Nitrogen dioxide production in a nitric oxide inhalation system using the Servo Ventilator 900C

During nitric oxide (NO) inhalation therapy, toxicity may be produced by the reactive metabolite nitrogen dioxide (NO₂). The purpose of the present study was to determine the NO₂ concentration in a NO inhalation system used for respiratory failure in children at relatively low concentrations of NO (< 20 ppm). The production of NO₂ in the NO inhalation system using the Servo Ventilator 900C connected to the test lung under each of 30 combinations of NO concentrations (0, 4, 8, 12, 16, and 19 ppm) and inspired oxygen (O₂) concentrations (21, 40, 60, 80, and 100%). Pressure controlled ventilation was used with a respiratory rate of 20 breaths/min. NO and NO₂ measurements were obtained on the inspiratory side of the Y-piece connected to the test lung. At a given NO level, increases in the concentration of inspired O₂ resulted in increases in the concentration of NO₂ produced, as did increases in the amount of NO at a given concentration of O₂. The mean NO₂ concentration at the inspiratory site of the Y-piece did not exceed 0.05 ppm (the limit of NO₂ as an outdoor air pollutant in the United States) when the NO concentration did not exceed 8 ppm, regardless of the O₂ concentration. NO inhalation therapy for children with severe respiratory failure using the Servo Ventilator 900C can be performed safely when the concentration of NO does not exceed 8 ppm.     

The effects of antiviral agents on serum hepatitis B e antigen levels in chronic type B hepatitis

In the present study, aiming at the evaluation of the effects of antiviral therapy on hepatitis B e antigen (HBeAg) levels, serum HBeAg concentration was determined serially by a quantitative assay in 44 patients with chronic hepatitis B who received a total of 73 courses of antiviral treatment. The posttreatment HBeAg levels were significantly lower than pretreatment baseline in all treated groups, not only at the end of treatment but also 6 months after the completion of therapy. The proportional decrease in treated patients was significantly greater than in 15 untreated controls. Six months after the completion of treatment, serum HBeAg became negative in seven out of 25 treatments with interferon, seven out of 28 with adenine arabinoside, and five out of 20 with adenine arabinoside 5'-monophosphate. All patients who became negative for HBeAg had normalization of alanine aminotransferase as well. A progressive decrease in HBeAg in patients treated with multiple courses of drug was observed, and the frequency of negative tests increased, paralleling the number of courses of treatment. These results suggest that antiviral therapy may alleviate inflammatory changes in the liver by promoting clearance of HBeAg from the serum, and may eventually shorten the natural course of hepatitis associated with chronic hepatitis B virus infection.     

Inhibition of platelet adhesion to collagen by monoclonal anti-CD36 antibodies

Monoclonal anti CD36 antibodies capable of inhibiting platelet adhesion to collagen have not previously been identified. We have now prepared two groups of monoclonal antibodies. One group was prepared using, as immunogen, highly purified (99+%) CD36 prepared by a denaturing procedure. These antibodies (Mo series) reacted strongly with CD36 on protein blots but did not immunoprecipitate native CD36 from platelet lysates nor inhibit platelet adhesion to collagen. The second group of monoclonal antibodies (131 series) was prepared using CD36 purified to >95% by a non-denaturing procedure. These antibodies reacted with control platelets, but not Nak^a-negative platelets which lack CD36, as measured by flow cytometry and by immunoprecipitation. Three monoclonal antibodies of this latter group (131.4, 131.5 and 131.7) inhibited platelet adhesion to collagen in static systems under Mg²⁺-independent conditions but had little effect in the presence of Mg²⁺. 131.4 and 131.7 also inhibited adhesion to collagen using citrated whole blood in a parallel plate flow chamber at physiological shear rates (800 s⁻¹), whereas 131.5 was without effect. These are the first anti-CD36 monoclonal antibodies shown to be capable of inhibiting platelet adhesion to collagen and provide further evidence that CD36 plays a role in platelet–collagen interaction.     

CASE REPORT: A patient who developed an amoebic liver abscess during treatment with interferon

A 65-year-old female received recombinant interferon (IFN) α-2b daily for the treatment of chronic hepatitis C. Fever (39°C or higher) developed 14 days after the start of administration. Abdominal computed tomography suggested multiple liver abscesses, which had not been detected before IFN administration. An autopsy revealed an amoebic liver abscess. A subclinical infection of Entamoeba histolytica in this case developed into amoebic liver abscess during IFN administration.     

Oculomotor Nerve Schwannoma Associated with Acute Hydrocephalus: Case Report

A 37-year-old woman presented with an extremely rare large oculomotor schwannoma associated with acute hydrocephalus manifesting as semicoma and anisocoria. Brain computed tomography and magnetic resonance imaging revealed a tumor in the oculomotor cistern. Cerebral angiography revealed separation of the posterior cerebral artery (PCA) and superior cerebellar artery (SCA). The tumor was removed subtotally by two stage surgery. Histological examination revealed ordinary schwannoma. The diagnosis of oculomotor nerve schwannoma was based on the intraoperative finding of the tumor origin in the oculomotor nerve. Oculomotor nerve schwannoma can cause acute hydrocephalus and manifest as impaired consciousness. The angiographical separation of the PCA and SCA was very useful for the preoperative diagnosis of oculomotor nerve schwannoma.     

Convulsions associated with epidural analgesia during sevoflurane anaesthesia

A three-year-old girl who underwent an operation for adrenal neuroblastoma was anaesthetized with sevoflurane and epidural analgesia. In the immediate recovery period she had convulsions. The convulsions were successfully treated with thiopentone and sevoflurane, there were no neurological sequelae. The convulsions were considered to be a manifestation of mepivacaine toxicity because of a high plasma mepivacaine concentration. Complications of paediatric regional analgesia and manifestations of mepivacaine toxicity under sevoflurane anaesthesia are discussed.     

Nicorandil, a Potassium Channel Opener, Abolished Torsades de Pointes in a Patient with Complete Atrioventricular Block

TdP is a serious complication of AV block. We report a case of complete AV block with QT prolongation who had bouts of TdP resistant to lidocaine and isoproterenol. Temporary pacing could not be performed, because insertion of a pacing lead triggered TdP that deteriorated into ventricular fibrillation. Nicorandil, a potassium channel opener, shortened the QT interval and abolished TdP. This may suggest that potassium channel opening drugs are clinically effective against TdP associated with bradycardia-dependent QT prolongation.     

Spinal tract degeneration confined to the bilateral posterior columns in malnutrition: Report of an autopsy case

Abstract An autopsy case of malnutrition with spinal tract degeneration confined to the bilateral posterior columns is reported. The patient had schizophrenia in adolescence, and suffered from aplastic anemia in late middle age. Subsequently, he took little food due to delusions for 18 months until his death. He had malnutrition resulting in severe hypoproteinemia. He developed gait disturbance, loss of deep tendon reflexes and paresthesia of limbs. Neuropathological examination disclosed tract degeneration confined to the bilateral spinal posterior columns, in addition to the findings of aplastic anemia and hypoxic encephalopathy in the cerebrum. The myelin and axons were severely affected throughout the spinal cord; status spongiosus with many fatty-laden macrophages was seen in these lesions. Neurons in the posterior column nuclei were intact, while the dorsal roots and their ganglia were moderately affected. The unusual distribution and extension of the degeneration of the bilateral posterior columns in the poor nutritional state is discussed.     

Adrenocorticotropic Hormone Unresponsiveness Associated with Hypertrophic Cardiomyopathy

ABSTRACT. The clinical and autopsy findings in a case of adrenocorticotropic hormone unresponsiveness associated with hypertrophic cardiomyopathy are reported. A four-month-old female with feeding difficulties and skin hyperpigmentation from two months of age was admitted with convulsions. She was hypoglycemic with normal serum electrolytes and the presence of hypertrophic cardiomyopathy was indicated by electrocardiogram and echocardiogram. Cardiac arrest occurred on the second hospital day. Low serum Cortisol, high plasma adrenocorticotropic hormone, low urinary 17-ketosteroids, and normal urinary aldosterone excretion were documented after her death. Hypoplasia of the adrenal cortex with a persistent fetal zone and concentric hypertrophy of the heart were found at autopsy. We propose that the pathogenesis of this disease lies in impaired remodelling of the fetal adrenal cortex into the permanent cortex, and postulate an effect of adrenocorticotropic hormone on the myocardium as the cause of hypertrophic cardiomyopathy.