Biomedical subjects
Publications and source records attributed to S Joshi.
PURPOSE: This study was conducted to report a rare cause of colonic bleeding. METHODS: Case report. CONCLUSION: Surgical resection of congenital colonic varices is associated with a low incidence of morbidity and mortality, and a favorable long-term prognosis can be expected when there is no evidence of hepatocellular disease (portal hypertension).
Control of sympathetic preganglionic neurons appears to be mediated, in part, through polysynaptic pathways using spinal interneurons. To identify spinal interneurons antecedent to adrenal sympathetic preganglionic neurons, we injected herpes simplex virus type 1 into the adrenal gland of hamsters as this virus is an effective trans-synaptic tracer of neural pathways. After a three day survival period, immunocytochemistry was used to visualize virus-infected spinal cord cells. Infected sympathetic preganglionic neurons with somata that were either kite-shaped, elliptical or fusiform and that had extensive dendrite arbors were identified as well as a group of smaller round cells with finer processes. For comparison, in additional hamsters, labelling with the retrograde tracer Fluoro-Gold and histochemical reactions for the enzyme nicotinamide adenine dinucleotide phosphate-diaphorase were used to identify sympathetic preganglionic neurons. Sympathetic preganglionic neurons identified with Fluoro-Gold or herpes virus were present mostly in the nucleus intermediolateralis, pars intermediolateralis and nucleus intermediolateralis, pars funicularis of the spinal cord. The smaller herpes virus-infected cells were found mostly medial to the preganglionic neurons in lamina VII and also dorsally in lamina V of the spinal cord. Assessing immunoreactivity for glial fibrillary acidic protein demonstrated that the smaller herpes virus-infected cells were not reactive astrocytes. Furthermore, these cells were immunoreactive for two neuronal markers, neuron-specific enolase and for microtubule-associated protein 2. These findings suggest that these smaller round cells with finer processes are distinct from sympathetic preganglionic neurons and astrocytes and may be interneurons antecedent to the sympathetic preganglionic neurons.
Within the past few years, lectins have become a well-established means for understanding varied aspects of cancer and metastasis. Evidence is now emerging that lectins are dynamic contributors to tumor cell recognition (surface markers), cell adhesion and localization, signal transduction across membranes, mitogenic stimulation, augmentation of host immune defense, cytotoxicity, and apoptosis. To advance understanding of these lectin-dependent processes, attempts are being made to discover new lectins that have one or more of these functions and to develop lectin- (or glycoconjugate-) based tools that could be used to home in on tumor cells. This review will summarize current research on the lectins and recent advances in the development of lectin-based diagnostic and therapeutic tools for cancer. Additionally, the future potential of lectin-based diagnosis and therapy is discussed.
Explore the source record for details and available documents.
Two clinical results of peripheral blood stem cell support are commonly considered: (1) the effect on hematopoietic recovery and (2) the effect on the underlying malignancy. The dynamics of hematopoietic recovery after autologous bone marrow transplantation and after autologous peripheral blood stem cell transplantation in a clinical setting are similar if no exogenous cytokines are administered and the peripheral stem cells are collected while their numbers are not deliberately increased (mobilised). If mobilized peripheral stem cells are transplanted, hematopoietic recovery is accelerated. In some circumstances, patients who receive peripheral stem cell transplantation may experience an improved progression-free survival after high-dose therapy when compared with similar patients who receive autologous bone marrow transplantation. Explanations for such a survival advantage might include (1) a lower likelihood of occult tumor cells capable of restoring disease in peripheral stem cell autograft products than in bone marrow harvests, (2) a greater number of cytotoxic effector cells capable of destroying occult tumor cells in the peripheral stem cell collections than in bone marrow harvests, and (3) a different and advantageous pattern of immunologic recovery following autologous peripheral stem cell transplant compared to autologous bone marrow transplant.
Moloney murine leukemia virua (MoMuLV)-derived retroviral vectors were engineered to express human immunodeficiency virus type 1 (HIV-1) packaging (psi) signal and Rev response element (RRE) sequences in either sense or antisense orientation. The RRE sequences were expressed under the control of the herpes simplex virus (HSV) thymidine kinase (tk) promoter fused to the HIV-1 trans-activation-responsive (TAR) element, while the psi signal sequences were expressed under control of the HSV tk promoter. Both RRE and psi signal sequences were expressed as part of the 3' untranslated region of the neomycin phosphotransferase (neo) mRNA. The constructs were used to transfect/infect packaging cell lines and the retroviral vector particles released were used to infect a human CD4+ lymphocyte-derived MT4 cell line. The stable MT4 transformants, harboring proviral vector DNA expressing one to two copies of HIV-1 RRE and psi signal in either antisense or sense orientation, were each tested for their susceptibility to HIV-1 infection. Compared to the results obtained with the control cells lacking any of the test DNA sequences, the rate of HIV-1 production remained unaltered in RRE1+ (sense RNA containing a single copy of RRE) RNA-containing cells, whereas it was delayed in cells expressing both RRE2+ (sense RNA containing two copies of RRE) and RRE1- (antisense RNA containing a single copy of RRE) RNA-expressing cells. In cells expressing HIV-1 psi signal, HIV-1 production remained unaltered in psi + RNA-expressing cells, whereas it was delayed by up to 30 days in psi - RNA-expressing cells.(ABSTRACT TRUNCATED AT 250 WORDS)
CTL activity against HIV-1 antigens expressed on HLA-A-matched EBV-transformed B target cells was detected in 33% (6/18) of freshly isolated PBMC (FPBMC) from patients in the early stages of HIV-1 infection (CDCII). No CTL activity was detected in FPMBC in patients with AIDS (CDCIV). However, the presence of CTL activity did not correlate with the expression of CTL activation markers. A dual-color flow cytometric examination revealed that the CD8+ lymphocytes bearing the memory (CD29) and activation (S6F1) surface molecules increased in number as the HIV-1 infection progressed. This functional and phenotypic discrepancy in memory CD8+ lymphocytes suggests that the memory CD8+ lymphocytes have lost cytotoxic function and become "paralyzed" as the HIV disease progresses. Incubation of PBMC of HIV(+) patients with rIL-2 reactivated predominantly HIV-specific CTL. However, rIL-2 stimulation also activated a "polyclonal or polyreactive" cytotoxic function. The reactivation of CTL function is rIL-2 dosage dependent and the amount of rIL-2 required for reactivation is associated with the severity of the disease. HIV antigen specific CTL in HIV(+) patients can be selectively expanded by HIV antigen stimulation in the presence of rIL-2. These results suggest that the in vivo IL-2 deficiency occurring in HIV-1 infection may be responsible in part for the "paralysis" of HIV specific CTL activity. Such activity can be rescued nonspecifically by exogenous rIL-2 stimulation and expanded specifically by HIV-1 antigen stimulation.
Explore the source record for details and available documents.
Naproxen, a nonsteroidal anti-inflammatory drug has been evaluated for its anticataract action in the prevention of cataracts induced by selenite. Administration of a single dose of sodium selenite intraperitoneally resulted in the development of advanced cataracts in 100% of the eyes within 5-6 days. Treatment with naproxen resulted in showing a significant preventive effect. The biochemical parameters like glutathione, malonaldehyde or soluble and insoluble protein contents indicate that selenite causes cataract due to oxidative stress. The observations also suggest that naproxen acts as an anti-oxidant.
Explore the source record for details and available documents.
Nonocular malignant melanoma is a rare but lethal disease increasing in incidence and mortality in western countries with improved survival if diagnosed and treated early. This study reports its epidemiology from cancer registry data in six different parts of India; its anatomic distribution and trends in Bombay from 1964 to 1984. Age-adjusted incidence in Bombay patients shows no increase from 1964 to 1984 unlike in white caucasians. Males exceed females in patients 45 years or older unlike whites, but are equalled or exceeded by females in those less than 45 years. The sole of foot and internal mucous membranes are its major anatomic sites in Indians as in negroid blacks. This cancer in Indians resembles that in blacks and nonwhites in affecting less pigmented epithelia and skin. Susceptible melanosomes and ultraviolet light exposure may both be involved in its aetiopathogenesis.
Explore the source record for details and available documents.
Trans-dominant mutants of human immunodeficiency virus type 1 (HIV-1) Tat and Rev are attractive candidates for use in gene therapy in the treatment of HIV-1 infections because both are essential for viral replication. Retroviral vectors were constructed to allow either Tat-inducible or Tat- and Rev-inducible expression of trans-dominant mutants of Tat and Rev. These vectors were used to infect a human CD4+ lymphocyte-derived cell line, MT4. To determine the efficacy of various Tat and Rev mutants in inhibiting HIV-1 multiplication, MT4 cells containing mutant-expressing constructs were infected with HIV-1, and the amount of HIV-1 released in the culture medium was measured for up to 30 days. A high level of resistance was observed in cells expressing the double tat/rev mutant in a Tat-inducible manner.
A preliminary study of maternal smokeless tobacco use, mostly oral applications of burnt tobacco or 'mishri', in pregnancy showed 65 of 178 singleton liveborns occurred to users and 113 to non-users in Bombay, India. Eighty-three newborns, 42 to maternal tobacco users and 41 to non-users were < 2.5 kg birth weight, i.e. low birth weight (LBW; odds ratio 3.2; confidence interval 1.5-6.9; P < 0.001). Stratifying by gender yielded odds ratios of 1.6 (P > 0.1, NS) for male and 6.96 (confidence interval 2.5-19.4, P < 0.0005), for female newborns compared to normal birthweight boys and girls, respectively. Male:female newborns were 80.6:100 in maternal tobacco users compared to 105.5:100 in non-users. Defining LBW as < 2.0 kg yielded an odds ratio of 5.4 (confidence interval 1.8-15.2, P < 0.005) in maternal tobacco users' offspring. For babies weighing 2-2.5 kg at birth it was 2.76 (confidence interval 1.4-5.5, P < 0.01). Maternal use of 'mishri' tobacco in pregnancy may be associated with (1) the offsprings' low birth weight, (2) low birth weights in girls more than in boys; (3) decreased male:female ratio in live newborns, and (4) low birth weight of < 2.0 kg more than of 2-2.5 kg. Studies are needed to substantiate these findings. Gender differences in outcome suggest the in utero effect of maternal smokeless tobacco use on male and female fetuses may differ.
We designed a prospective study to compare the validity of airway pressure (AWP) monitoring with that of end-tidal CO2 (ETCO2) monitoring for early detection of air embolism. Subjects included 76 patients of both sexes who underwent neurosurgery in the sitting position. Anesthesia was maintained with O2, N2O, narcotics, pancuronium, and intermittent positive pressure ventilation (IPPV). Continuous monitoring was done of HR, ECG, intraarterial pressure, AWP, and ETCO2. A sudden and sustained decrease in ETCO2 during anesthesia in a hemodynamically stable patient was considered as a sign of air embolism. Concomitant changes in AWP and cardiovascular parameters were also recorded simultaneously. Onset time, stage of surgery, and duration of disturbances were recorded. At the same time, the chest was auscultated for any murmur. Aspiration of air through the CVP catheter was attempted for diagnosis and management of air embolism. ETCO2 monitoring detected 24 episodes (31.5%) of air embolism in 16 patients. We observed 10 episodes (13.1%) of tachycardia in nine patients and nine episodes (11.8%) of hypotension in eight of the 16 patients. Murmur was noted in four patients and air aspiration in six patients. Only six patients of the 16 had an increase in AWP along with the decrease in ETCO2. We conclude that AWP monitoring is neither a sensitive nor reliable indicator of air embolism.
The three-dimensional image-reconstruction problem solved here for optical-sectioning microscopy is to estimate the fluorescence intensity lambda(x), where x epsilon R3, given a series of Poisson counting process measurements [Mj(dx)]jJ = 1, each with intensity [formula: see text] with [formula: see text] being the point spread of the optics focused to the jth plane and sj(y) the detection probability for detector point y at focal depth j. A maximum a posteriori reconstruction generated by inducing a prior distribution on the space of images via Good's three-dimensional rotationally invariant roughness penalty [formula: see text] It is proven that the sequence of iterates that is generated by using the expectation maximization algorithm is monotonically increasing in posterior probability, with stable points of the iteration satisfying the necessary maximizer conditions of the maximum a posteriori solution. The algorithms were implemented on the DECmpp-SX, a 64 x 64 parallel processor, running at < 2 s/(64(3), 3-D iteration). Results are demonstrated from simulated as well as amoebae and volvox data. We study performance comparisons of the algorithms for the missing-data problems corresponding to fast data collection for rapid motion studies in which every other focal plane is removed and for imaging with limited detector areas and efficiency.
A cultivable acid fast stainable bacterium obtained from leprosy nodule showed similarity to M. leprae in antigenicity to serum antibodies of lepromatous leprosy patients. The antigenic similarity has been seen more clearly in the delipidified cell components of both these bacteria. An antigen of 35-38 kDa has been seen as a common antigen between M. leprae and the cultivable bacilli with binding ability to sera from leprosy patients. This cultivable bacterial component could be used for serodiagnosis of lepromatous leprosy.
Studies to establish the structure/function relationships of oligomycin sensitivity-conferring protein (OSCP) of mitochondrial ATP synthase were carried out using genetic engineering and biochemical approaches. A full-length cDNA clone encoding OSCP was isolated from a bovine heart cDNA library, and the mature form of OSCP was expressed in Escherichia coli using plasmid expression vector pKP1500. Recombinant OSCP was found to accumulate in the cytoplasmic inclusion bodies, by virtue of which the recombinant protein could be purified to greater than 85% purity by simple low speed centrifugation of cell lysates. Recombinant OSCP was found to be indistinguishable from OSCP isolated from mitochondria with respect to (i) apparent molecular mass on sodium dodecyl sulfate gel electrophoresis, (ii) immunological reactivity to anti-OSCP serum, (iii) biological activity in restoring oligomycin-sensitive ATPase and Pi-ATP exchange activities to OSCP-depleted ATP synthase complexes, and (iv) insensitivity of the biological activity to sulfhydryl-directed alkylating reagents. The amino-terminal sequence of the recombinant protein revealed that the initiating methionine was not removed by E. coli, although that apparently did not affect protein folding or its biological activity. Data on nested deletion mutations starting from the carboxyl terminus in OSCP demonstrated that, in each instance, the mutant form was expressed and the protein product was sequestered in cytoplasmic inclusion bodies, similar to the wild-type form. However, none of the variants, including the one in which only the last 10 residues were deleted, was able to restore cold-stable oligomycin-sensitive ATPase or Pi-ATP exchange activity in OSCP-depleted complexes. Taken together, these data suggest that amino acid residues 181-190 (or some of the residues in this region) in the OSCP sequence may be important for OSCP-F1 interactions.