Biomedical subjects
Publications and source records attributed to A Nath.
Binding of alpha-, beta-, gamma-hexachlorocyclohexane, p,p'-DDT and p,p'-DDE with bovine serum albumin (BSA) and locust brain homogenate was studied. Binding affinities of pesticides were higher for the locust brain homogenates than for BSA. Results of uptake by isolated locust brain revealed higher uptake of gamma-HCH than alpha-HCH. gamma-HCH uptake was also higher from locust haemolymph than either from BSA or from buffer.
A yellow lipoprotein was isolated and purified from haemolymph of desert locust, Schistocerca gregaria Forskal, by precipitation at low ionic concentration and by gel filtration. Sephadex G-200 resolved haemolymph into five protein peaks. First peak was of lipoprotein with molecular weight of 501,000 +/- 7000 (n = 3) and on electrophoresis, it separated into three bands. Maximum lipids from lipoprotein could be extracted with chloroform: methanol solvent system and were 52% by weight.
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Nuclear extracts from cultured rat hepatocytes were analyzed by gel mobility shift assay for protein binding to the cyclic AMP responsive elements CRE1 (-96/-77) and CRE2 (-152/-132) and the NF1-CTF binding site (-121/-99) of the phosphoenolpyruvate carboxykinase (PCK) promotor. Binding was very weak to the CRE2 and CRE1. The NF1-CTF site formed two complexes with nuclear protein. Protein binding was increased, when the NF1-CTF site was coupled to the CRE1, and further, when it was coupled to both the CRE1 and the CRE2. Complex formation was not altered by treatment of the hepatocytes with glucagon or with glucagon and insulin. Thus, protein binding was most efficient when all three elements were in context, which might be necessary for full transcriptional activation of the PCK gene.
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We performed an immunoperoxidase study on muscle biopsy specimens from 19 patients with polymyositis who were seropositive for human immunodeficiency virus (HIV) (21 specimens) and 5 HIV-seronegative patients with polymyositis and compared the findings. A quantitative analysis of T cells and T-cell subsets, B cells, natural killer cells, interleukin-2 receptor-positive cells, and macrophages was performed on serial sections from all the specimens. Localization of major histocompatibility complex (MHC)-I and -II antigens, alpha and gamma interferon, and HIV antigens (p24, gp120, and gp41) was performed using specific antisera. In specimens from HIV-positive and seronegative patients, the predominant cell population was CD8+ cells and macrophages invading or surrounding healthy muscle fibers that expressed MHC-I antigen on their surface. The endomysial infiltrates in specimens from HIV-positive patients differed from those seen in specimens from the seronegative patients only by a significant reduction of the CD4+ cells (12.6 +/- 3.2% versus 21.1 +/- 4.2%). HIV antigens were seen in occasional interstitial mononuclear cells (but not in muscle fibers) in 6 of the 21 specimens from HIV-positive patients. Interferon was not localized. We conclude that the development of HIV-associated polymyositis does not appear to be related to direct infection of the muscle fibers by HIV but rather is due to a T-cell-mediated and MHC-I-restricted cytotoxic process, perhaps triggered by HIV. Because this immunopathological mechanism is common in both HIV-associated polymyositis and polymyositis alone, it is suggested that viruses may also be responsible in triggering polymyositis.
Significant coronary artery disease affecting the septal perforator arteries can cause anginal pain, rhythm disturbances, or septal infarction. However, since these vessels are usually inaccessible to coronary bypass surgery, there is a tendency among angiographers and angioplasters to overlook lesions of the septal perforator arteries. Our experience suggests that if medical treatment is not sufficient to treat clinical manifestations resulting from septal perforator disease, then coronary angioplasty can be considered a therapeutic alternative for revascularization. We herein present 11 patients who underwent coronary angioplasty of a major septal artery and discuss angiographic and technical aspects of the procedure.
An angiographic study of eight patients with total occlusion of the left main coronary artery identified six patients with chronic occlusion and two with acute complete occlusion. In each of six patients, there were two to six different intercoronary collateral pathways. Altogether, a total of 13 specific collateral channels were recognized. One patient had evidence of unique homocollaterals represented by enlarged vasa vasorum, which created a vascular cuff that surrounded a totally obstructed left main artery. The ventricular function and hemodynamic parameters in these patients not only depend on the collateral vessels but may also be affected by the severity of coronary artery disease in the artery that supplies collaterals.
From January 1983 through December 1987, 98 patients underwent angioplasty of at least one diffusely diseased coronary artery. Diffuse coronary disease was described as: group I, narrowing greater than or equal to 50% that involved the entire vessel (40 patients), group II, long lesions greater than or equal to 2 cm in length (39 patients), group III, three or more lesions in the same vessel (19 patients). There were 65 men and 33 women, with a mean age of 60 years; 64 patients (65%) had unstable angina, 23 patients (23%) were diabetic, 31 (32%) had prior myocardial infarctions, and 12 had prior bypass surgery. Multivessel disease was present in 89% of patients. Angioplasty of only the diffusely diseased vessel was performed in 41 patients, and additional vessels were dilated in 57 patients. Overall, of 396 lesions (four per patient) and 197 vessels (two per patient) attempted, success was achieved in 382 lesions (96%) and 187 vessels (95%); angiographic success was achieved in 112 of 120 diffusely diseased vessels (93%). Clinical success was achieved in 91 patients (93%). The overall complication rate (death, myocardial infarction, urgent bypass surgery) was 8% (8 of 98): six patients (6%) had myocardial infarction (one Q wave, five non-Q wave), one patient (1%) had urgent bypass surgery, and two patients (2%) died (one during bypass surgery). The majority of complications (7 of 8 or 87%), including the two deaths, occurred in group I patients, with a 17.5% rate, versus 2.5% in group II and 0% in group III, p less than 0.002.(ABSTRACT TRUNCATED AT 250 WORDS)
Among 20,332 adult patients who underwent consecutive cardiac catheterization and coronary arteriography, 83 (0.4%) were angiographically identified as having an absent left main coronary artery. The angiographic characteristics of this coronary anomaly include: (1) the presence of two well-separated coronary ostia at the left aortic sinus resulting in separate origin of the left anterior descending and circumflex arteries; (2) an increased incidence of left coronary dominance; (3) a higher (6%) than usual (0.5% to 1.5%) incidence of myocardial bridging; (4) lack of a high incidence of congenital heart anomalies; and (5) an incidence of atherosclerotic coronary artery disease similar to that of patients whose left main artery is intact. In 39% of the patients difficulties in selectively cannulating the separate ostium of the circumflex artery and adequately opacifying this vessel resulted in a need to change the diagnostic catheter size. Recognition of this coronary anomaly is needed to ensure accurate angiographic interpretation and is important for patients undergoing cardiac surgery to selectively perfuse these separate vessels during cardiopulmonary bypass.
Human immunodeficiency virus type 1 (HIV-1) infection of the brain has been associated with a severe dementing illness in children and adults. However, HIV-1 antigens are most frequently found in macrophages and microglial cells. To determine the extent of susceptibility of neuroglial cells to infection, the HIV-1 genome was introduced into cells cultured from human fetal brain tissue. Astroglial cells rapidly transcribed the viral genome producing high levels of p24 protein and infectious virions which peaked two to three days posttransfection. Thereafter HIV-1 genome expression progressively diminished and a persistent phase of infection developed during which neither virus nor viral proteins could be demonstrated by immunodetection methods. Cocultivation with CD4+ T cells at any time during the persistent infection resulted in resumption of p24 synthesis and virus multiplication. The release of persistence did not require direct cell-cell contact between the glial and T cells, since separation of the two cell types across a permeable membrane resulted in a delayed but similar resumption of p24 synthesis and virus multiplication. The persistently infected glial cells could also be stimulated to produce viral p24 protein if either tumor necrosis factor alpha or interleukin-1 beta was added to the medium without T cells present. These results suggest that astrocytes may serve as an undetected reservoir for HIV-1 and disseminate the virus to other susceptible cells in the brain upon triggering by some cellular or biochemical signal.
The antibody response to the structural proteins of rubella virus was studied in patients with multiple sclerosis (MS). Irrespective of the antibody titer to whole rubella virus, the relative proportion of the IgG response to the surface glycoprotein E1 was diminished, and that to the surface glycoprotein E2 was elevated in MS patients when compared to a matched control population of normal health individuals or a group of patients with systemic lupus erythematosus and other collagen vascular diseases. No difference was observed in the response to the core protein of rubella virus on comparing the MS and normal control groups. This divergence in the relative antibody response to the viral surface proteins suggests that the vigorous antibody response to rubella virus reported in MS is not simply an expression of a nonspecific polyvalent B-cell response.
Five patients with significant atherosclerotic lesions of anomalous coronary arteries underwent coronary angioplasty of the anomalous vessel. Four patients had anomalous circumflex artery and 1 had an anomalous right coronary artery. Angiographic and clinical success was achieved in all 5 patients. To ensure adequate equipment selection special consideration should be given to angiographic characteristics of these vessels, such as the orifice configuration, exit angulation, the route the artery traverses and the location of the stenotic lesions. Major determinants for successful angioplasty in these patients are guiding catheter selection and advancement of the balloon catheter to the very proximal portion of the anomalous vessel to subsequently facilitate guide wire advancement. This data indicates that balloon angioplasty can be successfully utilized in patients with significant atherosclerotic disease of anomalous coronary arteries.
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To assess potential efficacy of longer inflations to reduce restenosis, 49 patients with nonacute total occlusions were randomized into two groups after successful guide wire passage across the occlusive stenosis. Twenty-one group I patients had all inflations less than 1 minute, while 28 group II patients received at least one inflation of 5 minutes' duration. There was no significant difference between group I and group II patients in mean age (56 +/- 3 versus 57 +/- 2 years), percent male sex (76% versus 68%), or frequency of left anterior descending (LAD) percutaneous transluminal coronary angioplasty (PTCA) (33% versus 32%), p = NS for all. All lesions post PTCA were less than or equal to 50% stenosed and no patient had coronary artery bypass surgery (CABG). Mean post PTCA stenosis was 29 +/- 2% for group I versus 33 +/- 2% for group II, p = NS. Clinical follow-up was available for all patients 8 +/- 0.6 months after PTCA. Recurrent symptoms were present in 8 of 21 (38%) group I patients compared with 12 of 28 (43%) patients in group II, p = NS. Angiographic follow-up was available in 32 patients (65%), with confirmation of restenosis in seven (33%) group I patients and in 11 (39%) group II patients, p = NS. In conclusion, this prospective study suggests that recurrence rates following successful PTCA of nonacute total occlusions is not modified by 5-minute versus 1-minute inflations.
Coronary angioplasty has been applied in patients with recent myocardial infarction, but results of angioplasty of multiple vessels early after myocardial infarction in patients with severe multivessel disease have not been reported. Coronary angioplasty of multiple vessels was performed in 105 patients 0 to 15 days (mean 5 +/- 4) after recent myocardial infarction. There were 77 men (73%) and 28 women (27%), with a mean age of 57 years. All patients had severe multivessel disease, 68% with two vessel and 32% with three vessel disease. Twenty-eight patients (27%) had successful thrombolysis before angioplasty and 70 (67%) had postinfarction angina. Mean left ventricular ejection fraction was 58 +/- 10% and was less than 45% in 13 patients (12%). Angioplasty was attempted in 319 lesions (mean 3 lesions per patient, range 2 to 9) and 252 vessels (mean 2.4 vessels per patient, range 2 to 4), with success in 302 lesions (95%) and 237 vessels (94%); angioplasty was done in two stages in 59 patients (56%). Clinical success was achieved in 102 patients (97%). Complications included myocardial infarction in six patients (5.7%) (one Q wave, five non-Q wave), urgent bypass surgery in two (1.9%) and death in one (0.9%); overall, seven patients (7%) had a major complication. All patients had a follow-up duration greater than 1 year (mean 31 months, range 12 to 73). Clinical recurrence developed in 24 patients (23%), of whom 21 had repeat angioplasty, 1 had bypass surgery and 2 were managed medically. Ten patients (9.8%) had a late infarction and 5 (4.9%) died of cardiac death during the follow-up period.(ABSTRACT TRUNCATED AT 250 WORDS)
The applications for coronary angioplasty have greatly expanded and the procedure is now increasingly used in complex and potentially high risk conditions. This report describes the short- and long-term effects of coronary angioplasty in 61 patients with severely depressed left ventricular function (ejection fraction less than or equal to 35%) with unstable or refractory anginal symptoms, or both, in whom revascularization was necessary despite increased risk. In a retrospective analysis of 1,260 patients undergoing angioplasty between January 1985 through December 1987, 61 had an ejection fraction less than or equal to 35%. The common clinical presentation was unstable angina (70%) with or without recent myocardial infarction. Mean left ventricular ejection fraction was 27 +/- 6%. Forty-five patients (74%) had multivessel disease. Clinical success after angioplasty was achieved in 55 patients (90%). Major complications (death, infarction and emergency bypass surgery) occurred in five patients (8.2%), with death in two (3.2%). During long-term (mean 21 +/- 11 months) follow-up study of the 55 patients with successful angioplasty, 13 (23%) died, including 3 of noncardiac causes, and 11 (20%) had clinically symptomatic recurrence. Continued clinical success was present in 39 patients (71%), of whom 28 (51%) were event-free patients and 11 (20%) had clinical recurrence; a successful second angioplasty procedure was performed in 9 because of restenosis. Thus, in patients with depressed left ventricular function, coronary angioplasty can be performed with a short-term success rate comparable to that of routine angioplasty or surgical procedures. However, acute complications are more frequent and the late mortality rate is higher than in patients with less depressed function.
A patient with human immunodeficiency virus infection had cellular and humoral immune responses studied longitudinally from the onset of generalized myasthenia gravis. Progressive decline in CD4+, CD45R+ and CD4+, CDw29+ T-cells, cellular immune responses to alloantigen and mitogen stimulation, and acetylcholine receptor antibody titers were associated with clinical improvement of all myasthenic symptoms.