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Biomedical subjects

R Bergman

Publications and source records attributed to R Bergman.

At least 37 records · Page 2Linked to original sources
PubMed1997

A study of coagulation and anti-endothelial antibodies in idiopathic livedo reticularis.

Livedo reticularis is associated with collagen vascular diseases and other vaso-occlusive disorders in a substantial number of cases. In the remaining cases the cause of livedo reticularis is still unknown. (i.e., idiopathic). We sought to determine a possible causal relationship between idiopathic livedo reticularis and autoimmune factors associated with the coagulation system, including antiendothelial cell antibodies. Nine patients with idiopathic livedo reticularis were studied. All patients were found to have normal platelet count, fibrinogen levels, and prothrombin and activated partial thromboplastin times, as well as negative results for Venereal Disease Research Laboratory and D-timer tests. Anticoagulant activity was detected in 2 patients: one had positive results of thromboplastin titration index and Russell's viper venom test, as well as increased levels of anticardiolipin antibodies and anti-endothelial cell antibodies; the other has positive thromboplastin titration index, mildly increased levels of anti-endothelial cell antibodies, and markedly increased levels of antinuclear antibodies. A third patient had mildly increased levels of anti-endothelial cell antibodies alone, and a fourth patient had mildly increased levels of antinuclear antibodies only. The clinical outcome was uneventful in all of the patients during an 18-month follow-up period. These findings suggest involvement of autoimmune factors associated with the coagulation system in some patients with idiopathic livedo reticularis, whose clinical significance remains to be determined.

Adolescent↗
PubMed1997

Young people considering nursing as a career: starters vs. non-starters.

This study focused on applicants who were accepted to a nursing education program but did not begin their studies, thus wasting time, effort and money. Of 953 accepted applicants, 27% did not enter the program. Significant variables differentiating starters from non-starters were higher psychometric score, higher paternal education, lower priority for nursing studies, older age, non-Israeli country of birth and not completed army service. The study relating to starters vs. non-starters is one aspect of a large study (Ehrenfeld, Rotenberg, Sharon, & Bergman, 1995). In most nursing education programs the number of applicants exceed the faculty's capacity, and suitable candidates must be rejected. It is therefore both wasteful and disappointing when accepted applicants change their mind and do not actually begin in the program. In light of the costs and complexities involved in the student screening process and the continuous efforts extended today all over the world to raise the standards of nursing education and care, the factors differentiating starters from non-starters may have important implications. The aim of the present study was to evaluate the screening process at the Tel Aviv University baccalaureate nursing program and determine which variables were predictive of starters and non-starters among accepted applicants.

Discriminant Analysis↗
PubMed1996

Insulin sensitivity and atherosclerosis. The Insulin Resistance Atherosclerosis Study (IRAS) Investigators.

BACKGROUND: Reduced insulin sensitivity has been proposed as an important risk factor in the development of atherosclerosis. However, insulin sensitivity is related to many other cardiovascular risk factors, including plasma insulin levels, and it is unclear whether an independent role of insulin sensitivity exists. Large epidemiological studies that measure insulin sensitivity directly have not been conducted. METHODS AND RESULTS: The Insulin Resistance Atherosclerosis Study (IRAS) evaluated insulin sensitivity (SI) by the frequently sampled intravenous glucose tolerance test with analysis by the minimal model of Bergman. IRAS measured intimal-medial thickness (IMT) of the carotid artery as an index of atherosclerosis by use of noninvasive B-mode ultrasonography. These measures, as well as factors that may potentially confound or mediate the relationship between insulin sensitivity and atherosclerosis, were available in relation to 398 black, 457 Hispanic, and 542 non-Hispanic white IRAS participants. There was a significant negative association between SI and the IMT of the carotid artery both in Hispanics and in non-Hispanic whites. This effect was reduced but not totally explained by adjustment for traditional cardiovascular disease risk factors, glucose tolerance, measures of adiposity, and fasting insulin levels. There was no association between SI and the IMT of the carotid artery in blacks. The association between SI and the IMT was stronger for the internal carotid artery than for the common carotid artery in all ethnic groups. CONCLUSIONS: Higher levels of insulin sensitivity are associated with less atherosclerosis in Hispanics and non-Hispanic whites but not in blacks. This effect is partially mediated by traditional cardiovascular risk factors.

Adult↗
PubMed1996

A new method for diffusion measurement in polymeric films based on a stacked sheet concept.

PURPOSE: To develop and evaluate a simple, yet well defined, method to measure diffusion in semi-solids, i.e. polymeric materials. METHODS: The method was based on a concept where equivalent discs of polymeric films were cut and stacked on top of each other. The diffusion process was allowed to proceed unidimensionally through the stack of films perpendicular to the film surface. After an appropriate time, the stack was analysed disc by disc with respect to solute content and from the concentration profile so obtained the diffusion coefficient was calculated. RESULTS: An all-in-one device was developed, manufactured in stainless-steel, that cuts circular discs and stores each one successively in a "stack" in the cell compartment. CONCLUSIONS: Data from a silicone based system shows that the method, although simple, is accurate and reproducible.

Diffusion↗
PubMed1996

An immunohistochemical study of p53 protein expression in classical Kaposi's sarcoma.

The present study was performed to determine the frequency of p53 protein immunoreactivity in classical Kaposi's sarcoma (KS) as a whole and in relation to the histological subtypes which are considered to correspond to the developmental stages of the tumor. The accumulation of p53 protein was studied immunohistochemically using monoclonal antibody BP53-12 on formalin-fixed paraffin-embedded sections of 36 KS lesions, of which 14 were classified histologically as early type and 22 as spindle-cell or mixed type. No positive immunoreactivity was detected in any of the 14 early-type lesions. Among the 22 spindle-cell and mixed variants, positive staining was detected in 5-10% of the tumor cells in one lesion, 1-5% of the cells in six lesions, and in < 1% of the cells in two lesions. These very small percentages of positively stained cells in less than half of the cases of the spindle-cell and mixed variants do not support a significant role for p53 in tumor progression and evolution in KS.

Adult↗
PubMed1996

Mucinous syringometaplasia. An immunohistochemical and ultrastructural study of a case.

Mucinous syringometaplasia (MS) is an unusual skin lesion of unknown etiology, characterized histologically by epidermal invaginations lined by mucin-laden goblet-like cells and by nonkeratinized squamous cells. The present case study was performed to elucidate further the characteristics of this lesion using immunohistochemistry and electron microscopy. The mucin-laden cells in the MS lesion stained positively for carcinoembryonic antigen, epithelial membrane antigen, and low molecular weight keratins. The ultrastructural examination, which was performed on deparaffined sections, revealed two morphological variants of mucous granules. Electron-dense mucous granules predominated in the mucus-containing cells, which were situated among the keratinocytes adjacent to the epidermal invaginations, mostly in the lower parts of the epidermis. Larger, electron-lucent granules containing flocculent material were found more abundantly in the cells lining the epidermal invaginations. Also, some of the mucus-containing cells showed bundles of tonofilaments; structures that appeared to be isolated short, stubby microvilli; and attachments to adjacent mucus-containing cells and keratinocytes by desmosomes. The ultrastructural and immunohistochemical findings in our case suggest that the mucinous changes occurred as a metaplastic process in the resident epidermal cells and were accompanied by changes in cellular antigen expression resembling those of simple secretory epithelium.

Adult↗
PubMed1996

Measurement of the maturation parameter by using computer-assisted interactive image analysis may be helpful in the differential diagnosis between compound Spitz nevus and malignant melanoma.

The so-called maturation parameter (MP) (that is, the ratio of the mean nuclear areas in the deep portion and in the superficial portion of a tumor) was measured and calculated using a computer-assisted interactive image analysis system in 29 compound Spitz nevi (SNs) and 37 primary invasive cutaneous malignant melanomas (MMs), of which 16 and 14 lesions, respectively, measured up to 1 mm in Breslow thickness (that is, thin). The MPs of the SNs and MMs were found to be 0.37-0.89 (mean +/- SD, 0.64 +/- 0.1) and 0.81-1.16 (mean +/- SD, 0.96 +/- 0.1), respectively (p < 0.001). The MPs of the subgroups of thin SNs and MMs were 0.56-0.87 (mean +/- SD, 0.67 +/- 0.1) and 0.86-1.10 (mean +/- SD, 0.98 +/- 0.1), respectively (p < 0.001). Most of the SNs and MMs had MP values of < 0.81 and > 0.89, respectively. This pattern of distribution prevailed in the subgroup of thin lesions. Thus, the previously shown difference in MPs between SN and MM for thicker lesions (> or = 1.0 mm) was demonstrated in this study in thin lesions (< or = 1.0 mm) as well. Although a relatively small area of overlap in MP values exists between compound SNs and MMs, including the thin ones, below this area the lower the MP value the more likely the diagnosis is SN, and vice versa.

Cell Nucleus↗
PubMed1996

The mirror as a therapeutic tool for patients with dementia.

The aim of the study was to examine changes in patient behavior that occurred as a consequence of looking in a mirror. How do dementia patients relate to their image in the mirror? Is the use of the mirror effective in raising levels of self-awareness, calmness and satisfaction? The survey was carried out on 100 patients suffering from dementia: 67 women and 33 men aged between 67 and 85. The findings showed that most responses to looking in the mirror were positive and raised the patients' awareness regarding self-care. In a small number of patients, looking into the mirror aroused feelings of anger or despair, followed by relief and calmness. Findings indicated that the use of mirrors enabled nurses and caregivers to communicate better with patients. Most patients appeared to benefit in various ways from looking into the mirrors. The staff felt that use of mirrors was an inexpensive and efficient therapeutic tool for improving care of demented aged patients.

Aged↗
PubMed1996

Insulin sensitivity and abdominal obesity in African-American, Hispanic, and non-Hispanic white men and women. The Insulin Resistance and Atherosclerosis Study.

Increased abdominal obesity has been related to lower insulin sensitivity (SI), independent of overall obesity, but it has been suggested that this relationship may be weaker in non-whites. In the Insulin Resistance and Atherosclerosis Study (IRAS), SI was estimated using a minimal model analysis of the frequently sampled intravenous glucose tolerance test in 1,625 men and women aged 40-69 years. Subjects included African-Americans, Hispanics, and non-Hispanic whites from Oakland and Los Angeles, CA, San Antonio, TX, and the San Luis Valley, CO. Minimum waist circumference was significantly (P = 0.0001) associated with SI after adjusting for age, sex, height, BMI, glucose tolerance status, ethnicity, and clinic. This relationship was significantly (P = 0.0001) stronger in subjects with normal glucose tolerance (NGT) (beta = -0.030, P = 0.0001) than in those with impaired glucose tolerance (IGT) (beta = -0.010, P = 0.02; NIDDM: beta = -0.013, P = 0.0001). There were no significant ethnic differences in effect size across the spectrum of glucose tolerance. Waist circumference was also positively related to fasting insulin, an indirect measure of insulin sensitivity, in NGT (P = 0.0001), IGT (P = 0.0003), and NIDDM (P = 0.0002). The waist-fasting insulin relationship was significantly weaker in African-Americans, relative to non-Hispanic whites, in NGT and IGT (tests of statistical interaction: P = 0.04 and P = 0.02, respectively). In general, these patterns were similar in models specifying waist-to-hip ratio (WHR), rather than waist circumference, as the independent variable. While some ethnic variability exists, a negative relationship between abdominal obesity and insulin sensitivity was confirmed for all three ethnic groups across the spectrum of glucose tolerance.

Adult↗
PubMed1996

Normolipidemic xanthelasma palpebrarum: lipid composition, cholesterol metabolism in monocyte-derived macrophages, and plasma lipid peroxidation.

The lipid compositions of 8 normolipidemic xanthelasma palpebrarum (XP) lesions were analyzed using thin-layer chromatography, with the adjacent uninvolved skin used as control. The lesions were found to be composed predominantly of cholesterol, mostly cholesteryl ester, whereas in the control specimens phospholipids predominated. The degradation rates of 125I-low-density lipoprotein (LDL), oxidized LDL, and acetyl LDL, and the rates of intracellular cholesterol synthesis from 1,2-(14)C-acetate, in blood monocyte-derived macrophages (MDM) from 3 normolipidemic patients, were similar to those of MDM from 3 normal control subjects. The mean levels of lipid peroxides and conjugated dienes under basal conditions, as well as following the addition of a free radical-generating compound (2,2-azobis-2-amidinopropane hydrochloride) to the plasma of 14 normolipidemic XP patients were significantly higher than those of 14 age- and sex-matched normal controls. We conclude that the predominant lipid accumulated in normolipidemic XP lesions is cholesteryl ester, but there is no evidence for intrinsic cellular cholesterol metabolism derangement in blood MDM from patients which could account for this. Since macrophage cholesterol accumulation can also result from enhanced uptake of increased levels of oxidized LDL, the increased plasma lipid peroxidation (derived from oxidized LDL) might lead to accumulation of cholesterol in macrophages and formation of foam cells via this mechanism.

Adult↗