ABSTRACT
N-Hexane is a solvent widely used in manufacturing as a cleaner, degreaser and component of rubber cement. Chronic exposure to n-hexane either through contact with unprotected skin or inhalation can lead to the development of clinical symptoms and electrophysiological changes similar to those of inflammatory demyelinating polyneuropathy which requires careful differential diagnosis. This article presents three cases of severe predominantly motor polyneuropathy with demyelinating features in 15- and 16-year-old adolescents. The results of laboratory tests were within normal limits; electroneuromyography revealed symmetrical involvement of sensory and motor fibers of the nerves of the legs and arms with a decrease in the speed of propagation of excitation and conduction blocks. Sural nerve biopsy revealed intraneural and perineural swelling without any signs of inflammation or fibrosis confirming the genesis of the neuropathy. Despite a relatively favorable prognosis there is no specific therapy for hexane poisoning and the recovery period can last up to several years.
Subject(s)
Hexanes , Peripheral Nervous System Diseases , Adolescent , Humans , Electromyography , Neural ConductionABSTRACT
The accuracy of the anesthetic vaporizers with modern vaporizing devices is complicated by necessity of providing small anesthetic vapor concentration for a wide range of gas flows, especially at small flows, and at use of a combination of inhalation anesthesia with intravenous one. Compliance with the requirements of the international standards concerning the accuracy of low-concentration anesthetic vapor batching also does not provide management of anesthesia depth at various stages of surgical operations. The problem is solved well by replacement traditional vaporizers with so-called barbotage ones equipped by adjustment of vapor concentration by modem electronic methods. It is even more promising to use direct injection of the liquid anesthetics into the respiratory contour of infusion pump. However, because individual sensitivity of patients to anesthetics is rather variable, these devices do not provide regulation of the depth of anesthesia. Therefore, stability rather than accuracy of batching of low-concentration anesthetics with evaporators used in apparatuses for inhalation anesthesia is of cardinal importance, Methods of objective instrumental evaluation of the depth of anesthesia require further research and implementation.
Subject(s)
Anesthesia, Inhalation/instrumentation , Anesthesia, Inhalation/methods , Dose-Response Relationship, Drug , Equipment Design , HumansABSTRACT
High-frequency oscillatory controlled lung ventilation in patients with spontaneous respiration and constant positive pressure in combination with periods of mandatory lung ventilation promoted a significant increase in PtkO2 and PtkCO2 normalization. The absence of spontaneous respiration was not accompanied by gas exchange deterioration. The efficacy of high-frequency oscillatory controlled lung ventilation depends on the severity of the lung damage. The improvement in arterial blood oxygenation might be associated with the improvement in ventilation-perfusion ratio and a slight effect on hemodynamics.
Subject(s)
High-Frequency Ventilation , Respiratory Distress Syndrome, Newborn/therapy , Evaluation Studies as Topic , Hemodynamics , Humans , Infant, Newborn , Respiratory Distress Syndrome, Newborn/physiopathology , Ventilation-Perfusion RatioABSTRACT
The structure of the neutral glycosphingolipids of the Ehrlich ascite carcinoma (EAC) cells was studied. The main four components were identified as glycosylceramide, lastosylceramide, N-acetylgalactosyllactosylceramide and galactosyl-N-acetyllactosylceramide (asialo-GM1). The neutral glycolipid pattern of the cells was found to depend on their density. Dilution of the cell suspension resulted in an increased content of asia-lo-GM1, whereas the content of the other neutral glycolipids remained unchanged. The possible connection between these changes and the earlier disclosed cell density dependence of the gangliosides in EAC cells is discussed.
