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Biomedical subjects

S Alam

Publications and source records attributed to S Alam.

At least 55 records · Page 3Linked to original sources
PubMed1999

Clinical scoring system: a valuable tool for decision making in cases of acute appendicitis.

OBJECTIVE: Decision making in cases of acute appendicitis poses a clinical challenge specially in developing countries where advanced radiological investigations do not appear cost effective and so clinical parameters remain the mainstay of diagnosis. The aim of our study was to devise a scoring system from our local database and test its accuracy in the preoperative diagnosis of acute appendicitis. METHODS: Clinical data from 401 patients having undergone appendectomy were collected to identify predictive factors that distinguished those with appendicitis from those who had a negative appendectomy. Ten such factors were identified and using Bayesian probability a weight was assigned to each and the results summated to get an overall score. A cut-off point was identified to separate patients for surgery and those for observation. The scoring system was then retrospectively applied to a second population of 99 patients in order to compare suggested actions (derived from the scoring system) to those actually taken by surgeons. The sensitivity, specificity and accuracy for the level of decision was then calculated. RESULTS: Of the 99 patients, the method suggested immediate surgery for 65 patients, 63 of whom had acute appendicitis (3.1% diagnostic error rate). Of the 33 patients in whom the score suggested active observation, 18 had appendicitis. The accuracy of our scoring system was 82%. The method had a sensitivity of 78%, specificity 89% and a positive predictive value of 97%. The negative appendectomy rate determined by our study was 7% and the perforation rate 13%. CONCLUSION: Scoring system developed from a local database can work effectively in routine practice as an adjunct to surgical decision making in questionable cases of appendicitis.

Acute Disease↗
PubMed1998

Immortalization by gene transfection.

Cultured cell lines that maintain specific differentiated phenotypes have been indispensable tools in cell biology. Progress in understanding the function of differentiated cells in vivo can be facilitated by creating cell lines via immortalizing gene transduction, if they retain the essential differentiated features of the same cells in vivo. Rodent cells immortalize spontaneously with a frequency of 10(-5) to 10(-6). Thus, it is easy to isolate immortal cells from rodent cell populations even without the transfer of immortalizing genes. Immortalizing genes can be used to increase this frequency to approximately 100%. In contrast, the spontaneous immortalization of human cells is a very rare event; the frequency is thought to be < 10(-12). Immortalizing genes can also be used to increase this frequency. Several genes that promise efficient immortalization of cultured cells have been identified. Immortalizing genes include simian virus 40 large T antigen, papillomaviruses E6 and E7, adenovirus E1A, Epstein-Barr virus, human T-cell leukemia virus, herpesvirus saimiri, oncogenes, and mutant p53 gene. Equally important, innovative means of gene delivery have been developed as well. These immortalizing genes, together with gene transfer methodologies, have provided the means to generate cell lines from cell types that are not abundant or are difficult to obtain in pure form in primary culture, are in short supply as human cells, and/or have brief lifetimes in culture. This chapter focuses primarily on the immortalization method by gene transfection. The chapter is not meant to be comprehensive, but rather to provide an account of the power and usefulness of immortalization methodology.

Animals↗
PubMed1998

Pleural perforation of an aspergilloma cavity occurring in a patient with interstitial lung disease.

An aspergilloma is a fungus ball resulting from colonization of pre-existing pulmonary cavities, which usually represents a non-invasive form of aspergillosis. Spontaneous rupture of the cavity containing the fungi into the pleural space is an unusual complication that has been reported occasionally in patients with leukemia and invasive aspergillosis. We report on this unusual complication occurring in a patient with underlying interstitial lung disease, in whom the aspergilloma cavity abruptly ruptured into the pleural space with subsequent hydropneumothorax and pleural spillage of the fungi.

Aspergillosis↗
PubMed1996

Inhibition of vascular smooth muscle cell proliferation by the calcium antagonist clentiazem: role of protein kinase C.

The proliferation of vascular smooth muscle cells has been implicated as a causative factor in atherogenesis. Calcium channel blockers have been shown to retard the progression of atherosclerosis. To elucidate the mechanism by which these drugs mediate such actions, we studied the effects of a new calcium antagonist, clentiazem, on the in vitro proliferation of vascular smooth muscle cells. PDGF-induced prolifertion of these cells is markedly inhibited by clentiazem. The probable involvement of protein kinase C (PKC) in this cellular response is suggested. Clentiazem appear to cause inhibition of PKC translocation that is induced by phorbol esters and PDGF-BB and the phosphorylation of the 80 kDa protein substrate of PKC in vascular smooth muscle cells. Moreover, treatment with clentiazem leads to a marked decrease in the number of specific phorbol ester binding sites. Analysis of the membrane bound isoenzymes of protein kinase C revealed that the inhibition was specific to delta enzymes. Arterial cholesterol ester hydrolysis is not significantly altered by clentiazem. Our results suggest that clentiazem may inhibit cell proliferation by regulating cytosolic PKC and preventing its membrane translocation and activation.

Adenosine Monophosphate↗
PubMed1996

Induction and persistence of a cytotoxic T lymphocyte (CTL) response against a herpes simplex virus-specific CTL epitope expressed in a cellular protein.

CD8+ cytotoxic T-lymphocytes recognize small epitope peptides in association with MHC class I molecules expressed on the cell surface. In this study, we have determined whether an 8 amino acid viral CTL epitope, when expressed in a cellular protein, can be appropriately processed, presented, and recognized by the corresponding epitope-specific CTL and whether it is capable of inducing a CTL response in vivo. An H-2Kb-restricted CTL epitope from herpes simplex virus type 1 (HSV-1) glycoprotein B (gB epitope, residues 498-505) was cloned into the mouse dihydrofolate reductase protein (DHFR) at amino acid position 87. The recombinant DHFRs were expressed in vaccinia virus recombinants. To distinguish the recombinant DHFR proteins from the endogenous DHFR, an antibody epitope, recognized by monoclonal antibody PAb 901 and derived from simian virus 40 (SV40) T antigen was tagged to the C-termini of recombinant DHFR proteins. In vivo expression of recombinant DHFR was demonstrated by immunoprecipitation with the monoclonal antibody PAb 901. The H-2b cells infected with recombinant vaccinia virus expressing the recombinant DHFR were specifically lysed by gB epitope-specific CTL. Furthermore, the recombinant DHFR was functional in inducing a long lasting HSV gB epitope-specific CTL response upon immunization of C57BL/6 (B6) mice. These results indicate that a viral epitope expressed in a cellular protein can be efficiently processed, presented, and recognized by epitope-specific CTL and show that cellular proteins expressing CTL epitopes can be used for induction of CD8+ T lymphocyte responses.

Animals↗
PubMed1996

Antinociceptive effects of epidural and intravenous ketamine to somatic and visceral stimuli in rats.

PURPOSE: To evaluate the antinociceptive effect of epidural and intravenous ketamine on somatic and visceral stimuli and to address the emergency reaction. METHODS: Rats were randomly allocated into nine groups (n = 6); five groups with chronically implanted epidural catheters received saline or 0.5, 1, 2 and 4 mg. kg-1 ketamine epidurally, four groups received saline, or 1, 5 and 10 mg. kg-1 ketamine i.v. To assess somatic and visceral antinociceptive effects, tail flick (TF) test and colorectal distension (CD) test were carried out, respectively. Emergence reactions were graded. Maximal possible effects (% MPE) were calculated. RESULTS: Epidural ketamine increased % MPE in both tests in a dose-dependent fashion for 30 min (vs saline group, P < 0.05). Epidural ketamine 0.5 mg. kg-1 produced an increase in % MPE in the CD test (P < 0.05) but failed in the TF test. Intravenous ketamine, 10 mg. kg-1, produced 100 +/- 0 (mean +/- SE) % MPE in the CD test but 36 +/- 15% MPE in the TF test. Dose response curves indicated greater visceral antinociception than somatic. All rats showed emergence reactions following intravenous ketamine 10 and 5 mg. kg-1. CONCLUSION: Both epidural and intravenous ketamine produce greater antinociceptive effects to visceral than to somatic stimulation, and that epidural ketamine has a low incidence of emergence reactions.

Analgesics, Non-Narcotic↗
PubMed1996

Noninfectious pulmonary complications after organ transplantation.

Organ transplantation is a successful and recognized option for patients with end-stage pulmonary, cardiac, hepatic, renal, and hematologic disease. As with any new technology, however, a set of complications has developed in the form of lung injury after transplantation as a result of ischemic, chemotherapeutic, radiation-induced, and immunologic damage to the lungs. Interstitial changes soon after transplantation are typically due to pulmonary edema, the adult respiratory distress syndrome, and reperfusion injury or allograft rejection (in the case of lung transplantation). Late pulmonary injury presents as obliterative bronchiolitis and lymphoproliferative disease. Bone marrow transplant recipients are unique because they develop the idiopathic pneumonia syndrome, diffuse alveolar hemorrhage, pulmonary venoocclusive disease, and graft-versus-host disease. New insights about these interstitial syndromes are the subject of this review.

Adult↗
PubMed1995

Anaesthetic management for caesarean section in a patient with Kawasaki disease.

Kawasaki disease (KD) or mucocutaneous lymph node syndrome is an acute febrile illness affecting mainly children under four years of age. The most important clinical feature of this disease is coronary arteritis associated with aneurysms and thrombotic occlusions, which may lead to ischaemic heart disease or sudden death. It has now been more than 20 yr since its first description, and a number of survivors of childhood KD have reached child-bearing age. Despite the possible fatal outcome of this disease in adult patients with coronary artery manifestations, no information is available regarding the obstetrical anaesthetic management of patients with a history of KD. The purpose of this report is to describe the successful use of epidural anaesthesia in a patient with a history of KD undergoing Caesarean section and to discuss the anaesthetic considerations that should be given to adult survivors of childhood KD.

Adult↗
PubMed1995

Diagnosis, pathogenesis, and treatment of sarcoidosis.

Sarcoidosis is a commonplace multisystem disorder characterized by the presence of noncaseating granulomas. Although the clinical syndrome of the disease is recognized throughout the world, the pragmatic understanding of its diagnosis and management remains poorly understood and controversial. Much of the frustration experienced in elucidating its pathogenesis is directly related to our inability to find the cause of the disease. This review provides a brief and practical discussion of the diagnosis, pathogenesis, and concept of disease activity. It also recommends guidelines for management based on available clinical, immunologic, and radiologic information enhanced by our experience at the University of Southern California during the past 30 years.

Adrenal Cortex Hormones↗
PubMed1994

Cloning of cDNAs encoding a cell-cycle-regulatory GTP-binding low-M(r) (GBLM) protein, Ran/TC4, from micronucleated Tetrahymena thermophila and amicronucleated Tetrahymena pyriformis.

Using PCR we have isolated two novel, closely related cDNA clones coding for a GTP-binding low-M(r) protein from Tetrahymena cells. The two clones from T. thermophila and T. pyriformis have open reading frames encoding proteins of 225 amino acids (aa) with a calculated M(r) of 25,648, and of 223 aa with a calculated M(r) of 25,421, respectively. The two gene products were very homologous to Ran/TC4 which are involved in chromatin condensation and control of the cell cycle: they possess much higher similarities to human, chicken, Schizosaccharomyces pombe and Dictyostelium discoideum Ran/TC4 homologues than those to other GTP-binding low-M(r) proteins, such as Ras and Rho. Thus, the two clones isolated from Tetrahymena were designated as Tt-ran and Tp-ran, respectively. Tt-ran and Tp-ran share 83% identity at nucleotide level, and about 92% identity and 94% homology at aa level. Tt- and Tp-Ran, as well as other Ran/TC4, contain the four consensus regions involved in GTP/GDP-binding and GTPase activities. However, at the C-terminal end, although all the known Ran/TC4 terminate in a consensus D-L motif, Tt-Ran and Tp-Ran do not have the unique aa sequence of other Ran/TC4, but have a F-N motif. Tt-ran and Tp-ran were actively transcribed in vivo as a 1.0-kb mRNA.

Amino Acid Sequence↗