Incidence of acquired demyelination of the CNS in Canadian children.

BACKGROUND: The incidence of acquired demyelination of the CNS (acquired demyelinating syndromes [ADS]) in children is unknown. It is important that physicians recognize the features of ADS to facilitate care and to appreciate the future risk of multiple sclerosis (MS). OBJECTIVE: To determine the incidence, clinical features, familial autoimmune history, and acute management of Canadian children with ADS. METHODS: Incidence and case-specific data were obtained through the Canadian Pediatric Surveillance Program from April 1, 2004, to March 31, 2007. Before study initiation, a survey was sent to all pediatric health care providers to determine awareness of MS as a potential outcome of ADS in children. RESULTS: Two hundred nineteen children with ADS (mean age 10.5 years, range 0.66-18.0 years; female to male ratio 1.09:1) were reported. The most common presentations were optic neuritis (ON; n = 51, 23%), acute disseminated encephalomyelitis (ADEM; n = 49, 22%), and transverse myelitis (TM; n = 48, 22%). Children with ADEM were more likely to be younger than 10 years, whereas children with monolesional ADS (ON, TM, other) were more likely to be older than 10 years (p < 0.001). There were 73 incident cases per year, leading to an annual incidence of 0.9 per 100,000 Canadian children. A family history of MS was reported in 8%. Before study initiation, 65% of physicians indicated that they considered MS as a possible outcome of ADS in children. This increased to 74% in year 1, 81% in year 2, and 87% in year 3. CONCLUSION: The incidence of pediatric acquired demyelinating syndromes (ADS) is 0.9 per 100,000 Canadian children. ADS presentations are influenced by age.

The interaction of MS and pregnancy: a critical review.

Previous research on the effects of pregnancy on multiple sclerosis (MS) is somewhat flawed, and well-controlled, well-designed studies are needed to validate trial findings. In general, pregnancy appears to have a protective effect on MS course, with fewer, less severe relapses, especially in the third trimester. The exacerbation rate is increased in the first 3 months after delivery, but the overall relapse rate is no different to that observed in non-pregnant MS patients. A woman's past history of relapses may be the best indicator of clinical course during and immediately after pregnancy. Pregnancy does not appear to affect the long-term course of MS.

The immune system and hormones: review and relevance to pregnancy and contraception in women with MS.

Two-thirds of multiple sclerosis (MS) patients are women, and the average age of onset overlaps the childbearing years. Clinicians are frequently asked, therefore, about the most appropriate form of contraception and the risk of an MS relapse/exacerbation during pregnancy and the post-partum period. This paper reviews the literature on the immune system and the effects of pregnancy, oral contraceptives and hormone replacement therapy on MS.

Elevated levels of polyamines and trypanothione resulting from overexpression of the ornithine decarboxylase gene in arsenite-resistant Leishmania.

The levels of trypanothione, a glutathione-spermidine conjugate, are increased in the protozoan parasite Leishmania selected for resistance to the heavy metal arsenite. The levels of putrescine and spermidine were increased in resistant mutants. This increase is mediated by overexpression of ornithine decarboxylase (ODC), the rate-limiting enzyme in polyamine biosynthesis. Gene overexpression is generally mediated by gene amplification in Leishmania but, here, the mRNA and the enzymatic activity of ODC are increased without gene amplification. This RNA overexpression is stable when cells are grown in the absence of the drug and does not result from gene rearrangements or from an increased rate of RNA synthesis. Transient transfections suggest that mutations in the revertant cells contribute to these elevated levels of RNA. Stable transfection of the ODC gene increases the level of trypanothione, which can contribute to arsenite resistance. In addition to ODC overexpression, the gene for the ABC transporter PGPA is amplified in the mutants. The co-transfection of the ODC and PGPA genes confers resistance in a synergistic fashion in partial revertants, also suggesting that PGPA recognizes metals conjugated to trypanothione.

Streptokinase thrombolysis of a chronically thrombosed mitral prosthetic valve.

Thrombus obstruction of a prosthetic heart valve is usually treated surgically. We report a well-documented case of an obstructed mitral prosthetic valve where fibrinolytic treatment was successful. Furthermore the thrombus formation probably had occurred 6 months earlier. Thus fibrinolysis appears to be a safe alternative to surgery although late occurrence of thrombosis may be possible.