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J Graham

Publications and source records attributed to J Graham.

At least 91 records · Page 5Linked to original sources
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↗
PubMed1981

Lymphocyte transformation to specific antigens associated with Crohn's disease.

Specific lymphocyte transformation to three micro-organisms that have been implicated in Crohn's disease was performed. These were Pseudomonas maltophilia, Mycobacterium kansasii and Rotavirus. No significant differences were observed for any of the antigens tested. Simultaneous testing of nonspecific stimulation by PHA also showed no difference between patients and controls. These results do not support an aetiological role for these organisms mediated by a purely cellular mechanism.

Adult↗
PubMed1981

Cerebellar calcification.

Previous autopsy studies have shown that cerebellar calcification is commoner in Queensland than elsewhere. Computed cranial tomography, which is more sensitive than skull radiography, has confirmed that cerebellar and basal ganglia calcification occur more commonly in patients examined in Queensland than in North America. Although no distinctive neurological syndrome could be demonstrated, the affected patients showed a high incidence of hypertension, hyperuricaemia and raised serum creatinine levels. There is evidence that cerebellar calcification is a marker of previous lead intoxication. Common occurrence of renal impairment in these patients may be due to associated lead nephropathy. Subclinical lead exposure is associated with hyperuricaemia.

Adult↗
PubMed1980

Urinary bladder metastases from breast carcinoma.

Four patients with primary carcinoma of the breast metastatic to the urinary bladder are described. Hematuria was present in 3 of the 4 patients. Two of the 4 women had received steroidal drugs which may have a role in the development of this unusual metastasis. This complication developed no sooner than 32 months after diagnosis of malignant breast disease and occurred shortly before death in 2 of the patients. Bladder metastasis in women with a history of breast carcinoma may be more prevalent than has previously been suspected.

Aged↗
PubMed1980

A light microscopic and electron microscopic study of the superficial layers of the superior colliculus of the tree shrew (Tupaia glis).

Histochemical, Golgi, and electron microscopic methods were used to study the superficial layers of the superior colliculus of the tree shrew. Following horseradish peroxidase injections in the dorsal lateral ceniculate nucleus (LGd) and the pulvinar (Pul), retrogradely labeled somata were found in the upper two-thirds and the lower third of the stratum griseum superficiale (SGS), respectively, as has been described by Albano et al. ('79). In tissue prepared with Golgi methods, somata, similar in locatin and shape to those projecting to the LGd, had narrow, vertically oriented dendritic arbors, which were confined to the upper two-thirds of th SGS. Cells located in the lower third of the SGS had larger somata, similar to those projecting to the Pul, and wider dendritic arbors, which were confirmed to the lower two-thirds of the SGS. Electron microscopic comparison of the number of degenerating terminals following enucleation and striate cortex lesion indicated that within the SGS terminals from the retina overwhelmingly outnumbered those from the cortex. In both types of material, degenerating terminals were observed throughtout the SGS. However, the majority of te degenerating striate terminals were found in the lower SGS. Thus, cells that project to the LGd and those that project to the Pul differ not only with respect to location, size, and dendritic morphology, but also with respect to the proportion of retinal and straite afferents which terminate in the region of their dendritic trees.

Animals↗