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Biomedical subjects

S Zaman

Publications and source records attributed to S Zaman.

At least 55 records · Page 3Linked to original sources
PubMed1993

Early child health in Lahore, Pakistan: X. Mortality.

Mortality during the first two years of life among 1476 Pakistani infants born between September 1984 and March 1987 is described according to age, causes of death, area of living, season of the year and sex. The mortality rate (deaths under two years/1000 live births) projected over the whole population of Pakistan was 127 and under one year 114. During the first two years of life, the mortality rate was 133/1000 in the village, 159 in the periurban slum, 107 in the urban slum and 17 in the upper middle class group. In the latter group all deaths had occurred within 72 hours after birth. The overall major causes of death were acute and prolonged diarrhoea (36%), asphyxia neonatorum (13%), respiratory infections (13%), septicaemia (11%) and tetanus (9%). A clear age dependency was noted with 14% of deaths occurring during the first 24 hours of life (asphyxia neonatorum in 86%), and 57% dying within the first 28 days of life. In the later age groups, infections were mainly responsible for 82% of total deaths. Early mortality was therefore extremely high in the poorer areas studied and the cause of death was highly age dependent. Any interventions for reducing mortality must therefore be directed towards better antenatal care and safe delivery and postnatally, towards preventing infections, especially during the first six months of life.

Age Factors↗
PubMed1993

Poliovirus antibody titres, relative affinity, and neutralising capacity in maternal milk.

Varying titres of secretory IgA antibodies to poliovirus type 1 were found previously in the milk of unvaccinated, lactating Pakistani mothers during two different years, reflecting the antigenic exposure on mucosal membranes. To study further the changes in the extent and the form of antigenic exposure reflected in the human milk, human milk samples from Pakistani, Indian, Japanese, and Swedish mothers were collected. The quality and the neutralising capacity of the antibodies was also studied. Secretory IgA, IgG, and IgM antibodies to poliovirus type 1 were determined using enzyme linked immunosorbent assay (ELISA) and relative affinity was measured in ELISA by elution with potassium thiocyanide. Microneutralisation tests were also performed. The higher secretory IgA antibody titres to poliovirus type 1 in the unvaccinated, naturally exposed Pakistani and Indian mothers' milk, compared with the Swedish and Japanese mothers, presumably reflect the epidemiological situation in these countries. Neutralising capacity and the relative antibody affinity seemed to be higher both in the Pakistani mothers and the group without natural exposure but only given inactivated poliovirus vaccine, that is the Swedish mothers, than the group meeting only live vaccine strains, that is the Japanese mothers.

Antibodies, Viral↗
PubMed1992

Expression and characterisation of the korB gene product from the Streptomyces lividans plasmid pIJ101 in Escherichia coli and determination of its binding site on the korB and kilB promoters.

A 0.5kb Spel-BclI fragment containing the pIJ101 korB ORF was cloned into pUC8 under the control of the lacZ promoter, creating pQR206. In vitro coupled transcription-translation of pQR206 identified a protein product of approximately 10kDa, which corresponds to the predicted molecular weight deduced from the korB sequence. pQR206 was used to express the 10kDa KorB protein in vivo in E. coli. Crude E. coli protein extracts containing KorB were shown to bind to a 0.8kb kilB fragment and a 0.5kb korB fragment in gel retardation assays. DNasel footprinting indicated that the DNA recognition sequence of the KorB protein lies within a 60bp protected region encompassing the kilB promoter and a 36bp region encompassing the korB promoter.

Bacterial Proteins↗
PubMed1992

Estimates of the prevalence of childhood seizure disorders in communities where professional resources are scarce: results from Bangladesh, Jamaica and Pakistan.

Although numerous estimates of the prevalence of seizure disorders in populations in the less developed world have now been published, these estimates are difficult to interpret due to lack of comparability of study methods and criteria for case definition. The results reported in this paper are from a large, collaborative study of disabilities in 2- to 9-year-old children in which standard research procedures and case definitions were used in three diverse populations (located in Bangladesh, Jamaica and Pakistan). A two-phase study design (screening followed by professional evaluations) was used in this study allowing for the professional evaluation to serve as the criterion in the estimation of prevalence, even for rare disorders. As a result, the prevalence estimates reported here have a high degree of comparability across populations and exhibit unusually strong validity for population surveys. Febrile seizures were the most common type of seizure history in all three populations, with point estimates of lifetime prevalence ranging from 10.9 to 62.8 per 1000. The lifetime prevalence rates of epilepsy (recurrent unprovoked seizures) ranged from 5.8 to 15.5 per 1000. Lifetime prevalence rates of neonatal, all provoked and all unprovoked seizures, as well as estimates of the prevalence of active epilepsy, are also reported.

Age Factors↗
PubMed1991

Comparison of serum and salivary antibodies in children vaccinated with oral live or parenteral inactivated poliovirus vaccines of different antigen concentrations.

A new antigen-rich inactivated poliovirus vaccine (IPV) in ordinary (IPV1), double (IPV2) and quadruple (IPV4) antigen concentrations was given in 2 doses to 6 and 18 week old Pakistani infants. The immune responses to poliovirus types 1 and 3 were compared to those in infants given three doses of oral poliovirus vaccine (OPV) at 6, 12 and 18 weeks of age. Enzyme-linked immunosorbent assay, ELISA, was used to estimate IgG and IgA in serum and secretory IgA (SIgA) in saliva. Two to three years later, a follow-up of the serum antibody response was carried out in the same infants using a microneutralization test. Serum IgG antibody responses to poliovirus type 1 antigen after two doses of IPV1, IPV2 and IPV4 were not significantly higher than the response after three doses of OPV at 21 weeks of age (p greater than 0.05). The serum IgG responses to poliovirus type 3 were similar to those against type 1 in all the groups. Mean neutralizing antibody titres to poliovirus type 1 was significantly higher in the IPV2 group than the rest of the groups (p less than 0.01). For type 3, these titres were highest but not significantly, in the IPV4 group (p greater than 0.05). This study shows that two doses of a new antigen-rich IPV can give similar immediate serum antibody responses as OPV but higher late responses. SIgA antibodies in saliva were more efficiently induced by OPV after three doses than after 2 doses of IPV (p less than 0.05).

Antibodies, Viral↗
PubMed1991

Specific antibodies to poliovirus type I in breastmilk of unvaccinated mothers before and seven years after start of community-wide vaccination of their infants with live, oral poliovirus vaccine.

Secretory IgA (SIgA) antibodies against poliovirus type 1 were determined using the ELISA method in breastmilk samples obtained each month from 100 young, healthy, unvaccinated mothers living in urban slum areas of Lahore, Pakistan. The study covered two different groups, one in 1980-1981 and the other in 1987, before and seven years after a nation-wide expanded programme of childhood immunization (EPI) had started. The SIgA titres did not change neither with duration of lactation nor with time after vaccination in the infants of the mothers studied. The seasonal breastmilk IgA antibody titres to poliovirus type 1 corresponded to the epidemiological conditions existing both before (1980-81) and after general vaccination coverage with live, oral poliovirus vaccine (OPV) had reached 80% of the infant population (1987). Neutralization titres did not seem to correlate well with ELISA titres although colostrum samples had high levels of neutralizing antibodies. The wide variation between high (greater than 10,000) and low (less than 500) individual breastmilk IgA antibody titres observed during various seasons could be of consequence for the breast-fed baby. Colostrum, which was also found to have significant neutralization capacity, might interfere with the OPV now often given on the day of birth.

Adult↗
PubMed1991

Breast feeding and protection against neonatal sepsis in a high risk population.

Protection against neonatal sepsis by breast feeding was investigated in a developing community. A case-control study was carried out with 42 cases from a hospital and 270 controls, matched for age and socioeconomic conditions from the community. Exclusive breast feeding was extremely rare, most babies being partially breast fed and a few being given formula feed or animal milk. A highly significant odds ratio of 18 was obtained, showing that even partial breast feeding protects against neonatal sepsis in such a population.

Bacterial Infections↗
PubMed1990

Antibody-mediated immunity in the neonate.

Our knowledge about the protective value of the passive immunity provided by maternal IgG via placenta and SIgA via the milk is still incomplete. Although more detailed information is required it is clear that both forms of passive protection are important for the neonate. The immune response of neonates in secretions appears earlier and is more efficient than previously realized, providing SIgA as well as IgM in e. g. saliva. The presence of anti-antibodies (anti-idiotypes) in the transplacental IgG and milk SIgA may in fact actively prime the immune system of the fetus and the breast-fed infant. This could be one explanation why breast-fed infants seem to respond better to ordinary parenteral and peroral vaccines, in secretions as well as in serum than those fed a high or low protein formula.

Humans↗
PubMed1989

Adoptive immunotherapy administered via the hepatic artery and intralesional interleukin-2 in hepatocellular carcinoma.

We assessed the feasibility of using lymphokine-activated killer cells (adoptive immunotherapy) with infusions of interleukin-2 when given regionally in three patients with unresectable primary hepatocellular carcinoma (PHC). In 2 patients, 2 cycles, which included a bolus of LAK (10(7) to 10(8) cells followed by a 4-hourly infusion of IL-2 were administered via selective arterial catheterization of the hepatic artery. One further patient received 3 cycles of IL-2 alone by direct intralesional and perilesional injections. Minimal toxicity was observed and side effects such as fever were comparable to those observed with systemic infusions of IL-2 alone. Serial alpha-fetoprotein (AFP) levels initially fell but subsequently rose within 2 to 4 weeks of therapy. AFP levels had not reached pre-treatment values at 4 months in 2 patients, 1 of whom was alive and well at 15 months follow-up.

Carcinoma, Hepatocellular↗
PubMed1988

Macromolecular metabolism of a differentiated rat keratinocyte culture system following exposure to sulfur mustard.

A method for producing a stratified, squamous epithelium in vitro by cultivating rat keratinocytes on nylon membranes has been developed in this laboratory. This epidermal-like culture is being used to obtain a better understanding of the mechanism of skin vesication after topical exposure to the sulfur mustard bis(beta-chloroethyl) sulfide (BCES) dissolved in a selected solvent. Radiolabeled macromolecular precursors (thymidine, uridine, and leucine) have been used to study the effect of BCES on the synthesis of DNA, RNA, and protein, respectively, after topical exposure to the mustard at concentrations of 0.01-500 nmol/cm2 dissolved in 70% dimethyl sulfoxide (DMSO). From these and other studies it has been determined that exposure to even the low concentration of 0.01 nmol BCES/cm2 for 30 min results in significant inhibition of [3H]thymidine incorporation, although complete recovery occurs by 24 h. Significant inhibition of [3H]uridine and [14C]leucine incorporation is observed only after exposure to much higher concentrations of BCES (10-500 nmol/cm2). This suggests a very early lesion in macromolecular metabolism with DNA being the primary target.

Animals↗
PubMed1986

Comparison of the potency of d-propranolol, chlorhexidine and nonoxynol-9 in the Sander-Cramer test.

The potency of two new candidate spermicides, d-propranolol and chlorhexidine, was compared with an established agent nonoxynol-9 by the Sander-Cramer test. The lowest concentrations of nonoxynol-9, d-propranolol and chlorhexidine which consistently inhibited progressive forward sperm motility within twenty seconds were found to be 0.12, 0.44, and 4.81 mg/ml, respectively. These relative potencies and other properties of d-propranolol and chlorhexidine indicate that they should be further investigated as alternatives to nonoxynol-9 in spermicidal preparations.

Chlorhexidine↗
PubMed1985

Secretory and serum immunoglobulin class-specific antibodies to poliovirus after vaccination.

Immune responses in serum and saliva were studied in Pakistani children by enzyme-linked immunosorbent assay after natural exposure to poliovirus and vaccination with live or inactivated poliovirus vaccines. Swedish children unexposed to wild poliovirus who had almost 100% vaccination coverage with inactivated vaccine at 8, 9, and 18 months and at 5 years of age were analyzed for comparison. Natural exposure induced secretory IgA (SIgA) antibodies to poliovirus in the saliva of Pakistani infants at one month of age that reached adult levels at six months. No difference in levels of salivary antibody at eight months was observed between groups vaccinated with either live or inactivated vaccines. Vaccination with live or inactivated vaccine starting at 2 or 3 months of age resulted in high titers of IgG antibody to poliovirus in serum, the highest of which occurred after four doses of live vaccine. In Sweden, an increase of antibody in serum was observed after the third vaccination. IgA antibodies continued to increase subsequently, whereas IgG antibodies reached a plateau. The SIgA response in saliva initially appeared on the third vaccination, with a significant increase after the fourth. Repeated vaccination with inactivated poliovirus vaccine induces specific SIgA antibodies. Adults all had SIgA antibodies to poliovirus in saliva.

Adult↗