PRIMARY NEONATAL DUHAMEL PROCEDURE USING THE ENDO GIA STAPLER

The technique of performing the Duharnel procedure in the neonate with Hirschsprung's disease using the ENDO GIA stapler (originally designed for laparoscopic surgery) is described. This technique overcomes the problem of conventional staplers being too large to introduce into the neonatal anus.     

Predictors of registered nurses' organizational commitment and intent to stay

BACKGROUND: Health care reform has significantly altered employment relations. Research findings suggest that the presence or absence of supportive work environments helps explain the differences observed in employee attitudes and turnover intentions. PURPOSES: The purposes of this study were to examine frontline registered nurses' (RNs') perceptions of organizational culture and attitudes and behaviors and test a model linking culture to outcome (organizational commitment and intent to stay). METHODOLOGY: A non-experimental predictive survey design was used to test the model in a sample (N = 343) of acute care RNs employed in one Canadian province. Data were collected with the following scales: Emotional Climate, Practice Issues, Collaborative Relations, Psychological Contract Violation, General Job Satisfaction, Organizational Commitment Questionnaire, and Intent to Stay. FINDINGS: The response rate was 29.4%. Most respondents were middle aged and diploma prepared, were in their current positions for 5 years or more, had 10 or more years of nursing experience, and worked full time. Despite moderate levels of job satisfaction, RNs held negative perceptions of culture (emotional climate, practice-related issues, and collaborative relations), trust, and commitment and were unlikely to stay with current employers. Structural equation modeling provided support for the impact of culture, trust, and satisfaction on commitment and partial support for intent to stay, explaining 45 and 31% of the variance, respectively. PRACTICE IMPLICATIONS: The development and implementation of policies and interventions aimed at creating more supportive work environments and greater trust in employers and job satisfaction have merit. The most obvious benefit from such strategic interventions is the potential for improving RNs' organizational commitment and reducing turnover intentions.     

Studies on the structural prerequisites for the activation of the beta-endorphin receptor on the rat vas deferens

The inhibitory activity of a variety of opioid peptides was tested on the electrically stimulated rat vas deferens. Human beta-endorphin (beta h-EP) was the most potent of the opoioid-like peptides; it produced half-maximal inhibition of the neuromuscular twitching at a concentration of about 100 nM. The potency of beta h-EP was greater than that of camel, porcine, ovine or leucine5 beta h-EP, alpha-N-acetyl beta-ovine-EP was inactive. In contrast to beta-endorphin (beta-EP), methionine and leucine-enkephalin, dynorphin-(1-13), morphine and other narcotic analgesics were devoid of opioid-like activity. Fragments of beta-EP with amino acid deletions at the carboxy end of the molecule were considerably less potent than the parent compound. The fragment beta h-EP 1-21 was 70 times less potent than beta h-EP, whereas the segments beta h-EP 1-19 and beta h-EP 1-16 were both completely inactive. Deletions at the amino terminal of beta-EP yielded inactive compounds. The potency of beta h-EP was reduced in a dose-related fashion by applications of nanomolar concentrations of naloxone or N-allylnormetazocine and by micromolar concentrations of levorphanol or morphine. In decided contrast, opioid peptides such as methionine enkephalin, dynorphin-(1-13), beta-casomorphan derivatives or short chain beta h-EP segments such as beta-EP 1-16, beta-EP 1-19, beta-EP 6-31, beta-EP (1-5)-(16-31), methionine enkephalin plus beta-EP 6-31 or the N-acetyl beta-bovine-EP did not antagonize the inhibitory action of beta h-EP. The present results demonstrate that the rat vas deferens contains opioid receptors with considerable selectivity for beta-EP. It is concluded from this structure activity relationship study that the activation of the beta-EP receptor involves at least two sites of recognition on the beta-EP structure.     

A high-molecular-weight squid neurofilament protein contains a lamin-like rod domain and a tail domain with Lys-Ser-Pro repeats.

Previous studies have shown that two low molecular-weight neurofilament (NF) proteins (NF-60 and NF-70) from the squid Loligo pealei are translated from mRNAs that are splice variants of a single squid NF gene. In this study, we report the isolation and characterization of cDNA clones encoding a high-molecular-weight squid NF protein (NF-220), the mRNA of which derives from the same squid NF gene. All three proteins are identical in their amino-terminal and lamin-like rod domains but differ in their carboxyl-terminal tail regions. In contrast to the short tail domains of NF-60 and NF-70, the NF-220 protein has a longer tail domain containing an acidic cluster of amino acids immediately followed by repeated copies of the sequence motif Lys-Ser-Pro. The Lys-Ser-Pro domain is similar to that of mammalian medium NF (NF-M) and high NF (NF-H) proteins, where the serines are highly phosphorylated. Except for these Lys-Ser-Pro motifs, there is surprisingly little structural similarity between the squid NF-220 protein and mammalian NF-M and NF-H proteins. Furthermore, the location of introns in squid NF-220 protein shows that it is more closely related to nuclear lamins and type III intermediate-filament proteins than to vertebrate NF proteins.     

Selective amplification of additional members of the ADP-ribosylation factor (ARF) family: cloning of additional human and Drosophila ARF-like genes.

The ADP-ribosylation factor (ARF) family is one of four subfamilies of the RAS superfamily of low molecular weight GTP-binding proteins (G proteins). Highly degenerate oligonucleotides encoding two conserved regions were used in a PCR reaction to amplify cDNAs encoding each of the known ARF proteins and eight additional cDNA fragments encoding previously unreported human members of the ARF family. Additional sequences were obtained from yeast or fly libraries by using this technique. These oligonucleotides specifically amplify members of the ARF family but not the structurally related G protein alpha subunits or members of the other three subfamilies of the RAS superfamily. Fragments obtained by PCR were used to obtain full-length sequences encoding highly homologous ARF-like (ARL) gene products from human and Drosophila melanogaster libraries, termed ARL2 and Ar184F, respectively. The encoded proteins are each 184 amino acids long and are 76% identical, with 40-45% identity to human ARF1 and Drosophila arf-like (arl) proteins. These genes appear to be generally expressed in human tissues and during Drosophila development. The purified human ARL2 protein differed in several biochemical properties from human ARF proteins, including the complete absence of ARF activity. Thus, the ARF family of low molecular weight GTP-binding proteins includes at least 15 distinct but structurally conserved members, including both the functionally conserved ARF proteins and the functionally disparate ARL proteins. The latter proteins currently comprise two distinct gene products in Drosophila (arl and ARL84F) and one in man (ARL2).     

Direct visualization of endogenous Salmonella‐specific B cells reveals a marked delay in clonal expansion and germinal center development

CD4⁺ T cells and B cells are both essential for acquired immunity to Salmonella infection. It is well established that Salmonella inhibit host CD4⁺ T‐cell responses, but a corresponding inhibitory effect on B cells is less well defined. Here, we utilize an Ag tetramer and pull‐down enrichment strategy to directly visualize OVA‐specific B cells in mice, as they respond to infection with Salmonella‐OVA. Surprisingly, OVA‐specific B‐cell expansion and germinal center formation was not detected until bacteria were cleared from the host. Furthermore, Salmonella infection also actively inhibited both B‐ and T‐cell responses to the same coinjected Ag but this did not require the presence of iNOS. The Salmonella Pathogenicity Island 2 (SPI2) locus has been shown to be responsible for inhibition of Salmonella‐specific CD4⁺ T‐cell responses, and an examination of SPI2‐deficient bacteria demonstrated a recovery in B‐cell expansion in infected mice. Together, these data suggest that Salmonella can simultaneously inhibit host B‐ and T‐cell responses using SPI2‐dependent mechanisms.