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Biomedical subjects

S Rajan

Publications and source records attributed to S Rajan.

At least 73 records · Page 4Linked to original sources
PubMed1984

Biosynthesis of the antibiotic maduramicin. Origin of the carbon and oxygen atoms as well as the 13C NMR assignments.

The biosynthesis of maduramicin alpha and beta in a culture of Actinomadura yumaensis has been studied using 13C, 14C and 18O labeled precursors. The alpha component of this recently discovered polyether antibiotic, containing forty-seven carbon atoms in a seven-ring system, is derived from eight acetate, seven propionate and four methionine molecules. The beta component which is missing one methoxy group incorporates three methionine methyl groups. The carbohydrate moiety was enriched by methionine, but not significantly by acetate or propionate. Studies of the incorporation of 13C labeled precursors permit the 13C NMR assignment of maduramicin. The origin of oxygen atoms of maduramicin has been examined by feeding [1-13C, 18O2]acetate and [1-13C, 18O2]propionate separately in the fermentation culture and the resulting doubly labeled maduramicin samples were analyzed by the isotopic shifts in the 13C NMR spectra. These results are consistent with the initial formation of a triene, which is converted to maduramicin by cyclization of the triepoxide.

Actinomycetales↗
PubMed1983

Strontium-90 and caesium-137 in Indian tea.

The paper presents results of measurements made on tea samples, collected during 1961-1979 period for their strontium-90 and caesium-137 content. Tea was found to contain higher concentration of these radioisotopes compared to other food-stuffs having vegetative origin. Levels in tea are compared with those in leafy vegetables from both India and Japan. Interpretation for higher concentrations in tea compared to leafy vegetables is briefly given on the basis of agro-climatic conditions. The levels are also considered from the point of view of health hazard.

Cesium Radioisotopes↗
PubMed1983

Epithelioid sarcoma in the hand.

An illustrative case of epithelioid sarcoma in the hand of a young man, causing considerable diagnostic problems, is presented. Epithelioid sarcoma is a malignant lesion, first described by Enzinger in 1970. Although epithelioid sarcoma is the third commonest soft tissue sarcoma in the upper extremity (Bryan, 1974) it still causes confusion in differential diagnosis, both to the surgeon and to the pathologist. Because of its deceptively harmless appearance during the initial period and its clinical and microscopical similarity to an inflammatory process, it is often mistaken for a benign lesion. The purpose of our paper is to draw attention to this rare malignant tumour. This case illustrates a course similar to those described previously. (Enzinger, 1970: Santiago, 1972).

Adolescent↗
PubMed1982

The Niebauer-Cutter prosthesis in excision arthroplasty of the trapezium.

Sixteen patients had excision arthroplasty of the trapezium, using the Niebauer-Cutter prosthesis. The average period of postoperative follow-up was thirteen months. All patients had severe preoperative disabilities and the majority were relieved from resting pain and pain during active use of their hands. The postoperative range of motion with regard to the palmar and radial abduction was found to be satisfactory, while varying degrees of limitation of circumduction was the rule. There was no correlation between the patients' own judgment of the postoperative benefits and the objectively measured range of motion. One patient had a luxation of the prosthesis, while another had a subluxation when opposing the thumb. This frequency of luxation/subluxation seems to be less than that experienced with the other common type of prosthesis, the Swanson prosthesis. Although it is obvious that the ideal prosthesis for treatment of disabilities in the carpometacarpal joint of the thumb is still not available, it was concluded that the Niebauer-Cutter prosthesis is the best choice at the present.

Arthritis, Rheumatoid↗
PubMed1980

Lead-210 content of food samples in India.

The paper presents results of measurements made on cereals and composite meal samples collected from Bombay market for their lead-210 content. The details of sampling and analytical chemistry procedures are also given. The Pb210 contents of most of these samples were in the range of 1--5 pCi/kg of cereals samples. The concentrations in composite meal samples were mostly in the range of 1--3.5 pCi of 210Pb per composite meal. The assessment of daily intake of this isotope through food-stuffs has been made.

Edible Grain↗
PubMedDate not supplied

Coarctation of the aorta, aortic valvar stenosis, and supravalvar aortic stenosis with left coronary artery ostial stenosis: management using a staged hybrid approach.

In this report, we describe a case of coarctation of the aorta, congenital aortic stenosis with bicuspid valve, and supravalvar aortic stenosis with left coronary artery ostial stenosis. The child underwent staged treatment using a hybrid approach employing both surgical and interventional cardiology methods. A single pericardial patch repair technique for supravalvar aortic stenosis associated with left coronary ostial stenosis is also described.

Angioplasty, Balloon↗
PubMedDate not supplied

CT diagnosis of Meckel diverticulum in a paracolic internal hernia.

The autopsy incidence of internal hernia has been reported to be between 0.2% and 0.9%, and these hernias are usually diagnosed on imaging due to their complications or at surgery. Meckel diverticulum is the most common congenital anomaly of the gastrointestinal tract, occurring in 1% to 3% of the population according to autopsy studies. The condition also is usually diagnosed at surgery, by barium studies or scintigraphy, or on cross-sectional imaging due to complications. We present an unusual case of a large Meckel diverticulum in a right paracolic hernia diagnosed on multidetector computed tomography. This diagnosis was made after attacks of subacute intestinal obstruction with the aid of multiplanar reconstructions. This case emphasizes the role of multidetector computed tomography and postprocessing techniques such as multiplanar reconstruction in the diagnosis of bowel pathology.

Adult↗
PubMedDate not supplied

Age-associated alterations in sympathetic neural interactions with the immune system.

We have examined age-related alterations in sympathetic noradrenergic (NA) innervation in primary and secondary lymphoid organs from mouse and rat. As the thymus involuted with age, the density of NA innervation and norepinephrine (NE) concentration increased markedly. Total thymic NE was not altered significantly with age, suggesting that NA innervation is maintained as the thymus involutes. In the rat spleen, NA innervation and NE concentration were diminished with age. Enhanced antibody responses and in vitro proliferation to a T-dependent protein antigen were observed following selective destruction of NA nerve fibers with the neurotoxin 6-hydroxydopamine (6-OHDA), demonstrating that the diminished NA innervation in the aged spleen is capable of signaling the immune system. Plasticity of NA nerves in old rats was demonstrated following lesioning with 6-OHDA and in intact rats treated with L-deprenyl, a monoamine oxidase B inhibitor. These age-related alterations in NA innervation of lymphoid organs occur concurrently with age-associated changes in immune function. Understanding the functional relationship between these two physiological systems in aging will contribute to a greater understanding of sympathetic nervous system regulation of immune function.

Age Factors↗
PubMedDate not supplied

Thoracotomy approach for congenital and acquired heart defects: its possible applications in the current era.

From April 1975 to February 1995, 305 patients (260 females and 45 males) underwent open heart surgical procedures through the thoracotomy approach. Their ages ranged from 4 months to 55 years (mean age 21.8 +/- 13 years). Two hundred and ninety-seven patients were operated through the right and eight through the left thoracotomy approach. Two hundred and sixteen patients had congenital heart disease and 89 patients had acquired heart diseases, which included ostium secundum defect (190 patients), sinus venosus defect (11 patients), partial atrioventricular (AV) canal defect (5 patients), complete AV canal (1 patient), ventricular septal defect (4 patients), Tetralogy of Fallot (3 patients), anomalous origin of left coronary artery from pulmonary artery (3 patients), mitral valve lesions (83 patients), including tricuspid valve lesions (5 patients) and coronary artery disease (2 patients). Postoperative recovery was observed to be faster (mean hospital stay 7.8 days vs mid-sternotomy 9.6 days), infection rate lower (0.35% vs median sternotomy 2.56%), postoperative drainage lower (148.8 +/- 86.2 mL vs median sternotomy 587 +/- 112.6 mL), and cosmetically found to be much more acceptable in the female population. There have been seven early and one late postoperative deaths which were unrelated to the operative approach. We conclude from this experience that thoracotomy can be safely used as an access for a wide variety of open cardiac surgical operations on the atrial and (upper) ventricular septae, AV valves, right ventricular outflow tract, and coronary artery reconstruction in some situations. It is also useful in some emergency and redo operations with distinct advantages over the median sternotomy approach. We feel its use should be increased as newer subsets of patient populations are being subjected to primary and redo cardiac operations.

Adolescent↗
PubMedDate not supplied

Extensive endarterectomy, onlay patch, and internal mammary bypass of the left anterior descending coronary artery.

The incidence of diffuse disease requiring multiple endarterectomies is high among the Oriental population. The technique of LAD endarterectomy and reconstruction is difficult, and often it is a challenging problem. From June 1987 to September 1994, 2376 patients from seven countries underwent coronary artery bypass graft surgery, among whom 610 patients had endarterectomy. One hundred thirty-six patients underwent LAD endarterectomy, and among them, 69 had extensive endarterectomy. The LAD was reconstructed with IMA onlay patch in 41 patients and with saphenous vein onlay patch in 28 patients. Three patients had evidence of postoperative myocardial infarction and seven patients died in the postoperative period. Twelve patients were postoperatively restudied and in all of them, the graft to LAD was patent. Use of internal mammary artery onlay patch after endarterectomy is advantageous since it may be associated with higher long-term patency and low incidence of reoperation. To our knowledge, this has not been reported anywhere.

Adult↗
PubMedDate not supplied

State spending for Medicare and Medicaid home care programs.

Congressional attempts to curtail spending growth in Medicare home health may affect Medicaid, given the number of Medicare enrollees who qualify for Medicaid-covered home care services. This DataWatch examines interactions between the Medicare and Medicaid home care programs using state-level expenditure data for 1995 and through case studies in five states: Connecticut, Louisiana, Minnesota, New Mexico, and New York.

Costs and Cost Analysis↗
PubMedDate not supplied

Publicly subsidized health insurance: a typology of state approaches.

Using information from case studies, published documents, and the Current Population Survey, this paper describes and classifies state approaches to providing health insurance to low-income populations (as of 1997). It examines the link between the scope of state efforts and uninsurance rates for low-income populations. Findings indicate that the breadth of state policies contributes to differences in insurance coverage for low-income persons across states.

Eligibility Determination↗
PubMedDate not supplied

Batista procedure as a bridge to cardiac transplantation.

A 37-year-old male patient with dilated cardiomyopathy and end-stage heart failure underwent Batista procedure. After 6 months, he underwent orthotopic heart transplantation. Though he did not survive the procedure, we conclude that Batista procedure may serve as a cost-effective biological bridge to cardiac transplantation.

Adult↗