Alterations in gonadotropin-releasing hormone-dependent gonadotropin secretion in rats with polycystic ovaries.

A single injection of estradiol valerate (EV) to adult female rats induces a persistent anovulatory polycystic ovarian (PCO) condition. During the 8-20-wk interval following EV treatment, this condition is associated with a selective compromise of LH release, decreased pituitary content of LH, and decreased GnRH-stimulated LH secretion. A marked increase in mean plasma concentrations of LH and enhanced LH response to GnRH occur after 20 wk post-EV treatment. Despite this apparent improvement, the PCO condition remains unchanged. The present study was undertaken to elucidate the underlying causes for these spontaneous improvements in LH parameters. We reasoned that these changes may be the result of alterations in 1) pituitary GnRH receptor levels; or 2) the mode of LH secretion, i.e. GnRH-dependent versus GnRH-independent; or 3) post-GnRH receptor events. Hence, we assessed pituitary GnRH receptor concentration as well as the pituitary content of LH and FSH in rats with PCO of 9 wk and 22 wk duration. To examine the possibility of a change in the mode of LH secretion, we examined the effects of in vivo suppression of LH secretion by treatment with a GnRH antagonist [N-Ac-D-Nal1, D-Phe2,3, D-Arg6, Phe7, D-Ala10]-GnRH (GnRH-ANTAG) in the same groups of animals. Mean pituitary weights were greater in the 9-wk-PCO than in the 22-wk-PCO animals. The pituitary concentration of GnRH receptors (on either a weight or milligram pituitary-membrane protein basis) was similar in the 9-wk- and 22-wk-PCO animals. Pituitary LH and FSH contents, however, were significantly higher (5-fold and 2-fold, respectively) in 22-wk-PCO rats compared to the 9-wk-PCO animals.(ABSTRACT TRUNCATED AT 250 WORDS)     

Fts insertional mutant of Salmonella typhimurium

Abstract Cellulolytic and xylanolytic polysaccharidase enzyme activities from the multi-enzyme complex of Postia placenta MAD 698 were dissociated. Decayed wood extracts were fractionated by methyl-hydrophobic interaction chromatography and analyzed for reducing sugars and by viscosimetry and Western blot. Fractionated endoglucanases had molecular masses of 35 and 40 kDa on SDS-PAGE. Western blots probed with anti-endoglucanase and anti-xylanase antibodies revealed two endoglucanase bands at 35 and 40 kDa, but no commonality with the major xylanase band at 36 kDa. Anti-endoglucanase antibody inhibited endoglucanase enzyme activity.     

Non-invasive measurements of exhaled NO and CO associated with methacholine responses in mice

Background

Nitric oxide (NO) and carbon monoxide (CO) in exhaled breath are considered obtainable biomarkers of physiologic mechanisms. Therefore, obtaining their measures simply, non-invasively, and repeatedly, is of interest, and was the purpose of the current study.

Methods

Expired NO (E_NO) and CO (E_CO) were measured non-invasively using a gas micro-analyzer on several strains of mice (C57Bl6, IL-10^-/-, A/J, MKK3^-/-, JNK1^-/-, NOS-2^-/- and NOS-3^-/-) with and without allergic airway inflammation (AI) induced by ovalbumin systemic sensitization and aerosol challenge, compared using independent-sample t-tests between groups, and repeated measures analysis of variance (ANOVA) within groups over time of inflammation induction. E_NO and E_CO were also measured in C57Bl6 and IL-10-/- mice, ages 8–58 weeks old, the relationship of which was determined by regression analysis. S-methionyl-L-thiocitrulline (SMTC), and tin protoporphyrin (SnPP) were used to inhibit neuronal/constitutive NOS-1 and heme-oxygenase, respectively, and alter NO and CO production, respectively, as assessed by paired t-tests. Methacholine-associated airway responses (AR) were measured by the enhanced pause method, with comparisons by repeated measures ANOVA and post-hoc testing.

Results

E_NO was significantly elevated in naïve IL-10^-/- (9–14 ppb) and NOS-2^-/- (16 ppb) mice as compared to others (average: 5–8 ppb), whereas E_CO was significantly higher in naïve A/J, NOS-3^-/- (3–4 ppm), and MKK3^-/- (4–5 ppm) mice, as compared to others (average: 2.5 ppm). As compared to C57Bl6 mice, AR of IL-10^-/-, JNK1^-/-, NOS-2^-/-, and NOS-3^-/- mice were decreased, whereas they were greater for A/J and MKK3^-/- mice. SMTC significantly decreased E_NO by ~30%, but did not change AR in NOS-2^-/- mice. SnPP reduced E_CO in C57Bl6 and IL-10^-/- mice, and increased AR in NOS-2^-/- mice. E_NO decreased as a function of age in IL-10^-/- mice, remaining unchanged in C57Bl6 mice.

Conclusion

These results are consistent with the ideas that: 1) E_NO is associated with mouse strain and knockout differences in NO production and AR, 2) alterations of E_NO and E_CO can be measured non-invasively with induction of allergic AI or inhibition of key gas-producing enzymes, and 3) alterations in AR may be dependent on the relative balance of NO and CO in the airway.     

Biomarkers in osteoarthritis

Biomarkers aid the study of osteoarthritis (OA) in a number of different ways. In this article we summarise briefly their multiple uses and reflect on how the study reported in a previous edition of Arthritis Research & Therapy should promote further investigation of cartilage oligomeric matrix protein (COMP). COMP is foremost among hitherto investigated biomarkers and is most consistently shown to predict knee OA progression. Precisely what role it plays in OA pathogenesis remains unclear and elucidating this may be key to defining, and then targeting, the cellular pathways involved in OA.     

DETECTING DESERTIFICATION PROCESSES USING TM AND ETM+ DATA, NORTH OF ISFAHAN, IRAN

 Aims Desertification results in ecological and biological diminution of the earth, and can happen naturally or cause by anthropogenic activities. This process especially affects arid and semi-arid regions, such as the Isfahan region, where the spread of desertification is reaching critical proportions. The aim of this study is to use remotely sensed data to review the trend of desertification in the northern of Isfahan, Iran. Methods Multi-temporal images were employed to evaluate the trend of desertification, specifically the TM and ETM+ data of September, 1990 and September, 2001. Geometric and radiometric corrections were applied to each image prior to image processing and supervised classification, and vegetation indices were applied to produce a land use map of each image in nine classes. The land use classification s in the two map images were compared and changes between land use classes were detected over the 11 year period using a fuzzy and post-classification technique. Important findings The maps and their comparison with false color composite images showed the differences efficiently. With the fuzzy and post-classification method the land use changes were sited on the map. Fuzzy confirmed 53% changed area and 47% unchanged areas in the study region. The results verify the desertification expansion in the study areas. Because of poor land management, agricultural lands converted to desert and abandoned areas, and some marginal pasture lands had to be changed to agricultural land which are desertification spreading according to United Nations Conference on Desertification (UNCOD). Also farmland and pastures have been converted to urban and industrial areas, and the rangelands have been spoiled due to opencast mine excavations. With the mine margins eroding as well as their debris accumulating on the pasture lands, desertification has become worse. Three areas of less-elevated mountains have remained unchanged. This study confirmed that the anthropogenic activities accelerated the desertification process and severely endangered the remaining areas.     

Prostate cancer: serum and tissue markers

The detection of prostate cancer, its clinical staging, and the prediction of its prognosis remain topics of paramount importance in clinical management. The digital rectal exam, although once the "gold standard," has been largely supplanted by a variety of techniques including serum and tissue-based assays. This article reviews recent progress in the development of prostate-specific antigen assays with greater specificity; molecular markers for prostate cancer (DNA ploidy, nuclear morphometry, markers of proliferation, and cell adhesion molecules); the link between vitamin D deficiency and the clinical emergence of prostate cancer; the possible correlation of serum insulin-like growth factor levels with the risk for developing prostate cancer; and the latest advances in radiologic staging.     

Evaluation and treatment of men with biochemical prostate-specific antigen recurrence following definitive therapy for clinically localized prostate cancer

Early detection and monitoring by serum prostate-specific antigen (PSA) measurement has increased the number of men presenting with potentially curable prostate cancer. Most will choose radical prostatectomy or some form of radiation therapy for treatment, but some will have evidence of biochemical disease recurrence following therapy, shown by a rising PSA level without other clinical evidence of disease. Radical prostatectomy involves the removal of all prostate tissue, causing the serum PSA to decline to undetectable levels within four to six weeks following surgery; a subsequent rise in the serum PSA to a detectable level indicates disease recurrence. Patients should be evaluated to assess whether rising PSA levels indicate local recurrence or early metastatic disease. The advantages of salvage radiation, endocrine therapy, and other treatment modalities in local disease recurrence must be weighed against potential side effects and the resulting decrease in quality of life. Radiation therapy does not immediately eradicate all PSA-producing cells; therefore the persistence of a detectable PSA does not necessarily imply residual cancer, but rising PSA levels indicate treatment failure. Salvage surgery can be performed after radiotherapy for the purpose of removing all viable cancer cells, but should be weighed against a higher incidence of surgical complications; cryoablation offers a less invasive therapeutic modality.     

Frequent occurrence of recognition Site-like sequences in the restriction endonucleases

Background  

There are two different theories about the development of the genetic code. Woese suggested that it was developed in connection with the amino acid repertoire, while Crick argued that any connection between codons and amino acids is only the result of an "accident". This question is fundamental to understand the nature of specific protein-nucleic acid interactions.