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Biomedical subjects

L Rochon

Publications and source records attributed to L Rochon.

At least 19 recordsLinked to original sources
PubMed1994

Sarcomatoid carcinoma of the head and neck.

BACKGROUND: Sarcomatoid carcinoma (SC) of the upper aerodigestive tract is a rare malignancy of which the diagnosis, optimum treatment, and prognosis remain controversial. A series of 17 patients with SC is presented, along with an analysis of potential prognostic factors, outcome following treatment, and patterns of failure. MATERIALS AND METHODS: Hospital charts and pathology material were reviewed in all cases. The end points chosen were overall survival (OS), disease-free survival, and local control above the clavicles. RESULTS: There were 15 male and 2 female patients with a median age of 70 years. With a median follow-up length of 29 months, the median survival time was 32 months with an actuarial survival of 72% and 42% at 2 and 5 years, respectively. CONCLUSION: All recurrences were detected within 30 months from diagnosis. There was an OS advantage for patients with early-stage disease, patients with extralaryngeal presentations, and patients treated with surgery.

Aged↗
PubMed1992

Fourth branchial cleft cyst.

Remnants of the fourth branchial arch are uncommon clinical entities. They may present in either the neck or chest in association with aortic arch development. They are encountered more frequently in younger individuals as an asymptomatic left-sided neck mass, recurrent neck abscess or suppurative thyroiditis. In view of the rarity of this lesion, we thought it worthwhile to present the case of a 25-year-old female with a diagnosed fourth branchial cleft cyst in her left lower neck. The embryology and management of these cases is discussed.

Adult↗
PubMed1991

Spindle cell myoepithelioma of the nasal cavity.

Minor salivary gland neoplasms with mesenchymal-like features are uncommon in the sinonasal tract. We herein report a case of spindle cell myoepithelioma of the nasal cavity in a 69-year-old woman who presented with a rapidly expanding tumor accompanied by episodes of epistaxis. Although initially considered as a mesenchymal neoplasm, ultrastructural and immunophenotypical characterization demonstrated its myoepithelial nature. In the sinonasal setting, this unusual neoplasm may be confused with soft tissue tumors showing spindle cell or myxoid features. Staining for cytokeratin is found to be the most useful adjunct to diagnosis.

Aged↗
PubMed1990

Extracranial primitive neuroectodermal tumor of the head and neck.

Malignant peripheral neuroectodermal tumors are rare neoplasms of the head and neck. We describe a case of a teenage girl presenting with this neoplasm in the head and neck. The clinical histological and ultrastructural features are reviewed and presented, along with guidelines for the management of this highly aggressive neoplasm.

Adolescent↗
PubMed1990

Triploidy arising from a first meiotic non-disjunction in a mother carrying a reciprocal translocation.

We report on a 22 year old mother, a carrier of a 6;14 balanced reciprocal translocation, who aborted a triploid conceptus carrying a similar translocation. We showed the maternal origin of this triploidy, after non-disjunction at meiosis I. The phenotypic expression as a non-molar pregnancy, the contribution of the maternal translocation, and possible aetiological factors of triploidy are discussed.

Adult↗
PubMed1990

Multifocal cytomegalovirus-associated hepatic lesions simulating metastases in AIDS.

Fatty infiltration of the liver has been described in association with a large number of systemic conditions. The authors describe a case of multifocal fatty infiltration simulating metastatic disease. The patient had acquired immunodeficiency syndrome and pathologically proved cytomegalovirus hepatitis. To the authors' knowledge, neither entity has been described in association with this radiologic finding.

Acquired Immunodeficiency Syndrome↗
PubMed1990

Alterations in adipocyte response to lipolytic hormones during cold acclimation.

The effects of cold exposure (7 days, 5 degrees C) and cold acclimation (21 days, 5 degrees C) on the regulation of lipolysis were investigated in adipocytes isolated from epididymal fat pads of rats. Catecholamines stimulated lipolysis in an affinity sequence typical of the beta 1-adrenoceptor subtype: one-half maximum velocity (1/2 Vmax) isoproterenol (35 nM) much greater than 1/2 Vmax norepinephrine (150 nM) approximately 1/2 Vmax epinephrine (200 nM). Cold exposure markedly decreased the sensitivity (1/2 Vmax) and the responsiveness (Vmax) of the adipocytes to the lipolytic action of catecholamines. Addition of adenosine deaminase to fat cells isolated from cold-exposed rats did not normalize the lipolytic activity, suggesting that extracellular adenosine was not responsible for the obtunded lipolysis. This effect of cold exposure was transient as the lipolytic response to catecholamines was normal in fully cold-acclimated animals. Remarkably, the responsiveness of adipocytes to the lipolytic action of glucagon (200 nM) and adrenocorticotropic hormone (ACTH, 1 microM) progressively increased during cold acclimation. Adipocyte lipolytic response to dibutyryl adenosine 3',5'-cyclic monophosphate (cAMP) and theophylline was normal in cold-exposed rats, indicating that the lipolytic defect resides at an early step in the lipolytic cascade (pre-cAMP). On the other hand, the antilipolytic effect of insulin on norepinephrine-induced lipolysis significantly decreased during cold acclimation, particularly at physiological levels of insulin (nanomolar level). These results demonstrate that the transient decrease in the lipolytic action of catecholamines observed during cold acclimation is compensated by 1) an increased responsiveness of adipocytes to glucagon and ACTH and 2) by a decreased effectiveness of insulin to induce antilipolysis.(ABSTRACT TRUNCATED AT 250 WORDS)

Acclimatization↗
PubMed1987

Effects of exercise training on energy balance of ovariectomized rats.

The purpose of the present study was to investigate both the respective and interactive roles of exercise training and ovarian hormones on the regulation of energy balance. Female rats were divided into sedentary and exercise-trained groups. Each group thus formed was further divided into a sham-operated group, an ovariectomized group, or ovariectomized estradiol-treated group. Rats were exercise trained on a rodent motor-driven treadmill. After 33 days of treatment, rats were killed and the energy contents of carcasses, feces, and food were determined. Brown adipose tissue (BAT) thermogenesis was assessed through mitochondrial GDP binding. The results show that ovariectomy led to increases in food intake, body weight, and protein gains, whereas estradiol treatment abolished these effects. The results also show that exercise training reduced fat gain. Exercise training interacted with ovariectomy on energy gain; in sedentary rats ovariectomy enhanced the energy gain, an effect that disappeared in exercise-trained rats. However, exercise training was found to alter neither body weight and protein gains nor energy intake. Ovariectomy did not affect energy expenditure when the results are expressed in relative terms (kJ.kg body wt-0.67.day-1). Similarly, exercise training did not modify energy expenditure (kJ.kg body wt-0.67.day-1) once the cost of the training program was subtracted. BAT mitochondrial GDP binding was not affected by any of the experimental treatments. The present results therefore suggest that neither ovariectomy nor exercise training affect energy expenditure through regulatory forms of BAT-mediated thermogenesis.

Adipose Tissue, Brown↗
PubMed1987

Immunopathological characteristics of nasal polyps.

The presence of immunoglobulins in nasal polyps and surrounding mucosa was studied by direct immunofluorescence in 14 patients. Specific and total IgE were determined in polyps and in the sera of this group. Significant immunofluorescence to IgE was demonstrated in 12 polyps but in only four samples of adjacent mucosa. Eight polyps showed significant immunofluorescence to IgM. Six patients had elevated total IgE levels within polyp sac fluid in the absence of elevated serum values. In seven cases, specific IgE was found in polyp sac fluid which could not be detected on skin or serum testing. These results may suggest local production of IgE and support the concept of nasal polyps being a manifestation of a local allergic phenomenon.

Adolescent↗
PubMed1985

Vascular abnormalities in a fetus with multiple pterygia.

We describe a 16-week fetus with a lethal multiple pterygium syndrome and hydrops. No bony abnormalities were noted on radiographic or anatomical examination. A prominent meshwork of dilated, thin-walled vessels was present in the subcutis over the entire body. This abnormal vascularity may have caused pterygium formation and death of the fetus.

Abnormalities, Multiple↗
PubMed1985

Measurement of antigen-specific IgE in nasal secretions of patients with perennial rhinitis.

Sixteen of 53 patients with rhinitis had positive skin tests corresponding with serum-specific IgE (RAST). Concomitant positive nasal secretion (NS) RAST was found in 10/16. Four patients with both negative skin tests and serum RAST had positive NS RAST. In a subset of patients with perennial rhinitis, specific IgE may be detected only in NS. Further studies are necessary to document the clinical relevance of such NS IgE antibodies.

Absorption↗
PubMed1985

The immunological basis of nasal polyp formation.

Forty-six patients were studied to assess the role of immunological factors in the formation of nasal polyps. Total IgE levels did not correlate with positive skin testing and were generally higher in polyp sac fluid than in corresponding sera. Asthmatics had significantly higher IgE levels in both serum and polyp fluid than nonasthmatics. Specific IgE (RAST) found in polyp specimens could not be detected by conventional skin or serum testing in nine of 15 patients. By direct immunofluorescence IgE was present in 81% of polyp specimens compared with 13% in mucosal controls. These data indicate that nasal polyp formation may be an IgE mediated disease process and conventional skin or serum testing may not detect this local allergic process.

Adult↗
PubMed1982

Nasal polyposis--a multidisciplinary study.

Thirty-seven adults with nasal polyps were assessed in a multidisciplinary fashion. It was found that 43% of patients were allergic and 57% had asthma. Performing a polypectomy did not alter lower airway flow rates. Eosinophilia was prominent in nasal secretions of both atopics and nonatopics. Histological characteristics could not distinguish the "allergic" from the "inflammatory" polyp. Immunofluorescent studies indicated an abundance of polyp IgE leading to speculation of an IgE mediated process in polyp formation.

Adult↗
PubMed1980

Osteofibrous dysplasia.

Osteofibrous dysplasia is a benign, slowly progressive lesion which generally involves one tibia of an infant or young child, and presents as anterior bowing associated with a painless mass. Surgical intervention is usually not indicated but, when carried out, recurrences are common. Osteofibrous dysplasia is readily distinguished histologically from fibrous dysplasia by fibrous stroma, containing bone trabeculae which are rimmed by osteoblasts, and by a "zonal architecture." The radiographic appearance is that of a benign, lucent, intracortical lesion which is expansile and produces bowing of the tibia. Four patients with this condition are presented.

Age Factors↗