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Biomedical subjects

D A Reynolds

Publications and source records attributed to D A Reynolds.

10 recordsLinked to original sources
PubMed1986

Chiari innominate osteotomy in adults. Technique, indications and contra-indications.

The results are reported of 44 consecutive Chiari innominate osteotomies performed on 39 adult patients aged between 18 and 55 years for symptoms arising from disproportion between the acetabulum and the femoral head. Predisposing causes included congenital dysplasia of the acetabulum, congenital subluxation of the hip, and Perthes' disease. Follow-up averaged 5 years 2 months. Four pre-operative categories of dysplasia and degeneration were recognised. The analysis of the results from each category made possible the recognition of clinical and radiological features likely to provide a satisfactory result. Of 32 cases now considered to have been selected appropriately, 29 (90%) achieved a significant and apparently lasting improvement. In the other 12 cases there were 9 failures--an unacceptable proportion. The features predisposing to these poor results are discussed. The operation is not difficult. It is safe, and is less demanding than the complex alternative "double", "triple" and "dial" osteotomies. In successful cases there is reduction in symptoms and in limp, and improvement of radiological appearances beginning six months after surgery and progressing to a maximum recovery two to three years later.

Acetabulum↗
PubMed1986

Characterization of human neuroblastoma cell lines established before and after therapy.

Six new cell lines have been established from human neuroblastomas. Cell line SMS-KAN, from primary tumor before therapy, and line SMS-KANR, from bone marrow after chemotherapy and radiotherapy, were established from the same patient. Cell lines SMS-KCN (from primary tumor before any therapy) and SMS-KCNR (from bone marrow after chemotherapy) were established from another patient. Two other lines (SMS-MSN and SMS-SAN) were established from different patients before any therapy was given. Cell lines established from recurrent disease after chemotherapy (SMS-KANR and SMS-KCNR) had significantly shorter doubling times and increased plating efficiencies compared to those of cell lines derived from the same patient before chemotherapy (SMS-KAN and SMS-KCN). All cell lines contained tyrosine hydroxylase, aromatic L-amino acid decarboxylase, and dopamine-beta-hydroxylase. Measurable amounts of choline acetyltransferase were also detected in SMS-KAN and SMS-KANR. Karyotype analysis showed all cell lines except SMS-MSN to be pseudodiploid with modal numbers of 46 and deletions of the short arm of chromosome 1; SMS-MSN had a modal number of 57-58 chromosomes. All cell lines had double-minute chromosomes, except SMS-KANR, which had abnormally banding regions. These new cell lines provide in vitro models of neuroblastoma suitable for the study of differences in neuroblastoma cell populations before chemotherapy as compared to the cell populations that proliferate after therapy.

Catecholamines↗
PubMed1982

Selective toxicity of 6-hydroxydopamine and ascorbate for human neuroblastoma in vitro: a model for clearing marrow prior to autologous transplant.

6-Hydroxydopamine (6-OHDA) is a neurotoxin for catecholaminergic neurons and neuroblasts. Since frequent marrow involvement in neuroblastoma restricts the exploitation of stored autologous bone marrow for rescue postchemotherapy, the potential for tumor-specific in vitro specificity of 6-OHDA was studied. The cytotoxic effect of 6-OHDA on 12 human neuroblastoma cell lines was compared to the effect on nonneuroblastoma cell lines. Most neuroblastoma cell lines were very sensitive to 6-OHDA (average concentration killing 50% of cells, 22 microgram/ml; range, 2.8 to 65.4). Cells derived from catecholamine-producing tumors were more sensitive to 6-OHDA than were those from non-catecholamine producers. By contrast, human fibroblasts, lymphoblastoid cell lines, and normal marrow were relatively insensitive to 6-OHDA; the concentration needed to kill 50% of cells for most of these cells exceeded 100 microgram/ml. Leukemia cell lines and a rhabdomyosarcoma cell line were intermediate in sensitivity. Ascorbate and 6-OHDA were synergistic in toxicity for human neuroblastoma cells. Thus, in vitro addition of 6-OHDA and ascorbate was rapidly lethal for human neuroblastoma cells at concentrations which were minimally toxic for hematopoietic cells. This differential toxicity provides a possible means for selective destruction of neuroblastoma cells in bone marrow harvested for autologous transplantation.

Ascorbic Acid↗
PubMed1981

Growth changes in fractured long-bones: a study of 126 children.

In this study of fractures of the shaft of the tibia and femur in children, the growth rate of these long bones after injury was assessed by serial radiographical measurements of bone length, accurate to the nearest millimetre. Within three months of injury the rate of growth was at its maximum and was 38 per cent in excess of normal. The rate then decreased but remained significantly raised for two years and returned to normal in the tibia approximately 40 months after injury and in the femur between 50 and 60 months. The uninjured tibia in the same limb as a fractured femur also underwent an acceleration of growth, but to a lesser degree. An uninjured femur was not so affected by an injured tibia. The growth rate in these limbs was unaffected by the age or sex of the child, or the site or direction of the fracture. These findings may be of clinical use in the timing of corrective treatment where a leg length discrepancy exists as a result of injury to, or malunion of, a long bone in the lower limb of a child.

Adolescent↗
PubMed1971

Effects of thiabendazole treatment on weight gains by Nebraska range cattle.

The results of these studies indicate that a high percentage of Nebraska range cattle are infected with gastrointestinal parasites, but at a subclinical level of infection. However, significant differences were not observed in average daily gain between thiabendazole-treated range cattle and unmedicated controls in three of four field trials. In the three trials the average improvement in daily gain in animals receiving thiabendazole once averaged .01 lb greater than untreated controls. During a 120 day grazing period this improvement would not be sufficient to pay for the wormer or cost of additional labor.

Analysis of Variance↗
PubMed1969

Assembly of protein and nucleoprotein particles from extracted tobacco rattle virus protein and RNA.

Protein extracted from tobacco rattle virus by treatment with formic or acetic acid reassociated in vitro to form rings and tubular structures of indeterminiate lengths in 0.25 molar glycine at pH 7.5 to 9.5. When tobacco rattle virus RNA that had been extracted with phenol was incubated with the protein at 9 degrees C, particles with more regular lengths formed; these particles correspond in size and sedimentation properties to the short particles that normally accompany infection by tobacco rattle virus. The biological activity of the reconstitutted short particles was identical to that of native short particles.

Acetates↗