Gamma Isomer Research Articles

Photocatalytically active Ag-doped TiO2 coatings developed by plasma electrolytic oxidation in the presence of colloidal Ag nanoparticles

The plasma electrolytic oxidation process of Ti foil in the presence of a colloidal solution of Ag nanoparticles was used for the synthesis of exceptionally photocatalytically active Ag-doped TiO2 coatings. UV–Vis absorption spectroscopy was applied to follow the changes in the surface plasmon resonance band of the Ag nanoparticles as a function of the Ag:PO43− ratio in a phosphate-based electrolyte solution. Transmission electron microscopy revealed the size of the Ag nanoparticles in the range of 3–12 nm. The XRD patterns of the Ag-doped TiO2 coatings confirmed the crystalline anatase TiO2 phase regardless of the dopant concentration and without metallic Ag or crystalline Ag oxide forms. The typical porous morphology of the Ag–TiO2 coatings was observed by scanning electron microscopy. A significantly improved photocatalytic activity of the Ag–TiO2 coatings in the degradation process of the insecticide lindane (gamma isomer of benzene hexachloride) and test molecule methyl orange compared to pure TiO2 was determined using the GC technique. The degradation efficiency of Ag-doped TiO2 coatings is higher for lindane than for methyl orange.

Использование 3D-спектров флуоресценции для идентификации подлинности масла виноградной косточки

Falsification of grape seed oil causes serious damage to consumers and shows unfair competition in the market. 3D fluorescence spectroscopy was used to characterize oil flurophores and differentiate samples by identification criteria: method of preparation, raw material used, and manufacturer. During the study, 3D excitation-emission spectra of several samples of grape seed oil from various manufacturers available on the Russian market were obtained. One of the samples with confirmed production histories was used for comparison. The results of analysis of the obtained spectra by zones of maxima on the hypersurface of the absorption-emission matrix were correlated with individual fluorophores and their groups of functional ingredients of the oil, providing its physiological activity. The possibility of using the obtained data for identification of grapeseed oil samples and prompt detection of falsifications is shown. All samples were tested in hexane. It has been shown that genuine oil samples have distinctly differentiated regions of very high intensity on the hypersurface of the excitation-radiation matrix intensity with peaks characteristic of all isomers of tocopherols and tocotrienols with a predominance of the gamma isomer with an EEM maximum of 292/324 nm. There are also intense regions of absorption of carotenoids 325/453 nm and isomeric forms of chlorophyll 405–436/650–670 nm, the  form being the prevailing one. The absorption regions of procyanidins are intense 280 /316–324 nm; gallic acid 260/390 and coumaric acid 270/420. The uniqueness of the 3D fluorescence spectra for each oil and the formation of the resulting data pool in the form of a three-dimensional matrix allows them to be used for machine learning and the isolation of significant parameters by standard chemometrics.

Degradation effectiveness of hexachlorohexane (ϒ-HCH) by bacterial isolate Bacillus cereus SJPS-2, its gene annotation for bioremediation and comparison with Pseudomonas putida KT2440

The contamination of Hexachlorohexane (Lindane) in soil and water has toxic effects due to its persistent nature. In our study, an indigenous HCH (gamma isomer) degrading bacterium viz Bacillus cereus SJPS-2 was isolated from Yamuna river water using enrichment culture method. The growth curve indicated that Bacillus cereus SJPS-2 was able to degrade ϒ-HCH effectively with 80.98% degradation. Further, process was improved by using immobilization using alginate beads which showed enhanced degradation (89.34%). Interestingly, in presence of fructose, the ϒ-HCH degradation was up to 79.24% with exponential growth curve whereas the degradation was only 5.61% in presence of glucose revealing diauxic growth curve. Furthermore, The FTIR results confirmed the potential lindane degradation capability of Bacillus cereus SJPS-2 and the bonds were recorded at wavelengths viz. 2900-2500 cmˉ1, 3300-2800 cmˉ1 and 785-540 cmˉ1. Similarity, the GC studies also reconfirmed the degradation potential with retention time (RT) of ethyl acetate and lindane was 2.12 and 11.0 respectively. Further, we studied the metabolic pathway involved for lindane utilization in Bacillus cereus using KEGG-KASS and functional gene annotation through Rapid Annotation using Subsystems Technology (RAST) resulted in the annotation of the lin genes (lin A, lin B, lin C, lin X, lin D, lin E) and respective encoding enzymes. The comparative ϒ-HCH degradation potential of B. cereus and P. putida KT2440 was also evaluated. The island viewer showed the different colors on circular genome indicate the coordinates of genomic islands resulted with some common genomic islands (GEIs) between both bacteria indicating the possibility of horizontal gene transfer at contaminated site or natural environment. These genomic islands (GEIs) contribute in the rearrangement genetic material or to evolve bacteria in stress conditions, as a result the metabolic pathways evolve by formation of catabolic genes. This study establishes the potential of Bacillus cereus SJPS-2 for effectual ϒ-HCH degradation.

Морфофункциональная характеристика эндокринного отдела поджелудочной железы под воздействием γ-ГХЦГ

In the last decades of the twentieth century, in the national economy of many countries, organochlorine pesticides were most widely used, characterized by stability in the external environment, the ability to cumulate in various tissues of organisms. Lindane (the gamma isomer of hexachlorocyclohexane) is listed as a restricted persistent organic pollutant and is an ecotoxic substance with severe and chronic effects on the human body. The study of the effect of lindane on carbohydrate metabolism at the present stage is still insufficient. This fact led to the study of the effect of γ-HCH on the insulinogenic function of the pancreas in in vivo and in vitro experiments. In experiments in vivo, the animals of the experimental groups were once orally administered γ-HCH at a dose equal to 1/5 DL50. Isolated pancreatic islets, precipitated in vitro and fixed on mica plates, were exposed to γ-HCH in amounts equivalent to 1/5 to 1/4 DL50. Paraffin sections of pancreatic tissue from experimental and control animals were stained with aldehyde fuchsin according to Gomori, and tissue preparations were also examined by a highly specific method for detecting insulin in β-cells using diethylpseudoisocyanin staining, followed by examination of the preparations in the ultraviolet light of a luminescent microscope. The samemethods were used to study preparations of isolated pancreatic islet tissue on the 4th day of cultivation. The influence of orally administered γ-HCH on the level of immunoreactive insulin in the blood of experimental animals was also studied. The insulin level was determined by the enzymatic-immunological method. The concentration of IRI was established before the start of the experiment and 4-4.5 hours after acute inoculation. Results and their significance. In the study of stained preparations of the pancreas of experimental animals, numerous islets of ordinary sizes were revealed, the cytoplasm of which was filled with aldehyde-fuccin granularity in quantities indistinguishable from those observed by microscopy of preparations of control animals. The value of the fluorescence coefficient in the histofluorimetric study of the control and experimental preparations did not differ significantly. However, the content of IRI in the blood serum showed a distinct decrease in the first hours after priming. In experiments in vitro, when studying the effect of γ-HCH on cultured tissue, introduced into the nutrient medium on the second day, in the field of view of the microscope, single, small pancreatic islets were revealed. Their number on a constant area of the plates was significantly lower than the value of the same indicator in the study of control preparations. Thus it has been shown that γ-HCH does not affect the histostructure of the endocrine pancreas, but causes a significant decrease in IRI in the blood serum, as well as a change in the histochemical characteristics of cultured β-cells.

QUALITY CONTROL, SAFETY OF RAW MEAT AND TURKEY MEAT PATE AND JUSTIFICATION OF RECIPES AND STERILIZATION REGIMENS

In the study of the toxicity of turkey meat, it was found that the content of toxic elements in the tested batches did not exceed the permitted levels. Thus, the lead content in meat was 0.08 mg / kg, which is 6.2 times (P <0.05) less than the determined norm, the arsenic content was at the level of 0.02 mg / kg or 5 times (P <0.05) is less than the standard, and cadmium and mercury are not detected at all. Based on the defined function and constraints, we create a spreadsheet in MS Excel according to functional dependency. The built-in Excel Solution Finder was used to determine the optimum composition of components. The purpose of optimizing the recipe composition of the original products is its balance in basic nutrients, the maximum approximation to the following requirements of healthy nutrition is observed at the ratio of proteins: fats: carbohydrates - 1: 1,3: 4; essential amino acids lysine: tryptophan: methionine - 1: 3: 3; fatty acid composition of polyunsaturated: saturated: monounsaturated - 1: 3: 6; Omega 6: Omega 3 - 10: 1; the ratio of trace elements: Ca: Mg = 1: 1,5; Ca: P = 1: 0.6. The highest percentage (31%) of canned pate is made from turkey meat, namely turkey meat. The specified meat raw material has undergone laboratory testing and meets the requirements of quality and safety regulations. Beef liver is included in the recipe in the amount of 10% of the total mass of raw materials and at its nutritional value complements the quality indicators of pate. In order to give a gentle texture to the pate, a fermented pork skin in the brine is put into the recipe. The indices of mass fraction of moisture of rock were 66.8% (P <0.01), fat - 20.0% (P <0.01), protein - 8.2% (P <0.01), ashes - 1.46% (P <0.01), carbohydrates - 3.5% (P <0.01) and are within the limits specified by the regulatory documentation. The caloric content of the meat pate is low and is only 226.8 kcal. The results of studies of turkey meat pate showed that the mass concentration of toxic elements meets regulatory standards, in particular the lead content was 0.02 mg / kg (P <0.03) or 30 times less than the allowable level, cadmium - 0.01 mg / kg (P <0.01) or 30 times less, arsenic - 0.05 mg / kg (P <0.01) or 20 times less, mercury - 0.005 mg / kg ( P <0.01) or 20 times less. Indicators of organochlorine pesticide content were in particular the gamma isomer of HCG - 0.04 mg / kg (P <0.01) or 2.5 times less than normal, DDT and its metabolites - 0.03 mg / kg (P <0.05) or 3.3 times less.

Process optimization of γ- Hexachlorocyclohexane degradation using three novel Bacillus sp . strains

Abstract In the present investigation three lindane degrading bacterial isolates, HP-9, H-10 and HP-13 were isolated from agricultural soil by enrichment culture technique. These isolates were characterized- HP-9 as Bacillus sp. Cal6F, HP-10 as Bacillus sp. Lad2A and HP-13 as Bacillus sp. Ym7A by 16S rRNA sequencing and their 16S rRNA sequence were submitted to National Centre of Biotechnology Information (NCBI) Gene Bank with accession numbers, KJ937291, KJ944283 and KJ944284, respectively. They efficiently degraded up to 100 mg/l of lindane within 10 days under the optimized physiological conditions of: pH 7, temperature 30 °C, shaking speed 120 rpm, NaCl (1–3%) and initial lindane concentration 100 mg/ml. The maximum rate of inorganic chloride ion release was 0.49 mg/ml, 0.40 mg/ml, 0.40 mg/ml and the rate of gamma isomer of lindane involved in degradation observed was 75.65%, 64.77% and 62% for HP-9, HP-10 and HP-13, respectively. Lindane degradation was further confirmed by gas chromatography and Sphingomonas japonicum MTCC 6362 was used as a reference strain. Degradation kinetics was studied by using first order kinetic equation. Half-life periods during degradation were found to be 1.35, 1.48 and 1.75 days for the three isolates. The addition of galactose enhanced the degradation rate up to 10% whereas maltose, lactose and xylose had adverse effect and leads to decrease in degradation up to 40%. It was observed that addition of beef extract greatly enhanced lindane degradation rate followed by malt extract and peptone. The addition of glucose as a co-substrate and H2O2 as an electron donor greatly enhanced the lindane degradation rate.

Effects of exposure to three environmental chemicals on the selected biochemical parameters of the blood plasma of rainbow trout, Oncorhynchus mykiss (Walbaum)

Abstract Rainbow trout Oncorhynchus mykiss at a weight of 115 ± 24 g (mean ± SD) were experimentally injected with di(2-ethylhexyl)phthalate (DEHP), 2,3,7,8-tetrachlorodibenzo-p-dioxine (TCDD) and gamma isomer of hexachlorocyclohexane (γ-HCH ) to evaluate nitrogen metabolism (total protein [TP], blood urea nitrogen, uric acid [UA], creatinine), carbohydrate metabolism (glucose), mineral metabolism (inorganic phosphate[P], total calcium [Cat]), and catalytic activity of enzymes (alanine aminotransferase [ALT], aspartate aminotransferase [AST], alkaline phosphatase [ALP], lactate dehydrogenase [LD]). After 21 days, the tested xenobiotics, administered by the intraperitoneally route, caused the following effect: in comparison with negative controls, fish injected with DEHP at concentrations of 200 or 50 mg kg-1 of body weight were found to have a higher level of P and lower level of Cat and decreased catalytic concentrations of ALT, AST, ALP and LD in the plasma of the peripheral blood. A higher level of TP and P and a decreased catalytic concentration of ALT were found when TCDD was administered at a dose of 2 μg kg-1. A decrease in the catalytic concentrations of ALT and ALP occurred in fish injected with γ-HCH in a dose of 50 mg kg-1. UA and P levels were decreased in fish injected with γ-HCH in a dose of 5 mg kg-1. DEHP and TCDD caused neutrophilic leucocytosis with a marked left shift. Both concentrations of γ-HCH led to an increase in polychromatophilic erythrocytes. The frequency of micronuclei varied in all experimental groups, including the controls, ranging between 0.8 and 2.1 ‰. Histological examination in fish injected with DEHP at a concentration of 200 mg kg-1 revealed eosinophilic droplets in the epithelium of renal tubules and histological examination in fish injected with γ-HCH at a higher concentration revealed an increased activation of sinusoidal cells in the liver, a fibrous thickening of bile duct walls, bile duct hyperplasia and a periductal inflammatory.

Effects of Pesticide use in Rice Fields on Birds

Waterbird use of agricultural wetlands has increased as natural wetlands have declined. Use of rice (Oryza sativa) habitats by some waterbird species is considered essential to sustaining populations. Although use of rice habitats by waterbirds has been documented throughout the world, little information is available on potential risks as a result of chemicals used in rice cultivation. The current review summarizes understanding of the use and consequences to birds of pesticide applications in rice habitats. Historically, organochlorine pesticides known to be applied for pest management in rice cultivation included dichlorodiphenyltrichloroethane (DDT), aldrin, dieldrin, endrin, heptachlor, technical hexachlorocyclohexane (HCH), toxaphene, endosulfan and sodium pentachlorophenate. Endosulfan and purified HCH (the gamma isomer lindane) are still in use. Cholinesterase-inhibiting insecticides currently used in rice include carbofuran, monocrotophos, phorate, diazinon, fenthion, phosphamidon, methyl parathion and azinphos-methyl—many products known to cause acute poisoning in birds. In addition, herbicides, fungicides, molluscicides and other pesticide types are used in rice cultivation. Some of the chemicals are highly toxic to birds and associated with mortality; several have the potential of causing adverse reproductive effects. Because of the large area under rice cultivation worldwide, the volume of pesticides applied to rice fields is significant. Innovations within the past few decades in rice production have increased pesticide use resulting in biodiversity losses in production areas and pollution of water resources. Management practices that address adverse effects of pesticide use in rice fields include increased adoption of Integrated Pest Management principles and less toxic products.

Monitoring of pesticide residues in Riyadh dates by SFE, MSE, SFC, and GC techniques

In the present work, simple and rapid extraction and analysis techniques of insecticide (OCPs, OPPs, pyrethroids), fungicide, acaricide, and herbicide residues in three cultivars’ of date fruits viz., Khalas, Sukkari, Nabout Seif and their seeds have been applied. The date cultivars were collected from eight local markets of Riyadh, KSA. The extraction of pesticide residues from the three varieties of date samples was conducted by rapid and new extraction techniques, Supercritical Fluid Extraction (SFE) and Microwave Solvent Extraction (MSE). The analysis was performed, without clean-up, by Supercritical Fluid Chromatography (SFC) and Gas Chromatography (GC) using different detectors. The results showed that the SFE, MSE, SFC and GC techniques are clearly faster, more sensitive and more cost effective than conventional methods. The recovery efficiency of SFE and MSE was 99% and 97%, respectively. The recoveries, MDL (Minimum Detection Limit) and repeatability achieved in this study meet the standards set for tolerance level monitoring of these pesticides. The mean levels of some tested residues of pyrethroids, herbicides, and fungicides in dates and their seeds are below the MRL (Maximum Residue Level). However, lindane (BHC gamma isomer), dieldrin, dimethoate, chlorpyrifos and all tested acaricide residues in date fruit samples exceeded the MRLs indicating a hazardous trend in the date palm cultivation. The data also showed a higher concentration of OP dimethoate in the date seeds, which is sometimes, used as animal feed. The present results provide important information on the current contamination status of the date fruits in Riyadh markets and point to the action needed for controlling the excessive application of pesticides. This study is the first monitoring and screening of pesticide residues of 6 groups in Saudi Arabian dates.

Vitamin E exhibits bone anabolic actions in normal male rats

Recently, vitamin E has been found to promote the bone structure of nicotine-treated rats well above their baseline values, thus suggesting that vitamin E may have some anabolic action. A bone anabolic agent acts by improving the bone structure leading to stronger bone. To assess the possible anabolic action vitamin E on bone, we supplemented alpha-tocopherol (ATF) or gamma-tocotrienol (GTT) at 60 mg/kg or vehicle [normal control (NC) group] for 4 months to normal male rats and measured their bone structure and biomechanical properties. Histomorphometric analysis revealed that vitamin E-supplemented rats have better trabecular volume, thickness, number, and separation than rats receiving vehicle only. For the first time we reported that GTT improves all the parameters of bone biomechanical strength, while ATF only improved some of the parameters compared to the NC group. Vitamin E supplementation, especially with the gamma isomer, improves bone structure, which contributed to stronger bone. Therefore, vitamin E has the potential to be used as an anabolic agent to treat osteoporosis or as bone supplements for young adults to prevent osteoporosis in later years.

Sperm motility in the fishes of pesticide exposed and from polluted rivers of Gomti and Ganga of north India

Investigation of lethal dose of γ-HCH (gamma isomer of hexachlorocyclohexane), DDT (dichlorodiphenyltrichloroethane) and chlorpyrifos on spermatozoa motility after 40 days exposure in catfish, Heteropneustes fossilis was done under laboratory conditions. The sperm motility was done in the fishes captured from unpolluted ponds of Gujartal considering as reference site and polluted rivers Gomti and Ganga of north India at pre-spermiating stage. Results indicate that 1 ppm of γ-HCH, DDT and chlorpyrifos was lethal dose on sperm motility. The motility of spermatozoa decreased in insecticide exposed fish as well as in the fishes of polluted rivers when compared with their respective controls. The sperm motility was highest at 1:2000 (testicular milt: extender) dilution and duration of sperm motility was 90 s after post-activation. The duration of motility also declined in the fishes captured from polluted rivers when compared with the same species captured from the reference site. It is concluded that the insecticides decrease the sperm motility and its duration in exposed fish as well as in the captured fishes from polluted rivers causing the decline in fish population of riverine systems due to influence of xenobiotics on the endocrine system.

Exposure and recovery response of isomers of HCH, metabolites of DDT and estradiol-17β in the female catfish, Heteropneustes fossilis

Effects of 40 days of exposure and 20 days of recovery response at sublethal concentration of technical grades of gamma isomer of hexachlorocyclohexane (γ-HCH, 0.025 ppm, 99.8%) and dichlorodiphenyltrichloroethane (DDT, 5.0 ppm) in tissue (liver, brain and ovary) bioconcentrations, gonadosomatic index (GSI) and plasma levels of estradiol-17β (E2) have been estimated during prespawning phase in the catfish Heteropneustes fossilis (Bloch). The results indicated that the tissue bioconcentrations of both HCHs (HCH isomers) and DDTs (metabolites of DDT) in liver, brain and ovary were in preferential order (liver > brain > ovary). The GSI and plasma levels of E2 were declined in response to exposure of γ-HCH and DDT. On withdrawal of exposure of pesticide there was recovery of HCHs in exposed fish for all tissues studied, whereas DDTs exposed fish showed recovery only in liver. Recovery of E2 production was also recorded in γ-HCH exposed fish whereas very little recorded in DDT exposed fish. It is suggested that HCHs and DDTs have preferential order (liver > brain > ovary) of their tissue bioconcentrations and HCH/DDT-withdrawal-dependent recovery during studied phase.

The acute Toxicological effects of Gammalin 20 on the lung and Pancreas of Guinea Pig

The acute toxicological effects of Gammalin 20 (gamma Isomer of hexachlorocyclohexane) on the lungs and Pancreas of Guinea Pig were investigated. Twenty-Eight Guinea Pigs of 300gm average body wt were used for the study. Five dose levels 0.0gkg., 0.82gkg –1 ., 1.63gkg -1 ., 3.25gkg -1 and 6.5gkg -1 were obtained after a range finding test using five guinea pigs and administered intra peritoneally, into the animals. Signs and symptoms of toxicity (Irritability, staggering, laboured breathing, convulsion and death) were observed, scored in this order of severity and found to be dose dependent. Histopathological examination of the lungs revealed edema, congestion and disruption of lung architecture. The Pancreas showed acute toxic inflammatory reaction, edema, acute pancreatitis and disruption of Pancreatic architecture. LD 50 of gammalin 20 in the male guinea pig using intraperitoneal route was 1.87gkg -1 . gammalin 20 therefore based on classification of toxicity of chemicals was found to be slightly toxic to the male guinea pig using intraperitoneal route of administration. Journal of Applied Sciences and Environmental Management Vol. 8 (1) 33 - 35

DFT Study on the Five Isomers of PW12O403-: Relative Stabilization upon Reduction

The electronic characteristics and the redox properties of each isomer of PW(12)O(40)(3)(-) depend on the arrangement adopted by the metal-oxide framework. At the DFT/BP86 level, we computed the structures of the five isomers of PW(12)O(40)(3)(-) in oxidized form. The energy scale fits the experimental findings as well as the number of rotated triads of the metal-oxide core since the energy grows as follows: alpha < beta < gamma < delta < epsilon. The reduced clusters behave differently as long as the beta form becomes the most stable isomer after the second reduction. The gamma isomer also gains stability upon reduction, but not enough to be competitive with beta. For the 4-fold reduced PW(12) cluster, the energy difference computed between beta and gamma in solution is 11 kcal mol(-)(1). This large difference proves that the beta --> gamma isomerization is not favored upon simple reduction. The other isomers, delta and epsilon, are much more unstable than alpha or beta in any reduction state.

Dichlorobis(2-phenylazopyridine)ruthenium(II) complexes: characterisation, spectroscopic and structural properties of four isomers.

The didentate ligand 2-phenylazopyridine (azpy) can--in theory--give rise to five different isomeric complexes of the type [Ru(azpy)2Cl2], of which three have been known since 1980. The molecular structures of the cis-dichlorobis(2-phenylazopyridine) ruthenium(II) complexes alpha-[Ru(azpy)2Cl2] and beta-[Ru(azpy)2Cl2](in which the coordinating pyridine nitrogen atoms are in mutually trans and cis positions, respectively, whilst the azo nitrogen atoms are in mutually cis positions) were unambiguously determined in the early 1980s. The third isomer, gamma-[Ru(azpy)2Cl2], has for two decades, erroneously, been assumed to be the all-trans isomer. In a recent communication we have proven that for this gamma isomer the chloride ions are indeed in a trans geometry, but the pyridine nitrogen and azo nitrogen atoms of the two azpy ligands are in mutually cis geometries. In this paper the isolation of a fourth isomer is presented, the hitherto unknown delta-[Ru(azpy)2Cl2]. The isomeric structure of delta-[Ru(azpy)2Cl2] has been determined by 1H-NMR spectroscopy and single-crystal X-ray diffraction analysis, and is the all-trans isomer. The bis(azpy)-ruthenium(II) isomers are of interest because of the pronounced cytotoxicity they exhibit against tumour cell lines and could be very useful in the search for structure-activity relationships of antitumour-active ruthenium complexes, as among the isomers there is a significant difference in activity. It is of paramount importance to have a good understanding of the structural and spectroscopic properties of these complexes, which in this paper are compared and discussed, with a particular emphasis on 1D and 2D 1H NMR spectroscopies.

Toxicité du lindane sur la reproduction

The present paper bears on the main effects of lindane (gamma isomer of hexachlorocyclohexane) on endocrine and reproductive functions in mammals. This pesticide, once widely used to kill lice and a variety of pests that attack agricultural products, livestock and trees, has been progressively eliminated from many applications since the mid-1970s in Europe or USA, but is still used in the rest of the world. Lindane is absorbed through respiratory, digestive or cutaneous routes and accumulates in fat tissues. It damages human liver, kidney, neural and immune systems and induces birth defects, cancer and death. Chronic administration results in endocrine disruption in birds as well as in mammals. Treatment with 1-40 mg of lindane/kg b.w. disrupts testicular morphology, decreases spermatogenesis, inhibits testicular steroidogenesis, reduces plasma androgen concentrations and may adversely affect reproductive performances in males. In females, lindane disrupts the estrous cycle, reduces serum estrogen and progesterone levels, decreases sexual receptivity whereas in pregnant dams it decreases whelping rate and litter size. These effects were also observed in some rats exposed to residual environmental doses. In addition, there is concern that irreversible effects may be induced when animals are exposed to endocrine disrupting chemicals during critically susceptible phases of sexual differentiation or development. These effects would results from (i) alterations of gonade or gamete cell membranes (ii) cell metabolism changes including alterations of ionic exchanges (mainly calcium or potassium), direct or free radical-mediated inhibition of steroidogenesis (iii) or neuroendocrine changes leading to a decrease in sexual performance of either parents or their offsprings exposed in utero or through lactation.

Effects of lindane on steroidogenesis and steroidogenic acute regulatory protein expression.

Lindane, the gamma isomer of hexachlorocyclohexane (HCH), is one of the oldest synthetic pesticides still in use worldwide. Numerous reports have shown that this pesticide adversely affects reproductive function in animals. Although the pathogenesis of reproductive dysfunction is not yet fully understood, recent reports indicate that lindane can directly inhibit adrenal and gonadal steroidogenesis. Because Leydig cells play a pivotal role in male reproductive function through the production of testosterone, the mouse MA-10 Leydig tumor cell line was used to assess the potential effects of gamma-HCH and its isomers, alpha-HCH and delta-HCH, on steroid production, steroidogenic enzyme expression and activity, and steroidogenic acute regulatory (StAR) protein expression. StAR mediates the rate-limiting and acutely regulated step in hormone-stimulated steroidogenesis, the intramitochondrial transfer of cholesterol to the P450(scc) enzyme. Our studies demonstrate that alpha-, delta-, and gamma-HCH inhibited dibutyryl ([Bu](2)) cAMP-stimulated progesterone production in MA-10 cells in a dosage-dependent manner without affecting general protein synthesis; and protein kinase A or steroidogenic enzyme expression, activity, or both. In contrast, each of these isomers dramatically reduced (Bu)(2)cAMP-stimulated StAR protein levels. Therefore, our results are consistent with the hypothesis that alpha-, delta-, and gamma-HCH inhibited steroidogenesis by reducing StAR protein expression, an action that may contribute to the pathogenesis of lindane-induced reproductive dysfunction.

ORGANOCHLORINE INSECTICIDES IN SUBSTANTIA NIGRA IN PARKINSON'S DISEASE

The concentrations of organochlorine (OC) compounds in the substantia nigra (SN) were compared in Parkinson's disease (PD) with concentrations in brain from cortical Lewy body dementia (CLBD), Alzheimer's disease (AD), and nondemented nonparkinsonian controls (CON). The levels of the gamma isomer of hexachlorocyclohexane (g HCH, lindane) were significantly higher in PD tissues (mean +/- SD: 0.56 +/- 0.434 mug/g lipid) than in the other three groups (CLBD 0.052 +/- 0.101 mug/g lipid; AD none detected; CON 0.125 +/- 0.195; all differences from PD significant at p < .05, Mann-Whitney U-test). Dieldrin (HEOD) was higher in PD brain than in AD or control brain, while 1,1'-(2,2-dichloroethenyl diene)-bis(4-chlorobenzene) (p,p-DDE) and total Aroclor-matched polychlorinated biphenyls (matched PCBs) were only higher in PD substantia nigra when these concentrations were compared with those of CLBD. These findings are not inconsistent with the hypothesis derived from epidemiological work and animal studies that organochlorine insecticides produce a direct toxic action on the dopaminergic tracts of the substantia nigra and may contribute to the development of PD in those rendered susceptible by virtue of cytochrome P-450 polymorphism, excessive exposure, or other factors.

A review of the use and place of lindane in the protection of stored products from the ravages of insect pests.

Raucourt (1945) and Slade (1945), more or less simultaneously, brought the insecticidal activity of benzene hexachloride to the attention of the world. The American Medical Association Committee on Pesticides (1951) ascribes the original manufacture of the molecule (by the photochlorination of benzene) to Michael Faraday in 1825. Papers by Rosenstiehl (1862), Heys (1871), and Bodewig (1879) present chemical information but the insecticidal effect does not appear to have been noticed until approximately 1939. A. E. Grant and Imperial Chemical Industries were granted a British patent for BHC as an insecticide in 1939, and Hardie a U. S. patent in 1940. Raucourt (1945) records that M. L. Grindaux held at that time a similar patent in France. Slade (1945) made it clear that considerable was known then about the molecular structure of BHC including recognition of the gamma isomer as the most highly insecticidal form. Later the gamma isomer became referred to as lindane. BHC was assessed for use in the control of stored product pests soon after its insecticidal nature was recognized. Slade (1945) referred to its use for cockroaches, the grain weevil (Sitophilis granarius L.), the hide beetle, and the clothes moth but reported the Mediterranean flour moth to be resistant.

Regioselective Porphyrin Bridge Cleavage Controlled by Electronic Effects. Coupled Oxidation of 3-Demethyl-3-(trifluoromethyl)mesohemin IX and Identification of Its Four Biliverdin Derivatives.

This report describes the nonenzymatic oxidative cleavage of the title porphyrin (2) performed with oxygen and ascorbic acid in aqueous pyridine at 37 degrees C (coupled oxidation), via hydrolysis of the corresponding verdoheme intermediates, followed by esterification of the resulting free acid mesobiliverdin analogues to their dimethyl esters 4 (alpha isomer), 5 (beta isomer), 6 (gamma isomer), and 7 (delta isomer). The four biliverdin derivatives were purified by HPLC, and their structures were confirmed by FAB MS and also by UV-vis and (1)H NMR spectroscopies. The purity of each compound was checked by (19)F NMR, and the four regioisomers were assigned through their 2D-NMR ROESY spectra and confirmed by UV-vis spectroscopy. The ratio of regioisomers was determined by (19)F NMR spectroscopy before any purification of single compounds was attempted: alpha:beta:gamma:delta 11:6:26:57 (%). This unusually high regioselectivity was attributed to the electron-withdrawing effect of the CF(3) group on the electronic structure of porphyrin as shown considering the ab initio calculations of an iron(II) beta-substituted (trifluoromethyl)porphyrin used as a model compound. In porphyrin 2, the oxidation clearly takes place at the electron richest meso positions, the order of reactivity strictly following that of electron density, pointing out that the regiospecificity of the bridge cleavage can be effectively controlled by the electronic effects of some strategic substituents in the chromophore. The relevance of all these results in the study of the mechanism of the reactions involved in the natural catabolism of heme, catalyzed by heme oxygenase, is discussed. The advantages of 2 derived from this work, which make it a suitable model compound for the enzymatic reaction, are also discussed.