Functional characterization and genetic mapping of alk8

The novel type I TGFβ family member receptor alk8 is expressed both maternally and zygotically. Functional characterization of alk8 was performed using microinjection studies of constitutively active (CA), kinase modified/dominant negative (DN), and truncated alk8 mRNAs. CA Alk8 expression produces ventralized embryos while DN Alk8 expression results in dorsalized phenotypes. Truncated alk8 expressing embryos display a subtle dorsalized phenotype closely resembling that of the identified zebrafish dorsalized mutant, lost-a-fin (laf). Single-strand conformation polymorphism (SSCP) analysis was used to map alk8 to zebrafish LG02 in a region demonstrating significant conserved synteny to Hsa2, and which contains the human alk2 gene, ACVRI. Altogether, these functional, gene mapping and phylogenetic analyses suggest that alk8 may be the zebrafish orthologue to human ACVRI (alk2), and therefore extend previous studies of Alk2 conducted in Xenopus.     

A Longitudinal Study of Steller Sea Lion Natality Rates in the Gulf of Alaska with Comparisons to Census Data

Steller sea lion (Eumetopias jubatus) numbers in the Western Distinct Population Segment are beginning to recover following the dramatic decline that began in the 1970s and ended around the turn of the century. Low female reproductive rates (natality) may have contributed to the decline and remain an issue of concern for this population. During the 2000s we found high natality among Steller sea lions in the Gulf of Alaska indicating a healthy population. This study extends these previous estimates over an additional three years and tests for interannual variations and long-term trends. We further examine the proportions of pups to adult females observed on the rookery and nearby haulouts during the birthing season to assess whether census data can be used to estimate natality. Open robust design multistate models were built and tested using Program MARK to estimate survival, resighting, and state transition probabilities in addition to other parameters dependent on whether or not a female gave birth in the previous year. Natality was estimated at 70% with some evidence of interannual variation but a long-term increasing or decreasing trend was not supported by the data. Bootstrap and regression comparisons of census data with natality estimates revealed no correlation between the two methods suggesting that census data are not an appropriate proxy for natality in this species. Longitudinal studies of individual animals are an appropriate method for estimating vital rates in species with variable detection over time such as the Steller sea lion. This work indicates that natality remains high in this region and is consistent with a population in recovery.     

Depth Discrimination in Diffuse Optical Transmission Imaging by Planar Scanning Off-Axis Fibers: INITIAL Applications to Optical Mammography

We present a method for depth discrimination in parallel-plate, transmission mode, diffuse optical imaging. The method is based on scanning a set of detector pairs, where the two detectors in each pair are separated by a distance δD_i along direction δ D _i within the x-y scanning plane. A given optical inhomogeneity appears shifted by α_i δ D _i (with 0≤ α_i ≤1) in the images collected with the two detection fibers of the i-th pair. Such a spatial shift can be translated into a measurement of the depth z of the inhomogeneity, and the depth measurements based on each detector pair are combined into a specially designed weighted average. This depth assessment is demonstrated on tissue-like phantoms for simple inhomogeneities such as straight rods in single-rod or multiple-rod configurations, and for more complex curved structures which mimic blood vessels in the female breast. In these phantom tests, the method has recovered the depth of single inhomogeneities in the central position of the phantom to within 4 mm of their actual value, and within 7 mm for more superficial inhomogeneities, where the thickness of the phantom was 65 mm. The application of this method to more complex images, such as optical mammograms, requires a robust approach to identify corresponding structures in the images collected with the two detectors of a given pair. To this aim, we propose an approach based on the inner product of the skeleton images collected with the two detectors of each pair, and we present an application of this approach to optical in vivo images of the female breast. This depth discrimination method can enhance the spatial information content of 2D projection images of the breast by assessing the depth of detected structures, and by allowing for 3D localization of breast tumors.     

Relationship of Smokefree Laws and Alcohol Use with Light and Intermittent Smoking and Quit Attempts among US Adults and Alcohol Users

IntroductionLight and intermittent smoking (LITS) has become increasingly common. Alcohol drinkers are more likely to smoke. We examined the association of smokefree law and bar law coverage and alcohol use with current smoking, LITS, and smoking quit attempts among US adults and alcohol drinkers.MethodsCross-sectional analyses among a population-based sample of US adults (n = 27,731) using restricted data from 2009 National Health Interview Survey and 2009 American Nonsmokers'' Rights Foundation United States Tobacco Control Database. Multivariate logistic regression models examined the relationship of smokefree law coverage and drinking frequency (1) with current smoking among all adults; (2) with 4 LITS patterns among current smokers; and (3) with smoking quit attempts among 6 smoking subgroups. Same multivariate analyses were conducted but substituted smokefree bar law coverage for smokefree law coverage to investigate the association between smokefree bar laws and the outcomes. Finally we ran the above analyses among alcohol drinkers (n = 16,961) to examine the relationship of smokefree law (and bar law) coverage and binge drinking with the outcomes. All models controlled for demographics and average cigarette price per pack. The interactions of smokefree law (and bar law) coverage and drinking status was examined.ResultsStronger smokefree law (and bar law) coverage was associated with lower odds of current smoking among all adults and among drinkers, and had the same effect across all drinking and binge drinking subgroups. Increased drinking frequency and binge drinking were related to higher odds of current smoking. Smokefree law (and bar law) coverage and drinking status were not associated with any LITS measures or smoking quit attempts.ConclusionsStronger smokefree laws and bar laws are associated with lower smoking rates across all drinking subgroups, which provides further support for these policies. More strict tobacco control measures might help reduce cigarette consumption and increase quit attempts.     

Detection of an exon 53 polymorphism in the dystrophin gene

We utilized a heteroduplex method to screen for small mutations in Duchenne muscular dystrophy patients who did not have deletions or duplications. A dystrophin exon 53 heteroduplex band was identified in 14.4% of the affected patients. Direct sequencing of the amplified product from DNA producing the heteroduplex revealed the presence of a polymorphism in the coding region. The codon for asparagine was converted from AAT to AAC.     

Comprehensive Analysis of the 16p11.2 Deletion and Null Cntnap2 Mouse Models of Autism Spectrum Disorder

Autism spectrum disorder comprises several neurodevelopmental conditions presenting symptoms in social communication and restricted, repetitive behaviors. A major roadblock for drug development for autism is the lack of robust behavioral signatures predictive of clinical efficacy. To address this issue, we further characterized, in a uniform and rigorous way, mouse models of autism that are of interest because of their construct validity and wide availability to the scientific community. We implemented a broad behavioral battery that included but was not restricted to core autism domains, with the goal of identifying robust, reliable phenotypes amenable for further testing. Here we describe comprehensive findings from two known mouse models of autism, obtained at different developmental stages, using a systematic behavioral test battery combining standard tests as well as novel, quantitative, computer-vision based systems. The first mouse model recapitulates a deletion in human chromosome 16p11.2, found in 1% of individuals with autism. The second mouse model harbors homozygous null mutations in Cntnap2, associated with autism and Pitt-Hopkins-like syndrome. Consistent with previous results, 16p11.2 heterozygous null mice, also known as Del(7Slx1b-Sept1)4Aam weighed less than wild type littermates displayed hyperactivity and no social deficits. Cntnap2 homozygous null mice were also hyperactive, froze less during testing, showed a mild gait phenotype and deficits in the three-chamber social preference test, although less robust than previously published. In the open field test with exposure to urine of an estrous female, however, the Cntnap2 null mice showed reduced vocalizations. In addition, Cntnap2 null mice performed slightly better in a cognitive procedural learning test. Although finding and replicating robust behavioral phenotypes in animal models is a challenging task, such functional readouts remain important in the development of therapeutics and we anticipate both our positive and negative findings will be utilized as a resource for the broader scientific community.     

Family Physicians' Barriers to Cancer Screening in Extremely Obese Patients

Extremely obese women are less likely than nonobese women to receive breast and cervical cancer screening examinations. Reasons for this disparity are unclear and may stem from patient and/or physician barriers. This sequential mixed‐methods study used individual in‐depth interviews of 15 family physicians followed by a mail survey of 255 family physicians (53% response rate) to understand the barriers they faced in performing cancer screening examinations in extremely obese women. Barriers fell into three main areas: (i) difficulty doing pelvic and breast exams; (ii) inadequate equipment; and (iii) challenges overcoming patient barriers and refusal. This led some physicians to avoid performing breast and pelvic examinations on extremely obese women. Having more knowledge about specific examination techniques was associated with less difficulty in palpating lumps on breast and pelvic examinations (P < 0.005). Physicians perceived that embarrassment, aversion to undressing, and avoidance of discussions related to their weight were the most frequent barriers extremely obese women had with getting physical examinations. Educating and/or motivating patients and addressing fears were strategies used most frequently when patients refused mammograms or Pap smears. Interventions focusing on physician barriers, such as educating them on specific examination techniques, obtaining adequate equipment and supplies, and providing resources to assist physicians in dealing with patient barriers and refusal, may be fruitful in increasing cancer screening rates in extremely obese patients. Future research studies testing the effectiveness of these strategies are needed to improve cancer outcomes in this high‐risk population.     

Mzm1 Influences a Labile Pool of Mitochondrial Zinc Important for Respiratory Function

Zinc is essential for function of mitochondria as a cofactor for several matrix zinc metalloproteins. We demonstrate that a labile cationic zinc component of low molecular mass exists in the yeast mitochondrial matrix. This zinc pool is homeostatically regulated in response to the cellular zinc status. This pool of zinc is functionally important because matrix targeting of a cytosolic zinc-binding protein reduces the level of labile zinc and interferes with mitochondrial respiratory function. We identified a series of proteins that modulate the matrix zinc pool, one of which is a novel conserved mitochondrial protein designated Mzm1. Mutant mzm1Δ cells have reduced total and labile mitochondrial zinc, and these cells are hypersensitive to perturbations of the labile pool. In addition, mzm1Δ cells have a destabilized cytochrome c reductase (Complex III) without any effects on Complexes IV or V. Thus, we have established that a link exists between Complex III integrity and the labile mitochondrial zinc pool.     

The ability of females to predict male status via urinary odors

In an earlier study, estrous female hamsters were found to prefer the urinary odors of dominant males. This study investigated whether estrous females would exhibit preferential responding to randomly chosen, socially naive males before dominance testing occurred. Estrous females were indeed found to exhibit such preferences. Such discriminative abilities are discussed with reference to adaptive mating strategies for females.