Clinical course of patients with anti-RNP antibodies. A prospective study of 32 patients

Thirty-two patients with high and low anti-RNP antibody titers were followed prospectively during a mean observation of 65 months. The following 4 titer patterns were observed: persistently high, low increasing to high, high decreasing to low and persistently low titers. At first admission, 17 of the 23 patients with high anti-RNP titers did not fulfill the criteria of defined connective tissue diseases (CTD). The clinical courses were characterized by the appearance of new organ manifestations and at the end of the study 17/23 fulfilled the criteria for mixed CTD (MCTD). A development towards systemic lupus erythematosus (SLE) was seen in one, concomitant with decreasing anti-RNP titer. None developed symptoms compatible with progressive systemic sclerosis. The 9 patients with a low anti-RNP titer were characterized by a stable clinical course, including 4 with SLE, 2 with Raynaud's phenomenon, and one each with Sjögren's syndrome, discoid lupus erythematosus and rheumatoid arthritis + Sjögren's syndrome. The most frequently occurring clinical manifestations among the patients with MCTD were Raynaud's phenomenon, puffy hands, arthritis, myalgias, and sicca symptoms. Myositis and impaired pulmonary function were also seen, but glomerulonephritis was not. The symptoms were fluctuating and the manifestations clinically different from other well defined CTD. The morbidity was moderate and the mortality low. High anti-RNP titer observed at any time seems associated with a clinical syndrome phenotypically different from other CTD favoring the notion of MCTD being a distinctive clinical syndrome.

A collaborative study of cancer incidence and mortality among vinyl chloride workers

A large European multicentric cohort study has been coordinated by the International Agency for Research on Cancer with the objectives of investigating the dose-response relationship between liver cancer and exposure to vinyl chloride and assessing cancer risk for sites other than the liver. A nearly threefold increase in liver cancer was detected on the basis of 24 observed deaths and 8.4 expected (standardized mortality ratio 286, 95% confidence interval 186-425). The excess from liver cancer was clearly related to time since first exposure, duration of employment, and estimated ranked and quantitative exposures. Other cancer sites investigated on the basis of a priori hypotheses were either not in excess (lung) or apparently unrelated to the exposure variables (brain and lymphoma).

Surgical treatment of forefoot deformity with special reference to polyarthritis

Among 523 patients consecutively treated for forefoot pain and deformity, 64 had inflammatory arthritis. Most patients no longer had difficulties finding shoes that fit after the deformities were surgically corrected. Although about one half of the patients had some residual symptoms after treatment, 57 (89%) were satisfied with the operation. If the deformities are corrected early, joint resections can be avoided and toe function preserved.

Pregnancy outcome in patients with high titer anti-RNP antibodies. A retrospective study of 40 pregnancies

In a retrospective study the outcome of 40 pregnancies in 20 women with a high titer of anti-RNP antibodies was evaluated. In the 18 pregnancies that occurred after disease onset, transient proteinuria was noted in 3 and transient thrombocytopenia in 2. Deep venous thrombosis was observed in one patient. Preeclampsia in another woman necessitated cesarean sections in 2 pregnancies with successful outcome. The observed complications may all be seen in normal pregnancies. There was no evidence of exacerbation of maternal disease during pregnancy or in the postpartum period. Our study indicates that in women with high anti-RNP titer the risk of fetal loss or maternal worsening of disease seems slight.

Restricted dose and duration of corticosteroid treatment in patients with polymyalgia rheumatica and temporal arteritis

To analyze whether corticosteroids in low doses during limited time periods could be safely used in the treatment of patients with polymyalgia rheumatica (PMR) or temporal arteritis (TA) the records of 91 patients diagnosed between 1980 and 1987 were reviewed. The mean initial prednisolone dose was in patients with PMR 18 mg/day and the mean duration of treatment was 17 months. In patients with TA the mean initial dose was 31 mg/day and the mean duration of treatment 16 months, and in all the corticosteroid treatment was terminated within 24 months. Patients with coexisting TA and PMR demanded longer treatment compared to patients with either TA or PMR and thus 18/91 patients were treated for more than 2 years. No visual or neurological complications occurred after treatment with corticosteroids had been initiated. Our study indicates that most patients with PMR or TA can be treated safely with an initial prednisolone dose of 10 mg given twice daily. With few exceptions corticosteroid treatment can be terminated within 24 months.

Recombinant 70-kD protein used for determination of autoantigenic epitopes recognized by anti-RNP sera

A panel of high- and low-titre anti-RNP-positive patient sera was tested for reactivity with human snRNP proteins. The U1 snRNP-specific 70-kD peptide was found to be the most prominent RNP antigen recognized by high-titre anti-RNP sera, mainly found in patients with mixed connective tissue disease (MCTD). The reactivity with the 70-kD protein was further analysed with recombinant fusion proteins containing different segments of the protein. One major and two minor antigenic regions were found. Most patient sera, both with high- and low-titre anti-RNP antibodies, only recognized the major region. The most aminoterminal region, showing partial sequence homology with a mouse retroviral p30 gag protein, contained an epitope that was recognized by one serum only.

The role of GSH depletion and toxicity in hydroquinone-induced development of enzyme-altered foci

Hydroquinone (HQ) may activate oxygen via redox cycles in biological systems and may also deplete glutathione (GSH). Both these reactions are potentially harmful, and we have studied their possible involvement in hydroquinone-induced development of gamma-glutamyltranspeptidase (GGT)-positive enzyme-altered foci in rat liver. The effect of HQ was compared to the effect of duroquinone, catechol, resorcinol and phenol. The dose was 100 mg/kg per day and the test substances were administered for 7-12 weeks in these foci experiments. HQ gave an increased number of foci and increased the foci volume, while none of the other compounds had any significant effect on these parameters. HQ, duroquinone and resorcinol were also tested at a higher dose level (200 mg/kg per day), but this dose gave a lower number of foci than the 100-mg dose. HQ, duroquinone and catechol induced single-strand breaks in hepatic DNA. Single doses of HQ (200 mg/kg) increased malondialdehyde excretion in urine, indicating in vivo lipid peroxidation. Duroquinone, phenol and resorcinol were negative with respect to malondialdehyde excretion. Catechol could not be properly tested as the 200-mg dose killed several animals. HQ and catechol induced hepatic ornithine decarboxylase activity. This effect was correlated to GSH depletion. An in vitro model for toxicity studies with hepatocytes from carcinogen-treated rats was also used. In this model HQ could be shown to be selectively toxic to GGT-negative cells in the presence of extracellular GSH. The toxicity was preceded by a rapid depletion of GSH. Catechol also depleted GSH and could be shown to be selectively toxic, but higher concentrations than those used for HQ had to be used. Duroquinone, phenol and resorcinol were not selectively toxic to GGT-negative cells. As duroquinone can be regarded as a more potent inducer of redox cycles than HQ, it can be concluded that the foci data provide no evidence for an involvement of redox cycles in HQ induced development of enzyme-altered foci. They suggest that GSH depletion may act to develop enzyme-altered foci, and the in vitro data indicate a mechanism by which GSH depletion and toxicity may induce this effect.

Proposed treatment of cystic lesions in the first metatarsal in polyarthritic patients

Inflammatory arthritis frequently produces severe deformities of the forefoot. Erosions and cystic changes in the metatarsal bones are not uncommon in patients with inflammatory arthritis. This report presents two patients who were treated with a bone graft and bone transposition with a good result.

Three industrial solvents investigated for tumor promoting activity in the rat liver

Dioxane, perchloroethylene, and trichloroethylene were investigated as rat liver altered foci promoters in an initiation/promotion protocol. Animals were initiated with diethylnitrosamine, 30 mg/kg, injected i.p. 24 h after 2/3 partial hepatectomy. The chemical under study was administered by gavage once a day, 5 times a week for 7 weeks. Ten days after the last administration the animals were killed. Liver sections were stained for gamma-glutamyl-transpeptidase (GGT) and the number and total volume of GGT-positive foci was studied. Dioxane (1000 mg/kg) significantly increased the number and total volume of foci while a marginal effect was noted for the high dose of trichloroethylene (1100 mg/kg). A high dose of perchloroethylene (1100 mg/kg) had no effect.

Correlation of xylene exposure and methyl hippuric acid excretion in urine among paint industry workers

Different calculations of methyl hippuric acid excretion in urine were correlated to the time-weighted average (TWA) of the xylene exposure of a complete workday for 40 paint industry workers exposed to 12 different solvents. The 8-h TWA xylene exposure varied between 0 and 865 (median 69) mg/m3. The amount of methyl hippuric acid excreted in about 24 h showed only a slightly higher linear correlation to the xylene exposure than the amount of methyl hippuric acid excreted per hour during the latter part of the workshift among the 37 subjects exposed to TWA xylene air concentrations of 0-200 mg/m3. It was concluded that the methyl hippuric acid excretion rate during the latter part of the workshift can be used for crude xylene exposure categorizations.

Mortality and cancer incidence among Swedish paint industry workers with long-term exposure to organic solvents

Cause-specific mortality was studied in a cohort of 416 men who had worked for at least five years in the Swedish paint manufacturing industry during the period 1955-1975. The calculations of expected numbers were based on national, male, calendar-year, and cause-specific death rates for the period 1961-1981. Ninety-six paint industry workers had died, whereas 110 deaths were expected. Three workers had died from multiple myeloma (0.6 expected), and the excess might be related to solvent exposure. Three cleaners had died from infectious urinary tract disease, in comparison to 0.2 deaths expected from all genitourinary diseases, in this small and very heavily exposed group. This association might possibly indicate a modifying effect on the prognosis of urinary tract morbidity from solvents.

What church examination records can tell us about the inheritance of reading disability

Long before the establishment of a general school system in Sweden (1842), a vast majority of the adult population had reached some reasonable level of reading literacy. The level of reading skill among the members of a household was assessed by the parish priest at annual catechetical examinations, and the results of these examinations were recorded in church registers. Eventually (in the 18th century) a 5-point grading scale was developed. In the present investigation, these unique records were used to study the transmission of low reading marks over successive generations in 17 families. For comparison, a set of 17 family trees originating from good readers was traced. The average scores of the descendants of poor readers were significantly lower than corresponding scores for descendants of good readers. However, the transmission patterns in the family trees of poor readers did not indicate any simple genetic mechanism. In another study, two dyslexic cases living today were traced backward to ancestors born around 1750. In one of the cases, a massive familial pattern of reading disability down to the eighth generation was observed, while most ancestors of the other case had average or above average reading skill as judged by the priests. The reasons for the absence of a simple hereditary pattern were critically discussed.

Normal serum activities of liver enzymes in Swedish paint industry workers with heavy exposure to organic solvents

The serum activities of the liver enzymes alanine aminotransferase, aspartate aminotransferase, ornithine carbamyl transferase, and gamma-glutamyl transferase were examined in 47 paint industry workers and unexposed age matched referents. The workers were exposed to a mixture of industrial solvents, of which xylene was the main component in most cases. The median total exposure was about 50% of Swedish 1981 threshold limit values according to measurements of individual solvent exposure performed at the same time. No differences in enzyme activities were shown either when the whole exposed and referent groups were compared or when the five workers with outstanding solvent exposures of five times the TLV or more were compared with their referents. It is concluded that in most workers the liver seems to remain largely undamaged from inhalation exposure to a commonly used mixture of non-chlorinated solvents. In many workers this seems to hold true even for high exposures for limited periods.

Environmental factors and uptake of cadmium among brazers using cadmium-containing hard solders

The influence of different work factors on the uptake of cadmium has been studied in 102 brazers working at least 10% of their work day with cadmium-containing hard solders. The blood concentrations of cadmium varied between less than 1 and 113 micrograms/L (less than 9 and 1010 nmol/L). Blood cadmium concentrations were below 10 micrograms/L (89 nmol/L) in 71 brazers and 31 brazers had levels equal to or above that value. The importance of some environmental factors on the blood-level of cadmium was studied with discrimination analysis. The length of the splice was found to be almost the sole determining factor for the cadmium concentration in blood. All brazers working with splices shorter than 2 cm had blood concentrations below 10 micrograms/L, while 87% of the brazers working with splices longer than 10 cm had blood concentrations equal to or above 10 micrograms/L. Other factors like age, sex, exposure time, smoking habit and brazing method were devoid of any measurable importance.

Aluminium in the blood and urine of industrially exposed workers

Blood and urine aluminium concentrations were studied in industrially exposed workers using electrothermal atomic absorption spectrometry. Welders and workers making aluminium powder and aluminium sulphate had higher concentrations in blood and urine than non-exposed referents. Workers in the electrolytic production of aluminium had higher urine but not blood concentrations than the referents. Thus aluminium was found to be absorbed by all industrially exposed workers. Blood concentrations were lower than those presumably associated with aluminium induced encephalopathy in patients receiving dialysis.

Delayed dimethylformamide biotransformation after high exposures in rats

Rats were exposed to two dimethylformamide (DMF) air concentrations (2250 and 565 ppm for 4 h). Concentrations of DMF and the biotransformation product monomethylformamide (MMF) were measured in blood and some tissues at different times after the end of exposure. MMF concentrations 0 and 3 h after the end of the high exposure were generally lower than MMF concentrations at the same time after the low exposure. The results suggest that DMF biotransformation to MMF is delayed after the high exposure. As the hepatotoxic effect of DMF has been correlated with MMF, this could contribute to the previously observed slower appearance of hepatotoxicity after a high compared to a low DMF dose.

Some observations on dimethylformamide hepatotoxicity

Dimethylformamide (DMF) and its biotransformation products monomethylformamide (MMF) and formamide (F) were administered intraperitoneally to rats. Serum levels of sorbitol dehydrogenase (SDH) were studied at 3 h intervals from 9 h to 30 h after administration. Liver histology at 12, 21 and 30 h proved elevated SDH levels to be an indication of liver necrosis. DMF 479 mg/kg produced elevated enzyme levels at 27 h and 30 h while half the dose, 240 mg/kg, produced elevated levels from 15 h onwards. MMF 387 mg/kg produced elevated SDH levels at all times studied. F did not give elevated levels at any time. DMF (479 mg/kg) and MMF (387 mg/kg) administered simultaneously produced elevated SDH levels from 24 h onwards. These findings suggest that DMF hepatotoxicity is mediated by a degradation product of MMF and that DMF delays the hepatotoxic effect induced by MMF.

Chromosome aberrations and sister chromatid exchanges in Swedish paint industry workers

Workers in the Swedish paint industry exposed to a mixture of organic solvents, mainly containing xylene or toluene, were investigated for genotoxic effects. No difference in the frequency of sister chromatid exchanges (SCE), 0.192 and 0.193 per chromosome, respectively, was noted in the peripheral lymphocytes of the exposed group of 17 workers and their matched reference group. No correlation was found between xylene or toluene exposure and SCE frequency nor between total solvent exposure and SCE frequency. The frequency of chromosome aberrations was also investigated for the five most exposed workers and their matched referents, and no difference was found. There was no correlation between SCE and chromosome breaks.

On the morphology of live spermatozoa of human semen

Live and dead spermatozoa of human semen were distinguished and evaluated separately with respect to their morphology after supravital staining with buffered eosin. This evaluation was shown to be almost as reliable as that of the commonly stained smear. Different samples from the same individual were found to be similar with respect to both the total population and the live population. Different types of abnormalities were not equally common in the live and dead populations. Tapered heads were more common in the live population and abnormal midpieces more common in the dead, whereas abnormal tails and cytoplasmic droplets occurred with the same frequency in both populations. However, neither the frequency of all spermatozoal abnormalities nor that of abnormal heads or midpieces studied separately showed strong correlations in the two populations, in contrast to the frequencies of tapered heads, cytoplasmic droplets, and abnormal tails. No constant relationship was found between the live population and the entire sperm population with respect to numerical differences or quotients between the figures for abnormal cell frequency.Therefore, study of the morphology of the live sperm population gives supplementary information about the qualities of semen not attained by previous methods of study.