PubMed Health⌕ Search

Biomedical subjects

R G Robinson

Publications and source records attributed to R G Robinson.

At least 217 records · Page 12Linked to original sources
PubMed1986

Mechanisms of lateralized hyperactivity following focal brain injury in the rat.

Recent work in this lab which explores the differential behavioral and neurochemical changes following left versus right cerebral damage is reviewed and neural mechanisms which may account for this asymmetry are proposed. Damage to the right frontoparietal cortex in rats, caused by either ischemia or suction, produces hyperactivity for as long as a month after surgery. These lesions also produce decreases in norepinephrine (NE) levels in both ipsilateral and contralateral cortex and in the locus coeruleus. Similar lesions in the left cortex, however, do not produce these behavioral or biochemical changes. Similar lateralized responses have also been produced by intracortical injections of NE neurotoxins, by cortical island lesions, by destroying cortical efferents, and by producing lesions in the nucleus accumbens, which receives a cortical input. These lateralized responses suggest that the neural mechanisms that mediate this phenomenon include both cortical and subcortical components. It is proposed that the neuroanatomical asymmetry is in either accumbal efferents or their postsynaptic connections.

Animals↗
PubMed1986

Cold water stress abolishes hyperactivity produced by cortical suction lesions without altering noradrenergic depletion.

The effect of forced cold water (15 degrees C) swimming on catecholamine depletions and behavioral hyperactivity produced by focal right hemispheric cortical suction lesions was assessed. Through the 30-day postoperative period, lesion and sham-operated control animals were placed in cold water for 5 min either four times at weekly intervals, once during the first postoperative week, or not at all. The effect of this cold water swim test was different for lesion and control animals. Stress at weekly intervals produced hyperactivity in control animals, but weekly stress in animals with focal suction lesions blocked the development of their expected hyperactivity. A single stress experience, 1 week postoperative, was also sufficient to block the development of hyperactivity in the lesion group. Stress, although affecting behavior, did not alter the pattern of norepinephrine depletions in animals receiving right hemispheric cortical suction lesions.

Animals↗
PubMed1986

Lateralized response to cortical injury in the rat: interhemispheric interaction.

This study was conducted to investigate the role of interhemispheric interaction in the production of spontaneous hyperactivity following right but not left frontal cortical suction lesions in the rat. Bilateral lesions, either simultaneous or left followed 1 week later by right, led to spontaneous hyperactivity and bilateral depletions of cortical norepinephrine concentrations. Rats given corpus callosum sectioning as neonates and frontal cortical suction lesions as adults developed spontaneous hyperactivity only when the right hemisphere was injured. These data suggest that lateralized spontaneous hyperactivity as elicited by small suction lesions of the right hemisphere does not depend on interhemispheric release or interaction and that at least the cortical mechanism is in the right hemisphere itself.

Animals↗
PubMed1986

Hematologic depression following therapy with strontium-89 chloride.

Initial clinical trials using strontium-89 (Sr-89) chloride for the treatment of painful skeletal metastases have observed minimal or no hematological depression secondary to the radiostrontium. A patient with marked bone marrow depression temporally related to the administration of the Sr-89 is reported, and the need for close hematological monitoring is emphasized. Bone marrow tumor replacement may predispose patients to marrow depression from radiostrontium, and such patients should be treated with caution.

Aged↗
PubMed1986

Two-year longitudinal study of post-stroke mood disorders: comparison of acute-onset with delayed-onset depression.

Patients who developed post-stroke depression 3 to 24 months after hospital discharge (N = 21) were compared with patients who developed depression during hospitalization (N = 26) and patients who never developed depression over 24 months of follow-up (N = 15). During the acute hospitalization and at follow-up, the three groups were not significantly different in their demographic characteristics, neurological impairment, intellectual impairment, or quality of social support. The acute depression group, however, showed an increased correlation between impairment and depression from hospitalization to follow-up. Findings suggest that impairment does not produce depression, but, once depression occurs, it may interact with impairment to influence post-stroke recovery.

Acute Disease↗
PubMed1986

Depression influences intellectual impairment in stroke patients.

Patients with ischaemic lesions of the left cerebral hemisphere were examined for depression and intellectual impairment: in non-depressed patients, the severity of impairment was related to both lesion volume and location, as assessed by CT scan analysis. Cognitive impairment in patients with major depression was greater than predicted by lesion volume alone, and when patients were matched for severity of impairment, depressed patients had smaller lesion volumes than the non-depressed. After six months, non-depressed patients had significantly less cognitive impairment than depressed patients who showed no improvement. Both depression and lesion volume were significantly and independently related to cognitive impairment. These findings suggest that post-stroke depression can produce a true dementia in its own right, and that treatment of post-stroke depression might benefit cognitive function.

Adult↗
PubMed1986

Strontium 89 for palliation of bone metastases.

At the University of Kansas Medical Center, systemic use of strontium 89 ((89)Sr), a betaemitting radioisotope, was evaluated in the treatment of metastatic carcinoma to bone for relief of bone pain. Eighty-five patients were treated with systemic (89)Sr in the dosage of 30 to 40 μCi/kg. All patients had multiple bone metastases, the majority with primary breast or prostatic cancer. The response to treatment was evaluated by daily diary entries, changes in the amount of pain medication, periodic bone scans, and other laboratory values.In the patients who survived (47) and who were observed for three or more months, overall results showed 15 percent becoming pain free; 23 percent showed marked improvement with decreased consumption of pain medication; 53 percent showed mild but significant improvement in pain relief and decrease in pain medication requirement; and 9 percent showed no improvement. No patients noted a worsening of bone pain after the treatment. There was a combined favorable response in 91 percent (43/47) of patients with some meaningful palliation after (89)Sr therapy. This study, using (89)Sr systemic therapy, suggests that this isotope may be a valuable adjuvant therapy for palliation of pain from metastatic bone lesions.

Aged↗
PubMed1986

Imaging studies in neonatal herpes simplex encephalitis.

Herpes simplex encephalitis (HSE) is the most common form of sporadic encephalitis in man and usually results in death or permanent neurologic deficit. Neonatal HSE does not show the characteristic anatomic localization in the temporal lobe observed in adults and in older children which suggests that the disease process is different in this age group. The abnormalities observed with radionuclide brain imaging and computed tomography (CT) are more diffuse and bilateral. The clinical outcome of the disease is highly dependent on early institution of therapy. Therefore, early diagnosis is critical. Knowledge of neonatal HSE imaging patterns may alert the clinician to the proper diagnosis.

Brain↗
PubMed1986

The Tolosa-Hunt syndrome: computed tomographic changes and reversal after steroid therapy.

Painful ophthalmoplegia, or Tolosa-Hunt syndrome, is due to nonspecific inflammation of the cavernous sinus. We report two cases of the Tolosa-Hunt syndrome, which, on high resolution fourth-generation CT scan, showed an abnormality in the cavernous sinus consisting of an enhancing soft tissue mass. Both the clinical findings and the CT lesion resolved after high-dosage corticosteroid therapy.

Adrenal Cortex Hormones↗
PubMed1985

Right and left cortical lesions asymmetrically alter cerebrovascular permeability in the rat.

Vascular permeability and intravascular space in the rat cerebral cortex and hypothalamus were assessed 5 and 14 days after the production of either right or left hemisphere frontal cortical suction lesions. Rats were intravenously injected with large (dextran, 50,000 kdalton) and small (inulin, 5000 kdalton) molecular tracers and tissue samples were removed for assay after 7 min. Five days following lesions of the right but not left hemisphere, inulin levels in the cortical region posterior and contralateral to the lesion site were significantly higher than control values. Dextran levels were not increased in this region by lesions of either hemisphere. However, both right and left hemisphere lesions led to a significant elevation of inulin and dextran levels (inulin higher than dextran) in the cortex surrounding the lesion site. Fourteen days after lesion of either hemisphere, tracer levels were not elevated over control in any region examined. These results suggest that both right and left hemisphere cortical lesions transiently increase local vasopermeability (and perhaps intravascular space), but that only right hemisphere lesions selectively increase inulin in cortex distant from the lesion site, probably from lesion-induced alterations in cerebrovascular permeability.

Animals↗
PubMed1985

Journal matters.

Explore the source record for details and available documents.

Authorship↗