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Biomedical subjects

S Franz

Publications and source records attributed to S Franz.

25 records · Page 2Linked to original sources

Ultrametricity in three-dimensional edwards-anderson spin glasses

We perform an accurate test of ultrametricity in the aging dynamics of the three-dimensional Edwards-Anderson spin glass. Our method consists in considering the evolution in parallel of two identical systems constrained to have fixed overlap. This turns out to be a particularly efficient way to study the geometrical relations between configurations at distant large times. Our findings strongly hint towards dynamical ultrametricity in spin glasses, while this is absent in simpler aging systems with domain growth dynamics. A recently developed theory of linear response in glassy systems allows us to infer that dynamical ultrametricity implies the same property at the level of equilibrium states.

Journal Article↗

[Changes in colitis surgery. I: Is there a standard in primary surgical treatment?].

In a 15 years period surgery of ulcerative colitis expanded from ileostomy (IS) via Kock's pouch (KP) and ileoanal pouch (IAP) to ileorectal anastomosis (IRA). Interactions between availability of methods and frequency of operations are investigated retrospectively in order to establish an optimal primary procedure. With an overall amount of 80 operations the yearly operative frequency raised in correlation to the introduction of continence reconstructive procedures. As a consequence of this fact history of disease was shortened to less than 8 year and global colitis-associated morbidity markedly decreased. For patients readiness to undergo operation Kock's pouch was only important at the beginning (n = 9/11.3%). Most decisive was IAP (n = 49/61.3%) which could be realized last even in an one-stage-procedure with better early results due to improved patients conditions and simplified technical modifications. IRA (n = 7/8.8%) played only a limited role in the last years for selected patients, whereas IS (n = 15/18.8%) kept reserved for contraindications to reconstructive surgery. For all procedures operative complications decreased from 46.1% (12/26) to 11.0% (6/54) and lethality to 0%. Late complications were related to proctectomy (nerve damage) and construction of IAP (pouchitis in 34.8% and defunctioning of the pouch in 10.4%), whereas IRA was free of specific morbidity so far. Surgery of ulcerative colitis is characterized today by restoration of anal continence. The advantage of the changed surgical concept lies within the ability to perform colectomy at an earlier stage of the disease. Safe construction of IAP is the most important technical progress. Early operation of colitis and late morbidity of pouch justify (preliminary) IRA. Thus, surgical standard in colitis-surgery is defined more individually.

Adolescent↗

Role of insulin in lipoprotein secretion by cultured rat hepatocytes.

To study the effect of insulin on lipoprotein synthesis and secretion by the liver, apoprotein and lipid levels were measured in primary rat liver cell cultures grown on fibronectin-coated dishes. Triglycerides, phospholipids, apoprotein (apo) B, apo-E, and apo-C-III3 all accumulated in culture media linearly for periods up to 20 h. During incubations, cellular triglyceride contents increased slightly, while cellular apoprotein and phospholipid contents remained constant. In the absence of insulin, rates of accumulation in media of triglycerides, apo-B, apo-C-III3, and apo-E were 2.5 +/- 0.3 micrograms/mg and 33 +/- 5, 24 +/- 3, and 162 +/- 32 ng/mg cell protein per h, respectively. On gel permeation chromatography and density gradient ultracentrifugation, the majority of apoproteins in media were found to be associated with very low density lipoproteins (VLDL) and very little eluted or sedimented with albumin. Incubations in the presence of 50-800 microU/ml of insulin resulted in dose-dependent decreases of triglyceride, phospholipid, apo-B, and apo-E accumulation in the media, paralleled by increases in the cellular contents of these lipoprotein components. The inhibitory effects of insulin on secretion were reversible. Levels of apo-C-III3 and albumin were not affected by insulin. In addition to decreasing secretory rates, the proportion of apo-B, apo-E, and apo-C-III3 associated with VLDL also decreased after the addition of insulin. Concomitantly, the proportion of apo-B eluting with LDL and apo-C-III3, and apo-E eluting near albumin increased. Control experiments, in which exogenous 125I-VLDL or endogenously labeled [14C]VLDL were added to cultures, revealed that the insulin-induced differences in VLDL accumulation and the lipid association of media apoproteins were not due to differences in the processing of VLDL by cells cultured in the presence or absence of insulin. Therefore, it appears that insulin may inhibit the secretion of VLDL perhaps by reducing the intracellular association of lipids and apoproteins.

Animals↗

[Sonography of the teat of cattle, sheep and goats in comparison with other methods of diagnostic imaging--a review].

Beside the clinical examination of udder/teat imaging methods e.g. sonography, radiography and endoscopy allow diagnosis. This publication will give a summary of currently used and potentially usable methods of diagnostic imaging applied to the teat. Advantages and disadvantages of the several methods were compared--as quoted in literature and completed by own experiences.

Animals↗