Regioselective ring opening of steroidal epoxide with hydrides: formation of C(2)- and C(3)-deoxyasiatic acid derivatives

In their 4 short years in medical school, members of the Class of '98 have witnessed massive changes within the health care system. These are going to have a direct, and often negative, impact on the way they practise. Despite this, members of this group can't wait to become full-fledged members of the medical profession.     

Chromatographic stability of glucose-silica

The observation that changes in bronchial osmolarity can induce bronchoconstriction in asthma inspired the experimental studies which, unexpectedly, revealed that frusemide is an effective bronchoprotective agent against a variety of osmotic and non osmotic stimuli. Although the mechanism of this protective effect is not fully understood, studies in vivo and in vitro suggest that frusemide may inhibit the activation of different cell types induced by bronchoconstrictor stimuli. Other loop diuretics also exert bronchoprotective activity, but frusemide appears to be the more effective bronchoprotective agent of this family, regardless of their diuretic potency and lipid solubility. Despite the relatively large amount of experimental evidence, there is currently little information on the clinical effectiveness of frusemide in asthma and a long-term controlled study is currently in progress. The observations that treatment with a combination of inhaled acetylsalicylate and frusemide results in a markedly increased bronchoprotective effect compared to either drug alone, opens a new perspective in the possible clinical use of these drugs. Preliminary studies suggest that the association of these drugs is well tolerated and may result in a remarkable steroid sparing effect in patients with steroid dependent asthma, for whom a convenient alternative to long-term steroid therapy is not currently available.     

Multicast Communication on Network Computers

Channel-oriented packet casting is a predominant feature of Micros, an operating system designed to explore control and communication techniques for network computers containing thousands of hosts.     

Gender and credibility introduction effects on perceived counselor characteristics.

Explored the effects of counselor gender, participant gender, and high or low credibility introduction on 8th graders' perceptions of counselor expertness, attractiveness, trustworthiness, and confidence in the counselor. 240 male and female Ss listened to an audiotape of a high or low credibility introduction and to a counseling session with a male or female counselor and then completed a modified Counselor Rating Form and the Help with Specific Problems Scale. Multivariate and univariate ANOVAs yielded significant main effects for Participant Gender and Credibility Introduction and a significant interaction effect for Counselor Gender?×?Credibility Introduction. Results are compared with studies of adult Ss, and a new scheme for classifying types of credibility cues is proposed. (39 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Function and production of nitric oxide in the coronary circulation of the conscious dog during exercise

This study determined the changes in NO production from the coronary circulation of the conscious dog during exercise. The role of endogenous NO as it relates to coronary flow, myocardial work, and metabolism was also studied. Mongrel dogs were chronically instrumented for measurements of coronary blood flow (CBF), ventricular and aortic pressure, and ventricular diameter, with catheters in the aorta and coronary sinus. Acute exercise (5 minutes at 3.6, 5.9, and 9.1 mph) was performed, and hemodynamic measurements and blood samples were taken at each exercise level. Nitro-L-arginine (NLA, 35 mg/kg IV) was given to block NO synthesis, and the exercise was repeated. Blood samples were analyzed for oxygen, plasma nitrate/nitrite (an index of NO), lactate, glucose, and free fatty acid (FFA) levels. Acute exercise caused significant elevations in NO production by the coronary circulation (46 +/- 23, 129 +/- 44, and 63 +/- 32 nmol/min at each speed respectively, P < .05). After NLA, there was no measurable NO production at rest or during exercise. Blockade of NO synthesis resulted in elevations in myocardial oxygen consumption and reductions in myocardial FFA consumption for comparable levels of CBF and cardiac work. The metabolic changes after NLA occurred in the absence of alterations in myocardial lactate or glucose consumptions. NO production by the coronary circulation is increased with exercise and blocked by NLA. The absence of NO in the coronary circulation during exercise does not affect levels of CBF, because it shifts the relationship between cardiac work and myocardial oxygen consumption, suggesting that endogenous NO modulates myocardial metabolism.     

Molecular origins and evolution of immunoglobulin heavy-chain genes of jawed vertebrates

Cartilaginous fish are the most ancient extant jawed vertebrates possessing bona fide immunoglobulin (Ig) and T-cell receptor molecules. The study of these animals is critical for understanding the origins of the vertebrate immune system. Here, Samuel Schluter, Ralph Bernstein and John Marchalonis review the latest data concerning heavy-chain variable genes and associated isotypes in these animals, and propose a model for the early origins of Igs.