Accuracy of the One-Point in Vivo Calibration of “Wired” Glucose Oxidase Electrodes Implanted in Jugular Veins of Rats in Periods of Rapid Rise and Decline of the Glucose Concentration

SummaryWe compared the relative abilities of unfractionated heparin and annexin V to prevent fibrin accretion onto injured jugular veins in vivo. Heparin was used to accelerate the inhibition of thrombin by antithrombin III, and annexin V was used to inhibit the assembly of the prothrombinase complex on phospholipid surfaces, thereby blocking thrombin generation. Rabbit jugular veins were isolated in situ, a 2 cm segment was injured by perfusing it with air, and then blood flow was re-established. Five minutes later, each rabbit was injected with heparin (20 U/kg) or annexin V (0.3 mg/kg) and then with 125I-fibrinogen. The amount of 125I-fibrin accumulation onto each injured vessel wall segment was measured 4 h later. Each injured vessel was completely deendothelialized as a result of the air perfusion as demonstrated by electron microscopy. 125I-fibrin accretion onto the injured jugular veins was enhanced 2.4-fold as compared to the uninjured veins in sham-operated animals. Heparin treatment did not reduce fibrin accretion, whereas, annexin V treatment decreased fibrin accretion by 60%, p <0.05. This latter effect was achieved without sustained circulating anticoagulation. Additional experiments confirmed that the inhibitory effect of annexin V on fibrin accretion was associated with a surface specific effect, since more annexin V bound to the injured jugular vein segments as compared to the non-injured jugular veins. We conclude that, i) mild vessel wall injury (selective de-endothelialization) in veins results in a thrombogenic vessel wall; ii) the thrombogenecity of which is not inhibited by prophylactic doses of heparin; but iii) is inhibited by annexin V, which binds to injured vessel wall surface, and inhibits thrombin generation independently of antithrombin III.

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STUDIES IN CONGENITAL GENERALIZED LIPODYSTROPHY

Acta Endocrinologica ◽

10.1530/acta.0.0720495 ◽

1973 ◽

Vol 72 (3) ◽

pp. 495-505 ◽

Cited By ~ 7

Author(s):

Oddmund Søvik ◽

Svein Oseid

Keyword(s):

Biological Activity ◽

Insulin Response ◽

Epididymal Adipose Tissue ◽

Large Individual ◽

Immunoreactive Insulin ◽

List Type ◽

Glucose Load ◽

Congenital Generalized Lipodystrophy ◽

The One

ABSTRACT The biological activity of plasma insulin from 4 cases of congenital generalized lipodystrophy has been studied, using rat diaphragm and epididymal adipose tissue in vivo. The results are compared with previous data on plasma immunoreactive insulin obtained in these patients. 2 of the 4 cases exhibited unusually high biological insulin activities during the fasting state as well as after an intravenous (iv) glucose load. In the fat pad assay activities as high as 10 000 μU insulin per ml were observed. During childhood the biological insulin activities were generally high, although there were large individual variations. However, in the one case studied after the age of puberty, the insulin response to a glucose load was negligible. Taken together, the biological and immunological activities observed strongly suggest the presence of pancreatic insulin in these patients. It appears that the circulating insulin has a fully biological activity. The decreasing insulin activities after cessation of growth are in agreement with the appearance of frank diabetes at this time.

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In vivo calibration of the T2* cardiovascular magnetic resonance method at 1.5 T for estimation of cardiac iron in a minipig model of transfusional iron overload

Journal of Cardiovascular Magnetic Resonance ◽

10.1186/s12968-021-00715-6 ◽

2021 ◽

Vol 23 (1) ◽

Author(s):

Peter Diedrich Jensen ◽

Asbjørn Haaning Nielsen ◽

Carsten Wiberg Simonsen ◽

Ulrik Thorngren Baandrup ◽

Svend Eggert Jensen ◽

...

Keyword(s):

Rank Correlation ◽

Calibration Data ◽

Iron Loading ◽

Spearman Rank Correlation ◽

Calibration Equation ◽

Spearman Rank ◽

Cardiac Iron ◽

In Vivo Calibration ◽

Spearman Rank Correlation Coefficient

Abstract Background Non-invasive estimation of the cardiac iron concentration (CIC) by T2* cardiovascular magnetic resonance (CMR) has been validated repeatedly and is in widespread clinical use. However, calibration data are limited, and mostly from post-mortem studies. In the present study, we performed an in vivo calibration in a dextran-iron loaded minipig model. Methods R2* (= 1/T2*) was assessed in vivo by 1.5 T CMR in the cardiac septum. Chemical CIC was assessed by inductively coupled plasma-optical emission spectroscopy in endomyocardial catheter biopsies (EMBs) from cardiac septum taken during follow up of 11 minipigs on dextran-iron loading, and also in full-wall biopsies from cardiac septum, taken post-mortem in another 16 minipigs, after completed iron loading. Results A strong correlation could be demonstrated between chemical CIC in 55 EMBs and parallel cardiac T2* (Spearman rank correlation coefficient 0.72, P < 0.001). Regression analysis led to [CIC] = (R2* − 17.16)/41.12 for the calibration equation with CIC in mg/g dry weight and R2* in Hz. An even stronger correlation was found, when chemical CIC was measured by full-wall biopsies from cardiac septum, taken immediately after euthanasia, in connection with the last CMR session after finished iron loading (Spearman rank correlation coefficient 0.95 (P < 0.001). Regression analysis led to the calibration equation [CIC] = (R2* − 17.2)/31.8. Conclusions Calibration of cardiac T2* by EMBs is possible in the minipig model but is less accurate than by full-wall biopsies. Likely explanations are sampling error, variable content of non-iron containing tissue and smaller biopsies, when using catheter biopsies. The results further validate the CMR T2* technique for estimation of cardiac iron in conditions with iron overload and add to the limited calibration data published earlier.

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The One-Year In Vivo Comparison of Lithium Disilicate and Zirconium Dioxide Inlays

Materials ◽

10.3390/ma14113102 ◽

2021 ◽

Vol 14 (11) ◽

pp. 3102

Author(s):

Rini Behera ◽

Lora Mishra ◽

Darshan Devang Divakar ◽

Abdulaziz A. Al-Kheraif ◽

Naomi Ranjan Singh ◽

...

Keyword(s):

Zirconium Dioxide ◽

Clinical Performance ◽

Lithium Disilicate ◽

Study Groups ◽

Resin Cement ◽

Internal Surfaces ◽

Colour Match ◽

One Year ◽

The One

The objective of the present study was to evaluate the one-year clinical performance of lithium disilicate (LD) and zirconium dioxide (ZrO2) class II inlay restorations. Thirty healthy individuals who met the inclusion criteria were enrolled for the study. The patients were randomly divided into two study groups (n = 15): LD (IPS e.max press) and ZrO2 (Dentcare Zirconia). In the ZrO2 group, the internal surfaces of the inlays were sandblasted and silanized with Monobond N (Ivoclar, Leichsteistein, Germany). In the LD group, the internal surfaces of the inlays were etched with 5% hydrofluoric acid. The ceramic inlays were cemented with self-cure resin cement (Multilink N). Clinical examinations were performed using modified United State Public Health Codes and Criteria (USPHS) after 2 weeks, 4 weeks, 6 months and 1 year. The one-year survival rate was evaluated. In total, one failure was observed in the ZrO2 group. The survival probability after 1 year for the ZrO2 inlays was 93%, and for the LD inlays was 100%, which was statistically insignificant. The differences between both groups for most USPHS criteria (except for colour match) were statistically insignificant. Within the imitations of the present study, the lithium disilicate- and zirconia dioxide-based inlays exhibited comparable clinical performances. However, the colour and translucency match was superior for the lithium disilicate restorations.

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Four methods for glucose assay compared for various glucose concentrations and under different clinical conditions.

Clinical Chemistry ◽

10.1093/clinchem/28.12.2405 ◽

1982 ◽

Vol 28 (12) ◽

pp. 2405-2407 ◽

Cited By ~ 18

Author(s):

O Giampietro ◽

A Pilo ◽

G Buzzigoli ◽

C Boni ◽

R Navalesi

Keyword(s):

Glucose Oxidase ◽

Glucose Concentration ◽

Normal Subjects ◽

Maintenance Hemodialysis ◽

Oral Glucose ◽

Glucose Assay ◽

Glucose Tolerance Tests ◽

Uremic Patients ◽

Reducing Substances ◽

Clinical Conditions

Abstract Glucose was measured by the ferricyanide, the Beckman glucose oxidase, and the hexokinase procedures in 228 plasma samples taken during standard oral glucose-tolerance tests in 17 normal subjects and in 21 chemical diabetics. The neocuproine method was also used to measure glucose concentration in 156 samples (78 before and 78 after dialysis) collected from six diabetic and uremic patients who were on maintenance hemodialysis. Ferricyanide in all conditions and neocuproine in uremic patients overestimated glucose concentrations over the entire experimental range as compared with either enzymic method. This bias or systematic error of the reducing vs the enzymic procedures, due to nonglucose reducing substances ("saccharoids"), becomes considerably greater when their concentration is increased as in chronic uremia. Also, the inverse relation between glucose concentration and overestimation of glucose by the reducing methods has been detected. With respect to the hexokinase method, a mild but significant underestimate of glucose oxidase readings has been observed for higher glucose concentrations. We find neocuproine to be the most imprecise of these procedures.

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Effect of microbial isolates on microbial yield estimation in RUSITEC system

BSAP Occasional Publication ◽

10.1017/s0263967x0003295x ◽

1998 ◽

Vol 22 ◽

pp. 306-308

Author(s):

M. D. Carro ◽

E. L. Miller

Keyword(s):

Protein Synthesis ◽

Liquid Phase ◽

Solid Phase ◽

Liquid Fraction ◽

Microbial Protein ◽

Microbial Protein Synthesis ◽

Continuous Culture System ◽

The One

The estimation of rumen microbial protein synthesis is one of the main points in the nitrogen (N)-rationing systems for ruminants, as microbial protein provides proportionately 0.4 to 0.9 of amino acids entering the small intestine in ruminants receiving conventional diets (Russell et al., 1992). Methods of estimating microbial protein synthesis rely on marker techniques in which a particular microbial constituent is related to the microbial N content. Marker : N values have generally been established in mixed bacteria isolated from the liquid fraction of rumen digesta and it has been assumed that the same relationship holds in the total population leaving the rumen (Merry and McAllan, 1983). However, several studies have demonstrated differences in composition between solid-associated (SAB) and fluid-associated bacteria in vivo (Legay-Carmier and Bauchart, 1989) and in vitro (Molina Alcaide et al, 1996), as well in marker : N values (Pérez et al., 1996). This problem could be more pronounced in the in vitro semi-continuous culture system RUSITEC, in which there are three well defined components (a free liquid phase, a liquid phase associated with the solid phase and a solid phase), each one having associated microbial populations.The objective of this experiment was to investigate the effect of using different bacterial isolates (BI) on the estimation of microbial production of four different diets in RUSITEC (Czerkawski and Breckenridge, 1977), using (15NH4)2 SO4 as microbial marker, and to assess what effects any differences would have on the comparison of microbial protein synthesis between diets.This study was conducted in conjunction with an in vitro experiment described by Carro and Miller (1997). Two 14-day incubation trials were carried out with the rumen simulation technique RUSITEC (Czerkawski and Breckenridge, 1977). The general incubation procedure was the one described by Czerkawski and Breckenridge (1977) and more details about the procedures of this experiment are given elsewhere (Carro and Miller, 1997).

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In vitro and in vivo evaluation of oxygen effects on a glucose oxidase based implantable glucose sensor

Analytica Chimica Acta ◽

10.1016/0003-2670(93)85009-9 ◽

1993 ◽

Vol 281 (3) ◽

pp. 513-520 ◽

Cited By ~ 63

Author(s):

Yanan Zhang ◽

George S. Wilson

Keyword(s):

Glucose Oxidase ◽

Glucose Sensor ◽

In Vivo Evaluation ◽

Oxygen Effects

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Effects of embryo culture on global pattern of gene expression in preimplantation mouse embryos

Reproduction ◽

10.1530/rep.1.00297 ◽

2004 ◽

Vol 128 (3) ◽

pp. 301-311 ◽

Cited By ~ 193

Author(s):

Paolo Rinaudo ◽

Richard M Schultz

Keyword(s):

Gene Expression ◽

Preimplantation Embryos ◽

Expression Analysis Systematic Explorer ◽

Cell Stage ◽

Global Pattern ◽

Preimplantation Mouse Embryos ◽

Preimplantation Mouse ◽

Global Patterns ◽

The One

Culture of preimplantation embryos affects gene expression. The magnitude of the effect on the global pattern of gene expression, however, is not known. We compared global patterns of gene expression in blastocysts cultured from the one-cell stage in either Whitten’s medium or KSOM + amino acids (KSOM/AA) with that of blastocysts that developed in vivo, using the Affymetrix MOE430A chip. The analysis revealed that expression of 114 genes was affected after culture in Whitten’s medium, whereas only 29 genes were mis-expressed after culture in KSOM/AA. Expression Analysis Systematic Explorer was used to identify biological and molecular processes that are perturbed after culture and indicated that genes involved in protein synthesis, cell proliferation and transporter function were down-regulated after culture in Whitten’s medium. A common set of genes involved in transporter function was also down-regulated after culture in KSOM/AA. These results provide insights as to why embryos develop better in KSOM/AA than in Whitten’s medium, and highlight the power of microarray analysis to assess global patterns of gene expression.

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Regulation of c-met expression in B16 murine melanoma cells by melanocyte stimulating hormone

Journal of Cell Science ◽

10.1242/jcs.112.5.623 ◽

1999 ◽

Vol 112 (5) ◽

pp. 623-630

Author(s):

D. Rusciano ◽

P. Lorenzoni ◽

M.M. Burger

Keyword(s):

Melanoma Cells ◽

Parental Cell ◽

Melanocortin Receptor ◽

Parental Cell Line ◽

Melanocyte Stimulating Hormone ◽

Murine Melanoma ◽

The One ◽

Murine Melanoma Cells ◽

Stimulating Hormone

B16 murine melanoma cells selected in vivo for enhanced liver metastatic ability (B16-LS9) show on the one hand an increased expression and constitutive activation of the proto-oncogene c-met (the receptor for hepatocyte growth factor/scatter factor), and on the other hand a more differentiated phenotype, when compared to the parental cell line, B16-F1. Following this observation, we have tried to establish whether there is a direct relationship between differentiation and c-met expression in B16 melanoma cells. Treatment of these cells with differentiating agents indicated that c-met expression was strongly induced by melanocyte stimulating hormone, while retinoic acid had almost no influence. c-met induction was triggered by engagement of the melanocortin receptor, cAMP elevation and PKA/PKC(α) activation, as respectively shown by the effects of ACTH, cAMP elevating agents and specific PK inhibitors. Regulation of c-met expression via the melanocortin receptor and cAMP raises the intriguing possibility that autocrine and/or paracrine mechanisms acting in vivo on this circuit might influence (through c-met expression and activation) the metastatic behavior of these tumor cells, which we have shown to be dependent on their c-met expression.

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