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Biomedical subjects

G Stefan

Publications and source records attributed to G Stefan.

At least 19 recordsLinked to original sources
PubMed1997

Food safety issues affecting the dairy beef industry.

The ability of dairy farmers to market cull cows and veal calves may be affected by the final rule on Pathogen Reduction and HACCP (Hazard Analysis Critical Control Points) Systems, a sweeping reform of USDA food safety regulations that was published on July 25, 1996. Although the regulations apply only to slaughter and processing plants handling meat and poultry, the rule will have an impact on food animal producers, including dairy farmers. Under this regulation, plant operators are required to evaluate potential hazards and to devise and implement controls that are appropriate for each product and plant to prevent or reduce those hazards. Processing plants may need to consider the potential hazards associated with incoming animals, such as illegal drug residues, which may result in marked changes in the relationships among some producers, livestock markets, and slaughter plants. Such information may actually improve the marketability of some animal classes because documentation will help the packer ensure the safety of products for sale to domestic and foreign markets. Dairy scientists are in an excellent position to explain the food safety issues to dairy farmers and to help develop the appropriate strategies that are necessary to guide the changes needed. These scientists can be conduits for information, the research leaders for practical solutions to reduce public health risks, and valuable resources to help farmers adjust to the impact of these new in-plant regulatory systems.

Animals↗
PubMed1986

Echocardiographic determination of left ventricular haemodynamics following acute and chronic administration of frusemide (Lasix) to patients with heart failure.

Twenty patients (8 females) with NYHA class II symptoms of chronic left ventricular heart failure completed a study to investigate the hemodynamic effects of intravenous and oral frusemide. Echocardiography indicated that frusemide 20 mg intravenously produces a transient undesired hemodynamic effect in the prediuretic phase without any influence on the patient's clinical symptoms. Once diuresis is established the hemodynamic conditions are reversed and there is an improvement in cardiac function. There is no evidence of a direct positive inotropic effect of the drug. Repeated oral dosing with frusemide 40 mg/day for 3 weeks produced an improvement in cardiac hemodynamics particularly during the first 2 weeks of treatment. The possible underlying mechanisms for these observations are discussed.

Coronary Circulation↗
PubMed1977

[Sources of error in the preparation and interpretation of echocardiograms (author's transl)].

Diagnostic ultrasound is able to provide important information on cardiac structure and motion. Diagnostic errors and misinterpretations however are not uncommon, due to the manner in which data are acquired and recorded during the echocardiographic examination. This paper discusses the characteristic echocardiographic patterns of a variety of important changes in the mitral valve, the left ventricle, and the interventricular and interatrial septum as well as the influence of respiration on the performance of echocardiography. Essential pitfalls in establishing a correct diagnosis in each of these conditions are emphasized and supported by illustrations.

Cardiomyopathy, Hypertrophic↗
PubMed1976

[Diagnosis of atrial septum defects by M-mode echocardiography (author's transl)].

By means of M-Mode echocardiography it is possible to depict the interatrial septum, which is of importance for the diagnosis of certain congenital cardiac defects such as atrial septum defect. The echo of the interatrial septum moves in the shape of a wave, synchronous with the heart beat and shows an amplitude of about 10 mm. A dilatation of the right atrium makes the echo move dorsally, a left atrial dilatation makes the echo move closer to that of the anterior thoracic wall. If the sound beam crosses an atrial septum defect, there is a complete disappearance of echo in the region of the interatrial septum.

Echocardiography↗
PubMed1976

[Possibilities of erroneous interpretation of echocardiograms].

Diagnostic ultrasound is capable of providing important information on cardiac structures and motion. Diagnostic misinterpretations and errors, however, are not uncommon, due to the manner in which data are acquired and displayed during an echocardiographic examination. This paper discusses the typical echocardiographic patterns of a variety of important conditions concerning the mitral valve, the left ventricle, the interatrial and interventricular septum as well as the influence of respiration on the performance of echocardiograms. Essential pitfalls in establishing a correct diagnosis in each of these conditions are discussed and demonstrated by illustrations.

Cardiomyopathy, Hypertrophic↗
PubMed1976

[Echocardiographic evaluation of left ventricular function during therapy with cardiovascularly effective drugs].

The task of this study was to examine the feasibility of applying echocardiography in determining alterations of left ventricular performance during administration of vasoactive drugs. Patients suffering from congestive heart failure were treated with Digitalis, other patients with normal hearts were subjected to infusion therapy of Isoproterenol, Propranolol, Verapamil and Calcium chloride. A new concept for interpretation of function curves relating the velocity of circumferential fiber shortening (VCF) and time was introduced to establish the inotropic, bathmotropic and chronotropic effects of vasoactive drugs to the myocardium. It can be concluded that echocardiography is a feasible tool in determining changes of left ventricular dynamics during administration of vasoactive drugs, in indicating the individual dosage of a vasoactive drug in each patient and the follow-up the course of the therapeutic success.

Digoxin↗