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Biomedical subjects

E B Sansone

Publications and source records attributed to E B Sansone.

At least 37 records · Page 2Linked to original sources
PubMed1987

Ethidium bromide: destruction and decontamination of solutions.

Ethidium bromide in water, TBE buffer, Mops buffer, and cesium chloride solution may be completely degraded by reaction with sodium nitrite and hypophosphorous acid. Only non-mutagenic reaction mixtures were produced. Destruction was greater than 99.8% in all cases; the limit of detection was 0.5 micrograms ethidium bromide per milliliter of solution. Ethidium bromide also may be removed completely from the above solutions by using Amberlite XAD-16 resin. The limit of detection was 0.05 micrograms ethidium bromide per milliliter of solution (0.27 micrograms/ml when cesium chloride solution was used).

Decontamination↗
PubMed1987

Assessment of the risks associated with the use of chemical carcinogens in biomedical research.

Estimates of occupational exposure to chemical carcinogens in biomedical research based on environmental monitoring data, efficiency of containment devices, and accident data suggest that workers may be exposed to a few tenths of a microgram of these carcinogens per work day. Environmental exposure to carcinogenic polycyclic aromatic hydrocarbons and N-nitroso compounds exceeds one microgram per day. Because occupational exposure to chemical carcinogens in the laboratory can be readily controlled and because environmental exposure appears to be greater than the occupational exposure that does occur, the relative risk of occupational exposure does not seem to constitute a major health problem.

Air Pollutants, Occupational↗
PubMed1987

Reductive destruction of dacarbazine, procarbazine hydrochloride, isoniazid, and iproniazid.

Reductive destruction of dacarbazine, procarbazine hydrochloride, isoniazid, and iproniazid using nickel-aluminum alloy in basic solution is described. Solutions of dacarbazine 10 mg/mL were prepared by adding dacarbazine 100 mg, citric acid 100 mg, and mannitol 50 mg to 10 mL of water. Aqueous solutions of procarbazine hydrochloride 10 mg/mL were prepared from commercially available capsules, and aqueous solutions of isoniazid 10 mg/mL and iproniazid 5 mg/mL were prepared from powdered drug. Reductive destruction of drugs was accomplished by mixing each solution with an equal volume of 1 M potassium hydroxide solution and adding 1 g of nickel-aluminum alloy for each 20 mL of basified solution. The resulting mixtures were stirred for 20 hours (96 hours for iproniazid) and analyzed by high-performance liquid chromatography and gas chromatography for the presence of residual drug and degradation products. Dacarbazine solutions were also subjected to destruction by photolysis and by oxidation using potassium permanganate in sulfuric acid, and the results were compared with those obtained by reductive destruction. All reaction mixtures were tested for mutagenicity in Salmonella strains. All drugs subjected to reductive destruction were completely degraded to the limits of detection of the assay and produced only nonmutagenic reaction mixtures. The only acceptable results for dacarbazine were obtained by the reductive destruction method. Reduction of dacarbazine, procarbazine hydrochloride, isoniazid, and iproniazid with nickel-aluminum alloy in dilute base appears to be a good method for the destruction of these toxic compounds.

Alloys↗
PubMed1986

Oxidative destruction of hydrazines produces N-nitrosamines and other mutagenic species.

As part of the joint International Agency for Research on Cancer-National Cancer Institute program for the evaluation and development of methods for the degradation of chemical carcinogens, four oxidative techniques for the degradation of hydrazines were investigated. The oxidizing agents used were as follows: sodium hypochlorite, calcium hypochlorite, potassium iodate, and potassium permanganate in sulfuric acid. In each case, at least 99% of the hydrazine initially present was destroyed; however, the potential usefulness of these methods was compromised by the formation (in some reaction mixtures) of carcinogenic N-nitroso compounds and/or unknown mutagenic species. Oxidative degradation of hydrazines is recommended only for the decontamination of glassware and for the treatment of spills, for which reductive degradation methods are not suitable.

Animals↗
PubMed1986

Prediction of activated carbon performance for sequential adsorbates.

A packed bed of carbon granules was exposed to benzene and carbon tetrachloride sequentially to determine the adsorption characteristics of the bed under dynamic flow conditions. We found that the total adsorption space of the carbon was invariant at a fixed relative pressure and temperature. This finding allowed us to predict carbon performance for adsorbates introduced concurrently and/or sequentially.

Adsorption↗
PubMed1985

Destruction of cyanogen bromide and inorganic cyanides.

Cyanogen bromide in water and seven organic solvents and sodium cyanide in water may safely and efficiently (greater than 99.7%) be destroyed using sodium hydroxide (1 M) solution and commercially available sodium or calcium hypochlorite. Details are given of an analytical procedure which can be used to check the final reaction mixture for the presence of residual cyanogen bromide or cyanide.

Calcium↗
PubMed1985

The effect of moisture on the adsorption of chloroform by activated carbon.

The effect of moisture on the ability of a granular activated carbon to adsorb chloroform vapor from a flowing airstream was studied under three test conditions: (1) chloroform and water vapor were introduced concurrently into a dry carbon bed; (2) dry chloroform was introduced into a humidified carbon bed; (3) humidified chloroform was introduced into a carbon bed at the same relative humidity. The criterion for bed performance was the time when the downstream chloroform concentration was 1% of that in the inlet stream. Chloroform concentration was essentially constant at 108 +/- 2 micrograms/cm3; relative humidities (RH) varied from 0 to 97%. No RH effect on the adsorption of chloroform by the carbon was observed in test (1); tests (2) and (3) showed monotonic decreases in chloroform adsorption for RH greater than 40%. These results indicated that, for a dry carbon bed, the 1% breakthrough time for chloroform adsorbed from atmospheres of RH from 13% to 95% was essentially the same as that when RH = 0%. For humidified carbon beds, no change in 1% breakthrough time for chloroform was observed until RH was greater than 40%.

Adsorption↗
PubMed1985

Validation of techniques for the destruction of dimethyl sulfate.

It has been reported that dimethyl sulfate (DMS) can be degraded with sodium hydroxide solution (1 mol/L), sodium carbonate solution (1 mol/L), or ammonium hydroxide solution (1.5 mol/L). This has now been confirmed. Complete destruction of undiluted DMS or DMS in solvents miscible with water (methanol, ethanol, DMSO, DMF, acetone) or solvents partially miscible or immiscible with water (toluene, p-xylene, benzene, 1-pentanol, ethyl acetate, chloroform, carbon tetrachloride, acetonitrile) could be obtained using any of the above methods. Reaction times were 15 min after homogeneity was obtained for undiluted DMS, 15 min for solutions in methanol, ethanol, DMSO, and DMF, one hour for solutions in acetone, three hours for acetonitrile, and one day for the other solvents listed above. The final reaction mixtures were tested for mutagenicity, and when the solutions were not cytotoxic, no mutagenic response was obtained. DMS in solution was determined by a colorimetric method. The products of the reactions were found to be methanol when NaOH and Na2CO3 were used and methylamine, dimethylamine, trimethylamine, and methanol when ammonium hydroxide was used. The stability of DMS in various solvents was also determined.

Animals↗
PubMed1984

Airborne transfer of contaminants in ventilated spaces.

To assess the effectiveness of directional air flow and the influence of a disturbance such as opening and closing doors on the airborne transfer of contamination, the concentration of a tracer gas (ethane) was measured at various locations in a model consisting of four adjacent rooms between two corridors. Each room had two doors opening into the corridor. Ethane concentrations were measured as a function of pressure drop (0, +/- 0.005, +/- 0.01, and +/- 0.02 in. H2O) and time of door opening and closing (3, 6, and 9 sec). A hydrocarbon analyzer was used to measure the concentration of ethane. Contamination was transferred in the direction of decreasing static pressure and was proportional to the magnitude of the pressure differential. Opening and closing a door led to exchange of air between the spaces separated by the door regardless of the sign of the pressure differential that existed when the door was closed. The extent to which a space was contaminated by opening and closing a door was directly proportional to the time the door was open. Contaminant concentration differences between adjacent spaces were greatest when the connecting door was kept closed and the pressure differential was least. The findings indicate that modification of current practices may lead to improved protection of personnel, animals, and experiments from contamination.

Air Movements↗
PubMed1984

Destruction of carcinogenic and mutagenic N-nitrosamides in laboratory wastes.

The chemical degradation of five N-nitrosamides used widely for the experimental induction of cancer has been studied with the goal of identifying, and experimentally validating, reliable methods that can be recommended for the destruction of carcinogenic N-nitrosoureas and related compounds in laboratory wastes. Although data are not yet complete, preliminary evidence indicates that none of the five methods studied thus far is ideal for hazard-control purposes. Decomposition with 1 mol/L potassium hydroxide solution destroyed the N-nitrosamides, but generated diazoalkanes, which are carcinogenic, toxic and potentially explosive. Treatment with strong acid in the presence of sulfamic acid or iron filings completely decomposed all N-nitrosamides without forming diazoalkanes, but failed in the presence of solvents which were immiscible with water. Cleavage with hydrogen bromide in glacial acetic acid proceeded to a point of maximum degradation, following which gradual reformation of the N-nitrosamide was observed; this resynthesis could be avoided by carefully bubbling nitrogen through the reaction mixture, but degradation was slow or failed completely in the presence of hydroxylic solvents. Permanganate oxidation was effective in sulfuric acid solution, but was incomplete when an alcohol or dimethyl sulfoxide was present. Salmonella typhimurium tester strains TA1535, TA1530 and TA100, which detect base-pair substitutions in DNA, detected mutagenic degradation products in each of the destruction methods, with the exception of the hydrobromic acid/acetic acid procedure.

Carcinogens↗
PubMed1983

Safe disposal of carcinogenic nitrosamines.

A simple one-step procedure for chemically degrading nitrosamine residues generated in the research laboratory is described. Treatment with aluminum-nickel alloy powder and aqueous alkali rapidly reduced all 11 nitrosamines studied to the corresponding amines. Hydrazines were produced as transitory intermediates, but these potential carcinogens were also easily reduced under the conditions employed, and no products except amines, ammonia, and, in some cases, alcohols were detected in the final reaction mixtures. Reduction proceeded smoothly in every other solvent system tested, except that reactions in acetone or dichloromethane solution were sometimes slow, incomplete, and/or led to unidentified products; therefore, we cannot recommend the procedure for use in these solvents. Otherwise, the method was efficient, reliable, and inexpensive and has been recommended as one of the preferred means of degrading potentially carcinogenic nitrosamines to innocuous products. Details of its application to some decontamination and disposal problems commonly encountered in the research laboratory are provided. Data illustrating this procedure's advantages over six other reducing systems are also presented.

Chemical Phenomena↗
PubMed1981

Assessment of environmental contamination associated with a mammalian cell transformation assay.

To estimate worker exposures to, and environmental contamination from, test chemicals and organic solvents used in an in vitro assay to assess the carcinogenic potential of chemicals, sodium fluorescein, a noncarcinogenic fluorescent material, was dissolved in tissue culture medium used to maintain early passage hamster embryo cells. Personal an environmental samples were taken over a 14-d period. The assay was performed according to standard procedures in a ventilated glove box or laminar flow safety cabinet. Considerably more than 99% of the chemical contamination found was recovered from the interiors of the glove box and hood and from disposable equipment. Contamination outside the containment units (less than 1 microgram) resulted from intralaboratory transport of chemicals, treated cultures, and contaminated equipment. We conclude that the standard operating particles and procedures provided adequate safeguards for personnel and the environment.

Animals↗