Electrophysiologic effects of anterior septal arterial occlusion

The effect of reduction in anterior septal arterial flow on the conduction system was studied in seven anesthetized dogs. After 2 hours of occlusion P-Q, A-H and H-V intervals as well as atrioventricular nodal effective and functional refractory periods were significantly prolonged, sinoatrial conduction time was prolonged and the heart rate was decreased. The duration of the His bundle electrogram was significantly prolonged and the configuration altered. However, QRS duration did not prolong significantly. Fifteen minutes after reperfusion, A-H interval, duration of the His bundle electrogram, effective refractory period and functional refractory period returned toward control values. However, the H-V and QRS intervals as well as sinoatrial conduction time were unchanged after reperfusion. Thus, reduction of anterior septal arterial flow influences not only the distal but also the proximal portion of the conduction system; the most vulnerable part is probably the His bundle. The distal portion of the conduction system is directly influenced by ischemia itself, whereas the proximal portion is influenced through other mechanisms induced by reduction of anterior septal arterial flow.     

Lower Serum Albumin Level Is Associated With an Increased Risk for Loss of Residual Kidney Function in Patients Receiving Peritoneal Dialysis

Preserving residual kidney function (RKF) is important in the management of patients on peritoneal dialysis. However, few studies have examined the association between serum albumin level and the risk of RKF loss. We prospectively recruited 104 patients who began peritoneal dialysis treatment at our hospital between 2006 and 2016. The primary outcome was complete RKF loss, defined as urine volume < 100 mL/day. Serum albumin level at baseline was the main exposure. During a median observation period of 24 months, 33 patients developed RKF loss. A Cox proportional hazards model showed that hypoalbuminemia was associated with an increased risk of RKF, even after adjustments for potential confounding factors. Multivariable‐adjusted linear regression analysis also showed that hypoalbuminemia was associated with greater rates of decline in 24‐h urine volume and in renal Kt/V urea. Our findings suggest that hypoalbuminemia is associated with an increased risk of RKF loss in patients with peritoneal dialysis.     

Lidocaine‐Propitocain Cream,a Eutectic Mixture of Local Anesthetics,Effectively Relieves Pain Associated With Vascular Access Intervention Therapy in Patients Undergoing Hemodialysis: A Placebo‐Controlled,Double‐Blind,Crossover Study

Vascular access intervention therapy (VAIVT) is necessary to maintain vascular access in patients undergoing hemodialysis. VAIVT‐associated vasodilatation is painful. However, few reports have focused on effective pain relief at the time of VAIVT. The present study was performed to determine whether lidocaine‐propitocain cream, a eutectic mixture of local anesthetics (EMLA), effectively reduces VAIVT‐associated pain in patients undergoing hemodialysis. This placebo‐controlled, double‐blind, crossover study was conducted in a single center. Among 210 patients who underwent a total of 437 VAIVT procedures from August 2017 to June 2018, 30 patients were randomly allocated to either the EMLA–placebo arm or placebo–EMLA arm at the time of VAIVT. EMLA application significantly reduced the visual analog scale score compared with placebo (47.0 ± 21.1 vs. 68.6 ± 20.7 mm, respectively; P < 0.05). EMLA is a safe and effective treatment for relief of VAIVT‐associated pain in patients undergoing hemodialysis.     

Neurotrophin production in brain pericytes during hypoxia: a role of pericytes for neuroprotection

Neurotrophins are crucial regulators of neuronal survival and death. Evidence suggests that cells comprising the neurovascular unit (NVU) cooperatively mediate neuronal development, survival and regeneration. The aim of this study was to test whether cerebrovascular cells, endothelial cells and pericytes, produce neurotrophins and play neuroprotective roles during hypoxic insults. We examined the expression of neurotrophins and their receptors in cultured human cerebral microvascular endothelial cells and pericytes, astrocytes and the rat neuronal cell line PC12. Differentiated PC12 cells expressed TrkA, the NGF receptor, which was significantly upregulated by hypoxia at 1% O(2) and regulated neuronal survival. Both pericytes and astrocytes expressed three neurotrophins, i.e. NGF, BDNF and NT-3, while TrkB and TrkC, specific receptors for BDNF and NT-3, were expressed in astrocytes, but not pericytes. In response to hypoxia, among the neurotrophins expressed in pericytes and astrocytes only NT-3 expression was significantly upregulated in pericytes. Treatment of astrocytes with NT-3 significantly activated Erk1/2 and increased the expression of NGF both at mRNA and protein levels. The MEK1 inhibitor U0126 or siRNA-mediated knockdown of TrkC abolished the NT-3-induced upregulation of NGF in astrocytes. Taken together, cerebral microvascular pericytes and astrocytes are potent producers of neurotrophins in the NVU. In response to hypoxia, pericytes increase NT-3 production, which induces astrocytes to increase NGF production through the TrkC-Erk1/2 pathway. The interplay between pericytes and astrocytes through neurotrophins in the NVU may play an important role in neuronal survival under hypoxic conditions.     

Distributions of calcitonin gene-related peptide and substance P in the human maxillary sinus of Japanese cadavers

BackgroundSubstance P (SP) and calcitonin gene-related peptide (CGRP) are released by the nociceptive sensory nerve and are involved in blood flow, pain and inflammation in the nasal mucosa. The purpose of this study was to assess the distribution of the SP and CGRP nerve fibres related to blood supply within human Schneiderian membrane of the maxillary sinus (MS).Material and methodsIn this study, the MS from Japanese cadavers was examined by whole-mount immunohistochemistry. Human male cadavers (ranging in age from 80 to 90 years) were used in this study.ResultsSP- and CGRP-positive fibres were found around large vessels of the medialis superior alveolar branches and also within the floor region of the MS. The floor region of the MS was composed of complex branches of these fibres.ConclusionOur results give useful information for surgical sinus floor elevation in this region of the MS. These anatomical features may assist in the execution of a successful surgical procedure.     

The use of infliximab in the prevention of postsurgical recurrence in polysurgery Crohn's disease patients: a pilot open-labeled prospective study

Purpose

Crohn's disease (CD) commonly recurs after surgery, and a number of patients need repeated surgery, especially smokers and those with repeated surgeries or penetrating disease. Whether infliximab prevents postsurgical recurrence in high-risk CD remains unknown. In the present pilot open-labeled study, we investigated the safety and efficacy of scheduled infliximab, which was started early after surgery, in maintaining remission of CD patients who have undergone multiple surgeries due to penetrating disease.

Methods

Eleven patients (nine male, two female; age range, 26–48?years) who had undergone repeated surgeries (median, 4; range, 2–5) for penetrating disease were enrolled. Two to 4?weeks after surgery, the patients were started on intravenous infliximab (5?mg/kg) at an 8-week interval. The primary end points were the proportion of patients in clinical remission at the end of the study, the rate of endoscopic/radiologic remission at 24?months, and the rate of adverse effects.

Results

One patient dropped out due to non-compliance, and ten patients were eligible for analysis. Clinical remission was maintained in six of ten patients (60.0%) at the end of the study. At 24?months, four out of ten patients were in endoscopic or radiological remission (40.0%). Two patients experienced adverse effects (18.2%), one of whom elected to withdraw from the study.

Conclusion

The findings of no major safety concern and possible clinical benefit in our study suggest that further investigation of infliximab as a treatment for prevention of postsurgical recurrence in high-risk CD is warranted.