Toxicity and radioprotective properties of 1,3-oxazine and 1,3-thiazine derivatives]

Toxicity and radioprotective properties of 18 derivatives of oxazine and thiazine with a varying degree of the cycle saturation were studied in experiments on mice. Monotypic regularity in variations of their toxic properties relative to the chemical structure was noted. 4,4,6-Trimethyl-2-dimethylamino-4H-1,3-oxazine exerted a pronounced radioprotective action.     

Monitoring protein stability and aggregation in vivo by real-time fluorescent labeling

In vivo fluorescent labeling of an expressed protein has enabled the observation of its stability and aggregation directly in bacterial cells. Mammalian cellular retinoic acid-binding protein I (CRABP I) was mutated to incorporate in a surface-exposed omega loop the sequence Cys-Cys-Gly-Pro-Cys-Cys, which binds specifically to a biarsenical fluorescein dye (FlAsH). Unfolding of labeled tetra-Cys CRABP I is accompanied by enhancement of FlAsH fluorescence, which made it possible to determine the free energy of unfolding of this protein by urea titration in cells and to follow in real time the formation of inclusion bodies by a slow-folding, aggregationprone mutant (FlAsH-labeled P39A tetra-Cys CRABP I). Aggregation in vivo displayed a concentration-dependent apparent lag time similar to observations of protein aggregation in purified in vitro model systems.     

Is it a safe practice to administer oxygen during uncomplicated delivery: A randomized controlled trial?

Background

Newborns exposed to oxygen suffer from an oxidative stress with significant alterations in the concentrations of superoxide dismutase (SOD) and glutathione (GSSG).

Objective

To investigate the biological and clinical effects of oxygen administration to delivering mothers.

Methods

We conducted a randomized, double-blinded, controlled trial on a cohort of delivering women (n = 56) with an uncomplicated term pregnancy. Women were randomly assigned to one of two groups: Oxygen group or Room Air group. The Oxygen group received 100% oxygen (2 l/min) via nasal cannula for at least 30 min before delivery. Subjects in the Room Air group were connected to a nasal cannula while on room air. Concentrations of SOD (μg/g of Hb) and GSSG (μM/ml) were measured in maternal and umbilical cord blood. Bivariate and multivariate analyses were used to compare the two groups using the SAS system.

Results

Maternal SOD and GSSG did not differ between the two groups at baseline or after delivery. Concentrations of SOD and GSSG in umbilical cord blood did not differ between groups. More infants in Oxygen Group required delivery room resuscitation (20% vs. 0%, P = 0.03). This difference could not be explained by mode of delivery, infant sex, or other confounders.

Conclusions

Maternal exposure to oxygen during delivery is not associated with changes in umbilical cord SOD or GSSG. Further studies are needed to explore mechanisms responsible for the need of resuscitation in the oxygen group.     

Reflection of induced and amplified food motivation in impulse activity of the masticatory muscles during electrostimulation of the “hunger center” in the lateral hypothalamus in rabbits

We studied reflection of artificially induced and amplifi ed food motivation in impulse activity of the masticatory muscles during electrostimulation of “hunger center” of the lateral hypothalamus in the absence and presence of food. The threshold stimulation of the lateral hypothalamus in hungry and satiated animals in the absence of food induced incessant food-procuring behavior paralleled by regular generation of spike bursts in masticatory muscles with biomodal distributions of intervals between pulses. This reaction of masticatory muscles during stimulation of the lateral hypothalamus in the absence of food was an example of the anticipatory reaction reflecting characteristics of the action result acceptor. Higher level of hunger motivation during threshold stimulation of the lateral hypothalamus in hungry and satiated rabbits in the course of effective food-procuring behavior increased the incidence of spike burst generation during the food capture phase, but did not modify this parameter during the chewing phase. Impulse activity of the masticatory muscles reflected convergent interactions of food motivation and support excitation on neurons of the central generator of chewing pattern.     

Method of Evaluation of Dynamic Changes in Food Motivation in Rabbits during Successful Food-Procuring Behavior

We developed a method for evaluation of dynamic changes in the level of food motivation in rabbits during successful food-procuring behavior. Quantitative and temporal parameters of food consumption over each successive cycle of food-procuring behavior were used. The amount of consumed food was converted into electrical signal using an electronic balance incorporated into a hardware-software complex. Temporal parameters of food-procuring activity were determined by changes in electric signal in real-time mode. This method makes it possible to record simultaneously food-procuring activity and impulse activity of masticator muscles and esophageal muscles, which enables parallel analysis of rhythms of food consumption, mastication, and swallowing.     

Building the “Bridge”: Linking Gerontology Education to a Local Retirement Community

ABSTRACT

There has been a substantial increase in the number of aging-related educational programs in the United States over the last two decades. Many of these programs utilize an experiential-learning approach, such as intergenerational service-learning, to train gerontology students to work effectively with older adults. This paper presents a model of training called the Bridge program, which is based in experiential learning and incorporates some of the broader goals of service-learning. Launched in 2003, the Bridge program involves graduate students residing in a retirement community for at least one academic year. The main goals of the program include: educating the students and the public about the aging process, recruiting future gerontologists, providing research opportunities for the Bridge students, and contributing to the retirement community. Evaluation of the program reveals several critical issues for successful implementation.     

Inappropriate Angiogenic Response as a Novel Mechanism of Duodenal Ulceration and Impaired Healing

Background  

Despite recent advances and better understanding of the etiology and the pathogenesis of gastrointestinal ulcer diseases, e.g., duodenal ulcer, the molecular events leading to ulcer development, delayed healing, and recurrence remain poorly elucidated.