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Biomedical subjects

A Brun

Publications and source records attributed to A Brun.

At least 37 records · Page 2Linked to original sources
PubMed1990

Colloid cysts of the third ventricle: correlation of MR and CT findings with histology and chemical analysis.

Eight patients with colloid cysts of the third ventricle were examined with CT and MR. In six, surgical resection was performed and the material was subjected to histologic evaluation; the concentrations of trace elements were determined by particle-induced X-ray emission. Stereotaxic aspiration was performed in two. The investigation showed that colloid cysts are often iso- or hypodense relative to brain on CT (5/8), but sometimes have a center of increased density. Increased density did not correlate with increased concentration of calcium or other metals but did not correlate with high cholesterol content. Colloid cysts appear more heterogeneous on MR (6/8) than on CT (3/8), despite a homogeneous appearance at histology. High signal on short TR/TE sequences is correlated with a high cholesterol content. A marked shortening of the T2 relaxation time is often noticed in the central part of the cyst. Analysis of trace elements showed that this phenomenon is not related to the presence of metals with paramagnetic effects. Our analysis of the contents of colloid cysts does not support the theory that differing metallic concentrations are responsible for differences in MR signal intensity or CT density. We did find that increased CT density and high MR signal correlated with high cholesterol content.

Adult↗
PubMed1990

Vaccination against pseudorabies with glycoprotein gI+ or glycoprotein gI- vaccine.

Subunit pseudorabies vaccines that contained only purified glycoproteins of either of 2 strains of pseudorabies virus (PRV) were prepared and subsequently tested for safety and efficacy. The strains of virus used for vaccine production differed in at least 2 properties. One strain (Kojnok) was virulent for pigs and was believed to code for the entire complement of viral glycoproteins. The other (Kaplan) was a deletion mutant that was unable to code for structural viral glycoproteins gI and gp63. Purified glycoproteins were dispersed in an oil-in-water emulsion and were administered IM to pigs. Both vaccines were found to be safe and effective immunogens. Neither caused any local or general reactions, as verified by examination of the injection site (local safety) and by vaccination of pregnant sows in PRV-infected and noninfected herds. Sows vaccinated with the gI+ or gI- vaccine protected their pigs at levels of 93 and 92%, respectively, against a severe challenge exposure that killed 98% of pigs born from nonvaccinated sows. Vaccinated pigs were tested for active immunity by intranasal challenge exposure with the NIA 3 strain. Protection was quantitated by measuring the relative daily weight difference, expressed in percent per day, between vaccinated and control pigs during the first week after challenge exposure (delta G7); the estimated differences were 2.25 and 2.13% for gI+ and gI- vaccines, respectively. The absence of gI and gp63 did not affect the efficacy of this type of subunit glycoprotein vaccines.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

The apparent autoxidation rate of catechols in dopamine-rich regions of human brains increases with the degree of depigmentation of substantia nigra.

The concentrations of the 5-S-cysteinyl adducts of dopamine (DA), 3,4-dihydroxyphenylacetic acid (DOPAC) and 3,4-dihydroxyphenylalanine (DOPA) and the levels of noradrenaline (NA), DA, DOPAC and DOPA were determined in the putamen (PUT), caudate nucleus (CN) and substantia nigra (SN) of human post mortem brains with or without depigmentation and degeneration of the SN. The levels of DA, DOPAC and DOPA decreased with the degree of depigmentation and degeneration in the three brain regions while NA levels only decreased in SN and PUT. In general, the concentrations of the 5-S-cysteinyl adducts did not differ, but the ratios of 5-S-cysteinyl-DA/DA, 5-S-cysteinyl-DOPAC/DOPAC and 5-S-cysteinyl-DOPA/DOPA were higher in patients with a more depigmentated and degenerated SN, except for the 5-S-cysteinyl-DA/DA ratio in the PUT. Higher ratios were also found in the cell body areas compared to the neuron terminal areas. Thus depigmentation and degeneration of dopaminergic SN neurons, seem to be correlated to enhanced rates of autoxidation, possibly due to an impaired antioxidant capacity.

Aged↗
PubMed1989

The potency testing of pseudorabies vaccines in pigs. A proposal for a quantitative criterion and a minimum requirement.

A criterion for the potency testing of pseudorabies vaccine based on the difference between the mean weight gain during the seven days after pathogenic challenge of vaccinated or control piglets is proposed. This criterion, termed delta G7, has been studied as a function of initial weight variation of the animals, different challenge strains and the period between challenge and the end of the test. The statistical analysis of results optimizes the experimental parameters and gives rise to a quantitative test which discriminates between vaccinates and controls and substantiates a proposal for a minimum vaccine potency requirement. The implementation of the method proposed is compatible with current practice in control laboratories.

Animals↗
PubMed1988

The impact of time after portacaval shunt in the rat on behavior, brain serotonin, and brain and muscle histology.

We investigated open field behavior, cellular fluorescence of brain serotonin and serotonin metabolism in different regions of the central nervous system (CNS), and brain and muscle histology in rats 3 weeks or 6 months after surgical end-to-side portacaval shunt (PCS). The results revealed a similar disturbance of the CNS serotonin at 3 weeks and 6 months after PCS in the rat. Progressive neurohistological changes were present between 3 weeks and 6 months after PCS. The open field behavioral impairment appeared, however, to diminish with time. There was no evidence from muscle biopsies that lesions in the muscles or in the peripheral nerves contributed to the motor disturbance.

5-Hydroxytryptophan↗
PubMed1979

Immunisation against panleukopenia: early development of immunity.

The time necessary to obtain the immunity of cats against Panleukopenia has been studied by means of a modified live vaccine. This vaccine makes it possible to obtain a very early post-vaccinal immunity: the full immunity is reached 72 hr after the inoculation of the vaccine by the subcutaneous route. Furthermore, we have demonstrated that a sensitive kitten can be admitted in a contaminated environment immediately after vaccination without showing any clinical evidence of the disease.

Animals↗
PubMed1979

Neonatal non-ketotic hyperglycinemia: a clinical, biochemical and neuropathological study including electronmicroscopic findings.

In a family of four children, three died within 8 days after birth. The fourth child survived after a critical first week with the same symptoms as the siblings. He was at the age of four found to have non-ketotic hyperglycinemia. The histories and neuropathology of the other children were then reexamined. It seems highly probable that all siblings suffered from non-ketotic hyperglycinemia. This report points to the clinical, biochemical and neuropathological diagnostic problems in this disease and also adds new information on the ultrastructural changes, not hitherto visualized.

Amino Acid Metabolism, Inborn Errors↗
PubMed1978

Limbic lobe involvement in presenile dementia.

Limbic lobe involvement in presenile dementia was studied from a neuropathological and neuropsychiatric viewpoint. The material consisted of seven cases of Alzheimer's disease, four cases of Pick's disease, and four cases of Jacob-Creutzfeldt's disease. These three groups showed different patterns of distribution of the degeneration characteristic for each group, in particular for the first two. Among the groups, these patterns differed with regard to involvement both of nonlimbic and limbic areas. Thus the Alzheimer group had a mainly temporoparieto-occipital and posterior cingulate gyrus involvement. The Pick group in many respects showed an inverse distribution with frontotemporal and anterior cingulate gyrus accentuation of the damage. Basal temporal limbic areas were involved in both groups. The Jacob-Creutzfeldt group had a less schematic lesion pattern, without involvement of limbic areas. From a neuropsychiatric aspect, these differences were reflected in symptoms that could be referred both to areas spared and those more pronouncedly destroyed by the degenerative process. Thus the Alzheimer group long retained emotional qualities that were lost early in the Pick group. The possible relationship between neurotransmitters and regional accentuation of the degeneration is discussed.

Aged↗
PubMed1978

The Zellweger syndrome: subcellular pathology, neuropathology, and the demonstration of pneumocystis carinii pneumonitis in two siblings.

The first Scandinavian cases of Zellweger syndrome (ZS) are described. A brother and sister, children of first cousins, had the typical clinical symptoms and pathological findings. Extensive metabolic studies in the boy were negative. Pipecolic acid in the urine was not elevated. Both children died at 14 weeks of age. Two months earlier the girl had suffered severe intestinal bleeding. Both had pneumocystic carinii pneumonia at autopsy although no evidence of immune deficiency had been found in the boy. The girl had used up her visible iron depots while the boy still had abundant but probably physiologic amounts of hemosiderin in the RES. Most of the cerebral abnormalities are unspecfic and possibly related to anoxia or other causes of delayed maturation. The white matter abnormalities in ZS patients may only be quantitatively different from the common "fatty metamorphosis" in infants. Previously reported ultrastructural abnormalities (absence of peroxisomes and very sparse smooth endoplasmic reticulum, as well as mitochondrial abnormalities) which are possibly unique for ZS, are confirmed. It is stressed that these were seen despite phenobarbital treatment which normally stimulates the formation of smooth endoplasmic reticulum.

Abnormalities, Multiple↗
PubMed1978

Effects of vitamin B12 deficiency on lipid metabolism of the rat liver and nervous system.

1. Rats bred from vitamin B12-depleted dams were fed on a vitamin B12-deficient diet for 12-15 months and developed a severe vitamin B12 deficiency, as judged from methylmalonic acid excretion and tissue vitamin B12 levels at slaughter. Control rats were supplemented with vitamin B12 in the drinking-water. 2. Neurological signs were recorded after 7 months but the motor nerve conduction velocities remained normal. Neuropathological examination revealed mild changes in the peripheral nerves but no changes in the central nervous system. 3. The amounts of total lipids and phospholipids were normal, but in all examined tissues the proportions of pentadecanoate (C15 fatty acid) and heptadecanoate (C17 fatty acid) were considerably increased in vitamin B12 deficiency. 4. 3H2O was incorporated to the same extent into the fatty acids of nervous tissue from vitamin B12-deficient and control rats after 48 h. Less 3H was found in the liver fatty acids of the vitamin B12-deficient rats. 5. Neurological dysfunction can be demonstrated in the vitamin B12-deficient rat; the relation of the biochemical and neuropathological changes to the neurological signs needs further study.

Animals↗
PubMed1978

Normal chromosome banding pattern in Alzheimer's disease.

Lymphocyte chromosomes were studied in 10 female patients with Alzheimer's disease, including 5 cases with positive heredity for organic dementia. The chromosomes were analyzed by means of the Giesma banding technique. All patients had a normal karyotype with a completely normal banding pattern in all metaphases analyzed. It may be concluded that chromosomal changes demonstrable with methods available today are not involved in the causation of Alzheimer's disease, whether sporadic or with positive heredity for organic dementia starting in the presenile or senile periods.

Aged↗