The receptor 2B4 belongs to the Ig superfamily and is found on the surface of all murine natural killer (NK) cells as well as T cells displaying non-MHC-restricted cytotoxicity. Previous studies have suggested that 2B4 is an activating molecule because cross-linking of this receptor results in increased cytotoxicity and ␥-interferon secretion as well as granule exocytosis. However, it was recently shown that the gene for 2B4 encodes two different products that arise by alternative splicing. These gene products differ solely in their cytoplasmic domains. One form has a cytoplasmic tail of 150 amino acids (2B4L) and the other has a tail of 93 amino acids (2B4S). To determine the function of each receptor, cDNAs for 2B4S and 2B4L were transfected into the rat NK cell line RNK-16. Interestingly, the two forms of 2B4 had opposing functions. 2B4S was able to mediate redirected lysis of P815 tumor targets, suggesting that this form represents an activating receptor. However, 2B4L expression led to an inhibition of redirected lysis of P815 targets when the mAb 3.2.3 (specific for rat NKRP1) was used. In addition, 2B4L constitutively inhibits lysis of YAC-1 tumor targets. 2B4L is a tyrosine phosphoprotein, and removal of domains containing these residues abrogates its inhibitory function. Like other inhibitory receptors, 2B4L associates with the tyrosine phosphatase SHP-2. Thus, 2B4L is an inhibitory receptor belonging to the Ig superfamily.

Design: Descriptive epidemiologic study of time trends and a nested case-control study. Setting: Texas. Participants: Cases in the Texas Birth Defects Registry. Outcome Measures: Time trends in the birth prevalence of plagiocephaly overall and by region, demographic group, and clinical subgroup. Trends in percentage of cases using specific facilities or procedures. Results: From 1999 to 2007, the prevalence of plagiocephaly in Texas increased from 3.0 cases per 10 000 live births to 28.8, an average increase of 21.2% per year. This was highly statistically significant. The time trend was most pronounced in the Dallas/Fort Worth region and in certain health care facilities. It was observed in all demographic and clinical subgroups. Cases born in 2004 and 2005 were not more likely to be postnatally acquired when compared with cases born in 1999 and 2000. There was no commensurate decrease in other birth defects of the face or skull. Conclusions: A small part of the trend might have been due to delayed compliance with the infant supine sleeping recommendation and a slight increase in preterm births. It was not due to changes in birth defect coding practice or trends in multiple births, torticollis, or oligohydramnios. Because the plagiocephaly trend was observed mainly in patients visiting certain health care facilities, among mild cases, and among cases with minimally invasive procedures, we suspect it may be due mainly to changes in available therapies and insurance reimbursement practices.

No abstract

Men who have sex with men (MSM), particularly racial/ethnic minority MSM, are disproportionately affected by HIV in the United States and Texas. Bareback sex or condomless anal intercourse (CAI) can be a high HIV risk behavior. Despite this, a majority of MSM continues to engage in barebacking. Research suggests racial/ethnic differences in barebacking exist; however, these conclusions remain unclear due to insufficient sample sizes to compare racial/ethnic groups. Our cross-sectional correlational design explores barebacking correlates (substance use during sex, safe sex fatigue, and optimistic HIV treatment beliefs) within and between racial/ethnic groups among 366 MSM. Regression models are significant for Latino and African-American MSM alone and for all MSM combined, though not significant for European-American and Other Race/Ethnicity MSM alone. Our findings suggest motivations and behaviors underlying barebacking among MSM vary by racial/ethnic membership with clinical implications for informing culturally sensitive HIV interventions and prevention programs for target racial/ethnic groups.

No abstract

According to National HIV Behavioral Surveillance system data, human immunodeficiency virus (HIV) testing increased among gay, bisexual, and other men who have sex with men from 2008 to 2011 in cities funded by the Centers for Disease Control and Prevention's Expanded Testing Initiative, suggesting that focused HIV testing initiatives might have positive effects.

The rate of drug and opioid overdose deaths in the United States has more than tripled over the past 15 years. The ability to conduct public health surveillance on nonfatal overdoses is limited. The current study used National HIV Behavioral Surveillance (NHBS) data to estimate recent and lifetime history of nonfatal overdose events in persons who inject drugs in 7 cities. Recent and lifetime experience of overdose events ranged from 3% to 20% and from 29% to 63%, respectively. Adapting systems such as NHBS may be useful in responding to and monitoring emergent public health problems such as the overdose epidemic.

No abstract