Mitochondrial dysfunction in rabies virus infection of neurons

Infection with the challenge virus standard-11 (CVS) strain of fixed rabies virus induces neuronal process degeneration in adult mice after hindlimb footpad inoculation. CVS-induced axonal swellings of primary rodent dorsal root ganglion neurons are associated with 4-hydroxy-2-nonenal protein adduct staining, indicating a critical role of oxidative stress. Mitochondrial dysfunction is the major cause of oxidative stress. We hypothesized that CVS infection induces mitochondrial dysfunction leading to oxidative stress. We investigated the effects of CVS infection on several mitochondrial parameters in different cell types. CVS infection significantly increased maximal uncoupled respiration and complex IV respiration and complex I and complex IV activities, but did not affect complex II–III or citrate synthase activities. Increases in complex I activity, but not complex IV activity, correlated with susceptibility of the cells to CVS infection. CVS infection maintained coupled respiration and rate of proton leak, indicating a tight mitochondrial coupling. Possibly as a result of enhanced complex activity and efficient coupling, a high mitochondrial membrane potential was generated. CVS infection reduced the intracellular ATP level and altered the cellular redox state as indicated by a high NADH/NAD+ ratio. The basal production of reactive oxygen species (ROS) was not affected in CVS-infected neurons. However, a higher rate of ROS generation occurred in CVS-infected neurons in the presence of mitochondrial substrates and inhibitors. We conclude that CVS infection induces mitochondrial dysfunction leading to ROS overgeneration and oxidative stress.     

Proposed guidelines for the management of nodding syndrome

Nodding Syndrome is a poorly understood neurologic disorder of unknown aetiology that affects children and adolescents in Africa. Recent studies have suggested that the head nods are due to atonic seizures and Nodding Syndrome may be classified as probably symptomatic generalised epilepsy. As part of the Ugandan Ministry of Health clinical management response, a multidisciplinary team developed a manual to guide the training of health workers with knowledge and skills to manage the patients. In the absence of a known cause, it was decided to offer symptomatic care. The objective is to relieve symptoms, offer primary and secondary prevention for disability and rehabilitation to improve function. Initial management focuses on the most urgent needs of the patient and the immediate family until ‘stability’ is achieved. The most important needs were considered as seizure control, management of behavioural and psychiatric difficulties, nursing care, nutritional and subsequently, physical and cognitive rehabilitation. This paper summarises the processes by which the proposed guidelines were developed and provides an outline of the specific treatments currently being provided for the patients.     

Comparison of periodontal open flap debridement versus closed debridement with Er,Cr:YSGG laser

Background

Traditional periodontal open flap debridement (OFD) results in reduced pocket depth (PD), clinical attachment loss (CAL), gingival recession (GR) and postoperative pain and discomfort. The quest to overcome these shortcomings has led to research into Er,Cr:YSGG laser assisted pocket therapy (ELAPT). This study was designed to compare the clinical outcomes of ELAPT versus OFD.

Methods

Fifteen patients with a PD of ≥5 mm and ≤8 mm at two sites were selected. Test sites (Group 1) were treated by ELAPT and the control (Group 2) by OFD. Clinical parameters were recorded at baseline, 3 and 6 months and included Plaque Index (PI), Gingival Index (GI), modified Sulcular Bleeding Index (mSBI), PD, CAL and GR.

Results

Both treatments produced a reduction in PI, GI, mSBI and PD, an increase in GR, and a gain in CAL at 3 and 6 months. The mean gain of CAL in Group 1 at 3 and 6 months (1.60 ± 0.78 and 1.80 ± 0.63) was similar (p > 0.05) to the value of Group 2 (1.93 ± 0.88 and 2.00 ± 0.54). GR increased significantly (p < 0.05) only in Group 2 at 3 and 6 months (1.80 ± 0.56 and 1.87 ± 0.64) compared to Group 1 (0.50 ± 0.68 and 0.60 ± 0.74).

Conclusions

ELAPT compared with OFD results in similar CAL gains with less GR and significant reductions in PD, GI and mSBI, and may be considered as an alternative to surgical therapy.     

Glycoprotein E (gE) specified by bovine herpesvirus type 5 (BHV-5) enables trans-neuronal virus spread and neurovirulence without being a structural component of enveloped virions

Bovine herpesvirus 5 (BHV-5) is a neurovirulent alpha-herpesvirus that causes fatal encephalitis in calves. We previously demonstrated that deletion of a glycine-rich epitope in the gE ectodomain dramatically reduced BHV-5 neurovirulence. To investigate the role of gE cytoplasmic tail sequences in the neuropathogenesis of BHV-5 in rabbits, we constructed a BHV-5gE recombinant virus with a short residual cytoplasmic domain lacking the YXXL motifs and the acidic (BHV-5gEAm480). In vitro, BHV-5gEAm480 produced on the average smaller plaques, compared with wild-type BHV-5, but it produced on the average substantially larger plaques than the gE ORF-deleted BHV-5. The truncated gE was not phosphorylated, and was not endocytosed from the cell surface. Importantly, the truncated gE was not incorporated into enveloped infectious virions, but its glycosylation and interaction with gI were not affected. In a rabbit model of infection, the BHV-5gEAm480 remained highly virulent, while the gE-null virus was avirulent. The gEAm480 mutant virus invaded most of the central nervous system (CNS) structures that are invaded by the wild-type BHV-5. The number of neurons infected by BHV-5gEAm480 was very similar to the number infected by BHV-5 wild-type and gEAm480-rescued viruses. Collectively, the results suggest that gE functions in transsynaptic transmission of BHV-5 and neurovirulence without being a structural component of the virion particle.     

PEGylation of Carbonate Apatite Nanoparticles Prevents Opsonin Binding and Enhances Tumor Accumulation of Gemcitabine

pH sensitives carbonate apatite (CA) has emerged as a targeted delivery vehicle for chemotherapeutics agent with tremendous potential to increase the effectivity of breast cancer treatment. The major challenge for intravenous delivery of drug-incorporated nanoparticles is their rapid opsonization, resulting in accumulation within the organs of reticuloendothelial system, such as liver and spleen. Therefore, surface modification by polyethylene glycol was implemented to improve the half-life of drug-particle complexes and enhance their uptake by target tissues. A simple, rapid, and sensitive triple quadrupole liquid chromatography–mass spectrometry method was developed and validated for quantification of gemcitabine in plasma, various organs and tumor tissues of mice with breast carcinoma, whereas sodium dodecyl sulfate-polyacrylamide gel electrophoresis, quadrupole-time of flight liquid chromatography–mass spectrometry and analysis by SwissProt.Mus_musculus database were performed for protein separation, identification, and homology search by comparing the de novo sequence tag. PEGylated CA exhibited almost 6-fold increase in gemcitabine accumulation in tumor with significant reduction in other organs within 1 h of intravenous administration, compared to free drug. In addition, plasma drug amount was found to be higher in PEGylated particles, implying their role in prolonging blood circulation time of particle-bound gemcitabine. Investigation of protein corona composition demonstrated notable reduction in opsonin interactions after PEGylation of CA particles. Overall, the results indicate that the composition and dynamics of protein corona subjected to alteration by PEGylation play crucial roles in affecting successful nanoparticle-based targeted delivery of a cytotoxic drug.     

Use of designing for behaviour change framework in identifying and addressing barriers to and enablers of animal source feeding to children ages 8–23 months in Bandarban Hill District in Bangladesh: Implications for a nutrition-sensitive agriculture programme

Inadequate diet quality is a cause of undernutrition among children 6–23 months of age in Bangladesh, particularly in remote and isolated areas such as Bandarban District. Feeding animal source foods can help to combat stunting and wasting problems among children, but it may not be accessible or acceptable. A barrier analysis using the Designing for Behavior Change Framework was conducted in Bandarban district with participants from 4 ethnic groups, to explore potential barriers and key motivators by examining 12 behavioural determinants of consumption of animal-source food in complementary feeding for children 8–23 months. Data were collected from 45 mothers of children 8–23 months, who provided animal-source foods to their children (doers), and from 45 mothers who did not (non-doers), for a total of 90 interviews. Nine determinants were statistically significantly different between doers and non-doers as follows: self-efficacy, positive consequences, negative consequences, social norms, access, reminders, perceived risk, perceived severity and perceived action efficacy. Nearby access to purchase animal-source foods, rearing poultry or livestock at home and the support of household and community members are enablers to feeding animal-source food. In contrast, these same factors are barriers for non-doers. The lack of money to spend on animal-source foods is also a barrier. An integrated nutrition-sensitive and gender-transformative animal-based food production, and inclusive market programme could increase access to meat and eggs at the household level, increase opportunities to earn income and support gender-equitable household workloads and decision-making for optimal child feeding.     

Primary motor cortex long‐term plasticity in multiple system atrophy

In humans, intermittent and continuous theta‐burst stimulation (iTBS and cTBS) elicit long‐term changes in motor‐evoked potentials (MEPs) reflecting long‐term potentiation (LTP)‐ and depression (LTD)‐like plasticity in the primary motor cortex (M1). In this study, we used TBS to investigate M1 plasticity in patients with MSA. We also assessed whether responses to TBS reflect M1 excitability as tested by short‐interval intracortical inhibition (SICI), intracortical facilitation (ICF), short‐interval intracortical facilitation (SICF), and the input/output curves. We studied 20 patients with MSA and 20 healthy subjects (HS). Patients were clinically evaluated with the Unified Multiple System Atrophy Rating Scale. The left M1 was conditioned with TBS. Twenty MEPs were recorded from the right first dorsal interosseous muscle before TBS and 5, 15, and 30 minutes thereafter. In a subgroup of 10 patients, we also tested MEPs elicited by SICI, ICF, SICF, and input/output curves, before TBS. Between‐group analysis of variance showed that at all time points after iTBS MEPs increased, whereas after cTBS they decreased only in HS. In both subgroups tested, patients with predominant parkinsonian and cerebellar features, iTBS and cTBS left MEPs unchanged. MSA patients had reduced SICI, but normal ICF, SICF, and input/output curves. No correlation was found between patients' clinical features and responses to TBS and M1 excitability variables. These findings suggest impaired M1 plasticity in MSA. © 2013 International Parkinson and Movement Disorder Society     

Gender identity shows a high correlation with Prader score in patients with disorders of sex development (DSD) presenting in mid childhood

Objective

In developing countries like Bangladesh, delayed presentation for disorders of sex development (DSD) is common, and provides some special problems for management. There remains significant controversy about appropriate sex assignment in this group. We aimed, therefore, to assess gender identity (GI) in 50 consecutive patients with DSD presenting to a referral centre in Chittagong, Bangladesh, and correlate it with Prader score, to see if the latter could be used to predict GI.

Methods

A cross-sectional, case–control study of 50 consecutive children with DSD and 50 children with vascular anomalies was conducted in the Pediatric Surgical Clinic, Chittagong Medical College and Hospital. After informed consent, patients and controls provided oral answers to a GI questionnaire and had a detailed history and physical examination. Sex-typed activities were assessed by observations of a structured toy play and the child’s selection of a toy to keep. Both patients and parents then completed the Child Game Participation Questionnaire.

Results

There were no differences in age (2–16 years, mean 8.74) between controls and DSD patients (11 46, XX DSD, 32 46, XY DSD, 4 MGD, 3 ovo-testicular DSD). Fifteen of the DSD patients (30 %) came from consanguineous marriages and only 2 of the control patients had consanguinity of their parents. For the 13-question GI interview, there was no overall difference between DSD cases and controls. For the 46, XX DSD subgroup, there was a significantly higher score (11.1 ± 7.1) compared with control girls (4.5 ± 4.7) (p < 0.05), while for DSD and control boys, there was a positive correlation with age and GI (p < 0.01). Prader score correlated with GI score in both control (r = 0.91) and DSD patients (r = 0.75) (p < 0.01), DSD girls played significantly less with girls’ toys than controls (p < 0.01), but there was no differences for the boys. Composite scores on GI and gender-related behaviour correlated with Prader score for DSD patients (r = 0.61) (p < 0.01).

Conclusion

This study supports the view that GI and gender-role behaviour should be assessed routinely in DSD patients presenting after the neonatal period, so that sex assignment is in accordance with behaviour. Prader scores showed a good correlation with GI and gender role behaviour.