Search PubMed⌕ Search

Biomedical subjects

D J Krellenstein

Publications and source records attributed to D J Krellenstein.

23 records · Page 2Linked to original sources
PubMedDate not supplied

Norepinephrine, potassium and overdrive suppression.

The influence of norepinephrine on ventricular overdrive suppression and attendant potassium shifts has been studied in isolated perfused canine hearts with complete atrioventricular block. It was found that: 1) there is a potassium loss during the drive and a potassium uptake after the drive); 2) reducing the driving rate from 240 to 120/min decreases potassium loss; 3) norepinephrine increases potassium uptake and spontaneously beating ventricles and during the recovery from 120/min drive; 4) norepinephrine enhances K loss during and after a 240/min drive; 5) norepinephrine shortens the overdrive pause under all the conditions tested; 6) in ventricles driven at a constant rate, norepinephrine causes a small loss of ptoassium; 7) reserpinized hearts show a small potassium loss during drive and a larger potassium uptake after drive; yet, the suppression is longer; 8) norepinephrine increases K loss with drive and decreases overdrive suppression in reserpinized hearts; 9) norepinephrine enhances the increase in oxygen consumption caused by overdrive; and 10) norepinephrine antagonizes the depressant effect of high [K]0 on automaticity. It is concluded that norepinephrine shortens the pause independently of potassium levels and antagonizes the inhibittory influence of high K. The effect or norepinephrine on K movements depends on the ventricular rate and such rate-dependence is related to oxygen availability with respect to the increased metabolic demand.

Animals↗
PubMedDate not supplied

Computed tomography of mediastinal collaterals in SVC syndrome.

A patient undergoing treatment for abdominal lymphoma presented with a superior vena cava (SVC) syndrome. The presence of a wide mediastinum and "nodular" mediastinal densities on CT presented a diagnostic problem, necessitating thoracotomy. The thoracotomy was negative for tumor or infection. We believe that the presence of an indwelling catheter and mediastinal lipomatosis resulted in the SVC syndrome. The "nodular" densities represented an unusual set of mediastinal collaterals that must be distinguished from adenopathy.

Catheters, Indwelling↗
PubMedDate not supplied

Bronchoscopy in diffuse lung disease: evaluation by open lung biopsy in nondiagnostic transbronchial lung biopsy.

Transbronchial lung biopsy through the flexible bronchoscope is used widely for the diagnosis of diffuse lung disease; however, a significant number of specimens obtained by the bronchoscopic 2-mm biopsy forceps will reveal nonspecific findings, eg, interstitial fibrosis or nonspecific pneumonitis. Such a report may be an accurate reflection of the presence of idiopathic pulmonary fibrosis or nonspecific pneumonitis, but may merely indicate that the true diagnosis has been missed. We retrospectively studied 38 patients with diffuse lung disease whose transbronchial lung biopsies yielded nonspecific abnormalities. Subsequently, these patients were subjected to open lung biopsies. Nineteen of the 38 patients (50%) had a specific diagnosis made by open lung biopsy. The diagnoses included bronchiolitis obliterans, alveolar proteinosis, metastatic carcinoma, lymphoma, tuberculosis, and bronchioloalveolar cell carcinoma. Although transbronchial lung biopsy is useful in the diagnosis of many diffuse lung diseases, it is not a replacement for open lung biopsy. When nonspecific findings by transbronchial lung biopsy do not correlate with the clinical picture, open lung biopsy should be performed.

Adolescent↗