Stimulation of peptide elongation by thyroxine

This study suggests that thyroxine stimulates peptide elongation in a cell-free rat liver polyribosome system. The thyroxine effect persists in the presence of sufficient aurintricarboxylic acid to prevent polyuridylic acid-stimulated peptide initiation. In addition, thyroxine stimulates elongation of pre-existing polyphenylalanine chains providing conclusive evidence that the effect does not depend on peptide initiation. Thyroxine does not stimulate release of nascent peptides from ribosomes into the supernatant phase of the reaction mixture. Therefore in this protein-synthesis system the thyroxine effect is expected to occur at one or more of the reactions of peptide chain elongation, which include aminoacyl-tRNA binding, peptide bond synthesis and translocation.     

Reovirus antibodies among animals in Taiwan

Serum specimens for reovirus antibody survey were collected from 60 pigs, 50 buffalos, 30 rabbits, 30 guinea pigs, 20 albino rats, 60 Swiss mice, 15 Taiwan monkeys, 14 goats and 12 dogs. Serum antibodies were measured by the hemagglutination inhibition (HI) test. HI antibodies to reovirus were found in a high percentage of pigs, albino rats, Swiss mice, dogs and goats, and less frequently in rabbits, guinea pigs, Taiwan monkeys and buffalos.     

Hypnotizability and phobic behavior

Hypnotizability ratings of 24 phobic patients interested in the therapeutic use of hypnosis were compared with those of an equal number of smokers keen to quit smoking through hypnosis. The mean Stanford Hypnotic Susceptibility Scale score of phobics was 8.08 on a 12-point scale. The mean of smokers was 6.08. The difference was significant beyond the .01 level (two-tailed). Thirty percent of smokers were essentially nonresponsive. No phobics were nonresponsive. Those with multiple phobias scored more highly than those with a single phobia. These findings are in accord with the view that among psychiatric patients whose hypnotizability is assessed in a treatment context, hysterics are most responsive. The implications both for theory and for a specific treatment strategy are discussed.     

Endogenous reproductive hormones and nocturnal rhythms in partner preference and sexual behavior of ATD-treated male rats

Male rats received subcutaneously silastic capsules, containing the aromatase inhibitor 1,4,6-androstatriene-3,17-dione (ATD), shortly after birth. Control males were given silastic capsules containing cholesterol. The capsules were removed at the age of 21 days. In adulthood, blood serum was collected early and late in the dark phase of the light/dark cycle (experiment I). Testosterone and luteinizing hormone and follicle stimulating hormone (FSH) fluctuated nocturnally, both in ATD and control males, with highest levels late in the dark phase. FSH levels were significantly higher in ATD males. Nocturnal levels of inhibin, a selective suppressor of pituitary FSH secretion, also fluctuated in both ATD and control males, with lowest levels late in the dark phase. In experiment II, ATD and control males were tested for partner preference behavior in a three-compartment box (choice: sexually active male vs. estrous female) early and late in the dark phase. When gonadally intact, ATD males, but not controls, showed a clear nocturnal rhythmicity in partner preference behavior and sexual behavior. Early in the dark phase, such ATD males preferred the vicinity of and interaction with a sexually active male. Late in the dark phase, this preference for the active male shifted to a preference for the estrous female. Control males preferred the estrous female. After castration and subsequent treatment with testosterone via silastic capsules, which ensured constant blood serum levels, ATD males continued to show their nocturnal rhythms in partner preference behavior and in sexual behavior. Thus, the underlying mechanism of the nocturnal rhythmicity phenomenon is an organizational effect of neonatal ATD treatment rather than an activational effect of fluctuating serum hormone levels.     

The oxytocin challenge test

In a group of 152 high-risk pregnancies, 266 oxytocin challenge tests were reviewed. There were 137 patients with persistently negative oxytocin challenge tests with only one false-negative test being recorded. Fifteen patients who displayed a positive test at some time in their antepartum course are discussed along with other aspects of the oxytocin challenge test.     

Device to limit inflation of a pulmonary artery catheter balloon

OBJECTIVE: The most serious complication seen with pulmonary artery catheters is rupture of the pulmonary artery. The effectiveness of an external safety balloon added to the pulmonary artery balloon inflation port was tested. DESIGN: The external balloon is designed to inflate and absorb excess volume from the inflation syringe after the internal balloon contacts the vessel wall. When the catheter tip is in a small pulmonary artery, expansion of the external balloon indicates that the catheter tip is in a noncompliant or small vessel. SETTING: The external balloon was tested in a bench simulation. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The pulmonary artery balloon was slowly inflated inside 2.6-, 3.0-, 4.7-, 8.6-, and 11.6-mm internal diameter polyvinyl chloride tubes, with and without the external safety device in place. Without the external balloon, the average balloon pressure was 1647 +/- 145 (SD) mm Hg in the 2.6-mm vessel. With the external balloon in use, the maximum pulmonary artery balloon pressure was 473 +/- 7.2 mm Hg in the 2.6-mm vessel. CONCLUSIONS: The external balloon can limit balloon pressures within the pulmonary artery and identify when excessive volumes are being forced into the pulmonary artery balloon.     

Headache characteristics in subarachnoid haemorrhage and benign thunderclap headache

One third of patients with aneurysmal subarachnoid haemorrhage (ASAH) present with headache only. A prompt diagnosis is crucial, but these patients must be distinguished from patients with non-haemorrhagic benign thunderclap headache (BTH). The headache characteristics and associated features at onset in subarachnoid haemorrhage and benign thunderclap headache were studied to delineate the range of early features in these conditions. In this prospective study, one of two observers interviewed 102 patients with acute severe headache by means of a standard questionnaire. The patients were alert on admission and had no focal deficits. ASAH was subsequently diagnosed in 42 patients, non-aneurysmal perimesencephalic haemorrhage (PMH) in 23 patients, and BTH in 37 patients. Headache developed almost instantaneously in 50% of patients with ASAH, 35% of patients with PMH, and 68% of patients with BTH and within 1 to 5 minutes in 19%, 35%, and 19%, respectively. Loss of consciousness was reported in 26% of patients with ASAH, 4% of patients with PMH and 16% of patients with BTH, and transient focal symptoms in 33%, 9%, and 22% respectively. Seizures and double vision had occurred only in ASAH. Vomiting and physical exertion preceding the onset of headache were more frequent in patients with ASAH (69% and 50%) and those with PMH (83% and 39%) than in those with BTH (43% and 22%). Headache developed almost instantaneously in only half the patients with aneurysmal rupture and in two thirds of patients with benign thunderclap headache. In patients with acute severe headache, female sex, the presence of seizures, a history of loss of consciousness or focal symptoms, vomiting, or exertion increases the probability of ASAH, but these characteristics are of limited value in distinguishing ASAH from BTH. Aneurysmal rupture should be considered even if focal signs are absent and the headache starts within minutes.