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Biomedical subjects

B Mullen

Publications and source records attributed to B Mullen.

29 records · Page 2Linked to original sources
PubMed1986

Primary anterior mediastinal tumors in children and adults.

This review details pertinent anatomical, radiological, pathological, and clinical information regarding primary anterior mediastinal tumors. Although the majority of these lesions are included in one of several subgroups, for example, thymic tumors, teratomas, or thyroid abnormalities, other less common entities will occasionally be encountered by the practicing surgeon. Likewise, there are variations in the frequency distribution of anterior mediastinal lesions in children as opposed to adults. Management of these individual lesions is outlined.

Adult↗
PubMed1986

The diagnosis of emphysema. A computed tomographic-pathologic correlation.

To assess the accuracy of computed tomography (CT) in the diagnosis of emphysema, we performed CT on 32 patients prior to surgery for removal of suspected tumors. The CT scans were assessed visually for emphysema by 2 independent radiologists and 1 chest physician. Intraobserver and interobserver variation were assessed. Pathologic emphysema was graded on the resected lung specimens. These grades were correlated with the CT scores and with pulmonary function tests obtained prior to surgery. Significant correlation was found between the pathologic grade on resected lung specimens and the preoperative CT score of both the resected lobe (r greater than or equal to 0.57, p less than 0.001) and the whole lung (r greater than or equal to 0.63, p less than 0.001). Compared with pulmonary function tests, CT was a better predictor of emphysema and distinguished patients with moderate emphysema from patients with normal lungs. We conclude that CT is a useful adjunct in assessing the presence and severity of emphysema.

Adult↗
PubMed1983

Sequential analysis of hepatic carcinogenesis. Regeneration of liver after carbon tetrachloride-induced liver necrosis when hepatocyte proliferation is inhibited by 2-acetylaminofluorene.

The effect of inhibition of hepatocyte proliferation by dietary 2-acetylaminofluorene (2-AAF) on the restoration of liver in rats after a necrogenic dose of carbon tetrachloride has been studied. The liver weights remained low during the entire feeding period of the 2-AAF, and virtually no hepatocyte proliferation was seen, as determined autoradiographically after thymidine incorporation and by the absence of mitotic figures. Oval cell proliferation was extensive. Morphometric analysis showed (a) equal and maximum liver cell necrosis by 24 hours in both the experimental and control groups, (b) similar kinetics of removal of dead liver cells, and (c) similar values for the mean liver cell area. The distance between the portal triad and terminal hepatic vein in animals on the dietary 2-AAF was considerably reduced. Massive hepatocyte proliferation began after termination of the 2-AAF diet, and the liver returned to normal appearance within 14 days. The oval cells disappeared during this period of liver cell restoration. A new hypothesis for oval cell proliferation based on differential inhibition of hepatocyte proliferation resulting in unbalanced growth of ductular cells is presented.

2-Acetylaminofluorene↗
PubMed1982

The effectiveness of attention and rejection as coping styles: a meta-analysis of temporal differences.

The purpose of this study was to conduct a meta-analysis [16] of research comparing the effects on physical adaptation of two cognitive strategies for coping with stressors: attention and rejection. Attention refers to focusing attention on the stressor and/or on one's rejection to it; rejection refers to focusing attention away from the stressor and/or one's reaction to it. For studies examining the immediate effects of attention and rejection, rejection produced better physical adaptation (i.e. fewer symptoms, reduced physiological responses) than attention. For studies looking at the long term effects of attention and rejection, attention produced better physical adaptation than rejection. Mechanisms which could produce these effects, and their implications, are discussed.

Adaptation, Physiological↗
PubMed1981

Life events, perceived control and illness: the role of uncertainty.

The health implications of recognizing the difference between situations that are controllable and those that are not has been noted by a variety of sources. With this notion in mind, the present study examined the relationship between perceptions of control and desirability of life events and subsequent health in a college student sample. Subjects indicated which of a list of life events had occurred to them over a three-month span and also specified how desirable each was and to what extent they were in control of its occurrence. Illness was reported for the following month. The results indicated that both undesirable uncontrollable events and undesirable events of uncertain controllability were significantly related to the occurrence of illness. Of greatest interest was the finding that the occurrence of events of uncertain controllability was more strongly related to illness than events perceived as totally uncontrollable. The results are discussed in terms of research and theory stressing the adaptative significance of the ability to discriminate controllable situations from uncontrollable ones.

Adaptation, Psychological↗
PubMed1981

Coronary-prone behavior, social insecurity and stress among college-aged adults.

One hundred and seventy-four male college students completed a student version of the Jenkins Activity Scale, the Macmillan stress inventory, measures of social insecurity, and items concerning personal habits and preferences. Social insecurity and Type A behavior emerged as independent but additive factors associated with negative stress experience. Type A's as compared to Type B's, reported feeling more stress, having and desiring less social support, being more interested in various performance standards and being upset for a longer period of time following poor school performance. Interestingly, no difference emerged between A's and B's regarding the temporal impact of successful school performance. High Social Insecurity subjects reported feeling more stress, having less social support, being more upset following poor school performance and being more interested in social comparison information as compared to their Low Social Insecurity counterparts. The results are interpreted as supportive of the notion that social insecurity and Type A behavior may contribute to coronary heart disease by affecting one's exposure and physiological reactions to everyday life stressors.

Adult↗
PubMed1981

Crystalline tissue deposits on a case of multiple myeloma.

Crystalline tissue deposits were found at the time of autopsy in a 52-year-old male subject who had had multiple myeloma for 6 1/2 years and in whom the hyperviscosity syndrome had developed terminally. The tissue deposits were digested by trypsin, but could not be further characterized by immunohistochemical techniques. The crystals varied in size and shape and were located in tissue histiocytes, renal tubular cells, Leydig's cells, and adrenocortical cells. No crystals were identified within plasma cells. Their presence in the present case may have been related to the relatively long course of the disease, the high levels of serum proteins terminally, and unusual physicochemical structure of the secreted proteins, or possibly to the effects of chemotherapy.

Adipose Tissue↗
PubMedDate not supplied

Umbilical vein and placental vessels from newborns with hereditary haemorrhagic telangiectasia type 1 genotype are normal despite reduced expression of endoglin.

Hereditary haemorrhagic telangiectasia, HHT, is an autosomal dominant disorder that affects approximately 1 in 8000 people. HHT1 is associated with mutations in the ENG (Endoglin) gene and with haploinsufficiency. The disorder is characterized by focally dilated vessels, which can lead to arteriovenous malformations and serious complications even in young children. In the current study, umbilical cord and placenta samples from newborns with ENG mutations were analyzed to estimate the level of corresponding protein and look for potential vascular dysplasia. We confirmed, using metabolic labelling and flow cytometry, that endoglin levels were significantly reduced to median values of 47 per cent (range 32-56 per cent) and 58 per cent (46-90 per cent), respectively, in human umbilical vein endothelial cells derived from newborns with ENG mutations (HHT1 group; n=18) relative to samples from newborns shown not to have the familial mutation (non-HHT group). We also quantified the relative expression of endoglin by estimating the endoglin/PECAM-1 staining ratio in tissue sections. We observed significantly lower values in the HHT1 group, compared to the non-HHT group for the umbilical vein (n=9; median 0.6 vs 0.9; ranges 0.2-1.0 and 0.5-1.5) and for placental stem villus vessels (n=9 and 10; median 0.42 vs 0.93; ranges 0.24-0.58 and 0.56-1.18). No differences in the estimated umbilical vein cross-sectional area and in the proportion of vessels present in placental villi were observed in sections from the HHT1 group relative to the non-HHT group. Thus, blood vessels from HHT1 individuals are maintained intact in the umbilical vein and placenta during pregnancy and delivery, despite a significant reduction in endoglin expression.

Antigens, CD↗
PubMedDate not supplied

Social and temporal bases of self-evaluation in the elderly: theory and evidence.

With what standards do the elderly evaluate their abilities, and do these standards differ from those used earlier in the life cycle? As in other stages of the life cycle, two forms of information are important in making self-evaluations-social comparison and temporal comparison. Social comparison refers to comparisons with other persons to gauge one's relative standing, while temporal comparison refers to comparisons of one's present performance with past performances on similar tasks to gauge improvement or deterioration. This study proposes that temporal comparison standards are used more by the elderly than social comparison standards and that this represents a reversal of the tendency found earlier in life. Social, cognitive, and physical reasons for this shift in the manner in which important abilities and traits are evaluated are discussed. Relevant empirical research, which supports the hypothesis, is reviewed. Finally, we discuss how the present hypothesis has an important implication for understanding self-esteem and morale in the elderly.

Aged↗