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51.
Background: Men who have sex with men (MSM) have higher rates of substance use compared to men who have sex with women. Among MSM, drug use is linked to higher-risk sexual behavior and acquisition of HIV and other sexually transmitted infections. Objectives: We hypothesize that time since first acting on one's same sex attraction, or one's “gay age”, could be predictive of drug using behavior. Methods: We examined this question among 176 MSM, aged 18–35, presenting at a public sexual health clinic. Behavioral data were captured using interviewer- and self-administered surveys and clinical data were extracted from medical records. We used modified Poisson regression to examine associations between gay age and recent recreational drug use, and separately, between gay age and recent marijuana use. Results: In total, 43% of participants reported recent marijuana use and 26% of participants reported recent use of other drugs. The associations between gay age and marijuana use and other drug use varied by HIV status. After adjustment for biological age, race, and education, a one-year increase in gay age was associated with significantly increased drug use among HIV-negative men (adjusted prevalence ratio (aPR): 1.08; 95% confidence interval (CI): 1.03–1.14), but we observed no association between gay age and drug use among HIV-positive men (aPR: 0.96, 95% CI: 0.86–1.07). Gay age was not associated with marijuana use in HIV-negative (aPR: 1.00, 95% CI: 0.95–1.04) or HIV-positive (aPR: 1.06, 95% CI: 0.98–1.14) men. Conclusions: In summary, HIV-negative MSM who had experienced more time since first same-sex experience had significantly increased prevalence of recent drug use.  相似文献   
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Primary hepatic malignancies are relatively rare in the pediatric population, accounting for approximately 1%–2% of all pediatric tumors. Hepatoblastoma and hepatocellular carcinoma are the most common primary liver malignancies in children under the age of 5 years and over the age of 10 years, respectively. This paper provides consensus-based imaging recommendations for evaluation of patients with primary hepatic malignancies at diagnosis and follow-up during and after therapy.  相似文献   
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Adrenal tumors other than neuroblastoma are uncommon in children. The most frequently encountered are adrenocortical carcinoma and pheochromocytoma. This paper offers consensus recommendations for imaging of pediatric patients with a known or suspected primary adrenal malignancy other than neuroblastoma at diagnosis and during follow-up.  相似文献   
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Obligate social parasites, or inquilines, exploit the colonies of free-living social species and evolved at least 80 times in ants alone. Most species of the highly specialized inquiline social parasites are rare, only known from one or very few, geographically isolated populations, and the sexual offspring of most inquiline species mates inside the maternal colony. Therefore, inquiline populations are believed to be small and genetically homogeneous due to inbreeding. To comparatively study the genetic diversity of the socially parasitic fungus-growing ant, Mycocepurus castrator, and its only known host species, Mycocepurus goeldii, and to infer the parasite’s conservation status, we developed 21 microsatellite markers for the host species, M. goeldii, and evaluated whether these markers cross-amplify in the social parasite, M. castrator. We isolated and characterized a total of 21 microsatellite loci for M. goeldii. The loci were screened for 24 individuals from geographically distant and genetically divergent populations in Brazil. The number of alleles per locus ranged from 18 to 4, the observed heterozygosity ranged from 0.25 to 0.636, and the probability of identity values ranged from 0.011 to 0.146. Preliminary analyses show that these markers cross amplify in the closely related social parasite species M. castrator. These newly developed loci provide tools for studying the genetic diversity and the evolution of social parasitism in the Mycocepurus host–parasite system.  相似文献   
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