Pathogenicity of Acholeplasma laidlawii for the goat udder.
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Acholeplasma laidlawii↗
Biomedical subjects
A Singh
Publications and source records attributed to A Singh.
Rapid detection of chlorine-induced bacterial injury by the direct viable count method using image analysis.
A modified direct viable count method to detect living bacteria was used with image analysis for the rapid enumeration of chlorine-injured cells in an Escherichia coli culture. The method was also used for determining chlorine-induced injury in coliform isolates and enteric pathogenic bacteria. Cultures were incubated in phosphate-buffered saline, containing 0.3% Casamino Acids (Difco Laboratories, Detroit, Mich.), 0.03% yeast extract, and optimal concentrations of nalidixic acid. Samples were withdrawn before and after incubation and stained with acridine orange, and cell lengths and breadths were measured by computerized image analysis. After incubation, cells which exceeded the mean preincubation length (viable cells) were enumerated and the results were compared with those obtained by the plate count method. Injury in the chlorine-exposed cell population was determined from the difference in viable count obtained with a nonselective Casamino Acids-yeast extract-nalidixic acid medium and a selective Casamino Acids-yeast extract-nalidixic acid medium containing sodium deoxycholate or sodium lauryl sulfate. The levels of injury determined by the direct viable count technique by using image analysis were comparable to those determined by the plate count method. The results showed that image analysis, under optimal conditions, enumerated significantly higher numbers of stressed E. coli than the plate count method did and detected injury in various cultures in 4 to 6 h.
Chlorine↗
Characterization of Pseudomonas aeruginosa adherence to mouse corneas in organ culture.
The present study was designed to obtain further information on the nature of the corneal macromolecule(s) to which Pseudomonas aeruginosa adheres and how adherence might be prevented. Scarified adult mouse corneas in organ culture were treated with trypsin or lipase to determine whether the receptor molecule(s) was protein or lipid in nature. Trypsin (20 micrograms/ml) treatment of the cornea for 5 min had no significant effect on bacterial adherence, and longer periods of enzyme exposure resulted in extensive surface cell lysis. In contrast, lipase treatment (50,000 U/ml) for 1 h caused little visible cell lysis and significantly reduced bacterial adherence. To test further the lipid nature of the receptor, a highly purified monosialoganglioside (GM1) preparation (500 micrograms/ml) was used to preincubate (1 h) the cornea prior to bacterial application, and this also inhibited bacterial adherence. Similar corneal treatment with gangliotetraosylceramide (asialo GM1) (500 micrograms/ml) had little effect on ocular bacterial binding. Premixing of the bacterial inoculum with GM1 prior to corneal application had no significant effect on inhibiting bacterial binding, but similarly premixing the bacterial inoculum with asialo GM1 transiently decreased adherence. Lastly, premixing of the bacterial inoculum or preincubation of corneas with fibronectin (500 micrograms/ml for 1 h) both decreased bacterial adherence. These findings provide evidence that the receptor-adhesin interactions of P. aeruginosa at the ocular surface in organ culture are complex, involve a glycolipid moiety, and may be blocked by a ganglioside containing at least one sialosyl residue or by fibronectin, which may bind to membrane-associated gangliosides.
Animals↗
Inhibition of microvascular endothelial cell proliferation by vitreous following retinal scatter photocoagulation.
Laser photocoagulation of pig retina induced breakdown of the blood-retinal barrier, with the appearance of serum proteins in the vitreous as determined by sodium dodecyl sulphate/polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblotting techniques. Vitreous from lasered eyes inhibited the proliferation of cultured retinal microvascular endothelial cells in comparison with vitreous from non-lasered control eyes, and the inhibitory effect in the lasered eyes persisted for at least seven days. Inhibition was specific for endothelial cells, since no effect was observed when retinal pericytes or Tenon's fibroblasts were the target cells. These results suggest that indirect scatter photocoagulation may induce regression of neovascularisation by causing breakdown of the blood-retinal barrier and thus releasing into the vitreous serum components which result in inhibition of retinal microvascular endothelial cell growth.
Animals↗
Sustained improvement in left ventricular function after successful coronary angioplasty.
The short and long term effects of successful percutaneous transluminal coronary angioplasty on left ventricular function, at rest and on exercise were investigated in 49 patients. Thirty-four had had no previous infarction (group 1) and 15 had (group 2). Technetium-99m gated blood pool images were obtained at rest and during exercise before, six weeks after, and a mean of fifteen months after successful angioplasty. Before angioplasty the mean (SD) ejection fraction fell significantly on exercise in both groups from 58 (10)% to 53 (13)% in group 1 and from 48 (10)% to 40 (16)% in group 2. This change was paralleled by a worsening wall motion score (from 0.6 (0.4) to 1.6 (1.2) in group 1 and from 2.3 (1.9) to 3.3 (2.4) in group 2). Six weeks after the procedure there was little change in resting ejection fraction but it increased significantly on exercise (to 62 (11)% in group 1 and to 53 (13)% in group 2). There was a concomitant significant improvement in the exercise wall motion score (to 0.4 (0.6) in group 1 and to 1.8 (1.1) in group 2). This improvement in exercise ejection fraction and wall motion was maintained at later follow up with no significant deterioration in either variable and a clearly sustained improvement in ejection fraction (60 (10)% in group 1 and 51 (10)% in group 2) and wall motion score (0.2 (0.2) in group 1 and 1.3 (0.8) in group 2) compared with values before angioplasty. The initial improvement in left ventricular function on exercise after successful angioplasty was maintained for at least 9-24 months both in patients with previous myocardial infarction and in those without.
Angioplasty, Balloon, Coronary↗
Efficacy of betaxolol in the treatment of stable exertional angina pectoris: a dose-ranging study.
To assess the efficacy of oral betaxolol in the treatment of stable exertional angina pectoris and to determine the relationship between betaxolol doses/serum concentrations and clinical/hemodynamic responses the authors studied 24 patients prior to and following stepwise administration of 5, 10, 20, 40, and 80 mg doses. The major endpoint for the study was the achievement of clinical beta blockade (heart rate 50-60 beats/min and less than or equal to 20% rise in treadmill stage I heart rate). Betaxolol produced a decrease in mean angina pectoris frequency from 6.6 +/- 1.9 episodes/week with placebo to 0.2 +/- 0.5 episode/week during clinical beta blockade (p less than 0.00005). Mean treadmill exercise time increased from 3.1 +/- 1.7 min with placebo to 7.3 +/- 2.3 min with doses sufficient to reduce angina pectoris frequency greater than or equal to 75% (p less than 0.00005) and to 8.0 +/- 2.3 min during clinical beta blockade (p less than 0.00005). The mean doses of betaxolol required to produce a greater than or equal to 75% decrease in angina pectoris frequency and clinical beta blockade were 12 +/- 5 mg (range 5-40 mg) and 28 +/- 29 mg (range 5-80 mg) respectively. Mean serum concentrations associated with these clinical endpoints were 23.8 +/- 9.7 ng/mL and 59.7 +/- 54.0 ng/mL respectively. The results indicate that betaxolol, in widely ranging doses, is highly effective in reducing angina pectoris frequency and improving exercise capacity in patients with stable exertional angina pectoris.
Angina Pectoris↗
Effect of insulin-like growth factor-type I (IGF-I) and insulin on the secretion of sex hormone binding globulin and IGF-I binding protein (IBP-I) by human hepatoma cells.
Dietary factors are known to modulate concentrations of sex hormone-binding globulin (SHBG). In the present study we have investigated the possibility that insulin like growth factor-type I (IGF-I) may be an additional regulator of SHBG using cultured human hepatoma cells which secrete SHBG. The inhibitory effect of insulin on SHBG secretion by these cells was confirmed but, in addition, IGF-I was shown to inhibit SHBG secretion by about 40% at a concentration of 100 nmol/l. A similar degree of inhibition was achieved using insulin at a concentration of 10 mumol/l. Insulin, but not IGF-I, was also found to inhibit the secretion of a low molecular weight IGF-binding protein (IBP-I), which is also secreted by hepatoma cells. It is concluded that IGF-I is an additional regulator of SHBG secretion by these cells and that it may be involved in regulating SHBG secretion in vivo in response to dietary factors.
Carcinoma, Hepatocellular↗
Synthetic detergents induced-biochemical and histological changes in skin of guinea pigs.
The linear alkylbenzene sulphonate (LAS) based synthetic detergents-induced decrease in lipid peroxydation and increase in histamine content in exposed skin of guinea pigs in a dose-dependent manner. Histopathological alterations of exposed skin included moderate degree of hyperkeratinization at lower concentration but necrosis, scarring, sloughing as well as discontinuity of epidermis at higher concentrations. The results shows that the contact of skin with detergents causes dermal toxicity.
Alkanesulfonates↗
Serum lipids in healthy tribals living at high altitudes in the Himalayas.
Serum lipids of 70 healthy volunteer tribals (36 males, 34 females) living at high altitudes (3100-4500 metres) in the Himalayas were studied. The mean total cholesterol, triglycerides, HDLc, LDLc and VLDLc levels for the group were 178.6 +/- 19.5, 101.4 +/- 18.3, 44.1 +/- 12.4, 114.5 +/- 17.3 and 20.2 +/- 3.6 mg/dl respectively. There was no significant difference between the two sexes and the various age groups. The total cholesterol/HDL ratio for men and women was 4.2 and 3.9 respectively. The various interacting factors responsible for overall pattern of lipids in these individuals is discussed.
Adult↗
Poliomyelitis in community development block Chhachhrouli, Haryana.
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Adolescent↗
Taste bud density in circumvallate and fungiform papillae of the bovine tongue.
Taste bud quantitation may provide useful parameters for interspecies comparisons of the gustatory system. The present study is a morphometric analysis of bovine taste papillae. Circumvallate and fungiform papillae from six bovine tongues were serially sectioned and, following staining, analyzed. Circumvallate papillae were found to have a mean volume of 3.66 +/- 2.82 mm3, a mean number of taste buds per papilla of 445 +/- 279, and a mean taste bud density of 155 +/- 112 buds/mm3. Values for lateral fungiform papillae for the same three parameters were 0.384 +/- 0.184 mm3, 13.2 +/- 13.4, and 40.8 +/- 46.6 buds/mm3, respectively. Values for dorsal fungiform papillae were 0.438 +/- 0.246 mm3, 4.39 +/- 4.78, and 14.0 +/- 17.1 buds/mm3, respectively. Circumvallate papillae were found to have a significantly greater volume, number of taste buds per papilla, and taste bud density than either type of fungiform papilla. These data should serve as background for biochemical, endocrinological, or neurological studies involving the bovine tongue.
Animals↗
Should neonates with specific "risk factors" be admitted to the special care nursery?
Existing criteria for admission of newborns to the special care nursery, Sarawak General Hospital, resulted in the admission of many neonates with certain risk factors ("at risk" neonates). To test whether such babies could be safely and better cared for in postnatal wards, 392 of these babies were randomly allocated into two groups. One group of 196 was admitted to the special care nursery and the other group of 196 was cared for with their mothers in the postnatal wards. The two groups were compared for mortality, morbidity and breastfeeding. There was no significant difference in mortality and morbidity between the two groups. While in hospital a larger proportion of babies cared for in postnatal wards were breastfed, compared to babies admitted to the special care nursery. In addition, they initiated their breastfeeding earlier. Babies with these risk factors should therefore be cared for with their mothers in the postnatal wards.
Breast Feeding↗
Binary conjugational transfer system of vectors pRK290 and pLAFRI is proficient both ways between Escherichia coli and Rhizobium.
Wide host range vector plasmids pRK290 and pLAFRI carrying genomic fragments of Rhizobium are transferable both ways between R. meliloti and R. leguminosarum cells on the one hand and to E. coli cells on the other, in triparental matings involving E. coli cells carrying pRK2013, the helper for Tra functions to the vector plasmids. The vector plasmids pRK290 and pLAFRI can be employed for recovering clones harbored by R. leguminosarum and R. meliloti by transfer to Rhizobium cells by direct matings of the library with them.
Cloning, Molecular↗
An efficient synthesis of phosphatidylcholines.
This article deals with two of the major steps involved in phospholipid synthesis: the preparation of the optically pure precursors, sn-glycero-3-phosphocholine (GPC) and -ethanolamine, from a convenient lipid source such as egg yolk, and acylation of hydroxyl groups present in those precursors involving an acid to yield the corresponding phospholipid. Phosphatidylcholines and phosphatidylethanolamines were separated from lipids extracted from egg yolk using low-pressure column chromatography. The advantages of this method include the use of smaller volumes of solvents and silica gel and reuse of adsorbent. Acylation of GPC is aided by ultrasound from a common laboratory bath cleaner. Ultrasound-assisted base-catalyzed esterification of GPC is accomplished between 2-6 hours providing a phospholipid in more than 80% yield. This scheme is particularly valuable in the synthesis of polymerizable phospholipids.
Acylation↗
Zinc and copper status in women by physical activity and menstrual status.
Zinc and copper status of 33 eumenorrheic and 12 amenorrheic runners and 19 eumenorrheic and 8 amenorrheic nonrunners was studied. Three-day diet records and fasting blood samples were collected and analyzed. No indices of zinc or copper status differed as a function of menstrual status. Although zinc intakes of runners tended to be higher than nonrunners, plasma zinc concentrations tended to be lower. Runners had significantly higher erythrocyte zinc concentrations than nonrunners (12.4 +/- 0.2 vs 11.5 +/- 0.3 micrograms/g; p less than 0.05). Copper intakes of runners also tended to be higher than nonrunners. Mean plasma copper concentration of runners was significantly higher than nonrunners (18.8 +/- 0.5 vs 16.1 +/- 0.6 mumol/L; p less than 0.01) but erythrocyte copper was significantly lower (1.06 +/- 0.02 vs 1.26 +/- 0.03 micrograms/g; p less than 0.01). The observed differences between runners and nonrunners suggest that chronic exercise may induce redistribution of zinc and copper.
Adult↗
Spectrum of seronegative spondarthritides (SSA) with special reference to HLA profiles.
The present study describes the profile of seronegative spondarthritides (SSA) in young servicemen. SSA was diagnosed in 63 patients from a prospective study on spondyloarthropathy. The SSA group consisted of ankylosing spondylitis (AS, 40 patients), Reiter's syndrome (RS, 6) and SSA undifferentiated (SSA-U, 17). The chief clinical and radiological features of the group were due to sacro-iliitis/spondylitis, peripheral arthritis and enthesopathy. Except for RS, extra-articular features were sparse. Mucosal lesions were not evident. Radiologically, sacro-iliitis varied from 24% in SSA-U to 100% in AS, and was disproportionately less when compared to its clinical extent. Dominant lower limb arthritis (poly and oligo) was seen in AS (40%), SSA-U (88.2%) and RS (100%). HLA A and B were typed in patients and controls. HLA AI had a significant negative association (p less than 0.05) with AS and the SSA group, and its relative risk (R) was consistently low (0.2-0.3). HLA B27 was present in 65.7%, 73%, 67%, 41% and 9% of the SSA group, AS, RS, SSA-U and controls respectively (p less than 0.05). Significant R values of A and B loci antigens in disease groups are presented. When compared with available Indian literature, this study highlights the variability and overlap in the disease. Disease markers currently available have limitations in defining the various subsets of SSA.
Adult↗
Morphologic features of lymph vessels in caprine hemal nodes.
The distribution and characteristics of lymph vessels in caprine hemal nodes were studied after glutaraldehyde fixation and epoxy resin embedding. Histologically, the lymph vessels were characterized by thin walls and wide lumens containing inspissated lymph in which a few cells were suspended. The lymph vessels contrasted sharply with adjacent blood sinuses that were filled with elements of circulating blood. A circumferential lymph vessel in the cortex joined radial branches in the medulla that met at the hilum to drain through a large efferent lymph channel. Ultrastructurally, the lymph vessel wall comprised endothelial cells supported by a continuous basal lamina, collagen fibrils, and adventitial reticular cells. The cytoplasm of endothelial cells had fenestrations, plasmalemma-associated vesicles, vacuoles, and focal splits that enclosed large compartments. Many compartments contained erythrocytes and lymphocytes. Modifications of the endothelial cells signified their endowment with features that favored transendothelial transport. The distribution of lymph vessels and the finding of only efferent lymph channels are related to the roles of hemal nodes in blood storage by hemoconcentration and in immune defense mechanisms.
Animals↗
Effect of exercise and cavity size on right ventricular function in morbid obesity.
To assess the effect of exercise and to determine the influence of the right ventricular (RV) internal dimension on RV systolic function in morbid obesity, M-mode and 2-dimensional echocardiography and radionuclide ventriculography were performed on 22 patients whose body weight was at least twice the ideal body weight and who had no clinical or laboratory evidence of underlying organic heart disease or pulmonary disease. RV ejection fraction was measured at rest and during peak supine bicycle exercise. RV exercise response was defined as the change in RV ejection fraction during peak exercise. There was a significant negative correlation between percent over ideal body weight and RV exercise response (r = 0.86, p less than 0.00005) and between RV internal dimension and RV exercise response (r = 0.60, p less than 0.005). There were significant positive correlations between resting RV and left ventricular (LV) ejection fraction (r = 0.56, p less than 0.01) and between RV and LV exercise response (r = 0.70, p less than 0.0005). The subgroup with a high-normal or enlarged RV internal dimension (greater than or equal to 2.0 cm, n = 10) experienced no significant change in RV ejection fraction with exercise, whereas the subgroup whose RV internal dimension was less than 2.0 (n = 12) experienced a significant increase in RV ejection fraction from 44 +/- 10% at rest to 58 +/- 11% at peak exercise (p less than 0.03). The results suggest that in morbidly obese individuals without underlying cardiopulmonary disease RV dilatation may predispose to RV systolic dysfunction and assessment of RV systolic function should optimally include evaluation of RV exercise response.
Adult↗