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Biomedical subjects

P Harber

Publications and source records attributed to P Harber.

85 records · Page 5Linked to original sources
PubMed1978

Activation of the kallikrein-kinin system in Rocky Mountain spotted fever.

Activation of the kallikrein-kinin system, as indicated by increased plasma kallikrein and depleted plasma kininogen, prekallikrein, and kallikrein inhibitor, was observed in five patients with Rocky Mountain spotted fever. Four of the patients had petechial rashes characteristic of vasculitis. Three patients had alterations in coagulation consistent with disseminated intravascular coagulation, although no hemorrhagic syndrome was found. Our data, along with the known physiologic actions of kinins, suggest a possible role for the kallikrein-kinin system in the pathophysiology of vasculitis, disseminated intravascular coagulation, circulatory shock, and other complications of infection with Rickettsia rickettsii.

Adult↗
PubMed1977

Laboratory-acquired Rocky Mountain spotted fever. The hazard of aerosol transmission.

Nine patients with laboratory-acquired Rocky Mountain spotted fever were seen during the period 1971 to 1976. Investigation of each case revealed either definite or probable exposure to an aerosol containing infectious rickettsiae; in no case was there evidence of parenteral exposure either by accidental self-inoculation or by tick bite. These illnesses are believed to represent infection acquired via the respiratory route. This report emphasizes the aerosol hazard of Rickettsia rickettsii in the laboratory and discusses the possibility of respiratory transmission of Rocky Mountain spotted fever in nature. The illness occurred only in personnel who had received either no vaccination or the primary series of the commercial (Lederie) vaccine against this infection. Other personnel who had received the primary series with multiple booster vaccinations demonstrated increased immunity as measured by humoral antibody titers and rickettsial antigen-induced lymphocyte transformation; no cases of clinical disease developed in these multiply-vaccinated personnel.

Adult↗
PubMedDate not supplied

Comparative short-term health responses to sulfur dioxide exposure and other common stresses in a panel of asthmatics.

We studied 14 unmedicated sulfur dioxide (SO2)-sensitive asthmatics to test the hypothesis that SO2 exacerbates asthma more than other everyday respiratory stressors. In Phase I, subjects underwent controlled exposures to 0.0, 0.5, and 1.0 ppm SO2 with light, medium, and heavy exercise (average ventilation 30, 36, and 43 l/min, respectively). Lung function, symptoms of asthma, and psychophysical (stamina) changes were measured. Function, symptom, and stamina responses correlated modestly. Increasing SO2 had stronger unfavorable effects than increasing exercise. In Phase II, subjects performed eight different physical tasks in SO2-free ambient air while symptoms and stamina were measured. Fast stair-climbing evoked symptoms similar to the effects of 0.5 ppm SO2/light exercise, while stamina reduction was comparable to 0.5 ppm SO2/heavy exercise. In Phase III, subjects recorded time-activity patterns, symptoms, and stamina during randomly selected intervals on a typical weekday and weekend day. Most reported activities were sedentary. Infrequent, strenuous Phase III exercise increased symptoms more than did 0.5 ppm SO2/light exercise, but with less effect on stamina. We conclude that for typical mild asthmatics, ten-minute SO2 exposures at concentrations > 0.5 ppm and ventilation > 30 l/min can cause short-term asthma manifestations more intense than those usually experienced from everyday stresses without SO2 exposure.

Activities of Daily Living↗
PubMedDate not supplied

Program optimization: a semi-quantitative approach.

The authors describe a quantitative model used to express the relative costs and benefits of alternative approaches to pulmonary prevention. This approach identifies the factors that a program director must consider in planning preventive interventions for respiratory disease of workers.

Cost-Benefit Analysis↗
PubMedDate not supplied

Pulmonary prevention: programmatic characterization.

Pulmonary disease is a major cause of morbidity and mortality in workers. This chapter describes a variety of preventive methods that can be used in dealing with occupational pulmonary disease. These preventive programs should be selected based upon the unique characteristics of each worksite, including the nature of occupational risks, the characteristics of the population, and the capabilities of the health care system.

Humans↗
PubMedDate not supplied

Pulmonary function testing in pulmonary prevention.

Pulmonary function testing plays an important role in the prevention of environmental lung disease when used in surveillance programs, research programs, and clinical practice. This paper focuses upon the interpretation of lung function data acquired during occupational disease surveillance and examines several potential pitfalls in spirometry surveillance programs.

Humans↗
PubMedDate not supplied

The evaluation of pulmonary fitness and risk.

In summary, medical evaluation for placement decisions must carefully consider the work requirements and the condition of the individual at the present time and in the future. In all situations, the right of the individual to a job must be balanced against the need to protect the potential worker against any adverse effects. Methods of accommodation of the respiratory-impaired worker must also be considered. As discussed elsewhere in this issue (Chapter 4), there are legal requirements for accommodation of the impaired worker. Accommodation may involve worksite modification, change in work schedule, or change in work practices. Specifically, if an individual cannot meet the exertion requirements of the job, it may be possible to modify them. For example, a punch press operator with chronic obstructive lung disease who is unable to carry the raw materials to the press once a day may be able to work if another worker carries the raw materials or if a suitable mechanical assist device is provided. Furthermore, proper workplace controls can decrease exposure levels; if there is no exposure to a toxic substance, then preexisting disease should not influence placement. In one very provocative study, McGrath demonstrated that with stringent environmental controls, persons with occupational asthma to trimellitic anhydride could continue working safely with this substance. Finally, many persons may be able to work on a part-time basis or during certain shifts. Medical evaluation for proper placement is not a single decision to be made on the basis of a one-time evaluation. An iterative approach may be employed, in which the worker's response to a particular placement may be monitored. In this way, individuals who develop adverse effects will be detected. Follow-up contact between the clinician and the worker in borderline situations should be encouraged both to detect any adverse reactions and to facilitate rapport such that the employee will feel comfortable in relating problems to the clinician. Thus, placement decisions must be made carefully with attention to the many factors involved. Ultimately, the physician must use the best available information when serving as an advisor to the potential employer and to the potential employee.

Humans↗
PubMedDate not supplied

Defining "disease" in epidemiologic studies of pulmonary function: percent of predicted or difference from predicted?

Epidemiologic studies often seek to determine the presence and magnitude of association between a trait and a disease, and spirometry test results are often used to define "disease". We evaluated two methods of comparing observed to predicted FEV1. The percent of predicted method is the ratio of a subject's observed to predicted result, and the residual method is the difference between the predicted and the observed result. FEV1 data from 541 men were used for computer simulated sampling for epidemiologic study of groups with different age structures. The residual method was superior because it produced more consistent measures of association, was less likely to produce an apparent association when one did not exist, and is more consistent with the statistical basis of the commonly employed prediction equations.

Adult↗
PubMedDate not supplied

Occupational respiratory function testing--an algorithmic approach.

Pulmonary function testing is an essential component of many occupational respiratory programs. Testing is performed for several different reasons. Proper selection of tests depends on whether they are used for screening a healthy population, establishment of a clinical diagnosis in a specific individual, or determination of work ability or disability. There are many pulmonary conditions and relevant exposures. The appropriate tests should be chosen based on the specific situation.

Algorithms↗