Subepithelial Plexus Research Articles

Aberrant Corneal Homeostasis in Neurosurgery-Induced Neurotrophic Keratopathy.

The characteristic features of neurotrophic keratopathy have been well documented by in vivo and in vitro studies using animal models. However, case reports of neurotrophic keratopathy induced by neurosurgery are limited. We describe the clinical characteristics, anterior segment optical coherence tomography (AS-OCT) and in vivo confocal microscopy (IVCM) findings of neurotrophic keratopathy induced by surgery for intracranial lesions. This is a case series including 6 eyes of 3 patients (mean age, 69.67 ± 12.50 years) with unilateral neurotrophic keratopathy. The clinical findings of three patients were described and IVCM findings of three patients were analyzed. The duration of neuropathy ranged from 2 to 30 years (median, 22 years). Thickening of the epithelial layer and higher reflection density of the anterior stroma were observed during the healing process using AS-OCT. The mean nerve fiber density of the subepithelial plexus, as determined by IVCM, was 1943 ± 1000 μm/mm2 for neurotrophic eyes and 2242 ± 600.3 μm/mm2 for contralateral eyes (p = 0.0347). The mean respective dendritic cell densities were 30.8 ± 21.8 and 6.25 ± 5.59 cells/mm2 (p < 0.0001), while the mean basal cell sizes were 259 ± 86.5 and 185 ± 45.9 μm2 (p < 0.0001), respectively. These findings suggest that neurosurgery-induced neurotrophic keratopathy may be associated with alterations in the healing process and immune cell distribution in the cornea.

Subgemmal neurogenous plaque of posterolateral region in tongue: A case report and review of literature.

IntroductionThe subgemmal neurogenous plaque is a well-defined subepithelial neural plexus associated with taste buds, located within foliate, fungiform, and circumvallate papillae of the human tongue, that is poorly known by dentists and medical professionals. The hyperplasia of subgemmal neurogenous plaque may occur and it manifests as a papule, nodule, plaque, or ulcer in the lateral posterior border of the tongue inducing the overdiagnosis of reactive, cystic, or neoplastic lesions. The aims of this study are to report a case of a patient with subgemmal neurogenous plaque, and to provide a comprehensive review of other subgemmal neurogenous plaque in the posterolateral tongue with challenging diagnosis.Presentation of caseA 28-year-old female with a little yellowish nodule, asymptomatic, located in posterior left lateral border of the tongue. Accurate diagnosis was based in excisional biopsy and histopathological examination showing a superficial neurofibroma-like pattern, and a neuroma-like in the deep zone. The final diagnosis was subgemmal neurogenous plaque.DiscussionThe subgemmal neurogenous plaque has an erythematous nodule or papule in the border of the tongue that are frequently misdiagnosis as foliate papillitis and lymphoepithelial cyst. Despite the subgemmal neurogenous plaque be considered a normal structure, the biopsy is recommended for differential diagnosis with other benign or malignant lesions in tongue.ConclusionContributing with the dentists and medical professionals in their clinical practice, we reviewed the literature and added a case of subgemmal neurogenous plaque in the posterolateral region of the tongue, highlighting the importance of its recognition to avoid misdiagnosis.

Corneal confocal microscopic characteristics of acute angle-closure crisis

BackgroundTo investigate characteristics of the acute angle-closure crisis (AACC) and fellow eyes using confocal microscopy.MethodsUnilateral AACC patients hospitalized at the Xi’an People’s Hospital from October 2017 to October 2020 were recruited in this cross-sectional study. Age-matched participants scheduled for cataract surgery were enrolled as a healthy control group. Corneal epithelial cells, subepithelial nerve fiber plexus, stromal cells, and endothelial cells were examined by confocal and specular microscopy.ResultsThis study enrolled 41 unilateral AACC patients (82 eyes) and 20 healthy controls (40 eyes). Confocal microscopy revealed that the corneal nerve fiber density, corneal nerve branch density and corneal nerve fiber length were reduced significantly in AACC eyes. The stromal cells were swollen and the size of the endothelial cells was uneven with the deposition of punctate high-reflective keratic precipitate on the surface. In severe cases, the cell volume was enlarged, deformed, and fused. The corneal subepithelial nerve fiber, stromal layer, and endothelial layer were unremarkable in the fellow eyes, and the density of the endothelial cells was 2601 ± 529 cells/mm2, which was higher than 1654 ± 999 cells/mm2 in AACC eyes (P < 0.001). Corneal edema prevented the examination of 17 eyes using specular microscopy and in only four eyes using confocal microscopy. There were no significant differences in endothelial cell density between confocal and specular microscopy in the AACC eyes (P = 0.674) and fellow eyes (P = 0.247). The hexagonal cell ratio reduced significantly (P < 0.001), and average cell size and coefficient of variation of the endothelial cells increased significantly compared with fellow eyes (P < 0.001, P = 0.008).ConclusionsAACC eye showed decreased density and length of corneal subepithelial nerve fiber plexus, activation of stromal cells, increased endothelial cell polymorphism, and decreased density.

A FoxL1-CreERT-2A-tdTomato Mouse Labels Subepithelial Telocytes.

A FoxL1-CreERT-2A-tdTomato Mouse Labels Subepithelial Telocytes.

Chemical-neuroanatomical organization of peripheral sensory-efferent systems in the pond snail (Lymnaea stagnalis)

Perception and processing of chemical cues are crucial for aquatic gastropods, for proper elaboration of adaptive behavior. The pond snail, Lymnaea stagnalis, is a model species of invertebrate neurobiology, in which peripheral sensory neurons with different morphology and transmitter content have partly been described, but we have little knowledge regarding their functional morphological organization, including their possible peripheral intercellular connections and networks. Therefore the aim of our study was to characterize the sensory system of the tentacles and the lip, as primary sensory regions, and the anterior foot of Lymnaea with special attention to the transmitter content of the sensory neurons, and their relationship to extrinsic elements of the central nervous system. Numerous bipolar sensory cells were demonstrated in the epithelial layer of the peripheral organs, displaying immunoreactivity to antibodies raised against tyrosine hydroxylase, histamine, glutamate and two molluscan type oligopeptides, FMRFamide and Mytilus inhibitory peptide. A subepithelial plexus was formed by extrinsic serotonin and FMRFamide immunoreactive fibers, whereas in deeper regions axon processess of different origin with various immunoreactivities formed networks, too. HPLC–MS assay confirmed the presence of the low molecular weight signal molecules in the three examined areas. Following double-labeling immunohistochemistry, close arrangements were observed, formed by sensory neurons and extrinsic serotonergic (and FMRFamidergic) fibers at axo-dendritic, axo-somatic and axo-axonic levels. Our results suggest the involvement of a much wider repertoire of signal molecules in peripheral sensory processes of Lymnaea, which can locally be modified by central input, hence influencing directly the responses to environmental cues.

Subepithelial telocytes are an important source of Wnts that supports intestinal crypts.

Tissues with rapid cellular turnover, such as the mammalian hematopoietic system or the intestinal epithelium, are dependent upon stem and progenitor cells, which through proliferation provide differentiated cells to maintain organismal health. Stem and progenitor cells, in turn, are thought to rely upon signals and growth factors provided by local niche cells to support their function and self-renewal. Several cell types have been proposed to provide the signals required for the proliferation and differentiation of the ISC in the crypt1–6. Here, we identify subepithelial telocytes as an important source of Wnt proteins, without which intestinal stem cells cannot proliferate and support epithelial renewal. Telocytes are large but rare mesenchymal cells that are marked by Foxl1 and PDGFRα expression and form a subepithelial plexus that extends from the stomach to the colon. While supporting the entire epithelium, Foxl1+ telocytes compartmentalize the production of Wnt ligands and inhibitors to enable localized pathway activation. Conditional gene ablation of Porcupine (Porcn), which is required for functional maturation of all Wnt proteins, in Foxl1+ telocytes causes rapid cessation of Wnt signaling to intestinal crypts, followed by loss of stem and transit amplifying cell proliferation and impaired epithelial renewal. Thus, Foxl1+ telocytes are an important source of niche signals to intestinal stem cells.

Morphological, Histological and Immunohistochemical Study of the Rabbit Uterus during Pseudopregnancy

Ten mature virgin rabbit does (4-5 months old) with mean weight of 2.4 kg were induced to ovulate; by intramuscular injection of HCG (50-70 IU). The day of induction was considered 0 days. Uteri were obtained from 14 h, 3, 7, 18 days post induction. At first stage of pseudopregnancy; the two uteri became hyperemic and slightly swollen. The uterine epithelium and endometrial glands epithelium were of columnar type with oval basal nuclei. The endometrial glands were few in number and small in size. The endometrial glands showed apocrine activity. The uterus had six longitudinal folds and the uterine epithelium form crypts. The endometrium had slight vascularization. At middle stage of pseudopregnancy, the two uteri became hyperemic and more swollen. This stage characterized by; mucosal folding, glandular formation, epithelial proliferation and thickening of the uterine wall. At last stage of pseudopregnancy; the two uteri became flaccid and more swollen. This stage characterized by dramatic changes in the uterine architecture in the form of: increased epithelial proliferation and crypt formation increase the complexity of luminal folding, increase in length, size and abundance of the uterine endometrial glands, increase in the uterine micro vascular development (increased abundance of the large microvessels and development of subepithelial capillary plexuses). Tunica vascularis could be demonstrated between the inner circular and outer longitudinal smooth muscle fibers of the myometrium at the all stages of psedopregnancy. Telocytes with its characteristic morphology could be demonstrated in the myometrium of the rabbit uterus during pseudopregnancy. Cell-specific immuno-localization of progesterone receptors alpha (PRA) in the rabbit uterus during pseudopregnancy revealed that, there were mild, moderate and strong nuclear PRA immunostaining in the endometrial epithelial cells, endometrial glands and in the smooth muscles fibers of the myometrium of the first, middle and last stages of pseudopregnancy respectively. The present study revealed that the morphological, histological and immunohistochemical changes in the rabbit uterus during pseudopregnancy resembled that occurred during early stage of pregnancy. These changes were characterized by dramatic changes in the uterine architecture in the form of: increased epithelial proliferation and crypt formation increase the complexity of luminal folding, increase in length, size and abundance of the uterine endometrial glands, increase in the uterine microvascular development. These uterine changes were accompanied with PRA immunolocalization in the uterine tissues.

Corneal iontophoresis and cross linking: a preliminary report of our experience.

To evaluate the effect induced by UVA radiation with corneal iontophoresis and cross-linking. From February 2013 to August 2014 we saw 15 eyes of 15 patients, age range 19-38 years (10 women and 5 men) keratoconus stage 1-2. Vision evaluation was carried out with ETDRS scale and Topography and Pachymetry. To evaluate line of demarcation with the confocal microscope and corneal optical coherence tomography (OCT) and the pain with the Faces Pain Scale. At 6 months there was a stabilization of vision and topography, with a slight improvement at 1 year of vision of 1 line and of the Km of 0.5 diopters. The in vivo microscopic examination with the confocal microscope showed that the line of demarcation was not particularly evident, it was irregular and when present was more evident at 150-200 µ depth, there was a keratinocyte activation in the anterior stroma with slight oedema. There were also superficial epithelial alterations present and only slight involvement of the subepithelial nervous plexus, there were no alterations of the endothelium. The Faces Pain Scale the pain score was 2±1. We have to stress the usefulness of Corneal optical coherence tomography (OCT) also pre and post iontophoretic treatment. Further, larger studies and longer follow-ups are needed, recent studies have shown the absorption of riboflavin with iontophoresis is 50% with respect to the classic technique, the percentage of riboflavin in the anterior 2/3 of the corneal stroma would be, however, efficacious to provide good results.

Laser Scanning In Vivo Confocal Microscopy of Clear Grafts after Penetrating Keratoplasty.

Purpose. To evaluate the changes of keratocytes and dendritic cells in the central clear graft by laser scanning in vivo confocal microscopy after penetrating keratoplasty (PK). Methods. Thirty adult subjects receiving PK at Shandong Eye Institute and with clear grafts and no sign of immune rejection after surgery were recruited into this study, and 10 healthy adults were controls. The keratocytes and dendritic cells in the central graft were evaluated by laser scanning confocal microscopy, as well as epithelium cells, keratocytes, corneal endothelium cells, and corneal nerves (especially subepithelial plexus nerves). Results. Median density of subepithelial plexus nerves, keratocyte density in each layer of the stroma, and density of corneal endothelium cells were all lower in clear grafts than in controls. The dendritic cells of five (16.7%) patients were active in Bowman's membrane and stromal membrane of the graft after PK. Conclusions. Activated dendritic cells and Langerhans cells could be detected in some of the clear grafts, which indicated that the subclinical stress of immune reaction took part in the chronic injury of the clear graft after PK, even when there was no clinical rejection episode.

Collagen cross-linking in keratoconus in Asian eyes: visual, refractive and confocal microscopy outcomes in a prospective randomized controlled trial.

To evaluate the safety and efficacy of collagen cross-linking (CXL) in the treatment of keratoconus. A prospective randomized sham-controlled clinical trial was undertaken and 43 eyes with moderate to severe keratoconus were randomized into two groups that is the treatment (n = 23) and the sham (n = 20) group. CXL was performed with riboflavin (0.1 in 20 % dextran) followed by UVA radiation (365 nm, 3 mW/cm(2), 30 min). In the sham group, only riboflavin was administered without UVA radiation. Uncorrected distance visual acuity (UDVA), corrected distance visual acuity, intraocular pressure, corneal thickness, keratometry, endothelial count, confocal microscopy were evaluated at baseline and at 1 week, 1, 3, and 6 months. In cases where CXL was done, UDVA improved by mean 0.11 ± 0.06 logMAR units at 6 months (P = 0.01). The refractive cylinder and spherical equivalent decreased by mean of 0.62 D (P = 0.01) and 0.5 D (P = 0.19), respectively. Ultrasonic central corneal thickness decreased by mean 22.7 ± 10.3 μm (P = 0.01). The maximum and minimum keratometry decreased by mean of 1.2 ± 0.8 D (P = 0.01) and 0.83 ± 1.2 D (P = 0.39), respectively. The specular count and intraocular pressure did not show any significant change. In the sham group, no significant change was observed in any parameter. Confocal analysis showed that the epithelial healing was complete at 1 week after crosslinking. The sub-epithelial plexus showed loss of nerve plexus at 1 month, regeneration of nerve fibers which started at 3 months and was complete at 6 months. The anterior stroma showed loss of keratocytes with honeycomb oedema and apoptotic bodies till 3 months. The regeneration of keratocytes started at 3 months and was complete at 6 months of follow-up. Collagen cross-linking is an effective procedure to halt progression in keratoconus. The confocal microscopic changes correlate with the outcomes in the treatment and the sham groups.

Iberian pig early pregnancy: Vascular endothelial growth factor receptor system expression in the maternofetal interface in healthy and arresting conceptuses

In Iberian pigs, a high conceptus loss occurs during the first 30 days of gestation. Although the exact causes for these losses have not been determined to date, the importance of blood vessel development during early pregnancy has been noted. The aim of this study was to analyze the messenger RNA (mRNA) and protein expression of VEGF-rs (vascular endothelial growth factor, the VEGFR1, and the VEGFR2 receptor system) and elucidate a possible relationship with the conceptus status (healthy or arrested) on gestational Days (gd) 22 and 32. Both mRNA and protein expression for VEGF-rs molecules were consistently expressed in conceptuses and endometrium during the pregnancy period analyzed. In endometrium, a significant increase in VEGF mRNA and VEGFR2 mRNA expression in healthy sites was observed as pregnancy advances (P < 0.001 and P < 0.05, respectively), whereas VEGFR1 mRNA expression was maintained at a constant level. Interestingly, a significantly elevated VEGFR2 mRNA expression (P < 0.05) was observed on gd 22 in endometrium from arrested conceptuses. Furthermore, VEGF mRNA and VEGFR1 mRNA expression in trophoblasts from healthy conceptuses decreased as pregnancy proceeded (P < 0.001). Arrested trophoblasts on gd 32 showed higher VEGFR2 mRNA expression than healthy conceptuses (P < 0.05). Although, in endometrium attachment sites, the pattern of VEGF-rs immunostaning was not affected by conceptus status, the immunoexpression of VEGF-rs in healthy attachment sites increased slightly but consistently as gestation proceeded. In arresting trophoblasts, VEGF and VEGFR2 staining decreased from gd 22 to 32. Moreover, the number of VEGF and VEGFR1-positive capillaries in the subepithelial vascular plexus of endometrium was related to the conceptus status, showing a moderate increase in healthy sites as pregnancy advances. In conclusion, it appears that VEGF-rs is expressed and related to vascular development in Iberian pigs between gd 22 and 32. The upregulated expression of VEGF mRNA and VEGFR2 mRNA in healthy uterine sites suggests a significant role for these angiogenic factors in early pregnancy.

Hysteroscopic Diagnosis of Endometrial Vascular Dystrophy

Endometrial vascular dystrophy was first described in 1991 by Jacques E. Hamou [1] as a rare but distinctive hysteroscopic finding. In his original report, Hamou identified 2 variants of vascular dystrophy. The first was characterized by tiny dilated capillaries (spiral vessel–like) that homogeneously covered the entire endometrial surface. In the second variant, meshed or branching capillaries break up into the subepithelial plexus just underneath the basal endometrial layer.

An Overview of Molecular and Cellular Mechanisms Associated with Porcine Pregnancy Success or Failure

Prenatal mortality remains one of the major constraints for the commercial pig industry in North America. Twenty to thirty per cent of the conceptuses are lost early in gestation and an additional 10-15% is lost by mid-to-late gestation. Research over the last two decades has provided critical insights into how uterine capacity, placental efficiency, genetics, environment, nutrition and immune mechanisms impact successful conceptus growth; however, the exact cause and effect relationship in the context of foetal loss has yet to be determined. Similar to other mammalian species such as the human, mouse, rat, and primates, immune cell enrichment occurs at the porcine maternal-foetal interface during the window of conceptus attachment. However, unlike other species, immune cells are solely recruited by conceptus-derived signals. As pigs have epitheliochorial placentae where maternal and foetal tissue layers are separate, it provides an ideal model to study immune cell interactions with foetal trophoblasts. Our research is focused on the immune-angiogenesis axis during porcine pregnancy. It is well established that immune cells are recruited to the maternal-foetal interface, but their pregnancy specific functions and how the local milieu affects angiogenesis and inflammation at the site of foetal arrest remain unknown. Through a better understanding of how immune cells modulate crosstalk between the conceptus and the mother, it might be possible to therapeutically target immune cells and/or their products to reduce foetal loss. In this review, we provide evidence from the literature and from our own work into the immunological factors associated with porcine foetal loss.

Recovery of Corneal Sensitivity, Calcitonin Gene-Related Peptide–Positive Nerves, and Increased Wound Healing Induced by Pigment Epithelial–Derived Factor Plus Docosahexaenoic Acid After Experimental Surgery

To assess function of regenerated corneal nerves in correlation with epithelial wound healing after experimental nerve damage in rabbits treated with pigment epithelial-derived factor (PEDF) plus docosahexaenoic acid (DHA). An 8-mm stromal dissection was performed in the right eyes of adult New Zealand rabbits. Treatment with PEDF+DHA was for 6 weeks. Corneal sensation was measured weekly by Cochet-Bonnet esthesiometer. After 8 weeks, immunofluorescence with βIII-tubulin, calcitonin gene-related peptide, and substance P antibodies was performed to quantify nerves. Also, rabbits were treated with PEDF+DHA for 4 weeks after lamellar keratectomy, followed by 8-mm epithelial debridement and epithelial defect assessment. One week after surgery, corneas were stained with anti-Ki67 antibody to assess cell proliferation. Eight weeks after surgery, calcitonin gene-related peptide-positive nerve fibers in the PEDF+DHA group were similar to normal rabbit corneas but were decreased in the vehicle. Substance P was localized in the subepithelial plexus but appeared in epithelial cells after nerve injury regardless of treatment. Five weeks after surgery, an increase in corneal sensitivity occurred in the PEDF+DHA group and reached normal values by 8 weeks. Pigment epithelial-derived factor plus DHA increased epithelial wound healing after lamellar keratectomy. One week after epithelial injury, Ki67-positive cells increased in the limbal area. Pigment epithelial-derived factor plus DHA promotes regeneration of calcitonin gene-related peptide-positive corneal nerves, accelerating wound healing and return of corneal sensitivity. Pigment epithelial-derived factor plus DHA represents a new approach to regenerate nerves and a potential treatment for prevention of severe dry eye after surgery or diseases of the ocular surface.

Preliminary investigation on tear film alterations in latent herpes stromal keratitis

To investigate tear film alterations in patients with latent herpes stromal keratitis (HSK). Prospective comparative case series study. Twenty-four patients with latent HSK in one eye and 28 age and gender matched healthy individuals were recruited. All subjects were evaluated by subjective symptoms of dry eye, tear film break-up time (BUT) and Schirmer I test (SIT). Laser in vivo confocal microscopic investigation was performed in 12 patients with severe tear film instability (BUT ≤ 5 s). Data distribution and homogeneity of variance was analyzed. Statistical comparisons of the mean values between different groups were performed using Kruskal-Wallis test, Mann-Whitney test or student t-test. Most of latent HSK patients (n = 22/24, 91.7%) had symptoms as dryness, burning sensation, redness and foreign body sensation. Both eyes of patients with latent HSK had hyposecretion (SIT, control eyes (16.2 ± 3.2) mm/5 min; affected eyes (10.4 ± 7.8) mm/5 min; lateral eyes (11.2 ± 8.8) mm/5 min; control and affected, U = 135.0, P < 0.001; control and lateral, U = 155.0, P = 0.001) and decreased tear film stability [BUT, control eyes (12.1 ± 0.7) s, affected eyes (4.3 ± 3.3) s, lateral eyes (9.2 ± 4.4) s; control and affected, U = 28.0, P < 0.001; control and lateral, U = 114.0, P < 0.001] as compared to control group (Kruskal-Wallis nonparametric test). The value of BUT showed significant difference between affected eyes and healthy eyes (U = 90.0, P < 0.001), whereas no difference of the value of SIT was found (U = 273.0, P = 0.757). Abnormal SIT (≤ 10 mm/min) and BUT (≤ 10 s) was presented in 14 (58.3%) and 23 (95.8%) affected eyes, as well as in 14 (58.3%) and 17 (70.8%) lateral eyes, respectively. Laser in vivo confocal microscopy investigation in 12 affected corneas with abnormal tear film showed morphological alterations as corneal epithelial metaplasia with polymorphism and enlarged cells, reflective nuclei, and decreased nucleus/cytoplasm ratio; decreased nerve density in subepithelial plexus and obvious branching and beading, which is similar to those changes caused by dry eye. Most of latent HSK patients had abnormal tear film. Dry eye related alterations could be found in affected corneas with abnormal tear film by in vivo confocal microscopy.

Sympathetic nerve-dependent regulation of mucosal vascular tone modifies airway smooth muscle reactivity

The airways contain a dense subepithelial microvascular plexus that is involved in the supply and clearance of substances to and from the airway wall. We set out to test the hypothesis that airway smooth muscle reactivity to bronchoconstricting agents may be dependent on airway mucosal blood flow. Immunohistochemical staining identified vasoconstrictor and vasodilator nerve fibers associated with subepithelial blood vessels in the guinea pig airways. Intravital microscopy of the tracheal mucosal microvasculature in anesthetized guinea pigs revealed that blockade of α-adrenergic receptors increased baseline arteriole diameter by ~40%, whereas the α-adrenergic receptor agonist phenylephrine produced a modest (5%) vasoconstriction in excess of the baseline tone. In subsequent in vivo experiments, tracheal contractions evoked by topically applied histamine were significantly reduced (P < 0.05) and enhanced by α-adrenergic receptor blockade and activation, respectively. α-Adrenergic ligands produced similar significant (P < 0.05) effects on airway smooth muscle contractions evoked by topically administered capsaicin, intravenously administered neurokinin A, inhaled histamine, and topically administered antigen in sensitized animals. These responses were independent of any direct effect of α-adrenergic ligands on the airway smooth muscle tone. The data suggest that changes in blood flow in the vessels supplying the airways regulate the reactivity of the underlying airway smooth muscle to locally released and exogenously administered agents by regulating their clearance. We speculate that changes in mucosal vascular function or changes in neuronal regulation of the airway vasculature may contribute to airways responsiveness in disease.

Innervation of the Labia Minora of Prepubertal Girls

IntroductionSurgical and histologic sources of information give little reference to innervation, vascular, and epithelial details of the labia minora. Little is known about areas of nerve density, epithelial qualities, and vascular compartments of the labial minora that contribute to sexual arousal and orgasm. Surgical procedure development and counsel about surgical risks related to labioplasty and surgical flaps created from labial tissue may be based on inadequate information. MethodsLabial samples from 10 normal girls (aged 2–9 years) who underwent surgery for labial fusion utilized waste tissue strips for immunohistochemical identification of S-100 and neuronal nitric oxide synthase (nNOS) in the labia minora. ResultsVascular and lymphatic plexus lie within the reticular dermis, which contains a dense mesh of nerve fibers with a higher concentration of nerve fiber at the level of the subepithelial plexus. Dense innervations are located at the epidermis, extending along the basal and spinous layers of the epithelium of labia minora. Nerve bundles in the papillary dermis are associated with sebaceous and eccrine glands and nerve terminals located throughout the epithelium. The introital epithelium of the labia minora is highly innervated with widespread and intense staining, detected in the introital border of the labia minora versus the external one. The dermis appeared to display S-100 and nNOS immunolabelling. S-100 was also immunopositive in the epidermis. ConclusionLabia minora is highly innervated along its entire edge. Related vascular compartment tissue involved in engorgement during sexual arousal makes this tissue important for sexual response. Labioplasty risks removal of tissue with an important contribution to sensory sexual arousal. Movement of labial tissue during genitoplasty may have different sensory outcomes dependent on which labial surface is used.

Cogan Syndrome: Confocal Microscopy Assessment of Corneal Damage

To perform in vivo assessment of corneal alterations in patients with Cogan syndrome (CS) and to correlate these findings with prior histopathologic descriptions. Four consecutive patients (8 eyes) presenting with typical CS underwent confocal microscopy examination. At the moment of evaluation, ocular inflammation was quiescent in all the patients. The images were studied singularly, and then compared to those obtained from 5 healthy controls. Statistical analysis was performed with Student t test. All the cases showed multiple brightly reflective deposits in the stroma with moderate reflectivity of the surrounding stromal tissue. The outer corneal layers and the endothelium were spared. In 3/4 of the patients, the nerve fibers of the subepithelial plexus were thin and poorly reflective, with interruptions and lack of the typical branching pattern. No cells different from keratocytes could be detected in either case or control eyes. Corneal vascularization was present in one case. In CS-affected eyes, corneal thickness was 552+/-62 microm on average, and endothelial cell count was 2466+/-288 cells/mm(2). Statistical significance was not reached compared to the control group. Confocal microscopy was able to provide detailed images of corneal alterations in CS. This confirmed the interstitial nature of the keratitis and showed an excellent accordance with prior histopathologic findings. The absence of inflammatory cell infiltration may be explained by the prolonged control of ocular inflammation in our patients, which may also have limited stimuli for corneal neovascularization.

S1799 Specialized Spinal Afferent Neurons to Detect Mucosal Shear in Guinea-Pig Colon

Background and aims. Extrinsic sensory neurons to the gut mediate both sensation and gastrointestinal reflexes important for gut function in health and disease. Different classes of afferents which convey various types of information about the gut wall and contents can be reliably identified by characterizing the morphology of their physiologically-identified peripheral axons. “Muscular mucosal” afferents have been identified on the basis of their responses to both colorectal distension and to light mucosal stroking. Methods. Extracellular recording from colonic nerves in isolated preparations of guinea pig distal colon were combined with biotinamide filling In Vitro. Results. When all layers of the colon were present in the preparation, a class of afferents could be strongly activated by light von Frey hairs (0.1 10 mN, maximum instantaneous firing: 83+/-18 Hz, n=6). The same units could also be activated by circumferential distension with constant loads (10 100mN) evoking firing of 52+/-30 Hz (n=10). Both types of activity were preserved in preparations where the muscularis externa had been removed prior to recording, suggesting that transduction sites were located in the submucosa or mucosa. Surprisingly, afferents of this class also fired in concert with spontaneous contractions of preparations, measured under isotonic conditions. The action potentials of these units were significantly larger and of shorter duration than action potentials from mechanonociceptors axons recorded from the same nerve trunks (341+/-146 vs 139+/-34μV P<0.01, 0.4+/-0.1 vs 1.1+/-0.8 ms, P<0.05, n=9). None of 9 “muscular mucosal” axons recorded responded to focal application of capsaicin (0.3 μM) and their mechanosensitivity persisted in calcium-free solution (with raised [Mg++]). This suggests that they are intrinsically mechanosensitive rather than relying on release of mediators from other cells. Biotinamide dye filling revealed fine branching axons running in the subepithelial plexus in regions corresponding closely to mechanosensitive receptive fields of these units (n=4). Conclusions. We conclude that “muscular mucosal” afferents comprise a discrete and distinctive class of spinal afferent innervation, well suited to detect physiological levels of mucosal shear in the distal colon of the guinea-pig.

S1800 Characterization of a Reproducible Gastric Pain Model Using Oral Capsaicin Titration: A Placebo-Controlled, Double-Blind Study

Background and aims. Extrinsic sensory neurons to the gut mediate both sensation and gastrointestinal reflexes important for gut function in health and disease. Different classes of afferents which convey various types of information about the gut wall and contents can be reliably identified by characterizing the morphology of their physiologically-identified peripheral axons. “Muscular mucosal” afferents have been identified on the basis of their responses to both colorectal distension and to light mucosal stroking. Methods. Extracellular recording from colonic nerves in isolated preparations of guinea pig distal colon were combined with biotinamide filling In Vitro. Results. When all layers of the colon were present in the preparation, a class of afferents could be strongly activated by light von Frey hairs (0.1 10 mN, maximum instantaneous firing: 83+/-18 Hz, n=6). The same units could also be activated by circumferential distension with constant loads (10 100mN) evoking firing of 52+/-30 Hz (n=10). Both types of activity were preserved in preparations where the muscularis externa had been removed prior to recording, suggesting that transduction sites were located in the submucosa or mucosa. Surprisingly, afferents of this class also fired in concert with spontaneous contractions of preparations, measured under isotonic conditions. The action potentials of these units were significantly larger and of shorter duration than action potentials from mechanonociceptors axons recorded from the same nerve trunks (341+/-146 vs 139+/-34μV P<0.01, 0.4+/-0.1 vs 1.1+/-0.8 ms, P<0.05, n=9). None of 9 “muscular mucosal” axons recorded responded to focal application of capsaicin (0.3 μM) and their mechanosensitivity persisted in calcium-free solution (with raised [Mg++]). This suggests that they are intrinsically mechanosensitive rather than relying on release of mediators from other cells. Biotinamide dye filling revealed fine branching axons running in the subepithelial plexus in regions corresponding closely to mechanosensitive receptive fields of these units (n=4). Conclusions. We conclude that “muscular mucosal” afferents comprise a discrete and distinctive class of spinal afferent innervation, well suited to detect physiological levels of mucosal shear in the distal colon of the guinea-pig.