Manic episodes are one of the major diagnostic symptoms in a spectrum of neuropsychiatric disorders that include schizophrenia, obsessive-compulsive disorder and bipolar disorder (BD). Despite a ...possible association between BD and the gene encoding phospholipase Cγ1 (PLCG1), its etiological basis remains unclear. Here, we report that mice lacking phospholipase Cγ1 (PLCγ1) in the forebrain (Plcg1
; CaMKII) exhibit hyperactivity, decreased anxiety-like behavior, reduced depressive-related behavior, hyperhedonia, hyperphagia, impaired learning and memory and exaggerated startle responses. Inhibitory transmission in hippocampal pyramidal neurons and striatal dopamine receptor D1-expressing neurons of Plcg1-deficient mice was significantly reduced. The decrease in inhibitory transmission is likely due to a reduced number of γ-aminobutyric acid (GABA)-ergic boutons, which may result from impaired localization and/or stabilization of postsynaptic CaMKII (Ca
/calmodulin-dependent protein kinase II) at inhibitory synapses. Moreover, mutant mice display impaired brain-derived neurotrophic factor-tropomyosin receptor kinase B-dependent synaptic plasticity in the hippocampus, which could account for deficits of spatial memory. Lithium and valproate, the drugs presently used to treat mania associated with BD, rescued the hyperactive phenotypes of Plcg1
; CaMKII mice. These findings provide evidence that PLCγ1 is critical for synaptic function and plasticity and that the loss of PLCγ1 from the forebrain results in manic-like behavior.
Background. Better understanding of complications and outcomes of adults hospitalized with respiratory syncytial virus (RSV) infection is necessary. Methods. A retrospective cohort study was ...conducted on all adults (≥18 years) admitted to 3 acute care general hospitals in Hong Kong with virologically confirmed RSV infection during 2009–2011 (N = 607). Adults hospitalized for seasonal influenza during the period were used for comparison (n = 547). Both infections were prospectively diagnosed following a standard protocol. Independent reviews of chest radiographs were performed by radiologists. Main outcome measures were all-cause death, respiratory failure requiring ventilatory support, and hospitalization duration. Cox proportional hazards models were used for analyses. Results. The mean age of RSV patients was 75 (SD, 16) years; 87% had underlying conditions. Lower respiratory and cardiovascular complications were diagnosed in 71.9% (pneumonia, 42.3%; acute bronchitis, 21.9%; chronic obstructive pulmonary disease/asthma exacerbation, 27.3%) and 14.3% of patients, respectively; 12.5% had bacterial superinfections. Supplemental oxygen and ventilatory support were required in 67.9% and 11.1%, respectively. Crude all-cause mortality was 9.1% and 11.9% within 30 days and 60 days, respectively; mean length of stay of survivors was 12 (SD, 13) days. Advanced age, radiographic pneumonia, requirement for ventilation, bacterial superinfection, and elevated urea level and white blood cell count were independently associated with poorer survival. Systemic corticosteroid use was associated with longer hospitalization and secondary infections. The overall outcomes of survival and length of stay were not significantly different from those in influenza. Conclusions. RSV can cause severe lower respiratory complications in older adults, resulting in respiratory failure, prolonged hospitalization, and high mortality similar to seasonal influenza. Corticosteroids did not seem to improve outcomes. The unmet need for antiviral therapy and vaccination against RSV in adults should be promptly addressed.
In vitro models of the blood-brain barrier (BBB) are critical tools for the study of BBB transport and the development of drugs that can reach the CNS. Brain endothelial cells grown in culture are ...often used to model the BBB; however, it is challenging to maintain reproducible BBB properties and function. 'BBB organoids' are obtained following coculture of endothelial cells, pericytes and astrocytes under low-adhesion conditions. These organoids reproduce many features of the BBB, including the expression of tight junctions, molecular transporters and drug efflux pumps, and hence can be used to model drug transport across the BBB. This protocol provides a comprehensive description of the techniques required to culture and maintain BBB organoids. We also describe two separate detection approaches that can be used to analyze drug penetration into the organoids: confocal fluorescence microscopy and mass spectrometry imaging. Using our protocol, BBB organoids can be established within 2-3 d. An additional day is required to analyze drug permeability. The BBB organoid platform represents an accurate, versatile and cost-effective in vitro tool. It can easily be scaled to a high-throughput format, offering a tool for BBB modeling that could accelerate therapeutic discovery for the treatment of various neuropathologies.
Culture-based blood-brain barrier (BBB) models are crucial tools to enable rapid screening of brain-penetrating drugs. However, reproducibility of in vitro barrier properties and permeability remain ...as major challenges. Here, we report that self-assembling multicellular BBB spheroids display reproducible BBB features and functions. The spheroid core is comprised mainly of astrocytes, while brain endothelial cells and pericytes encase the surface, acting as a barrier that regulates transport of molecules. The spheroid surface exhibits high expression of tight junction proteins, VEGF-dependent permeability, efflux pump activity and receptor-mediated transcytosis of angiopep-2. In contrast, the transwell co-culture system displays comparatively low levels of BBB regulatory proteins, and is unable to discriminate between the transport of angiopep-2 and a control peptide. Finally, we have utilized the BBB spheroids to screen and identify BBB-penetrant cell-penetrating peptides (CPPs). This robust in vitro BBB model could serve as a valuable next-generation platform for expediting the development of CNS therapeutics.
Background and purpose
Generalized cerebral ischaemia from cardiovascular dysfunction usually leads to presyncopal dizziness, but several studies reported a higher frequency of rotatory vertigo in ...cardiovascular patients. Whether generalized cerebral ischaemia due to cardiovascular disorders may produce objective vestibular dysfunction was investigated.
Methods
Thirty‐three patients with orthostatic dizziness/vertigo due to profound orthostatic hypotension and 30 controls were recruited. All participants underwent recording of eye movements during two orthostatic challenging tests: the Schellong and the squatting−standing tests. Most patients had neuroimaging, and patients with abnormal eye movements were subjected to follow‐up evaluations.
Results
Symptoms associated with orthostatic dizziness/vertigo included blurred vision, fainting and tinnitus. Ten (30%) of 33 patients developed rotatory vertigo and nystagmus during the Schellong (n = 5) or squatting−standing test (n = 5). Four of them showed pure downbeat nystagmus whilst five had downbeat and horizontal nystagmus with or without torsional component. Patients with orthostatic nystagmus had shorter duration of orthostatic intolerance than those without nystagmus (1.0 ± 1.6 vs. 11.0 ± 9.7 months, P < 0.001). In two patients, orthostatic nystagmus disappeared during follow‐up despite the persistence of profound orthostatic hypotension.
Conclusions
Generalized cerebral ischaemia caused by orthostatic hypotension induces rotatory vertigo due to objective vestibular dysfunction. The presence of orthostatic vertigo and nystagmus has an association with the duration of orthostatic intolerance.
Background & Aims Biliary epithelial cells (BECs) are considered to be a source of regenerating hepatocytes when hepatocyte proliferation is compromised. However, there is still controversy about the ...extent to which BECs can contribute to the regenerating hepatocyte population, and thereby to liver recovery. To investigate this issue, we established a zebrafish model of liver regeneration in which the extent of hepatocyte ablation can be controlled. Methods Hepatocytes were depleted by administration of metronidazole to Tg(fabp10a:CFP-NTR) animals. We traced the origin of regenerating hepatocytes using short-term lineage-tracing experiments, as well as the inducible Cre/loxP system; specifically, we utilized both a BEC tracer line Tg(Tp1:CreER T2 ) and a hepatocyte tracer line Tg(fabp10a:CreER T2 ) . We also examined BEC and hepatocyte proliferation and liver marker gene expression during liver regeneration. Results BECs gave rise to most of the regenerating hepatocytes in larval and adult zebrafish after severe hepatocyte depletion. After hepatocyte loss, BECs proliferated as they dedifferentiated into hepatoblast-like cells; they subsequently differentiated into highly proliferative hepatocytes that restored the liver mass. This process was impaired in zebrafish wnt2bb mutants; in these animals, hepatocytes regenerated but their proliferation was greatly reduced. Conclusions BECs contribute to regenerating hepatocytes after substantial hepatocyte depletion in zebrafish, thereby leading to recovery from severe liver damage.
A polymer nanofibrous matrix suitable for polymer electrolytes in high‐performance lithium polymer batteries is presented. The poly(vinylidene fluoride) (PVdF) nanofibrous membrane (see Figure) was ...produced by electrospinning, which is briefly outlined. The characterization of the membrane—its porosity, network structure, mechanical strength, and electrochemical properties—is described.
Upon mild liver injury, new hepatocytes originate from preexisting hepatocytes. However, if hepatocyte proliferation is impaired, a manifestation of severe liver injury, biliary epithelial cells ...(BECs) contribute to new hepatocytes through BEC dedifferentiation into liver progenitor cells (LPCs), also termed oval cells or hepatoblast‐like cells (HB‐LCs), and subsequent differentiation into hepatocytes. Despite the identification of several factors regulating BEC dedifferentiation and activation, little is known about factors involved in the regulation of LPC differentiation into hepatocytes during liver regeneration. Using a zebrafish model of near‐complete hepatocyte ablation, we show that bone morphogenetic protein (Bmp) signaling is required for BEC conversion to hepatocytes, particularly for LPC differentiation into hepatocytes. We found that severe liver injury led to the up‐regulation of genes involved in Bmp signaling, including smad5, tbx2b, and id2a, in the liver. Bmp suppression did not block BEC dedifferentiation into HB‐LCs; however, the differentiation of HB‐LCs into hepatocytes was impaired due to the maintenance of HB‐LCs in an undifferentiated state. Later Bmp suppression did not affect HB‐LC differentiation but increased BEC number through proliferation. Notably, smad5, tbx2b, and id2a mutants exhibited similar liver regeneration defects as those observed in Bmp‐suppressed livers. Moreover, BMP2 addition promoted the differentiation of a murine LPC line into hepatocytes in vitro. Conclusions: Bmp signaling regulates BEC‐driven liver regeneration through smad5, tbx2b, and id2a: it regulates HB‐LC differentiation into hepatocytes through tbx2b and BEC proliferation through id2a; our findings provide insights into promoting innate liver regeneration as a novel therapy. (Hepatology 2017;66:1616–1630).
Background and purpose
The inferior cerebellar peduncle (ICP) contains various fibres to and from the cerebellum relating to the integration of the proprioceptive and vestibular functions. However, ...the full clinical features of isolated unilateral ICP lesions have not been defined in humans.
Methods
Eight consecutive patients with isolated unilateral ICP lesions at the pontine level (six with stroke, one with multiple sclerosis and one with brainstem encephalitis) received bedside neurological and neuro‐otological evaluations and underwent laboratory tests including measurements of the subjective visual vertical (SVV) and ocular torsion, bithermal caloric tests and pure tone audiometry.
Results
All patients developed isolated acute vestibular syndrome (AVS) with ipsilesional spontaneous nystagmus (n = 7) and contralesional ocular tilt reaction (OTR) and/or SVV tilt (n = 7). In view of the normal head impulse test in all patients and skew deviation in one, our patients met the criteria for AVS from central lesions. Five patients showed a directional dissociation between the OTR/SVV tilt and body lateropulsion that fell to the lesion side whilst the OTR/SVVtilt was contraversive.
Conclusions
A unilateral ICP lesion at the pontine level leads to the development of isolated AVS. However, a negative head impulse test and directional dissociation between OTR/SVV tilt and body lateropulsion may distinguish lesions involving unilateral ICP at the pontine level from those affecting other vestibular structures.
Background
There is no consensus on the best method of preventing postoperative pancreatic fistula (POPF) after pancreaticoduodenectomy (PD). This multicentre, parallel group, randomized equivalence ...trial investigated the effect of two ways of pancreatic stenting after PD on the rate of POPF.
Methods
Patients undergoing elective PD or pylorus‐preserving PD with duct‐to‐mucosa pancreaticojejunostomy were enrolled from four tertiary referral hospitals. Randomization was stratified according to surgeon with a 1 : 1 allocation ratio to avoid any related technical factors. The primary endpoint was clinically relevant POPF rate. Secondary endpoints were nutritional index, remnant pancreatic volume, long‐term complications and quality of life 2 years after PD.
Results
A total of 328 patients were randomized to the external (164 patients) or internal (164) stent group between August 2010 and January 2014. The rates of clinically relevant POPF were 24·4 per cent in the external and 18·9 per cent in the internal stent group (risk difference 5·5 per cent). As the 90 per cent confidence interval (−2·0 to 13·0 per cent) did not fall within the predefined equivalence limits (−10 to 10 per cent), the clinically relevant POPF rates in the two groups were not equivalent. Similar results were observed for patients with soft pancreatic texture and high fistula risk score. Other postoperative outcomes were comparable between the two groups. Five stent‐related complications occurred in the external stent group. Multivariable analysis revealed that soft pancreatic texture, non‐pancreatic disease and high body mass index (23·3 kg/m2 or above) predicted clinically relevant POPF.
Conclusion
External stenting after PD was associated with a higher rate of clinically relevant POPF than internal stenting. Registration number: NCT01023594 (https://www.clinicaltrials.gov).
Internal stenting is better
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