An uncommon aetiology of perforated gastric ulcer.
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Aged↗
Biomedical subjects
M Ahmad
Publications and source records attributed to M Ahmad.
A patient with recurrent acute abdominal pain.
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Abdominal Pain↗
Induction of stromelysin gene expression by tumor necrosis factor alpha is inhibited by dexamethasone, salicylate, and N-acetylcysteine in synovial fibroblasts.
Proinflammatory cytokines, altered connective tissue metabolism, and overexpression of matrix metalloproteinases (MMPs) such as stromelysin compared to tissue inhibitors of metalloproteinases (TIMPs) result in synovial inflammation and erosion of arthritic cartilage. Tumor necrosis factor alpha (TNF-alpha) is a major synovial inflammatory mediator responsible for inhibiting extracellular matrix (ECM) synthesis and stimulating degradation of cartilage ECM by activated MMPs in arthritic joints. To suppress these effects and to gain insight into the mechanism of TNF-alpha action, we identified the inhibitors of TNF-alpha stimulation of stromelysin gene expression. In bovine synovial fibroblasts, TNF-alpha did not affect a recently identified inhibitor, TIMP-3, but induced stromelysin mRNA expression in a dose- and time-dependent fashion (3- to 5-fold) which required de novo protein synthesis. Stimulation by TNF-alpha was potently inhibited (99-100%) by the synthetic glucocorticoid, dexamethasone. Sodium salicylate dose-dependently inhibited (100%) the TNF-alpha action. Indomethacin and ibuprofen were partially inhibitory. Free radical scavenger antioxidant, N-acetylcysteine (but not other antioxidants) also suppressed the TNF-alpha induction (36-100%) of stromelysin suggesting involvement of reactive oxygen species in the induction process. TNF-alpha induction of stromelysin gene expression can therefore be inhibited at the gene expression level by several pharmacological agents which are likely to function via arachidonic acid metabolites, free radical scavenging or interference with the activator protein 1, polyoma virus enhancer A-binding protein 3, and nuclear factor kappaB classes of transcription factors. Our results may help to elucidate the mechanism of TNF-alpha action and explain the beneficial role of these agents in the treatment of inflammatory diseases.
Acetylcysteine↗
Multidisciplinary approach for the management of post-herpetic neuralgia in elderly patients.
Post-herpetic neuralgia is associated with significant distress and morbidity. The management of acute neuritis and/or post-herpetic neuralgia can be particularly difficult. A multidisciplinary approach is required. A team consisting of the primary care physician, pain specialist, neurologist, geriatrician, pain psychologist, psychiatrist, and a physiatrist with an integrated approach will provide the best results. Early interventional therapy with sympathetic nerve blocks may significantly decrease the need for long-term opioid therapy, as well as long-term use of anticonvulsants, antidepressants, or membrane stabilizers. Early referral to a multidisciplinary pain center may furthermore decrease the behavioral trauma and family disruption associated with this painful condition.
Aged↗
Immunization coverage in three districts of North West Frontier Province (NWFP).
AIM: This community-based study was conducted to assess the progress of Expanded Programme on Immunization (EPI) in North West Frontier Province (NWFP) of Pakistan. METHOD: In this cross sectional survey, 120 randomly selected clusters in 03 districts of NWFP were included, 2673 children in the age group 12-35 months of 2583 randomly selected families were visited. RESULTS: The results showed that 65% of children were fully immunized, but out of them only half could be verified by immunization, need of 2nd and 3rd dose and no faith in immunization were the major causes of failure of immunization programme. Moreover, mother too busy, absence of vaccinator and inconvenient place of immunization were the obstacles pointed out by the parents. CONCLUSION: This study suggests the areas where improvement can be made to achieve the real target of immunization coverage. It is concluded that despite of more than 20 years of efforts by EPI, the ultimate objectives have not been achieved.
Child, Preschool↗
Ossification of posterior spinal ligament causing atypical cord compression.
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Cervical Vertebrae↗
Natural killer (NK) cell-mediated cytotoxicity: differential use of TRAIL and Fas ligand by immature and mature primary human NK cells.
Mature natural killer (NK) cells use Ca2+-dependent granule exocytosis and release of cytotoxic proteins, Fas ligand (FasL), and membrane-bound or secreted cytokines (tumor necrosis factor [TNF]-alpha) to induce target cell death. Fas belongs to the TNF receptor family of molecules, containing a conserved intracytoplasmic "death domain" that indirectly activates the caspase enzymatic cascade and ultimately apoptotic mechanisms in numerous cell types. Two additional members of this family, DR4 and DR5, transduce apoptotic signals upon binding soluble TNF-related apoptosis-inducing ligand (TRAIL) that, like FasL, belongs to the growing TNF family of molecules. Here, we report that TRAIL produced or expressed by different populations of primary human NK cells is functional, and represents a marker of differentiation or activation of these, and possibly other, cytotoxic leukocytes. During differentiation NK cells, sequentially and differentially, use distinct members of the TNF family or granule exocytosis to mediate target cell death. Phenotypically immature CD161(+)/CD56(-) NK cells mediate TRAIL-dependent but not FasL- or granule release-dependent cytotoxicity, whereas mature CD56(+) NK cells mediate the latter two.
Antibodies, Monoclonal↗
Cloning of a brain N-methyl-D-aspartate- and D, L-epsilon-2-amino-4-propyl-5-phosphono-3-pentanoic acid (CGP 39653)-binding protein.
A complex of four proteins isolated from neuronal membranes has ligand binding sites for N-methyl-d-aspartate (NMDA) receptor agonists and antagonists and forms NMDA-activated ion channels upon reconstitution into lipid membranes. In this study, the cDNA of a subunit of this complex containing binding sites for the competitive antagonists of NMDA receptors was cloned. The cDNA clone coded for a protein of 719 amino acids (78.9 kDa). The expressed protein had binding activity for the agonists l-[3H]glutamate and [3H]glycine, the antagonist (+/-)-[3H]-(E)-2-amino-4-propyl-5-phosphonopentanoic acid ([3H]CGP 39653), but not the ion channel inhibitors. The cloned cDNA had no homology to other cloned cDNAs. Northern blot analyses indicated high expression of an 3.8 kb poly(A+) RNA in brain, but not in other tissues. These findings indicate that proteins that have recognition sites for NMDA receptor activators and inhibitors and that differ from the well-characterized NMDA receptor proteins NR1-3 are expressed in mammalian brain.
2-Amino-5-phosphonovalerate↗
Identification and characterization of murine caspase-14, a new member of the caspase family.
We report here the identification and characterization of a new member of the mouse caspase family, named caspase-14. Northern blot analysis of mRNA from various tissues with caspase-14-specific probe showed a major transcript size of approximately 2.4 kb and variant transcripts of 2.0 kb and 1.5 kb. The major transcript is detected mainly in the liver and to a lesser extent in the brain and kidney. Caspase-14 cDNA encodes a 257-amino acid-long protein that has significant homology to other members of the caspase family. Like other caspases, caspase-14 has a conserved active site, pentapeptide QACRG. However, it lacks an NH2-terminal prodomain or a caspase recruitment domain, suggesting that it could be a downstream caspase that depends on other initiator caspases for activation. Consistent with this, procaspase-14 can be processed in vitro by the death receptor-associated caspase-8 and caspase-10 but not other caspases, and in vivo after stimulation of cells with anti-Fas agonist antibody or Tumor Necrosis Factor-Related Apoptosis Inducing Ligand. Furthermore, procaspase-14 can be cleaved by granzyme B. These observations suggest that caspase-14 may play a role in death receptor and granzyme B-induced apoptosis.
Amino Acid Sequence↗
Distinct, autosomal recessive form of spondyloepimetaphyseal dysplasia segregating in an inbred Pakistani kindred.
We describe a large inbred kindred from a remote area of Pakistan, comprising eight generations, with a distinct form of spondyloepimetaphyseal dysplasia (SEMD). We evaluated 16 affected individuals: 11 males and 5 females. Analysis of the pedigree strongly suggests autosomal recessive inheritance, and consanguineous loops could account for all the affected individuals being homozygous for the abnormal allele. The clinical findings included short stature evident at birth, short bowed lower limbs, mild brachydactyly, kyphoscoliosis, an abnormal gait, enlarged knee joints, precocious osteoarthropathy, and normal intelligence. Radiographs demonstrated delayed epiphyseal ossification at the hips and knees, platyspondyly with irregular end plates and narrowed joint spaces, diffuse, early osteoarthritic changes, primarily in the spine and hands, and mild brachydactyly. Mild metaphyseal abnormalities were seen predominantly at hips and knees. This distinctive phenotype is distinct from other autosomal recessive forms of SEMD because of the mild degree of metaphyseal involvement, the type of brachydactyly, and the absence of loose joints or other clinical findings.
Abnormalities, Multiple↗
Generation of constitutively active recombinant caspases-3 and -6 by rearrangement of their subunits.
Caspases play a major role in the transduction of the apoptotic signal and execution of apoptosis in mammalian cells. Ectopic overexpression of the short prodomain caspases-3 and -6 precursors in mammalian cells does not induce apoptosis. This is due to their inability to undergo autocatalytic processing/activation and suggests that they depend on the long prodomain caspases for activation. To investigate directly the apoptotic activity of these two caspases in vivo, we engineered constitutively active recombinant caspases-3 and -6 precursors. This was achieved by making contiguous precursor caspases-3 and -6 molecules, which have their small subunits preceding their large subunits. Unlike their wild type counterparts, these recombinant molecules were capable of autocatalytic processing in an in vitro translation reaction, suggesting that they are catalytically active. They were also capable of autoprocessing and inducing apoptosis in vivo independent of the upstream caspases. Furthermore, their autocatalytic and apoptotic activities were inhibited by the pancaspase inhibitor z-VAD-fluoromethylketone, but not by CrmA or Bcl-2, thus directly demonstrating that the targets of inhibition of apoptosis by CrmA and Bcl-2 are upstream of caspases-3 and -6. Since caspases-3 and -6 are the most downstream executioners of apoptosis, the constitutively active versions of these caspases could be used at very low concentrations in gene therapy model systems to induce apoptosis in target tissues or tumors.
Amino Acid Chloromethyl Ketones↗
Cryptochrome blue-light photoreceptors of Arabidopsis implicated in phototropism.
Phototropism-bending towards the light-is one of the best known plant tropic responses. Despite being reported by Darwin and others over a century ago to be specifically under the control of blue light, the photoreceptors mediating phototropism have remained unknown. We have characterized a blue-light photoreceptor from Arabidopsis, named CRY1 for cryptochrome 1; this photoreceptor is a flavoprotein that mediates numerous blue-light-dependent responses. In Arabidopsis, HY4 (the gene encoding CRY1) is a member of a small gene family that also encodes a related photoreceptor, CRY2, which shares considerable functional overlap with CRY1. Here we report that mutant plants lacking both the CRY1 and the CRY2 blue-light photoreceptors are deficient in the phototropic response. Transgenic Arabidopsis plants overexpressing CRY1 or CRY2 show enhanced phototropic curvature. We conclude that cryptochrome is one of the photoreceptors mediating phototropism in plants.
Anthocyanins↗
Blk, a BH3-containing mouse protein that interacts with Bcl-2 and Bcl-xL, is a potent death agonist.
We identified and cloned a novel murine member of the pro-apoptotic Bcl-2 family. This protein, designated Blk, is structurally and functionally related to human Bik and localized to the mitochondrial membrane. Blk contains a conserved BH3 domain and can interact with the anti-apoptotic proteins Bcl-2 and Bcl-xL. Ectopic expression of Blk in mammalian cells induces apoptosis, which can be inhibited by mutations in the BH3 domain and by overexpression of Bcl-2 or Bcl-xL but not by CrmA. The apoptotic activity of Blk is also inhibited by a dominant negative caspase-9, suggesting that Blk induces apoptosis through activation of the cytochrome c-Apaf-1-caspase-9 pathway.
Adaptor Proteins, Signal Transducing↗
Role of activating protein-1 in the regulation of the vascular cell adhesion molecule-1 gene expression by tumor necrosis factor-alpha.
Endothelial cell surface expression of VCAM-1 is one of the initial steps in the pathogenesis of atherosclerosis. The inflammatory response transcription factor nuclear factor (NF)-kappaB plays an important role in the regulation of VCAM-1 expression by various stimuli including tumor necrosis factor (TNF)-alpha. Other transcription factors may modulate this response through interaction with NF-kappaB factors. Since c-Fos/c-Jun (activating protein-1 (AP-1)) are expressed in vascular endothelium during proinflammatory conditions, we investigated the role of AP-1 proteins in the expression of VCAM-1 by TNF-alpha in SV40 immortalized human microvascular endothelial cells (HMEC). TNF-alpha induced expression of both early protooncogenes, c-fos and c-jun. The ability of TNF-alpha to activate the kappaB-motif (kappaL-kappaR)-dependent VCAM-1 promoter-chloramphenicol acetyltransferase (CAT) reporter gene lacking a consensus AP-1 element was markedly inhibited by co-transfection of the expression vector encoding c-fos ribozyme, which decreases the level of c-fos by degrading c-fos mRNA, or c-fos or c-jun oligonucleotides. Conversely, co-transfection of c-Fos and c-Jun encoding expression vectors potentiated the p65/NF-kappaB-mediated transactivation of the VCAM-1 promoter-CAT reporter gene. Furthermore the c-Fos encoding expression vector potentiated by 2-fold the transactivation activity of a chimeric transcriptional factor Gal/p65 (containing the transactivation domain of p65 and the DNA binding domain of the yeast transcriptional factor Gal-4). Consistent with the promoter studies, curcumin and NDGA, inhibitors of AP-1 activation, markedly inhibited the ability of TNF-alpha to activate the expression of VCAM-1 mRNA levels at concentrations that did not inhibit the activation of NF-kappaB. In gel mobility supershift assays, the antibodies to c-Fos or c-Jun inhibited the binding of TNF-alpha-activated nuclear NF-kappaB to the kappaL-kappaR, suggesting that both c-Fos and c-Jun interacted with NF-kappaB. These results suggest that AP-1 proteins may mediate the effect of TNF-alpha in the regulation of VCAM-1 expression through interaction with NF-kappaB factors in endothelial cells.
Cell Line, Transformed↗
The quantitative anatomy of the vertebral artery groove of the atlas and its relation to the posterior atlantoaxial approach.
STUDY DESIGN: An evaluation of the vertebral artery groove of the atlas vertebra using dry bony vertebrae. OBJECTIVES: To measure the dimension of the vertebral artery groove of the atlas and to define its relation to the posterior midline. SUMMARY OF BACKGROUND DATA: Anatomic descriptions of the vertebral artery groove of the atlas exist, but very little quantitative data focused on this groove have been reported. METHODS: Fifty dry atlas vertebrae were obtained for this study. Anatomic evaluation focused on the vertebral artery groove and its relation to the midline. A total of eight linear and two angular measurements were made bilaterally. The mean, range, and standard deviation were calculated for all of the specimens and for male and female specimens separately. RESULTS: Differences in dimensions of male and female specimens were found to be statistically significant in one linear and two angular parameters. The average depths of the medial and lateral entrances, lengths of the axis, and thicknesses of the vertebral artery groove for male and female specimens were 9 mm, 6 mm, 14 mm, and 4 mm, respectively. The average angle of the vertebral artery groove axis for both genders was 64 degrees lateral to the sagittal plane. The distances from the midline to the medial-most edge of the vertebral artery groove on the inner and outer cortexes for male and female specimens averaged 10 mm, with a minimum of 8 mm, and 18 mm, with a minimum of 12 mm, respectively. CONCLUSIONS: The results of this study suggest that dissection on the posterior aspect of the posterior ring should remain within 12 mm lateral to the midline, and dissection on the superior aspect of the posterior ring should remain within 8 mm of the midline.
Adult↗
Alopecia universalis associated with a mutation in the human hairless gene.
There are several forms of hereditary human hair loss, known collectively as alopecias, the molecular bases of which are entirely unknown. A kindred with a rare, recessively inherited type of alopecia universalis was used to search for a locus by homozygosity mapping, and linkage was established in a 6-centimorgan interval on chromosome 8p12 (the logarithm of the odds favoring linkage score was 6.19). The human homolog of a murine gene, hairless, was localized in this interval by radiation hybrid mapping, and a missense mutation was found in affected individuals. Human hairless encodes a putative single zinc finger transcription factor protein with restricted expression in the brain and skin.
Alopecia↗
Isolation and characterization of EMS induced splicing defective point mutations within the intron of the nrdB gene of bacteriophage T4.
The nrdB gene of bacteriophage T4 codes for the small subunit of ribonucleotide reductase and contains a 598-base-pair self-splicing intron which is closely related to other group I introns of T4 and eukaryotes. The screening, isolation, and mapping of 31 nrdB intron mutations were conducted by the strategic usage of the white halo phenotype exhibited by T4 mutants defective in dyhydrofolate reductase or thymidylate synthase. These intron mutations cluster towards the ends, mainly the 3' end, and show a defect in self-splicing. These mutations map in regions of conserved structural elements, thus supporting secondary structure predictions. A distinct pattern of clustering is observed with the highest number of mutations mapping within three of the smaller regions (A, C, and D) of the nrdB intron and no mutations mapping in the largest (B) region. The highest density of mutations mapped in the smallest region (C) of the intron, containing only 96 bases, thus showing a distinct pattern of clustering within the catalytic core.
Bacteriophage T4↗