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Biomedical subjects

M W Green

Publications and source records attributed to M W Green.

At least 37 records · Page 2Linked to original sources
PubMed1994

Mood and cognitive performance effects of isocaloric lunches differing in fat and carbohydrate content.

Eighteen subjects consumed low-fat/high-carbohydrate (LFHC) (29% fat, 54% carbohydrate, 15% protein), medium-fat/medium-carbohydrate (MFMC) (45% fat, 42% carbohydrate, 12% protein), and high-fat/low-carbohydrate (HFLC) (62% fat, 24% carbohydrate, 13% protein) isocaloric lunches in random order on 3 separate days. The MFMC lunch was similar in energy and macronutrient composition to the habitual lunchtime intake of the subjects. A battery of cognitive performance tasks together with mood and appetite ratings were carried out before and during the 3 h after lunch. Results showed longer reaction times following the LFHC and HFLC lunches compared to the MFMC lunch, which produced an improvement in performance on this task. In addition, subjects rated themselves as more drowsy, uncertain and muddled, and less cheerful after the LFHC and HFLC lunches compared to the MFMC lunch, and as less tense after the LFHC meal. These findings indicate that the macronutrient content of lunch can have significant acute effects on subsequent mood and performance. In particular, higher than usual proportions of fat or carbohydrate produced a relative impairment of cognitive efficiency.

Adult↗
PubMed1994

Expression and polarized targeting of a rab3 isoform in epithelial cells.

Pathways of polarized membrane traffic in epithelial tissues serve a variety of functions, including the generation of epithelial polarity and the regulation of vectorial transport. We have identified a candidate regulator of polarized membrane traffic in epithelial cells (i.e., rab3B), which is a member of the rab family of membrane traffic regulators. Rab3B is highly homologous to a brain-specific rab3 isoform (rab3A) that targets in a polarized fashion to the presynaptic nerve terminal, where it probably regulates exocytosis. The coding region for human rab3B was cloned from epithelial mRNA using a reverse-transcription polymerase chain reaction strategy. This cDNA clone hybridized to a single mRNA species in Northern blots of poly(A)+ RNA isolated from epithelial cell lines. A rab3B-specific antibody that was raised against recombinant fusion protein recognized a 25-kD band in immunoblots of cell lysates prepared from cultured epithelial cells (e.g., T84 and HT29-CL19A), but not from a variety of nonepithelial cells (e.g., PC12 neuroendocrine cells). Immunofluorescence analysis confirmed that rab3B protein is preferentially expressed in cultured epithelial cells as well as in a number of native epithelial tissues, including liver, small intestine, colon, and distal nephron. Rab3B localized to the apical pole very near the tight junctions between adjacent epithelial cells within all of these cell lines and native epithelial tissues, as determined by immunofluorescence and immunoelectron microscopic analysis. Moreover, this pattern of intracellular targeting was regulated by cell contact; namely, rab3B was reversibly retrieved from the cell periphery as epithelial cell contact was inhibited by reducing the extracellular Ca2+ concentration. Our results indicate that neurons and epithelial cells express homologous rab3 isoforms that target in a polarized fashion within their respective tissues. The pattern and regulation of rab3B targeting in epithelial cells implicates this monomeric GTPase as a candidate regulator of apical and/or junctional protein traffic in epithelial tissues.

Animals↗
PubMed1994

Habituation patterns to colour naming of eating-related stimuli in anorexics and non-clinical controls.

The current study was an investigation into intra-session changes in the pattern of Stroop colour-naming impairments with body shape-related words and food-related words. The subject pool comprised anorexic women and a control group of non-clinically disordered women. The results indicated that anorexic women show greater colour-naming decrements that non-disordered controls for both types of eating-related words. Stroop interference significantly decreased across the course of the experiment with the body-shape words for the anorexic subjects, thereby indicating habituation to the semantic content of those words. There was no comparable process of habituation observed with the food-related words.

Anorexia Nervosa↗
PubMed1993

Developmental onset of eating related color-naming interference.

The current study was an investigation into the possible developmental aspects of the "Eating Stroop" effect, as produced by non-eating disordered subjects. The subject pool comprised male and female subjects, ranging in age from 9 to 14 years. Their task was to color-name a series of Stroop arrays, comprising food-related words, body shape-related words, and two sets of neutral matched control words. It was found that there were significant performance decrements for both food and shape-related words with the 14-year-old girls. The results indicated a possible color-naming decrement with food-related words for the 11-year-old girls, but not shape words. No color-naming decrements were found with the 9-year-old group, or the male subjects. The results are interpreted in terms of cultural pressures on women to diet to attain an "ideal" body shape and the different developmental stages at which such pressures exert themselves.

Adolescent↗
PubMed1993

Selective attention to food and body shape words in dieters and restrained nondieters.

The current study investigated the presence of an attentional bias towards the processing of body shape and food-related material amongst noneating disordered women. Subjects carried out a computer-based Stroop color-naming task in which they had to name the colors of food-related words, body shape-related words, and two sets of matched neutral words. Significant color-naming disruptions of both food and body shape-related material were found for highly restrained eaters, irrespective of whether they were currently dieting. There were no reliable differences in color-naming times found for low to medium restrained eaters. Procedural differences probably account for the failure of previous studies to reveal such effects in nonclinical groups.

Adolescent↗
PubMed1993

Comparison of planimetry and image analysis for the discrimination between normal and abnormal cells in cytological smears of suspicious lesions of the oral cavity.

Light microscope analysis of cytological smears of suspicious lesions of the oral cavity is used as a method for detecting early cancer in the oral cavity. The sensitivity of this approach can be improved by quantitative analysis of the cells in the cytological smears. We have compared the efficiency of planimetry and the Vids V system of image analysis, as quantitative methods for discriminating between normal and abnormal cells in cytological smears of suspicious lesions in the oral cavity. Both methods detected an increase in nuclear area and a decrease in cytoplasmic area in abnormal epithelial cells from dysplastic lesions of increasing severity. However, image analysis was better able to discriminate between benign and malignant cells on the basis of nuclear size. Thus the Vids V system of image analysis is more appropriate than planimetry for quantitative analysis of cytological smears from the oral cavity.

Cell Size↗
PubMed1993

Dieting, dietary restraint and cognitive performance.

In a volunteer sample of female undergraduates, concerns about eating, body weight and body shape were found to increase with the level of self-reported dietary restraint. These concerns were greatest, however, in a subsample of subjects who were currently dieting to lose weight, and greater than in equally restrained but non-dieting subjects. Furthermore, the dieting subjects performed less well on a demanding cognitive task than the non-dieting subjects. These results show that it is important to distinguish between dietary restraint and actual dieting behaviour. They also highlight the need for further research to examine the effects of dieting on cognitive functioning.

Adolescent↗
PubMed1992

Cytokeratin expression in oral exfoliative cytology: effect of temperature and fixation.

The identification of keratin expression within oral cytology may be useful in the diagnosis of clinically suspicious oral mucosal lesions. There may be wide variation in the temperature at which such smears are stored, prior to processing. Conventionally, rapid fixation or storage at low temperatures is recommended to preserve kertin expression within tissue biopsies. No previous study has assessed whether this is true for oral cytology. Smears were taken from clinically normal buccal mucosa. For each temperature assessed (-70, -40, -22, +5, +20 and +26 degrees C), one smear was spray-fixed (Vale Smear Fix) and one air-dried, prior to storage for 4 days, and then staining with the pan-epithelial antikeratin antibody, LP34. Preservation of keratin expression was assessed as either weak (zero to few positive cells) or strong (most cells positive). The results were analysed using logistic regression with the statistical modelling package, GLIM. Over the range of temperatures studied, spray fixation did not appear to improve the identification of keratin expression. Although the best preservation was obtained at lower temperatures, keratin expression was still adequate after 4 days at 20 degrees C. Hence, a delay in processing of 4 days would still allow detectable expression in oral exfoliative cytology even at room temperature.

Adolescent↗
PubMed1992

Preservation of keratin expression in oral mucosa using a novel transport medium.

Cellular expression of keratins (intermediate filaments) can be demonstrated by immunocytochemistry using unfixed tissue. However, for practical reasons, provision of fresh tissue to the laboratory is often difficult. Recently a fresh tissue transport medium (Patent applied for) has been developed which allows keratin immunocytochemistry to be performed up to 4 days after biopsy. In this study oral mucosal biopsies from 10 patients were hemisected, half placed in the new transport medium at 4 degrees C and the other half immediately frozen in liquid nitrogen. After 4 days frozen sections of both halves of the biopsies were stained by immunocytochemistry using various antikeratin antibodies. The morphology and staining characteristics of the two halves of the biopsies were then assessed. No significant difference could be found in either morphology or preservation of keratin expression in specimens stored in transport medium, as compared to those in liquid nitrogen. This new transport medium may offer considerable advantage for the provision of a histologic and immunocytochemical diagnostic service.

Cacodylic Acid↗
PubMed1991

Detection of field change in oral cancer using oral exfoliative cytologic study.

Four smears were taken from the normal buccal mucosa of 55 oral cancer patients and 76 cancer-free patients. In each case, two were stained by the Papanicolaou method and two underwent Feulgen hydrolysis. Quantitative assessment of nuclear area (NA) and cytoplasmic area (CA) of the Papanicolaou smears was undertaken using a semiautomatic image analysis system. DNA profiles were assessed from the Feulgen smears using a Vickers M85 microdensitometer (Vickers Instruments, York, England) and were found to be diploid for all patients. Results were then analyzed with respect to those patients who took alcohol, tobacco, combination of alcohol and tobacco, and those who took neither. A significant reduction in CA for the oral cancer group (P equals 0.001) but no change in NA (P equals 0.74) was observed. A detailed analysis of alcohol and tobacco habits could identify no significant role for these two factors, in the reduction in cytoplasmic area. Such field change may prove to be of value in predicting the development of second malignant tumors.

Adult↗
PubMed1991

Review article: the medical management of trigeminal neuralgia.

Trigeminal neuralgia results from disturbances in the trigeminal root entry zone which generate repetitive action potentials. Drugs which relieve the pain of trigeminal neuralgia depressed these potentials. Anticonvulsants which exert this or related effects, and which have been demonstrated to be efficacious in trigeminal neuralgia, include carbamazepine, phenytoin, clonazepam, and valproic acid. Baclofen may act by facilitating segmental inhibition of the trigeminal complex. The mechanism of action of pimozide for treating trigeminal neuralgia is not known. Carbamazepine is suggested as the drug of first choice; baclofen or clonazepam could be added if carbamazepine monotherapy is ineffective. When these fail, monotherapy with phenytoin, pimozide, or valproic acid would be a reasonable next step.

Anticonvulsants↗
PubMed1991

Quantitative cytology of oral smears. A comparison of two methods of measurement.

Previous quantitative cytologic studies employing planimetry to assess oral smears established a "discriminant line" for separating normal and abnormal cases. The use of the Vids V semiautomatic image analysis system to make these measurements was analyzed to determine whether the results obtained by the two methods were comparable. In measuring the same cells by both methods, no significant variation in nuclear size was detected; however, there was a statistically significant variation in the measurements of cytoplasmic area. Further analysis suggested that the cytoplasmic areas differed by a constant amount, not a constant proportion, between the two methods; this may be due to the ability of the Vids V system to more clearly display the cell boundaries. The appropriateness of techniques for comparing different methods is discussed.

Cytodiagnosis↗
PubMed1990

The effect of distant malignancy upon quantitative cytologic assessment of normal oral mucosa.

In 1962 Nieburgs et al. reported specific changes within cells taken from normal buccal mucosa, in those with malignant disease distant from the oral cavity. Few have attempted to confirm these findings. Given the potential application of the observations of Nieburgs et al., a quantitative investigation seemed necessary. Two groups were studied: 40 patients with malignant disease outside the oral cavity and 40 healthy patients attending for routine dental treatment. Both groups were matched for age and sex, with anemia excluded. Quantitative cytologic assessment of nuclear (NA) and cytoplasmic area (CA) and DNA distribution (using DNA cytophotometric study) were calculated from cells in normal buccal mucosal smears. No significant difference in NA (P = 0.28) was found between the two groups. However, a significant reduction in CA (P = 0.005) was found within the distant malignancy group. DNA distribution was invariably diploid. Previous studies on the effect of distant malignancy and nutritional deficiency have concentrated on examination of the nucleus, with exclusion of the cytoplasm. Important changes, such as the one reported, may therefore have gone unrecorded, particularly since oral smears have rarely been quantitatively assessed. The cause of this decrease in CA in distant malignancy patients is discussed with regard to the patients' nutritional state. The buccal smear may yet prove of value in assessing nutritional deficiency consequent to internal malignancy.

Cell Nucleus↗
PubMed1990

Evidence of field change in oral cancer.

Evidence of field change in oral cancer was assessed using quantitative cytomorphometric analysis of smears taken from normal buccal mucosa in oral cancer and cancer-free patients. The nuclear areas (NA) and cytoplasmic areas (CA) were calculated using a semi-automatic image analysis system. A statistically significant reduction in CA (p = 0.002) but no change in NA was observed for the oral cancer group. This change occurred irrespective of tobacco and alcohol usage. We believe this to be the first evidence for true field change since Slaughter's original hypothesis in 1946.

Aged↗
PubMed1990

Quantitative exfoliative cytology of normal buccal mucosa: effect of smoking.

The effect of cigarette smoking on the oral mucosa was assessed through the application of quantitative cytomorphometric analysis to smears obtained from clinically normal buccal mucosa. The nuclear (NA) and cytoplasmic (CA) area of cells within each smear were measured using a Vids V semi-automatic image analysis system. Mean values for NA (smokers--78.74 microns 2, non-smokers--72.28 microns 2 and for CA (smokers--3273.9 microns 2, non-smokers--3098.96 microns 2) were obtained. A two-sample t-test revealed a significant elevation in NA for smokers, but no significant variation in CA between the two groups. These results would suggest that for normal buccal mucosa smoking does appear to influence cytomorphology.

Aged↗
PubMed1990

Genetic complementation in cystic fibrosis pancreatic cells by somatic cell fusion.

The biochemical defect that underlies the genetic disorder cystic fibrosis (CF) has been proposed to involve an altered regulation of epithelial Cl- permeability by agents such as adenosine 3',5'-cyclic monophosphate (cAMP). We report here the successful complementation of this functional defect achieved by using the technique of somatic cell fusion to introduce the normal CF allele into mutant cells. CF epithelial cells were fused with transfectant mouse fibroblasts that contain the normal human gene. The resulting heterokaryons were examined for restoration of cAMP-activated Cl- transport using an optical assay of Cl- permeability. Our results provide direct evidence for the involvement of the protein product of the normal CF allele in modulating epithelial Cl- permeability.

Animals↗
PubMed1989

Quantitative assessment of various fixatives on nuclear and cytoplasmic areas in oral cytology.

Both nuclear and cytoplasmic areas are parameters known to be of significance in the diagnosis of malignancy. However, few studies have assessed the effect of fixation on exfoliative cytology and none has looked at such influences upon oral smears. Hence the method of fixation may influence directly diagnostic cytology. The effect of three methods of fixation upon the nuclear and cytoplasmic areas of cells removed from the buccal mucosa was quantitatively assessed. The three methods employed, prior to Papanicolaou staining, were: direct immersion in diethylether and ethanol (1:1 v/v), spray fixation (Vale Smear Fix) and air drying. Three smears from each of 21 patients were used, each slide being allocated randomly a method of fixation. After 24 h all smears were processed for Papanicolaou's stain. The nuclear and cytoplasmic areas were calculated using semi-automated image analysis. No significant differences were found in the two areas whichever method of fixation was used.

Adult↗