Industrial hygiene, chemical and biological assessments of exposures to a chlorinated phenolic sapstain control agent

A two-year study of the occupational exposure of workers in a lumber mill to a wood preservative containing chlorophenol has been conducted. The methods were biological (urine) monitoring, industrial hygiene assessment and a questionnaire related to worker-perceived health effects. Approximately 40 workers exposed to the wood preservative and 40 unexposed controls working in other locations of the plant participated in the study. Evaluation of work conditions, assessment of urinary levels of tetra- and pentachlorophenol, and administration of a medical questionnaire were performed at a six-month intervals over a two-year period. Industrial hygiene ratings of exposures and adequacy of protection were evaluated in relation to the results of biological monitoring. Workers who came into contact with freshly treated and still wet wood had consistently higher urinary levels of tetrachlorophenol. Workers stationed adjacent to the spray applicator also had higher tetrachlorophenol levels. There was no statistically significant relationship between the subjective ratings by the industrial hygienist of exposure and adequacy of worker protection with the urinary levels of tetrachlorophenol. Nor was there a consistent pattern linking exposure ratings with adequacy of protection. The short half-life of tetrachlorophenol in the urine makes this a good indicator of only the most recent exposure. The differences in urinary levels between controls and exposed workers were large, with averages of 240.4 ppb for exposed workers and 14.6 for controls. Traditional industrial hygiene evaluation techniques, in conjunction with biological monitoring, proved to be the most effective method of assessing both exposure and work practices. Exposed workers reported a statistically significant increase of positive answers to known signs and symptoms of chlorophenol exposure compared with the controls. There was no statistically significant relationship between the number of these health problems reported and the mean urinary levels of tetra- or pentachlorophenol for the exposed group; however, for certain variables (heavy vs. light exposure, inadequate vs. adequate protection, greater than 100 ppb urinary tetrachlorophenol vs. less than 100 ppb), those with heavier exposure, inadequate protection or higher urinary tetrachlorophenol reported on the average more health problems over the two-year period. Firm statistical conclusions could not be drawn because of the small size of the study population.     

Evaluation of the biological significance of leukocyte infiltration of the thyroid in Graves' disease.

Graves' goiter size and gland function may be affected by interferon-gamma influencing actions of the thyroid-stimulating antibody. Goiter weight (n = 20), lymphocytic infiltration and class II antigen expression were assessed. The largest goiters, strikingly, has least infiltration but, overall, the looked-for negative correlation between goiter size and lymphocyte infiltration did not materialize. This was presumably due, in part, to inhibiting antibodies in many (8/18) patients' sera. In addition, our data do not support a major pathogenetic role for class II antigen in Graves' disease.     

Deprivation of form vision suppresses diurnal cycling of retinal levels of leu-enkephalin

Deprivation of form vision by the fitting of translucent occluders suppressed the diurnal cycling of enkephalinergic amacrine cells (the ENSLI amacrine cells), in the chicken. Daily periods of normal vision or enforcing temporal contrast using strobe lighting appeared to restore normal functioning of the ENSLI cells. These results suggest that the ENSLI cells are involved in retinal circuits that assess the quality of the visual image and control eye growth.     

Aortic dissection without intimal rupture: diagnosis and management.

A 59-year-old man had symptoms of aortic dissection. Computed tomography and angiography showed a large intramural hematoma of the ascending and descending aorta without intimal defect or false lumen. The hematoma resolved completely within 7 weeks with medical treatment. His symptoms recurred 6 months later. Computed tomography and angiography demonstrated a type B dissection with a false lumen and an intimal defect. This case illustrated the progressive nature of aortic dissection without intimal rupture. The diagnostic criteria and therapeutic options are discussed.     

Abnormal Papanicolaou smears. Comparison of cytology, colposcopy and cervical swab DNA hybridization.

Cervical swab sampling for DNA hybridization was performed on 89 women attending a colposcopy clinic. In situ hybridization studies for human papillomavirus (HPV) types 6/11, 16/18 and 31/33/35 were performed on the specimens. Biopsy specimens were obtained from 65 patients. The cytologic, colposcopic and histologic results were classified into five groups and assigned a score of 0-5, depending upon the diagnosis. An increasing score correlated positively with the presence of HPV, especially types 16/18 and 31/33/35. A comparison was made of the sensitivity, specificity, and positive and negative predictive values for the standard method of colposcopic evaluation versus the standard method combined with DNA cervical swab sampling. No significant changes in the parameters were found when the DNA cervical swab was added.     

IL-12 and IL-23: master regulators of innate and adaptive immunity

Summary: Initiation of an effective immune response requires close interactions between innate and adaptive immunity. Recent advances in the field of cytokine biology have led to an increased understanding of how myeloid cell‐derived factors regulate the immune system to protect the host from infections and prevent tumor development. In this review, we focus on the function of interleukin (IL)‐23, a new member of the IL‐12 family of regulatory cytokines produced by activated macrophages and dendritic cells. We propose that IL‐12 and IL‐23 promote two distinct immunological pathways that have separate but complementary functions. IL‐12 is required for antimicrobial responses to intracellular pathogens, whereas IL‐23 is likely to be important for the recruitment and activation of a range of inflammatory cells that is required for the induction of chronic inflammation and granuloma formation. These two cytokines work in concert to regulate cellular immune responses critical for host defense and tumor suppression.     

Troublesome crying in infants: effect of advice to reduce stimulation.

The observation that babies with troublesome crying improve quickly in hospital suggested that, if true, a common, quickly reversible, factor may operate. Histories from parents of such babies suggest that much work goes into trying to console them. It is hypothesised that this may lead to excessive stimulation and the improvement seen in hospital reflects a reduction in stimulation. Two studies were undertaken. (1) Carers were asked to agree to randomisation of their infants to hospital or home management. Those at home were advised to reduce stimulation. A 10 point questionnaire was used to describe distress in mothers of subjects and age matched controls. (2) A randomised controlled study compared advice to reduce stimulation with an empathic interview using a +5 to -5 scale to chart change. In the first study too few subjects agreed to randomisation and thus a rigorous study to validate the observation could not proceed. There was good evidence, however, that crying improved. Results from the home group justified the second study. The median distress score for subjects was 7/10 and for controls 3/10 (p less than 0.001). In the second study at seven days, 18/22 subjects given advice scored +2 or better on the change chart for crying, compared with 7/20 of those who did not receive advice (p less than 0.01). After the latter received advice 79% improved (95% confidence interval 61 to 97%). For babies under 12 weeks, the customary upper limit for a diagnosis of colic, 14/15 subjects advised improved compared with 6/12 who were not advised (p less than 0.02). These studies have shown that infants with troublesome crying admitted to hospital seem to improve quickly as do those whose carers are advised to reduce stimulation.     

Oligoclonal immunoglobulins in HIV infection

We tested 150 patients infected with human immunodeficiency virus (HIV) for the presence of oligoclonal bands in serum, prompted by reports that these abnormal proteins may have prognostic significance. Sixty HIV-negative individuals from "at-risk" groups were tested along with 80 HIV-negative, healthy blood donors for the presence of these bands. All sera were tested by isoelectric focusing, because it is more sensitive for this purpose than more-conventional electrophoretic techniques. In the HIV-positive group, 61% of the sera had oligoclonal bands; in the HIV-negative "at-risk" group, 36% had bands. No bands were detectable in sera from the healthy blood-donor group. Some patients were also followed for differing periods throughout their infection, and changes in their oligoclonal banding patterns could not be correlated with disease progression. The fact that oligoclonal bands were found to be present without HIV infection in a substantial number of individuals from within the "at-risk" groups leads us to conclude that the presence of oligoclonal bands in HIV infection is of limited prognostic significance.