Evaluation of toxicity of the mycotoxin citrinin using yeast ORF DNA microarray and Oligo DNA microarray

BACKGROUND: Mycotoxins are fungal secondary metabolites commonly present in feed and food, and are widely regarded as hazardous contaminants. Citrinin, one of the very well known mycotoxins that was first isolated from Penicillium citrinum, is produced by more than 10 kinds of fungi, and is possibly spread all over the world. However, the information on the action mechanism of the toxin is limited. Thus, we investigated the citrinin-induced genomic response for evaluating its toxicity. RESULTS: Citrinin inhibited growth of yeast cells at a concentration higher than 100 ppm. We monitored the citrinin-induced mRNA expression profiles in yeast using the ORF DNA microarray and Oligo DNA microarray, and the expression profiles were compared with those of the other stress-inducing agents. Results obtained from both microarray experiments clustered together, but were different from those of the mycotoxin patulin. The oxidative stress response genes – AADs, FLR1, OYE3, GRE2, and MET17 – were significantly induced. In the functional category, expression of genes involved in "metabolism", "cell rescue, defense and virulence", and "energy" were significantly activated. In the category of "metabolism", genes involved in the glutathione synthesis pathway were activated, and in the category of "cell rescue, defense and virulence", the ABC transporter genes were induced. To alleviate the induced stress, these cells might pump out the citrinin after modification with glutathione. While, the citrinin treatment did not induce the genes involved in the DNA repair. CONCLUSION: Results from both microarray studies suggest that citrinin treatment induced oxidative stress in yeast cells. The genotoxicity was less severe than the patulin, suggesting that citrinin is less toxic than patulin. The reproducibility of the expression profiles was much better with the Oligo DNA microarray. However, the Oligo DNA microarray did not completely overcome cross hybridization

Analysis of Mechanisms of T-2 Toxin Toxicity Using Yeast DNA Microarrays

T-2 toxin is a mycotoxin that belongs to a group of type A tricothecenes found in agricultural products. The cytotoxicity of T-2 toxin was characterized by analysis of the yeast transcriptome upon challenge with T-2 toxin. Interestingly, T-2 toxin-induced yeast gene expression profiles were found to be similar to profiles obtained following cycloheximide treatment. Moreover, T-2 toxin treatment was found to activate facilitators, gluconeogenesis and cell arrest related genes such as mitogen-activated protein kinase genes (FUS3). T-2 toxin attacks the membrane and as a result the membrane transport system was disturbed. A large number of genes are induced to restore the toxicity caused by T-2 toxin. However, the data did not suggest that DNA damage by alkylation (Mag1, a gene 3-methyl-adenine DNA glycosylase, 0.46-fold down regulated), no induction of DNA repair mechanisms such as recombination (RAD26, RAD52 and etc.) and excision repair (RAD7, RAD14, RAD16, RAD23 and etc.). These results suggested that the toxicity of the T-2 toxin was due to the disturbance of the cell membrane of the yeast cell and that T-2 toxin caused mild mutagenesis

Comparison of short term surgical outcomes of male and female gastrointestinal surgeons in Japan: retrospective cohort study

男女の消化器外科医による手術成績は同等 --女性消化器外科医のさらなる活躍に向けて--. 京都大学プレスリリース. 2022-09-29.Study finds no differences in performance between male and female surgeons. 京都大学プレスリリース. 2022-10-04.[Objective] To compare short term surgical outcomes between male and female gastrointestinal surgeons in Japan. [Design] Retrospective cohort study. [Setting] Data from the Japanese National Clinical Database (includes data on >95% of surgeries performed in Japan) (2013-17) and the Japanese Society of Gastroenterological Surgery. [Participants] Male and female surgeons who performed distal gastrectomy, total gastrectomy, and low anterior resection. [Main outcome measures] Surgical mortality, surgical mortality combined with postoperative complications, pancreatic fistula (distal gastrectomy/total gastrectomy only), and anastomotic leakage (low anterior resection only). The association of surgeons’ gender with surgery related mortality and surgical complications was examined using multivariable logistic regression models adjusted for patient, surgeon, and hospital characteristics. [Results] A total of 149 193 distal gastrectomy surgeries (male surgeons: 140 971 (94.5%); female surgeons: 8222 (5.5%)); 63 417 gastrectomy surgeries (male surgeons: 59 915 (94.5%); female surgeons: 3502 (5.5%)); and 81 593 low anterior resection procedures (male surgeons: 77 864 (95.4%);female surgeons: 3729 (4.6%)) were done. On average, female surgeons had fewer post-registration years, operated on patients at higher risk, and did fewer laparoscopic surgeries than male surgeons. No significant difference was found between male and female surgeons in the adjusted risk for surgical mortality (adjusted odds ratio 0.98 (95% confidence interval 0.74 to 1.29) for distal gastrectomy; 0.83 (0.57 to 1.19) for total gastrectomy; 0.56 (0.30 to 1.05) for low anterior resection), surgical mortality combined with Clavien-Dindo grade ≥3 complications (adjusted odds ratio 1.03 (0.93 to 1.14) for distal gastrectomy; 0.92 (0.81 to 1.05) for total gastrectomy; 1.02 (0.91 to 1.15) for low anterior resection), pancreatic fistula (adjusted odds ratio 1.16 (0.97 to 1.38) for distal gastrectomy; 1.02 (0.84 to 1.23) for total gastrectomy), and anastomotic leakage (adjusted odds ratio 1.04 (0.92 to 1.18) for low anterior resection). [Conclusion] This study found no significant adjusted risk difference in the outcomes of surgeries performed by male versus female gastrointestinal surgeons. Despite disadvantages, female surgeons take on patients at high risk. Greater access to surgical training for female physicians is warranted in Japan

ニュータウンに居住する専業主婦の外出頻度および主観的健康感との関係

専業主婦については、活動量や運動量の制限などが報告されている一方、若年期からの地域とのつながりにより外出頻度は維持されやすいと考えられる. そこで高齢者で報告されている外出頻度と主観的健康感との関連が専業主婦でもみられるのか、年齢による影響を明らかにすることを目的とした. 研究は大阪府堺市南区の一地区内の全世帯(3,069世帯)に無記名自記式の質問紙調査を行い、回答数1,820(回収率58.0%)の中から専業主婦701名を分析対象とした. 質問項目は最近1週間の外出頻度、主観的健康感について尋ねた. その結果、外出頻度は60代、70代後半、80代以上と段階的に減少した. 主観的健康感は加齢とともに不安あり群が増加した. 外出頻度と主観的健康感の関連は50代以上で外出頻度が減少するとともに主観的健康感が低下する傾向を認めた. 以上より、健康維持、増進のためには50代から年代ごとの取り組みが必要であることが示唆された.Physical activity levels and the amount of exercise in housewives are reportedly low; however, a high frequency of outings is likely to be maintained due to connection with local residents. This study aimed to identify the relationship between the frequency of outings and self-rated health in housewives, and investigate age-related effects. Anonymous self-administered questionnaires were distributed to 3,069 households in one district of Minami-ku, Sakai-shi, Osaka, and, of the 1,820 responses (response rate: 58.0%), 701 housewives were analyzed. Questionnaire items included the frequency of outings and self-rated health over the past one week. As the results of the questionnaire, the frequency of outings gradually decreased as the age advanced from their 60s to 80s or over. Regarding self-rated health, the number of subjects with anxiety increased with age. Among the subjects aged 50 or over, there was a decreasing trend in the frequency of outings and self-rated health. The findings suggest the need to take appropriate measures to maintain and promote the health of housewives aged 50 and over according to their age group

Design of Sphingomonad-Detecting Probes for a DNA Array, and Its Application to Investigate the Behavior, Distribution, and Source of Rhizospherous Sphingomonas and Other Sphingomonads Inhabiting an Acid Sulfate Soil Paddock in Kalimantan, Indonesia

Throughout Central and South Kalimantan, Indonesia, strongly acidic soil (pH 2.1–3.7) is widely distributed, and the local acidic soil-tolerant plants, including local rice varieties, often possess sphingomonads in their rhizosphere and rhizoplane. To investigate the behavior of sphingomonads inhabiting the rhizosphere of such acid-tolerant plants, we designed 13 different DNA array probes (each of 72 mer) specific to a group of sphingomonads, using a hypervariable V6 region of the 16S rRNA gene. This DNA array system was used preliminarily for an analysis of microfloral dynamisms, particularly of sphingomonads, in acidic paddock ecosystems, and the results suggest that the acid-tolerant local rice shares rhizospherous sphingomonads with wild Juncus sp., a predominant weed that thrives in acidic paddocks during the off-season for rice farming. This tentative conclusion supports the bio-rationality of the traditional rice farming system with respect to functional rhizobacteria