Alcohol and tension reduction: cognitive and physiological effects

Previous research indicates that the tension reduction hypothesis of alcoholism has received little empirical support. There is also evidence that cognitive and social variables mediate the effects of alcohol. The present investigation with 40 male undergraduates examined separately the cognitive and pharmacological effects of alcohol by manipulating Ss' expectancies. It was found that although alcohol is a pharmacologic sedative and reduces anxiety, the cognition that one is drinking alcohol increases anxiety. (15 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Changes in CNS responsiveness during hibernation

The ability of the midbrain reticular formation (MRF) to produce thermogenic responses and to trigger arousal from hibernation was tested during successive quarters of individual hibernation bouts. Golden-mantled ground squirrels (Citellus lateralis) were implanted with bilateral cannula guides into the MRF. Single, bilateral, 1-mul injections of acetylcholine (ACh) at concentrations of 50, 100, or 200 mug/mul were delivered in each quarter of the same bout or in selected quarters of different bouts. The results show that the magnitude of thermogenic responses evoked by ACh stimulation of the MRF was depressed during the early portion of the bout and increased as time in the bout elapsed. Furthermore, the magnitude of responses evoked during hibernation was depressed in comparison to those evoked during euthermia, indicating the influence of inhibition on the responsiveness of the CNS during hibernation. We suggest that during hibernation, a progressive change in responsiveness of the CNS, perhpas focused in the MRF, controls the duration of each hibernation bout.     

Rheographic assessment of cerebral blood volume and correlations with changes in intracranial pressure

The authors present a four electrode rheographic technique for simiquantitative continuous measurement of CBV, by examining changes in cerebral tissue impedance induced by changes in blood content of the brain parenchyma. Correlation between the data obtained and ICP measurements permits conclusions regarding the behaviour of the cerebral blood bed. pCO2 regulates CBV, and the phenomenon is reversible according to a hystereris shaped time course in acute experiments. The rebound of ICP after sudden injections of CSF into the cisterna magna is of a vasogenic nature. Changes in CSF volume induce contrary changes in CBV. Pharmacological effects can be studied. The validity of the method is discussed.     

Selenium and vitamin E and incidence of retained placenta in parturient dairy cows. II. Prevention in commercial herds with prepartum treatment

In a series of field experiments in Ohio involving 193 parturient cows of the Holstein and Guernsey breeds, the prophylactic efficacy of selenium and vitamin E was tested under field conditions. Herds initially were chosen because of a chronic problem with retained placenta which could not be related to a known etiological factor. Each herd was divided into three groups. Group A received an injection of 50 mg of sodium selenite 40 days prepartum and 680 units of alpha tocopherol acetate followed by the same treatment 20 days prepartum. Group B received a single injection of 50 mg of sodium selenite 20 days prepartum, and 680 IU of vitamin E. Group C served as the control. Incidence of retained placenta was reduced from a mean of 51.2% in control cows to 8.8% for animals injected with selenium and vitamin E. No differences in efficacy were between Group A and B, and it appears that the single 20 day prepartum injection of 50 mg of sodium selenite and 680 IU of alpha tocopherol acetate is an effective prophylactic for prevention of retained placenta.     

Activities of mixed function oxidases, UDP-glucuronyl transferase and sulphate conjugation enzymes in galliformes and anseriformes

The activities of certain drug metabolizing enzymes have been measured in liver and kidney slice preparations from domesticated birds. Aminopyrine demethylase activity was significantly lower in liver slices from the duck (Aylesbury X Pekin, Khaki-Campbell) than from the rat (Wistar), and in the Aylesbury X Pekin duck lower than in the turkey (Triple 6 FLX), chicken (Brown Leghorn, Rhode Island Red X Light Sussex) and goose (Emden X Doulouse). The microsomal cytochrome P-450 was lower in duck liver (Aylesbury X Pekin) than in rat liver, and the aniline hydroxylase and aminopyrine demethylase activities in a 10,000 g supernatant fraction of liver were lower in duck preparations (Aylesbury X Pekin, Khaki-Campbell) than rat preparations. These observations suggest that the duck is likely to be susceptible to drugs which are metabolized by the cytochrome P-450 containing mono-oxygenases. UDP-Glucuronyl transferase activity was not detectable in liver and kidney slices from two mature geese. This observation was not the outcome of a deficiency of UDP-glucuronic acid, rapid breakdown of glucuronide by beta-glucuronidase or the presence of a substance inhibitory to UDP-glucuronyl transferase. Liver slices from geese, ducks (Aylesbury X Pekin) and chickens contained low UDP-glucuronyl transferase and high sulphate conjugation enzyme activities, whereas the reverse was found in Khaki-Campbell ducks. The activities of UDP-glucuronyl transferase and the sulphate conjugation enzymes were both relatively high in liver slices from the turkey and rat. The kidney contained lower enzyme activities than the liver except in the duck (Aylesbury X Pekin), in which low activities of aminopyrine demethylase and UDP-glucuronyl transferase were present in slices of both organs. In liver slices from chickens and geese the activities of aminopyrine demethylase and the sulphate conjugation enzymes were similar in mature and immature birds, and the activity of UDP-glucuronyl transferase was considerably higher in chicks and goslings than in mature birds of the same species. In the chick the activities of aminopyrine demethylase, UDP-glucuronyl transferase and the sulphate conjugation enzymes were higher in the duodenum than the remainder of the alimentary tract. The activities of these enzymes in pieces of duodenum were as high as those in slices of liver. The inclusion of sulphate in the incubation medium produced a significant increase in the synthesis of p-nitrophenyl sulphate in liver slices and not kidney slices except those from the duck. The kidney slices seemed to produce sufficient sulphate for the reaction of the sulphate conjugation enzymes to proceed at the maximum rate, but the liver slices did not do so.     

Response of stem cells in the mouse testis to fission neutrons of 1 MeV mean energy and 300 kV x rays. Methodology, dose-response studies, relative biological effectiveness

Microelectrode recording in the thalamus of pigeons subjected to tilt and sinusoidal rotational stimuli around the vertical, longitudinal and transversal axes revealed vestibularly driven units in two thalamic nuclei, the nucleus posteroventralis and the nucleus principalis precommissuralis. Many of these units responded in a complex manner suggesting that inputs from contralateral and ipsilateral cupulae and maculae converged on them. A few units received additional visual or proprioceptive information. The homology relationship with a mammalian vestibular thalamic nucleus is discussed briefly.     

The renal medulla and mechanisms of hypertension in the spontaneously hypertensive rat

A significant number of offspring from brother-sister matings of NIH-Okamoto-Aoki spontaneously hypertensive rats (SHRs) were found to be normotensive at 20 weeks of age. Over 20% of the animals that were hypertensive at this age had mild-to-moderate unilateral hydronephrosis at the time of sacrifice. In over 90% of the rats that did not develop hypertension spontaneously, ligation of one ureter raised blood pressure above 150 mm Hg within 2 weeks. In those rats made hypertensive by obstructing one ureter and in those that developed hypertension with accompanying naturally occurring hydronephrosis, subcutaneous implants of fragmented renal medulla from unrelated normal rats decreased blood pressure to normotensive levels. In contrast, medullary implants had no significant effect in rats developing hypertension spontaneously without hydronephrosis. Renal inner medullary plasma flow was low in the obstructed kidneys of hydronephrotic hypertensive SHRs but was elevated in the kidneys of nonhydronephrotic hypertensive SHRs. The hypertension in hydronephrotic SHRs appears to be related to an impairment of the antihypertensive function of the renal medulla. Such an impairment of medullary antihypertensive function does not appear to play a significant role in the hypertension in SHRs without hydronephrosis.     

Berylliosis as an auto-immune disorder

Four random samples representing populations at low (volunteer blood donors), intermediate, (VD clinic patients), high (family contacts of chronic antigen carriers) and very high (male homosexuals) risk of exposure to HBV were surveyed. Among HBsAg and anti-HBs negative individuals an average of 3.3% were found to be anti-HBc positive, and among those with anti-HBs, 19.4% were anti-HBc positive. Anti-HBc, with concurrent anti-HBs and without, was detected more frequently in the high risk samples than in the low risk. Individuals was a past history of acute viral hepatitis were more frequently anti-HBc positive than those without such a history, and anti-HBc positivity was frequently accompanied by serum transaminase elevation. Anti-HBc may persist for many years after an episode of acute hepatitis. In households of carriers, the highest frequency of anti-HBc was observed among spouses, which would argue for the possibility of sexual transmission. A significant excess of females with both types of antibody was observed in families of carriers. Anti-HBc determinations in conjunction with other HBV markers, provide a useful new tool for epidemiologic studies.