The use of intravenous immunoglobulin in Miller Fisher syndrome

We report a patient with Miller Fisher syndrome who was treated with an intravenous high-dose of immunoglobulin. This syndrome is considered to be a benign variety of acute inflammatory demyelinating polyneuropathy (Guillain-Barré syndrome). However, there have been several reports of the need for ventilatory support and a few cases have had a fatal outcome. We observed a case of progressive Miller Fisher syndrome in a 3-year-old boy. Following 2 episodes of apnea lasting about 50 s each, he was treated with intravenous immunoglobulin (400 mg/kg/day) for 5 consecutive days. His respiratory state, general muscle strength, truncal ataxia and emotional state improved remarkably after this therapy.     

O6-alkylguanine-DNA alkyltransferase inactivation by ester prodrugs of O6-benzylguanine derivatives and their rate of hydrolysis by cellular esterases

To modulate the bioavailability and perhaps improve the tumor cell selectivity of O6-alkylguanine-DNA alkyltransferase (AGT) inactivators, pivaloyloxymethyl ester derivatives of O6-benzylguanine (BG) were synthesized and tested as AGT inactivators and as substrates for cellular esterases. The potential prodrugs examined were the 7- and 9-pivaloyloxymethyl derivatives of O6-benzylguanine (7- and 9-esterBG), and of 8-aza-O6-benzylguanine (8-aza-7-esterBG and 8-aza-9-esterBG) and the 9-pivaloyloxymethyl derivative of 8-bromo-O6-benzylguanine (8-bromo-9-esterBG). The benzylated purines were all potent inactivators of the pure AGT and of the AGT activity in HT29 cells and cell extracts. Each ester was at least 75 times less potent than the corresponding benzylated purine against the pure human AGT. In contrast, the activities of esters and their respective benzylated purine were similar in crude cell extracts and in intact cells. The increase in potency of esters in cellular extracts could be explained by a conversion of the respective prodrug to the more potent benzylated purine in the presence of cellular esterases. The apparent catalytic activity (Vmax/Km) of liver microsomal esterase for 8-azaBG ester prodrugs was 70-130 times greater than for BG prodrugs and 10-20 times greater than for 8-bromo-9-esterBG. Tumor cell hydrolysis of the esters varied considerably as a function of cell type and prodrug structure. These data suggest that these or related prodrugs may be advantageous for selective AGT inactivation in certain tumor types.     

Kidney transplantation after a severe form of pseudotumor cerebri

Pseudotumor cerebri is a syndrome characterized by intracranial hypertension (intracranial pressure >200 mmH2O) and a normal ventricular system. The diagnosis should be made as early as possible to prevent impairment of vision. Several diseases have been reported in association with pseudotumor cerebri in pediatric patients, and have been occasionally also noted with chronic renal failure, heart and renal transplantation. We report a 7-year-old boy who complained of severe headaches and visual impairment 2 years after hemodialysis for renal hypoplasia. Pseudotumor cerebri was suspected and, despite treatment with corticosteroids, acetazolamide, and lumboperitoneal diversion, visual impairment worsened. Bilateral optic nerve sheath decompression (ONSD) was performed without success and the child completely lost his vision within 2 weeks. He was successfully transplanted 2 months later. Two years post transplantation, the blind child has a normal renal function and school performance. Pseudotumor cerebri must be rapidly suspected in a child with renal failure suffering from headaches and papilledema. Visual loss may progress rapidly and ONSD seems to be the best surgical treatment when medical treatment fails. In this patient renal transplantation was well tolerated, with no deterioration in the neurological status over 2 years of follow-up.     

HIGH TEMPERATURE FATIGUE BEHAVIOUR OF A CAST COBALT-BASE SUPERALLOY

Abstract The initiation and the propagation of fatigue cracks and the low cycle fatigue life of a cast cobalt base superalloy was studied at 293K, 973K and 1173K by optical and scanning electron microscopy. A substantial decrease in fatigue life occurred at 973 and 1173K when compared to room temperature life. A time-dependent bulk damage was evidenced at 1173K which was determined by quantitative microscopy for two plastic strain levels. High strain fatigue crack propagation experiments were carried out at room temperature and at 1173K. From these experiments the decrease of the overall fatigue life at high temperature was shown to result from a considerable reduction of the initiation period due to oxidation and also from a significant acceleration of the crack propagation rate in the presence of oxidation and bulk damage.     

Carcinogenic effect of chronic subcutaneous injections of 2,6-dimethylnitrosomorpholine in Sprague-Dawley rats

Sprague-Dawley rats received subcutaneous injections of 2,6-dimethylnitrosomorpholine (2,6-DMNM) at 3 different dose levels (1/5, 1/10 or 1/20 LD50) once weekly for life. Up to a 100% rate of tumors of the esophagus was detected in animals which received 1/10 and 1/20 LD50. In addition to tumors of this organ, neoplasms developed at different rates in the lungs and in the liver.     

Heat flux distribution from a volumetrically heated pool with high Rayleigh number

Experimental results are presented on the heat flux distribution at the boundaries of volumetrically heated pools at high enough Rayleigh numbers to be directly relevant to the problem of retention of a molten corium pool inside the lower head of a reactor pressure vessel. The experimental facility, named COPO, is a 2-dimensional “slice”, Joule-heated and geometrically similar in shape (torispherical at 1/2-scale) to the lower head of a VVER-440 reactor. The results show that: the heat flux on the side wall (vertical portion) is essentially uniform; the downward heat flux strongly depends on position along the curved wall; and average fluxes on the side in the downward direction are in agreement with existing correlations, but somewhat underestimated in the upward direction. For the shape considered, the heat flux along the lower curved wall seems to be independent of the presence and extent of the liquid pool (contained by the vertical sidewalls) portion above it.     

Risk of cancer in Finnish children living close to power lines

OBJECTIVE: To investigate the risk of cancer in children living close to overhead power lines with magnetic fields of > or = 0.01 microteslas (microT). DESIGN: Cohort study. SETTING: The whole of Finland. SUBJECTS: 68,300 boys and 66,500 girls aged 0-19 years living during 1970-89 within 500 m of overhead power lines of 110-400 kV in magnetic fields calculated to be > or = 0.01 microT. Subjects were identified by record linkages of nationwide registers. MAIN OUTCOME MEASURES: Numbers of observed cases in follow up for cancer and standardised incidence ratios for all cancers and particularly for nervous system tumours, leukaemia, and lymphoma. RESULTS: In the whole cohort 140 cases of cancer were observed (145 expected; standardised incidence ratio 0.97, 95% confidence interval 0.81 to 1.1). No statistically significant increases in all cancers and in leukaemia and lymphoma were found in children at any exposure level. A statistically significant excess of nervous system tumours was found in boys (but not in girls) who were exposed to magnetic fields of > or = 0.20 microT or cumulative exposure of > or = 0.40 microT years. CONCLUSIONS: Residentia magnetic fields of transmission power lines do not constitute a major public health problem regarding childhood cancer. The small numbers do not allow further conclusions about the risk of cancer in stronger magnetic fields.     

Fibromuscular dysplasia associated with intracranial giant aneurysm: report of a case

Although the correlation between fibromuscular dysplasia (FMD) and intracranial aneurysm is well established, the combination of FMD with a giant aneurysm is rare. This paper reports a patient with extracranial FMD associated with a giant intracavernous aneurysm compromising the trigeminal and abducens nerve. A review of the literature uncovered only four documented cases of FMD with concurrent giant intracranial aneurysms. The present case adds further weight to the argument for including FMD in the differential diagnosis list when confronted with a patient with a giant intracranial aneurysm. Absence of adequate collaterals in this patient eliminated ligation as a treatment strategy for the aneurysm.