Fetal pulmonary artery stiffness is a strong predictor of persistent pulmonary hypertension of the newborn - An echocardiographic study.

OBJECTIVE: Pulmonary artery stiffness (PAS) is a strong and independent predictor of mortality in adult patients with pulmonary hypertension (PH). But the change in PAS during perinatal period remains unknown. Here, we aimed to explore the feasibility and performance of PAS on predicting persistent pulmonary hypertension of the newborn (PPHN). METHODS: 1325 fetuses underwent a dedicated echocardiography screening for fetal heart defects during second trimester, third-trimester and neonatal period with the measurement of acceleration time (PAAT) and maximal frequency shift (MFS) of pulmonary artery flow. PAS (MFS/PAAT ratio) was calculated. RESULTS: Six fetuses were diagnosed as PPHN. Compared with the normal fetuses, those with PH had greater values of PAS during each period of time (second trimester, 52.6(46.2-54.5) vs. 32.4(28.0-39.4) kHz/s, p = 0.0003; third trimester, 52.9(46.1-55.3) vs. 29.7(27.3-33.3) kHz/s, p = 0.0002; neonatal period, 127.4(85.2-150.8) vs. 26.6(22.7-35.0) kHz/s, p < 0.0001). There was a statistically significant correlation between PAS and mean pulmonary artery pressure (p < 0.05) but no correlation between PAS and gestational age (p > 0.05) whether in normal fetuses or not. The area under receiver operating characteristic curve (AUC) of 0.97 for PAS during third trimester was superior to that for PAS during second trimester (AUC, 0.94) in predicting PPHN. The optimal cutoff value of PAS during third trimester was 37.40 KHz/s, with a sensitivity of 100%, a specificity of 91%, and an accuracy of 92%. CONCLUSION: There was a significant difference in PAS between normal fetuses and those with PH. PAS has a power performance on predicting PPHN.

[Role of goat in transmission of schistosomiasis japonica â £ Schistosome development in goat and egg count and distribution in goat feces].

OBJECTIVE: To describe the growth and development of Schistosoma japonicum in goat and the intensity and temporal distribution of eggs excreted by goat feces, so as to provide baseline data for the control and elimination of the role of goat in the transmission of schistosomiasis. METHODS: The goat animal models of schistosomiasis were established, and stool samples were collected for parasitological examinations. The number of adult worms recovered, variation of schistosomes in goat at different time points post-infection, number of eggs in schistosomes, variation in number and temporal profiles of eggs excreted from goat feces were observed. RESULTS: Of the 6 schistosome-infected goat, 415 adult worms were recovered, with a mean adult worm recovery of 34.58% (range, 23.00% to 45.50%). Among the 5 goat infected with 200 cercariae each, 47, 93, 77, 74 and 73 adult worms were recovered 2, 5, 8, 11 and 14 months post-infection, respectively. There were (200.00±42.33), (226.20±45.88), (168.20±25.85), (183.80±55.13) and (190.80±53.53) eggs detected in female schistosomes. The mean prepatent period of eggs excreted by 10 infected goat was (37.7±3.02) d. From 2 to 14 months post-infection, 7 batches of goat feces were hatched, and there were 30, 23, 14, 1 and 2 times for miracidium intensity of "++++", "+++", "++", "+" and "-", respectively, with 42.86%, 32.86%, 20.00%, 1.43% and 2.86% constituent ratios of miracidium intensity. CONCLUSIONS: Approximately 1/3 S. japonicum cercariae may develop to adults in goats post-infection, and the prepatent period of eggs is (37.7±3.02) d. There is no remarkable decrease seen in the number of adult worms, eggs in female schistosomes and eggs in goat feces within 14 months post-infection. Our findings suggest a long duration for infected goat in the transmission of schistosomiasis, and there is no evidence to prove the "self-cure" phenomenon in goat, indicating that goat is an important source of infection for schistosomiasis japonica.

Urinary S-phenylmercapturic acid as a key biomarker for measuring occupational exposure to low concentrations of benzene in Chinese workers: a pilot study.

OBJECTIVE: This study analyzed the level of urinary S-phenylmercapturic acid (U-SPMA) for low benzene exposure in a group of Chinese shoe-making workers. METHODS: Urinary samples from 55 workers exposed to benzene at levels lower than 10 parts per million (ppm) were collected at postshift. U-SPMA level was determined using high-performance liquid chromatography/mass spectrography (HPLC/MS) method. RESULTS: Good linearity of U-SPMA was observed within the range from 10 to 320 µg/L (r = 0.9994). Concentration of airborne benzene ranged from 0.71 to 32.17 mg/m³, and three segments were divided with different levels of exposure (≤6.0, 6.0 to 10.0, 10 to 32.5 mg/m³), the median U-SPMA concentrations were 49.55, 102.15, and 335.69 µg/g Cr, respectively. CONCLUSION: A good linear correlation was found between U-SPMA levels and airborne benzene concentrations. The selected method could be applied for detecting other working conditions in China.

[Study on the standard of health protection zone for petroleum processing industry].

OBJECTIVE: To establish health protection zone standards for petroleum processing industry. METHODS: The intensity of characteristic pollutants from fugitive emission were estimated by the inverse method of ground concentration through field survey and monitoring for representative petroleum processing industry, which was calculated health protection zone by using the model of atmospheric diffusion. RESULTS: Characteristic pollutant of fugitive emission source from petroleum processing industry was confirmed as hydrogen sulfide. When local average wind speed in the past five years was less than 2, 2-4 m/s and more than 4 m/s respectively and meanwhile the scale of petroleum processing industry was less than 8 million tons, the recommended value of health protection zone were 900, 800, 700 m respectively. Besides, when the scale of petroleum processing industry was more than 8 million tons and in the same wind speed level, the recommended value of health protection zone were 1200, 1000, 900 m respectively. CONCLUSIONS: Recommended value of health protection zone for petroleum processing industry was reasonable and feasible through revising and improving of the version of 1987's standard.

[A cross-sectional study about the effects of residential exposure to power transmission line on human nervous system symptoms and hematology].

OBJECTIVE: To investigate the possible effects on nervous system and health condition under the exposure to electromagnetic field. METHODS: Take the resident around the power transmission line as the objects and were divided into 3 groups by the distance from the power transmission line 20 m, 100 m and 500 m, respectively. Some living conditions and health conditions were recorded by face-to-face the questionnaire survey, and Hematological indices of each groups were examined including IgG, IgM, leukocyte formulae, erythrocyte, hemoglobin and platelet. RESULTS: There was no significant difference in each group, according exposure of daily life, such as drinking and smoking (P > 0.05). Compared with the each distance groups, it was presented significant difference between the distance from the power transmission line and the incidence of headache or dizziness, insomnia and easy weary and so on (P < 0.05). In hematology aspect, with the horizontal distance from the power transmission line decreasing, PLT level of residents was reductive and the difference was statistically significant (P < 0.001), whereas leukocyte formulae, erythrocyte, hemoglobin, IgG and IgM had no significant difference among each group (P < 0.05). CONCLUSION: Closely exposure to electromagnetic field may induce headache and so on and decrease the level of PLT.

Trans, trans-muconic acid as a biomarker of occupational exposure to high-level benzene in China.

OBJECTIVE: The work aimed to study the potential correlation between the high-level benzene exposure and its urinary metabolites S-phenylmercapturic acid (SPMA) and trans, trans-muconic acid (t,t-MA) in Chinese shoe-making workers. METHODS: Individual benzene-exposed levels were determined by gas chromatography analysis, urinary t,t-MA, and urinary SPMA were determined by high performance liquid chromatography-an ultraviolet detector and liquid chromatography/electrospray tandem mass spectrometry method, respectively. RESULTS: The concentration of benzene ranged from 2.57 to 146.11 mg/m³. And the correlation between benzene and t,t-MA was significantly higher than that of SPMA at the postshift, for example, the correlation coefficient was 0.905 and 0.537 for t,t-MA and SPMA, respectively. Moreover, The relative internal exposure index of t,t-MA (0.28 mg/g Cr: mg/m³) was more similar to the data supplied by American Conference of Governmental Industrial Hygienists compared to the index of SPMA (0.025 mg/g Cr:mg/m³). CONCLUSIONS: t,t-MA appeared to be a more specific biomarker than SPMA at high-level benzene exposure.

[Establishment of biological limit value of urinary S-phenylmercapturic acid for occupational exposure to benzene].

OBJECTIVE: To establish the biological exposure limit values of urinary S-phenylmercapturic acid (SPMA) for assessing occupational exposure to benzene. METHODS: Study participants were selected from 55 workers of benzene exposures below 32.5 mg/m(3). The concentration of personal exposure to benzene was measured by gas chromatography and sampled with personal sampler. The urine samples were collected at the end of work shift and individual internal exposure level was evaluated by determination of SPMA in urine by HPLC/MS method. Comparison of external and internal exposure was assessed by the relative internal exposure (RIE) index. RESULTS: The benzene exposure level ranged from 0.71 to 32.17 mg/m(3) (geometric mean 6.98 mg/m(3), median 7.50 mg/m(3)). The urinary SPMA at the end of the work shift were significantly correlated with benzene exposure, (microg/g Cr) = -8.625 + 18.367X (mg/m(3)), r = 0.8035, (P < 0.01). According to the occupational exposure limit for benzene in China and calculation of regression equation, the expected value of urinary SPMA was 101.58 microg/g Cr. Mean level of biotransformation of per mg/m(3) benzene to urinary SPMA was 18.23 microg/g Cr and the metabolic efficiencies of benzene transformation to urinary SPMA decreased with benzene exposure increased. CONCLUSION: Based on abroad documents and data, biological limit value for occupational exposure to benzene in China is recommended as follows: 100 microg/g Cr (47 micromol/mol Cr) for SPMA in the urine at the end of shift.

High-performance liquid chromatographic determination of urinary trans, trans-muconic acid excreted by workers occupationally exposed to benzene.

OBJECTIVE: To investigate the relationship between trans, trans-muconic acid (ttMA) as benzene metabolite of occupational workers and benzene concentration in air. METHODS: A rapid and sensitive high-performance liquid chromatography was developed to determine the level of urinary ttMA. ttMA was extrated from urinary samples in liquid-liquid phase a ODS (2) (5u) column (phi 4.6 mm x 150 mm) and detected at wavelength 264 nm in a UV detector using vanillic acid as an internal standard. The mobile phase was acetaticacid/tetrahydrofuran/methanol/water (v/v, 1:2:10:87). The method was validated with 56 urine samples collected from occupationally benzene-exposed individuals. RESULTS: A correlation coefficient (r = 0.9963) was found for ttMA ranging 0.10-10.00 microg/mL. The limit of detection was 0.10 microg/mL. The recovery and reproducibility were generally over 90%. There was a positive correlation between ttMA and benzene level in air. The equation was Y = 0.859 + 0.108C (before work, r = 0.6200) or Y = 1.980 + 0.179C (after work, r = 0.7930). CONCLUSION: This method can be used to determine and control the level of urinary ttMA in those who are occupationally exposed to benzene.

Effect of manganese on heat stress protein synthesis of new-born rats.

AIM: To study the effect of manganese (Mn) on heat stress protein 70 (HSP70) synthesis in the brain and liver of new-born rats whose mother-rats were exposed to Mn. METHODS: 32 female rats were randomly divided into four groups. One group was administrated with physiological saline only as control group, the other three groups were administrated with 7.5, 15 and 30 mg x kg(-1) manganese chloride (MnCl2) by intraperitioneal injection every two days for two weeks. After delivery, the mother-rats received MnCl2 unceasingly for a week with the same method. Then the contents of Mn Zn Cu and Fe in the livers of the new-born rats were determined by atomic absorption spectroscopy; The level of HSP70 in the brains and the livers of the new-born rats as detected by Western-dot-blotting, and the SOD activities were measured simultaneously. RESULTS: The contents of Mn in the livers of new-born rats of the experimental groups(respective 1.38+/-0.18, 2.73+/-0.65,3.44+/-0.89 microg x g(-1)) were significantly increased compared with the control group(0.88+/-0.18 microg x g(-1); P<0.01); The contents of Fe in the livers of new-born rats of 15 and 30 mg x kg(-1) experimental groups (426+/-125, 572+/-175 microg x g(-1), respectively) were significantly increased compared with the control group(286+/-42 microg x g(-1); P<0.05); the levels of Zn in the livers of the new-born rats of three experimental groups(254+/-49, 263+/-47, 213+/-28 microg x g(-1), respectively) were lower than those of the control group(335+/-50 microg x g(-1); respective P<0.05, P<0.01); and the levels of Cu showed no significant difference among the four groups(three experimental groups: 75+/-21, 68+/-241 and 78+/-18 microg x g(-1); control group: 83+/-9 microg x g(-1); P<0.05). There was a significant increase in the levels of HSP70 in the brains of new-born rats of the 30 mg x kg(-1) group (19.5 x 10(3)+/- 1.3 x 10(3)A;control group:14.3 x 10(3)+/-1.4 x 10(3)A; P<0.01) and the levels of HSP70 in the livers of new-born rats of three experimental groups(respective 19.6 x 10(3)+/- 3.9 x 10(3)A,18.5 x 10(3)+/-3.8 x 10(3)A, 22.4 x 10(3)+/-1.9 x 10(3)A) also increased than control group(13.3 x 10(3)+/-1.0 x 10(3)A;P<0.01), but the SOD activities showed no significant difference among brains of the four groups (experimental groups: 5.04+/-0.43, 4.83+/-0.48, 4.60+/-0.84 ku x g(-1); control group: 4.91+/-0.37 ku x g(-1); P<0.05). The SOD activities in the livers of 15 mg x kgP< group(5.41+/-0.44 ku x gP<) was lower than the control group(5.95+/-0.36 ku x gP<; P<0.05). CONCLUSION: While mother-rats were exposed to manganese, the metabolisms of Mn Zn and Fe of new-born rats in the livers were influenced and were situated in a stress status, thus HSP70 syntheses is induced in the brains and livers of new-born rats, but the mechanism of this effect in the developmental toxicity of Mn remains to be further studied.