Generic phytosanitary radiation treatment for tephritid fruit flies provides quarantine security for Bactrocera latifrons (Diptera: Tephritidae)

Bactrocera latifrons (Hendel) (Diptera: Tephritidae) is a quarantine pest of several solanaceous crops and tropical fruits that are treated using irradiation before export from Hawaii to the U.S. mainland. A dose of 150 Gy is approved as a generic irradiation treatment for tephritid fruit flies, but no confirmation of efficacy has been reported for B. latifrons. Dose response of B. latifrons was used to determine the most tolerant life stage and identify a dose that prevents adult emergence. Data indicated doses (plus 95% confidence limits) required to prevent adult emergence of 13.4 (10.0-29.6), 17.5 (14.4-24.8), and 88.1 (68.0-133.8) Gy for eggs, first instars and third instars, respectively. In large-scale confirmatory tests of the most radiotolerant life stage, a radiation dose of 150 Gy applied to B. latifrons late third instars in bell peppers (Capsicum annuum L.) resulted in no survival to the adult stage of 157,112 individuals, a treatment efficacy consistent with Probit 9-level mortality. The relative radiotolerance of melon fly Bactrocera cucurbitae Coquillet, and B. latifrons also was tested using a diagnostic radiation dose of 30 Gy. In diet, a mean of 6.9% of irradiated B. cucurbitae third instars developed to the adult stage, whereas no B. latifrons third instars developed to adults. In papaya, Carica papaya L., fruit, a mean of 3.3% of irradiated B. cucurbitae third instars developed to the adult stage, whereas 0.5% B. latifrons third instars developed to adults. This report supports the use of a generic radiation dose of 150 Gy in quarantine scenarios to control tephritid fruit flies on fresh commodities.     

Diverse trends in shell weight of three Southern Ocean pteropod taxa collected with Polar Frontal Zone sediment traps from 1997 to 2007

The impact of ocean acidification on key ocean calcifiers is predicted to be imminent, particularly in high-latitude ecosystems. Long-term field observations are essential to ground truth predictions of change in regional ecosystems. Here, we report on aragonitic pteropods collected to sediment traps at 800 m depth at 54°S, 140°E in the Polar Frontal Zone (PFZ) of the Southern Ocean from 1997 to 2007. Statistically significant trends were not identified in either mass or number flux from 1997 to 2007; however, differences emerged in decadal trends seen in shell weight for each of the three common taxa collected: Limacina helicina antarctica forma antarctica shells became significantly lighter (P < 0.05), L. retroversa australis shells became significantly heavier (P < 0.05) and L. helicina antarctica forma rangi shells did not change significantly. These results suggest that factors other than ocean acidification affect pteropod population variations on decadal timescales, with the potential to either amplify or counter the impact of decreasing aragonite saturation state, at least in the short term. Comparison to sea surface temperature and chlorophyll biomass did not identify these as significant drivers of the observed changes, and attribution across these multiple variables requires better understanding of pteropod physiology and ecology. Our PFZ pelagic pteropod observations provide a reference for evaluation of southern polar pteropod responses to changing ocean conditions in coming decades. Importantly, these data also raise the issue of taxonomic care when monitoring the region for impacts of ocean acidification on calcifiers.     

Effect of Vitamin D Supplementation on Cardiometabolic Risks and Health-Related Quality of Life among Urban Premenopausal Women in a Tropical Country – A Randomized Controlled Trial

Background

Many observational studies linked vitamin D to cardiometabolic risks besides its pivotal role in musculoskeletal diseases, but evidence from trials is lacking and inconsistent.

Aim

To determine whether Vitamin D supplementation in urban premenopausal women with vitamin D deficiency can improve cardiometabolic risks and health-related quality of life (HRQOL).

Design

A double-blind randomized controlled trial was conducted in Kuala Lumpur, Malaysia. A total of 192 vitamin D deficient (<50 nmol/l) premenopausal women were randomized to receive either vitamin D 50,000 IU or placebo once a week for 2 months and then monthly for 10 months. Primary outcomes were serum 25(OH)D, serum lipid profiles, blood pressure and HOMA-IR measured at baseline, 6 months and 12 months. HRQOL was assessed with SF-36 at baseline and 12 months.

Results

Ninety three and ninety-nine women were randomised into intervention and placebo groups respectively. After 12 months, there were significant differences in the serum 25(OH)D concentration (mean difference: 49.54; 95% CI: 43.94 to 55.14) nmol/l) and PTH levels (mean difference: −1.02; 95% CI: −1.67 to −0.38 pmol/l) in the intervention group compared to placebo group. There was significant difference between treatment group in both serum 25(OH)D and PTH. There was no effect of supplementation on HOMA-IR, serum lipid profiles and blood pressure (all p>0.05) between two groups. There was a small but significant improvement in HRQOL in the components of vitality (mean difference: 5.041; 95% CI: 0.709 to 9.374) and mental component score (mean difference: 2.951; 95% CI: 0.573 to 5.329) in the intervention group compared to placebo group.

Conclusion

Large and less frequent dosage vitamin D supplementation was safe and effective in the achievement of vitamin D sufficiency. However, there was no improvement in measured cardiometabolic risk factors in premenopausal women. Conversely vitamin D supplementation improves some components of HRQOL.

Trial Registration

Australian New Zealand Clinical Trial Registry ACTRN12612000452897     

KLOTHO allele status and the risk of early-onset occult coronary artery disease

We previously identified a functional variant of KLOTHO (termed "KL-VS"), which harbors two amino acid substitutions in complete linkage disequilibrium and is associated with reduced human longevity when in homozygosity. Klotho-deficient mice display extensive arteriosclerosis when fed a normal diet, suggesting a potent genetic predisposition. To determine whether klotho influences atherosclerotic risk in humans, we performed cross-sectional studies to assess the association between the KL-VS allele and occult coronary artery disease (CAD) in two independent samples of apparently healthy siblings of individuals with early-onset (age <60 years) CAD (SIBS-I [N=520] and SIBS-II [N=436]). Occult CAD was defined as the occurrence of a reversible perfusion defect during exercise thallium scintigraphy and/or as an abnormal result of an exercise electrocardiogram (SIBS-I, n=97; SIBS-II, n=56). In SIBS-I, the KL-VS allele conferred a relative odds of 1.90 (95% confidence interval 1.21-2.98) for occult CAD, after adjusting for familial intraclass correlations (P<.005). Logistic regression modeling, incorporating known CAD risk factors, demonstrated that the KL-VS allele is an independent risk factor (P<.019) and that the imposed risk of KL-VS allele status is influenced by modifiable risk factors. Hypertension (P<.022) and increasing high-density lipoprotein cholesterol (HDL-C) levels (P<.022) mask or reduce the risk conferred by the KL-VS allele, respectively, whereas current smoking (P<.004) increases the risk. Remarkably concordant effects of the KL-VS allele and modifying factors on the risk of occult CAD were seen in SIBS-II. These results demonstrate that the KL-VS allele is an independent risk factor for occult CAD in two independent high-risk samples. Modifiable risk factors, including hypertension, smoking status, and HDL-C level, appear to influence the risk imposed by this allele.     

Cooperative adhesion of ligand-receptor bonds

Cooperative (simultaneous) breakage of multiple adhesive bonds has been proposed as a mechanism for enhanced binding strength between adhesion molecules on apposing cell surfaces. In this report, we used the atomic force microscopy (AFM) to study how changes in binding affinity and separation rate of force-induced ligand-receptor dissociation affect binding cooperativity. The AFM force measurements were carried out using (strept)avidin-functionalized cantilever tips and biotinylated agarose beads under conditions where multiple (strept)avidin-biotin linkages were formed following surface contact. At slow surface separation of the AFM cantilever from the bead's surface, the (strept)avidin-biotin linkages appeared to rupture sequentially. Increasing the separation rate from 210 to 1950 nm/s led to a linear increase in the average rupture force. Moreover, force histograms revealed a quantized force distribution that shifted toward higher values with increasing separation rate. In measurements of streptavidin-iminobiotin adhesion, the force distribution also shifted toward higher values when the buffer was adjusted to a higher pH to raise the binding affinity. Together, these results demonstrate that the cooperativity of ligand-receptor bonds is significantly enhanced by increases in surface separation rate and/or binding affinity.     

Investigating the molecular basis of local adaptation to thermal stress: population differences in gene expression across the transcriptome of the copepod Tigriopus californicus

ABSTRACT: BACKGROUND: Geographic variation in the thermal environment impacts a broad range of biochemical and physiological processes and can be a major selective force leading to local population adaptation. In the intertidal copepod Tigriopus californicus, populations along the coast of California show differences in thermal tolerance that are consistent with adaptation, i.e., southern populations withstand thermal stresses that are lethal to northern populations. To understand the genetic basis of these physiological differences, we use an RNA-seq approach to compare genome-wide patterns of gene expression in two populations known to differ in thermal tolerance. RESULTS: Observed differences in gene expression between the southern (San Diego) and the northern (Santa Cruz) populations included both the number of affected loci as well as the identity of these loci. However, the most pronounced differences concerned the amplitude of upregulation of genes producing heat shock proteins (Hsps) and genes involved in ubiquitination and proteolysis. Among the hsp genes, orthologous pairs show markedly different thermal responses as the amplitude of hsp response was greatly elevated in the San Diego population, most notably in members of the hsp70 gene family. There was no evidence of accelerated evolution at the sequence level for hsp genes. Among other sets of genes, cuticle genes were up-regulated in SD but down-regulated in SC, and mitochondrial genes were down-regulated in both populations. CONCLUSIONS: Marked changes in gene expression were observed in response to acute sub-lethal thermal stress in the copepod T. californicus. Although some qualitative differences were observed between populations, the most pronounced differences involved the magnitude of induction of numerous hsp and ubiquitin genes. These differences in gene expression suggest that evolutionary divergence in the regulatory pathway(s) involved in acute temperature stress may offer at least a partial explanation of population differences in thermal tolerance observed in Tigriopus.     

Autoradiographic studies on the distribution of labeled maternal RNA in early mouse embryos

Maternal RNA of mouse eggs and embryos was labeled by exposure of growing ovarian oocytes to 3H-uridine in vivo 8 to 16 days before ovulation and fertilization. Labeled embryos from the 1-cell stage to the blastocyst stage were collected, fixed, and autoradiographs of plastic sections prepared. The observed grain density was similar in the pronuclei and in the cytoplasm of 1-cell embryos. Knowing the volumes of nucleus and cytoplasm, it was determined that 3% of the maternal RNA was found in the pronuclei. It is suggested that some of this nuclear RNA may be stable small nuclear RNAs (e.g. U1 RNA) retained from the germinal vesicle stage through meiotic maturation. During the 2-cell stage and beyond, maternal RNA is degraded and labeled precursor is reincorporated into nuclear RNA, making it difficult to accurately quantitate the amount of nuclear maternal RNA. It is known that about one third of the total maternal RNA is lost between the 8-cell and blastocyst stages. It was found that cytoplasmic grain densities in inner and outer cells of the morula and blastocyst were not significantly different. Thus, the loss of maternal RNA does not proceed more rapidly in the differentiating trophoblast than in the inner cell mass.     

The effects of dopaminergic antagonism by sulpiride on TRH and VIP-induced prolactin release in nonsuckled lactating rats

Prolactin (PRL) release was studied in female rats during midlactation using pharmacologic manipulations designed to mimic the hypothalamic effects of suckling. In the first experiment pituitary dopamine (DA) receptors were blocked by sulpiride (10 micrograms/rat i.v.). One hour later, thyrotropin-releasing hormone (TRH, 1.0 micrograms/rat i.v.) was given to induce PRL release. TRH released significantly more PRL following DA antagonism than when no DA antagonism was produced, suggesting that DA receptor blockade increased the sensitivity of the AP to TRH. In a second experiment, VIP (25 micrograms/rat) increased plasma prolactin 3-4 fold but this effect was not enhanced significantly by prior dopamine antagonism with sulpiride. We conclude that dopamine antagonism enhances the PRL releasing effect of TRH but not VIP in lactating rats.     

Resonance assignments for Oncostatin M, a 24-kDa α-helical protein

Summary Oncostatin M (OM) is a cytokine that shares a structural and functional relationship with interleukin-6, leukemia inhibitory factor, and granulocyte-colony stimulating factor, which regulate the proliferation and differentiation of a variety of cell types. A mutant version of human OM in which two N-linked glycosylation sites and an unpaired cysteine have been mutated to alanine (N76A/C81A/N193A) has been expressed and shown to be active. The triple mutant has been doubly isotope-labeled with ¹³C and ¹⁵N in order to utilize heteronuclear multidimensional NMR techniques for structure determination. Approximately 90% of the backbone resonances were assigned from a combination of triple-resonance data (HNCA, HNCO, CBCACONH, HBHACONH, HNHA and HCACO), intraresidue and sequential NOEs (3D ¹⁵N-NOESY-HMQC and ¹³C-HSQC-NOESY) and side-chain information obtained from the CCONH and HCCONH experiments. Preliminary analysis of the NOE pattern in the ¹⁵N-NOESY-HMQC spectrum and the ¹³C secondary chemical shifts predicts a secondary structure for OM consisting of four -helices with three intervening helical regions, consistent with the four-helix-bundle motif found for this cytokine family. As a 203-residue protein with a molecular weight of 24 kDa, Oncostatin M is the largest -helical protein yet assigned.To whom correspondence should be addressed.