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Biomedical subjects

R Ruff

Publications and source records attributed to R Ruff.

13 recordsLinked to original sources
PubMed1996

Visuospatial learning: Ruff Light Trail Learning Test.

The assessment of memory typically includes tests for both audioverbal and visuospatial processing, while measurements of learning have primarily utilized the audioverbal mode. However, there exists no compelling reason why learning should not also be assessed in the visuospatial mode. The Ruff Light Trail Learning Test (RULIT) represents such an option. Normative values utilizing 307 volunteers indicated neither significant gender nor educational differences. However, an age effect for those subjects 55 and older was demonstrated, and our data suggest that the major reason for the inferior learning in this older subgroup was their reduced memory capacities rather than their slowed visuospatial processing. Multiple components including learning curves, error analysis, and delayed recall are presented. Test-retest data also indicate an adequate reliability. The validity was compared to concurrently administered neuropsychological tests, and, finally, the potential for neuropsychological application of this new test is discussed.

Journal Article↗
PubMed1994

Efficacy study of THINKable in the attention and memory retraining of traumatically head-injured patients.

The efficacy of computer-assisted attention and memory retraining was evaluated with 15 severely head-injured patients. Training with selected exercises tailored to the individual's needs were provided from the THINKable program for up to 20 hours in both the attention and memory remediation modules. The experimental design evaluated outcome by juxtaposing multiple baseline procedures with a pre- and post-group comparison. Significant results were documented on the computerized tasks, psychometric measures and on patient and observer ratings of everyday behaviours of attention and memory.

Adolescent↗
PubMed1990

Hemodynamic effects of a lorazepam-fentanyl anesthetic induction for coronary artery bypass surgery.

Previous anesthetic induction techniques using the combination of a benzodiazepine (midazolam or diazepam) and fentanyl have been reported to produce marked hypotension. In this study, anesthesia was induced with a combination of lorazepam and fentanyl in patients undergoing coronary artery bypass graft surgery. In 10 patients, anesthesia was induced using an exponentially declining continuous infusion of lorazepam equivalent to a total infused dose of 0.1 mg/kg over 15 minutes, which was supplemented at 10 minutes by fentanyl, 75 micrograms/kg, given as an infusion over 5 minutes. In 8 additional patients, anesthesia was induced with an exponentially declining infusion of fentanyl to a total dose of 75 micrograms/kg over 15 minutes, which was supplemented at 10 minutes by lorazepam, 0.1 mg/kg, given as an infusion over 5 minutes. Hemodynamics were recorded during a 20-minute observation period. One patient in each group required treatment for bradycardia during the initial drug infusion (before the second drug was added). Four additional patients in the group receiving lorazepam followed by fentanyl required treatment for bradycardia or hypotension within 10 minutes of the beginning of the fentanyl infusion. When an infusion of lorazepam was added to the fentanyl infusion, hemodynamics remained stable; however, the reverse order produced a high level of bradycardia and hypotension.

Anesthesia, Intravenous↗
PubMed1989

Comparison of different methods for detecting human immune deficiency virus in human immunodeficiency virus-seropositive hemophiliacs.

Since the detection of antibodies against the human immune deficiency virus (HIV) does not definitely prove HIV infection in hemophiliacs, virus detection was attempted by virus isolation from the peripheral blood monocytes (PBL), by demonstration of p24 antigen and decline of p24 antibody, and by detection of viral DNA by the polymerase chain reaction (PCR). Virus isolation was optimized by immediate coculture of PBL and by replacement of the reverse transcriptase test by the p24 antigen test, whereas the elimination of CD8+ lymphocytes proved to be unnecessary. Virus detection was dependent on the clinical stage of the illness. Virus isolation in 70 of 211 patients (33%) was more sensitive than detection of p24 antigen or decline of p24 antibody. PCR was performed in 25 patients and indicated infection in all of 15 isolation-positive cases and in 6 of 10 patients from whom virus was not isolated. Changes from negative to positive virus culture and from a weakly fusiogenic to a highly fusiogenic isolate were often accompanied by a progression of the disease. The results suggest that reactivation of HIV occurs when immune deficiency has become manifest. Apparently virus isolation detects only the virus already reactivated in vivo, whereas the PCR may also detect latent virus.

Antibodies, Viral↗
PubMed1988

Familial 'sleep apnea plus' syndrome: report of a family.

We describe a familial disorder consisting of sleep apnea, anosmia, colorblindness, partial complex seizures, and cognitive dysfunction. The phenotypic expression of the syndrome suggests an autosomal dominant inheritance with incomplete penetrance.

Adult↗
PubMed1982

Experimental cerebral ischemia produced by extracranial vascular injury: protection with indomethacin and prostacyclin.

To determine whether the production of brain ischemia is modified by antiplatelet agents administered at the time of extracranial endothelial injury, we modified a four-vessel occlusion rat model so that an electrogenic platelet thrombus in one carotid artery produced cerebral ischemia. DC current was passed through an anode around the left carotid artery of 11 rats with preoccluded vertebral and contralateral carotid arteries. Five of six untreated rats became unresponsive because of carotid occlusion and resultant cerebral ischemia; none of five animals pretreated with indomethacin and infused with prostacyclin (PGI2) were clinically affected. Light- and electronmicroscopic studies showed arterial platelet-fibrin thrombi and ischemic brain damage in untreated rats. All rats had received radiolabeled platelets; radioactivity was increased in the electrogenically injured left carotid arteries from treated and untreated rats, but counts were reduced by more than 80% in indomethacin/PGI2-treated rats (p less than 0.01).

Animals↗
PubMed1980

Left hemisphere visual processes in a case of right hemisphere symptomatology. Implications for theories of cerebral lateralization.

A patient with a visuospatial disturbance characteristic of posterior right hemisphere disease was examined under different conditions of stimulus presentation. The visuospatial defect, which was shown by the failure to perceive abnormalities concerning the left side of objects and the misperception of spatial relations, was present under conditions of unrestricted visual exposure. However, when the stimulus material was briefly exposed in the right visual field, performance improved substantially. These data suggest that the visuospatial defect seen after right hemisphere disease is atributable to factors other than the incapacity of the left hemisphere to process visuospatial information. Our observations, together with other evidence, lead us to question those theories of cerebral lateralization based on the notion that visuospatial processing is special to the right hemisphere.

Brain Neoplasms↗