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Biomedical subjects

A Brun

Publications and source records attributed to A Brun.

At least 127 records · Page 7Linked to original sources
PubMed1990

In situ hybridisation in herpetic lesions using a biotinylated DNA probe.

In situ hybridisation was performed with a biotinylated DNA probe for herpes simplex virus (HSV) using high temperature denaturation on formalin fixed, paraffin wax sections of lung, brain, ganglion and keratinising and non-keratinising squamous epithelia. Eosinophilic viral nuclear inclusions or characteristically moulded multiple nuclei with altered chromatin, which were present in two cases of HSV encephalitis and one case of viral pneumonitis, all showed complete hybridisation visualised by an alkaline phosphatase/nitroblue tetrazolium detector system. HSV encephalitis and trigeminal ganglionitis, which were confirmed serologically or clinicopathologically but lacked nuclear changes, also gave positive dense nuclear signal in neurons, glias and satellite cells. No staining was present in the ganglion cells in trigeminal zoster, the glia in progressive multifocal leucoencephalopathy, or in a variety of cells in a lung coinfected with cytomegalovirus. In 10 herpetic blisters of squamous epithelia, infected cells hybridised strongly, while morphologically similar herpes zoster lesions remained negative. In neural tissues non-hybridisation staining was most obtrusive in corpora amylacea and seemed to reflect nonspecific probe adherence. In squamous epithelium, major non-hybridisation staining was caused by probe and antibody possibly adhering to intracellular keratin. The HSV probe permits specific detection of virus in the absence of characteristic nuclear changes and allows varicella zoster virus to be differentiated from HSV, provided that the aforementioned problems with non-hybridisation staining are borne in mind.

Biotin↗
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 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

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↗
PubMed1989

Structural changes in ageing and dementia of Alzheimer's type with special reference to recent etiologic and therapeutic theories.

On the basis of a large material of organic dementia, accumulated during a 20 year long prospective study, certain basic structural changes in dementia, mainly of Alzheimer's type (DAT) viz. the topography of lesions, the amyloid angiopathy and white matter changes are discussed with respect to their relevance for modern etiologic and pathogenetic theories and implications for the clinical picture and treatment in DAT. The topographic pattern and its evolution appears to be a relevant basis for the symptomatology and the picture shown by PET and regional cerebral blood flow studies. It lends some support to theories implicating the spread of a causative agent via olfactory pathways. The amyloid depositions, particularly those in the vessels present, both with regard to amount and topography, features which to some extent validate the modern etiological gene theories but which in other respects lend little or no support to the etiologic or pathogenetic importance ascribed to amyloid. The white matter changes, common in DAT and of an incomplete infarction type, may blur the DAT clinic and also serve to block axonal transport through the white matter and cause dysfunction or death of neurons dependent upon routes involved. It might thus influence therapeutic measures such as administration of transmitter substitutes or their precursors and the outgrowth or efficacy of transplanted cholinergic replacement neurons.

Aging↗
PubMed1988

Congenital lead encephalopathy in monkeys.

Thirty-one squirrel monkey fetuses were exposed to lead acetate given to the mothers perorally during the last three-fourths or two-thirds of pregnancy. The mean maternal blood lead concentration of the group was 37 micrograms/100 ml and the individual means ranged from 22-82 micrograms/100 ml. Examination of the central nervous system was performed in 15 of the offspring (one abortion, eight stillborns, three neonatal deaths, two killed fetuses and one killed newborn). The mean cerebral weight was reduced for the fetal age (about 10%). Three cerebra were paradoxically overweight for the fetal age as well as for the body weight, probably due to edema. Neurohistology revealed large numbers of characteristic perivascular, petechial hemorrhages in the white matter in six of the fifteen cerebra. In two of these cases, such hemorrhages were also found in the white matter of the cerebellum, brain stem and spinal cord. Examination of four recovered placentas (two after delivery and two at hysterotomies) indicated a lead dose-dependent weight reduction and revealed various pathological lesions. The extensive brain hemorrhages, as well as varying degrees of edema, were seen in stillborns and neonates, while prenatally sacrificed fetuses showed few or no petechial hemorrhages and no signs of edema. It is suggested that lead is involved in the parenchymal growth retardation and the endothelial changes in the prenatal brain, as well as the placental damage, and that prematurity, birth-associated mechanical stress and asphyxia contribute to or precipitate vascular lesions, which may form the basis of acute, or later apparent, neurobehavioral disturbances.

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↗
PubMed1988

Light-induced redistribution and photobleaching of protoporphyrin in erythrocytes from patients with erythropoietic protoporphyria: an explanation of the rapid fading of fluorocytes.

Erythrocytes from patients with erythropoietic protoporphyria (EPP) contain large amounts of protoporphyrin. By fluorescence microscopy it has been found that the erythrocytes show red fluorescence which fades very rapidly. During irradiation of erythrocytes from patients with EPP, a decrease in the fluorescence intensity and a red shift in the fluorescence emission maximum is observed. Since the human eye has a diminishing sensitivity in the red part of the spectrum, the red shift will augment the fluorescence decrease observed in the microscope. The decrease in fluorescence intensity is greater than what would be expected by photobleaching of protoporphyrin alone. We suggest that the rapid fading of fluorocytes observed in a fluorescence microscope can be explained both by photoinduced detachment of protoporphyrin from hemoglobin followed by a redistribution to the erythrocyte membrane and by protoporphyrin photobleaching.

Erythrocytes↗
PubMed1988

White matter changes in dementia of Alzheimer's type. Biochemical and neuropathological correlates.

A correlative neuropathological-biochemical study was undertaken in order to characterize the selective incomplete white matter infarctions (SIWI) frequently found in dementia of Alzheimer's type. The brain tissue analysed represented white matter with incomplete infarction, complete infarcts and with histologically normal tissue, in cases with dementia, mainly of Alzheimer and multi-infarct type, in nondemented subjects with cerebral infarcts and in age-matched control cases. The biochemical results verify the existence of the white matter changes and agree on their regional distribution as they appear in the morphological analyses. The increasing severity of SIWI as assessed histologically was reflected in a proportional reduction of several biochemically quantified white matter components. The histological difference between incomplete and complete infarction was also expressed biochemically. Incomplete white matter infarction with and without associated complete infarcts were biochemically similar. The aetiological significance of the loss of different white matter components is discussed. The biochemical data support the concept of SIWI as being an independent white matter disorder of cerebrovascular, hypoperfusional/hypoxic origin.

Aged↗
PubMed1988

Erythropoietic protoporphyria: a quantitative determination of erythrocyte protoporphyrin in individual cells by flow cytometry.

A fraction of the erythrocytes from patients with erythropoietic protoporphyria contains large amounts of protoporphyrin. By extraction methods, only a mean value of the protoporphyrin content in erythrocytes is obtained. In this study, flow cytometry was used to determine the protoporphyrin content in each individual erythrocyte. The mean erythrocyte protoporphyrin fluorescence, calculated from flow cytometric data, correlated linearly to the mean cellular protoporphyrin concentration measured by ethyl acetate/acetic acid extraction. This indicates that flow cytometry gives a reliable quantitative determination of protoporphyrin in individual cells. Erythrocytes from patients with erythropoietic protoporphyria had a markedly skewed distribution of protoporphyrin. In the most fluorescent erythrocytes (protoporphyrin concentration 3.3 mM), there was about one protoporphyrin molecule for every sixth haeme molecule. This might explain the slight anaemia in some of these patients.

Erythrocytes↗
PubMed1988

Ten-year survival among patients with supratentorial astrocytomas grade III and IV.

The Swedish Cancer Registry, in a linkage with the Swedish Registry of Statistics, was used to trace all patients operated on in Southern Sweden for histopathologically verified malignant primary central nervous system tumors during the years 1958 to 1975. Patients surviving 10 years after the operation were identified, and their original surgical specimens were reexamined. Six (0.5%) of 1147 patients were shown to have survived for between 12 and 28 years after surgery for supratentorial astrocytomas grade III and IV. All six patients are in good condition, without signs of tumor recurrence. The only obvious common denominator for the survivors is their youth at operation. Three patients were 7 to 11 years old at surgery, and none was older than 38 years. It is concluded that a cure may be possible in exceptional patients with the "incurable" astrocytoma grade III and IV.

Adolescent↗
PubMed1988

Proton microprobe and particle induced X-ray emission (PIXE) analysis for studies of pathological brain tissue.

Particle Induced X-ray Emission and proton microprobe analyses have been applied for the investigation of regional elemental distributions in connection with various pathological states in the brain. Malignant brain tumours and adjacent histologically intact tissue removed during surgery were analysed with PIXE. Systematic elemental variations, e.g., for calcium and selenium, were observed in the tumour front. The proton microprobe was applied to study the Ca and K concentrations in various cell strata in hippocampus following transient ischaemia in rat brain. Significant increases in the Ca level occurred in selectively vulnerable cells within 48 h after the ischaemia.

Animals↗