160 research outputs found
Characterization of eight novel proteins with male germ cell-specific expression in mouse
<p>Abstract</p> <p>Background</p> <p>Spermatogenesis and fertilization are highly unique processes. Discovery and characterization of germ cell-specific genes are important for the understanding of these reproductive processes. We investigated eight proteins encoded by novel spermatogenic cell-specific genes previously identified from the mouse round spermatid UniGene library.</p> <p>Methods</p> <p>Polyclonal antibodies were generated against the novel proteins and western blot analysis was performed with various protein samples. Germ cell specificity was investigated using testes from germ cell-less mutant mice. Developmental expression pattern was examined in testicular germ cells, testicular sperm and mature sperm. Subcellular localization was assessed by cell surface biotin labeling and trypsinization. Protein localization and properties in sperm were investigated by separation of head and tail fractions, and extractabilities by a non-ionic detergent and urea.</p> <p>Results</p> <p>The authenticity of the eight novel proteins and their specificity to spermatogenic cells were confirmed. In examining the developmental expression patterns, we found the presence of four proteins only in testicular germ cells, a single protein in testicular germ cells and testicular sperm, and three proteins in the testicular stages and mature sperm from the epididymis. Further analysis of the three proteins present in sperm disclosed that one is located at the surface of the acrosomal region and the other two are associated with cytoskeletal structures in the sperm flagellum. We name the genes for these sperm proteins Shsp1 (Sperm head surface protein 1), Sfap1 (Sperm flagellum associated protein 1) and Sfap2 (Sperm flagellum associated protein 2).</p> <p>Conclusion</p> <p>We analyzed eight novel germ cell-specific proteins, providing new and inclusive information about their developmental and cellular characteristics. Our findings will facilitate future investigation into the biological roles of these novel proteins in spermatogenesis and sperm functions.</p
Caffeine Intake, Coffee Consumption, and Risk of Cutaneous Malignant Melanoma
BACKGROUND: Caffeine has been shown to prevent ultraviolet radiation-induced carcinogenesis and to inhibit growth of melanoma cells in experimental studies. We evaluated the association among caffeine intake, coffee consumption, and melanoma risk among three large cohort studies.
METHODS: The analysis used data from 89,220 women in the Nurses' Health Study II (1991-2009), 74,666 women in the Nurses' Health Study (1980-2008), and 39,424 men in the Health Professionals Follow-up Study (1986-2008). We used Cox proportional hazards models to estimate the hazard ratios (HR) with 95% confidence intervals (CIs) of melanoma associated with dietary intakes.
RESULTS: We documented 2,254 melanoma cases over 4 million person-years of follow-up. After adjustment for other risk factors, higher total caffeine intake was associated with a lower risk of melanoma (≥393 mg/day vs. <60 mg/day: HR = 0.78, 95% CI = 0.64, 0.96; Ptrend = 0.048). The association was more apparent in women (≥393 mg/day vs. <60 mg/day: HR = 0.70, 95% CI = 0.58, 0.85; Ptrend = 0.001) than in men (HR = 0.94, 95% CI = 0.75, 1.2; Ptrend = 0.81), and more apparent for melanomas occurring on body sites with higher continuous sun exposure (head, neck, and extremities; ≥393 mg/day vs. <60 mg/day: HR = 0.71, 95% CI = 0.59, 0.86; Ptrend = 0.001) than for melanomas occurring on body sites with lower continuous sun exposure (trunk including shoulder, back, hip, abdomen, and chest; HR = 0.90, 95% CI = 0.70, 1.2; Ptrend = 0.60). This pattern of association was similar to that for caffeinated coffee consumption, whereas no association was found for decaffeinated coffee consumption and melanoma risk.
CONCLUSIONS: Increasing caffeine intake and caffeinated coffee consumption is associated with decreased risk of cutaneous malignant melanomas
Citrus Consumption and Risk of Basal Cell Carcinoma and Squamous Cell Carcinoma of the Skin
Animal experiments have demonstrated the photocarcinogenic properties of furocoumarins, a group of naturally occurring chemicals that are rich in citrus products. We conducted a prospective study for citrus consumption and risk of basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) of the skin based on data from 41530 men in the Health Professionals Follow-up Study (1986–2010) and 63759 women in the Nurses’ Health Study (1984–2010) who were free of cancers at baseline. Over 24–26 years of follow-up, we documented 20840 incident BCCs and 3544 incident SCCs. Compared to those who consumed citrus products less than twice per week, the pooled multivariable-adjusted hazard ratios were 1.03 [95% confidence interval (95% CI): 0.99–1.08] for BCC and 1.14 (95% CI: 1.00–1.30) for SCC for those who consumed two to four times per week, 1.06 (95% CI: 1.01–1.11) for BCC and 1.15 (95% CI: 1.02–1.28) for SCC for five to six times per week, 1.11 (95% CI: 1.06–1.16) for BCC and 1.22 (95% CI: 1.08–1.37) for SCC for once to 1.4 times per day and 1.16 (95% CI: 1.09–1.23) for BCC and 1.21 (95% Cl: 1.06–1.38) for SCC for 1.5 times per day or more (P trend = 0.001 for BCC and 0.04 for SCC). In contrast, consumption of non-citrus fruit and juice appeared to be inversely associated with risk of BCC and SCC. Our findings support positive associations between citrus consumption and risk of cutaneous BCC and SCC in two cohorts of men and women, and call for further investigations to better understand the potential photocarcinogenesis associated with dietary intakes
Systematic identification and integrative analysis of novel genes expressed specifically or predominantly in mouse epididymis
BACKGROUND: Maturation of spermatozoa, including development of motility and the ability to fertilize the oocyte, occurs during transit through the microenvironment of the epididymis. Comprehensive understanding of sperm maturation requires identification and characterization of unique genes expressed in the epididymis. RESULTS: We systematically identified 32 novel genes with epididymis-specific or -predominant expression in the mouse epididymis UniGene library, containing 1505 gene-oriented transcript clusters, by in silico and in vitro analyses. The Northern blot analysis revealed various characteristics of the genes at the transcript level, such as expression level, size and the presence of isoform. We found that expression of the half of the genes is regulated by androgens. Further expression analyses demonstrated that the novel genes are region-specific and developmentally regulated. Computational analysis showed that 15 of the genes lack human orthologues, suggesting their implication in male reproduction unique to the mouse. A number of the novel genes are putative epididymal protease inhibitors or β-defensins. We also found that six of the genes have secretory activity, indicating that they may interact with sperm and have functional roles in sperm maturation. CONCLUSION: We identified and characterized 32 novel epididymis-specific or -predominant genes by an integrative approach. Our study is unique in the aspect of systematic identification of novel epididymal genes and should be a firm basis for future investigation into molecular mechanisms underlying sperm maturation in the epididymis
Integrative characterization of germ cell-specific genes from mouse spermatocyte UniGene library
<p>Abstract</p> <p>Background</p> <p>The primary regulator of spermatogenesis, a highly ordered and tightly regulated developmental process, is an intrinsic genetic program involving male germ cell-specific genes.</p> <p>Results</p> <p>We analyzed the mouse spermatocyte UniGene library containing 2155 gene-oriented transcript clusters. We predict that 11% of these genes are testis-specific and systematically identified 24 authentic genes specifically and abundantly expressed in the testis via in <it>silico </it>and <it>in vitro </it>approaches. Northern blot analysis disclosed various transcript characteristics, such as expression level, size and the presence of isoform. Expression analysis revealed developmentally regulated and stage-specific expression patterns in all of the genes. We further analyzed the genes at the protein and cellular levels. Transfection assays performed using GC-2 cells provided information on the cellular characteristics of the gene products. In addition, antibodies were generated against proteins encoded by some of the genes to facilitate their identification and characterization in spermatogenic cells and sperm. Our data suggest that a number of the gene products are implicated in transcriptional regulation, nuclear integrity, sperm structure and motility, and fertilization. In particular, we found for the first time that Mm.333010, predicted to contain a trypsin-like serine protease domain, is a sperm acrosomal protein.</p> <p>Conclusion</p> <p>We identify 24 authentic genes with spermatogenic cell-specific expression, and provide comprehensive information about the genes. Our findings establish a new basis for future investigation into molecular mechanisms underlying male reproduction.</p
X-ray crystal structure, UV–Vis and NMR spectroscopic, and molecular docking studies of pyribencarb isomers
The crystal structures of the pyribencarb E and Z stereoisomers were determined using single-crystal X-ray crystallography. The isomers were confirmed a single data respectively by crystal analysis, LC-UVD mass spectrometry, and NMR spectroscopy. Pyribencarb E crystallizes in triclinic P−1 and the Z isomer in monoclinic P21/c, with the crystal structures showing comparable packing motifs. Moreover, molecular docking was carried out with cytochrome bc1, revealing binding energies in the ranges of −24.9 to −17.6 and −21.6 to −14.7kcal/mol for the E and Z isomers, respectively. Through a combined experimental and theoretical approach, this study contributes to our understanding of pesticides.
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Toxicometabolomics of lindane in adult zebrafish (Danio rerio) using GC-MS/MS and LC-Orbitrap-MS/MS
Lindane is a broad-spectrum persistent organochlorine pesticide that has been used to control pests for many years. In this study, its toxic mechanisms in adult zebrafish were investigated using targeted metabolomics with GC-MS/MS and non-targeted metabolomics with LC-Orbitrap-MS/MS. Zebrafish was exposed to lindane in water for 48 h in three groups: control, low exposure (1/10 LC50) and high exposure (LC50). In the zebrafish exposed to low concentration of lindane, 2.24–3.98 mg/kg of lindane were determined, while 35.67–56.46 mg/kg were observed in the zebrafish exposed to high concentration. A total of 118 metabolites were identified from 394 metabolites on GC-MS/MS and 45 metabolites were selected as biomarkers. A total of 62 metabolites were identified on LC-Orbitrap-MS/MS and 7 metabolites were selected as biomarkers. Three groups were well separated on partial least squares-discriminant analysis (PLS-DA), and a total of 52 metabolites in both the targeted and non-targeted metabolites were selected as biomarkers through VIP and ANOVA tests to construct a heatmap. Five metabolic pathways such as the pentose phosphate pathway (PPP), histidine metabolism, phenylalanine metabolism, alanine/aspartate/glutamate metabolism, and phenylalanine/tyrosine/tryptophan biosynthesis, were observed to show toxicologically significant alterations. Oxidative stress was also confirmed through MDA and ROS assays. Such perturbations of the metabolic pathways of zebrafish caused by the exposure to lindane resulted in significant toxicological effects
Translocation of residual ethoprophos and tricyclazole from soil to spinach
The dissipation of ethoprophos and tricyclazole in soil and their translocation tendency to spinach were investigated. Prior to field trials, the analytical method for the determination of these pesticide residues was optimized and validated on soil and spinach. The field trial was conducted under greenhouse conditions for two different pretreatment periods with the pesticides. After treating with pesticides 30 (PBI-30) and 60 days (PBI-60) before seeding, soil samples were collected on different days for the dissipation study of soil. Spinach samples were harvested from the soil, and 50% and 100% mature spinach samples were collected. The initial amounts of ethoprophos residue in the PBI-60 and PBI-30 soils were 0.21 and 2.74 mg/kg, respectively, and these both decreased to less than 0.01 mg/kg on the day of spinach harvest. Similar initial residues of tricyclazole were observed in the PBI-60 (0.87 mg/kg) and PBI-30 soils (0.84 mg/kg), and these decreased to 0.44 and 0.34 mg/kg, respectively. The half-lives of ethoprophos in the soils were calculated as 7.6 and 4.8 days, respectively, while relatively long half-lives of 36.5 and 77.0 days were calculated for tricyclazole. According to the pesticide residue amounts in the spinach, the translocation rate from the soil to the spinach was determined. In the case of ethoprophos, the residual amount was already rapidly degraded in the soil, and the translocation rate could not be confirmed. On the other hand, for tricyclazole, it was confirmed that 1.19 to 1.61% of the residual amount in soil was transferred to spinach. According to these results, safe management guidelines for tricyclazole in soil were suggested considering the maximum residue limit on spinach.This work was supported by the Rural Development Administration (PJ0152772020)
Predictors of Academic Procrastination in Asian International College Students
This study examined the relationships among acculturative stress, coping styles, self-efficacy, English language proficiency, and various demographic characteristics as predictors of procrastination behavior in Asian International students (N = 255) studying in the United States. Results of multiple logistic regression indicated that a collective coping style, avoidant coping style, academic self-efficacy, and English language proficiency were the significant predictors of academic procrastination in non-Indian Asian international students. Implications for college student affairs professionals and researchers are addressed
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