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Biomedical subjects

B Magnusson

Publications and source records attributed to B Magnusson.

At least 19 recordsLinked to original sources
PubMed1992

Comparative in vitro study of a series of organic nitroesters: unique biphasic concentration-effect curves for glyceryl trinitrate in isolated bovine arterial smooth muscle and lack of stereoselectivity for some glyceryl trinitrate analogues.

Four different organic nitroesters, constituting a homologous series based on unbranched polyalcohols, were compared with regard to in vitro relaxation of isolated bovine mesenteric arteries contracted with 2.5 microM phenylephrine. The organic nitroesters included ethylene glycol dinitrate (EGDN), dinitratopropane (DPN), glyceryl trinitrate (GTN), and tetranitratobutane. Glyceryl trinitrate exhibited a biphasic concentration-effect relationship, with pD2 values of 11.5 +/- 0.5 and 7.2 +/- 0.2 for the high-pD2 and low-pD2 component of the relaxation curve, respectively. The high-pD2 and low-pD2 component contributed 28 and 72% of the maximal response, respectively. EGDN, DPN, and tetranitratobutane induced monophasic concentration-effect curves with pD2 values of 7.4 +/- 0.1, 7.8 +/- 0.2, and 6.9 +/- 0.6, respectively. Stereoisomeric forms of DPN and tetranitratobutane showed no difference with regard to relaxing potency in bovine mesenteric artery. GTN has a partly unique mechanism for vascular smooth muscle relaxation that distinguishes this compound from other related organic nitroesters.

Animals↗
PubMed1992

Secondary polycythaemia associated with nocturnal apnoea--a relationship not mediated by erythropoietin?

A polysomnographic study was undertaken in nine patients with unexplained polycythaemia and nine age- and sex-matched controls. Circulating plasma levels of immunoreactive erythropoietin (IrEPO) were analysed before and after sleep. Seven out of nine polycythaemia patients were found to have sleep-disordered breathing and fulfilled the criteria for the sleep apnoea syndrome. Erythrocyte volume fraction was by definition higher among polycythaemia patients, and showed a weak positive correlation with minimum oxygen saturation during sleep (P less than 0.05). However, plasma IrEPO did not differ between the two groups or between morning and evening samples within the respective groups. In a separate study, IrEPO was repeatedly analysed during sleep in a group of six patients with severe obstructive sleep apnoea and six matched controls. No correlation with severity of sleep-disordered breathing was found. None of these patients had polycythaemia, and there was no obvious diurnal variation in IrEPO levels. A nocturnal sleep study may be warranted in patients with unexplained polycythaemia. Obstructive sleep apnoea does not appear to be related to increased IrEPO levels, although polycythaemia has been reported as a relatively common finding in this disease.

Circadian Rhythm↗
PubMed1991

The effect of alpha-interferon on bone marrow megakaryocytes and platelet production rate in essential thrombocythemia.

In 10 patients with previously untreated essential thrombocythemia (ET), by using 111In-labeled platelets and megakaryocyte morphometry, the relation between platelet production rate and bone marrow megakaryocytes was evaluated before and during alpha-2b-interferon (IFN) therapy. A highly significant decrease in platelet count occurred during IFN therapy; the platelet counts, at baseline and after 2 and 6 months of IFN therapy, were 1,102 +/- 345 x 10(9)/L, 524 +/- 169 x 10(9)/L (P less than .0001), and 476 +/- 139 x 10(9)/L (P less than .0001), respectively. The decrement in platelet count was mainly a result of diminished platelet production rate, which at baseline and after 2 and 6 months of IFN therapy was 89 +/- 30 x 10(10) platelets/d, 53 +/- 18 x 10(10) platelets/d (P = .0033), and 45 +/- 20 x 10(10) platelets/d (P less than .0001), respectively. Also, a slight shortening of platelet mean life-span (MLS) was observed in response to IFN treatment; platelet MLS was 7.96 +/- 0.69 days at baseline and 6.68 +/- 1.30 days (P = .012) after 6 months of IFN therapy. IFN induced a significant decrease in bone marrow megakaryocyte volume; both megakaryocyte nuclear and cytoplasmatic volumes were affected. The mean megakaryocyte volume was 372 +/- 126 x 10(2) pL/microL at baseline and 278 +/- 147 x 10(2) pL/microL (P = .049) after 6 months of IFN therapy. However, the number of megakaryocytes did not show any significant change in response to IFN. It is concluded that alpha-IFN reduces platelet production rate and the peripheral platelet count in ET mainly through an anti-proliferative action on the megakaryocytes and to a considerably lesser degree by a shortening of platelet MLS.

Adult↗
PubMed1991

Prevalence of iron deficiency and iron overload in the adult Icelandic population.

The aim of this cross-sectional study was to estimate the prevalence of iron deficiency and overload in the adult population in Iceland, a developed Scandinavian country. The study population consisted of 4240 individuals aged 25-74 years randomly selected from the national roster. Basic hematological, S-iron, S-total iron binding capacity (TIBC), and S-ferritin measurements were obtained on 2588 individuals (61.0%). The results indicated unusually large iron stores in the adult Icelandic population and significantly larger iron stores in the rural compared to the urban population. Iron deficiency was rare except in urban premenopausal women, where 1 in 4 showed evidence of iron deficiency and 3.2% had iron deficiency anemia. Seven patients with hereditary hemochromatosis were identified from a subgroup of 1887 subjects, resulting in a prevalence of 0.37%. Two of the hereditary hemochromatosis patients had been gastrectomized. Measures to improve the iron balance in urban premenopausal women cannot therefore include increased iron fortification of food but must be more directed towards the target group.

Adult↗
PubMed1990

Initial treatment in multiple myeloma: no advantage of multidrug chemotherapy over melphalan-prednisone. The Myeloma Group of Western Sweden.

From October 1983 until December 1986, 164 patients with multiple myeloma stage II-III were included in a prospective randomized multi-centre study comparing melphalan-prednisone (MP) with multidrug chemotherapy (MDC). The patients comprised 77% of all newly diagnosed myeloma stage II-III cases reported from 18 hospitals covering the entire Health Care Region of Western Sweden (1.5 million inhabitants). Patients randomized to MP (29 stage II and 55 stage III patients) were given oral melphalan and prednisone every 6 weeks. For patients randomized to MDC, stage II patients (n = 25) were given VMCP every 4 weeks and stage III patients (n = 53) VBAP and VMCP alternately every 4 weeks. For stage II patients, the response rate for MP compared to VMCP was 69 versus 56% and the median survival 46 versus 33 months. For stage III the response rate for MP compared to VBAP/VMCP was 58 versus 57% and the median survival 26 versus 24 months. No statistically significant differences were seen. The time to response and remission duration were also similar in both treatment arms. The dose intensity index (cumulative given/planned dose of myelosuppressive drugs) was greater than or equal to 0.8 in 89% of the MP patients and 81% of the MDC patients. Patients with index values less than 0.8 had the same response rate as patients with index greater than or equal to 0.8. This study has not demonstrated any advantage of MDC over traditional MP in multiple myeloma stage II-III.

Adult↗
PubMed1988

Gastric cancer after gastrectomy.

Inhabitants of Iceland who had undergone gastric resection for non-malignant diseases between 1930 and 1974 were identified and followed up at the Icelandic Cancer Registry in order to evaluate the risk of gastric cancer subsequent to gastric resection. There were 1,214 males and 581 females, contributing 30,792 person/years. The results show an overall 1.16-fold, not significant, increase in the relative risk for gastric cancer. In the first 15 years after operation the risk was decreased, 0.49, 95% confidence interval (CI) 0.24-0.90, but from 15 years or more following operation, the risk was 2.17, 95% CI 1.46-3.10. We conclude that for these subjects the risk is not significantly increased. Patients surviving 15 years or more after operation have an increased risk (p less than 0.001), but they do not contribute substantially to the number of gastric cancer patients in Iceland.

Female↗
PubMed1988

Pneumococcal vaccination in splenectomized patients with hematological disorders.

Seventy splenectomized patients were vaccinated with Pneumovax, a pneumococcal polysaccharide vaccine. Twenty-four of the patients had a malignant and 30 a nonmalignant hematological disorder. The remaining 16 were patients with no known hematological disorder, seven with intra-abdominal carcinomas and nine with non-malignant reasons for splenectomy. About 90% of the patients with non-malignant hematological disorders responded to vaccination with a rise in antibody titres, which was significantly higher than in the other two groups studied. Malignant hematological disorders lowered the response rate to 61-67%. Patients with no known hematological disorder but with intra-abdominal carcinomas also responded less frequently, while those in this group with other surgical reasons for splenectomy had a response rate comparable to healthy individuals. No serious side-effects were reported and we therefore conclude that all splenectomized patients should be vaccinated with a pneumococcal vaccine. However, it must always be born in mind that one third of the patients with malignant disease did not respond to vaccination.

Adult↗
PubMed1988

Swedish women and new technology.

This paper provides information and analysis on the overall situation of women in Sweden with regard to computer based new technology. It is based on a survey of computer use in Sweden, carried out in June 1984 by Statistics Sweden. The aim of the study was to ascertain the knowledge base and experience with computers of the Swedish population. In order to study whether sex differences exist a special analysis of the data was carried out. Women are involved in new technology in Sweden to a very great extent, however, there is male dominance in both the initiation and development of the technology. This may be as much reflective of general male and female roles in the workplace as of the nature of new technology itself.

Career Mobility↗
PubMed1987

A histologic comparative study of the midpalatal suture and periodontal ligament tissue in the beagle dog.

The present investigation describes the morphological difference between the suture and the periodontal ligament in beagle dogs. Specimens from five beagle dogs, 2 yr old, containing the anterior portion of the maxilla were used. Following routine histologic preparations frontal sections were cut with the microtome. The sections were stained and studied in the light microscope. The fibers in the midpalatal suture seemed coarser and less organized than the fibers in the periodontal ligament tissue. The vessels in the suture had thicker walls than the vessels in the periodontal ligament. A probable reason for the morphological differences between the two tissues is discussed.

Animals↗
PubMed1986

Iron losses in sweat.

The losses of iron in whole body cell-free sweat were determined in eleven healthy men. A new experimental design was used with a very careful cleaning procedure of the skin and repeated consecutive sampling periods of sweat in a sauna. The purpose was to achieve a steady state of sweat iron losses with minimal influence from iron originating from desquamated cells and iron contaminating the skin. A steady state was reached in the third sauna period (second sweat sampling period). Iron loss was directly related to the volume of sweat lost and amounted to 22.5 micrograms iron/l sweat. The findings indicate that iron is a physiological constituent of sweat and derived not only from contamination. Present results imply that variations in the amount of sweat lost will have only a marginal effect on the variation in total body iron losses.

Adult↗
PubMed1986

Haematological findings in chronic alcoholics after heavy drinking with special reference to haemolysis.

Haematological abnormalities are frequently found in heavy-drinking chronic alcoholics, but anaemia is generally a rare complication. When present, haemolysis is considered to be one of the most common causes. However, little is known about mild haemolysis without anaemia. The present report on eighteen male chronic alcoholics with a recent heavy debauche but without signs of severe liver disease gave support for the occurrence of a reversible low-degree haemolysis without concomitant gross changes of the erythrocytes. Thus the bone marrow showed an increased erythropoiesis in the absence of iron deficiency and known blood losses. Further, increased reticulocyte counts and low levels of haemopexin were noted in the early abstinence. Finally, during the withdrawal phase haptoglobin and haemopexin increased concomitantly with diminishing values of unconjugated bilirubin. The most likely cause of the proposed diminished red cell survival before the withdrawal is supposed to be a reduced membrane stability.

Adult↗
PubMed1986

In vitro growth characteristics of human odontogenic keratocysts and dentigerous cysts.

Using an in vitro system, the growth characteristics and enzyme histochemical properties of 3 odontogenic keratocysts and 3 dentigerous cysts were studied. It was found that the epithelial cells of the keratocysts but not of the dentigerous cysts grew in vitro. Furthermore, the epithelial-like cells of the keratocysts showed the same activities of acid phosphatase and NADH-diaphorase in vitro as earlier described in vivo. These enzymatic activities were increased in epithelial-like cells close to proliferating fibroblast-like cells, indicating a close relationship between these two cell types. The results are discussed in the light of the known clinical behaviour of the keratocyst and certain conclusions are also drawn concerning the suggested neoplastic potential of the keratocyst.

Adult↗
PubMed1986

Disturbed expression of ribonucleotide reductase and cytokeratin polypeptides in focal epithelial hyperplasia. An immunohistochemical study using monoclonal antibodies.

Four cases of focal epithelial hyperplasia (FEH) were studied immunohistochemically, using monoclonal antibodies against the M1 subunit of ribonucleotide reductase and different cytokeratin polypeptides. The FEH lesions showed, compared to normal oral mucosa, extensive alterations in their staining patterns. This included ectopic suprabasal M1 staining and the novel expression of cytokeratin polypeptides differing from those previously reported for other HPV infections. The results are discussed in relation to the causative agent, human papillomavirus, and its expression in focal epithelial hyperplasia.

Epithelium↗
PubMed1986

Expression of Class II transplantation antigens by epithelial cells in oral candidosis, oral lichen planus and gingivitis.

Biopsies from normal oral mucosa and oral mucosa affected by candidosis, lichen planus or gingivitis were compared with respect to the expression of two Class II transplantation antigens, HLA-DR and HLA-DQ, by epithelial cells and the relationship of these antigens to the distribution and frequency of T-lymphocytes. Indirect immunohistochemistry with different mouse monoclonal antibodies was used on frozen and acetone-fixed sections. To evaluate the results, a score system based upon the expression of the Class II transplantation antigens by epithelial cells and the frequency of T-lymphocytes was used. In oral candidosis there was a marked expression of HLA-DR antigens throughout the epithelium. In addition, this type of epithelium was the only one that expressed HLA-DQ antigens. An intense intraepithelial infiltration of T-lymphocytes was observed. Oral lichen planus and gingivitis did, to a much lesser extent, cause the expression HLA-DR antigens by the epithelial cells. In both lesions, the number of T-lymphocytes within the epithelium did not exceed the number found in epithelium of normal mucosa. In these types of lesions, the subepithelial infiltrate varied in intensity but was mainly composed of T-lymphocytes reactive with anti-Leu 3a antibodies. The results of the present study imply that epithelial expression of the two different Class II antigens are related to the frequency of the T-lymphocytes and to the proximity of these cells to the epithelial cells.

Adult↗
PubMed1986

Multiple craniofacial surgical interventions during 25 years of follow-up in a case of giant fibrous dysplasia. Case report.

Fibrous dysplasia may affect the jaws as a monostotic lesion which most often ceases to be active at the end of normal bone growth. In some cases there is no stabilization on completion of normal skeletal growth. This may lead to severe malformation and functional disturbance to the face. In these cases, the patient must be followed regularly and resection of the deformed tissue must be performed repeatedly as the recurrences appear. Attention is also brought to the fact that fibrous dysplasia may be difficult to separate from chronic sclerosing osteomyelitis, a condition that should be treated differently.

Adult↗
PubMed1985

Karyotypic evolution in Ph-positive chronic myeloid leukemia in relation to management and disease progression.

In a prospective study of 32 patients with chronic myeloid leukemia the frequency of chromosome abnormalities in addition to the Philadelphia chromosome (Ph) increased when the disease progressed. Before metamorphosis, 10 patients (31%) had developed additional abnormalities. Such abnormalities were present in three of them at the time of diagnosis; in the other seven, they were detected late in the chronic phase. New clonal abnormalities heralded or accompanied a more malignant phase of the disorder, usually a blastic leukemia. During metamorphosis, 78% of the patients had additional abnormalities, which in 68% of these cases comprised at least one of +8, +22q- or i(17q). Clones with additional abnormalities disappeared in eight cases, either spontaneously or in association with cytostatic therapy during the chronic or blastic phase. Involvement of chromosome #8, usually in the form of a trisomy, was found in 7 of 12 patients treated with busulfan, but was not found in any of the 10 hydroxyurea-treated patients, of whom 8 were splenectomized early during the chronic phase. Cells from the spleen, obtained by fine needle aspiration or splenectomy were cytogenetically examined in 18 cases during the chronic phase, but abnormalities in addition to the Ph were noted in only one patient, who was examined in the late chronic phase. The same abnormalities were present in bone marrow cells of this patient.

Adult↗
PubMed1983

Enzyme histochemistry of malignant fibroblastic histiocytic tumors. A light and electron microscopic analysis.

The enzyme pattern of 13 cases of malignant fibrous histiocytoma (MFH) and 11 cases of myxofibrosarcoma (MFS), a malignant myxomatous soft tissue tumor of fibroblastic histiocytic origin, has been studied. 6 of the 13 MFHs were analyzed enzyme histochemically at the light microscopic level and 7 on the ultrastructural level; of the 11 MFSs 9 were analyzed enzyme histochemically at the light microscopic level and 2 on the ultrastructural level. Differences were observed in the subjectively estimated enzyme activity between low grade MFS and high grade MFS and MFH, and also between histiocyte-like and fibroblast-like tumor cells. Generally a strong reaction of oxidoreductase enzymes (NADH2-diaphorase, NADPH2-diaphorase, glucose-6-phosphate dehydrogenase) and hydrolytic enzymes (acid phosphatase and leucine aminopeptidase) was found in the high grade tumors and was usually higher in the histiocyte-like than in the fibroblast-like cells. Ultrastructurally acid phosphatase occurred predominantly in primary and secondary lysosomes and Golgi zones of the histiocyte-like cells. A strong reaction of alkaline phosphatase was found light microscopically in 2 of 5 MFHs and 5 of 9 MFSs. Ultrastructurally alkaline phosphatase was located along the cytoplasmic membrane of predominantly fibroblast-like cells in 3 of 7 MFHs and 1 of 2 MFSs. The results agree with the concept of two main cell types in MFH and MFS, fibroblasts and histiocytes.

Adult↗