[A survey of performance of public health risk assessment in emergencies of institutions for disease control and prevention at different levels in China].

Objective: To understand the performance of public health risk assessment in emergencies of institutions for disease control and prevention at different levels in China, and provide suggestions for the improvement of public health risk assessment. Methods: A self-administered survey was conducted in professionals involved in public health risk assessment in emergencies from national institution, provincial institutions and some prefectural institutions for disease control and prevention (1-2 prefectural institutions were selected using convenience sampling in each province) between March and April in 2021. Results: A total of 79 institutions for disease control and prevention were investigated, including 1 national institution, 32 provincial institutions and 46 prefectural institutions. By April 2021, all the 79 institutions surveyed had conducted risk assessment of public health emergencies, in which 61 (77.2%) had established departments responsible for the public health risk assessment, i.e. emergency management office or communicable disease prevention and control office (section), and regular risk assessment mechanisms. The main sources of information for public health risk assessment were public health surveillance systems, including the National Notifiable Diseases Reporting System (100.0%) and Public Health Emergencies Management Information System (97.5%). Compared with the provincial institutions, the prefectural institutions were more likely to use specific disease surveillance systems (84.8% vs. 62.5%; χ2=5.09, P=0.024). The risk management recommendations made by 43 institutions for disease control and prevention (54.4%) after the risk assessment were accepted by the superior health administrative departments and used in epidemic prevention and control. Conclusions: Public health risk assessment in emergencies has been widely carried out by national, provincial and prefectural institutions for disease control and prevention in China. Specialized departments and mechanisms have been established, but the information sources are still confined to public health surveillance systems and the application of the risk assessment results still needs to be further improved.

Association between air pollution and atopic dermatitis in Guangzhou, China: modification by age and season.

BACKGROUND: The short-term effect of ambient air pollution on atopic dermatitis (AD), along with its effect modifiers, has not been fully addressed. OBJECTIVES: To examine the short-term associations between air pollution and AD, and to identify effect modifications by age and season. METHODS: We used the generalized additive model to evaluate the short-term effect of ambient air pollution on daily hospital visits for AD, adjusting for potential confounders. Subgroup analyses were performed to identify potential effect modifications by season and age (< 18 years and ≥ 18 years). RESULTS: A total of 29 972 hospital visits for AD were recorded in Guangzhou, China, from 19 January 2013 to 31 December 2017. Among them, 72·8% were visits by children and 51·4% occurred in the cool season. Acute and delayed effects on AD hospital visits were significant for all air pollutants. Stronger effects were seen in the cool season (approximately 1·7-3·0 times higher than effects in the warm season). Stronger effects were also observed in children (approximately 1·3-1·8 times higher than effects in adults). Sensitivity analyses indicated the results were robust. CONCLUSIONS: Air pollution might be an important trigger for AD in subtropical Guangzhou, China. Children are more vulnerable than adults, and the effects are stronger in the cool season.

HLA-B*13:01 and the dapsone hypersensitivity syndrome.

BACKGROUND: Dapsone is used in the treatment of infections and inflammatory diseases. The dapsone hypersensitivity syndrome, which is associated with a reported mortality of 9.9%, develops in about 0.5 to 3.6% of persons treated with the drug. Currently, no tests are available to predict the risk of the dapsone hypersensitivity syndrome. METHODS: We performed a genomewide association study involving 872 participants who had received dapsone as part of multidrug therapy for leprosy (39 participants with the dapsone hypersensitivity syndrome and 833 controls), using log-additive tests of single-nucleotide polymorphisms (SNPs) and imputed HLA molecules. For a replication analysis, we genotyped 24 SNPs in an additional 31 participants with the dapsone hypersensitivity syndrome and 1089 controls and performed next-generation sequencing for HLA-B and HLA-C typing at four-digit resolution in an independent series of 37 participants with the dapsone hypersensitivity syndrome and 201 controls. RESULTS: Genomewide association analysis showed that SNP rs2844573, located between the HLA-B and MICA loci, was significantly associated with the dapsone hypersensitivity syndrome among patients with leprosy (odds ratio, 6.18; P=3.84×10(-13)). HLA-B*13:01 was confirmed to be a risk factor for the dapsone hypersensitivity syndrome (odds ratio, 20.53; P=6.84×10(-25)). The presence of HLA-B*13:01 had a sensitivity of 85.5% and a specificity of 85.7% as a predictor of the dapsone hypersensitivity syndrome, and its absence was associated with a reduction in risk by a factor of 7 (from 1.4% to 0.2%). HLA-B*13:01 is present in about 2 to 20% of Chinese persons, 1.5% of Japanese persons, 1 to 12% of Indians, and 2 to 4% of Southeast Asians but is largely absent in Europeans and Africans. CONCLUSIONS: HLA-B*13:01 was associated with the development of the dapsone hypersensitivity syndrome among patients with leprosy. (Funded by the National Natural Science Foundation of China and others.).

Familial aggregation of lung cancer in a high incidence area in China.

To investigate whether lung cancer clusters in families in a high incidence county of China, an analysis was conducted using data on domestic fuel history and tobacco use for family members of 740 deceased lung cancer probands and 740 controls (probands' spouses). Lung cancer prevalence was compared among first-degree relatives of probands and of controls, taking into account various factors using logistic regression and generalised estimating equations. First-degree relatives of probands, compared with those of controls, showed an excess risk of lung cancer (odds ratio (OR)=2.05, 95% confidence interval (CI): 1.68-2.53). Overall, female relatives of probands had a greater risk than did their male counterparts, and the risk was 2.90-fold for parents of probands as compared with parents of spouses. Female relatives of probands had 2.67-fold greater risk than female controls. Lung cancer risk was particularly marked among mothers (OR=3.78, 95% CI: 2.03-7.12). Having two or more affected relatives was associated with a 2.69-5.40-fold risk increase. The risk elevation was also found for other cancers overall. Results confirm previous findings of a genetic predisposition to lung cancer, and also imply that lung cancer may share a genetic background with other cancers.

Characterization of water-in-crude oil emulsions in oil spill response.

The formation of water-in-crude oil emulsions occurs when crude oils are spilled into sea. The water-in-crude oil emulsions significantly change the properties of the spilled crude oils and in turn influence the choices made relating to oil spill countermeasures. The water-in-crude oil emulsions were characterized using various techniques in this study. The environmental scanning electron microscopy observation of water droplets in the emulsions is also presented. It is a powerful tool in emulsion observations.

Evaluation of nonwoven polypropylene oil sorbents in marine oil-spill recovery.

Mechanical recovery of oil by oil sorbents is one of the most important countermeasures in marine oil-spill response. Polypropylene is the ideal material for marine oil-spill recovery due to its low density, low water uptake and excellent physical and chemical resistance. Different forms of polypropylene nonwoven sorbents were evaluated in this study in terms of initial oil-sorption capacities and oil-retention properties. The investigation revealed that the fibre diameter, sorbent porosity and oil property are the most important factors in the oil-sorption performance of polypropylene nonwoven sorbents.

Impact of acid-related disorders in the United States.

Acid-related disorders are common conditions that negatively impact quality of life for a significant number of people nationwide. The pathology of these conditions involves an imbalance between acid secretion by gastric parietal cells and the ability of upper GI tract mucosa to defend against the effects of the acid. Therefore, therapy is targeted at elevating gastric pH. PPIs are used to control the effects of excessive acid secretion. This class of drugs has a unique mechanism of action that inhibits the final pathway to gastric acid secretion--the parietal cell proton pump.

Dysphagia. A practical approach to diagnosis.

Our diagnostic approach to a patient with dysphagia begins with detailed history taking and physical examination. On the basis of findings, a radiographic and/or endoscopic study of the esophagus is done. We usually have barium-swallow radiography done initially, and if the radiographs are equivocal, upper gastrointestinal endoscopy is performed. Manometric studies are reserved for patients with suspected motility disorders.

Ischemic colitis in a crack abuser.

We report a case of acute colitis temporally associated with smoking crack. Colonoscopy revealed a patchy left-sided hemorrhagic inflammation from the rectosigmoid colon to the splenic flexure. Biopsy specimens were consistent with resolving ischemic colitis. This entity should be considered in the differential diagnosis of acute bloody diarrhea in recreational drug users.

Alanine flux in obese and healthy humans as evaluated by 15N- and 2H3-labeled alanines.

Estimates of plasma alanine flux as measured in humans using L-[15N]-alanine or L-[3,3,3-2H3]alanine were compared by simultaneous intravenous infusion of both tracers. Plasma isotope enrichments were measured by chemical ionization gas chromatography-mass spectrometry. In 16 obese women before and during a hypocaloric diet and in 4 normal men in the postabsorptive and fed states, the fluxes were highly correlated (r2 = 0.93) although plasma alanine flux with the 2H tracer was two to three times greater than that obtained with [15N]alanine. The fluxes decreased with the hypocaloric diet in obese subjects and increased during the fed state in healthy adults. Thus, although the estimates of alanine flux differed according to the tracer used, both appear to give equivalent information about changes in alanine kinetics induced by the nutritional conditions examined.

The epidemiology of lung cancer in Xuan Wei, China: current progress, issues, and research strategies.

In Xuan Wei, a rural Chinese county of about one million people, females' annual lung cancer mortality is China's highest, and males' is among China's highest. Xuan Wei's very high indoor air pollution levels (sometimes exceeding 20 mg/m3), residentially stable population, relatively uncomplicated lifestyle, and wide geographic variation in lung cancer mortality render it highly amenable to quantitative, interdisciplinary investigation of chemical carcinogens due to indoor air pollution. To date, epidemiologic findings reveal a closer association of lung cancer with the indoor burning of "smoky" coal (as opposed to "smokeless" coal or wood) than with tobacco use or occupation. Current aerometric, chemical, and toxicologic findings tend to confirm this association, though the specific carcinogenic constituents of Xuan Wei indoor air pollution have not yet been determined. Chinese and American investigators are conducting interdisciplinary field and laboratory investigations to quantify the lung cancer risk attendant on indoor air pollution relative to other factors, to measure and compare the characteristics of pollution from different Xuan Wei fuels, to determine the relative etiologic importance of pollution composition and concentration, and to develop quantitative relationships between air pollution dose and lung cancer risk.

Response of alanine metabolism in humans to manipulation of dietary protein and energy intakes.

Healthy young adult men were studied with 3 different series of dietary regimens: different levels of protein intake ranging from 1.5 to 0.0 g . kg-1 . day-1; different levels of dietary energy intake; and an excessive intake of protein (3.9 g . kg-1 . day-1). Under each dietary condition, subjects were infused postabsorptively with L-[1-13C]leucine, L-[15N]alanine, and L-[3,3,3-2H3]alanine to measure leucine and alanine kinetics. Leucine flux was significantly reduced when protein intake was restricted (maximum reduction = 24%), but changed insignificantly with dietary energy change or excessive protein intake. Alanine flux and de novo synthesis increased significantly when protein intake was restricted (maximum increase = 50%), changed proportionally with changes in dietary energy, and was significantly reduced with high protein intake. Stepwise regression showed that dietary carbohydrate intake, not protein intake, was the primary factor affecting alanine de novo synthesis. In addition, the alanine 2H tracer produced a 2.5-fold greater measure of alanine de novo synthesis than did the alanine 15N tracer.

Quantitative aspects of glycine and alanine nitrogen metabolism in postabsorptive young men: effects of level of nitrogen and dispensable amino acid intake.

The nutritionally indispensable amino acids (IAA) alone do not maintain body nitrogen (N) balance; a source of "nonspecific" nitrogen from dispensable amino acids (DAA), such as from glycine and alanine or other N compounds, is required. However, the in vivo regulation of the metabolism of these amino acids in humans with varying nutritional states has received little study. Hence, the effects of N intake and the IAA:DAA ratio on kinetic aspects of whole-body alanine and glycine metabolism were examined in eight healthy young adult male subjects. They received an L-amino acid diet supplying N equivalent to about 1.5 g and 0.6 g protein (N X 6.25) per kilogram body weight per day. All were studies at each N level with the IAA:DAA ratio (wt/wt) of 1:1 and 1:0, each for a 7-d diet period. Constant primed, intravenous infusions of L-[1-13C]leucine together with either L-[15N]alanine (four subjects) or [15N]glycine (four subjects) were given to each subject at the end of the diet period, after an overnight fast, to determine rates of de novo whole-body alanine and glycine N synthesis. The rate of alanine synthesis was similar (P greater than 0.05) for all four diets. Glycine de novo N synthesis declined (P less than 0.01) with removal of dietary DAA, especially at the lower intake, where the mean rates [micromoles/(kilogram X hour)] were 59 and 20 for 1:1 and 1:0 ratios, respectively. The possible significance of reduced rates of glycine N synthesis for maintenance of protein nutritional status in the healthy adult is discussed.

Effects of meal consumption on whole body leucine and alanine kinetics in young adult men.

The effects of meal consumption on plasma leucine and alanine kinetics were studied using a simultaneous, primed, continuous infusion of L-[1-13C]leucine and L-[3,3,3-2H3]alanine in four healthy, young, adult male subjects. The study included an evaluation of the effect of sampling site on plasma amino acid kinetics, with blood being drawn simultaneously from an antecubital and dorsal heated hand vein. In comparison with the postabsorptive state, the ingestion of small hourly meals resulted in a 35% increase in plasma leucine flux and a 77% increase in leucine oxidation. Calculated entry of leucine into the plasma compartment from endogenous sources decreased by 65%. Plasma alanine flux more than doubled, indicating a significant enhancement in de novo alanine synthesis. 13C enrichment of leucine in venous and arterialized plasma did not differ significantly, but alanine flux calculated from isotopic measurement in venous plasma was substantially greater than that based on analysis of arterialized blood plasma.

Alanine kinetics in humans: influence of different isotopic tracers.

Whole-body alanine kinetics were studied using continuous infusions of [15N]-, [3,3,3-2H3]-, [1-13C]-, and [3-13C]alanine tracers in healthy male subjects in the postabsorptive state. Alanine kinetics were highly dependent on the choice of isotopically labeled alanine. Highest rates of alanine flux (mean +/- SE) were obtained with the [3,3,3-2H3]alanine (474 +/- 41 mumol X kg-1 X h-1). [1-13C]- and [3-13C]alanine tracers gave intermediate values (297 +/- 12 and 317 +/- 22 mumol X kg-1 X h-1, respectively). The slowest rates of alanine turnover were measured with [15N]alanine (226 +/- 7 mumol X kg-1 X h-1). These results emphasize the heterogeneous metabolism of different portions of the alanine molecule and the importance of choosing an appropriate alanine tracer for studying different aspects of alanine metabolism.

Leukocyte endogenous mediator alters protein dynamics in rats.

Leukocyte endogenous mediator (LEM), a low-molecular-weight peptide synthesized by monocytic cells during phagocytosis, has been implicated as the host's initiator of the protein metabolic response to infection and inflammation. To determine whether administration of LEM would alter protein kinetics, appearance and oxidation of plasma tyrosine as well as the rates of protein synthesis in liver and skeletal muscle were determined in fasted rats that received a 30-hour continuous infusion of either physiologic saline, LEM, or heat-inactivated LEM. The LEM was obtained from rabbit peritoneal exudate and the treatment solutions supplied 2.8 X 10(8) cell equivalents/100 g of body weight (BW) per day. Endogenous tyrosine oxidation increased from 4.0 +/- 0.4 mumol/100 g BW/h to 5.4 +/- 0.7 mumol/100 g BW/h in animals infused with heat-inactivated LEM and to 7.5 +/- 1.5 mumol/100 g BW/h in rats receiving LEM (P less than 0.01). Nonsecretory protein synthesis in the liver was greatest in rats administered LEM (2239 +/- 325 mg/d) when compared with control groups receiving physiologic saline (1122 +/- 195 mg/d) or heat-inactivated LEM (1374 +/- 62 mg/d; P less than 0.01), whereas skeletal protein synthetic rates were unchanged. Rates of muscle and collagen protein breakdown were estimated from the urinary excretion rate of Nt-methylhistidine and hydroxyproline, respectively, and their excretion rose by 30% (P less than 0.05) and 42% (P less than 0.05) with LEM administration. These results suggest that administration of LEM stimulates a mobilization of amino acids from peripheral tissues to support increased visceral protein anabolism while whole body amino acid oxidation is also enhanced. Since similar effects follow fever and infection, these results suggest that LEM may play an underlying role in the protein metabolic response to infection and inflammation.

An altered response by peripheral leukocytes to synthesize or release leukocyte endogenous mediator in critically ill, protein-malnourished patients.

LEM derived from fixed and circulating macrophages is involved in certain aspects of the metabolic response to infection. A reduction in the synthesis or release of LEM from leukocytes of nonstressed, protein-malnourished patients has been demonstrated. In this study, blood leukocytes from 15 protein-malnourished patients (serum albumin less than 2.5 gm/dl) who were critically ill were assayed for their in vitro capacity to produce LEM. Samples were taken before (day 0) and 3 or 7 days after the institution of parenteral nutrition. Hospitalized patients were judged capable of producing LEM (responders) if the percentage of polymorphonuclear leukocytes in the blood of the rats injected with their LEM was greater than 52% ( the minimum value obtained when LEM from 10 human volunteers was injected into the rats). With this criterion, eight patients were responders and only one died during their hospital stay, whereas five of seven nonresponders expired (p less than 0.05). On day 0, prior to intravenous nutritional support, there was no difference in the capacity to produce LEM between responding and nonresponding patients. However, those patients whose leukocytes were capable of responding received significantly greater quantities of dietary protein and calories over the 7-day study period than nonresponders (p less than 0.05). There was a correlation between the polymorphonuclear leukocyte response to LEM in rats and the patients' dietary protein intake (r = 0.719, p less than 0.005). these findings suggest that an appreciable fraction of severely ill, protein-malnourished patients have a reduced capacity to synthesize LEM, as judged by bioassay and an increased risk of mortality. The in vitro capacity to produce LEM in a critically ill population appears to be associated with the dietary intake of the patient.