Correction of increased prostacyclin synthesis in Bartter's syndrome by indomethacin treatment

The role of prostacyclin and thromboxane A2 in the pathogenesis of Bartter's syndrome was investigated by measurement of the urinary excretion of 6-keto-PGF1 alpha and thromboxane B2, respectively, in five patients. The prostaglandin metabolites were extracted from urine by a reproducible method and measured by specific radioimmunoassays. The patients with Bartter's syndrome excreted about four-times as much 6-keto-PGF1 alpha as the normal controls. In contrast, there was no significant difference in the urinary excretion of thromboxane B2 between the patients and the controls. In a second part of the study, three patients were treated with indomethacin (150 mg/day for four days), an inhibitor of prostaglandin synthesis. This regimen suppressed urinary excretion of 6-keto-PGF1 alpha by 43% and that of thromboxane B2 by 46%. It is suggested that the increase in prostacyclin production is responsible for both the hyperreninemia and and the other endocrine derangements as well as the hyporesponsiveness of blood pressure to intravenous infusion of vasopressors in patients with Bartter's syndrome.     

Differential diagnostic question: traumatic unconsciousness or amnestic episode?

Traumatic twilight state on the one and amnestic episode (transient global amnesia) on the other side are as a rule easy to differentiate from the patient's age, his behavior during the acute state of disease and the kind of its improving. Contrary to other authors' opinion, differentiation is not just possible by diagnosing an injury or its absence. In minor skull traumata preceding the traumatic twilight states injuries are often not manifest and otherwise amnestic episodes occasionnally occur after minor traumata. In a 64 years old woman an obviously typical amnestic episode appeared in direct connection with a probable fall on the back of the head. A 28 years old man underwent a five-hour amnestic episode whereas the EEG showed normal curves. The episode occurred 15 minutes after striking hard upon the ground with the back of the head during a ground roll without following unconsciousness. In both cases traumatic twilight states were not involved. In account of the interval of 15 minutes the trauma of the second case seems not be be the direct cause for the manifestation of amnestic episode. It also shows that the aspect of the disease in the rare occurrence in younger or middle-aged persons is on principle not different from that in old ones. Since a special medical examination during the acute state is only possible as exception the patient's amnestically seizable behaviour obtains greatest importance in differential diagnosis. For the rare coincidence the trauma is given no pathogenetic relevance in amnestic episodes.     

Methods for determining stability in continuum elastic-rod models of DNA

Elastic-rod models of DNA have offered an alternative method for studying the macroscopic properties of the molecule. An essential component of the modelling effort is to identify the biologically accessible, or stable, solutions. The underlying variational structure of the elastic-rod model can be exploited to derive methods that identify stable equilibrium configurations. We present two methods for determining the stability of the equilibria of elastic-rod models: the conjugate-point method and the distinguished-diagram method. Additionally, we apply these methods to two intrinsically curved DNA molecules: a DNA filament with an A-tract bend and a DNA minicircle with a catabolite gene activator protein binding site. The stable solutions of these models provide visual insight into the three-dimensional structure of the DNA molecules.     

Summary of US–Japan Exchange 2004: New Directions and Physics for Compact Toroids

Scientists from research institutions in the United States of America and Japan attended a USA Department of Energy sponsored joint international workshop on the subject of Compact Toroids (CT) in Santa Fe, NM, USA in September 2004. We outline here a summary of the topics that were discussed, some of the implications, and new directions that are likely to follow from this research. Experimental, theoretical and computational results were presented. The experimental devices and concepts, along with the theory and computational models comprise investigations of fundamental plasma physics, fusion science, and approaches to fusion energy that require magnetized plasmas.     

The philosophical underpinnings of peer review.

The current impetus for peer review had its origin in issues of cost containment, bolstered by intentions to improve quality of service. Peer review is usually conceived of as a way to either police a profession by ridding it of the few "bad actors" or to assure that services delivered meet minimum standards. The present article argues, however, that a more useful philosophy of peer review is to assume that it is at the heart of the definition of a profession. (2 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Computation of steady and time-dependent temperature distribution for building elements: A general three-dimensional solution

A computational method of temperature distribution calculation for building elements in two- and three-dimensional time-dependent heat flow problems is developed with a general approximate solution using, as a numerical approach, the finite difference method. An analytical evaluation method of the accuracy of calculations is developed. The method described was compared with experimental values and good correspondence was obtained. The time-dependent study which is presented includes thermal resistance and inertia (heat capacity) of the components' materials and different geometric compositions.     

Increased prolactin and thyrotrophin secretion following oral metoclopramide: dose-response relationships

In pregnant female rat, oxygen tension was measured in vivo with an oxygen microelectrode and the following statistically significant data (Student's test) were obtained: -- not significant variability in four groups of six control rats; -- highly significant decrease of oxygen tension twenty-four hours after biovariectomy in four groups of six operated rats; -- in twelve operated and treated by substitutive hormonotherapy rats, pO2 was at the same level than in control rats; -- in eighteen operated rats, the oxygen tension measured after embryonic death was identical to control rats. These experiments clearly demonstrate twenty four hours after biovariectomy a decreased oxygen tension. Simultaneously to this decrease, a diminution of uterine blood flow takes place. This pO2 diminution should be dependent on decrease of ovarian hormones since the substitutive hormonotherapy prevents its appearance. A good explanation of this phenomenon is the high requirement of hypoxic embryo for oxygen; moreover after the embryonic death, the intra-uterine pO2 increases.