The Role of Endolymphatic Hydrops in Patients with Pantonal Idiopathic Sudden Sensorineural Hearing Loss:A Cause or Secondary Reaction

The purpose of this study was to investigate the presence of endolymphatic hydrops(EH)in both affected and unaffected ears of patients with pantonal unilateral idiopathic sudden sensorineural hearing loss(ISSNHL)using three-dimensional fluid-attenuated inversion recovery magnetic resonance imaging(3D-FLAIR MRI)and further evaluate the significance of EH in this disorder.Twenty-seven ISSHL patients were enrolled in this study.3D-FLAIR MRI was performed 24 h after intratympanic injection of gadolinium-diethylenetriaminepentaacetic acid(Gd-DPTA).The incidences of EH in the affected ears and contralateral unaffected ears were compared and the correlations of EH with vertigo or prognosis were analyzed using the Chi-square test.The results showed that the incidence of EH was 68.0%(17/25)in the affected ears and 34.8%(8/23)in the unaffected ears.There was a statistically significant difference between affected ears and unaffected ears in regard to the incidence of EH(P<0.05).There were no significant correlations of EH with vertigo(P=1.000)or with prognosis(P=0.359)in the affected ears.In conclusion,there is EH in the inner ear of patients with pantonal ISSNHL;EH is not related to vertigo,a concomitant symptom of ISSNHL,and the prognosis of this condition.The presence of EH may be a secondary reaction following the impairment of the inner ears with pantonal ISSNHL.

Dexamethasone does not affect endolymphatic hydrops(EH)in patients with Meniere's disease within 24 h,and intratympanic administration of gadolinium plus dexamethasone simplifies high-quality imaging of EH using a novel protocol of 7 min

Background:Intratympanic administration of gadolinium chelate allows for a better visualization of endolymphatic hydrops(EH)using MRI than intravenous injection and was recently further improved to facilitate high-quality imaging of EH in 7 min.The aim of the present study was to simplify the intratympanic administration protocol by mixing gadolinium chelate with therapeutic dexamethasone and to evaluate the effects of this mixture on the visualization of EH in MRI.Materials and methods:In an in vitro study,the potential impact of gadolinium-diethylenetriamine pentaacetic acid(Gd-DTPA)on the stability of dexamethasone was evaluated by analyzing dynamic changes in dexamethasone with high-performance liquid chromatography(HPLC)after mixing with GdDTPA.Ten patients with definite Meniere's disease(MD)were recruited to study the potential interference of dexamethasone on MRI visualization of EH,and 49 patients with MD were recruited to evaluate the effect of intratympanic injection of Gd-DTPA mixed with dexamethasone on MRI of EH using a 3T MR machine and a novel heavily T2-weighted 3-dimensional fluid-attenuated inversion recovery reconstructed using a magnitude plus zero-filled interpolation(hT2FLAIR-MZFI)sequence.Results:The retention times and peak area of dexamethasone in HPLC were not modified by the addition of Gd-DTPA.EH grading in the cochlea and vestibule was not influenced in any ear by intratympanic injection of dexamethasone.Excellent inner ear images were obtained from all patients,and EHs with various grades were displayed.There were significant correlations between diagnosis and cochlear EH(p<0.01,Spearman's Rho),between diagnosis and vestibular EH(p<0.01,Spearman's Rho),and between cochlear and vestibular EH(p<0.01,Spearman's Rho).The distribution of Gd-DTPA plus dexamethasone negatively correlated with the grade of vestibular EH.Injury of the endolymph-perilymph barrier was detected in one cochlea and three vestibules of 59 inner ears with MD.Conclusions:Intratympanic administration of Gd-DTPA plus dexamethasone yielded high-quality MRI images of EH in patients with MD using a novel 7-min protocol and simplified the clinical application.Intratympanic administration of Gd-DTPA plus dexamethasone might be used to test its therapeutic effect in future work.

Endolymphatic hydrops in Meniere's disease secondary to otitis media and visualized by gadolinium-enhanced magnetic resonance imaging

Aimed to test the hypothesis that endolymphatic hydrops in Meniere's disease(MD) may be secondary to otitis media, history of a patient who developed MD as a complication of otitis media was reviewed. The inner ear was imaged using a 3.0 Tesla MR system post-intravenous injection of gadolinium-tetraazacyclododecane-tetraacetic acid(Gd-DOTA) in a standard single dosage(0.1 mmol/kg). Both t2-spc-rst-tra-iso(T2-weighted) and heavily T2-weighted 3-dimensional fluid-attenuated inversion recovery magnetic resonance imaging [h T(2)W-3D-FLAIR] sequences were applied. As a result, in the T2-weighted images, the perilymph and endolymph, cerebrospinal fluid surrounding the eighth nerve(N8), and middle ear granulation tissue showed intense signals. In the h T(2)W-3D-FLAIR images, evident enhancement by Gd-DOTA was observed in the middle ear cavity and the perilymphatic compartments of the cochlea. Cochlear endolymphatic hydrops was implicated by the enlarged scala media in the basalturn. In general, the Gd-DOTA uptake in the vestibule was weak, and signs of vestibular endolymphatic hydrops were obvious. The N8 on the diseased side was also significantly enhanced. To conclude, endolymphatic hydrops in MD may be induced by otitis media. Cochlear endolymphatic hydrops in MD secondary to otitis media may not follow the classical pattern.

Correlation of semi-quantitative findings of endolymphatic hydrops in MRI with the audiometric findings in patients with Meniere's disease

Purpose:To investigate the correlation between vestibular hydrops(VH),cochlearhydrops(CH),vestibular aqueduct non-visibility(VANV),and visually increased perilymphatic enhancement(VIPE)with the findings of pure-tone audiometry(PTA)in Meniere’s disease(MD)patients.Methods:In this cross-sectional study,53 ears belonging to 48 patients were divided into two groups and evaluated.In group“MD patients,”there were 24 ears of 19 patients diagnosed with the definite MD(14 patients with unilateral and 5 patients withbilateral involvements).The“control group”consisted of 29 non-symptomatic ears belonging to patients diagnosed with unilateral sudden sensory-neural hearing loss or unilateral schwannoma.All the patients underwent 2 sessions of temporal bone MRI using the same 3T system:an unenhanced axial T1,T2,and 3D-FLAIR MRI,an intravenous gadoliniumenhanced axial T1 fat-sat,and 4 h after the injection,an axial 3D-T2 cube and 3D-FLAIR session.VH,CH,VANV,and VIPE were assessed.Subsequently,the correlation between EH indices and PTA findings(in three frequency domains of low,middle,and high)were evaluated,and the predictive value of MRI was calculated.Results:VH was significantly correlated with the hearing threshold in the low,middle,and highfrequency domains.CH was also correlated with the hearing threshold in the low and middle domains.Contrarily,VIPE was not associated with hearing thresholds,and VANV was only correlated with the hearing threshold in low frequencies.Conclusion:The grade of VH,CH,and VANV were significantly correlated with the hearing thresholds in PTA.

Non-immune hydrops fetalis:Two case reports

BACKGROUND Fetal hydrops is a serious condition difficult to manage,often with a poor prognosis,and it is characterized by the collection of fluid in the extravascular compartments.Before 1968,the most frequent cause was the maternal-fetal Rh incompatibility.Today,90%of the cases are non-immune hydrops fetalis.Multiple fetal anatomic and functional disorders can cause non-immune hydrops fetalis and the pathogenesis is incompletely understood.Etiology varies from viral infections to heart disease,chromosomal abnormalities,hematological and autoimmune causes.CASE SUMMARY A 38-year-old pregnant woman has neck lymphoadenomegaly,fever,cough,tonsillar plaques at 14 wk of amenorrhea and a rash with widespread itching.At 27.5 wk a fetal ultrasound shows signs of severe anemia and hydrops.Cordocentesis is performed with confirmation of severe fetal anemia and subsequent fetal transfusion.The karyotype is 46,XX,array-comparative genome hybridization(CGH)negative,and infectious tests are not conclusive.In the following days there is a progressive improvement of the indirect signs of fetal anemia.At 33.6 wk,for relapse of severe fetal anemia,further fetal transfusions are necessary and an urgent cesarean section is performed.On the day 12 of life,for the detection of anemia,the newborn is subjected to transfusion of concentrated red blood cells and begins treatment with erythropoietin.Later there is a normalization of blood chemistry values and the baby does not need new transfusions.A 29-year-old pregnant woman,with Sjogren's syndrome and positive Anti-Ro/SSA antibodies,is subjected to serial fetal ecocardio for branch block.At 26.5 wk there is a finding of fetal ascites.Infectious disease tests on amniotic fluid are negative as well as quantitative fluorescent polymerase chain reaction,Array CGH.At cordocentesis Hb is 1.3 mmol/L,consequently fetal transfusion is performed.Also in this case,due to continuous episodes of relapse of fetal anemia with consequent transfusions,at 29.4 wk a cesarean section is performed.On day 9 of life,a treatment with erythropoietin is started in the newborn,but the baby needs three blood transfusions.The search for autoantibodies in the baby found SS-A Ro60 positive,SSA-Ro52 positive and SS-B negative.The hemoglobin values normalized after the disappearance of maternal autoantibodies.CONCLUSION An attempt to determine the etiology of hydrops should be made at the time of diagnosis because the goal is to treat underlying cause,whenever possible.Even if the infectious examinations are not conclusive,but the pregnancy history is strongly suggestive of infection as in the first case,the infectious etiology must not be excluded.In the second case,instead,transplacental passage of maternal autoantibodies caused hydrops fetalis and severe anemia.Finally,obstetric management must be aimed at fetal support up to an optimal timing for delivery by evaluating risks and benefits to increase the chances of survival without sequelae.

One-step thermokeratoplasty for pain alleviating and pre-treatment of severe acute corneal hydrops in keratoconus

AIM:To observe the efficacy of simplified one-step thermokeratoplasty for the treatment of severe acute corneal hydrops in keratoconus.METHODS:In this retrospective,noncomparative clinical study,10 patients(10 eyes) with acute hydrops in keratoconus were treated with simplified one-step thermokeratoplasty.Pain,changes in the corneal curvature,thickness,and size and morphology of the Descemet membrane breaks were detected before and after surgery.Eight patients were successfully treated using modified deep anterior lamellar keratoplasty(DALK).Graft transparency,visual acuity,and immunological rejection were evaluated for 6 to 12mo.RESULTS:Pain and corneal oedema were promptly alleviated,and the intrastromal ruptures diminished within 3 to 6wk after thermokeratoplasty.At 3 to 6wk after corneal oedema was faded,Descemet membrane breaks and intrastromal ruptures were healed.Two patients did not undergo subsequent corneal transplantation after thermokeratoplasty.Eight patients underwent DALK successfully and safely after thermokeratoplasty,without corneal perforation.Central corneal opacity faded or disappeared within 6mo.The mean best-corrected visual acuity was increased to 20/30 at 12mo after DALK.No one was observed with any immune rejection.CONCLUSION:One-step thermokeratoplasty can successfully and efficiently accelerate the absorption of prominent corneal oedema in severe acute hydrops patients.This simple procedure with no complications can be performed in the emergency department by residents.This method can improve the safety of DALK and obtain good postoperative vision.Long-term management of acute corneal hydrops using simplified one-step thermokeratoplasty seems promising.

Different compression sutures combined with intracameral air injection for acute corneal hydrops

·AIM:To evaluate the efficacy and safety of full-thickness sutures combined with intracameral air injection(FTS-AI)versus pre-Descemet’s membrane sutures combined with intracameral air injection(PDS-AI)in the management of acute corneal hydrops in keratoconus.·METHODS:The research included 8 patients(8 eyes)suffering from acute corneal hydrops caused by keratoconus.Four patients were randomly assigned to FTS-AI.And the other four were randomly assigned to PDS-AI.Corneal oedema,visual acuity,corneal thickness were assessed during follow-up.·RESULTS:The demographics,preoperative duration of symptoms and severity of corneal hydrops between the two groups were not significantly different.The mean corneal oedema resolution time after FTS-AI and PDSAI were 11±1.15 and 15±1.41 d,respectively(P=0.005).The maximum corneal thickness of the scarred region decreased in both groups at one week postoperatively(P<0.05).No obvious difference was found in the mean maximal corneal thickness between the two groups postoperatively.The BCVA improved significantly after FTS-AI and PDS-AI at three months postoperatively.No obvious difference was found in the BCVA after FTS-AI and PDS-AI at three months postoperatively.·CONCLUSION:FTS-AI and PDS-AI are safe and effective therapies to accelerate the resolution of corneal oedema in acute corneal hydrops secondary to keratoconus.Despite faster resolution of corneal oedema in the FTS-AI group,we recommend PDS-AI to avoid potential endothelium cell damage.

Contralateral delayed endolymphatic hydrops: Clinical features and long term outcome

Background:Contralateral delayed endolymphatic hydrops(CDEH)is a clinical entity characterized by fluctuating low frequency hearing loss and/or vertigo,mimicking Meniere’s disease(MD),that manifests after the appearance of severe non-hydropic hearing loss(NHHL)at the other ear.Objectives:to describe the clinical features and the course of 57 patients affected by CDEH.Method:this is a retrospective study;57 patients affected by CDEH,out of 1065 patients seen in the same period and affected by MD,were subjected to otoscopy,PTA threshold evaluation,impedance testing,ABR,research of positioning nystagmus,vestibular function evaluated by means of bithermal caloric test under video-oculographic,and MRI with gadolinium.Results:the CDEH was definite in 24 cases(42%),probable in 2(4%)and possible in 31(54%).The mean PTA threshold at the hydropic ear was 41 dB.At the last follow-up,40 patients(70%)did not report vertigo or fluctuating hearing loss.Among the 17 patients who still reported symptomatology,11(64%)were affected by fluctuating hearing loss alone,4(23%)reported a subjective worsening of hearing loss and 2(12%)an acute vertigo crisis.Conclusions:contralateral delayed endolymphatic hydrops is a relatively rare form of Meniere disease that manifests more frequently as a definite form or with fluctuating low-frequency hearing loss.The prognosis at a long term follow-up is relatively good in terms of vertigo resolution.Contralateral delayed endolymphatic hydrops rarely determines a severe hearing loss in the better ear.

An updated systematic review of Zika virus-linked complications

Objective: To determine the breadth of Zika virus(ZIKV)-associated brain anomalies in neonates and adults. Methods: Systematic review was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses(PRISMA) statement using electronic databases ScienceDirect, Pubmed, Medline, Scopus, and Global Health Library.Only those research articles, case studies, case-control studies, case-cohort studies, crosssectional studies, and organizational survey reports were included in the study that reported any fetal outcomes for pregnant women who had infected with ZIKV during the gestational period and ZIKV-related neurological complications in adults as well. Results: Out of total 72 retrieved articles, 50 met the inclusion criteria. We estimated a significant increase in incidence of neural abnormalities such as Guillain-Barre syndrome and microcephaly in the regions that are experiencing ZIKV outbreaks. Other neurological malformations found in ZIKV patients include hydrancephaly/hydrops fetalis, myasthenia gravis,meningoencephalitis and myelitis. Conclusion: Our systematic analysis provides the broad spectrum of neurological malformations in ZIKV infected patients and these data further support the causal link of ZIKV with neurological disorders.

Fetal Bradyarrhythmias:Etiopathogenesis,Diagnosis and Treatment:Between Literature Review and Experience of a Tertiary Center

Fetal arrhythmias reach up around 10%of the total third-level perinatal cardiology references.Sustained bradycardia is defined as a baseline fetal heart rate(FHR)of less than 110 bpm sustained for at least 10 min.The overall incidence of malignant fetal bradyarrhythmias,such as complete atrioventricular block(AVB)and channellopathies,is relatively rare,1:5000 pregnancies,but represents a serious emergency for the gynecologist,neonatologists,and pediatric cardiologists.Fetal complete AVB is strongly associated with maternal connective tissue disease,but it can be also associated with congenital heart disease and usually with a poorer prognosis with high risk of fetal hydrops and abortion.Currently,the treatment of severe fetal bradyarrhythmias is principally pharmacological and aims to increase the FHR,besides an early resolution of underlying causes,when possible,and a promptly management of fetal heart failure.Intrauterine electrostimulation nowadays is an experimental pioneering method,reserved for limited selected cases.

Diuretic Agents in Treatment of Sudden Deafness

Objective To study the role of diuretic agents in treating sudden deafness (SD) and explore the possibility of endolymphatic hydrops as a potential cause of SD. Methods Twenty-eight SD cases were reviewed. In 23 cases, treatment was initiated with routine agents. Diuretic agents were later added in 8 of these cases that failed to respond to routine treatment agents. Diuretic agents were included in the initial treatment in the rest 5 cases. In total, 13 cases received diuretics in addition to routine treatment agents and 15 cases received conventional treatment only. Results In the 8 cases who received diuretics after failed conventional treatments, 4 showed hearing improvement, whereas all 5 cases in which diuretics were included in the initial treatment demonstrated hearing improvement. Conclusion These results suggest a possible role of endolymphatic hydrops in the pathophysiologic course of SD. Diuretics should be considered when clear indications exist with no conflicts to other medical conditions.

Lethal Developmental Defects: An Overview

About 3% of all conceptions are associated with major congenital malformations, many of them are lethal developmental defect and genetic in origin or teratogenic (adverse effects of the environment during gametogenesis or early embryogenesis). Genetics with or without adverse environment has role in virtually every developmental defect/malformation disorders in causation, predisposition, susceptibility & modulation of disease. Advances in genetics, introduction of triple marker screening, routine obstetric ultrasound examination into obstetric practice & accesses to prenatal diagnosis helped in secondary prevention (early detection & termination) of lethal developmental defects. Ultrasound detection of fetal developmental defects/malformation is common now and often decision on pregnancy solely based on ultrasonic morphological description. This practice leads to difficulty in providing accurate counseling as well as preventing disorder in subsequent pregnancy, in particular early. Hence an understanding of reproductive genetics of major developmental disorders is important for today’s perinatal care specialists. This overview will outline the various lethal developmental defects observed in an advanced reproductive genetics set up and various approaches adopted to derive diagnosis. Detailed assessment of fetus after termination of pregnancy (spontaneous/induced) for fetal anomalies was carried out in most cases. As most cases was referred after termination in formalin routine chromosomal analysis was not possible however, in selected cases targeted FISH analysis with specific chromosomal probe was carried out to confirm clinical diagnosis. Detailed evaluation of fetus is important as this practice often helped in modification of genetic counseling, as well as course of management in the next pregnancy. No molecular diagnostic or screening work was carried out due to non availability of information and facility in past. However, this is important today as many of the lethal developmental defects are yet to be categorized etiopathologically, and hence immediate need is to start clinical registry along with biorepository of developmental defects cases for future research work on informative families, in particular with multiple affected fetuses/sibs, using genomics, proteomics, metabolomics, platforms.

Morbus Menière: Were the last 50 years of molecular biological research fruitless for Menière's disease?

After discovering an inner ear hemorrhage, Prosper Menière ascribed disease to the inner ear for the first time. Since that time, a lot of efforts have been made to determine the pathophysiologic causes of the classical symptoms sensorineural hearing loss, vertigo attacks, tinnitus and ear fullness. According to its express pattern Menière's disease may appear as classical andatypical disease. In the last decades, huge advances have taken place in biochemical and physiological research and in pathophysiological understanding of the inner ear and its diseases. This encloses stimulus perception and conduction, regulation of inner-ear fluid homeostasis and inner ear diseases with underlying genetics. Menière's disease pathophysiologic correlate is an endolymphatic hydrops which is characterized by changes of inner ear homeostasis with its parameters volume, concentration, osmolarity and pressure of the endolymph. Hormones, autonomous system and the immunsystem together with purinergic, adrenergic and muscarinic receptors, steroids, vasopressin, atrial natriuretic peptide and aquaporin channels regulate inner ear homeostasis. Consequently, general diagnostics comprise a magnetic resonance imaging with gadolinium, vestibular diagnostics and tone audiometry. Standard therapy for acute inner ear symptoms is limited to cortisone infusions together with a rheologic agent or a radical scavenger. For acute vertigo attacks and for the mainstay therapy antivertiginous pharmaceuticals are given. In severe cases destruction of the vestibular hair cells by ototoxic antibiotics, endolymphatic sac surgery or neurectomy of the vestibular nerve might be necessary. Certainly, in research there is a move from simple pharmaceutical therapy forward to nanoparticlebased, genetic-based and stem cell therapy.

Comparison of Transtympanic and Extratympanic Electrocochleography

Electrocochleography (ECoG) has been an important tool in the diagnosis of Meniere’s disease or endolymphatic hydrops. There are two methods employed, transtympanic and extratympanic. Many have regarded the results of these methods as being equally reliable. The purpose of this study is to determine any differences in sensitivity between the two methods. In this study patients with known endolymphatic hydrops or Meniere’s disease underwent ECoG testing with both the extratympanic method and the transtympanic method on the same day in the same ear. The results show a significant difference between the two methods, with the transtympanic wave values being smaller and therefore more sensitive than the extratympanic method. In addition, transtympanic ECoG resulted in better waveform morphology and better correlation with the audiometric findings in endolymphatic hydrops and Meniere’s disease. The results emphasize the superior role of transtympanic ECoG over extratympanic ECoG as a valuable component in the confirmation of Meniere’s disease or endolymphatic hydrops along with history and audiometric findings characteristic of the disease. Implications of the study promote the use of transtympanic ECoG rather than extratympanic ECoG in patients with symptoms suggestive of Meniere’s disease or endolymphatic hydrops.

Parvovirus B19 and Pregnant Women: A Bibliographic Review

Primary infection with parvovirus B19 is an uncommon but serious and treatable cause of chronic anemia in immuno compromised hosts. Widely distributed, it is responsible for a wide range of clinical manifestations, the characteristics and outcome of which depend on the interaction between the viral properties and the physiological and immune status of the infected individuals. Infection during pregnancy can result in fetal anemia, abortion, and hydrops. Pregnancy does not appear to affect the course of the infection, but the infection may affect the pregnancy. The diagnosis of B19V can be made by serological and molecular investigation of the mother, fetus and newborn. In these conditions, it seemed necessary for us to answer in this article the various questions raised by the occurrence of a contagion and/or an infection with Parvovirus B19 during pregnancy. Our objective was to determine at first the nature and the main characteristics of Parvovirus B19 as well as its propagation during the pregnancy and to show its risk for the pregnant woman and her fetus. The importance of the subject is proven by the data on the spread and incidence of the virus. Worldwide, the focus on pregnancy is due to the additional potentially fatal effects on the fetus. This document covers the important aspects of a medical investigation: causes, symptoms, tests and diagnosis.

Effects of electroacupuncture on cochlear morphology and expression of aquaporins in rats with AVP-induced endolymphatic hydrops

Objective: The objective of this study was to investigate the effects of EA on EH and the regulation of AQP2 and AQP7 protein expression in rats.Methods: Twenty-four rats were allocated randomly to four groups of blank group, EH group,EH+tolvaptan group and EH + EA group(n = 6 per group). EH rat model was established by intraperitoneally injection of arginine vasopressin(AVP). EA was administered at acupoints "Baihui(百会 GV 20)"and "Tinggong(听宫 SI 19)". Rats in the EH + tolvaptan group and EH+ EA group were treated with tolvaptan and EA, respectively, after EH establishment. Hematoxylin-eosin staining was used to measure the cochlear hydrops degree, and then the ratio of scala media(SM) area to SM + scala vestibuli(SV) area(R value) was calculated. Immunohistochemical method was used to observe AQP2/AQP7 protein expression in the rat cochlear lateral wall after treatment.Results: ①There was no endolymphatic hydrops in the blank group. Reissner' s membrane was extended markedly and bulged into SV in cochleae of the EH group and endolymphatic hydrops was noted. Statistical analysis revealed that R value in the EH group showed a significant increase compared with that in the blank group(0.42 ± 0.02 vs. 0.31 ± 0.05, P=0.000). The distension of Reissner's membrane was less obvious in the EH + tolvaptan group and EH + EA group when compared with the EH group. R value in the EH + tolvaptan group and the EH + EA group was significantly less than that in EH group(0.32±0.04 vs. 0.42 ± 0.02, =0.001;0.35 ± 0.05 vs. 0.42 ± 0.02, P=0.012). The degree of the hydrops in the EH + EA group was not different from that in the EH + tolvaptan group(0.35 ± 0.05 vs. 0.32 ±0.04,P= 1.000). ②The AQP2 protein expression in the rat cochlear lateral wall of EH group was significantly increased when compared with the blank group(12.74 ± 5.18 vs. 5.92 ± 1.52, P = 0.014). The AQP2 protein expression in the rat cochlear lateral wall of EH + tolvaptan group and EH + EA group were all lower than that of the EH group(6.52 ± 2.73 vs. 12.74 ± 5.18. P = 0.029;6.95 ± 3.10 vs. 12.74 ± 5.18, P = 0.047).The AQP2 protein expression in the rat cochlear lateral wall of EH + EA group was not different from that in the EH + tolvaptan group(6.95 ± 3.10 vs. 6.52 ± 2.73, P= 1.000).③The AQP7 protein expression in the rat cochlear lateral wall of EH group was significantly increased when compared with the blank group(30.32 ± 6.39 vs 16.64 ± 3.21, P=0.000). The AQP7 protein expression in the rat cochlear lateral wall of EH + tolvaptan group and EH + EA group were all lower than that of the EH group(18.32 ± 2.45 vs.30.32 ± 6.39, P= 0.001;19.54 ± 4.61 vs. 30.32 ± 6.39, P= 0.003). The AQP7 protein expression in the rat cochlear lateral wall of EH + EA group was not different from that in the EH + tolvaptan group(19.54 ±4.61 vs. 18.32 ± 2.45, P= 1.000).Conclusions: These results indicate that repeated EA stimulation exerted the same effects as tolvaptan application on AQPs levels and subsequent aquaretic effects. And dehydrating effect of EA on the inner ear might be associated with its down-regulation of both AQP2 and AQP7 protein expression, thereby provide a potential molecular mechanism involved in the treatment of Meniere's disease by EA.

Arginine Vasopressin-Aquaporin-2 Pathway-Mediated Dehydration Effects of Electroacupuncture in Guinea Pig Model of AVP-Induced Endolymphatic Hydrops

Objective: To investigate the effects of electroacupuncture(EA) on endolymphatic hydrops(EH) and the regulation of arginine vasopressin(AVP)-aquaporin-2(AQP2) pathway in guinea pigs. Methods: EH was induced in male guinea pigs by an intraperitoneal injection of AVP. For the treatment, EA was delivered to Baihui(GV 20) and Tinggong(SI 19) acupoints, once per day for 10 consecutive days. In histomorphological studies, cochlear hydrops degree was evaluated by hematoxylin-eosin(HE) staining, and then the ratio of scala media(SM) area to SM + scala vestibuli(SV) area(R value) was calculated. In mechanical studies, a comparison of plasma AVP(p-AVP) concentrations, cyclic adenosine monophosphate(cAMP) levels, vasopressin type 2 receptor(V2R) and AQP2 mRNA expressions in the cochlea were compared among groups. Results: EA significantly reduced cochlear hydrops in guinea pigs(P=0.001). EA significantly attenuated the AVPinduced up-regulation of p-AVP concentrations(P=0.006), cochlear c AMP levels(P=0.003) and AQP2 mRNA expression(P=0.016), and up-regulated the expression of V2R mRNA(P=0.004) in the cochlea. Conclusion: The dehydrating effect of EA might be associated with its inhibition of AVP-AQP2 pathway activation.

Effect of electroacupuncture on arginine vasopressin-induced endolymphatic hydrops

OBJECTIVE: To investigate the influence of electroacupuncture(EA) on experimentally induced endolymphatic hydrops(EH) in guinea pigs, and elucidate the association between the dehydrating effect of EA and changes in stria vascularis ultrastructure and expression of vasopressin type 2 receptor(V2R), cyclic adenosine monophosphate(cAMP),and aquaporin 2(AQP2) in the endolymphatic sac(ES).METHODS: The EH model was established by intraperitoneal injection of arginine vasopressin(AVP).As a treatment, EA was delivered to Baihui(GV 20)and Tinggong(SI 19) acupoints, once daily for 10 consecutive days. For histomorphological studies,degree of cochlear hydrops was evaluated by hematoxylin-eosin staining, and the ratio of scala media(SM) area to SM + scala vestibuli area was calculated. In mechanical studies, ultrastructural changes in stria vascularis tissue were examined by transmission electron microscopy. In addition, cAMP levels and mRNA expression levels of V2 R and AQP2 in the ES were compared among groups.RESULTS: EA treatment significantly reduced cochlear hydrops compared with hydropic guinea pigs(P = 0.015). Furthermore, EA attenuated ultrastructural changes in the stria vascularis tissue following EH, significantly upregulated the expression of V2 R(P = 0.016), and attenuated AVP-induced upregulation of both cAMP(P = 0.038) and AQP2 expression(P = 0.017) in the ES.CONCLUSION: Collectively, the results of the present study suggest that the dehydrating effect of EA is associated with improvement of stria vascularis ultrastructure and V2 R-cAMP-AQP2 signaling pathway regulation in the ES.

MRI detection of endolymphatic hydrops in Meniere's disease in 8 minutes using MIIRMR and a 20-channel coil after targeted gadolinium delivery

Background:Endolymphatic hydrops(EH)become visible in vertigo patients,particularly in those with Meniere's disease(MD),in vivo using gadolinium-enhanced MRI.However,the image quality is not satisfying after intravenous injection of gadolinium chelate(GdC),and occasional failure in GdC uptake has been noticed after traditional intratympanic injection.In the present report,targeted delivery of GdC and using a cost-effective MRI system to obtain high quality images of EH in only 8 min will be fntroduced.Methods:39 MD patients were recruited in the study.First,0.1 ml of 20-fold diluted gadolinium-diethylenetriamine acid(Gd-DTPA)was delivered onto the posterior upper part of the tympanic medial wall using a soft-tipped micro-irrigation catheter through an artificially perforated tympanic membrane.Inner ear MRI was performed 24 h after Gd-DTPA administration using a 3T MR machine and a 20-channel head/neck coil with an 8 min sequence of medium inversion time inversion recovery imaging with magnitude reconstruction(MIIRMR).The parameters were as follows:TR 16000 ms,TE 663 ms,inversion time 2700 ms,flip angle 180°,slices per slab 60.Results:Efficient inner ear uptake of Gd-DTPA was detected 24 h after delivery and it created excellent contrast in the inner ear of all cases.High quality images demonstrating EH in the vestibule and cochlea were obtained.Conclusion:Targeted delivery of minimum Gd-DTPA(0.1 ml,20-fold dilution)onto the posterior upper portion of the tympanic medial wall and MRI with MIIRMR in a 3T machine and 20-channel head/neck coil are clinically practical to obtain high quality images displaying EH.