Isthmus Region Research Articles

Ultrastructure of the tubular glands in the isthmus region of the oviduct in laying and natural moulting commercial egg-type chickens.

The study investigated the ultrastructural characteristics of tubular gland and duct cells, as well as luminal gland cells in the isthmus region of the oviduct of laying and natural moulting hens. Tubular glands in laying birds were composed of type 1 and 2 cells. Based on the preponderance of each cell type, in relation to the location of a developing egg in the oviduct of the domestic fowl, these gland cells may represent different functional states of the same cell. The findings of the study on natural moulting birds suggest that autophagy is a process confined to the early stages of degeneration, while necrosis occurs in the terminal stages.

Ruptured caesarean scar ectopic pregnancy: a diagnostic dilemma in a resource-limited setting

BackgroundCaesarean scar pregnancy (CSP) remains a very rare form of ectopic pregnancy associated with serious life threatening obstetric complications and even death in case of late diagnosis and treatment.Case presentationWe report a case of a ruptured caesarean scar pregnancy in a 29 year-old gravida 5, para 3 with a past obstetric history of two consecutive caesarean sections done 9 and 5 years ago respectively. The patient presented with intermittent lower abdominal pains on a 20 weeks gestation associated with mild epigastralgia and 2 previous episodes of mild pervaginal bleeding (2 and 1 months ago respectively before consultation) managed with injectable progesterone. Her evolution 4 h later was marked by an increase in the intensity of the abdominal pain, an unmeasurable blood pressure and a feeble pulse. Immediate paracentesis revealed 10 cc of fresh non coagulating blood. The diagnosis of ruptured ectopic pregnancy with abundant hemoperitoneum was considered and an emergency laparotomy with fluid and blood resuscitation was carried out. A midline laparotomy revealed a ruptured caesarean scar ectopic pregnancy with an abundant hemoperitoneum. Careful resection of the placenta and repair of the ruptured isthmic region of the uterus was carried out. Recovery after surgery was without complications and the patient was discharged on the 6th day following surgery.ConclusionCaesarean scar pregnancy remains a very rare obstetric condition. Late diagnosis of this condition can be associated with serious life threatening obstetric complications. The rarity of the condition warrants a high index of suspicion among clinicians.

Cotyledonoid Dissecting Leiomyoma of the Uterus: An Unexpected Diagnosis After Delivery

Cotyledonoid dissecting leiomyoma, also known as Sternberg tumor, is a rare benign uterine tumor with a gross and radiologicalappearance that may suggest the possibility of a malignancy. We report a case of a thirty-eight-year-old female patient who presentedwith menorrhagia and abdominal pain one month after delivery by cesarean section. An ultrasound scan showed a heterogeneouspelvic mass, near the isthmic region, with 25 x 24 x 23 mm without vascularization so the possibility of placenta accreta could not beexcluded. During hysterectomy, we also removed a small grey mass in the right ovary. Microscopic examination revealed a proliferationof a sparsely cellular tissue with extensive hyalinization and coagulative necrosis, composed of spindle shaped muscle cells withoutcellular atypia or mitoses. The patient is without evidence of recurrence one year and six months post-surgery.

1375 Cutaneous adnexal cysts revisited: A novel classification based on morphological and molecular features

Cutaneous cysts have been classified by many dermatopathologists in different ways. We propose a novel classification of cutaneous adnexal cysts according to their origin in the folliculo-sebaceous unit and sweat glands. By examining the lining of the cystic structure, its origin can be easily identified. Epidermal cysts have an epithelial wall containing a granular layer and the keratinization through the lumen is lamellar, indicating an infundibular origin Tricholemmal cysts have an undulating epithelial wall with no granular layer and a compact keratinization, showing an isthmic origin. In steatocystoma, dermoid cyst and folliculosebaceous hamartoma, the epithelial lining shows a crenulated appearance which is seen in the sebaceous duct. Hidrocystoma shows the characteristic cuboidal epithelial lining of sweat glands with decapitation secretion in its apocrine forms. Metabolizing acquired dioxin-induced skin hamartoma (MADISH) is a cystic lesion with no sebaceous glands showing lamellar keratinization. Cytokeratin expression pattern is also consistent with the origin of the cysts. For example, the sebaceous duct keratin CK17 is expressed in steatocystoma, dermoid cyst and folliculo-sebaceous hamartoma. Epidermal cyst expresses CK10 as tricholemmal cyst, which also expresses CK17. Eccrine and apocrine hidrocystoma shows a broader expression of cytokeratins (CK1, CK5, CK7, CK8, CK10, CK14, CK18, CK19). CK16 is only expressed by folliculo-sebaceous hamartoma. In MADISH, as in folliculo-sebaceous hamartoma, CK15 is expressed. Follicular stem cell marker Lrig1 is expressed at the isthmic region of human folliculosebaceous and the activation of β-catenin in Lrig1-positive stem cells gives rise cystic proliferations reminiscent of MADISH in mice. Recently, cutaneous keratocyst and steatocystoma unified as sebaceous duct cyst has been proposed to be a hamartoma resembling the sebaceous duct. The classification proposed here aims to simplify the complexity of cutaneous adnexal cysts and to have a better understanding of the origin of the cystic lesions of the skin.

Predictors of external pancreatic fistulas development after surgical treatment of infected pancreatonecrosis

Aim. To determine the risk factors for the development of external pancreatic fistulas in the outcome of infected pancreatonecrosis, which do not close as a result of conservative treatment.
 Materials and methods. The results of treatment were analyzed in 44 patients with pancreatonecrosis. The influence of different risk factors for the development of external pancreatic fistulas after surgery for infected pancreatonecrosis was studied, using Spearman’s correlation coefficient.
 Results. The repeated surgeries one year after pancreatonecrosis were required by 9 % of patients in connection with pancreatic cysts and for 11.36 % – with external pancreatic fistulas. There was observed a positive correlation of a mean value between the formation of external pancreatic fistulas, which did not close after intensive conservative therapy and the localization of necrosis zone in the region of isthmus (r = 0.31, p = 0.00), its depth 50 % and more (r = 0.46, p = 0.00), quantity of outflow (r = 0.55, p = 0.00) with amylase activity > 1000 units (r = 0.53, p = 0.00).
 Conclusions. Localization of necrosis zone in the region of isthmus, necrosis depth 50 % and more, quantity of control drainage outflow > 150 ml, high amylase activity in drainage > 1000 units are predictors of the formation of external pancreatic fistulas in the outcome of acute destructive pancreatitis, which need surgical correction.

Subxiphoid Minimally Invasive Epicardial Ablation (Convergent Procedure) With Left Thoracoscopic Closure of the Left Atrial Appendage

The Convergent Procedure is a combined epicardial and endocardial ablation performed by a cardiac surgeon and electrophysiologist to treat symptomatic persistent and long standing persistent atrial fibrillation. The epicardial ablation is performed on the entire width of the posterior left atrial wall using monopolar radiofrequency via a subxiphoid incision. There is no sternotomy and cardiopulmonary bypass is not utilized. The surgical ablation is then followed by endocardial voltage mapping and ablation, allowing for complete lesion set creation. Left atrial appendage exclusion can be performed via left thoracoscopic approach at the same time as the surgical ablation. The Convergent Procedure is a truly hybrid, collaborative procedure which combines the strengths of minimally invasive cardiac surgery and percutaneous electrophysiologic techniques to treat a challenging disease process.

Defining the Identity and Dynamics of Adult Gastric Isthmus Stem Cells

The gastric corpus epithelium is the thickest part of the gastro-intestinal tract and is characterized by rapid tissue turnover. Several markers have been proposed for gastric corpus stem cells in both isthmus and base regions. However, the identity of isthmus stem cells (IsthSCs) and the interaction between distinct stem cell populations is still under debate. Here, based on unbiased genetic labeling and biophysical modeling, we show that corpus glands are compartmentalized into two independent zones, with actively-cycling stem cells maintaining the pit-isthmus-neck region and slow-cycling reserve stem cells maintaining the base. Independent lineage tracing based on Stmn1 and Ki67 expression confirmed that rapidly-cycling IsthSCs maintain the pit-isthmus-neck of corpus glands. Finally, single cell RNA-seq analysis is used to define the molecular identity and lineage relationship of a single, cycling IsthSC population. These observations define the identity and functional behavior of a single population of actively-cycling IsthSCs.

Hysteroscopic Isthmoplasty: Step-by-Step Technique

Study ObjectiveTo demonstrate our technique for surgical hysteroscopy performed with a standard-size resectoscope or miniresectoscope in 3 cases of isthmocele. DesignStep-by-step demonstration of the technique using slides, pictures, and video (educative video) (Canadian Task Force classification III). SettingIsthmocele is a characteristic semidiverticular anomaly of the anterior isthmic wall of the uterus, located at the site of a previous cesarean delivery scar. The etiopathogenesis of isthmocele remains poorly understood, although several hypotheses have been proposed. Factors that may possibly play a role in niche development include a very low incision through cervical tissue, inadequate suturing technique during closure of the uterine scar, surgical interventions that increase adhesion formation, and patient-related factors that impair wound healing or increase inflammation or adhesion formation. The treatment of isthmocele focuses on relieving symptoms (i.e., postmenstrual spotting, suprapubic pelvic pain, dysmenorrhea, dyspareunia, and infertility), and, consequently, asymptomatic cases should not be treated. Various surgical approaches have been described to treat isthmocele-related symptoms, including hysteroscopy, laparoscopy, vaginal, robotic, and combined techniques. InterventionOur local Institutional Review Board approved the study protocol. The procedures were performed in operative room using a 26 Fr and 16 Fr continuous-flow resectoscope under general anesthesia. The surgical technique involves resection of the fibrotic tissue of the lower margin and then the upper margin of the pouch using a cutting loop, until the underlying muscular tissue is reached, followed by resection of the inflamed and necrotic tissue of the base of the pouch. Similar surgical maneuvers are performed on the contralateral side (right anterolateral wall) for complete ablation of the isthmic region (inverted ablation). ConclusionAccording to the most recent literature, hysteroscopic hystmoplasty appears to be a safe and effective treatment option in cases of isthmocele with a niche at least 2 mm deep and a residual myometrial thickness of at least 3 mm to improve postmenstrual bleeding. When residual myometrial thickness is <3 mm, the hysteroscopic approach is not recommended, mainly because of the risk of bladder injury. In these symptomatic cases, laparoscopic or vaginal repair may be considered.

Expression of bone morphogenetic protein receptors in bovine oviductal epithelial cells: Evidence of autocrine BMP signaling

Members of the transforming growth factor beta (TGF-β) family, including bone morphogenetic proteins (BMPs), are expressed in the epithelial cells of the mammalian oviduct. These signaling molecules play important roles in development and tissue homeostasis; however, little is known about their function in the mammalian oviduct. In the present study, RT-qPCR was used to analyze the mRNA abundance of BMP type I (BMPR1A, BMPR1B, ACVR1) and type II receptors (BMPR2, ACVR2A, ACVR2B) in the bovine oviduct epithelial cells (BOEC) isolated from ampulla and isthmus at both the follicular (FP) and the luteal (LP) phase of the estrous cycle. Results indicate that mRNAs for all the BMP receptors studied are expressed in the BOEC. Significant mRNA abundance differences were observed for both BMPR1B and ACVR2B when comparing both the ampulla and isthmus regions with the greater abundance at the isthmus. When both FP and LP samples were compared, ACVR2B mRNA showed greater abundance during the LP, with significant differences in the isthmus region. These variations highlight differences between the isthmus and ampulla regions of the oviduct. By means of wound healing assays on BOEC primary cultures, exogenous recombinant human BMP5 induced a significant increase in wound healing at 24h. The observed changes at the mRNA abundance of components of the signaling pathway and the BMP5 effect on oviductal epithelial cells suggest a possible autocrine role for the BMP pathway that could affect epithelial cell functions necessary for normal physiology and reproductive success in BOEC homeostasis.

Mouse Fgf8‐Cre‐LacZ lineage analysis defines the territory of the postnatal mammalian isthmus

The isthmus is recognized as the most rostral segment of the hindbrain in non-mammalian vertebrates. In mammalian embryos, transient Fgf8 expression defines the developing isthmic region, lying between the midbrain and the first rhombomere, but there has been uncertainty about the existence of a distinct isthmic segment in postnatal mammals. We attempted to find if the region of early embryonic Fgf8 expression (which is considered to involve the entire extent of the prospective isthmus initially) might help to identify the boundaries of the isthmus in postnatal animals. By creating an Fgf8-Cre-LacZ lineage in mice, we were able to show that Fgf8-Cre reporter expression in postnatal mice is present in the same nuclei that characterize the isthmic region in birds. The 'signature' isthmic structures in birds include the trochlear nucleus, the dorsal raphe nucleus, the microcellular tegmental nuclei, the pedunculotegmental nucleus, the vermis of the cerebellum, rostral parts of the parabrachial complex and locus coeruleus, and the caudal parts of the substantia nigra and VTA. We found that all of these structures were labeled with the Fgf8-Cre reporter in the mouse brain, and we conclude that the isthmus is a distinct segment of the mammalian brain lying caudal to the midbrain and rostral to rhombomere 1 of the hindbrain.

Bovine embryo-oviduct interaction in vitro reveals an early cross talk mediated by BMP signaling.

Signaling components of bone morphogenetic proteins (BMPs) are expressed in an anatomically and temporally regulated fashion in bovine oviduct. However, a local response of this signaling to the presence of the embryo has yet to be elucidated. The aim of the present study was to evaluate if early embryo-oviduct interaction induces changes in the gene expression of BMP signaling components. For this purpose, we used an in vitro co-culture system to investigate the local interaction between bovine oviductal epithelial cells (BOEC) from the isthmus region with early embryos during two developmental periods: before (from the 2-cell to 8-cell stage) or during (from the 8-cell to 16-cell stage) the main phase of embryonic genome activation (EGA). Exposure to embryos, irrespective of the period, significantly reduced the relative abundance of BMPR1B, BMPR2, SMAD1, SMAD6 and ID2 mRNAs in BOEC. In contrast, embryos that interacted with BOEC before EGA showed a significant increase in the relative abundance of SMAD1 mRNA at the 8-cell stage compared to embryos cultured without BOEC. Moreover, embryos at the 16-cell stage that interacted with BOEC during EGA showed a significant increase in BMPR1B, BMPR2 and ID2 mRNA. These results demonstrate that embryo-oviduct interaction in vitro induces specific changes in the transcriptional levels of BMP signaling, causing a bidirectional response that reduces the expression levels of this signaling in the oviductal cells while increases them in the early embryo. This suggests that BMP signaling pathway could be involved in an early cross talk between the bovine embryo and the oviduct during the first stages of development.

Peri-mitral atrial flutter: personalized ablation strategy based on arrhythmogenic substrate.

The aim of this study is to characterize the arrhythmogenic substrate for peri-mitral atrial flutter (PMAFL), thereby determining a personalized ablation strategy to treat PMAFL. Thirty-six consecutive PMAFL patients (mean age: 63.8 ± 11.3, 23 males) underwent detailed three-dimensional electroanatomic mapping in left atrium (LA). The LA was divided into septal-anterior wall (SAW), posterior inferior wall (PIW), and mitral isthmus (MI) region, respectively. Ablation strategy was determined based on the endocardial bipolar voltage map. Based on electrophysiological substrates, 10, 17, and 9 cases were classified into iatrogenic, spontaneous, and no-substrate PMAFL, respectively. The mean voltage in SAW was significantly lower in spontaneous PMAFL (iatrogenic: 1.07 ± 0.66 mV; spontaneous: 0.65 ± 0.44 mV; no-substrate: 1.60 ± 0.53 mV, P <0.001), while iatrogenic PMAFL patients had the lowest voltage in MI (0.51 ± 0.23 mV vs. 1.55 ± 0.78 mV, 1.61 ± 0.56 mV, P <0.001). No low-voltage or slow conduction zone was found in the no-substrate PMAFL group. Fifteen spontaneous PMAFLs were successfully terminated by modified septal-anterior (9/10) or conventional anterior ablation line (6/7). Eight iatrogenic PMAFLs (8/10) were terminated by reinforcing the previous ablation areas. Cardioversion without PMAFL ablation was done in no-substrate PMAFL patients. After a median follow-up of 12 (7-39) months, two spontaneous PMAFL patients received redo procedures for recurrence due to "gap" conduction. The ablation strategy for PMAFL patients should be based on the arrhythmogenic substrate, but not the indiscriminate MI ablation. No-substrate PMAFLs during AF ablation could be monitored after cardioversion and might not need further ablation.

The abnormal expression of oxytocin receptors in the uterine junctional zone in women with endometriosis.

BackgroundThe junctional zone (JZ), also called as the endometrial-myometrial junction, is related to peristaltic-like movements in the non-pregnant uterus. Hyperperistalsis and dysperistalsis of uterus constructions might underlie many important disorders such as dysmenorrhea, infertility, endometriosis, implantation failure. The major proteins for uterine contraction of the non-pregnant uterus may be Oxytocin (OT) and oxytocin receptor (OTR). The objective of this study was to inspect the expression of OTR in isthmic and mid-fundal parts of the uterine junctional zone at different stages of the follicular cycle in patients with and without endometriosis.MethodsUterine biopsies containing endometrium and junctional zone were collected from the isthmic and mid-fundal parts of the anterior wall after hysterectomy. The OTR expression was evaluated by immunohistochemistry.ResultsIn the control uterus, OTR expression in the isthmic region was significantly higher than in the fundal region in the proliferative phase (p < 0.05) but significantly lower in the secretory phase (p < 0.05). And the expression of OTR in the proliferative phase was significantly higher than that in the secretory phase in both isthmic and fundal regions (p = 0.000 and 0.049, respectively). However, in endometriosis uteri, OTR expression in the isthmic region showed no significant difference with that in the fundal region in both proliferative and secretory phases (p = 0.597 and 0.736, respectively). In both isthmic and fundal regions, OTR expression was not significantly different between the proliferative phase and secretory phase (p = 0.084 and 0.222, respectively). OTR expression in fundal regions of revised ASRM I and II endometriosis were lower than that of revised ASRM III and IV (p = 0.049). In the fundal region of JZ, the expression of OTR in ovarian endometriosis was significantly lower than that in deep infiltrating endometriosis (p = 0.046). The expression level of OTR in the funds region is positively associated with the severity of dysmenorrhea in endometriosis group (r = 0.870, p < 0.05). Comparing to normal uteri, the expression of OTR in the secretory phase was significantly higher in the endometriosis uteri (p < 0.05). In the fundus of endometriosis uteri, OTR expression was significantly higher in both the proliferative and secretory phases (p = 0.045 and 0.028, respectively).ConclusionOTR expression in the JZ of women with endometriosis changes significantly, which may result in abnormal uterine contractile activity, reducing the endometriosis-related fertility and dysmenorrhea.

Adult gastric stem cells and their niches.

Adult gastric stem cells replenish the gastric epithelium throughout life. Recent studies have identified diverse populations of stem cells, progenitor cells, and even differentiated cells that can regain stem cell capacity, so highlighting an unexpected plasticity within the gastric epithelium, both in the corpus and antrum. Two niches seem to co-exist in the gastric unit: one in the isthmus region and the other at the base of the gland, although the precise features of the cell populations and the two niches are currently under debate. A variety of gastric organoid models have been established, providing new insights into niche factors required by the gastric stem cell populations. Here we review our current knowledge of gastric stem cell populations, their markers and interactions, important niche factors, and different gastric organoid systems. WIREs Dev Biol 2017, 6:e261. doi: 10.1002/wdev.261 For further resources related to this article, please visit the WIREs website.

Selection of Critical Isthmus in Scar-Related Atrial Tachycardia Using a New Automated Ultrahigh Resolution Mapping System.

Accurate activation mapping of reentrant scar-related atrial tachycardias (AT) allows efficient radiofrequency ablation by targeting the critical isthmus (CI). We aimed to assess the electrophysiological properties of CI channels during mapping with the IntellaMap Orion basket and the Rhythmia system. We prospectively studied 33 AT (post- atrial fibrillation ablation or surgical mitral valve repair). The noise of bipolar electrogram (EGM) was systematically measured at 10 prespecified sites, as well as on a standard catheter and on the surface ECG. Bipolar EGM of CI regions were analyzed for amplitude, duration, and conduction velocity. The isthmus region to be targeted was chosen based solely on propagation. For each AT, 25 684±14 276 EGMs were automatically annotated. Noise of the Orion EGM was 0.011±0.004 mV, lower than that of a standard catheter (0.016±0.019) and surface ECG (0.02±0.01; P<0.05). For reentrant AT, within the CI, bipolar EGM amplitude (0.08±0.11 mV) and conduction velocity (0.27±0.19 m/s) were lower than those orthodromically before (0.62±0.93 mV; 1±0.49 m/s) and after (0.80±1.59 mV; 1±0.73 m/s) the isthmus (P<0.001 for all). In 97% of AT, ablation at the CI resulted in AT termination. No complications occurred. This new automated ultrahigh resolution mapping system produces low noise and allows accurate diagnosis of AT circuits. CI on reentrant scar-related AT showed much lower EGM amplitude with a significantly slower conduction velocity than the surrounding parts of the circuit. Ablation of the areas of slow conduction resulted in a high acute success.

Anatomic characteristics of the mitral isthmus region: The left atrial appendage isthmus as a possible ablation target

The mitral isthmus is a part of the postero-inferior area of the lateral left atrial wall located between the mitral annulus and the left inferior pulmonary vein ostium. Linear ablation lesions are created within the mitral isthmus for the invasive treatment of left atrial arrhythmias. However, the anatomy of this region is not fully understood. The aim of this study has been to provide a detailed morphometric description of the mitral isthmus region and to propose another possible isthmus within the investigated heart area that may serve as a potential new ablation target. Two hundred autopsied, non-atrial fibrillation hearts (23.5% deriving from females) whose donors were a mean of 47.6±17.6years old were investigated. We macroscopically assessed the anatomy of the postero-inferior area of the lateral left atrial wall. The mean mitral isthmus length was 28.8±7.0mm and was significantly longer than the left atrial appendage (LAA) isthmus (14.2±4.8mm) (p=.00). The distance between the LAA orifice and the left inferior pulmonary vein ostium (18.4±4.8mm) was longer than the LAA isthmus (p=.00) and shorter than the mitral isthmus (p=.00). The LAA isthmus was longer in hearts with a common left pulmonary vein (p=.037). In 65.5% of all cases the area between the right and left mitral isthmus lines was completely smooth. In the remaining hearts, crevices and diverticula (18.0%), intertrabecular recesses (7.0%), trabecular bridges (3.5%), or co-existence of these structures (6%) could be observed. The LAA isthmus line was smooth in 95.5% of all cases, with only small crevices in the remaining 4.5%. In conclusion, regardless of the anatomical variants of the left-sided pulmonary veins, the mitral isthmus area is quite uniform in size. The LAA isthmus is considerably shorter than the mitral isthmus. The mitral isthmus line has many unwanted structures that may entrap the catheter, which is not the case for the LAA isthmus. We proposed the LAA isthmus line for potential clinical use.

Gustatory and general visceral centers and their connections in the brain of adult zebrafish: a carbocyanine dye tract-tracing study.

The central connections of the gustatory/general visceral system of the adult zebrafish (Danio rerio) were examined by means of carbocyanine dye tracing. Main primary gustatory centers (facial and vagal lobes) received sensory projections from the facial and vagal nerves, respectively. The vagal nerve also projects to the commissural nucleus of Cajal, a general visceral sensory center. These primary centers mainly project on a prominent secondary gustatory and general visceral nucleus (SGN/V) located in the isthmic region. Secondary projections on the SGN/V were topographically organized, those of the facial lobe mainly ending medially to those of the vagal lobe, and those from the commissural nucleus ventrolaterally. Descending facial lobe projections to the medial funicular nucleus were also noted. Ascending fibers originating from the SGN/V mainly projected to the posterior thalamic nucleus and the lateral hypothalamus (lateral torus, lateral recess nucleus, hypothalamic inferior lobe diffuse nucleus) and an intermediate cell- and fiber-rich region termed here the tertiary gustatory nucleus proper, but not to a nucleus formerly considered as the zebrafish tertiary gustatory nucleus. The posterior thalamic nucleus, tertiary gustatory nucleus proper, and nucleus of the lateral recess gave rise to descending projections to the SGN/V and the vagal lobe. The connectivity between diencephalic gustatory centers and the telencephalon was also investigated. The present results showed that the gustatory connections of the adult zebrafish are rather similar to those reported in other cyprinids, excepting the tertiary gustatory nucleus. Similarities between the gustatory systems of zebrafish and other fishes are also discussed. J. Comp. Neurol. 525:333-362, 2017. © 2016 Wiley Periodicals, Inc.

Histologic Assessment of Debridement of the Root Canal Isthmus of Mandibular Molars by Irrigant Activation Techniques Ex Vivo

IntroductionThis study aimed to evaluate the efficacy of a new irrigation system (EndoIrrigator Plus; Innovations Endo, Nasik, India) using a histologic method ex vivo. MethodsMandibular molars with a normal pulp extracted for periodontal reasons (N = 68) were assessed for the presence of an isthmus using cone-beam computed tomographic imaging. Root canals of the included molars (n = 40) were instrumented up to a ProTaper F2 instrument (Dentsply Maillefer, Baillagues, Switzerland) using 3% sodium hypochlorite as irrigant in a closed apical design. Final irrigation delivery/activation was performed as follows (n = 10): group 1, syringe irrigation; group 2, apical negative pressure delivery with continuous warm activated irrigation and evacuation system (CWAIS); group 3, manual dynamic agitation (MDA); and group 4, passive ultrasonic irrigation (PUI). Untreated teeth (n = 5) served as histologic controls. The isthmus regions (1, 3, and 5 mm from the apex) were analyzed by hematoxylin-eosin stain to calculate the percentage of remaining pulp tissue (RPT) relative to the area of the isthmus. Results were analyzed using the Mann-Whitney U test (P = .05). ResultsCWAIS showed significantly less RPT than the other groups at all 3 root levels (P < .05). MDA showed significantly less RPT at 1 and 3 mm from the apex compared with PUI and syringe irrigation (P < .05). There was no significant difference between PUI and MDA at the 5-mm level (P > .05). ConclusionsNone of the methods could completely clean the isthmus. CWAIS left behind the least amount of RPT.

Roles of EDNs in regulating oviductal NO synthesis and smooth muscle motility in cows.

Endothelins (EDNs) participate in various physiological events including smooth muscle contraction, nitric oxide (NO) synthesis, and embryonic development. In this study, we investigated the regional roles of EDNs produced by bovine oviductal epithelial cells in NO synthesis and smooth muscle motility. Quantification of mRNA expressions indicated that expression of EDN receptor B (EDNRB) in the ampullary region was higher after ovulation than before ovulation, whereas expression of EDNRA in the isthmic region was higher after ovulation than before ovulation. Immunohistochemistry revealed that the EDN receptors (EDNRA and EDNRB) were expressed in the epithelium, whereas smooth muscle showed positive staining only for EDNRA. The expressionsPlease suggest whether 'NOS2' can be treated as the updated symbol for 'iNOS' as per gene nomenclature. of inducible NO synthase (iNOS) protein and its mRNA (NOS2) in cultured epithelial cells isolated from the ampulla were stimulated by EDN1, but not by EDN2 or EDN3, after 1h of incubation. In isthmic epithelial cells, none of the EDNs affected the expression of NOS2 Isometric contraction tests indicated that spontaneous waves were strong in the isthmic region but weak in the ampullary region. EDN1 modulated smooth muscle motility in both the regions. The overall findings suggest that EDN1 plays region-specific roles in smooth muscle motility and epithelial NO synthesis, providing an optimal oviductal microenvironment for transport of gametes, fertilization, and development/transport of early embryo.

Immunohistochemical expression of anti-oxidants in bovine oviduct epithelial cells of estral and luteal phases

The present study aimed to evaluate immunohistochemical distributions of anti-oxidative enzymes Cu ZnSuperoxide dismutase (SOD-1), catalase, and Glutation peroxidase-1 (GPX1) in the bovine oviduct epithelial cells of estral and luteal phases. The results indicated both ciliated and secretoric cells of the oviduct mucosa exibited varying degrees of immureactivity for all. The SOD-1 and GPX1 immunostainings were more conspicuous in luteal phase while catalase immunostaining was more apparent in estral phase, especially in the isthmus region of the oviduct. In contrast to catalase, GPX1 immunoractivity was absent or limited in the isthmus. All regions of the oviduct mucosa had similar SOD-1 immunoreactivity. SOD-1 and GPX1 immunoreactivities were more apparent in samples of the luteal phase while catalase immnureactivity was higher in those of the estral phase. Presence of anti-oxidative enzymes catalase, SOD, and GPX1 immunostainings in the bovine oviduct suggests that the bovine oviduct epithelial cells are most likely engaged into synthesis of such enzymes and possibly the source of anti-oxidative enzymes in oviduct fluid. The oviduct regions, each of which executes different reproductive functions, varied by means of catalase and GPX1 expressions, suggeting that anti-oxidants may possibly contribute to different physiological proceses in the reproductive cycle. Furthermore, anti-oxidant expressions also varied between luteal and estral phases, suggesting that oviduct epithelial cells are possibly influenced by hormonal changes in regard to anti-oxidant expression. Presence of SOD-1 immunoreactivity in some but not all basal cells of the oviduct epithelial lining should be further investigated for possible heterogeneities among basal cells and for origin of secretory and ciliated cells