Short Introduction:Nanoparticles (NPs) represent a new line in the investigations and treatment of group of diseases. Furthermore, it is found in many products and enters the body by different roots as ingestion and inhalation. Lung is more liable to exposure to these particles. Safety of these particles on the lung needs to be examined.Aim of the Work:To study the effect of gold NPs (GNPs) on the histological structure of the lung tissue.Materials and Methods:Thirty-six healthy male albino rats were randomly divided into three groups including control group (Group I) and two GNP-treated groups (Group II received low dose and Group III received high dose daily for 14 days). At the end of the experiment, all the rats were sacrificed; lungs were dissected and processed to be examined by light and electron microscopy.Results:GNPs induced inflammatory infiltration dilatation and congestion of the blood vessels in association with the collapse of lung alveoli and extravasations of red blood cells. Caspase-3 immunohistochemical reaction showed strong positive reaction in Group III mainly. Ultrastructure observation revealed affection of type II pneumocyte and thickening in the alveolar wall.Conclusions:GNPs led to histological changes in the lung tissue.

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a-Amylase of the thermophilic actinomycete Thermomonospora vulgaris was partially purified. Maximal enzyme activity was obtained a t 60 "C and p H 6.0. KM value was 1.4%. The effect of some metal salts on enzyme activity was studied. Enzyme activity was inhibited by KCN, EDTA, and iodoacetate. Inhibition by EDTA was completely nullified by CaCI,, but the inhibition by iodoacetate was not overcome by 2-mercaptoethanol. Exposure of t h e enzyme t o p H 7.0 and 9.0 for 2 hr. did not affect the enzyme, but exposure to p H 3.0 for few minutes completely inactivated the enzyme. Exposure of the enzyme to 60 "C resulted in a n appreciable inactivation and exposure t o 80 "C completely inactivated the enzyme. Addition of CaCl,, 2-mercaptoethanol, or enzyme substrate did not stabilize the 60 "C exposed enzyme. However, bovine serum albumin had a protective effect when the enzyme was exposed to 60 "C but not to 80 "C. The enzyme was stable in the presence of 8 M urea.Studies on amylases of thermophilic actinomycetes are rare. To our knowledge, only two investigations QII amylases of thermophilic actinomycetes were reported in the literature HARTMAN 1966, 1967). They dealt with the formation and properties of the amylases elaborated by a strain of Thermoactinomyces vulgaris. The present investigation deals with the study of some properties of the amylase produced by the thermophilic actinomycete Thermomonospora vulgaris which has been isolated from the soil of oasis El-Dakhla of Egypt. Haterials and methodsOrganism, media, and cultures: Thermomonospora vulgaris was isolated from soil of oasis ElDakhla using KOSMATCHEV agar medium (KOSMATCHEV 1956). The same medium was used for growing the organism in liquid cultures using 250 ml Erlenmeyer flasks each contained 50 ml of sterile medium. After inoculation, the flasks were incubated a t 55 "C. At the end of the incubation period (3-4 days) the mycelium was harvested and the culture filtrates were collected.Enzyme assay: Enzyme activity was determined by following the disappearance of MERCK'S soluble starch using the method of SMITH and ROE (1949). One enzyme unit is defined as the quantity of protein that hydrolyzes 1 mg of starch in one minute under specified conditions. Protein was determined by the method of SUTHERLAND et al. (1949). Identification of products: Maltose and glucose were identified as products of the action of the enzyme on soluble starch. The identification was made by descending paper chromatography using WHATMAN No. 1 filter paper and a solvent system consisting of n-butanol-pyridine-water (5 : 3 : 2). Alkaline silver nitrate reagent was used for colour development. Results and discussionE n z y m e p r e c i p i t a t i o n Attempts to precipitate T h . vulgaris amylase from the culture filtrates with ammonium sulfate (up to 0.9 saturation) were not consistently successful, probably because the culture filtrates represent a fairly dilute solution of proteins. For this reason pre- 272

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Background: Gold nanoparticles [GNPs] are significant scientific achievements which are effectively employed in medicine. However, in vivo biological impact of these particles should be assessed to investigate their safety on human health. Aim: Study of the biological effect of different gold nanoparticles doses on the liver of adult female rats exploring the novel mechanisms of gold nanoparticles induced liver damage. Materials and Methods: Forty adult female rats were separated into one control group [Group I] and two GNPs-treated groups [Group II; 40μg/kg and Group III; 400μg/kg]. Specimens of the liver were taken to be processed for the light and electron microscopy in addition to immunohistochemical staining technique for the p53 protein, tumor necrosis factor alpha [TNF-α] and B-cell lymphoma 2 [Bcl-2]. Results: Administration of gold nanoparticles to adult female rats caused various histological deterioration in the liver depending on the dose. Hepatocytes showed vacuolated cytoplasm and pyknotic nuclei. Dilation and congestion of the central veins, blood sinusoids, hepatic artery and portal vein were seen. Disrupted endothelial layer was observed in some central veins. An apparent increase in kupffer cells and mononuclear cellular infiltration were observed. The immunohistochemical results demonstrated a significant increase in p53 and TNF-α and decrease in Bcl-2 immunoreactions. Ultrastructurally, swollen or damaged mitochondria, dilated rough endoplasmic reticulum [RER] and apparent glycogen depletion were observed in the hepatocytes. Conclusion: Gold nanoparticles induced various dose dependent histological deterioration, inflammation and apoptosis in the liver of adult female rats. So, it should be given cautiously to females to avoid liver damage.

alpha-Amylase of the thermophilic actinomycete Thermomonospora vulgaris was partially purified. Maximal enzyme activity was obtained at 60degreeC and pH 6.0. KM value was l.4%. The effect of some metal salts on enzyme activity was studied. Enzyme activity was inhibited by by KCN, EDTA, and iodoacetate. Inhibition by EDTA was completely nullified by CaCl2, but the inhibition by iodoacetate was not overcome by 2-mercaptoethanol. Exposure of the enzyme to pH 7.0 and 9.0 for 2 hr. did not affect the enzyme, but exposure to pH 3.0 for few minutes completely inactivated the enzyme. Exposure of the enzyme to 60degreeC resulted in an appreciable inactivation and exposure to 80degreeC completely inactivated the enzyme. Addition of CaCl2, 2-mercaptoethanol, or enzyme substrate the 60degreeC exposed enzyme. However, bovine serym albumin had a protective effect when the enzyme was exposed to 60degreeC but not to 80degreeC. The enzyme was stable in the presence of 8 M urea.

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