Preparative Synthesis of dTDP-L-Rhamnose Through Combined Enzymatic Pathways

dTDP-L-rhamnose, an important precursor of O-antigen, was prepared on a large scale from dTMP by executing an one-pot reaction in which six enzymes are involved. Two enzymes, dTDP-4-keto-6-deoxy-D-glucose 3,5-epimerase and dTDP-4-keto-rhamnose reductase, responsible for the conversion of dTDP-4-keto-6-deoxy- D-glucose to dTDP-L-rhamnose, were isolated from their putative sequences in the genome of Mesorhizobium loti, functionally expressed in Escherichia coli, and their enzymatic activities were identified. The two enzymes were combined with an enzymatic process for dTDP-4- keto-6-deoxy-D-glucose involving TMP kinase, acetate kinase, dTDP-glucose synthase, and dTDP-glucose 4,6- dehydratase, which allowed us to achieve a preparative scale synthesis of dTDP-L-rhamnose using dTMP and glucose-1-phosphate as starting materials. About 82% yield of dTDP-L-rhamnose was obtained based on initial dTMP concentration at 20 mM dTMP, 1 mM ATP, 10 mM NADH, 60 mM acetyl phosphate, and 80 mM glucose-1- phosphate. From the reaction with 20 ml volume, approximately 180 mg of dTDP-L-rhamnose was obtained in an overall yield of 60% after two-step purification, that is, anion exchange chromatography and gel filtration for desalting. The purified product was identifiedbyHPLC, ESI-MS,andNMR,showingabout95%purity

A Prospective Study of Venous Thromboembolic Prophylaxis Using Foot Pumps Following Total Knee Replacement in a Chinese Population

AbstractPurposeThe purpose of this study was to evaluate foot pumps as mechanical prophylaxis for deep vein thrombosis (DVT) following total knee replacement (TKR) in a Chinese population.MethodsAll consecutive patients following TKR during 2002–2006 received routine duplex ultrasound surveillance for DVT 9 days postoperatively. The demographic data and risk factors were recorded. No medication was given for DVT prophylaxis in all patients.ResultsWe evaluated 91 consecutive TKRs in 85 patients. Although 44 knee replacements (Group 1) done before December 2004 were not given foot pumps, 47 knee replacements (Group 2) done afterwards were given foot pumps. All patients were followed up for more than 6 months. DVT was detected in three cases (6.8%) in Group 1 compared with four knees (8.5%) in Group 2. Proximal thrombosis was observed in two knees (4.5%) in Group 1 compared with two knees (4.3%) in Group 2. No patient had pulmonary embolism. Six out of 59 (10.2%) patients who underwent the operations under general anaesthesia suffered from DVT, whereas one in 28 (3.6%) patients operated under spinal anaesthesia had DVT. All had no statistical significance.ConclusionThe rate of proximal DVT after TKR was low (4.5%) without pharmacological prophylaxis. We advise against the use of pharmacological prophylaxis in Chinese population for TKRs because of the low risk of proximal DVT and its possible bleeding complications. Foot pump did not lower the rate of DVTfurther, and its use for DVT prophylaxis in TKR is not necessary

A Price Worth Paying: The Case for Controlling Marine Emissions in the Pearl River Delta

The Pearl River Delta (PRD) is a region with a single airshed, but different administrative and legal practices for controlling air quality. Under the Regional Cooperation Plan on Building a Quality Living Area (QLA Plan) released in June 2012 the Governments of Hong Kong, Guangdong and Macau have outlined a strategy to collaborate in reducing emissions from vessels throughout the PRD. This report provides evidence designed to assist policymakers in the region with this objective. It focuses on regulating toxic exhaust emissions from ocean-going vessels (OGVs) -- the most significant contributors of marine emissions. The findings show that marine sources of sulphur dioxide (SO2) emissions currently account for 519 premature deaths per annum in the PRD. These deaths could be reduced by 91% should an Emission Control Area (ECA) mandating the use of fuels with lower sulphur content be introduced. The report also demonstrates that three less comprehensive control measures would also reduce OGV emissions and associated public health impacts by 41-62%. Policymakers are encouraged to introduce these measures as stepping-stones on the way to establishment of an ECA for the PRD

Cardiovascular risks of chemo-immunotherapy for lung cancer: A population-based cohort study.

Despite their proven efficacy for treating lung cancer, the cardiovascular risks associated with programmed cell death protein 1 (PD-1) inhibitors and their combinations with chemotherapy (chemo-immunotherapy) are unclear. This study aimed to investigate these associations. This retrospective cohort study included Hong Kong patients with lung cancer receiving PD-1 inhibitors during 2013-2021. Patients with non-concurrent use of PD-1 inhibitors and chemotherapy, any use of tyrosine kinase inhibitors or other immunotherapy agents, and those with prior stroke, heart failure, or myocardial infarction were excluded. PD-1 inhibitors and chemo-immunotherapy were compared for major adverse cardiovascular events (MACE), a composite of cardiovascular mortality, heart failure, stroke, and myocardial infarction. All patients were followed up until the end of 2021. Inverse probability of treatment weighting was used to balance covariates between the two treatment groups. In total, 713 patients (333 PD-1 inhibitors users and 380 chemo-immunotherapy users) were analysed. Over a mean follow-up of 1.4 ± 1.3 years, 24 had MACE, with an observed incidence of 2.8 [1.6-4.8] events per 100 person-year for patients on PD-1 inhibitors, and 2.1 [1.2-3.8] per 100 person-year for patients on chemo-immunotherapy. No significant between-group difference in MACE incidence was observed (log-rank p = 0.641). The cardiovascular risks associated with PD-1 inhibitors and chemo-immunotherapy may not be significantly different amongst patients with lung cancer. Cardiovascular events associated with either regimen may be uncommon. [Abstract copyright: Copyright © 2022 The Author(s). Published by Elsevier B.V. All rights reserved.

Genome-wide genetic aberrations of thymoma using cDNA microarray based comparative genomic hybridization

BACKGROUND: Thymoma is a heterogeneous group of tumors in biology and clinical behavior. Even though thymoma is divided into five subgroups following the World Health Organization classification, the nature of the disease is mixed within the subgroups. RESULTS: We investigated the molecular characteristics of genetic changes variation of thymoma using cDNA microarray based-comparative genomic hybridization (CGH) with a 17 K cDNA microarray in an indirect, sex-matched design. Genomic DNA from the paraffin embedded 39 thymoma tissues (A 6, AB 11, B1 7, B2 7, B3 8) labeled with Cy-3 was co-hybridized with the reference placenta gDNA labeled with Cy-5. Using the CAMVS software, we investigated the deletions on chromosomes 1, 2, 3, 4, 5, 6, 8, 12, 13 and 18 throughout the thymoma. Then, we evaluated the genetic variations of thymoma based on the subgroups and the clinical behavior. First, the 36 significant genes differentiating five subgroups were selected by Significance Analysis of Microarray. Based on these genes, type AB was suggested to be heterogeneous at the molecular level as well as histologically. Next, we observed that the thymoma was divided into A, B (1, 2) and B3 subgroups with 33 significant genes. In addition, we selected 70 genes differentiating types A and B3, which differ largely in clinical behaviors. Finally, the 11 heterogeneous AB subtypes were able to correctly assign into A and B (1, 2) types based on their genetic characteristics. CONCLUSION: In our study, we observed the genome-wide chromosomal aberrations of thymoma and identified significant gene sets with genetic variations related to thymoma subgroups, which might provide useful information for thymoma pathobiology.ope

Is 'oil pulling' a 'snake oil'? : a clinical trial

The traditional Ayurveda practice of ‘oil pulling’ has become a recent phenomenon and concerns about its efficacy have been raised. Objectives: (1) to determine awareness about the practice of ‘oil pulling’ among a group of young adults, and to determine variations in awareness with respect to socio-demographic factors, oral health behaviours (oral hygiene and dental attendance) and use of natural health products; (2) to determine the effectiveness of ‘oil pulling’ and conventional oral hygiene practice compared to the use of conventional oral hygiene practice alone in terms of oral hygiene and (3) to determine the effectiveness of ‘oil pulling’ and conventional oral hygiene practice compared to the use of conventional oral hygiene practice alone in terms of gingival health. Methods: Group members recruited seventy-four young adults to participate in a clinical trial over a two-month period comparing the effectiveness of (a) ‘oil pulling’ and conventional oral hygiene methods (toothbrush and toothpaste) versus (b) conventional oral hygiene methods alone. Oral hygiene was assessed using the Plaque Index - PI (Silness and Löe, 1964) and the proportion of sites with visible plaque (PVP). Gingival health was assessed using the Gingival Index – GI (Silness and Löe,1963) and the proportion of sites with gingival bleeding (PGB). Participants were block randomized in groups of four to a cross over clinical trial and assessments were conducted at one-month and two-months. Results: Approximately a quarter (28.4%, 21) of participants was aware of the practice of ‘oil pulling’. Awareness of the practice was associated with reported use of natural dental/oral health products (p0.05). There were observed significant differences in gingival health among both the test and control groups from baseline to one-month (p0.05). No significant differences were observed in oral health parameters from one-month to two-month among neither the test nor control groups (p>0.05). Conclusion: Awareness of the practice of ‘oil pulling’ is relatively common and is associated with use of natural dental/oral health products. Findings from the clinical trial failed to support the adjunct use of ‘oil pulling’ in addition to conventional oral hygiene practices.published_or_final_versio

The photometric observation of the quasi-simultaneous mutual eclipse and occultation between Europa and Ganymede on 22 August 2021

Mutual events (MEs) are eclipses and occultations among planetary natural satellites. Most of the time, eclipses and occultations occur separately. However, the same satellite pair will exhibit an eclipse and an occultation quasi-simultaneously under particular orbital configurations. This kind of rare event is termed as a quasi-simultaneous mutual event (QSME). During the 2021 campaign of mutual events of jovian satellites, we observed a QSME between Europa and Ganymede. The present study aims to describe and study the event in detail. We observed the QSME with a CCD camera attached to a 300-mm telescope at the Hong Kong Space Museum Sai Kung iObservatory. We obtained the combined flux of Europa and Ganymede from aperture photometry. A geometric model was developed to explain the light curve observed. Our results are compared with theoretical predictions (O-C). We found that our simple geometric model can explain the QSME fairly accurately, and the QSME light curve is a superposition of the light curves of an eclipse and an occultation. Notably, the observed flux drops are within 2.6% of the theoretical predictions. The size of the event central time O-Cs ranges from -14.4 to 43.2 s. Both O-Cs of flux drop and timing are comparable to other studies adopting more complicated models. Given the event rarity, model simplicity and accuracy, we encourage more observations and analysis on QSMEs to improve Solar System ephemerides.Comment: 23 pages, 5 appendixes, 16 figures, 7 table

Fios e desafios da atenção à saúde da criança no estado do Espírito Santo: análise da mortalidade de zero a cinco anos com gestores do Programa Estadual de Saúde da Mulher e da Criança

Trata-se de um estudo de abordagem qualitativa que objetivou discutir a mortalidade de zero a cinco anos, no estado do Espírito Santo, no lapso de agosto de 2011 a agosto de 2012, a partir de matérias veiculadas por um jornal diário da mídia impressa de grande circulação, a saber A Gazeta. As referidas matérias constituíram uma hemeroteca que subsidiou a criação de um painel reprográfico. Os sujeitos da investigação foram os técnicos que compõem a equipe da Coordenação do Programa Estadual de Saúde da Mulher e da Criança, e a produção do material de estudo se deu a partir da análise de um grupo focal, com roteiro semiestruturado, tendo como partida a análise de uma cópia do painel contendo todas as máterias. Todo o material foi gravado e filmado. A Análise Institutucional foi a baliza norteadora de toda a elaboração e descrição do estudo. Conforme preconiza este quadro teórico proposto por Lourau, a etapa final do projeto constituiu-se em uma restituição concreta parte do procedimento científico, tratando-se da discussão das produções na pesquisa com os interessados, de modo a possibilitar a sua interferência direta neste processo. O estudo demonstrou que os sujeitos, a partir do dispositivo analisador natural, a morte de crianças menores de cinco anos, conseguiram fazer uma reflexão sobre o quanto é necessário buscar uma interlocução com os demais setores e perceber que a análise institucional, com sua potência de provocar a autoanálise e a autogestão, proporcionou-lhes uma possibilidade de repensar seus processos de trabalho na atenção à saúde da criança

Cardiovascular risks of chemo-immunotherapy for lung cancer: A population-based cohort study

Despite their proven efficacy for treating lung cancer, the cardiovascular risks associated with programmed cell death protein 1 (PD-1) inhibitors and their combinations with chemotherapy (chemo-immunotherapy) are unclear. This study aimed to investigate these associations. This retrospective cohort study included Hong Kong patients with lung cancer receiving PD-1 inhibitors during 2013-2021. Patients with non-concurrent use of PD-1 inhibitors and chemotherapy, any use of tyrosine kinase inhibitors or other immunotherapy agents, and those with prior stroke, heart failure, or myocardial infarction were excluded. PD-1 inhibitors and chemo-immunotherapy were compared for major adverse cardiovascular events (MACE), a composite of cardiovascular mortality, heart failure, stroke, and myocardial infarction. All patients were followed up until the end of 2021. Inverse probability of treatment weighting was used to balance covariates between the two treatment groups. In total, 713 patients (333 PD-1 inhibitors users and 380 chemo-immunotherapy users) were analysed. Over a mean follow-up of 1.4 ± 1.3 years, 24 had MACE, with an observed incidence of 2.8 [1.6-4.8] events per 100 person-year for patients on PD-1 inhibitors, and 2.1 [1.2-3.8] per 100 person-year for patients on chemo-immunotherapy. No significant between-group difference in MACE incidence was observed (log-rank p = 0.641). The cardiovascular risks associated with PD-1 inhibitors and chemo-immunotherapy may not be significantly different amongst patients with lung cancer. Cardiovascular events associated with either regimen may be uncommon