Accumulation of the proteolytic marker peptide ubiquitin in the trophoblast of mammalian blastocysts

Ubiquitination is a universal protein degradation pathway in which the molecules of 8.5-kDa proteolytic peptide ubiquitin are covalently attached to the epsilon-amino group of the substrate's lysine residues. Little is known about the importance of this highly conserved mechanism for protein recycling in mammalian gametogenesis and fertilization. The data obtained by the students and faculty of the international training course Window to the Zygote 2000 demonstrate the accumulation of ubiquitin-cross-reactive structures in the trophoblast, but not in the inner cell mass of the expanding bovine and mouse blastocysts. This observation suggests that a major burst of ubiquitin-dependent proteolysis occurs in the trophoblast of mammalian peri-implantation embryos. This event may be important for the success of blastocyst hatching, differentiation of embryonic stem cells into soma and germ line, and/or implantation in both naturally conceived and reconstructed mammalian embryos.     

Effects of Ballota nigra on blood biochemical parameters and insulin in albino rats

Ingestion of aqueous 70% ethanol extract of Ballota nigra (400 mg/kg body weight for 7 days) by albino rats (n=10) was investigated to study its effects on glucose, total cholesterol, triglycerides, aspartate aminotransferase (AST), alanine aminotransferase (ALT), troponin I (TnI), serum creatine kinase (CK), total protein, total bilirubin and blood urea. Ballota nigra extract caused a significant decrease in blood glucose, total serum cholesterol and CK levels. Blood levels of TnI, AST, ALT, triglycerides, total bilirubin, total protein and blood urea were unchanged. The hypoglycemic effect of Ballota nigra extract on albino rats was further investigated by conducting a glucose tolerance test intraperitoneally (IPGTT). Healthy rats that were fasting for 18 hours followed by administration of a dose of 400 mg/kg body weight of the crude extract of Ballota nigra, orally. A significant decrease in blood glucose levels (after 15, 30, and 45 minutes) with a significant increase in serum insulin level (after 15 and 30 minute) was noted. These results suggest that, the crude extract of Ballota nigra have hypoglycemic, insulin-releasing and cholesterol lowering effects in rats.     

Effects of long-term use of fluoxetine on fertility parameters in adult male rats

The effects of long-term ingestion of fluoxetine on fertility were investigated in Sprague-Dawley male rats. Adult male rats were exposed to fluoxetine at a concentration of 200 mg/kg for 60 days. Long-term ingestion of fluoxetine for 60 days caused a great decrease in spermatogenesis in seminiferous tubules of the testes. Sperm motility and density were also significantly reduced in cauda epididymides and testes of the treated group. The weights of reproductive organs (testes, epididymides, ventral prostrate and seminal vesicle) were decreased considerably. The hormonal assay also showed significant decrease in testosterone levels and FSH levels. Testicular cell population dynamics also demonstrated a decrease in the number of both primary and secondary spermatocystes and spermatids in the treatment group. The number of female rats impregnated by male rats on long-term fluoxetine diet had decreased. The number of implantations and the number of viable fetuses were also notably decreased in female rats impregnated by male rats ingested fluoxetine. Fluoxetine caused a slight decrease in body weight, when initial and final body weights were compared in the experimental groups. Levels of ALT and AST were found to be significantly increased in the treated group when compared to the control. Histometery of reproductive organs confirmed these results. In conclusion, these results confirm that the long-term fluoxetine ingestion produce adverse effects on fertility and reproductive system in adult male rat. Thus, it would be of great interest to investigate the impact via long -term treatment with fluoxetine in male human fertility.     

Effects of Ballota nigra on glucose and insulin in alloxan-diabetic albino rats

The hypoglycemic effect of Ballota nigra extract on albino rats was investigated. Alloxan-induced diabetes mellitus was accompanied by several fold increases in plasma glucose. Administration of aqueous extract of B. nigra extract significantly reduced glucose in both healthy and diabetic rats. These results suggest that B. nigra possess hypoglycemic effects in rats and therefore, can be useful for the treatment of diabetes mellitus.     

Effects of grazing on plant species diversity and carbon partitioning in semiarid rangelands of northeastern China

Grasslands are one of the most widespread landscapes worldwide, covering approximately one-fifth of the world’s land surface, where grazing is a common practice. How carbon storage responds to grazing in steppes remains poorly understood. We quantified the effects of grazing on community composition and species diversity, and carbon storage in two typical grasslands of northeastern China, one in Horqin and the other one in Hulunbeier. In both grasslands, grazing did not influence plant species diversity. However, it substantially decreased aboveground carbon by 31% and 54% in Horqin and Hulunbeier, respectively. Fenced and grazing treatments showed a similar belowground carbon at both locations. The predominant carbon pool in the study grassland ecosystem was found in the upper 100 cm soil depth, from 98.2 to 99.1% of the total carbon storage. There were no significant effects of grazing on soil carbon neither in the whole profile nor in the uppermost 20 cm soil depth in the two study grasslands. Studies on the effects of varying rangeland management, such as region disparity and grazing systems, may have important consequences on species diversity and carbon partitioning, and thus on rangeland stability and ecosystem functioning.     

Environmental gradients and community attributes underlying biodiversity patterns of semi-arid Mediterranean grasslands

Protection and/or establishment of forest plantation have been used as a management strategy to conserve and stop the deterioration of semi-arid Mediterranean grasslands ecosystems, producing a mosaic of vegetation types. This study was intended to investigate the changes in grassland community in response to protection and forest tree plantation practice as well as to explore the underlying environmental gradients responsible for the observed differences or similarities among these vegetation types. Two multivariate analysis methods including discriminate analysis and non-metric multi-dimensional scaling were used to quantify changes in community composition and attributes following different management practices (free grazing, protection with open grassland, sparse and dense forest tree plantations). This was investigated using species frequency, species abundance, or habitat characteristics. The study results showed that habitat types differed significantly between each other and were significantly separated using multivariate approaches. Discrimination based on habitat characteristics and species composition indicated that protection (or grazing) and light (or shade) explained more than 90% of the observed variability in community changes in response to the protection and forest tree plantation. Also, results indicated that shade effect can be attributed to tree canopy cover and/or litter accumulation on the ground. It could be hypothesized that protection from grazing and afforestation resulted in complex environmental gradients of which shade, litter accumulation as well as protection from grazing disturbance are major constituents. A careful manipulation of protection and afforestation can be used to create a spatially different environmental gradients leading to greater habitat diversity as well as a greater species diversity, and better conservation means of grassland in semi-arid areas.     

Application of magnetic techniques in the field of drug discovery and biomedicine

Magnetic separation technology, using magnetic particles, is quick and easy method for sensitive and reliable capture of specific proteins, genetic material and other biomolecules. The technique offers an advantage in terms of subjecting the analyte to very little mechanical stress compared to other methods. Secondly, these methods are non-laborious, cheap and often highly scalable. Moreover, techniques employing magnetism are more amenable to automation and miniaturization. Now that the human genome is sequenced and about 30,000 genes are annotated, the next step is to identify the function of these individual genes, carrying out genotyping studies for allelic variation and SNP analysis, ultimately leading to identification of novel drug targets. In this post-genomic era, technologies based on magnetic separation are becoming an integral part of todays biology laboratory. This article briefly reviews the selected applications of magnetic separation techniques in the field of biotechnology, biomedicine and drug discovery.     

Adverse effects of rosemary (Rosmarinus officinalis L.) on reproductive function in adult male rats

Ingestion of rosemary (Rosmarinus officinalis L.) by two groups of adult Sprague-Dawley rats at levels of 250 and 500 mg/kg body wt for 63 days was investigated for its effects on fertility. Body weight and absolute and relative testes weights were not affected, but the average weights of epididymides, ventral prostates, seminal vesicles, and preputial glands decreased significantly. A significant decline in spermatogenesis in testes due to a decrease in the number of primary and secondary spermatocytes and spermatids in treatment group 2 (500 mg/kg) is attributed to a significant decrease in testosterone. Sperm motility and density were also significantly decreased in the cauda epididymis and in the testes of rosemary-treated male rats in group 2. In addition, the treatment markedly increased the number of fetal resorptions in female rats impregnated by group 2 males, thereby reducing their fertility.     

Alterations in the serum glycome due to metastatic prostate cancer

Glycomic profiles derived from human blood sera of 10 healthy males were compared to those from 24 prostate cancer patients. The profiles were acquired using MALDI-MS of permethylated N-glycans released from 10-microL sample aliquots. Quantitative permethylation was attained using solid-phase permethylation. Principal component analysis of the glycomic profiles revealed significant differences among the two sets, allowing their distinct clustering. The first principal component distinguished the 24 prostate cancer patients from the healthy individuals. It was determined that fucosylation of glycan structures is generally higher in cancer samples (ANOVA test p-value of 0.0006). Although more than 50 N-glycan structures were determined, 12 glycan structures, of which six were fucosylated, were significantly different between the two sample sets. Significant differences were confirmed through two independent statistical tests (ANOVA and ROC analyses). Ten of these structures had significantly higher relative intensities in the case of the cancer samples, while the other two were less abundant in the cancer samples. All 12 structures were statistically significant, as suggested by their very low ANOVA scores (<0.001) and ROC analysis, with area under the curve values close to 1 or 0. Accordingly, these structures can be considered as cancer-specific glycans and potential prostate cancer biomarkers. Therefore, serum glycomic profiling appears worthy of further investigation to define its role in cancer early detection and prognostication.