Expression of a lipocalin in prokaryote and eukaryote cells: quantification and structural characterization of recombinant bovine beta-lactoglobulin.

In this paper we quantify and characterize the expression of recombinant beta-lactoglobulin (rBLG) in prokaryote and eukaryote cells. In Escherichia coli we used the pET26 vector, which permits the secretion of rBLG in periplasm. We studied the expression of rBLG in COS-7 cells and in vivo in mouse tibialis muscle. The expression of rBLG was measured by two immunoassays specific, respectively, for BLG in its native and denatured conformation. We observed that rBLG was essentially expressed in a denatured form in E. coli even in the periplasm, whereas rBLG in eukaryote cells was found in its native conformation.     

Q fever urban cases in Romania

Q fever urban sporadic cases in Romania in the 1981-87 period are reviewed as concerns their incidence, seasonality and epidemiological data. Urban cases represented 76.8% as against 23.2% rural cases from the 134 Q fever sporadic cases detected in this period. Cases were distributed throughout all months with peaks during April (18.4% of cases) and June (19.4%). Infections were not related to contact with livestock or domestic birds or with raw milk drinking. Cases could not be identified as Q fever occupational ones. 36.7% of patients were working in nonalimentary industry and only 12.6% were involved in meat industry, veterinary or human medical practices. New studies concerning unusual sources of urban infection such as dogs, cats or urban street pigeons are emphasized.     

De novo t(2;13)(p24.3;q14.2) and retinoblastoma

Summary The two probes H3-8 and H2-42, known to be located in 13q14, were mapped by in situ hybridization to either side of the 13 breakpoint of an apparently balanced de novo t(2;13)(p24.3;q14.2) detected in a patient with retinoblastoma as the only phenotypic manifestation.     

Standardized method for evaluation of hand disinfection by surgical scrub formulations

A standardized protocol for the evaluation of hand disinfection by surgical scrub formulations was applied to volunteers in a multicenter trial. Povidone iodine (PVI), chlorhexidine (CHX), and a nonmedicated soap (NMS) were tested. The scrubbing procedure involved three daily hand washings for five consecutive days; surviving bacteria were counted daily after being collected in a suitable neutralizing solution. Immediate efficacy (IE), cumulative efficacy (CE), and remanent effect (RE) were calculated by reference to the control hand. Statistical analyses of IE, CE, and RE showed significant differences among the three scrub formulations. IEs of PVI and CHX were equivalent and different from IE of NMS; CE and RE of CHX were higher than those of PVI and NMS. On the basis of the statistical analysis, the population size required for further studies aimed at detecting significant differences between surgical scrub formulations could be estimated.     

Inhibition ofCandida albicans andStaphylococcus aureus by phenolic compounds from the terrestrial cyanobacteriumNostoc muscorum

Phenolic compounds were determined in methanolic extract from the algal mass of aNostoc muscorum culture. Bioassays with two human pathogens,Candida albicans andStaphylococcus aureus indicated that algal phenolic compounds evoked significant growth inhibition for both species (89.1% and 88.2%, respectively). It is suggested that this strong inhibitory effect is of potential medicinal value.     

Activation of Ca2+-dependent processes during heat shock: role in cell thermoresistance

In this brief review, it is proposed that some Ca2+-dependent processes are induced upon subjecting cells to hyperthermic temperature, and play an essential role in the final cell responses. The triggering signal does not involve external Ca2+. Instead, it is most likely to be generated by a redistribution of Ca2+ between the internal pools. A role for heat-induced Ca2+-dependent processes is supported by findings that Ca2+-active agents such as chelators, ionophores, or anticalmodulin drugs modify the cytotoxic action of hyperthermia and that some heat shock proteins are calmodulin-binding proteins. Furthermore, within minutes at hyperthermic temperature, changes are observed in the pattern of phosphoproteins suggesting that heat shock activates kinase or phosphatase activities, processes which are often mediated by Ca2+. Suggestive evidence that these phosphorylation events are determinants of cell thermoresistance is provided by the fact that one of these proteins whose phosphorylation changes rapidly upon hyperthermia is a heat shock protein (HSP28) and that the content of HSP28 is elevated not only in thermotolerant cells but also in a family of thermoresistant variants isolated after mutagenesis of Chinese hamster cells.     

New chromosome 21 DNA markers isolated by pulsed field gel electrophoresis from an ETS2-containing Down syndrome chromosomal region

To generate new chromosome 21 markers in a region that is critical for the pathogenesis of Down syndrome (D21S55-MX1), we used pulsed field gel electrophoresis (PFGE) to isolate a 600-kb NruI DNA fragment from the WA17 hybrid cell line, which has retained chromosome 21 as the only human material. This fragment, which contains the oncogene ETS2, was used to construct a partial genomic library. Among the 14 unique sequences that were isolated, 3 were polymorphic markers and contained sequences that are conserved in mammals. Five of these markers mapped on the ETS2-containing NruI fragment and allowed us to define an 800-kb high-resolution PFGE map.     

Spruce budworm growth,development and food utilization on young and old balsam fir trees

Laboratory rearing of spruce budworm, Choristoneura fumiferana, in conjunction with field rearing, gravimetric analyses, a transfer experiment, and foliage chemical analyses at six dates during the period of budworm feeding activity indicated that the age of balsam fir, Abies balsamea, trees (70-year-old mature trees or 30-year-old juvenile trees) affected tree suitability for the spruce budworm via the chemical profile of the foliage. Insects reared on old trees had greater survival and pupal weight, shorter development times, and caused more defoliation than those reared on young trees. Young trees were more suitable for the development of young larvae (instars 2–5), while old trees were more suitable for the development of older, sixth-instar larvae. These results were confirmed by the laboratory transfer experiment. Young larvae fed foliage from young trees had higher relative growth rates (RGR), digestibility (AD), and efficiency of conversion of ingested foliage (ECI) than those fed foliage from old trees. These differences appeared to be related to the high N:tannins ratio, and the high contents of P present in young trees during the development of the young larvae. Old larvae fed foliage from old trees had higher relative growth rates, relative consumption rates (RCR), and digestibility of the foliage than those fed foliage from young trees. The high digestibility of the foliage of old trees was compensated for by a lower efficiency of conversion of digested food (ECD), which in turn resulted in no significant effect of tree age on the efficiency of conversion of ingested foliage by old larvae. The low relative consumption rate of old larvae fed foliage from young trees appeared to be related to the low N:tannins ratio, and the high contents of bornyl acetate, terpinolene, and °-3-carene present in young trees during the budworm sixth instar. Variations in these compounds in relation to tree age may serve as mechanisms of balsam fir resistance to spruce budworm by reducing the feeding rate of sixth instar larvae.     

Retinoic acid modulates the pattern of cell division in embryos ofLymnaea stagnalis (Mollusca)

All-trans retinoic acid is well known as a modulator of positional specification in vertebrate development. A similar mechanism may operate in molluscan development. Molluscan development is characterized by an invariant pattern of cell divisions, which allows the study of individual cells in the developing organism. Low concentrations of exogenous retinoic acid applied during gastrulation affect the cell division pattern in the early larval stage of the molluscLymnaea stagnalis. A few cells from the apical plate, a larval organ consisting of seven large cleavage-arrested cells, were induced by retinoic acid to resume cell division. They typically formed an area of proliferating small cells that resembles the adjacent areas of precursor cells of adult ectoderm. The identification of individual cells that are transformed by retinoic acid may provide new insights into the mechanisms underlying positional specification within the embryo.     

Distribution of deletions and seven point mutations on CYP21B genes in three clinical forms of steroid 21-hydroxylase deficiency

To characterize mutations in the CYP21B gene that are responsible for congenital adrenal hyperplasia (CAH), DNA samples from 91 French patients have been studied by allelic-specific oligonucleotide hybridization and Southern blot analysis. Seven sites mostly found in the CYP21A pseudogene and deletions of the functional CYP21B gene have been screened. Gene conversions involving small DNA segments accounted for 57% of the tested mutations and probably cause 74% of the mutations responsible for the disease. Complete deletion of the CYP21B gene accounted for 18% of the CAH mutations in the whole sample and for 21% in the classical form of the disease. Three mutations were found associated with specific clinical forms of the disease: a G-C substitution in the seventh exon was associated with the late-onset form of the disease, and both an 8-bp depletion in the third exon and complete deletion of CYP21B were associated with the salt-wasting form.