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Biomedical subjects

L E Johnson

Publications and source records attributed to L E Johnson.

52 records · Page 3Linked to original sources
PubMed1969

Lomofungin, a new antibiotic produced by Streptomyces lomondensis sp. n.

Lomofungin is a new antimicrobial agent obtained from the culture broth of Streptomyces lomondensis sp. n. UC-5022. Lomofungin is an acidic, olive-yellow, crystalline compound which inhibits, in vitro, a variety of pathogenic fungi, yeasts, and gram-positive and gram-negative bacteria.

Anti-Bacterial Agents↗
PubMed1968

Kalafungin, a new antibiotic produced by Streptomyces tanashiensis strain Kala.

Kalafungin is a new antimicrobial agent obtained from the culture broth of a soil isolate of Streptomyces tanashiensis, designated Streptomyces tanashiensis strain Kala UC-5063. Kalafungin is a chemically stable, nonpolyene agent which is ex-extremely inhibitory in vitro against a variety of pathogenic fungi, yeasts, protozoa, gram-positive bacteria, and, to a lesser extent, gram-negative bacteria.

Anti-Bacterial Agents↗
PubMedDate not supplied

Right parasternal imaging: an underutilized echocardiographic technique.

If the echocardiographer uses only standard imaging planes, he or she may fail to obtain vital information about the aorta, atrial septum, superior and inferior vena cavae, and the coronary arteries. The evaluation of caval-to-systemic venous atrial connections (Senning or Mustard) in transposition of the great arteries of systemic vena caval or right atrial-to-pulmonary anastomosis (Fontan) in tricuspid atresia and single ventricle may not be adequately seen when only the standard left parasternal, apical, subcostal, and suprasternal imaging planes are used. Therefore, the use of the right parasternal imaging plane may help to provide crucial information regarding these areas when the standard views are unable to delineate them adequately. The right parasternal window is an additional echocardiographic window that should become part of a complete echocardiographic examination.

Aorta↗
PubMedDate not supplied

The acute hemodynamic effects of milrinone in dogs with severe idiopathic myocardial failure.

To examine the effects of acute oral milrinone administration (0.75 mg/kg) on dogs with severe idiopathic myocardial failure and the effect of prolonged milrinone administration on survival time, we measured hemodynamics before and 2 hours after drug administration and recorded survival time and cause of death in 13 dogs with dilated cardiomyopathy. Hemodynamics were measured using a Swan-Ganz catheter and femoral artery puncture along with recording an M-mode echocardiogram. Cardiac index increased from 1.92 +/- 0.54 to 3.06 +/- 0.81 L/min/m2, stroke volume index increased from 11.3 +/- 4.3 to 16.7 +/- 6.3 ml/beat/m2, and pulmonary capillary wedge pressure decreased from 23 +/- 8 to 12 +/- 8 mmHg. A clinically significant increase in heart rate was observed in seven dogs, resulting in a statistically significant increase in heart rate for the group from 174 +/- 34 to 194 +/- 44 beats/minute. Mean arterial blood pressure did not change significantly for the group but did decrease more than 20 mmHg in three dogs, suggesting a predominant primary vasodilating effect of milrinone in these dogs. An increase in contractility appeared to be the predominant reason for the improved hemodynamics in seven dogs. Eight dogs died of causes other than worsening heart failure, including four of eight Doberman pinschers that died suddenly, presumably from an acute tachyarrhythmia. Two dogs that had the greatest increase in an index of contractility are alive more than 2 years after the initiation of milrinone administration.

Animals↗
PubMedDate not supplied

Submaximal exercise testing using lactate threshold and venous oxygen tension as endpoints in normal dogs and in dogs with heart failure.

Twelve normal dogs and 7 dogs with experimentally induced heart failure were chronically instrumented to measure hemodynamic variables and blood gas tensions at rest and during graded treadmill exercise. Three groups of 4 normal dogs each (group 1, 15 to 20 kg; group 2, 21 to 30 kg; group 3, 31 to 40 kg) were exercised on a treadmill at a 16% grade at 1, 2, and 3 miles per hour, and at a 22% and a 26% grade at 3 miles per hour (5 total exercise levels) until blood lactate concentration increased to a value greater than 1 mmol/L. Blood lactate concentration and blood gas tensions were measured 5 and 15 minutes after starting exercise, and cardiac output was measured between 8 and 10 minutes of exercise. Results indicated that the same exercise protocol could be used for dogs ranging in size from 15 to 40 kg. Blood lactate concentration increased in normal dogs at varying workloads, but always at or above a workload of 3 miles per hour at a 16% grade. Dogs with class IV heart failure always experienced an increase in blood lactate concentration when walked at 1 mile per hour at a 16% grade for 5 minutes. A femoral vein PO2 between 21 and 24 mm Hg in normal dogs, and between 16 and 22 mm Hg in dogs with heart failure was always associated with an increase in blood lactate concentration. The primary problem with this exercise protocol was the unwillingness of some dogs to walk on the treadmill during the preselection phase. We conclude that we have devised a submaximal exercise test that can be used to evaluate exercise capability in dogs ranging in size from 15 to 40 kg, that the described exercise protocol can be used to identify decreased flow reserve in dogs with class IV heart failure induced by rapid ventricular pacing, and that either femoral vein oxygen tension or blood lactate concentration can be used as the endpoint for submaximal exercise testing in dogs.

Analysis of Variance↗
PubMedDate not supplied

Eating disorders in female adolescents with insulin dependent diabetes mellitus.

Recent case reports have suggested an association between anorexia nervosa and/or bulimia with insulin-dependent diabetes mellitus (IDDM). Fifty-eight females aged fifteen to twenty-two with IDDM for more than one year were assessed for the presence of eating disorders. Patients were screened for eating and weight pathology using the Eating Disorder Inventory (EDI) and Eating Attitudes Test-26 (EAT-26). Glycosylated hemoglobin (HbA1) was measured to assess metabolic control. Subjects who scored above the cut-off points associated with eating and weight pathology were interviewed. Clinically significant eating and weight pathology was found in 20.7 percent of the population. Of these subjects, anorexia nervosa was found in 6.9 percent and the syndrome of bulimia, based on DSM-III criteria, was found in 6.9 percent. In patients with bulimia, there was a strong inverse correlation between bulimic symptoms and metabolic control. These findings suggest that anorexia nervosa may be more common in female adolescents with IDDM than in nondiabetic populations and that bulimic symptoms may be a risk factor for poor metabolic control.

Adolescent↗
PubMedDate not supplied

Homogeneous sample preparation of raw shrimp using dry ice.

Sample homogeneity is critical to accurate and reproducible analysis of trace residues in foods. A method of uniform sample preparation using dry ice is described for shrimp. Other sample preparation techniques for raw shrimp produce nonhomogeneous samples. Sample homogeneity was determined through analysis of chloramphenicol added to intact tiger or white shrimp prior to sample preparation. Simulated chloramphenicol residue levels were 50, 15, 10, and 5 ppb. No significant differences were noted when analyses of shrimp inoculated with chlor-amphenicol prior to sample preparation with dry ice were compared with analyses of shrimp spiked after grinding with dry ice. Grinding shrimp with dry ice produced samples with homogeneous chloramphenicol residues. This technique should be applicable to other tissues and vegetable products.

Animals↗