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Biomedical subjects

M S Hossain

Publications and source records attributed to M S Hossain.

At least 19 recordsLinked to original sources
PubMed2003

Identification of white spot syndrome virus latency-related genes in specific-pathogen-free shrimps by use of a microarray.

To investigate whether specific-pathogen-free (SPF) shrimps are asymptomatic carriers of white spot syndrome virus (WSSV), we used a WSSV-specific DNA microarray to measure WSSV gene expression in SPF and WSSV-infected shrimps. Three WSSV genes were found to be relatively highly expressed in SPF shrimps. Reverse transcription-PCR using nested primers as well as real-time detection confirmed that these genes have no detectable counterparts in GenBank; structural analysis of the putative proteins revealed helix-loop-helix and leucine zipper motifs. Viral sequences could be PCR amplified from genomic DNA of SPF shrimp, further supporting the suggestion that these shrimps are asymptomatic carriers.

Animals↗
PubMed2003

A retrospective study on genito urinary Rhabdomyosarcoma.

A retrospective study was carried out on Genitourinary Rhabdomyosarcoma in the Department of Paediatric Surgery of Bangabandhu Sheikh Mujib Medical University, Dhaka, Bangladesh during the period January 1990 to December 1999. Total thirteen patients were treated during this period, age ranging from 1 month to 12 years. Eight patients were male and five were female (M: F = 1.6: 1). Diagnosis was made by history, thorough physical examination, digital rectal examination, ultrasonography, intravenous urography, CT scan and biopsy. All the patients were treated with chemoradiation theraphy as a first line of management and surgical excision was done for local residual tumours. Eight children (61.5%) were asymptomatic after completion of chemo-radiation therapy. Three (23.07%) patients discontinued the chemo-radiation schedule. Residual mass was present in one (7.7%) case for which partial cystectomy was done and the patient died in the 5th post operative day. Another patient (7.7%) who had pulmonary metastasis at the time of diagnosis, died during chemo-radiation therapy.

Child↗
PubMed2002

Risk factors & clinical presentations--a study of eighty-five hospital admitted stroke cases.

Stroke is the commonest neurological cause of morbidity and mortality. Changes in risk factors may influence stroke incidence. Definitive diagnosis of the type of stroke is necessary for management and it has a strong impact on stroke outcome. A total of eighty-five consecutive stroke patients irrespective of age and sex admitted during the period of August 2000 to June 2001 were studied. They were asked about occupation, area of habitat, smoking habit, family history of ischaemic heart disease and/or stroke, any febrile illness, recent history of productive cough, dysuria and diarrhoea. They were searched for hypertension, diabetes mellitus, ischaemic heart disease, valvular heart disease and dislipidaemia. In every patient complete blood count, urine examination, fasting blood glucose and serum lipids, ECG, x-ray chest were performed. CT scan of brain was performed in 68 cases. Male was found 81.18% of cases with age 62.54 +/- 13.08 (m +/- SD) years. Female were 18.82% of cases with age 58.81 +/- 12.77 (m +/- SD). 75.29% of patients were belongs to middle class family. 51.76% of patients came from rural area and 48.24% of patients came from urban area. 78.82% of patients were hypertensive. Infection was associated with 37.65% of cases. Hemiplegia was commonest presentation (88.24%). Though altered consciousness was found more in haemorrhagic stroke (54.84%) but it was not significantly. High from ischaemic cases (p > 0.10) Male suffer more from stroke. Hypertension is the commonest risk factor. Infection is a common association of stroke. Altered consciousness is not a reliable guide to differentiate between ischaemic and haemorrhagic stroke is hospitalized cases.

Aged↗
PubMed2001

Effects of docosahexaenoic acid on annular lipid fluidity of the rat bile canalicular plasma membrane.

The role of docosahexaenoic acid (DHA) in the fluidity of the annular lipid regions and their associated membrane-bound proteins is still not as well understood as that in the global (bulk) lipid regions. We therefore studied the effects of dietary DHA on the relationship between annular and global lipid fluidity and membrane-bound enzymes such as 5'-nucleotidase and Mg(2)+-ATPase in the rat bile canalicular membrane. Dietary DHA caused significant increases in 5'-nucleotidase and Mg(2)+-ATPase activity and in global and annular lipid fluidity, a higher increase in fluidity in the annular lipids than the global lipids, and a decrease in the cholesterol-to-phospholipid molar ratio in the canalicular membrane. Plasma total cholesterol and LDL cholesterol decreased, and fecal cholesterol increased in the DHA-fed rats. No changes were observed in oxidative markers, but glutathione peroxidase increased in the liver with DHA feeding. Annular lipid fluidity, but not global lipid fluidity, correlated remarkably well with DHA, synchronously with the activities of 5'-nucleotidase and Mg(2)+-ATPase. The data indicate that the DHA-induced increase in annular lipid fluidity is responsible for the increases observed in the enzyme activity. We therefore concluded that the increased activity of membrane-bound enzymes and transporters induced by DHA and the concomitant increase in annular lipid fluidity comprise one of the mechanisms involved in DHA-induced clearance of plasma cholesterol.

5'-Nucleotidase↗
PubMed2000

In vivo acute depletion of CD8(+) T cells before murine cytomegalovirus infection upregulated innate antiviral activity of natural killer cells.

In this study, we investigated the effect of depletion of CD8(+) T cells on the activity of natural killer (NK) cells at an early phase of murine cytomegalovirus (MCMV) infection. For CD8(+) T cell depletion, mice were intraperitoneally treated with anti-CD8 mAb, purified from 2.43 hybridoma, for 2 consecutive days before or after infection. Three days after infection, we found that an acute depletion of CD8(+) T cells before infection caused a significant decrease in the viral load in liver and spleen. This effect coincided with an increase in numbers of CD3(-) NK1.1(+) cells in spleen and their expression of the early activation molecule CD69. Although cytolytic activity of NK cells increased on day 3 of infection in CD8-depleted mice, the level of IFN-gamma decreased in serum and supernatant of cultured spleen cells. In contrast to the effect of acute depletion of CD8(+) T cells before infection, the depletion after infection had no effect on the viral load or number and cytolytic function of NK cells. Lack of effects of CD8(+) T cell depletion on the viral load and NK cytolytic activity is also observed in CD8(+) knockout mice. In conclusion, the results suggest that an acute depletion of CD8(+) T cells before MCMV infection effectively upregulated the antiviral activity of NK cells. This effect appears to be mediated through an increase in numbers, activation and cytolytic activity of NK cells.

Animals↗
PubMed2000

Protective effect of black seed oil from Nigella sativa against murine cytomegalovirus infection.

In this study, antiviral effect of black seed oil (BSO) from Nigella sativa was investigated using murine cytomegalovirus (MCMV) as a model. The viral load and innate immunity mediated by NK cells and Mφ during early stage of the infection were analyzed. Intraperitoneal (i.p.) administration of BSO to BALB/c mice, a susceptible strain of MCMV infection, strikingly inhibited the virus titers in spleen and liver on day 3 of infection with 1x10(5) PFU MCMV. This effect coincided with an increase in serum level of IFN-gamma. Although BSO treatment decreased both number and cytolytic function of NK cells on day 3 of infection, it increased numbers of Mφ and CD4(+) T cells. On day 10 of infection, the virus titer was undetectable in spleen and liver of BSO-treated mice, while it was detectable in control mice. Although spleen of both control and BSO-treated mice showed similar CTL activities on day 10 after infection, serum level of IFN-gamma in BSO-treated mice was higher. Furthermore, BSO treatment upregulated suppressor function of Mφ in spleen. These results show that BSO exhibited a striking antiviral effect against MCMV infection which may be mediated by increasing of Mφ number and function, and IFN-gamma production.

Animals↗
PubMed2000

Characterization of CD4- CD8- CD3+ T-cell receptor-alphabeta+ T cells in murine cytomegalovirus infection.

In this study, we have investigated that after the intraperitoneal infection with murine cytomegalovirus (MCMV), the CD3+ CD4- CD8-(double negative; DN) T-cell receptor (TCR)alphabeta+ T cells increased in peritoneal cavity, liver and spleen in both resistant C57BL/6 and susceptible BALB/c mice. The total cellular population of these cells showed peak levels around day 5 after infection in all the three investigated organs and the following phenotypical and functional characteristics emerged. The peritoneal DN TCRalphabeta+ T cells expressed highly skewed TCRVbeta8 on day 5 after infection compared with the uninfected mice, but those in spleen and liver showed moderate and low skewed TCRVbeta8, respectively. The percentages of NK1.1+ DN TCRalphabeta+ T cells gradually decreased as did modulation of some of their activation markers consistent with an activated cell phenotype. The peritoneal DN TCRalphabeta+ T cells on day 5 after infection expressed the genes of interferon-gamma (IFN-gamma), tumour necrosis factor-alpha, Eta-1 (early T-cell activation-1) and MCP-1 (monocyte chemoattractant protein 1) but lacked expression of interleukin-4 (IL-4). After in vitro stimulation with phorbol 12-myristate 13-acetate and calcium ionophore in the presence of Brefeldin A, higher frequencies of intracellular IFN-gamma+ DN TCRalphabeta+ T cells were detected in all three investigated organs of infected mice compared with those of uninfected mice. Stimulation of peritoneal DN TCRalphabeta+ T cells with plate-bound anti-TCRbeta monoclonal antibodies showed proliferation and also produced IFN-gamma but not IL-4. These results suggest that DN TCRalphabeta+ T cells were activated and may have an antiviral effect through producing IFN-gamma and some macrophage-activating factors during an early phase of MCMV infection.

Animals↗
PubMed2000

Mediation of the immunomodulatory effect of beta-estradiol on inflammatory responses by inhibition of recruitment and activation of inflammatory cells and their gene expression of TNF-alpha and IFN-gamma.

BACKGROUND: Estrogen has long been reported to show immunomodulatory effects on immune responses, yet, its specific anti-inflammatory mechanism is not clear. METHODS: In this study, we analyzed the effects of beta-estradiol (E2), at its contraceptive dose, on both T cell-independent and T cell-dependent inflammations, and the associated immune mechanism, in female mice. The T cell-independent inflammation was locally induced either with an intradermal injection of olive oil in the footpad, or by an intraperitoneal injection of proteose peptone (PP). The T cell-dependent inflammation was induced by an intraperitoneal injection of the purified protein derivatives (PPD). RESULTS: While E2 inhibited olive oil-induced inflammation as monitored by the decrease in footpad swelling, it did not affect the gene expression of monocyte chemoattractant protein-1 and IL-6 by cells at the inflammatory locus. E2 also inhibited PP-induced inflammation as monitored by the decrease in the number of inflammatory peritoneal exudate cells (PEC) coinciding with a marked decrease in the number of macrophages and granulocytes (Gr. 1+). While E2 did not affect the gene expression of monocyte chemoattractant protein-1 and IL-6 by PP-elicited PEC, it decreased both gene expression and production of TNF-alpha. E2 also decreased the number of cells expressing the lymphocyte function-activated protein-1 in PP-elicited PEC, but not for CD62L. In purified protein derivative-induced T cell-dependent inflammation, E2 decreased the total cellularity of PEC and the relative numbers of CD3+ and CD4+ T cells, and the number of cells expressing the lymphocyte activation markers CD40, CD44, CD69 and IL-2Ralpha in PEC. Furthermore, while E2 did not affect the gene expression of the early T lymphocyte activation protein-1 by PEC, it decreased the gene expression of INF-gamma. CONCLUSION: Collectively, the results suggest that E2-mediated inhibition of inflammatory responses may be due to a combination of suppression of homing and activation of inflammatory cells and their production of TNF-alpha and IFN-gamma.

Adjuvants, Immunologic↗
PubMed2000

Vibrio cholerae O139 Bengal: a descriptive study.

A prospective study was conducted to determine the clinical and laboratory characteristics and the clinical course of cholera due to Vibrio cholerae O139 Bengal. The study subjects included 22 adult males with stool culture-proven V. cholerae O139. On enrollment, mean +/- SD concentrations (mmol/L) of serum sodium, potassium, chloride, and bicarbonate were 134 +/- 3, 4 +/- 1, 102 +/- 4, and 13 +/- 4 respectively, and stool sodium, potassium, chloride, and bicarbonate concentrations were 120 +/- 24, 18 +/- 6, 93 +/- 16, and 37 +/- 9 respectively. Seventeen patients (7.8%) had faecal leukocytes ranging from 11 to 50 per high-power field. All V. cholerae O139 isolates (100%) were susceptible to tetracycline, erythromycin, and ciprofloxacin, 92% to furazolidine, and only 5% to trimethoprim-sulphamethaxazole. The median (interquartile) volume of liquid stool during the first 24 hours was 9 (5-12) litre. The median (interquartile) volume of liquid stool and the amounts of intravenous and oral rehydration fluids required during the entire study period were 16 (9-24) litre, 9 (6-18) litre, and 14 (9-20) litre respectively. The median (interquartile) duration of diarrhoea was 80 (48-104) hours. The median (interquartile) duration of excretion of V. cholerae O139 in stool was 5 (3-6) days. Clinical and laboratory features, and case management of cholera due to V. cholerae O139 are very similar to conventional cholera due to V. cholerae O1.

Adolescent↗
PubMed1999

Structural relationship of lambda-type light chains with AL amyloidosis.

Three human amyloidogenic Bence Jones proteins, NIG76 VlambdaII, NIG204 VlambdaI, and NIG250 VlambdaV, were characterized. In a comparative study, three amino acids, Ser-25a, Thr-68, and Val-95, were found to be common to amyloidogenic proteins of the VlambdaII subgroup. NIG204 had an insertion of Pro residue following position 30 (30a). Proteins having an insertion at this position are invariantly amyloidogenic. NIG250 had a characteristic VlambdaV VL domain, with Mcg+ and KERN+ CL domain isotypes. Following the protein DEL, this is the second example of this subgroup. No common residue is found in the other subgroup proteins but unique substitutions do occur. It would seem that any substitution that causes an alteration in the protein conformation may lead to its being more prone to association with the amyloid processes.

Amino Acid Sequence↗
PubMed1999

Association of age-related decrease in platelet membrane fluidity with platelet lipid peroxide.

The influence of age on platelet lipid peroxide (LPO), platelet membrane fluidity and the composition of fatty acid was investigated in female Wistar rats widely ranging in age from 14 to 720 days old. LPO levels were significantly higher (p<0.05) in the platelets of upper age groups than in those of lower age groups, showing a significantly positive correlation with age (r=0.84, p<0.0001). Membrane fluidity, assessed by 1,6-diphenyl-1,3,5-hexatriene (DPH) fluorescence polarization, was significantly reduced with age. The composition of fatty acid demonstrated an age-related elevation (p<0.05) in the unsaturation index. The rises in the LPO levels revealed a significantly positive correlation with DPH-polarization (r=0.73, p<0.0001). Thus our results suggested that the age-related deterioration of platelet membrane fluidity, despite a significant elevation in the unsaturation index, was due to the age-related higher basal levels of LPO in platelets.

Aging↗
PubMed1999

Protective effects of hochu-ekki-to, a Chinese traditional herbal medicine against murine cytomegalovirus infection.

The innate immunity against murine cytomegalovirus (MCMV) at the early phase of infection is mediated by NK cells and macrophages. We studied the effects of hochu-ekki-to (HET), a traditional Chinese herbal medicine, on the regulation of innate immunity mediated by NK cells and macrophages. We found the oral administration of HET to increase both the number of leukocytes in the spleen and liver and the splenic NK cell cytotoxicity associated with the increased induction of serum IFN-alpha/beta after an MCMV infection but it had no effect on liver NK cells. However, no differences were found in the serum IL-12, IFN-gamma, TNF-alpha and nitric oxide (NO) production in the culture of macrophages between the HET- and PBS-treated mice on day 2 after MCMV infection. In addition, HET-treated splenic and peritoneal macrophages were found to show a higher intrinsic resistance against in vitro MCMV infection than that of PBS-treated mice. Therefore, the HET-induced effects on NK cells and macrophages selectively reduced the viral load in the spleen but not in the liver at an early phase of MCMV infection. HET may thus be useful in the treatment of human cytomegalovirus infection which commonly occurs in HIV-infected AIDS patients.

3T3 Cells↗
PubMed1999

Structural relationship of kappa-type light chains with AL amyloidosis: multiple deletions found in a VkappaIV protein.

Two amyloidogenic Bence Jones proteins (Am37 VkappaIV and NIG1 VkappaI) and one non-amyloidogenic protein (NIG26 VkappaIII) were characterized. The protein Am37 had four deletions when compared with the translated germ-line gene sequence: two Ser residues following position 27 (27e, 27f) in CDR1 and two amino acids Pro-44, and Tyr-49 in FR2 were deleted. A strictly conserved salt-bridge-forming amino acid, Asp-82, was replaced by the hydrophobic residue Leu. In a comparative study of amyloidogenic and non-amyloidogenic proteins, five amino acids (Ser-10, Ala-13, Ser-65, Gln-90, and Ile-106) were found to be unique to NIG1 and several other amyloidogenic proteins. Additional substitutions also occur within these proteins. These substitutions might be significant in altering protein folding as well as in contributing to their aggregation as amyloid fibrils.

Amino Acid Sequence↗
PubMed1999

Antioxidative effects of docosahexaenoic acid in the cerebrum versus cerebellum and brainstem of aged hypercholesterolemic rats.

Female Wistar rats (100 weeks old) were divided into two groups; one group was fed a high-cholesterol diet (HC) and the other a high-cholesterol diet plus docosahexaenoic acid (HC-fed DHA rats). Fatty acid concentrations in brain tissues were analyzed by gas chromatography. In the HC-fed DHA rats, brain catalase (CAT), GSH, and glutathione peroxidase (GPx) increased in the cerebrum but not in the brainstem or cerebellum. The rate of increase was 23.0% for CAT, 24.5% for GSH, and 26.3% for GPx compared with that in the HC animals (p < 0.05). In the cerebrum of the HC-fed DHA rats, CAT and GPx increased, with an increase in the ratio of DHA to arachidonic acid. The cerebrum, unlike the other areas of the brain, seems to be more sensitive to DHA in stimulating CAT and GPx. We suggest that DHA plays an important role in inducing an antioxidative defense against active oxygen by enhancing the cerebral activities of CAT, GPx, and GSH.

Aging↗
PubMed1999

The hypotensive effect of docosahexaenoic acid is associated with the enhanced release of ATP from the caudal artery of aged rats.

Fish oils have been shown to lower blood pressure in hypertensive subjects. To determine the mechanism of this hypotensive effect, we examined the effects of docosahexaenoic acid (DHA), one of the (n-3) polyunsaturated fatty acids in fish oil, on blood pressure and on the release of adenyl purines, such as ATP, ADP, AMP and adenosine, from the caudal arteries of aged rats. Aged female Wistar rats (100 wk) were fed a high cholesterol diet and were administered intragastrically ethyl all-cis-4,7,10,13,16,19-docosahexaenoate [300 mg/(kg.d)] for 12 wk (DHA group) or vehicle alone (control group). Compared with the controls, rats supplemented with DHA had significantly greater (10.1%) DHA concentrations in the caudal arteries. This was associated with more total (n-3) arterial fatty acids, a greater unsaturation index of arterial fatty acids, 43.9% lower plasma noradrenaline levels and the repression of the elevation in blood pressure observed with advancing age. The amount of purines released, both spontaneously and in response to noradrenaline, from arterial segments of DHA-supplemented rats was significantly higher than that released from tissues of control rats. Regression analysis revealed significant negative relationships between the total amount of purines released from the artery and the systolic (SBP) and diastolic (DBP) blood pressures. These results suggest that in aged rats, supplementation with DHA alters the membrane fatty acid composition as well as the amount of ATP released from vascular endothelial cells and decreases plasma noradrenaline, and that these factors may ameliorate the rise in blood pressure normally associated with advancing age.

Adenosine Triphosphate↗