Prevalence and genetic diversity of pneumococcal serogroup 6 in Australia

The prevalence of the newly discovered pneumococcal serotype 6C has increased in some countries since the introduction of seven-valent conjugate pneumococcal vaccine (PCV7). The distribution of invasive serogroup 6 serotypes, in Australia, including 6C and 6D, has not been reported previously. During the period 1999 to 2008, 6097 isolates were referred to the New South Wales Pneumococcal Reference Laboratory for serotyping. Of these, 847 were identified by Quellung reaction as belonging to serogroup 6 and 702 were available for further study. Serotypes were determined by serotype-specific PCR as follows: 6A, 197 (28.1%); 6B, 452 (64.4%); 6C, 52 (7.4%) and one 6D. The average numbers of invasive serogroup 6 isolates, per annum, fell from 62.2 before (2000-2005) to 49.7 after (2006-2008) the introduction of PCV7. The proportions of invasive 6B fell (from 72.4% to 47.3%, p 0.03), those of 6C rose (from 3.3% to 17%, p 0.02) significantly and those of 6A remained fairly constant (24.3% vs 27%, p 0.69) between the two periods. All 6C and 6D and selected 6A and 6B isolates were further characterized by multilocus sequence typing and sequence analysis of cps genes cpsA-cpsB (wzg-wzh) and wchA-wciN(beta) -wciO, wciP. Results showed considerable diversity within serotype 6C, apparently as a result of both mutation and recombination. Sequence typing indicates that, in Australia, 6C has been largely derived from 6A. The genetic diversity and rapid increase in incidence of serotype 6C causing invasive pneumococcal disease has potential implications for vaccine efficacy.

Multiplex polymerase chain reaction-based reverse line blot hybridization assay to detect common genital pathogens

The objective of the present paper is to develop and apply a multiplex polymerase chain reaction (mPCR) based reverse line blot (RLB) hybridization assay to facilitate the diagnosis of genital infections by detection of seven recognized or putative genital pathogens (Neisseria gonorrhoeae, Chlamydia trachomatis, Ureaplasma urealyticum, Ureaplasma parvum, Mycoplasma genitalium, Mycoplasma hominis and Trichomonas vaginalis). Species-specific biotin-labelled primer pairs were used in a single mPCR to amplify target regions in each of seven pathogens. The amplified biotin-labelled PCR products were hybridized with membrane-bound-specific oligonucleotide probes and were detected by chemiluminescence. Two hundred and eleven specimens (104 male urethral and 107 female vaginal swabs), collected from patients with suspected genital infections attending the Wuhan First Hospital Sexually Transmitted Diseases (STD) clinic, were tested by mPCR/RLB and results were confirmed by single PCR using different species-specific targets. The sensitivity of the assay was assessed using dilutions of positive DNA controls with known copy numbers, for each target. The assay correctly identified all reference strains and detected potential pathogens in a high proportion of clinical specimens. There was no cross-reaction between the seven pathogens. The mPCR/RLB can detect <or= 10(2) copies of the target gene fragments. Comparison of mPCR/RLB and single PCR assays showed discrepant results in six of 211 (2.8%) clinical specimens, which were positive by mPCR/RLB assay, but negative by the corresponding single PCR. Nested PCR on the six discrepant specimens gave results consistent with those of mPCR/RLB. In conclusion, the mPCR/RLB hybridization assay is sensitive and specific, and able to rapidly detect genital pathogens in clinical specimens.

The rag locus of Porphyromonas gingivalis might arise from Bacteroides via horizontal gene transfer

Porphyromonas gingivalis is regarded as one of the risk factors of periodontitis. P. gingivalis exhibits a wide variety of genotypes. Many insertion sequences (ISs), located in their chromosomes, made P. gingivalis differentiate into virulent and avirulent strains. In this research, we investigated the prevalence of P. gingivalis in the gingival crevicular fluid (GCF) among periodontitis patients from Zhenjiang, China, detected the P. gingivalis rag locus distributions by multiplex polymerase chain reaction (PCR), and analyzed the origin of the P. gingivalis rag locus based on evolution. There were three rag locus variants co-existing in Zhenjiang. The results showed that the rag locus may be associated with severe periodontitis. This work also firstly ascertained that the rag locus might arise, in theory, from Bacteroides sp. via horizontal gene transfer.

Differentiation of Chlamydia trachomatis lymphogranuloma venereum-related serovars from other serovars using multiplex allele-specific polymerase chain reaction and high-resolution melting analysis

Lymphogranuloma venereum (LGV) is a sexually transmitted infection caused by Chlamydia trachomatis serovars L1, L2 and L3. Consequently, more specific and sensitive detection methods that are rapid and inexpensive are necessary to differentiate between C. trachomatis serovars. The purpose of this study was to identify and differentiate LGV-related C. trachomatis serovars from rectal swabs using high-resolution melting analysis (HRMA) and multiplex allele-specific polymerase chain reaction (MAS-PCR). Fifteen clinical samples from patients in Sydney were first screened and confirmed as C. trachomatis by using the COBAS®AMPLICOR PCR analyser. The same samples were assayed for C. trachomatis and LGV by HRMA and MAS-PCR of the polymorphic membrane protein H ( pmpH) gene. Both methods indicated that two of 15 samples were serovar L2 and the remainder (13/15) other C. trachomatis serovars. Both HRMA and MAS-PCR are inexpensive, rapid, easy methods that are useful tools for the identification of LGV in clinical and research laboratories.

Chromosomal distribution of 18S-25S rDNA in four Lupinus species visualized by fluorescence in situ hybridization

The number and position of 18S-25S rDNA sites in 4 selected Lupinus species are reported for the first time. L. atlanticus, L. subcarnosus and L. paniculatus had two rDNA loci, while L. albus exhibited only one loci. Among these 4 species, all of them exhibited one large pair of strong signals that extends from the short arm to a NOR on a chromosome satellite. L. atlanticus, L. subcarnosus, L. paniculatus had one more locus of 18-25S rDNA, but a pair of weak hybridization signals were observed in L. paniculatus when 18S-25S rDNA was used as probe. The results are discussed in terms of the evolutionary relationships among these species.

Pulmonary functional map on V/Q SPECT and TGFβ1 during radiotherapy and post-treatment lung function in patients with non-small cell lung cancer

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Background: Current research focus on the TGFß1 and pulmonary perfusion (Q) SPECT pre or post-treatment to predict lung toxicity in patients with non-small-cell lung cancer (NSCLC). However, ventilation (V) is also important, while the change of V/Q SPECT map and TGFβ1 during radiotherapy (RT) maybe more predictive for the lung function post-treatment. Methods: Patients with stage I-III NSCLC undergoing radiation based treatment were included and V/Q SPECT-CT, circulating TGF ß1 and carbon monoxide diffusing capacity (DLCO), as the key parameter of pulmonary function test, were assessed pre-, during- and 3 months post-RT. Patients were treated with conformal radiation therapy of more than 60 Gy, with or without chemotherapy per standard of care based on their stage of disease. The defects of V/Q SPECT images were defined by semi-quantitive method. Results: Total 45 patients with stage I-III NSCLC undergoing radiation (>60 Gy) were enrolled. All patients had functional defects (V, or Q or both) at or adjacent to the tumor and the V/Q defects were mismatched in 40%, 50% and 23% patients, pre-, during- and post-RT, respectively. After 45 Gy, the V and Q defects improved remarkably in 38.4% and 34.6% patients respectively, and the V scores were also improved significant during-RT (p<0.01). The Q scores of ipsilateral lung and V score of both lungs during-RT were correlated with DLCO 3 months post-RT margin-significantly (p=0.07) and significantly (p=0.02). The TGFß1 level decreased significantly during-RT and TGFß1 ratios (over the pre-RT level) at 4- and 6-week during-RT correlated with DLCO 3 months post-RT significantly (p=0.05). Conclusions: The V/Q SPECT map and TGFß1 level change during RT, and these changes are predictive for the lung function post-treatment in patients with NSCLC.

No significant financial relationships to disclose.

Comparative proteomic analysis of radiation induced changes in non small cell lung cancer patients with or without radiation induced lung toxicity

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Background: Radiation-induced lung toxicity (RILT) is dose limiting in the treatment of non small cell lung cancer (NSCLC). Early prediction of RILT would allow physicians to individualize treatment. This work aims to study if radiation induces differential changes in plasma proteomics in patients with and without RILT. Methods: 20 Patients with NSCLC in 3 stage- matched groups and treated with radiation therapy (RT) or chemoradiation were included in this analysis: 6 grade 0 (group 0), 8 grade 1 (group 1), and 6 grade ≥ 2 RILT (group 2). Platelet poor plasma was obtained pre-RT, at 2-, 4-, 6-week during-RT, and 1-, 3-month post-RT. The plasma proteomic characterizations from patients with and without RILT were compared using a multiplexed quantitative proteomics approach involving ExacTag labeling, reverse-phase high-performance liquid chromatography (RP-HPLC), and nano-LC electrospray tandem mass spectrometry (LC-ESI-MS/MS). ANOVA model was applied for significance test. Results: 23 common proteins were detected in all 20 patients, 9 of them, Ceruloplasmin, Prothrombin, Complement C3, Beta-2-glycoprotein (β2GP1) 1, Vitronectin, Complement factor I, Complement factor H, Complement C4-A, Complement C7, had significant difference among 3 groups. At baseline (Pre-RT), the levels of Vitronectin and C4-A in group 2 were both significantly higher than that in group 0 (p=0.008 and 0.021, respectively). At 2-week during RT, the levels of Ceruloplasmin, Prothrombin and β2GP1 in group 1 were significantly higher than that in group 0 (p=0.017, 0.011 and 0.013, respectively). At 4-week during RT, the levels of β2GP1 in group 1 and group 2 were significantly higher than that in group 0 (p=0.005 and 0.014). At 6-weeks during RT, Prothrombin, C3, Complement factor H, C7 and Complement factor I also had some significant changes among three groups. Conclusions: Plasma proteins related to inflammation, coagulation and fibrosis, such as β2GP1, change differently during RT in patients with and without RILT. This proteomic approach may identify new markers during treatment to predict RILT for adapting treatment to patient. Fundings: ASCO career developmental award, grant from Pardee foundation, and RTOG translational research program.

No significant financial relationships to disclose.

Statistical and kinetic studies of the changes in soybean quality during storage as related to soymilk and tofu making

The objective of this study was to develop statistical equations and kinetic models to describe the changes of soybean quality during storage. Significant correlations (P < 0.0001) were found among most of quality attributes including color parameters (Hunter L, a, b, and DeltaE), solid extractability (as expressed by soymilk solids content), soymilk pH and protein content, tofu yield, hardness, and protein content. Regressed linear equations were developed between color indices (L/L(0), DeltaE) and soymilk/tofu making properties. Empirical equations were developed to relate soybean color indices (L/L(0), DeltaE) and storage conditions including variables of initial moisture content (MC), relative humidity (RH), temperature (T), and duration (t). Kinetics of the changes in soybean color and extractability during storage at 70% RH and 22 to 40 degrees C were investigated. The kinetics was well described by zero-order kinetics. The Arrhenius equation adequately described the temperature dependence of the reaction rate constants for all parameters, from which the activation energies and rate constant were obtained. The equations developed in this study provided simple methods to monitor soybean quality and predict quality changes of soybeans during storage at various conditions.

Determination of Cr(VI) concentration in diluted samples based on the paper test strip method

At present, there are many methods for Cr(VI) concentration determination in diluted samples, however, these methods have their own inherent drawbacks, such as long response time, complicated pretreatment, expensive equipment etc. In this paper, a paper-based test strip method specific for determination of diluted Cr(VI) samples was developed. In this method, Aliquat 336, as an anion exchanger was loaded into filter paper to form a test strip. This test strip was used to pre-concentrate Cr(VI) when contacting with the diluted Cr(VI)-containing solution. The Cr(VI)-containing test strip was then immersed into a diphenylcarbazide (DPC) solution (a color forming solution), and the color intensity was correlated to the Cr(VI) concentration. The detection range of the present method was found to be 0.02-1.50 mg/L. The results also showed that the method gave a high selectivity for Cr(VI) in the diluted samples to be tested. The method was applied to synthesized samples and the results, which were compared to those from a reference method, showed that the developed method is an effective, reliable way for Cr(VI) determination in diluted samples.

Disintegration of solid foods in human stomach

Knowledge of the disintegration of solid foods in human stomach is essential to assess the bioavailability of nutrients in the gastrointestinal (GI) tract. A comprehensive review of food gastric digestion, focusing on disintegration of solid foods, is presented. Most of the research reviewed in this paper is contained in the medical, pharmaceutical, food, and nutritional literature. Stomach physiology is briefly introduced, including composition and rheological properties of gastric contents, stomach wall motility in fed/fasted states, and hydrodynamic and mechanical forces that act on the ingested food. In vivo and in vitro methods used for studying food and drug digestion in GI are summarized. Stomach emptying rate, which controls the rate of absorption of nutrients, is highly related to the disintegration of foods. This topic is highlighted with focus on the important mechanisms and the influence of chemical and physical properties of foods. Future research in this area is identified to increase our fundamental understanding of the food digestion process in the stomach as related to the food composition, material properties such as texture and microstructure, and chemical characteristics. This information is necessary to develop new guidelines for seeking innovative processing methods to manufacture foods specifically targeted for health.