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Biomedical subjects

O Johansson

Publications and source records attributed to O Johansson.

At least 109 records · Page 6Linked to original sources
PubMed1992

Oral prostaglandin E2 influences the enterochromaffin-like and somatostatin cell populations in the oxyntic mucosa of the rat.

Our aim was to study the effects of long-term oral administration of different doses of prostaglandin E2 (PGE2) and of a synthetic analogue on the endocrine cells and on selected epithelial cells of the rat oxyntic mucosa. The endocrine cells were visualized by immunohistochemical staining and by the Sevier-Munger method. Quantification of the mucosal cells was performed at a light-microscopic level using stereological methods. The highest dose of 15-R-15-methylprostaglandin E2 (MePGE2) increased the total volume of enterochromaffin-like (ECL) cell profiles whereas no changes were observed after treatment with PGE2. On the other hand, the total mucosal volume of chromogranin A-immunoreactive cells was significantly reduced by both doses of natural PGE2. The highest dose of PGE2 increased the total volume of somatostatin-immunoreactive cells. The serotonin-immunoreactive cells were very few and unaffected by treatments. E2 prostaglandins induced hyperplasia and hypertrophy of epithelial cells. A selective trophic action on the mucous but not on the parietal cells was observed. The area of the parietal cells was increased in rats treated with the analogue. The gastric acid content was increased in rats treated with the highest doses of E2 prostaglandins. The plasma level of somatostatin was significantly increased in rats given MePGE2 and the highest dose of PGE2. The cell population of chromogranin A-immunoreactive cells did not reach the levels of the NECL cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗
PubMed1992

Expression of growth-associated protein 43 and nerve growth factor receptor in human skin: a comparative immunohistochemical investigation.

The growth-associated protein 43 (GAP43) is a neuronal membrane protein involved in axonal growth and regeneration as well as in the modulation of synaptic plasticity. It is present in sensory and sympathetic neurons, where it is consistently associated with the expression of nerve growth factor receptor (NGFr). We investigated, by means of immunohistochemistry, the presence and distribution of the GAP43-immunoreactivity (IR) and of the NGFr-IR in the adult normal human skin from various body regions. In adjacent sections, a comparison with the distribution of the neuronal markers protein gene product 9.5 (PGP 9.5), substance P (SP), and calcitonin gene-related peptide (CGRP) was performed. Our results indicate that in adult human skin 1) a GAP43-IR is morphologically present in epidermal and dermal nerve fibers; 2) a NGFr-IR is associated with neuronal as well as non-neuronal elements of cutaneous nerves; 3) the basal epidermal cell layer expresses a NGFr-IR, which is unevenly distributed according to the different body areas; and 4) there is suggestive evidence for a simultaneous expression of GAP43-, NGFr-, PGP 9.5-, SP-, and CGRP-IR in at least part of the cutaneous nerve fibers. The presence of GAP43-immunoreactive nerve fibers might be a marker of a continuous synaptic remodeling in adult skin, whereas the distribution of the NGFr-IR could be relevant for our understanding of the maintenance of the neuronal-target relationship(s).

Adult↗
PubMed1992

Dimensions of capsular collagen fibrils: image analysis of rapid compared with slow tissue expansion for breast reconstruction.

Thirty women who were to undergo breast reconstruction by tissue expansion were randomly divided into two groups. Those in the first group were to undergo expansion once a day (rapid expansion) and the second group once a week (slow expansion). When the expanders were replaced by permanent prostheses, biopsy specimens were taken from the capsules around the expanders, and were examined by transmission electron microscopy at a magnification x 22,000. The diameters of the collagen fibrils in the capsules were analysed by an interactive image analysis system and measured. An analysis of variance was performed on a test series to optimize the sample. Ninety fibrils from each patient (two patients were excluded), were analysed and there were no significant differences in collagen fibrillar diameters (about 50 nm) between those who had undergone rapid or slow expansion, or between patients who had also undergone radiotherapy to the chest wall and those who had not. These results indicate that the collagen fibrils may still be in a transitional stage, and that further longer term studies are desirable. It is difficult, however, to see how they could be justified ethically in patients who are otherwise well.

Adult↗
PubMed1991

Immunohistochemical localization of porcine diazepam-binding inhibitor (DBI) to rat endocrine pancreas.

The occurrence of diazepam-binding inhibitor (DBI), isolated and characterized from porcine upper intestine, was examined in the pancreas of Sprague-Dawley albino rats using indirect immunofluorescence. The polypeptide was found in the endocrine Langerhans islets and, utilizing double-labelling controls, it was shown to be present within the peripherally located glucagon-containing cells. Regulation of islet hormone production may therefore be under DBI control.

Animals↗
PubMed1991

Altered cutaneous innervation in psoriatic skin as revealed by PGP 9.5 immunohistochemistry.

There is conflicting evidence in the literature as to whether cutaneous nerves are altered in psoriasis or not. In this study, antibodies to protein gene product (PGP) 9.5 were used to visualize cutaneous nerves in biopsies from involved and uninvolved skin of nine patients with psoriasis and from normal skin of eight healthy controls. A profound reduction in the epidermal nerve fibre density was observed in the involved psoriatic skin. These intraepidermal nerve fibres were also mostly short and found in the basal layer. Only a few nerve fibres were found in the suprabasal layer and they were non-varicose, long fibres going straight up without branching. In the uninvolved skin of psoriatic patients, the distribution and number of the intraepidermal nerve fibres was similar to that observed in normal skin. In the dermis, the distribution and the number of the nerve fibres showed no differences between involved psoriatic skin, uninvolved psoriatic skin, and normal skin. The results support previous studies in which alterations of cutaneous nerves in psoriasis have been described.

Adult↗
PubMed1991

Morphometric evaluation of collagen fibril dimensions in expanded human breast skin.

A great innovation in plastic surgery in recent years has been skin expansion, which has provided the discipline with new possibilities for skin reconstruction. At present, little is known about the biology of skin expansion although it is clear that cell proliferation occurs both in the epidermis and the dermis. During previous morphological investigations of skin under expansion we recorded a number of signs comparable with those seen in wound healing. In the present study, the collagen fibril diameter of of skin before and under expansion has been recorded using an IBAS computer-based morphometric system. Preferentially, we have studied the papillary dermis where the most conspicuous morphological events occur.

Adult↗
PubMed1991

Diazepam binding inhibitor and the endocrine pancreas.

Regulation of blood glucose homeostasis is complex. Its major hormonal regulators include insulin, glucagon and somatostatin from the endocrine pancreas. Secretion of these hormones is controlled predominantly by the supply of nutrients in the circulation but also by nerve signals and other peptides. Thus, it is likely that peptides, released from cells of the gut or endocrine pancreas or from peptidergic nerves, affect glucose homeostasis by modulating the secretion of insulin, glucagon and somatostatin. When searching for novel gut peptides with such effects, diazepam binding inhibitor (DBI) was isolated from the porcine small intestine. By immunocytochemistry, DBI has been demonstrated to occur not only in the gut but also in endocrine cells of the pancreatic islets, namely in the somatostatin-producing D-cells in pig and man, and in the glucagon-producing A-cells in rat. Porcine DBI (pDBI; 10(-8)-10(-7) M) has been shown to suppress glucose-stimulated release of insulin from both isolated islets and perfused pancreas of the rat. Furthermore, secretion of insulin stimulated by either the sulfonylurea glibenclamide or the phosphodiesterase inhibitor 3-isobutyl-1-methylxanthine (IBMX), was inhibited by the peptide. In contrast, arginine-induced release of insulin was unaffected by pDBI. Moreover, pDBI decreased arginine-induced release of glucagon from the perfused rat pancreas, whereas release of somatostatin was unchanged. Notably, rat DBI, structurally identical with rat acyl-CoA-binding protein, has also been demonstrated to inhibit glucose-stimulated release of insulin in the rat, both in vivo and in vitro. Long-term exposure of cultured fetal rat islets to pDBI (10(-8) M) significantly decreased the synthesis of DNA in islet cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Evidence for gamma-melanocyte stimulating hormone containing nerves and neutrophilic granulocytes in the human skin by indirect immunofluorescence.

gamma-melanocyte stimulating hormone (gamma-MSH)-like immunoreactivity has been found by indirect immunofluorescence in nerve fibers and terminals as well as in neutrophilic granulocytes of normal human skin. A preferential localization to sensory nerves was seen; abundant nerve fibers displaying gamma-MSH immunoreactivity were observed as free nerve endings in the basal layer of the epidermis and in the upper dermis, close to the Merkel cells, in Meissner's corpuscles, around the external root sheath of the lower part of the hair follicles, and in nerve bundles of the deeper parts of the dermis. Very few fibers were seen to be associated with sweat glands and most blood vessels, although arterioles were densely innervated. Thus, gamma-MSH should be considered for possible role as a sensory or axon-reflex chemical messenger. Furthermore, the presence of gamma-MSH in neutrophilic granulocytes raises the possibility that gamma-MSH may play a role in the genesis of post-inflammatory hyperpigmentation, nevi, and melanomas.

Adult↗
PubMed1991

Langerhans' cell histiocytosis in an adult.

A woman with typical skin lesions of histiocytosis X is reported. Electron microscopic and immunohistochemical investigations revealed a large number of markedly long Birbeck Langerhans' cell granulae. During treatment with Interferon alpha -2b, the patient developed infarctus cerebri and died.

Adult↗
PubMed1991

Peptide T a new treatment for psoriasis? A study of nine patients.

Nine patients with recalcitrant and long-standing psoriasis were treated over a period of 28 days with 2 mg Peptide T iv, once daily (22-34 micrograms/kg bodyweight). Eight of them showed an improvement of less than 50% by day 28 and one deteriorated. The patients were evaluated for a further 3 months when no topical or systemic treatment was given. Five patients recovered by more than 50%, during the months following termination of the therapy. Two patterns of healing were noted: firstly, a steady clearance beginning immediately with the Peptide T infusions; secondly, a clearance pattern preceded by deterioration. No serious side effects were noted.

Adult↗
PubMed1990

Increased 5-hydroxytryptamine immunoreactivity in traumatized spinal cord. An experimental study in the rat.

The possibility that serotonin (5-hydroxytryptamine, 5-HT) is involved in the early tissue reactions occurring in spinal cord trauma was examined in a rat model using an immunocytochemical technique. The injury was made in the form of a 5-mm long and 2.5-mm wide lesion of the right dorsal horn at the level of T10-11. Injured rats, pretreated with the 5-HT synthesis blocking agent, p-chlorophenyl alanine (p-CPA) were compared with untreated injured controls and the animals were allowed to survive for 5 h. The distribution of 5-HT was examined in proximal and distal cross- sections of the cord, located 2 and 5 mm away from the injury. Normal rats showed immunoreactive material in nerve cell processes and in a few nerve cell bodies of the ventral horns. The trauma to the spinal cord caused a marked increase in 5-HT immunoreactivity in the segments located 2 mm proximal and distal to the injury, particularly in the ipsilateral ventral horn. The segment located 5 mm distal to the lesion showed a similar increase in immunoreactivity but it was apparently less pronounced in the corresponding proximal segment. Treatment with p-CPA markedly reduced the trauma-induced increase in 5-HT immunoreactivity in all the segments. These immunohistochemical findings were in line with the changes in the contents of 5-HT measured biochemically in corresponding spinal cord segments. At the onset of the trauma to the spinal cord 5-HT is thus present in the tissue, mainly in the form of 5-HT-containing nerve cell processes.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

Protein gene product 9.5-immunoreactive nerve fibres and cells in human skin.

Sections of human skin were processed according to the indirect immunofluorescence technique with a rabbit antiserum against human protein gene product 9.5 (PGP 9.5). Immunoreactivity was detected in intraepidermal and dermal nerve fibres and cells. The intraepidermal nerves were varicose or smooth with different diameters, running as single processes or branched, straight or bent, projecting in various directions and terminating in the stratum basale, spinosum or granulosum. The density of the intraepidermal nerves varied between the different skin areas investigated. PGP 9.5-containing axons of the lower dermis were found in large bundles. They separated into smaller axon bundles within the upper dermis, entering this portion of the skin perpendicular to the surface. Then they branched into fibres mainly arranged parallel to the epidermal-dermal junctional zone. However, the fibres en route to the epidermis traversed the upper dermis more or less perpendicularly. Furthermore, immunoreactive dermal nerve fibres were found in the Meissner corpuscles, the arrector pili muscles, hair follicles, around the eccrine and apocrine sweat glands and around certain blood vessels. Such fibres were also observed around most subcutaneous blood vessels, sometimes heavily innervating these structures. Numerous weakly-to-strongly PGP 9.5-immunoreactive cells were found both in the epidermis and in the dermis.

Fluorescent Antibody Technique↗
PubMed1990

Paraganglionic cell response to chronic imipramine and handling stress: an ultrastructural study.

The ultrastructure and connectivity of monoamine-storing paraganglionic cells in the rat superior cervical ganglion were investigated following chronic treatment with imipramine (Tofranil, Ciba-Geigy) and compared with uninjected unhandled controls and saline injected animals. The study reveals a significant decrease in the number of dense core vesicles in the drug-treated group (P less than 0.001) which is regarded as a specific effect due to receptor blocking actions of imipramine. A significant reduction in the maximum diameter of the external rim and internal cores of the vesicles (P less than 0.05) in the drug-treated group is mimicked to a certain extent by saline injections, indicating a mixed effect of stress handling and specific alteration. Although the paraganglionic cell morphology is unaltered in the group comparisons, the interrelationship of the paraganglionic cells to surrounding neural processes is significantly altered in both the control versus saline and the control versus drug group comparisons (P less than 0.05). The drug- and saline-induced alterations of neural connectivity may reflect stress-induced general changes demonstrating the plasticity of the paraganglionic cell population.

Animals↗
PubMed1990

The specificity and cellular origin of phenylethanolamine N-methyltransferase (PNMT)-like immunoreactivity in psoriatic skin.

Phenylethanolamine N-methyltransferase (PNMT)-like immunoreactivity has been found in psoriatic skin and in this study, PNMT-like immunoreactivity was investigated in the involved and uninvolved skin of six patients with lichen planus and four patients with lichen simplex. No PNMT immunoreactivity was observed in these diseases. Studies were carried out using cultured fibroblasts from two patients with psoriasis from uninvolved and involved areas of skin and from two controls using antibodies to PNMT, as well as antibodies to the chemical messengers somatostatin, substance P, parathyroid hormone and peptide histidine isoleucine amide. No immunoreactivity to these substances was found, and fibroblasts are unlikely to be the cellular origin of the PNMT-like immunoreactivity as seen in psoriatic skin.

Adolescent↗
PubMed1990

Inflammatory system activation during cardiopulmonary bypass as an indicator of biocompatibility: a randomized comparison of bubble and membrane oxygenators.

As the exposure of blood to foreign material during cardiopulmonary bypass (CPB) leads to triggering of inflammatory systems, the inflammatory response was used as an indicator of the biocompatibility of oxygenators. Activation of complement and neutrophil granulocytes during CPB was studied in 96 patients undergoing coronary bypass, with randomized comparisons between four different oxygenators, two of bubble and two of membrane type. Seven patients undergoing thoracotomy without CPB served as controls. During CPB there was significant complement activation, measured as changes in the ratio C3d/C3, with no demonstrable difference between the bubble and membrane oxygenator groups. Such change was not seen in the controls. Neutrophil granulocytes released significant amounts of the granule proteins lactoferrin and myeloperoxidase during CPB, but not during thoracotomy without CPB. The plasma concentrations of lactoferrin and myeloperoxidase were significantly lower in the membrane oxygenator groups, possibly indicating better biocompatibility. The strong inflammatory response with both oxygenator types, however, indicates that presently used CPB devices have unsatisfactory biocompatibility.

Adult↗