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Biomedical subjects

J F Loutit

Publications and source records attributed to J F Loutit.

At least 55 records · Page 3Linked to original sources
PubMed1976

Osteopetrosis of microphthalmic mice -- a defect of the hematopoietic stem cell.?

The recessive genes mi and gl in the homozygous state determine, among other phenotypic effects, osteopetrosis in the house mouse. From a stock carrying mi derived from Grüneberg (1963) the mi gene was bred into the standard CBA/H inbred strain. Microphthalmic mice of these two stocks and their hybrids were treated as newborn by intraperitoneal injection and at weaning or maturity by intravenous injection of cell suspensions containing hematopoietic stem cells from phenotypically normal mice. Resolution of much of the osteopetrosis but not the other phenotypic effects occurred within a few months in the majority of cases, provided syngeneic or H-2 compatible allogeneic cells were given: it did not occur spontaneously or on giving H-2 incompatible cells or on giving compatible material by an inappropriate route. The results accord with hypotheses that (1) osteoclasis of scaffoldtype woven bone is impaired in mi mi, (2) that osteoclastic cells are derived through circulating monocytes from hematopoietic stem cells, and (3) in mi mi this defect can be overcome by a transplant of normal hemopoietic stem cells.

Age Factors↗
PubMed1976

Vasoformative non-osteogenic (angio) sarcomas of bone-marrow stroma due to strontium-90.

In a series of experiments, mainly CBA/H, but also C2H/H, mice aged 3 months were injected intraperitoneally with solutions of 90Sr Cl2, the dose per mouse varying from 7 to 20 muCi, and compared with similar mice treated with 226Ra or 239Pu, discussed elsewhere. In male mice, the commonest tumour resulting at each dose of 90Sr was non-osteogenic (angio) sarcoma, a tumour not seen after 226Ra. In females, this tumour occurred far less frequently than osteosarcoma. In CBA mice of both sexes converted to radiation chimaeras (which are sterile) and similarly treated with 90Sr, the only skeletal tumours were osteosarcomas. When only half the body of CBA mice was X-irradiated with 1000 rad and the mice given 90Sr, non-osteogenic sarcoma occurred predominantly in those mice X-irradiated in the cephalic half. The results suggest that intact testes may provide co-factors for this type of neoplasm, whereas others have shown that oestrogens facilitate murine osteosarcoma. The non-osteogenic osteosarcomas arise from damaged stromal elements in bone-marrow of selected bones. The risk to this component of bone-marrow, as well as to haematopoietic tissue, should be considered in radiation protection.

Animals↗
PubMed1976

Radiographic features of bone in several strains of laboratory mice and of their tumours induced by bone-seeking radionuclides.

The natural radiographic appearance of the various bones of the skeleton are described for several strains of laboratory mice. The Harwell substrains of CBA, A and 101 are generally similar and become osteoporotic on ageing. Harwell C57BL have similar, but more delicately chiseled, bones. Harwell C3H mice have bones with stouter cortices and may show osteosclerosis on ageing. CF1 females (donated by Dr M. Finkel) showed osteosclerosis and osteophytic outgrowths when aged. NMRI mice (donated by Dr A. Luz) appeared larger than the pure-strain Harwell mice. In general, mouse bones are simple tubular structures with an ivory cortex and a marrow cavity. Cancellous trabecular bone is scanty, even in vertebrae, flat bones and the metaphyses of long bones. Bone-seeking radionuclides administered to mice lead to skeletal tumours: (a) osteosarcomata, which are commonly radio-opaque to a variable degree owing to calcified tumour bone, but which may be osteolytic, (b) primitive mesenchymal (angio-) sarcomata which are non-osteogenic and osteolytic, (c) fibrosarcomata--which also are osteolytic--and to local or general lymphomata from irradiation of parental cells in bone marrow, but no special radiological features have been found associated with these last-named tumours.

Aging↗
PubMed1975

Viruses in osteosarcomas induced by 226Ra. A study of the induction of bone tumours in mice.

Three groups (15 in each) of 3-month-old mice were injected intraperitoneally with 0-5 muCi 226Ra. They were male and female C3H/H and female CBA/H. The groups were matched by similar controls that were not injected. Osteosarcomas were found in 14/15 of the female C3H/H mice--animals known to carry mammary-tumour viruses in milk--compared with 6/15 in their male counterparts. In CBA/H female mice, which have a very low incidence of both mammary tumours and leukaemia, osteo-sarcomas developed in 7/15 of the animals. The CBA/H mice lived about 5-8 months longer and revealed their osteosarcomas at a correspondingly later time than C3H/H mice. Virus particles were observed in each of the three mammary tumours and in 15 out of the 17 osteosarcomas examined by electron microscopy. No definitive statement can be made from this experiment whether or not osteosarcoma was caused by a virus; but the results suggest that viruses may be a contributory factor in the development of osteosarcoma in these animals.

Animals↗
PubMed1974

Histochemical phosphatases and metachromasia in murine tumours induced by bone seeking radionuclides.

Tumours induced in mice, either CBA normal and chimaerical, or C3H, by (90)Sr or (226)Ra or plutonium have been examined histochemically with (1) diazotate fast red violet LB salt in naphthol AS-MX phosphate buffer at pH 8·6 and 5·2, (2) 1: 9 dimethyl methylene blue (Taylor).It is concluded:(a) The diagnosis of osteosarcoma is facilitated with Taylor's Blue which stains osteoid metachromatically. Cells of osteosarcoma, like normal osteoblasts, contain alkaline phosphatase but this may be lost by mutation either in the original tumour or subsequently on passage of the tumour serially to compatible hosts.(b) Osteosarcomata may contain giant-cells of two forms, bizarre tumour cells and osteoclasts; the latter contain acid phosphatase. Osteosarcomata which retain their osteoid on serial passage have few cells containing acid phosphatases.(c) Primitive mesenchymal cell tumours of angiomatous form may occur, if the bone marrow is irradiated, e.g. by (90)Sr-(90)Y and Pu. These tumours lack osteoid and cells interpretable as osteoblasts or osteoclasts (though they destroy bone).(d) Tumours classifiable as fibrosarcomata occur rarely, and may be truly of fibroblastic origin or be mutated osteosarcomata.(e) Lymphomata also occur when the marrow is irradiated ((90)Sr-(90)Y and Pu). They may be generalized, when their cells may contain alkaline phosphatase or lack it. They may be localized to abdominal viscera, the reticulo-sarcomatous form, in which case the cells lack alkaline phosphatase.

Acid Phosphatase↗
PubMed1970

Malignancy from radium.

Human experience of the toxicity of radium acts as a guide for the setting of occupationally permissible levels for radioactive nucleides, especially bone-seekers. Reviewing the published statements and photomicrographs in early reports especially those of Martland (1931) one can make a case that malignancy was induced in bone-marrow (leukaemia, malignant myelosclerosis) as well as in bone (osteosarcoma) by radium, especially with large doses. Three case reports of radium intoxication in Britons are noted as compatible with this suggestion, after revised interpretation in two of them.

Aged↗