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Biomedical subjects

T Hovig

Publications and source records attributed to T Hovig.

At least 73 records · Page 4Linked to original sources
PubMed1984

Phagocytosis of non-opsonized Escherichia coli by mouse peritoneal macrophages. An electron microscopic study.

Phagocytosis of non-opsonized Escherichia coli by mouse peritoneal macrophages (MPM) was studied by means of light microscopy, scanning electron microscopy and transmission electron microscopy. During a phagocytosis period of 90 min the surface morphology changed. Early in the phagocytosis period the MPM were polar with many ridges and villi, and little ruffling. At the end of the period the cells appeared well spread with a smooth surface and extensive ruffling. Two modes for ingestion of bacteria seemed to exist. The bacteria were ingested either by membrane folds rising from the macrophage surface, fitting tightly to the bacteria or by bacteria sinking into the cytoplasm of the MPM. Early in the period of phagocytosis most bacteria were attached to the surface. Ten per cent of the bacteria attached were never ingested. Bacteria ingested were located in phagolysosomes that were either of a tight or a loose type. After a phagocytosis period of 90 min the phagolysosomes contained bacteria at different stages of degradation. During the degradation the bacteria showed several morphological changes including a decrease in the density of the endoplasm, detachment of the bacterial membrane from the cell wall and deformities in the bacterial cell wall.

Animals↗
PubMed1982

Pacing induced angina and platelet reactivity.

Platelet function was studied during pacing-induced angina pectoris in nine patients with coronary heart disease. Blood was sampled via catheters from the coronary sinus and the aorta at rest and during angina. The influence of the sampling procedures on the platelet function was evaluated in blood collected via catheters and via short venflons. The catheter induced pseudopod formation in the platelets. The aggregation response was similar, while platelet retention as measured with Hellem's method for native blood, was slightly lower in blood collected via catheters than via venflons. At rest the maximal rate of primary, ADP-induced aggregation was lower in blood from the coronary sinus than from the aorta, as was the percentage of platelets retained in glass bead columns. The ability of platelets to produce prostaglandin metabolites, estimated from malondialdehyde formation after thrombin stimulation was also moderately, but significantly lower in coronary sinus blood. During pacing-induced angina primary, ADP-induced aggregation and platelet retention values remained significantly lower in blood that had passed the coronary circulation than the aortic blood. There were no differences between aortic or coronary sinus samples collected at rest than during pacing. Unchanged platelet counts indicates that trapping of platelets did not occur. Thus, platelet reactivity was lower in coronary sinus than aortic blood at rest in patients with coronary heart disease, and a moderate pacing-induced angina did not influence this pattern.

Adenosine Diphosphate↗
PubMed1981

Characterization of a human epithelial cell line with special reference to its ultrastructure.

A commercially available cell line (NCTC 2544) originating from presumably normal human skin was chosen as an in vitro model system for subsequent studies of the effects of different agents on human epithelial cells. The cell line, therefore, was ultrastructurally and otherwise characterized at intervals by techniques which allow standardized controls of the model. The cell line was classified as epithelial both by phase contrast microscopy and transmission electron microscopy. The cells were polygonal, fully developed desmosomes were demonstrated and no extracellular filamentous material was observed. Specific epidermal markers like keratohyalin granules or keratinosomes were not demonstrated. Comparison of the nuclear morphology of cells from 1, 3 and 6 days old cultures revealed that only minor changes took place. The same was true for cytoplasmic features. Thus this cell line has a well-defined ultrastructural morphology. Flow cytometry studies showed the cell line to be tetraploid, with no sub-populations with other ploidies. Surface antigens were typed by a microcytotoxicity assay using 12 different antisera. The electrophoretic patterns of the isoenzymes lactate dehydrogenase and glutathione reductase were human. The cells did not form colonies in soft agar. Though several parameters indicate that this cell line is not a HeLa cell contaminant, this possibility cannot, however, be totally excluded.

Antigens, Surface↗
PubMed1981

Ultrastructural studies on the effect of photoactivated 8-methoxy psoralen. Nuclear changes in a human epithelial cell line.

An established human epithelial cell line was exposed to photoactivated 8-methyoxy psoralen (PUVA); the cells were fixed and processed for electron microscopy 2 hours, 3 days and 6 days thereafter, and the nuclear morphology compared to controls. In the light microscope the cells fixed 3 and 6 days after PUVA exposure showed an increase in the number of multinucleated cells. At the ultrastructural level an increased number of cells with nuclear indentations, cytoplasmic invaginations, pseudoinclusions, nuclear bodies and multiple nucleoli were seen. An increased number of perichromatin granules per cell section and a decrease in heterochromatin situated marginally were observed. In cells from 6 day-old cultures 15 out of 50 nuclei were seen divided into 3-12 nuclear elements, compared with none in the controls. The smaller of these elements tended to be heterochromatic and the larger euchromatic. Generally the nuclear elements were smooth in outline, but elements of bizarre shape were also seen. These consisted of nuclear fragments united by heterochromatic extensions of uniform diameter. When comparing the morphology of PUVA exposed cells with the morphology of non-malignant and malignant cell lines, the PUVA exposed cells appeared to show an increase in morphological markers corresponding to those determined in malignant cells. The possibility that PUVA therapy may cause cancerous transformation is discussed.

Cell Line↗
PubMed1981

Argyria-tissue deposition of silver as selenide.

Generalized argyria was precipitated in a patient by treating gingival erosions with a solution of silver nitrate for several months. High silver concentrations were measured in skin biopsies. treatment with penicillamine did not increase the urinary silver excretion, indicating that silver is deposited in tissues in a chemically stable and apparently inert form. Electron microscopy showed that in the kidney, silver was deposited mainly in the basal membranes as electron-dense particles. These particles were studied by using X-ray emission spectrometry and electron diffraction. the particles consisted of Ag2Se in the low temperature orthorhombic alfaform. The lattice parameters are: a = 0.433 nm, b = 0.693 nm and c = 0.784 nm. This selenide complex seems to be remarkably non-toxic, since the renal function of the patient was unaffected and only negligible reactive changes were observed in kidney biopsies.

Argyria↗
PubMed1981

Familial lecithin:cholesterol acyltransferase deficiency. Report of a fourth family from northwestern Norway.

The tenth Norwegian patient with familial LCAT deficiency is reported. Her family lives in the same area as the three previously reported Norwegian families. The patient is a 26-year-old female with typical findings of the disease--proteinuria and corneal opacities. Total cholesterol was normal, but the main part was present in the free form. Triglycerides were slightly elevated. Kidney function was normal. A large molecular weight fraction of LDL was present in plasma.

Adult↗
PubMed1979

An atypical manifestation of multiple myeloma in a 24-year-old male.

A structurally unusual, B-cell-derived malignant tumour is reported in a 24-year-old male. The gross autopsy findings were those of classical myelomatosis, with extensive and centrally located skeletal infiltrates and typical myeloma kidneys. The tumour cells were, however, morphologically very unusual. All elements were markedly pyroninophilic, indicating active protein synthesis, but typical plasma cell characteristics were lacking. The cells were ultrastructurally characterized by large and distended vacuoles, often with ribosomal granules attached, and containing an amorphous material. Virtually all tumour elements were found to be heavily loaded with IgG(kappa) in immunofluorescence studies. IgG paraprotein was also found in serum, and kappa light chains in the urine. It is concluded that the tumour represents an intermediate form between multiple myeloma and a tumour originating from the large pyroninophilic, immunoglobulin-secreting lymphocytes.

Adult↗
PubMed1979

Familial cardiomyopathy. Autosomally, dominantly inherited congestive cardiomyopathy with two cases of septal hypertrophy in one family.

A family with inherited congestive cardiomyopathy is presented. The diagnosis is based on clinical, morphological and laboratory evaluations. The first observed sign of the disease is arrhythmia and/or conduction defects. The onset of symptoms of pump failure is in adult life, and affected persons die within several years. Three persons have died suddenly. Septal hypertrophy was present in two affected persons. The mode of transmission is probably autosomal dominant. The recognition of arrhythmia as an early sign of the disease offers the opportunity of an early diagnosis.

Adult↗
PubMed1979

Characterization of peripheral blood, spleen and bone marrow cells from a patient with hairy cell leukaemia.

The peripheral blood cells, spleen cells and bone marrow cells from a patient with hairy cell leukaemia were studied by means of several immunological methods and by phase contrast and electron microscopy. Both by light and electron microscopy the cells had the morphology of hairy cells. 60 % of all the peripheral blood cells, and 80 % of the spleen cells had membrane-bound IgGk immunoglobulin. 60 % of the peripheral blood lymphocytes and 90 % of the spleen cells were positive for Ia-antigens, and 80 % of the peripheral blood, and 70 % of the spleen cells had receptors for complement factor C3. The percentages of cells with receptor for the Fc part of IgC and receptors for sheep red blood cells (SRBC) were low both in peripheral blood and in spleen. Reduced numbers of peroxidase positive cells and cytotoxic plaque-forming cells were also observed as well as reduced lymphocyte responses after stimulation of peripheral blood lymphocytes with PHA, PWM, ConA, PPD and allogeneic cells. A normal antibody-dependent cell cytotoxicity (ADCC) and PHA-induced cytotoxicity was observed for the peripheral blood lymphocytes of the patients. Our results suggest that the hairy cells in our patient are derived from B lymphocytes and have a monoclonal origin.

Aged↗
PubMed1978

Carnitine-induced uptake of L-cartinine into cells from an established cell line from human heart (CCL 27).

L-Carnitine is actively transported into Girardi human heart cells, an established cell line from human heart. The present study was undertaken to investigate the effect of different concentrations of L-Carnitine in the growth medium on the rate of uptake of L-[3H] carnitine. Increasing the concentration of L-Carnitine from 2 to 100 mumol/l in the growth medium of cells, increased the rate of uptake of L-[3H] carnitine by about 50%. The maximal effect was reached after approx. 72 h incubation. The increase in rate seemed to be caused by synthesis of increased number of carriers, as judged by the increase of V with unchanged apparent Km for the transport process. This effect of L-carnitine could be inhibited by cycloheximide, indicating the dependence on intact protein synthesis. The morphology of the cells was studied by electron microscopy. No myofilaments were found, thus the cells are dedifferentiated and no longer typical muscular cells.

Biological Transport, Active↗
PubMed1978

In vitro interaction between cultured cells and human blood platelets.

The effects of washed human cultured cells (tumour cells and Chang liver cells) on human blood platelets in heparinized plasma were studied. Platelet aggregation was induced by suspensions of the tumour cells. Ultrastructural examination showed that the platelets, especially in the central regions of the aggregates, were tightly packed and the alpha-granules were mostly present. In the periphery of the aggregates the platelets appeared swollen and devoid of organelles, and fibrin strands were seen. The platelet aggregation was not completely abolished by incubation with apyrase. The washing fluids from the tumour cells also induced platelet aggregation, but the aggregation could be abolished by incubation with apyrase. When three different lines of the Chang cells were used, suspensions of two lines of these cells induced platelet aggregation, but the third line did not. Presence of ADP could be demonstrated in the washing fluids from the cultured cells, except for the one line of Chang cells which did not induce platelet aggregation. The experiments indicated that the platelet aggregation induced by the various types of cells was mediated via ADP, but with a possible additional effect of coagulation activity.

Adenosine Diphosphate↗
PubMed1978

Transient intestinal lymphangiectasia.

Intestinal lymphangiectasia may be more protean in clinical manifestations and less rare than earlier suspected. A recent report points out that there are two types of the disorder, one congenital and the other acquired and transitory. A case is reported which fulfills the current clinical, laboratory, radiological and histological criteria for the diagnosis of the disease, and represents the first report in Scandinavia of transient intestinal lymphangiectasis with rapid and complete recovery within a few months after initiation of MCT diet.

Child↗
PubMed1978

Pseudo-exfoliation fibrils examined by negative staining.

Pseudo-exfoliation (PE) material, collected from lenses extracted because of cataract, has been examined by negative staining. The material was fragmented by ultrasound into single fibrils and small collections of fibrils. The fibrils were composed of a small number of filamentous subunits associated with or surrounded by a fuzzy material which had side excrescences at regular intervals of 50--55 nm or 25--30 nm. The side excrescences correspond to the cross-bands of the PE fibrils. It is proposed that the PE fibrils are composed of a few subunits of a fibrillar protein, which form a core to which glycosaminoglycan side chains are attached. The visible periodicity of the PE fibrils, appearing as cross-bands, is thought to be caused by clusters of glycosaminoglycan distributed at regular intervals along the fibrils.

Cytoskeleton↗
PubMed1978

"Non-secretory" plasma cell dyscrasia with normal serum immunoglobulins.

A well documented case of non-secretory myelomatosis with extensive skeletal lesions has been studied by immunohistologic techniques, electron microscopy, various electrophoretic procedures and different studies of serum and urine. In addition, the various lymphocyte populations have been studied by immunofluorescent techniques, rosette formation and stimulation with PHA and PWM mitogens. The ultrastructural studies revealed a well preserved structure of most of the plasma cells, often with a prominent nucleolus. The Golgi apparatus (GOL) was often large and in some cells there appeared to be a striking development of non-granular (smooth) endoplasmic reticulum in association with the GOL. Various non-crystalline inclusions were seen outside the cisternae of the endoplasmic reticulum. The cells contained large amounts of immunoglobulins of the IgG (kappa) class. No paraprotein was present in serum. Normal amounts of serum immunoglobulins were detected. No abnormalities could be demonstrated in the B or T cell system. It is concluded that the defect must be localized to the plasma cells themselves and not to the precursor cells of the B system.

Aged↗