羟氨苄青霉素引起大疱性类天疱疮样疹

The task of inventing and developing active ingredients with useful biological activities requires a search for novel chemical substructures. This process may trigger the discovery of whole classes of chemicals of potential commercial interest. Similar biological effects can often be achieved by completely different compounds. However, compounds within a given structural family may exhibit quite different biological activities depending on their interactions with different intracellular proteins like enzymes or receptors. By varying the functional groups and structural elements of a lead compound, its interaction with the active site of the target protein, as well as its physicochemical, pharmacokinetic, and dynamic properties can be improved. In this context, the introduction of fluorine into active ingredients has become an important concept in the quest for a modern crop protection product with optimal efficacy, environmental safety, user friendliness, and economic viability. Fluorinated organic compounds represent an important and growing family of commercial agrochemicals. A number of recently developed agrochemical candidates represent novel classes of chemical compounds with new modes of action; several of these compounds contain new fluorinated substituents. However, the complex structure-activity relationships associated with biologically active molecules mean that the introduction of fluorine can lead to either an increase or a decrease in the efficacy of a compound depending on its changed mode of action, physicochemical properties, target interaction, or metabolic susceptibility and transformation. Therefore, it is still difficult to predict the sites in a molecule at which fluorine substitution will result in optimal desired effects.

The Unique Role of Fluorine in the Design of Active Ingredients for Modern Crop Protection

Minerals are inorganic nutrients, usually required in small amounts from less than 1 to 2500 mg per day, depending on the mineral. As with vitamins and other essential food nutrients, mineral requirements vary with animal species. For example, humans and other vertebrates need large amounts of calcium for construction and maintenance of bone and normal function of nerves and muscles. Phosphorus is an important constituent of adenosine triphosphate (ATP) and nucleic acid and is also essential for acid-base balance, bone and tooth formation. Red blood cells can not function properly without iron in haemoglobin, the oxygen-carrying pigment of red blood cells. Iron is also an important component of the cytochromes that function in cellular respiration. Magnesium, copper, selenium, zinc, iron, manganese and molybdenum are important co-factors found in the structure of certain enzymes and are indispensable in numerous biochemical pathways. Vertebrates need iodine to make thyroid hormones. Sodium, potassium and chlorine are important in the maintenance of osmotic balance between cells and the interstitial fluid. Magnesium is an important component of chlorophyll in plants. The interactions between nutrition and diseases, nutrition and drug metabolism have been reported. Excessive intake of some minerals can upset homeostatic balance and cause toxic side effects. For example, excess sodium intake is associated with high blood pressure and excess iron can cause liver damage. Also, severe shortages or self-prescribed minerals can alter the delicate balance in body functions that promotes health. The knowledge of the biochemistry of the mineral elements is also essential because individuals suffering from a chronic illness or taking medications that affect the body’s use of specific nutrients need to be enlightened. The aim of this paper is to review the biochemical functions and the importance of the mineral elements in health and disease conditions of humans, animals and plants as this will assist in the prevention of nutrition-related diseases and maintenance of good health for humans and animals that depend on plants for food. This paper could also serve as a ready source of literature review for researchers involved in nutritional sciences.

	 

	Key words: Mineral elements, humans, animals, plants, nutrition.

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The importance of mineral elements for humans, domestic animals and plants: A review

日本には約110種の蚊が産する。その中で医学的に重要なのは, 幼虫(ボウフラ)が人里近くの水域に発生し, 雌成虫がヒトから好んで吸血する種である。西日本ではアカイエカ(南西諸島ではネッタイイエカにおきかわる), チカイエカ, コガタアカイエカ, ヒトスジシマカなどが最も重要である。これらの種は生態がことなるので, その被害に対する効果的対策もことなる。雌成虫が吸血源となる動物を発見して完了するまでの過程は複雑で, わかつていない点もある。

Biology of mosquitoes.

Chitin is the most widespread amino polysaccharide in nature. The annual global amount of chitin is believed to be only one order of magnitude less than that of cellulose. It is a linear polymer composed of N-acetylglucosamines that are joined in a reaction catalyzed by the membrane-integral enzyme chitin synthase, a member of the family 2 of glycosyltransferases. The polymerization requires UDP–N-acetylglucosamines as a substrate and divalent cations as co-factors. Chitin formation can be divided into three distinct steps. In the first step, the enzymes‘ catalytic domain facing the cytoplasmic site forms the polymer. The second step involves the translocation of the nascent polymer across the membrane and its release into the extracellular space. The third step completes the process as single polymers spontaneously assemble to form crystalline microfibrils. In subsequent reactions the microfibrils combine with other sugars, proteins, glycoproteins and proteoglycans to form fungal septa and cell walls as well as arthropod cuticles and peritrophic matrices, notably in crustaceans and insects. In spite of the good effort by a hardy few, our present knowledge of the structure, topology and catalytic mechanism of chitin synthases is rather limited. Gaps remain in understanding chitin synthase biosynthesis, enzyme trafficking, regulation of enzyme activity, translocation of chitin chains across cell membranes, fibrillogenesis and the interaction of microfibrils with other components of the extracellular matrix. However, cumulating genomic data on chitin synthase genes and new experimental approaches allow increasingly clearer views of chitin synthase function and its regulation, and consequently chitin biosynthesis. In the present review, I will summarize recent advances in elucidating the structure, regulation and function of insect chitin synthases as they relate to what is known about fungal chitin synthases and other glycosyltransferases.

Insect chitin synthases: a review.

Boric acid toxicity to the German cockroach, Blattella germanica: Alterations in midgut structure, and acetylcholinesterase and glutathione S-transferase activity

An insecticide containing azadirachtin, a tree ﺮﻴﺛﺄﺗ ﺔﺳارد ﺚﺤﺒﻟا اﺬه لوﺎﻨﺗ (Azadirachta indica) extract, was tested against Culex pipiens mosquito larvae and pupae in east of the Republic of Algeria under laboratory conditions. First, after treatment of larval stage, LC50 and LC90 values for Azadirachtin were 0.35 and 1.28 mg/L in direct effect and 0.3-0.99 mg/l in indirect effect, respectively. Second, after treatment of the pupal stage, the LC50 and LC90 in direct effect were measured as0.42 -1.24mg/l and in indirect effect was 0.39mg/l-1.14mg/l respectively. Mosquito adult fecundity were markedly decreased and sterility was increased by the Azadirachtin after treatment of the fourth instar and pupal stage. The tretment also prolonged the duration of the larval stage. The results show that the Azadirachtin is promising as a larvicidal agent against Culex pipiens, naturally ocurring biopesticide could be an alternative for chemical pesticides.

https://www.jjbs.hu.edu.jo/files/v2n1/3.pdf

Larvicidal Activity of a Neem Tree Extract (Azadirachtin) Against Mosquito Larvae in the Republic of Algeria

Effects of diflubenzuron on the pupal-adult development of Tenebrio molitor L. (Coleoptera, Tenebrionidae): Growth and development, cuticle secretion, epidermal cell density, and DNA synthesis

Seasonal variations in the concentrations of four trace heavy metals (cadmium (Cd), copper (Cu), lead (Pb) and zinc (Zn)) were determined in Donax trunculus (Mollusca, Bivalvia) at two contaminated sites in the gulf of Annaba (East of Algeria): El Battah and Sidi Salem  The average concentrations of the metals exhibited the following order: Zn>Cu> Pb>Cd for the two sites The statistical analysis revealed a significant effect of seasons for all metals measured, the highest values being recorded in winter for Zn and in summer for the other metals Contrary to expectation, both sites were contaminated with trace heavy metals analysed Although the highest levels were detected in Sidi Salem beach, there was no significant difference on trace heavy metal concentrations between sites, except for Cd The implication of this metal contamination for local population was discussed

Noureddine Soltani

Papers

Boric acid toxicity to the German cockroach, Blattella germanica: Alterations in midgut structure, and acetylcholinesterase and glutathione S-transferase activity

Larvicidal Activity of a Neem Tree Extract (Azadirachtin) Against Mosquito Larvae in the Republic of Algeria

Effects of diflubenzuron on the pupal-adult development of Tenebrio molitor L. (Coleoptera, Tenebrionidae): Growth and development, cuticle secretion, epidermal cell density, and DNA synthesis

Seasonal variations of Cd, Cu, Pb and Zn in the edible mollusc Donax trunculus (Mollusca, Bivalvia) from the gulf of Annaba, Algeria

Effects of ecdysone agonist halofenozide against Culex pipiens