Fatal Meningitis in Swine after Intrathecal Administration of Adeno-associated Virus Expressing Syngeneic Interleukin-10.

Interleukin-10 (IL-10) delivered by intrathecal (i.t.) gene vectors is a candidate investigational new drug (IND) for several chronic neurological disorders such as neuropathic pain. We performed a preclinical safety study of IL-10. A syngeneic large animal model was used delivering porcine IL-10 (pIL-10) to the i.t. space in swine by adeno-associated virus serotype 8 (AAV8), a gene vector that was previously found to be nontoxic in the i.t. space. Unexpectedly, animals became ill, developing ataxia, seizures, and an inability to feed and drink, and required euthanasia. Necropsy demonstrated lymphocytic meningitis without evidence of infection in the presence of normal laboratory findings for body fluids and normal histopathology of peripheral organs. Results were replicated in a second animal cohort by a team of independent experimenters. An extensive infectious disease and neuropathology workup consisting of comprehensive testing of tissues and body fluids in a specialized research veterinary pathology environment did not identify a pathogen. These observations raise the concern that i.t. IL-10 therapy may not be benign, that previously used xenogeneic models testing the human homolog of IL-10 may not have been sensitive enough to detect toxicity, and that additional preclinical studies may be needed before clinical testing of IL-10 can be considered.

The epidemiology of intermittent and chronic ataxia in children in Manitoba, Canada.

AIM: To determine the epidemiology of chronic ataxia in children in Manitoba, Canada. METHOD: A retrospective study using multiple sources and disease codes identified children (age 0-16y) with chronic ataxia (>2mo duration or recurrent episodes of ataxia) seen at Winnipeg Children's Hospital from 1991 to 2008. Patients with isolated peripheral nerve diseases, vestibular disorders, or brain tumors were excluded. RESULTS: We identified 184 patients (males=females; mean age 15y, SD 7y 8mo) with chronic ataxia. Median age at the presenting symptom onset was 1 year 3 months and at ataxia onset 3 years 1 month. Median duration of follow-up was 6 years 5 months. During the study period, the crude incidence rate was 5.77 in 10,000; the crude prevalence rate was 6.59 in 10,000; and the crude mortality rate 0.446 in 10,000. The most common presenting symptoms were developmental delay, ataxia, or seizures. The most common diagnoses (known in 129) were Angelman syndrome (n=16), ataxia telangiectasia (n=13), mitochondrial disease (n=9), Friedreich ataxia (n=7), stroke (n=7), and familial/genetic episodic ataxia (n=7). INTERPRETATION: Chronic ataxia is a relatively common early-presenting symptom in childhood. A specific diagnosis is possible in 70% of patients after extensive investigations. The mortality rate is relatively low and the disease burden is high with significant comorbidities including developmental delay and epilepsy.

Partial rescue of NT-3 null mutant phenotype by a PDGF-ß regulated transgene.

The phenotype of neurotrophin-3 (NT-3) null mutant mice is characterized by sensory ataxia and early postnatal death. Previous analysis revealed a severe depletion of peripheral sensory, sympathetic and parasympathetic neurons. Most of the deficits are established early during embryonic development. Whereas absence of proprioceptive afferents can explain the sensory ataxia, the reasons for early postnatal death are unclear. To circumvent the limitations imposed by early mortality of null mutants we generated mouse line expressing NT-3 transgenes driven by the platelet-derived growth factor ß-chain (PDGF-ß) promoter, which is known to be active in neurons and mesenchyme derivatives. Mice carrying one or two PDGF-NT3 transgenes on a background null for wildtype NT-3 were generated by crossing with an NT-3 null strain. Although still ataxic, mice from this cross could survive for periods longer than a year. Histological analysis revealed a limited rescue of muscle spindles and parvalbumin immunoreactive sensory neurons.

Combined-modality therapy for primary central nervous system lymphoma: long-term data from a Phase II multicenter study (Trans-Tasman Radiation Oncology Group).

PURPOSE: To assess, in a multicenter setting, the long-term outcomes of a brief course of high-dose methotrexate followed by radiotherapy for patients with primary central nervous system lymphoma (PCNSL). METHODS AND MATERIALS: Forty-six patients were entered in a Phase II protocol consisting of methotrexate (1 g/m(2) on Days 1 and 8), followed by whole-brain irradiation (45-50.4 Gy). The median follow-up time was 7 years, with a minimum follow-up of 5 years. RESULTS: The 5-year survival estimate was 37% (+/-14%, 95% confidence interval [CI]), with progression-free survival being 36% (+/-15%, 95% CI), and median survival 36 months. Of the original 46 patients, 10 were alive, all without evidence of disease recurrence. A total of 11 patients have developed neurotoxicity, with the actuarial risk being 30% (+/-18%, 95% CI) at 5 years but continuing to increase. For patients aged>60 years the risk of neurotoxicity at 7 years was 58% (+/-30%, 95% CI). CONCLUSION: Combined-modality therapy, based on high-dose methotrexate, results in improved survival outcomes in PCNSL. The risk of neurotoxicity for patients aged>60 years is unacceptable with this regimen, although survival outcomes for patients aged>60 years were higher than in many other series.

High mortality of subjects with endemic ataxic polyneuropathy in Nigeria.

BACKGROUND: Endemic ataxic polyneuropathy, a neurological syndrome that was thought to be benign, has been shown to persist in some communities in south-western Nigeria, where it was first described in the 1950s. OBJECTIVES: This study was conducted to compare mortality of cases and controls, and to determine if mortality is related to exposure to cyanide from cassava foods. MATERIAL AND METHODS: Cases of endemic ataxic polyneuropathy and two groups of controls, one group living in an endemic community and the other group living in a non-endemic community, were followed for 25 months. The outcome was death from medical causes. RESULTS: A total of 5970 subjects, 204 cases and 5766 controls - 4000 controls in the endemic community and 1766 controls in the non-endemic community, were followed. A total of 153 subjects died, 24 cases, 115 controls in the endemic community, and 14 controls in the non-endemic community. Relative risks of death (95% CI), adjusted for age and gender, were 4.5 (2.3-8.9) for cases (P < 0.0001), but 2.6 (1.5-4.6) for controls living in the endemic community (P = 0.001). CONCLUSION: This study shows that endemic ataxic polyneuropathy decreases survival. The finding of lower risk of death in the community with higher exposure to cyanide from cassava foods indicates that mortality of endemic ataxic polyneuropathy is not associated with exposure to cyanide from cassava foods.

Opsoclonus-myoclonus-ataxia syndrome in neuroblastoma: clinical outcome and antineuronal antibodies-a report from the Children's Cancer Group Study.

BACKGROUND: Opsoclonus-myoclonus-ataxia (OMA) is a paraneoplastic neurologic syndrome affecting 2-3% of children with neuroblastoma. Although children with OMA and neuroblastoma may have higher survival, many experience a significant amount of late neurologic impairment, which may be immunologically mediated. The aim of this study was to compare the outcome of neuroblastoma patients with and without OMA, relating to prognostic factors, treatment, and the presence or absence of anti-neuronal antibodies. PROCEDURE: Questionnaires were mailed out requesting information on the current neurologic status of patients who submitted sera at diagnosis to the Children's Cancer Group serum bank from 1980 to 1994. Information was requested on clinical and biological patient characteristics as well as clinical aspects of the patients identified as having OMA syndrome, including presentation and treatment for OMA, late sequelae of OMA, the presence or absence of antineuronal antibodies, and survival. Sera from 16 of the OMA patients and 48 case-controls with neuroblastoma were assayed for anti-neuronal antibodies. RESULTS: Of the 675 responses received, 21 patients had OMA. Ninety percent of OMA patients presented with non-metastatic disease, vs. 35% of non-OMA patients. Estimated 3-year survival for the OMA patients with nonmetastatic disease (stage I, II, III) greater than 1 year of age was 100% vs. 77% for similar non-OMA patients (P = 0.0222). At follow-up, 14/19 evaluable OMA patients displayed some form of developmental or neurologic abnormality. There was no significant correlation of late sequelae with antineuronal antibodies, age, time between OMA symptoms and diagnosis, or treatment given for tumor or OMA. There was a significant correlation of late sequelae with lower stage disease (I and II) compared to more advanced disease (III and IV). CONCLUSIONS: Patients with OMA and neuroblastoma have excellent survival but a high risk of neurologic sequelae. Favorable disease stage correlates with a higher risk for development of neurologic sequelae. The role of anti-neuronal antibodies in late sequelae of OMA needs further clarification.

Ataxia and abnormal cerebellar microorganization in mice with ablated contactin gene expression.

Axon guidance and target recognition depend on neuronal cell surface receptors that recognize and elicit selective growth cone responses to guidance cues in the environment. Contactin, a cell adhesion/recognition molecule of the immunoglobulin gene superfamily, regulates axon growth and fasciculation in vitro, but its role in vivo is unknown. To assess its function in the developing nervous system, we have ablated contactin gene expression in mice. Contactin-/- mutants displayed a severe ataxic phenotype consistent with defects in the cerebellum and survived only until postnatal day 18. Analysis of the contactin-/- mutant cerebellum revealed defects in granule cell axon guidance and in dendritic projections from granule and Golgi cells. These results demonstrate that contactin controls axonal and dendritic interactions of cerebellar interneurons and contributes to cerebellar microorganization.

The behaviour of healthy awake cats following intravenous and intramuscular administration of midazolam.

The onset of action and behavioural effects following intravenous (i.v.) and intramuscular (i.m.) administration of 0.05, 0.5, 1.0, 2.0 and 5.0 mg/kg of midazolam were studied for 2 h in 20 awake, healthy cats. All cats, except one that received 0.05 mg/kg i.m., showed effects of the drug, whereas no effects were observed in cats administered only the vehicle in which midazolam was dissolved. The onset of action was rapid following both i.v. and i.m. administration, some cats became ataxic, while others assumed positions of sternal or lateral recumbency. Even after administration of the highest dose (5.0 mg/kg), anaesthesia was not induced, with swallowing reflexes and conscious perception of a clamp placed on the tail still present in all cats. An abnormal arousal state was observed in many cats after administration of midazolam. During the first hour, restlessness was more commonly observed, while from 1 to 2 h, sedation was more prominent in cats that received the highest dose. Ataxia occurred in all but one cat, was short-lived in cats that received the lower doses, but still present at 2 h in all cats that received 2.0 and 5.0 mg/kg. Midazolam caused some of the cats to behave differently when approached and restrained compared with behavioural patterns identified prior to administration of the drug. The cats were more likely to behave abnormally following i.v. administration rather than i.m. administration and, for the most part, abnormal behaviour was equally distributed between the two extremes; cats being easier to approach and restrain and cats being more difficult to approach and restrain. Food consumption increased significantly, during the 2 h period, following all i.m. doses and all but the highest (5.0 mg/kg) i.v. dose, with most of the food being consumed in the first hour after administration.