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PubMed1986

Mechanisms of chloroform and carbon tetrachloride toxicity in primary cultured mouse hepatocytes.

Mechanisms of chloroform (CHCl3) and carbon tetrachloride (CCl4) toxicity to primary cultured male B6C3F1 mouse hepatocytes were investigated. The cytotoxicity of both CHCl3 and CCl4 was dose- and duration-dependent. Maximal hepatocyte toxicity, as determined by lactate dehydrogenase leakage into the culture medium, occurred with the highest concentrations of CHCl3 (5 mM) and CCl4 (2.5 mM) used and with the longest duration of treatment (20 hr). CCl4 was approximately 16 times more toxic than CHCl3 to the hepatocytes. The toxicity of these compounds was decreased by adding the mixed function oxidase system (MFOS) inhibitor, SKF-525A (25 microM) to the cultures. The addition of diethyl maleate (0.25 mM), which depletes intracellular glutathione (GSH)-potentiated CHCl3 and CCl4 toxicity. The toxicity of CHCl3 and CCl4 could also be decreased by adding the antioxidants N,N'-diphenyl-p-phenylenediamine (DPPD) (25 microM), alpha-tocopherol acetate (Vitamin E) (0.1 mM), or superoxide dismutase (SOD) (100 U/mL) to the cultures. These results suggest that: in mouse hepatocytes, both CHCl3 and CCl4 are metabolized to toxic components by the MFOS; GSH plays a role in detoxifying those metabolites; free radicals are produced during the metabolism of CHCl3 and CCl4; and free radicals may be important mediators of the toxicity of these two halomethanes.

Animals↗
PubMed1993

Effects of chloroform and bromodichloromethane on DNA synthesis in male F344 rat kidney.

We have been investigating the actions of chloroform (CHCl3) and bromodichloromethane (BDCM) in rat kidney after different routes of exposure. Male F344 rats were exposed by gavage with corn oil or water as the diluting vehicle. All experiments lasted 30 days with gavage exposures 5 days per week for 4 weeks (20 doses). All animals were injected IP with bromodeoxyuridine (BrdU) 3 times over a 6-day period at 50 mg/kg/injection. Kidney tissue was fixed and slides were stained with hematoxylin and eosin for routine viewing and by the PAP (peroxidase-antiperoxidase) technique using anti-BrdU to label cells in DNA synthesis. There were no significant changes in gross parameters evaluated between the control rats and the rats exposed to CHCl3 or BDCM. Rats exposed via corn oil gavage to CHCl3 displayed a segment-specific epithelial cell necrosis (6/6 high dose, 2/6 low dose). The lesions were primarily localized to the second segment of the proximal tubule, although some spread to cells in the first segment was occasionally observed. No histologic lesions were observed in the kidneys of rats exposed to BDCM. Preliminary results indicate a significant increase in DNA synthesis in the CHCl3-treated rats and a slight increase in DNA synthesis in BDCM-treated rats with corn oil as the diluent. The increase in BrdU labeling was primarily in cells of the S2 segment of the proximal tubule and interstitial cells of CHCl3-exposed animals and in cells of the S3 segment of BDCM-exposed animals.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗
PubMed1996

Ingestion, inhalation, and dermal exposures to chloroform and trichloroethene from tap water.

Individuals are exposed to volatile compounds present in tap water by ingestion, inhalation, and dermal absorption. Traditional risk assessments for water often only consider ingestion exposure to toxic chemicals, even though showering has been shown to increase the body burden of certain chemicals due to inhalation exposure and dermal absorption. We collected and analyzed time-series samples of expired alveolar breath to evaluate changes in concentrations of volatile organic compounds being expired, which reflects the rate of change in the bloodstream due to expiration, metabolism, and absorption into tissues. Analysis of chloroform and trichloethene in expired breath, compounds regulated in water, was also used to determine uptake from tap water by each route (inhalation, ingestion, or absorption). Each route of exposure contributed to the total exposure of these compounds from daily water use. Further, the ingestion dose was completely metabolized before entering the bloodstream, whereas the dose from the other routes was dispersed throughout the body. Thus, differences in potential biologically effective doses depend on route, target organ, and whether the contaminant or metabolite is the biologically active agent.

Adult↗
PubMed1999

Chloroform: An EPA test case.

In March 1998, the U.S. Environmental Protection Agency (EPA) published a proposal to raise the drinking water maximum contaminant level goal (MCLG) for chloroform, a suspected human carcinogen, from zero to 300 parts per billion. The proposal marked a departure from the agency's traditional reliance on linear dose-response models in performing risk assessment, and reflected the new thinking contained in the 1996 draft update to the agency's cancer risk assessment guidelines. The updated guidelines emphasize mechanisms of action and descriptions of the conditions under which carcinogenic hazards are likely to be expressed.

Animals↗
PubMed2005

DNA extraction and quantitation of forensic samples using the phenol-chloroform method and real-time PCR.

Forensic laboratories are increasingly confronted with problematic samples from the scene of crime, containing only minute amounts of deoxyribonucleic acid (DNA), which may include polymerase chain reaction (PCR)-inhibiting substances. Efficient DNA extraction procedures, as well as accurate DNA quantification methods, are critical steps involved in the process of successful DNA analysis of such samples. The phenol-chloroform method is a sensitive method for the extraction of DNA from a wide variety of forensic samples, although it is known to be laborious compared with single-tube extraction methods. The relatively high DNA recovery and the quality of the extracted DNA speak for itself. For reliable and sensitive DNA quantitation, the application of real-time PCR is described. We modified a published real-time PCR assay, which allows for the combined analysis of nuclear and mitochondrial DNA, by introducing 1) improved hybridization probes with the use of minor groove binders; 2) an internal positive control (for both nuclear and mitochondrial DNA) for the detection of PCR inhibitors; and 3) different amplicon lengths for the determination of the degradation state of the DNA. The internal positive controls were constructed by site directed mutagenesis by overlap extension of the wild-type mitochondrial and nuclear DNA target with the advantage that no additional probes, which are cost-intensive, are required. The quantitation system is accomplished as a modular concept, which allows for the combined determination of the above-mentioned features (quantity/inhibition or quantity/degradation) depending on the situation.

Base Sequence↗
PubMed2005

A large, voltage-dependent channel, isolated from mitochondria by water-free chloroform extraction.

We examined ion channels derived from a chloroform extract of isolated, dehydrated rat liver mitochondria. The extraction method was previously used to isolate a channel-forming complex containing poly-3-hydroxybutyrate and calcium polyphosphate from Escherichia coli. This complex is also present in eukaryotic membranes, and is located primarily in mitochondria. Reconstituted channels showed multiple subconductance levels and were voltage-dependent, showing an increased probability of higher conductance states at voltages near zero. In symmetric 150 mM KCl, the maximal conductance of the channel ranged from 350 pS to 750 pS. For voltages >+/-60 mV, conductance fluctuated in the range of approximately 50- approximately 200 pS. In the presence of a 1:3 gradient of KCl, at pH = 7.4, selectivity periodically switched between different states ranging from weakly anion-selective (V(rev) approximately -15 mV) to ideally cation-selective (V(rev) approximately +29 mV), without a significant change in its conductance. Overall, the diverse, but highly reproducible, channel activity most closely resembled the behavior of the permeability transition pore channel seen in patch-clamp experiments on native mitoplasts. We suggest that the isolated complex may represent the ion-conducting module from the permeability transition pore.

Animals↗
PubMed2000

A chloroform extract obtained from a decoction of Ficus carica leaves improves the cholesterolaemic status of rats with streptozotocin-induced diabetes.

The antidiabetic effects of Ficus carica leaf extracts have been reported previously. From the aqueous decoction of fig leaves, after treatment with HCI, centrifuging, treatment with sodium hydroxide (NaOH) and extraction with chloroform (CHCl3), the administration of the organic phase rats with streptozotocin-induced diabetes led to a decline in the levels of total cholesterol and an decrease in the total cholesterol/HDL cholesterol ratio (with respect to the control group), together with a reduction of the hyperglycaemia.

Animals↗
PubMed2005

Photochemical reactions of poly(3-butoxythiophene-2,5-diyl) with chloroform.

Photochemical reactions of poly(3-butoxythiophene-2,5-diyl) with chloroform under irradiation with light were studied. The reactions were separately carried out under air, oxygen, and nitrogen. The obtained results showed that this reaction belongs to the pseudo-first-order reaction with a rate constant k(obs) of 1.4 x 10(-5) s(-1) at room temperature. The presence or absence of air, oxygen, and nitrogen did not have obvious effects on the reaction rate under irradiation with light.

Air↗
PubMed1997

Changes in plasma lipoproteins as toxicity markers for carbon tetrachloride, chloroform, and dichloromethane.

Effects of single intraperitoneal (i.p.) administration of carbon tetrachloride (CCl4), chloroform (CHCl3), and dichloromethane (CH2Cl2) on lipoproteins in plasma and liver were investigated in rats. Changes in lipoproteins caused by these solvents were compared with changes in traditional hepatotoxicity markers such as GPT (ALT). Following the administration, concentrations of lipoproteins (VLDL, LDL, HDL), triglyceride, cholesterol, and GPT activity in plasma were determined through changes in liver weight, liver content of triglyceride, malon dialdehyde (MDA), and glutathione (GSH). Time-course study revealed that changes in plasma and liver reached their peaks at 19 or 32 hr following the administration of CCl4 or CHCl3. Peaks of changes were observed at 8 or 19 hr following the administration of CH2Cl2. Dose dependency of these changes was investigated at dosages of 3, 30, and 300 mg/kg of CCl4 or CHCl3, and 300, and 1,000 mg/kg of CH2Cl2. Significant decreases in triglyceride and apolipoproteins in VLDL fraction were observed at 3 mg/kg of CCl4. Such VLDL components decreased at 30 mg/kg of CHCl3. HDL decreased significantly at 300 mg/kg of CH2Cl2 and marked increase in LDL occurred at 1,000 mg/kg of the solvent. Liver weight and liver content of triglyceride and MDA significantly increased at 30 mg/kg of CCl4, while significant increase in GPT activity was observed at 300 mg/kg of CCl4 and CHCl3. GPT increased significantly at 1,000 mg/kg of CH2Cl2. These results revealed that changes in plasma lipoproteins can serve as sensitive and simple markers for liver disorders caused by chlorinated hydrocarbon solvents such as CCl4, CHCl3, or CH2Cl2.

Analysis of Variance↗
PubMed1983

Comparative renal and hepatotoxicity of halomethanes: bromodichloromethane, bromoform, chloroform, dibromochloromethane and methylene chloride.

The renal and hepatotoxicities of five selected halomethanes, which are drinking water contaminants, were evaluated following a 14-day exposure. Bromodichloromethane, bromoform, chloroform, dibromochloromethane and methylene chloride were administered at three dose levels. Toxicity was evaluated by measuring changes in total body weight, uptake of p-aminohippurate into renal cortical slices, blood urea nitrogen, serum creatinine, and serum glutamate-pyruvate transaminase levels and by performing a histopathologic examination of liver and kidney tissues. Dose-related effects on the liver and kidney were detected with the uptake of p-aminohippurate into kidney slices and with the histopathologic evaluation of tissues. Treatment-related effects seen in the methylene chloride exposed mice were less pronounced as compared to the other halomethane treatment groups. In general, histopathological changes were the most sensitive indicators of both liver and kidney damage.

Animals↗
PubMedDate not supplied

Cellulose-walled microcapsules: 1. The effect of the solvent-non solvent proportions on the preparation of microcapsules from the system ethyl cellulose-chloroform-ethane diol.

The phase diagram of the system ethyl cellulose-chloroform-ethane diol has been studied and the differing phase regions determined. The effect of temperature of these regions is recorded. The phase diagram is used to determine the optimal conditions for the preparation of microcapsules with a phenobarbitone core and the size distribution of the microcapsules is recorded.

Cellulose↗
PubMed1978

Selective modification of the renal and the hepatic toxicities of chloroform by induction of drug-metabolizing enzyme systems in kidney and liver.

Renal and hepatic microsomal enzyme activities were measured in ICR male mice treated with phenobarbital (PB), 3-methylcholanthrene (3MC), 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) or polychlorinated biphenyls (PCB). The effect of these agents on subsequently administered single doses of chloroform (CHCI3) were also determined. 3MC, TCDD and PCB increased renal as well as hepatic microsomal enzyme activities. PB increased hepatic but not renal microsomal enzyme activities. The hepatotoxicity of CHCI3 was increased by pretreatment with PB but decreased by pretreatment with TCDD. 3MC and PCB were without effect on CHCI3-induced liver damage. Pretreatment with 3MC, TCDD or PCB reduced the renal toxicity of CHCI3, but PB had no effect on CHCI3-induced kidney damage. Since at least one product of enzymatic metabolism of CHCI3 is believed to be a toxic, reactive intermediate the differential effects of inducers of microsomal drug-metabolizing enzyme activities on the renal and hepatic toxicities of CHCI3 strongly suggest that the CHCI3 metabolite(s) ultimately responsible for renal and hepatic damage are not generated at a common site. That is the metabolite responsible for hepatic is probably generated in the liver and the metabolite responsible for renal damage is probably generated in the kidney.

Animals↗
PubMed1996

Dr. Edward Lawrie's remarks on the findings of Hyderabad chloroform commissions in his annual report of 1303 Fasli.

This article is a re-presentation of the important remarks of Dr. Edward Lawrie with regard to the Chloroform Commissions as found in the administrative report of the Nizam's Government for 1893-94. It seems that these remarks might have been presented by Dr. Lawrie to the Nizam's Government in the form of an annual report in 1303 Fasli. Though these findings were later proved to be wrong, but the value of Dr. Lawrie efforts will remain as a landmark in the history of medicine.

Anesthesiology↗
PubMedDate not supplied

[Comparative effect of ether, chloroform and fluothane on brain cortical neurons].

In tests staged on 35 cats it was established that chloroform and fluothane display the biological activity which is 5 times as high as that of ether with respect to the brain cortex neurons. The reactive properties of individual neurons of the brain cortex are dissimilar and this, other conditions of anesthetization being equal, determines their unequal resistance to the action of anesthetics.

Animals↗
PubMed2002

Effects of temperatures, pH-values, ultra-violet light, ethanol and chloroform on the growth of isolated thermophilic Bacillus phages.

Seven thermophilic Bacillus phages were characterized with reference to their host range, time of appearance, morphology of plaques, thermal inactivation, stability, lipid presence and inactivation by ultraviolet irradiation. Response surface methodology was adapted to describe the response of growth parameters to environmental changes. Most phages are susceptible to temperatures above 60 degrees C and inactivated immediately at 103 degrees C. Most phages are resistant to pH ranges 5 to 9 and almost all to pH 7 to 8. Both phages 46 and 80 were highly resistance to UV exposure for 13 minutes and 20 minutes, respectively. The presence of chloroform or 75% ethanol showed no effect on almost all isolated phages that indicate of possibility of the absence of lipids. The isolated phages were slow in their growth, possibly due to the lower gross growth efficiency.

Bacillus↗
PubMed1976

Mechanisms involved in enhancement of plasma fibrinolytic activity by chloroform.

The effects of a single 1-min extraction with chloroform (CHCl3) on plasma fibrinolytic activity has been examined by 125I-fibrin solid phase assay, using normal plasma and plasma depleted of plasminogen (PLG) by lysine-Sepharose affinity chromatography. Fibrinolytic activity of normal plasma is increased (40%-175%), and more than 95% of antiplasmin activity is removed. The increase is demonstrable in PLG-depleted plasma, and is not inhibited by tranexamic acid (0.01 M). Purified PLG is not activated to plasmin by ChCl3 treatment. Bio-Gel A 0.5 m fractionation of CHCl3-extracted, PLG-depleted plasma reveals fractions with the following activities: (1) streptokinase-activatable, PLG-independent fibrinolytic activities; (2) PLG activator activities; and (3) plasmin-stimulated but PLG-independent fibrinolytic activities, which include activities inhibited by hexadimethrine bromide and which cofractionate in part with plasmin-stimulated procoagulant activities. In addition, similar fractionation of nonextracted plasma reveals two non-plasmin fibrinolytic activities (approximately 30,000 and 13,000 daltons) activated by streptokinase and plasmin, respectively. The findings indicate that the enhanced fibrinolytic activity resulting from CHCl3 treatment is independent of plasmin as the ultimate fibrinolytic enzyme, although activities stimulated by plasmin may contribute, and that such treatment is a useful maneuver for study of PLG-dependent and PLG-independent fibrinolytic mechanisms, and their interactions.

Blood Coagulation↗