An IGF-I promoter polymorphism modifies the relationships between birth weight and risk factors for cardiovascular disease and diabetes at age 36

BACKGROUND: Biochemical testing for pheochromocytoma by measurement of fractionated plasma metanephrines is limited by false positive rates of up to 18% in people without known genetic predisposition to the disease. The plasma normetanephrine fraction is responsible for most false positives and plasma normetanephrine increases with age. The objective of this study was to determine if we could improve the specificity of fractionated plasma measurements, by statistically adjusting for age. METHODS: An age-adjusted metanephrine score was derived using logistic regression from 343 subjects (including 33 people with pheochromocytoma) who underwent fractionated plasma metanephrine measurements as part of investigations for suspected pheochromocytoma at Mayo Clinic Rochester (derivation set). The performance of the age-adjusted score was validated in a dataset of 158 subjects (including patients 23 with pheochromocytoma) that underwent measurements of fractionated plasma metanephrines at Mayo Clinic the following year (validation dataset). None of the participants in the validation dataset had known genetic predisposition to pheochromocytoma. RESULTS: The sensitivity of the age-adjusted metanephrine score was the same as that of traditional interpretation of fractionated plasma metanephrine measurements, yielding a sensitivity of 100% (23/23, 95% confidence interval [CI] 85.7%, 100%). However, the false positive rate with traditional interpretation of fractionated plasma metanephrine measurements was 16.3% (22/135, 95% CI, 11.0%, 23.4%) and that of the age-adjusted score was significantly lower at 3.0% (4/135, 95% CI, 1.2%, 7.4%) (p < 0.001 using McNemar's test). CONCLUSION: An adjustment for age in the interpretation of results of fractionated plasma metanephrines may significantly decrease false positives when using this test to exclude sporadic pheochromocytoma. Such improvements in false positive rate may result in savings of expenditures related to confirmatory imaging.     

Opiine parasitoids (Hymenoptera: Braconidae) of tropical fruit flies (Diptera: Tephritidae) of the Australian and South Pacific region

Opiine wasps are parasitoids of dacine fruit flies, the primary horticultural pests of Australia and the South Pacific. A taxonomic synopsis and distribution and host records (44% of which are new) for each of the 15 species of dacine-parasitizing opiine braconids found in the South Pacific is presented. Species dealt with are Diachasmimorpha hageni (Fullaway), D. kraussii (Fullaway), D. longicaudata (Ashmead), D. tryoni (Cameron), Fopius arisanus (Sonan), F. deeralensis (Fullaway), F. ferrari Carmichael & Wharton sp. n., F. illusorius (Fischer) comb. n., F. schlingeri Wharton, Opius froggatti Fullaway, Psyttalia fijiensis (Fullaway), P. muesebecki (Fischer), P. novaguineensis (Szépligeti) and Utetes perkinsi (Fullaway). A potentially undescribed species, which may be a colour morph of F. vandenboschi (Fullaway), is diagnosed but not formally described. Fopius vandenboschi sensu stricto, Diachasmimorpha fullawayi Silvestri, Psyttalia concolor Szépligeti and P. incisi Silvestri have been liberated into the region but are not considered to have established: a brief diagnosis of each is included. Biosteres illusorius Fischer is formally transferred to the genus Fopius. A single opiine specimen reared from a species of Bactrocera (Bulladacus) appears to be Utetes albimanus (Szépligeti), but damage to this specimen and to the holotype (the only previously known specimen) means that this species remains unconfirmed as a fruit fly parasite: a diagnosis of U. cf. albimanus is provided. Psyttalia novaguineensis could not be adequately separated from P. fijiensis using previously published characterizations and further work to resolve this complex is recommended. A key is provided to all taxa.     

Isolation and characterization of microsatellite markers from Pacific white shrimp (Litopenaeus vannamei)

We report the development of 11 polymorphic microsatellite loci in pacific white shrimp (Litopenaeus vannamei) using an unenriched genomic library. The number of the alleles ranged from two to 18 and observed hererozygosity ranged from 0.0286 to 0.9429, indicating that these markers will be useful for population studies and mapping in pacific white shrimp. Seven loci were detected deviated from Hardy–Weinberg, caused by deficiency of heterozygote, suggesting population genetic structure across the sampled population. No evidence for linkage disequilibrium was found.     

Neuraminidase Receptor Binding Variants of Human Influenza A(H3N2) Viruses Resulting from Substitution of Aspartic Acid 151 in the Catalytic Site: a Role in Virus Attachment?

Changes in the receptor binding characteristics of human H3N2 viruses have been evident from changes in the agglutination of different red blood cells (RBCs) and the reduced growth capacity of recently isolated viruses, particularly in embryonated eggs. An additional peculiarity of viruses circulating in 2005 to 2009 has been the poor inhibition of hemagglutination by postinfection ferret antisera for many viruses isolated in MDCK cells, including homologous reference viruses. This was shown not to be due to an antigenic change in hemagglutinin (HA) but was shown to be the result of a mutation in aspartic acid 151 of neuraminidase (NA) to glycine, asparagine, or alanine, which caused an oseltamivir-sensitive agglutination of RBCs. The D151G substitution was shown to cause a change in the specificity of NA such that it acquired the capacity to bind receptors, which were refractory to enzymatic cleavage, without altering its ability to remove receptors for HA. Thus, the inhibition of NA-dependent agglutination by the inclusion of oseltamivir carboxylate in the assay was effective in restoring the anti-HA specificity of the hemagglutination inhibition (HI) assay for monitoring antigenic changes in HA. Since the NA-dependent binding activity did not affect virus neutralization, and virus populations in clinical specimens possessed, at most, low levels of the “151 mutant,” the biological significance of this feature of NA in, for example, immune evasion is unclear. It is apparent, however, that an important role of aspartic acid 151 in the activity of NA may be to restrict the specificity of the NA interaction and its receptor-destroying activity to complement that of HA receptor binding.A characteristic feature of human influenza viruses is their frequent antigenic change to evade host immunity and cause recurrent annual epidemics of disease. As a consequence, available vaccines do not confer long-term immunity, and their composition is regularly reviewed by the WHO Global Influenza Surveillance Network (GISN) and updated to reflect changes in the antigenic characteristics of circulating viruses (2, 43).The two surface glycoproteins of the virus, hemagglutinin (HA) and neuraminidase (NA), perform clearly defined complementary roles in virus infection. Virus HA is responsible for the attachment of virus to sialic acid-containing glycoconjugates on susceptible cells, and it is antibody to HA, which neutralizes virus infectivity, that is of prime importance in immunity (37). Antibody to NA also contributes to the suppression of disease (3, 16). NA is responsible for destroying receptors for HA by removing the terminal sialic acid moieties from, and thereby inactivating, potentially inhibitory molecules such as mucins in the respiratory tract and from receptors on the surface of virus-infected cells to promote the release of progeny virus, thereby aiding virus transmission (1, 21, 26, 34). Thus, since NA may also cleave receptors from target cells, the maintenance of a balance between the receptor binding and receptor-destroying properties of HA and NA, respectively, is important in optimizing their respective functions in virus replication and maintaining epidemic potential (29, 41).Virus neutralization is principally the result of the inhibition of the attachment of HA to its receptor (9), and the hemagglutination inhibition (HI) assay is a simple and generally robust surrogate assay for monitoring antigenic relationships among viruses and is the principal basis for changes in vaccine composition recommended by the WHO (2, 43). Many mutations resulting in antibody escape cause amino acid substitutions close to the HA receptor binding site, which may influence receptor binding affinity and/or specificity as well as antigenicity (7, 37, 44). In turn, changes in receptor avidity and binding characteristics of HA, possibly associated with antigenic changes, may influence the effectiveness of the antibody inhibition of the agglutination of red blood cells (RBCs) in the standard HI assay and thereby complicate the interpretation of antigenic relationships (8, 12, 44).Antigenic drift among H3N2 viruses has been more muted in recent years. Whereas the antigenic drift of viruses between 1992 and 1997 required four changes in the H3N2 vaccine component, there was little progressive antigenic change in the HAs of A/Sydney/5/97(H3N2)-like viruses during the subsequent 5 years prior to the emergence of the A/Fujian/411/2002(H3N2)-like viruses (20) or among the more recently isolated A/Wisconsin/67/2005(H3N2)-like viruses between 2005 and 2009 (see below). Changes in the receptor binding characteristics of HA have been apparent from changes in the spectrum of RBCs agglutinated by the viruses, e.g., the loss of agglutination of chicken RBCs by H3N2 viruses circulating in the early 1990s (28, 31) and more recently by the poorer growth characteristics following the emergence of A/Fujian/411/2002-like viruses, particularly in embryonated eggs (22), which has “hampered” the selection of suitable vaccine candidates. Amino acid substitutions in residues 190 and 226 in the HA receptor binding site were implicated in the changes in hemagglutination (28, 31), while changes that increased the receptor binding of HA or decreased the enzyme activity of NA were shown to increase the growth of virus in eggs (22). Studies of differences among H3N2 viruses in their relative abilities to bind to and elute from RBCs of different species led Gulati et al. (11) to conclude that the more recently isolated Fujian/411/2002-like viruses bound different forms of sialic acid, which were not cleaved by the virus enzyme. However, studies using glycan arrays failed to identify any differences in receptor binding specificities, or in the amino acid sequences, of HAs that correlated with differences in hemagglutination (18).Another peculiar feature of many MDCK cell isolates of A/Wisconsin/67/2005-like viruses, isolated between 2005 and 2009, has been the poor inhibition of agglutination of turkey (and guinea pig) RBCs by reference postinfection ferret antisera, with the consequent difficulty in interpreting antigenic relationships from HI data (as reported herein). Here we describe the results of a series of experiments that demonstrate that this phenomenon is not due to changes in antigenicity or simply to changes in HA receptor binding but is the result of the selection in MDCK cells of changes in NA that promote NA-dependent, NA inhibitor-sensitive hemagglutination, which is refractory to inhibition by anti-HA antibody. The replacement of aspartic acid 151 of NA by glycine, which did not affect significantly the activity of the enzyme or its ability to remove receptors for HA, was shown to alter the specificity of NA, resulting in the attachment of virus via its NA to sialic acid receptors refractory to catalytic cleavage.     

Relationships of Exodontiella, a non-alysiine, exodont member of the family Braconidae (Insecta, Hymenoptera)

The placement of Exodontiella Wharton is re-examined in light of the discovery of four additional individuals. Genomic DNA was extracted from one of the individuals, the D2 expansion segment of the 28S rRNA gene was sequenced, and the sequence compared to selected taxa within the Braconidae. Based on the molecular data and the morphological study, Exodontiella is formally transferred from the Opiinae to the Gnamptodontinae. The genus and its included species are redescribed.     

Molecular diagnostics of economically important Ceratitis fruit fly species (Diptera: Tephritidae) in Africa using PCR and RFLP analyses

The predominantly Afrotropical fruit fly genus Ceratitis contains many species of agricultural importance. Consequently, quarantine of Ceratitis species is a major concern for governmental regulatory agencies. Although diagnostic keys exist for identification of all described Ceratitis species, these tools are based on adult characters. Flies intercepted at ports of entry are usually immatures, and Ceratitis species cannot be diagnosed based on larval morphology. To facilitate identification of Ceratitis pests at ports of entry, this study explores the utility of DNA-based diagnostic tools for a select group of Ceratitis species and related tephritids, some of which infest agriculturally important crops in Africa. The application of the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method to analyse three mitochondrial genes (12S ribosomal RNA, 16S ribosomal RNA, and NADH-dehydrogenase subunit 6) is sufficient to diagnose 25 species and two species clusters. PCR analysis of the internal transcribed spacer region 1 (ITS-1) is able to distinguish three of the five species left unresolved by mitochondrial DNA analysis.     

Acceptance and suitability of different host stages of Ceratitis capitata (Wiedemann) (Diptera: Tephritidae) and seven other tephritid fruit fly species to Tetrastichus giffardii Silvestri (Hymenoptera: Eulophidae)

Tetrastichus giffardii Silvestri is a gregarious eulophid endoparasitoid of several tephritid fruit fly species. Host stage suitability was studied using nine age groups of Ceratitis capitata (Wiedemann) (Diptera: Tephritidae), namely, eggs less than 24 h and between 24 and 48 h old, and 1- to 7-day-old larvae. Life table studies for T. giffardii using C. capitata as host were done at 26 ± 5 °C and 55–60% RH. Egg load in relation to age of the female parasitoid was also assessed as was the effect of host deprivation on adult longevity. Host acceptance and suitability were examined with respect to eight species of tephritids. Potential hosts so tested were five Ceratitis species, the Medfly, C. capitata, the mango fruit fly, Ceratitis cosyra (Walker), the Natal fruit fly, Ceratitis rosa Karsch, Ceratitis fasciventris (Bezzi), and Ceratitis anonae Graham; two Bactrocera species, the melon fruit fly, Bactrocera cucurbitae (Coquillett) and the newly invasive Bactrocera invadens Drew, Tsuruta, and White; and one Dacus species, the lesser pumpkin fly, Dacus ciliatus Loew. No parasitoids were obtained from eggs while all larval stages were suitable though at varying degrees. Parasitism and number of progeny was related to host age in a curvilinear manner with maxima at 4- to 5-day-old larvae. By contrast, development time decreased with age of host larvae while sex ratio was not affected. The intrinsic rate of increase was 0.17 ± 0.01; gross and net reproductive rates were 64.9 ± 4.3 and 44.9 ± 3.8, respectively. Non-ovipositing females lived significantly longer than ovipositing ones. The females accepted all host species tested, but only C. capitata, D. ciliatus and, to a much lesser extent, C. cosyra were suitable. In the remaining host species, most eggs were encapsulated. In C. capitata and D. ciliatus, percent parasitism was similar, but number of progeny was lower and the sex ratio, as the proportion of females, was higher when the parasitoid was reared on D. ciliatus. Progeny per puparium were also similar for the two hosts. In the light of these results it can be concluded that T. giffardii has a narrow host range, but it attacks and successfully develops in larvae representing a wide range of ages.     

Apical-basal polarity, Wnt signaling and vertebrate organogenesis

Wnt proteins elicit several distinct signal transduction cascades and regulate multiple cellular processes that have proven essential for embryonic development in all metazoans investigated. During embryonic development, epithelial cells become polarized along two axes: apical/basal and within the plane of the tissue. Growing evidence suggests that polarization along each axis is essential for normal embryonic development and that this polarization is regulated in part by the different branches of the Wnt pathway. Here, we review the role of A/B cell polarity in vertebrate organogenesis with a focus on the involvement of canonical Wnt signaling in this process.     

Some Analyses and Recommendations on Diet Formulation for Conservation Breeding of the Galapagos Rice Rat of Isla Santiago, Nesoryzomys swarthi

Nesoryzomys swarthi, the most endangered of the three surviving, endemic Galapagos “rice rats,” was only discovered in the early 20th Century and was considered extinct until its rediscovery in 1997 at a north‐central coastal location on Isla Santiago. Potential threats to the entire genus include invasive rodent species, feral cats, new diseases, and climate change. These threats have been the basis for conservation breeding recommendations (as yet unmet) by several observers during the last several decades. This paper considers likely dietary requirements of N. swarthi in light of recent studies on the ecology of this species plus new data on the nutrient composition of Opuntia galapageia (a “resource refuge” for this species) and circulating vitamin values of animals sampled on Isla Santiago. It is concluded that, despite some unusually high mineral values for O. galapageia, a diet for N. swarthi under human care should be the same as it is for most other rodents, noting some caution in regard to possible needs for mineral and/or protein adjustment. Zoo Biol. 31:498–505, 2012. © 2012 Wiley Periodicals, Inc.     

河西走廊春季不同盐碱土壤中微生物数量、酶活性与理化因子的关系

【目的】揭示盐碱土壤微生物量与土壤因子间的关系。【方法】选择河西走廊不同盐碱程度的11个样点在春季进行采样,研究了土壤的微生物数量、酶活和理化性质,并对其进行方差分析、简单相关分析、逐步回归分析和主成分分析。【结果】河西地区原生盐碱地、次生盐碱地与农田土在土壤理化性质和土壤微生物数量等方面均有差异;河西地区土壤较贫瘠,土壤微生物数量较低,且分布有规律性,即原生盐碱土<次生盐碱土<农田土;放线菌、真菌、碱性磷酸酶、脲酶和有效磷5个因子是引起土壤微生物数量、酶活性与理化因子之间相关性的主要因素。【结论】结果证实河西地区盐碱土壤中磷的循环很大程度上影响着土壤微生物数量。