Search results for "Biophysics"

Visual tasks and stance width influence the spatial magnitude and temporal dynamics of standing body sway in 6- to 12-year old children.

2017

Diabetes, oxidative stress and therapeutic strategies.

2014

Abstract Background Diabetes has emerged as a major threat to health worldwide. Scope of Review The exact mechanisms underlying the disease are unknown; however, there is growing evidence that excess generation of reactive oxygen species (ROS), largely due to hyperglycemia, causes oxidative stress in a variety of tissues. Oxidative stress results from either an increase in free radical production, or a decrease in endogenous antioxidant defenses, or both. ROS and reactive nitrogen species (RNS) are products of cellular metabolism and are well recognized for their dual role as both deleterious and beneficial species. In type 2 diabetic patients, oxidative stress is closely associated with ch…

Different mechanism of relaxation induced by aporphine alkaloids in rat uterus.

1993

Abstract We have examined the uterine relaxant action of three aporphine molecules (S-glaucine, S-boldine and R-apomorphine) in two experimental conditions, with and without calcium in the bathing solution, and compared these effects with those obtained with the calcium antagonists verapamil and diltiazem. The present study shows that the alkaloids relax the uterine muscle but with different mechanisms of action. In Ca2+-containing solution all three alkaloids relaxed the uterus previously contracted by KCl or acetylcholine, but in Ca2+-free medium only R-apomorphine was able to relax oxytocin-induced contraction. The calcium antagonists, verapamil and diltiazem, relaxed KCl- or acetylcholi…

The Microwave Syndrome: A Preliminary Study in Spain

2003

A health survey was carried out in Murcia, Spain, in the vicinity of a Cellular Phone Base Station working in DCS‐1800 MHz. This survey contained health items related to “microwave sickness” or “RF syndrome.” The microwave power density was measured at the respondents' homes. Statistical analysis showed significant correlation between the declared severity of the symptoms and the measured power density. The separation of respondents into two different exposure groups also showed an increase of the declared severity in the group with the higher exposure.

Properties of tuberomammillary histamine neurones and their response to galanin.

1991

Histaminergic neurones in the tuberomammillary nucleus possess electrophysiological properties which distinguish them from other neurones in their neighborhood. Their resting potential is -50 mV and they are spontaneously active at about 2 Hz in a slice preparation. They display a transient outward rectification and an anomalous inward rectification. Bath application of galanin (0.1 microM) reduced their firing rate significantly and hyperpolarized them slightly.

Aldosterone biosynthesis induced by ACTH and angiotensin II in newborn rat adrenocortical cells transfected by c-EJ-Ha-ras oncogene

1991

Abstract Adrenocortical cells were obtained by fractionated trypsination of newborn rat adrenal glands and transfected with a plasmid containing the EJ T24 -Ha-ras oncogene. Isolation of adhesive cells led to a proliferative cell line with an overexpression of 21 kDa ras protein. These cells incubated with corticosterone or deoxycorticosterone as the precursor produced a high level of 18-hydroxycorticosterone and aldosterone as identified by gas chromatography- mass spectrometry. ACTH and angiotensin II increased the basal production of aldosterone nineteen-fold and six-fold respectively. Under ACTH stimulation the ratio between aldosterone and 18-hydroxycorticosterone production was 1:3. T…

Carboxyl nonsteroidal anti-inflammatory drugs are efficiently glucuronidated by microsomes of the human gastrointestinal tract.

2004

Limited studies have been carried out on the biotransformation of carboxyl nonsteroidal anti-inflammatory drugs (NSAIDs) in the liver. However, the role of the intestine in NSAID metabolism has not been investigated. In this report, the contribution of UDP-glucuronosyltransferases (UGTs) in the human gastrointestinal (GI) tract from five donors to the glucuronidation of the NSAIDs, RS-ketoprofen, S-naproxen, RS- and S-etodolac, was investigated. UGT activity and, for some donors, mRNA levels were evaluated. All NSAIDs were glucuronidated throughout the GI tract; however, glucuronidation was low in stomach and duodenum as compared to the remainder of the intestine. RT-PCR analysis demonstrat…

Inhibition of Melatonin in the Plasma of Third-Generation Male Mice under the Action of ELF Magnetic Fields

1998

The pineal gland has been considered a magnetic receptor organ that regulates circadian rhythms by means of the secretion of melatonin, a potent oncostatic agent that prevents the initiation and promotion of cancer. ELF electromagnetic radiation, similar to that generated by power lines, can alter melatonin plasma levels.To study this effect, 4 OF1 mice generations have been reared subjected to a lifelong 15 μT, 50 Hz magnetic field action. This magnetic field was generated inside a Helmholtz coil system. The concentration of melatonin in the blood has been determined on 40 male mice of the third generation by means of RIA, as they reached sexual maturity (3 months).A radical decrease, more…

Electrospun bioactive mats enriched with Ca-polyphosphate/retinol nanospheres as potential wound dressing

2015

Background While electrospun materials have been frequently used in tissue engineering no wound dressings exist that significantly improved wound healing effectively. Methods We succeeded to fabricate three-dimensional (3D) electrospun poly(D,l-lactide) (PLA) fiber mats into which nanospheres, formed from amorphous calcium polyphosphate (polyP) nanoparticles (NP) and encapsulated retinol (“retinol/aCa-polyP-NS” nanospheres [NS]), had been incorporated. Results Experiments with MC3T3-E1 cells revealed that co-incubation of the cells with Ca-polyP together with retinol (or incubation with retinol/aCa-polyP-NS) resulted in a significant synergistic effect on cell growth compared with particle-…

Eating disorders on the web: risks and resources.

2009

Our work is aimed at exploring the recent literature data on web sites, forums, and blogs, which promote eating disorders as normal life styles and their implication in the changes of the psychopatology of such disorders. We also want to understand whether new technologies have an impact in the course of the disorders or, on the other hand, whether they can also represent an instrument for searching help or information about them. The search strategy included a search of PsycINFO, Medline, and Ovid databases to identify research reports about pro-ana sites and their implication on the course of anorexia using the following key words: pro-ana, thinspiration, anorexia-web, online help eating …