SIV envelope glycoprotein determinants of macrophage tropism and their relationship to neutralization sensitivity and CD4-independent cell-to-cell transmission

Macrophages are target cells for human immunodeficiency virus (HIV) and simian immunodeficiency virus (SIV) infection that serve as viral reservoirs in brain, lung, gut, and other tissues, and play important roles in disease pathogenesis, particularly HIV/SIV-associated neurological disease. Macrophages express low levels of the HIV/SIV receptor CD4, but mechanisms by which macrophage-tropic viruses use low CD4 to mediate spreading infections are poorly understood. One mechanism involves enhanced envelope glycoprotein (Env) interaction with CD4 or CCR5, but this phenotype is frequently associated with increased neutralization sensitivity to antibodies targeting CD4/CCR5 binding sites. Moreover, this mechanism does not explain how these neutralization-sensitive viruses evade immune responses while establishing spreading infections. In this dissertation, we sought to identify SIV Env determinants for macrophage tropism and characterize mechanisms by which they enhance virus replication in macrophages. To identify viral variants capable of inducing macrophage-associated pathogenesis, we cloned Env sequences from SIV-infected macaques at early and late stage infection, and identified an early variant in blood that shares >98% sequence identity with the consensus sequence of late variants in brain from macaques with neurological disease. SIV clones encoding this Env variant mediated high levels of fusion, replicated efficiently in rhesus PBMC and macrophages, and induced multinucleated giant cell formation upon infection of macrophage cultures. We identified an N-linked glycosylation site, N173 in the V2 region, as a determinant of macrophage tropism. Loss of N173 enhanced SIVmac239 macrophage tropism, while restoration of N173 in SIVmac251 reduced macrophage tropism, but enhanced neutralization resistance to CD4/CCR5 binding site antibodies. SIVmac239 N173Q, which lacks the N173 glycosylation site, mediated CD4-independent fusion and cell-to-cell transmission with CCR5-expressing cells, but could not infect CD4-negative cells in single-round infections. Thus, CD4-independent phenotypes were detected only in the context of cell-cell contact. The N173Q mutation had no effect on SIVmac239 gp120 binding to CD4 in BIACORE and co-immunoprecipitation assays. These findings suggest that loss of the N173 glycosylation site increases SIVmac239 replication in macrophages by enhancing CD4-independent cell-to-cell transmission through CCR5-mediated fusion. This mechanism may facilitate escape of macrophage-tropic viruses from neutralizing antibodies, while promoting spreading infections by these viruses in vivo

Natural orifice transluminal endoscopic surgery: A transtracheal approach for the thoracic cavity in a live canine model

BackgroundThe present study aimed to evaluate the performance of transtracheal thoracic exploration and pericardial window creation in a canine survival model.MethodsTransthoracic exploration was performed in 14 dogs. Under general anesthesia, after an incision in the right lateral wall of the middle–lower portion of the trachea was made, a 9-mm metal tube was advanced into the thoracic cavity. For thoracic cavity exploration and pericardial window creation, a flexible bronchoscope was introduced through the metal tube into the thoracic cavity. After thoracoscopy, a Dumon stent (Novatech, Grasse, France) was used to cover the tracheal incision site and facilitate healing. Animals were evaluated by endoscopy 1 and 2 weeks later. Animals were humanely killed, and necropsy was performed 2 weeks after the transtracheal natural orifice transluminal endoscopic surgery.ResultsFourteen dogs underwent transtracheal thoracic exploration lasting for an average of 110 minutes (range, 80–150), with 3 perioperative deaths. At 2 weeks after pericardial window creation, endoscopy revealed normal healing of the tracheal incision sites in all 11 surviving animals. Necropsy on the 11 animals at 2 weeks showed 9 adhesions around the pericardial window and 5 adhesions around the tracheal incision region. No mediastinitis or abscesses could be identified.ConclusionsTranstracheal thoracic exploration is technically feasible. Increasing surgical experience together with improvement in endoscopic techniques will further facilitate the development of natural orifice transluminal endoscopic surgery for thoracic diseases

Automatic Precipitation Measurement Based on Raindrop Imaging and Artificial Intelligence

Rainfall measurement is subjected to various uncertainties due to the complexity of measurement techniques and atmosphere characteristics associated with weather type. Thus, this article presents a video-based disdrometer to analyze raindrop images by introducing artificial intelligence technology for the rainfall rate. First, a high-speed CMOS camera is integrated into a planar LED as a backlight source for appropriately acquiring falling raindrops in different positions. The falling raindrops can be illuminated and used for further image analysis. Algorithms developed for raindrop detection and trajectory identification are employed. In a field test, a rainfall event of 42 continuous hours has been measured by the proposed disdrometer that is validated against a commercial PARSIVEL² disdrometer and a tipping bucket rain gauge at the same area. In the evaluation for 5-min rainfall images, the results of the trajectory identification are within the precision of 87.8%, recall of 98.4%, and F1 score of 92.8%, respectively. Furthermore, the performance exhibits that the rainfall rate and raindrop size distribution (RSD) obtained by the proposed disdrometer are remarkably consistent with those of PARSIVEL² disdrometer. The results suggest that the proposed disdrometer based on the continuous movements of the falling raindrops can achieve accurate measurements and eliminate the potential errors effectively in the real-time monitoring of rainfall

Comparison of visual outcomes after epiretinal membrane surgery

AbstractPurposeTo elucidate the anatomical and visual outcomes of patients with idiopathic epiretinal membranes (ERM) who underwent vitrectomy, membrane removal only, or with internal limiting membrane (ILM) peeling under the assistance of different dyes.MethodsA retrospective chart review of patients with idiopathic ERM who received surgical treatment between January 2004 and December 2009. The patients were grouped according to the usage of staining materials assisting ILM peeling. Group 1 consisted of 61 eyes that underwent conventional vitrectomy and ERM peeling without staining-assisted ILM peeling. Group 2 consisted of 20 eyes with triamcinolone acetonide-assisted ILM peeling following conventional vitrectomy. Group 3 consisted of 23 eyes with indocyanine green-assisted ILM peeling following conventional vitrectomy.ResultsThis study included 104 eyes from 104 patients. There was no significant difference in age, sex, preoperative visual acuity, retinal thickness or follow-up duration among the three groups. Overall, the mean best-corrected visual acuity improved significantly from baseline 0.15 to postoperative 0.41 (p<0.0001). Among the three groups, the mean logarithm minimum angle of resolution acuity markedly improved. There was no significant difference in postoperative visual acuity among groups. As measured by ocular coherent tomography, the mean central foveal thickness decreased from 465.21±86.18 to 299.16±70.14μm. Although there was no difference between groups, postoperative retinal thickness was thicker than that observed in the normal population. The incidence of recurrent ERM was 13.1% in Group 1 and 0% in Groups 2 and 3; this incidence was significantly higher than in the conventional surgery group. Visual outcome was statistically more deteriorated in recurrent cases than in non-recurrent cases (p=0.011).ConclusionsERM surgeries with or without dye-assisted ILM peeling showed similar results. Moreover, the incidence of recurrence is lower in the ILM peeling groups and plays a primary role in determining the final postoperative vision outcome

Analysis of Surgically Treated Intraspinal Tumors in Southern Taiwan

The medical records of 117 patients with spinal tumors who underwent surgery with pathologic confirmation from January 1999 to April 2004 at Kaohsiung Medical University Hospital were reviewed. Data from this review were compared with those obtained from the same institution 10 years earlier (covering the period 1988-1995) and from other reported series. There were 69 male and 48 female patients aged from 13 to 87 years old (mean age, 51.9). The most common pathologic findings were metastasis in 45.3% (53/117), nerve sheath tumors in 28.2% (33/117), menin-giomas in 12% (14/117) and neuroepithelial tumors in 6% (7/117). The peak ages at diagnosis were 41-50 years and 61–70 years. A slight male predominance was noted for all tumors, except meningiomas. Motor weakness, even paralysis, was the major clinical presentation (64–86%), followed by sensory deficits (50%) and pain (42%). The location of tumors was most often in the thoracic (50.4%; 59/117), lumbosacral (27.4%; 32/117) and cervical spine (22.2%; 26/117) segments. Among the metastatic tumors, the lung (22.6%) and breast (15.1%) were the most common primary sites of origin, followed by unknown origin, the liver (hepatocellular carcinoma), the gastrointestinal tract and the nasopharynx (nasopharyngeal cancer)

High levels of serum macrophage migration inhibitory factor and interleukin 10 are associated with a rapidly fatal outcome in patients with severe sepsis

SummaryObjectivesThe aim of this study was to delineate the association between high macrophage migration inhibitory factor (MIF) and interleukin 10 (IL-10) levels in the early phase of sepsis and rapidly fatal outcome.MethodsOne hundred and fifty-three adult subjects with the main diagnosis of severe sepsis (including septic shock) admitted directly from the emergency department of two tertiary medical centers and one regional teaching hospital between January 2009 and December 2011, were included prospectively. MIF and IL-10 levels were measured and outcomes were analyzed by Cox regression analysis according to the following outcomes: rapidly fatal outcome (RFO, death within 48h), late fatal outcome (LFO, death between 48h and 28 days), and survival at 28 days.ResultsAmong the three outcome groups, IL-10 levels were significantly higher in the RFO group (p < 0.001) and no significant differences were seen between the LFO and survivor groups. After Cox regression analysis, each incremental elevation of 1000 pg/ml in both IL-10 and MIF was independently associated with RFO in patients with severe sepsis. Each incremental elevation of 1000 pg/ml in IL-10 increased the RFO risk by a factor of 1.312 (95% confidence interval 1.094–1.575; p=0.003); this was the most significant factor leading to RFO in patients with severe sepsis.ConclusionsPatients with RFO exhibited simultaneously high MIF and IL-10 levels in the early phase of severe sepsis. Incremental increases in both IL-10 and MIF levels were associated with RFO in this patient group, and of the two, IL-10 was the most significant factor linked to RFO

The effect of turbulent viscous shear stress on red blood cell hemolysis

[[abstract]]Non-physiologic turbulent flow occurs in medical cardiovascular devices resulting in hemodynamic stresses that may damage red blood cells (RBC) and cause hemolysis. Hemolysis was previously thought to result from Reynolds shear stress (RSS) in turbulent flows. A more recent hypothesis suggests that turbulent viscous shear stresses (TVSS) at spatial scales similar in size to RBCs are related to their damage. We applied two-dimensional digital particle image velocimetry to measure the flow field of a free-submerged axisymmetric jet that was utilized to hemolyze porcine RBCs in selected locations. Assuming a dynamic equilibrium for the sub-grid scale (SGS) energy flux between the resolved and the sub-grid scales, the SGS energy flux was calculated from the strain rate tensor computed from the resolved velocity fields. The SGS stress was determined by the Smagorinsky model, from which the turbulence dissipation rate and then TVSS were estimated. Our results showed the hemolytic threshold of the Reynolds stresses was up to 517 Pa, and the TVSSs were at least an order of magnitude less than the RSS. The results provide further insight into the relationship between turbulence and RBC damage.[[incitationindex]]SCI[[booktype]]紙本[[countrycodes]]JP

Aberrant Sensory Gating of the Primary Somatosensory Cortex Contributes to the Motor Circuit Dysfunction in Paroxysmal Kinesigenic Dyskinesia

Paroxysmal kinesigenic dyskinesia (PKD) is conventionally regarded as a movement disorder (MD) and characterized by episodic hyperkinesia by sudden movements. However, patients of PKD often have sensory aura and respond excellently to antiepileptic agents. PRRT2 mutations, the most common genetic etiology of PKD, could cause epilepsy syndromes as well. Standing in the twilight zone between MDs and epilepsy, the pathogenesis of PKD is unclear. Gamma oscillations arise from the inhibitory interneurons which are crucial in the thalamocortical circuits. The role of synchronized gamma oscillations in sensory gating is an important mechanism of automatic cortical inhibition. The patterns of gamma oscillations have been used to characterize neurophysiological features of many neurological diseases, including epilepsy and MDs. This study was aimed to investigate the features of gamma synchronizations in PKD. In the paired-pulse electrical-stimulation task, we recorded the magnetoencephalographic data with distributed source modeling and time-frequency analysis in 19 patients of newly-diagnosed PKD without receiving pharmacotherapy and 18 healthy controls. In combination with the magnetic resonance imaging, the source of gamma oscillations was localized in the primary somatosensory cortex. Somatosensory evoked fields of PKD patients had a reduced peak frequency (p &lt; 0.001 for the first and the second response) and a prolonged peak latency (the first response p = 0.02, the second response p = 0.002), indicating the synchronization of gamma oscillation is significantly attenuated. The power ratio between two responses was much higher in the PKD group (p = 0.013), indicating the incompetence of activity suppression. Aberrant gamma synchronizations revealed the defective sensory gating of the somatosensory area contributes the pathogenesis of PKD. Our findings documented disinhibited cortical function is a pathomechanism common to PKD and epilepsy, thus rationalized the clinical overlaps of these two diseases and the therapeutic effect of antiepileptic agents for PKD. There is a greater reduction of the peak gamma frequency in PRRT2-related PKD than the non-PRRT PKD group (p = 0.028 for the first response, p = 0.004 for the second response). Loss-of-function PRRT2 mutations could lead to synaptic dysfunction. The disinhibiton change on neurophysiology reflected the impacts of PRRT2 mutations on human neurophysiology

Clinical Efficacy and Post-Treatment Seromarkers Associated with the Risk of Hepatocellular Carcinoma among Chronic Hepatitis C Patients

This follow-up study enrolled chronic hepatitis C patients to evaluate the treatment efficacy and to identify post-treatment seromarkers associated with risk of hepatocellular carcinoma (HCC) among patients with a sustained virological response (SVR) or nonsustained virological response (NSVR). A total of 4639 patients who received pegylated interferon and ribavirin during 2004–2013 were followed until December 2014. HCC was confirmed through health examinations and data linkage with a national database. A total of 233 HCC cases were reported after 26,163 person-years of follow-up, indicating an incidence of 8.9 per 1000 person-years: 6.9 for SVR and 21.6 for NSVR per 1000 person-years. The associated risk of HCC in patients with SVR was 0.37 (0.22–0.63) for those without cirrhosis and 0.54 (0.31–0.92) for those with cirrhosis compared with their respective counterparts with NSVR. Among patients with SVR, advanced age, male gender, cirrhosis, decreased platelet count, and increased aspartate aminotransferase and α-fetoprotein levels were associated with HCC (p < 0.001). The treatment of chronic hepatitis C patients before they developed cirrhosis showed a higher efficacy than did the treatment of those who had already developed cirrhosis. Patients with SVR may still have a risk of HCC and need to be regularly monitored