Idiopathic thrombotic thrombocytopenic purpura (TTP) occurs primarily due to the formation of autoantibody against ADAMTS13, a specific von Willebrand factor-cleaving protease, resulting in low ADAMTS13 activity and subsequent accumulation of large vWF multimers, platelet aggregation and thrombus formation in the microvasculature of tissues. Limited clinical data suggest that the administration of anti-CD20 antibody (rituximab) may be useful in treating acute refractory or chronic relapsing idiopathic TTP. We carried out a systematic review with pooled data analysis using individual patient data to evaluate the efficacy of rituximab in these settings. Fifteen case series and 16 case reports comprising 100 patients were eligible for the study. Median age was 39 years. Male constituted 31 % and female 69 %. Complete remission was seen in 98 %, non-response in 2 % and relapse after complete remission in 9 %. For patients with complete remission, median follow-up was 13 months. Median platelet recovery from the first dose of rituximab was 14 days. ADAMTS13 inhibitor positivity and severe ADAMTS13 deficiency were highly predictive of the response to rituximab, implying that these can be useful markers in predicting response to rituximab in acute refractory or chronic relapsing idiopathic TTP.

Singapore is in the process of rolling out a number of national e-health initiatives, including the National Electronic Health Record (NEHR). A critical enabler in the journey towards semantic interoperability is a Logical Information Model (LIM) that harmonises the semantics of the information structure with the terminology. The Singapore LIM uses a combination of international standards, including ISO 13606-1 (a reference model for electronic health record communication), ISO 21090 (healthcare datatypes), and SNOMED CT (healthcare terminology). The LIM is accompanied by a logical design approach, used to generate interoperability artifacts, and incorporates mechanisms for achieving unidirectional and bidirectional semantic interoperability.

A hybrid standards-based approach has been adopted in Singapore to develop a Logical Information Model (LIM) for healthcare information exchange. The Singapore LIM uses a combination of international standards, including ISO13606-1 (a reference model for electronic health record communication), ISO21090 (healthcare datatypes), SNOMED CT (healthcare terminology) and HL7 v2 (healthcare messaging). This logic-based design approach also incorporates mechanisms for achieving bi-directional semantic interoperability.

BACKGROUND Cytomegalovirus retinitis is a neglected disease in resource-poor settings, in part because of the perceived complexity of care and because ophthalmologists are rarely accessible. In this paper, we describe a pilot programme of CMV retinitis management by non-ophthalmologists. The programme consists of systematic screening of all high-risk patients (CD4 <100 cells/mm3) by AIDS clinicians using indirect ophthalmoscopy, and treatment of all patients with active retinitis by intravitreal injection of ganciclovir. Prior to this programme, CMV retinitis was not routinely examined for, or treated, in Myanmar. METHODS This is a retrospective descriptive study. Between November 2006 and July 2009, 17 primary care AIDS clinicians were trained in indirect ophthalmoscopy and diagnosis of CMV retinitis; eight were also trained in intravitreal injection. Evaluation of training by a variety of methods documented high clinical competence. Systematic screening of all high-risk patients (CD4 <100 cells/mm3) was carried out at five separate AIDS clinics throughout Myanmar. RESULTS A total of 891 new patients (1782 eyes) were screened in the primary area (Yangon); the majority of patients were male (64.3%), median age was 32 years, and median CD4 cell count was 38 cells/mm3. CMV retinitis was diagnosed in 24%(211/891) of these patients. Bilateral disease was present in 36% of patients. Patients with active retinitis were treated with weekly intravitreal injection of ganciclovir, with patients typically receiving five to seven injections per eye. A total of 1296 injections were administered. CONCLUSIONS A strategy of management of CMV retinitis at the primary care level is feasible in resource-poor settings. With appropriate training and support, CMV retinitis can be diagnosed and treated by AIDS clinicians (non-ophthalmologists), just like other major opportunistic infections.

BACKGROUND: A restrictive chromatin state has been thought to be operant in the pathophysiology of schizophrenia. Our objective was to ascertain whether differences exist between baseline levels of a repressive chromatin mark such as dimethylated lysine 9 of histone 3 (H3K9me2) in patients with schizophrenia and healthy controls and whether a histone deacetylase (HDAC) inhibitor in an in vitro assay would differentially affect chromatin structure based on diagnosis. METHODS: We obtained blood samples from 19 healthy controls and 25 patients with schizophrenia and isolated their lymphocytes. We measured baseline H3K9me2 levels (normalized to total histone 1) in the lymphocytes from all participants via Western blot analysis. To examine the effects of an HDAC inhibitor on H3K9me2, we cultured the lymphocytes from participants with trichostatin A (TSA) for 24 hours and then measured changes in H3K9me2 relative to the control condition (dimethyl sulfoxide). RESULTS: Patients with schizophrenia had significantly higher mean baseline levels of H3K9me2 than healthy controls (6.52 v. 2.78, p = 0.028). Moreover, there was a significant negative correlation between age at onset of illness and levels of H3K9me2 (Spearman's rho =-0.588, p = 0.008). In the lymphocyte cultures, TSA induced divergent responses in terms of H3K9me2 levels from patients with schizophrenia compared with healthy controls (F(1,14)= 5.082, p = 0.041). LIMITATIONS: The use of lymphocytes to study schizophrenia has its limitations because they may not be appropriate models of synaptic activity or other brain-specific activities. CONCLUSION: Our results provide further evidence that schizophrenia is associated with a restrictive chromatin state that is also less modifiable using HDAC inhibitors.

Through inhibitory G protein-coupled melatonin receptors, melatonin regulates intracellular signaling systems and also the transcriptional activity of certain genes. Clock genes are proposed as regulatory factors in forming dopamine-related behaviors and mood and melatonin has the ability to regulate these processes. Melatonin-mediated changes in clock gene expression have been reported in brain regions, including the striatum, that are crucial for the development of dopaminergic behaviors and mood. However, it is not known whether melatonin receptors present in striatum mediate these effects. Therefore, we investigated the role of the melatonin/melatonin receptor system on clock gene expression using a model of primary neuronal cultures prepared from striatum. We found that melatonin at the receptor affinity range (i.e., nm) affects the expression of the clock genes mPer1, mClock, mBmal1 and mNPAS2 (neuronal PAS domain protein 2) differentially in a pertussis toxin-sensitive manner: a decrease in Per1 and Clock, an increase in NPAS2 and no change in Bmal1 expression. Furthermore, mutating MT1 melatonin receptor (i.e., MT1 knockouts, MT1(-/-)) reversed melatonin-induced changes, indicating the involvement of MT1 receptor in the regulatory action of melatonin on neuronal clock gene expression. Therefore, by controlling clock gene expression we propose melatonin receptors (i.e., MT1) as novel therapeutic targets for the pathobiologies of dopamine-related behaviors and mood.

DNA methylation in post-mitotic neurons is reported to serve a variety of functions from survival during development to the consolidation of memory. Of particular interest with regards neuronal functioning is the change in site-specific methylation of a variety of gene promoters in the context of neuronal depolarization and the coding of new information. We examined the expression of DNMT1 and DNMT3a, representative of a maintenance and de novo methyltransferase respectively, in response to in-vitro depolarization of cortical neurons, using standard techniques such as high potassium (KCl) or the sodium channel agonist veratridine. KCl and veratridine mediated depolarization caused a modest but significant and replicable reduction in the mRNA and protein expression of both DNMTs that was time and dose dependent. These effects were supported by parallel increases in the mRNA expression of BDNF exon-1 and exon-4 as a typical response of neurons to depolarization and to rule out the possibility of impaired transcriptional activity as a trivial explanation. In addition to effects on mRNA and protein expression, functional DNA methyltransferase activity was reduced in nuclear protein extracts from cells exposed to a depolarization condition. Also, these changes could not be explained by differential neuronal loss as measured by cell viability cytochemistry. Our results support the idea that a reduction in DNA methyltransferase activity in the activated and depolarized neuron could contribute to the enhanced intensity and multiplicity of gene expression frequently reported.

* Here, cytokinin-induced nitric oxide (NO) biosynthesis and cytokinin responses were investigated in Arabidopsis thaliana wild type and mutants defective in NO biosynthesis or cytokinin signaling components.* NO release from seedlings was quantified by a fluorometric method and, by microscopy, observed NO biosynthesis as fluorescence increase of DAR-4M AM (diaminorhodamine 4M acetoxymethyl ester) in different tissues.* Atnoa1 seedlings were indistinguishable in NO tissue distribution pattern and morphological responses, induced by zeatin, from wild-type seedlings. Wild-type and nia1,2 seedlings, lacking nitrate reductase (NR), responded to zeatin with an increase within 3 min in NO biosynthesis so that NR does not seem relevant for rapid NO induction, which was mediated by an unknown 2-(2-aminoethyl)2-thiopseudourea (AET)-sensitive enzyme and was quenched by 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-1-oxy-3-oxide (PTIO). Long-term morphological responses to zeatin were severely altered and NO biosynthesis was increased in nia1,2 seedlings. As cytokinin signaling mutants we used the single-receptor knockout cre1/ahk4, three double-receptor knockouts (ahk2,3, ahk2,4, ahk3,4) and triple-knockout ahp1,2,3 plants. All cytokinin-signaling mutants showed aberrant tissue patterns of NO accumulation in response to zeatin and altered morphological responses to zeatin.* Because aberrant NO biosynthesis correlated with aberrant morphological responses to zeatin the hypothesis was put forward that NO is an intermediate in cytokinin signaling.

In this study we examined the regulation by putrescine (put), spermidine (spd) and spermine (spm) of nitric oxide (NO) biosynthesis in Arabidopsis thaliana seedlings. Using a fluorimetric method employing the cell-impermeable NO-binding dye diaminorhodamine-4M (DAR-4M) we observed that the polyamines (PAs) spd and spm increased NO release in the seedlings strongly whereas arginine (arg) and putrescine (put) had little or no effect. Spm, the most active PA, stimulated NO release with no apparent lag phase. The response was quenched by addition of 2-aminoethyl-2-thiopseudourea (AET), an inhibitor of the animal NO synthase (NOS) and plant NO biosynthesis, and by 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-1-oxy-3-oxide (PTIO), an NO scavenger. By fluorescence microscopy, using the cell-permeable NO-binding dye diaminorhodamine-4M acetoxymethyl ester (DAR-4M AM), we observed that PAs induced NO biosynthesis in specific tissues in Arabidopsis seedlings. Spm and spd increased NO biosynthesis in the elongation zone of the Arabidopsis root tip and in primary leaves, especially in the veins and trichomes, while in cotyledons little or no effect of PAs beyond the endogenous levels of NO-induced fluorescence was observed. We conclude that PAs induce NO biosynthesis in plants.