Suitability of Bemisia tabaci (Hemiptera: Aleyrodidae) instars for the parasitization by Encarsia bimaculata and Eretmocerus sp. nr. furuhashii (Hymenoptera: Aphelinidae) on glabrous and hirsute host plants

The host instar preferences of Encarsia bimaculata and Eretmocerus sp. nr. furuhashii parasitizing Bemisia tabaci and their development on four host plants, collard, eggplant, cucumber and tomato, were studied in the laboratory. Both of the parasitoids accepted all nymphal stages of B. tabaci, but E. bimaculata preferred third and fourth instars while Er. sp. nr. furuhashii preferred second and third instars under both choice and no choice conditions. Regardless of host stage parasitized, adults of parasitoids emerged only from fourth instars. When given the simultaneous choice of all instars, E. bimaculata reduced parasitization of first and second instars (3.73 and 4.76%, respectively) while increasing parasitization of third and fourth instars (5.44 and 6.93%, respectively), in contrast Er. sp. nr. furuhashii increased its parasitization of second and third instar nymphs (1.27 and 3.17%, respectively) and decreased that of first and fourth instars (7.0 and 3.06%, respectively). Host plants did not significantly influence instar preference for either parasitoid. Developmental periods of both the parasitoids from egg to adult emergence were longest when first instars were parasitized and shortest when fourth instars were selected. Parasitoid developmental time was generally shorter on glabrous plants than on hirsute plants.     

Metabolism of DHEA in postmenopausal women following percutaneous administration

The marked decline in serum dehydroepiandrosterone (DHEA) with age is believed to play a role in health problems associated with aging, these health issues being potentially preventable or reversible by the exogenous administration of DHEA. In the present study, liquid chromatography/mass spectrometry/mass spectrometry (LC/MS/MS) and gas chromatrography/mass spectrometry (GC/MS) were used to measure the serum levels of DHEA and 11 of its metabolites in seventy-five 60-65-year-old Caucasian women who received 3g of 0.1%, 0.3%, 1.0% or 2.0% DHEA cream or placebo applied twice daily on the face, upper chest, arms and legs. The serum levels of DHEA increased 574% over control at the 2.0% DHEA dose while the sum of the androgen metabolites androsterone glucuronide (ADT-G), 3alpha-androstenediol-3G (3alpha-diol-3G) and 3alpha-diol-17G increased by only 231%. On the other hand, serum testosterone and dihydrosterone were increased by 192% and 275%, respectively, above basal levels compared to 139% and 158% for estrone and estradiol. Such data show that the transformation of exogenous DHEA in postmenopausal women is preferentially into androgens rather than into estrogens. On the other hand, the present data indicate that serum DHEA measurements following DHEA supplementation in postmenopausal women are an overestimate of the formation of active androgens and estrogens and suggest a decreased efficiency of transformation of DHEA into androgens and estrogens with aging.     

Synthesis of PHAs from waster under various C:N ratios

Polyhydroxyalkanoates (PHAs) production was carried out under various C:N ratios. A ratio of 100 resulted best polymer yield. C-source was an important factor in synthesis. For example, as the ratio of valeric acid (C5) to butyric acid (C4) in N-free medium was increased, the mole fraction of HV in the copolymer increased. When soy waste was used as a C-source a copolymer, a high HV mole fraction (HB:HV, 75:25) was produced while when malt waste was used, a much lower HV mole fraction (HB:HV, 90:10) was generated. It was concluded that activated sludge bacteria could be induced to produce PHAs using food wastes as C-sources and this could be the basis for production of biodegradable plastics.     

HYPERSENSITIVE TO RED AND BLUE 1 and its C-terminal regulatory function control FLOWERING LOCUS T expression

The red and far-red light-absorbing phytochromes and UV-A/blue light-absorbing cryptochromes regulate seedling de-etiolation and flowering responses. The signaling steps that mediate the photoreceptor regulation on key flowering genes remain largely unknown. We report that a previously identified photomorphogenic mutant, hypersensitive to red and blue 1 (hrb1), flowered late and showed attenuated expression of FLOWERING LOCUS T (FT) over both long days and short days. Transgenic plants that overexpress the full-length HRB1, or its C-terminal half, flowered early and accumulated more FT messages under short-day conditions. The transgenic plants also displayed hyposensitive de-etiolation phenotypes, and the expression of these phenotypes requires the action of PIF4. The double mutant of hrb1/cry2 showed a flowering phenotype and an FT expression pattern similar to hrb1 under long-day conditions, suggesting that HRB1 may function downstream of cry2 under long-day conditions. In contrast, hrb1/phyB-9 showed a flowering phenotype and an FT expression pattern similar to phyB-9 over both long days and short days, indicating a modulatory role of HRB1 in the flowering pathway mediated by phyB. Overexpression of HRB1 did not affect the expression of the central clock oscillators, TOC1 and CCA1. HRB1 therefore represents a signaling step that regulates FT expression downstream of red and blue light perception.     

Discovery of orally bioavailable and novel urea agonists of the high affinity niacin receptor GPR109A

A urea class of high affinity niacin receptor agonists was discovered. Compound 1a displayed good PK, better in vivo efficacy in reducing FFA in mouse than niacin, and no vasodilation in a mouse model. Compound 1q demonstrated equal affinity to GPR109A as niacin.     

Novel scaffold for cathepsin K inhibitors

Pyrrolopyrimidine, a novel scaffold, allows to adjust interactions within the S3 subsite of cathepsin K. The core intermediate 10 facilitated the P3 optimization and identified highly potent and selective cathepsin K inhibitors 11-20.     

Développementin vitro de la lignée germinale foetale mâle chez le rat, la souris et l’homme

The key role of the foetal germ cell line in the reproductive capacity of the adult has been known for a long time. More recently, the observed increase in male reproductive disorders such as the decline of sperm count and quality and the increased incidence of testicular cancer has been postulated to be due to alterations of foetal and neonatal testicular development in response to increasing environmental pollution. However, few tools are available to study foetal and neonatal germ cell line development and the effects of physiological or toxic substances on this process. The authors have developed an organ culture system in which foetal or neonatal testis is grown on a filter floating on a synthetic medium free of serum, hormones or biological factors. This study, using rats and mice, first compared the long-term morphological and functional development of Sertoli and germ cells in thisin vivo system. In rats, these cells developed normally over a period of two weeksin vitro. Fewer cells were produced thanin vivo, but a similar level of differentiated function was observed. Germ cells, which are difficult to maintainin vitro, resumed mitosis after a quiescent period, at the same time asin vivo. Similar results were obtained with mouse fetuses, but this model was less efficient. This culture model can be used to study post-natal development of the germ cell lineage in testes derived from foetuses on the last day of foetal life and invalidated for P63, that do not survive after birth. This gene was found to be involved in the regulation of germ apoptosis which resumes after birth in the mouse. Lastly, this model applied to the human species (from 6 to 12 weeks of gestation) showed that testicular architecture and germ cells can be maintained for 4 days with better efficiency at younger stages than at older stages. p]In conclusion, testicular architecture and intercellular communications are sufficiently preserved to sustain gametogenesisin vitro with no added factors. This method is potentially useful to study the effects of various factors, particularly xenobiotics.     

Detection of the 35delG/GJB2 and del(GJB6-D13S1830) mutations in Venezuelan patients with autosomal recessive nonsyndromic hearing loss

Severe to profound hearing impairment affects 1 of every 1000 newborn children each year. Inheritance accounts for 60% of these cases, of which 70% are nonsyndromic. The most common cause of autosomal recessive nonsyndromic hearing loss (ARNSHL) is mutation in GJB2, a gene on chromosome 13, which encodes a gap junction protein named Connexin 26. Mutations in GJB2 are responsible for 40% of genetic childhood deafness. The most common mutation, 35delG, predominates in many ethnic groups. Some families with linkage to the DFNB1 locus have none or only one mutated allele in GJB2, however, some subjects can exhibit a large deletion in another connexin gene, GJB6, resulting in a monogenic or digenic pattern of inheritance in this complex DFNB1 locus that contains both genes (GJB2 and GJB6). The aim of the study was to determine (1) the frequency for the 35delG (27.5%), del(GJB6-D13S1830) (2.5%) and del(GJB6-D13S1854) (0.0%) mutations in a cohort of 40 Venezuelan patients with ARNSHL and (2) the carrier frequency 35delG (4%), del(GJB6-D13S1830) (0%) and del(GJB6-D13S1854) (0%) in the Venezuelan population with no familial history of hearing impairment. One patient (2.5%) was detected as double heterozygote for the deletion del(GJB6-D13S1830) and 35delG mutation. This result has direct clinical implications because we include the molecular detection of the deletion del(GJB6-D13S1830) during the evaluation of the diagnosis of deafness in the Venezuelan population.     

Molecular characteristics and expression analysis of calreticulin in Chinese shrimp Fenneropenaeus chinensis

Calreticulin (CRT), as an endoplasmic reticulum luminal resident protein, plays important roles in Ca(2+) homeostasis and molecular chaperoning. CRT on the surface of the cell can modulate cell adhesion, phagocytosis and integrin-dependent Ca(2+) signaling. The full length cDNA of calreticulin (FcCRT) was cloned from Chinese shrimp Fenneropenaeus chinensis. It consists of 1672 bp with an open reading frame of 1221 bp, encoding 406 amino acids. This is the first reported cDNA sequence of calreticulin in Crustacea. The deduced amino acid sequence of FcCRT showed high identity with those of Bombyx mori (88%), Drosophila melanogaster (83%), Mus musculus (82%) and Homo sapiens (82%). Highest expression of FcCRT was detected in ovary by Northern blot and in situ hybridization. Different mRNA levels of FcCRT were detected at various molting stages. Expression of FcCRT was induced significantly after 3 h of heat shock treatment, reached the maximum at 4 h and dropped after that. Differential expression profiles of FcCRT were observed in hepatopancreas and haemocytes when shrimp were challenged by white spot syndrome virus (WSSV). From the above results, we inferred that FcCRT might play important roles in Ca(2+) homeostasis, chaperoning and immune function in shrimp.     

Functional expression of recombinant human stefin A in mammalian and bacterial cells

Recombinant human cysteine protease inhibitor, stefin A, was expressed in both Escherichia coli and BS-C-1 monkey kidney cells utilizing pET and recombinant vaccinia virus systems, respectively. The expressed protein was purified and analyzed by SDS-PAGE and Western blot analysis utilizing a polyclonal antibody against rat cystatin alpha. In both cases the purified protein appeared as a single band corresponding to the molecular weight of stefin A ( approximately 10kDa). Viability of the expressed stefin A was determined by the inhibition of the plant cysteine protease, papain. Recombinant human stefin A expressed in both E. coli and BS-C-1 cells, was shown to almost completely inhibit papain. The expression of a fully functional recombinant human stefin A in the bacterial system provides a highly efficient tool for the production of large quantities of the protein. This can be an important tool in kinetic studies as well as in production of antibodies for other analytical studies (immunoblot, immunohistochemical studies, etc.). Expression in the mammalian cells, on the other hand, can provide a significant research tool to study the functional roles of stefin A in mammalian systems such as regulation of cysteine proteases.