Nutritional supplementation improves ovulation and pregnancy rates in female goats managed under natural grazing conditions and exposed to the male effect

Two experiments were conducted to determine if nutritional supplementation improved ovulation and pregnancy rates in female goats managed under grazing conditions and submitted to the male effect. In Experiment 1, one group of does did not receive nutritional supplementation, while the other group was supplemented daily for 7 days starting at the time when the males were introduced to the females. The ovulation rate at the second male-induced ovulation was greater (P < 0.05) in supplemented (2.0 ± 0.1) than in non-supplemented (1.6 ± 0.1) does. For Experiment 2, female goats were supplemented for 0, 7, 14 or 28 days, starting 9 days following buck introduction. The proportion of does that were pregnant in the group supplemented for 28 days was greater (P < 0.05) than in the non-supplemented group, but did not differ from 14-day and the 7-day supplemented groups. The proportion of pregnant does was greater (P < 0.05) in the group supplemented for 14 days compared to the group supplemented for 7 days and the non-supplemented group. These latter two groups did not differ (P > 0.05). In conclusion, feed supplementation for 7 days, starting at the time when males were introduced increased ovulation rate and feed supplementation for 14 or 28 days starting 9 days after males were introduced improved pregnancy rates in goats managed under grazing conditions and exposed to males.     

Simultaneous detection of N-acetyl-L-cysteine and physiological low molecular mass thiols in plasma by capillary electrophoresis

N-acetyl-l-cysteine (NAC) is a therapeutic drug widely used as mucolytic agent in the treatment of respiratory diseases. Recently it has been proposed that NAC administration may modify the plasma levels of low molecular weight thiols (LMW) like cysteine, homocysteine and glutathione, though it has been still debated if their plasma concentration increases or decreases during the therapy. Therefore research calls for methods able to analyze simultaneously NAC and the other plasma LMW thiols in order to evaluate if NAC is able to modify plasma thiols concentration and in particular to reduce homocysteine levels in hyperhomocysteinemia. In this paper we present a new capillary electrophoresis method that allows a baseline separation of plasma NAC from the physiological thiols. The proposed method has been utilized to measure the drug and the physiological LMW thiols in NAC administered chronic obstructive broncho-pneumopathy (COPB) disease patients.     

Syndromic Management and STI Control in Urban Peru

Background

Syndromic management is an inexpensive and effective method for the treatment of symptomatic sexually transmitted infections (STIs), but its effectiveness as a method of STI control in at-risk populations is questionable. We sought to determine the potential utility of syndromic management as a public health strategy to control STI transmission in high-risk populations in urban Peru.

Methodology

We surveyed 3,285 at-risk men and women from three Peruvian cities from 2003–05. Participants were asked about the presence of genital ulcers, discharge, or dysuria in the preceding six months. Participants reporting symptoms were asked about subsequent health-seeking and partner notification behavior. Urine and vaginal swab samples were tested for Neisseria gonorrhoeae and Chlamydia trachomatis by nucleic acid testing. Serum was tested for syphilis and Herpes Simplex Virus-Type 2 antibodies.

Findings

Recent urogenital discharge or dysuria was reported by 42.1% of participants with gonorrhea or chlamydia versus 28.3% of participants without infection. Genital ulceration was reported by 6.2% of participants with, and 7.4% of participants without, recent syphilis. Many participants reporting symptoms continued sexual activity while symptomatic, and approximately half of all symptomatic participants sought treatment. The positive and negative predictive values of urogenital discharge or genital ulcer disease in detecting STIs that are common in the study population were 14.4% and 81.5% for chlamydia in women and 8.3% and 89.5% for syphilis among gay-identified men.

Conclusions

In our study, STIs among high-risk men and women in urban Peru were frequently asymptomatic and symptomatic participants often remained sexually active without seeking treatment. Additional research is needed to assess the costs and benefits of targeted, laboratory-based STI screening as part of a comprehensive STI control program in developing countries.     

PIK3CA mutations in human solid tumors: Role in sensitivity to various therapeutic approaches

Phosphatidylinositol 3-kinases (PI3Ks) are a group of lipid kinases that regulate signaling pathways involved in cell proliferation, adhesion, survival and motility. The PI3K pathway is considered to play an important role in tumorigenesis. Activating mutations of the p110α subunit of PI3K (PIK3CA) have been identified in a broad spectrum of tumors. Analyses of PIK3CA mutations reveals that they increase the PI3K signal, stimulate downstream Akt signaling, promote growth factor-independent growth and increase cell invasion and metastasis. In this review, we analyze the contribution of the PIK3CA mutations in cancer, and their possible implications for diagnosis and therapy.     

RNA-Dependent Oligomerization of APOBEC3G Is Required for Restriction of HIV-1

The human cytidine deaminase APOBEC3G (A3G) is a potent inhibitor of retroviruses and transposable elements and is able to deaminate cytidines to uridines in single-stranded DNA replication intermediates. A3G contains two canonical cytidine deaminase domains (CDAs), of which only the C-terminal one is known to mediate cytidine deamination. By exploiting the crystal structure of the related tetrameric APOBEC2 (A2) protein, we identified residues within A3G that have the potential to mediate oligomerization of the protein. Using yeast two-hybrid assays, co-immunoprecipitation, and chemical crosslinking, we show that tyrosine-124 and tryptophan-127 within the enzymatically inactive N-terminal CDA domain mediate A3G oligomerization, and this coincides with packaging into HIV-1 virions. In addition to the importance of specific residues in A3G, oligomerization is also shown to be RNA-dependent. Homology modelling of A3G onto the A2 template structure indicates an accumulation of positive charge in a pocket formed by a putative dimer interface. Substitution of arginine residues at positions 24, 30, and 136 within this pocket resulted in reduced virus inhibition, virion packaging, and oligomerization. Consistent with RNA serving a central role in all these activities, the oligomerization-deficient A3G proteins associated less efficiently with several cellular RNA molecules. Accordingly, we propose that occupation of the positively charged pocket by RNA promotes A3G oligomerization, packaging into virions and antiviral function.     

Activation of vascular endothelial nitric oxide synthase and heme oxygenase-1 expression by electrophilic nitro-fatty acids

Reactive oxygen species mediate a decrease in nitric oxide (NO) bioavailability and endothelial dysfunction, with secondary oxidized and nitrated by-products of these reactions contributing to the pathogenesis of numerous vascular diseases. While oxidized lipids and lipoproteins exacerbate inflammatory reactions in the vasculature, in stark contrast the nitration of polyunsaturated fatty acids and complex lipids yields electrophilic products that exhibit pluripotent anti-inflammatory signaling capabilities acting via both cGMP-dependent and -independent mechanisms. Herein we report that nitro-oleic acid (OA-NO₂) treatment increases expression of endothelial nitric oxide synthase (eNOS) and heme oxygenase 1 (HO-1) in the vasculature, thus transducing vascular protective effects associated with enhanced NO production. Administration of OA-NO₂ via osmotic pump results in a significant increase in eNOS and HO-1 mRNA in mouse aortas. Moreover, HPLC-MS/MS analysis showed that NO₂-FAs are rapidly metabolized in cultured endothelial cells (ECs) and treatment with NO₂-FAs stimulated the phosphorylation of eNOS at Ser¹¹⁷⁹. These posttranslational modifications of eNOS, in concert with elevated eNOS gene expression, contributed to an increase in endothelial NO production. In aggregate, OA-NO₂-induced eNOS and HO-1 expression by vascular cells can induce beneficial effects on endothelial function and provide a new strategy for treating various vascular inflammatory and hypertensive disorders.     

Role of hypoxia and autophagy in MDA‐MB‐231 invasiveness

Survival strategies adopted by tumor cells in response to a hypoxic stress include activation of hypoxia‐inducible factor 1 (HIF‐1) and autophagy. However, the importance and the function of each molecular response is not well defined. In the present study, we investigated invasiveness, migration, matrix metalloproteinases (MMPs) activity, and cell survival of MDA‐MB‐231 cells under normoxia, hypoxia, and hypoxia/reoxygenation (H/R). Moreover, to assess the importance of hypoxia and autophagy on the parameters studied, cells were either left untreated or treated with Chetomin (a selective inhibitor of HIF‐1α) or trifluoperazine (TFP, an activator of autophagy). We found that hypoxia and H/R stimulated invasiveness and migration of MDA‐MB‐231 cells with an increased MMP‐2 activity. Chetomin and TFP differently regulated the cellular behavior under the oxygenation conditions studied. In fact, Chetomin was most effective in inhibiting cell invasion, MMPs activity, and cell survival under hypoxia but not normoxia or H/R. By contrast, TFP inhibition of cell invasion, migration, and cell survival was independent from oxygenation conditions. TFP‐induced autophagy was inhibited by light chain protein 3 (LC3) silencing or 3‐methyladenine (3MA) treatment. In fact, LC3‐silenced cells were able to invade in the presence of TFP without any GATE16 processing and p62 degradation. Immunofluorescence assay showed that LC3 silencing inhibited TFP‐induced autophagosome formation. However, we also showed that both TPF treatment and LC3 silencing caused cytoskeleton impairments suggesting a possible interaction between LC3 and cytoskeleton components. In conclusion, our study shows that hypoxia and autophagy by acting on common (HIF‐1α) or separate (MMPs, cytoskeleton) targets differently regulate cell invasion, MMPs activity, and survival. J. Cell. Physiol. 223: 359–368, 2010. © 2010 Wiley‐Liss, Inc.