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Biomedical subjects

D J Levine

Publications and source records attributed to D J Levine.

17 recordsLinked to original sources
PubMed2001

Usefulness of combining necrosis and platelet markers in triaging patients presenting with chest pain to the emergency department.

BACKGROUND: Myocardial injury and platelet activation play important roles in the pathogenesis of unstable coronary syndromes. We sought to determine whether the combined measurement of platelet and necrosis markers would improve risk stratification, and yield higher diagnostic utility in patients presenting to the emergency department with chest pain. METHODS AND RESULTS: Platelet and soluble P-selectin together with myoglobin, creatine kinase, CK-MB fraction, and troponin I were measured from the autologous samples in 122 consecutive patients. Statistical analysis revealed strong Spearman correlation coefficients (0.141--0.412; p<0.001) between platelet expression of P-selectin and plasma levels of necrosis markers. Platelet P-selectin and necrosis markers were independent predictors (c-index>0.7) for acute myocardial infarction, while plasma P-selectin exhibited random distribution. Elevated soluble P-selectin and myoglobin were the most valuable in identifying patients with congestive heart failure. None of the markers were useful for triaging chest pain patients with unstable angina. Analysis of incremental gains (Chi-squares) reveals that with respect to platelet P-selectin, myoglobin adds 50 % to AMI diagnostic value, and creatine kinase yields an additional 20 % in triaging these patients. The diagnostic value of soluble P-selectin is substantially (72 %) increased by myoglobin measurements, and enhanced even further (44 %) by adding cardiac troponin I for identifying heart failure patients among the chest pain population. CONCLUSION: Simultaneous determination of platelet and necrosis markers improve the early diagnosis of acute myocardial infarction and congestive heart failure among patients with chest pain presenting into the Emergency Department. Well controlled clinical trials are needed to prove the advantage of combining platelet and necrosis data over presently used techniques in emergency medicine.

Adult↗
PubMed2000

Moderate alcohol consumption is associated with decreased platelet activity in patients presenting with acute myocardial infarction.

Moderate alcohol consumption (MAC) and platelet inhibition have been independently associated with a reduced risk for the development of acute myocardial infarction (AMI). The effects of MAC on the initial platelet status in patients presenting with AMI are not elucidated. Here we sought to define the effects of MAC on platelet characteristics in AMI patients before applying any reperfusion strategies. The study was designed as an analysis within the cohort study in 23 patients with AMI enrolled in the GUSTO-III. Platelets were investigated by different techniques, including aggregometry, flow cytometry, and ELISA. MAC patients exhibited mild, but consistent, inhibition of platelet aggregability, surface receptor expression, and released substances as compared to non-alcohol consuming patients. These differences were significant for 5 microM ADP (p = 0.04), 10 microM ADP-induced aggregation (p = 0.02); P-selectin (p = 0.01), and PECAM-1 (p = 0.02) platelet-bound expression. Our study confirms that moderate alcohol consumption is associated with diminished platelet activation in patients presenting with AMI. The ability of MAC to favorably modulate the pre-reperfusion platelet status in such patients is of clinical importance, and further investigation in large-scale clinical trials seem warranted.

Aged↗
PubMed1999

Clinical utility of available methods for determining platelet function.

Determination of platelet function has become increasingly important as new antiplatelet drugs are being developed. Objective means to monitor the pharmacological effects of these agents, in order to maximize efficacy and minimize toxicity, is needed. The available methods for determination of platelet function at the current time are reviewed, including platelet aggregometry, the PFA-100, flow cytometry, platelet contractile force, the rapid platelet function assay, the clot signature analyzer, Sonoclot, and thromboelastography. The principle, advantages, disadvantages, and clinical utility of each method is presented. The uses of the various methods of determining platelet function reported in the literature are summarized, in an effort to provide information regarding the applicability of those different methods.

Humans↗
PubMed1996

The classic intrafascial Semm hysterectomy as an alternative to abdominal hysterectomy.

STUDY OBJECTIVE: To compare the classic intrafascial Semm hysterectomy (CISH) with abdominal hysterectomy. DESIGN: Retrospective analysis. SETTING: Community hospital. PATIENTS: The first 100 women with intractable uterine bleeding, leiomyomata, and chronic pelvic pain. INTERVENTIONS: The CISH procedure, initially with the Endo GIA stapler, but later, electrocoagulation and suture to lower costs and eliminate automatic staple complications. MEASUREMENTS AND MAIN RESULTS: Operating time for CISH decreased and our ability to remove larger uteri increased as we became more proficient. Complications were limited to one cystotomy and four transfusions. The average hospital stay was 36 hours and most patients were back to normal activity in 3 weeks. CONCLUSION: Our experience suggests that the CISH is organ preserving, is minimally invasive, decreases recovery time, and can be performed in women in whom an open abdominal approach once would have been the only option.

Adult↗
PubMed1992

Human studies with the chelating agents, DMPS and DMSA.

Meso-2,3-dimercaptosuccinic acid (DMSA) is bound to plasma albumin in humans and appears to be excreted in the urine as the DMSA-cysteine mixed disulfide. The pharmacokinetics of DMSA have been determined after its administration to humans po. For the blood, the tmax and t1/2 were 3.0 h + 0.45 SE and 3.2 h + 0.56 SE, respectively. The Cmax was 26.2 microM + 4.7 SE. To determine whether dental amalgams influence the human body burden of mercury, we gave volunteers the sodium salt of 2,3-dimercaptopropane-1-sulfonic acid (DMPS). The diameters of dental amalgams of the subjects were determined to obtain the amalgam score. Administration of 300 mg DMPS by mouth increased the mean urinary mercury excretion of subjects over a 9 h period. There was a positive correlation between the amount of mercury excreted and the amalgam score. DMPS might be useful for increasing the urinary excretion of mercury and thus increasing the significance and reliability of this measure of mercury exposure. DMSA analogs have been designed and synthesized in attempts to increase the uptake by cell membranes of the DMSA prototype chelating agents. The i.v. administration of the monomethyl ester of DMSA, the dimethyl ester of DMSA or the zinc chelate of dimethyl DMSA increases the biliary excretion of platinum and cadmium in rats.

Adult↗
PubMed1985

The decision to discontinue hemodialysis.

The patient who wishes to discontinue chronic hemodialysis poses a complex dilemma that crosses both ethical and psychiatric boundaries, but clearly demonstrates the role of the liaison psychiatrist in clarifying issues of diagnosis and informed consent. This paper presents an edited transcript of a clinical case conference where a 72-year-old man reviews his reasons for demanding that hemodialysis be discontinued. Issues of differential diagnosis and the question of autonomy and free will are discussed in the context of the tasks for the liaison psychiatrist.

Aged↗
PubMed1985

Psychiatric aspects of cigarette smoking.

Smoking has been viewed in divergent ways throughout history. While for some cultures it has been considered a crime, for others it has been invested with magical powers and even medicinal potential. In our century, society has come to realize the health risks associated with smoking. This has led to controversies between government and the tobacco industry as well as between physician and patient. In spite of their knowledge of its deadly consequences, many individuals are unable to stop smoking. The tenacity of this habit can be explained in terms of the various psychological motivations for smoking in combination with the physiologic addiction to nicotine. While some people are able to stop the habit, many relapse in spite of a variety of quitting methods. These range from the doctor's advice to stop, education programs, group and individual psychotherapies, behavioral techniques, hypnosis, and the use of nicotine gum. With a growing understanding of what distinguishes categories of smokers and with a new appreciation for the role of nicotine in addiction to smoking, more effective antismoking strategies can be fashioned to meet the specific needs of the potential quitter.

Behavior Therapy↗
PubMedDate not supplied

Synthesis and properties of the monomethyl ester of meso-dimercaptosuccinic acid and its chelates of lead (II), cadmium(II), and mercury(II).

The monomethyl ester of meso-dimercaptosuccinic acid (MoMeDMSA) and its chelates with lead(II), cadmium(II), and mercury(II) have been synthesized. The mercury(II) chelate of MoMeDMSA is formed by the coordination of the two sulfur atoms in MoMeDMSA, whereas the lead(II) and cadmium(II) chelates are formed by the coordination of one sulfur and one oxygen atom. The solubilities of the chelates are pH dependent; the mercury(II) chelate dissolves when the uncoordinated carboxylic acid dissociates, but the lead(II) and cadmium(II) chelates are solubilized only after the uncoordinated mercapto group is dissociated. The cadmium(II) chelate is dimeric and the lead(II) and mercury(II) chelates are monomeric at the concentrations and conditions used in this study. The acid dissociation constants of the chelating agent and the uncoordinated groups in its metal chelates have been determined in 50% v/v methanol-water. These acid-base properties in addition to the polarity of the chelating agent contribute to the effectiveness in the in vivo mobilization of intracellular in vivo deposits of cadmium. The biliary excretion of cadmium in rats increased by a factor of 173 upon administration of the relatively toxic, nonpolar dimethyl ester of DMSA whereas the administration of the less toxic, more polar monomethyl ester increased the biliary excretion of cadmium by a factor of 63. On the other hand, meso-DMSA which is highly polar and less toxic is known to be without effect on biliary excretion of cadmium. The monomethyl DMSA, therefore, appears to have properties that are intermediate between those of DMSA and its dimethyl ester, as far as both chelating properties and biliary excretion of cadmium are concerned.

Animals↗
PubMedDate not supplied

Determination and metabolism of dithiol chelating agents: the zinc chelate of the dimethyl ester of meso-2,3-dimercaptosuccinic acid increase biliary excretion of cadmium and platinum.

meso-2,3-Dimercaptosuccinic acid is an orally active chelating agent useful for the treatment of lead intoxication. Since it is believed to be extracellular in its distribution, analogs have been synthesized in a search for one that will enter the cell and successfully complete for firmly bound intracellular toxic heavy metals such as cadmium and platinum. The biological properties of the zinc chelate of DiMeDMSA, ([Zn(DiMeDMSA)2]2- with tetramethylammonium or sodium as the counterion, have been investigated in the rat. In short-term (hourly) experiments, [Zn(DiMeDMSA)2]2- increased the biliary excretion of cadmium and platinum. In experiments of longer duration (days), severe renal toxicity was noted even in the absence of any exogenously administered cadmium chloride or cis-dichlorodiammineplatinum(II). The zinc content of the kidneys of rats receiving Na2[Zn(DiMeDMSA)2]2- was found to be about 10-fold greater than rats receiving saline or meso-dimethyldimercaptosuccinic acid. Although it appears that the source of the zinc is the injected [Zn(DiMeDMSA)2]2-, at this time it is unknown as to whether the toxicity is due to the Zn chelate molecule, per se, or Zn derived from the molecule after its degradative biotransformation.

Animals↗