Release of neuropeptides during intracellular stimulation of single identified Aplysia neurons in culture.

An important criterion for classifying a substance as a neurotransmitter is that it is released in an activity-dependent fashion. We have utilized cell culture of individual neurons of Aplysia to demonstrate the release of the neuropeptides SCPA and SCPB (small cardioactive peptides A and B). Neurons B1 and B2 were isolated from the buccal ganglion of Aplysia and maintained in cell culture. The cells grew new processes, which were immunoreactive to antibodies for the neuropeptide SCPB. These processes contained SCPA and SCPB that were detectable by bioassay on snail heart. The cells synthesized the SCPs from radiolabeled precursors and transported the peptides to their neurites. Single cells released SCPs in a calcium-dependent fashion upon intracellular electrical stimulation. Taken together, these results provide critical evidence that SCPs are neurotransmitters. The results also indicate that the cell culture of individual identified neurons can be used to investigate the release of peptides.     

Conditions associated with normal levels of prostate-specific antigen and elevation of prostatic acid phosphatase.

Thirteen cases are reported with normal levels of prostate-specific antigen and elevated prostatic acid phosphatase (PAP). Conditions that were associated with an elevated PAP were myeloproliferative syndromes (four cases), metastatic nonprostatic carcinoma (six cases), prostatic carcinoma (one case), tuberculosis with a concurrent lupus-like syndrome (one case), and osteomyelitis (one case). The inclusion of PAP in the initial investigation of cases with suspected prostatic disease results in a decreased specificity.     

Cerebral Effects in Superior Vena Caval Cannula Obstruction: The Role of Brain Monitoring

A pediatric cardiac case of transient obstruction of the superior vena cava by the venous cannula before cardiopulmonary bypass is presented. With venous obstruction and increase in central venous pressure, reduced cerebral blood flow velocities and absence of diastolic Doppler flow were detected. This was followed by regional cerebral venous oxygen desaturation and global electroencephalographic slowing. Reposition of the venous cannula led to the recovery of these physiologic indicators and a noncomplicated clinical outcome.     

Cloning and expression analysis of the chick DAN gene, an antagonist of the BMP family of growth factors.

Differential screening-selected gene aberrative in neuroblastoma (DAN) is a member of a cystine knot protein family that includes Cerberus and Gremlin. First isolated in a screen to identify genes down-regulated in transformed rat fibroblasts, DAN has subsequently been cloned in Xenopus, mouse, and human. Overexpression of DAN suppresses the transformed phenotype and retards the cell's entry into S phase. Biochemical analyses have demonstrated DAN's ability to bind bone morphogenetic proteins and antagonize their signaling activity. In this study, chick DAN was cloned and sequenced, revealing a conserved cystine knot region as well as an N-glycosylation site. A riboprobe was designed from the 3' chick DAN coding sequence and used for analysis of DAN in the developing chick embryo by in situ hybridization. Chick DAN was expressed beginning at stage 10 in the developing somites and the medial otic epithelium. Expression in the neural layer of the eye became apparent at stage 14. By stage 17, expression had expanded to the base of the hindbrain. Limb bud labeling began at stage 20, whereas expression in the branchial arches appeared at stage 25. Chick DAN expression generally corresponded to that of mouse DAN expression as shown by comparative in situ hybridization. However, chick DAN was found in the otic epithelium and notochord, whereas mouse DAN was restricted to the overlying otic ectomesenchyme and was absent from the notochord. This observation suggests that DAN may play different roles in chick and mouse otic and notochord development.     

Attachment style, childhood adversity, and behavioral risk among young men who have sex with men.

PURPOSE: To examine relationships among childhood adversity, attachment style (one's core beliefs regarding the self and others), and the following risk behaviors and contexts among young men who have sex with men (YMSM): homelessness, daily substance use, participation in sex work, involvement in the criminal justice system, and being out of school or work. METHODS: Using a targeted sampling approach, we recruited 569 YMSM aged 17-28 years from natural venues in New York City including bars, clubs, parks, and bus stations. Youth completed a structured interview assessing lifetime and current risk and protective contexts and behavior. Data were analyzed using univariate and multivariate statistical methods, including hierarchical logistic regression. RESULTS: After controlling for demographic characteristics and childhood adversity, YMSM with a fearful attachment style were more likely to have been homeless (OR 2.93, 95% CI 1.65-5.18), to have participated in sex work (OR 2.35, 95% CI 1.44-3.85), to use substances daily (OR 2.79, 95% CI 1.29-6.03), to have been involved in the criminal justice system (OR 2.04, 95% CI 1.38-3.01), and to be out of school/work (OR 2.47, 95% CI 1.47-4.15). Three subgroups were particularly vulnerable: YMSM who identified as heterosexual, or bisexual, and/or transgender. CONCLUSIONS: A fearful attachment style contributes to some YMSM remaining outside of the protective systems of family, school, and work, and is associated with risky contexts where they are less likely to encounter prosocial peers and adults. Further, it is associated with risk behavior. Although gay-identified youth are generally found to have poor outcomes when compared with the general population of adolescents, in the present report, YMSM who identified as heterosexual were at particular risk. Attachment theory can guide interventions by informing how individuals experience relationships and manage developmental transitions.