Induction of chromosomal damage in CHO-K1 cells and their repair-deficient mutant XRS5 by X-ray and particle irradiation

The cytogenetic effects of X-rays and Au ions were investigated in repair-proficient CHO-K1 cells and their radiosensitive mutant strain xrs5, which shows a defect in the rejoining of DNA double-strand breaks. Both cell lines were synchronized by mitotic shake off, irradiated in G1-phase with either 250 kV X-rays or 780 MeV/u Au ions (LET: 1150 keV/micrometer) and chromosome aberrations were analyzed in first post-irradiation metaphases. Isoeffective doses of X-rays for the induction of aberrant cells and aberrations per cell were about 14 times lower for xrs5 than for CHO-K1 cells. After high LET radiation the difference in the cytogenetic response of both cell lines was drastically diminished. Furthermore, the analysis of the aberration types induced by sparsely and densely ionizing radiation showed for both cell lines specific changes in the spectrum of aberration types as LET increases. The experimental results are discussed with respect to the different types of lesions induced by sparsely and densely ionizing radiation.

Neutron spectra at flight altitudes and their radiological estimation

Since the publication of the ICRP-report 60, air crews and other frequently flying persons are considered as occupationally exposed people. At civil flight levels neutrons contribute the major part to the radiologically relevant dose to men. The quantification of the neutron dose, and herewith the radiation risk due to neutrons, suffers from spectral data available especially in the energy range above 20 MeV. Experimental data were recently obtained at a low flight level on top of the mountain Zugspitze at 3000m using a modified Bonner sphere spectrometer. The resulting spectra are compared with Monte-Carlo transport calculations from top of the atmosphere down to 700 g/cm2. These data and others from the literature are used to calculate operational and risk related quantities, i.e. ambient dose equivalent and effective dose.

Risk and incidence of asthma attributable to occupational exposure among HMO members

Occupational asthma may account for a significant proportion of adult-onset asthma, but incidence estimates from surveillance of physician reports and workers' compensation data (0.9 to 15/100,000) are lower than expected from community-based cross-sectional studies of asthma patients. We conducted a prospective cohort study of 79,204 health maintenance organization members between the ages of 15 and 55 at risk for asthma. Computerized files, medical records, and telephone interviews were used to identify and characterize asthma cases. Evidence for asthma attributable to occupational exposure was determined from work-related symptoms and workplace exposure. The annual incidence of clinically significant, new-onset asthma was 1.3/1,000, and increased to 3.7/1,000 when cases with reactivation of previously quiescent asthma were included. Criteria for onset of clinically significant asthma attributable to occupational exposure were met by 21% (95% CI 12-32%) of cases giving an incidence of 71/100,000 (95% CI 43-111). Physicians documented asking about work-related symptoms in 15% of charts, and recorded suggestive symptoms in three cases, but did not obtain occupational medicine consultation, diagnose occupational asthma, report to the state surveillance program, or bill workers' compensation for any of them. These data suggest that the incidence of asthma attributable to occupational exposures is significantly higher than previously reported, and accounts for a sizable proportion of adult-onset asthma.

Biological monitoring of radiation exposure

Complementary to physical dosimetry, biological dosimetry systems have been developed and applied which weight the different components of environmental radiation according to their biological efficacy. They generally give a record of the accumulated exposure of individuals with high sensitivity and specificity for the toxic agent under consideration. Basically three different types of biological detecting/ monitoring systems are available: (i) intrinsic biological dosimeters that record the individual radiation exposure (humans, plants, animals) in measurable units. For monitoring ionizing radiation exposure, in situ biomarkers for genetic (e.g. chromosomal aberrations in human lymphocytes, germ line minisatellite mutation rates) or metabolic changes in serum, plasma and blood (e.g. serum lipids, lipoproteins, lipid peroxides, melatonin, antibody titer) have been used. (ii) Extrinsic biological dosimeters/indicators that record the accumulated dose in biological model systems. Their application includes long-term monitoring of changes in environmental UV radiation and its biological implications as well as dosimetry of personal UV exposure. (iii) Biological detectors/biosensors for genotoxic substances and agents such as bacterial assays (e.g. Ames test, SOS-type test) that are highly sensitive to genotoxins with high specificity. They may be applicable for different aspects in environmental monitoring including the International Space Station.

Loss of lung function among sheet metal workers: ten-year study

One hundred and twenty-two sheet metal workers in New England were examined over a 10-year interval for loss of pulmonary function and the development of asbestosis or asbestos-related pleural fibrosis. Regression models using the generalized estimating equation (GEE) approach were created to investigate the relationship between exposure and pulmonary function after adjusting for smoking status, age, height, and asbestos-related x-ray changes. A history of shipyard work was a significant contributor to the loss of forced vital capacity (FVC). Among smokers, loss in forced expiratory volume at 1 sec (FEV1) also had a significant relationship to prior shipyard work. There was a borderline significant relationship between percentage predicted FEV1 and cumulative years of asbestos exposure in smokers, as well as years-since-initial-exposure in never-smokers. This study supports previous findings of obstructive airway changes in asbestos-exposed workers and identifies shipboard work as an important predictor of loss in pulmonary function even years after shipyard exposure to asbestos has ceased.

Field testing of new aerosol sampling method with a porous curved surface as inlet

A new aerosol sampling method, utilizing a porous curved surface as the sampling inlet, has recently been developed. Previous laboratory evaluations of this method have demonstrated its important features, such as low wind sensitivity and good filter collection uniformity. In this study a prototype incorporating the new method was evaluated in the field as a stationary and personal sampling device. The small sampler, utilizing a 25-mm filter is called the button aerosol sampler and was evaluated for collecting total airborne dust and fungal spores. The study was performed in nine poorly maintained inner-city houses during environmental cleanups at different cleanliness levels. The button sampler was used in parallel with the standard 37-mm closed-face filter cassette. Four collocated samplers of each type were tested at all sites as stationary samplers, and three samplers of each type were tested at two sites as personal samplers. Aerosol samples were collected on filters and analyzed using the gravimetric method for total dust and epifluorescence microscopy for fungal spores. The average particle concentration values measured with the button sampler and with the standard sampling cassette were found to correlate well within ranges of 10(1)-10(3) micrograms/m3 for total dust and 10(3)-10(5) spores/m3 for airborne fungi. The measurement results obtained with the new button sampler showed lower intersample variations of the measured concentration levels and higher uniformity of the particle deposits on the filters than those obtained with the standard cassette.

Health impairments among refuse derived fuel workers

We conducted this study to address concerns regarding a perceived increase in bronchitis, skin rashes, and diarrhea and long term health effects in workers at two Refuse Derived Fuel (RDF) processing plants. We abstracted medical records to assess symptom occurrence, and to identify spirometry and lab abnormalities. Overall FEV1 and FVC showed no decrease over time for workers with more than five years of exposure. The primary self reported symptoms were low back pain and headaches followed by skin rashes, colds, 'flu', hay fever and ear problems. Conclusions from this analysis are limited by lack of standardized protocols or a control group. However, results from this analysis pointed out potential occupational health problems among RDF workers for future epidemiological and environmental studies.

Medical information on the Internet: a study of an electronic bulletin board

OBJECTIVE

To assess medical information provided in a medically oriented Internet discussion group, in terms of the professional status of the individuals providing information, the consistency of the information with standard medical practice, and the nature of the evidence cited in support of specific claims or recommendations.

DESIGN

Standardized review of 1,658 consecutive messages on a particular online discussion group during a 5-month period.

SETTING

An online discussion group for sufferers of painful hand and arm conditions.

SUBJECTS

All participants in this discussion group during the study period.

MEASUREMENTS AND MAIN RESULTS

Professional training of those offering medical information, consistency of the advice and recommendations offered with conventional medical practice, and nature of evidence cited in support of medical claims were determined. Of all messages, 55.9% (927) addressed a medical topic. Of these, 79% (732) provided medical information, of which 89.3% (654) were authored by persons without professional medical training, and 5.1% (37) were authored by trained health professionals. Approximately one third of the medical information provided was classified as unconventional. Personal experience was the basis of information provided in 61% of the nonprofessionals' messages and 13.5% of the professionals' messages, while no source was given as the basis of information provided in 29.8% of the nonprofessionals' messages and 67.6% of the professionals' messages. A published source was cited in 9.2% of the nonprofessionals' and 18.9% of the professionals' messages.

CONCLUSIONS

These findings suggest that medical information available on Internet discussion groups may come from nonprofessionals and may be unconventional, based on limited evidence, and/or inappropriate.

Melon ascorbate oxidase: cloning of a multigene family, induction during fruit development and repression by wounding

A small family of at least four genes encoding melon ascorbate oxidase (AO) has been identified and three members of it have been cloned. Preliminary DNA sequence determination suggested that melon AO genes code for enzymes homologous to ascorbate oxidases from other plants and similar to other multicopper oxidases. We describe detailed molecular studies addressing melon AO expression during organ specific differentiation, fruit development and ripening, and in response to wounding. In particular, AO transcript accumulation was induced in ovaries and the outer mesocarp of mature preclimacteric melon fruits, before the expression of genes encoding the necessary enzymatic activities for ethylene biosynthesis. On the other hand, AO was not expressed in late stages of fruit ripening and was repressed in wounded fruits. The role of ethylene in transcriptional regulation of AO is discussed.

Batch lot variability in permeation through nitrile gloves

Many factors should be considered in the selection of chemical protective clothing, but the majority of selections are based on manufacturers' permeation data composed of average results for three replicates; usually no information about variability is provided. It was hypothesized that variability across batch lots might be considerable, and that variability may be due to cure factors that may vary from one site to another within the same company. Glass transition temperature (Tg) has been demonstrated to be an indicator of cure, and so its relationship to permeation parameters was examined. Steady state permeation rate, breakthrough detection time (BDT), cumulative permeation at 125 minutes (ASTM F1407), and Tg (ASTM E1356) were measured for two makes of nitrile gloves presumably in four batches. Tg was not related to any of the permeation parameters even though batch-to-batch variability was statistically significant for all parameters except BDT. A comparison with recent ASTM round-robin results indicates that some of the variability may be due to the method; however, manufacturer quality control must be suspected as the major source of variability based on the results of this study.

Compliance versus risk in assessing occupational exposures

Assessments of occupational exposures to chemicals are generally based upon the practice of compliance testing in which the probability of compliance is related to the exceedance [gamma, the likelihood that any measurement would exceed an occupational exposure limit (OEL)] and the number of measurements obtained. On the other hand, workers' chronic health risks generally depend upon cumulative lifetime exposures which are not directly related to the probability of compliance. In this paper we define the probability of "overexposure" (theta) as the likelihood that individual risk (a function of cumulative exposure) exceeds the risk inherent in the OEL (a function of the OEL and duration of exposure). We regard theta as a relevant measure of individual risk for chemicals, such as carcinogens, which produce chronic effects after long-term exposures but not necessarily for acutely-toxic substances which can produce effects relatively quickly. We apply a random-effects model to data from 179 groups of workers, exposed to a variety of chemical agents, and obtain parameter estimates for the group mean exposure and the within- and between-worker components of variance. These estimates are then combined with OELs to generate estimates of gamma and theta. We show that compliance testing can significantly underestimate the health risk when sample sizes are small. That is, there can be large probabilities of compliance with typical sample sizes, despite the fact that large proportions of the working population have individual risks greater than the risk inherent in the OEL. We demonstrate further that, because the relationship between theta and gamma depends upon the within- and between-worker components of variance, it cannot be assumed a priori that exceedance is a conservative surrogate for overexposure. Thus, we conclude that assessment practices which focus upon either compliance or exceedance are problematic and recommend that employers evaluate exposures relative to the probabilities of overexposure.

p53 gene mutation pattern in rat liver tumors induced by vinyl chloride

Vinyl chloride (VC) induces angiosarcomas of the liver (ASL) and hepatocellular carcinomas (HCCs) in humans and rodents. We examined the presence of p53 gene mutations in ASL and HCC induced by VC in Sprague Dawley rats; 25 ASL and eight HCCs were analyzed for point mutations in exons 5-8, using PCR amplification, single-strand conformation polymorphism analysis, and direct DNA sequencing. Mutations were found in 11 (44%) of the ASL and in 1 HCC. A 12-base pair deletion was found in one tumor; all others were base pair substitutions. Nine of the point mutations were observed at A:T base pairs (5 A:T --> T:A; 2 A:T --> G:C, and 2 A:T --> C:G), and of three G:C --> A:T transitions, only one was at a CpG site. In ASL, four mutations were found in exon 5, two in exon 6, and six in exon 7; the base pair substitution found in one HCC was in exon 8. One ASL exhibited two point mutations, including a silent one. Two ASL exhibited the same mutation in codon 203 and two other samples in codon 253. Codon 235 was found to be mutated in three ASL. These data show that p53 is often mutated in ASL induced by VC in rats and, as observed in ASL in humans exposed to VC, the majority of the missense mutations involved A:T base pairs. The characteristic patterns of mutations found suggest that a common mechanism operates in VC-induced p53 mutagenesis in both species, and these mutations are consistent with the formation of DNA etheno adducts by VC in the liver. The A:T --> T:A transversion observed in the first nucleotide of codon 253 in two rat ASL is equivalent to the A:T --> T:A transversion characterized previously in codon 255 in one human ASL associated with VC exposure.

Concentrations of soluble CD95 and CD8 antigens in the plasma and levels of CD8+CD95+, CD8+CD38+, and CD4+CD95+ T cells are markers for HIV-1 infection and clinical status

Apoptosis mediated via the CD95 (FAS/APO-1) receptor is thought to play a role in the depletion of CD4+ T cells in HIV infection. In the present study expression of the CD95 antigen on lymphocyte subsets and the plasma level of soluble CD95 (sCD95) were determined in HIV-1-infected adults. The expression of CD95 was increased on CD8 cells in all groups of HIV+ individuals, while increased expression of CD95+ cells on CD4 cells was limited to individuals with CD4 counts of < 200 mm3. The proportion of CD4+ that expressed CD95 was inversely correlated with the percentage of CD4+ PBL. The concentration of sCD95 was significantly higher in the plasma of HIV-infected individuals than in normal controls. The level of sCD95 in HIV-infected subjects showed no correlation with the percentage of PBL expressing CD95, indicating that the increased level of sCD95 did not reflect release from CD95+ PBL. The plasma sCD95 concentration was significantly correlated with the percentage of CD8+ cells and, particularly, with CD8+ CD38- cells. A striking inverse correlation was found between the sCD95 plasma concentration and the proportion of CD4+ CD95+ cells out of the total CD4+ population. There was no correlation between the serum level of sCD95 and that of soluble CD8 (sCD8), both of which were increased in the plasma of HIV+ individuals. Unlike the level of sCD95, the level of sCD8 in the plasma of HIV+ individuals. Unlike the level of sCD95, the level of sCD8 in the plasma of HIV+ individuals was correlated with the percentage of CD95+ and CD8+ CD38+ cells. The present study indicates that plasma sCD95 may be one of the factors that regulate apoptotic death of lymphocytes in HIV infection.

Risks of developing noise-induced hearing loss in employees of urban music clubs

Noise-induced hearing loss has previously been reported among rock musicians. This study sought to determine whether a hazard of noise-induced hearing loss exists for music club employees other than musicians themselves. Sound levels at eight live-music clubs were measured and symptoms of noise exposure in 31 music club employees were assessed by questionnaire. The average sound level at the various clubs during performances ranged from 94.9 to 106.7 dBA. The overall sound level average, including both performance and ambient levels, ranged from 91.9 to 99.8 dBA. Symptoms of noise exposure, such as tinnitus and subjective hearing loss, correlated with sound intensity. Only 16% reported regular use of hearing protection. We conclude that employees of music clubs are at substantial risk of developing Noise-Induced Hearing Loss, due to chronic noise exposure which consistently exceeded safe levels. Hearing protection is used much too infrequently. The development of hearing conservation programs for this large group of workers is essential.

Dosimetry for occupational exposure to cosmic radiation

In the course of their work, aircraft crew and frequent flyers are exposed to elevated levels of cosmic radiation of galactic and solar origin and secondary radiation produced in the atmosphere, aircraft structure, etc. This has been recognised for some time and estimates of the exposure of aircraft crew have been made previously and included in, for example, UNSCEAR (United Nations Scientific Committee on the Effects of Atomic Radiation) publications. The recent increased interest has been brought about by several factors--the consideration that the relative biological effectiveness of the neutron component as being underestimated; the trend towards higher cruising altitudes for subsonic commercial aircraft and business jet aircraft; and, most importantly, the recommendations of the International Commission on Radiological Protection (ICRP) in Publication 60, and the revision of the Euratom Basic Safety Standards Directive (BSS). In 1992, the European Dosimetry Group (EURADOS) established a Working Group to consider the exposure to cosmic radiation of aircraft crew, and the scientific and technical problems associated with radiation protection dosimetry for this occupational group. The Working Group was composed of fifteen scientists (plus a corresponding member) involved in this field of study and with knowledge of radiation measurement at aviation altitudes. This paper is based on the findings of this Working Group. Where arrangements are made to take account of the exposure of aircraft crew to cosmic radiation, dose estimation procedures will not be necessary for persons for whom total annual doses are not liable to exceed 1 mSv, and therefore, in general, for crew on aircraft not routinely flying above 8 km. Where estimates of effective dose and, in the case of female staff who are pregnant, equivalent dose to the embryo or fetus, are required (for regulatory or other purposes), it was concluded that the preferred procedure was to determine route doses and fold these with data on staff rostering.

Exposures to inhalable and "total" oil mist aerosol by metal machining shop workers

Several recent studies have compared worker personal aerosol exposures as measured by the current method with those obtained by a new approach based on collecting the inhalable fraction, intended to represent all the particles that are capable of entering through the nose and/or mouth during breathing. The present study investigated this relationship for a metal machining facility where aerosols were generated from severely refined, nonaqueous ("straight") cutting oils used during the lathe working of metal rod stock. Workers (n = 23) wore two personal aerosol samplers simulataneously, one of the 37-mm type (for "total" aerosol exposure, E37) and the other of the Institute of Occupational Medicine (IOM) type (for inhalable aerosol exposure, EIOM). The data were analyzed by weighted least squares linear regression to determine the coefficient S in the relation EIOM = S.E37. It was found that S = 2.96 +/- 0.60. This ratio-in which exposure to inhalable aerosol was greater than to "total" aerosol-is consistent with previous observations in other industries. The relative coarsenss of the oil mist aerosol, as estimated by cascade impactor measurements, probably explains the difference between the sampling methods. The collection of large "splash" droplets, may also contribute. Future occupational aerosol standards for metalworking fluids will be based on the new, health-related criteria, and exposures will be assessed on the basis of the inhalable fraction. Results of studies like that described here will enable assessment of the impact on future workplace aerosol exposure assessments of introducing new standards.

Stillbirth after occupational exposure to N-methyl-2-pyrrolidone. A case report and review of the literature

N-methyl-2-pyrrolidone is a solvent that is increasingly used in a variety of industries, including petroleum refining, microelectronics, pesticide formulation, and veterinary medicine. Animal studies have demonstrated fetotoxic effects after maternal exposure to doses that have minimal to no adverse effect on the mothers. The fetotoxicity comprises resorption, stillbirth, and low birthweight and delayed ossification in surviving young. We report a human case of intrauterine growth retardation followed by fetal demise at 31 weeks gestation. The mother was a laboratory worker with no other apparent risk factors, who sustained occupational exposure to N-methyl-2-pyrrolidone throughout the first trimester of pregnancy. Laboratory work and solvent exposure have both previously been associated with adverse reproductive outcomes. Laboratories and other industries that use suspected reproductive toxins should have reproductive health policies in place that allow for decision-making based on toxicologic review, exposure assessment, and medical evaluation. These policies should allow for voluntary removal of prospective parents until environmental assessment and controls are instituted.

Does pregnancy increase the risk for development and progression of diabetic nephropathy?

OBJECTIVE

This study was designed to determine whether pregnancy and increasing parity in women with insulin-dependent diabetes mellitus (1) increases the risk for diabetic nephropathy and (2) accelerates the progression of diabetic nephropathy.

STUDY DESIGN

The study included women with insulin-dependent diabetes mellitus who enrolled in our diabetes-in-pregnancy trial with a pregnancy that continued beyond 20 weeks' gestation and who were delivered between 1978 and December 31, 1991, to allow for a minimum of 3 years' follow-up. Pregnancy and follow-up information was obtained from the medical records and from our computerized database. For patients followed up elsewhere, information was obtained from their current physicians. Life-table analysis was used to determine (1) the risk for nephropathy developing de novo as a function of duration of disease and the association of this risk with parity and (2) the risk of renal failure developing in women with preexisting nephropathy and its association with parity.

RESULTS

The study population included 182 pregnant women with insulin-dependent diabetes mellitus: 46 with overt nephropathy (group F) and 136 without nephropathy (group NF). Pregnancy and increasing parity did not increase the overall risk for nephropathy (44% after 27 years of diabetes). In group NF 10% had nephropathy within 10.1 +/- 4.2 years of the pregnancy. Proteinuria appearing during pregnancy and glycemic control during pregnancy were significantly associated with the subsequent development of nephropathy. In group F 26% had end-stage renal disease after a median period of 6 years from the pregnancy. Pregnancy or increasing parity did not increase the risk for renal failure in women with nephropathy.

CONCLUSIONS

Our data support the premise that pregnancy in women with insulin-dependent diabetes mellitus does not increase the risk of subsequent nephropathy and does not accelerate progression of renal disease in women with preexisting nephropathy.

Sensitivity of p53 lysine mutants to ubiquitin-directed degradation targeted by human papillomavirus E6

The activity of the p53 tumor suppressor protein is regulated, at least in part, through the stability of the protein. p53 degradation in normal cells is controlled by ubiquitin-dependent proteolysis, and activation of p53 following DNA damage is associated with an increase in the stability of the protein. The human papillomavirus-encoded E6 protein abrogates p53 function by targeting it for rapid degradation, also through the ubiquitin pathway. Although the p53 protein is ubiquitinated following interaction with E6, we show here that none of the lysine residues within p53 are specifically required for E6-targeted degradation. Mutation of lysine residues within the C-terminus of p53 resulted in resistance to E6-mediated degradation in vitro, although the ability of the two proteins to form a complex was not affected. The same mutant was efficiently targeted for degradation in cells, however, illustrating a lack of correlation between the in vitro and the in vivo assays.

DNA double strand break production and rejoining in V79 cells irradiated with light ions

Low energy protons and other densely ionizing light ions are known to have RBE>1 for cellular end points relevant for stochastic and deterministic effects. The occurrence of a close relationship between them and induction of DNA dsb is still a matter of debate. We studied the production of DNA dsb in V79 cells irradiated with low energy protons having LET values ranging from 11 to 31 keV/micrometer, i.e. in the energy range characteristic of the Bragg peak, using the sedimentation technique. We found that the initial yield of dsb is quite insensitive to proton LET and not significantly higher than that observed with X-rays, in agreement with recent data on V79 cells irradiated with alpha particles of various LET up to 120 keV/micrometer. By contrast, RBE for cell inactivation and for mutation induction rises with the proton LET. In experiments aimed at evaluating the rejoining of dsb after proton irradiation we found that the amount of dsb left unrepaired after 120 min incubation is higher for protons than for sparsely ionizing radiation. These results indicate that dsb are not homogeneous with respect to repair and give support to the hypothesis that increasing LET leads to an increase in the complexity of DNA lesions with a consequent decrease in their repairability.

sbmC, a stationary-phase induced SOS Escherichia coli gene, whose product protects cells from the DNA replication inhibitor microcin B17

Microcin B17 (MccB17) is a ribosomally synthesized peptide antibiotic of 43 amino acids that induces double-strand breaking of DNA in a DNA gyrase-dependent reaction. As a consequence, the SOS regulon is induced and massive DNA degradation occurs. In this work we have characterized an Escherichia coli gene, sbmC, that in high copy number determines high cell resistance to MccB17. sbmC encodes a cytoplasmic polypeptide of 157 amino acids (M(r), 18,095) that has been visualized in SDS-polyacrylamide gels. The gene is located at min 44 of the E. coli genetic map, close to the sbcB gene. sbmC expression is induced by DNA-damaging agents and, also, by the entry of cells into the stationary growth phase. A G-->T transversion at the fifth nucleotide of the quasicanonical LexA-box preceding the gene makes recA cells 16-fold more resistant to exogenous MccB17. The gene product, SbmC, also blocks MccB17 export from producing cells. Altogether, our results suggest that SbmC recognizes and sequesters MccB17 in a reversible way.

Results of a survey to assess curriculum needs for academic training programs in hazardous substances

With the advent of new industrial hygiene academic training programs in hazardous substances, located at nine United States universities, a curriculum needs assessment survey was developed at the University of Minnesota and completed by members of the joint American Industrial Hygiene Association/American Conference of Governmental Industrial Hygienists Hazardous Waste Committee and members of the Health and Safety Subcommittee of the Hazardous Waste Action Coalition. The survey asked respondents to indicate whether 27 course subjects (1) should be required, (2) may be required or elective, (3) should be elective, or (4) should not be offered. Respondents were also asked to recommend additional course subjects, research needs in the hazardous materials and waste field, and certifications to be pursued. Results from 50 completed surveys (50% response rate) showed that about half of the respondents work for consulting companies and have more than 15 years of experience in the hazardous material or waste field. The courses receiving the most "required" responses included (1) the relevant regulations, (2) worker training in health and safety, (3) waste management technology, (4) pollution prevention, and (5) treatment technology. Of elective subjects, respondents recommended education in communications, public affairs, negotiations and conflict resolution, property inspection, government relations, and air pollution modeling. Respondents indicated the strongest research needs were in the areas of direct reading instruments (improved versions and their use for personal exposure monitoring) and heat stress management of personnel wearing protective clothing. Respondents felt that the best qualifications to pursue after graduation were the Certified Industrial Hygienist designation alone, or in combination with the Certified Safety Professional designation.

Exposure to violence and victimization and depression, hopelessness, and purpose in life among adolescents living in and around public housing

This study examines the relationships between exposure to violence and depression, hopelessness, and purpose in life among black adolescents living in or around public housing developments. Black adolescents (N = 225, males = 44%) ages 11 to 19 years in a southern city were administered an anonymous questionnaire. Depression was correlated with the exposure to violence (r = .28), family conflict (r = .29), and corporal punishment (r = .32) scales, perceived probability of being alive at age 25 years (r = -.14), socioeconomic status of head of household (r = .14), anticipated socioeconomic status as an adult (r = .21), and number of sexual partners (r = .22). Based on multiple regression analysis, corporal punishment, family conflict, educational level of head of household, and perceived probability of being alive at age 25 years explained 18% (p < or = .0001) of the variation in depression. Family conflict, corporal punishment, and unemployed head of household explained 11% of the variation in the hopelessness scale. Unemployed head of household, the corporal punishment scale, and number of sexual partners explained 9.7% of the variation in purpose in life. Even when accounting for other social factors, exposure to violence in the home was associated with psychological distress in this sample of adolescents.

Interstitial deletions of the short arm of chromosome 4 in patients with a similar combination of multiple minor anomalies and mental retardation

Interstitial deletions of chromosome 4 have been described rarely and have had variable presentations. We describe the phenotypic characteristics associated with interstitial deletion of the p14-16 region of chromosome 4 in 7 patients with multiple minor anomalies in common, and with mental retardation. A review of published cases of interstitial deletions of the short arm of chromosome 4 is provided. These deletions present a distinct phenotype which is different from that of Wolf-Hirschhorn syndrome.

Decreased platelet counts in infants of diabetic mothers

Infants of diabetic mothers (IDMs) have hematologic indices consistent with increased fetal erythropoiesis, presumably in response to chronic intrauterine hypoxemia. We hypothesized that increased erythropoiesis, as is evident from increased nucleated erythrocyte counts, would be accompanied by interrelated changes in thrombopoiesis and would correlate with maternal glycemic control during pregnancy. We compared absolute nucleated erythrocyte counts and platelet counts obtained in the first 24 hours of life in 32 term, nonasphyxiated IDMs with 47 controls. The IDM group had higher absolute nucleated erythrocyte counts (1.0 +/- 1.3 x 10(9)/L versus 0.4 +/- 0.7 x 10(9)/L; p < 0.05), and lower platelet counts (235 +/- 77 x 10(9)/L versus 348 +/- 79 x 10(9)/L; p < 0.001) than controls. Absolute nucleated erythrocyte counts correlated inversely with platelet counts (r = -0.28; p < 0.02). These neonatal hematologic measurements did not correlate with various parameters of maternal glycemic control. We conclude that in IDMs, increased erythropoiesis is accompanied by decreased platelet counts. These data are consistent with the theory of an erythropoietin-induced shift of fetal multipotent stem cell differentiation toward erythropoiesis at the expense of thrombopoiesis.