Biomedical subjects

Nadir Arber

Publications and source records attributed to Nadir Arber.

40 records · Page 3Linked to original sources

PubMed2002

The usefulness of an inflammation meter to detect the presence of infection/inflammation in elderly patients.

BACKGROUND: Medical personnel who work in small geriatric institutions most frequently do not have access to realtime laboratory facilities. METHODS: In order to present a new method to determine the presence of an inflammatory response and for the assessment of its intensity, 118 patients aged 77 +/- 6 years with various bacterial infections were evaluated as well as 129 elderly individuals with various stressful conditions but no acute infections who served as controls. The leukocyte and erythrocyte adhesiveness/aggregation tests were performed by using a simple slide test and image analysis. The availability of the CD11b/CD18 and CD62L antigen on the leukocytes' surface was measured by whole blood flow cytometry, and the quantitative C-reactive protein by using laser nephelometry and specific antihuman C-reactive protein antibodies. RESULTS: A significant difference was noted between patients and controls for all variables obtained by the slide test and image analysis. In addition, a highly significant correlation was noted between the number of leukocytes counted on the slides and white blood cell count, between the leukocyte adhesiveness/aggregation test and quantitative C-reactive protein, and between the degree of erythrocyte adhesiveness/aggregation and either the Westergren sedimentation or fibrinogen concentration. CONCLUSIONS: By using our low-cost and real-time slide test, any medical or paramedical personnel can get relevant information regarding the presence of an acute phase response at the point of care.

Age Factors↗

PubMed2002

A simple biomarker to exclude the presence of low grade inflammation in apparently healthy individuals.

BACKGROUND: Atherosclerosis is accompanied by a low grade inflammatory response. HYPOTHESIS: To use erythrocyte aggregability as a biomarker to exclude the presence of low grade inflammatory response in apparently healthy individuals. METHODS: The adhesiveness/aggregation of red blood cells was quantitated by using a simple slide test and image analysis. RESULTS: We included 121 apparently healthy individuals and found a significant correlation between the degree of erythrocyte adhesiveness/aggregation and either the concentration of high sensitive CRP (r = 0.6, P < 0.001), erythrocyte sedimentation rate (r = 0.5, P < 0.0001) or fibrinogen (r = 0.5, P < 0.0001). By using certain cutoff points for the erythrocyte adhesiveness/aggregation test we could define individuals with a very low grade inflammatory response. CONCLUSIONS: By using this inexpensive and rapid assessment, we could clearly discriminate between individuals with a very low inflammatory response and those with a more intense one. This biomarker should be further evaluated as a possible screening test for use in large populations of apparently healthy individuals in whom the detection of low grade inflammation might contribute to guiding appropriate lifestyle modifications and therapeutic interventions.

Adult↗

PubMed2002

Colonic epithelial cell proliferation decreases with increasing levels of serum 25-hydroxy vitamin D.

Epidemiological evidence suggests a potential role for vitamin D in colon cancer prevention. Vitamin D, absorbed from the intestine or derived from solar ultraviolet light, is metabolized in the liver to 25-hydroxyvitamin D (25-OH D(3)). Previous studies examining effects of vitamin D upon carcinogenesis have focused upon the active metabolite 1,25-dihydroxyvitamin D [1,25-(OH)(2) D(3)], which interacts with nuclear vitamin D receptors in several organs. Until recently, the metabolism of 25-OH D(3) to 1,25-(OH)(2) D(3) was believed to occur only in the kidney, but more recent studies have shown that 25-OH D(3) conversion to 1,25-(OH)(2) D(3) can occur in other tissues. We examined the association between fasting levels of 25-OH D(3), 1,25-(OH)(2) D(3), and BsmI polymorphism of the vitamin D receptor (VDR) gene with indices of colonic epithelial cell proliferation and differentiation in a chemoprevention study, after giving vitamin D or calcium and taking rectal biopsies that were incubated with bromodeoxyuridine. Vitamin D receptor polymorphism was determined by genotyping of the 3' BsmI polymorphism in intron eight of the VDR gene. No significant changes in cell proliferation or in differentiation were found in subjects between study start and end. However, fasting serum levels of 25-OH D(3) showed a highly significant decrease with whole crypt labeling index and the size of the proliferative compartment (phi h). There was no correlation between serum levels of 1,25-(OH)(2) D(3) and the proliferative parameters. Calcium supplementation induced a significant effect upon the relationship between serum 25-OH D(3) and rectal epithelial cell labeling index and phi h when studied by covariance analysis without a relationship with 1,25-(OH)(2) D(3) levels. VDR genotype did not influence the effects of serum 25-OH D(3) or serum 1,25-(OH)(2) D(3) levels upon proliferation. These data suggest that there might be a local effect of 25-OH D(3) on colonic epithelial cells through conversion of 25-OH D(3) to 1,25-(OH)(2) D(3). Subsequent studies have demonstrated the presence of 1alpha-hydroxylase mRNA in normal colorectal epithelium and in colorectal cancer. Thus, vitamin D may have an important role in determining the effects of calcium on colorectal epithelial proliferation and may explain some of the discrepancies found previously in studies that examine the direct role of calcium on the colorectal epithelium.

Adult↗

PubMed2002

Oral contraceptive use and cyclin D1 overexpression in breast cancer among young women.

Cyclin D1, an important cell cycle regulator, is overexpressed in several human cancers including breast. Both estrogens and progestins activate the transcription of the gene; antiestrogens have been shown to reduce cyclin D1 protein levels. Cyclin D1 protein overexpression has been strongly associated with well-differentiated, estrogen receptor-positive tumors. Little is known, however, as to whether epidemiological risk factors are related to this molecularly defined subset of tumors. Using a population-based study of young women <45 years in New Jersey, we analyzed whether oral contraceptives (OCs) and other risk factors were associated with the overexpression of cyclin D1 in breast cancer tissue. We measured cyclin D1 status in paraffin-embedded, archived tissue from 78.8% of the breast cancer cases using immunohistochemistry. Cyclin D1 was overexpressed in 33.7% of the cases (123 of 365). We used unordered polytomous logistic regression to estimate the odds ratios (ORs) for two case groups--(a) breast cancer with cyclin D1 overexpression (n = 123) and (b) breast cancer without overexpression (n = 242)--compared with 462 population-based controls. The multivariate-adjusted OR for ever use of OCs was 1.6 [95% confidence interval (CI), 1.0-2.5] for cases that overexpressed cyclin D1 and 1.0 (95% CI, 0.7-1.5) for those with no overexpression. Among women who started using OCs at least 20 years before the reference date, the OR was increased 2-fold for breast cancer with cyclin D1 overexpression (OR, 2.2; 95% CI, 1.2-4.0) but not for breast cancer without cyclin D1 overexpression (OR, 1.1; 95% CI, 0.7-1.8). If replicated, these findings suggest that early OC use may be associated with the subset of mammary tumors that overexpress cyclin D1.

Adult↗