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Biomedical subjects

J Graham

Publications and source records attributed to J Graham.

At least 361 records · Page 20Linked to original sources
PubMed1984

Speech ratings by speech clinicians, parents and children.

Ratings of speech samples of children with cleft palate were obtained from speech clinicians in a Cleft Palate Clinic, speech clinicians in the public schools, parents of children with clefts, parents of children without clefts, children with clefts and children without clefts. Analyses of the obtained ratings suggest that nasality and articulation ratings obtained from adult groups do not differ appreciably. Correlations between ratings of nasality and articulation are interpreted as suggesting that speech clinicians are more likely to differentiate between these two variables than other listener groups.

Adolescent↗
PubMed1983

Influence of platelet lysate on colony formation of human breast cancer cells.

The effect of platelet lysate on the growth of human breast cancer cells was studied in the two-layer soft agar culture system. Lysate was prepared from frozen-thawed outdated human platelets. Eighteen to 446 colonies (mean: 85) grew from 50 of 57 tumors plated at a density of 5 X 10(5) cells/plate, yielding control plating efficiencies from 0.004-0.089. The viability of the cells plated ranged from 10-80%. All tumors were also plated with 200 micrograms/ml platelet lysate. Significant enhancement of colony formation (CF) (p less than 0.025) appeared in 26 of the 57 tumors tested. The number of colonies grown from these 26 tumors ranged from 36-580 (mean: 152). The extent of enhancement varied from 1.25-3.19. Significant suppression of CF (p less than 0.025) appeared in 6 of the 57 tumors. The extent of the suppression varied from 0.35-0.67. Platelet lysate induced no change in CF in the 7 tumors that failed to form colonies in control plates. There was no relationship between tumor cell viability and either the number of colonies appearing in control plates or the response of CF to platelet lysate. By contrast, there was a significant correlation (p less than 0.005) between viability and the extent of enhancement of CF by lysate. Concentrations of lysate varying from 50-400 micrograms/ml did not yield a consistent dose-related increase in CF. The results indicate that platelet lysate significantly enhances colony formation from a substantial percentage of human breast tumors.

Agar↗
PubMed1983

Buoyant densities of macromolecules, macromolecular complexes, and cell organelles in Nycodenz gradients.

Nycodenz is a new nonionic iodinated density gradient medium which has several advantages over metrizamide. Although, overall, biological samples band at similar densities in Nycodenz and metrizamide gradients, a number of significant differences were found. As compared with metrizamide, not only does Nycodenz appear to interact less with proteins but also the buoyant density of chromatin is less affected by the amount loaded onto the gradient. A high degree of resolution is obtainable using Nycodenz gradients; thus, it is possible to separate density-labeled DNA and to subfractionate subcellular membrane fractions.

Animals↗
PubMed1983

Stimulation of human tumor colony formation by platelet lysate.

The effect of platelet lysate on the growth of colonies of human tumor cells was examined in vitro by using the human tumor stem cell assay. Lysates were prepared from freeze-thawed outdated platelets. Eighteen to 446 colonies (mean 85) grew from 211 of 299 tumors plated at a density of 5 X 10(5) cells/plate. The plating efficiency ranged from 0.001% to 0.35%. The viability of the cells plated ranged from 10% to 90%. Platelet lysate significantly enhanced (p less than 0.05) colony formation from cells from 99 (47%) of 211 patients. The number of colonies grown with lysate from these 99 tumors ranged from 36 to 580 (mean 152). The enhancement factor varied from 1.25 to 6.69. Platelet lysate significantly decreased colony formation (p less than 0.05) from cells from 27 (13%) of the 211 tumors and had no effect on 85 (40%). Maximum increases over control occurred after 6 days in 79 (94%) of 84 tumors and after 10 days in 5 (6%). The extent of enhancement by platelet lysate of tumor colony formation correlated with cell viability (r = 0.545, p less than 0.005). The growth-promoting activity for human tumors was nondialyzable, stable with heating at 56 degrees or 70 degrees C for 30 min and at 100 degrees C for 2.5 min, substantially inactivated by heating at 100 degrees C for 5 min, and totally inactivated by heating at 90 degrees C for 30 min. It was partially inactivated by trypsin and abolished by periodate oxidation. The results suggest that a proportion of tumors of epithelial and mesodermal origin are responsive in vitro to growth-promoting factor(s) derived from human platelets.

Blood Platelets↗
PubMed1983

Scoliosis and growth. An analysis of the literature.

A review of the literature discloses the buckling phenomenon as responsible for the initiation of lateral deformation and the progression of small curves in idiopathic scoliosis. From the point of view of parsimony, buckling explains how ligamentous laxity, increased interdiscal flexibility, muscular asymmetries, neurologic lesions, morphologic, anthropometric, and sexual differences would contribute to development of the deformity. Thus, a buckling theory seems to embody the fragmented character of present information about the etiology of idiopathic scoliosis.

Adolescent↗
PubMed1982

Lead mine waste: hazards to livestock.

Waste from disused lead mines is used for a variety of purposes and has been implicated in outbreaks of lead poisoning in animals. Three outbreaks of lead poisoning, two in cattle and one in farm dogs, occurred in the south of Scotland. In the first outbreak, three housed suckler cows died and two were clinically affected but recovered after treatment. In the second, four heifers died and two recovered after therapy. Blood samples taken from cattle in both outbreaks contained lead in concentrations from 0 . 59 to 2 . 00 ppm (normal blood lead level 0 . 05 to 0 . 25 ppm). Post mortem examinations revealed signs of lead poisoning. Metallic particles in the rumens and abomasums of affected animals suggested mine waste as the source of the lead and subsequently it was found that the material had been used in the construction of a ramp over which silage was pushed (outbreak 1) and to fill potholes on the farm (outbreak 2). Covering the relevant areas with concrete prevented further occurrences. Farm dogs were affected over a period where mine waste was used to resurface a road. Two dogs died, six others showed signs of lead poisoning and others, with no clinical signs, had elevated blood lead levels.

Animals↗
PubMed1982

Some topographical connections of the striate cortex with subcortical structures in Macaca fascicularis.

Subcortical connections of the striate cortex with the superior colliculus (SC), the lateral pulvinar (Pl), the inferior pulvinar (Pi) and the dorsal lateral geniculate nucleus (LG) were studied in the macaque monkey, Macaca fascicularis, following cortical injections of tritiated proline and/or horseradish peroxidase. All four structures were shown to receive topographically organized projections from the striate cortex. The exposed surface of the striate cortex was found to be connected to the rostral part of the SC and the caudal part of the LG. Injections of the exposed striate cortex close to its rostral border resulted in label in adjoining parts of the Pl and Pi. The ventral half and dorsal half of the calcarine fissure were connected with the medial and lateral parts of the SC, the ventrolateral and dorsomedial portions of the Pl and Pi and the lateral and medial parts of the LG, respectively. Injections located at the lateral posterior extreme of the calcarine fissure resulted in label at the optic disc representation in the LG. The horseradish peroxidase material demonstrated that LG neurons in all laminae and interlaminar zones project to the striate cortex.

Animals↗
PubMed1982

Relation of concentrations of Haemophilus influenzae type b in cerebrospinal fluid to late sequelae of patients with meningitis.

Forty-four patients with Haemophilus influenzae type b meningitis had follow-up evaluations approximately one year after hospital discharge. Patients with greater than or equal to 10(7) colony-forming units of H. influenzae type b per milliliters CSF had significantly greater frequencies of speech impairment (P less than 0.001), hearing loss (P = 0.04), and moderate or severe neurologic sequelae (P less than 0.01). Patients with greater than or equal to 1 microgram H. influenzae b antigen/ml CSF had a greater incidence of hearing loss (P = 0.03) but not of speech abnormalities (P = 0.06) or other neurologic sequelae (P = 0.64). Glucose concentrations less than 10 mg/dl correlated with the incidence of hearing loss (P = 0.02) and speech impairment (P = 0.02). "Partial" antibiotic therapy, CSF protein concentrations, and number of CSF polymorphonuclear leukocytes did not correlate well with sequelae. These data indicate that pretreatment concentrations of H. influenzae b and glucose concentrations in CSF were the best predictors of late sequelae of patients with H. influenzae b meningitis.

Adolescent↗
PubMed1982

Effects of visual cortical lesions on receptive-field properties of single units in superior colliculus of the rabbit.

1. One hundred seventy-nine single units were studied in the superior colliculus of seven Dutch-belted rabbits following ablation of the ipsilateral visual cortex. The response characteristics of these units were compared with those of 284 single units recorded from the superior colliculus of 20 intact animals. 2. In both the upper and lower parts of the stratum griseum superficiale and in the stratum griseum intermediate, there were smaller proportions of direction-selective visual units in the decorticated animals than in normal ones. 3. In the upper stratum griseum superficiale, a larger proportion of units responded to stroboscopic illumination in the decorticated animals than in normal ones. Also, in the decorticated animals, there was a larger proportion of units whose responses to a small moving stimulus were inhibited by the simultaneous presentation of stroboscopic illumination. 4. In both the upper and lower parts of the stratum griseum superficiale, a larger proportion of visual units responded well to stationary stimuli and a smaller proportion of visual units showed habituation in decorticated animals compared to normal ones. 5. In the lower stratum griseum superficiale, the receptive fields of units were larger and were more elongated in the anterior-posterior dimension in the decorticated animals than in normal ones. 6. In the two preparations, units did not differ in responsiveness or spontaneous activity; and visual units did not differ in the sustained or transient nature of their responses, the selectivity for light or dark stimuli, the selectivity for onset or offset of the stimuli, or the selectivity for stimulus velocity. 7. This study provides evidence for the importance of the visual corticotectal projection in the elaboration of the visual receptive-field properties of units in the superior colliculus of the rabbit. In addition, this study shows that the subdivisions of the superior colliculus are differentially affected by the loss of the visual corticotectal projection.

Animals↗
PubMed1982

Three-dimensional lordosimeter. A device for the nonradiographic assessment of spinal configuration.

A technique is presented for the nonradiographic assessment of spinal configuration. Its use in the assessment of scoliotic curvatures is discussed in the light of existing radiographic and nonradiographic techniques. The reproducibility of point-encoding measurements relative to a fixed standard is shown to be 98.8 percent. The correlation of pointencoded spinal angles with similar data taken from x-rays is significant at p less than 0.0005. The average standard deviation in the measurement of spinal angles of 10 successive trials on five test subjects is 3.55 degrees +/- 1.95 degrees.

Humans↗
PubMed1981

Origins of the pretectal and tectal projections to the central lateral nucleus in the cat.

The pretectal and tectal projections to the thalamic intralaminar nuclei in the cat were studied following horseradish peroxidase injections centered in the central lateral nucleus. Retrogradely labeled neurons were found in both the pretectum and the superior colliculus, ipsilateral and, to a lesser extent, controlateral to the injection site. Labeled pretectal neurons were found throughout all pretectal nuclei; the densest concentrations were in the medial pretectal nucleus, the anterior pretectal nucleus and the nucleus of the posterior commissure. The major source of tectal projections were the small neurons in the stratum griseum intermediate.

Animals↗
PubMed1981

Origins of the projections of the superior colliculus to the dorsal lateral geniculate nucleus and the pulvinar in the rabbit.

The origins of the projections of the superior colliculus to the dorsal lateral geniculate nucleus and to the pulvinar in Dutch-belted rabbits were investigated using horseradish peroxidase (HRP) methods. Following injections of HRP in the dorsal lateral geniculate nucleus, retrogradely labeled neurons were found in the upper two-thirds of the stratum griseum superficiale of the ipsilateral superior colliculus. Most of the labeled somata were spindle-shaped, and their major axes tended to be perpendicular to the surface of the superior colliculus. In contrast, following injections of the pulvinar, labeled neurons were found in the lower third of the ipsilateral stratum griseum superficiale. In these cases, the labeled somata were larger than those labeled following dorsal lateral geniculate injections and were multipolar in shape.

Animals↗