Biomedical subjects
Publications and source records attributed to V Narayan.
Mesenteric tumors are rare, most commonly encountered lesions are fibromatoses and leiomyoma. A case of hemangiopericytoma of mesentery in a 38 years old female is reported for its rarity. The classical histological findings and recticulin stain to demonstrate blood vessels & recticulin fibers, encircling individual tumor cells aids in the correct diagnosis.
BACKGROUND AND OBJECTIVE: The purpose of this study was to investigate the effects of low-power laser irradiation on wound healing in genetic diabetes. STUDY DESIGN/MATERIALS AND METHODS: Female C57BL/Ksj/db/db mice received 2 dorsal 1 cm full-thickness incisions and laser irradiation (830 nm, 79 mW/cm(2), 5.0 J/cm(2)/wound). Daily low-level laser therapy (LLLT) occurred over 0-4 days, 3-7 days, or nonirradiated. On sacrifice at 11 or 23 days, wounds were excised, and tensile strengths were measured and standardized. RESULTS: Nontreated diabetic wound tensile strength was 0.77 +/- 0.22 g/mm(2) and 1.51 +/- 0.13 g/mm(2) at 11 and 23 days. After LLLT, over 0-4 days tensile strength was 1.15 +/- 0.14 g/mm(2) and 2.45 +/- 0.29 g/mm(2) (P = 0.0019). Higher tensile strength at 23 days occurred in the 3- to 7-day group (2.72 +/- 0.56 g/mm(2) LLLT vs. 1.51 +/- 0.13 g/mm(2) nontreated; P < or = 0.01). CONCLUSION: Low-power laser irradiation at 830 nm significantly enhances cutaneous wound tensile strength in a murine diabetic model. Further investigation of the mechanism of LLLT in primary wound healing is warranted.
Serial plain radiographic, ultrasound and CT findings of an unusual case of pulmonary blastoma are described with a review of the literature.
Two large-scale yeast two-hybrid screens were undertaken to identify protein-protein interactions between full-length open reading frames predicted from the Saccharomyces cerevisiae genome sequence. In one approach, we constructed a protein array of about 6,000 yeast transformants, with each transformant expressing one of the open reading frames as a fusion to an activation domain. This array was screened by a simple and automated procedure for 192 yeast proteins, with positive responses identified by their positions in the array. In a second approach, we pooled cells expressing one of about 6,000 activation domain fusions to generate a library. We used a high-throughput screening procedure to screen nearly all of the 6,000 predicted yeast proteins, expressed as Gal4 DNA-binding domain fusion proteins, against the library, and characterized positives by sequence analysis. These approaches resulted in the detection of 957 putative interactions involving 1,004 S. cerevisiae proteins. These data reveal interactions that place functionally unclassified proteins in a biological context, interactions between proteins involved in the same biological function, and interactions that link biological functions together into larger cellular processes. The results of these screens are shown here.
BACKGROUND AND OBJECTIVE: The effects of low-level laser light irradiation are still highly contested, and the mechanisms of its action still unclear. This study was conducted to test the effects of low-level laser irradiation at 660 nm on human lymphocytes and to investigate the possible mechanisms by which these effects are produced. STUDY DESIGN/MATERIALS AND METHODS: Whole blood obtained by phlebotomy was irradiated at 660 nm by using energy fluences between 0 and 5.0 J/cm(2). The lymphocytes were isolated after irradiation of the whole blood. For the control experiment, the lymphocytes were first isolated and then irradiated at the same wavelength and energy fluence for comparison. The proliferation of lymphocytes and the formation of free radicals and lipid peroxides were monitored. Hemoglobin was also irradiated in a cell-free environment to test for the production of lipid peroxides. RESULTS: Lymphocyte proliferation was significantly higher (P<0.05) as expressed by a Stimulation Index in samples irradiated in the presence of whole blood compared with lymphocytes irradiated after isolation from whole blood. Free radical and lipid peroxide production also increased significantly when samples were irradiated in the presence of red blood cells. CONCLUSION: The present study supports the hypothesis that one mechanism for the photobiostimulation effect after irradiation at 660 nm is the reaction of light with hemoglobin, resulting in oxygen radical production.
A prospective study of children attending an Accident and Emergency Department was carried out at the Royal Aberdeen Children's Hospital, to determine the association between injury risk and seat restraint usage, and to estimate the likely impact of seat restraint usage at various target levels on the incidence of non-fatal injuries. The subjects were all 91 cases of non-fatal childhood road traffic accidents attending the casualty department between December 1989 and November 1990. The main outcome measures were relative risks of three grades of injury severity and four types of non-fatal injury, population attributable risk fractions and estimated likely reduction in incidence of non-fatal injury at three set target levels of seat restraint usage. It was found that 42 (46 per cent) children presenting to the A&E Department were unrestrained; 78 (85.7 per cent) children sustained some injury. The relative risk for children travelling unrestrained in a car for all injuries combined is 1.7 (95 per cent confidence interval (CI) 1.17-2.45), the relative risk for head injury is 3.13 (1.78-5.51) and for face injury 3.03 (1.44-6.37). The risk of sustaining any moderate or worse injury was 3.25 (1.05-10.07). It is estimated that 24.4 per cent (minimum 5.5 per cent; maximum 45 per cent) of all non-fatal injuries sustained by a child car passenger can be prevented if all children are restrained in a child safety seat or seat restraint; 49.5 per cent of head injuries (minimum 43.4 per cent; maximum 71.9 per cent) and 48.4 per cent of face injuries (minimum 21.9 per cent; maximum 75.3 per cent) are preventable.(ABSTRACT TRUNCATED AT 250 WORDS)
There is growing emphasis on health promotion in primary care. The success of this endeavour depends in part on the ability of members of the primary health care team to provide appropriate and practical advice and support, relating to lifestyle. A study of 58 primary health care professionals was carried out in the Grampian region of Scotland to assess their nutritional knowledge and their ability to provide practical dietary advice, particularly in relation to the prevention of coronary heart disease. Overall, the primary health care workers had a broad understanding of recommendations for healthy eating, but there was some confusion over specific aspects of these recommendations. Health professionals also found it difficult to translate knowledge into practical dietary advice tailored to an individual case. If health promotion in primary care is to work effectively, the infrastructure necessary for effective training and continuing education has to be addressed.
Apparent motion was investigated as a stimulus for optokinetic nystagmus (OKN) and self-motion perception (vection). Apparent motion was stimulated by stroboscopically illuminating vertical stripes on the interior of a large drum that rotated about the observer at 20, 40 and 60 deg/sec. We determined threshold stroboscopic frequencies (f) for the appearance of smooth continuous apparent motion and measured responses of pursuit, OKN, optokinetic after nystagmus (OKAN) and vection, to stroboscopic frequencies at, above and below f. Pursuit occurred for all of these stimuli. However OKN, OKAN and vection only occurred for frequencies equal to or greater than the threshold for continuous apparent motion. Our results suggest that pursuit can occur as a response to apparent motion generated by both small and large image displacements, while OKN and vection are responses to apparent motion generated by small image displacements only. These results suggest that different afferent sources are utilized for the control of pursuit and of the slow phase of OKN.
During the first few months of life after birth human infants when tested monocularly move their unoccluded eye nasalward in darkness after viewing a large textured visual field moving either nasalward or temporalward. The eye movements in darkness are optokinetic after nystagmus (OKAN) which is an aftereffect of a reflex horizontal following eye movement, optokinetic nystagmus (OKN). Not until 4-5 months of age did temporalward field motion evoke OKAN with temporalward slow phase. The nasalward slow phase of OKAN that responded earlier to temporalward field motion appears to underlie the delayed development of reflex following eye movements in the temporalward direction.
A new form of graphical case analysis is described which quantifies static interactions between accommodative convergence, convergence accommodation, and prism adaptation. A clinical gradient measure of the CA/C ratio is compared to haploscopic measures to demonstrate the validity of the new clinical technique for measuring convergence accommodation. Graphical and computational methods are illustrated which predict the quantitative interactions between accommodation and convergence that occur after the phoria is partially corrected by lenses or prisms. Complete correction of convergence accommodation errors with spherical lenses or elimination of the stimulus to convergence accommodation by full correction of the associated phoria with prism will simplify the correction of binocular disorders by preventing the complex interactions of accommodative convergence with convergence accommodation. The new form of graphical analysis quantifies the predicted stress upon binocular vision induced by convergence accommodation.
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A helmet apparatus permitted duration, peak velocity, and peak acceleration measurements as functions of magnitude of horizontal head rotation; these "main sequence" data give evidence for multipulse-step neurological signals appropriate for time optimal control of head rotation similar to those of saccadic eye movements.
In a double-blind crossover study in which patients received placebo or active drug for varying periods, we evaluated the ability of guanidine hydrochloride (20 to 35 mg/kg per day perorally) to improve the rate of recovery in patients with moderate or severe botulism, type A, intoxication. Among 14 patients who received conventional botulism therapy, there was no improvement in recovery rate in those who received guanidine compared with the nontreated group. Individual patients in the treated group showed neither an acceleration in their rate of improvement when they received guanidine nor a regression in their progress when the drug was stopped. Individual patients, likewise, noted no subjective improvement when they received the drug compared with the placebo. Treatment with guanidine does not enhance recovery from botulism.
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Serum immunoglobulin (Ig) G responses to a variety of mycobacterial antigens were measured in children from the UK, in children with tuberculosis from Hyderabad, India and Dhaka, Bangladesh, classified according to whether the disease was disseminated or localized, and in non-tuberculous controls. Anti-lipoarabinomannan (LAM) IgG responses in UK children showed a marked trough between 6 months and 3 years coincident with the reported peak incidence of disseminated tuberculosis. Geometric mean IgG responses to sonicates of slow-growing mycobacteria (rich in LAM) in 36 children with disseminated tuberculosis were markedly lower than in 99 children with localized tuberculous lesions (for Mycobacterium scrofulaceum P < 0.01, for M. tuberculosis P < 0.01, and for M. vaccae P < 0.01). Responses to purified LAM were also lower in the disseminated tuberculosis group (P < 0.05) but there was no difference between the groups in their response to mycobacterial 65 kDa protein. Multiple regression analysis showed that the reduced response to sonicated mycobacterial antigens and to LAM in children with disseminated disease was independent of age, nutritional status, skin test reactivity, duration of previous symptoms, and city of origin. There was no evidence for sequestration of antibody to immune complexes. These findings are compatible with the hypothesis that children with low levels of antibody to sonicated mycobacterial antigen and to LAM, or those who cannot mount an antibody response, are predisposed to dissemination. A role for antibody in preventing disseminated forms of tuberculosis in childhood has implications for the development of improved vaccines and for the optimum timing of vaccination with bacille Calmette-Guérin.