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Biomedical subjects

D D Johnson

Publications and source records attributed to D D Johnson.

At least 127 records · Page 7Linked to original sources
PubMed1980

Diabetic ketoacidosis in a community-based population.

Ninety-two cases of diabetic ketoacidosis were identified in residents of Rochester, Minnesota, over a 52-year period; 42% occurred in patients with juvenile-onset diabetes. The most common cause of diabetic ketoacidosis was infection. In 23% of the patients, diabetic ketoacidosis was the initial manifestation of diabetes mellitus. The frequency of retinopathy, neuropathy, and glomerulosclerosis was significantly increased in the surviving diabetic patients with ketoacidosis in comparison with diabetic patients matched for age and sex who did not experience ketoacidosis. Seven deaths occurred in the first 24 hours of diagnosis of ketoacidosis, but only one could be attributed to ketoacidosis alone. An additional six patients died within 48 hours of the recognition of ketoacidosis. The major cause of all deaths occurring within 48 hours of hospitalization for ketoacidosis was myocardial infarction.

Adolescent↗
PubMed1980

Membrane versus bubble oxygenator for cardiac operations. A prospective randomized study.

The advantages of membrane oxygenators over bubble oxygenators for cardiopulmonary bypass during clinical cardiac operations are controversial. A prospective randomized double-blind experimental design was utilized in 64 adult patients undergoing elective cardiac operations with either the Travenol microporous polyprolyene membrane oxygenator or the Bentley Q-100 bubble oxygenator. Sixteen patients in each group underwent coronary artery bypass grafting (CABG) and 16 underwent valvular or other types of operation. The two oxygenator groups were comparable in terms of patient characteristics and perioperative management. Both oxygenators functioned acceptably for an average duration of 115 minutes. Higher relative platelet counts (percent of control) were observed immediately after bypass in CABG patients in whom the membrane oxygenator was used. Otherwise, no significant differences were noted in objectively assessed results between the two oxygenators in regards to bleeding, pulmonary, renal, cardiac, and neurologic function, duration of ICU stay, and postoperative hospital stay. Thus no significant advantages in terms of clinical results could be detected with this type of membrane oxygenator versus another type of bubble oxygenator for elective cardiac operations in adults.

Adult↗
PubMed1980

Excretion of Mycobacaterium avium from lesions in the intestine and tonsils of infected swine.

Five 8-week-old pigs were given an oral dose of approximately 10(8) viable units of Mycobacterium avium and confined in such a way as to prevent ingestion of fecal material. At necropsy 70 to 79 days later, there were granulomatous lesions, some containing acid-fast organisms, in the tonsils, aggregated lymphatic follicles (Peyer's patches) of the jejunum and ileum, mucosa of the caudal portion of the ileum, ileocecal valve, and cecum. The organism was isolated from tonsils, intestine, and swabs from the surface of some of these tissues. Mycobacterium avium that apparently orignated from lesions in the pigs was first detected in the feces 20 to 23 days after the animals were inoculated. The number of organisms excreted began to decrease at 55 days, and none was isolated from feces at 69 days. It was concluded that lesions in the intestine and possibly the tonsils were the sources of the organisms in the feces. The role of tonsil and intestine lesions of swine as sources of perpetual herd infections is discussed.

Animals↗
PubMed1979

Does preservation of the posterior chordae tendineae enhance survival during mitral valve replacement?

During a 30-month period, 51 patients underwent mitral valve replacement. There were 3 hospital deaths (5.9%), 2 of which were due to ventricular rupture. The 3 patients who died were among 13 patients in whom mitral valve replacement was combined with tricuspid or aortic valve operation or both. Postmortem findings in the 2 patients who died of ventricular rupture showed that the ventricular tears were located between the atrioventricular groove and the unresected papillary muscle stumps, in an area of ventricle formerly tethered by the posterior chordae tendineae. In the last 14 patients in the series, the posterior leaflet of the mitral valve and its chordae tendineae were left intact, and there was no mortality or prosthetic valve dysfunction. In patients with myxomatous or ischemic disease, the posterior leaflet was left completely intact. For patients with fibrocalcific rheumatic disease, we have developed a technique of partial excision and debridement of the posterior leaflet, preserving the intermediate and basal chordae tendineae attachments. With the techniques described, preservation of all or part of the posterior leaflet and its chordae tendineae does not appear to interfere with prosthetic valve function and, by reducing the risk of ventricular rupture, should enhance survival after mitral valve replacement.

Adult↗
PubMed1979

Mycobacterium avium abortion in a sow.

A 2-year-old sow aborted her entire near-term litter of 11. Gross and histologic examination of a fetus suggested a tuberculous infection, and a yellow-pigmented Mycobacterium avium serotype 1 was subsequently isolated from the fetal tissue. Efforts to rebreed the sow were unsuccessful. She was anergic to skin tests with purified protein derivative of M. avium on two occasions but had M. avium specific in vitro lymphocyte immunostimulation. Gross granulomatous lesions were found in the liver, kidneys, and endometrium when the sow was necropsied 5 months after the abortion. Histologic examination showed diffuse and focal non-encapsulated granulomas in lymph nodes, tonsils, kidney, liver, spleen, lung, and uterine and vaginal walls. There were a few encapsulated calcified foci in the endometrium. The centers of some granulomas in the tonsils, liver, kidneys, and some lymph nodes were caseated. The yellow-pigmented M. avium was isolated from the reproductive organs and from 11 of 12 other tissues cultured.

Abortion, Spontaneous↗
PubMed1979

Photically induced experimental exophthalmos: role of Harderian and pituitary glands.

Exposure of adult male and female albino rats to high-intensity illumination for 17.5 hr results in a marked, transient exophthalmos, which persists for approximately 48 hr after the light exposure. Upon examination of the Harderian glands in these rats, a significant glandular weight increase was observed up to 2 days after light treatment. Analysis of individual glandular components showed that this weight increase was due to an increase in fluid content of the glands. The lipid and residue contents in the Harderian glands of exposed rats decreased significantly. When animals were hypophysectomized (HYPEX) prior to the short-term illumination period, there was no visible exophthalmos. However, when the Harderian glands were analyzed at necropsy, they had a similar relative increase in weight as compared to glands of intact rats, and this again was the result of increased fluid composition. The exophthalmos induced in intact animals resulting from an enlargement of the Harderian glands seemingly was due directly to a radiant energy-dependent mechanism and not to any pituitary hormone mediation. The edematous phenomenon was similar in Harderian glands of HYPEX rats, but visible exophthalmos was lacking, probably because of the atrophied condition of the glands in the absence of the pituitary.

Animals↗
PubMed1978

Epileptiform seizures in domestic fowl. VII. Plasma phenytoin concentrations and anticonvulsant activity.

Acute dose-response studies with phenytoin were conducted to determine the relationship between plasma levels and anticonvulsant effect in epileptic chickens. Phenytoin produced statistically significant reductions in both the incidence and severity of seizures in photosensitive epileptic chickens when the plasma concentrations exceeded 8.15 +/- 0.89 microgram/ml. A high correlation exists between plasma phenytoin concentrations and both the reduction in incidence or severity of seizures. However, the appearance of plasma concentration dependent neurological toxicities resulted in a failure to achieve complete protection against intermittent photic stimulation induced seizures.

Animals↗
PubMed1978

Epileptiform seizures in domestic fowl. VIII. Anticonvulsant activity of primidone and its metabolites, phenobarbital and phenylethylmalonamide.

Primidone is an effective anticonvulsant against seizures induced in epileptic fowl by exposure to intermittent photic stimulation. Epileptic fowl metabolize primidone to phenobarbital. Pretreatment of epileptic fowl with SKF 525A to prevent the metabolism of primidone to phenobarbital indicated that primidone itself had anticonvulsant activity. Phenylethylmalonamide, a second metabolite of primidone, did not have anticonvulsant activity when administered at the same dose as primidone.

Animals↗
PubMed1978

Epileptiform seizures in domestic fowl. IX. Implications of the absence of anticonvulsant activity of ethosuximide in a pharmacological model of epilepsy.

Acute dose--response studies were conducted to determine if ethosuximide had anticonvulsant activity against seizures evoked by stroboscopic stimulation of epileptic fowl and to correlate the observed effects with the concentration of the drug in the plasma. Ethosuximide, in doses that produced mean plasma concentrations of 366 microgram/ml and signs of sedation, did not reduce seizure susceptibility. Twice daily administration of ethosuximide produced mean plasma concentrations of 430 microgram/ml after 36 h without affecting seizure susceptibility even in the presence of marked sedation. Previous studies have shown that epileptic fowl are sensitive to the anticonvulsant effects of phenobarbital, phenytoin, and primidone at plasma concentrations similar to those required in humans. Since ethosuximide has a high specificity against petit mal seizures in humans, the failure of ethosuximide to provide protection indicates that epileptic fowl represent a relatively specific pharmacological model for drugs effective against generalized tonic--clonic and focal cortical epilepsies in humans.

Animals↗
PubMed1977

Epileptiform seizures in domestic fowl. VI. Plasma phenobarbital concentrations and anticonvulsant activity.

The relationship between plasma phenobarbital concentrations and anticonvulsant activity was determined against seizures induced in epileptic chickens by intermittent photic stimulation (IPS). Intraperitoneally administered phenobarbital produced a plasma-concentration-dependent reduction in both the incidence and severity of seizures. Complete protection against IPS-induced seizures was observed for a period of 6 h after acute phenobarbital administration during which the mean plasma phenobarbital concentrations were between 16.2 +/- 0.91 and 13.6 +/- 1.0 microgram/lm. Plasma phenobarbital concentrations below 3.6 +/- 0.06 microgram/ml had no measurable effect.

Animals↗
PubMed1975

Studies on the mechanism of the protective and antidotal actions of diazepam in organophosphate poisoning.

The effect of diazepam on soman-induced bradycardia and respiratory depression in rabbits has been investigated. Diazepam prevents the bradycardia produced by soman in conscious rabbits. Although atropine will reverse the respiratory depression produced by soman in anesthetized rabbits, diazepam enhances the depression and renders rabbits less susceptible to this action of atropine.

Animals↗
PubMed1975

Epileptiform seizures in domestic fowl. V. The anticonvulsant activity of delta9-tetrahydrocannabinol.

The anticonvulsant activity of delta9-tetrahydrocannabinol (delta9-THC) has been determined against seizures induced in epileptic chickens by intermittent photic stimulation (IPS) and in epileptic and nonepileptic chickens by Metrazol. Intravenous administration of the drug reduced both the severity and incidence of seizures evoked by IPS in epileptic chickens. This anticonvulsant action was accompanied by a reduction in frequency of inter-ictal slow-wave high-voltage electroencephalographic activity and by the absence of spiking during IPS. delta9-THC did not affect the incidence of Metrazol-induced seizures in epileptic or nonepileptic chickens.

Animals↗