PubMed Health⌕ Search

Biomedical subjects

R Rettenmaier

Publications and source records attributed to R Rettenmaier.

9 recordsLinked to original sources

Osteoinduction with COLLOSS, COLLOSS E, and GFm.

This study provided data relevant to three major goals. It confirmed that both COLLOSS and COLLOSS E contain osteo- and chondro-inductive BMPs as shown by their ability to produce new bone in an ectopic location in rats. Second, based on the area of bone produced in standardized implant sections by osteoinductive growth factors in GFm, COLLOSS , and COLLOSS E and their respective collagenous carrier matrices, the study showed that COLLOSS was 0.1, and COLLOSS E 0.3 time as potent as 10 microg of GFm. Finally, the study showed that ordinary and accelerated endochondral bone formation were more frequent in response to GFm than to COLLOSS and COLLOSS E, whereas membranous bone formation was more frequent in response to COLLOSS E than to COLLOSS or GFm.

Animals↗

Determination of vitamins A and E in liver tissue.

A simple, efficient and robust method for the simultaneous determination of the two vitamins A and E in liver tissue has been developed and evaluated. The assay consists of a saponification step followed by a single extraction of the resulting solution with a mixture of n-hexane/toluene. The vitamins are quantified in the extract using two separate HPLC lines running on straight phase mode. The eluted compounds were detected with a fluorescence detector. Recoveries of spiked samples were found to be 92.4% for vitamin A and 95.2% for alpha-tocopherol. The coefficient of variation was found to be +/- 4.27% for retinol and +/- 4.64% for alpha-tocopherol. The described analytical method has proven to be very effective and fast, enabling the processing of a large number of samples within a short period of time. It is highly specific and sensitive covering a wide range of different concentrations in the samples. It may be applied therefore in routine assays of samples with great variability concerning the vitamin concentrations in the tissue.

Animals↗

Vitamin content of camel milk.

The content of vitamin C, vitamin B2 and fat-soluble vitamins E and A in camel milk was studied. The milk samples were collected from 20 individual camels (Camelus dromedarius) in two different occasions. The study showed that camel milk contains considerably less vitamin A and B2 than cow milk while the content of vitamin E was about the same level. The level of vitamin C was in average three times higher than that of cow milk.

Animals↗

A simple method for the determination of riboflavin in human milk.

A fluorometric method for the determination of total riboflavin in human milk is described. Flavin-adenine dinucleotide (FAD) is hydrolyzed to riboflavin by enzyme treatment. Then the fluorescence of total riboflavin is measured in the aqueous phase at pH 4.5. The coefficient of variation was found to be 2.48% (n = 58). The procedure is simple, reproducible and allows the simultaneous analysis of a considerable number of samples. The recoveries are in the range of 95.8-100.8%.

Amylases↗

Clinical chemical methods for the routine assessment of the vitamin status in human populations. Part II: The water-soluble vitamins B1, B2 and B6.

Simple and proven techniques for the assay of the coenzyme stimulation of the erythrocyte enzymes transketolase, glutathione reductase and glutamate oxaloacetate aminotransferase are described. The results found in a cohort of 150 blood donors and their comparison with the values for total thiamine in whole blood and pyridoxal phosphate in erythrocytes are presented.

Aspartate Aminotransferases↗

[Assay of vitamin B1 in food and biological material (author's transl].

A fluorometric method for the estimation of the vitamin B1 content in food and biological materials is described. Acid hydrolysis is followed by enzymatic treatment to liberate the vitamin B1 of the sample. Interfering substances in the extract are removed to a great extent by chromatography on Amberlite CG 50, a weakly acidic cation exchanger. After oxidation and extraction into an organic medium, the fluorescence of thiochrome is measured. The procedure is simple, reproducible and not susceptible to interference. The recoveries are good.

Chromatography, Ion Exchange↗

Haematological and blood chemistry changes in ewes and lambs following supplementation with vitamin E and selenium.

1. For methods of vitamin E and selenium supplementation were evaluated using thirty-nine pregnant ewe-lambs fed on a ration containing 0.043 mg Se/kg and 25 mg vitamin E/kg. Treatments were control, fortified mineral mix (ESe salt) (300 mg vitamin E, 3 mg Se), ruminal Se pellets (505 mg Se), drench (300 mg vitamin E, 3 mg Se) and intramuscular injection (600 mg vitamin E, 3 mg Se). Only ewes supplemented, commencing approximately 50 d before parturition. 2. Birth weights were similar for all treatments and live-weight gains of lambs to 56 d of age were improved in all supplemented groups (P less than 0.05). There were no clinical cases of nutritional muscular dystrophy. 3. Se concentrations in whole blood were more than doubled in both lambs and ewes drenched or injected; responses to ESe salt and pellets were much smaller. 4. Plasma tocopherol levels were increased in injected dams and their lambs (P less than 0.001). 5. Haemoglobin concentration and erythrocyte counts were significantly higher (P less than 0.01) in control ewes and lambs than in treated lambs. 6. Lactate dehydrogenase (EC 1.1.1.27), creatine kinase (EC 2.7.3.2) and aspartate aminotransferase (EC 2.6.1.1) activities were increased in lambs from control, ESe salt and pellet groups (P less than 0.001). Glutathione peroxidase (EC 1.11.1.9) activity responded to Se supplementation in both ewes and their lambs (P less than 0.001) and the response was highest in the injected group, followed in order, by the drench, pellet, Ese salt and control groups. 7. These studies indicated that in terms of the haematological and blood chemistry changes investigated, the intramuscular injection was most effective, followed by the oral drench. Ruminal pellets and fortified salt were less satisfactory.

Animals↗