[Determination of dimethyl oxalate and diethyl oxalate in workplace air by high performance liquid chromatography].

Objective: To establish a high performance liquid chromatography method for the simultaneous determination of dimethyl oxalate (DMO) and diethyl oxalate (DEO) in workplace air. Methods: From January 2022 to January 2023, air samples were collected by silica gel tubes, desorbed by acetonitrile, separated by C18 chromatographic column, detected by photo-array detector, and retention time was used to characterize and peak area was used to quantify at 210 nm wavelength. Results: The linear relationships of DMO and DEO were good, r>0.999. The detection limits of DMO and DEO were 0.39 and 0.52 µg/ml, respectively. The quantitative limit was 1.28 µg/ml for DMO and 1.72 µg/ml for DEO. Average desorption efficiency for DMO was 82.40%-92.72%, and DEO was 94.13%-97.69%. The intra-assay precision of DMO was 1.87%-6.18%, and DEO was 2.25%-3.31%. Inter-assay precision of DMO was 3.29%-5.73%, and DEO was 1.38%-2.94%. Average sampling efficiencies were 100% for both DMO and DEO. Breakthrough capacity of DMO was 37.61 mg (200 mg solid adsorbent), DEO was >28.11 mg (200 mg solid adsorbent). Samples should be stored at 4 ℃ for at least 7 days. Conclusion: This method is easy to operate and has strong practicability. All indicators meet the requirements of the specification, and it is suitable for the simultaneous determination of DMO and DEO in the workplace air.

[Study on determination of 2-thioxothiazolidine-4-carboxylic Acid in urine by high performance liquid chromatography].

Objective: To establish a high performance liquid chromatography method for the determination of 2-thioxothiazolidine-4-carboxylic acid (TTCA) in urine. Methods: After acidification with hydrochloric acid, TTCA in urine was first extracted by ethyl acetate with excessive sodium chloride, then gradient separated by a symmetry C18 column and then detected by a diode array detector. The quantification was based on a working curve of external standard method. Results: The linear relationship of TTCA in urine was good in the range of 0.03-10.00 mg/L, and the correlation coefficient was 0.9999. The detection limit and minimum quantitative concentration of TTCA in urine were 0.008 mg/L and 0.027 mg/L. The intra-assay precision of the method was 0.9%-1.4%, the inter-assay precision was 1.3%-3.5%, and the average recovery was 85.0%-92.7% while the concentrations of TTCA in urine was 0.8, 2.0 and 8.0 mg/L, respectively (n=6) . Conclusion: The gradient elution high performance liquid chromatography method has simple operation and high sensitivity, and it is suitable for the determination of TTCA on a low level in urine for occupational workers exposure to carbon disulfide.

[Determination of five phenolic compounds in workplace air by composite sampling tube-high performance liquid chromatography].

Objective: To develop a method for simultaneous determination of Dydroquinone, Resorcinol, Pyrocatechol, 4-Nitrophenol and 2, 4-Dinitrophenol in workplace air by high performance liquid chromatography. Methods: Air samples were collected by composite tube (front end glass fiber filter membrane, back section silica gel) , 10% methanol was desorbed, separated by C18 chromatographic column, detected by photo-diode array (PDA) detector, and quantitatively determined by external standard method at the wave-length of 230 nm. Results: The linear relationship of 5 phenolic compounds was good (r>0.999) . The detection limit of glass fiber filtration membrane and silica gel adsorbent were 0.13-0.41 g/ml and 0.16-1.04 g/ml respectively. The quantitative limit of glass fiber filtration membrane was 0.44-1.36 g/ml, and the silica gel adsorbent was 0.52-3.46 g/ml. The average desorption efficiency of glass fiber membrane and silica gel adsorbent were 97.5%-100.1% and 86.9%-100.3%, respectively. In and between batches, the precision glass fiber filtration membrane was 0.71%-4.88%, 0.91%-4.82%, silica gel adsorbent was 0.47%-4.62%, 0.76%-5.52%. Samples can be stored for at least 30 days at -20 ℃. The possible co-existing interferences of aniline, phenol, p-nitrochlorobenzene, o-nitrophenol and trinitrophenyl did not interfere with the determination. Conclusion: The sensitivity, precision, accuracy and linear range of this method all meet the requirements of the specification. The collection and preservation of samples can also meet the requirements of the limits. It is suitable for the simultaneous determination of hydroquinone, resorcinol, hydroquinone, hydroquinone, hydroquinone, p-nitrophenol and 2, 4-dinitrophenol in the air of the workplace.

[Clinical characteristics, diagnosis and treatment of human babesiosis: a review].

Babesiosis is an important tick-transmitted zoonosis caused by hematotropic parasites of the genus Babesia, zoonosis disease, which is widely distributed across the world. There are 12 species of Babesia causing human diseases, including B. microti, B. divergens, B. venatorum and B. duncani. The clinical symptoms of human Babesia infections mainly include fever, headache, chills, myalgia and fatigue, and severe infections may cause death. The diagnosis of babesiosis mainly depends on laboratory testing combined with clinical manifestations and epidemiological surveys, and the diagnostic techniques mainly include microscopic examinations of the blood smears, serological tests and molecular biological assays. Currently, azithromycin-atova-quone or clindamycin-quinine combinations are common treatments for babesiosis. This review summarizes the clinical features following human infections with various species of Babesia, the diagnostic techniques and diagnostic criteria of babesiosis and the currently available treatments for babesiosis.

[Analysis of the effects on menopausal symptoms, quality of Life, and cardiovascular risk factors of five different therapy in women at early stage of menopause].

OBJECTIVE: To explore the effects of five different therapy in women at early stage of menopause on menopausal symptoms, quality of Life and cardiovascular risk factors. METHODS: A total of 140 women at early stage of menopause were randomly divided into five groups. Thirty women took Conjugated estrogen and medroxyprogesterone acetate(CEE+ MPA) sequential therapy, 27 women took estradiol valerate and medroxyprogesterone acetate(E2V+ MPA) sequential therapy, 26 women took estradiol valerate and Progesterone Soft Capsules(E2V+ P) sequential therapy, 30 women took Kuntai capsule, and 27 took Cohosh extract.Patients in the Menopausal Hormone Therapy(MHT) groups took twelve cycles of treatment course, in the botanical drug and Chinese patent drug groups took twelve months. The KMI scalewas used to measure the level of menopausal symptoms. MENQOL scale was used to measure the health-related quality of life before and at the 3(rd) month, 6(th) month, 9(rd) month and 12(th) month after the treatment. Some serological indicators which related to cardiovascular risk factors were collected before and at the 12(th) month after the treatment. RESULTS: (1) KMI: It showed that the KMI in five groups after the treatment were significantly different(P<0.01), the group of CEE+ MPA decreased most(13±1). The KMI after the treatment were all significantly lower than that before. (2)MENQOL: It showed that the MENQOL in five groups were significantly different(P<0.01), the group of CEE+ MPA decreased most (84±3), then the group of Kuntai(85±3). The MENQOL after the treatment were all significantly lower than that before. (3)The change of cardiovascular risk factors: it showed that the serological indicators FBGin group of CEE+ MPA after the treatment were significantly lower than that before(P<0.05); the TC, LDL, FI in group of E2V+ MPA after the treatment were significantly lower than that before(P<0.05); the FBG, FI in group of E2V+ P after the treatment were significantly lower than that before(P<0.05). CONCLUSION: The MHT, botanical drug and Chinese patent drug have great clinical curative effects in treating perimenopause syndrome, improving the health-related quality of life and decreasing risk factors of cardiovascular disease.With rare adverse events and good clinical medication safety, they could be widely applied to clinic to women at early stage of menopause who was suffering menopausal symptoms.

Practices and thinking of laboratory detection in the aid to West Africa to fight against Ebola.

BACKGROUND: The outbreak of Ebola virus disease in West Africa has brought great disaster to the people's health in affected countries. China dispatched first group of public health experts and medical staff to Sierra Leone in September 2014 to fight Ebola. METHODS: To systematically collect huge amount of primary data, and to make analysis, draw conclusions and lessons in terms of six aspects, respectively as training before departure, local disease information, track of epidemic situation, transformation of temporary laboratory, detection of Ebola virus samples as well as assessment through single blind test. RESULTS: 1) Our team has launched preparatory works in advance before going to Sierra Leone. 2) Malaria is the country's severest infectious disease. 3) Observation centers were overcrowded with large number of suspected cases being inspected, implying high risk of nosocomial infection. 4) A BSL-II laboratory with 3 work areas and 2 buffer areas was built, achieving several major functions within 6 days. 5) Confirmed by South African Raqqa laboratory, our detection accuracy reached 100%. 6) At one week before return, the daily average sample amount of our team reached 66 cases and our detection capability was equivalent to that of USA. CONCLUSIONS: Successful experience from fighting against Ebola in Sierra Leone could be summarized as: 1) Optimized processes and scientific security measures are prerequisite to improving the detection ability. 2) The close collaboration between laboratory and observation center has created a new model of China's foreign aid. 3) Comprehensive information investigation and training lay a solid foundation for the successful completion of tasks.

Isolation and characterization of the Chrysanthemum nitrate transporter CmNRT1.

In this study, the nitrate transporter gene CmNRT1 was isolated from the chrysanthemum variety 'Nannongxuefeng'. The full-length cDNA contains an open reading frame of 1761 bp encoding 587 residues. Using qRT-PCR, we found that CmNRT1 was induced by 10 mM NO3(-) in roots and shoots. Two Arabidopsis thaliana transgenic plants expressing CmNRT1 were selected for functional analyses. Root (15)N influx in wild-type and transgenic A. thaliana lines under 10 or 0.2 mM (15)NO3 was tested. Our results indicate that CmNRT1 encodes a constitutive component for a low-affinity transporter.

Salicylic acid-induced changes in physiological parameters and genes of the flavonoid biosynthesis pathway in Artemisia vulgaris and Dendranthema nankingense during aphid feeding.

Phloem-feeding aphids cause serious damage to plants. The mechanisms of plant-aphid interactions are only partially understood and involve multiple pathways, including phytohormones. In order to investigate whether salicylic acid (SA) is involved and how it plays a part in the defense response to the aphid Macrosiphoniella sanbourni, physiological changes and gene expression profiles in response to aphid inoculation with or without SA pretreatment were compared between the aphid-resistant Artemisia vulgaris 'Variegata' and the susceptible chrysanthemum, Dendranthema nankingense. Changes in levels of reactive oxygen species, malondialdehyde (MDA), and flavonoids, and in the expression of genes involved in flavonoid biosynthesis, including PAL (phenylalanine ammonia-lyase), CHS (chalcone synthase), CHI (chalcone isomerase), F3H (flavanone 3-hydroxylase), F3'H (flavanone 3'-hydroxylase), and DFR (dihydroflavonol reductase), were investigated. Levels of hydrogen peroxide, superoxide anions, MDA, and flavonoids, and their related gene expression, increased after aphid infestation and SA pretreatment followed by aphid infestation; the aphid-resistant A. vulgaris exhibited a more rapid response than the aphid-susceptible D. nankingense to SA treatment and aphid infestation. Taken together, our results suggest that SA could be used to increase aphid resistance in the chrysanthemum.

Molecular authentication of Gynostemma pentaphyllum through development and application of random amplification polymorphic DNA sequence-characterized amplified region marker.

Due to the morphological similarities of aerial parts, it is difficult to distinguish Gynostemma pentaphyllum from Cayratia japonica, which is usually an adulterant of the former. To develop a reliable method for the identification and authentication of G. pentaphyllum, a combination of random amplification polymorphic DNA (RAPD) technique with sequence-characterized amplified region (SCAR) markers was studied. Twenty-five samples of G. pentaphyllum and two samples of C. japonica were collected from different regions in Guangxi or bought from different provinces in China. Through the RAPD analysis, significant genetic polymorphism was observed among the intraspecies samples of G. pentaphyllum. Furthermore, a specific marker, J-750, was obtained for authentication. Therefore, the SCAR marker for G. pentaphyllum (359 bp) was developed from the RAPD amplicon. With PCR amplification using the SCAR primers, a specific band of 359 bp was distinctly visible for all tested samples of G. pentaphyllum, but was absent in the samples of C. japonica. Furthermore, the results revealed that the SCAR marker was useful for the identification and authentication of G. pentaphyllum irrespective of whether samples were fresh, dry, or of commercial origin. The SCAR marker obtained in this study successfully authenticated G. pentaphyllum through an integrated PCR system containing SCAR and control primer combinations of two pairs. In addition, it was also used for simultaneous discrimination of G. pentaphyllum from C. japonica.

Effects of alfalfa meal on the intestinal microbial diversity and immunity of growing ducks.

This study was conducted to investigate the effects of alfalfa meal diets on the intestinal microbial diversity and immunity of growing egg-type ducks. A total of 128 healthy 7-week-old female egg-type Shaoxing ducks were selected and randomly assigned into four dietary treatments: 0%, 3%, 6% and 9% alfalfa meal for 8 weeks. Each treatment consisted of four replicates of eight ducks each. Polymerase chain reaction denaturing gradient gel electrophoresis (PCR-DGGE) was used to characterize the microbiota. The results showed that the DGGE fingerprints of the V6-V8 fragments of the 16S rRNA from the caeca and faeces of ducks fed 3%, 6% and 9% alfalfa meal had significantly higher microbiota species richness than those fed 0% alfalfa meal (p < 0.05). The Shannon-Weiner index of the microbiota from the caeca and faeces of ducks fed 3%, 6% and 9% alfalfa meal was significantly higher than those fed 0% alfalfa meal (p < 0.05). Molecular analysis of the caecal and faecal DNA extracts showed that the alfalfa meal diet promotes the intestinal microbial diversity, as indicated by their higher species richness and Shannon-Weiner index. However, the groups did not significantly differ in terms of average daily gain, feed intake and gain-to-feed ratio (p > 0.05), and the 3-9% alfalfa meal did not affect the growth performance of the growing egg-type ducks. The proliferation of T and B lymphocytes was significantly greater (p < 0.05) in the groups supplemented with 3%, 6% and 9% of alfalfa meal than the unsupplemented control group, and alfalfa meal promoted the lymphocytes proliferation of the growing egg-type ducks. Dietary alfalfa meal supplementation increases intestinal microbial community diversity and improves of the immune response growing egg-type ducks.

Lyme borreliosis caused by diverse genospecies of Borrelia burgdorferi sensu lato in northeastern China.

The variety of Borrelia burgdorferi sensu lato (B. burgdorferi) genospecies leads to distinction in clinical manifestations of Lyme borreliosis (LB). There are reports of LB clinical characteristics in China, where the B. burgdorferi genospecies in ticks and animal hosts are different from those in Europe and North America. During May to September in 2010 and 2011, all patients who had erythema migrans (EM, more than 5 cm in diameter) after a recent tick-bite, and sought medical care at Mudanjiang Forestry Central Hospital, Heilongjiang Province of northeastern China, were enrolled in the study. Specific PCR was used to determine the B. burgdorferi genospecies in the disseminated patients. Of 265 EM patients, B. burgdorferi DNA was detected in blood specimens from 15 of 55 disseminated patients. Sequence analyses of 5S-23S rRNA, flagellin, ospC, 16S rRNA and ospA genes revealed that 11 patients were infected with Borrelia garinii, three with Borrelia afzelii and one with Borrelia valaisiana-related genospecies. Among 15 patients, 40%, 13.3% and 13.3% manifested pruritus, pain and ulceration, respectively. Systemic symptoms, arthralgia or a swollen joint and lymphadenopathy were observed in 26.7%, 13.3% and 6.7% patients, respectively. In northeastern China, three genospecies of LB patients were detected. The B. burgdorferi genospecies identified in this study was predominantly B. garinii. A case infected with B. valaisiana-related genospecies was reported for the first time.

New insights into the prolactin-RsaI (PRL-RsaI) locus in Chinese Holstein cows and its effect on milk performance traits.

Prolactin (PRL) plays central roles in mammals' reproduction, gland development, milk secretion, and the expression of milk protein genes. In dairy cattle, the PRL gene is a potential quantitative trait locus and genetic marker related to milk performance traits. Here, a total of 586 randomly selected Chinese Holstein cows were genotyped for locus PRL-RsaI. One haplotype block containing eight SNPs was identified in the region from intron 3 to intron 4 of the PRL gene in Chinese Holstein cows. One tag SNP (7545 G → A) was selected to represent the haplotype block defined by the genotypic data. The cows with genotype AA of this tag SNP had a higher milk yield at 305 days (8457 ± 938 kg) than the cows with GA (7537 ± 1278 kg; P < 0.01) or GG (7757 ± 1174 kg; P < 0.05). This suggests that the haplotype block examined in this study contains important markers for milk production traits in Chinese Holstein cows.

Expression profiling analysis of hypoxic pulmonary disease.

Exposure of humans to low levels of environmental oxygen results in alveolar hypoxia and normally causes chronic pulmonary hypertension and morphological alterations of precapillary pulmonary vessels. In this study, the microarray dataset GSE11341 was used to identify potential differentially expressed genes related with human lung microvascular endothelial cell hypoxia. In addition, gene ontology term enrichment analysis was performed to explore their underlying functions. In addition, we also investigated the small molecules by comparing with the Connectivity Map. We found that hypoxia samples of 3, 24, and 48 h relative to 0 h displayed 22, 21, and 29 differentially expressed genes, respectively. Among them, six genes (ADM, HMOX1, VEGFA, EGLN3, APOLD1, and ANGPTL4) were closely related to pulmonary microvascular endothelial cell hypoxia response. Three drugs (pindolol, sulfapyridine, and ciclopirox) were selected as candidates to treat hypoxia-related pulmonary diseases. In conclusion, our results provide some underlying drug targets for treatment of hypoxic pulmonary patients.

An SduI polymorphism at intron 20 of the Chinese Holstein cow STAT4 gene and its effect on milk performance traits.

The signal transducer and activator of transcription (STAT) genes are responsive to a wide range of cytokines, growth factors, and hormones, and thus control important biological processes. In humans, STAT4 mutations have been identified as genetic markers for rheumatoid arthritis, systemic lupus erythematosus, and primary Sjögren's syndrome, whereas little research has been conducted on bovine STAT4 mutations and their potential effects. Herein, 585 Chinese Holstein cows were used to investigate STAT4 mutations and their effects on milk performance traits. One haplotype block, containing g.95879G>A, g.96013G>C, was identified in intron 20 of the bovine STAT4 gene by restriction fragment length polymorphism-polymerase chain reaction and DNA sequencing. Two single nucleotide polymorphisms were significantly associated with milk yield at 305 days (P < 0.05), and with protein percentage (P < 0.05). Chinese Holstein cows with the haplotype GGGG had higher milk yields at 305 days and lower protein percentages. These results suggest that the 2 single nucleotide polymorphisms of STAT4 could be used as genetic markers for milk performance traits in Chinese Holstein cows.

Re-analysis of expression profiles for revealing new potential candidate genes of heart failure.

BACKGROUND: Chronic heart failure (HF) is characterized by diminished cardiac output and pooling of blood in the venous system. AIM: We used the GSE1145 microarray data to identify potential genes that related to heart failure to construct a regulation network. MATERIALS AND METHODS: In the network, some of transcription factors (TFs) and target genes have been proved to be related to heart failure in previous study. The gene MYC, RELA, HIF1A, NFκB1 and SMAD3 are as hub nodes in our transcriptional network and have a close relationship with heart failure. RESULTS: The study did not address regulation network but researched for the significant pathways related to chronic heart failure. Besides, RELA and NFκB1 interfere with each other in response to HF. CONCLUSIONS: It is demonstrated that transcriptional network analysis is useful in identification of the candidate genes in heart failure.

DNA polymorphisms of the Hu sheep melanocortin-4 receptor gene associated with birth weight and 45-day weaning weight.

The melanocortin-4 receptor (MC4R) has important roles in regulating food intake, energy balance, and body weight in mammals. In pigs and cattle, MC4R mutations have been identified as genetic markers for growth and traits. Compared with abundant research conducted on other livestock species, little is known about mutations of the ovine MC4R gene. We investigated the effect of MC4R polymorphisms on birth weight and on 45-day weaning weight in 144 Hu sheep. Four single nucleotide polymorphisms (SNPs; g.1016 G/A, g.1240 T/C, g.1264 G/A, and g.1325 A/G) were identified in the 3ꞌ-untranslated region of Hu sheep MC4R by PCR-single-strand conformation polymorphism and DNA sequencing. A haplotype block, containing g.1240 T/C, g.1264 G/A, and g.1325 A/G, was constructed within the Hu sheep MC4R gene. Four SNPs were found to be significantly associated with 45-day weaning weight, while the haplotype block was significantly associated with birth weight. Hu sheep with the genotypes GG in g.1016 G/A or with the genotype CCAAGG in the haplotype block, had higher 45-day weaning weights. We conclude that these 4 SNPs of the MC4R gene have potential as genetic markers for early growth traits in Hu sheep.

Effects of alfalfa meal on growth performance and gastrointestinal tract development of growing ducks.

A study was conducted to evaluate effects of alfalfa meal on growth performance and gastrointestinal tract development of growing layer ducks to provide evidence for application of alfalfa meal in the duck industry. Two hundred and fifty-six healthy Shaoxing 7-wk old growing layer ducks were selected and randomly allocated to 1 of 4 dietary treatments based on corn and soybean meal and containing 0, 3, 6, and 9% of alfalfa meal for 8 wks. Each treatment consisted of 4 replicates of 16 ducks each. Briefly, birds were raised in separate compartments, and each compartment consisted of three parts: indoor floor house, adjacent open area and a connecting water area. The results showed: i) Growing ducks fed alfalfa meal diet were not significantly different in average daily gain, feed intake and gain-to-feed ratio from those fed no alfalfa diet (p>0.05). ii) Alfalfa meal increased the ratio crop, gizzard to live weight, caecum to live weight, the caecum index of growing ducks (p<0.05). iii) Villus height in duodenum and jejunum of growing ducks increased significantly with the increase of alfalfa meal levels (p<0.05). Crypt depth in duodenum and jejunum of growing ducks decreased significantly with the increase of alfalfa meal levels (p<0.05). This experiment showed that feeding of alfalfa meal to growing layer ducks could improve gastrointestinal tract growth and small intestinal morphology without effect on performance. This experiment provides evidence that alfalfa meal is a very valuable feedstuff for growing layer ducks.