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J Iqbal

Publications and source records attributed to J Iqbal.

At least 73 records · Page 4Linked to original sources
PubMed1997

Ontogeny of androgen receptor-like immunoreactivity in the reproductive tract of male Monodelphis domestica.

The distribution of nuclear androgen receptor-like immunoreactivity was studied in the reproductive tract of the developing and adult gray short-tailed Brazilian opossum (Monodelphis domestica), using the well-characterized rabbit polyclonal androgen receptor antibody, PG21. Androgen receptor-like immunoreactivity was first detected on the fifth day of postnatal age, in the mesenchymal tissues of the ductus deferens, gubernaculum testis, inguinal, and scrotal areas; the urogenital sinus; and the genital tubercle. Androgen receptor-like immunoreactivity was first seen in the interstitial cells of the epididymis at 45 days of age; the testes developed androgen receptor-like immunoreactivity at 60 days of age. The epithelium of prostatic glands contained androgen receptor-like immunoreactivity only in the adult. The presence of androgen receptor-like immunoreactivity during development correlated well with the known androgen dependence of the differentiation of most reproductive organs.

Aging↗
PubMed1997

Autoradiographic localization of arginine vasopressin binding sites in the brain of adult and developing Brazilian opossums.

We are utilizing the Brazilian short-tailed opossum, Monodelphis domestica, to study the development of the vasopressinergic system. Earlier studies demonstrated that arginine vasopressin-like immunoreactivity was present very early in the Brazilian opossum brain, suggesting a role for vasopressin in the developing central nervous system of mammals. In this study, we have utilized [3H]arginine vasopressin autoradiography to describe the distribution of arginine vasopressin binding sites in adult and developing Brazilian opossum brains. In general, arginine vasopressin binding patterns in adult opossum brains resembled those of other species. However, we found very few labelled areas in neonatal Brazilian opossum brains. At birth, only the ventral tegmental area and the nucleus of the solitary tract were labelled. Binding was not evident in the forebrain until 25 days of postnatal age. The anterior pituitary was heavily labelled from birth onward, but binding in the brain itself remained at low levels until 35 days postnatal. Heavy binding was observed in only a few areas of the brain in adults, including the dorsal part of the lateral septal nucleus, the suprachiasmatic nucleus, the dorsal and median raphe, the nucleus of the solitary tract, and the caudal part of the spinal trigeminal nucleus. Surprisingly, arginine vasopressin binding sites in the Brazilian opossum appeared much later than arginine vasopressin immunoreactivity and, in many cases, after neurogenesis was complete. These findings suggest that the arginine vasopressin binding sites are not playing a developmental role in opossums, although the peptide is present at an early age.

Age Factors↗
PubMed1997

Increasing ciprofloxacin resistance among prevalent urinary tract bacterial isolates in Bangladesh.

Ciprofloxacin was evaluated along with other commonly used antibiotics against a total of 425 clinical isolates obtained from urine samples. Samples were collected from outdoor patients from different parts of Dhaka city. Susceptibility tests were done by the standardized disk diffusion method. Among the tested drugs, the percent susceptible rates observed were: ciprofloxacin (74%), ampicillin (29%), cephalexin (54%) and trimethoprim-sulfamethoxazole (43%) tested against all organisms; gentamicin (73%) tested against gram-negative organisms and erythromycin (72%) tested against gram-positive organisms. Ciprofloxacin showed better activity against gram-negative isolates (80%) compared to the other antibiotics. However, strains highly resistant to ciprofloxacin were detected among commonly isolated gram-negative urinary pathogens: Escherichia coli (18%), Klebsiella species (19%) and Pseudomonas species (30%). Overall susceptibility rate for gram-positive cocci was significantly low for all the antibiotics tested including ciprofloxacin (62%). Minimal inhibitory concentration (MIC) of ciprofloxacin was measured for all resistant and susceptible urinary tract infection (UTI) isolates. This study indicates emerging ciprofloxacin resistance among most UTI bacterial pathogens. Increasing resistance against ciprofloxacin demands coordinated monitoring of its activity, and rationale use of the antibiotic in UTI.

Anti-Infective Agents↗
PubMed1997

Pyuria as predictor of bacteriuria in catheterized patients.

Six hundred and nine urine samples were analyzed for pyuria to assess its efficacy as a predictor of bacteriuria, in catheterized patients, using different techniques of pus cells estimation. In 235 and 323 urine samples, pus cells were counted per high power field in centrifuged and uncentrifuged urine respectively, while in 51 urine samples pus cells were counted per cubic millimeter in uncentrifuged urine. All the urine samples were simultaneously cultured. Pyuria (pus cells > 10/HPF or CMM) was correlated with bacteriuria (colony count > 10(5) per ml). The overall efficacy of pyuria as a predictor of bacteriuria was low (52.01-60.78%) and there was no significant difference among the different techniques. It was concluded that pyuria as predictor of bacteriuria is the least reliable technique to be recommended in routine clinical practice.

Bacteriuria↗
PubMed1997

Leishmanicidal activity of Nystatin (mycostatin): a potent polyene compound.

The susceptibility of promastigote of Leishmania major to Nystatin in vitro was examined. L. major (MHOM/PK/88/DESTO) promastigote were cultured in medium 199 supplemented with 10% heat inactivated foetal bovine serum and 2% urine. The growth of the promastigote was monitored in the absence and presence of the experimental compound (Nystatin) for upto 5 days post-inoculation. The EC50 value (the concentration of drug necessary to inhibit the growth rate of cells to 50% of the control value) obtained for Nystatin against the promastigote of L. major was less than 9.76 iu ml. Certain polyene compounds like Amphotericin-B and Nystatin (mycostatin) are familiar for their fungicidal activity. Amphotericin-B is used since long as antileishmanial drug as well. Results obtained suggest that Nystatin has a very good anti leishmanial activity in vitro. The mode of action proposed for this drug is same as for Amphotericin-B as both of these polyene compounds interact with the various sterols present on the surface of the parasite, thus unusual gaps and pores are formed on the surface that results in the leakage of the ions. This leakage finally leads to the destruction of the parasite.

Amphotericin B↗
PubMed1996

An in vitro transcription assay for yeast mitochondria using organellar lysates.

The nuclear gene NUC1 encodes the major mitochondrial (mt) ribonuclease in the yeast Saccharomyces cerevisiae. We describe an in vitro mt transcription assay system based on lysates of purified mitochondria from a petite (rho-, mt deletion mutant) yeast strain in which NUC1 has been insertionally inactivated. Control in vitro run-on transcription assays using intact mitochondria demonstrate that the rate of incorporation of labeled precursor into mt RNA is identical in organelles from the nuc1 rho- mutant and its otherwise isochromosomal NUC1 parent strain. Brij-35 lysates of mitochondria from the nuc1 strain incorporate precursor into mt RNA at nearly the same rate as do intact organelles from that strain, while similar mt lysates from NUC1 cells show no such incorporation. Other control studies show that mt lysates from the nuc1 strain retain functional mt cAMP-dependent protein kinase and other critical activities. When the cloned template DNA encoding the yeast mt 21S rRNA gene, which is not retained in the nuc1 rho- strain, is added to mt lysates from that strain, transcripts are produced from the template under standard assay conditions.

Base Sequence↗
PubMed1996

Plasmodium falciparum: differential parasite growth inhibition mediated by antibodies to the antigens Pf332 and Pf155/RESA.

Plasmodium falciparum-reactive antibodies can inhibit growth of parasite blood stages in vitro by interfering at different stages of parasite development. Antibodies reactive with repeat sequences in Pf155/ring-infected surface antigen (Pf155/RESA) or in antigen Pf332 inhibit parasite growth as determined by a reduction of newly infected erythrocytes. Antibodies to Pf155/RESA have been implicated in merozoite invasion inhibition. Since it was considered unlikely that antibodies to the late stage antigen Pf332 act on merozoite invasion, we investigated at what developmental stage this growth inhibition takes place. Parasites were cultured in the presence of antibodies to repeat sequences of either Pf332 or Pf155/RESA and were examined with regard to the distribution of different stages and their morphology. As expected, antibodies to both antigens decreased the number of ring stages after reinfection. They did not affect the intraerythrocytic development of ring stages or trophozoites. However, antibodies to Pf332 induced high levels of schizonts displaying an abnormal morphology while antibodies to Pf155/RESA induced considerably lower levels of degenerated schizonts. Thus, Pf332-reactive antibodies seem to interfere with the schizont development by blocking the rupture of mature schizonts or, alternatively, by interfering intraerythrocytically with late stage parasites.

Amino Acid Sequence↗
PubMed1996

A probable cis-regulatory element on yeast mitochondrial DNA responsible for cAMP-mediated transcription.

Studies from this laboratory have suggested that mitochondrial (mt) transcription in yeast (Saccharomyces cerevisiae) is governed by changing cellular cAMP levels, and that the mechanism of such transcriptional regulation requires cAMP-dependent protein kinase (PKA) activity; these observations, in turn, suggest a trans-activation process for nucleotide-dependent mt transcriptional control. Here we demonstrate a sequence-specific mtDNA-phosphorylated protein interaction, a requisite part of such a control mechanism, using filter-binding and gel mobility shift assays with mt protein extracts and mtDNA from rho- strains whose retained mt genes show cAMP-sensitive expression. We demonstrate that the protein-mt DNA interaction depends on PKA activity, that it specifically involves a tripartite GC-rich sequence element on yeast mtDNA, and that it does not involve mt coding or promoter sequences. Sequence analysis indicates that the GC-rich element undergoing protein interaction is present in ten copies on the yeast mt genome, and that each copy is located 5' to a strong mt promoter; the elements appear in both orientations relative to, and at varying distances upstream from, the putatively associated mt promoter elements. The mt element shows no sequence homology to relevant nuclear cis-elements examined and is unrelated to published vertebrate mt cis-elements. Several lines of evidence and argument strongly suggest that this GC-rich element functions as the cis-regulatory sequence involved in cAMP-mediated transcriptional control in yeast mitochondria.

Cyclic AMP↗
PubMed1996

Childhood steroid-sensitive nephrotic syndrome: does the histology matter?

Renal biopsy specimens from 51 children with steroid-sensitive nephrotic syndrome who were following a frequently relapsing or steroid-dependent course were reviewed by two histopathologists. In all cases the biopsy was performed prior to the commencement of an 8-week course of cyclophosphamide. The clinical courses of these patients both prebiopsy and for a minimum of 2 years after completion of cyclophosphamide therapy were analyzed using retrospective case note analyses. The distribution of histologic diagnoses differed significantly from that reported by the International Study of Kidney Disease in Children in their study of children who underwent biopsy at the time of presentation, there being an excess of focal segmental glomerulosclerosis and mild mesangial hypercellularity in this series. The prebiopsy clinical course did not predict for histologic diagnosis, and there was no correlation between prebiopsy course or histology and postcyclophosphamide course. The findings of this study support the clinical impression that steroid sensitivity rather than histology is the major determinant of prognosis in childhood nephrotic syndrome and that frequency of relapse alone is not an indication for biopsy.

Adrenal Cortex Hormones↗
PubMed1996

Identification of a cAMP-dependent protein-DNA interaction at a sequence near the yeast mitochondrial rRNA genes.

We have shown that expression of yeast mitochondrial (mt) rRNA genes (S. cerevisiae) is controlled in a cAMP-dependent manner via PKA, suggesting a trans-activation process involving phosphorylation-dependent protein-mt DNA interaction. We used filter-binding assays, mt protein extracts, and mt DNA from a rho-mutant strain retaining the 21S rRNA gene to demonstrate such an interaction. Competition assays with the cloned 21S-related mt DNA fragment undergoing interaction showed that a sequence in that fragment is present in mt DNA from a rho-strain retaining the 16S mt rRNA gene, but not in a VAR1-retaining rho-strain that lacks cAMP-mediated mt transcription. The sequence of the 21S-related mt DNA fragment undergoing protein interaction includes a GC cluster; that GC cluster sequence is also present near the 16S gene but not near VAR1. These and other data are consistent with a role for the GC cluster in cAMP-mediated expression of mt rRNA genes.

Cyclic AMP↗
PubMed1996

Prevalence of seromarkers of HBV and HCV in health care personnel and apparently healthy blood donors.

Ninety-five health care workers and 91 controls were screened for seromarkers of both HBV (HBsAg, HBeAg, Anti-HBc) and HCV (anti-HCV) by ELISA. The control group showed a much higher frequency of seromarkers for both the viruses. HBsAg was positive in 5% of study group (health care personnel) and 14% of controls. Anti-HBc as a marker of past HBV-exposure was positive in 28% of study group as compared to 36% of controls. Overall, 33% of study group and 48% of control showed one or the other marker of HBV Anti-HCV was positive in 4% of study group and 14% of controls. This study suggests that health care workers are not particularly a high risk group as compared to rest of the population.

Adult↗
PubMed1996

Sero-prevalence of HIV: six years' experience at Shaikh Zayed Hospital, Lahore.

Sero-prevalence of HIV was tested among 16,170 individuals. They included 215 patients with sexually transmitted diseases (STD), 77 I/V drug users, 21 commercial sex workers, 987 patients on haemodialysis, 119 subjects referred for HIV testing, 12,482 voluntary blood donors, 360 ante-natal attenders, 73 tuberculosis patients, 674 Pakistanis travelling abroad and 1162 persons who had received multiple blood transfusions. Ten persons were seropositive (0.06%). All of them came from the 119 subjects, suspected to be suffering from AIDS. The predominant mode of transmission was heterosexual (50%), blood transfusion (30%), homosexual (10%) and vertical (10%). All cases acquired infection outside the country. Comparisons have been made with other national studies.

Adult↗
PubMed1996

Veno-occlusive disease of the small bowel. An entity in search of identity.

Veno-occlusive disease of the bowel is a rare entity, and, to our knowledge, only two studies have been reported in the literature; these reports describe 11 patients with veno-occlusive disease of the small and large bowels. We describe a patient who developed veno-occlusive disease of the small bowel, whose histologic findings were somewhat different from those previously reported.

Adult↗
PubMed1995

Ontogeny of oxytocin-like immunoreactivity in the Brazilian opossum brain.

The neuropeptide oxytocin (OT) has been shown to function as a neurotransmitter and/or neuromodulator in addition to its hormonal function in the periphery in the adult central nervous system (CNS). Previously, we have studied the postnatal neurogenesis of the paraventricular and supraoptic nuclei and ontogeny of arginine vasopressin-like immunoreactivity in the Brazilian opossum brain, Monodelphis domestica. In this study, we have described the ontogeny of oxytocin-like immunoreactivity (OT-IR) in the opossum brain. As a marsupial, opossum pups are in an extremely immature state, with neurogenesis and morphogenesis continuing into the second week of postnatal life. Thus, opossum pups are a good model for developmental studies. In the adult opossum brain, OT-IR was localized in regions as reported for the adult rat and other species, except for a few differences. These findings suggest similar functional roles for OT in the adult opossum brain as in other mammals. Unlike the prenatal expression of arginine vasopressin, OT-IR was first detected in the forming median eminence on day 1 of postnatal life (1 PN). Between 3 and 5 PN, OT-IR was present in the hypothalamic supraoptic and paraventricular nuclei and posterior pituitary. At this time, neurogenesis of these nuclei is not completed. By 10 to 15 PN, OT-IR was seen in several brain areas, and begins to resemble that of the adult between 45 and 60 PN. These results indicate that the time course of appearance of the OTnergic system does not directly parallel the early expression of the vasopressinergic system. However, the expression of OT-IR in the opossum brain before neurogenesis and morphogenesis is completed suggests a potential role for OT in developmental events. Similar to arginine vasopressin, oxytocin may also be involved in the regulation of autonomic functions that are essential for the opossum's adaptation to an ex utero environment. Future studies utilizing experimental manipulations of the OTnergic system will help determine the significance of this peptide in the neonatal opossum.

Animals↗
PubMed1995

Androgen receptor-like immunoreactivity in the Brazilian opossum brain and pituitary: distribution and effects of castration and testosterone replacement in the adult male.

Androgens are involved in a variety of centrally mediated functions after binding to their intracellular receptors. In the present report, we have employed the androgen receptor antibody, PG-21, and indirect immunohistochemistry to examine the distribution of cells containing androgen receptor-like immunoreactivity (AR-IR) in the intact adult male Brazilian opossum brain and pituitary. Additional adult males were castrated to examine the effects of withdrawal of circulating androgens and testosterone replacement on AR-IR. Immunoblots and immunohistochemical controls demonstrated that the androgen receptor in the opossum brain and peripheral tissues are of a similar molecular mass as to has been reported for the rat. Cells containing AR-IR were widely distributed throughout the brain of intact adult males. The highest number of immunoreactive cells were present in the dorsal and ventral nuclei of the lateral septum, medial division of the bed nucleus of the stria terminalis, medial preoptic area, median preoptic nucleus, nucleus of the lateral olfactory tubercle, central amygdaloid nucleus, anterior cortical amygdaloid nucleus, posterior amygdaloid nucleus, subiculum, ventromedial hypothalamic nucleus, arcuate-median eminence region, and ventral premammillary nucleus. The anterior pituitary gland also contained a high number of cells containing AR-IR. The general distribution of AR-IR both in the brain and anterior pituitary gland resembled that reported for other mammalian species. Castration of the adult males four days prior to perfusion eliminated androgen receptor immunostaining throughout the brain except for a few lightly immunostained cells in the ventral nucleus of the lateral septum and stria terminalis. Androgen receptor immunostaining was decreased in the anterior pituitary gland following castration and became cytoplasmic. Testosterone administration 2 h before perfusion restored AR-IR both in the brain and anterior pituitary gland. These data suggested that immunohistochemical detection of bound (nuclear) androgen receptors as seen with PG-21 antibody in the brain and anterior pituitary gland of the opossum is dependent upon circulating androgens. Further, the wide distribution and similarity in localization of androgen receptors in the opossum brain and anterior pituitary gland to that of other species suggests that androgen receptors might be involved in similar functions in the opossum as has been reported for other species.

Animals↗
PubMed1995

Ontogeny of arginine vasopressin-like immunoreactivity in the Brazilian opossum brain.

The neuropeptide arginine vasopressin is involved in many centrally mediated functions and brain development. In this study, we have examined the ontogeny of arginine vasopressin-like immunoreactivity (AVP-IR) in the Brazilian opossum (Monodelphis domestica) brain to further understand the involvement of AVP in the forming central nervous system. Monodelphis is a small pouchless marsupial and its pups are born in an extremely immature state before neurogenesis is completed. In the adult brain, cell bodies containing AVP-IR were found in several nuclear groups and areas, and immunoreactive fibers were found to be widely distributed throughout the brain. The distribution of AVP-IR in the adult opossum brain generally resembled that reported for other species including the rat, however, some differences in localization of immunoreactive cells were observed. In the developing opossum brain, AVP-IR was first seen in the mesencephalon and diencephalon between embryonic days 12 and 13. Subsequently, a distinct group of AVP immunoreactive cells was present in the forming supraoptic nucleus on day 1 of postnatal life (1 PN) and at 3 PN in the paraventricular nucleus. Between 1 and 3 PN, a few cells transiently expressed AVP-IR in the forming thalamus and tegmental area. At these ages a few immunoreactive fibers were also detected in the forming cerebellum. These fibers were not seen at later ages in these areas. By 5 PN, an increased expression of AVP-IR was seen in the forming supraoptic and paraventricular hypothalamic nuclei, median eminence, and posterior pituitary. At 7 PN, immunoreactive cells and fibers were seen in several forebrain areas. The distribution pattern of AVP-IR became adult-like by 60 PN. A sex difference in the amount of AVP-IR in the lateral septum was also observed in the opossum brain at 60 PN. This difference persisted in the adult brain. Due to the early presence of AVP-IR in the Monodelphis brain before neurogenesis and morphogenesis is completed, we suggest that AVP may be involved in morphogenesis of the central nervous system. In addition, AVP may have a significant physiological function in regard to homeostasis before the forebrain contributes to these control mechanisms. Further studies, including physiological and developmental manipulations, will define the significance of the early presence of AVP during the differentiation and maturation of the central nervous system in Monodelphis.

Animals↗
PubMed1995

Postnatal neurogenesis of the hypothalamic paraventricular and supraoptic nuclei in the Brazilian opossum brain.

We have used bromodeoxyuridine (BrdU) single and BrdU-arginine vasopressin-oxytocin (BrdU-AVP-OT) double and triple label immunohistochemistry to characterize postnatal neurogenesis of the supraoptic and paraventricular nuclei in the Brazilian opossum. Developing pups received a single injection of BrdU between days 1 and 11 postnatally. All brains were collected on day 60 of postnatal life (60 PN). Single label BrdU immunohistochemistry revealed that an injection at 1 PN resulted in heavy labelling in the hypothalamus including the area of the paraventricular nucleus, whereas only approximately one third of the cells in the supraoptic nucleus were labelled. Analysis of data indicated that neurogenesis of the supraoptic and paraventricular nuclei is completed by days 5 and 7 PN, respectively. Double and triple label immunohistochemistry demonstrated that following BrdU injection on day 1 or 2 PN, few of the AVP and OT secreting cells in the supraoptic nucleus were double labelled with either peptide and BrdU, and no double labelled cells were seen following BrdU injection on day 5 PN. Similarly, in the paraventricular nucleus most of the AVP and OT secreting magnocellular cells were not double labelled with either peptide and BrdU. Whereas several double labelled cells were observed in the parvicellular part following BrdU injection on day 1 or 2 PN. No double labelled cells were present in any component of the paraventricular nucleus following injection on day 7 PN or later. These results indicate that the majority of the AVP and OT secreting magnocellular neurons are born prenatally and the OT and AVP parvicellular group of neurons are born during postnatal life. Our results also demonstrate that in contrast to that of eutherian rodents such as the rat and mouse, neurogenesis in the opossum hypothalamus continues into the postnatal period and provides a unique opportunity to study the neuroanatomical development of diverse regions such as the paraventricular nucleus.

Age Factors↗