Erythrocyte arginase, pyrimidine 5''-nucleotidase (P5N), and deoxypyrimidine 5''-nucleotidase (dP5N) as indices of lead exposure.

The activities of three erythrocyte (rbc) enzymes, arginase, pyrimidine 5'-nucleotidase (P5N), and deoxypyrimidine 5'-nucleotidase (dP5N), were compared in 16 lead workers and 14 age matched controls as correlates of blood lead (PbB) and unextracted zinc protoporphyrin (EP) concentrations. Subjects with PbB of 0.9-2.5 microM (19-52 micrograms/dl) had 6.5 +/- 0.6 IU of P5N activity with uridine monophosphate (UMP) as substrate, significantly less (p less than 0.001) than the 12.0 +/- 0.7 IU activity of controls with PbB 0.3-0.6 microM (6-12 micrograms/dl). The mean activity of rbc dP5N with either deoxyuridine monophosphate (dUMP) or thymidine monophosphate as substrate, and of rbc arginase, did not differentiate the two groups. The correlation coefficients of ln PbB with the selected substrates for P5N and dP5N were: UMP, r = -0.75; dUMP, r = -0.61; TMP, r = -0.23. The correlation coefficient of ln PbB and arginase activity was -0.03. Rbc P5N (UMPase) is a significant correlate of PbB, equivalent to rbc protoporphyrin. HPLC assay of rbc UMPase activity is a sensitive and rapid assay that appears to meet criteria for a reliable clinical laboratory index of blood lead concentrations.     

Erythrocyte arginase, pyrimidine 5'-nucleotidase (P5N), and deoxypyrimidine 5'-nucleotidase (dP5N) as indices of lead exposure

The activities of three erythrocyte (rbc) enzymes, arginase, pyrimidine 5'-nucleotidase (P5N), and deoxypyrimidine 5'-nucleotidase (dP5N), were compared in 16 lead workers and 14 age matched controls as correlates of blood lead (PbB) and unextracted zinc protoporphyrin (EP) concentrations. Subjects with PbB of 0.9-2.5 microM (19-52 micrograms/dl) had 6.5 +/- 0.6 IU of P5N activity with uridine monophosphate (UMP) as substrate, significantly less (p less than 0.001) than the 12.0 +/- 0.7 IU activity of controls with PbB 0.3-0.6 microM (6-12 micrograms/dl). The mean activity of rbc dP5N with either deoxyuridine monophosphate (dUMP) or thymidine monophosphate as substrate, and of rbc arginase, did not differentiate the two groups. The correlation coefficients of ln PbB with the selected substrates for P5N and dP5N were: UMP, r = -0.75; dUMP, r = -0.61; TMP, r = -0.23. The correlation coefficient of ln PbB and arginase activity was -0.03. Rbc P5N (UMPase) is a significant correlate of PbB, equivalent to rbc protoporphyrin. HPLC assay of rbc UMPase activity is a sensitive and rapid assay that appears to meet criteria for a reliable clinical laboratory index of blood lead concentrations.     

Utilization of soy protein isolate mixed with rice protein in Japanese women

Utilization and requirement of soy protein isolate (SPI) and SPI-rice combination were examined in twenty-five female students. After 1 day on protein-free diet, each subject received a low-protein diet for 10 days. The protein sources were SPI for ten subjects and SPI-rice combination, in which the ratio of two proteins was 6:4, for fifteen subjects. The nitrogen intakes were about 45, 65 and 85 mg/kg in both the two series of experiments. Energy intake was at an approximate maintenance level of 36.1 +/- 3.0 kcal/kg. Apparent nitrogen balance improved with increase in nitrogen intake. The regression equations between nitrogen intake (X, mg/kg) and balance (Y, mg/kg) are shown in the following: SPI: Y = 0.411 X - 40.8 (n = 10, r = 0.812) SPI and rice protein: Y = 0.392 X -32.7 (n = 15, r = 0.739) From the above equations, the maintenance intakes of SPI and SPI-rice combination for an apparent nitrogen equilibrium were calculated to be 99 and 83 mg N/kg, respectively. Digestibilities were 98.2 +/- 5.0% for SPI and 93.1 +/- 6.1% for SPI-rice combination. The NPUs of SPI at intake levels of 40, 60 and 80 mg N/kg were 47 +/- 24 (n = 4), 49 (n = 2) and 44 +/- 3 (n = 4), respectively. The NPUs of SPI and rice mixed protein at intake levels of 45, 70 and 90 mg N/kg were 67 +/- 13 (n = 5), 51 +/- 7 (n = 5) and 54 +/- 12 (n = 5), respectively. It was concluded from the present study that both SPI and the SPI-rice combination had a high nutritive efficiency comparable with that of egg protein.     

镉对大鼠体内钙贮留的影响

为探讨镉对机体钙贮留的影响以及两者之间存在的关系,本实验采用大白鼠进行亚慢性镉毒性试验。研究结果表明:体内镉负荷、尿镉排出量与钙贮留量之间存在着负相关关系。     

茶多酚对铅脂质过氧化损伤拮抗作用的研究

目的 探究茶多酚（TP）对铅（Pb）致细胞脂质过氧化损伤的拮抗作用。方法 Wistar雄性大鼠60只随机分为6组,分别给予0、50、100、300mg/kg不同浓度TP灌胃、第6、8、10天分别给予乙酸铅40mg/kg腹腔注射,对照组给予蒸馏水灌胃,腹腔注射生理水。第11日眶静脉采血,继续TP灌胃1周后处死动物,取股动－静脉混合血、肝、脑组织实验。结果 （1）单纯染铅组大鼠体重较非染铅组明显降低,差异有显著性（P＜0．05）,而同时予TP100、300mg/kg灌胃可明显拮抗铅对大鼠生长抑制,末次染铅24h、1周的大鼠体重与TP相关系数为r＝0．973（P＜0．01）和r＝0．9979（P＜0．01）,呈正相关。（2）末次染铅24h、1周的染铅大鼠较非染铅大鼠血、肝、脑丙二醛（MDA）含量明显升高,差异有显著性（P＜0．05）;超氧化物歧化酶（SOD）活力抑制,差异有显著性（P＜0．05）,TP100、300mg/kg灌胃可拮抗铅的上述作用;同时染铅大鼠血、肝、脑谷胱甘肽（GSH)水平、谷胱甘肽－S－转移酶（GST）活力亦发生明显改变,而TP100、300mg/kg灌胃可拮抗铅的作用。结论 TP可明显拮抗铅致大鼠血、肝、脑脂质过氧化损伤而具有防治、拮抗铅中毒的重要功能。     

Utilization and requirement of dietary protein taking into account the dermal and miscellaneous nitrogen losses in Japanese women

Utilization and requirement of mixed protein in the conventional Japanese diet and the obligatory integumental and miscellaneous nitrogen losses were measured in female subjects. Twelve female students aged 18 to 24 years were given conventional low-protein diets at N intake levels of 50, 70, and 90 mg/kg/day for 10 days. Constituents of the diets corresponded to those of average intake of the Japanese in recent years (1982). N balances were estimated and regression equations between N intake (X) and N balance (Y) were calculated by the multiple level-constant variation method. The equation was Y = 0.426X - 40.0 (n = 36, r = 0.615, p less than 0.01) and the intersection of the regression line with zero nitrogen balance was 93.9 +/- 14.3 mg N/kg/day. The mean digestibility was 92.2 +/- 4.7%. In another experimental group, nitrogen losses due to hair, nails, and menstruation in ten Japanese women were 0.624 +/- 0.172, 0.020 +/- 0.005, and 1.76 +/- 0.68 mg/kg/day, respectively. In a third experimental group, mean of the integumental N losses was 2.8 mg/kg/day in both the subjects given a low-protein diet (19 women) and an ordinary-protein diet (4 women). It increased to 12.7 mg N/kg/day when subjects exercised in summer (4 subjects). The protein requirement in the conventional Japanese diet estimated as the sum of the mean requirement of dietary protein and obligatory dermal and miscellaneous nitrogen losses in Japanese women was 99.1 mg N/kg/day or 0.62 g protein/kg/day. The net protein utilization (NPU) of the proteins at the N intake level for N equilibrium was estimated as 48.     

Effect of diets containing dry beans (Phaseolus vulgaris, L.) on the rat excretion of endogenous nitrogen

Wistar rats of 60.5 +/- 5.0 g fasted for 24 h were injected intraperitoneally with 10 microCi of [14C]glycine. One to two hours after injection the rats were fed a diet containing 10.53 +/- 0.75% protein provided by dry beans or casein, or a protein-free diet and submitted to a 4-d nitrogen balance. Radioactivity in the feces of rats fed casein, cooked beans and raw beans was roughly 2, 5 and 10 times greater, respectively, than in the feces of those fed the protein-free diet. Apparent protein digestibility showed a strong negative linear correlation (r = -0.9805, P less than or equal to 0.01) with radioactivity in the feces. Positive correlation (P less than or equal to 0.01) was demonstrated between radioactivity and either total carbon or total nitrogen in the feces of rats injected with [14C]glycine. Mean value for the radioactivity in the urine of rats fed the different diets did not differ significantly (P less than or equal to 0.05). Endogenous nitrogen excretion of rats on bean diets was estimated by the ratio of total endogenous N to marker N, based on the protein-free diet. The results indicated that rats fed bean-containing diets excreted significantly more endogenous nitrogen than those fed the casein diet, even though the casein diet had stimulated twice as much endogenous excretion than the protein-free diet. As a consequence, apparent digestibility and biological value of bean protein are generally underestimated, although the "real" biological value was not affected by the endogenous nitrogen excretion of the rat.     

驱铅益智口服液对染铅大鼠学习记忆影响

目的 探讨驱铅益智口服液对染铅大鼠学习记忆障碍的改善作用.方法 72只SD大鼠随机分为6组:阴性对照组、模型对照组、乙二胺四乙酸二钠盐(EDTA)组和低、中、高剂量口服液治疗组;除阴性对照组外,其余5组用2%醋酸铅灌胃3周造模;EDTA组腹腔注射0.5%EDTA-Na_2,低、中、高剂量组分别灌胃给予1 250,2 500和5 000 mg/(kg·bw)驱铅益智口服液,连续3周;采用避暗穿梭试验和Morris水迷宫试验,观察各组染铅大鼠学习记忆行为,采用氢化物发生-原子吸收光谱法测定血液和海马组织铅含量.结果 与模型对照组比较,中、高剂量组大鼠主动回避正确率(IAP)分别为68.1%和70.3%,明显高于模型对照组的54.9%(P<0.05);被动回避潜伏期(LOPA)分别为16.44和13.88 s,明显短于模型对照组27.43 s(P<0.01);口服液组血液和海马组织铅含量低于模型对照组(P<0.05或P<0.01);LOPA与海马组织铅含量呈正相关(r=0.475,P=0.014);IAP与海马组织铅含量呈负相关(r=-0.353,P=0.002).结论 驱铅益智口服液可通过减低血液与海马组织铅浓度改善学习和记忆功能.     

Biological monitoring of fluctuating occupational exposures to styrene

Nine workers occupationally exposed to styrene producing refrigerator lorries were analyzed. The styrene exposure was monitored 8 hours a day, for 5 days a week, for 1 week. We collected from workers a urine sample before and after each work shift. Moreover, alveolar air samples were obtained at the end of all work shifts. On Thursday afternoon and on Friday morning blood samples were taken from workers. The relationship between styrene exposure and biological data is reported and discussed. Alveolar, urinary and blood concentrations of styrene were comparable, suggesting similar kinetics. Biological styrene concentrations were significantly correlated with the mean daily environmental concentrations, but higher correlation coefficients were found with afternoon exposures. A narrow linear relationship between alveolar (Y) and urinary (X) styrene concentrations was found (Y = 0.359; r = 0.8579; n = 45; p less than 0.001). Urinary concentrations of mandelic acid (Y) confirmed a good relationship with the mean styrene exposure (X) (Y = 2.7 x +169; r = 0.4677 n = 45; p less than 0.01).     

人外周血淋巴细胞体外乙酸铅染毒后氧化应激损伤研究

目的 研究乙酸铅染毒人外周血淋巴细胞致氧化应激与DNA氧化损伤情况。
方法 分别用浓度为0 μmol/L、20 μmol/L、40 μmol/L和80 μmol/L的乙酸铅染毒人外周血淋巴细胞6 h、12 h、24 h, 应用2', 7'-二氯二氢荧光素二乙酸酯(DCFH-DA)染色分析和流式细胞仪检测染毒后细胞内活性氧类(ROS)水平, 高度水溶性四唑盐(WST-1)法检测染毒后细胞内总超氧化物歧化酶(T-SOD)活性, 酶联免疫吸附测定法(ELISA)试剂盒检测染毒后细胞8-羟基脱氧鸟苷(8-OHdG)水平, 并对ROS、T-SOD、8-OHdG三指标间的关系进行相关性分析。
结果 乙酸铅染毒6 h后, 各染毒组人外周血淋巴细胞ROS水平均高于对照组, 差异有统计学意义(P < 0.01);20 μmol/L染毒组人外周血淋巴细胞T-SOD和8-OHdG水平与对照组相比, 差异无统计学意义(P>0.05), 而40 μmol/L和80 μmol/L染毒组人外周血淋巴细胞T-SOD和8-OHdG水平均高于对照组, 差异有统计学意义(P < 0.01)。乙酸铅染毒12 h和24 h后, 各染毒组人外周血淋巴细胞ROS、T-SOD和8-OHdG水平均高于对照组, 差异有统计学意义(P < 0.01)。相关性分析显示, 细胞内ROS含量与T-SOD活性呈负相关(r_{6 h}=-0.865、r_{12 h}=-0.890、r_{24 h}=-0.801, P < 0.01), 与8-OHdG含量呈正相关(r_{6 h}=0.840、r_{12 h}=0.829、r_{24 h}=0.866, P < 0.01)。
结论 乙酸铅染毒人外周血淋巴细胞后会诱导细胞ROS生成, 抑制细胞内抗氧化酶SOD活性, 造成人外周血淋巴细胞氧化应激状态增强和DNA氧化性损伤。
     

Elevated plasma homocysteine and low vitamin B-6 status in nonsupplementing older women with rheumatoid arthritis

OBJECTIVE: The purpose of this study was to determine if nonsupplementing older women (aged >or=55 years) with rheumatoid arthritis had higher plasma homocysteine and lower B-vitamin status compared to healthy controls. Elevated plasma homocysteine, a risk factor for cardiovascular disease, may help explain why individuals with rheumatoid arthritis have an increased risk of cardiovascular disease. METHODS: Older, free-living women were classified as rheumatoid arthritis (n=18) or healthy control (n=33). Participants were not using B-vitamin supplements. Fasting blood samples were measured for pyridoxal 5'phosphate (PLP) (the metabolically active coenzyme form of vitamin B-6), folate, red blood cell folate, vitamin B-12, transcobalamin II, homocysteine, C-reactive protein, and lipid concentrations. Participants completed 7-day weighed food records, the Stanford Health Assessment Questionnaire (HAQ), and a visual analog pain scale. RESULTS: PLP concentrations were lower in the rheumatoid arthritis vs healthy control participants (4.93+/-3.85 vs 11.35+/-7.11 ng/mL [20+/-16 vs 46+/-29 nmol/L]; P<0.01) whereas plasma homocysteine was higher in the rheumatoid arthritis group (1.63+/-0.74 vs 1.15+/-0.38 mg/L [12.1+/-5.5 vs 8.5+/-2.8 micromol/L]; P=0.02). Red blood cell folate concentrations were lower in the rheumatoid arthritis vs healthy control participants [414+/-141 vs 525+/-172 ng/mL [938+/-320 vs 1,190+/-390 nmol/L]; P=0.02). No significant differences were found for plasma folate, vitamin B-12, and transcobalamin II. An inverse correlation was found between PLP concentrations and the HAQ disability index (r=-0.37; P<0.01). A positive correlation was found between homocysteine concentrations and the HAQ disability index (r=0.36; P=0.01). Total cholesterol and low-density lipoprotein cholesterol levels were lower in the rheumatoid arthritis group (cholesterol 191+/-43 vs 218+/-33 mg/dL [4.95+/-1.11 vs 5.65+/-0.85 mmol/L]; P=0.02; low-density lipoprotein cholesterol 110+/-36 vs 137+/-29 mg/dL [2.85+/-0.93 vs 3.55+/-0.75 mmol/L]; P<0.01). No significant differences were seen between groups for protein (g/day), fat (g/day), cholesterol (mg/day), folate (microg/day), vitamin B-12 (microg/day), and vitamin B-6 (mg/day) dietary intakes. CONCLUSIONS: Poor vitamin B-6 status and elevated plasma homocysteine concentrations were seen in older women with rheumatoid arthritis compared to healthy controls and may contribute to their increased risk of cardiovascular disease.     

孕期不同阶段铅暴露对大鼠胎盘和仔鼠的影响

目的探讨孕期不同阶段铅暴露对大鼠胎盘和子代的影响。方法108只大鼠随机分为4组,于孕期不同阶段饮服0.025%醋酸铅。对照组孕期全程饮服蒸馏水;实验1组孕早期染毒,孕后期饮服蒸馏水;实验2组孕早期饮服蒸馏水,孕后期染毒;实验3组孕期全程染毒。孕末期腹腔静脉取血,原子吸收光谱法测定血铅,检测仔鼠数目、体重、身长和尾长。从大体、光镜和电镜等不同水平观察铅对大鼠胎盘结构的影响。结果实验组大鼠孕末期血铅水平均高于0.483μmol/L;孕期全程染毒组的胎盘重量[(0.31±0.13)g]和仔鼠的体重[(2.08±0.88)g]、身长[(2.37±0.32)cm]、尾长[(0.98±0.09)cm]均最低,与对照组比较,差异均有统计学意义。血铅水平与胎盘重量呈负相关,与仔重无相关性。实验组胎盘海绵带滋养叶巨细胞和空泡化细胞增多,迷路带及海绵带滋养细胞呈退行性改变,绒毛周围纤维蛋白沉积增多。胎盘超微结构显示胎盘滋养细胞周围微绒毛短小、稀疏,线粒体肿胀、数目减少,粗面内质网扩张,膜上核糖体数量减少。结论孕期不同阶段铅暴露可能对胎盘滋养细胞有损伤作用,从而妨碍胎盘的血液供应及母子间营养物质及氧气的交换,导致胎盘重量减低和仔鼠生长发育不良。     

子宫内铅暴露对仔鼠牙齿萌出和釉质发育的影响

目的观察母鼠妊娠期间不同剂量铅暴露对仔鼠牙齿萌出情况和釉质发育的影响。方法27只怀孕SD大鼠随机分为铅暴露高剂量组、低剂量组和对照组,每组9只。铅暴露组饮用去离子水中加入醋酸铅进行染毒[以铅(Pb2+)含量计算高剂量组200mg/L、低剂量组50mg/L],对照组饮用去离子水。染毒自大鼠孕第1天持续至自然分娩。仔鼠出生后第26天在下切牙龈乳头水平进行第1次标记,并于出生后第36天在同一牙龈乳头水平行二次标记。第2次标记当日取全血测定血铅并处死仔鼠。测定切牙铅含量,应用立体显微镜观察牙齿形态并测量切牙两次标记间距离,应用电子探针测定切牙釉质钙、磷含量并计算比值。结果高、低剂量铅暴露仔鼠组血铅较对照仔鼠组增高,差异有统计学意义(P<0.01);高、低剂量铅暴露仔鼠组齿铅[(77.3±6.3)、(27.8±4.5)μg/g]与对照仔鼠组[(6.6±0.8)μg/g]相比,差异有统计学意义(P<0.01)。铅暴露仔鼠组切牙较小,牙尖磨耗明显并多见舌侧髓腔暴露,高铅剂量组更为明显。高、低剂量铅暴露仔鼠组切牙萌出速率[(0.25±0.08)、(0.30±0.09)mm/d]与对照仔鼠组[(0.39±0.09)mm/d]比较,铅暴露组萌出较为缓慢,三组间差异有统计学意义(P<0.01)。仔鼠釉质钙/磷比分析显示,随铅染毒剂量的增加,钙/磷比(1.68±0.54、1.37±0.47)降低,     

Predictions of energy intake and energy allowance of patients with Duchenne muscular dystrophy and their validity.

Patients with Duchenne muscular dystrophy are so malnourished that energy supplementation is crucial. Their degree of energy deficiency was assessed as difference between their energy intake and their energy allowance, which were deduced from easily measured parameters. A significant, negative relationship was found between the basal metabolic rate (BMR) (Y, %, BMR/standard BMR) and body weight (X, %, body weight/standard body weight) in the patients, from which the formula for the BMR was deduced to be Y = -1.116X + 174.5 (n = 202, r = -0.72, p less than 0.001). Thus, it is possible to estimate the energy allowance for individual patients by a factorial procedure from the presumed BMR and a factor for physical activity. In addition, their energy intake was calculated from a constant protein-energy % (14.6%) in their diet and nitrogen intake which was deduced from a significant positive correlation between their nitrogen intake (Y, mg/kg/day) and their nitrogen excretion in 24 h urine samples (X, mg/kg/day). This correlation conformed to the equation Y = 1.053X + 32.4 (n = 267, r = +0.76, p less than 0.001). The validities of the above predictions for energy intake and allowance were examined by plotting the degree of energy deficiency (% ratio of presumed intake/presumed allowance) against the concentrations of retinal binding protein, prealbumin and transferrin in the serum, because rapid turnover proteins are sensitive to energy deficiency. Significant positive correlations were obtained with both variables, suggesting that these predictions were valid.     

Aging and activity of 5-aminolevulinate hydrolyase in the blood of humans and rats.

Activity of 5-aminolevulinate hydrolyase (delta-aminolevulinic acid dehydrase, ALAD, EC 4.2.1.24) in the blood was determined in relation to age in humans and rats, and the following findings were obtained: (1) In the group which consisted of 47 women (mean age 46, ranged 24 to 62 years) living in a rural district, where the atmospheric lead concentration was 0.5 micron/m3, a significant negative correlation between ALAD activity and age was observed statistically (r = -0.54). However, in the group which consisted of 53 women of similar age group living in an urban district, where the atmospheric lead concentration was 1.9 microng/m3, showed a lower level of the ALAD activity than that of the former group and no correlation was found r = -0.01) between ALAD activity and age. (2) The ALAD activity of intact rats showed a decrease with age. The decrease proceeds rapidly within 8 weeks of age and becomes stable after reaching 25 weeks of age or 300 g of body weight. The value of the activity after 25 weeks of age was about one tenth of that at 5 weeks of age or 100 to 130 g of body weight. (3) Fifteen intact rats weighing 240 to 705 g were divided into three groups according to their body weight and were injected with lead acetate solution equivalent to 1 mg Pb/kg intraperitoneally in order to examine the sensitivity to lead in rats that have variation of ALAD activity by age or by body weight. The ALAD activity of these rats fell to the same level in all groups independently of the activity or the body weight before injection.     

Effects of carbon monoxide air pollution in pregnancy on neonatal nucleated red blood cells

In an analytical cross-sectional study, the effects of carbon monoxide air pollution on carboxyhaemoglobin (COHb) and absolute nucleated red blood cells (nRBC) of the cord venous blood, were evaluated in 41 newborns delivered by caesarean section at term to mothers who had lived in an air-polluted area in the centre of Tehran during their pregnancies (study group). The parameters used were compared with 32 cord venous bloods of term caesarean-delivered newborns of mothers living in a healthy air area outside the city during their pregnancies. A significant difference was observed between the two groups in the cord COHb levels (mean +/- SD 10.51 +/- 4.79 vs. 1.58 +/- 0.96, P <0.001), cord nRBC (723.87 +/- 275.23 x 10(6)/L vs. 248.44 +/- 160.79 x 10(6)/L, P <0.001). A significant correlation was found between ambient carbon monoxide and cord COHb in the study and control groups, respectively (r=0.863, P=0.0001; r=0.691, P=0.0001), and also cord COHb and cord nRBC in the study group (r=0.360, P=0.01). Neonates born to mothers exposed to carbon monoxide air pollution had increased circulating absolute nRBC counts compared with those of the control group. We speculate that air pollution exposure in pregnancy should be avoided, because it may have negative effects on fetal oxygenation.     

病房护士的睡眠质量对日周性作业疲劳的影响

目的 探讨病房护士的睡眠质量对日周性作业疲劳的影响.方法 利用整群抽样的方法,调查了浙江省杭州市的3所三等甲级医院479名病房护士(非孕期、非病假)的睡眠质量及其日周性作业疲劳情况.采用匹茨堡睡眠质量指数量表(PSQI)评定睡眠质量;使用作业疲劳症状自评量表(2002)评定被调查对象1天的疲劳情况;自拟一般资料问卷收集护士的一般资料.结果 病房护士的睡眠质量普遍较差:PSQI总均分为7.31±3.45,PSQI7分的病房护士有200位(41.75%),睡眠总分与学历呈负相关(r=-0.11,P＜0.01),学历与睡眠质量、入睡时间和睡眠时间呈负相关;睡眠与婚姻、工龄、职称、职务无相关性.病房护士的睡眠质量与作业疲劳存在密切的关联:(1)睡眠总分与1天4个时间点的疲劳均分呈正相关(r值分别为0.42,0.34,0.25,0.33,P值均0.01).(2)睡眠总分与4个时间点疲劳的5个因子有相关性.(3)睡眠的7个因子之间以及4个时间点的疲劳均分之间也呈明显的相关.(4)睡眠质量与作业疲劳的多元回归分析结果显示,睡眠质量、日间功能、睡眠障碍以及催眠药物的使用是导致工作疲劳的重要因素.(5)睡眠质量与延迟下班无相关(r=0.06,P=-0.17).结论 应重视病房护士的睡眠质量,了解护士的工作疲劳程度,科学地安排工作任务和流程,合理地进行人力资源管理,注重睡眠卫生的宣传和教育,劳逸结合,提高病房护士的睡眠质量,降低工作疲劳感.     

运用事件相关电位探讨铅暴露对儿童认知功能的影响

目的运用事件相关电位(ERP)探讨铅暴露对儿童认知功能的影响。方法选取2017年3月至2019年11月就诊于上海交通大学医学院附属新华医院儿童重金属门诊的66例儿童为研究对象,检测受试儿童血铅水平,进行智力测试、心理行为评估,收集ERP的失匹配负波(MMN)和P3a,采用多元线性回归分析铅暴露与儿童认知功能的关系。结果66例儿童的平均年龄为(62.73±8.65)月龄,血铅水平为42.50(12.00~120.75)μg/L;儿童语言分、操作分和智商总分均值分别为(111.12±14.71)分、(111.56±14.62)分和(112.53±13.64)分,其中儿童血铅与语言分为负相关关系(r=-0.257,P<0.05);儿童血铅水平与父亲的受教育程度、母亲的受教育程度和家庭收入均呈负相关关系(r值分别为-0.498、-0.431、-0.349,均P<0.05),尚未发现血铅水平与心理行为量表评估之间的相关关系(均P>0.05);血铅水平、年龄与大脑Cz区的MMN波幅存在负相关关系(r值分别为-0.293、-0.307,均P<0.05),尚未发现儿童血铅与MMN潜伏期以及P3a的波幅和潜伏期之间存在相关关系(均P>0.05);多元线性回归分析结果显示,控制混杂因素后,儿童血铅水平与MMN波幅之间的回归系数β值及95%CI为-0.01(-0.02~0.00),标准回归系数为-0.34,P<0.05。结论血铅水平与MMN波幅为负相关关系,提示铅暴露影响了儿童大脑对信息的自动加工处理,可以将ERP作为一种客观灵敏的手段评估铅暴露对儿童认知功能的影响。     

Lead exposure in highway toll-booth workers

Biomarkers of lead exposure (blood lead, BPb) and effect (erythrocyte protoporhyrin, EP, and activity of delta-aminolevulinic acid dehydratase, ALAD) were measured in 68 male toll-booth operators (aged 22-60 years) on the Zagreb-Karlovac motorway. Average values (arithmetic mean +/- standard deviation) were: 61.8 +/- 29.3 micrograms/L for BPb, 0.70 +/- 0.20 mumol/L erythrocytes for EP, and 50.6 +/- 9.8 U/L erythrocytes for ALAD. All were within the normal range determined for general population (BPb < 150 micrograms/L, EP < 1.62 mumol/L erythrocytes, and ALAD > 35 U/L erythrocytes). A significant positive correlation was found between BPb and EP (r = 0.367, P < 0.01) and an inverse correlation between BPb and ALAD (r = -0.271, P < 0.05) and for EP and ALAD (r = -0.381, P < 0.01). Significant correlations were found between BPb or ALAD and smoking index (r = 0.486, P < 0.01, and r = -0.322, P < 0.01, respectively), whereas BPb also significantly correlated with blood gamma-glutamyl transferase (GGT) activity, which may indicate hepatotoxic effect of alcohol consumption (r = 0.334, P < 0.01). Among standard spirometric tests, BPb inversely correlated with FEV1 (r = -0.251, P < 0.05) and Tiffenau index (r = -0.280, P < 0.05), whereas ALAD positively correlated with FEF75-85 (r = 0.261, P < 0.05) and Tiffenau index (r = 0.314, P < 0.01). Among standard hematologic tests, BPb positively correlated with MCV (r = 0.282, P < 0.05), EP inversely correlated with erythrocyte count (r = -0.253, P < 0.05), and ALAD positively correlated with MCHC (r = 0.306, P < 0.05) and inversely with MCV (r = -0.250, P < 0.05). Although PbB values in these workers are within occupational exposure limits, they are higher than in corresponding occupations in developed countries. This may be explained by greater exposure to lead in ambient air, tobacco (through mainstream and sidestream smoking) and alcohol in this population.     

腺苷蛋氨酸对发育期铅暴露大鼠的保护作用及其长时程增强机制研究

目的 探讨S-腺苷L-蛋氨酸(S-adenosyl-L-methionine,SAM)对发育期慢性铅暴露大鼠血铅浓度、肝脏、脑、海马组织氧化损伤的影响,及其对铅暴露引起的长时程增强(long-term potentiation,LTP)和双脉冲易化(paired-pulse facilitation,PPF)的损伤的修复作用.方法 采用抽签法将受孕Wistar大鼠按每组3只随机分为3组:对照组,全程饮用自来水,仔鼠断乳后每天腹腔注射生理盐水;染铅组,孕期与哺乳期染铅,仔鼠断乳后每天腹腔注射生理盐水;铅+SAM注射组,孕期与哺乳期染铅,仔鼠断乳后每天腹腔注射20 mg/kg的SAM,22 d后测定各组仔鼠血铅浓度和肝脏、脑、海马组织氧化指标,并在位记录各组大鼠海马齿状回PPF和LTP.结果 对照组、染铅组和铅+SAM组血铅浓度分别为(27.5±3.8)、(159.3±10.9)、(33.1±9.5)μg/L,铅+SAM组与染铅组比较差异有统计学意义(F=213.5,P＜0.01);SAM能提高染铅组肝脏、脑组织的谷胱苷肽(GSH)水平、降低丙二醛(MDA)水平,与染铅组比较差异均有统计学意义(P＜0.05);与对照组兴奋性突触后电位(field excitatory postsynaptic potential,EPSP)LTP幅度[(131±4.5)%]相比,染铅组LTP[(112±2.1)%]明显下降,而铅+SAM组能修复LTP至(120±2.6)%,差异有统计学意义(F=26.1,P＜0.05).结论 SAM对临床上慢性铅中毒儿童尤其是学习记忆损伤的修复可能具有一定作用.