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Biomedical subjects

H A Stubbs

Publications and source records attributed to H A Stubbs.

14 recordsLinked to original sources
PubMed1994

Mortality factors in geriatric blunt trauma patients.

OBJECTIVE: To examine various clinical factors for their ability to predict mortality in geriatric patients following blunt trauma. DESIGN: In this retrospective study, trauma registries and medical records from three trauma centers were reviewed for patients 65 years and older who had sustained blunt trauma. The following variables were extracted and examined independently and in combination for their ability to predict death: age, gender, mechanism of injury, admission blood pressure, and Glasgow Coma Scale score, respiratory status, Trauma Score, Revised Trauma Score, and Injury Severity Score. SETTING: Three urban trauma centers. PATIENTS: Geriatric trauma patients entering three trauma centers (Stanford [Calif] University Hospital, Vanderbilt University Medical Center, Nashville, Tenn, and Maryland Institute for Emergency Medical Services Systems, Baltimore) following blunt trauma during a 7-year period (1982 to 1989). RESULTS: The Injury Severity Score was the single variable that correlated most significantly with mortality. Mortality rates were higher for men than for women and were significantly higher in patients 75 years and older. Admission variables associated with the highest relative risks of death included a Trauma Score less than 7; hypotension (systolic blood pressure, < 90 mm Hg); hypoventilation (respiratory rate, < 10 breaths per minute); or a Glasgow Coma Scale score equal to 3. CONCLUSIONS: Admission variables in geriatric trauma patients can be used to predict outcome and may also be useful in making decisions about triage, quality assurance, and use of intensive care unit beds.

Abbreviated Injury Scale↗
PubMed1992

Risk factors for Lyme disease in a small rural community in northern California.

A 1-year prospective study of risk factors for seropositivity to and contraction of Lyme disease among members of a small rural community (population, approximately 150) was conducted in northwestern California in 1988-1989. The initial rate of seropositivity for Borrelia burgdorferi for 119 current or former residents ranged from 15 to 20% among three laboratories, with statistically significant interlaboratory agreement. Questionnaires were completed by 93 current residents at entry and 80 residents a year later to evaluate the association of serologic status with 20 categorical and 47 continuous variables. Seropositive subjects had resided in the study area about 2 years longer, were bitten by unspecified biting flies more often, and were less likely to have engaged in hiking than seronegative subjects. One of 59 seronegative subjects seroconverted a year later (annual incidence = 1.7%). The cumulative frequency of seropositivity for Lyme disease in the study population was > or = 24%. Of 83 subjects examined physically, 13 were diagnosed as having definite and 18 as having probable Lyme disease. The seropositivity rate was significantly higher (38.7%) among individuals with definite/probable Lyme disease than in asymptomatic subjects (13.5%). Subjects who were seronegative or free of Lyme disease reported nearly as many tick bites as subjects who were seropositive or had a diagnosis of the disease. Age, time spent outdoors in the fall multiplied by a clothing index, and woodcutting were significantly associated with Lyme disease in logistic regression analyses.

Adult↗
PubMed1992

Hematuria as a predictor of abdominal injury after blunt trauma.

Among the 1,484 patients included in the Renal Trauma Project with evidence of blunt trauma and hematuria, 160 patients were found to have both hematuria and a significant intra-abdominal injury not related to the genitourinary system. The incidence of abdominal injury generally increased with the degree of hematuria, approaching 24% in patients with gross hematuria. For each category of degree of hematuria, patients with shock had a significantly higher incidence of abdominal injury (p < 0.05) than patients without shock. The incidence of abdominal injury in patients with microscopic hematuria and shock was 29%, and it was 65% for patients with both gross hematuria and shock. All patients with gross hematuria after blunt abdominal trauma and all patients with microscopic hematuria and a history of shock should be evaluated for both urologic and extra-renal abdominal injuries.

Abdominal Injuries↗
PubMed1990

Host-seeking behavior of adult Ixodes pacificus (Acari: Ixodidae) as determined by flagging vegetation.

Diurnal host-seeking by adults of the western black-legged tick, Ixodes pacificus Cooley & Kohls in relation to vegetative habitat type and meterological factors was investigated at a coastal and an inland site in northern California. Host-seeking behavior and relative tick abundance were determined with a tick drag method from late fall to midwinter 1987-1988. At the inland site, tick abundance usually was significantly greater in chaparral-grassland ecotones than in adjoining dense chaparral on the south-facing slope of a mountaintop, whereas both of these vegetative types produced significantly fewer ticks on a north slope compared with a contiguous south-facing slope. There was no evidence for an association between tick abundance and plant species within ecotonal chaparral. Multiple regression analyses revealed that tick abundance in ecotonal chaparral at the inland site and in grassland at the coastal site was not associated consistently with either ambient temperature or relative humidity. Compared with the inland site, ticks were considerably more abundant at the coastal site where sampling occasionally yielded more than 100 ticks per 100 drag samples. The incidence of infection with Borrelia burgdorferi Johnson, Schmid, Hyde, Steigerwalt & Brenner, the etiologic agent of Lyme borreliosis, in adult ticks collected in the morning (1.5%) versus afternoon (2.2%), and in male (1.3%) versus female ticks (2.5%), at the coastal site in winter was similar.

Animals↗
PubMed1989

Determinants of bone density among athletes engaged in weight-bearing and non-weight-bearing activity.

To identify the factors associated with greater bone density among athletic individuals, we recruited three distinct groups of young male subjects. Twenty were nationally ranked water polo players, 19 were engaged in weight-training programs, and 20 subjects comprised a nonexercising comparison group. All participants had measurements of spinal trabecular and integral bone density by quantitative computed tomography as well as a determination of hip bone density by dual photon absorptiometry. A series of potential predictor variables included maximal O2 uptake, back strength, leg strength, total kilocalories expended per day, body mass index, paraspinous muscle cross-sectional area, percent body fat, daily calcium intake, and age. We found no significant differences for any of the bone density measures between the two groups of athletic subjects, whereas bone density was generally significantly lower among the nonexercisers compared with either exercise group. Correlation analysis found only weak and somewhat inconsistent relationships when each of the subgroups was examined separately; however, when all subjects were assessed collectively, many more correlations reached significance. Paraspinous muscular area was found to be most robust in this regard, being significantly correlated with all three bone density measures (r = 0.33-0.55). By using step-wise regression analysis in each subgroup, we observed a consistent significant contribution (R2 = 0.18-0.44) of paraspinous muscle area to the variability in bone density at the spine and the hip. When the data of all three subgroups were pooled, regression analysis reconfirmed the importance of the muscle parameter (R2 = 0.06-0.27) to bone density variation, but more importantly it showed that differentiation based on exercise status was most significant (R2 = 0.18-0.22).

Adolescent↗
PubMed1987

Botulinum toxin for benign essential blepharospasm, hemifacial spasm and age-related lower eyelid entropion.

Purified botulinum A exotoxin was used in the treatment of forty seven patients with benign essential blepharospasm, 11 patients with hemifacial spasm and 2 patients with age-related entropion. The treatment was effective in all three groups for an average of 3-4 months when symptoms recurred and repeated chemodenervation with toxin was needed. The commonest complication was transient ptosis with an overall frequency of 7.8%. This incidence increased to 11.1% with toxin doses higher than 25 units per orbicularis. The treatment was well accepted by the patients, who were subsequently able to return to pre-blepharospasm lifestyles.

Adult↗
PubMed1985

Botulinum A toxin injection as a treatment for blepharospasm.

Thirty-nine patients with blepharospasm were treated with injections of botulinum A toxin into the lid and brow. The maximum number of injections in one patient was 16 over a period of 24 months. A reduction of abnormal movement occurred in all patients, lasting up to 170 days. Both the amount and the duration of effect were dose dependent. Reinjection for recurrence had effects similar to the original injection. Tearing, dry-eye symptoms, or transient ptosis occurred in 20% of injections, especially in patients who had had previous eyelid surgery.

Blepharospasm↗
PubMed1984

A proportionate mortality analysis of California agricultural workers, 1978-1979.

There are few published reports of epidemiologic studies of the risks of agricultural work. Members of this occupational group have been of special concern because of their exposure to pesticides, some of which are mutagens and animal carcinogens. A previous proportionate mortality study of California agricultural workers was based on deaths recorded among white males of this occupational group during 1959-1961. We have conducted a proportionate mortality analysis of all deaths recorded during 1978-1979 among California farm workers and farm owner/managers. In general, the findings of our study are consistent with those of the previous study. For farm workers, we found proportionate mortality ratios (PMRs) which were consistently elevated for all race and sex categories (in which there were 6 or more decedents) for deaths due to motor vehicle accidents, all respiratory disease, and all infective and parasitic diseases. The PMRs for the former three causes of death were also found to be elevated across several race and sex categories for farm owner/managers. We also found a significant and consistent deficit of deaths among farm workers and farm owner/managers due to arteriosclerotic heart disease. The proportionate cancer mortality ratios (PCMRs) for cancer of the stomach and cancer of other lymphatic tissue were elevated, although not necessarily statistically significantly, for several race and sex categories among farm workers and farm owner/managers. The PCMR for cancer of the cervix was statistically significant for white female farmworkers.

Accidents↗
PubMed1983

Feasibility of identifying high-risk occupations through tumor registries.

The primary objective of this study was to assess the feasibility of using a population-based tumor registry to identify occupational groups at high risk of developing cancer. The study group comprised 6,424 union members residing in the San Francisco/Oakland Standard Metropolitan Statistical Area (SMSA) who represent six occupations: asbestos workers, bakers, painters, plasterers, plumbers and roofers. Computer linkage of union rosters to the California Tumor Registry (CTR) file identified incident cases of cancer. The CTR's age-sex-year-specific incidence rates were used to calculate the expected number of cancer cases, and estimated standardized incidence ratios (SIRs). The results demonstrate, as expected, increased cancer incidence (SIR = 498) for trachea, bronchus, lung and pleura among asbestos workers, a group widely recognized as having high risk for respiratory cancers, and among painters (SIR = 199). Strengths and weaknesses of such an approach are discussed.

Asbestos↗
PubMed1981

Malignant melanoma among employees of Lawrence Livermore National Laboratory.

19 cases of malignant melanoma (MM) were observed during 1972-77 among approximately 5100 employees of the Lawrence Livermore National Laboratory, where high energy physics research is conducted. This number was significantly higher (p less than 2 X 10(-6)) than that expected in a comparable age/race/sex/geographical segment of the population of the San Francisco Bay Area. The excess seemed to occur only among laboratory employees and not among the surrounding community, which suggests that an occupational factor is responsible. Preliminary case-comparison findings suggest that MM risk is not associated with length of employment at the laboratory nor with type of monitored radiation exposure. Although the data did not support an association between MM incidence and all scientific job classifications combined, an excess relative risk was observed among chemists. The reasons for the MM excess have not been identified.

Adult↗
PubMed1981

Testicular function among epichlorohydrin workers.

Epichlorohydrin (1,2-epoxy-3-chloropropane) (ECH) is a colourless liquid used in the production of insecticides, agricultural chemicals, epoxy resins, and many other productions. It is highly reactive and an alkylating agent suspected of possessing carcinogenic properties in man. The results of a clinical-epidemiological investigation to ascertain whether exposure to ECH may be associated with sperm count suppression among ECH production workers at two chemical plants are presented. Medical histories and physical examinations with special emphasis on the genitourinary tract were completed on each participant. Blood samples and three semen specimens were also obtained. Since no internal control group were available, the data arising from this effort were analysed for each plant (plant A, 44 men; plant B, 84 men) using a control group of 90 chemical plants workers unexposed to any agents known to be toxic to the tests who were included in previous studies. This study provides no evidence that exposure to ECH at the concentrations existing at the two plants studied is responsible for sperm count suppression.

Chemical Industry↗
PubMed1979

Testicular function among carbaryl-exposed exployees.

A cohort of 101 male carbaryl production workers with at least 1 yr experience in the carbaryl area was selected from employment records. Of these individuals, 47 provided satifactory semen samples for analysis; 36 of the 47 provided blood for hormone assay. There were no major age or employment-status differences between those who agreed to participate and those who did not. In the absence of sufficiently detailed industrial hygiene exposure data, a subjective exposure classification was developed. No apparent relationships were found between sperm count and exposure category or years worked in classifications based on carbaryl exposure. Also, no relationship was found between fathering children and exposure to carbaryl. When the sperm-count distribution of the carbaryl-exposed workers was compared with a distribution of sperm counts representing a nonexposed (control) population, no overall differences were observed that could be related to carbaryl exposure. There was a small excess in the number of sperm counts less than 20 million per milliliter among the carbaryl-exposed men, but the excess was not significant at alpha = 0.05.

Adult↗
PubMed1979

Testicular function in DBCP exposed pesticide workers.

In mid-1977 a number of cases of infertility among male pesticide workers in California came to light. A description of this problem was published as a Preliminary Communication in The Lancet. A larger clinical-epidemiological study was undertaken to better understand the exposure-effect relationships involved. Of 142 non-vasectomized men providing semen samples, 107 had been exposed to 1,2-dibromo-3-chloropropane (DBCP) and 35 had not been exposed. There was a clearcut difference in both the distribution of sperm counts and the median counts between the exposed men and the not-exposed men, Of the exposed, 13.1% were azoospermic, 16.8% were severely oligospermic, and 15.8% were mildly oligospermic. Among the controls, 2.9% were azoospermic, none were severely oligospermic, and 5.7% were mildly oligospermic. Under workplace conditions, DBCP appears to have a selective effect on the seminiferous tubules.

Antinematodal Agents↗