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51.
Eduardo?S?SilvaEmail author Gerard?J?Schoone Celia?MF?Gontijo Reginaldo?P?Brazil Raquel?S?Pacheco Henk?DFH?Schallig 《Kinetoplastid biology and disease》2005,4(1):4
Background
The direct agglutination test (DAT) has proved to be a very important sero-diagnostic tool combining high levels of intrinsic validity and ease of performance. Otherwise, fast agglutination screening test (FAST) utilises only one serum dilution making the test very suitable for the screening of large populations. 相似文献52.
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Margarida Cepa Georgina Correia-da-Silva Elisiário J Tavares da Silva Fernanda MF Roleira Margarida Borges Natércia A Teixeira 《BMC cell biology》2008,9(1):41
Background
Aromatase, the cytochrome P-450 enzyme (CYP19) responsible for estrogen biosynthesis, is an important target for the treatment of estrogen-dependent breast cancer. In fact, the use of synthetic aromatase inhibitors (AI), which induce suppression of estrogen synthesis, has shown to be an effective alternative to the classical tamoxifen for the treatment of postmenopausal patients with ER-positive breast cancer. New AIs obtained, in our laboratory, by modification of the A and D-rings of the natural substrate of aromatase, compounds 3a and 4a, showed previously to efficiently suppress aromatase activity in placental microsomes. In the present study we have investigated the effects of these compounds on cell proliferation, cell cycle progression and induction of cell death using the estrogen-dependent human breast cancer cell line stably transfected with the aromatase gene, MCF-7 aro cells. 相似文献54.
Raphael B. Costa Gregório MF Camargo Iara DPS Diaz Natalia Irano Marina M. Dias Roberto Carvalheiro Arione A. Boligon Fernando Baldi Henrique N. Oliveira Humberto Tonhati Lucia G. Albuquerque 《遗传、选种与进化》2015,47(1)
Background
An important goal of Zebu breeding programs is to improve reproductive performance. A major problem faced with the genetic improvement of reproductive traits is that recording the time for an animal to reach sexual maturity is costly. Another issue is that accurate estimates of breeding values are obtained only a long time after the young bulls have gone through selection. An alternative to overcome these problems is to use traits that are indicators of the reproductive efficiency of the herd and are easier to measure, such as age at first calving. Another problem is that heifers that have conceived once may fail to conceive in the next breeding season, which increases production costs. Thus, increasing heifer’s rebreeding rates should improve the economic efficiency of the herd. Response to selection for these traits tends to be slow, since they have a low heritability and phenotypic information is provided only later in the life of the animal. Genome-wide association studies (GWAS) are useful to investigate the genetic mechanisms that underlie these traits by identifying the genes and metabolic pathways involved.Results
Data from 1853 females belonging to the Agricultural Jacarezinho LTDA were used. Genotyping was performed using the BovineHD BeadChip (777 962 single nucleotide polymorphisms (SNPs)) according to the protocol of Illumina - Infinium Assay II ® Multi-Sample HiScan with the unit SQ ™ System. After quality control, 305 348 SNPs were used for GWAS. Forty-two and 19 SNPs had a Bayes factor greater than 150 for heifer rebreeding and age at first calving, respectively. All significant SNPs for age at first calving were significant for heifer rebreeding. These 42 SNPs were next or within 35 genes that were distributed over 18 chromosomes and comprised 27 protein-encoding genes, six pseudogenes and two miscellaneous noncoding RNAs.Conclusions
The use of Bayes factor to determine the significance of SNPs allowed us to identify two sets of 42 and 19 significant SNPs for heifer rebreeding and age at first calving, respectively, which explain 11.35 % and 6.42 % of their phenotypic variance, respectively. These SNPs provide relevant information to help elucidate which genes affect these traits. 相似文献55.
Willem Daniel Francois Venter Lee Fairlie Charles Feldman Peter Cleaton-Jones Matthew Chersich 《PloS one》2016,11(1)
South African doctors (n = 211) experienced in antiretroviral therapy use were asked via an online questionnaire about the WHO 2013 adult antiretroviral integrated guidelines, as well as clinical and personal issues, in three hypothetical scenarios: directing the Minister of Health, advising a family member requiring therapy amidst unstable antiretroviral supplies, and where doctors themselves were HIV-positive. Doctors (54%) favoured the 500 cells/μl WHO initiation threshold if advising the Minister; a third recommended retaining the 350 cells/μl threshold used at the time of the survey. However, they favoured a higher initiation threshold for their family member. Doctors were 4.9 fold more likely to initiate modern treatment, irrespective of their CD4 cell count, for themselves than for public-sector patients (95%CI odds ratio = 3.33–7.33; P<0.001, although lower if limited to stavudine-containing regimens. Doctors were equally concerned about stavudine-induced lactic acidosis and lipoatrophy. The majority (84%) would use WHO-recommended first-line therapy, with concerns split between tenofovir-induced nephrotoxicity (55%), and efavirenz central nervous system effects (29%). A majority (61%), if HIV-positive, would pay for a pre-initiation resistance test, use influenza-prophylaxis (85%), but not INH-prophylaxis (61%), and treat their cholesterol and blood pressure concerns conventionally (63% and 60%). Over 60% wanted viral loads and creatinine measured six monthly. A third felt CD4 monitoring only necessary if clinically indicated or if virological failure occurred. They would use barrier prevention (83%), but not recommend pre-exposure prophylaxis, if their sexual partner was HIV-negative (68%). A minority would be completely open about their HIV status, but the majority would disclose to their sexual partners, close family and friends. Respondents were overwhelmingly in favour of continued antiretrovirals after breastfeeding. In conclusion, doctors largely supported adult WHO guidelines as public policy, although would initiate treatment at higher CD4 counts for their family and themselves. Resistance to INH-prophylaxis is unexpected and warrants investigation. 相似文献
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Background
In the months leading up to the 2010 FIFA World Cup in South Africa, international media postulated that at least 40,000 foreign sex workers would enter South Africa, and that an increased HIV incidence would follow. To strengthen the evidence base of future HIV prevention and sexual health programmes during international sporting events, we monitored the supply and demand of female sex work in the weeks before, during and after the 2010 FIFA World Cup.Methodology/Principal Findings
We conducted three telephonic surveys of female sex workers advertising online and in local newspapers, in the last week of May, June and July 2010. The overall response rate was 73.4% (718/978). The number of sex workers advertising online was 5.9% higher during the World Cup than before. The client turnover rate did not change significantly during (adjusted rate ratio [aRR] = 1.05; 95%CI: 0.90–1.23) or after (aRR = 1.06; 95%CI: 0.91–1.24) the World Cup. The fraction of non-South African sex workers declined during (adjusted odds ratio [aOR] = 0.50; 95%CI: 0.32–0.79) and after (aOR = 0.56; 95%CI: 0.37–0.86) the World Cup. Relatively more clients were foreign during the World Cup among sex workers advertising in the newspapers (aOR = 2.74; 95%CI: 1.37–5.48) but not among those advertising online (aOR = 1.06; 95%CI: 0.60–1.90). Self-reported condom use was high (99.0%) at baseline, and did not change during (aOR = 1.07; 95% CI: 0.16–7.30) or after (aOR = 1.13; 95% CI: 0.16–8.10) the Word Cup.Conclusions/Significance
Our findings do not provide evidence for mass-immigration of foreign sex workers advertising online and in local newspapers, nor a spike in sex work or risk of HIV transmission in this subpopulation of sex workers during the World Cup. Public health programmes focusing on sex work and HIV prevention during international sporting events should be based on evidence, not media-driven sensationalism that further heightens discrimination against sex workers and increases their vulnerability. 相似文献58.
Katja J Teerds Federica MF van Dissel-Emiliani Maria P De Miguel Mieke de Boer-Brouwer Lina M Körting Eddy Rijntjes 《Reproductive biology and endocrinology : RB&E》2007,5(1):43-9
Background
The initial steps of stem Leydig cell differentiation into steroid producing progenitor cells are thought to take place independent of luteinizing hormone (LH), under the influence of locally produced factors such as leukaemia inhibitory factor (LIF), platelet derived growth factor A and stem cell factor. For the formation of a normal sized Leydig cell population in the adult testis, the presence of LH appears to be essential. 相似文献59.
LJ Melchers MJAM Clausen MF Mastik L Slagter-Menkema JE van der Wal GBA Wisman JLN Roodenburg E Schuuring 《Epigenetics》2015,10(9):850-860
Hypermethylation is an important mechanism for the dynamic regulation of gene expression, necessary for metastasizing tumour cells. Our aim is to identify methylation tumour markers that have a predictive value for the presence of regional lymph node metastases in patients with oral and oropharyngeal squamous cell carcinoma (OOSCC). Significantly differentially expressed genes were retrieved from four reported microarray expression profiles comparing pN0 and pN+ head-neck tumours, and one expression array identifying functionally hypermethylated genes. Additional metastasis-associated genes were included from the literature. Thus genes were selected that influence the development of nodal metastases and might be regulated by methylation. Methylation-specific PCR (MSP) primers were designed and tested on 8 head-neck squamous cell carcinoma cell lines and technically validated on 10 formalin-fixed paraffin-embedded (FFPE) OOSCC cases. Predictive value was assessed in a clinical series of 70 FFPE OOSCC with pathologically determined nodal status. Five out of 28 methylation markers (OCLN, CDKN2A, MGMT,
MLH1 and DAPK1) were frequently differentially methylated in OOSCC. Of these, MGMT methylation was associated with pN0 status (P = 0.02) and with lower immunoexpression (P = 0.02). DAPK1 methylation was associated with pN+ status (P = 0.008) but did not associate with protein expression. In conclusion, out of 28 candidate genes, two (7%) showed a predictive value for the pN status. Both genes, DAPK1 and MGMT, have predictive value for nodal metastasis in a clinical group of OOSCC. Therefore DNA methylation markers are capable of contributing to diagnosis and treatment selection in OOSCC. To efficiently identify additional new methylation markers, genome-wide methods are needed. 相似文献
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Physiological and biochemical characterization of NERICA‐L‐44: a novel source of heat tolerance at the vegetative and reproductive stages in rice 下载免费PDF全文
Rajeev N Bahuguna Jyoti Jha Madan Pal Divya Shah Lovely MF Lawas Sangeetha Khetarpal Krishna S.V. Jagadish 《Physiologia plantarum》2015,154(4):543-559
The predicted increase in the frequency and magnitude of extreme heat spikes under future climate can reduce rice yields significantly. Rice sensitivity to high temperatures during the reproductive stage is well documented while the same during the vegetative stage is more speculative. Hence, to identify and characterize novel heat‐tolerant donors for both the vegetative and reproductive stages, 71 rice accessions, including approximately 75% New Rice for Africa (NERICAs), were phenotyped across field experiments during summer seasons in Delhi, India, and in a controlled environment study at International Rice Research Institute , Philippines. NERICA‐L‐44 (NL‐44) recorded high seedling survival (52%) and superior growth and greater reproductive success exposed to 42.2°C (sd ± 2.3) under field conditions. NL‐44 and the heat‐tolerant check N22 consistently displayed lower membrane damage and higher antioxidant enzymes activity across leaves and spikelets. NL‐44 recorded 50–60% spikelet fertility, while N22 recorded 67–79% under controlled environment temperature of 38°C (sd ±1.17), although both had about 87% fertility under extremely hot field conditions. N22 and NL‐44, exposed to heat stress (38°C), had similar pollen germination percent and number of pollen tubes reaching the ovary. NL‐44 maintained low hydrogen peroxide production and non‐photochemical quenching (NPQ) with high photosynthesis while N22 avoided photosystem II damage through high NPQ under high‐temperature stress. NL‐44 with its reproductive stage resilience to extreme heat stress, better antioxidant scavenging ability in both vegetative tissue and spikelets and superior yield and grain quality is identified as a novel donor for increasing heat tolerance at both the vegetative and reproductive stages in rice. 相似文献