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L Wetter

Publications and source records attributed to L Wetter.

9 recordsLinked to original sources

A comparative study in rats of measures of the availability of dietary zinc and iron.

The purpose of this study was to compare three measures of the availability of dietary Zn and Fe in order to test their validity. Thirty-six 5-wk-old rats were fed deionized water and wheat crispbread made from endosperm flour, whole-grain flour, or endosperm flour supplemented with Zn and Fe to the whole-grain levels ad libitum for 14 d. The retention of 65Zn and 59Fe from test meals of the same breads after 1 wk and the sum of the excretion of endogenous Zn and Fe (injected 65Zn and 59Fe) with the Zn and Fe balances, respectively, were used as independent measures of Zn and Fe absorption. Measurements of Zn absorption, Zn balance, and serum Zn concentration gave quite different results with regard to the availability of Zn in the three breads, presumably because of the homeostatic regulation of the absorption and excretion of Zn when the Zn in the diet is in excess of the body's needs. Measurements of Fe absorption, Fe balance, and Fe concentrations in liver and serum were consistent in demonstrating overloading of Fe in the group given wheat-endosperm crispbread supplemented with Zn and Fe, but there was evidence that the isotope retention method overestimated iron absorption.

Animals↗

The availability of zinc in endosperm, whole grain and bran-enriched wheat crispbreads fed to rats on a Zn-deficient diet.

The hypothesis that factors such as dietary fibre and phytate in wheat bran limit the availability of Zn was tested in growing rats fed on low-Zn diets with different wheat crispbreads as the major source of Zn. Six groups of six weanling male rats each were fed on 5 parts semi-synthetic Zn-deficient diet and 1 part wheat-endosperm crispbread for 1 week. At the beginning of the second week, the crispbread in the diet of five groups was exchanged for crispbread made using one of the following wheat flours: (1) whole grain, (2) bran-enriched whole grain, (3) endosperm with Zn added to the whole-grain level, (4) endosperm with Zn added to the bran-enriched level, (5) whole grain with Zn added to the bran-enriched level. These diets were given ad lib. together with deionized water for 2.5 weeks. The relative absorption of Zn was lowest from the three non-supplemented diets (75-82%). All the added Zn was absorbed. As appetite, body-weight increase, Zn absorption, Zn retention and the Zn concentrations in serum and bone differed only slightly among groups fed on diets with similar Zn concentrations, it is concluded that factors such as dietary fibre or phytate in wheat bran limit the availability of Zn in wheat crispbreads very little when all the Zn is needed for growth and development in rats.

Animals↗

The extent of coprophagy in rats with differing iron status and its effect on iron absorption.

The purpose of this study was to determine the prevalence of coprophagy in rats with differing iron status and its effect on the measurement of iron absorption from test meals with and without bran. Two experiments were performed using radioisotope-labelled microspheres added as a non-digestible marker for the ingested faeces and the diet and 59Fe added as a marker for the nonhaem iron in the test meal. In this study, coprophagy occurred at group mean rates of between 5 and 22% and was independent of the iron status of the rats or the presence or absence of bran in the diet. The relative absorption of iron, measured as the retention of 59Fe from a single meal, was affected to the same extent in groups with the same iron status, if it was affected at all. Thus comparisons of iron absorption from diets with and without bran should not be affected by coprophagy.

Animals↗

The importance of the body's need for zinc in determining Zn availability in food: a principle demonstrated in the rat.

1. The hypothesis that the availability of zinc in a food is limited by factors in the food was tested against the hypothesis that Zn absorption is homeostatically regulated by the body according to its need for Zn. 2. The experimental model used was the short-term administration to rats of a parenteral nutrition solution with no added Zn in an attempt to increase their need for Zn in an anabolic phase. 3. The absorption and retention of 65Zn from a piece of endosperm-wheat crisp-bread in rats injected intraperitoneally with the parenteral nutrition solution was more than 40% higher than that in a control group injected with physiological saline (9 g sodium chloride/l). 4. The results indicate that the availability of Zn in the bread is not fixed but variable and dependent on the body's need for Zn.

Animals↗

Effects of zinc oxide in an occlusive, adhesive dressing on granulation tissue formation.

The role of zinc in an occlusive, adhesive dressing (Zn-tape) was investigated in two experiments in the rat. In the first one Zn-tape was compared with a similar tape without zinc components and also with an inert plastic coated fabric with regard to the wound inflammatory reaction in excisional wounds. In the second experiment we attempted to assess possible systemic effects of zinc absorbed from Zn-tape-treated excisional wounds by studying the granulation tissue formation in subcutaneously implanted Ivalon sponges. The excisional wounds were treated with either the Zn-tape or a titanium tape in which the zinc oxide was replaced by an equivalent amount of titanium dioxide (Ti-tape). The granulation tissue produced was evaluated histologically, histochemically and biochemically. The plain adhesive mass and the Ti-tape elicited an intense inflammatory reaction as indicated both by high activities of alkaline phosphatases and histological examination. The Zn-tape reduced inflammatory processes in the granulation tissue of the excisional wounds. Zinc levels in serum and liver were raised in Zn-tape-treated animals. We conclude that zinc oxide in the Zn-tape affects inflammatory reactions in the granulation tissue of the wounds, possibly through a continuous release of zinc ions and by modifying the adhesive components of the Zn-tape. There was no evidence of a systemic effect of zinc absorbed from the excisional wounds on the granulation tissue formation in the implanted Ivalon sponges.

Acid Phosphatase↗

Is hemoglobin concentration a predictor for the outcome of distal gangrenous lesions in diabetics?

The predictive value of some routine laboratory tests given on admission was evaluated in a retrospective study to determine whether any given value could predict the outcome of distal gangrenous lesions and amputations in diabetic and nondiabetic patients. There was no difference in preoperative hemoglobin concentration between successful and unsuccessful amputations in 45 diabetic and 59 nondiabetic patients. In another group of 191 diabetic patients with distal gangrenous lesions, the lesions healed after nonsurgical treatment in 112 patients, 54 patients were submitted to amputation and 25 patients died before the lesions healed. Patients submitted to amputation had lower hemoglobin levels and higher erythrocyte sedimentation rates and white blood counts than patients in whom the lesions healed, whilst there were no differences between these two groups concerning blood glucose concentration or body temperature.

Aged↗