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Biomedical subjects

L Boquist

Publications and source records attributed to L Boquist.

At least 37 records · Page 2Linked to original sources
PubMed1979

Laryngeal chondrosarcoma in Sweden.

Between 1958 and 1972, 5 cases of posterior cricoid chondrosarcoma were reported to the Swedish Cancer Registry. These cases, and one recently observed case of laryngeal chondrosarcoma, are presented in this study of one female and five male patients. The tumours grow slowly and recur locally, but have not metastasized, and none of the patients has died from tumour disease. The clinical and morphological findings indicate that these tumours represent secondary chondrosarcomas developing from pre-existing benign ecchondromas. The reason for the uniformity as to localization is not known. The microscopic appearance varied in different parts of the same tumour. The presently obtained data and review of the literature indicate that laryngeal chondrosarcomas are extremely rare, locally invasive, but usually not metastasizing tumours. Conservative laryngeal operation is suggested as primary treatment. Total laryngectomy is necessary only after local recurrences involving a major portion of the cricoid cartilage.

Aged↗
PubMed1979

Transplantable osteosarcoma in mice. Structural characterization of a transplantable osteosarcoma obtained in an allogenic system.

Light microscopic, histochemical and ultrastructural studies of a transplantable mouse osteosarcoma were carried out. The osteosarcoma grew in CBA mice after injection of cultured cells derived from a Dunn osteosarcoma. The tumour differed from the original Dunn osteosarcoma with respect to metastatic potential and structural features. The transplantable tumour was an anaplastic, richly vascularized fibroblastic osteosarcoma with alkaline phosphatase activity and rather sparse osteoid formation, resulting in death of the animals within 6 to 8 weeks. Virus particles were found intracellularly, mainly localized to cisterns of rough endoplasmic reticulum, and extracellularly often close to plasma membranes and collagen fibres. Sign suggestive of formation of collagen fibres by tumour cells were observed. A possible viral influence upon the tumour was suggested also by its growth behaviour in vitro. The results indicate that this new transplantable tumour, obtained in an allogenic system, represents a clonal derivative of the original Dunn osteosarcoma.

Animals↗
PubMed1979

Mitochondrion-secretory granules complexes in pancreatic islet B-cells.

Mitochondrion-Secretory Granule Complexes (MSGC) are present in rodent pancreatic islet B-cells, characteristically showing fusion of mitochondria and secretory granules, absence of granule membrane and external mitochondrial membrane at place of contact, often invagination of internal mitochondrial membrane at place of contact forming an electron lucent space directly continuous with the "halo" of the secretory granules, and occurrence of potassium pyroantimonate precipitates in either or both of mitochondria and secretory granules. The MSGC are believed to possess functional significance, possibly playing a role in translocation of ions between mitochondria and secretory granules in the B-cells.

Animals↗
PubMed1979

Influence of 1,25-dihydroxycholecalciferol on parathyroid activity in patients with primary hyperparathyroidism.

Parathyroid morphology and blood chemistry were studied in five patients with primary hyperparathyroidism treated with 1,25-dihydroxycholecalciferol (1,25-DHCC) for 2 to 11 days before planned operation. Before the institution of treatment all patients were hypercalcemic, whereas the serum immunoreactive parathyroid hormone (iPTH) concentration either was elevated or normal. During the treatment the urinary phosphate excretion was significantly increased, whereas the calcium excretion and the serum concentrations of calcium and phosphate were unaffected or only slightly changed. Serum iPTH decreased during the first days of treatment, but returned then to increased levels close to the pretreatment ones. The treatment was tolerated well by the patients. Light and electron microscopy of the removed parathyroid glands disclosed one adenoma in each of the five patients, the other glands exhibiting either a slight hyperplasia or a normal appearance. Both the adenomatous and the non-adenomatous parathyroid tissue showed a predominance of dark chief cells and three of the adenomas exhibited a varying number of atrophic and oxyphil cells. The non-adenomatous glands were composed of atrophic and dark chief cells. Signs of low functional activity were ultrastructurally observed in the parathyroid parenchymal cells. It is suggested that 1,25-DHCC treatment of patients with primary hyperparathyroidism inhibits parathyroid hormone secretion.

Adult↗
PubMed1979

Structural changes in parathyroid glands exposed to vitamin D metabolites in vitro.

Isolated parathyroid glands from normal adult Mongolian gerbils were incubated for 10 minutes to 16 1/2 hours at high, medium or low concentrations of Ca2+, with or without added 1,25-dihydroxycholecalciferol (1.25-DHCC) or 25-hydroxycholecalciferol (25-HCC), after which they were studied electron microscopically. 1,25-DHCC appeared to potentiate the inhibitory action of high calcium on parathyroid activity, whereas 25-HCC had no structurally detectable effect.

Animals↗
PubMed1978

Effect of metabolic alkalosis on the B-cell sensitivity to alloxan in vivo.

Metabolic alkalosis was induced in starved mice by treatment with NaHCO3, which did not significantly alter the blood glucose concentration, but protected against the diabetogenic effect of subsequently given alloxan. This protection and the alkalosis had disappeared 4 hr after NaHCO3 treatment. Protection against alloxan, and metabolic alkalosis, were found also in starved mice pretreated with sodium lactate. The findings indicate that metabolic alkalosis, directly or indirectly, protects against alloxan toxicity in vivo.

Alkalosis↗
PubMed1978

Osteosarcoma. A multifactorial clinical and histopathological study with special regard to therapy and survival.

A multifactorial analysis was performed on all 153 unequivocal cases of genuine osteosarcoma recorded in the Swedish Cancer Registry for the years 1958 through 1968. Cases of so-called parosteal osteosarcoma, soft-tissue osteosarcoma and osteosarcoma secondary to Paget's disease of bone were not included. The osteosarcomas were subclassified as follows: osteoblastic (69 per cent), chondroblastic (19 per cent) and fibroblastic (12 per cent). The overall 5-year survival rate was 22 per cent; 55 per cent for those who had undergone amputation above the joint proximal to the involved skeletal part, 22 per cent for those amputated on the involved skeletal part, 11 per cent for those treated with local extirpation of the tumor, and 1 per cent in cases in which the lesion was not radically removed. Tumors of the femur, humerus and scapula were as malignant as axial tumors. The former carried a 5-year survival rate of 13 per cent, regardless of whether the patients had been treated with exarticulation or amputation on the involved skeletal part. Patients with axial tumors showed a 5-year survival rate of 15 per cent. These survival data suggest that proximal amputation alone might suffice for lesions situated distally to the knee and elbow joints, while tumors in the humerus and femur should be treated with amputation combined with multicytostatic treatment or immunotherapy and axial tumors with local resection and multicytostatic or immunologic treatment.

Adolescent↗
PubMed1978

Telangiectatic osteosarcoma.

Of the 242 cases of osteosarcoma recorded in the Swedish Cancer Registry for the years 1958 through 1968 only one was found to represent telangiectatic osteosarcoma. Another case was recently diagnosed in our department. The characteristic morphologic features of these neoplasms were anaplastic stroma, high mitotic activity, osteoid-formation, widely anastomosing blood spaces, and alkaline phosphatase activity. The experience gathered indicates that telangiectatic osteosarcoma constitutes a histopathologic variant of genuine osteosarcoma with a serious prognosis, necessitating the same kind of treatment as for the genuine tumour.

Adolescent↗
PubMed1978

Giant serpentine intracranial aneurysm after carotid ligation. Case report.

A case is reported of a giant aneursym of the intracavernous portion of the left internal carotid artery that was treated initially with a left common carotid artery ligation. Six months later the aneurysm was partially removed. During this time the development and evolution of thrombus formation, a serpentine channel, and a hypervascular capsule was easily followed with recreated computerized tomography and angiography of the aneurysm.

Adult↗
PubMed1978

Factors affecting the beta-cell sensitivity to alloxan in vivo. Influence of pre- and post-treatment with protective substances.

Blood glucose and pancreatic islet morphology were studied in mice subjected to different kinds of treatment both before and after alloxan administration. d-Glucose, d-mannose, d-fructose, NaHCO3 and sodium lactate protected against alloxan when given before, but not when given after alloxan, whereas l-leucine protected when administered before, and also when injected 1 or 3 min after alloxan. No protection was seen in animals receiving l-leucine 10 min following alloxan. The findings may indicate that the mechanism for alloxan protection by l-leucine differs from that of the other compounds tested.

Alloxan↗
PubMed1978

Pancreatic B-cell sensitivity to alloxan in vivo. A study of antagonizing compounds, serum inorganic phosphate and acid-base balance.

Serum glucose, inorganic phosphate, acid-base balance and islet morphology were studied in mice subjected to different kinds of treatment before alloxan administration. In preceding studies, pretreatment with D-glucose, D-mannose, D-fructose, sodium lactate and NaHCO3, but not with D-galactose, was found to protect against alloxan toxicity. In this study alloxan antagonism was found by pre-treatment with L-leucine, but not with L-arginine or NaH2PO4. Blood analyses, carried out 10 minutes after injection of the test compounds, disclosed that the serum inorganic phosphate concentration was decreased in mice given D-glucose, D-mannose, D-fructose, sodium lactate, NaHCO3, L-leucine, and L-arginine, but was not affected in those treated with D-galactose, and was increased in those receiving NaH2PO4. With the exception of L-arginine, blood pH was increased in the groups which exhibited decreased serum inorganic phosphate concentration; pH was not affected in mice treated with D-galactose, L-arginine and NaH2PO4. Alterations in inorganic phosphate and hydrogen ion concentration may affect the B-cell sensitivity to alloxan ("Pi-pH hypothesis").

Acid-Base Imbalance↗
PubMed1977

Pancreatic islets subjected to different concentrations of glucose in vitro. A study with special regard to mitochondrial changes.

Isolated pancreatic islets of mice and gerbils were cultured for 6 days at low (2mM) or high (20mM) concentrations of glucose after which they were studied using qualitative and quantitative electron microscopy, histo- and microchemistry, and X-ray microanalysis. Compared with the islets cultured at high glucose, those subjected to low glucose exhibited enhanced succinate dehydrogenase activity, a decreased content of adenosine triphosphate, and an increased volume of B-cell mitochondria which often were rounded or oval.

Adenosine Triphosphate↗
PubMed1977

Ultrastructural changes in the parathyroids of Mongolian gerbils induced experimentally in vitro. Effects of variations in Ca2+ and Mg2+ concentrations.

Isolated parathyroid glands from normal adult Mongolian gerbils were incubated for 15 minutes to 3 1/2 hours either at high or low concentrations of Ca2+ and Mg2+ after which they were studied ultrastructurally, using the pyroantimonate technique and x-ray analysis for identification and son concentrations were mainly composed of suppressed chief cells with moderate or high cytoplasmic density, sparsely developed endoplasmic reticulum, often large Golgi complex, occassional cytoplasmic accumulations of secretory granules, lipoid bodies, glycogen-like particles, and numerous often large mitochondria. Ca2+-containing precipitates were found mainly in mitochondria. Autophagic vacuoles contained Ca2+-loaded degenerating mitochondria. Glands exposed to low concentrations of Ca2+ and Mg2+ were mainly composed of stimulated and active chief cells; characteristic features were a moderate or low cytoplasmic density, prominent endoplasmic reticulum, small Golgi complex, medium-sized, or small mitochondria, and smooth electron lucent vacuoles with or without an association of mitochondria. Ca2+-containing precipitates were found mainly in smooth vacuoles and cytosol, but also in mitochondria and routh vacuoles. Myelin-like figures and crystalloid bodies occurred in some mitochondria, and normal or degenerating mitochondria withoug Ca2+-loading were seen in autophagic vacuoles. In addition, some stimulated chief cells exhibited double membrane-limited sequestered areas of cytoplasm with a rich content of free ribosomes and glycogen-like particles. The chief cell mitochondria seem to possess capacity for rapid accumulation of Ca2+, associated with an increase in volume at functional suppression. At stimulation of parathyroid function the endoplasmic reticulum is prominent in the active cells, and there seems to be a decrease in the volume and Ca2+-content of the mitochondria occasionally associated with degenerative changes, and a decrease also in the number of free ribosomes and glycogen-like particles in the stimulated cells.

Animals↗
PubMed1977

The effect of immunotherapy with BCG on the development of radiostrontium (90Sr)-induced osteosarcoma.

The development of radiostrontium-induced osteosarcoma was studied in BCG-treated and in untreated control mice. Within the observation period of 420 days after the administration of radiostrontium there was a total tumour-incidence of 89.5 and 90.5 per cent for the respective groups of animals. There was no statistically significant difference between the two groups, neither with regard to the time of the first roentgenographic appearance of the osteosarcoma, nor concerning the total tumour incidence , nor with regard to the distribution of the primary sites of the tumours. The tumours of the BCG-treated animals showed a clear tendency to a slower growth rate in comparison to that of the tumours in the control animals. This effect was probably immunological in nature. The mortality in osteosarcoma following radiostrontium administration, however, showed no significant difference between the two groups. Light microscopical and ultrastructural examination did not disclose any clear structural difference between the tumours from BCG-treated and untreated control animals.

Animals↗
PubMed1977

Effect of 1.25-dihydroxycholecalciferol administration on blood glucose and pancreatic islet morphology in mice.

1.25-dihydroxycholecalciferol (DHCC) administration to fed and starved mice had no effect on the blood-glucose concentration or the light-microscopic appearance of the endocrine or exocrine pancreas. Electron microscopy, however, disclosed changes which appeared early after the injection and were more marked in starved than in fed animals. The B-cells exhibited mitochondrial hypertrophy, studied both by qualitative and quantitative methods, invagination and vacuolation of mitochondrial membranes, increased occurrence of light secretory granules, multiple rough endoplasmic cisternae, multi-lamellar bodies, and a rather rich Ca2+-containing pyroantimonate precipitation mainly localized to nuclei and mitochondria. A tendency to mitochondrial hypertrophy was observed also in some D-cells. The A-cells were unaffected. The findings indicate that the endocrine pancreas (or at least the B-cells) is affected in some way, directly or indirectly, by DHCC.

Animals↗
PubMed1977

Effects of 1.25-dihydroxycholecalciferol, parathormone and Ca2+ on the pancreatic B-cell sensitivity to alloxan.

The sensitivity to alloxan was investigated by blood and urine glucose determination and light and electron microscopic study of the endocrine pancreas in groups of mice differing from each other with respect to food ingestion and treatment before alloxan administration. Because of differences in occurrence of glucosuria, degree and duration of hyperglycemia, and severity of structural lesions, it was concluded that starvation increases the alloxan sensitivity and that pre-treatment with 1.25-dihydroxycholecalciferol (DHCC) or parathormone (PTH), but not with Ca2+, enhances the alloxan effect. The serum-calcium concentration determined 10 minutes after pre-treatment was significantly increased in the group given Ca2+, but not in the groups injected with DHCC or PTH. Starved mice injected with DHCC or PTH 10 minutes before alloxan administration exhibited a pronounced second hyperglycemia of long duration, and extensive, selective B-cell necrosis. Starvation and increased serum concentration of DHCC and PTH are believed, directly or indirectly, to induce B-cell alterations which increase the alloxan sensitivity.

Alloxan↗
PubMed1977

Angiography in giant-cell tumours of bone.

The angiographic appearance of 9 cases of genuine giant-cell tumour of bone, 6 cases of aneurysmal bone cyst and one case of non-ossifying fibroma is described. Differential diagnosis would appear to be possible to a certain extent. The non-ossifying fibroma was poorly vascularized. The genuine giant-cell tumours were hypervascularized as well as some of the aneurysmal bone cysts making a differential diagnosis in these cases impossible. On the other hand, a poorly vascularized tumour devoid of soft tissue component and arteriovenous fistulas is probably an aneurysmal bone cyst. A hypervascular soft tissue component is of great prognostic value in cases of geniune giant-cell tumour.

Angiography↗