Permeability of individual human erythrocytes to thiourea

The osmotic swelling to haemolysis of individual red blood cells by isosmotic thiourea has been studied using microcine photography. 2. Crenation occurs immediately upon addition of isosmotic thiourea. The cell becomes a crenated sphere without volume decrease. 3. Subsequently, the cell volume increases linearly with time with maximum swelling occurring at about 102 sec which is 81% of the total haemolysis time. 4. At maximum swelling, the cell volume is 92% greater than the initial cell volume. This volume increase is about double that measured with other permeating substances. 5. The much larger maximum volume implies that thiourea increases the area of the cell membrane. This increase varies from 0 to 75% for individual cells, with a mean of 22%. 6. Membrane expansion varies inversely as the initial cell membrane area and cell volume (r=0-790). 7. Using the increased surface area, increased maximum volume and the swelling time, the mean permeability is calculated to be 5-52 X 10(-7) cm/sec (S.D. of mean=+/-1-19 X 10(-7) cm/sec). The distribution of permeabilities represents a normal distribution. 8. The pre-lytic potassium loss ranged from 0 to 36% with a mean value of 16-5%. This is consistent with values reported in the literature for slow haemolysis. As with other permeants the distribution is skewed towards lower values. 9. Membrane permeability of individual cells varies with the amount of membrane expansion observed. Coefficient of correlation between permeability and expansion index is 0-674. 10. There is no correlation between permeability and the reciprocal of the haemolysis time (r=-0-035). The correlation between permeability and the reciprocal of the swelling time is also poor (r=0-303), probably owing to the variability in membrane expansion by thiourea in individual cells. 11. As has been shown previously for faster permeants, the permeability coefficient cannot be calculated from the haemolysis time. Because thiourea alters the membrane area and the haemolytic volume, the coefficient cannot be calculated from the swelling time unless the changes in the membrane area are also taken into account.     

Is clubbing a feature of the anti-phospholipid antibody syndrome?

A patient with the anti-phospholipid antibody syndrome and digital clubbing is described. No recognized cause for the clubbing was found. It is suggested that platelet aggregation and microthrombi formation as a result of anti-phospholipid antibody may be involved in the pathogenesis of the digital clubbing. This may be a new feature of the anti-phospholipid antibody.     

Role of cognitively stimulating home environment in children's academic intrinsic motivation: a longitudinal study

The short- and long-term, and direct and indirect, relations between cognitively stimulating home environment and academic intrinsic motivation were investigated in a longitudinal study from childhood through early adolescence. Structural equations modeling was used to test the hypothesis that home environment positively predicts academic intrinsic motivation over this period. It was also hypothesized that home environmental processes would positively predict motivation controlling for socioeconomic status (SES). When children were age 8, home environment (comprising both direct observations and parent report) and SES were measured. Academic intrinsic motivation was assessed at ages 9, 10, and 13. Results supported the hypotheses. Home environment had statistically positive and significant, direct and indirect paths to academic intrinsic motivation from childhood through early adolescence, indicating both short- and long-term effects across these ages. Moreover, home environment was significant above and beyond SES. The findings revealed that children whose homes had a greater emphasis on learning opportunities and activities were more academically intrinsically motivated.     

Treatment of restlessness in dying patients: more than just sedation]

The aim of this study was to evaluate the efficacy of a minimal-intervention smoking cessation program tailored to meet the needs of patients in a pneumology practice. Six-months open study was designed, multicenter, involving four pneumology practices in different Spanish cities. Smokers with or without respiratory disease who consulted a pneumologist were included. Patients were grouped according to their phase in the self-change process toward smoking cessation: precontemplation or contemplation. The level of physical dependence on nicotine was assessed using a revised version of the Fagerstr?m test. CO in exhaled air was also measured. Precontemplators were advised to quit smoking and given a booklet about smoking addiction. Contemplators were additionally given a practical guide to quitting. Advice on quitting was different for the two different phases. Smokers were reexamined twice: 8 weeks and 6 months later. We evaluated the success of the physician's intervention of encouragement to abstain (a level of CO in exhaled air [10 ppm was required]) and we recorded change of phase in the cessation process. Three hundred thirteen subjects were enrolled: 222 men (70.9%) and 91 women (29.1%). After 6 months, 40 (43%) of the precontemplators had changed phase and 21 of them (23%) had stopped smoking; 61 (28%) of the 221 contemplators had changed phase and 20 of them (9%) had quit smoking. Personalized minimal intervention in subjects with or without disease gives good results in terms of success in quitting as well as progress toward cessation.     

Retinal tears 180 degrees and greater. Management with vitrectomy and intravitreal gas

A new technique for the treatment of giant retinal dialysis of 180 degrees or more has been devised. After the lens and vitreous have been removed via the pars plana, the patient is rotated into a prone position on a special operating table. The retina is unfolded by filling the eye completely with gas and is held in place by gas. The patient is then brought back into the normal supine position, and a scleral encircling procedure is added. The initial success rate of reattachment is 12 out of 14 cases. Afterward, many eyes develop massive periretinal proliferation. After six months or more of follow-up, the retina remained attached in six of 14 cases.     

Preliminary study of the effects of feeding ethyl mercury chloride on four breeds of chickens

Different breeds of chickens namely Single Comb White Leghorn (S.C.W.L.), New Hamsphire (N.H.), Iraqi (IRQ) and a cross (CRS.) S.C.W.L. X N.H. X IRQ. were housed in small pens (20 females and 2 males each) and given, in the diet, 40% wheat treatmed with ethyl mercury chloride, for 88 days. Throughout the whole experiment all birds remained active and showed no symptoms of toxicity. The Iraqi breed was significantly higher than the other breeds with respect to egg production. The results also indicated that mercury in egg white is almost three times as much as that in the yolk, although there was no significant difference between the breeds. The liver and kidney of the four breeds tended to accumulate the highest amount of mercury. Significant differences appeared between sexes according to liver and kidney. White Leghorn and local breeds behaved the same, but N.H. had the highest concentration of mercury in most tissues.