Search PubMed⌕ Search

Biomedical subjects

I Lundberg

Publications and source records attributed to I Lundberg.

At least 91 records · Page 5Linked to original sources

A clinical, serological, and histopathological study of myositis patients with and without anti-RNP antibodies.

Twenty-nine patients with myositis, including 10 with polymyositis (PM), 6 with dermatomyositis (DM), and 13 with myositis associated with a connective tissue disease (CTD), were followed up for a mean observation time of 49 months. The 13 patients with CTD-associated myositis were further separated by the presence or absence of anti-RNP antibodies. The functional disability at diagnosis was pronounced without differences between the groups. The patients with anti-RNP antibodies did not differ from the other patients regarding initial muscle weakness, erythrocyte sedimentation rate, or creatinine phosphokinase values, but the histopathological muscle changes were generally milder. Rapid improvement of muscle strength on moderate doses of corticosteroids was seen in most patients. At the end of study, corticosteroid treatment had been withdrawn from 17 patients because of remission, including 6 of the 7 patients with anti-RNP antibodies. The presence of electromyographic changes compatible with myositis, pronounced muscle weakness before treatment, and a low erythrocyte sedimentation rate seemed to indicate a less favorable outcome unrelated to diagnostic subgroupings. However, the combination was rarely found among the anti-RNP-positive patients.

Adolescent↗

Clinical manifestations and anti-(U1)snRNP antibodies: a prospective study of 29 anti-RNP antibody positive patients.

Twenty-nine anti-RNP positive patients were followed prospectively with a mean observation time of 65 months (29-120 months). The clinical course was correlated to the presence of IgM and IgG anti-(U1)snRNP antibodies as revealed by immunoblotting from sequentially obtained sera. There was a striking dissociation between the fluctuating course, with the appearance of new manifestations followed by remissions, and the stability of the anti-snRNP antibody specificities where an appearance or a disappearance of anti-snRNP specificities was a rare phenomenon. The main epitope recognized by the IgG antibodies was the 70 kDa protein and of the IgM antibodies the B/B' proteins. No shift from the IgM to the IgG isotype was observed. The presence of IgG anti-70 kDa and IgM anti-B/B' antibodies was highly associated with presence of arthralgias, Raynaud's phenomenon and arthritis. Further, an association was noted between the combined presence of IgG anti-70 kDa, anti-A and anti-C antibodies and IgM anti-B/B' and puffy hands, myositis, pulmonary fibrosis and sclerodactyly, i.e. all manifestations of mixed connective tissue disease (MCTD). On the contrary, serositis as often seen in SLE was correlated to the presence of IgG anti-B/B' antibodies. Thus the longitudinal analysis of the correlation between anti-snRNP antibody specificities and clinical manifestations support the concept of MCTD as a distinct entity.

Adolescent↗

IgG and IgM anti-snRNP reactivity in sequentially obtained serum samples from patients with connective tissue diseases.

Sequentially obtained serum samples from 30 patients with connective tissue disease positive for antibody to ribonucleoprotein (RNP) were examined to determine the specificities of IgG and IgM antibodies to snRNP during the disease course using immunoblotting of nuclear extracts. The antibody patterns were correlated with disease activity. The patterns of antibody to snRNP of individual patients were mainly stable during the study but changes in levels of antibody to snRNP were seen corresponding to changes in clinical activity. These results indicate that increased reactivity of serum IgM antibodies against the B/B' proteins seems to precede a clinically evident exacerbation of disease whereas IgG antibody reactivity to the 70 K protein peaks at the time of a disease flare.

Autoantibodies↗

Diagnoses of alcohol abuse and other neuropsychiatric disorders among house painters compared with house carpenters.

The incidence of alcoholism and the incidence of other neuropsychiatric diagnoses were compared between the 767 house painters and the 1212 house carpenters, born in 1925 or later, who were members of the Stockholm branches of their respective trade unions in 1965 and who had been members for at least 10 years before 1970. Four different outcome registers were used: (1) the alcohol crime register, which contained all persons who had broken any law regulating the handling and consumption of alcohol (follow up period 1972-6). (2) The register of diagnoses at early retirement (follow up period 1971-84). (3) The register of diagnoses at discharge from inpatient psychiatric care (follow up period 1968-83). (4) The register of causes of death (follow up period 1965-86). Exposures to solvents and consumption of alcohol were evaluated by interviews with samples of the cohorts. A high average cumulative exposure to solvents was found among the painters. The mean consumption of alcohol was similar in the two cohorts. The incidence of diagnoses of neuropsychiatric disorders was higher in painters than in carpenters in all registers. Alcoholism was the most common neuropsychiatric disorder diagnosed and showed the highest relative risk. The excess of alcoholism among the painters was, however, due singularly to painters who had several registrations in the alcohol crime register or diagnoses of alcoholism in multiple registers. Thus the study implies that excessive alcohol consumption or severe damage due to alcohol, or both, but not less severe problems, were more common in painters than in carpenters. This suggests an interaction between exposure to solvents and intake of alcohol causing an increase in diagnosis of alcoholism among painters.

Adult↗

Epidemiology of occupational neurobehavioural hazards. Methodological experiences from organic solvent research.

Neurobehavioral hazards have been identified since long in occupational health, e.g. lead, mercury, certain solvents, and many others agents. There are reviews and books on "Occupational neurology" or "Prevention of neurotoxic illness in working populations". Many methods have been applied for studies of the central and peripheral nervous systems in humans: registered diagnoses, questionnaire ratings, clinical evaluation, psychometric tests, neurophysiological and neuroradiological methods, cerebrospinal fluid components etc. Some neurological disorders are well defined, while neuropsychiatric syndromes often are less precisely diagnosed. Decreased subclinical test results in exposed groups might predict an increased risk for later, more serious disorders but the longitudinal information on clinical importance is often lacking. Some historical lessons from the epidemiology of occupational neurology will be repeated and a few reflections on the suitability of different diagnostic entities for epidemiological research shall be made. Since the beginning of the 1970s' a number of studies from the Scandinavian countries have demonstrated long-term neurobehavioral effects from working conditions with relatively moderate exposure to organic solvents. Similar findings have been verified in studies from some countries outside Scandinavia while other studies have been inconclusive. Those results have caused considerable controversy and have been discussed at international conferences and in scientific journals. Very different outcomes have been investigated in those solvent studies, however, and most studies have had a cross-sectional design with inherent problems. The exposure has been assessed in different ways, e.g. by years of occupation, hygienic measurements of the present working conditions, biological monitoring, retrospective assessments on qualitative or semi-quantitative scales. Sometimes single solvent exposures have been studied but most of the studies concern mixtures of solvents from aromatic and aliphatic hydrocarbons. As the designs have varied the exposure assessment has been crude and many different outcomes have been studied, it is hardly surprising that the results and the interpretations have differed. The first results from a comprehensive investigation on 135 solvent exposed painters and 71 carpenters as referents, selected from active members of the respective trade union 1965-70 and investigated in the late 80s, will be presented. Clinical, including psychiatric, diagnostic work up and neuropsychological as well as neurophysiological tests have been performed. Psychological test results from military conscripts at age 19 were available for all. The individual exposure history has been carefully assessed.(ABSTRACT TRUNCATED AT 400 WORDS)

Case-Control Studies↗

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).

Adult↗

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.

Adolescent↗

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.

Adolescent↗

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.

Adolescent↗

MRI evaluation of the size and symmetry of the planum temporale in adolescents with developmental dyslexia.

MRI technique was used to examine the size and symmetry of the plana temporale in 19 dyslexic students in grade 8 and in carefully matched control subjects. The results demonstrated a high frequency of planum symmetry among the dyslexics (70%) whereas symmetry was observed in only 30% of the control subjects. It was not possible to demonstrate any clear association between symmetry/asymmetry of planum temporale and handedness. Word-reading strategies among the dyslexics and control subjects were investigated with computerized tasks where accuracy and naming latency were recorded. All subjects with pure phonological deficits in reading had symmetrical plana temporale indicating a possible neuroanatomical basis for a characteristic symptom of linguistic processing deficiency in developmental dyslexia.

Adolescent↗

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.

Adult↗

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.

Adrenal Cortex Hormones↗

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.

Animals↗