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Biomedical subjects

L Boquist

Publications and source records attributed to L Boquist.

At least 55 records · Page 3Linked to original sources
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↗
PubMed1977

The endocrine pancreas in early alloxan diabetes. Including study of the alloxan inhibitory effect of feeding and some hexoses.

Starved animals were sensitive to alloxan, whereas a more or less inhibitory effect towards alloxan was observed in fed animals, and in starved animals pretreated with glucose, mannose or fructose, but not in those pretreated with galactose. The islets of starved controls possessed larger B-cell mitochondria than those of fed ones. The earliest B-cell changes in the alloxan-treated animals were localized to the mitochondria which showed swelling, and disruption of inner and occasionally outer membranes. Later, many mitochondria were disintegrated, and the endoplasmic reticulum and Golgi complex disorganized. The secretory granules were preserved, although sometimes with atypical configuration, in degenerating but non-necrotic B-cells, suggesting that insulin stored in granules is not released until the cells are necrotic. Finally, frank necrosis was seen in some B-cells, whereas others were unaffected. The Ca2+-precipitation studied by pyroantimonate technique and x-ray analysis differed in the B-cells of the alloxan-treated animals from that in the controls; the former animals exhibited no or only sparse precipitation in mitochondria and secretory granules, but a rich precipitation in the cytoplasmic ground substance, whereas the precipitation in the controls mainly was localized to mitochondria and secretory granules. The primary site of alloxan action in the B-cells is believed to be localized to the mitochondria.

Animals↗
PubMed1977

Thyroid carcinoma in children.

A study was made of 24 children under 15 years with thyroid cancer diagnosed during the years 1959-1967. None of the children had received irradiation treatment prior to diagnosis. Treatment took the form of surgery in combination with hormone and/or irradiation therapy. Of the 24 patients, only one died as a result of postoperative complications, even though 17% had lung metastases and 58% lymph gland metastases. The children were observed on average seven years, 10 months and the longest period of observation was 12 years, six months. The treatment recommended is total lobectomy on the affected side and subtotal on the opposite side. Cervical lymph glands with metastases are extirpated. Thyroid hormone treatment should be given immediately after surgery.

Adenocarcinoma↗
PubMed1977

Low doses of 1,25-dihydroxycholecalciferol increase mature bone mass in adult normal rats.

Low doses of 1,25-DHCC cause a significant increase in trabecular and cortical bone mass of the mature rat skeleton by stimulated endosteal bone formation. The increased serum contents of calcium and inorganic phosphate give rise to a moderate nephrocalcinosis. An increased bone resorption occurs upon toxic dose levels causing profound nephrocalcinosis. Similar doses of 25-HCC do not affect the mature bone.

Animals↗
PubMed1976

Primary carcinoma of the appendix.

Primary adenocarcinoma of the appendix is rare and less than 200 cases are on record. The present material consisted of 20 cases collected from different hospitals. The cases are described in respect of sex and age-distribution, symptoms, treatment and prognosis. Of 7 patients with malignant mucocele, 6 subjected to appendectomy only, were still alive 5 years after the operation. Of 12 patients with colonic type of adenocarcinoma, 3 had been treated with appendectomy only. Of these, 2 were still alive 5 years after the operation. The remaining 9 patients had undergone right hemicolectomy. Only one of them was alive 5 years after the operation. A compilation of a further 39 cases garnered from the literature, however, showed that 60% had survived at least 5 years after right hemicolectomy, compared with 46% after appendectomy alone. Appendectomy alone is probably a sufficiently radical operation for malignant mucocele provided the tumor has not grown through the submucosa and that it is confined to the tip of the appendix. Right hemicolectomy is indicated for the colonic type of adenocarcinoma.

Adenocarcinoma↗
PubMed1976

Fibrosarcoma of bone. A demographic, clinical and histopathological study of all cases recorded in the Swedish cancer registry from 1958 to 1968.

The clinical records, radiographs and histopathological material of all forty-one patients recorded as suffering from fibrosarcoma of bone in the Swedish Cancer Registry for the years 1958 to 1968 have been analysed; in addition, four cases were found on histological review of a series of osteosarcomas. From this re-examination, twenty-four patients with genuine fibrosarcoma of bone were identified; twenty-two had primary neoplasms and two secondary. No sex or geographical differences were found. The tumours showed a prevalence for patients in the adult and older age groups. Half of the tumours arose from femoral or tibial metaphysial bone adjacent to a knee joint. All the tumours were of the medullary type. Almost one-third presented with a pathological fracture, and soft-tissue extension had occurred in all but three tumours. In contrast to previous reports, these tumours were more malignant than osteosarcomas and showed a five-year survival rate of only 4-2 per cent. In accessible sites, ablative surgery was used as the primary treatment, Fibrosarcoma of bone is a distinctive lesion and should be distinguished carefully from periosteal and soft-tissue fibrosarcomas because of differences in prognosis and treatment.

Biopsy, Needle↗
PubMed1976

Onto- and phylogenetical aspects on insulin-producing islet-cell tumors.

When onto- and phylogenetical aspects are taken into account when studying insulin-producing islet-cell tumors, it becomes clear that the recently discovered "type IV" islet parenchymal cells (or "delta 1" -cells) may play an important role in various states of hypoglycemia, both of neoplastic and non-neoplastic origin. Moreover, it becomes obvious that increased attention to this kind of islet cell through intensified light-microscopical, histochemical, ultrastructural and experimental investigations covering a wide range of animals, may help to clarify several unsolved problems in the cytological composition of the islets of Langerhans. The occurrence of islet-cell tumors (or hamartomas) in the most primitive vertebrate islet parenchyma known, viz. that of the hagfish, Myxine glutinosa, is reported, as well as an additional case of mixed carcinoid-islet-cell tumor in a human pancreas.

Adenoma, Islet Cell↗
PubMed1976

Genuine giant-cell tumour of bone; a combined cytological, histopathological and ultrastructural study.

Three patients with a giant-cell tumour of bone were studied clinically, roentgenologically and morphologically, using cytological, histopathological and electron microscopic methods. The tumours were composed of giant cells possessing a great number of mitochondria and stromal cells exhibiting prominent endoplasmic reticulum and Golgi complex. Mitotic activity was only found among the stromal cells. Autophagic vacuoles, lysosomal bodies and degenerative changes of varying severity were found mainly or exclusively among the giant cells, which may indicate that these cells represent an involutionary form of tumour cell. The giant-cell tumours of bone are believed to arise from undifferentiated cells of the bone marrow. Fine-needle aspiration biopsy represents a valuable complement to histopathological examination in the identification of giant cell lesions and diagnosis of genuine cell tumours of bone.

Adult↗
PubMed1976

The fine structure of the parathyroid glands of rats with disuse osteoporosis.

The parathyroid glands were studied ultrastructurally in two groups of rats: one control group and one group with an immobilized hindleg. The aim was to see whether immobilization has any effect on the fine structural appearance of the parathyroid glands. No morphological differences were recorded between the two groups. Nor were any signs of increased functional activity observed. The results denote that no increased parathyroid activity occurs after immobilization of an extremity in rats.

Animals↗
PubMed1975

Occurrence of oxyphil cells in suppressed parathyroid glands.

Parathyroid glands from Mongolian gerbils cultured for 7 days at a high calcium concentration and examined by electron microscopy, were found to contain suppressed chief cells containing numerous mitochondria, and some oxyphil cells containing an abundance of medium-sized or large mitochondria with calcium-containing precipitates. It is suggested that parathyroid chief cells may be transformed into oxyphil cells, under certain conditions, and that the associated increase in the number and size of the mitochondria may be related to an intracellular accumulation of calcium.

Animals↗
PubMed1975

Ultrastructural study of calcium-containing precipitation in human parathyroid glands.

Using the potassium pyroantimonate technique for ultrastructural localization of cations and X-ray elemental analysis with both energy dispersive and wave-length dispersive systems, calcium-containing precipitates were found in normal, hyperplastic and adenomatous human parathyroid glands. Differences were observed between oxyphil cells, and suppressed, stimulated and active chief cells in the content and localization of intracellular precipitation. The oxyphil cells and suppressed chief cells possessed precipitates mainly in nuclei and medium-sized and large mitochondria, whereas the stimulated chief cells possessed precipitates in normal-appearing and morphologically altered mitochondria, and in smooth-surfaced vacuoles and cytosol. The active chief cells usually showed a rather sparse precipitation.

Adenoma↗
PubMed1975

Annulate lamellae and crystalline inclusions in granular endoplasmic reticulum of the islet organ and associated tissues of a cyclostome, Myxine glutinosa.

Cytoplasmic annylate lamellae were found in the islet organ of a cyclostome, the hagfish (Myxine glutinosa), predominantly in cells interpreted as young proliferating beta-cells, and also in endocrine cells and enterocytes of the bile duct and gut and in the endothelial cells of small blood vessels. A close association was observed annulate lamellae and granular endoplasmic reticulum. Both in cells with and in those without annulate lamellae, crystalline inclusions of proteinaceous nature were seen in granular endoplasmic reticulum. These inclusions were occasionally closely associated to annulate lamellae, and a direct continuity could be seen between granular endoplasmic reticulum and the outer nuclear membrane surrounding an inclusion partially situated in the perinuclear cisterna. Rod-shaped structures and rounded electron dense bodies were seen in the nuclei of some islet parenchymal cells. The presence of annulate lamellae in the islet organ and associated tissues of Myxine glutinosa is believed to be related to the very high phylogenetic age of this species. The close association observed between annulate lamellae, granular endoplasmic reticulum, crystalline inclusions, and sometimes also nuclear membranes, may be of functional significance.

Animals↗
PubMed1975

Giant-cell tumors of the spine and sacrum causing neurological symptoms.

Pain and neurological disturbances were the most frequent symptoms in patients with giant-cell tumors of the spine (4 cases) and sacrum (1 case). A good prognosis is possible in patients with vertebral tumor localization. There were no recurrences at follow-up 6 to 16 years after the first admission. The patient with a sacral tumor is alive more than 15 years after the first admission with some remaining neurological symptoms. Early surgical and/or radiation therapy is important. If institution of treatment is delayed more than three months after the onset of nerve root symptoms, there is a great risk of development of irreversible neurological lesions.

Adolescent↗