Influence of zinc deficiency on synthesis and cross-linking of rat skin collagen

The New Pharmaceutical Compositions of Zinc Oxide Nanoparticles and Triterpenoids for the Burn Treatment

We studied oleogels containing zinc oxide nanoparticles (ZnO NPs) and lupane triterpenoids in sunflower oil for the treatment of burns. The modification of ZnO was carried out by treatment with alcohol solutions of betulin, betulonic acid, betulin diacetate and betulin diphosphate. The properties of modified ZnO NPs were studied by powder XRD (average sizes of 10-20 nm), FTIR (νZnO 450 cm-1), UV-vis (345-360 nm), and blue-violet emission (380-420 nm). The identification and assay of modified ZnO NPs and triterpenoids were estimated. The treatment by oleogels of deep II-degree burns was studied on rats using histological studies, Doppler flowmetry and evaluation of enzymes activity and malonic dialdehyde (MDA) level. After the action of oleogels, burn wound area, and the necrosis decreased twice on the 10th day in comparison with the 1st day after burn. The microcirculation index in the near-wound zone by 20-30% improved compared with the group without treatment. Evaluation of the enzyme activity and the MDA level after treatment by oleogels during the course of 10 days showed them returning to normal. The improvement of antioxidant biochemical indexes, as well as wounds' healing, was mainly determined by the influence of zinc oxide nanoparticles.

Zinc in wound healing: theoretical, experimental, and clinical aspects

Zinc is an essential trace element in the human body and its importance in health and disease is appreciated. It serves as a cofactor in numerous transcription factors and enzyme systems including zinc-dependent matrix metalloproteinases that augment autodebridement and keratinocyte migration during wound repair. Zinc confers resistance to epithelial apoptosis through cytoprotection against reactive oxygen species and bacterial toxins possibly through antioxidant activity of the cysteine-rich metallothioneins. Zinc deficiency of hereditary or dietary cause can lead to pathological changes and delayed wound healing. Oral zinc supplementation may be beneficial in treating zinc-deficient leg ulcer patients, but its therapeutic place in surgical patients needs further clarification. Topical administration of zinc appears to be superior to oral therapy due to its action in reducing superinfections and necrotic material via enhanced local defense systems and collagenolytic activity, and the sustained release of zinc ions that stimulates epithelialization of wounds in normozincemic individuals. Zinc oxide in paste bandages (Unna boot) protects and soothes inflamed peri-ulcer skin. Zinc is transported through the skin from these formulations, although the systemic effects seem insignificant. We present here the first comprehensive account of zinc in wound management in relation to current concepts of wound bed preparation and the wound-healing cascade. This review article suggests that topical zinc therapy is underappreciated even though clinical evidence emphasizes its importance in autodebridement, anti-infective action, and promotion of epithelialization.

Reduced growth and skeletal changes in zinc-deficient growing rats are due to impaired growth plate activity and inanition

We investigated the effects of dietary zinc deficiency on skeletal metabolism in an animal model. Thirty 21-d-old male Sprague-Dawley rats were fed for 28 d either a zinc-deficient (ZD) diet (1 mg zinc/kg) or a normal diet ad libitum (AL, 50 mg zinc/kg) or in the same quantity as the ZD (pair-fed, PF). Only in the ZD group were general physical signs of zinc deficiency observed. Compared with the AL and PF rats, ZD rats showed significantly lower mean values in ponderal growth rate, femur weight and length, circulating levels of insulin-like growth factor-I, bone mechanical properties and concentration of zinc and, on histomorphometry, a decrease in the thicknesses of the overall growth plate and hypertrophic cartilage. In contrast, although bone volume was significantly lower in the ZD and PF rats than in the AL rats, no difference was observed between the ZD and PF rats. Osteoclast surface/bone surface and osteoclast number/bone surface ratios were significantly greater in PF rats than in the other two groups and not different in ZD and AL rats. Collectively, these data indicate that zinc deficiency has profound effects on the skeletal system of growing rats. In particular, the effects of zinc deficiency on bone growth and mass are the result of the reduced activity of the growth plate, likely mediated by impairment in the insulin-like growth factor-I system. We did not demonstrate an effect on bone mass via increased bone resorption.

Histochemical demonstration of heavy metals in mouse skin

The localization of heavy metals in normal mouse skin was investigated light microscopically using the Neo-Timm staining method. Positive staining was found in the horny layer of epidermis, connective tissue of dermis and in hair roots. Chelation of heavy metals by pretreatment with diethyldithiocarbamate prevented this staining. The study demonstrates that heavy metals, mainly zinc, are localized in the mouse skin and that the Neo-Timm staining method is useful for the investigation of the role of zinc in this organ.

The effects of halofuginone and salinomycin, alone and in combination, on live performance and skin characteristics of female broilers: influence of a high-proline diet supplemented with ascorbic acid and zinc

Live performance and carcass quality of female broilers were evaluated under four coccidiostat programs (CP) and two feed treatments. The CP consisted of halofuginone (H) and salinomycin (S), fed either continuously (HH and SS) or in rotational programs (HS and SH), during the starter (1 to 21 d) and grower (22 to 35 d) periods, respectively. All groups received an unmedicated withdrawal feed from 36 to 42 d. Feed treatments consisted of a control and a fortified diet high in proline and supplemented with additional ascorbic acid and zinc (50 birds per pen; 4 pens per feed; 8 pens per CP). In addition to live performance and skin puncture strength, carcass quality attributes following processing (at 43 d of age) were assessed. No CP by feed interactions were detected for any of the variables measured. The CP treatments did not differ for live performance. Birds on fortified feed were heavier at 21 d (P < .001) and had an improved feed conversion at 42 d (P < .05). Skin puncture strength was significantly reduced for the birds fed H, either in continuous (HH) or rotational programs (HS and SH). Skin sores-scratches and tears were lowest for the SS and SH groups. The HH treatment resulted in fewer grade A carcasses (P < .001). Halofuginone, when fed continuously or in the starter feed, affected carcass quality of broilers. Higher dietary proline or supplementation with ascorbic acid and zinc did not appear to alleviate the effects of halofuginone on skin quality.

An approach to patient assessment and preparation in cutaneous oncology

An outline of the many phases of preoperative evaluation of the dermatologic surgery patient is presented. Special emphasis is given to patient assessment and to patient preparation. The purpose of this review is not to create a compendium of steps that one must slavishly perform before each surgical procedure. Instead, it represents an effort to emphasize the importance of adequate preoperative evaluation and to discuss some of the subtleties that may be overlooked by the dermatologic surgeon.

Nifedipine, its action on the cationic concentrations in heart, vessels, skeletal muscle and blood in tissues of normotensive and spontaneously hypertensive rats (SHR)

1. The cationic tissue distribution, obtained by atomic absorption spectrophotometry, was different in normotensive (Wistar) and spontaneously hypertensive male rats (SHR). 2. In both groups, nifedipine (4.2 mg/100 g body wt, by gastric intubation, during 10 days) altered the cationic composition mainly in the aorta, atria and in SHR also in the vein. 3. In normotensive Wistar rats (NWR), nifedipine provoked a higher concentration of divalent cations (Ca2+, Mg2+ and Zn2+) in the ascending part of the aorta and reduced the monovalent (Na+) concentration in the aorta, vein and skeletal muscle. 4. In spontaneously hypertensive rats (SHR) the pathognomonic higher cationic concentrations in the aorta, right atrium and vein are significantly (P less than 0.05) reduced after nifedipine treatment.

Intestinal metallothionein in lethal-milk mice with systemic zinc deficiency

Lethal-milk (C57BL/6J-lm) mice over 12 months of age exhibit clinical signs of systemic Zn deficiency. Such lm mice have increased concentrations of metallothionein (MT) in the intestinal mucosa. Various concentrations of Cd or Zn were added to the drinking water. MT was assayed using the Cd-saturation/hemolysate method and for sulfhydryl concentration (MT has 33% cysteine residues) with Ellman's reagent. As assayed by both methods, mucosa from untreated lm mice contained approximately twice as much MT as did the C57BL/6J-(+lm/+lm) (B6) controls. Treatment with 150 and 500 ppm Zn removed the genotypic differences observed for the untreated and Cd-treated mice. These results are consistent with the lm mutation affecting Zn metabolism through impaired MT metabolism as measured for the intestinal mucosa. These studies do not eliminate the possibility that the liver may also contribute.

Cutaneous tissue repair: practical implications of current knowledge. II

This article reviews the scientific basis for the certain factors that delay wound repair in the clinical setting. A brief history of wound healing is given, followed by a discussion of endogenous local factors (bacterial infection, hypoxia, foreign body, and desiccation) and endogenous systemic factors (nutritional deficiencies, aging, coagulation disorders, and the Ehlers-Danlos syndromes) associated with poor wound repair. Also reviewed are the mechanisms by which exogenously administered agents (glucocorticoids, antineoplastic agents, and anticoagulants) may delay healing. Commonly used topical antimicrobials, their spectrum of activity, and evidence of effects on wound healing are examined. Finally, properties of commercially available wound coverings and wound care in the future are discussed.

Zinc concentration in normal and healing gingival tissues in beagle dogs

Previous studies have shown that the administration of zinc (Zn) may enhance the healing of gingival and other wounds. This study was undertaken to determine if Zn concentration ([Zn]) is increased in healing gingival tissues and if oral supplementation of Zn would result in a local increase in [Zn] within these tissues. On Day 0, biopsies were obtained from the maxillary left buccal gingiva of each of 10 beagle dogs. Gingival biopsies were taken from the healing original biopsy sites on Day 14. On Day 15, oral supplementation of Zn gluconate (250 mg/day, equivalent to 32.5 mg of elemental Zn) was begun in seven dogs. Three dogs remained as unsupplemented controls. Two weeks later (Day 28), normal gingival biopsies were obtained from the right side of the maxilla and on Day 42 final biopsies were taken from the same healing sites. In addition, serum samples were obtained on Days 0, 14, 28 and 42. All samples were analyzed for Zn content using atomic absorption spectrophotometry. The [Zn] of healing tissues was significantly higher (P less than 0.0005) than normal tissues. This was also true when healing tissues were compared to normal tissues during the Zn supplementation phase (Day 28 vs. Day 42; P less than 0.005). Zn supplementation resulted in significant increases in Zn levels in normal (Day 0 vs. Day 28; P less than 0.05) and healing tissues (Day 14 vs. Day 42; P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of serum zinc level on amount of collagen-hydroxyproline in the healing gut during total parenteral nutrition: an experimental study

Changes of serum zinc level in dogs receiving either a zinc-free solution or a zinc-supplement solution during total parenteral nutrition (TPN) and the influence of variety of serum-zinc level on serum albumin and collagen-hydroxyproline (C-Hyp) in the incised intestine were investigated. The serum zinc level of zinc-free dogs that was 126.0 +/- 34.3 micrograms per deciliter at the initiation of TPN decreased significantly to 80.0 +/- 15.0 micrograms per deciliter during the one week of TPN, whereas that of zinc-supplement dogs did not decrease during the same period of TPN. Lowering of the serum albumin value was more evident in zinc-free dogs than in zinc-supplement dogs. The amount of C-Hyp in the incised area of the intestine of zinc-free dogs was 2.63 +/- 0.66 micrograms per milligram and that of zinc-supplement dogs was 4.26 +/- 1.04 micrograms per milligram and this difference was significant. It was found that serum zinc level during TPN sharply reflects a supplement of zinc, and C-Hyp in the incised gut and serum albumin of zinc-free dogs are lower than those of zinc-supplement dogs.

Effect of zinc deficiency on appetite and plasma amino acid concentrations in the rat

1. Levels of zinc in liver and plasma of the Zn-depleted rats fluctuated with the feeding cycle and were significantly higher at the bottom than at the top of the cycle. As Zn deficiency became more severe fluctuations in plasma Zn diminished. Concentrations of Zn in liver, in contrast to levels in plasma and femur, were not markedly lowered by day 15. 2. In contrast to ad lib-fed (AL) and overnight-fasted (OF) controls, some pair-fed (PF) controls had elevated levels of Zn in liver and plasma. 3. Intakes of water and food were significantly correlated in Zn-deficient rats. Packed cell volumes were significantly higher for Zn-depleted than for AL and PF rats. 4. Food intakes and plasma glucose concentrations were related in AL, OF and PF control rats but not in Zn-deficient rats. 5. At day 15 of Zn deficiency the order of total plasma amino acid concentrations in the groups of rats was AL greater than Zn-deficient greater than OF greater than PF. Many of the differences between the AL and OF groups for individual plasma amino acids also appeared in the Zn-deficient group at the top and bottom of the feeding cycle. Differences in individual amino acid concentrations at the top and bottom of the feeding cycle tended to be opposite in the PF and the Zn-deficient group. Levels of tyrosine and tryptophan in plasma were correlated (P less than 0.05) with the cyclic feeding pattern of the Zn-deficient group; however, the ratios tryptophan or tyrosine: sum of other large neutral amino acids did not correlate significantly with the eating habits of Zn-deficient rats.

A light and electron microscopic study of mannosidosis

The present work investigated the light and electron microscopic changes in hypertrophied gingiva in a patient with mannosidosis. The biopsy specimens studied covered a period of 20 months; biopsy specimens were taken before and after a therapeutic trial with oral and local zinc sulfate. The intensity of the disease was progressive, in spite of the zinc, and was characterized by marked hyperplasia of the epithelium and severe inflammation of the stroma. Many of the cells in the inflammatory infiltrate, as well as cells indigenous to the gingiva, showed a striking vacuolation of their cytoplasm. Histiocytes were most numerous and also were most heavily vacuolated, but fibroblasts, endothelial cells, plasma cells, and epithelial cells also manifested the vacuolar change. In the histiocytes, the vacuoles occupied most of the cytoplasm, ranged widely in size, and were contiguous, molded, and intercommunicating. The vacuoles were bound by a single membrane and were filled predominantly by a finely granular material of medium density but also by varying amounts of coarser, darker granules, fragmented membranes, myelin-like figures, lipid droplets, and small vesicles. The vacuoles were interpreted as being consistent with secondary lysosomes that contained excessively stored substrate, similar to what has been observed in the mucopolysaccharidoses, in which the vacuoles have also been demonstrated histochemically and cytochemically to contain acid phosphatase, a known lysosomal marker.