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Biomedical subjects

B Levine

Publications and source records attributed to B Levine.

At least 55 records · Page 3Linked to original sources
PubMed2000

Assessment of strategic self-regulation in traumatic brain injury: its relationship to injury severity and psychosocial outcome.

Standard neuropsychological tests administered in a constrained and artificial laboratory environment are often insensitive to the real-life deficits faced by patients with traumatic brain injury (TBI). The Revised Strategy Application Test (R-SAT) creates an unstructured environment in the laboratory in which environmental cues and internal habits oppose the most efficient strategy, thus mimicking the real-life situations that are problematic for patients with TBI. In this study, R-SAT performance was related both to severity of TBI (i.e., depth of coma) sustained 2-3 years earlier and to quality of life outcome as assessed by the Sickness Impact Profile. This relationship held after accounting for variance attributable to TBI-related slowing and inattention. These findings support the validity of the R-SAT and suggest that behavioral correlates of quality of life outcome in TBI can be assessed in the laboratory with unstructured tasks.

Acute Disease↗
PubMed2000

Lamotrigine distribution in two postmortem cases.

Lamotrigine (Lamictal) is a new anticonvulsant drug recently approved for use in the United States. Although a therapeutic range for lamotrigine has not been definitively established, a range of between 2 and 14 mg/L has been reported. Two cases are presented in which lamotrigine was identified in cases investigated by the Office of the Chief Medical Examiner, State of Maryland. Lamotrigine was identified by gas chromatography-nitrogen-phosphorus detection following an alkaline extraction. A DB-5 column provided analytical separation; no derivatization was required. Confirmation was achieved by full scan electron ionization gas chromatography-mass spectrometry. In Case 1, primidone (11 mg/L) and phenobarbital (5.5 mg/L) were found in the heart blood in addition to lamotrigine (8.3 mg/L); in Case 2, no drugs other than lamotrigine (52 mg/L) were detected in the heart blood. The peripheral blood concentration in Case 2 was 54 mg/L. The liver lamotrigine concentrations in the two cases were 41 and 220 mg/kg. The medical examiner ruled that the cause of death in Case 1 was seizure disorder and the manner of death was natural. In Case 2, the medical examiner ruled that the cause of death was lamotrigine intoxication and the manner of death was undetermined.

Adult↗
PubMed2000

An unusual drug death involving maggots.

Toxicologic analysis of decomposed specimens provides greater analytical challenges than those encountered with fresh postmortem specimens. Despite the difficulties involved, in cases in which the cause of death is not determined at autopsy or when there is a strong indication of drug intoxication, all reasonable steps must be undertaken to perform as comprehensive a drug screen as possible. An unidentified white male was found in a field near a river. The body was decomposed and skeletonized, and 3- to 4-mm maggots were present on the body. Near the body was an empty bottle of secobarbital that had been prescribed to a female. There was no evidence of injury. Calf muscle and maggots were sent for toxicologic analysis. No volatile substances or drugs were detected in the calf muscle. Because intoxication due to secobarbital was strongly suggested from the scene investigation, the only other specimen available, the maggots, were tested for acid-neutral drugs. Secobarbital was identified by retention time and was confirmed by full-scan electron ionization gas chromatography/mass spectrometry. Based on the available information, the medical examiner ruled that the cause of death was secobarbital intoxication and the manner of death was suicide.

Autopsy↗
PubMed2000

Confabulation and multiple sclerosis: a rare association.

BACKGROUND: Fantastic confabulation in the context of Multiple Sclerosis (MS) has not previously been reported in the literature. The association is of interest because clearly demonstrable brain pathology in MS together with other cognitive and behavioural correlates may further our understanding of the neural basis underlying confabulation. METHODS: A single case report with magnetic resonance imaging of the brain and detailed neuropsychological evaluation. RESULTS: Confabulation occurred together with disinhibited and stimulus bound behaviour. While the patient's physical and emotional state limited the range of psychometric tests administered, the results revealed an inability to maintain focused, regulated information processing. Although memory difficulties were present, they were not in the nature of a severe amnesic disorder. The patient appeared to have a broad fund of knowledge, but the associations binding the information together and putting it into context were loose. All three features of a triad of responses previously described in confabulating patients were present, namely an inability to withhold answers, to monitor one's own responses and provide verbal self corrections. MRI of the brain showed bilateral periventricular lesions and discrete frontal lesions with 53% of the total lesion volume distributed in frontal areas. Cortical atrophy, most marked in frontal regions also was conspicuous. CONCLUSIONS: Confabulation linked to frontal lobe involvement may occur as part of the changes in mentation found in MS. It is, however, rare and although associated with impaired memory, may be found in the absence of a severe amnesic disorder. This conclusion is discussed in the light of observations from the literature suggesting that frontal involvement is a prerequisite before fantastic confabulation occurs.

Brain↗
PubMed2000

Fatal methadone poisoning in children: Maryland 1992-1996.

The prevention of accidental poisoning by prescribed an over-the-counter medication has been successfully addressed by the use of child-resistant containers. Nevertheless. accidental methadone poisoning in children remains a problem. The Office of the Chief Medical Examiner for the State of Maryland has investigated four deaths in children due to methadone poisoning over a 4-year period. Three of the cases occurred within a 3-month period. Two victims accidentally ingested methadone within 3 days of each other. The authors address the continuing danger of methadone poisoning to children and identify factors contributing to this problem.

Accidents, Home↗
PubMed2000

Status of alcohol absorption in drinking drivers killed in traffic accidents.

One issue which constantly confronts the forensic toxicologist in drinking driver cases is the relationship between the breath or blood alcohol concentration (AC) of the driver at the time of an event such as a traffic stop or an accident and the AC measured at a time subsequent to the event. In theory, the AC can be rising, on a plateau or declining at the time of the event. Several studies have indicated that the overwhelming majority of drinking drivers are on a plateau or are post-absorptive at the time of the event. In this study, driver fatality cases investigated by the Office of the Chief Medical Examiner, State of Maryland during a three-year period were reviewed. Included in this study were cases positive for alcohol in the blood at a cutoff of 0.01 g/dL and death occurring within 15 min of the accident. In fact, many of these deaths were instantaneous or near instantaneous based on the injuries documented by the medical examiner at autopsy. The blood and urine were analyzed for alcohol by head-space gas chromatography and urine AC to blood AC ratios were calculated. A total of 129 cases were included in this study. Eleven of the 129 cases (8.5%) had urine to blood AC ratio less than 1.0. It is likely that these individuals were in the absorptive phase at the time that the accident occurred. Thirty-two cases had a urine to blood AC ratio between 1.0 and 1.2 inclusive. In these cases, the subject could be viewed as in the plateau phase of the blood AC versus time curve. The remaining 86 cases had a urine to blood AC ratio greater than 1.2. This suggests that these individuals were in the post-absorptive state at the time of the accident. The information acquired from this study provides additional evidence to support the notion that the vast majority of individuals are not in the absorptive phase at the time of a traffic stop or an accident.

Absorption↗
PubMed1999

Induction of autophagy and inhibition of tumorigenesis by beclin 1.

The process of autophagy, or bulk degradation of cellular proteins through an autophagosomic-lysosomal pathway, is important in normal growth control and may be defective in tumour cells. However, little is known about the genetic mediators of autophagy in mammalian cells or their role in tumour development. The mammalian gene encoding Beclin 1, a novel Bcl-2-interacting, coiled-coil protein, has structural similarity to the yeast autophagy gene, apg6/vps30, and is mono-allelically deleted in 40-75% of sporadic human breast cancers and ovarian cancers. Here we show, using gene-transfer techniques, that beclin 1 promotes autophagy in autophagy-defective yeast with a targeted disruption of agp6/vps30, and in human MCF7 breast carcinoma cells. The autophagy-promoting activity of beclin 1 in MCF7 cells is associated with inhibition of MCF7 cellular proliferation, in vitro clonigenicity and tumorigenesis in nude mice. Furthermore, endogenous Beclin 1 protein expression is frequently low in human breast epithelial carcinoma cell lines and tissue, but is expressed ubiquitously at high levels in normal breast epithelia. Thus, beclin 1 is a mammalian autophagy gene that can inhibit tumorigenesis and is expressed at decreased levels in human breast carcinoma. These findings suggest that decreased expression of autophagy proteins may contribute to the development or progression of breast and other human malignancies.

Animals↗
PubMed1999

Screening postmortem blood and tissues for nine classes [correction of cases] of drugs of abuse using automated microplate immunoassay.

A commercially available enzyme-linked immunosorbant assay (ELISA) was evaluated as a screening procedure for the detection of nine classes of abused drugs in postmortem blood and tissue specimens. Specifically, postmortem blood, fluid and/or tissue homogenates were screened for amphetamine (AMP), methamphetamine (MET), barbiturates (BARB), benzodiazepines (BZD), cannabinoids (CNB), cocaine (benzoylecgonine; BE), morphine-specific (MOR), opiates (class; OPI), phencyclidine (PCP) and lysergic acid diethylamide (LSD) by ELISA and by coated tube radioimmunoassay (CTR) (BARB, BE, OPI, PCP, LSD) or double-antibody radioimmunoassay (DAR) (AMP/METH, BZD, CNB). Specimens that screened 'positive' by any method were confirmed and quantitated by gas chromatography/mass spectrometry (GC/MS). The only assay that appeared to perform less optimally than RIA was the MOR assay (five false negatives). However, this assay is very specific for free morphine while the GC/MS confirmation method provided a total morphine value. The OPI assay was more sensitive, producing fewer false negatives, and is recommended for broad class opiate screening. EIA is an adequate alternative to RIA for screening postmortem specimens, including blood and tissue, for nine major classes of drugs.

Amphetamine↗
PubMed1999

Cloning and genomic organization of beclin 1, a candidate tumor suppressor gene on chromosome 17q21.

The beclin 1 (BECN1) gene encodes a 60-kDa coiled-coil protein that interacts with the prototypic apoptosis inhibitor Bcl-2. Previous studies indicate that beclin 1 maps to a region approximately 150 kb centromeric to BRCA1 on chromosome 17q21 that is commonly deleted in breast, ovarian, and prostate cancer. The complete cDNA sequence of beclin 1 encodes a 2098-bp transcript, with a 120-bp 5' UTR, 1353-bp coding region, and 625-bp 3' UTR. Hybridization screening of a human genomic PAC library identified PAC 452O8, which contains the complete beclin 1 gene. Determination of the exon-intron structure of beclin 1 reveals 12 exons, ranging from 61 to 794 bp, which extend over 12 kb of the human genome. FISH analysis of human breast carcinoma cell lines using PAC 452O8 as probe identified allelic beclin 1 deletions in 9 of 22 cell lines. Sequencing of genomic DNA from 10 of these cell lines revealed no mutations in coding regions or splice junctions. Additionally, Northern blot analysis of 11 cell lines did not identify any abnormalities in beclin 1 transcripts. These results indicate that human breast carcinoma cell lines frequently contain allelic deletions of beclin 1, but not beclin 1 coding mutations.

Alleles↗
PubMed1999

The interpretation of cocaine and benzoylecgonine concentrations in postmortem cases.

This study examined cocaine and benzoylecgonine concentrations in 100 consecutive deaths where either compound was identified in blood or urine specimens to determine whether any relationship between these concentrations and cause of death can be found. Forty-seven of the 100 cases were deaths attributed to cocaine, narcotic or combined cocaine and narcotic intoxication. There were 13 cases of cocaine intoxication where no psychoactive substance other than ethanol was detected. The mean cocaine concentration in these deaths was 908 ng/ml; three cases had cocaine concentrations greater than 2000 ng/ml, while the other ten cases had cocaine concentrations less than or equal to 700 ng/ml. The mean cocaine concentration in non-cocaine deaths where no psychoactive substance other than ethanol was detected was 146 ng/ml. This difference was not statistically significant. However, the average blood benzoylecgonine concentration in the 13 cocaine deaths was significantly higher than in the 19 non-cocaine deaths. A review of combined cocaine and narcotic deaths suggest that the narcotic is the main causative agent in these deaths.

Adolescent↗
PubMed1999

Anti-CD3/anti-CD28 monoclonal antibody-coated suture enhances the immune response of patients with head and neck squamous cell carcinoma.

OBJECTIVE: To test whether anti-CD3/anti-CD28 (alphaCD3/alphaCD28) monoclonal antibodies could be coated on surgical suture and used to enhance T-cell immune function in patients with advanced-stage head and neck squamous cell carcinoma (HNSCC). DESIGN: AlphaCD3/alphaCD28 monoclonal antibodies at varying concentrations and ratios were coated on surgical sutures and tested on peripheral blood mononuclear cells from normal donors to identify the optimal stimulating condition. Immune-enhancing properties of alphaCD3/alphaCD28 monoclonal antibody suture were tested on peripheral blood mononuclear cells and regional lymph node mononuclear cells isolated from patients with advanced HNSCC and on normal donor peripheral blood mononuclear cells. Proliferation, T-cell phenotype, and cytokines were measured during 8-day in vitro stimulation with alphaCD3/alphaCD28 suture and compared with alphaCD3/alphaCD28-coated tissue culture plastic, a previously recognized carrier. RESULTS: Optimal stimulation was observed with monofilament nylon incubated with alphaCD3/alphaCD28, 2 microg/mL, at a 1:1 ratio for 18 hours at 37 degrees C. Strong proliferation of peripheral blood mononuclear cells and lymph node mononuclear cells in patients with HNSCC was induced by alphaCD3/alphaCD28 suture. There was no difference in maximal proliferation between alphaCD3/alphaCD28 plastic and suture. On day 6 after alphaCD3/alphaCD28 suture stimulation, T-cell subpopulations expressing CD3, CD4, CD8, CD28, and CD45RO were enhanced. Suture stimulation significantly enhanced interleukin 2 secretion when compared with plastic stimulation (P = .01). Both alphaCD3/alphaCD28 suture and plastic stimulated interferon gamma secretion. CONCLUSIONS: To our knowledge, this study is the first to report the modification of surgical suture to create an immunomodulant. AlphaCD3/alphaCD28-coated suture expanded T cells from patients with HNSCC and induced a T(H)1 immune response, which may be a useful therapeutic tool in the treatment of HNSCC and other diseases.

Adjuvants, Immunologic↗
PubMed1999

Tissue distribution of mirtazapine (Remeron) in postmortem cases.

Mirtazapine (Remeron) is a member of the relatively new class of tetracyclic antidepressants. There are published cases of mirtazapine's detection as an incidental finding in postmortem cases; however, case reports with associated tissue concentrations and interpretations are not available. This report documents the tissue distribution of mirtazapine in eight postmortem cases in which it was identified but did not contribute to the cause or manner of death. The following mean mirtazapine concentrations (milligrams per liter or milligrams per kilogram) were found: heart blood 0.12 (range, < 0.01-0.33, n = 7); peripheral blood 0.09 (< 0.01-0.14, n = 4); urine 0.61 (0.01-3.2, n = 7); liver 0.88 (0.04-3.6, n = 6), kidney 0.21 (0.02-0.48, n = 5); and bile 0.62 (0.11-1.6, n = 6). In each case, the mirtazapine concentration in heart blood was approximately equal to that of peripheral blood, indicating that postmortem redistribution was not a factor in evaluating postmortem blood concentrations in these cases. However, because the liver mirtazapine concentrations were 5-30 times the blood concentrations, the potential for postmortem redistribution cannot be excluded. Additionally, because urine concentrations of the parent compound were consistently greater than the blood concentrations, urine is an adequate screening specimen for mirtazapine.

Antidepressive Agents, Tricyclic↗
PubMed1999

Tissue distribution of tramadol and metabolites in an overdose fatality.

Tramadol (Ultram) is a centrally acting, synthetic analgesic agent. Although it has some affinity for the opiate receptors, tramadol is believed to exert its analgesic effect by inhibiting the re-uptake of norepinephrine and serotonin. There are several published cases of tramadol's involvement in drug-related deaths and impairment. Reports of deaths involving tramadol alone with associated tissue concentrations are rare. This report documents a case in which tramadol overdose was identified as the cause of death. The following tramadol concentrations were found in various tissues: blood, 20 mg/L; urine, 110.2 mg/L; liver, 68.9 mg/kg; and kidney, 37.5 mg/kg. Tissue distributions of the two primary metabolites, N-desmethyl and O-desmethyl tramadol, are also reported. In each tissue or fluid except urine, the tramadol concentration was greater than either metabolite, consistent with other reports of drug-impaired drivers and postmortem cases. The O-desmethyl metabolite concentration was greater than the N-desmethyl metabolite concentration in all tissues; this is in contrast to other postmortem reports, in which the majority of cases report concentrations of O-desmethyl as less than those of N-desmethyl. This may be useful as an indicator of time lapse between ingestion and death.

Adult↗
PubMed1999

Resistance of interleukin-1beta-deficient mice to fatal Sindbis virus encephalitis.

Interleukin-1beta (IL-1beta) concentrations are frequently elevated in central nervous system (CNS) viral infections, but the pathophysiologic significance of such elevations is not known. To examine the role of IL-1beta in CNS viral pathogenesis, we compared the natural histories of IL-1beta-deficient and wild-type 129 SV(ev) mice infected with a neurovirulent viral strain, neuroadapted Sindbis virus (NSV). We found that the incidence of severe paralysis and death was markedly decreased in NSV-infected IL-1beta-/- mice compared to NSV-infected wild-type mice (4 versus 88%, P < 0.001). Despite this marked difference in clinical outcome, no differences in numbers of apoptotic cells or presence of histopathologic lesions in the brains of moribund wild-type mice and those of clinically healthy IL-1beta-/- mice could be detected. These results suggest that IL-1beta deficiency is protective against fatal Sindbis virus infection by a mechanism that does not involve resistance to CNS virus-induced apoptosis or histopathology.

Alphavirus Infections↗
PubMed1999

Effect of eprosartan and enalapril in the treatment of black hypertensive patients: subgroup analysis of a 26-week, double-blind, multicentre study. Eprosartan Multinational Study Group.

A double-blind comparator study was performed in 528 hypertensive patients [baseline sitting diastolic blood pressure (SitDBP) 95-114 mmHg]. The primary objective was to compare the incidence of drug-related cough in patients treated with enalapril and eprosartan. The secondary objective was to compare antihypertensive efficacy between treatments. This paper reports the results of a prespecified subgroup analysis performed in the 40 black patients recruited into the study. Eprosartan was titrated from 200 mg b.i.d. to 300 mg b.i.d. and enalapril from 5 mg o.d. to 20 mg o.d. over 12 weeks. Hydrochlorothiazide (HCTZ) 12.5-25 mg o.d. could be added where required to the treatment for the final six weeks of the titration phase if SitDBP > or = 90 mmHg. Patients received the maximum titrated dosage during the maintenance phase. In the study overall, the incidence of cough at monotherapy endpoint was significantly higher in the enalapril-treated group than in the eprosartan-treated group (p = 0.018). This trend was reflected in the black subgroup but the numbers were too small to confirm significance. At study endpoint the mean change in SitDBP was -10.5 +/- 1.9 mmHg and -9.6 +/- 2.4 mmHg for eprosartan-treated and enalapril-treated patients, respectively. The mean change in SitSBP for eprosartan-treated black patients was -18.8 +/- 3.5 mmHg and for enalapril-treated patients was -10.5 +/- 3.7 mmHg. The black subpopulation mirrored the response of the study as a whole. Both treatments lowered BP with a further reduction evident following the addition of HCTZ at week 18. In conclusion, eprosartan is effective and appears to be safe in black hypertensive patients. The combination of eprosartan and HCTZ was also well tolerated and provided additional efficacy in those patients not responding to eprosartan alone. The incidence of treatment-associated cough in the black subgroup was low, but there were no apparent differences between treatment groups.

Acrylates↗
PubMed1999

The acute period of recovery from traumatic brain injury: posttraumatic amnesia or posttraumatic confusional state?

OBJECT: The goal of this study was to characterize more fully the cognitive changes that occur during the period of acute recovery after traumatic brain injury (TBI). METHODS: The pattern of performance recovery on attention and memory tests was compared with the results of the Galveston Orientation and Amnesia Test (GOAT). Tests of memory and attention were administered serially to a hospitalized group of patients with TBI of varying severity. The tests differed in their level of complexity and/or requirement for more effortful or strategic processing. The authors found a regular pattern to recovery. As expected, ability to perform on simpler tests was recovered before performance on more effortful ones. The ability to recall three words freely after a 24-hour delay (the operational definition in this study of return to continuous memory) was recovered last, later than normal performance on the GOAT. Ability to perform simple attentional tasks was recovered before the less demanding memory task (recognition); ability to perform more complex attentional tasks was recovered before the free recall of three words after a 24-hour delay. This recovery of attention before memory was most notable and distinct in the group with mild TBI. CONCLUSIONS: The period of recovery after TBI, which is currently termed posttraumatic amnesia, appears to be primarily a confusional state and should be labeled as such. The authors propose a new definition for this acute recovery period and argue that the term posttraumatic confusional state should be used, because it more appropriately and completely characterizes the early period of recovery after TBI.

Adolescent↗
PubMed1999

Zolpidem distribution in postmortem cases.

Zolpidem is the prototype of a class of sedative hypnotic drugs that are derivatives of imidazopyridine and is sold in the United States under the trade name Ambien. Over a four-year period, zolpidem was identified in eight cases investigated by the Office of the Chief Medical Examiner, State of Maryland. Zolpidem was identified by gas chromatography-nitrogen-phosphorus detection (GC-NPD) following an alkaline extraction and was confirmed by full-scan electron impact gas chromatography/mass spectrometry. Zolpidem was quantitated by GC-NPD in all specimens received. Five of the cases presented were deaths due to drug intoxication. In three of these cases, zolpidem was an incidental finding because the drug fatalities resulted from other drugs. In the other two cases of drug intoxication, zolpidem was present in elevated concentrations and was a contributing, but not exclusive cause of the drug intoxication. The remaining three cases were deaths that were not caused by drugs. The blood zolpidem concentrations in these cases were therapeutic (0.28, 0.12 and 0.19 mg/L, respectively). In six of the eight cases where both blood and urine were analyzed, the blood concentration was higher than the urine concentration. The distribution of zolpidem into the liver and kidney failed to identify any sequestration of the drug into either specimen.

Chromatography, Gas↗