Chronic exposure to formaldehyde: relationship to hepatic metallothionein synthesis, indices of oxidant stress, and immunotoxicity

This study included forty male albino rats divided into four groups. Each group consisted of ten rats. The first group was exposed to formaldehyde for two weeks, the second for four weeks and the third for six weeks. The last group of animals served as controls and received phosphate buffered saline, the vehicle used to dissolve formaldehyde. Immediately after sacrifice, the liver of each animal was homogenized and used for determination of glutathione-S- transferase [GST], metallothionein, total thiols, catalase, lipid peroxides [LPER], nitric oxide[NO] and adenosine deaminase [ADA]. The study revealed significant increase in GST which remained significant irrespective to the time of exposure. Metallothionein was significantly increased in these animals in a time dependant manner. The levels of GST activity and metallothionein were significantly correlated reflecting the carcinogenic potential of formaldehyde. Meanwhile, rats exposed to formaldehyde exhibited significantly decreased levels of total thiols which remained significant in the three groups due to involvement of glutathione in the metabolism of formaldehyde. Oral administration of formaldehyde was associated with increased oxidant stress manifested by significantly decreased catalase activity and enhanced lipid peroxides and ceruloplasmin after two weeks of oral exposure. Thereafter, such oxidant stress was gradually corrected as manifested by gradual increase in catalase activity and decrease of lipid peroxides and ceruloplasmin. These changes could be due to enhancement of metallothionein which has an important antioxidant action; a viewpoint supported by the significant positive correlations between metallothionein and catalase. NO levels showed significantly decreased levels in the three groups of animals

Effect of azadirachta indica NEEM extract on paracetamol induced hepatotoxicity

This work aimed to investigate the effect of water soluble extract on rats given hepatotoxic dose of paracetamol on histological and biochemical basis. The animals were divided into four groups, each was 12 rats. The first group received neem extract and paracetamol, the second group was given neem extract and saline, the third group was given paracetamol and the last group received saline and served as controls. The liver of each animal was examined histologically and part of it was homogenized and the homogenate was used to determine the liver enzymes, GOT, GPT and albumin. Also, the homogenate was used to determine the degree of oxidant stress by determination of total thiols and catalase. The histological results showed that the hepatotoxic effects of paracetamol were greatly ameliorated by the plant extract. Biochemically, this was shown by the significant decrement of liver enzymes GOT and GPT and the degree of oxidant stress manifested by increased levels of total thiols and catalase. Thus, these data supported the hepatoprotective effect of the plant on paracetamol induced toxicity

study of hematotoxicity and nephrotoxicity in gasoline filling station workers in Assiut

This study included forty-three male workers from eight gasoline filling stations and eleven unexposed controls of comparable age. The study revealed significantly increased plasma levels of TNF-alpha in exposed workers compared with the controls which correlated with duration index of exposure as well as urinary phenol excretion representing a biological monitor of benzene exposure. TNF-alpha could be derived from bone marrow cells reflecting hematotoxicity or kidney tissues and reflecting nephrotoxicity. The decreased RBCs sialic acid seems to reflect the associated hemolytic effect of benzene. Meanwhile, increased urinary sialic acid besides enhanced urinary excretion of tubular enzymes seemed to reflect nephrotoxicity affecting the glomerular filter and proximal renal tubules manifested also by increased albumin excretion. The marked correlations observed between these indices and duration index of exposure suggested a common source of origin. The results proved that those workers were greatly affected by benzene so, they should be examined periodically at least by routine blood picture and urine analysis as well as by simple determination of sialic acid. The period of exposure should also be decreased

Chronic toxic effect of plant growth promoting hormone, gibberellic acid, on the liver cells of adult male albino rat

Gibberellic acid is one of the plant growth promoting hormones that is used in agriculture to increase the growth of fruits and vegetables. The toxic effect of chronic oral exposure to this growth promoter on the histological structure of liver cells of rats was investigated into three groups, each was 12 rats. The first group received a daily oral dose of 70 mg/kg of gibberellic acid dissolved in distilled water for one month then animals were sacrificed. The second group received the same dose of gibberellic acid for one month then animals were left to recover and were sacrificed after two months from the last dose. The third group of animals served as controls and received a daily oral dose of distilled water. Liver specimens were taken from animals of each group, prepared for and examined by light and electron microscopes. The significant histological changes in the liver cells after exposure to gibberellic acid were presented in the form of swelling of the majority of cells, depletion of glycogen, appearance of large amounts of smooth endoplasmic reticulum, appearance of large areas of rarified cytoplasm separating dense areas of cellular organelles, increased of lysosomes, swelling and degeneration of many cells. Following substance withdrawal, a few cells became nearly similar to those of the controls, while the majority of cells remained affected. These data supported the deleterious effects of gibberellic acid on the liver after chronic oral exposure and the recovery from these effects might need a longer time. So, the need for protection from the hazards of these substances should be searched for and continued

Value of enzymatic examination of blood stains in determination of the period of gestation

The objective of this work is to establish the diagnostic efficiency of the determination of the ratio between heat-stable [H-S] and total [T] alkaline phosphatase activities in dry blood stains on an absorbent surface [Cotton Cloth] in cases of pregnancy. Blood samples were obtained from healthy adult males and nonpregnant females [Control group, 10 cases, 5 males and 5 females], pregnant females at different stages of pregnancy [30 samples, 10 in each trimester] and patients with elevated values of alkaline phosphatase [obstructive jaundice, 9 samples]. The blood stains were left at room temperature for different periods up to 6 months. The values of [H-S] and [T] alkaline phosphatase were measured in the serum of the control group and the blood stains of all groups and then we determined the ratio between them [H-S/T]. We found that the values of [H-S] and [T] alkaline phosphatase in the serum were higher than those in the blood stains of the control group but the ratio was the same. There was a statistically significant progressive rise in the ratios between [H-S] and [T] alkaline phosphatase in blood stains of pregnant females at different trimesters and a significant decreased ratio in the blood-stains of the group of obstructive jaundice. The same results were obtained with aged blood stains up to 6 months

Elevated serum cadmium among workers of Assiut Cement Factory: source, assessment and toxicological studty

The present study was conducted on 72 male workers of Assiut Cement Factory complaining of some renal troubles together with 30 healthy controls. Significant increase in the level of serum and urinary cadmium was observed among those workers. Other renal variables including B2-microglabulin [B2-MG] and N-acetyl Beta-glucosaminidase [NAG] were also significantly increased denoting renal impairment. An interesting finding in this study was the elevation of serum calcium and serum alkaline phosphatase among the workers compared with controls. The levels of these bioindices were correlated with the level of serum and urinary cadmium. Dose response relations were observed between B2-MG and NAG and urinary cadmium. The source of cadmium was searched for including the waste products of the factory and its surroundings and the drinking water. Water of the well supplying the factory proved to be the main source of pollution among the workers

Lead poisoning from a retained bullet in the middle ear

A rare case of lead intoxication caused by a bullet lodged in the middle ear for four years was discussed. A review of previously reported cases of lead poisoning from projectiles was presented