Utility of Induced Sputum in Assessing Bacterial Etiology for Community-Acquired Pneumonia in Hospitalized Children.

BACKGROUND: Diagnostic testing for bacterial etiology of community-acquired pneumonia (CAP) is insensitive. Induced sputum (IS) is an attractive option for the evaluation of the lower respiratory tract. METHODS: Children aged 0-18 years with CAP were enrolled in the Etiology of Pneumonia in the Community (EPIC) study between 2010 and 2012. Blood and respiratory specimens were assessed by culture and polymerase chain reaction (PCR). The radiographic CAP was determined by a study radiologist. Sputum was induced with hypertonic saline. IS specimen was high quality (HQ) if Gram stain showed >25 white blood and <10 epithelial cells per low-powered field; all others were low quality (LQ). We compared IS pathogen prevalence between HQ and LQ IS, and by radiographic pneumonia. Pathogen concordance with EPIC etiology was assessed. Length of stay (LOS) was compared by receipt of IS pathogen-concordant antibiotics. RESULTS: Out of 977 children, 916 (94%) children enrolled in Memphis, Tennessee, produced IS; 794 (87%) had radiographic CAP and 174 (19%) were HQ. HQ IS yielded pathogenic bacteria more often than LQ (64% vs 44%; P < .01); however, pathogens were isolated at similar rates in HQ IS in patients with and without radiographic CAP (64% vs. 63%; P = .6). Pathogens from study specimens matched an IS pathogen in only 9/42 (21%) patients with radiographic CAP. Median LOS was similar among patients with radiographic CAP regardless of receipt of IS pathogen-concordant antibiotics (3.1 days), non-pathogen-concordant antibiotics (2.7 days), or no antibiotics (3.2 days; P = .5). CONCLUSIONS: Bacterial pathogens were isolated from most IS cultures regardless of radiographic CAP and quality of IS. IS cultures infrequently corresponded with sterile site cultures. Isolation of pathogens from pediatric IS reflects oropharyngeal carriage and is insufficient to determine bacterial etiology of CAP.

Dopamine dynamics associated with, and resulting from, schedule-induced alcohol self-administration: analyses in dopamine transporter knockout mice.

Preclinical and clinical evidence suggest an association between alcoholism and the primary regulator of extracellular dopamine concentrations, the dopamine transporter (DAT). However, the nature of this association is unclear. We determined if 10 days of voluntary alcohol self-administration followed by withdrawal could directly alter DAT function, or if genetically mediated changes in DAT function and/or availability could influence vulnerability to alcohol abuse. Heterozygous (DAT+/-) and homozygous mutant (DAT-/-) and wild-type (DAT+/+) mice were allowed to consume 5% alcohol in a schedule-induced polydipsia (SIP) task. In vivo fixed potential amperometry in anesthetized mice was used to (1) identify functional characteristics of mesoaccumbens dopamine neurons related to genotype, including dopamine autoreceptor (DAR) sensitivity, DAT efficiency, and DAT capacity, (2) determine if any of these characteristics correlated with alcohol drinking observed in DAT+/+ and DAT+/- animals, and (3) determine if SIP-alcohol self-administration altered DAR sensitivity, DAT efficiency, and DAT capacity by comparing these characteristics in wild-type (DAT+/+) mice that were SIP-alcohol naïve, with those that had undergone SIP-alcohol testing. DAT-/- mice consumed significantly less alcohol during testing and this behavioral difference was related to significant differences in DAR sensitivity, DAT efficiency, and DAT capacity. These functional characteristics were correlated to varying degrees with g/kg alcohol consumption in DAT+/+ and DAT+/- mice. DAR sensitivity was consistently reduced and DAT efficiency was enhanced in SIP-alcohol-experienced DAT+/+ mice when compared with naïve animals. These results indicate that DAR sensitivity is reduced by SIP-alcohol consumption and that DAT efficiency is modified by genotype and SIP-alcohol exposure. DAT capacity appeared to be strictly associated with SIP-alcohol consumption.

A mouse model of Waardenburg syndrome type IV resulting from an ENU-induced mutation in endothelin 3.

A line of mutant mice (114-CH19) exhibiting white spotting and preweaning lethality was identified during an N-ethyl-N-nitrosourea (ENU) mutagenesis screen. The trait segregated as a semidominant bellyspot with reduced penetrance. Homozygous mutant mice showed preweaning lethality, and exhibited white spotting over the majority of the body surface, with pigmented patches remaining around the pinnae, eyes and tail. Linkage analysis localized 114-CH19 on mouse chromosome 2, suggesting endothelin 3 (Edn3) as a candidate gene. Sequence analysis of Edn3 identified a G > A transversion that encodes an arginine to histidine substitution (R96H). This mutation is predicted to disrupt furin-mediated proteolytic cleavage of pro-endothelin that is necessary to form biologically active EDN3. This mutation is novel among human and mouse EDN3 mutants, is the first reported EDN3 ENU mutant, and is the second reported EDN3 point mutation. This study demonstrates the power of using ENU mutagenesis screens to generate new animal models of human disease, and expands the spectrum of EDN3 mutant alleles.

Transrectal gene therapy of the prostate in the canine model.

Direct transrectal delivery of therapeutic genes utilizing adenoviral vectors for advanced prostate cancer may offer effective treatment at the molecular level. Large animal models to assess feasibility and the intraprostatic and systemic dissemination patterns of these vectors have not been reported. For these studies, a replication-deficient (E1(-)/E3(-)) recombinant adenovirus (AdRSVlacZ) expressing bacterial beta-galactosidase (beta-gal) was delivered under transrectal ultrasound guidance. Two prostate biopsies, followed by concurrent injection of 4.8 x 10(9) pfu of the adenoviral vector divided into either 1 or 2 mL of diluent, were performed (n=4). Swabs of the rectum, sputum, and urine were collected and after 72 hours, the animals were sacrificed. Specimens were assayed for the presence of virus and beta-gal activity. Rectal swabs were transiently positive, whereas urine and sputum samples showed no detectable vector throughout the experiment. Beta-gal activity was observed at the prostate injection sites with detectable activity noted up to 7.5 mm away from the injection site. Systemic dissemination was observed regardless of the injected volume. In conclusion, transrectal prostate biopsy with concurrent prostate injection is a feasible method to deliver therapeutic adenoviral vectors for the treatment of prostate cancer; however, systemic distribution and temporary rectal shedding of virus should be anticipated.