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Biomedical subjects

M Kuhn

Publications and source records attributed to M Kuhn.

At least 181 records · Page 10Linked to original sources
PubMed1992

Quality assurance in the emergency department: evaluation of the ECG review process.

STUDY OBJECTIVE: To determine whether the review of emergency department ECGs by cardiologists contributes to the quality of patient care. STUDY DESIGN: We retrospectively analyzed ED ECGs and compared interpretations of the treating emergency physicians with those of the reviewing cardiologists. We then evaluated the ED care of patients with potentially significant ECG abnormalities that were not detected by the treating emergency physicians, as well as the care of patients whose ECGs were "flagged" by the reviewing cardiologists as needing follow-up. SETTING: University hospital. PARTICIPANTS: Four hundred consecutive ECGs obtained on ED patients. MEASUREMENTS AND MAIN RESULTS: Thirty-three of the 400 tracings had undetected potentially significant or critical ECG abnormalities; this adversely affected patient care in two cases. These two tracings were not flagged by the reviewing cardiologists. Thirteen ECGs were flagged by the cardiologists; patient care was not altered in any of these cases. CONCLUSION: Review of ED ECGs by cardiologists did not affect patient care at our institution.

Aged↗
PubMed1992

Endothelin release and shift in prostaglandin balance are involved in the modulation of vascular tone by recombinant erythropoietin.

Hypertension is the main side effect developing in patients suffering from renal anemia who are treated with recombinant human erythropoietin (rhEPO). We investigated the effect of rhEPO on the vascular tone of rabbit aorta. rhEPO had no direct vasoconstrictor effect, but it enhanced norepinephrine (NE)-induced contractions of rabbit aortic rings. Relaxations to acetylcholine (ACh, 1 microM) were unaltered in the presence or absence of rhEPO, indicating that the endothelium-dependent NO pathway was not affected by rhEPO. In rings of human renal artery and rabbit aorta, rhEPO (200 U/ml) increased the synthesis of constrictor prostanoids. The cyclooxygenase inhibitors indomethacin and aspirin abolished the increase in prostanoid production. However, they did not completely suppress the rhEPO-induced enhancement of NE contractions in rabbit aorta. We further investigated the effect of rhEPO on prostanoid and endothelin-1 synthesis in cultured human endothelial cells. Endothelial cells from human umbilical veins (HUVEC) were isolated and cultured. After incubation with rhEPO, the formation of prostaglandin (PG) I2 (analyzed as its stable metabolite 6-keto-PGF1 alpha), PGF2 alpha, PGE2, thromboxane (Tx) B2, and of endothelin-1 (ET-1) was measured by radioimmunoassay (RIA). rhEPO (200 U/ml) increased the formation of PGF2 alpha and TxB2 and decreased the formation of PGI2 in HUVEC. The release of ET-1 was increased by nearly 90% in the presence of rhEPO (200 U/ml). We conclude that a shift in the balance of constrictor and relaxing prostanoids as well as an increased synthesis of ET-1 may contribute to the hypertensive side effect of rhEPO therapy. ET-1 may at least in part be responsible for the unexpectedly low inhibitory effect of indomethacin on rhEPO-enhanced contractions of rabbit aorta.

Animals↗
PubMed1992

Structural and functional properties of the p60 proteins from different Listeria species.

The major extracellular protein p60 of Listeria monocytogenes seems to be required for this microorganism's adherence to and invasion of 3T6 mouse fibroblasts but not for adherence to human epithelial Caco-2 cells. Western blot analysis with polyclonal antibodies against p60 of L. monocytogenes indicated the presence of cross-reacting proteins in the culture supernatants of all Listeria species. Protein p60 of L. monocytogenes could restore adhesion of the L. monocytogenes mutant RIII (impaired in the synthesis of p60) to mouse fibroblasts more efficiently than that of Listeria grayi. The amino acid sequences of the p60-related proteins of L. innocua, L. ivanovii, L. seeligeri, L. welshimeri, and L. grayi indicated highly conserved regions of about 120 amino acids at both the N-terminal and the C-terminal ends. The middle portions of these proteins, consisting of about 240 amino acids, varied considerably. These parts include the repeat domain consisting of repetitions of Thr (T) and Asn (N) which was present only, albeit in different arrangements, in the p60 proteins of L. monocytogenes and L. innocua. The p60-related proteins of L. grayi, L. ivanovii, L. seeligeri, and L. welshimeri each contained an insertion of 54 amino acids which was absent in the p60 proteins of L. monocytogenes and L. innocua.

Amino Acid Sequence↗
PubMed1992

Nitrates.

Nitrates have been used for the last 130 years to treat and control the symptoms of angina pectoris. Within the last 15 years, nitrates also have been shown to limit infarct size and to be beneficial in the treatment of patients with severe intractable heart failure, cardiogenic shock, severe mitral and aortic regurgitation, hypertensive episodes, and portal hypertension. The adequate use of nitrates to treat these disorders requires the ability to document a hemodynamic response and to closely monitor the adverse consequences of this therapy. Nitrates work by directly relaxing smooth muscle in resistance and capacitance vessels, thereby causing generalized dilation. Nitrates reduce preload and, at higher doses, reduce systemic vascular resistance and afterload. This chapter reviews the physiologic mechanisms that underlie nitrate therapy, the appropriate indications for nitrate use, the usefulness of specific agents, and their appropriate nursing implications.

Cardiovascular Diseases↗
PubMed1992

Angiotensin-converting enzyme inhibitors.

The angiotensin-converting enzyme (ACE) inhibitors available today include captopril (Capoten), enalapril (Vasotec), enaloprilat (Vasotec IV), lisinopril (Prinivil, Zestril), benazepril (Lotensin), fosinopril (Monopril), and ramipril (Atace). These drugs are used in the treatment of hypertension and congestive heart failure. They also are used in treating renovascular hypertension not amenable to surgery and are being studied to decrease left ventricular size after infarction and to determine whether they slow the rate of internal hyperplasia. Angiotensin-converting enzyme inhibitors have negative inotropic and chronotropic effects. This chapter discusses the ACE inhibitors and their actions, uses, adverse effects, contraindications, and nursing implications.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1992

Lipid-lowering drugs.

Controlling hyperlipidemia is an important aspect in the treatment and prevention of coronary artery disease. This article provides the clinician with a general reference for currently used lipid-lowering agents. Lipoproteins present in the plasma are defined and a brief overview of their functions is presented. Normal lipid uptake from the intestine and normal lipid metabolism are discussed to provide a basis for an understanding of the pharmaceutical treatment of hyperlipidemia. Guidelines are reviewed for interpreting lipid profiles according to the National Cholesterol Education Program. An evaluation of the agents currently used to treat hyperlipidemia is included. Lipid-lowering agents cause alterations in liver function; therefore, patients taking these medications are monitored closely. Patient teaching, including adverse effects of the medications, diet therapy and other alterable risk factors, is also reviewed.

Cholesterol↗
PubMed1992

[Liver angiography--technique, indications and significance in focal liver processes].

Retrospective analysis of 155 liver angiographies and the literature data was carried out to appraise the current relevance of liver angiography in digital subtraction technique (i.a. DSA) for diagnosis of focal liver changes. A focal liver lesion was detected by angiography in 58 out of the 80 patients (72.5%) we investigated with a confirmed hepatic space occupation; an angiography correlate of the tumour type diagnosed was shown in 41 out of 69 (59.4%) of malignancies confirmed by surgery or biopsy histology; in the benign lesions, the angiographic diagnosis was consistent with the histological result in five out of six cases. DSA is thus usually clearly inferior to the tomographic sonography, CT and MRI in detection and qualification of the tumour type. However, it is still indispensable for planning operations or chemoembolization and for exact imaging of the portal perfusion conditions because of the frequent vascular anomalies in the anatomy of the liver.

Adenoma, Bile Duct↗
PubMed1991

[The importance of the clinical differential diagnosis in the evaluation of a suspected drug reaction].

An adverse drug reaction has always to be considered if an obscure clinical picture is encountered. On the other hand every agency involved in drug monitoring has to take note of clinical differential diagnosis. Two examples illustrate how it was possible to explain by simple clinical evaluations suspected adverse drug reactions as manifestations of organic diseases.

Appetite Depressants↗
PubMed1991

[Spontaneous remission in histiocytosis X with lung and bone involvement].

Histiocytosis X is very rare in the adult. Since the illness is frequently asymptomatic it often causes diagnostic and therapeutic problems. Up to the present, assessment of the long-term course in the adult has required individual case records. A uniform therapeutic concept does not exist. According to prevailing opinion, asymptomatic patients do not require therapy. Our case record describes the spontaneous course in a young asymptomatic patient in whom histiocytosis X, which had affected lungs and bones, healed within 16 months.

Adult↗
PubMed1991

Glyceryl trinitrate increases platelet cyclic GMP after metabolism in fibroblasts.

Glyceryl trinitrate had no direct effect on cyclic GMP levels in platelets. However, in the presence of fibroblasts (RFL-6 cells), glyceryl trinitrate increased platelet cyclic GMP up to 7.8 fold (11.5 fold in the presence of superoxide dismutase). Fibroblasts alone had no effect. Endothelial cells alone increased platelet cyclic GMP up to 4.1 fold (9.6 fold in the presence of superoxide dismutase), but glyceryl trinitrate had no additional effect. Thus fibroblasts, but not endothelial cells, metabolize glyceryl trinitrate to a nitric oxide-like material that stimulates platelet soluble guanylyl cyclase.

Animals↗
PubMed1991

[Pleural empyema--rational diagnosis and therapy].

A pyothorax is a relatively rare occurrence in a general hospital and is posing a number of problems. Among these the long mean duration of hospitalisation is of note lasting 47 days for 24 patients at our clinic. The course and the mortality rate are influenced by early detection and judicious use of interdisciplinary treatment. Small effusions accompanying pneumonia are frequent and likely to disappear after treatment of the underlying disease. In these instances a precipitate punction may lead to secondary infection. In case of a sterile punctate the pH value and consideration of glucose and LDH values determine further measures. Computed tomography is of great value since it yields decisive information not available from conventional radiography. If the empyema is not segregated in compartments a closed drainage with a large caliber chest-tube ist the method of choice. Limited thoracotomy is advised when several empyema chambers develop after short duration of the illness. Persistent disease or widespread scarring necessitate decortication in most cases.

Adolescent↗
PubMed1991

Does EDRF/NO regulate its own release by increasing endothelial cyclic GMP?

EDRF/NO released from bovine aortic endothelial cells was measured by transferring conditioned medium to rat fetal lung fibroblasts (RFL-6 cells). These cells contain considerable amounts of soluble guanylyl cyclase. The increase in cyclic GMP in these cells provided a sensitive bioassay for EDRF/NO activity. Bovine aortic endothelial cells released a material that markedly enhanced cyclic GMP in RFL-6 cells. The synthesis of this substance could be stimulated with bradykinin (10 nM) or Ca2+ ionophore A23187 (1 microM) and was completely prevented by treatment of the endothelial cells with the EDRF/NO synthesis inhibitor, NG-L-arginine (100 microM), or incubation of the RFL-6 detector cells with the inhibitor of soluble guanylyl cyclase, methylene blue (10 microM). The release of EDRF/NO by bradykinin and A23187 was accompanied by an about two-fold increase in the cyclic GMP content in the producing endothelial cells. Incubation of bovine aortic endothelial cells with atrial natriuretic peptide (0.1 microM) or sodium nitroprusside (10 microM) enhanced their cyclic GMP content 6.5-fold and 4.1-fold, respectively. These increases in endothelial cyclic GMP levels had no effect on basal or bradykinin- and A23187-stimulated release of EDRF/NO. We conclude that cyclic GMP does not feed back on EDRF/NO formation or release in bovine aortic endothelial cells.

Animals↗
PubMed1991

Studies on the pathogenicity of Listeria monocytogenes.

The characterization of mutants of Listeria monocytogenes with reduced virulence properties is described. Reduction in the amount of the extracellular protein p60 (encoded by the ipa gene) leads to cell filaments with impaired invasiveness. Mutants which cannot synthesize listeriolysin are still invasive but unable to survive within phagocytic cells. One type of listeriolysin-negative mutants is defective in the synthesis of a positive regulatory element PrfA which coordinately regulates the listeriolysin gene (lisA) together with several other genes, including those for a phosphatidylinositol-specific phospholipase and a metalloprotease.

Antigens, Bacterial↗
PubMed1991

Verapamil administration to patients with contraindications: is it associated with adverse outcomes?

STUDY OBJECTIVES: To determine if the use of verapamil in patients with contraindications is associated with adverse sequelae, thereby assessing whether process measures of the quality of care are correlated with patient outcomes. DESIGN: Retrospective chart review comparing the incidence of adverse outcomes and drug failure in patients with and without contraindications to verapamil administration. SETTING: University hospital emergency department. PARTICIPANTS: All patients more than 12 years old who received IV verapamil during the study period. MEASUREMENTS: The presence or absence of contraindications to verapamil, the occurrence of complications, and the frequency of drug failure were determined by chart review. MAIN RESULTS: Patients with contraindications to verapamil experienced a significantly higher incidence of adverse outcomes and drug failures than those without contraindications. The presence of contraindicated rhythms, low pretreatment blood pressure, and signs of congestive heart failure were each specifically associated with an increased risk of adverse sequelae. CONCLUSION: Verapamil should not be administered to patients with contraindications to its use. In this instance, quality assurance process measures correlate with patient outcomes.

Adult↗
PubMed1991

Electrocortical mapping, MRI, and neuropsychological measures: evidence of Alzheimer's disease in the presence of vascular lesions.

We report here a case study of a 76-year-old woman with a high school education, whose presenting psychiatric symptomatology indicated dementia of unknown etiology. Neuropsychological test results were consistent with AD, but diagnosis was complicated by an MRI showing a large right hemisphere cortical infarct and scattered subcortical changes leading to a diagnosis of possible AD. Electrocortical mapping showed the right hemisphere infarct, and gave independent evidence suggestive of AD in the relatively intact left hemisphere. This case demonstrates the utility of multidimensional assessment as an aid to differential diagnosis.

Clinical Conference↗