Knockdown of leptin A expression dramatically alters zebrafish development

Using morpholino antisense oligonucleotide (MO) technology, we blocked leptin A or leptin receptor expression in embryonic zebrafish, and analyzed consequences of leptin A knock-down on fish development. Embryos injected with leptin A or leptin receptor MOs (leptin A or leptin receptor morphants) had smaller bodies and eyes, undeveloped inner ear, enlarged pericardial cavity, curved body and/or tail and larger yolk compared to control embryos of the same stages. The defects persisted in 6-9days old larvae. We found that blocking leptin A function had little effect on the development of early brain (1day old), but differentiation of both the morphant dorsal brain and retinal cells was severely disrupted in older (2days old) embryos. Despite the enlarged pericardial cavity, differentiation of cardiac cells appeared to be similar to control embryos. Formation of the morphants' inner ear is also severely disrupted, which corroborates existing reports of leptin receptor expression in inner ear of both zebrafish and mammals. Co-injection of leptin A MO and recombinant leptin results in partial rescue of the wild-type phenotype. Our results suggest that leptin A plays distinct roles in zebrafish development.     

Enhanced alveolar bone loss in a model of non-invasive periodontitis in rice rats

Oral Diseases (2012) 18 , 459–468 Objective: The rice rat (Oryzomys palustris) develops periodontitis‐like lesions when fed a diet rich in sucrose and casein (H‐SC). We aimed to establish whether this model can accurately mimic the development of human periodontitis. Materials and Methods: For this purpose, 28‐day‐old rice rats (15/group) were assigned to standard (STD) or H‐SC diets and sacrificed after 6, 12, and 18 weeks. Jaws were processed for morphometric, histometric, histologic, histomorphometric, and micro‐CT analyses. Results: We found a progressive increase in horizontal alveolar bone loss (ABL) with age in maxillae of rats fed the STD diet as determined by morphometry. The H‐SC diet exacerbated horizontal ABL at the palatal surface at 12 and 18 weeks. Furthermore, increased vertical ABL was detected in mandibles and maxillae of rats fed the H‐SC diet for 12 and/or 18 weeks by histometry and micro‐CT. Remarkably, the H‐SC diet significantly increased bone remodeling at the interproximal alveolar bone of mandibles from rats fed for 6 weeks, but not in those fed for longer periods. Conclusions: These findings indicate that the H‐SC diet induced a transient increase in alveolar bone remodeling, which is followed by ABL characteristic of moderate periodontitis.     

A dopamine electrochemical sensor based on a platinum–silver graphene nanocomposite modified electrode

A platinum–silver graphene (Pt–Ag/Gr) nanocomposite modified electrode was fabricated for the electrochemical detection of dopamine (DA). Electrochemical studies of the Pt–Ag/Gr nanocomposite towards DA detection were performed by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The CV analysis showed that Pt–Ag/Gr/GCE had enhanced electrocatalytic activity towards DA oxidation due to the synergistic effects between the platinum–silver nanoparticles and graphene. The DPV results showed that the modified sensor demonstrated a linear concentration range between 0.1 and 60 μM with a limit of detection of 0.012 μM. The Pt–Ag/Gr/GCE presented satisfactory results for reproducibility, stability and selectivity. The prepared sensor also showed acceptable recoveries for a real sample study.

A platinum–silver graphene nanocomposite was synthesized and characterized. A nanocomposite modified electrode was fabricated in order to investigate the electrochemical detection of dopamine.     

Increased pulse wave velocity and carotid intima–media thickness in patients with carpal tunnel syndrome

Introduction: Carpal tunnel syndrome (CTS) is associated with cardiovascular risk factors. The aim of our study was to determine whether carotid intima–media thickness (CIMT) and carotid–femoral pulse wave velocity (cf-PWV), as surrogates of cardiovascular disease and arterial stiffness, are increased in patients with carpal tunnel syndrome. Methods: Forty patients with CTS and 40 gender- and age-matched controls underwent cf-PWV assessment, CIMT measurement, and nerve conduction study. Results: CIMT and cf-PWV were increased significantly in patients with CTS. They correlated positively with median sensory and motor nerve distal latency. Whereas both CIMT and PWV related to CTS, only CIMT independently predicted CTS. Conclusions: There is both increased pulse wave velocity and CIMT and a positive correlation between these parameters and median nerve sensory distal latency in patients with CTS. CTS appears to be associated with arterial stiffness and atherosclerotic burden, but the underlying mechanisms require further study. Muscle Nerve 47: 872–877, 2013     

Relaxin‐3 innervation of the intergeniculate leaflet of the rat thalamus – neuronal tract‐tracing and in vitro electrophysiological studies

Behavioural state is controlled by a range of neural systems that are sensitive to internal and external stimuli. The relaxin‐3 and relaxin family peptide receptor 3 (RXFP3) system has emerged as a putative ascending arousal network with putative involvement in regulation of stress responses, neuroendocrine control, feeding and metabolism, circadian activity and cognition. Relaxin‐3/γ‐aminobutyric acid neuron populations have been identified in the nucleus incertus, pontine raphe nucleus, periaqueductal grey (PAG) and an area dorsal to the substantia nigra. Relaxin‐3‐positive fibres/terminals densely innervate arousal‐related structures in the brainstem, hypothalamus and limbic forebrain, but the functional significance of the heterogeneous relaxin‐3 neuron distribution and its inputs to specific brain areas are unclear. Therefore, in this study, we used neuronal tract‐tracing and immunofluorescence staining to explore the source of the dense relaxin‐3 innervation of the intergeniculate leaflet (IGL) of the thalamus, a component of the neural circadian timing system. Confocal microscopy analysis revealed that relaxin‐3‐positive neurons retrogradely labelled from the IGL were predominantly present in the PAG and these neurons expressed corticotropin‐releasing factor receptor‐like immunoreactivity. Subsequently, whole‐cell patch‐clamp recordings revealed heterogeneous effects of RXFP3 activation in the IGL by the RXFP3 agonist, relaxin‐3 B‐chain/insulin‐like peptide‐5 A‐chain (R3/I5). Identified, neuropeptide Y‐positive IGL neurons, known to influence suprachiasmatic nucleus activity, were excited by R3/I5, whereas neurons of unidentified neurotransmitter content were either depolarized or displayed a decrease in action potential firing and/or membrane potential hyperpolarization. Our data identify a PAG to IGL relaxin‐3/RXFP3 pathway that might convey stress‐related information to key elements of the circadian system and influence behavioural state rhythmicity.     

Telemedicine-based new patient consultations for hernia repair and advanced abdominal wall reconstruction

Hernia - Telemedicine has emerged as a viable option to in-person visits for the evaluation and management of surgical patients. Increased integration of telemedicine has allowed for greater access...     

Uncertainties in BP management in dialysis patients

Hypertension in dialysis patients is extremely common. In this article, we review the current evidence for blood pressure (BP) goals in hemodialysis patients, and consider the effectiveness of interventions by which BP may be lowered, including manipulation of dietary and dialysate sodium; optimization of extracellular water; prolongation of dialysis time; and antihypertensive medication. Although two meta-analyses suggest lowering BP using antihypertensive drugs might be beneficial in reducing cardiovascular events and mortality, there are insufficient rigorously designed trials in hypertensive hemodialysis populations to determine preferred antihypertensive drug classes. We suggest aiming for predialysis systolic BP between 130 and 159 mm Hg, while at the same time acknowledge the significant limitations of the data upon which it is based. We conclude by summarizing current knowledge as regards management of hypertension in the peritoneal dialysis population and make recommendations for future research in this field.