Thus, omeprazole appears to induce CYP1A1 by initiating a protein tyrosine kinase-mediated signal transduction pathway, a different pathway from that inhibited by TCDD.

Benzoflavones↗
PubMed1998

The Ah receptor is not involved in 2,3,7,8-tetrachlorodibenzo- p-dioxin-mediated apoptosis in human leukemic T cell lines.

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is a common environmental pollutant causing public concern. Its toxic effects include disruption of the immune, endocrine, and reproductive systems, impairment of fetal development, carcinogenicity, and lethality in rodents. Here, we report that TCDD induces apoptosis in two cultured human leukemic lymphoblastic T cell lines. This cell death was found not to be dependent on an aryl hydrocarbon receptor and to be inhibited by the inhibitor of tyrosine kinases and caspases. Apoptosis-linked c-Jun N-terminal kinase is rapidly activated in these cells by the treatment with TCDD. A dominant-negative mutant of c-Jun N-terminal kinase prevented cell death in the treatment with TCDD. Furthermore, TCDD decreases the Bcl-2 protein level in these cell lines. These findings will help in the understanding of the molecular mechanism underlying TCDD-mediated immunotoxicity.

Apoptosis↗
PubMed1998

A protein encoded by the latency-related gene of bovine herpesvirus 1 is expressed in trigeminal ganglionic neurons of latently infected cattle and interacts with cyclin-dependent kinase 2 during productive infection.

Despite productive viral gene expression in the peripheral nervous system during acute infection, the bovine herpesvirus 1 (BHV-1) infection cycle is blocked in sensory ganglionic neurons and consequently latency is established. The only abundant viral transcript expressed during latency is the latency-related (LR) RNA. LR gene products inhibit S-phase entry, and binding of the LR protein (LRP) to cyclin A was hypothesized to block cell cycle progression. This study demonstrates LRP is a nuclear protein which is expressed in neurons of latently infected cattle. Affinity chromatography indicated that LRP interacts with cyclin-dependent kinase 2 (cdk2)-cyclin complexes or cdc2-cyclin complexes in transfected human cells or infected bovine cells. After partial purification using three different columns (DEAE-Sepharose, Econo S, and heparin-agarose), LRP was primarily associated with cdk2-cyclin E complexes, an enzyme which is necessary for G1-to-S-phase cell cycle progression. During acute infection of trigeminal ganglia or following dexamethasone-induced reactivation, BHV-1 induces expression of cyclin A in neurons (L. M. Schang, A. Hossain, and C. Jones, J. Virol. 70:3807-3814, 1996). Expression of S-phase regulatory proteins (cyclin A, for example) leads to neuronal apoptosis. Consequently, we hypothesize that interactions between LRP and cell cycle regulatory proteins promote survival of postmitotic neurons during acute infection and/or reactivation.

Animals↗
PubMed1997

Analysis of cyclin-dependent kinase activity after herpes simplex virus type 2 infection.

Small DNA viruses (adenoviruses, simian virus 40, or human papillomaviruses) induce S-phase progression but prevent cell division to provide precursors for viral DNA replication. Herpes simplex viruses types 1 or 2 (HSV-1 or HSV-2) contain genes which encode DNA-metabolizing enzymes, for example, ribonucleotide reductase, thymidine kinase and dUTPase, suggesting that S-phase factors are not required for an efficient infection. However, several studies indicated that HSV induces some events that occur during cell-cycle progression. To determine if HSV-2 induces S-phase entry, we examined serum-arrested African green monkey kidney cells (CV-1) after infection. Two hours after infection steady-state levels of the S-phase-specific cyclin, cyclin A, increased. S-phase cyclin-dependent kinase activity (CDK2) was stimulated 10-fold 8 h after infection but decreased at 16 or 24 h after infection. Mitotic CDK activity (CDC2) was not activated after infection, in part due to decreases in CDC2 protein levels and inactivation of enzymatic activity resulting from tyrosine phosphorylation of CDC2. Furthermore, CDK4 activity was not dramatically affected by infection. These studies indicate that HSV-2 infection selectively activates CDK2 after infection but cell-cycle progression does not occur. We hypothesize that infection activates certain components of the cell cycle which enhance viral gene expression and DNA replication.

Animals↗
PubMed1997

Multiple drug-resistant Shigella dysenteriae type 1 in Rajbari district, Bangladesh.

Twenty-one Shigellae isolates were obtained from bloody faecal specimens of diarrhoeal patients at Rajbari District Hospital from January 1994 to June 1995, and serogrouped. Fourteen (67%) isolates belonged to the Shigella dysenteriae serogroup and 7 (33%) to Shigella flexneri serogroup. Shigella dysenteriae strains were further serotyped; all were Shigella dysenteriae 1. Each strain was tested for resistance to 6 common antimicrobial agents. The two strains had different antibiotic susceptibility patterns. The 7 S. flexneri showed 6 different resistant patterns and the 14 S. dysenteriae 1 isolates had 4 resistance patterns. One of the S. dysenteriae 1 isolates was resistant to all 6 antimicrobial agents; 10 to 5, and twice to a different combination of 4 antimicrobials. The 14 (100%) S. dysenteriae 1 strains were resistant to 3 major antimicrobial agents: ampicillin, tetracycline, and chloramphenicol; 13 (93%) were resistant to 5 agents: ampicillin, tetracycline, chloramphenicol, trimethoprim-sulphamethoxazole, and nalidixic acid. Ciprofloxacin was the only drug active against all 7 S. flexneri and 13 of the 14 (93%) S. dysenteriae 1 strains.

Adolescent↗
PubMed1996

Differences in inducibility of CYP1A1-mRNA by benzimidazole compounds between human and mouse cells: evidences of a human-specific signal transduction pathway for CYP1A1 induction.

Three benzimidazole compounds, omeprazole (OP), thiabendazole (TBZ), and lansoprazole (LP), were compared with respect to the induction of CYP1A1-mRNA in human hepatoma cells, HepG2. OP was the most potent inducer among the three compounds, but LP was found to be a weak inducer. Induction by TBZ was at an intermediate level. None of these compounds induced CYP1A1-mRNA in a mouse hepatoma cell line, Hepa-1. The transient expression of mouse Cyp1a1-CAT gene into HepG2 cells showed that OP treatment of the transfectants induced CAT activity to the same degree as 2,3,7,8-tetrachlorodibenzo-p-dioxin treatment. Therefore, the cellular factors in human cells were able to work on the mouse regulatory element. The expression of human aryl hydrocarbon (Ah) receptor in the mouse Hepa-1 mutant cell line cl-19, which is defective in Ah receptor, did not increase the induction level of CYP1A1-mRNA by OP treatment. When the cultured medium of HepG2 cells in the presence of OP was added to the mouse Hepa-1 cell culture medium, CYP1A1-mRNA was not induced in Hepa-1 cells. It is thus concluded that metabolites of OP in human cells are not the ligands for the human Ah receptor. Therefore, in human cells, but not mouse cells, there must be an OP-sensitive activation factor for the human Ah receptor.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed1996

Seroepidemiological study of Epstein-Barr virus infection in Bangladesh.

A seroepidemiological study was carried out on 502 sera to determine the prevalence of EBV infection in a group of Bangladeshi people (age range: 15 days-90 years). All sera were tested for IgG antibody to the EBV viral capsid antigen (VCA) by a commercially available enzyme linked immunosorbent assay (ELISA) and the negative sera were checked subsequently by indirect immunofluorescence (IF) methods. The prevalence of EBV infection in the study group was 81.27%. 42.37% of infants had antibodies to EBV by the age of 1 year. A significant rise in the percentage of seropositives between 0-1- and 1-2-year-old children was demonstrated, indicating a high rate of primary infection at these ages. The prevalence of IgG antibody to VCA was 87.93% in the 2-10 years age group and was sustained at over 85% thereafter. Higher ELISA values were more common both in the 0-2- and > 25-year age groups, the latter being statistically significant (P < 0.025). Similar higher values were also observed in females as compared to males (P = 0.05). Eighteen out of 109 negative sera and two equivocal sera by ELISA were found to be positive by indirect IF, indicating a negative predictive value of 82% for ELISA. The concordance between the two methods was 97% with ELISA proving to be less sensitive than indirect IF. It is concluded that the prevalence of EBV infection in Bangladeshi population is similar to that observed in other developing countries and that ELISA can be used for seroepidemiological surveys; however, the sera negative by ELISA should be checked routinely by indirect IF.

Adolescent↗
PubMed1996

The latency-related gene of bovine herpesvirus 1 encodes a product which inhibits cell cycle progression.

Bovine herpesvirus 1 (BHV-1) establishes a latent infection in the sensory ganglionic neurons of cattle. The exclusive viral RNA expressed in a latent infection is the latency-related (LR) RNA, suggesting that it regulates some aspect of a latent infection. During the course of a productive infection, alphaherpesviruses induce certain events which occur during cell cycle progression. Consequently, we hypothesized that a BHV-1 infection might induce events in neurons which occur during cell cycle progression. In agreement with this hypothesis, cyclin A was detected in neurons of trigeminal ganglia when rabbits were infected. Neuronal cell cycle progression or inappropriate expression of cyclin A leads to apoptosis, suggesting that a viral factor inhibits the deleterious effects of cyclin A expression. The BHV-1 LR gene inhibited cell cycle progression and proliferation of human osteosarcoma cells. Antibodies directed against cyclin A or the LR protein coprecipitated the LR protein or cyclin A, respectively, suggesting that the two proteins interact with each other. We conclude that LR gene products inhibit cell cycle progression and hypothesize that this activity enhances the survival of infected neurons.

Animals↗
PubMed1995

Assignment of a locus (GLC3A) for primary congenital glaucoma (Buphthalmos) to 2p21 and evidence for genetic heterogeneity.

Primary congenital glaucoma (GLC3) is an inherited eye disorder that accounts for 0.01-0.04% of total blindness. Although a large number of chromosomal abnormalities have already been reported in patients with congenital glaucoma, the precise location and pathogenesis of this condition remain elusive. By using a group of 17 GLC3 families and a combination of both candidate regional and general positional mapping strategies, we have mapped a locus for GLC3 to the short arm of chromosome 2. Eleven families showed no recombination with 3 tightly linked markers of D2S177 (Z = 9.40), D2S1346 (Z = 8.83), and D2S1348 (Z = 8.90) with a combined haplotype lod score of 11.50. Haplotype and multipoint linkage analyses of 14 DNA markers from 2p indicated that the disease gene is located in the 2p21 region and is flanked by DNA markers D2S1788/D2S1325 (theta = 0.03; Z = 5.42) and D2S1356 (theta = 0.05; Z = 4.69). Inspection of haplotype and heterogeneity analysis confirmed that 6 families are not linked to the 2p21 region, thus providing the first proof of genetic heterogeneity for this phenotype. We therefore designated the locus on 2p21 GLC3A and positioned it in the overall linkage map of Tel-D2S405-D2S367-(D2S1788/D2S1325)-[(GLC3A++ +, D2S177)/(D2S1346/D2S1348)]-D2S1356-D2S119- D2S1761-D2S1248-D2S1352-D2S406- D2S441-Cen. Of the seven genes mapping to the 2p21 region, CAD, CALM2, and LHCGR are centromeric to D2S119 and can be excluded as a candidate for GLC3A, but mutations in PRKR, TIK, SOS1, or SPTBN1 may still be accountable for this phenotype. As human 2p21 shows homology with mouse chromosomes 11 and 17, the homolog of GLC3A is expected to reside on one of these two chromosomes.

Animals↗