Search PubMed⌕ Search

Biomedical subjects

J Arnold

Publications and source records attributed to J Arnold.

At least 217 records · Page 12Linked to original sources

Torsade de pointes and asystole in a child with complete heart block and prolonged QT interval.

Three-year-old girl with eight month history of convulsive syncope due to complete heart block, prolonged QT interval and paroxysms of ventricular tachycardia is described. An episode of torsade de pointes tachycardia followed by asystole was documented. The symptoms and electrocardiographic abnormalities were controlled by pacemaker therapy. The subset of "congenital heart block" patients with prolonged QT interval is at high risk of sudden death and should be regarded as a previously unrecognized form of Romano-Ward syndrome.

Arrhythmias, Cardiac↗

Effects of Met-enkephalin and naloxone on gastric emptying and secretion in rhesus monkeys.

Recent studies have demonstrated the presence of enkephalins in gastric neurons and endocrine cells; however, their role in the regulation of gastric function is unknown. The effect of Met-enkephalin (MET), the stable analogue of Met-enkephalin [D-Ala2]Met-enkephalinamide (DMET), and the opiate receptor antagonist naloxone were studied in five chair-adapted rhesus monkeys. A dye-dilution technique was used to determine simultaneously fractional emptying rate, hydrogen, sodium, potassium, and chloride ion output, and fluid output. Both MET and DMET significantly inhibited fractional emptying rate and H+ secretion following an 80-ml water meal. Only MET, however, significantly altered fluid and sodium ion output. Naloxone had no effect on gastric function following the water meal.

Animals↗

Early detection of aortic dilatation in ankylosing spondylitis using echocardiography.

Aortic root abnormalities including cusp thickening, subvalvular stenosis, and mild aortic root dilatation are the most common cardiac complications in patients with long standing ankylosing spondylitis (AS). Twenty-three patients with definite idiopathic AS (New York Criteria 1966) and twenty-two matched controls were studied with M-mode echocardiography. Only one of the AS patients had clinical aortic incompetence. Six of the AS patients had mildly dilated aortic roots (normal less than 3.7 cm) with a mean diameter of 3.9 cm (range 3.8 to 4.00 cm). None of the twenty-two controls matched for age, sex and blood pressure had dilated aortic roots, with a mean diameter of 3.3 cm (range 2.9 to 3.6 cm). No correlation existed between aortic dilatation and severity of disease estimated by acute phase proteins--caerulo plasmin, alpha 1-antitrypsin, alpha 1 acid glycoprotein, ferritin and C Reactive protein. Contrary to a previous report, mild aortic root dilatation occurs in long standing cases of AS. Although it is a non-specific finding, it does not appear to be related to age or blood pressure and may therefore be the forerunner of aortic incompetence.

Adolescent↗

Genetics and the origin of a vector population: Aedes aegypti, a case study.

Thirty-four population samples representing the worldwide distribution of the mosquito Aedes aegypti were analyzed for variation at 19 to 22 enzyme-coding genes. A multivariate discriminant analysis revealed that the genetic differences among populations in six geographic regions and between two subspecies enable one to determine the regional origin of a population. Such studies of population genetics may have quite general applicability in studying vector-borne diseases.

Aedes↗

Bioavailability and pharmacokinetics of a new, slow-release potassium chloride capsule.

The bioavailability of a new, slow-release potassium chloride product consisting of coated beads in a hard gelatin capsule was compared with the bioavailability of two marketed products, an elixir and a slow-release tablet, by determining the urinary excretion of potassium. Twelve healthy male volunteers were dosed with a total of 80 mEq of potassium, in a single dose for the capsule and tablet and in three 26.6-mEq doses at 6-hr intervals for the elixir. Mean recoveries in 24-hr urine potassium levels from all three dosage forms after subtracting normal urine potassium excretion levels were 50.8% from the capsule, 53.9% from the elixir, and 63.1% from the tablet. Maximum excretion rates were reached at 2.0 hr for the elixir, 6.8 hr for the capsule, and 4.0 hr for the tablet. Fewer side effects were reported with the capsule than with the elixir and tablet.

Adult↗

Bioavailability of theophylline following a rectally administered concentrated aminophylline solution.

A two-way complete crossover bioavailability study of solutions of theophylline given orally or rectally in 16 healthy subjects was conducted. Blood samples were obtained prior to dosing and at 0.25, 0.5, 0.75, 1, 1.5, 2, 2,5, 3, 3,5, 4, 4.5, 5, 6, 7, 8, 10, 12, and 24 hr. Plasma theophylline was determined by high-pressure liquid chromatography. In the fasting subjects solutions given orally were absorbed faster (0.95 versus 1.95 hr to peak), reaching a higher peak concentration (7.26 versus 4.87 microgram/ml) than the solutions given rectally. Depending on the method of computation, solutions given rectally were estimated to be 86% to 87% as biovailable as the solutions given orally, with 75% of the subjects having 80% or greater relative bioavailability.

Absorption↗

Lactose intolerance in adults in Senegal.

The isolated malabsorption of the lactose in the adult is an hereditary feature while is not found often in the white people but is spread out in black Africa. In Senegal, a ratio of about 29% is verified, changing according to the ethnic composition. Only the Peuhls, of semitic origin, show a full tolerance to lactose.

Adult↗