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Biomedical subjects

M R Khan

Publications and source records attributed to M R Khan.

At least 73 records · Page 4Linked to original sources
PubMed1996

Serum retinol and biochemical measures of iron status in adolescent schoolgirls in urban Bangladesh.

OBJECTIVE: To examine the relationship between serum retinol and biochemical indices of iron nutritional status amongst adolescent girls in urban Bangladesh. DESIGN: A cross-sectional study. SETTING: Girls' high schools in Dhaka City, Bangladesh. SUBJECTS: Adolescent girls, n = 225, aged between 12 and 15 years, from four urban schools participated in the study. Information on socio-economic conditions were obtained using a questionnaire. The height and weight of each girl were measured and a sample of blood was taken for biochemical analyses. RESULTS: Twenty-two per cent of the participants were found to be anaemic (Hb < 120 g/l), 15% had subnormal serum iron ( < 7.16 mumol/l) and about 25% were iron deficient judged by serum transferrin saturation (TS < 15%). Eleven per cent of the participants had low levels of serum retinol ( < 1.05 mumol/l). Anaemic girls (n = 51) were found to have significantly lower serum retinol as well as lower packed cell volume (PCV), mean corpuscular haemoglobin concentration (MCHC), serum iron, TS, and higher serum total iron binding capacity (TIBC) compared with those with normal haemoglobin levels. When the girls were classified by serum retinol, the third with the highest serum retinol had significantly higher levels of haemoglobin, PCV, MCHC and serum iron levels. When age, family size, family income, expenditure on food, education of the parents, supplementation with vitamin A or iron and menstruation at the time of study were accounted for by multiple regression analysis, a strong relationship was found for serum retinol concentration with PCV, MCHC, haemoglobin, serum iron and TS. For 1 mumol/l change in serum retinol concentration there was a 10.1 g/l change in haemoglobin whilst taking other factors into account. CONCLUSION: The data indicate that there is an interaction between serum retinol and biochemical indices of iron nutriture in adolescent girls who do not display any clinical signs of overt deficiency.

Adolescent↗
PubMed1995

Impaired immune response to natural infection as a correlate of vaccine failure in a field trial of killed oral cholera vaccines.

In a field trial carried out in 1985 in Matlab, Bangladesh, the authors evaluated whether subjects who developed Vibrio cholerae 01 infections during the first year after earlier receipt of B subunit-killed whole cell (BS-WC) or killed whole cell-only (WC) oral cholera vaccines exhibited deficient serum vibriocidal immune responses to these infections. After severe V. cholerae 01 infections (n = 70) in subjects > 5 years of age, the age group in which both vaccines were efficacious, a 6.5 geometric mean-fold rise of serum vibriocidal antibodies was observed among vaccinees, compared with an 18.6 geometric mean-fold rise in placebo-recipients (p < 0.01). Depressions of serum vibriocidal responses among vaccinees were even more marked after asymptomatic infections (n = 30): a 1.1 geometric mean-fold rise in vaccinees versus a 5.9 geometric mean-fold rise in placebo-recipients (p < 0.01). The authors conclude that subjects who failed to be protected by BS-WC and WC, despite being in the age group for which these vaccines were protective, exhibited poor immune responses even to the vigorous stimulus of natural infection. These findings raise the possibility that immune hyporesponsiveness may limit the potential efficacy attainable by cholera vaccines in populations with endemic cholera.

Administration, Oral↗
PubMed1995

Relationship between smoking and antioxidant nutrient status.

The present study was designed to investigate the relationship between smoking and antioxidant nutrient intake and status. Smoker (n 44) and non-smoker (n 44) male students attending Dhaka University, aged between 22 and 28 years and living in a University Hall of Residence, were selected for the present study. Mean age, body weight, BMI and blood pressure were similar for both the smokers and non-smokers. Mean energy, protein and fat intakes were similar for both groups. Smokers had lower intakes of dietary vitamin C, carotenes and Zn but only the difference in Zn intake was statistically significant. There was no significant difference between smokers and non-smokers for either serum vitamin A (retinol) or vitamin E (alpha-tocopherol) level. The plasma vitamin C level of smokers was significantly lower than that of non-smokers (P = 0.0004). Smokers had significantly lower serum Cu (P = 0.04) and higher serum Zn levels (P = 0.003). Further, a significant dose-response relationship between smoking and vitamin C status was observed. Linear-regression analysis showed a significantly positive correlation between dietary intake and plasma vitamin C values in non-smokers (r 0.50; P = 0.0005). On the contrary, no such association was observed in smokers. These findings suggest that smoking may cause an imbalance in antioxidant nutrient intake and status.

Adult↗
PubMed1995

Common aerobic bacteria in post operative wound infection and their sensitivity pattern.

Two hundred and four post-operative patients were examined and pus samples were collected with sterile cotton swabs from 64 patients with infected wounds. The samples were cultured aerobically and the isolates were identified as per standard methods. The prevalence rate of post-operative wound infection were 31.37% and the total number of bacterial isolates were 76 (37.25%). The isolates were identified up to their species level & they were E. coli, Staph. aureus, Kl. Pneumoniae, Ps. aeruginosa. Pr. vulgaris and S. pyogenes. Gram negative bacilli were the predominant organisms and among them E. coli was the most common. In antimicrobial susceptibility test Gentamycin and Cephalexin were found sensitive.

Bacteria, Aerobic↗
PubMed1994

Fractures of the distal femur in adults.

Nineteen adults sustaining 20 distal femoral fractures were followed for 18 months. Majority (70%) of the patients were males between the ages of 17 to 70 years and 68% sustained other injuries too. Fractures were classified by AO classification; most of them were intrarticular C1 type. Open reduction and internal fixation was carried out in 60% cases. Assessment of results taking into consideration the parameters of pain, deformity and range of movement were compared with the conservatively treated group.

Adolescent↗
PubMed1994

Hip involvement in childhood brucellosis.

We reviewed 190 children with brucellosis admitted over a 7.8-year period. Seventy of these had articular involvement (36%) and the most common site was the hip (18%). All but one patient had unilateral infection. The hip was the only joint infected in 20 patients (57%). The next most common articular site was the knee. All patients had painful limitation of movement and this was the only articular sign in 28 (80%). Extra-articular signs included fever and hepatosplenomegaly. Brucella infection should be considered in every child from an endemic area who presents with fever and joint symptoms. The insidious onset and a normal or low leucocyte count help the differentiation from acute septic arthritis. Children with hip involvement had a slower response to treatment, longer hospital stays and a higher incidence of complications and relapse than those without. Complications included dislocation (n = 4) and avascular necrosis of the femoral head (n = 1). Treatment by combination chemotherapy for 6 to 12 weeks usually achieves cure and prevents relapse. A multidisciplinary team approach to management is recommended.

Arthritis, Infectious↗
PubMed1993

The interaction of SO2 and root-knot nematode on tomato.

Intermittent exposure of tomato plants (cv. Pusa Ruby) to SO(2) at 286 microg m(-3) (3 h every heavy third day for 75 days) induced slight chlorosis of leaves. At 571 microg m(-3), considerable chlorosis with browning developed on the foliage. These symptoms were more pronounced and appeared earlier on SO(2)-exposed plants infected with Meloidogyne incognita race 1 (Mi), especially in post- and concomitant-inoculation exposures. Mi and/or SO(2) significantly reduced different parameters of plant growth. Synergistic (positive) interactions between SO(2) and Mi occurred in concomitant- and post-inoculation exposures at 286 and 571 microg m(-3), respectively. In other treatments, an antagonistic (negative) interaction was observed. However, in a few cases, additive effects of SO(2) and Mi were also recorded. Intensity of root-knot (galling) was enhanced at both concentrations of SO(2), while reproduction (egg mass production) of Mi was enhanced in concomitant-inoculation exposures at 286 microg m(-3) and inhibited at 571 micro m(-3). Exposure to SO(2) and/or Mi decreased the number and size of stomata but increased the number and length of trichomes on both the leaf surfaces. Stomatal aperture was significantly wider in the plants exposed to 571 microg SO(2) m(-3) alone and in pre-, post-, and concomitant-inoculation exposures at 286 or 571 microg m(-3). Stomatal aperture was directly related to foliar injury and reductions in growth, yield, and leaf pigments.

Journal Article↗
PubMed1993

The design and analysis of cholera vaccine trials: recent lessons from Bangladesh.

The recent spread of cholera to Latin America, together with the persistent burden of this disease in Asia and Africa, have stimulated efforts to evaluate new cholera vaccines in field settings. Although the standard experimental paradigm for vaccine field trials is well established, the success of these trials will also depend on suitable consideration of the epidemiology of cholera and of cholera vaccination in the setting under study. Epidemiological studies done in Bangladesh emphasize the importance of appreciating the poorly predictable, multifocal occurrence of cholera in estimating a probable incidence of cholera for a field trial. They also underscore how the filtering effect of enrolling subjects into a prospective trial can dramatically reduce the available population for study, and can yield a study sample whose expected risk of cholera differs markedly from that for the source population. Finally, the data highlight the subtle effects that the mode of surveillance and the choice of an outcome definition can have upon protective efficacy, and emphasize the need for subgroup analyses that address the distinctive variations in vaccine protection that may occur in subjects differing in age and in ABO blood groups, and in subjects exposed to classical versus El Tor cholera.

ABO Blood-Group System↗
PubMed1993

Pattern of external birth trauma in southwestern Saudi Arabia.

The pattern and associations of 62 instances of external birth trauma (EBT) in 57 of 2222 consecutive hospital-born neonates were studied. Macrosomia and vaginal instrumental or breech delivery were identified as significant risk factors for EBT. In contrast to previous reports, subgaleal hemorrhage (SGH) was the predominant form of trauma (n = 33) and it was associated with vacuum application in 28 of 33 (85%) neonates. Brachial plexus palsy (BPP) (n = 10) occurred with the highest frequency (6.4%) after breech delivery. Fractures were uncommon. Multiple injuries (10 items in 5 babies) were mainly associated with vacuum extraction. The high rate of vacuum extraction (VE) and problems with its use including a high VE failure rate (30/242 = 12.4%) were considered contributory to the unusual pattern of EBT seen in the study. Regular audit of delivery practices, greater care in excluding cephalopelvic disproportion and judicious use of VE are recommended to reduce the morbidity from EBT.

Birth Injuries↗
PubMed1993

Initiation of food supplements and stopping of breast-feeding as determinants of weanling shigellosis.

The association between the period elapsed since weaning and the risk of shigellosis was assessed between 1 November 1987 and 30 November 1989 for a cohort of 1085 Bangladeshi children aged < 3 years. The children were followed for 1 month after exposure to Shigella spp. in their residential neighbourhoods, and the 268 who developed microbiologically confirmed (n = 118) or clinically presumptive (n = 150) shigellosis were compared with the 817 control children who did not develop either syndrome. No increase in risk was noted among breast-fed infants who received food supplements within the previous 3 months compared with those who had received supplements for longer (adjusted odds ratio (OR) = 1.2; 95% confidence interval (CI) = 0.4-3.0). However, compared with breast-fed children, non-breast-fed children had an increased risk (adjusted OR = 2.0; 95% CI = 1.3-2.9; P < 0.001), which was largely attributable to a substantially increased risk in the 3 months after stopping breast-feeding (adjusted OR = 6.6; 95% CI = 2.9-14.6; P < 0.001). The early post-cessation risk was equivalent for confirmed and presumptive shigellosis, but was particularly pronounced among the severely malnourished (adjusted OR = 10.2; 95% CI = 3.1-33.3; P < 0.001). This complex temporal pattern of risk highlights the need for precise definitions of weaning to facilitate identification of children at high risk for invasive diarrhoeal syndromes.

Bangladesh↗
PubMed1993

Breast-feeding and the risk of life-threatening rotavirus diarrhea: prevention or postponement?

PURPOSE: To assess the relationship between breast-feeding and the risk of life-threatening rotavirus diarrhea among Bangladeshi infants and children younger than 24 months of age. DESIGN: Case-control study. SETTING: A rural Bangladesh community. PARTICIPANTS: One hundred two cases with clinically severe rotavirus diarrhea detected in a treatment center-based surveillance system during 1985 and 1986, and 2587 controls selected in three surveys of the same community during the same calendar interval. OUTCOMES: Cases and controls were compared for the frequency of antecedent breast-feeding patterns. RESULTS: Compared with other feeding modes, exclusive breast-feeding of infants was associated with significant protection against severe rotavirus diarrhea (relative risk (RR) = 0.10; 95% confidence interval [CI] = 0.03, 0.34). However, during the second year of life, the risk of this outcome was higher in breast-fed than in non-breast-fed children (RR = 2.85; 95% CI = 0.37, 21.71), and no overall protection was associated with breast-feeding during the first 2 years of life (RR = 2.61; 95% CI = 0.62, 11.02). CONCLUSIONS: Although exclusive breast-feeding appeared to protect infants against severe rotavirus diarrhea, breast-feeding per se conferred no overall protection during the first 2 years of life, suggesting that breast-feeding temporarily postponed rather than prevented this outcome. While not detracting from efforts to promote breast-feeding to alleviate the burden of diarrhea due to nonrotaviral enteropathogens, our findings cast doubt on whether such efforts will impact on the problem of severe rotavirus diarrhea.

Bangladesh↗
PubMed1992

Nonparticipation as a determinant of adverse health outcomes in a field trial of oral cholera vaccines.

The authors estimated the incidence rates of cholera and death between 1985 and 1988 for 32,642 age- and sex-eligible persons who did not participate in a randomized, placebo-controlled field trial of killed oral cholera vaccines in rural Bangladesh. As compared with 20,744 placebo recipients, the relative risk of cholera for all nonparticipants, adjusted for potentially confounding demographic variables, was 1.20 (95% confidence interval (CI) 1.03-1.41); this adjusted relative risk reflected elevated adjusted relative risks in nonparticipants who were medically ineligible (RR = 1.65; 95% CI 1.22-2.22) or refused to participate (RR = 1.19; 95% CI 1.01-1.41), but not in persons absent at the time of vaccination (RR = 1.00; 95% CI 0.78-1.28). The adjusted relative risk of death was also elevated in nonparticipants as compared with placebo recipients (RR = 1.28; 95% CI 1.10-1.48), with the same pattern of adjusted relative risks for different categories of nonparticipants: for ineligible subjects, 2.64 (95% CI 2.12-3.29); for refusers, 1.20 (95% CI 1.02-1.41); and for absentees, 0.95 (95% CI 0.75-1.22). The authors concluded that nonparticipation was associated with clinically cogent adverse health outcomes, but that the magnitude of these associations varied according to the reason for nonparticipation. These findings underscore the caution required in assessing vaccine efficacy with controls who are not vaccinated because of choices made by patients or vaccinators.

Administration, Oral↗
PubMed1992

Vicilin with carboxy-terminal KDEL is retained in the endoplasmic reticulum and accumulates to high levels in the leaves of transgenic plants.

Gene constructs were designed to test the effect of the endoplasmic reticulum (ER)-targeting signal, KDEL, on the level of accumulation of a foreign protein in transgenic plants. The gene for the pea seed protein vicilin was modified by the addition of a sequence coding for this tetrapeptide at its carboxyl terminus. The altered gene was placed under the control of a CaMV 35S promoter and its expression in the leaves of both tobacco and lucerne (alfalfa) was compared with that of an equivalent vicilin construct lacking the KDEL-coding sequence. The presence of the ER-targeting signal led to a greatly enhanced accumulation of the heterologous protein. In lucerne and tobacco leaves, the level of vicilin-KDEL protein was 20 and 100 times greater than that of the unmodified vicilin, respectively. These differences in expression level could not be explained by corresponding differences in the steady-state levels or the translatability of the mRNAs. However, when the stability of vicilin and vicilin-KDEL proteins was compared in their respective transgenic hosts, unmodified vicilin was found to be degraded with a half-life of 4.5 h while vicilin-KDEL was much more stable with a half-life of more than 48 h. Immunogold labelling of leaf tissues from transgenic lucerne and tobacco showed the presence of vicilin associated with large aggregates within the ER lumen of vicilin-KDEL plants. No such aggregates were detected in transgenic plants expressing wild-type vicilin. It is concluded that the carboxy-terminal KDEL caused the retention of the modified vicilin in the ER, and that this retention led to the increased stability and higher level of accumulation of vicilin-KDEL in leaves of transgenic plants.

Amino Acid Sequence↗
PubMed1992

Evidence that inactivated oral cholera vaccines both prevent and mitigate Vibrio cholerae O1 infections in a cholera-endemic area.

In a randomized, placebo-controlled field trial of B subunit-killed whole cell (BS-WC) and killed whole cell only (WC) inactivated oral cholera vaccines in rural Bangladesh, active surveillance of selected neighborhoods during the first year after vaccination identified 127 Vibrio cholerae O1 infections among 3285 three-dose recipients. For each vaccine, protective efficacy was greater against symptomatic (57%, P < .05 for BS-WC; 58%, P < .05 for WC) than against asymptomatic infections (46%, P < .05 for BS-WC; 32%, P = .09 for WC), and protection against each grade of infection was demonstrable for both the classical and El Tor biotypes. Although vaccine protection against symptomatic infections was evident in both young children and older persons, only persons vaccinated at age > 5 years were protected against asymptomatic infections. These results suggest that the inactivated oral vaccines acted both to protect against intestinal colonization by V. cholerae O1 and to interrupt the pathogenic sequence of established infections.

Adolescent↗
PubMed1992

Community-based evaluation of the effect of breast-feeding on the risk of microbiologically confirmed or clinically presumptive shigellosis in Bangladeshi children.

To assess the association between breast-feeding and the risk of microbiologically confirmed or clinically presumptive shigellosis, the authors performed a case-control analysis of Bangladeshi children younger than 3 years of age who were followed up for 1 month after exposure to Shigella in their residential neighborhoods. Two hundred sixty-nine cases with culture-confirmed shigellosis (n = 119) or clinically presumptive shigellosis (culture-negative dysentery, n = 150) were compared with 819 controls without Shigella diarrhea or other invasive diarrheal illnesses. The odds ratio relating breast-feeding to confirmed or presumptive shigellosis, adjusted for potentially confounding variables, was 0.48 (95% confidence interval = 0.32 to 0.72; P less than .001), suggesting a substantial protective effect. The protective association decreased with age but was still significant during the third year of life; appeared to be directly related to the degree of stunting; and was equivalent for confirmed and presumptive shigellosis. Notably, the protective association remained substantial against episodes due to Shigella which were resistant to at least one of the antibiotics customarily used for treatment of Shigella diarrhea (age-adjusted odds ratio = 0.40; 95% confidence interval = 0.22 to 0.74; P less than .01). These data suggest that breast-feeding confers a high level of protection against shigellosis throughout the first 3 years of life, especially among nutritionally compromised children, and thereby underscore the importance of promotion of breast-feeding as a central component of Shigella control programs in less developed settings.

Age Factors↗
PubMed1991

Biotype as determinant of natural immunising effect of cholera.

To test the hypothesis that clinical Vibrio cholerae O1 infections protect against recurrent cholera, treated cholera episodes in a rural Bangladesh population of 188,153 people who were followed between 1985 and 1988 were analysed. Of the 2214 people with initial episodes of cholera, 7 had a second episode. The incidence of cholera was 61% lower in subjects who had had an earlier episode than in those without such an episode. Whereas initial episodes of classical cholera were associated with complete protection against subsequent cholera, initial episodes of El Tor cholera were associated with negligible protection.

Adolescent↗
PubMed1991

Field trial of oral cholera vaccines in Bangladesh: serum vibriocidal and antitoxic antibodies as markers of the risk of cholera.

The relationship of serum vibriocidal (VC) and IgG anti-cholera toxin (CT) antibodies to the risk of cholera was evaluated during the first year of follow-up of recipients of three oral doses of B subunit (BS)-whole-cell vaccine, whole-cell vaccine, or Escherichia coli K12 strain placebo in Bangladesh. Acute sera from 121 cholera patients were compared with sera from 2592 contemporaneous community controls. Each doubling of VC titer was associated, on average, with a 22%-47% reduction of cholera risk in the three groups. In contrast, in the two groups that did not receive BS, anti-CT titers were directly associated with cholera and thus served as markers of higher cholera risk. Each vaccine conferred approximately 65% protective efficacy against cholera, but antibody titers did not correlate with vaccine efficacy, indicating that serum VC and anti-CT antibodies are poor markers of the longitudinal pattern of vaccine efficacy.

Administration, Oral↗