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Biomedical subjects

G Belanger

Publications and source records attributed to G Belanger.

18 recordsLinked to original sources
PubMed1997

Treatment of Alzheimer's disease with sabeluzole: functional and structural correlates.

Sabeluzole, a new benzothiazole derivative, has been shown to be neurobiologically active preclinically and clinically appears to exert beneficial effects on memory. In this study, sabeluzole (5 or 10 mg twice daily vs. placebo) was investigated in patients with probable Alzheimer's disease over 1 year, with assessments of cognitive performance and structural changes. Cognitive performance was measured using the Alzheimer's Disease Assessment Scale periodically during treatment. Potential structural correlates in the frontal horn, caudate, third ventricle and hippocampal regions were examined by obtaining computerized tomographic (CT) images before and after treatment. Patients receiving sabeluzole evidenced greater stability than did placebo-treated patients in some cognitive measures. CT measures showed no significant changes from baseline, but some weak associations were found between relative preservation of cognitive function and smaller structural declines in the third ventricle and hippocampus. Cognitive outcome measures suggest that sabeluzole may have potential in slowing the cognitive deterioration of Alzheimer's disease. Furthermore, the method used to explore potential benefits on a morphologic level, although negative in this study, could yet have potential.

Aged↗
PubMed1993

Feasibility study of intraarterial vs intravenous cisplatin, BCNU, and teniposide combined with systemic cisplatin, teniposide, cytosine arabinoside, glycerol and mannitol in the treatment of primary and metastatic brain tumors.

Sixteen patients with intracerebral tumors received intraarterial cisplatin, teniposide, and BCNU combined with intravenous cisplatin, teniposide, and cytosine arabinoside. Oral glycerol and intravenous mannitol were given along with the intravenous chemotherapy in an attempt to increase drug delivery to tumor by augmenting tumor blood flow. Thirteen additional patients were treated with the same regimen, but received all the chemotherapy intravenously. Of the 16 patients receiving intraarterial chemotherapy (median survival, 14 weeks), none responded, 5 (31%) were stable for > 8 weeks, 8 (50%) failed, and 3 (19%) were unevaluable due to early death. Of the 13 patients receiving all their treatment intravenously (median survival, 13 weeks), 3 (23%) responded, 1 (8%) was stable, 7 (54%) failed, and 2 (15%) were unevaluable due to early death. In the patients receiving intraarterial chemotherapy, toxicity included ipsilateral retinal toxicity (2 patients), ocular pain or headache (10), periorbital swelling and flushing (6), increased brain edema with focal neurological deficits and drowsiness (5), and catheter-related carotid artery thrombosis followed by fatal herniation (1). Myelosuppression was worse in patients who received all their treatment intravenously than in those receiving intraarterial chemotherapy (p < 0.05). Neutropenic sepsis developed in 4 patients on the intraarterial arm (1 fatal) and in 5 patients on the intravenous arm (2 fatal). Other toxic effects were similar whether or not patients received intraarterial treatment or only intravenous treatment. Overall, toxicity of this regimen was excessive, and response rates were lower than would have been expected with single agent therapy.

Adult↗
PubMed1993

Transcutaneous energy transfer system performance evaluation.

A transcutaneous energy transfer (TET) system has been developed to power implantable devices such as artificial hearts, defibrillators, and electrical stimulators. Transcutaneous coupling of power to these implanted devices remains a favorable alternative as percutaneous lines are avoided in order to eliminate the potential of infection and allow patient mobility. In vitro, in vivo, ex vivo, and human cadaver studies of the electrohydraulic ventricular assist device TET have demonstrated that power can be transmitted over a range of skin thicknesses of 3-15 mm and can tolerate radial misalignments of up to 20 mm. Sensitivity to coil separation and radial misalignment variations has been addressed by the development of an auto-tuning TET. The system has only a 10% attenuation in secondary coil voltage when metallic objects are in contact with the primary coil. The system has demonstrated a power transfer efficiency of 60-80% for power demands from 5 to 70 W. The TET secondary coil will provide an output voltage of 10-25 V for current demands from 0.5 to 4.0 A. TET chronic studies in porcine models have demonstrated no adverse effect to the tissue when up to 40 W of power can be delivered to an implanted load without the tissue-contacting surface of the coil exceeding 42 degrees C. In conclusion, the TET is a feasible alternative for tether-free power transmission.

Cadaver↗
PubMed1993

Pediatric infection with the human immunodeficiency virus.

While rates of infection with the HIV virus are decreasing, the number of children infected continues to increase. There are multiple implications for the practicing pediatric dentist. Many of these children will seek or be referred by other health care providers for treatment of resulting oral pathology. Dentists must be prepared to provide dental services to the HIV-infected child.

AIDS-Related Opportunistic Infections↗
PubMed1987

Interhemispheric subdural hematoma.

Although relatively uncommon, interhemispheric subdural hematoma (ISDH) occurs more frequently than was suspected before the advent of computerized tomographic (CT) scanning. When its mass is sufficiently large to compress the medial cerebral hemisphere, specific focal neurological abnormalities may occur. These include weakness of the contralateral leg, or contralateral hemiparesis with the leg being weaker than the arm. On the unenhanced CT scan ISDH is seen as a crescent shaped, midline hyperdensity. Treatment is dictated by the clinical course. Evacuation of the hematoma by parasagittal craniotomy is recommended if the symptoms are pronounced.

Aged↗
PubMed1984

Cisplatin plus cytosine arabinoside in adults with malignant gliomas.

A combination of cisplatin and cytosine arabinoside was used to treat 21 patients with glioblastomas and 5 patients with recurrent grade II gliomas. Cisplatin 60-100 mg/m2 was given I.V. in 250 ml 0.45% saline and preceded by 500 ml dextrose 5% in 0.45% saline. Mannitol 50 g was given I.V. concurrently with the cisplatin. Cytosine arabinoside 500-1000 mg/m2 was given by rapid I.V. infusion immediately after the cisplatin. Of 25 evaluable patients, 10 (40%) experienced objective tumor shrinkage on CT scan, and 6 (24%) stabilized. There were 2 complete remissions. Patients who had had no prior treatment had a higher response rate (58%) than those previously treated (23%). Myelosuppression occurred in some patients 2-3 weeks after treatment. Gastrointestinal toxicity (vomiting and diarrhea) was dose-limiting. Two patients had possible neurological toxicity. Recommended doses for further studies are cisplatin 90 mg/m2 and cytosine arabinoside 900 mg/m2.

Adult↗
PubMed1984

Treatment of malignant gliomas in adults with BCNU plus metronidazole.

Twenty-six adult patients with astrocytomas were treated with BCNU (1,3-bis(2-chloroethyl)-1-nitrosourea) 180-240 mg/m2 I.V. every 6-9 weeks, with metronidazole 1.5 g/m2 p.o. 12 h and 1 h before BCNU and again 6 h and 24 h after BCNU. Of twenty-two evaluable patients, 9 (41%) responded with evidence of reduced tumor size on CT scan, 3 (14%) stabilized and 10 (45%) failed. Patients with no prior chemotherapy or radiotherapy, good performance status, low grade tumors, and age less than or equal to 50 years had the highest response rates, although differences were not statistically significant. Median survival and duration of response have not been reached with a median follow-up time of ten months. Hematological toxicity was dose-limiting and was probably not augmented by the metronidazole. There was one death from infection that was possibly drug-related. Gastrointestinal toxicity was substantial, and was probably increased by the metronidazole. While the combination of BCNU and metronidazole were tolerable, the response rate seen was no higher than that noted for BCNU alone, and further studies using this dose-schedule are not recommended in astrocytomas.

Adult↗
PubMed1984

Spinal epidural lipomatosis: a complication of glucocorticoid therapy.

A 21-year-old woman receiving prolonged high dosage glucocorticoids developed spinal cord compression due to excessive accumulation of epidural fat. Computerized tomographic scanning confirmed the diagnosis and revealed a peculiar pattern of spinal cord displacement which we believe to be unique to compression by fat. Laminectomy did not afford relief, possibly because of prolonged neural compression or because of compression at a higher spinal level. Although an unusual complication of Cushing's syndrome, epidural lipomatosis should be considered when such a patient develops symptoms of spinal cord or cauda equina compression.

Adult↗
PubMed1981

Turnover rates of phosphoryl groups in ribosomal proteins of Physarum polycephalum. Evidence for two different mechanisms.

The rate of phosphate exchange in individual ribosomal proteins of Physarum polycephalum was determined in vivo. It was observed that the phosphoryl groups of S3, the major phosphoprotein, had a turnover rate of 1.5% per minute. The phosphoryl groups of proteins L1, L20 and L24 were stable. These results show that the phosphorylation of ribosomal proteins is regulated by at least two different mechanisms. The rapid turnover of phosphoryl groups of the major phosphoprotein is in agreement with the general observation that the phosphate content of this protein is modulated by the physiological state of the cells and possibly involved in the regulation of ribosome activity. The absence of phosphate exchange in acidic proteins suggests that these groups could play a structural role in the ribosome functions.

Adenosine Triphosphate↗
PubMed1978

Peridurography with metrizamide: animal and human studies.

Metrizamide (300 mg l/ml) was tested for spinal peridurography in conscious dogs and humans. Epidural metrizamide was non-irritating in volumes up to 12 ml. Larger volumes caused mild discomfort in two patients. Radiographic contrast was satisfactory, and there were no sequelae. Peridurography with metrizamide (300 mg l/ml) appears to be a safe, useful diagnostic procedure in ambulant patients.

Adult↗
PubMed1978

Traumatic central retinal vein occlusion.

A patient with the clinical picture of thrombosis of the central retinal vein following relatively minor head trauma is discussed. Only 2 reports in the literature have documented a similar event. It is suggested that the condition may have arisen as a result of an abnormality of the central retinal venous outflow system since such an abnormal pattern was discovered on orbital venography.

Adult↗
PubMedDate not supplied

Pediatric infection with the human immunodeficiency virus (HIV): head, neck, and oral manifestations.

The increasing incidence of HIV infection in the pediatric population is of concern for the practicing dentist. Long incubation periods of the virus, combined with difficulty in detection, results in many undiagnosed cases of prenatal and natal infections with HIV. As a result, many dentists will unknowingly treat HIV-positive children. This article presents most common features of pediatric HIV infection, placing special emphasis on manifestations which affect the head, neck, and oral tissues.

AIDS Dementia Complex↗
PubMedDate not supplied

Iohexol lumbar myelography: clinical study.

Forty-three patients underwent lumbar myelography with the new, nonionic contrast medium iohexol. Multiple laboratory examinations, neurologic examinations, and electrocardiograms showed no significant alterations after intrathecal injection of the contrast agent. Mild electroencephalographic changes were seen in one patient. Nineteen adverse reactions occurred in 13 patients; only one of them was considered severe. No patient experienced a seizure, auditory or visual hallucination, or similar neuropsychologic reaction. This is a distinct improvement over the side effects described for previous water-soluble contrast agents. The adverse reactions occurring with iohexol myelography are fewer in number and less severe than with metrizamide myelography, and radiographic visualization obtained with iohexol is equal to that obtained with metrizamide. With iohexol, it appears that the most disturbing and disabling neuropsychologic reactions have been reduced to an acceptable minimum.

Adult↗