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Biomedical subjects

R Patel

Publications and source records attributed to R Patel.

At least 19 recordsLinked to original sources
PubMed1979

Serum angiotensin converting enzyme activity in patients with chronic renal failure on long term hemodialysis.

Serum angiotensin converting enzyme activity was assayed by a spectrofluorometric method in 19 patients with chronic renal failure on long term hemodialysis and 19 control subjects. Converting enzyme activity was increased in 11 of 19 (58%) patients compared with the controls (p less than 0.005). There was no correlation between serum converting enzyme activity and plasma renin activity or blood pressure in the patients. Possible mechanisms responsible for the increased converting enzyme activity are discussed.

Adult↗
PubMed1979

The HLA antigens and ABO blood groups in an American Black population with mitral valve prolapse.

A total of 42 American Black patients with mitral valve prolapse and 194 healthy individuals of similar ethnic background were tested for the distribution of various HLA antigens and ABO blood groups. The most significant result was an increased frequency of Bw35 in patients (74%) as compared with controls (39%), with a P value of less than 0.0001; the relative risk was 4.45.

ABO Blood-Group System↗
PubMed1979

Microbial oxidation of gaseous hydrocarbons: epoxidation of C2 to C4 n-alkenes by methylotrophic bacteria.

Over 20 new cultures of methane-utilizing microbes, including obligate (types I and III) and facultative methylotrophic bacteria were isolated. In addition to their ability to oxidize methane to methanol, resting cell-suspensions of three distinct types of methane-grown bacteria (Methylosinus trichosporium OB3b [type II, obligate]; Methylococcus capsulatus CRL M1 NRRL B-11219 [type I, obligate]; and Methylobacterium organophilum CRL-26 NRRL B-11222 [facultative]) oxidize C2 to C4 n-alkenes to their corresponding 1,2-epoxides. The product 1,2-epoxides are not further metabolized and accumulate extracellularly. Methanol-grown cells do not have either the epoxidation or the hydroxylation activities. Among the substrate gaseous alkenes, propylene is oxidized at the highest rate. Methane inhibits the epoxidation of propylene. The stoichiometry of the consumption of propylene and oxygen and the production of propylene oxide is 1:1:1. The optimal conditions for in vivo epoxidation are described. Results from inhibition studies indicate that the same monooxygenase system catalyzes both the hydroxylation and the epoxidation reactions. Both the hydroxylation and epoxidation activities are located in the cell-free particulate fraction precipitated between 10,000 and 40,000 x g centrifugation.

Alkenes↗
PubMed1979

Microbial oxidation of gaseous hydrocarbons: production of methyl ketones from their corresponding secondary alcohols by methane- and methanol-grown microbes.

Cultures of methane- or methanol-utilizing microbes, including obligate (both types I and II) and facultative methylotrophic bacteria, obligate methanol utilizers, and methanol-grown yeasts were isolated from lake water of Warinanco Park, Linden, N.J., and lake and soil samples of Bayway Refinery, Linden, N.J. Resting-cell suspensions of these, and of other known C1-utilizing microbes, oxidized secondary alcohols to their corresponding methyl ketones. The product methyl ketones accumulated extracellularly. Succinate-grown cells of facultative methylotrophs did not oxidize secondary alcohols. Among the secondary alcohols, 2-butanol was oxidized at the highest rate. The optimal conditions for in vivo methyl ketone formation were compared among five different types of C1-utilizing microbes. Some enzymatic degradation of 2-butanone was observed. The product, 2-butanone, did not inhibit the oxidation of 2-butanol. The rate of the 2-butanone production was linear for the first 4 h of incubation for all five cultures tested. A yeast culture had the highest production rate. The optimum temperature for the production of 2-butanone was 35 degrees C for all the bacteria tested. The yeast culture had a higher temperature optimum (40 degrees C), and there was a reasonably high 2-butanone production rate even at 45 degrees C. Metal-chelating agents inhibit the production of 2-butanone, suggesting the involvement of metal(s) in the oxidation of secondary alcohols. Secondary alcohol dehydrogenase activity was found in the cell-free soluble extract of sonically disrupted cells. The cell-free system requires a cofactor, specifically nicotinamide adenine dinucleotide, for its activity. This is the first report of a nicotinamide adenine dinucleotide-dependent, secondary alcohol-specific enzyme.

Butanols↗
PubMed1979

Symptomatic hypomagnesemia associated with gentamicin therapy.

A 57-year-old male developed hypomagnesemia, hypokalemia and hypocalcemia during the course of repeated gentamicin therapy. Renal wasting of magnesium and potassium was demonstrated. Associated endocrine abnormalities included decreased level of serum immunoreactive parathyroid hormone and increased levels of plasma renin and aldosterone. Our findings are compared to those previously reported by other investigators.

Adult↗
PubMed1978

Cytomegalovirus infections in renal allograft recipients: correlative studies with histocompatibility antigens.

We studied 32 renal allograft recipients in order to determine whether or not any correlation could be demonstrated between the HLA and development of cytomegalovirus infection. There was a positive stastical correlation (P less than 0.01) of the development of cytomegaloviraemia and the number of HLA antigens mismatched in the recipient. There was no correlation between specific HLA antigens and predisposition to develop cytomegalovirus infection. The implication of our observations with regard to the pathogenesis of cytomegalovirus infection in renal allograft recipients is discussed.

Adult↗
PubMed1978

Proof by catheterization of mitral valvular origin of a systolic click.

A patient with a loud intermittent midsystolic click presented a problem in differential diagnosis between mitral valve prolapse (intracardiac origin of the click) and left pneumothorax (extracardiac origin). External phonocardiography performed at the time of cardiac catheterization revealed that this loud midsystolic click disappeared whenever a catheter was positioned across the mitral valve. It reappeared whenever the catheter was removed from the transmitral position. Selective left ventriculography confirmed the diagnosis of mitral valve prolapse.

Cardiac Catheterization↗
PubMed1978

Effects of gravitational stresses on mitral valve prolapse. I. Changes in auscultatory findings produced by progressive passive head-up tilt.

The effects of passive head-up tilt on systolic time intervals were assessed in 18 patients with mitral valve prolapse. In addition to causing prolongation of the pre-ejection period and shortening of left ventricular ejection time, this circulatory stress led to progressive shortening of the Q to click interval. In 1 patient, a systolic click became audible which had not been heard in the supine posture. In 7 patients the click disappeared during head-up tilt, usually at 60 degrees or 90 degrees. In 2 patients without a murmur while supine, a mid-late systolic murmur appeared with tilt; 1 of these 2 as well as another patient who had a soft late systolic murmur while supine developed loud systolic whoops at greater angles of tile. The correlations between Q to click interval and aortic valve opening to click interval, and both the angle and the sine of the angle of tilt were highly significant.

Adolescent↗
PubMed1978

Differentiation of posterior myocardial infarction from right ventricular hypertrophy and normal anterior loop by echocardiography.

The differentiation of posterobasal myocardial infarction (PMI) from either right ventricular hypertrophy (RVH) or normal subjects displaying an anterior loop (AL) by electrocardiography (ECG) or vectorcardiography (VCG) is difficult. M-mode echocardiography (echo) via the anterior and subxiphoid methods has been helpful in defining cardiac chamber size and wall motion abnormalities. We tested whether this relatively more direct method would better separate these entities compared with the other two techniques. ECG and VCG using established criteria failed to distinguish the three conditions effectively. By echo, distinguishing characteristics were observed in each of the groups. Thus, right ventricular diastolic dimension and wall thickness were significantly increased only in the RVH group, echo dimensions and wall motion were normal in the AL group and the posterior left ventricular systolic thickening response and ejection phase indices were significantly reduced only by the subxiphoid method in the PMI group. To test the specificity of the latter finding, posterior wall motion in three infarction groups (posterior, combined posteroinferior and inferior) were examined and suggested that the target of the subxiphoid beam focuses on a more superior posterobasal left ventricular segment than the anteriorly placed transducer. Echocardiography can differentiate PMI from either RVH or AL more directly than ECG or VCG, and may be of practical clinical importance.

Adult↗
PubMed1978

The mitral knock with atrial fibrillation. A possible source of auscultatory confusion.

A 29-year-old woman with atrial fibrillation and severe rheumatic mitral regurgitation initially had a very loud third heart sound with high-frequency components (mitral knock), as well as with a first heart sound of widely varying intensity. After long diastoles a faint first heart sound was heard, with distinct separation from the third heart sound of the preceding cycle; however, on short cycles the loud and high-pitched third heart sound combined with a loud first heart sound to simulate the combination of a first heart sound with an ejection click. Phonoechocardiographic studies clarified the identity of the transients.

Adult↗
PubMed1977

Coarctation of aorta with special reference to infants. Long-term results of operation in 126 cases.

A review of 126 cases of coarctation of the aorta confirms the need for surgical resection in infants with intractable congestive cardiac failure. The high association with additional cardiovascular abnormalities in patients presenting in early infancy contributes significantly to the mortality. Patients with large ventricular septal defects and coarctation of the aorta are at risk and may require pulmonary artery banding at the time of resection of the aortic coarctation. Long-term complications included restenosis (18 cases) and persistent hypertension (10 cases). In order to prevent persistent hypertension, it is suggested that elective resection of the coarctation be done at 1 year of age.

Adolescent↗
PubMed1977

Cardiovascular anomalies in thoracopagus twins and the importance of preoperative cardiac evaluation.

Four pairs of thoracopagus twins have been described. Cardiac catheterisation was performed in all the cases. Angiocardiographic and necropsy findings suggest that the most common abnormality was some form of univentricular heart. The communication between the 2 hearts was at atrial level in 2 cases. Separation was performed in 1 of these cases but only 1 of the twins survived for 14 hours after operation. It is suggested that full cardiac catheterisation with selective angiocardiogram is essential before separation is considered. Identical heart rates were observed in each pair and there was invariably a major communication between the hearts of the twins.

Female↗
PubMed1977

Pulmonary edema due to tetrachloroethylene.

A patient with massive exposure to tetrachloroethylene fumes presented with coma and severe pulmonary edema. Sequential blood gases, chest x-rays, and clinical findings showed dramatic improvement with conventional but aggressive management and the patient recovered completely. There was no evidence of permanent renal, hepatic, or central nervous system damage.

Adult↗