Intestinal trefoil factor/TFF3 promotes re-epithelialization of corneal wounds

Disorders of wound healing characterized by impaired or delayed re-epithelialization are a serious medical problem. These conditions affect many tissues, are painful, and are difficult to treat. In this study using cornea as a model, we demonstrate the importance of trefoil factor 3 (TFF3, also known as intestinal trefoil factor) in re-epithelialization of wounds. In two different models of corneal wound healing, alkali- and laser-induced corneal wounding, we analyzed the wound healing process in in vivo as well as in combined in vivo/in vitro model in wild type (Tff3(+)(/)(+)) and Tff3-deficient (Tff3(-)(/)(-)) mice. Furthermore, we topically applied different concentrations of recombinant human TFF3 (rTFF3) peptide on the wounded cornea to determine the efficacy of rTFF3 on corneal wound healing. We found that Tff3 peptide is not expressed in intact corneal epithelium, but its expression is extensively up-regulated after epithelial injury. Re-epithelialization of corneal wounds in Tff3(-/-) mice is significantly prolonged in comparison to Tff3(+/+) mice. In addition, exogenous application of rTFF3 to the alkali-induced corneal wounds accelerates significantly in in vivo and in combined in vivo/in vitro model wound healing in Tff3(+/+) and Tff3(-/-) mice. These findings reveal a pivotal role for Tff3 in corneal wound healing mechanism and have broad implications for developing novel therapeutic strategies for treating nonhealing wounds.     

Androgen receptors and testosterone in men--effects of protein ingestion, resistance exercise and fiber type

The purpose of this study was to examine the impact of protein ingestion on circulating testosterone and muscle androgen receptor (AR) as well as on insulin-like growth factor-I (MGF and IGF-IEa) responses to a resistance exercise (RE) bout in (57-72 year) men. Protein (15 g whey) (n=9) or placebo (n=9) was consumed before and after a RE bout (5 sets of 10 repetition maximums), and vastus lateralis muscle biopsies were taken pre, 1 and 48 h post-RE. The protein ingestion blunted the RE-induced increase in serum free and total testosterone while the RE bout significantly increased muscle AR mRNA levels in older men (P<0.05). However, protein ingestion did not significantly affect AR mRNA or protein expression, or MGF and IGF-IEa mRNA expression at 1 and 48 h post-RE. Immunohistochemical staining of muscle cross-sections was done with antibodies specific to AR and MyHC I and II and showed that there seems to be within or near the type-I muscle fibers a greater staining of ARs than within or near the type-II fibres. In conclusion, the protein ingestion hinders RE-induced increase in serum testosterone in older men but may not significantly affect muscle AR, MGF or IGF-IEa gene expression. Furthermore, the present study shows that even older men are able to increase muscle AR mRNA expression in response to a RE bout.     

Diversity and distribution of entomopathogenic nematodes (Rhabditida: Steinernematidae and Heterorhabditidae) in Turkey

The diversity and distribution of entomopathogenic nematodes in thefamilies Steinernematidae and Heterorhabditidae were assessed throughout anextensive soil survey in Turkey during 1999 and 2000. Entomopathogenic nematodeswere recovered from six out of seven regions sampled, with 22 positive sites(2%) out of 1080 sites sampled. A single nematode isolate was recovered at eachof the positive sites, of which 15 were steinernematid isolates and seven wereheterorhabditid isolates representing a total of four species. Based onmorphometric and molecular data, the nematode species were identified asHeterorhabditis bacteriophora, Steinernemafeltiae, S. affine, andSteinernema n. sp. The most common species was S.feltiae, which was isolated from 10 sites in six regions, followed byH. bacteriophora from seven sites in five regions,S. affine from four sites in two regions, andSteinernema n. sp. from one site. Heterorhabditisbacteriophora and S. feltiae have been found inmany parts of the world, whereas S. affine, so far, hasonly been recovered in Europe until our survey. Steinernemaaffine was isolated from the European (Marmara) as well as theAsiatic region (Middle Anatolia) of Turkey. A new undescribedSteinernema sp. was isolated from the most eastern region(East Anatolia) of Turkey. Soils of the positive sites were classified as sandy,sandy loam, or loam (68.2%) and sandy–clay–loam or clay loam (31.8%) and the pHranged from 5.6 to 7.9. The habitats from which the entomopathogenic nematodeswere isolated were broadly classified as disturbed (59.1%), which includedagricultural fields and poplar planted for lumber and wind breaks, andundisturbed (40.9%), which included pine forest, grassland, marsh and reed sites.Steinernema feltiae, S. affine, andH. bacteriophora were recovered from both disturbed andundisturbed habitats. The new Steinernema sp. was recoveredfrom grassland. Our survey showed that these nematodes occur widely throughoutTurkey, but at a frequency below that reported for other parts of the world.     

Calpain system dysregulation in rat brain at beta-amyloid-induced neurodegeneration

Experimental evidence of calcium-dependent proteolysis dysregulation in brain of the murine model of Alzheimer’s disease was obtained. Experimental treatment, consisting of intra-hippocampal injection of amyloid beta-peptide (Aβ_1–40), promoted activation of main calpain forms in murine brain along with a decrease in the content of a natural calpain inhibitor, calpastatin. As a result of a prognostic experiment on the correction of neurodegeneration induced in rats, neuroprotective properties of a steroid hormone estradiol were confirmed and a possible mechanism of the protective effect was suggested. The results allow consideration of both biochemical modifications in protein facilities of a pathology-affected brain and the mechanisms of neurodegeneration and neuroprotection.     

Prophylactic effects of magnesium and vitamin E in rat spinal cord radiation damage: evaluation based on lipid peroxidation levels

This study investigated the neuroprotective effects of magnesium sulfate prophylaxis and vitamin E prophylaxis in a rat model of spinal cord radiation injury. Groups were subjected to different treatment conditions for 5 days prior to irradiation, and outcomes were evaluated on the basis of lipid peroxidation levels in cord tissue. Four groups of rats were investigated: no radiation/treatment (n = 4), intraperitoneal (i.p.) saline 1 ml/day (n = 6), i.p. vitamin E 100 mg/kg/day (n = 6), and i.p. magnesium sulfate 600 mg/kg/day (n = 6). The thoracic cord of each non-control rat was exposed to 20 Gy radiation in a LINAC system using 6 MV x-rays, and malondialdehyde (MDA) levels (reflecting lipid peroxidation level) were determined 24 hours post-irradiation. The MDA levels in thoracic cord segments from the control rats were used to determine baseline lipid peroxidation. The mean levels in the control, saline-only, vitamin E, and magnesium sulfate groups were 12.12 +/- 0.63, 27.0 +/- 2.81, 17.71 +/- 0.44, and 14.40 +/- 0.47 nmol/mg tissue, respectively. The MDA levels in the saline-only group were significantly higher than baseline, and the levels in the vitamin E group were significantly lower than those in the saline group (P < 0.05 for both). The levels in the magnesium sulfate group were dramatically lower than those in the saline group (P < 0.001). The results indicate that i.p. magnesium sulfate has a marked neuroprotective effect against radiation-induced oxidative stress in the rat spinal cord.