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Biomedical subjects

B Benoit

Publications and source records attributed to B Benoit.

At least 55 records · Page 3Linked to original sources

Intraparenchymal epithelial (enterogenous) cyst of the medulla oblongata.

Intraparenchymal solitary cyst of the medulla oblongata was diagnosed on MRI examination in a 66-year-old woman with a nine year history of progressive brainstem dysfunction and three negative CT scan examinations. Craniotomy and drainage of the cyst to the IVth ventricle led to remarkable clinical recovery. Biopsy of the wall of the cyst revealed an epithelial lining with tonofilaments, desmosomes and surface coating on ultrastructural examination. Immunohistochemistry demonstrated positive reactions of epithelium for keratins, cytokeratins, epithelial membrane antigen and Ulex Europeus lectin, indicating endodermal origin of the cyst.

Aged↗

[Systematic inhibition of the luteinizing hormone with a gonadoliberin analog, triptorelin, during ovarian stimulation for fertilization in vitro. Choice of protocol].

The quality of ovarian stimulation for in vitro fertilization with or without an LH-RH analogue was investigated in a randomized trial involving 30 women divided into 3 groups. Group I women were treated with the conventional clomiphene citrate-human menopausal gonadotropin combination without LH-RH analogue. Group II women (long regimen) received a slow-release preparation of triptorelin (DTRp6-LH-RH), an LH-RH analogue, and human menopausal gonadotropin. Group II women (short regimen) were given triptorelin with human menopausal gonadotropin. Inhibition of the endogenous luteinizing hormone using triptorelin improved the results of in vitro fertilization in group II and group III women, but the short regimen was distinctly less compelling and less expensive than the long regimen.

Adult↗

Gangliocytoma of the cerebellum: ultrastructure and immunohistochemistry.

A 31-year-old man presenting with a cerebellopontine angle syndrome underwent subtotal resection of a gangliocytoma of the left middle cerebellar peduncle. The tumor was positive for 68-kD neurofilament protein and vasoactive intestinal peptide. No glial cells were identified on immunohistochemical or ultrastructural examination. Electron microscopic study of neoplastic ganglionic cells revealed the presence of dense core vesicles, synaptic junctions, Hirano bodies, and marked dystrophic changes in the neuritic processes. The nosology of this lesion is discussed. Similarities between the morphological changes shown by mature neoplastic ganglion cells and comparable structural alterations seen in the physiological senescence of nonneoplastic neurons are stressed.

Adult↗

Cellular blue nevus ("melanocytoma") of the spinal meninges: electron microscopic and immunohistochemical features.

A primary cellular blue nevus (melanocytoma) of the spinal canal in a 21-year-old woman is reported. Light microscopic examination revealed a melanotic neoplasm with histological patterns resembling schwannoma, dermal nevi, and neuroblastic-like tumor. The ultrastructural features of the neoplastic cells were similar to those in dermal blue nevi and melanomas. There was no evidence of arachnoidal cell differentiation. Immunohistochemistry revealed positive reactions for S-100 protein and neuron-specific enolase in many cells and no reactions for glial fibrillary acidic protein, cytokeratins, epithelial membrane antigen, 70-kD neurofilament protein, or Leu-7. Vimentin was strongly positive in the melanocytic cells as well as in the arachnoidal cells of involved meninges. The ultrastructural and immunohistochemical features support the nevoid nature of this tumor, which is frequently mislabeled as "melanotic meningioma."

Adult↗

[Beta-mimetics and Pourcelot's index].

In a series of 20 patients presenting a threat of premature delivery, the vascular resistance index of Pourcelot, in the umbilical artery, was measured before, and then 24 hours after starting a continuous Salbutamol perfusion. A moderate but significant decreased placental vascular resistances is noted under betamimetic treatment. Relaxation of the myometrium obtained with a tocolytic treatment could be implicated in this alteration of placental resistances.

Albuterol↗

Combined intraommaya methotrexate, cytosine arabinoside, hydrocortisone and thio-TEPA for meningeal involvement by malignancies.

Twenty-three adult patients with meningeal involvement by a variety of malignancies were treated with the intra-Ommaya combination of methotrexate, hydrocortisone, cytosine arabinoside, and thio-TEPA. Whole brain irradiation was also administered to most patients who had not previously received it. Most patients demonstrated improvement of cerebrospinal fluid parameters, but only 50% of the patients experienced neurological improvement. Patients who did not receive cranial irradiation and performance status 4 patients were less likely to respond than were patients who did receive cranial irradiation as part of their treatment and patients who were performance status 0-3. Four patients developed possible and 2 patients developed probable or definite serious neurological complications. Another 4 patients developed less severe, reversible neurological toxicity. It is possible (but still uncertain) that this regimen is more toxic than other less intensive regimens, and further studies should be undertaken cautiously.

Adult↗

Combined intraarterial and systemic chemotherapy for intracerebral tumors.

Twenty-six patients with intracerebral tumors (predominantly gliomas) were treated with intraarterial BCNU, VM-26, and cisplatin combined with the systemic administration of VM-26, methotrexate, vincristine, bleomycin, and procarbazine. Oral glycerol was given before i.v. VM-26. Twelve patients responded (46% of all patients and 63% of the fully evaluable patients). The response rate for gliomas was 50% if all patients were considered and 71% if only fully evaluable patients were considered. The response rate did not seem to be affected by glioma grade, prior chemotherapy, or pretreatment performance status. Median time to tumor progression for responders was 19 weeks. Median survival from initiation of treatment was 21 weeks for evaluable patients and 17 weeks for all patients. Median survival from initial diagnosis was 55 weeks. Myelosuppression was dose-limiting for the systemic chemotherapy. Reversible neurological toxicity was common, but tolerable. One patient developed ipsilateral blindness, and two patients developed prolonged neurological toxicity. Pulmonary toxicity was also seen. Vertebral artery infusions proved feasible, although difficult and more toxic than carotid infusions. Overall, this regimen was not more active than the intraarterial combination of BCNU, VM-26, and cisplatin without the systemic chemotherapy. Further studies of more intensive intracarotid therapy combined with different systemic drugs are being initiated.

Adolescent↗

Cytosine arabinoside plus cisplatin and other drugs as chemotherapy for gliomas.

Twenty-five evaluable patients with gliomas were treated with a combination of cytosine arabinoside plus cisplatin administered intravenously (IV). Ten of the 25 patients (40%) responded, including three of 13 patients (23%) with prior cranial radiation, and seven of 12 patients (58%) without prior cranial radiation. In a second study, intramuscular (IM) and oral caffeine were added to IV cytosine arabinoside plus cisplatin. Caffeine-induced seizures prevented escalation of the dose of caffeine to a level that would have been anticipated to potentiate the cytotoxicity of the cytosine arabinoside plus cisplatin. Twelve of 25 treated patients (48%) responded. Most of the patients had not received prior cranial radiation. In a third study, IV cytosine arabinoside was administered in combination with intracarotid and IV cisplatin, plus BCNU and tenoposide (VM-26). This study is continuing to accrue patients. Myelosuppression has been pronounced, but has generally been rapidly reversible. It is too early to comment on efficacy of this combination. Our results to date permit us to conclude that the combination of cytosine arabinoside plus cisplatin is capable of inducing regression of gliomas in some patients. We feel that further studies are warranted.

Antineoplastic Combined Chemotherapy Protocols↗

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↗

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↗

Management of acute subdural hematomas from aneurysmal rupture.

Subdural hematomas (SDH) from ruptured aneurysm (RA) are much less common than intracerebral (ICH) hematomas or subarachnoid (SAH) or intraventricular hemorrhage (IVH). With computerized tomography, preoperative diagnosis is now made more often. The authors have collected 18 such cases from a review of 897 cases of RA admitted to eleven medical centers in 1980 and 1981. Nine (50%) of these patients died prior to discharge from hospital. Four (22%) had surgery and died postoperatively and 9 (50%) were operated upon and survived. Thirteen (72%) of the patients showed anisocoria, decreased consciousness and unilateral weakness prior to surgery. Eight (89%) of the fatalities had shown preoperative herniation as opposed to only 5 (56%) of the survivors. The overall incidence of delayed ischemia due to vasospasm was 11% (2 cases). Those who died had greater midline shift and larger SDH on the admission CT scan. Sixteen (89%) of these patients were female. Thirteen (72%) had ruptured aneurysms on the internal carotid artery. All of these hematomas were unilateral and uniformly hyperdense, and the convexity hematomas were crescentic in shape. Seventeen (94%) had evidence of blood in locations other than the subdural space. If the patient is potentially salvageable and has a midline shift, the SDH should probably be evacuated immediately and the aneurysm clipped at the same operation since the development of a tentorial herniation has such an adverse effect on outcome.

Acute Disease↗

Intracarotid chemotherapy with a combination of 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU), cis-diaminedichloroplatinum (cisplatin), and 4'-O-demethyl-1-O-(4,6-O-2-thenylidene-beta-D-glucopyranosyl) epipodophyllotoxin (VM-26) in the treatment of primary and metastatic brain tumors.

Thirty-seven patients with intracranial primary or metastatic tumors were treated with an intraarterial combination of BCNU, cisplatin, and VM-26 to determine the efficacy, toxicity, and maximal tolerated doses for the combination. A transfemoral fluoroscopic approach was used to catheterize temporarily the internal carotid or vertebral artery. Thirteen of 19 (68%) evaluable primary brain tumors and 9 of 16 (56%) evaluable brain metastases responded. The response rate was lower in patients previously treated with both cranial irradiation and i.v. chemotherapy than in patients less heavily pretreated (54% vs. 82%), although even patients previously treated i.v. with all three of the study drugs responded. All five patients with both extracranial and intracranial evaluable tumor deposits experienced a greater response of their intracranial than of their extracranial tumor. Ipsilateral retinal and neurological toxicity were dose-limiting, with major toxicity (permanent decreased vision or hemiparesis) occurring in five of nine (56%) patients receiving doses of BCNU greater than or equal to 100 mg/m2 plus cisplatin, 60 mg/m2 plus cisplatin, 60 mg/m2, plus VM-26, 175 mg/m2. Only 9% of the patients treated with a lower VM-26 dose developed permanent severe toxicity, and the doses that we now recommend are: BCNU, 100 mg/m2; cisplatin, 60 mg/m2; and VM-26, 150 mg/m2. The response rate was also dose-related (100% at the highest doses tested vs. 57% at the lower doses).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

Intraventricular hemorrhage from ruptured aneurysm. Retrospective analysis of 91 cases.

Intraventricular hemorrhage (IVH) from aneurysm rupture is generally considered to be of grave prognostic significance. Ninety-one cases have been studied retrospectively from seven medical centers. The overall mortality rate was 64%. The dramatically poor condition of these patients leads to their rapid admission to the hospital. Eighty-seven percent were admitted on Day 0 or 1, and more than half were classified neurologically as Grade 4 or 5. A multiple regression analysis explained 56% of the variance in survival, using the variables of ventriculocranial ratio (VCR), day of admission, diastolic blood pressure, location of aneurysm, associated intracerebral hematoma, age, grade on admission, sex, and systolic blood pressure. No patient with a VCR of more than 0.25, as calculated from the initial computerized tomography (CT) scan, survived. No patient whose smallest VCR was 0.23 or more survived. This ratio can be simply measured with a millimeter ruler from the CT scan. Patients with IVH usually had enlarged ventricles, even initially. The overall results suggest that early management of intracranial hypertension should be more generally considered, although even when this was done the prognosis was still guarded. The timing of surgery was not an important determinant of outcome, although a significant number of patients died awaiting surgery.

Adolescent↗

Cyanide toxicity following nitroprusside induced hypotension.

Several recently reported deaths following the use of sodium nitroprusside have been attributed to the accumulation of the nitroprusside metabolite, cyanide. In this study, brief nitroprusside infusions (mean = 36 minutes) were administered in currently recommended doses during intracranial surgery. The peak blood cyanide following the infusions was 65.2 +/- 17.5 microgram per cent (mean +/- SE) (n = 13). It occurred within 45 minutes after infusion. The highest cyanide level detected was 205 microgram per cent, which is within the range of reported lethal blood cyanide levels. Metabolic acidosis developed in the four patients with the highest blood cyanide levels (range 90-205 microgram per cent). This occurred between 45 and 180 minutes following the cyanide peak. Blood ATP levels were depressed in the same patients. These findings are indicative of disturbed aerobic metabolism. We conclude that there is evidence of cyanide toxicity when nitroprusside is infused into patients using currently recommended doses. We recommend that for short infusions the dose of sodium nitroprusside should not exceed 0.5 mg/kg.

Acidosis↗