Role of zinc in health and disease

This review provides a concise overview of the cellular and clinical aspects of the role of zinc, an essential micronutrient, in human physiology and discusses zinc-related pathological states. Zinc cannot be stored in significant amounts, so regular dietary intake is essential. ZIP4 and/or ZnT5B transport dietary zinc ions from the duodenum into the enterocyte, ZnT1 transports zinc ions from the enterocyte into the circulation, and ZnT5B (bidirectional zinc transporter) facilitates endogenous zinc secretion into the intestinal lumen. Putative promoters of zinc absorption that increase its bioavailability include amino acids released from protein digestion and citrate, whereas dietary phytates, casein and calcium can reduce zinc bioavailability. In circulation, 70% of zinc is bound to albumin, and the majority in the body is found in skeletal muscle and bone. Zinc excretion is via faeces (predominantly), urine, sweat, menstrual flow and semen. Excessive zinc intake can inhibit the absorption of copper and iron, leading to copper deficiency and anaemia, respectively. Zinc toxicity can adversely affect the lipid profile and immune system, and its treatment depends on the mode of zinc acquisition. Acquired zinc deficiency usually presents later in life alongside risk factors like malabsorption syndromes, but medications like diuretics and angiotensin-receptor blockers can also cause zinc deficiency. Inherited zinc deficiency condition acrodermatitis enteropathica, which occurs due to mutation in the SLC39A4 gene (encoding ZIP4), presents from birth. Treatment involves zinc supplementation via zinc gluconate, zinc sulphate or zinc chloride. Notably, oral zinc supplementation may decrease the absorption of drugs like ciprofloxacin, doxycycline and risedronate

Cultivares de milho para o Estado do Espírito Santo.

Vinte e cinco cultivares de milho, de ciclo normal, e vinte e cinco de ciclo precoce foram avaliados de 1990 a 1992, em 10 ambientes do Estado do Espirito Santo, sendo seis com irrigacao e quatro sem irrigacao. O delineameto experimental foi o latico 5x5 com tres repeticoes para cada tipo de ensaio. Com base nos resultados recomendam-se os seguintes cultivares: Grupo Normal - AG612, G 700, AG 6601, P 3210, G 551, G 650, CONT 533, XL 604, C 135, P 3226; Grupo precoce - G 600, AG 122, C 505, C 431, C 805, BR 201, AG 513, G 85, AG 405, G 96, C e AG 519.Em media os cultivares do grupo normal e recoce avaliados com irrigacao forma 34,6% e 50,1%, repectivamente, mais produtivos que em condicoes sem irrigacao. As produtividades medias de graos forma de 5.559 kg/ha e 5.915 kg/ha para os grupos normal e precoce, respectivamente, tendo alcancado ate 6.707 e 7.202 kg/ha em analise conjunta nos 10 ambientes