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Biomedical subjects

R L Carter

Publications and source records attributed to R L Carter.

At least 109 records · Page 6Linked to original sources
PubMed1985

Transcapsular spread of metastatic squamous cell carcinoma from cervical lymph nodes.

The incidence, extent, and selected clinicopathologic correlations of transcapsular spread from metastatic tumor in the cervical lymph nodes have been investigated in 210 specimens obtained by radical neck dissection from 203 patients with squamous cell carcinomas of the head and neck. Transcapsular spread was detected in 137 of 159 (86 percent) positive specimens, and classified as macroscopic in 74 (54 percent) and microscopic in 63 (46 percent). Macroscopic transcapsular spread was seen most frequently in association with large nodal masses more than 3 cm in diameter (48 of 70 specimens, 69 percent), but also occurred in some specimens with smaller lymph nodes less than 3 cm in diameter (26 of 67 specimens, 39 percent). Anatomic structures most commonly invaded in areas of neck dissection with macroscopic spread from nodal metastases were skeletal muscle (39 dissections) and the adventitial coat of the internal jugular vein (27 dissections). Macroscopic transcapsular infiltration was associated with a high incidence (44 percent) of recurrent tumor in the ipsilateral neck, particularly within 12 months of surgery. Microscopic transcapsular growth was associated with a lower incidence (25 percent) of recurrent tumor in the ipsilateral neck but the difference did not reach statistical significance. Similar recurrence figures (32 percent) were found in the minority of patients whose nodal disease was intracapsular at the time of neck dissection. More precise definition of the morphologic extent of transcapsular spread could be important in clarifying its clinicopathologic correlations.

Adult↗
PubMed1985

Patterns and mechanisms of localized bone invasion by tumors: studies with squamous carcinomas of the head and neck.

Squamous carcinomas of the head and neck provide a useful model for analyzing patterns and mechanisms of tumor-associated bone destruction. Morphological studies show that a major part of the invasive process is mediated by local osteoclasts which erode bone in front of the advancing tumor. Functional studies indicate that both fresh tumors and tumor cell lines resorb calvarial bone in an in vitro test system, again by stimulating local osteoclasts. Prostaglandins of the E2 type are regularly released by the tumors, together with indomethacin-resistant, nonprostaglandin osteolysins. Control (nonneoplastic) tissues will resorb bone and release osteolytic factors, usually at lower levels of activity--such properties are thus tumor-associated rather than tumor-specific. Xenografts of squamous carcinomas resorb bone in vitro and synthesize osteolysins. They do not invade local bone in their hosts but some grafts regularly produce a systemic hypercalcemia. General implications are discussed, particularly for other human tumors which more frequently metastasize to bone. Possible pointers to the (partial) control of the destructive process are noted.

Adult↗
PubMed1985

Cull rates of dairy cattle with antibodies to bovine leukemia virus.

The relationship of cull rate to age was investigated retrospectively in dairy cows with and without antibodies to bovine leukemia virus (BLV). Banked sera from eight annual herd tests on one 200-cow herd were tested for presence of BLV antibodies by agar-gel immunodiffusion using the Mr 51,000 glycoprotein antigen of BLV. Age-specific cull rates were computed for BLV-antibody-positive and antibody-negative cows yearly from 2 to 7 years of age. Cull rates, transformed by the Arc-sin square root, were analyzed by weighted regression. Transformed cull rates increased significantly as BLV-antibody-positive cows aged (one-tailed P = 0.023) but not as antibody-negative cows aged (one-tailed P = 0.59). A Mantel-Byar survival analysis showed significantly longer survival beyond 3.5 years of age among antibody-negative cows than among antibody-positive cows (P = 0.008).

Age Factors↗
PubMed1984

Neoplastic invasion of the arterial wall and its modification by surgery: an experimental model.

Fragments of VX2 squamous carcinoma were transplanted into the femoral triangles of rabbits and the growth patterns of tumour invasion were compared in intact femoral arteries, ligated femoral arteries and in femoral arteriovenous (AV) anastomoses. Intact arteries were resistant to tumour; ligated arteries were invaded by tumour and, in most instances, destroyed; AV anastomoses were also invaded but some mural structures remained intact. The relative resistance of systemic arteries to neoplastic invasion appears to be due to a combination of the normal structure of the arterial wall and the normal dynamics of the arterial circulation. Infiltration is facilitated if arterial perfusion falls and/or the normal structure of the arterial wall is modified.

Animals↗
PubMed1984

Echocardiographic evaluation of responses to left ventricular volume loading by principal components and nomographic analysis.

Changes in performance of left ventricles (LV) with volume overloads are difficult to determine by conventional clinical methods. This information, however, is important for the proper timing of therapeutic interventions to preserve LV function. Seven size-adjusted (by regression with end-diastolic diameter, EDD) LV performance parameters from 100 normal echocardiograms (echos) were entered into a principal component analysis (PCA). Two factors (linear combination of the 7 parameters) were obtained from the analysis. Prediction limits (95%) about these two factors used in combination, correctly classified 92% of the normal echos. More detailed analysis of the two PCA factors revealed that the majority of the variability within the factors was explained by size-adjusted parameters resultant from the EDD posterior wall (factor 1) and EDD septal excursion (factor 2) regressions, respectively. Plots of the 95% prediction limits about these two regression lines provided nomograms. These nomograms used in combination, correctly classified 95% of the normal echos. When the performance parameters of 64 volume loaded ventricles were evaluated by PCA, four groups were identified. Ten ventricles (16%) were hypokinetic, 29 (45%) were hyperkinetic, 23 (36%) were nomokinetic, and 2 (3%) could not be classified. These classifications were supported by significant between group differences of shortening fraction, velocity of circumferential shortening, and velocity of circumferential expansion. Nomographic classification of the same volume loaded hearts was in excellent (94%) agreement with PCA classification. Nomographic analysis (derived from the PCA) is offered as a less complex, more clinically applicable echo method for evaluating LV performance of volume loaded hearts.

Adolescent↗
PubMed1984

A psychometric study of the family adaptability and cohesion evaluation scales.

The Family Adaptability and Cohesion Evaluation Scales (FACES), a measure of family functioning, contains three scales: cohesion, adaptability, and social desirability. These were slightly modified (FACES-R) on the basis of pilot data and were administered to 42 clinic families (families seeking or receiving psychological services) and 206 nonclinic families. Support for the scales was found in high coefficient alpha reliabilities and similarity of the sample means and standard deviations to those of the standardization sample. However, there was little agreement among family members' scale scores. Therapists' ratings of cohesion and adaptability did not correlate with scale scores among clinic families. There was no difference between clinic and nonclinic samples on the cohesion or adaptability scales, although the social desirability scale did discriminate between groups. Factor analysis suggested that cohesion, adaptability, and social desirability cannot be clearly differentiated using this measure.

Adaptation, Psychological↗
PubMed1984

Studies on synthesis and anticancer activity of selected N-(2-fluoroethyl)-N-nitrosoureas.

An activated carbamate, 2-nitrophenyl (2-fluoroethyl)nitrosocarbamate (3), was used to advantage in the synthesis of the water-soluble (2-fluoroethyl)nitrosoureas 6a--d from 2-aminoethanol, (1 alpha, 2 beta, 3 alpha)-2-amino-1,3-cyclohexanediol, cis-2-hydroxycyclohexanol, and 2-amino-2-deoxy-D-glucose. In a variation of this method, 2,4,5-trichlorophenyl (2-fluoroethyl)carbamate (4) was used to prepare the urea from which the essentially water-insoluble N-(2,6-dioxo-3-piperidinyl)-N-(2-fluoroethyl)-N-nitrosourea (6e) was derived. The anticancer activity of these nitrosoureas was determined against the murine tumors B16 melanoma and Lewis lung carcinoma and found to be significant and comparable to their chloroethyl counterparts. On the basis of results from both systems, the dihydroxycyclohexyl derivative 6b may be the most effective.

Animals↗
PubMed1984

On the statistical estimation of speech-organization distributions from aphasia data.

Statistical methods of estimating speech-organization distributions from aphasia data are presented. Under certain assumptions, estimators for the proportions of individuals with unilateral right-hemisphere speech, unilateral left-hemisphere speech and bilateral speech organization are derived, and the large-sample properties of these estimators are presented. It is shown that useful results can be obtained when the most questionable assumption is relaxed. The general methodology is presented in terms of a specific example--the estimation of speech organization distributions of right- and left-handed adults across the three speech types. Under the relaxed assumptions a test of the hypothesis that all left-handers are unilaterally organized is derived. Conservative bounds on the proportions of unilaterally organized (left- and right-hemisphere) and bilaterally organized left-handers are also derived. As an illustration, the results are applied to aphasia-incidence data from the literature. Several uncertainties and inadequacies of the available data are discussed. Although minor modifications of the present methods might be required for other examples, the main ideas would be the same.

Adult↗
PubMed1983

Diet therapy for rheumatoid arthritis.

Although diet therapy for arthritis has received considerable publicity, there is little objective information about its efficacy. We undertook a 10-week, controlled, double-blind, randomized trial of patients with active rheumatoid arthritis (RA). Twenty-six patients completed the study; 11 were on an experimental diet (a specific popular diet free of additives, preservatives, fruit, red meat, herbs, and dairy products) and 15 were on a "placebo" diet. Of 183 variables analyzed, there were no clinically important differences among rheumatologic, laboratory, immunologic, radiologic, or nutritional findings between patients on experimental and placebo diets. Six RA patients on the placebo and 5 on the experimental diet improved by objective criteria. Improvement averaged 29% for patients on placebo and 32% for patients on experimental diets. Two patients on the experimental diet improved notably, elected to remain on the experimental diet following the study period, have continued to improve, and noted exacerbations of disease upon consuming nonexperimental diet foods. Our study failed to provide evidence of objective overall clinical benefit of this diet as followed by a group of patients with longstanding, progressive, active RA. However, our data are not inconsistent with the possibility that individualized dietary manipulations might be beneficial for selected patients with rheumatic disease.

Arthritis, Rheumatoid↗
PubMed1983

Patterns and mechanisms of bone invasion by squamous carcinomas of the head and neck.

Patterns and mechanisms of local bone invasion by squamous carcinomas of the head and neck have been investigated. Detailed surgical pathology has shown that these tumors invade contiguous skeletal or metaplastic bone principally through an indirect process; the normal bone resorbing cells of the host (osteoclasts) are activated and erode bone in front of the advancing tumor edge. Tumor cells take over the destructive process when the osteoclast response has waned. These morphologic patterns have been reproduced in an in vitro model where calcium-45-labelled mouse calvaria, cocultured with a tumor for 3 days, are resorbed by osteoclasts. Freshly excised tumors, established tumor cell lines, and tumor xenografts release osteolysins in vitro which act as osteoclastic stimulants. They include both prostaglandins E2 and F2 alpha, and nonprostaglandin factors, and are derived from tumor cells and from the associated host stroma. Virtually all the tumors examined released osteolysins and resorbed bone in vitro independent of their site, size, degree of differentiation, and the presence or absence of clinical bone invasion.

Bone Neoplasms↗
PubMed1983

Treatment of advanced malignant melanoma with high-dose melphalan and autologous bone marrow transplantation.

Twenty-eight patients with advanced life-threatening metastatic malignant melanoma were treated with high dose (140-260 mgm-2) intravenous melphalan and autologous bone marrow. Cyclophosphamide "priming" 300 mgm-2 i.v. was given to 19 patients one week previously and this resulted in clinical but not histological evidence of amelioration of gastrointestinal toxicity. In 11 patients (43%) there was evidence of tumour response to treatment and in 2 patients complete remissions were observed. However in most patients, responses were short-lived and no patient lived longer than 17 months from start of treatment or 24 months from first recorded evidence of distant metastatic disease.

Adult↗
PubMed1983

Further observations on mechanisms of bone destruction by squamous carcinomas of the head and neck: the role of host stroma.

Mechanisms of bone invasion by squamous carcinomas of the head and neck have been investigated using fresh tumours and established tumour cell lines in an in vitro bone resorption assay with 45Ca-labelled mouse calvaria. Fresh tumours regularly resorb bone in vitro. Activity is consistently reduced by indomethacin. The tumours release E2 prostaglandins (PGE2) in amounts sufficient to account for approximately 50% of the bone resorption observed. Small amounts of non-prostaglandin (indomethacin-resistant) osteolytic factors are also produced. Control non-neoplastic tissues show a variable capacity to resorb bone in vitro; PGE2 levels in these tissues may be related to their content of inflammatory cells. Tumour cell lines also resorb bone in vitro but, for most lines, activity is not significantly blocked by indomethacin and PGE2 levels are generally insufficient to account for the osteolysis observed. Non-prostaglandin bone resorbing factors thus predominate. It is concluded that most squamous cancers of the head and neck are osteolytic in vitro and release a mixture of prostaglandin and non-prostaglandin factors which stimulate osteoclastic bone resorption. These factors are derived from both neoplastic and stromal elements, and are "tumour-associated" rather than "tumour-specific". In vitro bone resorption and prostaglandin release does not correlate with pathological features of the tumour or with post-operative survival.

Animals↗
PubMed1983

Perineural spread by squamous carcinomas of the head and neck: a morphological study using antiaxonal and antimyelin monoclonal antibodies.

Perineural spread has been demonstrated histologically in 65/180 (36%) major surgical resections for squamous carcinomas of the head and neck; the incidence in a smaller necropsy series was 18/20 (90%). Perineural infiltration was observed most commonly in the vicinity of carcinomas arising in the buccal cavity (31/63, 50%) and, at all sites, it was most commonly encountered near tumours less than or equal to 2.5 cm in diameter. Perineural spread near cervical node metastases was, by contrast, uncommon in the surgical series. Tumour within perineural spaces tends to be concentrated at the margin of the nerve and shows only limited extension inwards, but cells may track upwards and downwards within the spaces. Distant spread for greater than 2 cm is unusual, and interval sampling of involved nerves in necropsy material indicates that most perineural tumour cells are confined to the distal 1 cm of the affected nerve. Infiltrated nerves regularly show varying degrees of myelin and axonal degeneration, probably anoxic in origin, and segmental infarction of nerve trunks was observed in three patients. Fine changes in axons and myelin have been regularly demonstrated with two monoclonal antibodies, and the use of these new reagents is described.

Aged↗
PubMed1983

Epithelial markers in the diagnosis of nasopharyngeal carcinoma: an immunocytochemical study.

Immunocytochemical stains for three epithelial cell markers--keratin, epithelial membrane antigen (EMA) and carcinoembryonic antigen (CEA)--have been examined on paraffin-embedded material from 14 patients with nasopharyngeal carcinoma (NPC). Tumour cells staining positively for keratin were found in all cases and for EMA in eight; two tumours contained CEA-positive cells. Seven cases of Hodgkin's disease and 24 non-Hodgkin's lymphomas were uniformly negative. Keratin is the most reliable epithelial marker for identifying NPC and excluding lymphoma. The regular finding of stainable keratin in non-keratinising and anaplastic NPC supports the view that NPC is a homogeneous group exhibiting variable degrees of squamous differentiation.

Antigens↗