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Biomedical subjects

M Harris

Publications and source records attributed to M Harris.

At least 577 records · Page 32Linked to original sources
PubMed1985

Nuclear morphometry of epitheliosis and intraduct carcinoma of the breast.

Nuclear morphometry has been studied by a simple visual method in order to obtain an objective criterion for distinguishing epitheliosis from intraduct carcinoma in tissue sections. Nuclear area was found to be superior to the measurement of major or minor axes. Estimated area (major X minor axes), although less accurate than measured area, gave equally good discrimination. The best discrimination was obtained using the differences between the mean estimated nuclear area of the diseased duct and a normal duct in the same section. Using a difference of 20 micron2 as the dividing line, epitheliosis and intraduct carcinoma could be correctly classified by this criterion alone in 86% of the lesions studied.

Breast Diseases↗
PubMed1985

Automated thermatic condensation of gutta-percha root fillings in teeth with open (immature) apices.

Forty upper human premolar teeth with open (immature) apices were root filled by one of three methods, namely lateral condensation with sealer, automated thermatic condensation with sealer, and automated thermatic condensation without sealer. The completed root fillings were then assessed for apical defects, apical extrusions, radiographic voids, apical seal and surface adaptation. The majority of the results indicate that the automated thermatic technique without sealer produces marginally better root fillings in teeth with open apices than the other two methods. However, it is impossible to say whether this would confer any clinical advantage on the technique. The authors recommend that clinicians who wish to use the automated thermatic technique for condensing gutta-percha become highly proficient before its use on patients.

Bicuspid↗
PubMed1985

Nature of relapse after surgical mandibular advancement.

Pre-operative, post-operative and follow-up cephalometric records of 16 cases of mandibular retrognathia treated by surgical mandibular advancement were analysed retrospectively. The results showed good mean stability in the mandibular advancement with variable individual relapse. The pre-operative mandibular plane angle, magnitude of the advancement and post-operative increase in the posterior lower face height were the variables chiefly related to relapse. There appeared to be limited control over the posterior segment which was liable to distraction and rotation. The follow-up changes were time linked. Both mechanical and biological factors are postulated to explain the relapse.

Cephalometry↗
PubMed1985

Carcinomatous meningitis associated with infiltrating lobular carcinoma of the breast.

The records of 365 patients with advanced carcinoma of the breast were examined to identify those with CNS involvement. Nineteen (5.2%) developed parenchymal cerebral deposits and 10 (2.7%) developed meningeal infiltration during the course of their disease. Parenchymal cerebral deposits were almost exclusively associated with infiltrating duct carcinoma (95%) and meningeal infiltration (carcinomatous meningitis) was almost exclusively associated with infiltrating lobular carcinoma. Meningeal infiltration occurred late in the course of advanced disease and was associated with diffuse involvement of the bone marrow and abdominal structures.

Adult↗
PubMed1985

Single-dose dacarbazine and dactinomycin in advanced malignant melanoma.

Twenty-one patients with advanced malignant melanoma were treated with dacarbazine at a dose of 800 mg/m2 as a single infusion and dactinomycin at a dose of 1.2 mg/m2 every 3 weeks. Hematologic toxicity was mild and gastrointestinal toxicity was tolerable. The response rate for evaluable patients was 22%, which included both men and women with visceral disease. Three of the four responses were complete. Durations of response were 4, 6, 9, and 48+ months. We conclude that dacarbazine can be safely and effectively given as a single dose along with dactinomycin. The possibility that this combination may be more effective than single agents in obtaining complete responses in patients with visceral disease must be explored further.

Adult↗
PubMed1984

The prognostic significance of two epithelial membrane antigens expressed by human mammary carcinomas.

As many patients with mammary carcinoma are now treated by conservative forms of surgery, there is a need for prognostic information obtainable from the primary tumour alone. One possible source is the antigenic profile of tumour cells. Using an indirect immunoperoxidase technique, we stained histological sections of the primary tumour from 175 patients with each of two monoclonal antibodies (HMFG-1, HMFG-2), raised against milk fat globule membrane antigens known to be preserved in formalin-fixed tissues. Sections were assessed by light microscopy as to both the overall distribution of antigen expressed and its site in tumour cells. The findings were related to relapse-free survival by life-table analysis. The median duration of follow-up was 36 months. Two patterns of staining with antibody HMFG-1 gave information of prognostic significance but staining with HMFG-2 was without significance. Complete absence of staining with HMFG-1 in 13 patients was associated with an extremely poor prognosis and 10 (77%) of these patients developed metastases within 18 months of follow-up (p less than 0.001). Extracellular staining (ECS) in 22 patients, however, was associated with a favourable prognosis. As assessed by a semi-quantitative method, only one patient (5%) demonstrating a high level of ECS developed metastases (p less than 0,004). These two patterns were analysed for a relationship to other prognostic indicators. Absence of staining was independent of histological grade, tumour size, axillary lymph node status and menopausal status. ECS was associated with low histological grade although this relationship was not absolute. In addition to their use in diagnosis, we conclude that monoclonal antibodies such as HMFG-1 may be useful as prognostic indicators.

Antibodies, Monoclonal↗
PubMed1984

Psychogenic facial pain: presentation and treatment.

Ninety three patients took part in a two centre double blind controlled clinical trial designed to assess the efficacy of dothiepin (Prothiaden) as compared with placebo and a soft biteguard in the treatment of psychogenic facial pain. The results showed the superiority of dothiepin over placebo in achieving pain relief; 71% of patients were pain free in the dothiepin group at nine weeks compared with 47% in the placebo group. The biteguard conferred no benefit and compliance in its use was poor. Out of 84 patients followed up for 12 months, 68 (81%) became pain free. An adverse life event before development of pain, minimal previous surgical treatment, and freedom from pain at nine weeks were strong prognostic indicators for successful treatment. These results are clear evidence of the efficacy of dothiepin in psychogenic facial pain, though the drug may be needed for up to a year.

Adolescent↗
PubMed1984

High-frequency induction by 5-azacytidine of proline independence in CHO-K1 cells.

Proline independence in CHO-K1 Chinese hamster cells has in previous studies been characterized as an auxotrophic gene mutation. In the absence of direct proof, an alternative model must be considered, based on suppression of proline synthesis by DNA methylation changes at one or more loci concerned. This concept receives strong support from the present study, in which we show that treatment of CHO-K1 cells with 5-azacytidine induces a 10(5)-10(6) increase in background conversion to the proline-independent state. Revertants thus obtained, as well as those arising spontaneously or after treatment with ethyl methane sulfonate, are stable phenotypically in the presence or absence of proline. Proline independence in all variants examined was correlated with increased activity of pyrroline-5-carboxylate synthase. Four of five variants induced with 5-azacytidine showed simultaneous increases in activity of ornithine aminotransferase as well. Our data suggest that epigenetic, rather than genetic changes, underlie the transitions between proline dependence and independence in CHO-K1 cells.

Animals↗
PubMed1984

Variants inducible for glutamine synthetase in V79-56 cells.

V79-56 cells have an absolute requirement for exogenous glutamine and are not inducible for glutamine synthetase. Prototrophs arise spontaneously at approximately 1.0 X 10(-5) per cell per generation as measured by fluctuation tests. Higher frequencies of glutamine-independent variants may be obtained by treatment with the mutagen ethyl methane sulfonate, as well as by exposure to 5-azacytidine and sodium butyrate, which act primarily by affecting gene expression. Variants of all types show marked elevation of glutamine synthetase activity. Although this activity declines toward constitutive levels in the presence of glutamine, it is still inducible in variant cells. These populations, after a lag, regain the ability for progressive growth in glutamine-free medium. Thus, the stable variation seen here is in the potential for induction, rather than steady-state expression of glutamine synthetase at a higher level.

Animals↗
PubMed1984

Evidence for fibroblasts as the major source of prostacyclin and prostaglandin synthesis in dental cyst in man.

Periodontal cysts synthesize large amounts of prostaglandins and collagenase which probably cause the localized bone destruction essential for intraosseous cyst growth. Fragments of cyst wall, and fibroblasts cultured from them, synthesized prostacyclin (PGI2) in addition to prostaglandin E2 (PGE2), PGF2 alpha and collagenase in vitro. Soluble products from cultures of unstimulated and phytohaemagglutinin-stimulated blood mononuclear cells enhanced the synthesis of these prostaglandins in monolayer cultures of cyst-wall fibroblasts. It is therefore proposed that cyst capsule fibroblasts are the major source of these bone-resorbing factors, acting under the stimulus of lymphocytes and monocytes in chronically inflamed cysts. Cysts which were not infiltrated by chronic inflammatory cells (follicular cysts, a keratocyst, an ameloblastoma, and an aneurysmal bone cyst) also produced prostaglandins and collagenase, indicating that the stimulatory mechanism for the production of bone-resorbing factors in these cysts may differ from that in periodontal cysts.

6-Ketoprostaglandin F1 alpha↗