Search PubMed⌕ Search

Biomedical subjects

C W Lewis

Publications and source records attributed to C W Lewis.

At least 55 records · Page 3Linked to original sources
PubMed1992

Cytotoxic fungal spores in the indoor atmosphere of the damp domestic environment.

Eight-three fungal isolates collected and cultured from the air spora of damp public sector Scottish housing have been screened for cytotoxic properties. A bioassay procedure has been utilised for this purpose involving cytotoxic effects on human embryonic diploid fibroblast lung cells grown as monolayer cultures within the wells of microtitre plates. The MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] biochemical assay system employed has revealed that 39 (47%) of the moulds investigated possessed spore-associated cytotoxic properties; a value which emphasises the potential health hazards of the continual inhalation of toxigenic fungal propagules by occupants of mouldy houses. Penicillia, the most prevalent fungi found in the internal atmosphere of the domestic environment, accounted for the great majority of cytotoxic strains identified.

Air Microbiology↗
PubMed1991

Sources of air pollutants indoors: VOC and fine particulate species.

The average concentrations of a large number of fine particle aerosol and VOC species measured in ten Boise, Idaho, residences in wintertime have been apportioned according to their contributions from all inside sources and all outside sources, regarded as two composite source categories. Air change rates for the residences were in the range 0.2-0.8 hr-1. None of the residences had obvious major indoor sources (smokers, woodburning appliances, etc.). The two category apportionment was accomplished through use of the single chamber mass balance indoor air quality model given by Dockery and Spengler. The method depends on the availability of average concentrations measured outside each residence during the same sampling periods used for the inside measurements, and on the ability to identify one or more species that have negligible indoor sources. Calculated infiltration factors (the indoor/outdoor ratio in the absence of indoor sources) for fine particle species averaged 0.5, and varied in a reasonably way with measured air change rates, essentially independent of species. Infiltration factors for the VOCs were indistinguishable from unity. The relative importance of indoor and outdoor sources to measured indoor concentrations showed great variation between species and between residences. In most homes the indoor source contribution was dominant for fine particle Si, Ca, and Fe, while the infiltration contribution was dominant for S, K, Pb, Zn, mass, and extractable organic matter. Indoor contributions to individual VOCs were frequently very large at a few residences and negligible at the others.

Aerosols↗
PubMed1990

Reflex sympathetic dystrophy: a review.

Reflex sympathetic dystrophy is a unique traumatic disorder with unusual cutaneous signs. The case of a patient with an uncommon, poorly understood, sharply marginated geometric zone of erythema is reported. Pseudo-Kaposi's sarcoma developed in the same patient in the foot affected by reflex sympathetic dystrophy, an association not previously reported. For effective treatment this disorder must be diagnosed as early as possible. The clinical stages of evolution through which reflex sympathetic dystrophy progresses are described.

Adult↗
PubMed1990

Sources of mutagenic activity in urban fine particles.

Samples were collected during the winter of 1984-1985 in the cities of Albuquerque, NM and Raleigh NC as part of a US Environmental Protection Agency study to evaluate methods to determine the emission sources contributing to the mutagenic properties of extractable organic matter (EOM) present in fine particles. Data derived from the analysis of the composition of these fine particles served as input to a multi-linear regression (MLR) model used to calculate the relative contribution of wood burning and motor vehicle sources to mutagenic activity observed in the extractable organic matter. At both sites the mutagenic potency of EOM was found to be greater (3-5 times) for mobile sources when compared to wood smoke extractable organics. Carbon-14 measurements which give a direct determination of the amount of EOM that originated from wood burning were in close agreement with the source apportionment results derived from the MLR model.

Air Pollutants↗
PubMed1989

Damp housing, mould growth, and symptomatic health state.

OBJECTIVE: To examine the relation between damp and mould growth and symptomatic ill health. DESIGN: Cross-sectional study of random sample of households containing children; separate and independent assessments of housing conditions (by surveyor) and health (structured interview by trained researcher). SETTING: Subjects' homes (in selected areas of public housing in Glasgow, Edinburgh, and London). SUBJECTS: Adult respondents (94% women) and 1169 children living in 597 households. END POINTS: Specific health symptoms and general evaluation of health among respondents and children over two weeks before interview; and score on general health questionnaire (only respondents). MEASUREMENTS AND MAIN RESULTS: Damp was found in 184 (30.8%) dwellings and actual mould growth in 274 (45.9%). Adult respondents living in damp and mouldy dwellings were likely to report more symptoms overall, including nausea and vomiting, blocked nose, breathlessness, backache, fainting, and bad nerves, than respondents in dry dwellings. Children living in damp and mouldy dwellings had a greater prevalence of respiratory symptoms (wheeze, sore throat, runny nose) and headaches and fever compared with those living in dry dwellings. The mean number of symptoms was higher in damp and mouldy houses and positively associated with increasing severity of dampness and mould (dose response relation). All these differences persisted after controlling for possible confounding factors such as household income, cigarette smoking, unemployment, and overcrowding. Other possible sources of bias that might invalidate the assumption of a causal link between housing conditions and ill health--namely, investigator bias, respondent bias, and selection bias--were also considered and ruled out. CONCLUSION: Damp and mouldy living conditions have an adverse effect on symptomatic health, particularly among children.

Adolescent↗
PubMed1983

In vitro analysis of lymphocytes: markers and functions.

Current dermatologic literature is becoming replete with articles elucidating current concepts in the pathophysiology of lymphocytic diseases. Much of this knowledge emanates from the increasingly sophisticated and complex methods of identifying lymphocytes. No longer does it suffice to know that B lymphocytes or T lymphocytes are present, but rather the key information involves knowing what subsets of these cells are present and/or their functional status. The reader attempting to assimilate all this information is thus confronted with an overwhelming, as well as frequently changing, array of analytic methods. This paper is presented as a review of thinking, principles, and methods employed in research on lymphocytic disease.

B-Lymphocytes↗
PubMed1982

Dermatoses of pregnancy.

Pregnancy is a period of profound endocrine and metabolic changes which are tolerated by the body for a relatively short time. During gestation both physiologic and pathologic changes can occur in the skin, nails, and hair shafts which should be recognized and appropriately managed by the dermatologist. These changes can conveniently be placed into five broad categories: (1) physiologic changes in skin and appendages caused principally by the hormonal milieu, (2) cutaneous tumors affected by pregnancy, (3) diseases specifically associated with pregnancy, (4) genital infections of perinatal importance, and (5) other dermatologic diseases influenced by pregnancy. A discussion of each of these topics reveals the vast spectrum of dermatologic disease seen in pregnancy and underscores the important role of the dermatologist in the care of pregnant patients.

Autoimmune Diseases↗
PubMed1982

Contact urticaria.

Contact urticaria is an immediate wheal response generated by a wide variety of contactants in susceptible individuals. These contactants can be divided into three categories based on their mechanism of action: nonimmunologic, allergic, and unknown. The list of known illicitors of CU is growing rapidly, and the syndrome is being recognized more often. CU to certain preservatives in foods and pharmaceuticals may get increased attention in the future because of such widespread exposure to them both through contact and systemic absorption. A range of systemic reaction patterns can be seen in allergic CU, in some of the physical urticarias, and in exposure to ammonium persulfate. The danger of such systemic reactions should be borne in mind when performing rechallenge patch testing in the office.

Allergens↗
PubMed1981

Pityriasis rosea. Viral complement fixation studies.

Eleven patients were seen for pityriasis rosea and underwent acute and convalescent viral complement fixation tests for several respiratory viruses and Mycoplasma. Several patients (6/11) gave a history of antecedent upper respiratory illness; however, no significant rise in titer was seen on any of the complement fixation tests.

Adolescent↗
PubMed1980

Metastatic spermatocytic seminoma.

Spermatocytic seminoma is noted generally for its relative infrequency of regional or distant metastases. A case of metastatic spermatocytic seminoma is reported in which there was radiographic evidence of tumor recurrence within an irradiated area. The need for aggressive initial management and careful followup of patients with this entity is emphasized.

Dysgerminoma↗
PubMed1979

Carcinoma of the bladder treated by segmental resection.

We herein review 45 patients with carcinoma of the bladder treated by segmental resection from 1955 to 1976. Survival rates were similar to those reported in other series and compared favorably to those found with total cystectomy. Patients with high grade (III and IV) stage A tumors experienced a 100% recurrence rate and only 40% survived more than 5 years, whereas patients with low grade (I and II) stage A tumors had a 28% recurrence rate and 86% lived 5 years or more. Therefore, it is postulated that patients with high grade lesions, even though stage A, undergo more aggressive therapy. It also was found that extensive segmental resection, even though necessitating ureteroneocystostomy, resulted in a favorable 5-year survival rate.

Florida↗