Les effets auditifs aigus et chroniques du bruit

Résumé Cet article donne un aperçu des effets aigus et chroniques du bruit sur l'oreille et sur l'audition. Des observations anatomo-pathologiques et physiologiques sont comparées aux dégâts fonctionnels auditifs consécutifs à une surstimulation acoustique.

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Acute and chronic effects of noise on hearing

Summary A review of the main effects of noise exposure on the ear is presented: anatomical, histological and pathophysiological aspects of ear damage are compared with functional impairements of hearing following acute and chronic acoustic overstimulation.

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Akute und chronische Hörwirkungen des Lärms

Zusammenfassung Die vorliegende Arbeit gibt einen kurzen Überblick über die hauptsächlichen Ohrschäden, welche durch eine akute oder chronische Lärmexposition verursacht sind. Im besonderen werden die durch akustische Traumatisierung hervorgerufenen funktionellen Hörstörungen mit anatomopathologischen und pathophysiologischen Befunden in Beziehung gesetzt.

     

Pseudoaneurysms complicating organ transplantation: roles of CT, duplex sonography, and angiography

In a retrospective study of proved pseudoaneurysms (PAs) in 15 patients with transplanted organs (11 liver, three kidney, one pancreas), the results of computed tomography (CT), duplex sonography, and angiography were reviewed. Of the 15 cases of PA, eight occurred at the arterial anastomosis and seven were nonanastomotic. Three of the eight anastomotic PAs were caused by infection. Of the seven nonanastomotic PAs, four were caused by percutaneous biopsy, two were caused by infection, and one was of undetermined cause. In nine (60%) of the 15 patients the PAs were incidentally detected at imaging studies performed for other reasons. Diagnosis requires a high degree of suspicion. CT was performed in nine cases and duplex sonography in ten. The diagnosis of PA was made with CT in six (67%) patients and with duplex sonography in five (50%). CT and duplex sonography could not enable diagnosis when the PA was small, when the arterial anastomosis was not included in the field of study, or when enhancement with intravenously administered contract material was suboptimal. Angiography depicted the PAs in all 15 patients. In three liver transplant recipients with gastrointestinal tract bleeding, the causative PAs were detected only with angiography.     

Platelet transfusion therapy in acute leukemia: lack of effect of splenomegaly on transfusion requirements and risk of hemorrhage

Platelet transfusions are an important supportive measure during treatment for acute nonlymphocytic leukemia (ANLL). The presence of splenomegaly may produce decreased posttransfusion platelet increments leading some to recommend an increased dose of platelets per transfusion in this situation. Forty-nine newly diagnosed patients with ANLL were evaluated during 1980 and 1981, and 24% had palpable splenomegaly. Although treated with usual doses of platelets per transfusion, there was no detectable statistical increase in transfusion requirement or incidence of hemorrhage in patients with splenomegaly. Experimental evidence indicates that the splenic platelet pool enlarges with splenomegaly, but the life span of circulating platelets is not significantly changed. Furthermore, the splenic platelet pool is in dynamic equilibrium with the circulating platelet pool thus allowing these platelets to participate in hemostasis. Although posttransfusion increment in platelet count may be less, it appears that platelet transfusion therapy need not be altered solely because of splenomegaly.     

Peripheral blood B cell labeling indices are a measure of disease activity in patients with monoclonal gammopathies

Labeling indices (LI) provide a rapid measure of the bone marrow (BM) plasma cell proliferation rate and are useful in the diagnosis and prognosis of monoclonal gammopathies. Because circulating B cells may be a part of the neoplastic clone, we examined peripheral blood B cells that were producing the same cytoplasmic light chain isotype as the patient's monoclonal; protein (M-protein) and determined the peripheral blood LI (PBLI) by a two-color immunofluorescence bromodeoxyuridine method. The 105 patients studied were divided into three disease activity groups by standard clinical criteria. Median PBLI was 0.2% for the 29 patients with inactive monoclonal gammopathies (monoclonal gammopathy of undetermined significance [MGUS] and smoldering multiple myeloma [SMM]), 0.8% for the 35 patients with new, untreated multiple myeloma (MM), and 1.7% for the 41 patients with relapsed MM. These differences between groups were statistically significant (P less than .001, Wilcoxon). Four patients had high PBLI but clinically inactive gammopathy at the time of study, and all developed active MM within 6 months that required treatment. In 92 patients a BMLI was performed simultaneously with the PBLI (rank correlation coefficient, 0.69). In patients with new, untreated MM, use of both tests identified 72% of patients (23 of 32) with high LI, rather than 56% (18 of 32) by BMLI alone or 63% (20 of 32) by PBLI alone. These results suggest that PB B cells bearing the same cytoplasmic light chain isotype as the monoclonal protein are part of the malignant clone and can be kinetically active. The LI of these cells can provide a measure of disease activity and may help to differentiate active from inactive disease.