Natural Variant of Collagen-Like Protein A in Serotype M3 Group A Streptococcus Increases Adherence and Decreases Invasive Potential

Group A Streptococcus (GAS) predominantly exists as a colonizer of the human oropharynx that occasionally breaches epithelial barriers to cause invasive diseases. Despite the frequency of GAS carriage, few investigations into the contributory molecular mechanisms exist. To this end, we identified a naturally occurring polymorphism in the gene encoding the streptococcal collagen-like protein A (SclA) in GAS carrier strains. All previously sequenced invasive serotype M3 GAS possess a premature stop codon in the sclA gene truncating the protein. The carrier polymorphism is predicted to restore SclA function and was infrequently identified by targeted DNA sequencing in invasive strains of the same serotype. We demonstrate that a strain with the carrier sclA allele expressed a full-length SclA protein, while the strain with the invasive sclA allele expressed a truncated variant. An isoallelic mutant invasive strain with the carrier sclA allele exhibited decreased virulence in a mouse model of invasive disease and decreased multiplication in human blood. Further, the isoallelic invasive strain with the carrier sclA allele persisted in the mouse nasopharynx and had increased adherence to cultured epithelial cells. Repair of the premature stop codon in the invasive sclA allele restored the ability to bind the extracellular matrix proteins laminin and cellular fibronectin. These data demonstrate that a mutation in GAS carrier strains increases adherence and decreases virulence and suggest selection against increased adherence in GAS invasive isolates.     

Spread of old and new clones of epidemic methicillin-resistant Staphylococcus aureus in Poland

Objective: To study the relatedness among methicillin-resistant Staphylococcus aureus (MRSA) isolates originating from two regions of Poland using different epidemiologic typing methods.
Methods: Forty-five MRSA isolates (19 from Warsaw and 26 from the Grajewo region) were collected between 1995 and 1996. For phenotypic epidemiologic analysis, antimicrobial susceptibility testing (AST) with a panel of 19 antibiotics was performed. For genotypic epidemiologic analysis, pulsed-field gel electrophoresis (PFGE) of Smal-digested chromosomal DNA, restriction endonuclease analysis of plasmid (REAP) DNA digested by Hin dIII, random amplification of polymorphic DNA (RAPD) and binary typing (BT) of genomic DNA by hybridization with five different RAPD-generated strain-specific DNA probes, were used.
Results: Six clusters of clonally related strains were found among the MRSA isolates analyzed. Three of these, identified in both regions, were related to previously described Polish epidemic clones, designated HeEMRSA-Pol1 (heterogeneously methicillin resistant—18 isolates) and HoEMRSA-Pol1 (homogeneously resistant—two clones, six isolates each). The remaining three clones, identified in the Grajewo region only, are previously undescribed. One of these, represented by 11 isolates, appears to be new epidemic heterogeneous MRSA clone (HeEMRSA-Pol2). Results of PFGE and BT in general showed good correlation, and, in some cases, RAPD using AP1 and AP7 primers could discriminate between isolates belonging to single PFGE or BT types. Broad AST and REAP can provide useful additional information concerning relatedness.
Conclusion: Evidence for the spread of previously recognized epidemic MRSA clones in Poland and the presence of a new epidemic heterogeneously resistant clone of MRSA in hospitals outside Warsaw is documented.     

Screening for antibacterial activity in 72 species of wood-colonizing fungi by the Vibrio fisheri bioluminescence method

Resistance of pathogenic bacteria to antibiotics leads scientists to discover new antibacterial drugs. Ninety samples of wood-colonizing fungi were cultivated on agar plates, and their extracts tested for antibacterial activity using the Vibrio fischeri bioluminescence test. Two fungi species, Serpula lacrymans and Nectria vilior, were found to be a potential new source of thermostable antibiotics. Vibrio fischeri bioluminescence test was found to be a useful method for antibacterial activity screening from the samples of natural origin.     

Secular trend in age at menarche for women born between 1920 and 1979 in Rio de Janeiro, Brazil

PRIMARY OBJECTIVE: This article presents data on the secular trend in age at menarche for 1955 women from 16 to 76 years of age born between 1920 and 1979 and studied under the Nutrition and Health Survey conducted in the municipality of Rio de Janeiro, Brazil, in 1996. METHODS AND PROCEDURES: Age at menarche was defined by the retrospective method. Women were grouped according to decade of birth, and the trend was estimated using simple linear regression between age at menarche and year of birth for the following specific periods: 1920-1940, 1920-1960, 1960-1979 and 1920-1979. MAIN OUTCOMES AND RESULTS: Mean age at menarche decreased from 13.07 to 12.40 years when comparing the group of women born in the 1920s with the 1970s birth cohort, corresponding to a mean rate of -0.0123 years per year (p < 0.001). The downward trend was -0.0120 years per year (p > 0.05) for the 1920s, 30s and 40s, -0.0093 years per year (p < 0.05) for the period from 1920 to 1960, and -0.0224 years per year (p < 0.01) for the 1960s/70s. CONCLUSIONS: The results suggest a secular trend in age at menarche. The literature points to such environmental variables as improved living conditions and expanded access to health services. Within this context, age at menarche could be used as a marker for social development.     

Exploratory Efficacy of Calcium-Vitamin D Milk Fortification and Periodontal Therapy on Maternal Oral Health and Metabolic and Inflammatory Profile

In this 2 × 2 factorial, outcome-assessor blinded, feasibility randomised trial we explored the effect of a non-pharmaceutical multi-component intervention on periodontal health and metabolic and inflammatory profiles among pregnant women with periodontitis receiving prenatal care in a Brazilian public health centre. 69 pregnant women (gestational age ≤20 weeks, T0) were randomly allocated into four groups: (1) fortified sachet (vitamin D and calcium) and powdered milk plus periodontal therapy during pregnancy (early PT) (n = 17); (2) placebo sachet and powdered milk plus early PT (n = 15); (3) fortified sachet and powdered milk plus late PT (after delivery) (n = 19); (4) placebo sachet and powdered milk plus late PT (n = 18). Third trimester (T1) and 6–8 weeks postpartum (T2) exploratory outcomes included periodontal health (% sites with bleeding on probing (BOP)), glucose, insulin, C-Reactive Protein, serum calcium and vitamin D. The mean BOP was significantly reduced in the early PT groups, while BOP worsened in the late PT groups. No significant effect of fortification on BOP was observed. Changes in glucose levels and variation on birthweight did not differ among groups This feasibility trial provides preliminary evidence for estimating the minimum clinically important differences for selected maternal outcomes. A large-scale trial to evaluate the interventions’ clinical benefits and cost-effectiveness is warranted.     

Secular height trend: a literature review]

This paper presents a literature review of secular height trends. The principal topics included were definition of the phenomenon, use of historical data sets on height as an alternative approach for monitoring economic changes, the main theoretical explanations of the phenomenon, the beginning of military anthropometry, and past and current use in measuring secular height trends in recruits and children. The most important results showed that the positive secular trend can be attributed to environmental influences, especially improvements in health, economic, and social conditions. The mean reported rates in height increases varied with age, socioeconomic status, and country, so one must exercise caution in drawing inferences. World War II slowed the trend in several countries, including Brazil, but the trend was stronger in the post-war period than in the beginning of the century. Finally, we observed that data from military anthropometry are the most common source for estimating secular height trends.     

Laplace operators of infinite-dimensional Lie algebras and theta functions

Until recently, the generalized Casimir operator constructed by Kac [Kac, V. G. (1974) Funct. Anal. Appl. 8, 68-70] has been the only known element of the center of a completion of the enveloping algebra of a Kac-Moody algebra. It has been conjectured [Deodhar, V. V., Gabber, O. & Kac, V. G. (1982) Adv. Math. 45, 92-116], however, that the image of the Harish-Chandra homomorphism contains all theta functions defined on the interior of the complexified Tits cone and hence separates the orbits of the Weyl group. Developing the ideas of Feigin and Fuchs [Feigin, B. L. & Fuchs, D. B. (1983) Dokl. Akad. Nauk SSSR 269, 1057-1060], I prove this conjecture. Another application of this method is the Chevalley type restriction theorem for simple finite-dimensional Lie superalgebras.     

Accelerated fractionation in esophageal cancers: A multivariate analysis on 88 patients

: Accelerated fractionation was used to shorten overall treatment time to increase locoregional control and cause-specific survival.

: Eighty-eight patients with cancer of the esophagus ineligible for surgery were entered in the study between 1986 and 1993. Neoadjuvant chemotherapy was given to 64% of patients. Accelerated radiotherapy using the concomitant boost technique delivered a median dose of 65 Gy in a median overall treatment time of 32 days.

: The 3-year acturial local control rate in patients with T1, T2, and T3 tumors was 71%, 42%,and 33%, respectively. The 3-year cause-specific survival rates were 40%, 22%, and 6%, respectively. Sixteen percent of patients experienced Grafe 3 esophagitis. Late toxicity included esophageal stenosis and pulmonary fibrosis in 8% and 9% of the patients, respectively. Multivariate analysis demonstrated that T stage and overall treatment time were prognostic factors for cause-specific survival. T stage and neoadjuvant chemotherapy were independent prognostic factors for locoregional control.

: These findings suggest that accelerated giben in an overall treatment time of <35 days might be beneficial for easy-stage cancer of the esophagus. Neoadjuvant chemotherapy is not recommended, as it was a significant adverse prognostic factor in the multivariate analysis for local control. Accelerated fractionation can be carried out with modeate acure and late toxicity.