Fatty acid binding protein. Role in esterification of absorbed long chain fatty acid in rat intestine

Fatty acid binding protein (FABP) is a protein of 12,000 mol wt found in cytosol of intestinal mucosa and other tissues, which exhibits high affinity for long chain fatty acids. It has been suggested that FABP (which may comprise a group of closely related proteins of 12,000 mol wt) participates in cellular fatty acid transport and metabolism. Although earlier findings were consistent with this concept, the present studies were designed to examine its physiological function more directly. Everted jejunal sacs were incubated in mixed fatty acid-monoglyceride-bile acid micelles, in the presence or absence of equimolar concentrations of either of two compounds which inhibit oleate binding to FABP:flavaspidic acid-N-methyl-glucaminate and alpha-bromopalmitate. Oleate uptake, mucosal morphology, and oxidation of [14C]acetate remained unaffected by these agents, but oleate incorporation into triglyceride was inhibited by 62-64% after 4 min. The inhibition by flavaspidic acid was reversible with higher oleate concentrations. The effect of these compounds on enzymes of triglyceride biosynthesis was examined in intestinal microsomes. Neither flavaspidic acid nor alpha-bromopalmitate inhibited acyl CoA:monoglyceride acyl-transferase. Fatty acid:coenzyme A ligase activity was significantly enhanced in the presence of partially purified FABP, probably reflecting a physical effect on the fatty acid substrate or on the formation of the enzyme-substrate complex. Activity of the enzyme in the presence of 0.1 mM oleate was only modestly inhibited by equimolar flavaspidic acid and alpha-bromopalmitate, and this effect was blunted or prevented by FABP. We conclude that in everted gut sacs, inhibition of triglyceride synthesis by flavaspidic acid and alpha-bromopalmitate could not be explained as an effect on fatty acid uptake or on esterifying enzymes in the endoplasmic reticulum but rather can be interpreted as reflecting inhibition of fatty acid binding to FABP. These findings lend further support to the concept that FABP participates in cellular fatty acid transport and metabolism. It is also possible that FABP, by effecting an intracellular compartmentalization of fatty acids and acyl CoA, may play a broader role in cellular lipid metabolism.     

Automation in the hematology laboratory

In the routine laboratory for hematology conflicting results may be obtained for the red blood cell parameters with the Coulter Counter Model S. These parameters2) are: mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH) and mean corpuscular hemoglobin concentration (MCHC). When the values of the MCHC are above 36 g/dl something must be wrong with the blood sample of the patient. One of the reasons can be agglutination e.g. by cold agglutinins. The blood sample should be reanalysed before and after heating for 1 hour at 37 degrees C. If the values change: cold agglutinins are present; if no change occurs paraproteins, or other disturbing factors, such as bilirubin or high leucocyte levels, will be found. MCH values may also be high in some cases e.g. if the red blood cells are coated with antibodies (Coombs test positive) or after ingestion of medicines like Azathioprine. These examples show that it is possible in some cases to correlate immunological findings with the red blood cell parameters. In addition to the results with the Coulter Counter Model S, some observations on the Hemalog (Technicon) are also presented.     

Analysis of the exudate produced by Streptococcus mutans SL-1 colonies of sucrose-containing agar media

The watery exudate produced by Streptococcus mutans SL-1 colonies on sucrose-containing agar media was found to contain about 7% (wt/vol) of a water-soluble, branched dextran, 4% sucrose, and smaller (less than 1%) amounts of fructose, Folin-phenol-positive material, and lactic acid.     

The heroin epidemic in San Francisco: estimates of incidence and prevalence

Much attention has recently been focused on the question of the extent of heroin use in America. In a worthwhile effort to call public attention to the problem, many estimates of its size have evidenced a tendency toward exaggeration and aggrandizement. This paper presents methods of estimation of the extent of heroin addiction which, when carefully employed, should effectively correct such distorted estimates. Two general types of estimation are employed, incidence and prevalence. Incidence estimates are concerned with new cases of heroin addiction that occur in a specific population within a given amount of time. These estimates are based upon self-report data from addicts regarding date of first addiction. When corrected for the "lag phase" (that period of time between onset of first addiction and eventual visit to a treatment program), these data permit accurate retrospective charting of incidence trends. Prevalence estimates focus on all known cases of heroin addiction in a specific population within a given amount of time. Three separate types of prevalence estimates from three separate sources are outlined in this article: estimates based on overdose death data, estimates based on crime statistics, and estimates of "unknown" addicts. In outlining these methods, this article describes the fluctuations in heroin addiction in one major American city, San Francisco, California. After analyzing data gathered from a sample of 2,367 addicts contacted over a 3-year period, this study suggests that the incidence of heroin addiction seems to have declined after 1970. Possible factors underlying this apparent decline in heroin addiction are then discussed, including the post-1970 maturation of the "population at risk," the effectiveness of antidrug media messages, the changing drug fashions in the heroin subculture, and the gradual deterioration of the quality and potency of street heroin.     

Music preference as a factor of music distraction

The present study is an experimental analysis of music preference as a factor of music distraction measured by the Stroop tests. Significant differences were found amoung groups given, most preferred music, least preferred music, and no music (quiet). Each group of 10 subjects were randomly chosen from 42 screened subjects. Performance was better without music and better with most preferred than with least preferred music. The results were not consistent with those previously found for the effects of noise upon Stroop test performance.     

Circadian rhythms and photoperiodic time measurement in mammals

Many mammalian species display seasonal breeding patterns correlated with annual cycles of change in the physiology and morphology of the reproductive system. Such annual reproductive cycles are often photoperiodically controlled (i.e, the annual change in day length determines when reproductive activity begins and when it ends within the annual cycle). Photoperiodic control of seasonally appropriate changes in reproductive activity is dependent on an endogenous time measuring process. Among mammals the physiological basis of photoperiodic time measurement has been studied most extensively in the golden hamster. Studies with this species indicate that photoperiodic time measurement is executed by the circadian system. The time measuring process depends on a circadian oscillation of responsiveness to light with properties similar to those of the hypothetical rhythm originally proposed by Bünning to explain photoperiodic phenomena in plants. The available evidence strongly suggests the participation of the pineal gland and the suprachiasmatic nucleus (SCN) in the photoperiodic regulation of mammalian reproductive cycles. However, little is known regarding concrete physiological mechanisms, and the extent to which the SCN and the pineal gland may participate in the time measuring process per se remains to be determined.     

Study of TRH in the postganglionic sypnasis of the isolated human vas deferens

Cummulative dose-response curves to l-noradrenaline and in presence of different concentrations of TRH (10(-3), 10(-4), 10(-5), 10(-6), 10(-7), and 10(-8) M) were investigated. 25 segments of vas deferens (escrotal tract) were obtained from different surgical patients of urological disorders. At the lower concentration (greater than 10(-7) M), we can not appreciate any influence of TRH on the l-noradrenaline response. Nevertheless there was a reduction of response to l-noradrenaline, with displacement of the curves to the right side, for the high concentrations, and a proportional ratio to the concentration to TRH.     

Action of prolactin on ornithine decarboxylase activity in mammary gland explants of mice

Prolactin stimulated ornithine decarboxylase activity in mammary gland explants from midpregnant mice. The enhanced enzyme activity occurred in explants which were preincubated for 1 day in medium containing insulin, hydrocortisone, insulin plus hydrocortisone, or in medium containing no hormones. The largest prolactin effect was observed in tissues which were pretreated with insulin plus hydrocortisone; a greater than ten-fold increase in ornithine decarboxylase activity was observed when these tissues were incubated with prolactin for 2 hours. An effect of prolactin on ornithine decarboxylase activity was also observed in explants prepared from lactating mouse mammary glands.     

Althesin infusion for cardiac catheterisation

A trial of a continuous intravenous infusion of Althesin is described for sedation during cardiac catheterisation, both for children and adults. The conditions produced for the procedure were very satisfactory. The advantages and problems of its use are discussed. The technique justifies further trials.