Biomedical subjects

M Schultzberg

Publications and source records attributed to M Schultzberg.

114 records · Page 7Linked to original sources

PubMedDate not supplied

Immunohistochemical and behaviour pharmacological analysis of rats inoculated intranasally with vesicular stomatitis virus.

A temperature-sensitive mutant of vesicular stomatitis virus was inoculated intranasally into infant Sprague-Dawley rats aged 9 to 17 days. Rats receiving the virus at 9 days of age had an extensive spread of infection throughout the brain and the animals died after a few days. Rats inoculated at day 11 postnatally survived and the infection was limited to the olfactory pathways, hypothalamus, diagonal bands and the anterior raphe nuclei. Stereological measurements showed that the volume of infected neurons constituted 67 +/- 10% of the total neuronal volume in the dorsal raphe nucleus. Double-labelling experiments revealed that both 5-hydroxytryptamine- and substance P-immunoreactive neurons contained the virus antigen. The motor stimulant effect of amphetamine was studied at 3 months post infection. The increase in amphetamine-induced frequency and duration of rearing was significantly attenuated in infected rats and the amphetamine-induced locomotion was slightly reduced.

Administration, Intranasal↗

PubMedDate not supplied

IL-1beta and ICE mRNA are not altered upon beta-amyloid(25-35) induced neurotoxicity in human neuroblastoma cells.

The specific beta-amyloid(25-35) fragment induced cellular degradation of the human neuroblastoma cell line SH-SY5Y, but did not elicit an effect on the levels of interleukin-1beta and interleukin-1beta converting enzyme, as determined by semiquantitative reverse transcription-polymerase chain reaction and immunocytochemical analysis. The assays revealed constitutive expression of these proteins both at mRNA and protein level. It is conceivable that in the absence of glial elements, such as in the present neuroblastoma cell line, beta-amyloid triggers the toxicity through a direct action and/or through the production of other harmful molecules.

Amino Acid Chloromethyl Ketones↗

PubMedDate not supplied

Inflammatory mechanisms associated with brain damage induced by kainic acid with special reference to the interleukin-1 system.

The evidence of inflammatory processes in the clinical manifestations and neuropathological sequelae of epilepsy have accumulated in the last decade. Administration of kainic acid, an analogue of the excitatory amino acid glutamate, induces a characteristic behavioural syndrome and a reproducible pattern of neurodegeneration in several brain areas, closely resembling human temporal lobe epilepsy. Results from studies using the kainic acid model indicate that manipulation of pro- and anti-inflammatory cytokines can modify the outcome with regard to the behavioural syndrome as well as the neuropathological consequences. Interleukin-1 is one of the most important cytokines and has several actions in the brain that are critical for the host defense against injury and infection, and it is involved in the initiation of early stages of inflammation. It is believed that interleukin-1 plays a pivotal role in the neuroinflammation associated with certain forms of neurodegeneration, including cerebral ischemia, trauma and excitotoxic brain injury. In this review, we have summarized the experimental data available with regard to the involvement of the interleukin-1 system in kainic acid-induced changes in the brain and emphasized the modulatory role of interleukin-1beta in this model of epilepsy

Animals↗

PubMedDate not supplied

Induction of interleukin-1 beta mRNA and enkephalin mRNA in the rat adrenal gland by lipopolysaccharides studied by in situ hybridization histochemistry.

Interleukin-1 is a macrophage-derived cytokine, which can also be synthesized in other cell types. It has been shown to exert several activities in the nervous and endocrine system, including a potent activating effect on the hypothalamo-pituitary-adrenal axis. High levels of interleukin-1 have previously been found in the adrenal gland. The effect of bacterial lipopolysaccharides (2.0 mg/kg) on interleukin-1 beta mRNA was studied in the rat adrenal gland by in situ hybridization histochemistry using a synthetic oligonucleotide probe. A transient induction was observed, with the strongest hybridization signal seen after 1.5 h and subsequent decrease to near basal levels at 3 h. Similarly, the effect of lipopolysaccharides on preproenkephalin A mRNA expression in the adrenal gland was analyzed. Preproenkephalin A is a precursor for methionine-enkephalin, a neuropeptide known to be produced in the chromaffin cells, and also known to affect immunological functions. A low level of preproenkephalin A mRNA was seen in the adrenal medulla in animals injected with saline and 0.5 h after lipopolysaccharide administration. A small, but distinct increase in hybridization signal appeared at 1.5 h and a marked increased was observed at 3 h after administration of lipopolysaccharides. In addition to the different kinetics of expression after LPS administration, the two mRNA species showed a somewhat different morphological distribution in that IL-1 beta mRNA could be seen in both adrenal medulla and cortex, whereas preproenkephalin A expression was confined to the adrenal medulla.

Adrenal Glands↗

PubMedDate not supplied

Autonomic innervation of the tympanic membrane. An immunocytochemical and histofluorescence study.

The innervation of the tympanic membrane of the rat was investigated with respect to noradrenergic and peptide-containing nerve fibres. In sections, most of the nerves in both the flaccida portion and the tensa portion seemed to be of the small, unmyelinated types, though a few larger myelinated nerves were also found. Noradrenergic fibres, exhibiting specific catecholamine fluorescence (CA), were detected along the blood vessels in the pars flaccida and along the vascular network of the annulus fibrosus. In the pars flaccida, fibres exhibiting SP-like, VIP-like- and enkephalin-like immunoreactivity were noted. None of these peptides could be detected in the pars tensa. The exclusive localization of the oedema-provoking peptides, SP and VIP, to the pars flaccida may be of importance with regard to establishing pars flaccida as the initial site of effusion production in experimental secretory otitis media.

Animals↗

PubMedDate not supplied

Interleukin-1 immunoreactive nerve fibres in rat joint synovium.

The occurrence of interleukin-1 immunoreactive nerves in the synovial membrane of rat knee joints was investigated by immunohistochemistry. Synovial tissue sections from 11 rats consistently showed interleukin-1 positive nerve fibres. The majority of the fibres appeared in blood vessel walls. However, varicose interleukin-1 positive fibres were also seen to terminate amidst synoviocytes. The overall distribution resembled that of autonomic fibres previously identified in synovium. Further investigation by double staining disclosed the co-existence of interleukin-1 and neuropeptide Y in the synovial nerve fibres. It has been suggested that the nervous system is implicated in the pathogenesis of arthritis. Considering the role of the cytokine interleukin-1 in various immunogenic and inflammatory conditions, it may prove that neuronal interleukin-1 in the synovial membrane represents a pathway for mediating such effects in joint tissue.

Animals↗