Soil micromycete diversity in the hypersaline Dead Sea coastal area,Israel

In the present study, a soil microfungal community was examined over a one-year period (1999–2000) at the western shore of the Dead Sea. A total of 78 species from 40 genera were isolated. The most prominent features of mycobiota of the territory studied were: (i) the prevailing number of melanin-containing micromycetes (46 species, 65.5 % of the total isolate number); (ii) a large share of teleomorphic Ascomyceta (26 species, 18.5 % of isolates); (iii) combination of true soil and plant surface inhabiting species; (iv) spatial and temporal variation of the mycobiota composition; (v) very low fungal density (nearly 500-fold lower than in the Judean Desert soil). These features are formed under the extremely stressful xeric and oligotrophic conditions in which the Dead Sea coastal micromycete community exists. Nine species (Alternaria alternata, A. raphani, Aspergillus niger, Aureobasidium pullulans, Chaetomium globosum, Ch. murorum, Cladosporium cladosporioides, Penicillium aurantiogriseum, and Stachybotrys chartarum) were considered a characteristic micromycete complex for the Dead Sea coastal habitat based on the spatial and temporal occurrence of these species. Many of the micromycetes isolated, including almost all the species listed above, are known to be distributed worldwide occurring in different soil types. This confirms the conclusion of many mycologists working in areas with saline and arid soils that there is no halo-and thermophilous mycobiota characteristic for those soils.     

Bioethics: power and injustice: IAB presidential address

A major focus within the modern bioethics debate has been on reshaping power relationships within the doctor-patient relationship. Empowerment of the vulnerable has been achieved through an emphasis on human rights and respect for individual dignity. However, power imbalances remain pervasive within healthcare. To a considerable extent this relates to insufficient attention to social injustice. Such power imbalances together with the development of new forms of power, for example through new genetic biotechnology, raise the spectre of increasing social injustice. Attention will be drawn to the need to extend the bioethics debate to include ethical considerations regarding public health. Changes in political philosophy will also be required to reshape international power relations and improve population health.     

Regulation of tubulin polypeptides and microtubule function: Rki1p interacts with the β-tubulin binding protein Rbl2p

Genetic analysis of microtubule functions in the yeast Saccharomyces cerevisiae suggests that cells manage the levels and activities of the tubulin polypeptides. These reactions may be involved in protein folding, formation of the heterodimer, and maintenance of the appropriate balance between α- and β-tubulin. One protein involved in these functions is Rbl2p, which forms a complex with β-tubulin. Here we describe the identification of a novel yeast gene, RKI1, that interacts genetically with RBL2. Deletion of rki1 causes conditional defects in microtubule assembly and cell growth. Rki1p can be isolated in a complex containing Rbl2p. The results support the existence of cellular mechanisms for regulating microtubule function through the tubulin polypeptides. Received: 8 August 1998 / Accepted: 13 September 1998     

Mycobacterium tuberculosis ClpP1 and ClpP2 Function Together in Protein Degradation and Are Required for Viability in vitro and During Infection

In most bacteria, Clp protease is a conserved, non-essential serine protease that regulates the response to various stresses. Mycobacteria, including Mycobacterium tuberculosis (Mtb) and Mycobacterium smegmatis, unlike most well studied prokaryotes, encode two ClpP homologs, ClpP1 and ClpP2, in a single operon. Here we demonstrate that the two proteins form a mixed complex (ClpP1P2) in mycobacteria. Using two different approaches, promoter replacement, and a novel system of inducible protein degradation, leading to inducible expression of clpP1 and clpP2, we demonstrate that both genes are essential for growth and that a marked depletion of either one results in rapid bacterial death. ClpP1P2 protease appears important in degrading missense and prematurely terminated peptides, as partial depletion of ClpP2 reduced growth specifically in the presence of antibiotics that increase errors in translation. We further show that the ClpP1P2 protease is required for the degradation of proteins tagged with the SsrA motif, a tag co-translationally added to incomplete protein products. Using active site mutants of ClpP1 and ClpP2, we show that the activity of each subunit is required for proteolysis, for normal growth of Mtb in vitro and during infection of mice. These observations suggest that the Clp protease plays an unusual and essential role in Mtb and may serve as an ideal target for antimycobacterial therapy.     

The effect of addition of equine chorionic gonadotropin to a progesterone-based estrous synchronization protocol in buffaloes (Bubalus bubalis) under tropical conditions

Poor estrus expression and anestrus decrease the reproductive efficiency of buffaloes. The objective of this study was to determine whether the addition of equine chorionic gonadotropin (eCG) to an estrous synchronization protocol and timed insemination could improve ovulation and pregnancy rates of anestrous buffalo cows under tropical conditions. The study population comprised 65 lactating Murrah buffalo cows which were assigned to CIDR (n = 33) or CIDR + eCG (n = 32) treatment groups. Cows in the CIDR group were fitted for 8 d with a controlled intravaginal drug release (CIDR) device containing 1.38 g progesterone, received GnRH (10 μg i.m.) on D 0, PGF_2α (750 μg i.m.) on D 7, and GnRH (10 μg i.m.) on D 9; whereas cows in the CIDR + eCG group received the same treatment plus eCG (500 IU, i.m.) at the time of PGF_2α treatment. All cows were inseminated 16-20 h after the second GnRH treatment. Blood samples were obtained 10 d before the start of synchronization treatment (Day -10) and at the onset of treatment (Day 0). Cows with plasma progesterone concentrations <1 ng/mL recorded in both samples (Low-Low levels of P4) were classified as non-cyclic cows. Similarly, when either one or both of the sample pair contained concentrations of serum progesterone ≥1 ng/mL (High-High, Low-High, or High-Low levels of P4), the buffaloes were classified as cyclic cows. Ovulation rate, defined as the number of buffaloes with at least one corpus luteum 10 days after insemination, was significantly higher (P = 0.018) in the CIDR + eCG (84.4%) cows than in the CIDR cows (57.6%). Pregnancy rate was numerically lower in CIDR (27.3%) than CIDR + eCG (40.6%) cows, though differences were not significant (P = 0.25). Pregnancy rates for CIDR + eCG cows were similar to that of cows inseminated after natural estrus (40.9%; 29/71). In the non-cyclic animals, higher ovulation rates (P = 0.026) were recorded for the CIDR + eCG (81%) than for the CIDR cows (47.4%). Our results indicate that the addition of eCG to a progesterone-based estrous synchronization regimen substantially improves the ovulation rate in non-cyclic buffaloes. When this treatment is followed by timed AI, pregnancy rates achieved in anestrous buffaloes, whether cyclic and non-cyclic, may approach the rates observed in cows inseminated at natural estrus.     

CC chemokine receptor-3 (CCR3) antagonists: improving the selectivity of DPC168 by reducing central ring lipophilicity

DPC168, a benzylpiperidine-substituted aryl urea CCR3 antagonist evaluated in clinical trials, was a relatively potent inhibitor of the 2D6 isoform of cytochrome P-450 (CYP2D6). Replacement of the cyclohexyl central ring with saturated heterocycles provided potent CCR3 antagonists with improved selectivity against CYP2D6. The favorable preclinical profile of DPC168 was maintained in an acetylpiperidine derivative, BMS-570520.     

Genetic mapping of <Emphasis Type="Italic">Stb19</Emphasis>, a new resistance gene to <Emphasis Type="Italic">Zymoseptoria tritici</Emphasis> in wheat

Key message

A new and dominant R gene Stb19 is identified from a soft wheat cultivar ‘Lorikeet’ and was mapped on the distal region of chromosome 1DS. Two tightly linked KASP markers were also discovered and validated for molecular-assisted breeding programs.

Abstract

A new R gene, designated as Stb19, provides resistance to Zymoseptoria tritici in wheat. This new dominant gene resides on the short arm of chromosome 1D, exhibiting complete resistance to three Z. tritici isolates, WAI332, WAI251, and WAI161, at the seedling stage. A genetic linkage map, based on an F_2:3 population of ‘Lorikeet’ and ‘Summit,’ found the Stb19 gene at a 9.3 cM region on 1DS, closely linked with two Kompetitive Allele-Specific PCR markers, snp_4909967 and snp_1218021. Further, the two markers were tested and validated in another F_2:3 population and 266 different wheat accessions, which gave over 95% accuracy of resistance/susceptibility prediction. Combined with the physical location of the identified SNPs and the previous evidence of gene order on chromosome 1DS (centromere–Sr45–Sr33–Lr21–telomere), Stb19 is proposed to be located between Sr33 and Lr21. Thus, the newly discovered Stb19 along with the KASP markers represents an increase in genetic resources available for wheat breeding resistance to Z. tritici.

     

Using dynamic pupillometry as a simple screening tool to detect autonomic neuropathy in patients with diabetes: a pilot study

Background  

Autonomic neuropathy is a common and serious complication of diabetes. Early detection is essential to enable appropriate interventional therapy and management. Dynamic pupillometry has been proposed as a simpler and more sensitive tool to detect subclinical autonomic dysfunction. The aim of this study was to investigate pupil responsiveness in diabetic subjects with and without cardiovascular autonomic neuropathy (CAN) using dynamic pupillometry in two sets of experiments.