Comparative Characterization of Maxillary Expansion and Alternate Maxillary Expansions and Constrictions in Rats

The purpose of this study was to evaluate whether the cranial and circumaxillary sutures react differently to maxillary expansion （ME） and alternate maxillary expansions and constrictions （Alt-MEC） in a rat model. Twenty-two male Sprague-Dawley rats （6 weeks old） were used and divided into three groups. In ME group （n=9）, an expander was activated for 5 days. In Alt-MEC group （9 animals）, an al- ternate expansion and constriction protocol （5-day expansion and 5-day constriction for one cycle） was conducted for 2.5 cycles （25 days total）. The control group comprised 4 animals with no appliances used, each of two sacrificed on day 5 and day 25 respectively. Midpalatal suture expansion or constriction levels were assessed qualitatively and quantitatively by bite-wing X-rays and cast models. Distances between two central incisors and two maxillary first molars were measured on cast models after each activation. Circumaxillary sutures （midpalatal, maxillopalatine, premaxillary, zygomaticotemporal and frontonasal suture） in each group were characterized histologically. Results showed that midpalatal suture was wid- ened and restored after each expansion and constriction. At the end of activation, the widths between both central incisors and first molars in Alt-MEC group were significantly larger than those in ME group （P〈0.05）. Histologically, all five circumaxillary sutures studied were widened in multiple zones in Alt- MEC group. However, only midpalatal suture was expanded with cellular fibrous tissue filling in ME group. Significant osteoclast hyperplasia was observed in all circumaxillary sutures after alternate expan- sions and constrictions, but osteoclast count increase was only observed in midpalatal suture in ME group. These results suggested that cranial and circumaxillary sutures were actively reconstructed after Alt-MEC, while only midpalatal suture had active reaction after ME.

Changes in compressed neurons from dogs with acute and severe cauda equina constrictions following intrathecal injection of brain-derived neurotrophic factor-conjugated polymer nanoparticles

This study established a dog model of acute multiple cauda equina constriction by experimental constriction injury （48 hours） of the lumbosacral central processes in dorsal root ganglia neurons. The repair effect of intrathecal injection of brain-derived neurotrophic factor with 15 mg encapsulated biodegradable poly（lactide-co-glycolide） nanoparticles on this injury was then analyzed. Dorsal root ganglion cells （LT） of all experimental dogs were analyzed using hematoxylin-eosin staining and immunohistochemistry at 1,2 and 4 weeks following model induction. Intrathecal injection of brain-derived neurotrophic factor can relieve degeneration and inflammation, and elevate the expression of brain-derived neurotrophic factor in sensory neurons of compressed dorsal root ganglion Simultaneously, intrathecal injection of brain-derived neurotrophic factor obviously improved neurological function in the dog model of acute multiple cauda equina constriction. Results verified that sustained intraspinal delivery of brain-derived neurotrophic factor encapsulated in biodegradable nanoparticles promoted the repair of histomorphology and function of neurons within the dorsal root ganglia in dogs with acute and severe cauda equina syndrome.

NUMERICAL INVESTIGATION ON NON-NEWTONIAN FLOWS THROUGH DOUBLE CONSTRICTIONS BY AN UNSTRUCTURED FINITE VOLUME METHOD

This article presents a numerical investigation on a steady non-Newtonian flow through a two-dimensional channel with double constrictions. The power-law mode is employed in describing the non-Newtonian behavior of the flow. An unstructured finite volume method combined with a fractional-step projection method is developed for the discretization of incompressible equations governing the non-Newtonian flows. The important flow dynamics related with the arterial diseases, such as the wall shear stress and vortex generation, are also numerically studied in detail. Numerical results reveal that there are marked differences between Newtonian and non-Newtonian models.

Safety and efficacy of Kaffes intraductal self-expanding metal stents in the management of post-liver transplant anastomotic strictures

BACKGROUND Endoscopic management is the first-line therapy for post-liver-transplant anas-tomotic strictures.Although the optimal duration of treatment with plastic stents has been reported to be 8-12 months,data on safety and duration for metal stents in this setting is scarce.Due to limited access to endoscopic retrograde cholan-giopancreatography(ERCP)during the coronavirus disease 2019 pandemic in our centre,there was a change in practice towards increased usage and length-of-stay of the Kaffes biliary intraductal self-expanding stent in patients with suitable anatomy.This was mainly due to the theoretical benefit of Kaffes stents allowing for longer indwelling periods compared to the traditional plastic stents.METHODS Adult liver transplant recipients aged 18 years and above who underwent ERCP were retrospectively identified during a 10-year period through a database query.Unplanned admissions post-Kaffes stent insertion were identified manually through electronic and scanned medical records.The main outcome was the incidence of complications when stents were left indwelling for 3 months vs 6 months.Stent efficacy was calculated via rates of stricture recurrence between patients that had stenting courses for≤120 d or>120 d.RESULTS During the study period,a total of 66 ERCPs with Kaffes insertion were performed in 54 patients throughout their stenting course.In 33 ERCPs,the stent was removed or exchanged on a 3-month interval.No pancreatitis,perfor-ations or deaths occurred.Minor post-ERCP complications were similar between the 3-month(abdominal pain and intraductal migration)and 6-month(abdominal pain,septic shower and embedded stent)groups-6.1%vs 9.1%respectively,P=0.40.All strictures resolved at the end of the stenting course,but the stenting course was variable from 3 to 22 months.The recurrence rate for stenting courses lasting for up to 120 d was 71.4%and 21.4%for stenting courses of 121 d or over(P=0.03).There were 28 patients that were treated with a single ERCP with Kaffes,21 with removal after 120 d and 7 within 120 d.There was a significant improvement in stricture recurrence when the Kaffes was removed after 120 d when a single ERCP was used for the entire stenting course(71.0%vs 10.0%,P=0.01).CONCLUSION Utilising a single Kaffes intraductal fully-covered metal stent for at least 4 months is safe and efficacious for the management of post-transplant anastomotic strictures.

Numerical Study on Sinusoidal Fluctuated Pulsatile Laminar Flow Through Various Constrictions

Numerical simulations have been carried out for laminar sinusoidal pulsating flow in a tube with smooth single constriction.A second-order finite volume method has been developed to solve the fluid flow governing equations on a nonstaggered non-orthogonal grid.The effects of the Reynolds number,the Womersley number,the pulsatile amplitude,the constriction ratio and the constriction length on fluid flow in constricted tube will be investigated.It will be demonstrated that the dynamic nature of the pulsating flow greatly depends on the frequency of the flow changes.It is observed that the peak wall vorticity seems to increase with the increase of Reynolds number,the pulsating amplitude and the constriction ratio.The peak values of instantaneous wall vorticity are not greatly affected by the variation of Womersly number.The constriction length does not put a significant impact on the flow instantaneous streamline behaviors compared with other parameters.However,the peak wall vorticity increases monotonically with the decrease of the constriction length.

Construction of EMS-Induced Peanut Mutant Libraries and Identification of Pod-Related Traits Mutant Lines

Peanut(Arachis hypogaea L.)is an oil and economic crop of vital importance,and peanut pod is the key organ influencing the yield and processing quality.Hence,the Pod-related traits(PRTs)are considered as important agronomic traits in peanut breeding.To broaden the variability of PRTs in current peanut germplasms,three elite peanut cultivars were used to construct Ethyl methane sulfonate(EMS)-induced mutant libraries in this study.The optimal EMS treatment conditions for the three peanut varieties were determined.It was found that the median lethal dose(LD50)of EMS treatment varied greatly among different genotypes.Finally,the EMS-induced peanut mutant libraries were constructed and a total of 124 mutant lines for PRTs were identified and evaluated.Furthermore,“M-8070”,one of the mutant lines for pod constriction,was re-sequenced via high-throughput sequencing technology.The genome-wide variations between“M-8070”and its wild parent“Fuhua 8”(FH 8)were detected.2994 EMS-induced single nucleotide polymorphisms(SNPs)and 1188 insertion-deletions(InDels)between“M-8070”and its wild parent were identified.The predominant SNP mutation type was C/G to T/A transitions,while the predominant InDel mutation type was“1-bp”.We analyzed the distribution of identified mutations and annotated their functions.Most of the mutations(91.68%of the SNPs and 77.69%of the InDels)were located in the intergenic region.72 SNPs were identified in the exonic region,leading to 27 synonymous,43 nonsynonymous and 2 stop-gain variation for gene structure.13 Indels were identified in the exonic region,leading to 4 frame-shift,8 non-frame-shift and 1 stop-gain variations of genes.These mutations may lead to the phenotypic variation of“M-8070”.Our study provided valuable resources for peanut improvement and functional genomic research.

Safety and efficacy of balloon angioplasty compared to stent-basedstrategies with pulmonary vein stenosis:A systematic review and meta-analysis

BACKGROUND Pulmonary vein stenosis(PVS)is an uncommon but known cause of morbidity and mortality in adults and children and can be managed with percutaneous revascularization strategies of pulmonary vein balloon angioplasty(PBA)or pulmonary vein stent implantation(PSI).AIM To study the safety and efficacy outcomes of PBA vs PSI in all patient categories with PVS.METHODS We performed a literature search of all studies comparing outcomes of patients evaluated by PBA vs PSI for PVS.We selected all published studies comparing PBA vs PSI for PVS with reported outcomes of restenosis and procedure-related complications in all patient categories.In adults,PVS following atrial fibrillation ablation and in children PVS related to congenital etiology or post-procedural PVS following total or partial anomalous pulmonary venous return repair were included.The patient-centered outcomes were risk of restenosis requiring re-intervention and procedural-related complications.The metaanalysis was performed by computing odds ratios(ORs)using the random effects model based on underlying statistical heterogeneity.RESULTS Eight observational studies treating 768 severe PVS in 487 patients met our inclusion criteria.The age range of patients was 6 months to 70 years and 67%were males.The primary outcome of the re-stenosis requiring re-intervention occurred in 196 of 325 veins in the PBA group and 111 of 443 veins in the PSI group.Compared to PSI,PBA was associated with a significantly increased risk of re-stenosis(OR 2.91,95%CI:1.15-7.37,P=0.025,I2=79.2%).Secondary outcomes of the procedurerelated complications occurred in 7 of 122 patients in the PBA group and 6 of 69 in the PSI group.There were no statistically significant differences in the safety outcomes between the two groups(OR:0.94,95%CI:0.23-3.76,P=0.929,I^(2)=0.0%).CONCLUSION Across all patient categories with PVS,PSI is associated with reduced risk of re-intervention and is as safe as PBA and should be considered first-line therapy for PVS.

Hourglass-like constriction of the anterior interosseous nerve in the left forearm:A case report

BACKGROUND Hourglass-like constriction neuropathy is a rare neurological disorder.The main clinical manifestation is peripheral nerve injury with no apparent cause,and the pathomorphological change is an unexplained narrowing of the diseased nerve.The diagnosis and treatment of the disease are challenging and there is no accepted diagnostic or therapeutic approach.CASE SUMMARY This report describes a rare hourglass constriction of the anterior interosseous nerve in the left forearm in a 47-year-old healthy male who was treated surgically and gradually recovered function over a 6-mo follow-up period.CONCLUSION Hourglass-like constriction neuropathy is a rare disorder.With the development of medical technology,more examinations are now available for diagnosis.This case aims to highlight the rare manifestations of Hourglass-like constriction neuropathy and provides a reference for enriching the clinical diagnosis and treatment experience.

膨胀海绵地塞米松填塞治疗外耳道狭窄

目前外耳道狭窄以手术治疗为主。对于外耳道成形术后及慢性中耳炎术后瘢痕形成初期（术后2～4周）和继发于外耳道炎症、肉芽组织增生所致的狭窄，我们用膨胀海绵配合地塞米松治疗，取得满意疗效，现报道如下。

Molecular mechanisms underlying the effects of acupuncture on neuropathic pain

Acupuncture has been used to treat neuropathic pain for a long time, but its mechanisms of action remain unknown. In this study, we observed the effects of electroacupuncture and manual acu- puncture on neuropathic pain and on ephrin-B/EphB signaling in rats models of chronic constriction injury-induced neuropathic pain. The results showed that manual acupuncture and electroacu- puncture significantly reduced mechanical hypersensitivity following chronic constriction injury, es- pecially electroacupuncture treatment. Real-time PCR results revealed that ephrin-B1/B3 and EphB1/B2 mRNA expression levels were significantly increased in the spinal dorsal horns of chronic constriction injury rats. Electroacupuncture and manual acupuncture suppressed the high expres- sion of ephrin-B1 mRNA, and elevated EphB3/B4 mRNA expression. Electroacupuncture signifi- cantly enhanced the mRNA expression of ephrin-B3 and EphB3/B6 in the dorsal horns of neuro- pathic pain rats. Western blot results revealed that electroacupuncture in particular, and manual acupuncture, significantly up-regulated ephrin-B3 protein levels in rat spinal dorsal horns. The re- sults of this study suggest that acupuncture could activate ephrin-B/EphB signaling in neuropathic pain rats and improve neurological function.

Three-dimensional virtual operations can facilitate complicated surgical planning for the treatment of patients with jaw deformities associated with facial asymmetry: a case report

This article describes a case we experienced in which good postsurgical facial profiles were obtained for a patient with jaw deformities associated with facial asymmetry,by implementing surgical planning with SimPlant OMS.Using this method,we conducted LF1 osteotomy,intraoral vertical ramus osteotomy（IVRO）,sagittal split ramus osteotomy（SSRO）,mandibular constriction and mandibular border genioplasty.Not only did we obtain a class I occlusal relationship,but the complicated surgery also improved the asymmetry of the frontal view,as well as of the profile view,of the patient.The virtual operation using three-dimensional computed tomography（3D-CT）could be especially useful for the treatment of patients with jaw deformities associated with facial asymmetry.

Weld formation and heating mechanism in ultra-narrow gap withconstricted arc by ultra-fine granular flux

Ultra-narrow gap welding （UNGW） process with high stabilization, reliability and without spatter can be achieved with constricted arc by molten slag wall, which is made from melted flux. The experiments are carried out by changing voltage under different currents. The results indicate voltage range being fit for UNGW is about 22 -31 V under the current range of 200 -320 A. With the increasing of voltage, weld formation of UNGW has the law of lack of fusion on sidewall, good weld and undercut in turn under a certain current. In addition, the action relationships among arc, molten slag wall and sidewalls can be improved by properly adjusting voltage and current of arc, which makes cathode spot properly distribute in ultra-narrow gap. Therefore, the effective control of weld formation of UNGW has been achieved.

Mechanism of persistent hyperalgesia in neuropathic pain caused by chronic constriction injury

Transmembrane member 16 A(TMEM16 A) is involved in many physiological functions, such as epithelial secretion, sensory conduction, nociception, control of neuronal excitability, and regulation of smooth muscle contraction, and may be important in peripheral pain transmission. To explore the role of TMEM16 A in the persistent hyperalgesia that results from chronic constriction injury-induced neuropathic pain, a rat model of the condition was established by ligating the left sciatic nerve. A TMEM16 A selective antagonist(10 μg T16 Ainh-A01) was intrathecally injected at L5–6. For measurement of thermal hyperalgesia, the drug was administered once at 14 days and thermal withdrawal latency was recorded with an analgesia meter. For measurement of other indexes, the drug was administered at 12 days,once every 6 hours, totally five times. The measurements were performed at 14 days. Western blot assay was conducted to analyze TMEM16 A expression in the L4–6 dorsal root ganglion. Immunofluorescence staining was used to detect the immunoreactivity of TMEM16 A in the L4–6 dorsal root ganglion on the injured side. Patch clamp was used to detect electrophysiological changes in the neurons in the L4–6 dorsal root ganglion. Our results demonstrated that thermal withdrawal latency was shortened in the model rats compared with control rats.Additionally, TMEM16 A expression and the number of TMEM16 A positive cells in the L4–6 dorsal root ganglion were higher in the model rats, which induced excitation of the neurons in the L4–6 dorsal root ganglion. These findings were inhibited by T16 Ainh-A01 and confirm that TMEM16 A plays a key role in persistent chronic constriction injury-induced hyperalgesia. Thus, inhibiting TMEM16 A might be a novel pharmacological intervention for neuropathic pain. All experimental protocols were approved by the Animal Ethics Committee at the First Affiliated Hospital of Shihezi University School of Medicine, China(approval No. A2017-170-01) on February 27, 2017.

Esophagogastric anastomosis with invagination into stomach:New technique to reduce fistula formation

AIM: To present a new technique of cervical esophagogastric anastomosis to reduce the frequency of fistula formation. METHODS: A group of 31 patients with thoracic and abdominal esophageal cancer underwent cervical esophagogastric anastomosis with invagination of the proximal esophageal stump into the stomach tube. In the region elected for anastomosis, a transverse myotomy of the esophagus was carried out around the entire circumference of the esophagus. Afterwards, a 4-cm long segment of esophagus was invaginated into the stomach and anastomosed to the anterior and the posterior walls. RESULTS: Postoperative minor complications occurred in 22 (70.9%) patients. Four (12.9%) patients had serious complications that led to death. The discharge of saliva was at a lower region, while attempting to leave the anastomosis site out of the alimentary transit. Three (9.7%) patients had fistula at the esophagogastric anastomosis, with minimal leakage of air or saliva and with mild clinical repercussions. No patients had esophago- gastric fistula with intense saliva leakage from either the cervical incision or the thoracic drain. Fibrotic stenosis of anastomoses occurred in seven (22.6%) patients. All these patients obtained relief from their dysphagia with endoscopic dilatation of the anastomosis.CONCLUSION: Cervical esophagogastric anastomosis with invagination of the proximal esophageal stump into the stomach tube presented a low rate of esophagogastric fistula with mild clinical repercussions.

Three-dimensional analysis of the physiological foramen geometry of maxillary and mandibular molars by means of micro-CT

The aim of this study was to investigate the physiological foramen diameter, shape and distance between physiological and anatomical apex of maxillary and mandibular first and second molars. Accurate knowledge of the physiological foramina morphology; thus, inherent mechanical shaping technical hindrances, is decisive when taking the corresponding root canal final preparation decision. The morphological dimensions of a total of 1 727 physiological foramina were investigated by means of micro-computed tomography. Mean narrow and wide （to a high number, oval） diameters of the physiological foramen were 0.24, 0.22 and 0.33 mm and 0.33, 0.31 and 0.42 mm in mesiobuccal （MB）, distobuccal （DB） and palatal （P） roots in maxillary first molars; 0.24, 0.22 and 0.33 mm and 0.41, 0.33 and 0.44 in MB, DB, and P roots in maxillary second molars. Mandibular first molars showed mean narrow and wide diameters of 0.24 and 0.30 mm and of 0.39 and 0.46 mm in mesial （M） and distal （D） roots; second mandibular molars showed 0.25 and 0.31 mm and 0.47 mm in M and D roots. The mean distance between the physiological foramina and anatomical apex was 0.82, 0.81 and 1.02 mm and 0.54, 0.43 and 0.63 mm in MB, DB and P roots of the maxillary first and second molars, respectively. A mean distance of 0.95 mm （M） and 1.05 mm （D） in the first and 0.78 mm （M） and 0.81 mm （D） in the second mandibular molars was observed. Based on the results obtained, assumable recommendations for final preparation size of the physiological foramen were calculated. However, when taking into consideration, the resulting standard deviations of marginal errors must be cautiously considered when taking a final decision in clinical endodontic treatment.

Nuclear mechanics during constricted migration

Cell migration through narrow interstitial space in tissues is commonly seen in both physiological and pathological conditions. For example, immune cells have to squeeze through vasculature and extracellular matrix to reach the wound or diseased sites, and similarly cancer cells need to crawl through porous space in tissues to invade surrounding tumor-free regions. Therefore, the bulky stiff nucleus in the cell becomes a barrier during constricted migration making such process pore-size dependent with smaller pores exponentially alleviate the passage capability. However, in some cases, cells can actively deform their nuclei to squeeze through constrictions although some price needs to be paid. In this review, we focus on:(1) nuclear structures and morphological regulations,(2) proposed mechanisms that drive constricted migration,(3) short-term consequences such as nuclear envelope (NE) rupture and DNA damage during such process,(4) biophysical factors that facilitate NE rupture, and (5) long term consequences such as genomic variation caused by repetitive NE rupture. Both experimental results and modeling are provided with the intention to better understand the constricted migration.

Simulation Research of Magnetic Constriction Effect and Controlling by Axial Magnetic Field of Vacuum Arc

Based on magnetohydrodynamic (MHD) model of vacuum arc, the computer simulation of vacuum arc was carried out in this paper. In the MHD model, mass conservation equation, momentum conservation equations, energy conservation equations, generalized ohm's law and Maxwell equation were considered. MHD equations were calculated by numerical method, and the distribution of vacuum arc plasma parameters and current density were obtained. Simulation results showed that the magnetic constriction effect of vacuum arc is primarily caused by the Hall effect. In addition, the inhibition of axial magnetic field (AMF) on constriction of vacuum arc was calculated and analyzed.

Differential Expression of Alpha-Adrenoceptor Subtypes in Rat Dorsal Root Ganglion after Chronic Constriction Injury

Summary： mRNAs of alpha-adrenoceptor （α-AR） subtypes are found in neurons in dorsal root ganglion （DRG） and change after peripheral nerve injury. In this study, the distribution of α-AR subtype proteins was studied in L5 DRG of normal rats and rats with chronic constriction injury of sciatic nerve （CCI）. Using immunofluorescence technique, it was found that α1A-, α1B-, and α2A-AR proteins were expressed in large, medium, and small size neurons in normal DRG, and significantly increased in all size neurons 14 days after CCI. α1D- and α2C-AR was also expressed in all size neurons in normal DRG. However, α1D-AR was significantly increased and α2C-AR was decreased in small size neurons 14 days post CCI. α2B-AR neurons were not detectable in normal and CCI DRG. Co-expression of α1A- and α2A-AR in the same neuron was observed in normal DRG and increased post CCI. Collectively, these results indicated that there is distinct distribution of α-AR subtypes in DRG neurons, and the distribution and levels of expression of α-AR subtypes change differently after CCI. The up-regulation of α-AR subtypes in DRG neurons may play an important role in the process of generating and transmitting neuropathic pain.

Estrogen affects neuropathic pain through upregulating N-methyl-D-aspartate acid receptor 1 expression in the dorsal root ganglion of rats

Estrogen affects the generation and transmission of neuropathic pain,but the specific regulatory mechanism is still unclear.Activation of the N-methyl-D-aspartate acid receptor 1（NMDAR1） plays an important role in the production and maintenance of hyperalgesia and allodynia.The present study was conducted to determine whether a relationship exists between estrogen and NMDAR1 in peripheral nerve pain.A chronic sciatic nerve constriction injury model of chronic neuropathic pain was established in rats.These rats were then subcutaneously injected with 17β-estradiol,the NMDAR1 antagonist D（-）-2-amino-5-phosphonopentanoic acid（AP-5）,or both once daily for 15 days.Compared with injured drug na？ve rats,rats with chronic sciatic nerve injury that were administered estradiol showed a lower paw withdrawal mechanical threshold and a shorter paw withdrawal thermal latency,indicating increased sensitivity to mechanical and thermal pain.Estrogen administration was also associated with increased expression of NMDAR1 immunoreactivity（as assessed by immunohistochemistry） and protein（as determined by western blot assay） in spinal dorsal root ganglia.This 17β-estradiol-induced increase in NMDAR1 expression was blocked by co-administration with AP-5,whereas AP-5 alone did not affect NMDAR1 expression.These results suggest that 17β-estradiol administration significantly reduced mechanical and thermal pain thresholds in rats with chronic constriction of the sciatic nerve,and that the mechanism for this increased sensitivity may be related to the upregulation of NMDAR1 expression in dorsal root ganglia.

Successful removal of a penoscrotal constricting ring in a 49-year-old male

Placement of constricting devices around the penis and scrotum for autoerotic purposes or increasing sexual performance represents a well-known challenge for urologists and can result in serious complications.The removal of the constricting devices can be challenging and often requires resourcefulness and multidisciplinary approach.We report one case of successful removal of a penoscrotal constricting metal ring in a 49-year-old male using a handheld orthopaedic saw under ketamine and midazolam sedation in the emergency department.