AN INVESTIGATION OF THE EFFECT UPON RATS OF LONG-CONTINUED INGESTION OF ZINC COMPOUNDS, WITH ESPECIAL REFERENCE TO THE RELATION OF ZINC EXCRETION TO ZINC INTAKE

1927 ◽  
Vol 81 (2) ◽  
pp. 284-306 ◽  
Author(s):  
Katherine R. Drinker ◽  
Phebe K. Thompson ◽  
Marion Marsh
2004 ◽  
Vol 74 (4) ◽  
pp. 247-251 ◽  
Author(s):  
Lombardi-Boccia ◽  
Lanzi ◽  
Lucarini ◽  
Di Lullo

This study was undertaken to estimate the contribution of meat and meat products consumption to the daily intakes of trace elements (Fe, Zn, Cu, Se), heme iron, and selected B vitamins (thiamine, riboflavin, niacin) in Italy. Meat and meat products were selected on the basis of their consumption frequency reported by the most recent nationwide dietary individual survey carried out in Italy (INN-CA study). The daily intakes of total iron and heme iron were 1.65 and 1.13 mg/person/day. Zinc intake was 3.65 mg/person/day. Beef made the main contribution to iron, heme iron, and zinc daily intakes. Copper daily intake was 107.3 mug/person/day, with meat products provided the highest contribution (40 mug/person/day). Daily intake of selenium (7.14 mug/person/day) was provided mainly by poultry consumption. Thiamine intake was 228 mug/person/day, and meat products were the main source (110 mug/person/day). Riboflavin intake was 136 mug/person/day, with both beef and meat products as the main contributors (40 mug/person/day). Niacin intake was 7.53 mg/person/day, and poultry was the main source (2.28 mg/person/day). Meat and meat products were a valuable source of micronutrients, supplying 47, 48, and 24% of zinc, niacin, and thiamin daily requirements, respectively, and over 10% of iron, copper, selenium, and riboflavin daily average requirement values of the italian RDAs calculated for the population involved in the survey (INN-CA study).


According to the Tambovagrochemcenter data, zinc deficiency in animal rations exceeds 33%. To de-termine the efficiency of ration additives 3 groups of calves were formed, one of which was control and received regular feed, first test group received additional Zinc Sulphate, and second test group received additional Zinc Bioplex. To assess the results, we take into account the following values: chemical com-position and nutritional values of the feed, body mass value, amount of immunoglobulins in blood, bio-chemical and hematological values of blood, morphological values of fur and skin. Noticeable results were achieved in 4 months, with first and second test groups receiving accordingly 3,15% and 6,13% more body mass increase over the control group. A tendency towards higher albumin concentration in both test groups was noted, and calves of the second test group had higher amounts of hemoglobin and higher concentrations of it per erythrocyte. In samples of epidermis and hairs of the second test group the papillary layer was well developed, with the amount of hair and hair follicles exceeding 7 in the field of view, with the thickness of hairs being at least 70 μm. Inner papilla of hair contained 6 to 8 layers of hair, thickness of awn hairs reaching 80-90 μm, down hairs reaching 40 μm, with the hair cortex making up more than 80% of the hair thickness. Thus, introducing zinc salts and chelated zinc compounds to the milk-fed calves’ ration, has resulted in monetary profit increases over the control group by 255,0 and 612,0 roubles accordingly. By all researched values, the highest results were reached from adding zinc bioplex with approximately 360 mg added per animal for the entire duration of the growth process.


1926 ◽  
Vol 44 (4) ◽  
pp. 483-502
Author(s):  
Louise Pearce ◽  
Chester M. Van Allen

An analysis has been made of the organ weights of normal rabbits exposed to a constant illumination having none of the shorter ultraviolet rays and of other rabbits kept in darkness for periods of 2 to 12 weeks. The environment of constant illumination was associated with a well marked decrease in the relative weights of most organs, and in certain instances this occurred when the organ weights of the controls were becoming increasingly large. There was also an associated effect of stabilization of organ weight. The majority of the organs of rabbits caged in constant darkness also showed a tendency toward decreased and stabilized weights, but these effects were less pronounced than in the rabbits caged under conditions of constant illumination. A notable exception to this general result was the weight of the liver which was markedly increased. The results of this experiment support the conception that there is a relationship between light and the physical state of the animal organism which may be expressed in the concrete form implied by the trend or direction of organ weight.


2004 ◽  
Vol 77 (3) ◽  
pp. 512-541 ◽  
Author(s):  
Geert Heideman ◽  
Rabin N. Datta ◽  
Jacques W. M. Noordermeer ◽  
Ben van Baarle

Abstract This review provides relevant background information about the vulcanization process, as well as the chemistry of thiuram- and sulfenamide-accelerated sulfur vulcanization with emphasis on the role of activators, to lay a base for further research. It commences with an introduction of sulfur vulcanization and a summary of the reaction mechanisms as described in literature, followed by the role of activators, particularly ZnO. The various possibilities to reduce ZnO levels in rubber compounding, that have been proposed in literature, are reviewed. A totally different approach to reduce ZnO is described in the paragraphs about the various possible roles of multifunctional additives (MFA) in rubber vulcanization. Another paragraph is dedicated to the role of amines in rubber vulcanization, in order to provide some insight in the underlying chemical mechanisms of MFA systems. Furthermore, an overview of Model Compound Vulcanization (MCV) with respect to different models and activator/accelerator systems is given. In the last part of this review, the various functions of ZnO in rubber are summarized. It clearly reveals that the role of ZnO and zinc compounds is very complex and still deserves further clarification.


Nutrients ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 2502
Author(s):  
Nasser Laouali ◽  
Conor-James MacDonald ◽  
Sanam Shah ◽  
Douae El Fatouhi ◽  
Francesca Romana Mancini ◽  
...  

The serum copper (Cu) to zinc (Zn) ratio could be an important determinant of Type 2 diabetes (T2D) risk, but prospective epidemiological data are scarce. We aimed to investigate the association between T2D incidence and the dietary Cu/Zn ratio. A total of 70,991 women from the E3N cohort study were followed for 20 years. The intakes of copper and zinc were estimated at baseline using a validated food frequency questionnaire. We identified and validated 3292 incident T2D cases. Spline analysis showed that a Cu/Zn ratio < 0.55 was associated with a lower risk of T2D. Subgroup analyses comparing women in the highest versus the lowest quintile of Cu/Zn ratio showed the same pattern of association for obese women and those with zinc intake ≥8 mg/day. However, for women with zinc intake <8 mg/day, higher Cu/Zn ratio appeared to be associated with higher T2D risk. Our findings suggest that a lower dietary Cu/Zn ratio is associated with a lower T2D risk, especially among obese women and women with zinc intake >8 mg/day. Further studies are warranted to validate our results.


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