The isolated supported canine heart: a model for the evaluation of drug effects on regional myocardial blood flow

The present investigation was designed to determine the effect of propranolol on regional myocardial blood flow and oxygen consumption (MVO2) in the isolated supported dog heart preparation perfused at a constant coronary blood flow. The transmural distribution of blood flow, determined by the radioactive microsphere technique, was expressed as the epicardial/endocardial blood flow ratio (epi/endo). Propranolol (0.5 mg/kg i.v.) produced a significant decrease in heart rate and myocardial contractile force and an increase in coronary artery perfusion pressure due to an increase in coronary vascular resistance. These hemodynamic changes were accompanied by significant decreases in epi/endo (increased endocardial perfusion) and MVO2. Reduction of perfusion pressure to control by a decrease in total coronary blood flow produced no further change in epi/endo or MVO2. However, increasing heart rate to control increased epi/endo to predrug levels. Contractile force and MVO2 remained reduced below control. Norepinephrine infusion (1 mug/min intracoronary) produced a significant increase in heart rate and contractile force and decrease in perfusion pressure. These changes were accompanied by an increase in epi/endo and MVO2. Propranolol (0.5 mg/kg i.v.) abolished the response to norepinephrine. Propranolol may produce beneficial effects in angina pectoris by a decrease in epi/endo (via a reduction in heart rate) and MVO2 and by beta adrenergic blockade of the deleterious effects of catecholamines.     

Isolation of principal and basal cells from the epithelium of the hamster caput epididymidis by unit gravity sedimentation

A technique for the isolation of principal and basal cells from the epithelium of the hamster caput epididymides by unit gravity sedimentati on is described. The technique enzymatically disaggregates cells comprising the caput epididymides, and the resulting mixture of disperse d cells is separated by sedimentation in a shallow bovine serum albumin gradient at unit gravity into populations of spermatozoa, erythrocytes and several nucleated types. The separated somatic cell types and the homogeneity of each population were identified by light and electron microscopy. The purest fractions of the 6 populations, from smallest to largest, contained an average of 84% erythrocytes, 76% basal cells, 82% fibroblasts and intraepithelial lymphocytes, 68% small principal cells and 34% smooth muscle cells or 58% large principal cells. Cell viability following sedimentation was excellent, as concluded from elect ron micrographs revealing adenosine triphosphate content and fine struct ure. This technique should enable critical analyses of epididymal function in isolated epithelial cells.     

Laminaria augmentation of midtrimester pregnancy termination by intramuscular prostaglandin 15 (S) 15-methyl F2 alpha

A group of 15 midtrimester gravid patients underwent intracervical laminaria tent insertion prior to repeated intramuscular injections of 250mu g of prostaglandin 15 (S) 15-methyl F2 alpha at two-hour intervals for elective termination of pregnancy. This group was compared with a previously reported group of 80 patients who had received identical treatment without laminaria insertion. A significant reduction in mean abortion time and an increased 24-hour abortion rate were observed with the addition of laminaria. There was a proportionate decrease in gastrointestinal side effects as well as a reduced need for analgesia in the laminaria group with no complications attributable to the laminaria insertion.     

Urinary creatinine excretion and lean body mass

In a group of 34 adult and child subjects a high correlation (r = 0.988) was found between lean body mass, as determined by potassium-40 counting, and urinary creatinine excretion. The effect of technical errors was reduced by averaging the results of two or three 40K assays on each subject, and by making consecutive 3-day collections of urine. It appears that one can make a reasonable estimate of lean body mass from urinary creatinine excretion.     

Models for low resolution slit scan measurements based on high resolution laser scanning image analysis: DNA and nuclear dimensions

A laser scanning microscope has been developed and employed to make high precision measurements of cells from clinical cervical samples. These specimens have been stained with the DNA specific fluorochrome mithramycin and the fluorescent images analyzed to give information on nuclear size, DNA content and nuclear shape. This information has been used to develop low resolution parameters as measured with flow cytometers, thus permitting some comparisons between high resolution and low resolution features as measured from the same cells. The results indicate that both low resolution flow slit scan and high resolution pattern recognition techniques yield the same average cellular information. However, low resolution methods are insensitive to shape and the influence of shape on the broadening of low resolution features is now under investigation.     

Do increases in cigarette prices lead to increases in sales of cigarettes with high tar and nicotine yields?

We used scanner data on cigarette prices and sales collected from supermarkets across the United States from 1994 to 2004 to test the hypothesis that cigarette prices are positively correlated with sales of cigarettes with higher tar and nicotine content. During this period the average inflation-adjusted price for menthol cigarettes increased 55.8%. Price elasticities from multivariate regression models suggest that this price increase led to an increase of 1.73% in sales-weighted average tar yields and a 1.28% increase in sales-weighted average nicotine yields for menthol cigarettes. The 50.5% price increase of nonmenthol varieties over the same period yielded an estimated increase of 1% in tar per cigarette but no statistically significant increase in nicotine yields. An ordered probit model of the impact of cigarette prices on cigarette strength (ultra-light, light, full flavor, unfiltered) offers an explanation: As cigarette prices increase, the probability that stronger cigarette types will be sold increases. This effect is larger for menthol than for nonmenthol cigarettes. Our results are consistent with earlier population-based cross-sectional and longitudinal studies showing that higher cigarette prices and taxes are associated with increasing consumption of higher-yield cigarettes by smokers.     

Inter-relationships among gonadotrophins, reproductive steroids and inhibin in freemartin ewes

Freemartins are sterile XX/XY chimaeras that occur as a result of placental fusion between male and female fetuses during early pregnancy. Freemartins occur predominantly in cattle, although the prevalence of ovine freemartinism is increasing. In this study, the reproductive endocrinology of ovine freemartins was compared with that of normal sheep. Freemartins had significantly (P < 0.001) higher basal concentrations of LH and FSH than did normal ewes or rams, although the response of LH to GnRH (10 microg) was similar in freemartins, ewes and rams. Resting concentrations of oestradiol were similar in freemartins and ewes and were increased in both after eCG administration. Testosterone concentrations were higher in freemartins than in ewes, but were unresponsive to GnRH or eCG. Administration of 62.5 mg progesterone or 25 lg oestradiol twice a day for 3 days suppressed LH concentrations to baseline values in freemartins, ewes and rams. In ewes, 500 microg oestradiol administered twice a day caused preovulatory surges in LH concentrations, but suppressed LH in freemartins to baseline values. Thus, LH secretion can potentially be regulated in freemartins by gonadal steroids. FSH concentrations in freemartins were not suppressed by doses of inhibin that were effective in ewes and rams. Therefore, freemartins behave in part like castrated animals, as they have high basal concentrations of LH and FSH, which can be stimulated by GnRH and suppressed by gonadal steroids. Conversely, inhibin does not suppress FSH concentrations in freemartins, and freemartins have circulating concentrations of steroids intermediate between those of castrated and normal animals.     

Synthese substituierter 2-Nitrophenylhydrazone von 2-Oxodicarbonsäureestern und Untersuchung ihres Tautomerie- und Absorptionsverhaltens

Synthesis of Substituted 2-Nitrophenylhydrazones of 2-Oxodicarboxylic Acid Esters and Investigation of Their Tautomerism and Absorption Behaviour 32 Substituted 2-nitrophenylhydrazones of diethyl oxalacetate, 2-oxoglutaric acid and its 1-mono- and 1,5-dialkyl esters, resp., have been synthesized from substituted 2-nitrophenylhydrazines and 4,6-dinitro-1,3-dihydrazinobenzene and the carbonyl compounds named above. ¹H-n.m.r. spectra prove all products to have the constitution of hydrazones and not that of azo compounds or enhydrazines and also allow the assignation of the E- and Z-configuration, resp., to the hydrazone diastereomers. The absorption behaviour of all hydrazones is discussed with comparison of the different substitution patterns. Unexpectedly, the 4,6-dinitro-1,3-bishydrazones 27 – 32 show very high lg ϵ_max values (at about 4.8) due to their crossed two chromophoric systems.     

Säurekatalysierte Umsetzungen von Aromaten mit Alkanen und Cycloalkanen. IX. Alkylierungen mit 2,2,4-Trimethylpentan (Isooctan)

Acid-catalyzed Reactions of Aromatic Hydrocarbons with Alkanes and Cycloalkanes. IX. Alkylations with 2,2,4-Trimethylpentane (Isooctane) The non-conventional alkylation of benzene, toluene, ethyl- and isopropylbenzene, fluoro- and chlorobenzene with 2,2,4-trimethylpentane in the presence of acid catalysts is described. The composition of the rather complex reaction mixtures is determined by gas-liquid chromatography and mass spectrometry, tert. butylarenes being the main products beside alkylsubstituted indanes and tetralines. Their formation is interpreted as a competition between fragmentation and isomerization of the alkylating agent. By use of trifluoromethanesulfonic acid or combinations of catalysts from HF or HSO₃F with variant metallic fluorides at lower temperatures the selectivity of the reaction may be partially raised.