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Biomedical subjects

D Morgan

Publications and source records attributed to D Morgan.

At least 289 records · Page 16Linked to original sources
PubMed1979

Intestinal absorption of 25-hydroxyvitamin D3 in unanesthetized rat.

We investigated the mechanism and characteristics of 25-hydroxyvitamin D3 (25-OH-D3) absorption in the unanesthetized rat by using a single-pass intestinal perfusion technique. The rate of 25-OH-D3 absorption remained linear for a wide range of concentrations (2-900 nM). Absorption rate of 25-OH-D3 increased as the pH, the bile acid concentration, and thickness of the unstirred water layer were decreased. Absorption did not change after the additions of fatty acids of varied chain lengths and degrees of saturation. In rats with lymph and bile fistulas, 18.5% and 16.3% of the infused radio-activity appeared in the lymph and bile drainage, respectively. These experiments indicate that 25-OH-D3 is absorbed by a passive diffusion mechanism that is influenced by the intestinal pH, bile acid concentration, and thickness of the unstirred water layer, but not by the presence of fatty acids. Approximately equal fractions of the infused hydroxylated vitamin are recovered from the lymphatic and biliary fluids.

Animals↗
PubMed1979

Recurrent intracerebral blastomycotic granuloma: diagnosis and treatment.

We present a patient with a recurrent intracerebral blastomycotic granuloma. The computerized tomographic scan appearance of this lesion is illustrated. Of the 81 reported cases of intracranial blastomycosis, only 35 have represented solid intracerebral lesions; the other patients have had spinal lesions or meningitis. This patient represents the first reported recurrence of an intracerebral blastomycotic granuloma. The treatment utilized, surgical resection combined with intravenous and intraventricular amphotericin B, represents a unique approach to this problem. The diagnosis and currently advocated treatment of intracranial blastomycosis is reviewed, particularly in regard to the potential for recurrence of blastomycosis.

Adult↗
PubMed1979

Subclinical effects of chronic increased lead absorption--a prospective study. II. Results of baseline neurologic testing.

This report summarizes the results of baseline neurologic testing in a group of apparently healthy workers from a secondary lead smelter and a group of controls from nearby aluminum processing plants. The test battery included a standard neurologic examination nerve conduction measurements, quantitative oculomotor function tests and detailed audiologic studies. Lead workers and controls were intermixed so that the examiners were unaware of the status of any individual being tested. Although the lead workers reported significantly more neurologic symptoms than the controls, relatively few differences were found on quantitative neurologic testing. Decreased deep tendon reflexes occured more frequently in the lead workers than in the controls (22% vs. 11%) but the difference was of borderline significance (p=0.06) and other signs of peripheral neuropathy occurred with equal frequency in both groups. The mean motor conduction velocity and sensory latency measurements were not significantly different in the lead workers and in the controls and, of the six oculomotor function measurements, only the mean accuracy of saccadic eye movements was significantly (p less than 0.01) different in the two groups. High frequency hearing loss occurred with equal frequency and severity in both groups, consistent with the level of noise exposure in the lead and control plants.

Absorption↗
PubMed1978

Pharmacokinetics and metabolism of the anilide local anaesthetics in neonates. 11 Etidocaine.

The urinary elimination of etidocaine and several of its metabolites was investigated in neonates whose mothers had received one or more doses of etidocaine during labour. The urine collection period ranged among the neonates from 21.4 to 47.0 h post-partum. The total amounts of etidocaine and its metabolites recovered in neonatal urine represented a mean of 0.12% of the maternal dose. Some differences in the pattern of urinary metabolites were observed between neonates and adults. Mean half-life of elimination of etidocaine calculated from sigma-minus plots of the neonatal urinary data was 6.42 h. This is greater than that previously reported following intravenous administration of etidocaine to adults (2.6 h). The slower rate of elimination in neonates is probably due to an increased neonatal volume of distribution since there is evidence to show that etidocaine is extensively metabolised by the neonate.

Acetanilides↗
PubMed1978

Disposition of meperidine in pregnancy.

Plasma concentration-time profiles of meperidine after intravenous administration to 7 pregnant women during labor were investigated. There was considerable interpatient variation in initial plasma concentrations of meperidine and its volume of distribution. When the data in the literature on the disposition of meperidine in nonpregnant subjects were used for comparison, it was found that the initial dilution volume (V1), the volume of distribution at steady-state (Vss), and the apparent volume of distribution during the terminal exponential phase of drug elimination (Vbeta) were less (p less than 0.05) in pregnant subjects than in healthy nonpregnant control subjects but were not significantly different in pregnant subjects and nonpregnant surgical patients. Mean total systemic blood clearance was also significantly less in the pregnant subjects (843 ml/min) than previously reported for healthy nonpregnant control subjects (1,465 ml/min). The blood/plasma concentration ratio of meperidine in pregnant women (0.940) was higher than that in control subjects (0.768; p less than 0.01). Placental transfer of meperidine was investigated in 4 of the patients; in 2 the concentration of the drug was greater in cord plasma than in maternal plasma. Further study is indicated.

Adolescent↗
PubMed1978

Radioisotopic quantitation in microtitration plates by an autofluorographic method.

An autofluorographic record of drug titrations in microtitration plates has been obtained using cultures labelled with [35s] methionine after treatment with cytostatic drugs. By adding scintillation fluid directly to each culture well of the microtitration plate, and then centrifuging the evaporate the toluene and leave a flat even film of fluor, in situ scintillation is produced. When X-ray film is exposed to the plate the scintillation of individual wells is recorded as spots on the film. These may be interpreted by eye or by scanning densitometry.

Cell Line↗
PubMed1978

The identification of eight hydroxylated metabolites of etidocaine by chemical ionization mass spectrometry.

1. Eight hydroxylated metabolites of etidocaine have been identified in urine of man by g.l.c.-chemical ionization mass spectrometry, using methane and a mixture of methane and deuterium oxide as reactant gases. 2. The metabolites identified were N-(2,6-dimethyl-3- and 4-hydroxyphenyl-)-2-(N,N-ethylpropylamino)butyramides, N-(2,6-dimethyl-3- and 4-hydroxyphenyl)-2-aminobutyramides, N-(2,6-dimethyl-3- and 4-hydroxyphenyl)-2-(N-ethylamino)butyramides, and N-(2,6-dimethyl-3- and 4-hydroxyphenyl)-2-(N-propylamino)butyramides. 3. The eight metabolites represent about 10% of the oral dose of etidocaine.

Acetanilides↗
PubMed1978

Congenital saccular aneurysm in a 19-day-old neonate: case report and review of the literature.

A 19-day-old neonate presented with a massive intracranial hemorrhage which was found at autopsy to be due to a ruptured intracranial saccular aneurysm. Detailed histologic evaluation revealed that this was a true congenital lesion. A survey of the literature yielded 19 cases of saccular aneurysm in the first year of life. Together with this report, nine cases are now on record, containing sufficient histologic detail to suggest a congenital basis, contrary to the assertion casting doubt on the existence of the entity. Attention is drawn to the practical importance of recognizing this lesion as a rare cause of intracranial hemorrhage in the neonate, since successful surgical intervention has been reported in several cases.

Humans↗