Respiratory impairment and metal exposure in a group of 68 industrial welders

A group of 68 currently employed welders were examined who were exposed to welding fumes either for the whole or for at least half the working day and who used at least two welding processes, which were mainly manual metal arc welding and metal active gas welding, but also metal and tungsten inert gas welding, or oxyacetylene welding. The welders were classified into 3 groups according to the class of materials used, i.e.: 1) only mild and stainless steel; 2) mild and stainless steel and other metals; 3) only other metals. Chronic bronchitis symptoms were observed in 22% of the subjects; signs of suspected radiological fibrosis were present in 18%, initial signs of radiological fibrosis in 4%. Small airway disease was prevalent in the smokers (28 smokers versus 2 nonsmokers); one worker had an obstructive syndrome and another a restrictive syndrome (both were smokers). There was a good correlation between years of exposure and: 1) MEF25 in non-smokers; 2) urinary cobalt in the whole group. There was also a correlation between smoking and FEV1, MEF50, MEF25, PaO2 and urinary cadmium. Serum copper was higher in workers exposed full time than in those exposed part time. Urinary chromium and cobalt and serum copper were high in steel welders, lower in welders using steel and other metals and low in welders using other metals. Urinary chromium was similar in smokers and non-smokers. Serum zinc was found to be of little use for biological monitoring of welders. Urinary chromium was studied for one week in 10 full-time exposed steel welders. The difference between the chromium values at the end of the workshift and those at the beginning was small (low current exposure); the chromium values at the end of the workshift were not uniform in the whole group (different past exposure levels).     

Longitudinal study of workers of an aluminium die casting factory.

We conducted a 5-year longitudinal study on 76 workers of a high and medium aluminium alloy die-casting factory. As in a previous cross-sectional study conducted in 1986 and in accordance with the data in the literature, the 1990 follow-up study showed: a low prevalence of chronic bronchitis (as defined by the ECSC questionnaire on respiratory symptoms); normal mean functional values of FVC, FEV1, FEV1/FVC%. We did not find any significant difference in the levels of lung function over the period of 1986-90. These results show that workers in the secondary aluminium industry are not exposed to a significant risk of chronic pulmonary disease.     

Expression of HPCA-1 and HLA-DR antigens on growth factor- and stroma-dependent colony forming cells

The expression of HLA-DR and HPCA-1 antigens (recognized by the L243 and BI.3C5 antibodies respectively) on adult human bone marrow cells was examined by fluorescence activated cell sorting and colony assays. Nearly all the (day 14) lineage restricted and multipotential colony forming cells analysed in methylcellulose cultures in the presence of added growth factors express HLA-DR and HPCA-1 determinants. Two colour cell sorting reveals that the lineage restricted HLA-DR positive progenitors express variable levels of BI.3C5 positivity whereas most of the multipotential progenitors, the multi-CFC or CFU-GEMM, are highly BI.3C5 positive. The isolated HLA-DR and BI.3C5 positive populations also contain haemopoietic precursors which adhere to and form colonies on pre-formed stromal layers. Thus, haemopoietic progenitors assayed in both types of culture system can be analysed and enriched by simultaneous two-colour sorting using anti-HLA-DR and BI.3C5 monoclonal antibodies. Similarities in the antigenic phenotype of such cells, however, precludes the use of these reagents for segregating growth factor-dependent from stroma-dependent progenitors.     

Auditory brainstem evoked potentials (BAEPs) in lead-exposed workers.

Brainstem Evoked Potentials (BAEPs) were recorded in 49 lead exposed workers, and in a control group of 49 age- and sex-matched subjects, never exposed to neurotoxic substances. The mean duration of lead exposure was 7.4 (SD 5.6) yr. Blood lead concentration was analyzed in the morning of the experimental day (PbBc); an averaged PbB level was based on the levels of the 3 previous years (PbBm). Interpeak latency differences (IPLD) I-V, I-III and III-V were considered. The mean PbBc level was 54.6 (SD 16.1) micrograms/dl while the mean PbBm level was 53.5 (SD 15.9) micrograms/dl. Lead exposed workers showed a significant prolongation of IPLDs. IPLD I-V was longer in the subgroup with PbBm greater than 50 micrograms/dl (4.06 vs 3.98, c.l. 95% 0.00-0.16). These results are consistent with literature data and show that BAEPs may be a sensitive detector of subclinical lead effects on brainstem auditory pathways.     

Dysplasia and deoxyribonucleic acid aneuploidy in the assessment of precancerous changes in chronic ulcerative colitis. Observer variation and correlations

Cancer prevention in patients with long-standing ulcerative colitis depends on the detection of epithelial dysplasia in colorectal biopsy specimens. Deoxyribonucleic acid analysis by flow cytometry has also been used to examine biopsy specimens, and might be a more quantitative method of detecting precancerous change. Histology and flow cytometry were used to analyze 333 paraffin blocks from colectomy specimens of 58 patients with extensive ulcerative colitis; 22 of these patients had developed carcinoma. Interobserver agreement between three experienced pathologists grading the sections was good for high-grade dysplasia and no dysplasia, but poor for low-grade and indefinite dysplasia. Deoxyribonucleic acid aneuploidy was easier to recognize than dysplasia and, as with dysplasia, it was found to be associated with patients who had developed carcinomas. The presence of deoxyribonucleic acid aneuploidy correlated with the presence of dysplasia. We believe that dysplasia is a useful marker of premalignant change and that flow cytometry may be useful as a complement to histologic examination when dysplasia is suspected.     

Further cases of lead poisoning from wine

Lead intoxication has been reported to occur as a consequence of nonoccupational exposure, the source being mostly the leaching of lead from fluid containers in domestic use. Three such cases are described, for which the cause has been identified to be in the lining of the vat used to contain home-made wine. All cases are members of the same family.     

Differentiation Linked Expression of p28,33 (Ia-like) Structures on Human Leukaemic Cells

S ummary . A differentiation linked expression of 'Ia-like' (B cell associated) structures was detected by heterologous antisera against p28,33 antigen on human leukaemic cells in immunofluorescence test. A double fluorochrome immunofluorescence test was used to distinguish Ia⁺ ( p28,33 , ⁺) leukaemic cells from B lymphocytes. Leukaemic cells with varying intensities of anti-p28,33 staining were separated using the Fluorescence Activated Cell Sorter. The results indicate that p28,33 is very strongly expressed on undifferentiated blast cells from Philadelphia chromosome (Ph¹) positive 'lymphoid' blast crisis and non-T,non-B acute lymphoid leukaemia. In Ph¹ positive myeloid blast crisis and in acute myeloid leukaemia the p28,33 antigen was only moderately strongly expressed on myeloblasts and virtually absent on promyelocytes. The p28,33 antigen was also absent on the relatively more mature cells during the chronic phase of chronic myeloid leukaemia. Non-leukaemic samples such as bone marrow samples from fetus, and from patients with severe megaloblastic anaemia or myeloid hyperplasia (due to hypersplenism in Felty syndrome) were also found to contain p28,33 positive (and membrane immunoglobulin negative) immature blast cells.
On the basis of these observations the hypothesis is proposed that 'Ia-like' antigens on leukaemic cells reflect the origin of these leukaemias from haemopoietic stem cells which are themselves Ia positive. The corollary of this view is that 'Ia-like' membrane structures may play an important role not only in immunological responses of B cell, but also in the regulation of early haemopoietic cell differentiation.