Search PubMed⌕ Search

Biomedical subjects

O Johansson

Publications and source records attributed to O Johansson.

At least 199 records · Page 11Linked to original sources
PubMed1976

Immunohistochemical studies using antibodies to leucine-enkephalin: initial observations on the nervous system of the rat.

Enkephalins are peptides which have pharmacological properties similar to those of morphine. Guinea pigs were immunized with a leucine-enkephalin/thyroglobulin conjugate. Immunofluorescence histochemistry with antiserum revealed a widely distributed system of axons and their terminals in the nervous system of the rat. Prominent networks of enkephalin-like immunoreactivity were found in some brainstem nuclei and in portions of the limbic forebrain. The myenteric plexus in the gastrointestinal tract also contained fluorescent fibers. The distribution of the positive immunofluorescence parallels the occurrence of enkephalin as revealed by biochemical techniques. Some areas known to have a high opiate receptor density were also shown to contain striking networks of enkephalin-like immunoreactivity. Such findings provide morphological support for the hypothesis that enkephalins are contained in nerve terminals close to opiate receptors.

Animals↗
PubMed1976

Prognosis, recurrences and metastases correlated to histologic cell type in carcinoma of the uterine cervix.

An analysis of 230 patients treated with radiotherapy for cervical cancer stages I and II is presented. No positive correlation to cell type was found as regards the number of failures, recurrence rate or the frequency of regional or distant metastases. Although different biological behavior might be shown by cancers of varying cell types, adequate planning and staging before treatment seems to be of better prognostic value.

Adenocarcinoma↗
PubMed1976

Immunohistochemical studies on the localization and distribution of monoamine neuron systems in the rat brain. I. Tyrosine hydroxylase in the mes- and diencephalon.

The localization and distribution of tyrosine hydroxylase (TH), the first enzyme in the catecholamine synthesis, in the mes- and diencephalon has been studied with the indirect immunofluorescence technique of Coons and collaborators. Principally, TH was present in neuron systems with a distribution similar to known dopamine, noradrenaline and adrenaline systems. The present data, taken together with published and some unpublished results, indicate that all parts of most central dopamine neurons, i.e. cell body, dendrites, axon and nerve terminals, appear strongly fluorescent. The adrenaline neurons also appeared strongly fluorescent, except for their axons, which only exhibited a weak fluorescence. Only cell bodies of noradrenaline neurons were strongly fluorescent, whereas the nerve terminals and axons showed a weak or moderate fluorescence intensity. The fine noradrenaline nerve terminals in some areas, such as the thalamus, were invisible or, under favourable conditions, weakly fluorescent. Therefore, in the present study we are mainly dealing with the dopamine neurons of the upper brain stem. Our results demonstrate a widespread occurrence of TH-positive neuron systems in the mes- and diencephalon. The different mesencephalic dopamine systems and their ascending projections were visualized. Numerous TH-positive cell bodies were present along the ventricle system extending from the aqueductus cerebri to the most cranial periventricular parts of the third ventricle. The caudal part of these neurons, consisting of very small cell bodies, belong to the dorsal periventricular system described by Lindvall and Björklund. Several TH-positive cell bodies were also observed in the inferior collicle of young animals. In the superficial layers of the inferior collicles TH positive nerve terminals were seen. At the hypothalamic level the A11 to A14 cell groups as well as some additonal cell bodies and extensive nerve terminal plexuses appeared strongly fluorescent. The differences in the intensity of the TH-related immunofluorescence between various brain regions and between various neuron systems may well reflect differences in enzyme levels between the various catacholamine systems rather than be due to the existence of different types of TH.

Adrenergic Fibers↗
PubMed1975

Are there somatostatin-containing nerves in the rat gut? Immunohistochemical evidence for a new type of peripheral nerves.

Antibodies to somatostatin, a recently isolated hypothalamic peptide inhibiting growth hormone release, were used in immunohistochemical studies on the gastrointestinal tract. Somatostatin containing cells in the stomach, and somatostatin-containing nerves in the small and large intestine, could be demonstrated. These findings give evidence of a new type of nerve in the gut.

Animals↗
PubMed1975

Distribution of thyrotropin-releasing hormone (TRH) in the central nervous system as revealed with immunohistochemistry.

With the indirect immunofluorescence technique TRH-containing nerve terminals were found in the medial part of the external layer of the median eminence, the dorsomedial nucleus and the perifornical area, in extrahypothalmic nuclei such as nucleus accumbens, the lateral septal nucleus and in several motor nuclei of the brain stem and spinal cord. These findings suggest that TRH may act both as a hormone, released into the portal vessels, as well as a neurotransmitter or modulator, released at synapses in discrete regions of the brain and spinal cord.

Animals↗
PubMed1975

Evidence for an inhibitory gabergic control of the meso-limbic dopamine neurons: possibility of improving treatment of schizophrenia by combined treatment with neuroleptics and gabergic drugs.

Changes in dopamine (DA) turnover have been studied in rats after treatment with pimozide and/or gabergic drugs such as beta-(p-chlorophenyl)-GABA and aminooxyacetic acid using the tyrosine-hydroxylase inhibitor alpha-methyltyrosine and methylester (H44/68). The changes in DA levels were determined by quantitative microfluorimetrical analysis of the fluorescence in various DA terminal systems. Beta-(p-chlorophenyl)-GABA (5--20 mg/kg) and aminooxyacetic acid (25 mg/kg) counteracted the pimozide (1 mg/kg) induced increase in DA turnover in subcortical and cortical limbic regions but not in the caput of the caudatus. These findings indicate the existence of a strong and preferential inhibitory gabergic control of the mesolimbic DA neurons and offer the possibility of improving the treatment of schizophrenia provided that limbic DA receptors are involved in this disease. If so, lesions of gabergic pathways may exist in the schizophrenic brain.

Aminobutyrates↗
PubMed1975

Cellular localization of somatostatin in endocrine-like cells and neurons of the rat with special references to the A1-cells of the pancreatic islets and to the hypothalamus.

With the indirect immunofluorescence technique somatostatin, a recently isolated and structurally characterized hypothalamic tetradecapeptide, which inhibits growth hormone release, has been traced in different tissues of the rat. Somatostatin or somatostatin-like immunoreactivity (SLI) was present in both neurons and endocrine-like cells. Somatostatin positive nerve cell bodies were observed in the periventricular region in the anterior parts of the hypothalamus and in probable nerve endings in the external and internal layer of the median eminence and in the pituitary stalk and in the ventromedial, arcuate and ventral premammillary nuclei and to a small extent in the periventricular region. Somatostatin positive nerve fibers were also found in the posterior pituitary, indicating the existence of a third neurosecretory hypothalamo-hypophysial system, and in nerves in different layers of the wall of the small and large intestine. These nerves may possibly be of sensory nature since some cell bodies of the spinal ganglia showed a weak immunofluorescence. Somatostatin or SLI was found in certain cells localized in the periphery of the pancreatic islets. In parallel studies with glucagon antibodies it could be established that the somatostatin positive cells and the glucagon positive cells were not identical but localized extremely close to each other. Furthermore, with the Hellman-Hellerström silver staining technique it could be shown that virtually all somatostatin cells are argyrophilic and vice versa. Somatostatin positive cells thus constitute the socalled A1-cells (D-cells). Glucagon positive cells, on the other hand, do in all probability not exhibit argyrophilia. The occurrence of probable somatostatin containing cells in the pancreatic islets is of special interest in view of several recent studies demonstrating an inhibitory action of this peptide on glucagon and insulin secretion. Somatostatin or SLI was found in a rather small number of cells in the thyroid gland with a parafollicular position. These cells exhibited a positive immunofluorescence also after pretreatment of the antiserum with calcitonin. Furthermore, endocrine-like cells in the stomach and in the intestine were also somatostatin positive. A large number of cells in various tissues, especially in the lamina propria of the gastro-intestinal tract, showed a strong fluorescence both after incubation with control serum and with FITC conjugated serum alone. The present results indicate that somatostatin or a somatostatin-like peptide(s), in addition to its inhibitory action on growth hormone release, may play a physiological role at many other levels of the organism.

Animals↗