A clickable photoaffinity probe of betulinic acid identifies tropomyosin as a target

Target identification of bioactive compounds is important for understanding their mechanisms of action and provides critical insights into their therapeutic utility. While it remains a challenge, unbiased chemoproteomics strategy using clickable photoaffinity probes is a useful and validated approach for target identification. One major limitation of this approach is the efficient synthesis of appropriately substituted clickable photoaffinity probes. Herein, we describe an efficient and consistent method to prepare such probes. We further employed this method to prepare a highly stereo-congested probe based on naturally occurring triterpenoid betulinic acid. With this photoaffinity probe, we identified tropomyosin as a novel target for betulinic acid that can account for the unique biological phenotype on cellular cytoskeleton induced by betulinic acid.

Research progress on the influencing factors of post-traumatic stress disorder among fire emergency rescuers / 中华劳动卫生职业病杂志

Under the new situation of professionalization reform for fire rescue forces in China, the research on post-traumatic stress disorder (PTSD) of the emergency rescue personnel is expected to usher in a new stage. Based on some theoretical researches and practical results of domestic and foreign literature, this paper summarized the research results of the social and psychological factors of PTSD of emergency rescue personnel, and made suggestions and prospects for the future research and policy-making in related fields in China.

Fewer beams and segments result in a shorter delivery time and a better quality intensity-modulated radiotherapy plan in gastric cancer

Background: This study evaluated whether IMRT using fewer beams and segments could reduce delivery time without compromising plan quality in gastric cancer adjuvant radiotherapy

Materials and Methods: Fifteen patients with advanced gastric cancer who underwent D2, R0 surgery were included in this study. IMRT plans for each patient were designed as 7 equal beams with 40 segments, 5 beams with 25 segments and 4 beams with 20 segments. The dosimetric parameters were compared for the planned target volume [PTV]. The dose of normal organs at risk [OARs] was also assessed. The monitor units and treatment times of the different IMRT plans were calculated

Results: The 20-segment IMRT plan significantly reduced the PTV maximum dose compared to the 40-segment IMRT plan. The 20-segment IMRT plan improved left kidney and liver dose sparing in V20 and V30 as well as the 40-segment IMRT plan did and provided be4er protection for the V20 [13.86+/-7.78] of the right kidney, the V30 [9.25+/-4.04] of the le kidney, the D mean [19.68+/-2.47] of liver and D max [38.79+/-3.57] of the spinal cord. Irradiation times in the 20-segment and 25-segment plans decreased by 2.5 and 1.9 min, respectively, compared to the 40-segment IMRT plan

Conclusion: IMRT using fewer beams and segments reduced delivery time without compromising plan quality in gastric cancer adjuvant radiotherapy. Fewer segments IMRT plans lowered the monitor units and the treatment time

A Survey on Singaporean Women's Knowledge, Perception and Practices of Mammogram Screening

<p><b>INTRODUCTION</b>Singapore is the first Asian country to establish a nationwide breast screening programme, but our breast cancer screening uptake lags behind the Western countries. This survey focused on the subject of screening mammography, to assess the reasons for non-attendance and explore ways to improve our screening uptake.</p><p><b>MATERIALS AND METHODS</b>Females ≥21 years old were approached at primary healthcare clinics to participate in this survey, which questioned their knowledge, perception and expectations of breast screening.</p><p><b>RESULTS</b>There were 1011 respondents. Of the 740 respondents ≥40 years old, 332 respondents (45.5%) went for regular mammogram screening. Women who had lower household incomes [<$2000 (OR 0.49; 95% CI, 0.28 to 0.85); $2000 to $3999 (OR 0.59; 95% CI, 0.36 to 0.97)], did not know anyone with breast cancer (OR 0.62; 95% CI, 0.42 to 0.92), did not perform breast self-examination (OR 0.42; 95% CI, 0.28 to 0.62), had lower knowledge scores (OR 0.34; 95% CI 0.22 to 0.51), did not attend other health screening (OR 0.14; 95% CI, 0.05 to 0.41), and perceived mammography as embarrassing (OR 0.55; 95% CI, 0.31 to 0.96), were less likely to attend mammographic screening. Many did not know that screening is for the asymptomatic (51.2%), or the age to start screening (46.3%). Most respondents preferred to have their mammograms in the polyclinics (62.2%) and their screening reminders to be through short messaging service (SMS) (46.0%).</p><p><b>CONCLUSION</b>Our results show the current influences on Singapore women's screening practices, and also revealed that their understanding of mammogram screening is limited despite a high level of breast cancer awareness.</p>

Environmental biological model based on optimization of activated sludge process

A simplified environmental biological model has been developed based on biodegradation kinetics correlation to regulate and optimize wastewater treatment system of activated sludge process. All parameters included in the model are calibrated in accordance with reference data and experimental results and good agreements are achieved between calculated results and reference data or experimental results. The minimum bioreactor volume is used as objective function in the model and errors between optimal minimum volume of the model and each reported result of three references are found to be no more than 8.63% after validation. Comparisons between optimal results and experimental data demonstrate that the deviations are negligible. The optimal minimum volume is 9.21 m3 with the error of 6.40% to the practical bioreactor volume of a pilot treatment system. The environmental biological model has been applied to economically evaluate a former treatment system with native bacterium YZ1 and four operation periods of the pilot system with functional strain Fhhh compared with YZ1, Fhhh possesses higher biodegradation ability in purified terephthalic acid wastewater and a broader economic potential in the field of wastewater treatment

Melatonin reduces the expression of chemokines in rat with trinitrobenzene sulfonic acid-induced colitis

To investigate the effect of melatonin on the colon inflammatory injury of rats with colitis and determine whether this effect is associated with inhibition of chemoattractant molecules interleukin [IL-8] and monocyte chemoattractant protein [MCP-1]. The study was designed and implemented in JingMen No.1 People's Hospital, HuBei Province, from May 2006 to April 2007. It involved 72 animals divided into 6 groups of 12 each: normal group, model group, 5-aminosalisalicylic acid group,and melatonin group [dose of 2.5, 5.0, and 10.0mg/kg]. Rat colitis model was established by 2, 4, 6-trinitrobenzene sulfonic acid [TNBS] enema. Interlukin-8 and MCP-1 proteins in colon tissue were examined by immunohistochemistry and western blot. The messenger-RNA expressions of chemokines were determined by reverse transcription polymerase chain reaction analysis. Trinitrobenzene sulfonic acid enema resulted in pronounced pathological changes of colonic mucosa in model rats, which were in accordance with the significantly elevated myeloperoxidase activity. Expressions of chemokines were up-regulated in colitis. Melatonin treatment reduced colonic lesions and improved colitis symptom, and decreased the protein and mRNA expressions of IL-8 and MCP-1 significantly in colon tissues of rats with colitis. Chemokines IL-8 and MCP-1 are elevated in mucosal tissues in colitis and play an important role in the perpetuation of tissue destructive inflammatory processes; melatonin reduces colonic inflammatory injury of rats colitis through down-regulating the expressions of chemokines. Melatonin can be considered as a novel therapeutic alternative for the treatment of inflammatory bowel disease