Muscle Coat Research Articles

Report of a Case of Mucoepidermoid Carcinoma of the Esophagus

Abstract: We report a very rare case of mucoepidermoid carcinoma (MEC) of the esophagus. The patient was a 47‐year‐old man with a tumor of the submucosal type, associated with erosion on its top in the mid‐esophagus, detected by esophagoscopy. The lesion was stained with 3% iodine solution, but the site of the erosion was not. Endoscopic ultrasonography revealed a hypo‐echogenic tumor located mainly in the submucosal layer, preserving the muscle coat intact. Distal esophagectomy with esophago‐gastrostomy was performed via the retrosternal route. Microscopic study revealed the lesion to be compatible with a mucoepidermoid cancer (O‐l sep type, sm massive invasion, Iy2, v0, n3 (+) based on the classification of the Japanese Society of Esophageal Diseases). The diagnosis of MEC is very difficult, because this lesion grows and develops like a submucosal tumor. Considering this feature of MEC, endoscopic ultrasonography must be carried out for small submucosal tumors of the esophagus in order to detect MEC. Clarification of the endoscopic ultrasonographic characteristics of MEC is eagerly awaited.

Co-localization of nitric oxide synthase, neuropeptides and tyrosine hydroxylase in nerves supplying the human post-natal vas deferens and seminal vesicle.

To determine the distribution and patterns of co-localization of nitric oxide synthase (NOS), neuropeptides and tyrosine hydroxylase (TH) in intrinsic nerves of the human post-natal vas deferens and seminal vesicle. Double and triple immunolabelling methods were used in tissue from 10 male infants and children (age range 2 months to 3 years) obtained at post-mortem examinations carried out within 12 h of death. Most nerves supplying the muscle coat of either organ were TH-immunoreactive (-IR), most of which also contained neuropeptide Y (NPY) while a smaller proportion contained both NPY and NOS. Minor populations of the TH/NPY-IR intramuscular nerves contained calcitonin gene-related peptide (CGRP), galanin (GAL), met-enkephalin (m-ENK) or vasoactive intestinal polypeptide (VIP). Non-TH-IR intramuscular nerves were relatively infrequent and most contained NPY and either VIP or NOS. Presumptive secretomotor nerves formed subepithelial plexuses in both organs, most of which contained NPY co-localized with either VIP or NOS, with minor populations containing CGRP and/or GAL. TH- and substance P (SP) -IR nerves were not observed subepithelially. Perivascular nerve plexuses were mainly formed by TH-IR varicose nerves, most of which contained co-localized NPY and CGRP, with a smaller proportion containing NPY and NOS and minor populations containing VIP, m-ENK, SP or GAL. These results indicate that the autonomic control of the human vas deferens and seminal vesicle is provided by several immunohistochemically distinct nerve populations. Furthermore, NOS is present in a proportion of both the noradrenergic and non-noradrenergic nerves. Pharmacological studies are now required to elucidate the precise roles of nitric oxide and neuropeptides in the functional control of these organs.

Reliability of frozen section diagnosis of gallbladder tumor for detecting carcinoma and depth of its invasion.

An accurate frozen section diagnosis is important when deciding the surgical strategy against a gallbladder tumor intraoperatively. Little has been reported on the accuracy of frozen section diagnosis of the gallbladder. In a total of 86 consecutive patients with gallbladder tumor, the accuracy of the frozen section diagnosis was examined. There were 32 patients with polypoid lesions and 54 with nonpolypoid tumors. The frozen tissue diagnosis and final diagnosis were identical in 82 of the 86 cases, that is, benign in 65 and malignant in 17. The other four cases had different diagnoses, that is, conversion from benign to malignant in two and from malignant to benign in two. The overall accuracy of frozen diagnosis was 95.3% (97.0% for benign and 94.7% for malignant). In 32 polypoid lesions, the accuracy of frozen section diagnosis was 91% (93% for benign; 89% for malignant). In 54 nonpolypoid lesions, the accuracy of diagnosis was 98% (100% for benign; 93% for malignant). The diagnosis of depth of invasion was identical only in 7 (70%) of the 10 carcinoma cases examined, while it was diverse in the remaining 3, that is, conversion from adenocarcinoma invading the subserosa to that limiting to the mucosa in one, from carcinoma within the mucosa to that infiltrating the muscle coat in one, and from carcinoma affecting the muscle layer to that invading the subserosa in the other. Alterations of frozen section diagnosis about being benign or malignant and about the depth of invasion were encountered in seven patients, five of whom had a polypoid tumor. The intraoperative frozen tissue diagnosis is fairly reliable as to whether lesions are malignant or benign; however, accuracy is low in patients with polypoid lesions of the gallbladder. Also, frozen section diagnosis does not reliably measure the depth of invasion of gallbladder carcinoma.

Histopathologic study of esophageal atresia and tracheoesophageal fistula in an animal model

A histopathologic study of tracheoesophageal anomalies was conducted on an Adriamycin-treated animal model to determine how closely it resembles the human pattern. Adriamycin was administered (2 mg/kg body weight) to timed-pregnant rats on days 6 through 9 of gestation. The fetuses were recovered at term, dissected and prepared for histological studies. Dissection showed a similar range of variants of tracheoesophageal anomalies as seen in humans. Esophageal atresia with distal tracheoesophageal fistula was by far the most common type. Other varieties were seen such as esophageal atresia without a fistula, tracheal atresia and hypoplastic esophagus with atrophic mucosa, and muscle coat. Serial sectioning of the distal segment showed tracheobronchial elements extending to a variable distance from the origin of the fistula.

Peptidergic innervation of the internal anal sphincter in Hirschsprung's disease

The pathophysiology of the impaired sphincter function in Hirschsprung's disease is still unclear. The peptidergic innervation of the aganglionic large intestine is known to be disturbed. The present study analyzes the peptidergic innervation of the aganglionic internal anal sphincter (IAS) in comparison with that of the circular layer of ganglionic and aganglionic large intestine. Immunoreactivity for the following substances was analyzed: vasoactive intestinal polypeptide (VIP), substance P (SP), met-enkephalin (ENK), calcitonin gene-related peptide (CGRP), somatostatin (SOM), and neuropeptide Y (NPY). All patients were operated upon with Soave's endorectal pull-through technique and a posterior partial myectomy of the IAS. For comparison, specimens of resected IAS from adult patients operated upon for rectal cancer as well as autopsy specimens from a 2-year-old child were analyzed. Differences in the density of nerve fibers between the ganglionic and aganglionic large intestine were in accordance with previous studies. In sections of normoganglionic IAS moderately dense networks of nerve fibers immunoreactive for NPY, SOM, and VIP were observed. The occurrence of NPY and SOM was somewhat more frequent here compared to the colonic circular muscle coat, whereas the opposite was seen for VIP. In aganglionic IAS abundant nerve fibers immunoreactive for NPY, SOM, and VIP were observed. Only a few SP-, CGRP-, and ENK-immunoreactive fibers were found in normal and aganglionic IAS. It is concluded that there were moderate differences in the peptidergic innervation of the aganglionic IAS as compared to the normal ganglionic IAS and the circular muscle coat of the ganglionic and aganglionic large intestine.

Expression of HGF mRNA in human rejecting kidney as evidenced by in situ hybridization.

In situ hybridization was performed to demonstrate hepatocyte growth factor (HGF) mRNA in two patients with normal kidney and in 23 patients with allograft nephrectomy. In situ hybridization was combined with immunohistochemistry to identify HGF-producing cells. In the two patients with normal kidney, no HGF mRNA was obtainable. In 15 of the 23 allograft patients, signals of HGF mRNA were detectable. In six of these 15 patients, the signals were present mainly at the medullocortex junction, and in the other nine patients at the cortex and/or medulla. Strong and frequent signals were present in gland-like structures in 15 cases. Some scattered signals were also present in the fibrosed glomeruli in five cases, in the thickened intimas of large arteries in three cases, and in the arterial muscle coats of two cases. Combined immunohistochemistry and in situ hybridization showed that HGF mRNA-positive cells in gland-like arrangements were also positive for cytokeratin and negative for factor VIII. Cells with HGF mRNA signal and located in the arterial media were also positive for actin. These findings suggest that HGF mRNA is transcribed both in the urinary tubular epithelium and in the mesenchymal cells (fibroblasts, and smooth muscle cells in chronic vascular rejection and endothelial cells and/or mesangial cells in transplant glomerulopathy) in human rejecting kidney.

Expression of mRNA encoding decidualization-associated protein, a variant of acute-phase 2 macroglobulin, by rat uterine tissues during pregnancy and pseudopregnancy

The patterns of expression of mRNA encoding decidualization-associated protein (DAP) in the rat uterus from early, mid-, and late stages of pregnancy were examined by in situ hybridization to provide an insight into the function of DAP during pregnancy. Parallel studies were performed on rat uteri during the oestrous cycle and oil-induced deciduomata. DAP transcripts were absent in virgin uteri and during the day of implantation (day 5), low in early gestation tissues (days 8, 9) and high during midgestation (days 10-14). Expression of mRNA encoding DAP was first detected on day 8 of pregnancy in decidual cells of the lateral decidual glycogen wing areas. On day 9, mRNA encoding DAP was found in the same area as on day 8 as well as in the outer layer of cells in the antimesometrial decidua adjacent to the myometrium termed the fibrinoid capsula. On days 11 and 12, expression appeared in the decidual cells of the mesometrial decidua, and was particularly strong around the ectoplacental cone and blood vessels that were invaded by the trophoblast. By day 13 and throughout the remainder of pregnancy, expression occurred in the mesometrial decidua and metrial gland. No signal was observed in granulated metrial gland cells. mRNA encoding DAP was also found in the smooth circular muscle coat adjacent to the mesometrial decidua. A similar pattern and cellular localization of expression of mRNA encoding DAP expression was detected during the development of the deciduomata, artificially induced in the absence of a conceptus. The spatial and temporal patterns of expression correlated with a possible role for DAP in mediating fetal-maternal interactions and the establishment of the placental structure.

Ileocolic Intussusception with Trichuris Trichiura Infestation: A Case Report

Ileocolic Intussusception with <i>Trichuris Trichiura</i> Infestation: A Case Report

Developmental expression of laminin-5 and HD1 in the intestine: epithelial to mesenchymal shift for the laminin gamma-2 chain subunit deposition.

We report the expression pattern of hemidesmosome-associated proteins laminin-5, composed of alpha 3 beta 3 gamma 2 chains, and HD1 in the developing mouse and human intestine, an organ in which variations in structure and function parallel morphogenesis and differentiation. Immunocytochemistry analysis revealed the coexpression of laminin-5 and HD1 at the basal pole of differentiating epithelial cells. Distinct noticeable variations occurring in the location of laminin alpha 3 chain in development of mouse gut were stressed by the reverse transcriptase-polymerase chain reaction data. A peculiar finding was also the location of laminin gamma 2 chain in the intestinal muscle coat. The cellular origin of laminin gamma 2 chain was examined by immunocytochemistry on interspecies hybrid intestines with specific antibodies recognizing mouse antigens. Complementary and sequential production of laminin gamma 2 chain was observed, by epithelial cells as establishment of the basement membrane occurs and by mesenchymal cells in the more differentiated organ. These results support the concept of mesenchymal involvement in deposition of basement membrane molecules, a crucial process for intestinal differentiation. Taken together these data provide the first evidence for the coexpression of hemidesmosome-associated proteins in the gut, a non-stratified tissue.

'Medial defects' in the prenatal human cerebral arteries: an electron microscopic study.

Fine structural studies were performed to investigate the histogenesis of human intracranial arteries. Special attention was paid to whether "medial defects" exist in these arteries. Segments of the intracranial extracerebral arteries of normal human embryos (n=6) were examined with transmission electron microscopy. Focal defects of the medial smooth muscle cells were disclosed at every bifurcation of the developing arteries. This configuration persisted until the arteries obtained enough muscle coat. These areas, in which an absence of medial smooth muscle cells (ie, a medial defect) existed, were occupied by fibrous connective tissues of elastin and collagen. The medial defect observed at the arterial bifurcation of the embryos seems to be a development process that accompanies human ontogenesis rather than a congenital anomaly, supporting a possible pathogenesis for intracranial saccular aneurysms.

Neuro-muscular junctions of longitudinal and circular muscle fibers of the guinea-pig esophagus and their relation to myenteric plexus

The structure of the neuromuscular junctions (NMJs) and their relation to the myenteric plexus were studied by zinc iodide-osmic acid (ZIO) staining and by scanning electron microscopy in the guinea-pig esophagus. The esophageal muscle coat consisted of the inner circular and outer longitudinal striated muscle fibers. The myenteric plexus was located between the two muscle layers along its whole length and was characterized by a loose and irregular network. It was demonstrated that unmyelinated nerve fibers form NMJs with the muscle fibers of both layers. The NMJs in the longitudinal muscle can be classified as ‘plate’ type, whereas those of the circular muscle resemble the ‘grape’ type. The different NMJs in the two muscle layers probably correspond to different contractile properties. The whole-mount preparations with ZIO staining also demonstrated that some NMJs receive minute branches from the myenteric plexus. Therefore, it is likely that the myenteric plexus is involved in the control of striated muscles of the guinea-pig esophagus.

Nitric Oxide Synthase and Tyrosine Hydroxylase are Colocalized in Nerves Supplying the Postnatal Human Male Genitourinary Organs

Purpose The objective of this study was to examine the distribution of nitric oxide synthase (NOS) and the cathecholamine-synthesizing enzyme tyrosine hydroxylase (TH) in nerve fibers supplying the human neonatal male genitourinary organs. Materials and Methods An indirect double label immunofluorescence technique was employed on specimens obtained from infants and children at postmortem examination. Results Many nerve fibers immunoreactive for both NOS and TH were observed in the muscle coat of the vas deferens and the seminal vesicle, within the fibromuscular stroma of the prostate gland and at the bladder neck, and also formed perivascular plexuses in each of these organs. Double-labeled nerves occurred less frequently in the intramural ureters and superficial trigone while similar nerves in the bladder body were relatively sparse. Numerous nerves immunoreactive for NOS but not TH were observed at the base of the epithelium of each organ examined. Four types of autonomic ganglion cell were observed in nearby pelvic ganglia: those which contained NOS and TH, those which contained NOS alone, those which contained TH alone and those which contained neither NOS nor TH. Conclusion The results indicate that many of the noradrenergic nerves as well as non-noradrenergic nerves supplying the male genitourinary organs have the capacity to synthesize nitric oxide (NO) and that NO may play a significant role in the autonomic control of both the urinary and genital organs in the postnatal human male.

Applied Anatomy and Physiology of the Feline Lower Urinary Tract

Paired ureters, urinary bladder, and urethra constitute the lower urinary tract. Oblique passage of ureters through the bladder wall results in compression of the distal ureter to preclude urine reflux. Ureters are anchored by longitudinal ureteral musculature that outlines the bladder trigone and extends into dorsal submucosa of the urethra as urethral crest. The urinary bladder can be divided into apex, body, and neck. The male urethra has penile and pelvic components, the latter is divisible into preprostatic, prostatic, and postprostatic regions. The muscle coat of the bladder-urethra forms three functional entities in craniocaudal series. These are the detrusor muscle (to effect voiding), internal urethral sphincter (smooth muscle for generating tonic resistance), and external urethral sphincter (striated urethralis m. for phasic and voluntary continence). The vesical neck is a transition region. It is part of the internal urethral sphincter by virtue of its histology and innervation, but it contains detrusor fascicles that pull it open during micturition. Viscous accommodation plus sympathetic reflex inhibition of the vesical wall allows the urinary bladder to greatly expand in volume with minimal increase of intravesical pressure, within limits. At low volumes continence can be maintained by passive resistive elements of the urethral outlet. As volume increases, sympathetic reflex activity is necessary for continence. The striated external urethral sphincter is reflexly contracted to counter abrupt elevations of intravesical pressure and to maintain continence voluntarily. The pelvic plexus conveys sympathetic and parasympathetic innervation to the urinary tract. The pudendal nerve supplies the urethra and urethralis muscle. Ureters are largely independent of innervation. Internal and external urethral sphincters are activated by spinal reflexes, sympathetic and somatic reflexes, respectively. Normal micturition (sustained detrusor contraction and sphincter inhibition) is a brainstem-driven reflex, involving a spino-bulbo-spinal pathway and a pontine micturition center that switches from urine storage to micturition. All of the reflexes depend on neural activity in tension mechanoreceptors of the bladder wall and sacral afferent fibers.

A smooth muscle nodule producing 10-12 cycle/min regular contractions at the mesenteric border of the pacemaker area in the guinea-pig colon.

At the boundary between the proximal and distal divisions of the colon in the guinea-pig is a ring-like section which rhythmically contracts. HUKUHARA and his co-researchers demonstrated that antiperistaltic movements in the proximal colon start from this ring-like section, the so-called pacemaker area. Tissue specimens, 0.1-0.3 mm in width/height x 4-7 mm in length, were prepared from various parts of this area. Significantly, in the circular muscle at the mesenteric border, a nodular structure spontaneously producing 10-12 cycle/min regular mechanical contractions was found. Moreover, histological investigations after physiological recording revealed that the presence of the inner-most and/or outermost portions of the circular muscle coat was not necessary for these spontaneous activities. Champy-Maillet (ZIO) staining showed that smooth muscle cells in this spontaneously contracting nodule were heavily innervated. Transmission electron microscopy showed that the smooth muscle tissue of this particular area was characterized by scanty interstitial elements such as fibroblasts. Plasma membranes of adjacent smooth muscle cells were frequently in direct contact with each other, forming many gap junctions. Scanning electron microscopy in the specimen prepared using a NaOH-maceration method revealed fine three-dimensional relationships between nerve terminals and smooth muscle cells. The nodular structure described in this paper may provide a useful experimental model for the investigation of colonic motility and its neural control.

Neonatal intestinal perforation caused by intestinal muscularis defect associated with vascular ectasia

We describe a rare case of a viable preterm infant who developed a spontaneous localized perforation of the small bowel caused by a segmental absence of the intestinal musculature and associated with vascular ectasia. The findings may support a causal relationship between absence of the intestinal muscle coat and a vascular network disorder which may be responsible for the gastroenteric defect.

Nitrinergic nerves controlling pacemaker activities of the inner sublayer (P-layer) in the canine proximal colon circular muscles.

The inner sublayer (P-layer) of the circular muscle coat in the canine proximal colon has been known to produce spontaneous mechanical contractions associated with characteristic electrical activities called slow waves. We recorded the mechanical activities of tissue preparations from this P-layer. Normal Krebs solution (K+; 6 mM) was used as the perfusate. Elevation of extracellular K+ concentrations in the range of 12 mM and 36 mM induced intensified phasic contractions. Administration of an NO-synthase inhibitor, N omega-nitro-arginine methyl ester (L-NAME, 50 microM), enhanced both the spontaneous mechanical rhythms and high extracellular K(+)-induced contractions. Administration of the substrate for NO synthases, L-arginine (400 microM) remarkably suppressed the effects of L-NAME on the amplitude of the spontaneous rhythms and on responses to extracellular high K+. Histological structures of nerves in the P-layer were investigated by an NADPH (nicotinamide adenine dinucleotide phosphate)-diaphorase technique and by the immunohistochemistry of NO-synthases, since NO-producing (nitrinergic) nerves usually, if not always, show a histochemical NADPH-diaphorase positive reaction in formaldehyde-fixed specimens, and since features of ganglia and nerve strands in the outer subdivision of the submucosal plexus (plexus submucosus externus; or so-called Henle's plexus) together with the delicate network of nerve terminal varicosities within the P-layer were clearly visualized by this method. The topographical arrangement of nitrinergic nerves supported the view that they produce nitric oxide (NO), being one of the major chemical mediators of the neural control of the spontaneous rhythms in the P-layer.

Development of nerves containing nitric oxide synthase in the human male urogenital organs.

To determine the spatial and temporal distribution of nitric oxide synthase (NOS) in the urogenital organs of a series of human male fetuses, using an immunohistochemical technique. Thirteen pre-natal specimens ranging in gestational age from 13 to 30 weeks were acquired following abortion or miscarriage. The distribution of NOS, which catalyses the production of nitric oxide (NO), was revealed using an indirect immunolabelling technique and compared with the overall innervation of each specimen visualized using the general nerve-marker protein gene product 9.5 (PGP). At 13 weeks of gestation the majority of nerves supplying the developing prostate gland expressed NOS while similar nerves formed a very minor proportion of the total innervation to the urinary bladder and intramural ureters. With increasing gestational age, NOS-containing nerves became more numerous in the lower urinary tract, the majority occurring at the bladder neck and around the prostatic urethra. In contrast, NOS-containing nerves were not detected in the muscle coat of the vas deferens and seminal vesicle until 23 weeks of gestation and at 30 weeks still only formed a small proportion of the intramuscular nerves. From 23 weeks onwards NOS-containing nerves were present occasionally in the dense subepithelial nerve plexuses which developed in the bladder, prostate, vas deferens and seminal vesicle. Also from 23 weeks onwards, many of the epithelial cells lining the vas deferens, seminal vesicle and ejaculatory ducts showed immunoreactivity to NOS but no immunoreactivity was observed in the epithelial lining of the urinary bladder and the intramural ureters. Based on the comparative density of NOS-containing nerves and the difference in their temporal development among the various urogenital organs it is apparent that NO plays an increasingly important role in the autonomic control of the lower urinary tract during fetal development but that its involvement in the functional control of the vas deferens and seminal vesicle is relatively minor before birth.

The caecocolonic junction in humans has a sphincteric anatomy and function.

Sphincteric anatomy and function are present at the caecocolonic junction in several mammals. In humans, radiologists and endoscopists have respectively reported a circumferential contraction and a prominent ileocaecal fold at the border area between the caecum and the ascending colon. Anatomical findings on necropsy material failed to confirm its presence. Microscopic studies on surgical specimens showed the existence of muscular and innervational patterns different from those of adjacent areas. The aim of this work was to confirm the existence of a specialised fold at the caecocolonic junction in humans and to ascertain its role by carrying out a study of functional anatomy. Pancolonoscopies were performed on 100 patients and ileocaecal fold behaviour was observed before and after mechanical stimulation. Isolated ileocaecocolonic regions, surgically obtained, were filled with a fixative solution to study their macro and microscopic morphology after stimulation. Endoscopically, the ileocaecal fold was semilunar or circular in shape and spontaneous or evoked spasms occurred in 52 patients. A prominent circular fold could be seen in surgical specimens after stimulation. The entire muscle coat deeply penetrated this fold, showing the features characteristic of the ileocaecal junction. In particular, the inner portion of the circular muscle showed a peculiar arrangement and was thicker than elsewhere. These results show that in humans the caecocolonic junction is provided with a sphincter morphology and function. Little is known about its physiological relevance in ileal flow accommodation and caecal filling and emptying but it should not be underestimated with regard to some colonic motility disorders.

Laparoscopic cystomyotomy for bladder neck obstruction.

Laparoscopic cystomyotomy was used for the treatment of bladder neck obstruction in 18 male patients with a mean age of 36.4 +/- 10.4 (SD) years (range 22-43 years). Through an extraperitoneal laparoscopic approach, the bladder neck was exposed. A 1-in. linear incision was performed across the bladder neck, dividing the muscle coat but sparing the mucosa, which bulged through the gap. Patients were followed for a mean of 8.3 +/- 2.4 (SD) months (range 3-13 months). Improvement occurred in 16 patients (88.8%) and failure in 2 who had a calcified and contracted bilharzial bladder. No operative or postoperative complications were encountered. There was no retrograde ejaculation or restenosis. In conclusion, laparoscopic cystomyotomy is simple and easy with a short postsurgical recovery period.

Spatial distribution and pattern of extrinsic nerve strands in the aganglionic segment of congenital aganglionosis: Stereoscopic analysis in spotting lethal rats

The distribution and pathways of extrinsic enteric nerves in the aganglionic segment in Hirschsprung's disease have not been completely delineated. The zinc iodide-osmic acid method was used to investigate nerve fibers of the intestine in aganglionic rats. A light microscope equipped with a polarizing filter system clarified the major pathways and the fine distribution of extrinsic nerves in the aganglionic segment of a long-segment aganglionic rat model. Two sets of extrinsic nerve strands were observed in the distal aganglionic colon; one consisted of a continuous hypertrophied network located between the longitudinal and circular muscle coats, and the other involved branches that coursed along the blood vessels in the submucosal layer and that originated in the nearby mesentery. These two sets of nerve strands were connected by fine nerve fibers. Hypertrophied myenteric nerve strands were also present in normal (ganglionic) colon, fewer strands were found in the proximal aganglionic colon, and none were found in the ileum. The authors speculate that the ascending extrinsic nerve strands disappear from the ileum in cases of long-segment colonic aganglionosis, by the same mechanism that occurs in normally innervated bowel.