PCR-based identification of postmortem microbial contaminants--a preliminary study

Investigation of postmortem blood can reveal the presence of significant ethanol levels. However, in some instances it cannot easily be determined if the source of ethanol is from ingestion or from postmortem endogenous fermentation by contaminating microbes. Described here is a robust polymerase chain reaction (PCR)-based method for detecting the presence of common ethanol producing microbial contaminants in human blood. A set of DNA primers were designed for use in PCR to amplify and detect the genomic DNA from humans and three test microorganisms Escherichia coli, Proteus vulgaris, and Candida albicans. A rapid and reproducible protocol was developed for isolating genomic DNA from mixed human blood-microorganism samples that yields a suitable template for PCR. The organism-specific primer pairs can detect the presence of the target microorganisms in human blood at concentrations as low as 10 colony forming units/mL. The PCR products readily can be detected after agarose gel electrophoresis. This method provides an additional means of rapidly identifying microbial contaminants in postmortem blood samples.

Preparation of carboxyhemoglobin standards and calculation of spectrophotometric quantitation constants

A method was developed for the preparation of carboxyhemoglobin (COHB) standards, which were stable for more than four months with the prepared control remaining within acceptable limits during this time. A mathematical equation was developed to more accurately determine the constants A and B used in the equation COHB% = 100[(C - B)/(A - B)], where B = 0% COHB peak ratio at 540 nm and 579 nm; A = 100% COHB peak ratio at 540 nm and 579 nm; and C = the peak ratio at 540 nm and 579 nm for the blood being analyzed. The following equations were developed to calculate A and B: B = Pavg - (P) [(Pavg - Navg)/(P - N)]; A = B + (Pavg - Navg)/(P - N), Pavg = average peak ratio 540/579 for the positive standard run on the spectrophotometer; P = average decimal concentration measured on the CO-OXIMETER for the positive standard; Navg = average peak ratio 540/579 for the negative standard; N = average decimal concentration measured on the CO-OXIMETER for the negative standard. The new equations provided results consistent with those obtained from a CO-OXIMETER.

DNA typing as a strategy for resolving issues relevant to forensic toxicology

To investigate aircraft accidents, multiple postmortem biological samples of victims are submitted to the Civil Aeromedical Institute for toxicological evaluation. However, depending upon the nature of a particular accident, their body components are often scattered, disintegrated, commingled, contaminated, and/or putrefied. These factors impose difficulties with victim identification, tissue matching, and consequently authentic sample analysis and result interpretation. Nevertheless, these limitations can be overpowered by DNA typing. In this regard, three situations are hereby exemplified where DNA analysis was instrumental in resolving a tissue mismatching/commingling issue, pinpointing an accessioning/analytical error, and interpreting an unusual analytical result. Biological samples from these cases were examined for six independently inherited genetic loci using polymerase chain reaction (PCR) suitable for analyzing degraded DNA generally encountered in putrefied/contaminated samples. In the first situation, three of five specimen bags from one accident were labeled with two different names. DNA analysis revealed that one of these bags actually had commingled specimens, originating from two different individuals. Therefore, the sample was excluded from the final toxicological evaluation. In the second situation, an unacceptable blind control result was reported in a cyanide batch analysis. By comparing DNA profiles of the batch samples with those of the known positive and negative blind controls, it was concluded that the error had occurred during the analysis instead of accessioning. Accordingly, preventive measures were taken at the analytical level. The third situation was related to the presence of atropine at toxic concentrations in the blood (318 ng/mL) and lung (727 ng/g) with its absence in the liver, spleen, and brain. DNA analysis of the blood and liver samples exhibited their common identity, ensuring that the submitted samples had indeed originated from one individual. The selective presence of atropine was attributed to its possible administration into the thoracic cavity by the emergency medical personnel at the accident site for resuscitation, but circulatory failure prevented its further distribution. These examples clearly demonstrate the applicability of the PCR-based DNA typing to enhance the effectiveness of forensic toxicology operation.

Stereochemical determination of selegiline metabolites in postmortem biological specimens

In this study, findings related to an aircraft accident are reported. Biological specimens collected at autopsy from the pilot of the fatal accident and two types of tablets found at the accident scene were submitted for toxicological evaluation. It was determined that the pilot was dead at the crash site and the cause of death was multiple traumatic injuries. The tablets were identified as selegiline and levodopa, commonly prescribed for the treatment of Parkinson's disease. Selegiline, a stereospecific compound, is biotransformed into (-)-N-desmethylselegiline, (-)-methamphetamine, and (-)-amphetamine. The latter two levorotatory metabolites cannot be easily distinguished by routine analysis from their dextrorotatory isomers, which are controlled substances. It was, therefore, prudent to differentiate these isomers to determine if they resulted from the ingestion of a controlled substance, (+)-methamphetamine. Initial immunoassay drug screenings revealed the presence of amphetamine class drugs (867 ng/mL) in urine, amphetamine/methamphetamine (261 ng/mL) in urine, and methamphetamine (46 ng/mL) in blood. The gas chromatography-mass spectrometry (GC/MS) results revealed the presence of methamphetamine in the concentrations of 76 ng/mL of blood and 685 ng/mL of urine. The concentration of amphetamine was 52 ng/mL in blood and 320 ng/mL in urine. To determine the stereospecificity of these amines, the isolated amines from the biosamples were derivatized by a stereospecific agent, (S)-(-)-N-(trifluoroacetyl)-prolyl chloride, and characterized by a GC/MS method to be levorotatory. The 2.14 ratio of (-)-methamphetamine to (-)-amphetamine concentrations in the urine was consistent with a selegiline study in the recent literature. The stereospecific analysis, in conjunction with the history of the pilot being on Parkinson's medications, suggests that the source of these amines was selegiline. This conclusion substantiates the importance of the identification of enantiomers in evaluating and interpreting related analytical results for accident investigations.

PLACE OF MINILAP CHOLECYSTECTOMY IN AN ERA OF LAPAROSCOPIC CHOLECYSTECTOMY

In view of surgical and economic factors of our country, minilap cholecystectomy can be performed as an alternative to the laparoscopic cholecystectomy and offers almost similar results as laparoscopic surgery. We compared the operation time, post-operative hospital stay and return to full activity and the results were encouraging. We hope that this article justifies its claim to orthodoxy in the coming years.

Role of metabolites in aviation forensic toxicology

In aviation accident investigations, specimens from fatal aircraft victims are analyzed for drugs. The presence of drugs suggests possible associated medical conditions for which they might have been taken. As drugs are mostly present in therapeutic to subtherapeutic levels in aviation forensic toxicology cases, determination of parent drugs and their metabolites in multispecimens is of significance. Although chemically reactive metabolites are difficult to detect, physiologically active and inactive metabolites can be analyzed. Selective and sensitive techniques are available, but unavailability of metabolite reference standards, endogenous substance interference, and low tissue metabolite levels limit the analyses. However, the majority of primary metabolites can be effectively characterized/quantitated. Demonstrating the presence of drug (e.g., terfenadine, cocaine, THC) metabolites provides a compelling evidence for exposure to the parent drug and facilitates interpretation of results, particularly when the metabolites are active. Such analyses are not as helpful if the metabolites are also available as drugs (e.g., diazepam, temazepam, oxazepam).

Simultaneous gas chromatographic determination of four toxic gases generally present in combustion atmospheres

The measurement of combustion gases produced by burning aircraft cabin materials poses a continuing limitation for smoke toxicity research. Because toxic effects of gases depend on both their concentrations and the duration of exposure, frequent atmosphere sampling is necessary to define the gas concentration-exposure time curve. A gas chromatographic (GC) method was developed for the simultaneous analyses of carbon monoxide (CO), hydrogen sulfide (H2S), sulfur dioxide (SO2), and hydrogen cyanide (HCN). The method used an MTI M200 dual-column gas chromatograph equipped with 4-m molecular sieve-5A and 8-m PoraPlot-U wall-coated capillary columns and two low-volume, high-sensitivity thermal conductivity detectors. Detectability (in parts per million [ppm]) and retention times (in seconds) for the gases were as follows: CO, 100 ppm, 28 s; H2S, 50 ppm, 26 s; SO2, 125 ppm, 76 s; and HCN, 60 ppm, 108 s. The method was effective for determining these gases in mixtures and in the combustion atmospheres generated by burning wool (CO, HCN, and H2S) and modacrylic fabrics (CO and HCN). Common atmospheric gaseous or combustion products (oxygen, carbon dioxide, nitrogen, water vapor, and other volatiles) did not interfere with the analyses. However, filtration of the combustion atmospheres was necessary to prevent restriction of the GC sampling inlet by smoke particulates. The speed, sensitivity, and selectivity of this method make it suitable for smoke toxicity research and for evaluating performance of passenger protective breathing equipment. Also, this method can potentially be modified to analyze these gases when they are liberated from biosamples.

Aircraft fires, smoke toxicity, and survival

In-flight fires in modern aircraft are rare, but post-crash fires do occur. Cabin occupants frequently survive initial forces of such crashes but are incapacitated from smoke inhalation. According to an international study, there were 95 fire-related civil passenger aircraft accidents worldwide over a 26-yr period, claiming approximately 2400 lives. Between 1985 and 1991, about 16% (32 accidents) of all U.S. transport aircraft accidents involved fire and 22% (140 fatalities) of the deaths in these accidents resulted from fire/smoke toxicity. Our laboratory analyses of postmortem blood samples (1967-93) indicate that 360 individuals in 134 fatal fire-related civil aircraft (air carrier and general aviation) accidents had carboxyhemoglobin saturation levels (> or = 20%), with or without blood cyanide, high enough to impair performance. Combustion toxicology is now moving from a descriptive to a mechanistic phase. Methods for gas analyses have been developed and combustion/animal-exposure assemblies have been constructed. Material/fire-retardant toxicity and interactions between smoke gases are being studied. Relationships between gas exposure concentrations, blood levels, and incapacitation onset are being established in animal models. Continuing basic research in smoke toxicity will be necessary to understand its complexities, and thus enhance aviation safety and fire survival chances.

Exposures to carbon monoxide, hydrogen cyanide and their mixtures: interrelationship between gas exposure concentration, time to incapacitation, carboxyhemoglobin and blood cyanide in rats

Carbon monoxide (CO) and hydrogen cyanide (HCN) are generated during aircraft interior fires in sufficient amounts to incapacitate cabin occupants. For typical post-crash and in-flight fires, minimum protection periods of 5 and 35 min, respectively, have been suggested for breathing devices to protect the occupants from smoke. Relationships of blood carboxyhemoglobin (COHb) and cyanide (CN-) levels to incapacitation have not been well defined for these gases. Therefore, time to incapacitation (ti) and blood COHb and CN- at incapacitation were examined in rats exposed to CO (5706 ppm for 5-min ti; 1902 ppm for 35-min ti), HCN (184 ppm for 5-min ti; 64 ppm for 35-min ti) and their mixtures (equipotent concentrations of each gas that produced 5- and 35-min ti). Blood CO and HCN uptakes were evaluated at the two concentrations of each gas. With either gas, variation in ti was higher for the 35-min ti than the 5-min ti The COHb level reached a plateau prior to incapacitation at both CO concentrations, and COHb levels at the 5- and 35-min ti were different from each other. Blood CN- increased as a function of both HCN concentration and exposure time, but CN- at the 5-min ti was half of the 35-min ti CN- level. The HCN uptake at the high concentration was about three times that at the low concentration. In the high concentration CO-HCN mixture, ti was shortened from 5 to 2.6 min; COHb dropped from 81 to 55% and blood CN- from 2.3 to 1.1 microgram ml(-1). At the low-concentration CO-HCN mixture, where ti was reduced from 35 to 11.1 min, COHb decreased from 71 to 61% and blood CN- from 4.2 to 1.1 microgram ml(-1). Any alteration in the uptake of either gas by the presence of the other was minimal. Our findings suggest that specific levels of blood COHb and CN- cannot be correlated directly with the incapacitation onset and that postmortem blood COHb and CN- levels should be evaluated carefully in fire victims.

Biochemical and toxicological studies on the mixtures of three commonly-used herbicides in mice

Herbicidal-mixtures have not been adequately studied in biological systems. Therefore, mixtures of three commonly-used herbicides were evaluated. Alachlor (AL), atrazine (AT), picloram (PI), AL+AT, AT+PI, PI+AL and AL+AT+PI, at 10 ppm (in drinking water) of each herbicide, were provided to mice for 30, as well as for 90, days ad libitum; these herbicides and mixtures, at 100 mg/kg (in corn oil) of each herbicide, were also given to additional groups of mice by oral intubation daily for 21 days. In the 30-day test, the spleen/body weight ratios on Day 31 with respect to the control were increased in the AT (53%) and AL+AT (44%) groups. Decreases in the body weights were noted in the treated groups after Day 31 during the 90-day test. Serum glutamic-pyruvic transaminase (SGPT), glutamic-oxalacetic transaminase (SGOT) and alkaline phosphatase activities with AL+AT+PI were elevated by 36-92% on Day 91; SGPT (34%) and SGOT (73%) activities were increased with AL. During the 21-day oral intubation study, the mouse body weights in the mixture groups were generally lower than the control (p < or = 0.05). The liver/body weight ratios were elevated in all groups (16-38%); the spleen/body weight ratio increased with PI (50%). The kidney/body weight ratios were high with PI+AL and AL+AT+PI (p < or = 0.05). Excluding AT, the pentobarbital-induced sleep was less (51-77%) in the herbicide-treated groups. Also, necrosis of individual and small groups of hepatocytes was noted with the mixtures.(ABSTRACT TRUNCATED AT 250 WORDS)

Toxicological evaluation of mixtures of ten widely used pesticides

Toxicities of pesticidal mixtures in biological systems have not been explored adequately. Therefore, mixtures of ten widely used pesticides were evaluated for their toxicity in ICR male mice (21-24 g). Mice were given four mixtures of alachlor, aldrin, atrazine, 2,4-dichlorophenoxyacetic acid, DDT, dieldrin, endosulfan, lindane, parathion and toxaphene, at 0.01, 0.1, 1.0 and 10 ppm of each of these pesticides, in drinking water for 90 days ad libitum. Also, two mixtures at 2.5 and 5 mg kg-1 of each pesticide in 7.5% Tween-80 in water were administered to additional groups of mice by oral intubation daily for up to 14 days. In relation to the control, the 90-day exposure caused a dose-dependent increase in the liver/body weight ratio (3-44%), a decrease in the pentobarbital (60 mg kg-1, i.p.)-induced sleep time (11-79%) and an increase in the metabolism of aniline (233-399%), amidopyrine (79-231%), phenacetin (127-318%) and benzo[a]pyrene (286-1633%) in the 9000 g hepatic supernatants from the mixture-treated mice. Proliferation, dilatation and fragmentation of the endoplasmic reticulum and scattering of ribosomes were noticed with mixture livers. In the 5 mg kg-1 group, 90% of the animals died by Day 8; incidence of death was considerably less in the 2.5 mg kg-1 group. The serum cholinesterase activity was inhibited by ca. 50% in the 2.5 and 5 mg kg-1 groups on either one or both of Days 8 and 15; the liver/body weight ratio increased by 24-79% and the pentobarbital-induced sleep time decreased by 80-96%.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison of toxicity rankings of six aircraft cabin polymers by lethality and by incapacitation in rats

Polymeric aircraft cabin materials have the potential to produce toxic gases in fires. Lethality (LC50) in animal models is a standard index to rank polymers on the basis of their combustion toxicity. However, the use of times-to-incapacitation (ti) may be more realistic for predicting relative escape times from a fire. Therefore, LC50 and ti for polymers, polyamide (I), polystyrene (II), Nylon 6/6 (III), polysulfone (IV), polyethylene (V) and chlorinated polyethylene (VI), of different chemical classes were determined and compared. Male rats, 12/fuel loading, were exposed to the pyrolysis products from selected weights of each polymer for 30 min in a 265-L combustion/exposure system, and LC50 values were determined following a 14-d observation period. For each polymer, ti was measured at 16 g and at its respective LC50 using the inability of rats (n greater than or equal to 12) to walk in rotating cages as a criterion for incapacitation. LC50 (45.7-87.5 mg/L) of the polymers had the order of I less than II approximately III less than IV less than V less than VI, while their ti (6.6-21.1 min) at 16 g (60 mg/L) had the order of III approximately I less than V approximately II less than VI less than IV. Based on ti at LC50, polymers were grouped into III & V; I, II & VI; and IV. LC50 and ti did not exhibit the same relative toxic hazard rankings for these polymers; ti were also not equal at the LC50 concentrations. These findings demonstrate the possible involvement of different mechanisms of action for the combustion products of these polymers at the selected end points.

Metabolic aspects of the toxicology of mixtures of parathion, toxaphene and/or 2,4-D in mice

The effects of mixtures of parathion (PA;5 mg kg-1), toxaphene (TOX; 50 mg kg-1)and/or 2,4-dichlorophenoxyacetic acid (2,4-D; 50 mg kg-1) on the hepatic mixed-function oxygenase (MFO) system were studied in ICR male mice (21-24 g) by oral intubation daily for 7 days. In general, TOX and TOX-containing mixtures were found to induce the metabolism of amidopyrine (21-52%), aniline (58-72%), phenacetin (239-307%), pentobarbital (104-148%) and benzo[a]pyrene (143-304%) in the 9000 g liver supernatants and to increase the hepatic cytochrome P-450 contents (57-80%). Furthermore, the TOX pretreatment was effective in enhancing the biotransformation of PA or paraoxon (PO) in the supernatants. This enhancement was not altered significantly by 5 mM EDTA. Although TOX increased the aliesterase activity in the serum and liver homogenates and supernatants by 31-158%, the activity of paraoxonase was not affected in these preparations. The TOX-induced increase in the metabolism of PA or PO was, at least in part, associated with the MFO system, and paraoxonase did not have significant involvement in the increase. These findings suggest that the toxicity of the PA + TOX mixture would be lower than that of PA, as TOX has the ability to increase the biotransformation of PA, as well as of PO, and the levels of aliesterase, thereby providing a pool of noncritical enzymes for the binding of PO. Because of these properties of TOX, it is anticipated that the toxicity of the PA + TOX + 2,4-D mixture also would be lower than that of PA.

1(2-benzoylethyl)pyridinium chloride: a new potent and selective inhibitor of bovine brain and human placental choline acetyltransferase

A newly synthesized 1(2-benzoylethyl)pyridinium (BEP), an analog of the choline acetyltransferase (ChA) inhibitor (2-benzoylethyl)trimethylammonium (BETA), was evaluated for its ability to inhibit ChA from bovine brain and human placenta. Its ChA inhibitory properties were compared with that of BETA. BEP was found to be an effective inhibitor of ChA (I50: 10-18 microM). BEP, as well as BETA, was a linear noncompetitive inhibitor of ChA with respect to both substrates, acetylcoenzyme A and choline. BEP and BETA were poor inhibitors of electric eel acetylcholinesterase. These observations indicate that BEP is a potent and selective inhibitor of ChA. Furthermore, because of the possible delocalization of the positive charge at the N atom of the BEP molecule throughout the pyridine ring, it is anticipated that BEP would have a higher potential for lipid solubility, stability and selectivity than BETA.

A death due to self-administered fentanyl

A fatality resulting from the self-administration of fentanyl is described. The decreased was a health care professional with a known history of drug abuse. At the scene, a syringe partly filled with red fluid was found. Pathological findings disclosed pulmonary congestion, hemorrhage, and aspiration of gastric contents and passive congestion in the liver and kidneys. Initial drug screening revealed the presence of fentanyl in the fluid from the syringe and diazepam/oxazepam in the urine. Fentanyl, diazepam, nordiazepam, and oxazepam in the submitted samples were simultaneously quantitated using a gas chromatograph equipped with a nitrogen-phosphorus detector. The fentanyl concentrations (micrograms/L or micrograms/kg) in serum, blood, urine, bile, liver, kidney, brain, lung, and stomach tissue were 17.7, 27.5, 92.7, 58.2, 77.5, 41.5, 30.2, 83.4, and 31.6, respectively. The tissue levels of diazepam and its metabolites were lower than the reported lethal concentrations. The fentanyl concentration in the syringe contents was 2,800 micrograms/L. The toxicological findings and circumstantial evidence of the case indicate that the death resulted primarily from fentanyl overdose.

Toxicity of mixtures of parathion, toxaphene and/or 2,4-D in mice

The toxicity of the mixtures of parathion (PA), toxaphene (TOX) and/or 2,4-dichlorophenoxyacetic acid (2,4-D) was studied in ICR male mice (21-24 g) by oral intubation, in corn oil, daily for up to 14 days. On Day 15, the exposure was discontinued, and animals were monitored for an additional period of 7 days for the possible reversibility of the toxicity. The body weight gain decreased with the mixtures, as well as with the individual agricultural chemicals (ACs), during the 14-day period. The cholinesterase (ChE) activity in the serum and brain was inhibited in the animals of the groups of PA (1-10 mg kg-1) and PA (5 mg kg-1)-containing mixtures. TOX (50-200 mg kg-1) caused initial inhibitory effects of 20-65% on the serum ChE (Day 1) before producing increases of 53-64% in the enzyme activity by Day 15, with little effects on the brain ChE levels. 2,4-D (50-200 mg kg-1) resulted in significantly elevated levels of the serum ChE, with substantial decreased in the brain ChE activity. The serum glutamic pyruvic transaminase level was up (38-630%) in TOX (50 mg kg-1), 2,4-D (50 mg kg-1) or their mixture group. No pathological changes at the light microscopic level in the brain and liver were noticed. TOX and TOX-containing mixtures significantly increased the liver/body weight ratio and decreased the pentobarbital (60 mg kg-1, i.p., in saline)-induced sleep.(ABSTRACT TRUNCATED AT 250 WORDS)

Toxicological evaluation of a poisoning attributed to ingestion of malathion insect spray and correlation with in vitro inhibition of cholinesterases

A 24-year-old Caucasian male was found dead from unknown causes at his farm home. At the scene, partially filled bottles of ORTHO Malathion 50 Insect Spray and CLOROX bleach were found. At the time of autopsy, a strong odour of a petroleum based product was prominent in the small intestine and in the liquid stool. A similar odour was also present in the liquids of both bottles. Generalized visceral and vascular congestion with oedema in various tissues was markedly present. Toxicological analysis of the gastric contents, intestinal contents, bile and liquid samples from the malathion and bleach bottles revealed the presence of malathion in the concentrations of 2.1 g/kg, 98 g/kg, 570 mg/l, 54% and 11%, respectively. In the blood and urine, malathion was not detected. Xylenes and other common volatile components of the spray were detected in the liquids from the bottles and in the gastric and intestinal contents. The ability of the blood and bile samples to inhibit, in vitro, rat serum cholinesterase and electric eel acetylcholinesterase was consistent with their malathion concentrations as the bile inhibited both enzymes, while the blood did not. These findings conclude that the death was associated with the ingestion of a commercial malathion insect spray.

Interaction between phencyclidine and its pyrolysis product, 1-phenylcyclohexene

The interaction between phencyclidine (PCP) and its pyrolysis product, 1-phenylcyclohexene (PC), at metabolic level was evaluated in Swiss male mice (21-24 g). PC (1.1, 2.2 and 4.4 mmol/kg/day for 4 days, IP, in corn oil) treatment to mice induced the in vitro metabolism (p less than 0.05) of amidopyrine (17%), aniline (12%), phenacetin (62-100%), pentobarbital (20-26%), PCP (25-80%) and benzo[a]pyrene (81-147%) in the 9000 g liver fraction and the hepatic microsomal contents of cytochrome P-450 (18-42%). The induction of the mixed function oxygenase (MFO) system was consistent with the decreases in the concentrations of IP administered pentobarbital (0.27 mmol/kg, in saline) and PCP (16.4, 32.8 and 65.6 mumol/kg, in saline) in the serum, brain, liver and kidneys of PC pretreated mice. At 1 hr after the above doses of PC, the in vitro metabolism of amidopyrine, aniline, or phenacetin was not inhibited. However, the biotransformation of benzo[a]pyrene was inhibited by 33 to 45%. Though PC after a single dose did not alter the tissue concentrations of PCP, it increased the pentobarbital concentrations in the tissues studied (p less than 0.05). These results indicate that PC has a potential to induce the MFO system after the 4-day treatment. This property of PC plays an important role in the reduction of the action of PCP by enhancing its metabolism, thereby decreasing its tissue levels.

Influence of chlorpromazine on motility and calcium uptake of boar sperm

In the motility of sperm, which resembles the automaticity of smooth muscle in some features, calcium plays an important role. Chlorpromazine (CPZ), an inhibitor of calmodulin (CaM), decreases contractile responses of smooth muscle to agonists, alters microsomal calcium movements and inhibits human sperm motility. The involvement of CaM in the contraction of smooth muscle and in sperm motility and its presence in sperm cells have also been established. Therefore, the effects of CPZ on boar sperm motility and microsomal calcium uptake were studied. CPZ (0.05-0.5 mM) was found to depress the motility index of boar sperm. At 60 min time point, an inhibition of the motility index ranging from 28 to 85% was observed (p less than 0.05). The spermatozoa microsomal calcium uptake (5.2 nmol/mg protein/hr) was Mg++- and ATP-dependent and azide insensitive. Ionophore A23187 (1 microM) and EDTA (10 mM) inhibited the uptake (67-94%). The calcium uptake was inhibited (40-60%) by CPZ (0.25 and 0.5 mM). The CPZ-induced inhibition of the motility index or calcium uptake was overcome by additional CaCl2. The observations suggested that the CPZ-caused changes were calcium-mediated and possibly involved CaM.

Two tricyclic antidepressant poisonings: levels of amitriptyline, nortriptyline and desipramine in post-mortem biological samples

Two deaths due to amitriptyline and desipramine overdoses are reported. The first case deals with a 20-year-old Caucasian male who was found dead at his residence. Toxicological analysis of the blood, urine, liver and kidney revealed the presence of amitriptyline (1.7 mg/l, 0.13 mg/l, 36.0 mg/kg and 98.0 mg/kg) and nortriptyline (0.66 mg/l, 0.74 mg/l, 12.0 mg/kg and 37.0 mg/kg). The gastric content contained only 220 mg of amitriptyline. The urine also contained norverapamil, which was consistent with previous verapamil therapy. The second case involved a 19-year-old Caucasian male who attempted suicide earlier and was on desipramine medication. The blood, urine, liver and gastric content disclosed the presence of desipramine in the concentrations of 14.2 mg/l, 33.7 mg/l, 112.5 mg/kg and 180 mg, respectively. The levels of these tricyclics analyzed by high pressure liquid chromatography were in agreement with the levels reported in the literature. Though with the amitriptyline poisoning no significant anatomic changes were noted, the desipramine-caused death was further supported by the multisystem vascular congestion and ischemic changes consistent with cardiopulmonary failure.

Poisoning associated with potassium

A suicidal poisoning by intravenous administration of concentrated solution of potassium (K+) (chloride) is described in the study. A 30-year-old Caucasian female health professional was found dead in a motel. An intravenous needle was found inserted in the antecubital area in a right arm vein of the deceased. Attached to the needle, by a flexible tubing, was a 50 ml syringe four-fifths full of a clear liquid. Autopsy on the victim revealed pulmonary oedema and congestion. A routine toxicological analysis of biological samples ruled out the possibility of a drug overdose. However, the liquid from the syringe contained 1468 mmol of K+/l. Chloride ions were also present in high concentration in the liquid. The concentrations of K+ in the clear plasma and vitreous humour were 54 and 9.2 mmol/l respectively. It is suggested that the elevated level of K+ in the plasma or vitreous humour does not indicate necessarily a death due to the electrolyte. The evidence in this case is circumstantial and apparently can be expected to be so in any case where death is due to the intravenous infusion of a concentrated K+ solution.

[Parametric images in nuclear cardiology]

Parametric or the so-called functional images found an application in modern nuclear cardiology for the processing of radiodiagnostic data, particularly those of radionuclide ventriculography. The process of obtaining parametric images incorporates the transformation of digital scintigrams using arithmetic or more complicated mathematical procedures. As a result of it valuable radiodiagnostic parameters on the point of spatious resolution of the digital scintigrams are singled out from the whole complex of scintigraphic information. This method of scintigraphic data processing with obtained parametric images is recommended for a wider use in the other areas of nuclear medicine too.

Toxicity of 1-phenylcyclohexene and its interaction with phencyclidine

The toxicity of 1-phenylcyclohexene (PC), a pyrolysis product of phencyclidine (PCP), and its interaction with PCP were evaluated. The ip LD50 of PC in Swiss male mice was 22 mmol/kg. Treatment of mice with PC at 2.2 mmol/kg/day, ip, for up to 7 days increased the liver/body weight ratio, which returned to normal within 7 days after PC withdrawal. Increases of 32% in serum glutamic-oxalacetic transaminase (SGOT) and 94% in serum glutamic-pyruvic transaminase (SGPT) were observed within 4 hr following the initial (Day 1) dose of PC. Smaller increases in the SGOT activity continued following Day 2 and 3 PC administrations. The SGPT activity remained elevated after these treatments. Activities of both enzymes, however, returned to normal within 24 hr following daily PC injections. No pathologic changes were observed in liver, brain, spleen, kidneys, and lungs with light microscopy. PC treatment for 4 days at 2.2 or 4.4 mmol/kg produced proliferation along with dilatation and fragmentation of the endoplasmic reticulum in liver. Scattering of ribosomes in the cytoplasm and dilatation of rough-surfaced cisternae were prominent at the higher dosage. Pretreatment of animals for 4 days with PC (1.1, 2.2, and 4.4 mmol/kg, ip) decreased pentobarbital- (60 mg/kg) induced sleeping time by 27, 64, and 80% and lowered PCP- (16.4 mumol/kg) stimulated locomotor activity by 18, 28, and 41%, respectively. Pretreatment of animals with PC for 1 hr inhibited (ED50: 2.3 mmol/kg) the PCP-induced locomotion. These results indicate that the PC treatment during a 7-day period produces some undesirable effects on liver function, which are reversible on its discontinuation. However, PC also weakens toxic effects of PCP.

Effects of mecamylamine, nicotine, atropine and physostigmine on the phencyclidine-induced behavioral toxicity

Phencyclidine (PCP) has multifaceted actions on the cholinergic functions, including interaction with the central and peripheral cholinergic receptors. Therefore, to evaluate the possible involvement of the nicotinic and muscarinic acetylcholine (ACh) receptors during the behavioral toxicity of PCP, influence of various cholinergic modifiers on the PCP-induced behavioral effects in male Swiss mice was studied. PCP-induced (45 mumol/kg, IP) behavioral toxicity (circular movements, side-to-side head movements, and hyperactivity leading to convulsions) was blocked by pretreating the animals with secondary- or tertiaryamino -cholinergic modifiers, mecamylamine (ME; 14.9 and 29.9 mumol/kg), nicotine (NI; 12.3 and 30.8 mumol/kg) and physostigmine (PH; 0.16 and 0.31 mumol/kg). NI at 1.5 mumol/kg significantly potentiated the PCP-induced convulsions. Atropine (AT; 14.4 and 28.8 mumol/kg) pretreatments shortened the onset of circular movements. The locomotor activity of PCP (16.4 mumol/kg) was blocked by ME, NI, and PH. AT at 7.2 mumol/kg significantly potentiated the PCP-locomotion by 62%. These observations indicated that the behavioral actions of PCP, at least in part, are mediated by the central nicotinic and muscarinic ACh receptors. The involvement of cholinergic receptors in conjunction with the dopaminergic actions of PCP during these behaviors also has been discussed.