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Biomedical subjects

K Reichel

Publications and source records attributed to K Reichel.

At least 19 recordsLinked to original sources
PubMed2005

InEOS--new system component in Cerec 3D.

A new device for digitizing model surfaces for dental CAD/CAM applications is available with the inEOS scanner. It works according to the principle of stripe light projection. Both rotational scan mode of single prepared teeth and overview scan mode in which a complete model of the jaw can be acquired are possible. Detailed scans can be token in addition to improve the data quality. The software basis is the proven Cerec inLab 3D program. The virtually produced restorations can be milled either with the inLab milling unit or transferred to the Infinident milling center for central production. A clinical case which was treated by using the inEOS scanner is presented.

Adult↗
PubMed2004

Virtual Reality by Cerec inLab Framework.

Virtual Reality--meaning the visualization of abstract computer processes--is gaining increasing significance in the everyday routine of the dental laboratory working with CAD/CAM technology. This is indispensable especially when processing the new high-strength materials such as ZrO2. The average maximum chewing forces previously permitted a bridge in the posterior region only when metal ceramics were used. With the aid of modern computer technology, it is now possible to use the all-ceramic material of zirconium dioxide for these indications. The technical procedure in the dental laboratory corresponds largely to the production techniques that are known from use with aluminum oxide. VITA VM 9 (Vita Zahnfabrik, Bad Säckingen, Germany) is available as veneer material. Its coefficient of thermal expansion is perfectly matched to the ceramic.

Bite Force↗
PubMed2003

All-ceramic primary telescopic crowns with Cerec inLab.

On the one hand, all-ceramic primary telescopic dentures serve to satisfy the growing esthetic needs of older patients, and on the other hand guarantee good adhesive stability. With the aid of the Cerec inLab system, primary telescopic crowns made of Vita In-Ceram infiltration ceramic can be designed and milled after previous conventional determination of the over all insertion direction. The raw crowns gained in this way then require only minor improvement. The secondary parts are produced with the aid of electroforming. These are adhesively bonded to the tertiary structure. The special feature of adhesive bonding of the primary telescopic crowns requires uncompromisingly good cooperation between dentist and laboratory.

Aluminum Oxide↗
PubMed2003

3D software extension for Cerec inLab.

Three new software components for the Cerec inLab system, already proven in the dental laboratory area, are presented. They are all based on three-dimensional display. On the one hand, the design can be simplified, and on the other hand, the range of indications can be extended to inlays, onlays, veneers, and multiunit bridges with the aid of these new components.

Computer-Aided Design↗
PubMed1997

Effect of clenbuterol on growth, carcase and skeletal muscle characteristics in broiler chickens.

1. Male and female broiler chickens (144 in total) were given diets supplemented with clenbuterol (CB) at 0 (control) and at 1 mg/kg between 28 and 49 d of age to study the effect of CB on growth, carcase and skeletal muscle. 2. CB improved growth in males by increasing daily weight gain and final live weight and by lowering food conversion ratio. In females it changed the carcase composition by reducing abdominal fat pad and by increasing the proportion of protein. Consequently, carcase protein gain was increased in both sexes (11% and 16%, respectively). 3. Skeletal muscle weights were enhanced by between 6% and 22%. Muscle fibre diameters were increased in extensor hallucis longus (EHL) but not in gastrocnemius (GAS) muscle. This increase was more pronounced in females. EHL total muscle fibre number remained unchanged. The proportion of fast-twitch glycolytic fibres was increased at the expense of fast-twitch oxidative fibres in males only. Nuclear/cytoplasm and DNA/protein ratios tended to be decreased by CB. 4. From the elevated EHL muscle RNA/DNA, unchanged protein/RNA and translation activity it is suggested that CB stimulated protein synthesis at the pretranslational level. Reduced protein degradation is deduced from decreased neutral calcium-dependent proteolytic activity. 5. It is concluded that broiler chickens respond to long-term CB treatment as has been shown in various mammals. However, the sex-specific response in growth, carcase composition and skeletal muscle cellularity is more clearly apparent in broiler chickens.

Adrenergic beta-Agonists↗
PubMed1994

[The effect of the beta-adrenergic agonist clenbuterol on the growth of skeletal muscles of rats].

The effects of clenbuterol (CB) on the weights of 6 hindleg muscles as well as on structural and biochemical characteristics of extensor digitorum longus muscle (EDL) were studied on Wistar rats. Different CB-doses (5 vs. 18 mg/kg diet) were tested and rats of different sex were used. The 12 days treatment accelerated the growth of the 6 hindleg muscles by 13 to 24% without predominant response of fast twitch or slow twitch muscles. The higher muscle weights were achieved by fibre hypertrophy as demonstrated by increased fibre diameters (+13 to +16%), and not by fibre multiplication. There was no evidence for a selective fibre hypertrophy of one of the metabolic fibre types. Fibre type composition shifted to the fast glycolytic fibres (FTG +0.7 to +4.9%-units). There were no significant differences in responses between the sexes of CB-doses. Clenbuterol decreased the nucleus/cytoplasm ratio, measured as nuclei number/mm2 fibre area, between 24 and 28% and the DNA/protein ratio by 17%. RNA content and RNA/DNA ratio were enhanced by 25 and 22%, respectively; the protein/RNA ratio remained unchanged. The results suggest that clenbuterol changes fibre type composition and stimulates fibre growth in a pretranslational stage of protein synthesis without addition of nuclei by satellite cell proliferation.

Adrenergic beta-Agonists↗
PubMed1994

[Laparoscopic cholecystectomy as standard intervention in symptomatic cholecystolithiasis. Experiences with 1,277 patients].

As a result of 1277 laparoscopic cholecystectomies, which were performed as a standard procedure in uncomplicated and complicated symptomatic cholecystolithiasis, the complication-rates of conventional cholecystectomy and laparoscopic cholecystectomy are compared. It can be demonstrated, that the adoption of the principles of conventional cholecystectomy into laparoscopic technique and a careful preparation can reach the same high level of safety as the so called "gold-standard".

Adolescent↗
PubMed1993

[The passage, absorption and secretion of nitrogen during the postprandial period using 15N-labeled wheat and marker in growing rats].

After a 9 day preparation period 42 Wistar rats (live weight 100 g) were fed a diet of 15N labelled wheat supplemented with the marker TiO2 (impulse labelling). At 7 time intervals (0.5 to 6 h after feeding) 6 animals were killed and thereafter total N, 15N and TiO2 levels were estimated in the digesta of different intestinal sections. The following results were obtained: The transit rate of the marker amounted to 10.3 +/- 0.62% per hour of the intake. The endogenous part of N increased during passage from stomach (3.5%) to duodenum (38.6%), jejunum (59.1%), ileum (64.8%), large intestine (78.3%) and faeces (87.7%). The apparent N digestibility in the stomach increased with time reaching 26% 6 h after feeding. In the whole small intestine it was 66.3%, in the ileum 78.9% and in the large intestine 90.4%. The true digestibility (6 h after feeding) showed the same course, but was always some units higher (stomach 33.3%, whole small intestine 82.5%, ileum 92.2% and large intestine 93.5%). Apparent and true digestibility values in the ileum correspond best to the data of precaecal digestibility; those of the large intestine correspond to the postileal digestibility. The N disappearance rate in the stomach is the sum of absorption rate (16%/h) and transit rate into the small intestine (12.4 +/- 1.6 mg N/h). Most absorption occurred during passage through the small intestine (2/3 of total absorption). The absorption in the small intestine was about 80% of the N amount flowing from the stomach into the intestine. The amount lay between 18.2 and 26.1 mg N/h and half of this was of endogenous origin. The reabsorption rate of endogenous N for the whole intestinal tract was estimated to be 91.4%. The N secretion into the whole intestine increased during the 6 h after feeding up to 85.5 mg (64% of N intake), for which 77 +/- 5.5% was secreted into the small intestine. Secretion into the stomach was relatively small and up to 4 hours after feeding, amounted only to 3.0 ... 6.7 mg N.

Animal Feed↗
PubMed1993

[Effect of a beta-agonist and a beta-agonist/beta-antagonist combination on muscle growth, body composition and protein metabolism in rats].

In 3 experimental groups 9 female Wistar rats (initial live weight 150 g) were fed either the control diet, the control diet supplemented with 5 mg clenbuterol or the combination of 5 mg clenbuterol and 500 mg propranolol per kg diet over a 12-day period. The N-balance was estimated over days 6 to 10 followed by a 15N-tracer experiment for determining the influence of the feed additives on characteristics of protein metabolism on day 12. All differences in the means were concluded to be significant for P < 0.05. Live weight gain and feed efficiency were improved by clenbuterol. The animals treated with clenbuterol had 18%-24% higher muscle weights whereas the combined treatment increased the muscle weights by 10%-16% only. The good correlation between the increase of muscle weights and the total protein content indicates that clenbuterol does not change the relation between protein- and water accumulation. Histological-histochemical investigations showed that the higher muscle weights were achieved through muscle fibre hypertrophy. The number of muscle fibres remained constant. Concerning the distribution of the fibre types, clenbuterol increased the proportion of FTG-fibres (white, fast-twitch, glycolytic) on the expense of the FTO-fibres (fast-twitch, oxidative). While the number of nuclei per muscle fibre did not change, the nucleus-cytoplasm relation decreased by 24%. Compared to the animals fed the control diet, the N-balance in the clenbuterol-treated group was increased by 41%. Feeding the combination of clenbuterol and propranolol resulted in an increase of 24% only. Clenbuterol increased the N-content of the carcass by 6% and reduced the carcass fat content by 30%. In the group fed clenbuterol and propranolol, the N-content of the carcass only tended to be increased and the influence on carcass fat reduction was only 16%. The stimulated N-deposition in the carcass of clenbuterol-treated rats was obtained, since the calculated protein degradation rates were more reduced than protein synthesis rates. In-vitro investigations of the muscle protein synthesis and -protease activities support these results. The clenbuterol-induced increase in muscle protein was accompanied by an inhibition of the Ca-dependent protease activity and an increase of muscle DNA- and RNA-content. The additional application of propranolol reduced these effects of clenbuterol again. Since propranolol partly prevented the effects of clenbuterol on protein metabolism it is suggested that not only the lipolytic but also protein anabolic effects are caused by the beta-adrenergic action of clenbuterol.

Adrenergic beta-Agonists↗
PubMed1982

[Dependence of intestinal excretion of amino acids on the amino acid content of animal feed. 2. Intestinal excretion of amino acids feeding soybean oil meal].

In an experiment with 20 15N-labelled growing rats the excretion of amino acids and the excretion of metabolic faecal amino acids were investigated after the feeding of soybean oil meal as sole protein source. A low, yet statistically significant increase of the excretion of amino acids and metabolic faecal amino acids was ascertained in accordance with a growing quota of soybean oil meal in the ration. The true digestibility of amino acids ascertained according to conventional methods is above 90% and, under consideration of the increase of metabolic faecal amino acids, on average increases by 3.5 digestibility units (1.4 to 6.2).

Amino Acids↗
PubMed1981

[Dependence of metabolic fecal amino acids on the amino acid content of the feed. 1. Metabolic fecal amino acids of rats fed with maize].

The amount of metabolic fecal amino acids (MFAA) in dependence on the amino acid intake was determined for graded maize rations with 15N-labelled rats and the quota of labelled endogenous amino acids in faeces was calculated according to the isotope dilution method. The excretion of amino acids and MFAA in faeces are described as functions of the amino acid intake for 17 amino acids and regressively calculated. For all 17 amino acids investigated, there was a more or less steep increase of MFAA according to an increasing amino acid intake. In contrast to MFAA in N-free feeding, MFAA in feeding with pure maize (16.5% crude protein) increase to the 2- to 4.5-fold value. The thesis of the constancy of the excretion of MFAA can consequently be no longer maintained. The true digestibility according to the conventional method is, on an average of all amino acids, 7.3 units below the one ascertained according to the 15N-isotope method. For the limiting amino acids lysine and threonine the difference is biggest (23 resp. 17 units). Tryptophane as first limiting amino acid could not be determined. The true digestibility of nearly all amino acids ascertained for maize according to the isotope method is above 90%. For the limiting amino acids the expenditure resp. the loss of endogenous amino acids is biggest.

Amino Acids↗