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Biomedical subjects

A Kumar

Publications and source records attributed to A Kumar.

At least 1,027 records · Page 57Linked to original sources
PubMed1995

Utility of an observation unit in the emergency department of a tertiary care hospital in India.

This retrospective study was conducted to evaluate whether an observation unit (OU) attached to the emergency department (ED) of a tertiary care hospital in India is safe, is effective in minimizing hospitalization of acutely ill patients and is acceptable to the patients. Of 115,916 patients who attended the ED, 11,130 (9.6%) were observed in the OU. The average period of observation was 7.74 h. Of the patients observed, 21.3% required hospitalization, while 78.5% were discharged after treatment. Twenty-four patients left the hospital against medical advice, and three patients died in the OU. It is concluded that an OU in the ED is safe in treating acutely ill patients, is effective in reducing substantially the number of patients requiring admission to the hospital, and is acceptable to the patients.

Adolescent↗
PubMed1995

Somatosensory evoked potential changes following electro-acupuncture therapy in chronic pain patients.

Somatosensory evoked potentials were recorded in 20 healthy volunteers and 20 patients with chronic pain undergoing electro-acupuncture therapy. The values of absolute peak latency and amplitudes of N19 and P22 in the control group were compared with the corresponding baseline values in the study group and after electro-acupuncture therapy at three stages during a 10-treatment cycle. On these occasions the intensity of pain was recorded using a 100 mm visual analogue scale score. Each patient in the study group had 10 treatments given on alternate days. The absolute peak latency of N19 was significantly delayed (p < 0.05) in chronic pain patients when compared to the control group. This increase in latency of N19 persisted after the first electro-acupuncture treatment (p < 0.05), tended to revert to normal after the fifth treatment (p > 0.05) and reverted completely to control values after the 10th treatment (p > 0.05). Visual analogue scores also decreased significantly (p < 0.05) after the fifth and 10th electro-acupuncture sessions. These observations suggest that there is an interaction of the neural mechanisms of electro-acupuncture with the thalamic generator of somatosensory evoked potentials i.e. N19.

Acupuncture Analgesia↗
PubMed1995

Expression of IL-10, IL-4 and interferon-gamma in unstimulated and mitogen-stimulated peripheral blood lymphocytes from HIV-seropositive patients.

Infection of immune cells with HIV induces dysregulation of cytokines which may play a vital role in HIV pathogenesis. We analysed the expression of T helper type 1 (Th1) (interferon-gamma (IFN-gamma)) and Th2 (IL-4, IL-10) type cytokines in peripheral blood lymphocytes (PBL) from HIV+ patients. The semiquantitative reverse transcriptase polymerase chain reaction (RT-PCR) analysis revealed that IFN-gamma mRNA in unstimulated PBL was significantly decreased and IL-10 mRNA was significantly upregulated in patients with < 400 CD4+ T cells/mm3 (n = 30) as compared to patients with > 400 CD4+ T cells/mm3 (n = 6) and normal controls (n = 16). In addition, IL-10 mRNA levels were inversely associated with IFN-gamma expression. Similar results were obtained by measuring IL-10 production in the supernatants of PBL cultured in vitro without stimulation by employing an enzyme immunosorbent assay (ELISA). However, the levels of IL-4 and IFN-gamma produced by unstimulated PBL were undetectable by ELISA. Mitogen stimulation of PBL revealed two groups of HIV+ individuals based on IL-10 production. PBL from one set of individuals produced low levels of IL-10 (low IL-10 producers) whereas the other group produced IL-10 comparable to that of normal controls (IL-10 producers). Production of IL-4 was significantly reduced in HIV+ individuals with < 400 CD4+ T cells/mm3 as compared to the normal controls. However, ability to produce IFN-gamma by mitogen-stimulated total PBL and CD4+ purified cells was not impaired in HIV+ individuals. These results suggest that unstimulated and mitogen-stimulated PBL of HIV+ individuals exhibit dysregulation of Th2 type cytokines which may play a role in HIV immunopathogenesis.

Adult↗
PubMed1995

Dysregulated production of interleukin-10 (IL-10) and IL-12 by peripheral blood lymphocytes from human immunodeficiency virus-infected individuals is associated with altered proliferative responses to recall antigens.

The loss of immune function following infection with human immunodeficiency virus (HIV) may result from altered production of immunoregulatory cytokines such as interleukin-10 (IL-10) and IL-12. In this study, we analyzed IL-10 and IL-12 production by mitogen-stimulated peripheral blood mononuclear cells (PBMC) from HIV+ individuals and correlated their levels with proliferative responses to the recall antigens HIV p25 and influenza virus. We report two distinct groups of HIV+ patients. One group produced small amounts of IL-10, had PBMC that proliferated in response to recall antigens, and demonstrated enhanced recall antigen-induced proliferation upon addition of anti-IL-10 antibodies and/or IL-12. Conversely, the second group produced high levels of IL-10, had PBMC that failed to proliferate to recall antigens, and did not demonstrate enhanced proliferation upon addition of anti-IL-10 antibodies and/or IL-12. Mitogen-stimulated PBMC from both groups produced significantly lower levels of IL-12 than did those from HIV- controls. Analysis of the source of the IL-10-producing cell subset in PBMC demonstrated that in HIV+ individuals, IL-10 is produced by monocytes, while in HIV- controls, it is produced by both T cells and monocytes. Taken together, our results suggest that monocytes from HIV+ individuals secrete decreased amounts of IL-12, a Th1-type cytokine, which may lead to the development of Th2-type responses characterized by high IL-10 secretion and immune dysfunction.

Acquired Immunodeficiency Syndrome↗
PubMed1995

Interaction of nuclear protein p140 with human immunodeficiency virus type 1 TAR RNA in mitogen-activated primary human T lymphocytes.

Several lines of evidence suggest that cellular proteins play a role during human immunodeficiency virus type 1 (HIV-1) Tat-mediated trans activation. A recent report from this laboratory has shown that a 140-kDa HeLa nuclear protein (p140) binds specifically to the lower stem region of the Tat response element, TAR RNA. Since HIV-1 trans activation is most efficient in proliferating T cells, we investigated the binding of p140 to TAR RNA in unstimulated and mitogen-activated, G1-phase primary T lymphocytes. TAR RNA/protein-binding activity was low in resting cells but increased significantly within 2 h of activation and remained elevated for at least 48 h. Corresponding increases in p140 protein levels were observed with most but not all donors, suggesting that an additional nuclear factor(s) may be required for efficient binding of this protein to TAR RNA in activated T cells.

Base Sequence↗
PubMed1995

Interleukin-1 alpha stimulates dopamine release by activating type II protein kinase A in PC-12 cells.

A recent study from this laboratory [A. R. Gwosdow, N. A. O'Connell, and A. B. Abou-Samra. Am. J. Physiol. 263 (Endocrinol. Metab. 26): E461-E466, 1992] showed that the inflammatory mediator interleukin-1 alpha (IL-1 alpha) stimulates catecholamine release from primary cultures of rat adrenal cells. The present studies were conducted to determine whether 1) IL-1 alpha stimulates catecholamine/dopamine release from the adrenal medullary cell line PC-12 and 2) the adenosine 3',5'-cyclic monophosphate (cAMP)-protein kinase A (PKA) pathway is involved in IL-1 alpha-induced dopamine release from PC-12 cells. The results indicate that IL-1 alpha significantly (P < 0.05) elevated dopamine release after a 24-h incubation period. IL-1 alpha did not stimulate cAMP accumulation at any time period between 5 min and 2 h. In contrast, forskolin-treated cells elevated (P < 0.05) intracellular cAMP levels and increased dopamine release. Because IL-1 alpha did not affect cAMP accumulation, the effect of IL-1 alpha on PKA activity was investigated. IL-1 alpha increased (P < 0.05) PKA activity at 15 and 30 min and returned to control levels by 1 h. Forskolin also increased (P < 0.05) PKA activity. The type of PKA activated (P < 0.05) by IL-1 alpha was type II PKA. In contrast, forskolin activated (P < 0.05) type I and type II PKA. Inhibition of PKA with the PKA inhibitor H-8 blocked PKA activity and dopamine secretion by both IL-1 alpha and forskolin in PC-12 cells. These observations demonstrate that 1) IL-1 alpha stimulated dopamine release from PC-12 cells by activating PKA, 2) the mechanism of IL-1 alpha activation of PKA does not involve detectable increases in intracellular cAMP accumulation, and 3) IL-1 alpha activates type II PKA, which is used by IL-1 alpha to stimulate dopamine secretion from PC-12 cells.

Animals↗
PubMed1995

Urokinase receptor in human malignant mesothelioma cells: role in tumor cell mitogenesis and proteolysis.

Urokinase (uPA) interacts with its receptor (uPAR) to promote proteolysis and tumor migration, functions of potential importance in the pathogenesis of malignant mesothelioma. Immunohistochemistry of human malignant mesothelioma tissue and mesothelioma cells (MS-1) showed that mesothelioma cells express uPAR. We isolated uPAR from MS-1 cells by metabolic labeling and showed that it could be induced by phorbol myristate acetate (PMA), lipopolysaccharide (LPS), a transforming growth factor-beta (TGF-beta) or tumor necrosis factor-alpha (TNF-alpha). Experiments with MS-1 cells showed that uPA binding was saturable, specific, and reversible with a mean dissociation constant (Kd) of 5.4 +/- 1.1 nM. Binding was inhibited by a blocking antibody to uPAR and by the uPA amino-terminal fragment (ATF), but not by low molecular weight uPA. uPAR expression was regulated transcriptionally and translationally; antisense oligonucleotides blocked expression of uPAR protein. Plasminogen activator inhibitor-1 (PAI-1) inhibited PA activity of preformed uPA/uPAR complexes and increased cycling of the receptor from the cell surface. Stimulation of subconfluent MS-1 cells by high molecular weight or recombinant uPA, but not ATF or low molecular weight fragment, caused concentration-dependent incorporation of [3H]thymidine. These data indicate a novel mechanism by which malignant mesothelioma cells localize pericellular proteolysis and concurrently regulate tumor cell proliferation.

Cell Cycle↗
PubMed1995

Inhibition of factor Xa-mediated procoagulant activity of human lung fibroblasts and pleural mesothelial cells.

Extravascular fibrin deposition characterizes diverse forms of lung and pleural injury. Fibrin formation in these compartments is locally potentiated by the assembly and expression of the prothrombinase procoagulant complex (factors Xa, Va and II) at the surface of human lung fibroblasts and pleural mesothelial cells. We sought to identify structural domains on factor Xa that mediate expression of prothrombinase activity by these cells. In order to accomplish this objective, we used panels of monoclonal antibodies (MoAbs) to factor X to block prothrombinase assembly and function on the surface of cultured human lung fibroblasts and pleural mesothelial cells. Of 30 factor X MoAbs that recognized native factors X and Xa, 10 completely inhibited factor Xa function (prothrombin activation), and five others neutralized Xa function without affecting cell-binding, presumably by blocking the prothrombin binding site. Western blots showed that these inhibitory MoAbs reacted with the Xa heavy-chain. One MoAb that recognized the factor Xa light-chain blocked prothrombin activation at the factor Va binding site. Our results indicate that prothrombinase activity at the surface of lung parachymal or pleural cells can be blocked by MoAbs that interact with either the heavy- or light-chain of factors X. Antibodies that neutralize cell surface-expressed prothrombin activation offer a potential means to arrest pericellular fibrin formation in the lung and pleural space.

Animals↗
PubMed1995

Case report: spinal metastasis from carcinoma of the penis.

Carcinoma of the penis has a well documented metastatic pattern, regional lymph nodes being the predominant site of involvement. Distant metastasis is extremely rare, with a reported incidence of 1-10%. Osseous metastasis is even rarer and no case of metastasis to the spine has been reported previously. We present a case of carcinoma of the penis metastasizing to the spine.

Humans↗
PubMed1995

Post caloric nystagmus: an analysis of culmination frequency and maximum slow phase velocity.

Neurons of the vestibular nuclei receive substantial afferent inputs from various parts of the cerebellum and brainstem. The efferent output of the vestibular nuclei thus reflects the interaction of these connections. This study investigates the influence of lesions of the posterior neuro-axis (PNA) on thermally induced nystagmus in 70 such patients. The caloric responses of all these patients were analyzed automatically with respect to culmination frequency (CF), but an automated analysis of SPVMax was possible in only 36 of these patients. Analysis of both sets of data showed that the coefficient of variation of SPVMax was significantly greater than that of CF. Vestibular decruitment, which correlates well with PNA lesions, was noted in 83% of cases when CF was used. In contrast, when SPVMax was used, vestibular decruitment was noted in only 53% of patients. Considering the low coefficient of variation of CF and considering that vestibular decruitment is noted with greater reliability when this variable is used, it is recommended that caloric nystagmus should be analyzed with respect to frequency rather than SPVMax.

Adolescent↗
PubMed1995

Immunophenotype and ultrastructural studies in blast crisis of chronic myeloid leukemia.

Thirty-four patients with chronic myeloid leukemia in blast crisis (CML-BC) were evaluated for lineage differentiation with immunological markers and the presence of ultrastructural peroxidase. Eighteen (52.9%) were found to have myeloid blast crisis. Cytochemically, myeloperoxidase (MPO) could be detected only in six patients on light microscopy while in the remaining 12 patients, myeloid differentiation was confirmed only by demonstration of MPO either at ultrastructural level or by the reactivity with anti myeloperoxidase (anti MPO) antibody. Six (17.6%) had lymphoid blast crisis as identified by lymphoid specific markers (CD19; CD10; CD7; CD4) along with the absence of myeloid markers. Heterogenous blast cell populations with mixed lineage differentiation were seen in 4 (11.7%) patients. These cases showed both lymphoid (CD19, CD10) and myeloid (anti MPO and ultrastructural MPO) characteristics. A single case of megakaryoblastic blast crisis was identified with positivity for CD41 and CD42 along with the presence of platelet peroxidase at the ultrastructural level. Five cases (14%) of CML blast crisis remained unclassifiable. These results suggest that blast crisis in CML show an arrest of differentiation at an early stage when compared to de novo acute leukemias. This is particularly evident from the fact that MPO could only be demonstrated ultrastructurally or with anti MPO antibody in the majority of patients with myeloid differentiation. It is expected that utilisation of molecular studies including immunoglobulin and T-cell receptor gene rearrangement and m-RNA expression for myeloperoxidase will provide a better insight into the level of differentiation for the presently unclassifiable cases of CML-blast crisis.

Antigens, CD↗