Updating the profile of C-terminal MECP2 deletions in Rett syndrome

OBJECTIVES

This study aimed to compare the phenotype of Rett syndrome cases with C-terminal deletions to that of cases with different MECP2 mutations and to examine the phenotypic variation within C-terminal deletions.

METHODS

Cases were selected from InterRett, an international database and from the population-based Australian Rett Syndrome Database. Cases (n=832) were included if they had a pathogenic MECP2 mutation in which the nature of the amino acid change was known. Three severity scale systems were used, and individual aspects of the phenotype were also compared.

RESULTS

Lower severity was associated with C-terminal deletions (n=79) compared to all other MECP2 mutations (e.g. Pineda scale C-terminals mean 15.0 (95% CI 14.0-16.0) vs 16.2 (15.9-16.5). Cases with C-terminal deletions were more likely to have a normal head circumference (odds ratio 3.22, 95% CI 1.53 - 6.79) and weight (odds ratio 2.97, 95% CI 1.25-5.76). Onset of stereotypies tended to be later (median age 2.5 years vs 2 years, p<0.001 from survival analysis), and age of learning to walk tended to be earlier (median age 1.6 years vs 2 years, p=0.002 from survival analysis). Those with C-terminal deletions occurring later in the region had lower average severity scores than those occurring earlier in the region.

CONCLUSION

In terms of overall severity C-terminal deletion cases would appear to be in the middle of the range. In terms of individual aspects of phenotype growth and ability to ambulate appear to be particular strengths. By pooling data internationally this study has achieved the case numbers to provide a phenotypic profile of C-terminal deletions in Rett syndrome.

The risk of sodium toxicity from bed accumulation to key species in the vermifiltration wastewater treatment process

This study was undertaken to assess the toxicological risks from sodium accumulation in a vermifiltration wastewater treatment system to the key worm species, Eisenia fetida. The study found that sodium chloride (NaCl) is the more toxic of the common sodium salts found in wastewater to the worms. The research further found that the worms have an ability to detoxify NaCl although reproduction will be impaired if the worms are exposed to moderate concentrations of NaCl for a long period of time. The actual risk from NaCl toxicity in the vermifiltration process was low however. The low risk was due to the low solid-water partitioning constant of NaCl, which led to a very low predicted environmental concentration (PEC) for NaCl.

Influence of high gas production during thermophilic anaerobic digestion in pilot-scale and lab-scale reactors on survival of the thermotolerant pathogens Clostridium perfringens and Campylobacter jejuni in piggery wastewater

Safe reuse of animal wastes to capture energy and nutrients, through anaerobic digestion processes, is becoming an increasingly desirable solution to environmental pollution. Pathogen decay is the most important safety consideration and is in general, improved at elevated temperatures and longer hydraulic residence times. During routine sampling to assess pathogen decay in thermophilic digestion, an inversely proportional relationship between levels of Clostridium perfringens and gas production was observed. Further samples were collected from pilot-scale, bench-scale thermophilic reactors and batch scale vials to assess whether gas production (predominantly methane) could be a useful indicator of decay of the thermotolerant pathogens C. perfringens and Campylobacter jejuni. Pathogen levels did appear to be lower where gas production and levels of methanogens were higher. This was evident at each operating temperature (50, 57, 65 degrees C) in the pilot-scale thermophilic digesters, although higher temperatures also reduced the numbers of pathogens detected. When methane production was higher, either when feed rate was increased, or pH was lowered from 8.2 (piggery wastewater) to 6.5, lower numbers of pathogens were detected. Although a number of related factors are known to influence the amount and rate of methane production, it may be a useful indicator of the removal of the pathogens C. perfringens and C. jejuni.

The common BDNF polymorphism may be a modifier of disease severity in Rett syndrome

BACKGROUND

Rett syndrome (RTT) is caused by mutations in the transcriptional repressor methyl CpG-binding protein 2 (MECP2). Brain-derived neurotrophic factor (BDNF) is a neurotrophic factor playing a major role in neuronal survival, neurogenesis, and plasticity, and it has been shown that BDNF expression is regulated by MeCP2 through a complex interaction. A common polymorphism of BDNF (Val66Met [p.V66M]) has been found to correlate with severity and course of several neuropsychiatric disorders.

METHODS

We examined the association between disease severity score, assessed by the modified Percy score, and BDNF polymorphism, using regression methods, in 125 mutation-positive patients with RTT from the Australian Rett Syndrome Database and an Israeli cohort.

RESULTS

Those who were heterozygous (Val/Met) had slightly more severe disease than those who were homozygous for the wild-type (Val/Val) BDNF polymorphism (increased severity score 2.1, p = 0.09). In those with p.R168X, a commonly occurring MECP2 mutation in RTT, there was a 6-point increase in severity score for those who were heterozygous for the BDNF polymorphism, both unadjusted (p = 0.02) and adjusted for age (p = 0.03). Individuals with the p.R168X mutation and heterozygous for the BDNF polymorphism were also at an increased risk of seizure onset (hazard ratio 5.3, 95% confidence interval 1.6-17.7) compared with those homozygous for the wild-type BDNF allele.

CONCLUSIONS

In addition to mutation type and degree of X-chromosome skewing, the common brain-derived neurotrophic factor (BDNF) polymorphism appears to be another genetic modifier of Rett syndrome (RTT) severity. This suggests that BDNF function may play a significant role in the pathogenesis of RTT.

Costeff optic atrophy syndrome: new clinical case and novel molecular findings

3-Methylglutaconic aciduria (MGA) encompasses a heterogeneous group of disorders, often coinciding with elevated levels of urinary 3-methylglutaric acid. Type I MGA is a disorder of leucine metabolism, while the biological basis for the MGA is unclear for the other types (MGA types II-V). MGA type III (Costeff optic atrophy syndrome, autosomal recessive optic atrophy-3 or optic atrophy plus syndrome, OMIM 258501) is distinguished by early bilateral optic atrophy, later-onset spasticity, extrapyramidal dysfunction, ataxia, and occasional cognitive deficits. It is caused by homozygous mutations in the optic atrophy 3 gene (OPA3). We present a case of a patient with MGA who has infantile-onset optic atrophy, ataxia, extrapyramidal movements and spasticity, but with normal intellect. Sequencing of the patient's DNA revealed a homozygous nonsense mutation c.415C>T (p.Q139X) in exon 2 of transcript 2 of the OPA3 gene, as well as a common silent polymorphism c.231T>C in the same exon. This is the first nonsense mutation found in OPA3. The molecular findings in OPA3 are also reviewed, including mutations in OPA3 that result in autosomal dominant optic atrophy and cataract (ADOAC). The recessive mode of inheritance of MGA type III as a result of the p.Q139X mutation is supported by the carrier status of the unaffected father.

Achieving cellular resolution for in vivo retinal images of transgenic GFAP-GFP mice via image processing

In vivo retinal images of transgenic mice, expressing GFP under the control of the GFAP (glial fibrillary acidic protein) promoter, have very poor signal-to-noise ratio (SNR) and cellular resolution such that the analysis of GFAP-GFP expressing retinal cells from these images can be a very challenging task. We report an image averaging method based on a pixel rank matching criterion which significantly enhances both these image attributes. We also show that it compares favorably against direct image averaging and a commercial averaging routine available from the Heidelberg Retinal Angiograph 2 software.

The toxicity of ammonia/ammonium to the vermifiltration wastewater treatment process

This study was undertaken to assess the toxicity of ammonia/ammonium to key species within the vermifiltration process. The key species, the earthworm Eisenia fetida, was subjected to a series of tests in solid phase mesocosms and full-scale units. The solid phase tests showed a relatively low toxicity to ammonium with ammonium chloride having an LC50 for ammonium of 1.49 g/kg. Ammonium sulfate did not show an effect on mortality at 2 g/kg ammonium. The full-scale units showed that ammonia hydroxide can change the pH and concentration of ammonia in wastewater and while it caused some mortality to the worms its overall affect on system functioning was minimal with no significant difference in terms of worm survival found between treatments. The affect on nitrifying bacteria was also minimal with no linear trend shown with ammonia concentration.

MRI: imaging of stomach

The study is to determine the optimal MRI bowel preparation regime for visualization of the stomach anatomy. Eight healthy volunteers were asked to take water, 75% barium and blueberry juice. The image quality and tolerance of different stomach distension regime were evaluated. Blueberry juice gave the best distension, but the signal intensity was not very homogeneous. Taking into account the image quality, tolerability and adverse effects, it is concluded that water is the most desirable oral contrast for MR stomach imaging.

Transient multiple acyl-CoA dehydrogenation deficiency in a newborn female caused by maternal riboflavin deficiency

A newborn female presented on the first day of life with clinical and biochemical findings consistent with multiple acyl-CoA dehydrogenase deficiency (MADD). Riboflavin supplementation corrected the biochemical abnormalities 24 h after commencing the vitamin. In vitro acylcarnitine profiling in intact fibroblasts both in normal and riboflavin depleted media showed normal oxidation of fatty acids excluding defects in electron transfer flavoprotein (ETF), or ETF ubiquinone oxidoreductase (ETF:QO), or a genetic abnormality in flavin metabolism. In addition, sequencing of the genes encoding ETF and ETF:QO in the proband did not reveal any pathogenic mutations. Determination of the maternal riboflavin status after delivery showed that the mother was riboflavin deficient. Repeat testing done two years after the infant's birth and while on a normal diet showed that the mother was persistently riboflavin deficient and showed a typical MADD profile on plasma acylcarnitine testing. A possible genetic defect in riboflavin transport of metabolism in the mother is postulated to be the cause of the transient MADD seen in the infant. Sequencing of the SLC16A12, RFK and FLAD1 genes encoding key enzymes in riboflavin transport of metabolism in the mother did not identify any pathogenic mutations. The underlying molecular basis of the mother's defect in riboflavin metabolism remains to be established.

Toxicity of domestic wastewater pH to key species within an innovative decentralised vermifiltration system

The development of innovative decentralised wastewater treatment systems is pertinent to environmental sustainability. However for their appropriate use they require significant research and design to ensure they can be relied upon in the future and in most cases they have received less attention and research than large-scale sewage systems. This study assessed the likelihood of biological inhibition and disruption from pH to key species for vermifiltration. The test firstly assessed the buffer capacity of a vermicompost + manure media finding it had a relatively high buffering capacity for pH. The toxicity after the buffer capacity experiment showed that the species would survive between pH levels of 6.2 and 9.7. At the higher and lower pH levels however the survival of juveniles was impaired, probably due to their ability to uptake greater amounts of soluble salts and inability to regulate them. Overall the study showed that the tolerance of the key vermifiltration species to pH was far less than their survival as previously proposed and further research assessing their long-term population dynamics in a vermifiltration system with pH is warranted.

Solutions to a combined problem of excessive hydrogen sulfide in biogas and struvite scaling

The Woodman Point Wastewater Treatment Plant (WWTP) in Western Australia has experienced two separate problems causing avoidable maintenance costs: the build-up of massive struvite (MgNH4PO4. 6H2O) scaling downstream of the anaerobic digester and the formation of hydrogen sulfide (H2S) levels in the digester gas to levels that compromised gas engine operation and caused high operating costs on the gas scrubber. As both problems hang together with a chemical imbalance in the anaerobic digester, we decided to investigate whether both problems could be (feasibly and economically) addressed by a common solution (such as dosing of iron solutions to precipitate both sulfide and phosphate), or by using separate approaches. Laboratory results showed that, the hydrogen sulfide emission in digesters could be effectively and economically controlled by the addition of iron dosing. Slightly higher than the theoretical value of 1.5 mol of FeCl3 was required to precipitate 1 mol of dissolved sulfide inside the digester. Due to the high concentration of PO4(3-) in the digested sludge liquor, significantly higher iron is required for struvite precipitation. Iron dosing did not appear an economic solution for struvite control via iron phosphate formation. By taking advantage of the natural tendency of struvite formation in the digester liquid, it is possible to reduce the risk of struvite precipitation in and around the sludge-dewatering centrifuge by increasing the pH to precipitate struvite out before passing through the centrifuge. However, as the Mg2+/PO4(3-) molar ratio in digested sludge was low, by increasing the pH alone (using NaOH) the precipitation of PO4(3-) was limited by the amount of cations (Ca2+ and Mg2+) available in the sludge. Although this would reduce struvite precipitation in the centrifuge, it could not significantly reduce PO4(3-) recycling back to the plant. For long-term operation, maximum PO4(3-) reduction should be the ultimate aim to minimise PO4(3-) accumulation in the plant. Magnesium hydroxide liquid (MHL) was found to be the most cost-effective chemical to achieve this goal. It enhanced struvite precipitation from both, digested sludge and centrate to the point where more than 95% PO4(3-) reduction in the digested sludge was achieved.

Emerging approaches to integrated urban water management: cluster scale application

Integrated Urban Water Management (IUWM) seeks to extend Water Sensitive Urban Design to a total water cycle approach that includes reuse of wastewaters. This paper investigates the appropriateness of environmental technologies for application at a cluster scale in IUWM. Many environmental technologies are economically or physically unsuited to use on a municipal or unit scale. Cluster scale is a middle ground that will allow such environmental technologies to achieve full potential. The concept of cluster scale and the application of environmental technologies at this scale are discussed along with some examples of suitable technologies.

Small scale sanitation technologies

Small scale systems can improve the sustainability of sanitation systems as they more easily close the water and nutrient loops. They also provide alternate solutions to centrally managed large scale infrastructures. Appropriate sanitation provision can improve the lives of people with inadequate sanitation through health benefits, reuse products as well as reduce ecological impacts. In the literature there seems to be no compilation of a wide range of available onsite sanitation systems around the world that encompasses black and greywater treatment plus stand-alone dry and urine separation toilet systems. Seventy technologies have been identified and classified according to the different waste source streams. Sub-classification based on major treatment methods included aerobic digestion, composting and vermicomposting, anaerobic digestion, sand/soil/peat filtration and constructed wetlands. Potential users or suppliers of sanitation systems can choose from wide range of technologies available and examine the different treatment principles used in the technologies. Sanitation systems need to be selected according to the local social, economic and environmental conditions and should aim to be sustainable.

Hydrogen sulphide production tests and the detection of groundwater faecal contamination by septic seepage

The 'H2S test' is being advanced for microbiological water quality testing where conventional coliform based methods are impractical or too expensive. It involves ambient temperature incubation of water samples with nutrient formulated to generate hydrogen sulphide when 'faecal' bacteria are present. Recently a WHO review identified several concerns including the limited number of comparative studies, formulation variability, and false positives and negatives. In response we have compared the H2S test's ability to detect and quantify faecal contamination in an aquifer impacted by septic tank leachfields with measurements obtained concurrently using conventional bacterial indicators, coliphages, faecal sterol biomarkers, Cryptosporidium and Giardia. Like these other analytes, H2S testing detected a contamination gradient ranging from high (septic liquid) to moderate (exfiltration zones), to background (e.g. domestic bores), corresponding to indicator removal + dilution by factors > 10(6). Presence/absence tests could not distinguish between heavily and slightly contaminated waters, whereas multi-tube testing (e.g. 10 x 10 mL arrays) did. It was concluded that while the WHO review concerns are justified, the H2S test performance shows promise in sanitary survey work, can be improved by employing an mpn approach and has potential to aid in the protection of source water and identifying contaminated groundwater.

Technology for sustainability: the role of onsite, small and community scale technology

An overview of available onsite, small and community scale wastewater treatment technology shows that it is diverse compared to current technology for centralised collection and treatment of wastewater. An analysis of the onsite, small and community scale technology for achieving sustainability shows that it more conducive to achieving sustainability than the centralised technology. It is likely, however, that its application is in remote and rural areas, where the technology should be improved and integrated with other technology sectors (energy, food production) for improved sustainability. Opportunities exist in new urban developments to achieve similar outcomes, but concerted efforts are required to demonstrate or showcase sustainability benefits in real situations. A huge potential also exists for the use of onsite, small and community scale technology in developing countries for achieving the same sustainability outcomes. It is likely to succeed if the technology is modified to be of lower cost but based on the same science, and that research, development and demonstrations in developed countries are shown to be successful.

Subsurface flow reedbeds using alternative media for the treatment of domestic greywater in Monteverde, Costa Rica, Central America

This paper describes the performance of reedbeds using plastic (PET) bottle segments as an alternative low-cost media for the treatment of domestic greywater in Monteverde, Costa Rica, Central America. Twelve reedbeds consisting of four sets of triplicates were monitored through wet and dry seasons in order to determine the effect of media type (PET versus crushed rock) and the effect of plants. In both seasons, performance of the planted reedbeds with PET media, for BOD and fecal coliform removal, was either comparable to, or better than, that of the crushed rock systems. The planted PET reedbeds achieved fecal coliform removal rates > 99.9% in all cases equating to reductions of between 3 and nearly 5 log, with an average BOD outflow of 12.9 mg/L over both seasons. The hydraulic loading rate varied between 1.33 and 2.67 cm/day and hydraulic retention times (HRT) ranged from 3.5 to 7.5 days. The six reedbeds planted with Coix lacryma-jobi proved to be significantly more effective in pathogen removal and BOD reduction than the unplanted reedbeds. The planted PET reedbeds also increased their biomass by twice that of the planted crushed rock reedbeds during the study period. The majority of this increase was shown to be due to root growth. This paper discusses the implications of the above results for developing countries and identifies potential areas for further research.

Adoptive cellular immunotherapy for non-small cell lung cancer: a pilot study

BACKGROUND

Priming with autologous tumor vaccine followed by ex vivo expansion of activated T cells is a feasible experimental strategy. This paper describes the application of this cellular therapy to treat patients with late-stage non-small-cell lung cancer (NSCLC).

METHODS

Twenty-one patients with Stages III and IV NSCLC were treated. Tumor samples were obtained surgically (five patients) or by using aco-axial biopsy needle (16 patients). Each course of vaccination consisted of irradiated tumor cells, mixed with GM-CSF and injected intradermally on Day 1, followed by GM-CSF only on Days 2- 5. The course was repeated 10-14 days later. Lymphocytes were collected 10-14 day after the second course and ex vivo expanded using IL-2 and anti-CD3 Ab. The expansion products were then re-infused into the patients.

RESULTS

Twelve out of 16 biopsies resulted in optimal cell numbers for vaccine preparation. Nineteen out of 21 patients achieved a delayed type hypersensitivity (DTH response after two courses of vaccination. In 18/21 patients, the ex vivo expansion products contained > 1.6 x 10(10) cells. Subset analysis showed 77.0-97.2% T cells with a CD4:CD8 ratio of 0.65-4.0; natural killer cells were 2.0-18.6%. There were no significant toxicities. The median survival of all 21 patients was 18.6 months, with a 1-year survival of 51.6%.

CONCLUSION

Autologous tumor cell-vaccination may be combined with ex vivo expansion of lymphocytes as adoptive cellular immunotherapy for advanced NSCLC. Overall survival in this cohort of poor prognosis patients compared favorably with results reported in the literature.

A multicenter, randomized, placebo controlled, multiple-dose, safety and pharmacokinetic study of AIT-082 (Neotrofin) in mild Alzheimer's disease patients

A phase 1, randomized, double-blind, placebo-controlled, dose escalation study of the purine derivative, AIT-082 (Neotrofin, NeoTherapeutics) was conducted in mild Alzheimer's disease (AD) patients to evaluate multiple-dose safety, tolerability, and pharmacokinetics. Possible short-term effects of AIT-082 on cognition and memory were preliminarily investigated. AIT-082 is currently being developed as a potential treatment for Alzheimer's disease and other neurological disorders. Pre-clinical studies indicate that AIT-082 has memory enhancing properties, stimulates neuritogenesis and the production of neurotrophic factors. Patients received an oral dose of AIT-082 or placebo daily for one week. Thirty-six AD patients were divided into three dose cohorts; each dose cohort consisted of twelve patients with 8 patients randomized to AIT-082 and 4 to placebo. The 3 doses of AIT-082 evaluated in this study were 100 mg/day, 500 mg/day, and 2,000 mg/day. There were no serious adverse events at any dose and the drug was well tolerated without significant side effects. AIT-082 was orally and rapidly absorbed, resulting in peak serum concentrations within 2 hours with an elimination half-life of approximately 20 hours. Higher doses resulted in corresponding increases in peak concentrations and areas under the curve (AUC). There was an approximate 2-fold accumulation in AIT-082 with daily dosing (as reflected by the AUC) at steady state. There were no significant differences by treatment arm on the clinical or neuropsychological evaluations. AIT-082 was rapidly absorbed by the oral route with a half-life suitable for dosing once or twice daily. No problems with tolerability or safety were found. AIT-082 appears suitable for testing in larger clinical trials for the treatment of AD and other neurologic disorders.

Small water and wastewater systems: pathways to sustainable development?

Globally we are faced with billions of people without access to safe water and adequate sanitation. These are generally located in developing communities. Even in developed communities the current large scale systems for supplying water, collecting wastewater and treating it are not environmentally sustainable, because it is difficult to close the cycle of water and nutrients. This paper discusses the advantages of small scale water and wastewater systems in overcoming the difficulties in providing water and wastewater systems in developing communities and in achieving sustainability in both developed and developing communities. Particular attention is given to technology and technology choice, even though technology alone does not provide the complete answer. Disadvantages of small scale systems and how they may be overcome are discussed.