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Biomedical subjects

J French

Publications and source records attributed to J French.

At least 127 records · Page 7Linked to original sources
PubMed1983

Reaching for rattles: a preliminary study of contrast sensitivity in 7-10 month old infants.

Contrast sensitivity for a 3 cycles deg-1 sinusoidal grating in 7-10 month old infants was tested by presenting gratings and uniform fields on cylinders, with the former providing auditory reinforcement when the infant picked them up. The method shows that a contrast as low as 7.5% can commonly be detected at this age, compared with 1-2% for adults under comparable conditions. However, as the development of hand preferences with the task as an indicator of visual sensitivity, it is concluded that this method is not in its present form suitable for vision testing on a wide scale or in a clinical setting.

Discrimination Learning↗
PubMed1982

Effects of scopolamine hydrobromide on the development of the chick and rabbit embryo.

When 100 or 200 microgram of scopolamine hydrobromide were injected into hen eggs after they had been incubated for 96 h the major malformations of the embryo found were gastroschisis, exencephaly, reduction deformities of the limbs, microphthalmia and buphthalmia when the eggs were opened on the 12th day of incubation. Eight foetuses of one of eight New Zealand white rabbit does given scopolamine hydrobromide at the rate of 473 microgram/kg in their drinking water from the 10th to the 14th day of gestation showed malformations consisting of microphthalmia, buphthalmia, exencephaly and hydrocephaly. A second doe which similarly received 520 microgram/kg of the hydrobromide had four malformed foetuses showing microphthalmia and had two foetuses which were resorbed. However, there were no malformations in foetuses of eight does given bolus doses of scopolamine hydrobromide ranging from 37 to 184 microgram/kg by intramuscular injection every 12 h from the 10th to the 14th day of gestation. Results indicate interference by the drug with the function of the cholinergic nerves on the development of the chick and rabbit embryo.

Animals↗
PubMed1981

Mount St Helens eruptions, May 18 to June 12, 1980. An overview of the acute health impact.

Thirty-five known deaths were caused by the landslide and lateral blast of the May 18 eruption of Mount St Helens and at least 23 persons are missing. In 18 of 23 cases that reached autopsy, asphyxiation from ash inhalation was the cause of death. A rapidly established hospital surveillance system detected increases in the number of emergency room (ER) visits and admissions for asthma and bronchitis in communities with the heaviest ashfall after the May 18 eruption and the eruptions on May 25 and June 12. There were also increases in the number of ER visits for ash-related eye complaints in some areas. laboratory studies indicated that the May 18 ash was not acutely toxic, but the respirable portion contained 3% to 7% of crystalline free silica, a potential pneumoconiosis hazard to certain heavily exposed occupational groups. Continuing volcanic activity of Mount St Helens and future eruption of other volcanoes in the Cascade Range may pose a variety of health hazards, including blast, ashfalls, flooding, damage to public utilities, and possible psychosocial effects.

Asphyxia↗
PubMed1981

Results of intraventricular baffle procedure for ventricular septal defect and double outlet right ventricle or d-transposition of the great arteries.

Thirty patients with ventricular septal defect and d-transposition of the great arteries or double outlet right ventricle underwent placement of an intraventricular baffle to achieve physiologic correction. Eighteen of these patients also required an external conduit to establish continuity between the right ventricle and the pulmonary artery. There was an overall 22 percent early mortality rate, although the rate was 63 percent in patients who weighed less than 10 kg. There was an additional 20 percent late mortality rate, primarily related to conduction disturbances and pulmonary vascular obstructive disease, problems that have not occurred in patients operated on since 1974. Of the survivors, all are asymptomatic and as a group have achieved a significant weight gain. Many have residual hemodynamic abnormalities that required cardiac catheterization for precise assessment. Four patients have been reoperated on, with no additional mortality.

Adolescent↗
PubMed1981

Contrast sensitivity function of preschool children.

A procedure specifically adapted for children of preschool age has been used to measure contrast sensitivity in emmetropic children aged 3 to 5 years. Mothers of the children acted as adult observers using the same procedure. The results show that the contrast sensitivity function of adults and children is very similar, sensitivity for the children being slightly lower than that for adults at all spatial frequencies. The sensory and cognitive factors involved in these differences are discussed.

Adult↗
PubMed1981

The effects of some organic solvents on the absorption of digoxin by man.

Ten healthy subjects took each of 6 different solutions of 0.5 mg digoxin in a study of the effect of different solvents on absorption. Bioavailability was measured by the urinary recovery of digoxin in the eight days after each dosing. The six liquid preparation were aqueous solution, an organic solvent complex (lanoxicaps fill) for which solvent assisted absorption has been suggested, digoxin elixir, and three different solutions each comprising a single organic solvent in the concentration used in lanoxicaps plus water to make up the balance. Pure aqueous solution and lanoxicaps fill had the highest bioavailability as judged by urinary recovery but there was no significant different at the 5% level between the urinary recovery from the lanoxicap fill, the elixir and the two preparations with water as the preponderant solvent. It is concluded that the greater bioavailability of digoxin from lanoxicaps than from tablet formulations is more likely to ve due at least in part to delivery of digoxin already dissolved than to the identities of the solvents. The rate of intestinal digoxin uptake may possibly influence the degree of urinary recovery.

Adult↗
PubMed1980

A radioassay for GM1 ganglioside concentration in cerebrospinal fluid.

A radioassay for the rapid determination of GM1 ganglioside concentration in small volumes of CSF from individual patients is described. The assay utilizes the high-affinity interaction between cholera enterotoxin and GM1 ganglioside. The lower detection limit of GM1 ganglioside by this radioassay under the described incubation conditions is 2.5 ng/ml. The radioassay-determined lumbar CSF GM1 ganglioside concentrations in a small group of patients with diverse neurologic disorders are presented. The radioassay GM1 ganglioside concentration is in good agreement with the GM1 ganglioside concentration determined, in one patient, by the tlc-densitometry technique.

Colorimetry↗
PubMed1980

GM1 ganglioside concentration in the cerebrospinal fluid of neonates and children.

GM1 ganglioside concentration was measured by radioassay technique in individual samples of lumbar cerebrospinal fluid from 20 neonatal and 17 older pediatric patients. The lumbar CSF GM1 ganglioside concentration of neonates (76.6 +/- 27.4 ng/ml) is greater than that of older infants and children (31.9 +/- 22.2 ng/ml). The lower range of GM1 ganglioside concentration of CSF from older pediatric patients is similar to the previously reported adult CSF values. The mean CSF GM1 ganglioside concentration in pediatric patients with active neurologic disease (53.1 +/- 30.0 ng/ml) is greater than that of children without central nervous system pathology. The temporal evolution and magnitude above baseline values of lumbar CSF GM1 ganglioside concentration in three neonates was correlated with the clinical status of these patients.

Adolescent↗
PubMed1979

Transplantation of azaserine-induced carcinomas of pancreas in rats.

Two pancreatic adenocarcinomas which had been induced in Wistar/Lewis rats by azaserine treatment were transplanted into rats of the same strain by subcutaneous and intraperitoneal injection of minced tumor. Subsequently, we have serially transplanted into non-radiated recipients. Transplanted tumors have maintained evidence of acinar cell differentiation including the presence of zymogen granules in tumors studied by electron microscopy, and of lipase, amylase and trypsin activity in the supernatant of tumor homogenates. Histologically, the tumors vary from poorly differentiated solid carcinomas to well differentiated variants which form acini. Transplanted tumors are locally invasive and have metastasized to lung and liver in some recipients.

Adenocarcinoma↗
PubMed1979

Reye syndrome: computed tomographic documentation of disordered intracerebral structure.

Four patients with well documented Reye syndrome were examined with noncontrast computed tomography. Acute findings are those of diffuse cerebral edema with low density in deep white matter, increased gray-white matter differentiation, and evidence of secondary ventricular compression. The diffuse nature of the changes is unlike the more focal pattern often seen in true viral encephalitis. Residual changes after severe diseases are those of nonspecific cerebral degeneration and are most pronounced in the frontal lobes. Atrophic ventricular dilatation was observed in two cases. Computed tomography findings correlate with all known pathologic studies and with the subsequent clinical courses in the patients examined.

Brain↗
PubMed1979

Contrast sensitivity of the human neonate measured by the visual evoked potential.

Visual evoked potentials (VEPs) were recorded from a total of 97 1- to 10-day-old infants, with phase-reversing sinusoidal grating stimuli. The grating contrast or spatial frequency for which 50% of infants gave a statistically significant VEP was taken as a measure of threshold. This procedure yielded an estimate of neonatal acuity of 0.85 cycles/degree and an optimal contrast threshold of 50%. VEPs from an older infant showed good agreement with behavioral measures of sensitivity on the same individual. Comparison of the neonatal VEP results with behavioral data from 5-week-old infants, suggests little change in visual performance over the first month of life.

Evoked Potentials↗
PubMed1978

The comparative bioavailability of Lanoxin tablets and Lanoxicaps with and without sorbitol.

(1) The mean cumulative urinary digoxin excretion over 8 days was compared in 8 healthy volunteers after single doses of digoxin administered as 3 Lanoxin tablets of 0.25 mg, 3 digoxin tablets of 0.2 mg, 12 Lanoxicaps without sorbitol of 0.05 mg, 6 Lanoxicaps without sorbitol of 0.1 mg digoxin, 3 Lanoxicaps without sorbitol of 0.2 mg and 3 Lanoxicaps with sorbitol of 0.2 mg. (2) There was no significant difference between the 8 day cumulative urinary excretion for any of the Lanoxicaps treatments. (3) Cumulative urinary excretion after 3 digoxin tablets of 0.2 mg was significantly (P less than 0.05) lower than after all other treatments. (4) Cumulative urinary excretion after 3 Lanoxin tablets of 0.25 mg was not significantly different from that after any of the Lanoxicaps treatments except 0.1 mg Lanoxicaps without sorbitol, it was significantly (P less than 0.05) lower after the latter. (5) Mean urinary excretion of digoxin was 60% of ingested dose for all Lanoxicaps treatments and was significantly (P less than 0.05) higher than the mean value of 50% for both tablet treatments. (6) Enhanced absorption of digoxin from Lanoxicaps was confirmed and shown to be unrelated to the sorbitol content of the capsule shell.

Adult↗