Effect of cobalt-60 gamma radiation on total hemocyte content and biochemical parameters in Macrobrachium rosenbergii (De Man, 1879).

Purpose: The effect of low level cobalt-60 (60Co) gamma radiation on the freshwater prawn Macrobrachium rosenbergii was evaluated by observing their hemocyte counts and biochemical parameters. Materials and methods: Prawns were exposed to 3, 30, 300 and 3000 milligray (mGy) dose levels and their tissues of gills, hepatopancreas and muscle were analyzed. Results: The results showed that the number of hemocytes in the hemolymph and concentrations of protein and carbohydrate were significantly reduced in irradiated groups than compared to the control prawn. Increased aspartate transaminase (AST), alanine transaminase (ALT), lactate dehydrogenase (LDH), alkaline phosphatase (ALP), Acetyl choline esterase (AChE) in the irradiated groups reflects tissue damage. Conclusions: Hence, this study concludes that even low level of ionizing radiation (60Co gamma) can cause acute damages in gills, hepatopancreas and muscles in irradiated groups. Highlights 60Co exposures effect the THC and biochemical of prawn M. rosenbergii. Different dose levels such as 3, 30, 300 and 3000 mGy. Biochemical parameters serve as reliable indicators of physical status of organism. Self-regulating mechanisms might be the reason for preventing from the lethality. Suggested that nuclear industries should manage below 3 mGy.

Histological alterations in the hepatic tissues of Al2O3 nanoparticles exposed freshwater fish Oreochromis mossambicus.

Adverse effects of nanoparticles on aquatic environment and organisms have drawn much special attention to many researches. Aluminium oxide nanoparticles (Al2O3-NPs) have potential uses in varied fields and are seen entering into the ecosystem. Their potential toxicity to the freshwater fish is not much studied. Hence this study was framed to investigate the effect Al2O3 NPs on freshwater fish Oreochromis mossambicus in terms of sub lethal toxicity, histological changes and hepato somatic index (HSI) under laboratory conditions. Fishes were exposed to varying concentrations of Al2O3 NPs for 96hr. LC50 value was found to be in between 235 and 245ppm. The findings of the present work showed that the NPs were accumulated in the fish liver and caused major histological anomalies such as structural alterations in the portal vein, necrotic hepatocytes, vacuolation, aggregation of blood cells and melanomacrophages. Significant histological alterations were observed in the highest concentration. Our results evidenced that the Al2O3 NPs in the aquatic environment affects the health condition of the fishes.

Vertical distribution, composition profiles, sources and toxicity assessment of PAH residues in the reclaimed mudflat sediments from the adjacent Thane Creek of Mumbai.

A study on vertical distribution of magnetic susceptibility, carcinogenic and endocrine disrupting PAHs was performed in the reclaimed mudflat sediments adjacent to the Thane Creek of Mumbai. The 5-rings PAHs and ΣC-PAHs were more dominant at 120cm depth contributing 52.23% and 60.19% respectively to ∑PAHs. The average ratio values of LMW/HMW PAHs (0.58); Fla/(Fla+Pyr) (0.50); Ant/(Ant+Phe) (0.50); BaA/(Chry+BaA) (0.48); BaP/BghiP (2.06), Phe/Ant (1.03) and BaA/Chr (0.93) indicate that the PAH contamination might have raised due to inefficient combustion and pyrogenic emissions during the open burning of solid waste in the vicinity. This was further supported by the anthropogenic ferri(o)magnetic loading over the last 100years influencing the Creek sediments. The PAHs toxicity estimation was performed by calculating the toxic equivalent quantity (TEQ) value of 8.62ng TEQ/g which was below the safe level (600ng TEQ/g) suggested by the Canadian risk-based soil criterion for protection of human health.

Morphological and histological studies on freshwater prawn Macrobrachium rosenbergii (de man) irradiated with (60)Co gamma radiation.

This study was framed to investigate the (60)Co gamma radiation induced morphological and histological variations in freshwater prawn Macrobrachium rosenbergii. The LD50 value of (60)Co gamma irradiated M. rosenbergii observed (by probit analysis) at 30 Gy. Prawns were irradiated to four different dose levels (3 mGy, 30 mGy, 300 mGy and 3,000 mGy) using Theratron Phoenix TeleCobalt Unit [P-33] and one control group (without irradiation) maintained separately. Irradiated groups exhibited several morphological variations such as discoloration; damaged rostrum; opaque coloration in cephalothorax; black bands and dot formation in abdomen; deformed uropods and telson in tail regions when compared with control group. The Hepato Somatic Index reflected the severity of radiation on hepatopancreas. Histological variations in gills, hepatopancreas and muscles of irradiated groups were observed. In gills, structural changes such as swollen and fused lamellae, abnormal gill tips, hyperplasic, necrotic and clavate-globate lamellae were observed in gamma irradiated prawns. Accumulation of hemocytes in hemocoelic space, interstitial sinuses filled with abnormal infiltrated hemocytes, the tubular epithelium with ruptured basal laminae, abnormal and coagulated lumen, necrotic tubules, thickened basal laminae, tissue debris, necrotic hepatocytes were observed in irradiated prawn hepatopancreas. In muscle, shrinkage of muscular fiber and necrotic musculature were observed in irradiated prawns. These structural alterations of the organs it is felt could affect the vital physiological functions such as respiration, osmotic and ionic regulation in gills and muscles; absorption, storage and secretion of the hepatopancreas which in turn could adversely affect the growth and survival of freshwater prawn M. rosenbergii.

Evaluation of doses from ionising radiation to non-human species at Trombay, Mumbai, India.

In order to meet the proposed regulatory compliances for the protection of non-human species from the ionising radiation, a comprehensive dose-evaluation process for terrestrial and aquatic biota was worked out at Trombay. During this work, dose rate (external and internal) from ionising radiation to the terrestrial plants and marine organisms (mixed varieties of fish) was evaluated by estimating the concentration of anthropogenic ((137)Cs, (90)Sr) and natural radionuclides ((238)U, (232)Th and (40)K) in environmental matrices, such as soil, vegetation, sea water and sediment. The samples were processed as per the International Atomic Energy Agency protocol for the estimation of naturally occurring and anthropogenic radionuclides. The average values of radiation exposure to the terrestrial plants for (40)K, (90)Sr, (137)Cs, (232)Th and (238)U were 632.8 +/- 40.5, 167.4 +/- 48.2, 691.2 +/- 29.9, 48769 +/- 13203 and 1801 +/- 1495 microGy y(-1), respectively. In the case of marine organisms (fish), the maximum external exposure was 195 microGy y(-1) due to (40)K concentration in bottom sediment, whereas the minimum was 0.004 microGy y(-1) due to (137)Cs in sea water. Internal exposure to fish was maximum (700 microGy y(-1)) due to (40)K, whereas the minimum of 0.12 microGy y(-1) was due to (90)Sr. Considering the dose limit of 10 mGy d(-1) (3.65 Gy y(-1)), proposed by the US Department of Energy, evaluated radiation exposure (external + internal) and dose rate in the present study to the terrestrial plants and marine organisms are orders of magnitude less.

Selective separation of iron from uranium in quantitative determination of traces of uranium by alpha spectrometry in soil/sediment sample.

During this work, controlled redox potential methodology was adopted for the complete separation of traces of uranium from the host matrix of mixed hydroxide of Iron. Precipitates of Fe(+2) and Fe(+3) along with other transuranic elements were obtained from acid leached solution of soil by raising the pH to 9 with 14N ammonia solution. The concentration of the uranium observed in the soil samples was 200-600 ppb, whereas in sediment samples, the concentration range was 61-400 ppb.

Glutathione ethyl ester supplementation prevents mortality in newborn rats exposed to hyperoxia.

Human premature neonates suffer from respiratory distress syndrome due to immature lungs and require assisted ventilation with high concentrations of oxygen. Hyperoxic exposure and/or antioxidant deficiency causes an increase in the lung levels of reactive oxygen species (ROS) leading to oxidative stress-induced cellular damage. In this study, we explored the protective role of the nonenzymatic antioxidant glutathione, by administering glutathione ethyl ester (GSHEE), in newborn rats exposed to hyperoxia (>95% FiO(2)). Our results show that GSHEE supplementation (5 mmol/kg/day) prevents mortality in newborn rats exposed to hyperoxia. We further show that delayed GSHEE supplementation in newborn rats, pre-exposed to hyperoxia for 4 days, also prevents death. Electron microscopic studies on the lung of GSHEE-treated hyperoxic rats showed normal histology and an absence of the marked swelling and degeneration of mitochondria and lamellar bodies, which are typically observed in the hyperoxic lungs of newborn rats. Furthermore, there were no apparent differences in weight gain or general appearance/activity among room air and hyperoxic GSHEE-supplemented animals when monitored, post-treatment, in room air for 30 days. Our results show a preventive/therapeutic role of GSHEE supplementation against mortality caused in newborn rats due to hyperoxic exposure, and may further be applicable to a variety of degenerative diseases that are caused as a result of ROS accumulation.

Modulation of base excision repair by low density lipoprotein, oxidized low density lipoprotein and antioxidants in mouse monocytes.

In the present study, we found that oxidized low density lipoprotein, but not low density lipoprotein, down-regulated base excision repair activity in extracts of mouse monocyte cell line PU5-1.8. An enzyme required in this pathway, DNA polymerase beta, was also down-regulated. In contrast, treatment of monocytes with a combination of ascorbate and alpha-tocopherol up-regulated base excision repair activity and expression of DNA polymerase beta. Co-treatment of monocytes with antioxidants plus oxidized low density lipoprotein prevented down-regulation by oxidized low density lipoprotein. Oxidative DNA damage, as measured by 8-hydroxyguanine accumulation in genomic DNA, was found in cells treated with oxidized low density lipoprotein; 8-hydroxyguanine was not found in the cells treated with low density lipoprotein, antioxidants or oxidized low density lipoprotein plus antioxidants. These results establish a linkage between the DNA base excision repair pathway, oxidative DNA damage and oxidized low density lipoprotein treatment in mouse monocytes. Since oxidized low density lipoprotein is implicated in chronic disease conditions such as atherogenesis, these findings facilitate understanding of genetic toxicology mechanisms related to human health and disease.

Glutathione, a first line of defense against cadmium toxicity.

Experimental modulation of cellular glutathione levels has been used to explore the role of glutathione in cadmium toxicity. Mice treated with buthionine sulfoximine [an effective irreversible inhibitor of gamma-glutamylcysteine synthetase (EC 6.3.2.2) that decreases cellular levels of glutathione markedly] were sensitized to the toxic effects of CdCl2. Mice pretreated with a sublethal dose of Cd2+ to induce metallothionein synthesis were not sensitized to Cd2+ by buthionine sulfoximine. Mice sensitized to Cd2+ by buthionine sulfoximine were protected against a lethal dose of Cd2+ by glutathione mono isopropyl ester (L-gamma-glutamyl-L-cysteinylglycylisopropyl ester), but not by glutathione. These results are in accord with studies that showed that glutathione mono esters (in contrast to glutathione) are efficiently transported into cells and converted intracellularly to glutathione. The findings indicate that intracellular glutathione functions in protection against Cd2+ toxicity, and that this tripeptide provides a first line of defense against Cd2+ before induction of metallothionein synthesis occurs. The experimental approach used here in which cellular levels of glutathione are decreased or increased seems applicable to investigation of other types of metal toxicity and of other glutathione-dependent biological phenomena.