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Biomedical subjects

E J Thompson

Publications and source records attributed to E J Thompson.

233 records · Page 13Linked to original sources
PubMed1975

Bigeminal ventricular tachycardia with Wenckebach exit block.

A patient is presented in whom repeated attacks of ventricular tachycardia occurred. His last and fatal attack revealed an alternation or coupling of the cycle lengths of the ventricular beats. A large left ventricular wall aneurysm was found, which probably accounted for the unusual arrhythmias.

Aged↗
PubMedDate not supplied

Dobutamine stress echocardiography: a new, noninvasive method for detecting ischemic heart disease.

Pharmacologic induction of exercise with dobutamine hydrochloride, coupled with the technology of echocardiography, is an alternate method for evaluating ischemic heart disease. Dobutamine stress echocardiography involves obtaining echocardiographic images before, during, and after a titrated dobutamine infusion is administered. The study is positive if global or regional ventricular wall motion abnormalities develop. With our changing health care environment, this cost-effective, noninvasive diagnostic procedure is becoming a standard for determining the presence of coronary artery disease in those individuals who are unable or unwilling to undergo exercise stress testing.

Adrenergic beta-Agonists↗
PubMedDate not supplied

Oxidative metabolism of 1-(2-chloroethyl)-3-alkyl-3- (methylcarbamoyl)triazenes: formation of chloroacetaldehyde and relevance to biological activity.

(Methylcarbamoyl)triazenes have been shown to be effective cancer chemotherapeutic agents in a number of biological systems. Because of their chemical stability, it is likely that their activity in vivo is the result of a metabolic activation process. Previous studies have shown that 1-(2-chloroethyl)-3-methyl-3-(methylcarbamoyl)triazene (CMM) and 1-(2-chloroethyl)-3-benzyl-3-(methylcarbamoyl)triazene (CBzM) are metabolized by rat liver microsomes in the presence of NADPH to yield the ((hydroxymethyl)carbamoyl)triazene analogs of the parent compounds. The present studies show that both compounds are also oxidized at the chloroethyl substituent to yield chloroacetaldehyde and a substituted urea. In the case of CBzM metabolism, 47% of the metabolized parent compound was recovered as benzylmethylurea, 8% was recovered as benzylurea, and 26% was recovered as the ((hydroxymethyl)carbamoyl)-triazene and carbamoyltriazene metabolites. These results suggest that the chloroethyl group is the favored initial site of metabolism. In reaction mixtures containing initial concentrations of 300 microM CBzM, 78 microM chloroacetaldehyde was produced, as compared to 58 microM chloroacetaldehyde produced from the metabolism of 300 microM CMM. The formation of chloroacetaldehyde, a known mutagenic DNA alkylating agent, may explain the biological activity of these compounds.

Acetaldehyde↗
PubMedDate not supplied

The growth of malignant keratinocytes depends on signaling through the PGE(2) receptor EP1.

Recent discoveries shed light on the importance of prostaglandin (PG) production in the development of skin cancer. Work by Fischer et al. demonstrates that skin tumor promotion caused by ultraviolet B radiation can be decreased by up to 89% by blocking cyclooxygenase-2 (COX-2) with the drug Celecoxib. A similar study showed that Celecoxib can decrease new tumor formation by 44% in mice that already have tumors. These studies demonstrate the importance of COX-2 and PGs in the development of squamous cell carcinoma. We have explored growth signaling in a model of skin tumor progression. Because changes in PG production have been implicated in skin carcinogenesis, we examined this pathway. We found that malignant cell lines secrete more prostaglandin E(2) (PGE(2)) than the parental cells. We observed increased expression of COX-1 and -2. We also found that these cells express the PGE(2) receptors EP1 and EP4. When the cells are grown in the presence of indomethacin, the growth rate of the malignant cells is decreased. This effect can be reversed by addition of PGE(2) or an EP1 agonist to the medium. Thus, we have shown that skin tumor cells depend in part on PGE(2) signaling through the EP1 prostanoid receptor for their in vitro growth.

Animals↗
PubMedDate not supplied

Radiofrequency catheter ablation for Wolff-Parkinson White syndrome. Part 2: Preventing complications.

To significantly reduce the morbidity, mortality and life long dependence on antiarrhythmic medications, radiofrequency catheter ablation has emerged as the treatment of choice for patients with preexcitation disorders occurring with the Wolff-Parkinson-White (WPW) syndrome. Radiofrequency ablation is usually highly successful (> 95%), with a near zero mortality and low morbidity. This article, the last in a series of two, focuses on preventing complications for patients undergoing this procedure.

Adolescent↗
PubMedDate not supplied

Adenosine thallium imaging: pharmacodynamics and patient monitoring.

Because many critical care patients have cardiac, trauma, or other complications that rule out usual exercise cardiac stress testing, the new use of adenosine for thallium imaging may be used for these patients. Because of its vasodilating properties, adenosine can be combined with thallium imaging to determine the presence of coronary artery disease in persons unable to exercise. This author describes the pharmacodynamics of adenosine, the process of thallium imaging, and the interpretation of the images which help the nurse prepare the patient and prevent complications.

Adenosine↗
PubMedDate not supplied

Ensuring competencies of multidisciplinary staff in patient-focused care.

Faced with rising health care costs and consumer demands, hospitals are finding creative ways to streamline the delivery of patient care. One such approach is patient-focused care (PFC), in which hospitals bring services to the patient's beside and cross-train staff. The success of PFC depends on training and measuring staff competence in the new skills. This article describes how to implement an educational plan based on competencies for a successful transition to PFC.

Clinical Competence↗