Search PubMed⌕ Search

Biomedical subjects

B Winblad

Publications and source records attributed to B Winblad.

At least 505 records · Page 28Linked to original sources
PubMed1980

The effect of age on the activity and molecular properties of human brain monoamine oxidase.

The effect of age upon monoamine oxidase -A and -B (MAO-A and -B) in 23 different, regions of human brain was determined. There was a significant positive correlation with age in 19 out of 23 regions for MAO-B, but no positive correlation with age was found for MAO-A. The increased MAO-B activity was found, in 5 out of 5 regions tested, to be due entirely to an increased enzyme concentration, rather than due to an increased molecular turnover number of the enzyme. The responses of the mitochondrial marker enzymes succinate dehydrogenase (SDH) and malate dehydrogenase (MDH) were studied in 5 brain regions, and no consistent change in activity found with age. The lysosomal enzyme acid phosphatase was found to tend towards an increased activity with age. No difference in either the specific activities or molecular characteristics of MAO were found between men and women. Cross-correlation studies of the data, after compensation for the effects of age, indicated that the activities of the two enzyme forms are under some form of organized control across the whole brain. Such a finding is consistent with a genetic regulation of the enzyme forms.

Adult↗
PubMed1980

Renal function and morphology in long-term lithium and combined lithium-neuroleptic treatment.

Ten patients on long-term lithium therapy and ten on lithium and neuroleptics (combination therapy) were examined with renal biopsy and tests of renal function. Patients on combination therapy had more pronounced histopathological changes and lower concentrating capacity than patients on lithium alone. Patients on combination therapy had received a larger total dose of lithium and had had higher maximum serum lithium levels than patients on lithium alone. Patients with large daily urine volumes had a low concentrating capacity. There was a negative correlation between degree of histopathological lesions and urinary concentrating capacity. Estimation of urinary concentrating capacity seems to be of value for the assessment of renal lesions in lithium treatment.

Adult↗
PubMed1980

Hypoglycemia in Alzheimer's disease.

Glucose tolerance tests (GTT) were performed on patients with a) dementia of Alzheimer type, b) distal gangrene, c) cerebrovascular disease, and d) on non-diabetic controls. Fasting blood sugar was significantly lower and the areas under the GTT curves were significantly smaller in the dementia group than in the other three groups. It is discussed whether Alzheimer's disease is a generalized disease not only confined to brain tissue and whether the reduced blood glucose levels could impair the brain transmitter levels.

Aged↗
PubMed1980

Tympanic membrane changes after installation of polyethylene grommets. An experimental study in the rat.

The object of this study was to establish the morphological changes which occur when a polyethylene grommet is implanted in the normal tympanic membrane of experimental animals. We found a serous effusion around the grommet and in the attic during the first weeks after installation. All the grommets had been displaced away from the tympanic memebrane in a medical direction into the middle ear cavity. The displacement was most likely brought about by a squamous cell epithelial and connective tissue hyperplasia, which reached its maximum after 2--3 weeks. Neither atrophy, atelectasis, nor retraction was observed, whether in the pars flaccida or the pars tensa. A greyish, horseshoe-shaped configuration was seen in all specimens in the undisturbed front quadrants. No firm histo-pathological correlation was found to explain these changes. In these studies in the rat, the perforation appeared to heal, although delayed, in the same way as after a central perforation, once the polyethylene grommet had been ejected.

Animals↗
PubMed1980

Initial uptake and insulin releasing action of chloromercuribenzene-p-sulphonic acid (CMBS) in suspensions of pancreatic islet cells.

The effects of chloromercuribenzene-p-sulphonic acid on dispersed cells prepared from beta-cell-rich ob/ob-mouse islets were studied. 1) Chloromercuribenzene-p-sulphonic acid at concentrations of 0.1 mmol/l or higher diminished cell viability which was partially counteracted by increasing concentrations of bovine serum albumin. 2) The uptake of 203Hg-chloromercuribenzene-p-sulphonic acid after incubation for 4 seconds or longer showed that most of the non-toxic concentrations of chloromercuribenzene-p-sulphonic acid was bound to the cell within 40 seconds. Maximal uptake was achieved after 3 minutes of incubation. The uptake of radioactive chloromercuribenzene-p-sulphonic acid was inhibited by bovine serum albumin. 3) The dynamics of insulin release from perifused dispersed beta-cells embedded in fibrin showed a maximal 40--50-fold stimulation by 0.03 mmol/l chloromercuribenzene-p-sulphonic acid within 10 minutes of perifusion. 4) Scanning electron microscopy of beta-cells revealed no major changes in the cell surface under conditions of maximal binding and insulin releasing effects of chloromercuribenzene-p-sulphonic acid. These data support the concept that the ability of chloromercuribenzene-p-sulphonic acid to induce insulin release is related to its initial binding to the beta-cell surface. The binding of chloromercuribenzene-p-sulphonic acid and the subsequent release of insulin seem to occur without major changes in beta-cell surface morphology.

4-Chloromercuribenzenesulfonate↗
PubMed1979

Post-mortem distribution of dopamine and homovanillic acid in human brain, variations related to age, and a review of the literature.

The post-mortem brain concentrations of dopamine (DA) and homovanillic acid (HVA) were determined in 16 parts of the brain from patients with no history of neurologic or psychiatric illness. Fifteen men and nine women, with a mean age of 61.0 +/- 18.7 years (range 23--92 years) were included. They had died from either ischaemic heart disease or cancer. In the post-mortem investigation several factors were controlled: age, time between death and autopsy, time between autopsy and chemical analysis and storage time (-20 degrees C). The DA concentrations in the different brain areas were found to be positively intercorrelated, especially those in the basal ganglia, hippocampus and the mesencephalon. The HVA concentrations measured in various cortical structures were also positively intercorrelated. In several regions of the brain there was a significant inverse correlation between the DA and HVA concentrations. The DA and HVA concentrations did not differ according to sex, but age had a marked influence on the DA concentration. Significant decrease with age was observed in the nucleus caudatus, globus pallidus, mesencephalon, hippocampus and in the cortex gyrus hippocampus. These findings are discussed in relation to the effect of aging neurons. A review of human post-mortem investigations on DA and HVA concentrations is also presented.

Adult↗
PubMed1979

Effects of low ampicillin concentrations on penicillin sensitive and beta-lactamase producing strains of Neisseria gonorrhoeae.

The effects of therapeutic concentrations of ampicillin on non-beta-lactamase and beta-lactamase producing strains of Neisseria gonorrhoeae were studied. A small but significant fraction of bacteria in a gonococcal population was found to respond in a bacteriostatic rather than a bactericidal way upon ampicillin treatment. In agreement with this was the finding of morphologically unaltered cells in the scanning electron microscope after ampicillin exposure. Ampicillin treatment of beta-lactamase producing gonococci caused a significant release of the enzyme into the surrounding growth media. However, initially all beta-lactamase activity was cellbound. The rate of initial ampicillin hydrolysis was much higher in intact cells of N. gonorrhoeae (TEM-1) than in cells of Escherichia coli K-12 (TEM-1). This suggests that the diffusion rate of ampicillin is much higher in the former organism. The viability of gonococci (TEM-1) was unlike E. coli (TEM-1) affected by low concentrations of ampicillin. However, after complete hydrolysis of ampicillin, viable gonococci (probably bacteriostatic reacting cells) were able to initiate new growth. This heterogeneity of the cell population to penicillin killing is probably one reason why beta-lactamase producing gonococci despite a rather low MIC-value to ampicillin cause infections that are not susceptible to therapy by this agent.

Ampicillin↗
PubMed1979

Monoamines and monoamine metabolites in brains from demented schizophrenics.

The brains from 12 schizophrenic patients were investigated post-mortem for their content of noradrenaline (NA), dopamine (DA), 5-hydroxytryptamine (5-HT), homovanillic acid (HVA), and 5-hydroxyindolacetic acid (5-HIAA). Six of the schizophrenics had been lobotomized 25--30 years prior to death. A control group matched for age was collected in the autopsy room. The concentrations of NA, DA, and HVA in different parts of the brain from the schizophrenic group did not differ from those of the controls. 5-HT was determined in 11 nuclei or areas of the brain. The schizophrenic group had lower mean values compared with the controls, and in the hypothalamus, medulla oblongata, and hippocampus the difference was at a significant level. 5-HIAA was determined in six areas of the brain but only in a few cases. There was a trend towards lower means of 5-HIAA in the schizophrenics. Cause of death, medication, food intake, age, time between death and autopsy, time the corpses have lain in room temperature, and dissection technique are discussed in relation to these findings. These variables have to be kept under careful control before changes can be claimed as having pathogenetic importance for schizophrenia or for the progressing dementia in this disease.

Brain↗
PubMed1979

Changes in the brain catecholamines in patients with dementia of Alzheimer type.

Brain monoamine concentrations were determined post mortem in 19 patients with dementia of Alzheimer type. Samples were taken from 10 parts of the brain and compared with an age-matched control group. There were lower mean concentrations of dopamine in the demented group of patients in seven regions of the brain, and two of these were at a significant level. There were also significantly lower concentrations of homovanillic acid in the nucleus caudatus and in the putamen. The means of the concentrations of noradrenaline were also lower, and in the putamen and the cortex gyrus frontalis significant differnces were observed. The 5-hydroxytryptamine concentrations were slightly lower in the demented group but the differences did not reach significance. The degree of intellectual deterioration was negatively correlated with the noradrenaline concentrations in the hypothalamus and the cortex gyrus cinguli.

Aged↗
PubMed1979

The role of the pars flaccida in the mechanics of the middle ear.

The role played by the pars flaccida in the functioning of the middle ear is not altogether clear. The aim of our research was to study the movements of pars flaccida in altering the air volume in the middle ear. By using a sond placed either in the tympanic bulla or in the Eustachian tube in the rat, the middle ear can be insufflated or aspirated with exact volumes of air. Pars flaccida reacted promptly to the changes, while pars tensa remained immobile. A large air volume caused perforation of the pars flaccida. It seems that pars flaccida's function may consist in maintaining a constant middle ear pressure within certain limits, by changing its position.

Animals↗
PubMed1979

Monoamine oxidase in platelets and brains of non-psychiatric and non-neurological geriatric patients.

Monoamine oxidase (MAO) activity has previously been found to be high both in brain and in platelets in patients with Alzheimer's disease and low in patients with cycloid psychosis and suicidal behaviour and/or ethanol abuse. To establish if there is a correlation between brain and platelet MAO activities in patients without psychic disease, blood samples from patients in a geriatric ward were collected before death and from 4 different parts of the brain at autopsy. The MAO activities in platelets and brain were then estimated with different substrates. No correlation between the MAO activities in the two tissues was, however, found, regardless of the substrate used.

Age Factors↗