Risk factors for high blood lead levels among the general population in Taiwan

BACKGROUND: Tacrolimus (FK506) may represent a major advance in the management of allograft rejection after solid organ transplantation. In August 1994 a European heart transplantation pilot study was initiated to assess the efficacy and safety of tacrolimus when administered exclusively through an oral route. METHODS: Eighty-two heart transplant recipients were randomized to treatment (2:1 ratio) with either tacrolimus- (n=54) or cyclosporine-based therapy (n=28). RESULTS: No significant differences were evident between the two treatment groups in either rejection or survival rates at 1 year. Kaplan-Meier estimates of the freedom from rejection were 26.3% and 18.5%, respectively, for the tacrolimus and cyclosporine treatment groups (p=.444). Survival rates were 79.6% and 92.9% (p=.125). At 3 of the 5 centers, patients received antithymocyte globulin during the immediate postoperative period and fared better than those who did not (with acute rejection-free rates of 49.2% and 26.7% for tacrolimus and cyclosporine, respectively [p=.080], as opposed to 7.1% and 8.3% [p=.965]; patient survival rates of 84.6% and 93.3% [p=.382] vs 75.0% and 92.3% [p=.243]). The overall rates of infection, impaired renal function (31.5% vs 21.4%), and glucose intolerance (7.0% vs 4.3%) did not differ significantly between the tacrolimus and cyclosporine treatment groups. Tacrolimus seemed to possess an advantage with regard to a reduced requirement for antihypertensive therapy (59.5% vs 87.5%, p=.025). CONCLUSIONS: Immunosuppression with oral tacrolimus provides a viable alternative to treatment with cyclosporine, particularly when administered in conjunction with antibody therapy. Further studies are warranted to optimize the administration of tacrolimus in this indication.     

The relationship between blood pressure and biochemical risk factors in a general population

The relationship between blood pressure, ponderal index, sex, blood glucose, haemoglobin, serum uric acid, calcium cholesterol and creatinine, and albumin has been examined in 698 subjects aged between 44 and 49 years from the register of a group general practice. Sixty per cent of the variation in systolic pressure could be explained by statistically significant associations with diastolic pressure, sex, blood glucose, serum calcium, and cholesterol. The diastolic blood pressure (not corrected for systolic pressure) was significantly related only to ponderal index, haemoglobin in men, and cholesterol in women. Pulse pressure was also positively related to the risk factors blood glucose, serum cholesterol, and calcium. The possibility is discussed that one or more of these variables reduce aortic compliance and that the serum calcium contributes to this end. Diastolic, but not systolic pressure, had a prime association with relative weight, obesity being only basically associated with an increase in diastolic pressure.     

Lead exposure of workers in the ceramics industry and relevant factors

To clarify lead exposure and factors relevant to it, an occupational health survey and air lead-concentration survey were conducted among 425 workers in the ceramics industry in the Seto region in Aichi Prefecture. As for biological monitoring, blood lead level was measured according to sex, job, product, factory size and duration of lead exposure. The following major findings were obtained in the present analysis. Workers making dolomite novelties showed higher blood lead levels than those making porcelain novelties, semi-porcelain novelties and tableware. The difference in blood lead level by job was statistically significant, but not that by factory size. In males, the highest blood lead level was found for spray painting work (28.7 micrograms/dl), followed by glazing work (28.0 micrograms/dl), kiln work (23.3 micrograms/dl) and painting work (22.3 micrograms/dl). In females, the blood lead level for painting work (13.5 micrograms/dl) was lower than those for glazing work (26.1 micrograms/dl) and kiln work (31.4 micrograms/dl). The blood lead level was significantly increased with the number of years of lead exposure in females (painting work). It was coincidentally clarified that the environmental lead concentration varied according to the job in which workers were engaged. As protective measures against lead exposure for workers in the ceramics industry, the development of nonlead paint and glaze and the introduction of more effective dust collectors at the workplace should be established.     

Serum DDT and DDE levels in Singapore general population

Stimulation of afferents in the superior laryngeal nerve (SLN) leads to apnea and evokes reflexes in sympathetic neurons. It is not clear whether these reflexes are secondary to changes in the brainstem respiratory network or due directly to the afferent input on neurons belonging to central sympathetic pathways. To clarify this question, single thoracic preganglionic sympathetic neurons projecting into the cervical sympathetic trunk (CST) were classified as described previously and then tested for their responses to electrical stimulation of the superior laryngeal nerve (SLN) in chloralose-anesthetized, paralysed and artificially ventilated cats. SLN stimulation was performed with intensities sufficient to suppress central inspiratory activity detected by phrenic and recurrent laryngeal nerve recordings. Sympathetic neurons were tested under different levels of respiratory drive. Thirteen group I (putative muscle vasoconstrictor) neurons were mostly activated by SLN stimulation when respiratory drive was low, but depressed when it was high; this was due to the change in inspiration-related activity. Ten of eleven group II (putative cutaneous vasoconstrictor) neurons were depressed during SLN stimulation. This inhibition was independent of central respiratory drive. Inhibition also occurred in those neurons which predominantly discharged during postinspiration. Eight group III neurons which showed a discharge confined to inspiration were inhibited but mostly not silenced by SLN stimulation. Group IV (functionally unclassified) neurons either showed no response (n = 5) or were slightly inhibited (n = 2). The responses of group I neurons, but not the responses of group II and group III neurons, showed a significant positive correlation with those of systemic blood pressure. The observed responses corroborate the classification made previously. The results also demonstrate that the responses of sympathetic neurons to SLN stimulation are not merely due to the respiratory modulation of their activity, but rather consist of two components, one occurring independently of and the other secondary to, the changes in respiration.     

Nitrous oxide in blood and urine of operating theatre personnel and the general population

A prototype of a totally implantable vascular catheter-port system was evaluated on its design using three animals of different species. The catheter was placed either intravenously or intra-arterially, and connected to the port which was retained outside the body. Parameters used for design evaluation or functionality testing were focused on the use and handling of the port-catheter system such as easiness of flushing, injection, blood sampling, septum stiffness to prevent blood reflux after pushing the septum, and possible diffusion of blood into the saline present in the port-catheter system. This pilot experiment showed that the septum of the prototype port system was too flexible, and that the distance between septum and base of the port was too short. These findings have led to a major improvement of the catheter-port system, currently successfully used in cancer chemotherapy.     

Cardiovascular risk factors for early carotid atherosclerosis in the general population: the Edinburgh Artery Study

BACKGROUND: Recent attempts to identify cardiovascular risk factors affecting early-stage carotid atherosclerosis, measured by ultrasonographically assessed intima-media thickness, have been inconclusive. OBJECTIVE: To study the relationship between traditional cardiovascular risk factors and intima-media thickness. METHODS: Ultrasonic evaluation of the intima-media thickness of the common carotid artery was included in the 5-year follow-up examination of participants of the Edinburgh Artery Study. We had valid readings of intima-media thickness for 1106 men and women aged 60-80 years. Information on a range of cardiovascular risk factors had been collected during the baseline examination. RESULTS: For men, in addition to age, lifetime smoking (measured in terms of pack years) was the only cardiovascular risk factor associated with increased intima-media thickness (P< or = 0.01) in the univariate analysis. Both systolic blood pressure (P < or = 0.001) and the high-density lipoprotein (HDL: total cholesterol ratio (P < or = 0.01) were correlated with intima-media thickness for women. When all the variables had been included in a multivariate analysis, pack years of smoking and the HDL:total cholesterol ratio were associated with early atherosclerotic development in men. In an equivalent analysis for women, alcohol consumption, systolic blood pressure and the HDL:total cholesterol ratio were associated with intima-media thickness. CONCLUSION: These data suggest that risk factors affecting intima-media thickness differ for men and women. Further sex-specific analyses of prospective population studies are required in order to clarify the role of 'traditional' cardiovascular risk factors in the early stages of carotid atherosclerosis.     

Lead in the blood and protoporphyrin levels in erythrocytes in glass workers exposed to lead]

The craniofacial cephalometric dimensions, angles and dimensional ratios of five Finnish individuals with complete testicular feminization (CTF) were compared with their first-degree relatives and population female and male controls. The linear and angular measurements were made from standardized lateral cephalograms of patients and normal population controls from the 'Kvantti Study' series. The women with CTF tended to have cranial base and maxillary complex dimensions between those of the normal control females and males. Their mandibular corpus was found to be longer than in normal control females, while their ramus was shorter compared with that of normal males. They also showed a smaller sagittal length ratio of the maxilla to the mandible, a smaller ANB angle and a more acute gonial angle than in both normal control females and males. Comparison of the women CTF with their first-degree female relatives showed basically the same trends as when comparing them with normal female controls. As the phenotype in these females with CTF is due to insensitivity to, or lack of androgens, it is suggested that the presence of the Y chromosome in these females leads to craniofacial dimensions between those of normal females and males which influences the growth of the mandibular corpus. This follows the same general metric pattern that is observed in many of their adult head and body dimensions as well as in their dental arches.     

Cigarette smoking and other risk factors for silent cerebral infarction in the general population

Control dried organisms as lenticules are a dependable and convenient alternative to wet cultures for quality assurance and process controls in routine food microbiology. Lenticules are designed to give a fixed, reproducible inoculum over an extended period of time without loss of cultural characteristics or viability. During a period of 23 months, 596 paired counts were performed by both Miles and Misra and spiral plating techniques on lenticule controls. Correlation between the two methods and within batches was excellent. Only 14 counts (2.5%) fell outside the standard operating limit of 0.5 log10. All were within 1.0 log10. On two separate occasions, replicate runs were performed on five reconstituted lenticules from a batch. The counts obtained showed variation within and between lenticules only slightly in excess of what is expected by chance. Lenticule replicates performed by three other laboratories also produced satisfactory results. It is thought that lenticules could improve the accuracy of total plate counts and lead to a better standardization of quantitative methods in food microbiology within and between laboratories.     

Habitual physical activity in a population residing in the city of Barcelona

OBJECTIVES: To describe the sociodemographic distribution of habitual physical activity and to analyse its relationship with self-perceived health status and occupational status, among the population older that 16 years of age in the city of Barcelona, Spain. METHODS: A sample of 1,885 adult men and 2,196 women answered the Health Interview Survey of Barcelona in 1992. Those whose habitual activity required high physical exertion or walking were considered as active. Bivariate and multivariate analyses adjusting logistic regression models were used to study the relationship between habitual physical activity and the rest of variables, for each occupational situation. RESULTS: Fifty six percent of adults reported being physically active. Physical activity was lower among workers than non workers, although workers reported more physical exertion (14.5% in men and 8.0% in women). Physical activity was associated with occupation and educational level among male workers, but only with occupation among female workers. In the non working population, physical activity was lower among those who perceived their health status as fair or poor, compared with those that described it as good or very good, (ORa in men was 0.2, 95% confidence interval = 0.1-0.5; ORa in women was 0.5, 95% confidence interval = 0.3-0.8). CONCLUSIONS: More than half of the Barcelona population were physically active in an habitual manner. Among workers, this activity was mainly determined by the occupation. Non-workers with a poor self-perceived health status did less physical activity.     

Trichloroethene levels in human blood and exhaled breath from controlled inhalation exposure

The organic constituents of exhaled human breath are representative of bloodborne concentrations through gas exchange in the blood/breath interface in the lungs. The presence of specific compounds can be an indicator of recent exposure or represent a biological response of the subject. For volatile organic compounds, sampling and analysis of breath is preferred to direct measurement from blood samples because breath collection is noninvasive, potentially infectious waste is avoided, the sample supply is essentially limitless, and the measurement of gas-phase analytes is much simpler in a gas matrix rather than in a complex biological tissue such as blood. However, to assess the distribution of a contaminant in the body requires a reasonable estimate of the blood level. We have investigated the use of noninvasive breath measurements as a surrogate for blood measurements for (high) occupational levels of trichloroethene in a controlled exposure experiment. Subjects were placed in an exposure chamber for 24 hr; they were exposed to 100 parts per million by volume trichloroethene for the initial 4 hr and to purified air for the remaining 20 hr. Matched breath and blood samples were collected periodically during the experiment. We modeled the resulting concentration data with respect to their time course and assessed the blood/breath relationship during the exposure (uptake) period and during the postexposure (elimination) period. Estimates for peak blood levels, compartmental distribution, and time constants were calculated from breath data and compared to direct blood measurements to assess the validity of the breath measurement methodology. Blood/breath partition coefficients were studied during both uptake and elimination. At equilibrium conditions at the end of the exposure, we could predict actual blood levels using breath elimination curve calculations and a literature value partition coefficient with a mean ratio of calculated:measured of 0.98 and standard error (SE) = 0.12 across all subjects. blood/breath comparisons at equilibrium resulted in calculated in vivo partition coefficients with a mean of 10.8 and SE = 0.60 across all subjects and experiments and 9.69 with SE = 0.93 for elimination-only experiments. We found that about 78% of trichloroethene entering the body during inhalation exposure is metabolized, stored, or excreted through routes other than exhalation.     

Environmental urban lead exposure and blood lead levels in children of Mexico City

Lead contamination is now a leading public health problem in Mexico. However, there are few data on the lead content of various environmental sources, and little is known about the contribution of these sources to the total lead exposure in the population of children residing in Mexico City. We conducted a cross-sectional study in a random sample of 200 children younger than 5 years of age who lived in one of two areas of Mexico City. Environmental samples of floor, window, and street dust, paint, soil, water, and glazed ceramics were obtained from the participants' households, as well as blood samples and dirt from the hands of the children. Blood lead levels ranged from 1 to 31 micrograms/dl with a mean of 9.9 micrograms/dl (SD 5.8 micrograms/dl). Forty-four percent of the children 18 months of age or older had blood lead levels exceeding 10 micrograms/dl. The lead content of environmental samples was low, except in glazed ceramic. The major predictors of blood lead levels were the lead content of the glazed ceramics used to prepare children's food, exposure to airborne lead due to vehicular emission, and the lead content of the dirt from the children's hands. We conclude that the major sources of lead exposure in Mexico City could be controlled by adequate public health programs to reinforce the use of unleaded gasoline and to encourage production and use of unleaded cookware instead of lead-glazed ceramics.     

Hospital medical students: a population at risk for accidental exposure to blood

OBJECTIVE: Infections transmitted by blood such as viral hepatitis B and C or human immunodeficiency virus (HIV) are a true threat to health care workers. As medical students are exposed to accidental contamination during their hospital activities, we conducted a survey among medical students in Nice France to determine the frequency and circumstances of needle prick accidents and how the risk of blood exposure is managed. METHODS: A survey was conducted between December 1 and December 15, 1996 among second cycle medical students. An anonymous questionnaire was proposed to all students attending mandatory faculty classes. A blood-exposure accident was defined as a needle prick or a cut caused by another sharp object which occurred in the hospital. RESULTS: Among the 237 students enrolled in the classes, 200 (84%) responded to the survey. Among these, one-quarter had experienced a blood-exposure accident by needle prick. For students terminating their second cycle, this rate was 37%. In 58% of the cases, the accidents had occurred when the students were on duty (excepting hospital training courses). Blood drawing for gas measurements was the most frequent circumstance (44%). Only 39% of the students had declared the accident and 51% had had a serology control within 2 months. The serological status of the source patient was unknown to the students in nearly half the cases. Only one out of two students applied elementary safety measures systematically (gloves, not recapping the needle). Only 13% of the students stated they had received information about blood-exposure accidents and their prevention and less than 50% had a correct notion of the risk of hepatitis B and C and HIV transmission by needle pricks. CONCLUSION: The incidence of blood-exposure accidents in hospital medical students is high and probably underestimated by official statistics due to the low declaration rate. Measures should rapidly implemented to inform and train students on prevention. Our units are currently working with students, the medical faculty and the occupational medicine unit to reach these objectives.     

Serum alpha 1-antichimotrypsin levels and cardiovascular risk factors in the Japanese elderly population

Four materials used in lining prosthetic sockets were compared for their potential usefulness in below-knee applications. Tests carried out included determinations of resistance to compression, resistance to flexural abrasion and coefficients (static and dynamic) of friction. These tests were designed, respectively, to assess changes occurring during end-use brought about by extensive application of compressive or shear force, and to predict the ability to retain contact with the body and socket. Of the four materials in the study (Bock-Lite, Pedilin, polyurethane and silicone), Bock-Lite and silicone had high compression resistance, Bock-Lite had good resistance to flexural abrasion, and polyurethane and silicone had high coefficients of frictional resistance. Thus, Bock-Lite will be the most durable of the four materials but, since it had the lowest frictional coefficient, it may slip in use. Conversely, silicone and polyurethane, which will be retained in position more easily, are easily torn or compressed, so are likely to need replacement more frequently.     

Lead levels in exposed herring gulls: differences in the field and laboratory

We compared blood lead levels for herring gull (Larus argentatus) chicks exposed at two days of age in the field and the laboratory. One randomly selected chick in each family of three was injected with lead, the second with a sterile saline solution, and the third was not injected. Field birds were then completely free-living, and were entirely cared for by their parents. Blood was drawn at 35 or 45 days of age for comparison with laboratory-reared chicks. In both the laboratory and the field, blood lead levels were positively related to dose, and concentrations were lower at 45 than at 35 days of age. However, at each dose, the field birds had lower levels than did the laboratory birds. We postulate that this relates to higher overall activity and accelerated bone development in the field, and perhaps to a move varied diet. Wild young gulls were mobile and practiced flight more often than did laboratory-reared gulls. Growth metabolic, and behavioral factors may enhance deposition of lead in the bone, reducing blood lead. Thus, both in ecological risk assessments and in using birds as bioindicators, caution is required in extrapolating from laboratory studies in field conditions.     

Blood cadmium levels in a general male population with special reference to smoking

Blood-cadmium (Cd-B) level, blood pressure, and several biological parameters in blood were measured in 440 men who were not occupationally exposed to cadmium and who had a detailed smoking history. No significant correlation was found between Cd-B and blood pressure. Among biological parameters, those known to be related to smoking appeared significantly correlated with Cd-B. Analysis of smoking history showed that Cd-B is strongly elevated in current smokers, with a dose-effect relationship between daily consumption of tobacco and Cd-B; moreover, exsmokers had significantly higher Cd-B than nonsmokers. This finding shows that Cd-B partly reflects past exposure to cadmium.     

Traumatic events: prevalence and delayed recall in the general population

In awake animal and human auditory cortices, it is a common experience with electrophysiological and suitable imaging methods for responses to steady stimulation to be strongly state-dependent and to exhibit nonstationarities, even over short periods of observation. If such nonstationary behavior is also reflected by hemodynamic responses in the human auditory cortex, conventional methods of analysis of fMRI data, although applicable for instance to largely stationary responses in visual and other cortices, may be misleading in attempts to parcellate auditory cortex into fields and to demonstrate functional maps. Time-Windows, described in this article as a convenient tool for the detection and analysis of time-variant brain activities, solves some of these problems. Time-Windows demonstrates that activity is evoked reliably in three separate territories of human auditory cortex, parts of which may show nonstationary behavior, depending on the auditory stimuli and tasks.     

Familial cancer in the general population

In the course of collecting samples of human milk for the National Cancer Institute, family histories have been assembled since 1971. Ages, causes of death, reproductive histories, and the history and age of occurrence of cancer were obtained for all first degree relatives of the proband's parents. Two thousand and ninety cancers were identified in 31,945 persons. Cancers were confirmed by pathology reports, hospitals' and doctors' records, or death certificates. Of the family lineages, 65.9% had no cancers and 8.0% had two or more. For all cancers taken together, clustering was not significant but there was significantly more observed than expected cancers in lineages with cancer of breast, ovary, skin, corpus uteri, stomach, rectum, lung and bronchus, or colon. Little or no excess was observed in lineages with leukemia, lymphoma, and cancer of the cervix or prostate. The relative risk of breast cancer was increased 1.5 times for daughters and 3.8 times for sisters of women with the disease.     

Exposure to lead among the population of Barcelona: chronologic trends from 1984 to 1995

BACKGROUND: This study was designed to determine current lead exposure in the Barcelona population and to evaluate the changes occurred during the last 10 years. Blood lead concentration was investigated in a random sample of 694 healthy subjects (age range: 0-65 years). PATIENTS AND METHODS: Adults were random selected from a group of blood donors. Samples of children analysed were selected from subjects with a preoperatory analyses without any disease that could modify blood lead levels. Lead levels were determined by atomic absorption spectrometry. RESULTS: Blood lead concentration was 4.06 +/- 1.4 micrograms/dl in umbilical cord, 8.9 +/- 2.9 micrograms/dl in the paediatric population and 7.8 +/- 4.2 micrograms/dl in the total of adults analyzed. There was statistical differences between the younger subjects and the older population. In 1984 the results found were 18.6 +/- 6.6 micrograms/dl. CONCLUSIONS: The results obtained show that in the last 10 years a reduction on the blood lead levels was occurred. This reduction is parallel with a diminish in the lead petrol concentration in the ambient air.