N,N-disubstituted dithiocarbamates as cadmium antagonists: N-(4-methoxybenzyl)-N-dithiocarboxy-D-glucamine

The newly synthesized dithiocarbamate analog, N-(4-methoxybenzyl)-N-dithiocarboxy-D-glucamine (MeOBDCG) reduced whole-body cadmium levels 66% in cadmium-laden mice when given as 3 injections at 1.0 mmol/kg. Renal and hepatic Cd concentrations were reduced 78 and 85%, respectively. After 6 injections, the whole-body cadmium burden was reduced 71%, while renal and hepatic levels were lowered 84% and 91%, respectively. Mobilized cadmium was excreted almost exclusively by the fecal route. There was no evident toxicity consequent to treatment as judged by mouse body weights and by gross appearance of organs upon dissection. On a molar dose basis, MeOBDCG was more effective than N-benzyl-N-dithiocarboxy-D-glucamine (BDCG) in removing cadmium from both renal and hepatic deposits. An in-vitro assessment of the interaction of MeOBDCG, BDCG and N-methyl-N-dithiocarboxy-D-glucamine with murine cadmium-metallothionein (Cd-MT) revealed a direct relationship between the extent of cadmium depletion from Cd-MT and the relative in-vivo efficacies of the 3 analogs.

The mobilization of intracellular cadmium by butyl and amyl esters of meso-2,3-dimercaptosuccinic acid

The esters of the general structure, [CH(SH)COOR]2, i.e., Di-BDMS, R = CH2CH(CH3)2; Ds-BDMS, R = CH(CH3)CH2CH3; Di-ADMS, R = CH2CH2CH(CH3)2; and D3-ADMS, R = CH(CH2CH3)2 from the reaction of meso-2,3-dimercaptosuccinic acid with isobutyl, sec-butyl, isoamyl, and 3-amyl alcohols, respectively, have been prepared, characterized, and examined as chelating agents for the removal of cadmium from its aged intracellular deposits. All of these compounds depleted cadmium from such deposits and significantly reduced the whole body levels of cadmium. In the case of three (Ds-BDMS, Di-BDMS, and Di-ADMS) of these compounds, the reductions achieved are equal to or greater than that produced by 2,3-dimercapto-1-propanol (BAL) under similar circumstances. None of these compounds caused any redistribution of cadmium to the brain, and two of them (Di-BDMS and Di-ADMS) caused a very much larger reduction in the liver levels of cadmium than BAL. None was as effective as BAL in reducing kidney levels of cadmium. These compounds are not soluble in water and are administered as solutions in peanut oil. A comparison of the behavior of these compounds with others which have been reported to be effective in reducing body burdens of cadmium in chronic cadmium intoxication reveals that they are among the most effective. An analysis of the manner in which mobilizing efficacy changes with structure indicates that higher, purely alkyl analogs are not expected to be superior to these compounds, though other structural variations may be.

Mobilization of cadmium in mice by combined treatment with N-benzyl-N-dithiocarboxy-D-glucamine and diesters of meso-2, 3-dimercaptosuccinic acid

Mice which had received a non-lethal injection of cadmium (Cd) as CdCl2 nine days prior to therapy were treated with N-benzyl-N-dithiocarboxy-D-glucamine (BDCG) alone or in combination with either di(iso-butyl)dimercaptosuccinate (DiBDMS) or di(iso-amyl)-dimercaptosuccinate (DiADMS). Seven injections of BDCG (1.0 mmole/kg), DiBDMS (0.4 mmole/kg), and DiADMS (0.4 mmol/kg) reduced whole body Cd burdens 50%, 54% and 37%, respectively; coadministration of BDCG + DiBDMS and BDCG + DiADMS produced respective reductions of 65% and 61%. Seven injections of BDCG lowered renal Cd concentrations an average of 82%, but reduced hepatic Cd concentrations only 53%. The DMSA diesters were more effective in lowering hepatic Cd than in reducing the levels of Cd in the kidneys. The respective hepatic and renal Cd reductions were 50% and 20% after treatment with DiADMS, and were 73% and 30% after treatment with DiBDMS. Coadministration of BDCG with DiADMS reduced hepatic and renal Cd concentrations 74% and 82%, respectively, while BDCG co-administered with DiBDMS yielded respective reductions of 80% and 82%. It is suggested that combined use of these newer Cd complexing agents in studies of experimental Cd poisoning may now permit resolution of the issue of reversibility of Cd-induced nephrotoxicity.

Esters of meso-dimercaptosuccinic acid as cadmium-mobilizing agents

The dimethyl, diethyl, di-n-propyl, diisopropyl (Di-PDMS), and di-n-butyl esters of meso-2,3-dimercaptosuccinic acid were prepared by esterification of the parent acid and were subsequently purified and characterized. Their relative ability to mobilize cadmium from its aged (greater than 30 days) deposits was evaluated in mice in comparison with 2,3-dimercapto-1-propanol (BAL). All but the dimethyl ester were superior to BAL in reducing the hepatic cadmium levels, though none was superior in reducing renal cadmium levels. Their efficacy in reducing hepatic cadmium levels had the result that all except the dimethyl ester were significantly more effective than BAL in reducing total cadmium body burdens in mice. The most effective of these compounds, Di-PDMS, caused a reduction of whole body cadmium of 59% (i.e., to 41% of control values) under conditions where the corresponding reduction found for BAL was only 18% (i.e., to 82% of control value). The predominant route of excretion of cadmium subsequent to administration of these compounds is via the fecal route (greater than 99%). A synergistic effect was found in the reduction of whole body and kidney cadmium burdens when Di-PDMS was used in combination with trisodium calcium diethylenethriaminepentaacetate.

Effect of seasonal changes on cyanobacterial production and nitrogen-yield

A mixed culture of cyanobacteria (BGA) containingAulosira sp.,Aphanothece sp., andGloeotrichia sp. were grown throughout the year to assess the influence of seasonal variables on their biomass production and nitrogen (N)-yield under field conditions. The seasonal variables considered in this study, i.e., water temperature (maximum, minimum), solar radiation, sunshine hours, and rainfall, fluctuated widely. Attempts were made to establish a relationship between seasonal changes as independent variables and BGA productivity and N-yield as dependent variables. The analysis indicated that solar radiation was the prime factor. Estimates of BGA biomass production varied from 3.3 to 366.5 kg (dry wt)/ha/month, and N-yield ranged from 0.1 to 11.8 kg N/ha/month. The nitrogen accumulated during the study period was 71.2 kg N/ha. The variations explained by seasonal changes were 52.3 and 50.3% for biomass production and N-yield of BGA, respectively.

Use of the Topliss scheme for the design of more effective chelating agents for cadmium decorporation

The Topliss scheme, which designates a special series of substituents for use in sequence in the search for suitably substituted aromatic compounds with biological properties superior to the parent unsubstituted aromatic compound, has been applied to the design of new chelating agents for the decorporation of cadmium from its deposits in vivo. Substituted benzylamines have been used in the syntheses of the corresponding substituted sodium N-benzyl-D-glucamine-N-carbodithioates, i.e., RC6H4CH2N(CS2Na)CH2(CHOH)4CH2OH (or RBGDTC): CF3BGDTC, R = 3-CF3; MeBGDTC, R = 4-CH3; MeOBGDTC, R = 4-OCH3; ClBGDTC, R = 4-Cl. Examination of the behavior of these compounds as agents for the mobilization of cadmium from its deposits in vivo shows that such substitution can have an appreciable effect on the organ selectivity for cadmium removal, as well as the efficacy. Of the four compounds suggested by the Topliss scheme for pilot studies, two were much more effective than the parent compound (BGDTC), and of these the best one, sodium N-(4-methoxybenzyl)-D-glucamine-N-carbodithioate (MeOBGDTC) reduced kidney cadmium levels to 30% and liver cadmium levels to 50% of those obtained with the parent compound. Sodium N-[3-(trifluoromethyl)benzyl]-D-glucamine-N-carbodithioate (CF3BGDTC) was also found to be superior to the parent compound in reducing the liver cadmium levels, though it was equivalent in reducing renal cadmium levels.

Mobilization of aged in vivo cadmium deposits by diethyl dimercaptosuccinate

Diethyl dimercaptosuccinate (DEDMS) was prepared and found to be capable of mobilizing cadmium from mice one month after they had been given an injection (i.p.) of 0.03 mg CdCl2.2.5H2O containing 1.0 microCi of 109 CdCl2. When pure, DEDMS is a waxy solid with a melting point of 61-62 degrees C which is soluble in warm peanut oil. Its LD50 value (i.p.) in mice is approximately 2.6 mmol/kg, a value which allows it to be given at a higher dosage than other known lipid-soluble dithiols. This compound is especially effective in reducing hepatic and whole body levels of cadmium; it is not as effective as 2,3-dimercaptopropanol (BAL) in reducing renal cadmium levels.

Tachyphylaxis to topical steroid measured by histamine-induced wheal suppression

Ten healthy volunteers were studied to find out whether tachyphylaxis occurs on repeated application of topical steroids. The Singh and Singh modification of the Reddy and Singh (1976) technique was used. Fluocinolone acetonide cream (0.1%) under occlusion was applied daily for 14 days on the flexor aspect of the forearms. The wheal was induced by pricking with histamine acid phosphate solution and the volume of the wheal produced was calculated. The test was repeated on the same sites on alternate days for 14 days. The maximum wheal suppression, which gradually diminished, was observed on the 8th day. By the 14th day, there was practically total tolerance to topical steroid, which showed minimal suppression of histamine wheal formation. This confirms the occurrence of the phenomenon of tachyphylaxis by different experimental techniques.

Relative Potency of Topical Corticosteroid Preparations

Efficacy of ten topical corticosteroid preparations was evaluated on ten healthy volunteers by wheal suppression technique of Reddy and Singh motified by Singh and Singh. This double bind study revealed that clobetasol propionate (0.05%) and halcinonide (0.01%) oinment were the potent steroids i.e. 5 to 6 times more potent than hydrocortisone acetate ( 1%). Prednisolone (0.025%0 and hydrocortisone acetate ( 1%) were the least potent. The potency of other of other preparations such as fluocinolone acetonide (0.025%), betamethasone valerate (0.120/o), betamethasone dipropionate (0.64%), dexamethasone (0.04%), beclomethasone dipropiotiate (p.025%) and triamcinolone acetonide (0.1%) was in between. Mid potent steroids were, however 2 times more potent than hydrocortisone acetate (1%) The potency Of these -three groups of steroid preparations were significantly different from each other . The most potent steroids showed maximum efficacy on the 6th day and the remainig steroids on 8th day of continuous application under occlusion.

Bilateral Nevus Fuscocaeruleus Ophthalmomaxiliaris

A case of bilateral nevus fuscocaeruleus ophthalmomaxillaris with fluctuation in the intensity of colour during each menstrual cycle is reported. It is not described earlier in the literature.

Dyschromatosis Universalis

Hyperpigmented macules all over the body intermignled with mottled depigmentation were observed in two brothers from Varanasi. Hyperpigmented macules were present since birth and increased ill number and size during childhood. Depigmentation developed at the age of eigh, years and increased during adolescence. This entity described as dyschromatosis universalis in the Japanese and the Europeans has not been described in the Indians so far.

A Double Blind Comparative Evaluation of Ointment and Cream Bases Containing Corticosteroids

Efficacy of two corticosteroid Preparations (Halcinonide (0.1%) and fluocinglone acetonide (0.0125%) in two different bases (ointment and creams) was evaluated on ten healthy volunteers using the wheal suppression technique in a double blind manner. The ointment preparations were more potent than the cream preparations of the same corticosteroid, in the same concentration These differences were highly significant.

Immunological studies in leprosy. III-Cutaneous response to antigens in spectrum of leprosy

Delayed type of hypersensitivity response was assessed in 65 cases of leprosy of different types, and 18 control using lepromin (Dharmendra) and candida antigens. 0.1 ml of antigen was injected intra-dermally and results were recorded after 48 hours. The induration of 5 mm or more was taken as positive for early (Fernandez) reaction in lepromin test, and also for candida reaction. Both types of tests were positive in decreasing order from tuberculoid to borderline type while negative in borderline lepromatous and lepromatous type.

Immunological studies in leprosy--II: Study of lymphoblast transformation to PHA in different types of leprosy patients

Ninety cases of different types of leprosy were studied for lymphoblast transformation response using PHA-M. The difference of percentage was statistically analysed and found to be highly significant when total leprosy cases were compared with control cases and with different types of leprosy cases (P = less than .005), except control and TT where it was significant only (P = less than .05). The difference between TT and other types was also calculated and has been observed to be highly significant (P = less than .005). There was gradual decrease in lymphoblast transformation percentage from tuberculoid pole to lepromatous pole.

Status of T and B lymphocytes in peripheral blood

T and B lymphocyte percentage was studied by Erythrocyte (E) and Erythrocyte antibody complement (EAC) rosette formation respectively in 90 cases including 65 cases of different types of leprosy and 25 healthy controls. The patient with different types of leprosy were classified according to Ridley and Jopling (1962). The mean percentage of T-lymphocyte was observed in gradually decreasing manner from tuberculoid pole to lepromatous pole. The fall in T-lymphocyte percentage was highly significant when control cases were compared with total cases of leprosy and different histological types of leprosy. This indicates that there is a gradually increasing loss of cell mediated immune response from tuberculoid to lepromatous pole.

Digital Patterns in Vitiligo

Digital patterns of hundred vitiligo patients were compared with their first-degree relatives and normal controls. Significant differences were found in digital patterns of the two sexes in controls as well as patients. The digital patterns of male vitiligo patients were closer to female controls whereas female vitiligo patients were nearer to male controls. Digital patterns of the relative were in between the patients and controls. This Interesting finding is discussed in detail.

Effect of nutrients on the toxicity of pesticides carbofuran and hexachlorocyclohexane to blue-green alga Nostoc muscorum

The effects of various levels of nutrients like potassium phosphate (dibasic), calcium nitrate, and calcium chloride individually and in combinations were studied on the toxicity of the commonly used pesticides carbofuran and hexachlorocyclohexane (HCH) in growth medium to the N2-fixing blue-green alga Nostoc muscorum. It was observed that all these chemicals had some effects on toxicity. The toxicity of both carbofuran and HCH was reduced to some extent in the presence of higher concentrations of the nutrients when compared to normal levels of the chemicals in the medium. The higher doses of nutrients in combinations antagonized the effect of individual treatment and enhanced the toxicity of pesticides.

Effects of host aging, ions, and pH on the adsorption of the cyanovirus N-1 to Nostoc muscorum

The adsorption rate of the cyanovirus N-1 infecting the nitrogen-fixing blue-green alga Nostocmuscorum decreased with aging of algal cultures and the virus failed to adsorb to the dead host cells. The adsorption rate declined in saline magnesium chloride solution compared to that in algal growth medium. The addition of amino acids like L-tryptophan and L-phenylalanine failed to enhance the adsorption rate of the virus. Optimal pH of adsorption was 7.6 to 8;1.

Pesticide (hexachlorocyclohexane) inhibition of growth and nitrogen fixation in blue-green algae Anabaenopsis raciborskii and Anabaena aphanizomenoides

The effects of the pesticide hexachlorocyclohexane (HCH) on the nitrogen fixing blue-green algae Anabaenopsis raciborskii and Anabaena aphanizomenoides commonly found as blooms in fish ponds were studied. These algae were very sensitive to HCH, and a distinct decrease in growth rate was observed on prolonged incubation. Lower concentrations (10 microgram/ml) were algistatic and higher concentrations (60 microgram/ml) were algicidal. The inhibition of nitrogen fixation indicated that the presence of HCH might affect overall nitrogen economy of inland waters.

Effect of temperature on the adsorption and one-step growth of the Nostoc virus N-1

This study was an attempt to observe the effects of temperature on adsorption and one-step growth of the virus N-1 infecting the nitrogen-fixing cyanobacterium Nostoc muscorum. Adsorption rate was found to maximum at 40 degrees C whereas no adsorption occurred at 10 degrees C. The Q10 value was about 2.03 and the energy of activation, Ea was 16.3 kcal/mole for the adsorption process. The development cycle of the virus was temperature sensitive. With increase in temperature, a gradual increase in inhibition of virus yield i.e. 8.33% at 30 degrees C, 35.3% at 35 degrees C and complete inhibition at 40 degrees C was observed. Out of 7 h latent period, the early 4 h were temperature sensitive and heat treatment had a reversible inhibitory effect on virus development. The temperature treatment did not affect the rise period but burst-size was reduced.

Effect of physical and chemical agents on the blue-green algal virus N-1

The stability of the blue-green algal virus N-1, infecting the blue-green alga Nostoc muscorum, against temperature, EDTA and pH was studied. Ninety per cent thermal inactivation of virus occured at 55 degrees C in 20 minutes with an average inactivation rate constant of 0.07 per minute; at 60 degrees C the virus was completely inactivated within 5 minutes. 10(-4) M EDTA inactivated 30 per cent of free virus in 60 minutes; 10(-3) M EDTA was completely lethal. Intracellular virus was comparatively resistant to EDTA. The virus was stable in the pH range from 6.7 to 10.5 and was inactivated at acidic pH.

Mutation to resistance for virus N-1 in the blue-green alga Nostoc muscorum

The spontaneous and nitrosoguanidine induced N-1 virus resistant mutants of the blue-green alga Nostoc muscorum were isolated with the average mutation frequency of 3.55 X 10(-5) and 6.08 X 10(-4) respectively. Of the surviving colonies 8 per cent became virus sensitive,whereas out of the remaining 92 per cent 9.3 per cent showed lysogenic behaviour and 13.3 per cent showed poor or no nitrogen fixing ability. Mutation to virus-resistance was independent of the presence of the virus.Spontaneous host range mutants of virus were not found in repeated experiments.

Growth and nitrogen fixation of mutants defective in heterocyst differentiation in the blue-green alga Cylindrospermum sp

Three classes of spontaneous and N-methyl-N'-nitro-N-nitrosoguanidine (NTG)-induced mutants of the blue-green alga Cylindrospermum sp. were isolated in the presence of combined nitrogen. Mutants with complete loss of heterocyst differentiation formed longer filaments than the parent alga and were unable to grow in nitrogen-free medium and to fix nitrogen. The second type of mutants formed long filaments with terminal heterocysts. In the third type of mutants, paired proheterocyst differentiation occurred at regular intervals in long filaments and these were defective in their further development into mature heterocysts. Mutants with decreased heterocyst frequency due to defective differentiation and development showed less growth and nitrogen fixation in nitrogen-free medium than the parent alga.

Lysogeny of blue-green alga Plectonema boryanum by long tailed virus

Lysogeny and its induction with mitomycin C by the long tailed virus is reported. The active virus was liberated in the medium during the growth period and ability of trichomes to produce virus was not reduced by treatment with EDTA.

Photoreactivation of UV-irradiated blue-green algae and algal virus LPP-1

Ultraviolet (UV) sensitivity and photoreactivation of blue-green algae Cylindrospermum sp., Plectonema boryanum, spores of Fischerella muscicola and algal virus (cyanophage) LPP-1 were studied. The survival value after UV irradiation of filaments of Cylindrospermum sp. and Virus LPP-1 showed exponential trend and these were comparatively sensitive towards UV than F.muscicola and P.boryanum. Photoreactivation of UV-induced damage occurred in black, blue, green, yellow, red and white light in Cylindrospermum sp., however only black, blue and white light were capable of photorepair of UV-induced damage in P.boryanum, spores of F.muscicola and virus LPP-1 in infected host alga. Pre-exposure to yellow and black light did not show photoprotection. The non-heterocystous and nitrogen fixation-less mutants of Cylindrospermum sp. were not induced by UV and their spontaneous mutation frequency was not affected after photoreactivation. The short trichome mutants of P.boryanum were more resistant towards UV. The occurrence of photoreactivation of UV-induced killing wide range of light in Cylindrospermum sp. is the first report in organisms.

Sensitization of algal virus to UV by the incorporation of 5-bromouracil and mutations of host alga Plectonema boryanum

Ultraviolet light (UV) sensitivity and photoreactivation of algal virus (cyanophage) LPP-1 were studied after multiplication in host alga Plectonema boryanum in presence of 5-bromouracil (5-BU) alone and in conjunction with sulfanilamide. Virus particles containing 5-BU were more sensitive towards UV and also showed low photoreactivation. There was less incorporation of 5-BU in virus without pretreatment of host alga with sulfanilamide, an inhibitor of thymine synthesis. 5-BU-induced short trichome mutants of Plectonema boryanum were isolated. These mutants grew slowly in liquid medium as well as on agar plates and differed in other morphological characters. Reversion of short trichome mutants was observed with a frequency of about 10(-3), but revertants were different from parent alga. The short trichome mutants were sensitive to virus LPP-1 and resistant towards UV.