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11.
Glauber P Arêas R?de BB Schuab Felipe PG Neves Rosana R Barros 《Memórias do Instituto Oswaldo Cruz》2014,109(7):935-939
Streptococcus pyogenes is responsible for a variety of infectious
diseases and immunological complications. In this study, 91 isolates of S.
pyogenes recovered from oropharynx secretions were submitted to
antimicrobial susceptibility testing, emm typing and pulsed-field
gel electrophoresis (PFGE) analysis. All isolates were susceptible to ceftriaxone,
levofloxacin, penicillin G and vancomycin. Resistance to erythromycin and clindamycin
was 15.4%, which is higher than previous reports from this area, while 20.9% of the
isolates were not susceptible to tetracycline. The macrolide resistance phenotypes
were cMLSB (10) and iMLSB (4). The ermB gene was predominant,
followed by the ermA gene. Thirty-two emm types and
subtypes were found, but five (emm1, emm4,
emm12, emm22, emm81) were detected in
48% of the isolates. Three new emm subtypes were identified
(emm1.74, emm58.14, emm76.7).
There was a strong association between emm type and PFGE clustering.
A variety of PFGE profiles as well as emm types were found among
tetracycline and erythromycin-resistant isolates, demonstrating that antimicrobial
resistant strains do not result from the expansion of one or a few clones. This study
provides epidemiological data that contribute to the development of suitable
strategies for the prevention and treatment of such infections in a poorly studied
area. 相似文献
12.
Kosala GAD Weerakoon Senanayake AM Kularatne Deepthika H Edussuriya Sarachchandra KA Kodikara Laxman PG Gunatilake Vasanti G Pinto Ashoka B Seneviratne Sunethra Gunasena 《BMC research notes》2011,4(1):268
Background
In 2009, an outbreak of dengue caused high fatality in Sri Lanka. We conducted 5 autopsies of clinically suspected myocarditis cases at the General Hospital, Peradeniya to describe the histopathology of the heart and other organs.Methods
The diagnosis of dengue was confirmed with specific IgM and IgG ELISA, HAI and RT-PCR techniques. The histology was done in tissue sections stained with hematoxylin and eosin.Results
Of the 319 cases of dengue fever, 166(52%) had severe infection. Of them, 149 patients (90%) had secondary dengue infection and in 5 patients, DEN-1 was identified as the causative serotype. The clinical diagnosis of myocarditis was considered in 45(27%) patients. The autopsies were done in 5 patients who succumbed to shock (3 females and 2 males) aged 13- 31 years. All had pleural effusions, ascites, bleeding patches in tissue planes and histological evidence of myocarditis. The main histological findings of the heart were interstitial oedema with inflammatory cell infiltration and necrosis of myocardial fibers. One patient had pericarditis. The concurrent pulmonary abnormalities were septal congestion, pulmonary haemorrhage and diffuse alveolar damage; one case showed massive necrosis of liver.Conclusions
The histology supports occurrence of myocarditis in dengue infection.13.
James Arthos Claudia Cicala Tavis D Steenbeke Tae-Wook Chun Charles Dela Cruz Douglas B Hanback Prateeti Khazanie Daniel Nam Peter Schuck Sara M Selig Donald Van Ryk Margery A Chaikin Anthony S Fauci 《The Journal of biological chemistry》2002,277(13):11456-11464
Drug toxicities associated with HAART lend urgency to the development of new anti-HIV therapies. Inhibition of viral replication at the entry stage of the viral life cycle is an attractive strategy because it prevents de novo infection. Soluble CD4 (sCD4), the first drug in this class, failed to suppress viral replication in vivo. At least three factors contributed to this failure: sCD4 demonstrated poor neutralizing activity against most primary isolates of HIV in vitro; it demonstrated an intrinsic capacity to enhance viral replication at low concentrations; and it exhibited a relatively short half-life in vivo. Many anti-gp120 monoclonal antibodies, including neutralizing monoclonal antibodies also enhance viral replication at suboptimal concentrations. Advances in our understanding of the events leading up to viral entry suggest strategies by which this activity can be diminished. We hypothesized that by constructing a sCD4-based molecule that is large, binds multiple gp120s simultaneously, and is highly avid toward gp120, we could remove its capacity to enhance viral entry. Here we describe the construction of a polymeric CD4-IgG1 fusion protein. The hydrodynamic radius of this molecule is approximately 12 nm. It can bind at least 10 gp120 subunits with binding kinetics that suggest a highly avid interaction toward virion-associated envelope. This protein does not enhance viral replication at suboptimal concentrations. These observations may aid in the design of new therapeutics and vaccines. 相似文献
14.
Degeneration of the intervertebral disc 总被引:3,自引:0,他引:3
The intervertebral disc is a cartilaginous structure that resembles articular cartilage in its biochemistry, but morphologically
it is clearly different. It shows degenerative and ageing changes earlier than does any other connective tissue in the body.
It is believed to be important clinically because there is an association of disc degeneration with back pain. Current treatments
are predominantly conservative or, less commonly, surgical; in many cases there is no clear diagnosis and therapy is considered
inadequate. New developments, such as genetic and biological approaches, may allow better diagnosis and treatments in the
future. 相似文献
15.
Adam R Meir Jeremy CT Fairbank Deborah A Jones Donal S McNally Jill PG Urban 《Scoliosis》2007,2(1):1-16
Background
Loads acting on scoliotic spines are thought to be asymmetric and involved in progression of the scoliotic deformity; abnormal loading patterns lead to changes in bone and disc cell activity and hence to vertebral body and disc wedging. At present however there are no direct measurements of intradiscal stresses or pressures in scoliotic spines. The aim of this study was to obtain quantitative measurements of the intradiscal stress environment in scoliotic intervertebral discs and to determine if loads acting across the scoliotic spine are asymmetric. We performed in vivo measurements of stresses across the intervertebral disc in patients with scoliosis, both parallel (termed horizontal) and perpendicular (termed vertical) to the end plate, using a side mounted pressure transducer (stress profilometry)Methods
Stress profilometry was used to measure horizontal and vertical stresses at 5 mm intervals across 25 intervertebral discs of 7 scoliotic patients during anterior reconstructive surgery. A state of hydrostatic pressure was defined by identical horizontal and vertical stresses for at least two consecutive readings. Results were compared with similar stress profiles measured during surgery across 10 discs of 4 spines with no lateral curvature and with data from the literature.Results
Profiles across scoliotic discs were very different from those of normal, young, healthy discs of equivalent age previously presented in the literature. Hydrostatic pressure regions were only seen in 14/25 discs, extended only over a short distance. Non-scoliotic discs of equivalent age would be expected to show large centrally placed hydrostatic nuclear regions in all discs. Mean pressures were significantly greater (0.25 MPa) than those measured in other anaesthetised patients (<0.07 MPa). A stress peak was seen in the concave annulus in 13/25 discs. Stresses in the concave annulus were greater than in the convex annulus indicating asymmetric loading in these anaesthetised, recumbent patients.Conclusion
Intradiscal pressures and stresses in scoliotic discs are abnormal, asymmetrical and high in magnitude even in the absence of significant applied muscle loading. The origin of these abnormal stresses is unclear. 相似文献16.
Sampling statistics were determined for larvae, pupae and adults of the chrysomelid Rhyparida nitida associated with sugarcane in Australia and for symptoms of their damage. Iwao's patchiness regression was inappropriate for modelling the mean–variance relationships of the insect counts. Taylor's power law was used to model these data and relationships were developed for counts of small, medium and large larvae, all larvae combined, pupae and adults. The mean–variance relationships of counts of live shoots and shoots killed by larvae of R. nitida were modelled using Iwao's patchiness regression; Taylor's power law was not appropriate to either data set. Relationships to determine sample sizes for fixed levels of precision and fixed-precision-level stop lines for sequential sampling of the different stages and live and dead shoots were also developed. Neither the ln(x + 1) transformation nor the Healy and Taylor transformation consistently standardised the mean–variance relationships of insect counts and the appropriate transformation should be selected on a case-by-case basis. Counts of both live and dead shoots were adequately transformed by the Iwao and Kuno transformation. 相似文献
17.
Bruno Gomes Carla A Sousa Maria T Novo Ferdinando B Freitas Ricardo Alves Ana R Côrte-Real Patrícia Salgueiro Martin J Donnelly António PG Almeida João Pinto 《BMC evolutionary biology》2009,9(1):262-15
Background
Culex pipiens L. is the most widespread mosquito vector in temperate regions. This species consists of two forms, denoted molestus and pipiens, that exhibit important behavioural and physiological differences. The evolutionary relationships and taxonomic status of these forms remain unclear. In northern European latitudes molestus and pipiens populations occupy different habitats (underground vs. aboveground), a separation that most likely promotes genetic isolation between forms. However, the same does not hold in southern Europe where both forms occur aboveground in sympatry. In these southern habitats, the extent of hybridisation and its impact on the extent of genetic divergence between forms under sympatric conditions has not been clarified. For this purpose, we have used phenotypic and genetic data to characterise Cx. pipiens collected aboveground in Portugal. Our aims were to determine levels of genetic differentiation and the degree of hybridisation between forms occurring in sympatry, and to relate these with both evolutionary and epidemiological tenets of this biological group. 相似文献18.
Lee TK Allison RR O'Brien KF Khazanie PG Johnke RM Brown R Bloch RM Tate ML Dobbs LJ Kragel PJ 《Mutation research》2004,557(1):75-84
To assess the effect of Chinese ginseng in modifying the radiation-induced micronuclei (MN) yield in human G(o) peripheral blood lymphocytes (PBL), we conducted the cytokinesis-blocked (CB) MN assay in blood samples obtained from healthy volunteers (n=4). Before (137)Cs ex vivo irradiation, mononuclear cell cultures from each sample were incubated 24 h with different concentrations (0-2000 microg ml(-1)) of crude water extract of ginseng dry root. We found that (1) at 0 Gy and without the presence of ginseng, MN yield (mean+/-S.E.M.) was 11.7+/-2.7 per 1000 binucleated (BN) cells. Different concentrations of ginseng crude water extract did not affect the MN yields and the proliferative activity of PBL; (2) after 1 and 2 Gy exposure, radiation alone sharply increased the MN yields, respectively, to 119.6+/-17.4 and 340.5+/-20.9 per 1000 BN cells. However, treatment with ginseng for 24 h before radiation exposure, resulted in a significant linear decline of MN yields as ginseng concentration increases. Compared to radiation alone, the extent to which ginseng water extract reduced the MN yields induced by 1 Gy exposure was 46.0% at 1500 microg ml(-1) and 61.5% at 2000 microg ml(-1), and with 2 Gy exposure, it was 38.6% at 1500 microg ml(-1) and 46.5% at 2000 microg ml(-1); (3) MN data suggested a tendency for overdispersion relative to the Poisson model; and (4) over the different levels of ginseng concentrations, the trend in micronucleated BN index was as similar as that of the MN yields. These results indicated that (1) ginseng crude water extract exerts no apparent cytogentic effect on human PBL at concentrations up to 2000 microg ml(-1) as evaluated by the CBMN assay; and (2) the protection of ginseng water extract against (137)Cs-induced MN in human PBL is concentration-dependence. Therefore, our findings indicated that ginseng may have therapeutic value as a possible radioprotector for normal tissue during radiotherapy of cancer patients. 相似文献
19.
20.
Choline acetyltransferase activity of spinal cord cell cultures increased by co-culture with muscle and by muscle-conditioned medium 总被引:9,自引:3,他引:6
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Activity of the enzyme choline acetyltransferase (CAT), which mediates the synthesis of the neurotransmitter, acetylcholine, was increased up to 20- fold in spinal cord (SC) cells grown in culture with muscle cells for 2 wk. This increase was directly related to the duration of co-culture as well as to the cell density of both the SC and muscle involved and was not affected by the presence of the acetylcholine receptor blocking agent, α-bungarotoxin. Glutamic acid decarboxylase (GAD) activity was often markedly decreased in SC-muscle cultures while the activities of acetylcholinesterase and several other enzymes were little changed. Increased CAT activity was also observed when SC cultures were maintained in medium which had been conditioned by muscle cells or by undifferentiated cells from embryonic muscle. Muscle-conditioned medium (CM) did not affect the activities of SC cell GAD or acetylcholinesterase. Dilution or concentration of the CM directly affected its ability to increase SC CAT activity , as did the duration and timing of exposure of the SC cells to the CM. The medium could be conditioned by muscle cells in the presence or absence of serum, and remained effective after dialysis or heating to 58 degrees C. Membrane filtration data were consistent with the conclusion that the active material(s) in CM had a molecular weight in excess of 50,000 daltons. We conclude that large molecular weight material that is released by muscle cells is capable of producing a specific increase in CAT activity of SC cells. 相似文献