Biomedical subjects

R Siderits

Publications and source records attributed to R Siderits.

5 recordsLinked to original sources

PubMed1995

Dietary mustard, rape seed oils and selenium exert distinct effects on serum Se, lipids, peroxidation products and platelet aggregability.

OBJECTIVE: A degenerative cardiomyopathy (DCM) has been observed among mustard oil (MUST) users in China who eat 150 ml/week. Though the condition may be a selenium (Se) deficiency, MUST, rich in erucic acid (22:1), may bear a cardiotoxic or pro-oxidant substrate(s). The purpose of this feeding study was to compare the effects of feeding MUST, high erucic acid rape seed oil (HEAR), low erucic acid rape seed oil (LEAR) and corn oil, with or without Se addenda, on serum cholesterol, triglycerides, thiobarbituric acid reactive substances (TBARS), alpha-tocopherol, platelet aggregation and hepatic glutathione peroxidase (GSHPXase). Heart muscle pathology was evaluated. METHODS: Eighty male, weanling Wistar rats were divided into four dietary groups and fed AIN76A diet for 8 weeks with one of four oils: 1) MUST, 2) HEAR, 3) LEAR, or CORN oil. Half of each group received 0.43 mg/kg Se supplement. A purified diet was fed for 8 weeks. RESULTS: Neither Se nor oil type affected growth, though serum Se rose with dietary Se addendum (p < 0.01), and hepatic GSHPXase rose for each oil (p < 0.01). Se deprivation led to elevated serum cholesterol, except for the CORN oil group (p < 0.01). Only with LEAR did HDL cholesterol decrease. Serum triglycerides decreased with MUST and LEAR feedings (p < 0.05). In Se deficiency, HEAR led to elevated TBARS (p < 0.01), though not MUST, which contained twice as much alpha-tocopherol. Though supplementary Se protected the HEAR-fed animals from secondary peroxidation as TBARS (p < 0.01), the MUST group was not so protected. Ration Se also spared serum alpha-tocopherol for each diet group except the MUST/Se group (p < 0.05). MUST oil feeding resulted in increased platelet aggregation; MUST and HEAR resulted in increased platelet ATP release compared with CORN oil. CONCLUSION: Oxidative mechanisms may be involved in the DCM involving both Se limitation and pro-oxidant stress related to the usual intake of MUST. Human studies have been undertaken to test this thesis.

Adenosine Triphosphate↗

PubMed1995

Three-dimensional reconstruction of the human renal glomerulus.

The capillary bed of the human renal glomerulus is one of the more complex capillary structures in the human body. This paper illustrates three-dimensional reconstruction of the capillary bed from serial sections. It shows that, although traditional methods of three-dimensional rendering by computer fail to handle the complexities of the capillary structure, new methods based on filtering using three-dimensional mathematical morphology are capable of revealing previously unseen details. This is done at the expense of eliminating fine structure (small capillaries). An error analysis allows the degree to which fine details are lost to be estimated.

Capillaries↗

PubMed1992

Value of cytometric analysis for distinction of intraductal carcinoma of the breast.

The DNA nuclear content of 83 'pure' intraductal cancers (DCIS), 30 DCIS with an invasive component, 7 intraductal papillomas, 26 atypical hyperplasias, and 5 'hobnail' lesions was determined with a Cell Analysis Systems Image Analyzer (CAS 200). No consistent quantitative alteration of DNA or nuclear grade assessed by routine microscopy was observed for any ductal change diagnostic of DCIS. Fifty-eight percent of all DCIS were considered to be aneuploid, whereas all papillomas and atypical hyperplasias were diploid with normoproliferative S-phase and good nuclear grade. Use of ploidy, S phase, or nuclear grade for the distinction of DCIS and papillomas and atypical hyperplasia is limited, since their estimates would be comparable in 42%, 46%, and 40% of instances respectively. Poor nuclear grade was significantly more frequent in solid than cribriform types of DCIS. There were no significant differences in any parameters in DCIS with and without comedo necrosis. This represents further evidence against recognition of a unique comedo form of DCIS. DNA histograms of nuclei comprising the 'hobnail' lesions were aneuploid. Despite this their biologic nature is uncertain. No consistent differences in DNA content were noted between DCIS with and without an invasive component. This obfuscates insight into the role of DCIS in the development of invasive cancer of the breast.

Aneuploidy↗

PubMed1992

New techniques for three-dimensional data analysis in histopathology.

This paper describes two three-dimensional (3D) analytical techniques based on 3D mathematical morphology that have been found useful in quantifying the 3D spatial distribution of S-phase cells in a tubular tumor of the human breast. One technique is based on determining the normalized radial distribution of the S-phase cells with respect to the central axis of the tumor. The other technique is a novel extension of the polyhedra of Voronoi to quantify the distribution. The Voronoi polyhedron of a given S-phase cell nucleus is that polyhedron of minimal volume defined by planes all of which are perpendicular bisectors of the vectors extending from the given cell to all other S-phase cells in the tumor. Methods are demonstrated for generating these polyhedra and for histogramming their volumes. An illustration is given of using the histogram to sort the S-phase cells according to their 3D positional relationships. Displays showing the sorted cells in 3D and their associated Voronoi polyhedra are provided.

Adult↗

PubMed1991

DNA flow cytometric analysis of primary operable breast cancer. Relation of ploidy and S-phase fraction to outcome of patients in NSABP B-04.

Between 1971 and 1974, 1665 women with primary operable breast cancer were randomized into a National Surgical Adjuvant Breast and Bowel Project (NSABP) trial (B-04) conducted to evaluate the effectiveness of several different regimens of surgical and radiation therapy. No systemic therapy was given. Cells from archival paraffin-embedded tumor tissue taken from 398 patients were analyzed for ploidy and S-phase fraction (SPF) using flow cytometry. Characteristics and outcome of patients with satisfactory DNA histograms were comparable to those from whom no satisfactory cytometric studies were available. In patients with diploid tumors (43%), the mean SPF was 3.4% +/- 2.3%; in the aneuploid population (57%), the SPF was 7.9% +/- 6.3%. Only 29.9% +/- 17.3% of cells in aneuploid tumors were aneuploid. Diploid tumors were more likely than aneuploid tumors to be of good nuclear grade (P less than 0.001) and smaller size (P equals 0.03). More tumors with high SPF were of poor nuclear grade than were tumors with low SPF (P equals 0.002). No significant difference in 10-year disease-free survival (P equals 0.3) or survival (P equals 0.1) was found between women with diploid or aneuploid tumors. Patients with low SPF tumors had a 13% better disease-free survival (P equals 0.0006) than those with a high SPF and a 14% better survival (P equals 0.007) at 10 years than patients with high SPF tumors. After adjustment for clinical tumor size, the difference in both disease-free survival and survival between patients with high and low SPF tumors was only 10% (P equals 0.04 and 0.08, respectively). Although SPF was found to be of independent prognostic significance for disease-free survival and marginal significance for survival, it did not detect patients with such a good prognosis as to preclude their receiving chemotherapy. The overall survival of patients with low SPF was only 53% at 10 years. These findings and those of others indicate that additional studies are necessary before tumor ploidy and SPF can be used to select patients who should or should not receive systemic therapy.

Breast Neoplasms↗