Radiological abnormalities and asbestos exposure among custodians of the New York City Board of Education

Six hundred sixty custodians employed by the New York City Board of Education underwent examination from 1985 through 1987 for asbestos-related disease and other general medical conditions by the clinical staff of the Division of Environmental and Occupational Medicine of the Mount Sinai School of Medicine of the City University of New York. Two-thirds of the men (no women were examined) were 20 or more years from onset of any custodial work, with 44% having had at least 20 years of employment as custodial workers in New York City Board of Education schools. Twenty-four percent had begun custodial work in buildings 30 or more years earlier. Findings among them were of particular interest since asbestos-related disease might forecast what might be expected among school custodians with less seniority. Since the Board of Education, in selecting custodians for examination, had chosen only custodians currently employed, the study group comprised men still working in the school system. These, then, represented a "survivor population" (4% had retired between the time of enrollment in the study and the date of examination, and only one of the seventeen retirees had left work owing to disability). Although a considerable amount of clinical information was obtained, abnormalities on chest X-ray consistent with asbestos-induced scarring were used as the key index of disease resulting from exposure to asbestos. Since scarring of the lung tissue or lining of the lung or chest wall (pleura) may be present but undetectable on standard chest radiographs (a relatively insensitive diagnostic technique), the prevalence of abnormality on X-ray film represents a conservative estimate of the actual burden of scarring lung disease in the group. Such changes are indicative of previous asbestos exposure, however, and provide evidence of an increased risk of later asbestos-related malignancy. Overall, abnormalities on chest X-ray consistent with asbestos-related scarring were found in 28% of the men examined. The expected relationship of increasing prevalence of radiographic changes with increasing time since onset of exposure in buildings was demonstrated; among those with 35 or more years since beginning custodial work, 39% had abnormal films. This is evidence that custodial workers as a group have had asbestos exposure in the past, as reflected also in the work histories obtained at the time of examination. Eighty-four percent reported that they themselves removed asbestos-containing materials in the course of their work. Eighty-nine percent had been present in the work area during asbestos abatement projects in the schools in more recent years.(ABSTRACT TRUNCATED AT 400 WORDS)

Two leukocyte receptors (CD11a/CD18 and CD11b/CD18) mediate transient adhesion to endothelium by binding to different ligands

Upon stimulation with C5a, TNF, or phorbol dibutyrate (PDB), polymorphonuclear leukocytes (PMN) exhibit first an increase then a decrease in adhesion to unstimulated endothelial cells (EC). Essentially all of this adhesion is mediated by the CD18 family of leukocyte integrins on PMN. To determine the individual roles of CD11a/CD18 (LFA-1), CD11b/CD18 (CR3, Mac-1) and CD11c/CD18 (p150,95) in adhesion of PDB-stimulated PMN to unstimulated EC, mAb against the CD11 chains were used. mAb against CD11a or CD11b each blocked adhesion of PMN to EC by approximately 50%, but mAb against CD11c had no effect. Inasmuch as a combination of anti-CD11a and CD11b mAb completely blocked adhesion, it appears that CD11a/CD18 and CD11b/CD18 make approximately equal contributions to binding, and CD11c does not participate. Anti-CD11a or CD11b each blocked adhesion by about 50% throughout the transient time course of PDB-stimulated adhesion, indicating that the capacity of each of these receptors to bind EC is transiently activated by PDB. We next examined the role of ICAM-1 on EC as a ligand for CD18. Two anti-ICAM-1 mAb (LB-2 and 84H10) each inhibited PMN adhesion in a dose-dependent fashion, reaching a maximal inhibition of approximately 50%. Anti-ICAM-1 mAb blocked the CD11a/CD18-dependent portion of adhesion because concomitant use of anti-CD11a and anti-ICAM-1 did not cause additive inhibition. In contrast, anti-CD11b plus anti-ICAM-1 resulted in complete blockade of adhesion. This result suggests that CD11a/CD18 recognizes ICAM-1 on EC, but CD11b/CD18 recognizes a different ligand(s). To determine if CD11b CD18 has the ability to recognize ICAM-1, human macrophages were plated on culture surfaces coated with purified ICAM-1. Interaction of CD11a/CD18 with the surface-bound ICAM-1 resulted in selective down-modulation of CD11a/CD18 from the apical portion of the macrophages. In contrast, ICAM-1-coated surfaces did not down-modulate CD11b/CD18. The data suggest that CD11b/CD18 does not recognize ICAM-1, and that this receptor functions in adhesion of PMN to EC by recognizing novel ligand(s) on EC.

Two leukocyte receptors (CD11a/CD18 and CD11b/CD18) mediate transient adhesion to endothelium by binding to different ligands

Upon stimulation with C5a, TNF, or phorbol dibutyrate (PDB), polymorphonuclear leukocytes (PMN) exhibit first an increase then a decrease in adhesion to unstimulated endothelial cells (EC). Essentially all of this adhesion is mediated by the CD18 family of leukocyte integrins on PMN. To determine the individual roles of CD11a/CD18 (LFA-1), CD11b/CD18 (CR3, Mac-1) and CD11c/CD18 (p150,95) in adhesion of PDB-stimulated PMN to unstimulated EC, mAb against the CD11 chains were used. mAb against CD11a or CD11b each blocked adhesion of PMN to EC by approximately 50%, but mAb against CD11c had no effect. Inasmuch as a combination of anti-CD11a and CD11b mAb completely blocked adhesion, it appears that CD11a/CD18 and CD11b/CD18 make approximately equal contributions to binding, and CD11c does not participate. Anti-CD11a or CD11b each blocked adhesion by about 50% throughout the transient time course of PDB-stimulated adhesion, indicating that the capacity of each of these receptors to bind EC is transiently activated by PDB. We next examined the role of ICAM-1 on EC as a ligand for CD18. Two anti-ICAM-1 mAb (LB-2 and 84H10) each inhibited PMN adhesion in a dose-dependent fashion, reaching a maximal inhibition of approximately 50%. Anti-ICAM-1 mAb blocked the CD11a/CD18-dependent portion of adhesion because concomitant use of anti-CD11a and anti-ICAM-1 did not cause additive inhibition. In contrast, anti-CD11b plus anti-ICAM-1 resulted in complete blockade of adhesion. This result suggests that CD11a/CD18 recognizes ICAM-1 on EC, but CD11b/CD18 recognizes a different ligand(s). To determine if CD11b CD18 has the ability to recognize ICAM-1, human macrophages were plated on culture surfaces coated with purified ICAM-1. Interaction of CD11a/CD18 with the surface-bound ICAM-1 resulted in selective down-modulation of CD11a/CD18 from the apical portion of the macrophages. In contrast, ICAM-1-coated surfaces did not down-modulate CD11b/CD18. The data suggest that CD11b/CD18 does not recognize ICAM-1, and that this receptor functions in adhesion of PMN to EC by recognizing novel ligand(s) on EC.

Transient adhesion of neutrophils to endothelium

Fluorescently labeled polymorphonuclear leukocytes (PMN) were used to measure adhesion to human umbilical vein endothelial cells (EC) cultured in vitro. Stimulation of PMN with phorbol dibutyrate (PDB), TNF, or C5a caused an increase in adhesion followed by a return to prestimulation levels of adhesion of longer times of incubation. Maximal adhesion of PMN to EC occurred rapidly in response to C5a (5 min) and more slowly with TNF or PDB (15 min). PMN stimulated to adhere with C5a detached from EC by 15 min. PMN from CD11/CD18-deficient patients and PMN incubated with anti-CD18 mAbs failed to bind to EC despite maximal stimulation. Anti-CD11a/CD18 and anti-CD11b/CD18 each partially inhibited adhesion, and a combination of these two reagents completely blocked adhesion. The adhesion we measured was therefore completely dependent on CD11/CD18, and CD11a/CD18 and CD11b/CD18 each contributed to adhesion. Stimuli that enhanced adhesion of PMN to EC also enhanced expression of CD11b/CD18 on the cell surface, but the time course of expression correlated poorly with changes in adhesivity. To determine if changes in the expression of CD11b/CD18 are necessary for the changes in adhesivity, we used enucleate cytoplasts that did not increase expression of CD11b/CD18. Cytoplasts showed a normal rise and fall in adhesivity in response to PDB. We conclude that the transient adhesion of stimulated PMN to naive EC is regulated by changes in the nature of existing CD11/CD18 molecules on the PMN surface. Changes in expression of CD11b/CD18 may contribute to enhancement of adhesivity, but a definite role for this phenomenon has yet to be established.

CR3 (CD11b/CD18) expresses one binding site for Arg-Gly-Asp-containing peptides and a second site for bacterial lipopolysaccharide

Polymorphonuclear leukocytes (PMN) from three patients deficient in the CD18 family of receptors (LFA-1, CR3, and p150,95) exhibited an inability to bind erythrocytes coated with C3bi or bacterial LPS. These observations confirm that the CD18 family, and CR3 in particular, can bind the structurally dissimilar molecules C3bi and LPS. Further studies showed that LPS and C3bi bind to CR3 at distinct sites. mAb OKM10 against CR3 blocked binding of C3bi to PMN but did not block the binding of LPS. In contrast, mAb 904, directed against a different epitope on CR3, blocked binding of LPS to PMN but not binding of C3bi, thus suggesting that different regions of CR3 were involved in binding these two ligands. In addition, synthetic peptides based on the sequence in C3bi recognized by CR3 competitively blocked the binding of C3bi to CR3 but did not block the binding of LPS. Rather, occupation of the peptide binding site on CR3 by the synthetic peptides enhanced binding of LPS. These results indicate that CR3 has two distinct binding sites, one that recognizes ligands composed of protein and a second that recognizes LPS.

A prevalence study of denture stomatitis in subjects with diabetes mellitus or elevated plasma glucose levels

The purpose of this study was to determine if a relation between diabetes mellitus and denture stomatitis could be supported by observing an increased prevalence of denture stomatitis in subjects with either diagnosed diabetes mellitus or elevated plasma glucose levels. The study involved 301 subjects wearing either complete or partial maxillary dentures. Medical history information, oral examination records, and laboratory data were used for the study. No significant increase in the prevalence of denture stomatitis was found in those subjects with either previously diagnosed diabetes mellitus or elevated plasma glucose levels when compared with subjects with normal glucose metabolism.

Neurobehavioral assessment of Mohawk Indians for subclinical indications of methyl mercury neurotoxicity

A total of 200 male and 200 adult female Mohawk Indians were examined by means of performance tests as part of a total health evaluation of participants in a medical field survey on the St. Regis Reserve. Age-corrected performance test scores were studied in relation to blood, urinary, and hair methyl mercury (MeHg) levels, and local fish consumption. Males were found to eat more fish than females and had relatively higher MeHg levels than females. Blood and hair MeHg levels were significantly correlated with local fish consumption for both sexes. Biological indicators of MeHg absorption suggested low exposure levels but did not correlate significantly with performance test scores. These findings indicate that the time of examination, St. Regis residents were exposed to almost "background" levels of MeHg and did not exhibit either subclinical or clinical manifestations of MeHg neurotoxicity.

Noise-induced hearing loss and portable radios with headphones

Portable radio/cassette players with headphones have gained increasing popularity in recent years. Volume settings are often increased to override environmental noise, perhaps placing the listener at risk for noise-induced hearing loss (NIHL). A total of 190 public college students in NYC were studied via a self-administered questionnaire regarding the volume setting used and weekly exposure in hours to these units. Three popular models were tested using a Bruel and Kjaer sound level meter, octave band filter and artificial ear. Sound levels were measured at various frequencies (250-8000 Hz) and an overall measurement obtained using the "A"-weighted scale. Based on OSHA criteria for permissible noise dose (i.e. intensity X duration) in the work place, auditory risk criteria were developed. Of all students who used such radios 31.4% equalled or exceeded the maximum allowable dose permitted by these criteria (41.2% of the males and 29.2% of females). This sex-related difference in risk, while not statistically significant, warrants further investigation. Of the total 'at risk' group 50% exceeded the risk criteria by more than 100%. These results suggest that portable radios with headphones may be capable of causing permanent hearing loss in a large proportion of radio users.

Dagga (cannabis) usage among medical students in Johannesburg

Of 1 020 undergraduate medical students at the University of the Witwatersrand surveyed in 1981 as regards attitudes to and patterns of illicit drug use 868 completed the questionnaire; 32,4% had tried dagga (cannabis) and 16,4% were still using the drug. There was a large increase in the number of students using the drug as they advanced through their studies (6% of the 1st-year class as against 24% of the 5th-year class). The timing of dagga use and previous experimentation with habit-forming drugs are mentioned, and reasons for non-experimentation and attitudes towards legalization of dagga are analysed.

Terminal illness in a psychiatric patient--issues and ethics

A woman with paranoid psychosis and terminal breast cancer refused palliative radiation, demanding pain-killers and permission to leave hospital to go into the mountains and die on her own. Was it ethical to allow her to do so, or should a court order have been sought to impose hospital treatment on her? Should she have been persuaded to accept hospital care? When do those in charge deem a terminally ill patient unable to understand the issues, and dictate treatment? Our aim in this article is to highlight a number of ethical matters regarding patient care, as well as to try and determine the role a hospice should play with regard to the terminally ill patient with associated psychiatric disorder.

The contralateral diseased but asymptomatic carotid artery: to operate or not? An update

Bilaterally diseased carotid arteries were demonstrated in 147 patients in a personal series of 535 carotid reconstructions. A general policy of operating only on symptomatic patients was followed. Although stenotic and ulcerated plaques were known to be present in the contralateral artery, they were not repaired unless new symptoms occurred. No strokes were observed in these patients in a 20 year follow-up period. Twelve percent of the patients became symptomatic, leading to new arteriograms and a second artery repair. The patients at risk and their families were carefully instructed to report any symptoms of cerebrovascular insufficiency. If meticulous follow-up is carried out, the prophylactic repair of a truly asymptomatic diseased carotid artery is not believed necessary to prevent stroke.

Schizophrenic behavior as a function of role expectation

The hypothesis that the behavior of schizophrenic patients is determined in part by role expectation was investigated. The Holtzman Inkblot Technique and a word association task were administered to the same patients under two conditions: (1) Ss were led to believe that the interviewer was unaware of their patient status and expected them to behave in a normal manner; and (2) Ss were informed that the interviewer was interested in their behavior as mental patients. The results indicated that there was less evidence of pathology on the Holtzman when Ss were told that the interviewer expected them to behave in a normal manner. More specifically, there was less Pathognomonic Verbalization and more Form Appropriateness in the normal expectation condition. The findings are consistent with current views as to the pathogenic effects of labeling and institutionalization.