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Biomedical subjects

J F McCarthy

Publications and source records attributed to J F McCarthy.

At least 19 recordsLinked to original sources
PubMed1994

Effect of radiation therapy on detectable serum prostate specific antigen levels following radical prostatectomy: early versus delayed treatment.

Radiation therapy may be beneficial after radical prostatectomy in some patients with pathological stage C prostate cancer and in those with detectable postoperative prostate specific antigen (PSA) levels. A total of 64 men underwent postoperative radiation therapy following radical prostatectomy for pathological stage C disease (27), a detectable serum PSA level (11) or both conditions (26). Of the 27 men treated prophylactically for pathological stage C disease 18 (67%) had no evidence of recurrence after radiation within the first 6 months postoperatively (median followup 40 months, range 17 to 97). Of 22 men treated for delayed PSA elevation 15 (68%) currently are disease-free (median followup 27.5 months, range 15 to 47). Of 15 men treated within the first 6 months after radical prostatectomy for persistently detectable PSA levels 8 (53%) had an initial decrease in PSA to undetectable levels but only 5 (33%) had a durable complete response (median followup 36 months, range 8 to 56). We conclude that patients with pathological stage C disease who are most likely to benefit from postoperative radiation therapy are those with initially undetectable postoperative PSA levels. We observed no striking difference in treatment outcome between early and delayed adjuvant radiation therapy.

Combined Modality Therapy↗
PubMed1992

Biological markers of environmental and ecological contamination: an overview.

An approach, using biomarkers (biological responses) for assessing the biological and ecological significance of contaminants present in the environment is described. Living organisms integrate exposure to contaminants in their environment and respond in some measurable and predictable way. Responses are observed at several levels of biological organization from the biomolecular level, where pollutants can cause damage to critical cellular macromolecules and elicit defensive strategies such as detoxication and repair mechanisms, to the organismal level, where severe disturbances are manifested as impairment in growth, reproduction, developmental abnormalities, or decreased survival. Biomarkers can provide not only evidence of exposure to a broad spectrum of anthropogenic chemicals, but also a temporally integrated measure of bioavailable contaminant levels. A suite of biomarkers are evaluated over time to determine the magnitude of the problem and possible consequences. Relationships between biomarker response and adverse ecological effects are determined from estimates of animal health and population structure.

Animals↗
PubMed1991

DNA alterations and enzyme activities in Japanese medaka (Oryzias latipes) exposed to diethylnitrosamine.

Several molecular and biochemical markers of genotoxicity were adapted for measurement in the medaka, and were used to describe the effects of treatment of the organism with diethylnitrosamine (DEN). DEN treatment inhibited the activity of a detoxication enzyme activity (ethoxyresorufin-O-deethylase) and increased the activity of glutathione-S-transferase. This pattern of response has been described in preneoplastic rodent cells. No O6-ethyl guanine adducts were detected, and a slight, but statistically significant, increase in DNA strand breaks was observed. These results are consistent with the hypothesis that prolonged exposure to high levels of DEN induced alkyltransferase activity which enzymatically removes any O6-ethyl guanine adducts but does not result in strand breaks or hypomethylation of the DNA such as might be expected from excision repair of chemically modified DNA.

Animals↗
PubMed1990

A scheme for classifying carcinogens.

We present a scheme for classifying chemical carcinogens according to the weight of the evidence that each substance poses a human cancer hazard. The approach represents a logical extension of and builds upon those previously developed by the International Agency for Research on Cancer, the U.S. Environmental Protection Agency, and the so-called Tripartite Group of industrial scientists. It takes into account new scientific knowledge about chemical carcinogenesis and animal models. Eight categories are presented: known human carcinogen (Category 1), carcinogenic activity in animals, probable human carcinogen (Category 2), possible human carcinogen (Category 3), equivocal evidence for carcinogenic activity (Category 4), evidence inadequate for classification (Category 5), carcinogenic activity in animals; probably not a human cancer hazard (Category 6), carcinogenic activity in animals; considered not a human cancer hazard (Category 7), evidence of noncarcinogenicity (Category 8). Evidence useful for categorization includes human studies, animal bioassays, corroborative evidence from bioassays, and mechanistic studies relevant to determining the predictivity of animal responses for human hazard. Weighing this evidence to derive a conclusion about classification is a process that requires expert judgment; it cannot now be reduced to a simple set of decision rules. However, we identify the kinds of information that can be useful in this process, and indicate how each might most appropriately be used.

Animals↗
PubMed1990

Variability of measures of exposure to environmental tobacco smoke in the home.

We assessed the variability of four markers of environmental tobacco smoke exposure in 10 homes with 20 nonsmoking and 11 smoking household members. We obtained exposure questionnaires, saliva and urine for cotinine, and air particle samples for respirable particles and nicotine on 10 sampling days: every other day over 10 days, and then 1 day every other week over 10 wk. The mean concentrations of respirable particles in the 10 homes ranged from 32.4 to 76.9 micrograms/m3, and concentrations of nicotine ranged from 0.6 to 6.9 micrograms/m3. Linear regression models that included indicator variables for self-reported exposure explained 9 and 6% of the variability of the respirable particle and the nicotine concentrations, respectively. The individual mean urinary cotinine levels standardized to creatinine concentration ranged from 3.9 to 55.8 ng/mg Cr, and for salivary cotinine the mean levels ranged from 0.9 to 4.3 ng/ml. Indicator variables for self-reported exposure explained 8 and 23% of the variability of the urinary and salivary cotinine levels, respectively. We conclude that because of the marked variability of these measures, multiple measurements are needed to establish a stable profile of exposure to environmental tobacco smoke in the home.

Adolescent↗
PubMed1990

A personal monitoring study to assess workplace exposure to environmental tobacco smoke.

We enrolled 15 nonsmoking volunteers to evaluate the feasibility of measuring personal exposure to environmental tobacco smoke (ETS) at work and to characterize workplace exposures. During one workshift, we obtained questionnaires on exposure, saliva and urine for cotinine, and personal air samples for respirable particles and nicotine. The levels of cotinine, respirable particles, and nicotine varied widely with self-reports of exposure to ETS, but on average increased with increasing exposure.

Adult↗
PubMed1989

Patterns of mortality in Armenian parish records from eleven countries.

A study of the trends and distributions of mortality in parish records of Armenian churches from 11 countries spanning over 242 years is the basis of this report. In all parishes, the relative proportion of deaths in the older age groups gradually increased over the study period. Following a review of the most important causes of death, an effort was made to identify clusters and outbreaks of specific causes of death. Thus, in the 19th century, five epidemics of cholera were identified in one parish in Kutahya, Turkey (1831, 1848, 1865, 1871, and 1893). A review of the deaths due to the 1918 influenza pandemic revealed a major peak in October-December 1918 in Cairo, and deaths due to the same cause recorded in November-December 1918 in Rangoon, Dacca, and Calcutta. As observed elsewhere in the classic pattern of this pandemic, the largest number of these deaths were in persons who were in their twenties. In September-December 1942, in Thessaloniki, Greece, 31 deaths of all age groups were ascribed to a fever that was described as "toxic." The nature of this epidemic could not be explained. The observation that large numbers of recorded deaths occurred through violence and hunger during the First and Second World Wars as a result of the atrocities to which these communities were exposed sheds further light on historical events in those years.

Adolescent↗
PubMed1988

Copper oxide aerosol: generation and characterization.

Effluent gases from high temperature systems such as fossil fuel combustion and pyrometallurgical processes contain inorganic material which has the potential to interact with sulfur dioxide (SO2) on the surface of particles to form an irritant aerosol. The submicron fraction of this inorganic material is especially important as the fine particles may penetrate deep into the lung and cause serious health effects. A laboratory furnace was designed to produce a submicrometer copper oxide aerosol to stimulate emissions from copper smelters and other pyrometallurgical operations. The ultimate aim of this research is to investigate the interaction of SO2 and the copper oxide aerosol at different temperatures and humidities in order to determine the reaction products and their potential health effects upon inhalation. The initial work, as presented in this paper, was to reproducibly generate a submicrometer copper oxide aerosol and to characterize it in terms of size, morphology and composition. Two experimental regimes were set up. One admitted filtered air, without water vapor, into the furnace, and the other admitted filtered air and water vapor. The size and morphology of the aerosols were determined using an electrical aerosol analyzer and transmission electron microscopy. The particles appear as chain aggregates with a count median diameter of 0.026 micron when no water vapor was added and 0.031 micron when water vapor was added into the furnace. Composition of the aerosol was determined using x-ray photoelectron spectroscopy. The aerosol, with or without water in the furnace, consists of a mixture of copper(I) oxide and copper(II) hydroxide.

Aerosols↗
PubMed1987

Radiological findings in 1135 edentulous patients.

A sample consisting of 1135 edentulous patients with clinically healthy denture bearing areas, was examined radiologically. It appears that the diagnostic yield is high whereas the expected radiation induced risk is low. Patients should therefore be examined radiologically prior to full denture construction.

Adolescent↗
PubMed1986

The clinical significance of the elongated styloid process.

A group of 1135 edentulous patients was investigated radiographically and clinically to determine the relation between elongated styloid processes and four symptoms frequently encountered in patients suffering from Eagle's syndrome. The radiologic finding of elongated styloid processes and/or ossification of the stylomandibular or stylohyoid ligaments occurred in about 30% of the patients. In female patients, facial pain and pain on turning the head appear to be related to the radiologic finding.

Adolescent↗
PubMed1983

Effect of mixing conditions on irritant potency of zinc oxide and sulfur dioxide.

Measurement of mechanics of respiration in guinea pigs was used to assess the irritant potency of zinc oxide and sulfur dioxide mixed under different conditions of temperature and humidity. Concentrations were 1-2 mg/m3 zinc oxide and 1 ppm sulfur dioxide. Dry conditions of mixing (Chamber RH 30%) either at 24 degrees C in the exposure chamber or at 480 degrees C in a dry furnace gave a biological response which could be completely accounted for by responses to zinc oxide and/or sulfur dioxide alone. Chemical examination of the aerosols did not indicate the formation of particulate sulfur species. Zinc oxide and sulfur dioxide mixed dry at 480 degrees C and fed into the exposure chamber at 80% RH reacted to produce an irritant aerosol as evidenced by a rapid increase to levels 29% above control; reversal was rapid when exposure ended. Chemical studies indicated the presence of sulfite on these aerosols. Addition of water vapor to the furnace during mixing at 480 degrees C produced a different irritant aerosol. The resistance rose slowly to 19% above control values and remained elevated during the post-exposure hour. Chemical studies indicated the presence of sulfate, sulfite, and adsorbed sulfur trioxide on these aerosols.

Aerosols↗
PubMed1982

Respiratory response of guinea pigs to zinc oxide fume.

Guinea pigs were exposed for 1 hr to submicrometer zinc oxide fume at a concentration of approximately 1 mg/m3. Measurement of pulmonary mechanics was used to assess the response. The exposure produced a slight decrease in compliance which was statistically significant. The compliance showed a further decrease 1 hr post-exposure. In a second group of animals observed for two hours after exposure a progressive decrease in compliance was observed between the first and second post-exposure hours. No changes were observed in resistance, tidal volume, frequency, or minute volume.

Aerosols↗
PubMed1979

Ponasterone A: a new ecdysteroid from the embryos and serum of brachyuran crustaceans.

The apolar ecdysteroid present in the developing embryo of the blue crab, Callinectes sapidus Rathbun, is tentatively identified as ponasterone A (2 beta, 14 alpha, 20,22-pentahydroxy-5, beta-cholest-7-en-6-one) on the basis of chromatographic, immunological, and mass spectral evidence. The apolar ecdysteroid present in the serum of land crabs, Gecarcinus lateralis, in the late premolt stages of the intermolt cycle is also tentatively identified as ponasterone A on the basis of chromatographic and immunological evidence.

Animals↗