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Biomedical subjects

C Hirsch

Publications and source records attributed to C Hirsch.

At least 19 recordsLinked to original sources
PubMed1991

Bioconversion of the sodium salt of simvastatin (MK-733) to 6-desmethyl-6-alpha-hydroxymethyl simvastatin.

An actinomycete (MA 6474, ATCC 53828) isolated from a soil sample (Mutare, Zimbabwe) was found to biotransform the sodium salt of Simvastatin (MK-733) to 6-alpha-hydroxymethyl MK-733, 6-beta-hydroxymethyl MK-733, and 6-ring-hydroxy MK-733. The bioconversion efficiency to the desired compound, 6-alpha-hydroxymethyl MK-733, was enhanced by optimizing the physico-chemical parameters of the process. In shake flask cultures, addition of magnesium (0.125 mg/l Mg SO4.7H2O) to the medium resulted in a five-fold increase in the rate of bioconversion to the alpha diastereomer. The ratio of bioconversion products (6-alpha-hydroxymethyl,6-beta-hydroxymethyl, and 6-ring-hydroxy MK-733) was regulated by pH. Process improvements and scale up in 23-1 fermentors, which consisted of a controlled addition of substrate (MK-733), resulted in a 2-fold increase in alpha diastereomer production (42 vs. 79 U/ml) and a 23-fold rate increase in the formation of alpha-diastereomer. A high diastereomeric ratio (alpha: beta = 9:1) facilitated downstream processing.

Actinomycetales↗
PubMed1988

[Psychiatric care in Leipzig--10 years' regionalized care in a large city by 3 major clinics].

The paper deals with experience gained in the town of Leipzig in the course of the implementation of the regionalized organisation of psychiatric care. The idea behind the organisational structure is that of a complete psychiatric system of treatment, covering hospitalised, partially hospitalised, and out-patient treatment, supported by ancillary services, to provide continued care. The organisational structure has proved effective for basic psychiatric care in a large town.

Affective Disorders, Psychotic↗
PubMed1984

Rhinomanometry--a review.

After a short historical review, the advantages and disadvantages of the current rhinomanometric methods are discussed. In addition, the merits of spirometry or measurements of the air velocity are considered. The physics of nasal ventilation are described and the difficulty in nasal resistance measurement is studied. The different mathematical models representing nasal airflow are presented and the importance of the Broms' mathematical model is stressed.

Airway Resistance↗
PubMed1983

Induction of ovulation with clomiphene citrate followed by LH-RH in women.

Luteinizing hormone-releasing hormone (LH-RH) was used to induce ovulation following clomiphene priming to stimulate follicular growth. Ovulation was assumed to have occurred following LH-RH injection when progesterone levels started to rise within 48 h following treatment and LH pretreatment levels were below 8 mIU/ml. Ovulation occurred in eight of 10 patients following the administration of LH-RH and six pregnancies were achieved in the first 4 months of treatment.

Anovulation↗
PubMed1982

Physiologic cardiac hypertrophy corrects contractile protein abnormalities associated with pathologic hypertrophy in rats.

To evaluate the combined effects of cardiac overload imposed by hypertension and by chronic exercise, male and female rats were made hypertensive by unilateral renal artery stenoses and made to exercise in an 8-10-wk swimming program. Sedentary normotensive animals, sedentary hypertensive animals and normotensive animals exposed to the swimming program were also studied. Hypertension was associated with the development of cardiac hypertrophy, and this was exaggerated in hypertensive swimmers. Actomyosin, Ca2+-myosin, and actin-activated Mg2+-myosin ATPase activities were enhanced in normotensive swimmers, depressed in hypertensives and were normal or increased in hypertensive swimmers. Myosin isoenzyme analysis showed a predominant V1 pattern in normals; an increase in percent V1 isoenzyme is swimmers; a predominant V3 pattern in hypertensives; and a return to the predominant V1 pattern in hypertensive swimmers. These findings suggest that the hypertrophy imposed by hypertension and hypertrophy imposed by physical training using a chronic swimming program are distinctly different biological phenomena. Physical training by swimming prevents the changes in cardiac myosin induced by hypertension despite the exaggeration of hypertrophy.

Actomyosin↗
PubMed1975

The participation of the black aged in voluntary associations.

Racial differences in membership in and attendance of voluntary associations were analyzed for comparable samples of 753 black and 260 white residents of Philadelphia age 65 and over. A hypothesis suggesing aged blacks have higher rates of participation than aged whites was derived from the literature and tested by regression analysis. Potentially confounding variables, e.g., health and socioeconomic status, were entered into the regression equation as controls. The results of the regression analysis indicated the black aged belonged to more associations than the white aged and had higher rates of attendance. Examination of findings previously reported by Kent and Hirsch (1972) indicates part of the difference is due to the greater participation of aged blacks in church-related groups. Implications of the findings are briefly discussed.

Black or African American↗