Clandestine, or illegal, laboratories are operated by the criminal element to circumvent legal requirements with the goal of supplying drugs of abuse to the illicit market. Investigation of clandestine drug manufacturing laboratories is a high priority of the U.S. Drug Enforcement Administration (DEA) because elimination of these laboratories will prevent drugs of abuse from reaching the illicit drug traffic. One of the important responsibilities of forensic chemists assisting in investigations of clandestine drug laboratories is to be familiar with the methods of synthesis being used by clandestine laboratory, operators. A review of clandestine laboratory seizures during the period of 1978 through 1981 will be provided to familiarize forensic chemists with current information on the types of laboratories being seized in the United States and the methods of synthesis being used.
The Levine rat preparation, the gerbil stroke model, and appropriate control animals were used to determine if the 2,3,5-triphenyltetrazolium chloride (TTC) would selectively identify noninfarcted versus infarcted cerebral tissue. The TTC is frequently used to quantify infarcted myocardial tissue and has been shown to have great specificity, reproducibility, and efficacy. The TTC produces a red product upon reaction with the respiratory enzymes (dehydrogenases) present in non-infarcted tissues. Irreversibly damaged tissues, lacking dehydrogenases, do not form red reaction products. Six gerbil brains and seven rat brains were incubated with the TTC, and the unreacted areas were macroscopically identified. The brains were fixed and sectioned for routine hematoxylin and eosin staining to determine the specificity of the TTC. The TTC was found to react selectively only with non-infarcted cerebral tissue. The gross brain sections were evaluated by macroscopic morphometric analysis, and the unreacted area was always ipsilateral to ligation and correlated with histologic identification of infarct. The brains from neurologically intact animals demonstrated neither macroscopic nor histological evidence of infarction. This technique allows macroscopic quantification of infarct size by planimetry. The average area of infarct for the neurologically impaired rats was 34.7% and it was 31.4% for the impaired gerbils. The percentage of surface area of each infarcted slice was found to correlate with the severity of the neurologic deficit. We conclude that TTC staining is effective for macroscopically delineating cerebral infarcts in rats and gerbils, thus permitting quantification of infarct size.
Exhibits of illicit drugs in a large number of containers are frequently submitted to crime laboratories. The forensic chemist often needs to select randomly and then examine a number of these containers to provide information regarding the composition of the overall exhibit which is sufficient to support the requirements of the criminal justice system. Although various methods of sampling can be shown to provide samples that will allow statistical inferences to be made with a high degree of confidence, no procedure has been identified that specifically meets the sampling objectives associated with an exhibit of this sort. The authors have addressed this sampling problem by applying the probability theory of the hypergeometric distribution to the sampling of drug exhibits contained in multiple containers. The resulting model will permit strong probability statements to be made regarding the presence of the controlled substance in a predetermined quantity of the exhibit, thereby supporting the prosecution and sentencing of violators of controlled substance laws.
Aortic and renal vascular reconstruction often involve significant renal ischemia. Profound hypothermia during renal ischemia preserves renal tissue. However, in the clinical setting of vascular reconstruction specific attempts at cooling the kidney are often impractical, and renal ischemia frequently occurs at physiologic temperatures. This study demonstrates that minimal temperature changes during renal ischemia alter the functional and morphologic outcome. Rats anesthetized with halothane underwent a right nephrectomy and placement of a snare around the left renal pedicle for 45 minutes to produce renal ischemia. Seventy-five adult male Sprague-Dawley rats, weighing 250 to 350 gm were divided into three groups based on the body temperature maintained during renal ischemia (35 degrees C, 37 degrees C, 39 degrees C). Body temperature was continuously monitored with a rectal thermistor and maintained by adjustment of a heating pad and lamp. Two postischemic protocols were followed including a creatinine assessment protocol with blood samples collected at 24, 48, and 72 hours and a histologic assessment protocol with biopsy of the kidney at 30 hours. At 24 hours after ischemia plasma creatinine concentrations were increased in rats with elevated body temperatures (35 degrees C vs 37 degrees C; [p = 0.001], 37 degrees C vs 39 degrees C; [p = 0.150]). The 30-hour histologic assessment indicated a difference in morphologic outcome (35 degrees C vs 37 degrees C; [p = 0.063], 37 degrees C vs 39 degrees C; [p = 0.016]), with proximal tubular morphology being better maintained at lower temperatures.(ABSTRACT TRUNCATED AT 250 WORDS)
Attempts to minimize ischemic injury by interrupting a given ischemic period might be compromised if repeated bouts of reperfusion injury occurred. To determine whether intermittent ischemia improved or worsened functional and morphologic outcome of renal ischemia, halothane-anesthetized rats underwent a right nephrectomy and placement of a snare about the left renal vascular pedicle at 37 degrees C. Eleven animals underwent 45 minutes of continuous renal ischemia (C-ISC), whereas 10 animals received 45 minutes of vessel occlusion interrupted (I-ISC) at 15 and 30 minutes by snare release and 5 minutes of reperfusion. A group of three sham rats underwent the above procedure but did not have the snare tightened. Blood samples were drawn preoperatively and 24, 48, and 72 hours postoperatively for creatinine analysis. At 72 hours the animals were sacrificed and their kidneys morphologically evaluated. The C-ISC group had a significantly higher mean postoperative plasma creatinine (p < 0.01) as well as significantly higher plasma creatinine levels at 24 (p < 0.005) and 48 hours (p < 0.05) than did the I-ISC group. The C-ISC group also demonstrated significantly greater histologic damage than the I-ISC group (p < 0.002) when assessed by a pathologist blinded to the intervention. Sham rats did not demonstrate functional or morphologic damage. These data demonstrate a significantly improved outcome when 45 minutes of renal ischemia is interrupted by periods of reperfusion. We are led to conclude that in this setting reperfusion injury did not overwhelm the salutary effects of interrupting the 45-minute ischemic event.
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