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Biomedical subjects

M Hagman

Publications and source records attributed to M Hagman.

17 recordsLinked to original sources
PubMed1992

Preclinical neurophysiological signs of parkinsonism in occupational manganese exposure.

To study the effects from low level exposure to manganese, 30 men at steel smelting works and 60 nonexposed reference subjects, were neurophysiologically examined using: (i) Electroencephalogram (EEG), Event related auditory evoked potential (AEP/P300), Brain stem auditory evoked potential (BAEP) and diadochokinesometry. No group differences concerning EEG or BAEP were found. Diadochokinesis was slower and there was a tendency towards prolonged P300 latency in the exposed group as compared to the referents. These effects may be interpreted as early (subclinical) signs of disturbances of the same type as parkinsonism.

Adult↗
PubMed1991

Development of tolerance to the plasma amino acid-decreasing effect of ethanol in the rat.

Male Sprague-Dawley rats were treated for one month with daily intraperitoneal injections of ethanol (2 g kg-1), or saline. After this pretreatment, animals from each group were given acute doses of ethanol (2 g kg-1) or saline. Plasma amino acid concentrations and brain tyrosine, tryptophan, dopamine, 5-HT and 5-HIAA concentrations were measured in samples collected 1 h after the injections. Acute administration of ethanol induced a dramatic fall in the concentrations of 18 out of 20 plasma amino acids in animals pretreated with saline. In animals chronically pretreated with ethanol this decrease was much smaller. Furthermore, the decrease was significantly lower for 6 of the measured amino acids in the chronic ethanol group compared with the saline-treated control group. Tolerance to the plasma amino acid decreasing effect of ethanol had thus developed. This acquired tolerance might be explained by both pharmacokinetic and pharmacodynamic mechanisms. Chronic administration of ethanol induced increased concentrations of tyrosine and dopamine in the brain, probably due to increased transport of tyrosine into the brain caused by an increase in the ratio of tyrosine to large neutral amino acids in plasma.

Amino Acids↗
PubMed1991

Manganese exposure in steel smelters a health hazard to the nervous system.

In a study of the effects of low-level exposure to manganese (0.19-1.39 mg/m3 for 1-45 years) 30 men (aged 20-64 years) from two steel smelting works and 60 unexposed referents (aged 22-65 years) were examined with the use of a general health inquiry, electroencephalography, event-related auditory evoked potentials, brain-stem auditory evoked potentials, diadochokinesometry, simple and complex reaction time, finger tapping, digit span, mental arithmetic, vocabulary, a coding task, manual dexterity, symptoms, and mood scales, the diagnostic interview scheme, a dynamic rating scale for neurasthenic syndrome, and a comprehensive psychopathological rating scale. No group differences were found in the electroencephalography or the psychiatric examinations. However, there were increased frequencies of some symptoms, the diadochokinesis was slower, the P-300 latency and reaction time were increased, and finger-tapping and digit-span performance were impaired in the exposed group. These effects were interpreted as early (subclinical) signs of disturbances of the same type as parkinsonism.

Adult↗
PubMed1990

Dose-dependent decrease in rat plasma amino acids after acute administration of ethanol.

Male rats were given three different doses of ethanol in i.p. injections (0.66, 1.33 and 2.00 g kg-1). A dose-dependent decrease in the concentrations of most plasma amino acids was observed. For the total amino acid concentration this decrease was 5, 16 and 22%, respectively, compared with a saline-treated control group. It has previously been suggested that the oxidation of ethanol plays an important role in the amino acid decreasing effect of ethanol. In this study the lowest dose used (0.66 g kg-1) was calculated to be high enough to keep the enzyme systems involved in ethanol oxidation saturated during the 60 min course of the experiment. The observation that the ethanol-induced decrease in plasma amino acid levels was more pronounced with higher ethanol doses indicates that not only the oxidation of ethanol but also ethanol itself is important in the effect of ethanol on plasma amino acid concentrations.

Amino Acids↗
PubMed1989

Effect of 4-methylpyrazole on ethanol-induced decrease in rat plasma amino acids.

It has been shown earlier that an acute dose of ethanol causes an immediate decrease in the concentration of most plasma amino acids, and that this decrease involves both beta-adrenergic and adrenocortical mechanisms. In this work is shown that the oxidation of ethanol also plays an important role in the amino acid decreasing effect. Male rats were pretreated with 4-methylpyrazole, an inhibitor of liver alcohol dehydrogenase, in doses causing an 85% inhibition of the ethanol elimination. In this group the ethanol-induced decrease in amino acids was much less pronounced than in a control group pretreated with saline.

Amino Acids↗
PubMed1989

Diurnal rhythms in rat plasma amino acids.

To obtain detailed data on the diurnal rhythm in rat plasma amino acids, groups of rats were killed every two hours during 24 hours and the amino acids in plasma were measured. By using such a short interval between the blood samples, it was possible to reveal differences in rhythmicity between the various amino acids, more detailed than those previously described. Furthermore, it was found that those large neutral amino acids (LNAA) which compete with each other for the carrier mediated transport from plasma into the brain demonstrated different rhythms, whereby also the relation between these competing amino acids varied during the day. This finding might have implications for the transport of the various LNAAs into the brain, and secondarily also for the synthesis of the monoaminergic neurotransmitters in the neurons, for which the LNAAs tyrosine and tryptophan serve as precursors.

Amino Acids↗
PubMed1989

Increased adherence to vaginal epithelial cells and phagocytic killing of gonococci and urogenital meningococci associated with heat modifiable proteins.

Urogenital Neisseria meningitidis were characterized with regard to serogroup, colony morphology, the presence of heat modifiable proteins (HMP), attachment to human vaginal and buccal epithelial cells, and phagocytic killing by polymorphonuclear leukocytes. The findings were compared with those on gonococci, and with those on meningococci isolated from blood or cerebrospinal fluid, with regard to colony morphology, HMP and piliation. The opacity colony morphology characteristic could be used to predict the presence of HMP in gonococci but not in meningococci, and sodium dodecyl sulphate polyacrylamide gel electrophoresis had to be used to demonstrate this surface protein. The urogenital meningococci, serogroup Y, attached significantly more efficinetly to vaginal epithelial cells in the presence of HMP and behaved in this respect like those of gonococci. Gonococci and meningococci containing HMP were more sensitive to phagocytic killing than those without HMP. Meningococci from opaque and transparent colonies and isolated from patients with meningococcal disease had no demonstrable HMP. They showed low adherence to vaginal and buccal epithelial cells, with no difference between organisms from opaque or transparent colonies.

Bacterial Adhesion↗
PubMed1988

Factors of importance for prognosis in men with angina pectoris derived from a random population sample. The Multifactor Primary Prevention Trial, Gothenburg, Sweden.

A random population sample of middle-aged men from the Primary Prevention Trial was followed for 11.3 years from a first screening when different factors known to be associated with coronary artery disease (CAD) were analyzed. Men with uncomplicated angina pectoris (AP) (n = 167) derived from this population had an incidence of fatal and nonfatal CAD events 3 times higher than that of men without AP or myocardial infarction (n = 5,774). Men with myocardial infarction with or without AP had an incidence of CAD events 7 to 8 times higher than that of men without AP or myocardial infarction. Similar differences were found for new cases of uncomplicated AP (n = 128) and myocardial infarction detected at a second screening after 4 years and followed for 7.3 years. Pooled data from this series of men with uncomplicated AP showed the following factors to be associated in multivariate analysis with nonfatal or fatal CAD endpoints during follow-up: elevated serum cholesterol, elevated blood pressure, smoking and attack score. The risk increase associated with the first 3 factors was similar to the general population. These findings indicate that the same factors affecting prognosis after a first appearance of AP affect similarly patients with myocardial infarction and clinically healthy subjects. Preventive measures against these risk factors seem to be of similar importance among patients with AP, post-infarct patients and healthy subjects.

Angina Pectoris↗
PubMed1987

Risk factors for angina pectoris in a population study of Swedish men.

The Primary Preventive Trial in Göteborg, Sweden, a study of a random population sample of middle-aged men, made it possible to analyse the risk factor pattern cross-sectionally in 166 men with uncomplicated angina pectoris (AP) and compare with 5735 men without angina pectoris or myocardial infarction (MI). A prospective analysis was also performed concerning the risk factor pattern in 128 cases with uncomplicated AP and 34 cases with complicated AP (following an MI) respectively, appearing during a follow-up time of 4 years. At cross-sectional analysis, uncomplicated AP was related to elevated serum cholesterol, elevated systolic and diastolic blood pressure, increased relative body weight, smoking, diabetes mellitus, low physical activity during leisure time, dyspnea and mental stress. However at multivariate, prospective analysis only dyspnea, stress, diabetes mellitus and increased relative body weight were predictors for uncomplicated AP. In contrast, elevated serum cholesterol, high blood pressure, smoking, and high physical activity at work were predictors for complicated AP. Possible reasons for the apparent risk factor differences and different mechanisms in AP and MI are discussed.

Aged↗
PubMed1986

Clinical course and symptomatology of angina pectoris in a population study.

The clinical course of angina pectoris was studied in a follow-up study of 427 patients with angina from a general population sample. The subjects were men aged 56-65 years at the time of follow-up. After a mean follow-up time of 5.8 years, 55% were still suffering from angina pectoris, 15% had died and a further 19% were either free from chest pain or had chest pain considered to be of different origin. In the group with definite angina pectoris at follow-up (n = 236), 29% had sustained a myocardial infarction, 23% had symptoms of intermittent claudication, 36% were treated for hypertension and 15% had diabetes. Many of the angina patients suffered from other chest conditions in addition to anginal symptoms. Most of the patients (56%) had infrequent attacks (a few times per month or less often) and were not severely incapacitated by their symptoms. Only one fifth worked full time compared with more than half of those in the same age groups in the general population. Only 16 of those interviewed had undergone bypass surgery and a further 16 had disabling angina but, for various reasons, they had not been operated on. The implications are that most angina patients do well on pharmacological treatment alone even though they are limited socially as well as physically. Precipitating factors other than physical activity were also investigated and associations were found between susceptibility to cold, early morning angina, angina at rest and attacks of long duration, possibly indicating a mechanism of vasospasm superimposed on a fixed stenosis.

Aged↗
PubMed1977

Prevalence of angina pectoris and myocardial infarction in a general population sample of Swedish men.

A primary preventive trial against cardiovascular diseases has been in progress since 1970 in Göteborg, Sweden. The study population comprises all men in the city born in 1915-22 and 1924-25, a total of about 30 000 men. One third of this population constitutes the intervention group. The prevalence of angina pectoris and myocardial infarction among men aged 47-53 years has been studied in this group. The cases were identified by means of a postal questionnaire, direct interview at screening examination and by clinical examination. A validation of the postal questionnaire technique gave a sensitivity of 74% and a specificity of 94%. The minimum prevalence of angina pectoris amounted to 4.3% and the prevalence of myocardial infarction to 1.6%. In the angina series, 22% had suffered a myocardial infarction that preceded angina pectoris in 9%.

Angina Pectoris↗
PubMedDate not supplied

Neisseria meningitidis in specimens from urogenital sites. Is increased awareness necessary?

Neisseria meningitidis serogroups B type 2 and Y were isolated from urogenital specimens from three heterosexual patients. The first patient was a young man with the clinical signs and microscopic findings of a typical gonococcal urethritis. The second was a middle-aged woman with cervicitis, in whom neither Neisseria gonorrhoeae nor Chlamydia trachomatis were demonstrated by culture. In the third patient, a young woman, N. meningitidis was associated with cervicitis, acute salpingitis, and peritonitis. The patients' clinical symptoms responded quickly to antibiotic treatment. Meningococci of the same serogroup/serotype as the index cases were demonstrated in two of the sexual consorts in pharyngeal specimens but not in genitourinary specimens. Orogenital sexual practice seemed to be the most likely route of transmission. During the period of this study (August 1989-March 1990), the three meningococcal strains observed at the authors' laboratory represented 20% of the total number of urogenital isolates of pathogenic Neisseria. A greater awareness of this problem from medical, diagnostic, epidemiologic, and legal viewpoints is therefore needed.

Adult↗