Carol A. Newill

Effects of pulmonary function on mortality

Survivorship data from a 24 year longitudinal study of 874 male volunteers in the Baltimore Longitudinal Study of Aging were used to assess the role of pulmonary function on total mortality. Even when age and smoking were considered, the ratio of forced expiratory volume in 1 sec to its predicted value was significantly associated with mortality from all causes. Individuals with poorer pulmonary function showed greater mortality during the follow-up period of this study. This relationship was also seen among never smokers in this sample, further supporting the hypothesis that impaired pulmonary function is itself a predictor of total mortality and may contribute to a number of disease processes.

Task-related variation in airborne concentrations of laboratory animal allergens: Studies with Rat n I

To define airborne allergen exposure during various tasks with rats in a laboratory, concentrations of allergen Rat n I were measured by radioimmunoassay in extracts from filters in personal air sampling devices that were worn by laboratory workers while they were performing these tasks. The tasks included feeding, cage cleaning, handling, injection, surgery, and sacrifice. Median concentrations encountered during feeding or cleaning (21 ng/m3) and injection or handling (13 ng/m3) were higher than those associated with surgery or sacrifice (3.1 ng/m3; p less than 0.01). Area samples in animal-holding rooms contained 3.4 ng/m3 during animal handling and 2.3 ng/m3 at other times. Very low concentrations were found in air outside the handling room, in unused laboratories, or outside air. We concluded that certain tasks incur a higher risk of allergen exposure but that exposure may occur anywhere within an animal laboratory environment.

Epidemiological approach to the evaluation of genetic screening in the workplace.

Using several examples of genetic marker and disease associations in the workplace, the authors have applied formulas to estimate the sensitivity, specificity, and positive predictive value (PPV) of screening for these markers. Sensitivity, specificity, and PPV are affected independently by characteristics of the population being screened, ie, the genetic marker frequency, the disease frequency, and the magnitude of the relative risk (R). For a given disease frequency, when the genetic marker is less frequent than the disease, PPV increases with relative risk, although sensitivity remains low. When the genetic marker is more frequent than the disease, PPV remains low while sensitivity increases with R. When marker and disease frequencies are equal, PPV and sensitivity are equal and increase with R. However, when the disease frequency is very low, R must approach 100 before PPV or sensitivity approaches 50%. These relationships may be used effectively in the decision whether to implement a screening program in the workplace.

Gastrointestinal symptoms in autism spectrum disorder: A review of the literature on ascertainment and prevalence

There is no standard approach to measuring GI symptoms in individuals with ASD, despite postulated interactions. The objectives of this study were to (a) describe the range of GI symptom ascertainment approaches in studies of ASD, (b) describe the range of prevalence estimates across studies, and (c) assess associations between ascertainment approach and prevalence estimates. Studies published from 1/1/1980 to 1/31/2017 were collected via PubMed. Eligibility included studies with at least ten individuals with ASD that measured GI symptoms or conditions. We excluded review and hypothesis papers. We extracted information on study design, GI symptom ascertainment method, demographics, and ASD diagnostic criteria. From a subset of studies, we extracted GI symptom estimates. Out of a possible 386 titles, 144 were included. The prevalence range for constipation was 4.3–45.5% (median 22%), for diarrhea was 2.3–75.6% (median 13.0%), and for any or more than one symptom was 4.2–96.8% (median 46.8%). GI symptoms differed significantly by age of individuals, primary goal of study, study design, study sample, and who reported symptoms (P < .05). Due to small sample size, we were not able to test for associations between every GI symptom and study characteristic of interest, or examine associations between GI symptoms and intellectual or verbal disability. Studies used a broad range of methods to ascertain GI symptoms in ASD. GI symptoms varied widely across these studies, with significant differences by study characteristics. Our findings highlight the need for a reliable, valid GI assessment tool to be used consistently across studies of ASD. Autism Res 2018, 11: 24–36.

INBREEDING AND PREREPRODUCTIVE MORTALITY IN THE OLD ORDER AMISH. II. GENEALOGIC EPIDEMIOLOGY OF PREREPRODUCTIVE MORTALITY

The effects of offspring and parental inbreeding on prereproductive mortality (death before age 20 years) in the historical population of the Lancaster County, Pennsylvania, Old Order Amish were investigated using the Amish genealogic registry, which contains information on 42,465 births dating to the time of the pioneer migrants in the 1700s. Inbreeding coefficients for offspring and parents were computed using the path method of tracing common ancestors in the multigenerational pedigrees. In this population, prereproductive mortality declined from about 15% in the late 1800s to about 5% after 1930. Offspring inbreeding was found to be an independent predictor of prereproductive mortality after multivariate adjustment for demographic risk factors for mortality. Moreover, the higher the coefficient, the higher the relative risk of prereproductive death, and the higher the risk of multiple deaths in the same sibship. There was no evidence of declining inbreeding effects over 10 generations of continuous inbreeding, nor of any significant parental inbreeding effects. Because of the high levels of inbreeding, it could be shown that inbreeding accounts for about 40% of all prereproductive deaths in the present population. Genetic load analysis showed an average of about 1.7 lethal equivalents and a mostly mutational load.

Prospective study of occupational asthma to laboratory animal allergens: Stability of airway responsiveness to methacholine challenge for one year

The stability of airway hyperresponsiveness was studied in a group of 178 young adults working with laboratory animals. At the time of their entry into the study, 132 of 178 subjects (74%) had less than 20% response to the inhalation of 25 mg/ml methacholine, whereas 26 (15%) had a methacholine dose causing a 20% fall in forced expiratory volume in 1 second after fewer than 80 breath units. The distribution of methacholine responsiveness did not differ at 6 months and 1 year; 155 of 178 volunteers (90.4%) responded during the repeated challenges to doses within one dilution of their results at entry. One hundred forty-one subjects were consistently unreactive during the year, and 17 were consistently reactive. Approximately equal numbers gained and lost reactivity. Those with consistently positive responses to methacholine were more likely to have skin test reactivity and chest symptoms. The presence of consistent chest symptoms was loosely associated with consistent methacholine responsiveness; 55% of those with consistent hyperresponsive airways had symptoms, and 24% of those who consistently had symptoms had hyperresponsive airways. We concluded that the methacholine response is relatively stable during the course of a year in laboratory animal workers who remain at their jobs and that the presence of a positive skin test response to laboratory animals or of chest symptoms does not change the pattern of stable responsiveness.

Utilization of Personal Protective Equipment by Laboratory Personnel at a Large Medical Research Institution

Abstract The federal Guide for the Care and Use of Laboratory Animals (1985) recognizes allergy to laboratory animals (ALA) as an occupational hazard and calls for the development of methods for its prevention. The prevalence of symptomatic ALA (rhinitis and/or urticaria) ranges from 15–33 percent, and its costs include not only the medical consequences of chronic atopic disease but also the loss of highly trained personnel. Employers at many laboratory animal facilities provide personal protective equipment (PPE) as a preventive measure to reduce the risk of ALA. A survey of the use of PPE by a sample of laboratory animal personnel at a large medical research institution is reported here. During the week surveyed, 171/210 persons (81%) did not use any respiratory PPE (e.g., respiratory masks), indeed, 61/210 (29%) did not use any PPE whatsoever. Failure to use any PPE was related to the type of animal(s) to which the staff was exposed and to the work task performed, as well as certain demographic factors...