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Alternative splicing changes the CaV1.2 calcium channel electrophysiological property, but the in vivo significance of such altered channel function is lacking. Structure-function studies of heterologously expressed CaV1.2 channels could not recapitulate channel function in the native milieu of the cardiomyocyte. To address this gap in knowledge, we investigated the role of alternative exon 33 of the CaV1.2 calcium channel in heart function. Exclusion of exon 33 in CaV1.2 channels has been reported to shift the activation potential -10.4 mV to the hyperpolarized direction, and increased expression of CaV1.2Δ33 channels was observed in rat myocardial infarcted hearts. However, how a change in CaV1.2 channel electrophysiological property, due to alternative splicing, might affect cardiac function in vivo is unknown. To address these questions, we generated mCacna1c exon 33-/--null mice. These mice contained CaV1.2Δ33 channels with a gain-of-function that included conduction of larger currents that reflects a shift in voltage dependence and a modest increase in single-channel open probability. This altered channel property underscored the development of ventricular arrhythmia, which is reflected in significantly more deaths of exon 33-/- mice from β-adrenergic stimulation. In vivo telemetric recordings also confirmed increased frequencies in premature ventricular contractions, tachycardia, and lengthened QT interval. Taken together, the significant decrease or absence of exon 33-containing CaV1.2 channels is potentially proarrhythmic in the heart. Of clinical relevance, human ischemic and dilated cardiomyopathy hearts showed increased inclusion of exon 33. However, the possible role that inclusion of exon 33 in CaV1.2 channels may play in the pathogenesis of human heart failure remains unclear.

Enterovirus 71 (EV71) is the major causative agent of hand, foot, and mouth disease (HFMD) in young children and has been consistently associated with the most severe complications of the disease, including central nervous system inflammation and pulmonary edema. Increasing frequency and amplitude of EV71 outbreaks have raised awareness and concerns worldwide. Previous reports proposed that overwhelming virus replication combined with the induction of massive proinflammatory cytokines is responsible for the pathogenicity of EV71. Specifically, elevated interleukin-6 (IL-6) levels were observed consistently in patients and strongly correlated with disease severity. In this study, we show in the neonate mouse model that sustained high levels of IL-6 produced upon EV71 infection lead to severe tissue damage and eventually death of the animals. Administration of anti-IL-6 neutralizing antibodies after the onset of the clinical symptoms successfully improved the survival rates and clinical scores of the infected hosts. Compared to untreated infected controls, anti-IL-6-treated mice displayed reduced tissue damage, absence of splenic atrophy, and increased immune cell activation. In addition, markedly elevated systemic levels of IL-10 were measured in the protected animals. Furthermore, there was no significant difference in virus titers between anti-IL-6-treated mice and untreated mice, indicating that the anti-IL-6 antibody-mediated protection is independent of the virus load. Our findings thus demonstrate that IL-6 plays a major role in EV71-induced immunopathogenesis. As there is still neither vaccine nor treatment available against EV71, anti-IL-6 antibody treatment represents a potential therapeutic approach to providing protection from the most severe complications of the disease.

Objectives/Hypothesis: Currently available silicone and metallic stents for tracheal stenosis are associated with problems of granulations, mucus trapping, and difficult removals. Our aim was to develop a novel bioabsorbable tracheal stent with mitomycin C (MMC) drug elution to circumvent such problems. Study Design: A randomized animal study. Methods: Twenty-five rabbits were randomly assigned into five test groups: 1) controls (without stent), 2) silicone tubular stents (commercially available currently); 3) bioabsorbable helical stents; 4) bioabsorbable tubular stents; and 5) bioabsorbable tubular stents with MMC. Weekly tracheal endoscopy to document granulation, mucus plugging, and extent of tracheal stenosis was performed for 12 weeks. One rabbit was euthanized every 3 weeks for histological analysis of the trachea. In vitro MMC-release profiles in conditions mimicking tracheal conditions were studied. Results: The bioabsorbable tubular stents with 0.1 mg MMC drug elution performed the best, with the least mucus trapping and airway obstruction due to tracheal stenosis. Tracheal stenosis was most significant for the bioabsorbable helical stents, followed by the control group without stent, the group of bioabsorbable tubular stents, and then the silicone stents. After 12 weeks, tracheal stenosis for the bioabsorbable tubular stents with MMC was only half that of the silicone stents. Conclusions: This study reports on the development of a novel bioabsorbable tracheal stent with sustained MMC drug elution for preventing tracheal stenosis. Further studies are warranted to optimize stent design and drug dosage.

The distribution ofproneuropeptide Y-containing perikarya and nerve fibers in the brain of Rana esculenta and Xenopus lavis was determined with antisera directed toward neuropeptide Y and the carboxyl terminal flanking peptide. The distribution of proneuropeptide Y-like immunoreactivity was similar in both anurans. In the telencephalon, immunoreactive perikarya were found in the olfactory bulb, all subdivisions of the pallium, the septum, pars lateralis of the amygdala, the nucleus accumbens, and the anterior preoptic area. In the diencephalon, labelled perikarya were detected in the ventromedial, ventrolateral and central thalamic nuclei, the magnocellular preoptic nucleus, the suprachiasmatic nucleus, the posterior tuberculum, and the infundibulum. Amacrine-like cells were stained in the retina. In the pretectal area, posterior thalamic neurons showed intense, Golgi-like immunostaining. In the mesencephalon, immunoreactive cells were found in the reticular nucleus, the anteroventral tegmental nucleus, the optic tectum, the interpeduncular nucleus, and the torus semicircularis. In the rhombencephalon, labelled perikarya were detected in the secondary visceral nucleus, the central gray, the nucleus of the solitary tract, the dorsal column nuclei, and the spinal nucleus of the trigeminal nerve. Immunoreactive nerve fibers were observed in all areas of the brain that contained labelled perikarya. The densest accumulations were found in the accessory olfactory bulb, pars lateralis of the amygdala, the ventral habenula, the posterior pituitary, the optic tectum, the interpeduncular nucleus, and the saccular nucleus. The distribution of proneuropeptide Y-like immunoreactivity in the anuran brain showed many similarities to the distribution described for the amniote brain. © 1993 Wiley-Liss, Inc.

Monitoring liver fibrosis progression by liver biopsy is important for certain treatment decisions, but repeated biopsy is invasive. We envision redefinition or elimination of liver biopsy with surface scanning of the liver with minimally invasive optical methods. This would be possible only if the information contained on or near liver surfaces accurately reflects the liver fibrosis progression in the liver interior. In our study, we acquired the second-harmonic generation and two-photon excitation fluorescence microscopy images of liver tissues from bile duct-ligated rat model of liver fibrosis. We extracted morphology-based features, such as total collagen, collagen in bile duct areas, bile duct proliferation, and areas occupied by remnant hepatocytes, and defined the capsule and subcapsular regions on the liver surface based on image analysis of features. We discovered a strong correlation between the liver fibrosis progression on the anterior surface and interior in both liver lobes, where biopsy is typically obtained. The posterior surface exhibits less correlation with the rest of the liver. Therefore, scanning the anterior liver surface would obtain similar information to that obtained from biopsy for monitoring liver fibrosis progression.

SUMMARY 1 Intrathecal injection of ondansetron has the potential to reduce opioid-related side-effects. The aim of the present study was to determine whether this route of administration produces neuraxial injury. 2 Adult, non-pregnant female New Zealand white rabbits received a single bolus injection of a low (40 mg) or high (4.0 mg) dose of ondansetron into the intrathecal space between the 4th and 5th lumbar vertebrae. In some cases, ondansetron was coadministered with morphine (5 mg/kg). Control animals received a bolus injection of normal saline. Behavioural assessments were conducted at 1 and 24 h to determine overt changes in arousal and mobility, followed by histological evaluation of the excised spinal cord. 3 Of 45 animals investigated, 10 rabbits exhibited modest behavioural evidence of spinal injury, the incidence of which was equally distributed between the treatment groups. Haematoxylin and eosin, along with HAM56, staining of cross-sections of the cervical, thoracic and upper and lower lumbar areas revealed mild signs of inflammation. This, too, was equally distributed between the treatment groups, suggesting that any observed neuraxial injury was the result of needle trauma and not ondansetron neurotoxicity. 4 Collectively, these negative findings support conducting further experiments to fully assess the clinical usefulness of intrathecal ondansetron administration.

In contrast to the traditional Roux-en-Y reconstruction, an uncut Roux-en-Y provides biliopancreatic diversion and may preserve myoelectric continuity. Previous iterations of the uncut Roux have been plagued by recanalization of the uncut staple line in the afferent small bowel. Our aim was to determine if bovine pericardium buttress prevents recanalization of the stapled small bowel partition in a porcine model. Sixteen female pigs ( approximately 30 kg) underwent a side-to-side stapled jejunojejunostomy, 20 cm distal to the ligament of Treitz, with placement of a nondivided stapled partition with a single row of 2.5 mm width staples in the intervening jejunal loop. Nine animals in the experimental group had a bovine pericardium buttressed staple line (5 permanent, 4 absorbable), whereas seven animals in the control group had a nonbuttressed staple line. At 6 or 12 weeks, necropsy was performed and the primary outcome, staple line recanalization, was assessed grossly and histologically. Statistical analysis was performed by means of the chi-square test. There were no major complications and all animals gained weight. Overall, eight of nine bovine pericardium buttressed staple lines were grossly and histologically intact at necropsy, whereas all nonbuttressed uncut staple lines had recanalized completely (P0.05). At 6 weeks, both permanent (N=4) and absorbable (N=3) buttress preparations prevented recanalization. At 12 weeks the permanent buttress remained closed (N=1), but the absorbable buttress had allowed partial recanalization (N=1). The use of bovine pericardium buttress will prevent small bowel recanalization of uncut small bowel staple lines at early follow-up. Pilot data at intermediate follow-up suggest permanent buttress is more durable than absorbable buttress. These results warrant investigation of bovine pericardium for intestinal applications in humans.

The spread of dengue (DEN) worldwide combined with an increased severity of the DEN-associated clinical outcomes have made this mosquito-borne virus of great global public health importance. Progress in understanding DEN pathogenesis and in developing effective treatments has been hampered by the lack of a suitable small animal model. Most of the DEN clinical isolates and cell culture-passaged DEN virus strains reported so far require either host adaptation, inoculation with a high dose and/or intravenous administration to elicit a virulent phenotype in mice which results, at best, in a productive infection with no, few, or irrelevant disease manifestations, and with mice dying within few days at the peak of viremia. Here we describe a non-mouse-adapted DEN2 virus strain (D2Y98P) that is highly infectious in AG129 mice (lacking interferon-α/β and -γ receptors) upon intraperitoneal administration. Infection with a high dose of D2Y98P induced cytokine storm, massive organ damage, and severe vascular leakage, leading to haemorrhage and rapid death of the animals at the peak of viremia. In contrast, very interestingly and uniquely, infection with a low dose of D2Y98P led to asymptomatic viral dissemination and replication in relevant organs, followed by non-paralytic death of the animals few days after virus clearance, similar to the disease kinetic in humans. Spleen damage, liver dysfunction and increased vascular permeability, but no haemorrhage, were observed in moribund animals, suggesting intact vascular integrity, a cardinal feature in DEN shock syndrome. Infection with D2Y98P thus offers the opportunity to further decipher some of the aspects of dengue pathogenesis and provides a new platform for drug and vaccine testing., Author Summary The spread of dengue (DEN) worldwide combined with an increased severity of the DEN-associated clinical outcomes have made this mosquito-borne virus of great global public health importance. Infection with DEN virus can be asymptomatic or trigger a wide spectrum of clinical manifestations, ranging from mild acute febrile illness to classical dengue fever and to severe DEN hemorrhagic fever/DEN shock syndrome (DHF/DSS). Progress in understanding DEN disease and in developing effective treatments has been hampered by the lack of a suitable animal model that can reproduce all or part of the disease's clinical manifestations and outcome. Only a few of the DEN virus strains reported so far elicit a virulent phenotype in mice, which results at best in an acute infection where mice die within few days with no, few or irrelevant disease manifestations. Here we describe a DEN virus strain which is highly virulent in mice and reproduces some of the aspects of severe DEN in humans, including the disease kinetics, organ damage/dysfunction and increased vascular permeability. This DEN virus strain thus offers the opportunity to further decipher some of the mechanisms involved in DEN pathogenesis, and provides a new platform for drug and vaccine testing in the mouse model.

Background and study aims: The feasibility of performing endoscopic submucosal dissection (ESD) using the Master and Slave Transluminal Endoscopic Robot (MASTER), a robotics-enhanced surgical system, has been shown in our previous study. This study aimed to further explore, in an animal survival study, the 2-week outcome of using MASTER to perform ESD. Patients and methods: In this prospective study, ESD was performed on five female pigs (weighing 32.4 – 36.8 kg) under general anesthesia using the MASTER. The animals were observed for 2 weeks before being humanely killed for necropsy examination. The main outcome measures were completeness of resection, procedure-related complications, and survival at 2 weeks. Results: The procedure was successfully completed in all five pigs. It took a mean of 21.8 minutes (range 6 – 39 minutes) to complete the ESD of each gastric lesion. All lesions were excised en bloc; the average dimension of the lesions was 77 mm (range 25 – 104 mm). One pig sustained a small intraoperative perforation which was identified and successfully clipped. After completion of the ESD procedures, all pigs survived well for 2 weeks. Necropsy was performed, with intraoperative gastroscopy identifying all the ESD sites as healed. Histopathologic examination showed all ESD sites had healed with partial epithelialization. Microbiological tests of the peritoneal fluid showed only microbes typically found in pigs. Conclusion: Performing ESD with MASTER was feasible and safe in this 2-week animal survival study.