Quantifying a potential protective effect of buprenorphine on fatality risk during acute fentanyl exposures

INTRODUCTION

Buprenorphine is an important therapy for opioid use disorder and may also reduce the risk of fatal overdoses in fentanyl exposures. However, the role of buprenorphine in reducing this risk has not been quantified. This cross-sectional study examined the association between buprenorphine presence, decedent characteristics, and other factors with the predicted fentanyl concentrations in overdose deaths.

METHODS

The study identified unintentional fentanyl overdose decedents (n = 3036) from the West Virginia Forensic Drug Database, 2011 through mid-2020. The main outcome was fentanyl concentrations in overdose deaths in the presence and absence of buprenorphine. A multiple linear regression model examined the association of fentanyl concentrations with buprenorphine presence based on the concentrations of the parent drug buprenorphine (B) and its metabolite norbuprenorphine (N), adjusting for demographics, toxicological characteristics (presence of multiple opioids, benzodiazepines, stimulants, marijuana, and alcohol), and comorbidities. We used a B/N concentration ratio < 1 as an indirect indicator of longer-term buprenorphine exposure prior to drug overdose death.

RESULTS

The median fentanyl concentration was 65 % higher when buprenorphine was present (N = 168) vs. absent (N = 2868) (0.028 vs. 0.017 μg/mL, p < 0.001). In the multivariable model, statistically significant associations occurred between buprenorphine presence and increased fentanyl concentrations (+28.7 %) with a B/N ratio < 1. Obesity, male sex, alcohol presence, and comorbid cardiovascular diseases were statistically significantly associated with lower (-11.3 % to -20.7 %) fentanyl concentrations, whereas marijuana presence and a history of substance use disorder were associated with statistically significant higher fentanyl concentrations (+8.8 % to +31.3 %).

CONCLUSIONS

These findings suggest that sustained or longer-term buprenorphine intake might exert some protective effect on fatalities resulting from fentanyl exposure as documented by the association of higher fentanyl blood concentrations with buprenorphine presence among fatal drug overdoses. As fentanyl availability and overdose rates increase nationally, buprenorphine is a vital tool for effective opioid use disorder treatment that might also reduce the risk of fatality in an acute fentanyl exposure.

Oral Cavity Fluid as an Alternative Postmortem Matrix: Comparison to Simultaneously Collected Blood and Urine Specimens

ABSTRACT

In postmortem toxicology analysis, a variety of specimens consisting of fluids and tissues are often collected, each with an intrinsic value. Oral cavity fluid (OCF) is emerging as an alternative matrix in forensic toxicology for contributing to a diagnosis in postmortem cases; especially when blood is limited or not available. The aim of this study was to assess the analytical results obtained from OCF and compare them with blood, urine, and other traditional matrices collected from the same postmortem subjects. Of the 62 decedents studied (including 1 stillborn, 1 charred, and 3 decomposed subjects), 56 had quantifiable drugs and metabolites data in the OCF, blood, and urine. Notable findings were benzoylecgonine (24 cases), ethyl sulfate (23 cases), acetaminophen (21 cases), morphine (21 cases), naloxone (21 cases), gabapentin (20 cases), fentanyl (17 cases), and 6-acetylmorphine (15 cases), which were detected more frequently in OCF than in blood (heart, femoral, or body cavity) or urine. This study suggests that OCF is a suitable matrix for detecting and quantifying analytes in postmortem subjects compared with traditional matrices, particularly when other matrices are limited or difficult to collect because of body condition or putrefaction.

Characteristics of xylazine-related deaths in West Virginia-Xylazine-related deaths

BACKGROUND AND OBJECTIVES

The involvement of xylazine, a veterinary drug, in West Virginia (WV) human drug-related deaths was examined.

METHODS

WV drug deaths from 2019 (when xylazine was first identified) to mid-2021. Characteristics including toxicology findings were compared between xylazine and nonxylazine deaths.

RESULTS

Of 3292 drug deaths, 117 involved xylazine, and the proportions of deaths with it have increased (1% [2019] to 5% [mid-2021)]. Xylazine decedents had more cointoxicants, with fentanyl (98%) predominant followed by methamphetamine. Xylazine decedents had a significantly greater history of drug or alcohol misuse and hepatic disease.

CONCLUSIONS AND SCIENTIFIC SIGNIFICANCE

In one of the largest analyses of xylazine-involved deaths in a predominantly rural state, identification of xylazine was increasing with multiple cointoxicants (especially fentanyl), and was present in a few deaths with only one other substance involved. Health professionals should be aware of possible enhanced toxicity from xylazine ingestion especially since naloxone does not reverse xylazine's adverse effects.

Characterization of Unintentional Deaths Among Buprenorphine Users

OBJECTIVE

Medications used to treat opioid use disorder (OUD) reduce drug overdose risk. Buprenorphine is often the preferred treatment for OUD because of its high safety profile. Given expanding buprenorphine use, this study sought to examine buprenorphine-involved deaths (BIDs) and compare them with other drug-related deaths.

METHOD

West Virginia drug-related deaths from 2005 to early 2020 were identified. Study data included decedent demographics, toxicology, autopsy findings, and medical and prescription histories. Characteristics of BIDs compared with other drug-related deaths were statistically analyzed.

RESULTS

Among 11,764 drug-related deaths, only 564 (4.8%) involved buprenorphine. Buprenorphine alone was present in 32 deaths, of which 20 were considered the direct cause of death (0.2% of all drug-related deaths). Significantly more BIDs involved five or more drugs (23%) compared with other opioid deaths (14.9%). Co-intoxicants found most frequently in BIDs were benzodiazepines (47.3%), methamphetamine (27.1%), and fentanyl (22.9%). Cardiovascular and pulmonary comorbidities were identified in 43% and 21% of BIDs, respectively. Of the 564 BIDs, a current buprenorphine prescription was present in 132 deaths (23.4%).

CONCLUSIONS

Despite increasing buprenorphine use, BIDs comprised less than 5% of overall West Virginia drug-related deaths. Seldom was it the only drug found, and most decedents did not have current prescriptions for buprenorphine. Although buprenorphine is effective, with a wide safety margin, clinicians and patients should be aware that buprenorphine can be involved in overdose deaths, especially when buprenorphine is taken in combination with drugs such as benzodiazepines, methamphetamine, or fentanyl, and in persons with underlying cardiovascular or pulmonary comorbidities.

Fentanyl and other opioid involvement in methamphetamine-related deaths

BACKGROUND

Methamphetamine-related deaths have been rising along with those involving synthetic opioids, mostly fentanyl and fentanyl analogs (FAs). However, the extent to which methamphetamine involvement in deaths differs from those changes occurring in synthetic opioid involvement is unknown.

OBJECTIVES

To determine the patterns and temporal changes in methamphetamine-related deaths with and without other drug involvement.

METHODS

Data from all methamphetamine-related deaths in West Virginia from 2013 to 2018 were analyzed. Quasi-Poisson regression analyses over time were conducted to compare the rates of change in death counts among methamphetamine and fentanyl//FA subgroups.

RESULTS

A total of 815 methamphetamine-related deaths were analyzed; 572 (70.2%) were male and 527 (64.7%) involved an opioid. The proportion of methamphetamine only deaths stayed relatively flat over time although the actual numbers of deaths increased. Combined fentanyl/FAs and methamphetamine were involved in 337 deaths (41.3%) and constituted the largest increase from 2013 to 2018. The modeling of monthly death counts in 2017-2018 found that the average number of deaths involving fentanyl without methamphetamine significantly declined (rate of change -0.025, p < .001), while concomitant fentanyl with methamphetamine and methamphetamine only death counts increased significantly (rate of change 0.056 and 0.057, respectively, p < .001).

CONCLUSIONS

Fentanyl and FAs played an increasingly significant role in methamphetamine-related deaths. The accelerating number of deaths involving fentanyl/FAs and methamphetamine indicates the importance of stimulants and opioids in unintentional deaths. Comprehensive surveillance efforts should continue to track substance use patterns to ensure that appropriate prevention programs are undertaken.

Quantitation and Validation of 34 Fentanyl Analogs from Liver Tissue Using a QuEChERS Extraction and LC-MS-MS Analysis

Since 2013, drug overdose deaths involving synthetic opioids (including fentanyl and fentanyl analogs) have increased from 3,105 to 31,335 in 2018. Postmortem toxicological analysis in fentanyl-related overdose deaths is complicated by the high potency of the drug, often resulting in low analyte concentrations and associations with toxicity, multidrug use, novelty of emerging fentanyl analogs and postmortem redistribution. Objectives for this study include the development of a quick, easy, cheap, effective, rugged and safe (QuEChERS) extraction and subsequent liquid chromatography-mass spectrometry/mass spectrometry analysis, validation of the method following the American Academy of Forensic Sciences Standards Board (ASB) standard 036 requirements and application to authentic liver specimens for 34 analytes including fentanyl, metabolites and fentanyl analogs. The bias for all 34 fentanyl analogs did not exceed ±10% for any of the low, medium or high concentrations and the %CV did not exceed 20%. No interferences were identified. All 34 analytes were within the criteria for acceptable percent ionization suppression or enhancement with the low concentration ranging from -10.2% to 23.7% and the high concentration ranging from -7.1% to 11.0%. Liver specimens from 22 authentic postmortem cases were extracted and analyzed with all samples being positive for at least one target analyte from the 34 compounds. Of the 22 samples, 17 contained fentanyl and metabolites plus at least one fentanyl analog. The highest concentration for a fentanyl analog was 541.4 μg/kg of para-fluoroisobutyryl fentanyl (FIBF). The concentrations for fentanyl (n = 20) ranged between 3.6 and 164.9 μg/kg with a mean of 54.7 μg/kg. The fentanyl analog that was most encountered was methoxyacetyl fentanyl (n = 11) with a range of 0.2-4.6 μg/kg and a mean of 1.3 μg/kg. The QuEChERS extraction was fully validated using the ASB Standard 036 requirements for fentanyl, metabolites and fentanyl analogs in liver tissue.

Quantifying enhanced risk from alcohol and other factors in polysubstance-related deaths

BACKGROUND

To quantify how alcohol, polysubstance use and other factors influence opioid concentrations in drug-related deaths in West Virginia (WV), United States.

METHODS

Multiple linear regression models were employed to identify relationships among alcohol, other factors, and the concentrations of four commonly identified opioids (fentanyl, hydrocodone, oxycodone, methadone), accounting for demographic, toxicological and comorbid characteristics in WV drug-related deaths from 2005 to 2018.

RESULTS

Alcohol concentrations of 0.08% or above were associated with significant reductions in blood concentrations of fentanyl (27.5%), hydrocodone (30.5%) and methadone (32.4%). Significantly lower predicted concentrations of all opioids studied were associated with multiple opioid vs. single opioid presence, with predicted concentration reductions ranging from 13.7% for fentanyl to 65-66% for hydrocodone and oxycodone. Benzodiazepine presence was associated with small, non-statistically significant changes in opioid concentrations, while stimulant presence was associated with statistically significant reductions in hydrocodone and oxycodone concentrations.

CONCLUSIONS

Co-ingestion of alcohol, multiple opioids or stimulants were associated with significantly decreased predicted concentrations of commonly identified opioids in drug deaths. Further evidence is provided for enhanced risks from polysubstance use with opioids, which has important public health implications.

The Importance of Melatonin Detection in Pediatric Deaths

Melatonin is an endogenous hormone that regulates sleep patterns. It is available in varying formulations and dosages and is marketed as a natural substance that can alleviate insomnia. Recent news reports indicate that melatonin has been administered without appropriate authorization in daycare settings. Even though lethal outcomes have not been solely attributed to exogenous melatonin overdose, it has been relevant to select police and postmortem investigations. A quantitative liquid chromatography-tandem mass spectrometry (LC-MS/MS) assay was developed for the analysis of biological specimens. Results of 22 positive blood samples were evaluated based upon gender, age, and melatonin concentration from cases submitted by clinical, police, and death investigation agencies. Two cases are described. In Case 1, a 9-month-old was found unresponsive after cosleeping with a sibling. Allegations included exposure to an unspecified pesticide and dextromethorphan, and consumption of half a cigarette. There was admitted use of melatonin. Melatonin was quantified in blood and gastric fluid at concentrations of 13 ng/mL and 1200 ng/mL, respectively. In Case 2, a 13-month-old was found nonresponsive in a shared room. Melatonin was found within some of the sippy cups. The infant was extremely warm to the touch. Resuscitative efforts were unsuccessful and death was pronounce3d. Analysis showed a result of 210 ng/mL in blood. The presented quantitative LC-MS/MS method can successfully be applied to evaluate exposure to exogenous melatonin. Toxicology testing can assist in the investigation of these case types by substantiating the purposeful administration of melatonin.

Fentanyl and fentanyl-analog involvement in drug-related deaths

BACKGROUND

To describe and analyze the involvement of fentanyl and fentanyl analogs (FAs) in drug-related deaths in West Virginia (WV), United States.

METHODS

Retrospective analyses of all WV drug-related deaths from 2005 to 2017 were performed, including comparisons of demographic and toxicological characteristics among total deaths, deaths in which fentanyl/FAs were present, deaths in which they were absent, heroin-related deaths, and prescription opioid-related deaths.

RESULTS

Most of the 8813 drug-related deaths were overdoses, with about 11% resulting from transportation/other injuries in which drugs were contributors. Prescription opioid presence (without fentanyl) decreased by 75% from 2005-14 to 2015-17 (3545 deaths to 859 deaths, respectively), while fentanyl involvement in the deaths increased by 122% between these periods (487 to 1082 deaths). Ten FAs were identified (427 instances) after 2015. Alprazolam and ethanol were among the top five most frequently identified substances across years. Fentanyl, heroin and cocaine replaced oxycodone, diazepam and hydrocodone in the top five beginning in 2015. Few decedents had a prescription for fentanyl after 2015, with fewer prescriptions also present for other controlled substances identified.

CONCLUSIONS

Fentanyl, rapidly emerging FAs, and other illicit drugs in recent years pose a serious health threat even though prescription opioid-related deaths decreased over the same time period.

Additive Effects of Cointoxicants in Single-Opioid Induced Deaths

A forensic drug database (FDD) was used to capture comprehensive data from all drug-related deaths in West Virginia, with deaths also included from the northern New England states of Maine, Vermont, and New Hampshire. All four states serve predominantly rural populations under two million and all have similar state medical examiner systems that employ statewide uniform death certification policies and practices. This study focused on 1482 single opioid deaths (fentanyl, hydrocodone, methadone, and oxycodone) in the FDD from 2007-2011. We modeled relationships between the opioid concentrations and the presence or absence of the following commonly occurring non-opioid cointoxicants: benzodiazepines (alprazolam and diazepam), alcohol, tricyclic antidepressants, selective serotonin reuptake inhibitors, and diphenhydramine. Additional covariates of state, age, body mass index, and sex were included. Results showed that the presence of alcohol, benzodiazepines, and antidepressants were each associated with statistically significant lower concentrations of some but not all of the opioids studied, which may obscure the interpretation of postmortem toxicology results alone. Fentanyl concentrations appeared to be the least associated with the presence or absence of the variables studied, and cointoxicant alcohol appeared to be associated with lower concentrations in opioid concentrations than were most of the other factors in the model studied. These findings underscore the importance of documenting all potential cointoxicants in opioid-related deaths.

Parent and Metabolite Opioid Drug Concentrations in Unintentional Deaths Involving Opioid and Benzodiazepine Combinations

Effects of benzodiazepines on postmortem opioid parent and parent/metabolite blood concentration ratios were determined for fentanyl-, hydrocodone-, methadone-, or oxycodone-related accidental deaths. These opioids are partially metabolized by the CYP3A4 enzyme system, which is also affected by diazepam and alprazolam. Opioid/metabolite combinations examined were as follows: fentanyl/norfentanyl, hydrocodone/dihydrocodeine, methadone/EDDP, and oxycodone/oxymorphone. Parent opioid concentrations were analyzed for 877 deaths. Parent/metabolite concentration ratios were analyzed for 349 deaths, excluding cases with co-intoxicants present known to interfere with opioid elimination. Alprazolam in combination with diazepam significantly decreased median hydrocodone concentrations by 48% (p = 0.01) compared to hydrocodone alone. The methadone parent/metabolite concentration ratio was reduced by 35% in the presence of diazepam compared to methadone alone (p = 0.03). Benzodiazepines did not statistically significantly affect fentanyl or oxycodone concentrations. Possible factors affecting opioid concentrations and possible toxicity development, including any differential effects on specific opioids, should continue to be explored.

Fatal methadone toxicity: potential role of CYP3A4 genetic polymorphism

Methadone is difficult to administer as a therapeutic agent because of a wide range of interindividual pharmacokinetics, likely due to genetic variability of the CYP450 enzymes responsible for metabolism to its principal metabolite 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP). CYP3A4 is one of the primary CYP450 isoforms responsible for the metabolism of methadone to EDDP in humans. The purpose of this study was to evaluate the role of CYP3A4 genetic polymorphisms in accidental methadone fatalities. A study cohort consisting of 136 methadone-only and 92 combined methadone/benzodiazepine fatalities was selected from cases investigated at the West Virginia and Kentucky Offices of the Chief Medical Examiner. Seven single nucleotide polymorphisms (SNPs) were genotyped within the CYP3A4 gene. Observed allelic and genotypic frequencies were compared with expected frequencies obtained from The National Center for Biotechnology Information dbSNP database. SNPs rs2242480 and rs2740574 demonstrated an apparent enrichment within the methadone-only overdose fatalities compared with the control group and the general population. This enrichment was not apparent in the methadone/benzodiazepine cases for these two SNPs. Our findings indicate that there may be two or more SNPs on the CYP3A4 gene that cause or contribute to the methadone poor metabolizer phenotype.

Validation of blood and liver oxymorphone analysis using LC-MS-MS: concentrations in 30 fatal overdoses

A sensitive liquid chromatography-tandem mass spectrometry method was developed and validated for the quantitation of oxymorphone (OM) in human whole blood and liver. Sample preparation was done by solid-phase extraction, using deuterated OM as the internal standard. Separation was achieved using a Waters Aquity UPLC HSS T3 column. Analysis utilized positive electrospray ionization and multiple reaction monitoring. As part of the validation, studies were conducted to determine potential interference, selectivity, ion suppression/enhancement and carryover. Calibration model, limit of detection (LOD), lower limit of quantitation (LLOQ), precision and accuracy were also established. The linear range of the method was 2-500 ng/mL in blood and 5-500 ng/g in the liver. The LOD and LLOQ were 2 ng/mL for blood and 5 ng/g for the liver. Blood and/or liver specimens from 30 cases were analyzed. OM concentrations ranged from 23 to 554 ng/mL ( , n = 26) in blood and 48 to 1740 ng/g ( , n = 30) in the liver.

Cocaine detection in postmortem samples following therapeutic administration

Cocaine is one of the most widely abused drugs and one that is frequently encountered in forensic toxicology laboratories. Most often, the detection of cocaine would lead toxicologists and forensic pathologists to believe that the drug was used illicitly; however, cocaine is an effective local anesthetic and vasoconstrictor and is used clinically in surgeries of the eye, ear, nose, and throat. Therefore, it is important to note that the presence of cocaine and its metabolites in forensic samples cannot always be attributed to abuse and that a thorough investigation and review of medical records is warranted before an informed conclusion can be made. In this case report, a 54-year-old male died three days after an altercation in which he suffered multiple injuries. In addition to natural disease and injuries documented at autopsy, cocaine and its metabolites were detected in the decedent's urine, and a review of surgical records showed that earlier on the day of death, he was administered cocaine clinically during a procedure to repair nasal bone fractures. If not for this comprehensive investigation and review of surgical records, the assumption of cocaine abuse might have otherwise been made and the cause and manner of death incorrectly established.

Potential biomarkers of smoked fentanyl utilizing pyrolysis gas chromatography-mass spectrometry

Fentanyl is a potent opioid analgesic that is increasingly becoming a choice drug of abuse. Fentanyl transdermal patches (FTPs) are easily obtained and consumed by smoking the reservoir gel and/or the whole patch. This allows for an increased bioavailability when inhaled. A method using analytical pyrolysis was developed to identify possible biomarkers associated with smoked fentanyl and FTPs. Pyrolysis was carried out under anaerobic and aerobic conditions using helium and air coupled to a gas chromatograph-mass spectrometer. The presence of a trap enhanced recovery and afforded a positive identification of pyrolytic products. Anaerobic and aerobic pyrolysis of fentanyl and FTPs consistently yielded propionanilide as the major pyrolytic product along with pyridine and previously reported metabolites (norfentanyl and despropionyl fentanyl). Analysis of fentanyl resulted in chlorine-containing compounds, presumably formed from the HCl salt of fentanyl. Analysis of FTPs showed significant polymeric and hydrocarbon compounds and products likely derived from the gel matrix. Fentanyl in the FTPs was in the citrate salt form; therefore, the chlorine-containing pyrolytic products obtained with the neat drug were not observed. Based on this application, it may be possible to identify what salt form of the drug was smoked based on pyrolytic products and to target distinguishing metabolic products for future research.

Fatal all-terrain vehicle crashes: injury types and alcohol use

BACKGROUND

Since the 1990s, West Virginia has led the U.S. in the per-capita death rate from all-terrain vehicle (ATV) crashes, with rates eight times the national average and continually increasing. A comprehensive assessment was conducted of ATV fatalities to provide critical guidance for community interventions and public health policy to prevent further deaths.

METHODS

In 2007, death certificates for 2004 to 2006 with ICD-10 codes correlating to ATV crashes were used to identify decedents involved in crashes occurring in West Virginia. Data were abstracted from medical examiner records regarding crash circumstances, sustained injuries, and toxicology.

RESULTS

During 2004-2006, a total of 112 fatal ATV crashes were identified. Nearly all (92%) decedents were the ATV operator, and only 15% were known to have worn helmets. Among 54 traffic crashes, collisions (56%) and head injuries (65%) predominated, whereas the majority of 58 nontraffic crashes were rollovers (55%) and were most commonly associated with compression injuries of the thorax and abdomen (36%). Regardless of crash class (i.e., traffic versus nontraffic), alcohol was detected in the blood of 50% of decedents; of those, 88% had blood alcohol concentrations >OR=0.08% (mean=0.17%), West Virginia's legal limit. Drugs of abuse were identified in 21% of decedents, including marijuana (11%); opioid analgesics (7%); diazepam (6%); cocaine (2%); and methamphetamine (1%).

CONCLUSIONS

Fatal crash and injury types differ significantly depending on the location of ATV use, although alcohol and drug abuse are frequent risk factors in all types of ATV crashes. In addition to promoting helmet use, interventions are needed to address alcohol use among ATV users.

Patterns of abuse among unintentional pharmaceutical overdose fatalities

CONTEXT

Use and abuse of prescription narcotic analgesics have increased dramatically in the United States since 1990. The effect of this pharmacoepidemic has been most pronounced in rural states, including West Virginia, which experienced the nation's largest increase in drug overdose mortality rates during 1999-2004.

OBJECTIVE

To evaluate the risk characteristics of persons dying of unintentional pharmaceutical overdose in West Virginia, the types of drugs involved, and the role of drug abuse in the deaths.

DESIGN, SETTING, AND PARTICIPANTS

Population-based, observational study using data from medical examiner, prescription drug monitoring program, and opiate treatment program records. The study population was all state residents who died of unintentional pharmaceutical overdoses in West Virginia in 2006.

MAIN OUTCOME MEASURES

Rates and rate ratios for selected demographic variables. Prevalence of specific drugs among decedents and proportion that had been prescribed to decedents. Associations between demographics and substance abuse indicators and evidence of pharmaceutical diversion, defined as a death involving a prescription drug without a documented prescription and having received prescriptions for controlled substances from 5 or more clinicians during the year prior to death (ie, doctor shopping).

RESULTS

Of 295 decedents, 198 (67.1%) were men and 271 (91.9%) were aged 18 through 54 years. Pharmaceutical diversion was associated with 186 (63.1%) deaths, while 63 (21.4%) were accompanied by evidence of doctor shopping. Prevalence of diversion was greatest among decedents aged 18 through 24 years and decreased across each successive age group. Having prescriptions for a controlled substance from 5 or more clinicians in the year prior to death was more common among women (30 [30.9%]) and decedents aged 35 through 44 years (23 [30.7%]) compared with men (33 [16.7%]) and other age groups (40 [18.2%]). Substance abuse indicators were identified in 279 decedents (94.6%), with nonmedical routes of exposure and illicit contributory drugs particularly prevalent among drug diverters. Multiple contributory substances were implicated in 234 deaths (79.3%). Opioid analgesics were taken by 275 decedents (93.2%), of whom only 122 (44.4%) had ever been prescribed these drugs.

CONCLUSION

The majority of overdose deaths in West Virginia in 2006 were associated with nonmedical use and diversion of pharmaceuticals, primarily opioid analgesics.

Direct injection mass spectrometric confirmation of multiple drugs in overdose cases from postmortem blood using electrospray ionization-tandem mass spectrometry and MS(3)

Five cases of confirmed multiple-drug overdose were previously screened and quantified by the West Virginia Office of the Chief Medical Examiner; 26 different drugs and metabolites were identified and quantified in blood at > or = 10 ng/mL. In this study, whole blood from those five case samples was analyzed by a direct injection multi-stage mass spectrometric (MSn) method to confirm the identity of 26 analytes at or above 10 ng/mL using 16 different deuterium-labeled internal standards. Samples were spiked with internal standards, precipitated with acetonitrile, and centrifuged. Samples were further diluted with either 0.1% formic acid or 0.1% ammonium hydroxide in methanol prior to injection into an electrospray ionization ion trap mass spectrometer (MS). Ions were monitored as MS-MS or MS3 product ions. In all cases, analysis by MS-MS confirmed the presence of the drugs and metabolites when the internal standards were detected. Detection of characteristic MS3 ions was used for further confirmation of the presence of parent drugs in all but three instances. Total analysis time was less than 1 h. Although only useful for qualitative or confirmatory purposes, this direct injection MSn method provides a simple and rapid confirmation of multiple drugs that have been previously identified and quantified by gas chromatographic-MS or liquid chromatographic-MS analytical methods.

Validation of a Headspace GC Method for the Analysis of a Pyrolytic Product of Methamphetamine in Urine

A method has been developed and validated using headspace GC-FID for the identification of 1-phenylpropene in urine. This compound is a pyrolytic product of methamphetamine that has been previously proposed as a marker for smoked methamphetamine. The instrumentation used is the same as employed for blood alcohol determination. The extraction-free procedure is rapid, simple, and quantitative using 2-phenylpropene as the internal standard. The method was validated for linearity over a range of 0.1-20 microg/mL with a limit of detection of 0.05 microg/mL, limit of quantification of 0.1 microg/mL, interday accuracy within 3.2 to -5.3%, intraday accuracy better than 7.5%, interday precision of 7.5 to 10.7%, intraday precision of 2 to 8.6%, and recovery above 80%. For the robustness determination in urine, the accuracy of four different sources of urine at the mid control level (1 microg/mL) ranged from 1.6 to 19% error. The % relative standard deviation of the different urine sources ranged from 3.1 to 11%. Urine samples from nine methamphetamine-positive cases investigated by the Office of the Chief Medical Examiner of West Virginia were included in the study. 1-Phenylpropene was found in two methamphetamine-positive cases (0.25 and 0.44 microg/mL).

Identification of N,N-dimethylamphetamine formed by methylation of methamphetamine in formalin-fixed liver tissue by multistage mass spectrometry

Methamphetamine is methylated in the presence of unbuffered formalin solutions within hours at room temperature. The product, N,N-dimethylamphetamine, is also found in human liver exposed to methamphetamine followed by incubation with formalin. In the present study, a direct mass spectrometric method was developed to identify N,N-dimethylamphetamine in human liver before and after treatment with formalin. Human liver samples were obtained from four deaths that were investigated by the West Virginia Office of Chief Medical Examiner. Full toxicological analysis was conducted on samples from the decedents and methamphetamine was among the positive findings in each case. The method used to expose liver tissue to formaldehyde involved treating a small piece of liver from each case with formalin solution (20% v/v) for 24 h at room temperature. The formalin treated tissues were homogenized and the resulting suspension was sonicated for 5 min, and then centrifuged. Supernatant aliquots were directly analyzed by electrospray ionization (ESI) mass spectrometry without chromatographic isolation. Positive ion multistage mass spectra recorded in MS, MS/MS and MS/MS/MS (MS3) modes were used to confirm the presence of N,N-dimethylamphetamine and methamphetamine in the mixture. Liver tissue not treated with formalin did not contain a detectable level of N,N-dimethylamphetamine. Decreases in methamphetamine concentrations in liver tissue resulting from treatment with formalin were measured using deuterium-labeled methamphetamine as internal standard. The method can be completed in less than 2 h on thawed tissue. The results suggest that the process of fixing tissues with formalin may lead to false negative findings for methamphetamine.

Identification of anhydroecgonine ethyl ester in the urine of a drug overdose victim

Toxicological evaluation of postmortem urine collected from a 41-year-old deceased white male detected anhydroecgonine ethyl ester (ethylecgonidine, AEEE), a transesterification product of smoked cocaine co-abused with ethanol. A solid phase extraction (SPE) method was used to extract cocaine, AEEE, and related metabolites from urine. SPE on a 1 mL urine sample from the decedent followed by GC-MS detected AEEE. Other metabolites identified by GC-MS included cocaine, cocaethylene, and anhydroecgonine methyl ester (AEME). To determine whether some or all of the AEEE was artifactually produced in the heated GC injector port, an alternative LC-MS method was developed. LC/MS following SPE found at least 50 ng/mL of AEEE in the extract. The mass fragmentation (MS/MS and MS3) of AEEE detected in the urine was compared to spectra of authentic, synthesized compound. AEEE is a potential additional forensic marker for the co-abuse of smoked cocaine and ethanol.

Methylation of 3,4-Methylenedioxymethamphetamine in Formalin-Fixed Human Liver Tissue

3,4-Methylenedioxymethamphetamine (MDMA or ecstasy) is a commonly consumed recreational drug. As is the case with most secondary amines, MDMA reacts with formaldehyde under acidic conditions to form tertiary amines. This reaction is likely to occur in formalin-fixed tissue. In formalin solutions, MDMA is methylated producing 3,4-methylenedioxy-N,N-dimethylamphetamine (MDDA). MDDA standard was synthesized by treating methylenedioxyamphetamine HCl in formaldehyde solution. Structure confirmation was by electrospray ionization-mass spectrometry (MS) and MS-MS. Randomly chosen human liver pieces (100-200 mg) were injected with 2 microg of MDMA HCl. The liver pieces in centrifuge tubes were covered with 200 microL of formalin solution (20% v/v), held at room temperature for 24 h, and then homogenized. The resulting suspension was sonicated for 5 min and then centrifuged. Controls consisted of substitution of 200 microL of water in place of formalin solution. Supernatant aliquots (10 mciroL) were added to 500 microL of 0.1% formic acid in acetonitrile for MS analysis. Positive ion electrospray spectra recorded in MS, MS2, and MS3 modes were used to confirm the presence of methylated MDMA. Liver tissue containing added MDMA HCl but not treated with formalin did not show a detectable level of methylated MDMA.

Potential Marker for Smoked Methamphetamine Hydrochloride Based on a Gas Chromatography-Mass Spectrometry Quantification Method for trans-Phenylpropene

Residue from smoked methamphetamine hydrochloride contains pyrolytic products that are detectable by gas chromatography-mass spectrometry (GC-MS). A validated GC-MS method was developed for the determination of trans-phenylpropene, a pyrolytic product of methamphetamine HCl, in residue of smoked drug as well as in human urine. trans-Phenylpropene and an isomeric internal standard, 2-phenylpropene, were extracted from urine using n-hexane. The method was validated for linearity over a range of 0.1-10 microg/mL with a limit of detection of 0.05 microg/mL, limit of quantification of 0.1 microg/mL, interday accuracy within 10.5%, intraday accuracy better than 3.7%, interday precision of 15.4%, intraday precision of 14.4%, and recovery of 89.1%. The method was applied to the detection of trans-phenylpropene found in the residue of methamphetamine HCl heated beyond its melting temperature on aluminum foil under simulated smoking conditions. The method is applicable to the detection of trans-phenylpropene in urine as a potential marker for smoked methamphetamine HCl abuse.

Enzyme and receptor antagonists for preventing toxicity from the gamma-hydroxybutyric acid precursor 1,4-butanediol in CD-1 mice

1,4-Butanediol (1,4-BD), the diol alcohol precursor of gamma-hydroxybutyric acid (GHB), undergoes in vivo enzymatic biotransformation to GHB by alcohol dehydrogenase (ADH) and aldehyde dehydrogenase. The subsequent metabolite, GHB, is pharmacologically active at GABA(B) and GHB receptors. GHB can be metabolized in vivo to gamma-aminobutyric acid (GABA) and trans-4-hydroxycrotonic acid (T-HCA), which are also pharmacologically active at GABA(B) receptors and GHB receptors, respectively. Therefore, we speculate that 1,4-BD overdose toxicity can be prevented or attenuated with the ADH enzyme inhibitor 4-methylpyrazole (4-MP) as well as with CGP-35348 and NCS-382, novel high-affinity receptor antagonists of GABA(B) receptors and GHB receptors, respectively. In our murine model of acute 1,4-BD overdose, pretreatment of CD-1 mice with 4-MP significantly attenuated increases in blood GHB concentrations and prevented loss of the righting reflex and failure of the rotarod test. Also, pretreatment with CGP-35348 and its combination with NCS-382 significantly decreased the duration of failure for the rotarod test and the percentage of animals failing the rotarod test, respectively. However, pretreatment of CD-1 mice with NCS-382 alone produced prolonged failure of the rotarod test, an unexpected synergistic effect with 1,4-BD and presumably GHB, which has not previously been demonstrated.

Fatalities caused by the MDMA-related drug paramethoxyamphetamine (PMA)

The past several years have seen a marked increase in the recreational use of 3,4-methylenedioxymethamphetamine (MDMA) or "Ecstasy". MDMA use is especially common among young people participating in dance parties called "raves". Paramethoxyamphetamine (PMA) exhibits both structural and pharmacological similarity to MDMA. It may, however, be a more potent central stimulant, particularly in its effects on serotonergic transmission. Several fatalities from PMA have been reported in Australia, and here we report three recent fatalities that occurred in the midwestern United States in which each of the decedents believed that they were ingesting MDMA. Symptoms observed included agitation and bruxism, progressing to severe hyperthermia, convulsions, and hemorrhage. Blood was screened for drugs of abuse by enzyme immunoassay with the presence of amphetamines indicated in each case. Confirmation and quantitation for amphetamines was performed by gas chromatography-mass spectrometry. The deceased, two males ages 19 and 24 and a female age 18, had postmortem blood PMA concentrations of 1.07, 0.60, and 1.90 mg/L, respectively. PMA is not a contaminant of MDMA, and no MDMA was found in any of these cases. The primary metabolite of PMA is produced by O-demethylation to 4-hydroxyamphetamine, a reaction catalyzed by cytochrome P450 2D6. This enzyme is noted to be genetically polymorphic. Those with the "slow metabolizer" phenotype may be likely to have higher peak blood concentrations of PMA. Whether any of the decedents described herein were of the slow metabolizer phenotype is not known. Several groups have advocated the onsite use of the Marquis Test for the purpose of pill screening in efforts to distinguish PMA from MDMA. A dark purple is consistent with MDMA, whereas PMA imparts no color change in this test. PMA is often in the form of a white pill with a Mitsubishi symbol on one side. This design has been identified in at least one of these fatalities.

Induction of cytochrome P-450 enzymes after repeated exposure to 4-vinylcyclohexene in B6C3F1 mice

4-Vinylcyclohexene (VCH), an ovarian toxicant in mice, is known to irreversibly deplete ovarian follicles as a consequence of VCH diepoxide formation. Because ovotoxicity requires repeated dosing of VCH, the effect of consecutive daily doses of VCH (7.5 mmol/kg/day) on mouse liver microsomal activities and VCH epoxidation was determined. Cytochromes P-450 2B and 2A (CYP2B and CYP2A), principle isoforms involved in the bioactivation of VCH, as well as CYP2E1 and CYP3A were evaluated. VCH exposure increased total cytochrome P-450 content (35-83% above control levels) after either 5, 10, or 15 days of treatment. Western blot analysis revealed an induction of CYP2A, CYP2B, and CYP2E1 at day 10. Elevated levels of CYP2A and CYP2B correlated with marker androstenedione and testosterone 16alpha- and 16beta-hydroxylase activities. Microsomes prepared from mice pretreated with VCH for 10 days demonstrated an increase (>/=2-fold) in the rate of VCH monoepoxide and diepoxide formation. Microsomal VCH epoxidation was increased to a similar extent by phenobarbital, acetone, and dexamethasone treatment. An increase in cytosolic glutathione S-transferase activity was observed after repeated VCH treatment, an enzyme potentially involved in detoxification of the VCH epoxides. Interestingly, preliminary studies indicated that circulating levels of the monoepoxide (vinylcyclohexene 1, 2-monoepoxide) and diepoxide of VCH were elevated after repeated dosing of VCH. Overall, the results indicate that repeated exposure of VCH in mice induces cytochrome P-450-dependent activities, and in turn induction of its metabolism. Additional studies examining the toxicokinetics of VCH after repeated exposure are required to further delineate the relevance of induction in VCH-induced ovotoxicity.

Suppression of rat hepatic microsomal cytochromes P450 by cyclophosphamide is correlated with plasma thyroid hormone levels and displays differential strain sensitivity

Strain differences in cytochrome P450 (P450) expression were investigated in Sprague-Dawley (SDs) compared with Fischer 344s (F344s) rats after administration of cyclophosphamide (CPA). Animals received a single dose of CPA with sacrifice occurring 6 days post-treatment. At 130 mg/kg, male F344s displayed a greater sensitivity to CPA, as evidenced by a 68% loss of total hepatic microsomal P450 compared with only 35% in SDs. The most dramatic change in P450 was the loss of 2C11 (84% in F344s, 52% in SDs). In the SD, individual rat 2C11 activity was correlated (r2 = 0.76), with the level of plasma thyroxine in that animal. In male F344s administered CPA at 50 mg/kg, 43 and 44% losses in 2C11 activity (P < .05) and thyroxine (P < .01), respectively, were observed, whereas activities characteristic of P450s 2C11, 3A2, 2A2, 2C6 and 2E1/1A2 were unaffected in SDs at this dose. CPA also produced suppression of P450 in female SDs, including female-specific 2C12. Correlation was observed between the loss of P450 expression and change in body weight after treatment in both male and female animals, suggesting that CPA downregulates P450 expression secondary to decreased caloric intake. The anorectic effect of CPA is believed to result from potent central nervous system stimulation, accompanied by a state of adaptive hypothyroidism. It has been reported that CPA produces "feminization" of P450 expression in male rats. However, our findings suggest the alternative explanation that the effects of CPA on P450 expression result from decreased caloric intake.

Selective suppression of rat hepatic cytochrome P450 2C11 by chloramphenicol

Chloramphenicol produces mechanism-based inactivation of several rat hepatic microsomal P450 enzymes including 2C6, 2C11, 2B1/2 and 3A1/2. A preliminary study by this laboratory reported that 48 hr after in vivo treatment with chloramphenicol (CAP) 2C11 activity remained low, whereas activities catalyzed by 3A2 and 2C6 were almost fully restored (Halpert et al., Biochem. Pharmacol. 37: 3046-3048, 1988). Therefore, in experiments conducted to examine whether CAP affects P450 expression, Sprague-Dawley (SD) rats were treated with CAP (single i.p. injection, 300 mg/kg) and sacrificed at various times post-treatment. The loss of P450 2C6, 2C11 and 3A2 catalytic activities which is characteristic of inactivation was demonstrated 1 hr after CAP administration. However, at 4 and 6 days, 2C11-mediated progesterone 2 alpha-hydroxylase activity remained diminished by 52 and 45%, respectively. Similar decreases in anti-P450 2C11-reactive protein and 2C11 mRNA were observed at 6 days, suggesting that the compound acts at a pretranslational step. Evaluation of 2C11 regulators indicated that CAP causes a decrease in plasma thyroxine level in proportion to the loss of 2C11 activity, whereas testosterone appears to be unaffected. To minimize intragroup variability, the inbred Fischer 344 strain was then examined at 2 and 6 days after CAP treatment. Surprisingly, CAP caused no loss in 2C11 protein, although the compound does inactivate 2C11 in liver microsomes from Fischer 344 rats. These results suggest that CAP alters P450 expression in a manner distinct from previously described compounds.

Induction of P4502E1 by acetone in isolated rabbit hepatocytes. Role of increased protein and mRNA synthesis

The molecular mechanism(s) underlying induction of the hepatic microsomal cytochrome P4502E1 (2E1) by xenobiotics (e.g. ethanol and acetone) is controversial. Proposed mechanisms include increased rates of enzyme synthesis due to elevated 2E1 mRNA levels, enhanced translation of pre-existing mRNA, or stabilization of 2E1 protein. To further assess which, if any, of these events predominates during the initial stages of 2E1 protein induction, we investigated the effects of acetone treatment on 2E1 content in cultured rabbit hepatocytes, an in vitro system that allows for precise control of the cellular mileau. Hepatocytes harvested from female rabbits and plated on plastic dishes with serum-supplemented medium were 90-100% viable for at least 48 hr in culture. Analysis of immunoreactive 2E1 content and aniline hydroxylase activity in microsomes isolated from hepatocytes cultured for up to 24 hr revealed that 2E1 expression was equal to that of microsomes from unplated cells and by 48 hr of culture, 2E1 levels decreased by only 35%. Moreover, microsomes isolated from cells exposed to 17 mM acetone for 24 hr exhibited a 53 and 62% increase in aniline hydroxylase activity and 2E1 content, respectively, compared to untreated cells. To explain these increases, the rate of 2E1 protein synthesis was determined in untreated cells or in cells treated with 17 mM acetone by first exposing hepatocytes to medium supplemented with 35S-labeled methionine and cysteine ([35S]Met/Cys) and subsequently assessing radiolabel incorporation into 2E1 protein. While no difference was found between untreated and acetone-treated cells in the incorporation of [35S]Met/Cys into trichloracetic acid-precipitable microsomal proteins, immunoaffinity purification of 2E1 revealed that incorporation of 35S-labeled amino acids specifically into 2E1 was elevated by acetone to 200% of control values. Treatment of hepatocytes with the transcriptional inhibitor, alpha-amanitin, markedly inhibited this acetone-mediated increase in [35S]Met/Cys incorporation into 2E1. Analysis of hepatocyte RNA revealed that acetone increased 2E1 mRNA to 130 and 160% of control levels at 6 and 24 hr, respectively, and that these increases were prevented by pretreatment with alpha-amanitin. Our results indicate that acetone increases 2E1 protein levels in cultured rabbit hepatocytes by stimulating its rate of de novo synthesis. Since this increase in 2E1 synthesis stems, at least in part, from the acetone-mediated enhancement of hepatocyte 2E1 mRNA content and is inhibitable by alpha-amanitin, transcriptional activation of the rabbit CYP2E1 gene is apparently involved in the induction of 2E1 protein by acetone.

Bioactivation of halogenated hydrocarbons by cytochrome P4502E1

Numerous halogenated hydrocarbons of the alkane, alkene, and alkyne classes are metabolized by P450 enzymes to products that elicit cytotoxic and/or carcinogenic effects. Such halogenated hydrocarbons include anesthetics (e.g., halothane and enflurane) and industrial solvents (e.g., carbon tetrachloride, chloroform, and vinylidine chloride). Formation of reaction intermediates from these compounds occurs via P450-promoted dehalogenation, reduction, or reductive oxygenation, with certain hydrocarbons undergoing all three reaction types. Of the multiple forms of P450 present in liver microsomes, P4502E1 has been identified as the primary catalyst of hydrocarbon bioactivation in animals and, most likely, in humans as well. As hepatic concentrations of this P450 enzyme are highly inducible by ethanol and similar agents, prior exposure to 2E1-inducing compounds can play a pivotal role in halogenated hydrocarbon toxicity. Considering that metabolism governs the cytotoxicity and carcinogenicity of halogenated hydrocarbons, an understanding of the mechanism(s) underlying 2E1 induction in man becomes all the more important.

Supplemental growth hormone alters body composition, muscle protein metabolism and serum lipids in fit adults: characterization of dose-dependent and response-recovery effects

Using double-blind, placebo-controlled procedures, the effects of low and high therapeutic dosages of methionyl-human growth hormone (met-hGH) on body composition, muscle protein metabolism and serum lipids were studied in 7 fit adults without growth hormone (GH) deficiency. Dose-dependent changes in body composition were observed that in part appeared to be influenced by a response-recovery effect, as measured by responses factored according to the duration of washout between exposure to the low and high dosages of met-hGH (6 weeks vs. 12 weeks vs. 18 weeks). Increases in fat-free weight were accompanied by an increase in skeletal muscle protein metabolism. Basal levels of cholesterol were inversely related to peak levels of GH in response to exercise stimulation and IGF-I, while GH supplementation lowered levels of total cholesterol and high- and low-density lipoproteins. A dose-dependent effect occurred for total cholesterol, and the percent change in cholesterol was related to the percent change in insulin-like growth factor I (IGF-I). Endogenous levels of GH were attenuated in response to stimulation and IGF-I levels were increased after treatment with GH, but no dose-dependent changes were observed. We conclude that met-hGH alters body composition and muscle protein metabolism, and decreases stored and circulating lipids in fit adults with a pre-existing supranormal body composition. The physiological profile of the person was not as important as the treatment conditions in determining the somatic and physiological response outcomes.

Induction of cytochrome P450IIE1 in the obese overfed rat

Cytochrome P450IIE1 (IIE1) is a microsomal xenobiotic-activating enzyme that is inducible not only by various chemical agents but also by fasting and diabetes. Using a rat model that mimics human obesity, we have found that hepatic IIE1 levels are also increased by this common clinical disorder. Liver microsomes from rats made obese by feeding with an energy-dense diet displayed elevated aggregate P450 content (+28%) and enhanced catalytic activities associated with IIE1, including low-Km N-nitrosodimethylamine demethylation (+66%), aniline hydroxylation (+52%), p-nitrophenol hydroxylation (+170%), and acetaminophen-cysteine conjugate formation (+28%). In contrast, obesity had no significant effect on cytochrome b5 content, P450 reductase activity, benzphetamine demethylation, or erythromycin demethylation, with the latter two reactions being linked with rat IIC11 and IIIA1, respectively. The enhancement of IIE1-dependent drug-metabolizing activities noted in liver microsomes from obese rats was paralleled by a similar increase (111%) in hepatic IIE1 protein content in these animals, as assessed on immunoblots developed with anti-hamster IIE1 IgG. Anti-IIE1-inhibitable rates of microsomal p-nitrophenol metabolism, a reaction highly correlated with IIE1 content (r = 0.88, p less than 0.01), were over 3-fold higher in obese rats than in nonobese controls, providing additional evidence for the obesity-related increase of hepatic IIE1. The induction of IIE1 by the pathophysiological condition of obesity may provide a biochemical basis for the increased incidence of occult liver disease and certain cancers noted in obese individuals.

Supplemental growth hormone increases the tumor cytotoxic activity of natural killer cells in healthy adults with normal growth hormone secretion

Using double-blind, placebo-controlled procedures, the effects of methionyl-human growth hormone (met-hGH) on the tumor cytotoxic activity of natural killer (NK) cells were studied in seven healthy adults using a repeated measures experiment. Subjects were assigned at random to either a placebo (bacteriostatic water) treatment condition or a met-hGH (16.0 mg/wk of Protropin) treatment condition, then crossed-over to the alternative treatment. Treatments were delivered on alternate days (3 d/wk) for 6 weeks. Without bias from the met-hGH treatment, there was no evidence for GH hyposecretion as measured by the peak circulating GH response to exercise stimulation (14.1 +/- 3.1 ng/mL) or insulin-like growth factor (IGF-I) levels (0.82 +/- 0.09 U/mL). When compared with placebo, met-hGH induced a significant overall increase in the percent specific lysis (%SL) of K562 tumor target cells (placebo 22.2 +/- 1.7 v met-hGH 28.5 +/- 2.1 %SL; P = .008). NK activity was increased within the first week of treatment and this level was maintained throughout the remaining period of supplementation. There was a trend (P = .057) for the met-hGH-induced percent change in NK activity (NK%) to be inversely related to placebo IGF-I levels (r = -.761), while there were significant positive correlations between NK% and the met-hGH-induced percent changes in IGF-I (r = .727; P = .035), the fat-free mass (FFM)/fat mass (FM) ratio derived by hydrodensitometry (r = .792; P = .012), and the endogenous GH response to exercise (r = .469; P = .034).(ABSTRACT TRUNCATED AT 250 WORDS)

Exogenous growth hormone treatment alters body composition and increases natural killer cell activity in women with impaired endogenous growth hormone secretion

In order to assess the potential relationship between human growth hormone (GH) and body composition (BC) and natural immunity (NI), we measured the effects of exogenous GH on fat weight (FW), fat-free weight (FFW), and the cytotoxic activity of natural killer (NK) cells in women with impaired GH secretion. Mean peak serum concentrations of GH in response to L-dopa/arginine stimulation were 6.2 +/- 1.1 (SEM) ng/mL in 6 untreated subjects (US) and 5.4 +/- 1.5 ng/mL in 6 GH-treated subjects (TS). Moreover, the pretreatment circulating levels of IGF-I were low in both groups (US 684 +/- 121 mU/mL and TS 583 +/- 83 mU/mL), and they correlated with pretest levels of NK cell activity (r = .59, P less than .05) when both groups were combined. The TS were given 700 micrograms of human GH IM for an average of 14 days while the US were studied in parallel without GH treatment. As measured by hydrodensitometry or skinfold anthropometry, FW decreased (26.1 +/- 6.8 kg to 23.8 +/- 6.3 kg, P less than .05) and FFW increased (44.9 +/- 3.3 kg to 46.2 +/- 3.8 kg, P less than .05) in the TS. In the US, there were no significant (P less than .05) changes in either FW or FFW. Using a standard 51Cr release assay to measure the specific lytic (SL) activity of NK cells, mean SL activity increased from 24.4 +/- 7.0% to 44.1 +/- 8.9% (P less than .05) in the TS, whereas levels in the US were not altered significantly (P less than .05).(ABSTRACT TRUNCATED AT 250 WORDS)

Site of inhibitory action of CRE 9-41 on ACTH release from isolated rat pituitary cells

The corticotropin-releasing factor (CRF) analog CRF 9-41 inhibits CRF, but not forskolin or dibutyryl cyclic AMP, stimulated release of ACTH from isolated pituitary cells. CRF 9-41 also blocks CRF-stimulated accumulation of cyclic AMP in a parallel dose dependent fashion. CRF 9-41 has no effect on basal ACTH release or cAMP levels. This substantiates that the analog acts as a direct CRF antagonist and that the site of this inhibition is most likely at the level of binding of CRF to its receptor on the corticotrope. Various substances, including most prominently glucocorticoids, inhibit release of ACTH from the pituitary. In an effort to develop another class of inhibitors, Rivier et al recently synthesized analogs of corticotropin releasing factor (CRF). One among these, alpha-helical ovine CRF 9-41 blunts adrenalectomy and stress induced ACTH release in non-anesthetized rats. At micromolar concentrations, CRF 9-41, shifts rightward the dose response of isolated pituitary cells to ovine CRF. Thus, the authors suggested that CRF 9-41 acts as a competitive antagonist to CRF-induced ACTH secretion. CRF appears to act through stimulation of adenylate cyclase. To determine the potential site of action of CRF 9-41 in the activation sequence for adenylate cyclase, we studied its effects on pituitary cyclic AMP formation and ACTH secretion from dispersed anterior pituitary cells derived from normal adult rats, as well as, its interaction with cyclic nucleotide agonists.

Noninvasive vascular studies in management of rattlesnake envenomations to extremities

Twenty-five consecutive patients suffering rattlesnake envenomation to an extremity underwent noninvasive vascular arterial studies using contralateral extremities as controls. All but one received antivenin, and none underwent early surgical decompression. Pulse volume amplitudes in the envenomated extremities, reflecting pulsatile arterial blood flow, were increased in 24 of 25 patients (P less than .02) in spite of edema and discoloration. Ischemia requiring surgical procedures developed in three of seven patients with decreased skin temperatures, as compared to none of 18 with increased or mixed skin temperatures on the envenomated extremity (P less than .02). One of 24 survivors suffered a functional deficit. Most victims of rattlesnake bites have increased arterial pulsatile blood flow in an envenomated extremity and do well with medical therapy. Noninvasive arterial studies help select those who are more likely to require special surgical intervention.