Discussion of uncertainties and the impact of different neutron RBEs on all solid cancer radiation incidence risks obtained from the Japanese A-bomb survivor data.

The most recent publicly available data on all solid cancer incidence from the Life Span Study (LSS) of Japanese A-bomb survivors provides colon dose contributions weighted with a relative biological effectiveness (RBE) of 10 for neutrons, relative to gammas. However, there is evidence from several investigations that the neutron RBE for A-bomb survivors may be higher than 10. The change in the shape of the corresponding dose-response curves was evaluated by Hafner and co-workers in a previous study by applying sex-specific linear-quadratic dose models to previous LSS data for all solid cancer incidence that include separate neutron and gamma absorbed doses for several organs, in contrast to the most recent data. The resulting curvature change became significantly negative for males at an RBE of 140 for colon, 100 for liver, and 80 for organ averaged dose. For females, the corresponding RBE values were 110, 80, and 60 for colon, liver, and organ averaged doses. The present study compares three different methods to calculate the 95% confidence intervals in an analysis of the curvature with increasing RBE. Further, the impact of a higher neutron RBE on the work of the International Commission on Radiological Protection, and the importance of including uncertainties and performing sensitivity analysis of different parameters in radiation risk assessment are discussed.

Ovarian steroid hormones: effects on immune responses and Chlamydia trachomatis infections of the female genital tract.

Female sex hormones are known to regulate the adaptive and innate immune functions of the female reproductive tract. This review aims to update our current knowledge of the effects of the sex hormones estradiol and progesterone in the female reproductive tract on innate immunity, antigen presentation, specific immune responses, antibody secretion, genital tract infections caused by Chlamydia trachomatis, and vaccine-induced immunity.

Chlamydia trachomatis infection: host immune responses and potential vaccines.

Chlamydia trachomatis causes genital tract infections that affect men, women, and children on a global scale. This review focuses on innate and adaptive immune responses in the female reproductive tract (FRT) to genital tract infections with C. trachomatis. It covers C. trachomatis infections and highlights our current knowledge of genital tract infections, serovar distribution, infectious load, and clinical manifestations of these infections in women. The unique features of the immune system of the FRT will be discussed and will include a review of our current knowledge of innate and adaptive immunity to chlamydial infections at this mucosal site. The use of animal models to study the pathogenesis of, and immunity to, Chlamydia infection of the female genital tract will also be discussed and a review of recent immunization and challenge experiments in the murine model of chlamydial FRT infection will be presented.

Peptide immunization of guinea pigs against Chlamydia psittaci (GPIC agent) infection induces good vaginal secretion antibody response, in vitro neutralization and partial protection against live challenge.

Immunization of female guinea pigs with a chimeric peptide consisting of variable domain IV (VDIV) and a region known as GP8 from the major outer membrane protein of Chlamydophila caviae, formerly Chlamydia psittaci guinea pig inclusion conjunctivitis strain, was performed to assess whether humoral immune responses could be elicited in the reproductive tracts of immunized animals. The C. caviae strain is able to cause a sexually transmitted infection in the guinea pig that closely parallels C. trachomatis infections in humans. The best anti-VDIV antibody response in vaginal secretions was achieved by intraperitoneal priming with subsequent intravaginal boosting (P < 0.001). Dot-blot analyses of vaginal secretions confirmed that these anti-VDIV antibodies, produced against a linear peptide, were able to recognize and bind to whole conformational C. caviae elementary bodies. Following live intravaginal challenge with C. caviae, a significant reduction in the intensity (P = 0.01) and an apparent reduction in the duration of the infection was evident between the guinea pigs immunized with VDIV-GP8 and non-immunized controls.

Characteristics of fungal growth in soft contact lenses.

Six fungal species (Fusarium sp, Exophiala jeanselmei, Penicillium spp, Aspergillus niger, Paecilomyces spp, and Alternaria spp) were used to inoculate soft contact lenses. Four types of soft lenses were used: high-water (58%) and low-water (38%) content lenses and lenses that were unworn or worn for 1 day. The fungi displayed a range of macroscopic and microscopic features that allowed differentiation of species. There was no statistically significant effect of lens water content on growth rate and only Penicillium spp showed significantly higher growth for worn versus unworn lenses. A number of the fungi showed secretions, thought to be enzymes, which potentially aid in the process of lens penetration.

Analysis of promoter sequences from Lactobacillus and Lactococcus and their activity in several Lactobacillus species.

Promoter-active fragments were isolated from the genome of the probiotic organism Lactobacillus rhamnosus strain GG using the promoter-probe vector pNZ272. These promoter elements, together with a promoter fragment isolated from the vaginal strain Lactobacillus fermentum BR11 and two previously defined promoters (Lactococcus lactis and Lactobacillus acidophilus ATCC 4356 slpA), were introduced into three strains of Lactobacillus. Primer-extension analysis was used to map the transcriptional start site for each promoter. All promoter fragments tested were functional in each of the three lactobacilli and a purine residue was used to initiate transcription in most cases. The promoter elements encompassed a 52- to 1,140-fold range in promoter activity depending on the host strain. Lactobacillus promoters were further examined by surveying previously mapped sequences for conserved base positions. The Lactobacillus hexamer regions (-35: TTgaca and -10: TAtAAT) closely resembled those of Escherichia coli and Bacillus subtilis, with the highest degree of agreement at the -10 hexamer. The TG dinucleotide upstream of the -10 hexamer was conserved in 26% of Lactobacillus promoters studied, but conservation rates differed between species. The region upstream of the -35 hexamer of Lactobacillus promoters showed conservation with the bacterial UP element.

The bspA locus of Lactobacillus fermentum BR11 encodes an L-cystine uptake system.

BspA is a basic surface-exposed protein from Lactobacillus fermentum BR11. Sequence comparisons have shown that it is a member of family III of the solute binding proteins. It is 89% identical to the collagen binding protein, Cnb, from Lactobacillus reuteri. Compared with the database of Escherichia coli proteins, BspA is most similar to the L-cystine binding protein FliY. To investigate the function of BspA, mutants depleted for BspA were generated by homologous recombination with a temperature-sensitive plasmid. These mutants were significantly impaired in their abilities to take up L-cystine. Uptake rates of L-glutamine, L-histidine, and L-lysine, which are substrates for other binding proteins with similarity to BspA, were unaffected. Evidence was obtained that BspA is necessary for maximal resistance to oxidative stress. Specifically, inactivation of BspA causes defective growth in the presence of oxygen and sensitivity to paraquat. Measurements of sulfhydryl levels showed that incubation of L. fermentum BR11 with L-cystine resulted in increased levels of sulfhydryl groups both inside and outside the cell; however, this was not the case with a BspA mutant. The role of BspA as an extracellular matrix protein adhesin was also addressed. L. fermentum BR11 does not bind to immobilized type I collagen or laminin above background levels but does bind immobilized fibronectin. Inactivation of BspA did not significantly affect fibronectin binding; therefore, we have not found evidence to support the notion that BspA is an extracellular matrix protein binding adhesin. As BspA is most probably not a lipoprotein, this report provides evidence that gram-positive bacterial solute binding proteins do not necessarily have to be anchored to the cytoplasmic membrane to function in solute uptake.

Protein A as a fusion partner for the expression of heterologous proteins in Lactobacillus.

An expression system based on the Staphylococcus aureus protein A gene (spa) was developed to allow the production and export of proteins in Lactobacillus. Plasmid shuttle vectors were constructed that carried the eZZ gene, a synthetic gene based on the Protein A gene (spa) but lacking the carboxy-terminal membrane-anchoring region. A gene fusion was created between the eZZ gene and the VD4 region of a chlamydial major outer-membrane protein gene. Expression studies demonstrated the recognition of the spa regulatory signals by several Lactobacillus, with the recombinant protein being expressed (from 0.1 microgram of EZZVD4 fusion protein per ml in L. plantarum up to 10 micrograms of EZZ protein per ml in L. fermentum) and exported (levels up to 20% in L. fermentum) in several Lactobacillus strains.

Identification and characterization of a basic cell surface-located protein from Lactobacillus fermentum BR11.

Extraction of Lactobacillus fermentum BR11 cells with 5 M LiCl yielded a preparation containing a single predominant polypeptide with an apparent molecular mass of 32 kDa. A clone encoding an immunoreactive 32-kDa polypeptide was isolated from a pUC18 library of L. fermentum BR11 DNA by screening with an antiserum raised against whole cells of L. fermentum BR11. Sequence determination of the insert in the clone revealed a complete 795-bp open reading frame (ORF) that defines a 28,625-Da polypeptide (BspA). N-terminal sequencing of the LiCl-extracted polypeptide from L. fermentum BR11 confirmed that it is the same as the cloned BspA. BspA was found to have a sequence similar to those of family III of the bacterial solute-binding proteins. The sequences of two ORFs upstream of bspA are consistent with bspA being located in an operon encoding an ATP-binding cassette-type uptake system. Unusually, BspA contains no lipoprotein cleavage and attachment motif (LXXC), despite its origin in a gram-positive bacterium. Biotin labelling and trypsin digestion of whole cells indicated that this polypeptide is exposed on the cell surface. The isoelectric point as predicted from the putative mature sequence is 10.59. It was consequently hypothesized that the positively charged BspA is anchored by electrostatic interaction with acidic groups on the cell surface. It was shown that BspA could be selectively removed from the surface by extraction with an acidic buffer, thus supporting this hypothesis.

The guinea pig estrous cycle: correlation of vaginal impedance measurements with vaginal cytologic findings.

Immunologic responses elicited after vaginal immunization of laboratory mammals are affected by the stage of the animal's estrous cycle at which antigen is delivered. The study reported here documents vaginal impedance as an improved means of determining accurately precise stages of the estrous cycle of guinea pigs. Impedance changes were correlated with cytologic changes observed in vaginal smears taken from the animals. The start of the impedance peak corresponded with proestrus, the rising side of the peak with estrus, and the apex of the peak with metestrus; diestrus was seen approximately 3 days after the peak apex. These results contrast with those of previous studies. Various dosage regimens of estradiol (1 to 1,000 micrograms/animal over 1 to 6 days) were used in guinea pigs in an attempt to invoke an extended (> 6 h) estrogen-induced mucosa. Parenteral administration of 1,000 micrograms of estradiol to guinea pigs daily for 6 days induced a 2- to 3-day estrus stage in these animals.

Genetic modification of a vaginal strain of Lactobacillus fermentum and its maintenance within the reproductive tract after intravaginal administration.

Many micro-organisms cause important diseases of the female genital tract. Because systematic vaccination does not usually provide a good immune response at mucosal sites, commensal lactobacilli from the female genital tract were developed as vehicles to deliver continued doses of foreign antigen directly to the genital mucosal surface with the aim of stimulating strong local mucosal immune responses. Lactobacilli were shown to be common inhabitants of the genital tract of the animal model studied, the guinea-pig. One species, Lactobacillus fermentum, was found in all guinea-pigs studied and was chosen for genetic manipulation. Improved methods of electroporation were developed to enable the routine transformation of L. fermentum BR11 strain with the broad host range plasmid pNZ17. This recombinantly modified Lactobacillus strain was shown to possess good segregational stability over 120 generations in the absence of antibiotic selection. When this recombinant L. fermentum strain was administered to the vaginal tract of three guinea-pigs it persisted for only 5 days. Despite the relatively short period of persistence in these initial experiments, this novel vaccine approach could provide an effective means of stimulating mucosal immunity in the female genital tract.

Precise excision of Tn10 in Salmonella typhimurium: effects of mutations in the polA, dam, mutH and mutB genes and of methionine or ethionine in the plating medium.

Precise excision of Tn10 occurs at significantly elevated frequencies in cultures of the polA7 mutant strain of Salmonella typhimurium, is further increased in polA7 dam-1 and polA7 mutB strains and decreased in a polA7 mutH background. The numbers of precise excision events occurring in polA7 strains are also significantly increased when methionine (20 micrograms/ml or less) is present in the medium but decreased when ethionine (again, 20 micrograms/ml or less) is present. When both amino present, the outcome is about a 2-fold increase in precise excision events. The involvement of mismatch repair and methylation patterns in precise excision events is discussed.

An intercultural assessment of the type, intensity and number of crisis precipitating factors in three cultures: United States, Brazil and Taiwan.

The precipitating factors of crisis have cultural interpretations that make diagnostic criteria and intervention methods ethnologically different. The crisis precipitating factors of individuals seeking intervention in the Republic of China (Taiwan), Brazil and the United States (U.S.) were investigated toward the end of isolating correlates and discrepancies of ethnic-related precipitants of crisis. The primary objective of the study was to influence crisis intervention in the profession of nursing from the almost universally utilized Western Model, to one that takes cultural uniqueness into account. Stressors and stressor intensities which lead to help-seeking behavior of clients in selected crisis intervention facilities in the three countries were identified. A 60 question instrument ranked client responses according to Axis 4 of the Diagnostic and Statistical Manual-III of the American Psychiatric Association (APA, 1980; 1986). Each item also reflected one of four Human Response Patterns of the North American Nursing Diagnostic Association (NANDA) taxonomy, which was utilized as a clustering device in data analysis. Somatization versus psychologization of crisis precipitating factors was also measured through the NANDA categories. A convenience sample of 30 subjects were queried in each country by nurse interviewers. Data analysis through ANOVA showed cultural uniqueness and mutuality.

Fluctuation tests are more sensitive than plate tests in detection of chemicals which cause enhanced excision of transposon Tn10 in Salmonella typhimurium.

Precise excision of transposon Tn10, as judged by reversion of Salmonella typhimurium strain LT2 trp1014::Tn10 to Trp+, was not detectably enhanced following exposure to 9-aminoacridine, 5-azacytidine or mitomycin C in conventional treat-and-plate assays. By contrast, 7/13 chemicals, including 5-azacytidine and mitomycin C, were found to be capable of enhancing precise excision of Tn10 when tested in modified fluctuation assays. Despite earlier reports, precise excision is one activity of transposons which is not therefore refractory to enhancement by chemical mutagens.

Shared values: impact on staff nurse job satisfaction and perceived productivity.

A nationwide study on the impact of shared values on staff nurse job satisfaction and perceived productivity was done in 24 hospitals under different auspices, some of which were also Magnet Hospitals. Data were obtained from a 25% random sample of the staff nurse population (N = 2,336), 58% of the head nurse group, 65% of the clinical experts, and 66% of the top management. Staff nurses and clinical experts had more value congruence than did staff nurses and head nurses. A significant inverse correlation was found between value congruence and nurse job satisfaction and quality care. Explanations of the finding center on recent role changes for both staff nurses and head nurses, power differential, and evolving clarity of the staff nurse role. A serendipitious finding was that staff nurses reported fewer factors as important to their job satisfaction and perceived environment conducive to quality patient care than did other members of the nursing department. However, factors important to staff nurses were very important.

Modulation of mutagenesis involving precise excision of transposon Tn10.

Precise excision of transposon Tn10 results in reversion of the Trp- phenotype to Trp+ in a trp-1014::Tn10 strain of Salmonella typhimurium, and also occurs at a markedly higher frequency in a strain carrying the temperature-sensitive polA7 allele. The frequency with which precise excision events occurs can be modified by the plating medium, results indicating that the great majority of mutants which arise on broth-supplemented or tryptophan-supplemented minimal media actually arise on the selective plating medium. Trp+ revertants (1000) arising from excision of Tn10 were purified by re-streaking for single colonies; none were found to retain the Tn10 encoded resistance to tetracycline. Yields of Trp+ revertants of the polA7 strain were consistently higher when glycerol rather than glucose was used as sole carbon source in the selective medium. Clean excision of Tn10 can also be increased by ultraviolet irradiation in (R) plasmid-free strains, and is further increased in strains carrying an N-group plasmid (R205, R46 or pKM101). Ultraviolet-induced precise excision of Tn10 also occurs at a much enhanced frequency in a strain with a deletion through the uvrB gene; in this case, however, the addition of plasmid pKM101 leads to a decrease in yields of ultraviolet-induced precise excision events.

Antimutagenic effects of chemicals on mutagenesis resulting from excision of a transposon in Salmonella typhimurium.

We have found that a temperature-sensitive mutation in the polA gene of Salmonella typhimurium strain LT2 causes precise excision of transposon Tn10 to occur at significantly increased frequencies in cells incubated at the restrictive temperature. In our experiments, precise excision from a site in the tryptophan operon was measured by determining the frequency of reversion of the auxotrophic trp1014::Tn10 polA7 strain to prototrophy on defined medium containing a trace amount of broth. Because the yields of revertants at 37 degrees C were of the order of 200 colonies per plate, it was possible to measure the effects of chemical inhibitors on the processes involved in precise excision. We now report that all of the DNA-repair inhibitors we have studied (caffeine, ethionine, acriflavine, procaine and cinnamaldehyde) are effective inhibitors of precise excision of Tn10, and can therefore be defined as antimutagens.

Expectancy versus absorption in the prediction of hypnotic responding.

The Absorption Scale, a measure of imaginative involvement, was administered to 64 subjects in the context of a hypnosis experiment and to an additional 64 subjects in a context unrelated to hypnosis. Expectancies of responding to hypnotic suggestions were assessed both before trance induction and after trance induction but before administration of hypnotic test suggestions. Hypnotic depth was assessed on the Long Stanford Scale (LSS) before the administration of test suggestions, and on the Inventory of Hypnotic Depth (IHD) after the hypnosis session. Absorption was correlated with hypnotic responsivity and expectancy, but only when assesed in the hypnotic context. Completing the Absorption Scale in a hypnotic context appeared to affect hypnotic responsiveness by altering subjects' expectancies. Only postinduction expectancies were uniquely predictive of response to hypnotic test suggestions, and all variables except the LSS were predictive of IHD scores. Results of path analysis supported the hypothesis that trance inductions alter expectancies for responding to hypnotic suggestions and that these altered expectancies determine subsequent hypnotic behavior.

Revascularizacao cerebral em obstrucoes de arteria carotida interna e seus ramos. / Cerebral revascularization in obstruction of the internal carotid arteries and their branches

Os autores tentaram demonstrar que lesoes de arteria carotida denominadas inacessiveis, ja nao sao assim consideradas, visto que pela microcirurgia sao corrigidas. A vascularizacao cerebral e feita pela anastomose da arteria temporal superficial com ramos corticais temporais da arteria cerebral