The supinator muscle originates from the annular ligament of the radius, and the muscle fibers and ligament take a similar winding course. Likewise, the coccygeus muscle and the sacrospinous ligament are attached together, and show a similar fiber orientation. During dissection of adult cadavers for our educational curriculum, we had the impression that these ligaments grow in combination with degeneration of parts of the muscles. In histological sections of 25 human fetuses at 10-32 weeks of gestation, we found that the proximal parts of the supinator muscle were embedded in collagenous tissue when the developing annular ligament of the radius joined the thick intermuscular connecting band extending between the extensor carpi radialis and anconeus muscles at 18-22 weeks of gestation, and the anterior parts of the coccygeus muscle were surrounded by collagenous tissue when the intramuscular tendon became the sacrospinous ligament at 28-32 weeks. Parts of these two muscles each seemed to provide a mold for the ligament, and finally became involved with it. This may be the first report to indicate that a growing ligament has potential to injure parts of the "mother muscle," and that this process may be involved in the initial development of the ligament.
Supinator muscle; Coccygeus muscle; Sacrospinous ligament; Annular ligament of the radius; Human fetus
It is still unclear whether the longitudinal anal muscles or conjoint longitudinal coats (CLCs) are attached to the vagina, although such an attachment, if present, would appear to make an important contribution to the integrated supportive system of the female pelvic floor.
Materials and Methods
Using immunohistochemistry for smooth muscle actin, we examined semiserial frontal sections of 1) eleven female late-stage fetuses at 28-37 weeks of gestation, 2) two female middle-stage fetus (2 specimens at 13 weeks), and, 3) six male fetuses at 12 and 37 weeks as a comparison of the morphology.
In late-stage female fetuses, the CLCs consistently (11/11) extended into the subcutaneous tissue along the vaginal vestibule on the anterior side of the external anal sphincter. Lateral to the CLCs, the external anal sphincter also extended anteriorly toward the vaginal side walls. The anterior part of the CLCs originated from the perimysium of the levator ani muscle without any contribution of the rectal longitudinal muscle layer. However, in 2 female middle-stage fetuses, smooth muscles along the vestibulum extended superiorly toward the levetor ani sling. In male fetuses, the CLCs were separated from another subcutaneous smooth muscle along the scrotal raphe (posterior parts of the dartos layer) by fatty tissue.
In terms of topographical anatomy, the female anterior CLCs are likely to correspond to the lateral extension of the perineal body (a bulky subcutaneous smooth muscle mass present in adult women), supporting the vaginal vestibule by transmission of force from the levator ani.
Anal canal; levator ani muscle; longitudinal anal muscle; rectum; smooth muscle; embryology
The origin of the pubovisceral muscle (PVM) from the pubic bone is known to be at elevated risk for injury during difficult vaginal births. We examined the anatomy and histology of its enthesial origin to classify its type and see if it differs from appendicular entheses.
Parasagittal sections of the pubic bone, PVM enthesis, myotendinous junction and muscle proper were harvested from five female cadavers (51 - 98 years). Histological sections were prepared with hematoxylin and eosin, Masson’s trichrome, and Verhoeff-Van Gieson stains. The type of enthesis was identified according to a published enthesial classification scheme. Quantitative imaging analysis was performed in sampling bands 2 mm apart along the enthesis to determine its cross-sectional area and composition.
The PVM enthesis can be classified as a fibrous enthesis. The PVM muscle fibers terminated in collagenous fibers that insert tangentially onto the periosteum of the pubic bone for the most part. Sharpey’s fibers were not observed. In a longitudinal cross-section, the area of the connective tissue and muscle becomes equal approximately 8 mm from the pubic bone.
The PVM originates bilaterally from the pubic bone via fibrous entheses whose collagen fibers arise tangentially from the periosteum of the pubic bone.
pubovisceral muscle; avulsion injury; enthesis; myotendinous junction; elastic fiber; levator ani; pelvic floor dysfunction
To investigate why the development of a completely circular striated sphincter is so rare, we examined histological sections of 11 female and 11 male mid-term human fetuses. In male fetuses, the striated muscle initially extended in the frontal, rather than in the horizontal plane. However, a knee-like portion was absent in the female fetal urethra because, on the inferior side of the vaginal end, a wide groove for the future vestibule opened inferiorly. Accordingly, it was difficult for the developing striated muscle to surround the groove, even though there was not a great difference in width or thickness between the female vestibule and the male urethra. The development of a completely circular striated sphincter seems to be impossible in females because of interruption of the frontal plane by the groove-like vestibule. However, we cannot rule out the possibility that before descent of the vagina, the urethral striated muscle extends posteriorly.
Urethal rhabdosphincter; Genital tract; Urogenital sinus; Colliculus; Human fetus
Trietz ligament connects the duodeno-jejunal flexure to the right crus of the diaphragm. There are various opinions regarding the existence of the smooth muscle fibers in the ligament. We want to resolve this complexity with microscopic study of this part in cadavers.
Materials and Methods:
This study done on three cadavers in the medical faculty of Isfahan University of Medical Sciences. Three samples of histological specimens were collected from the upper, the central, and the lower parts of Trietz ligament and were stained by H and E staining and Mallory's trichrome stain. Three samples were collected from the regions of exact connection of the main mesentery to the body wall, the intestine, and the region between these two connected regions, and these specimens were stained.
In the microscopic survey, no collagen bundles were observed in the collected samples of the Trietz ligament after the dense muscular tissues. In the samples which were collected to work on collagen tissues stretching from the Trietz ligament to the main mesentery of intestine, no collagen bundles were observed.
Trietz ligament is connected to the right crus of the diaphragm from the third and the fourth parts of the duodenum. Number of researchers state that there are smooth and striated muscular tissues and some others, with regard to observations of histological phases made from the samples of Trietz muscles, conclude that it can probably be noted that muscular bundles or the dense connective tissue bundles of collagen cannot be observed in the way we imagine.
Collagen; duodenum; Trietz
The paracolpium or paravaginal tissue is surrounded by the vaginal wall, the pubocervical fascia and the rectovaginal septum (Denonvilliers' fascia). To clarify the configuration of nerves and fasciae in and around the paracolpium, we examined histological sections of 10 elderly cadavers. The paracolpium contained the distal part of the pelvic autonomic nerve plexus and its branches: the cavernous nerve, the nerves to the urethra and the nerves to the internal anal sphincter (NIAS). The NIAS ran postero-inferiorly along the superior fascia of the levator ani muscle to reach the longitudinal muscle layer of the rectum. In two nulliparous and one multiparous women, the pubocervical fascia and the rectovaginal septum were distinct and connected with the superior fascia of the levator at the tendinous arch of the pelvic fasciae. In these three cadavers, the pelvic plexus and its distal branches were distributed almost evenly in the paracolpium and sandwiched by the pubocervical and Denonvilliers' fasciae. By contrast, in five multiparous women, these nerves were divided into the anterosuperior group (bladder detrusor nerves) and the postero-inferior group (NIAS, cavernous and urethral nerves) by the well-developed venous plexus in combination with the fragmented or unclear fasciae. Although the small number of specimens was a major limitation of this study, we hypothesized that, in combination with destruction of the basic fascial architecture due to vaginal delivery and aging, the pelvic plexus is likely to change from a sheet-like configuration to several bundles.
Pelvic nerve plexus; Rectovaginal septum; Denonvilliers' fascia; Internal anal sphincter; Pubocervical fascia
There is little or no information about the distribution of elastic fibers in the human fetal head. We examined this issue in 15 late-stage fetuses (crown-rump length, 220-320 mm) using aldehyde-fuchsin and elastica-Masson staining, and we used the arterial wall elastic laminae and external ear cartilages as positive staining controls. The posterior pharyngeal wall, as well as the ligaments connecting the laryngeal cartilages, contained abundant elastic fibers. In contrast with the sphenomandibular ligament and the temporomandibular joint disk, in which elastic fibers were partly present, the discomalleolar ligament and the fascial structures around the pterygoid muscles did not have any elastic fibers. In addition, the posterior marginal fascia of the prestyloid space did contain such fibers. Notably, in the middle ear, elastic fibers accumulated along the tendons of the tensor tympani and stapedius muscles and in the joint capsules of the ear ossicle articulations. Elastic fibers were not seen in any other muscle tendons or vertebral facet capsules in the head and neck. Despite being composed of smooth muscle, the orbitalis muscle did not contain any elastic fibers. The elastic fibers in the sphenomandibular ligament seemed to correspond to an intermediate step of development between Meckel's cartilage and the final ligament. Overall, there seemed to be a mini-version of elastic fiber distribution compared to that in adults and a different specific developmental pattern of connective tissues. The latter morphology might be a result of an adaptation to hypoxic conditions during development.
Elastic fibers; Sphenomandibular ligament; Ear ossicles; Head; Human fetus
The granular cell tumor is most often a benign neoplasm of uncertain origin. Four uterine granular cell tumors in control and treated female B6C3F1 mice were identified in chronic studies at the National Toxicology Program. Two tumors occurred in untreated control animals and 2 in treated animals receiving different compounds. Tissue sections were evaluated histologically and stained with hematoxylin and eosin, periodic acid–Schiff with diastase resistance, Masson’s trichrome, toluidine blue, phosphotungstic acid–hematoxylin, and stained immunohistochemically with a panel of antibodies to muscle (desmin, alpha smooth muscle actin), neural (S-100, neuron specific enolase), epithelial (wide-spectrum cytokeratin), and macrophage (F4/80) markers. The main histomorphologic feature of tumor cells was the presence of abundant cytoplasmic eosinophilic granules that stained positive for periodic acid–Schiff with diastase resistance. Tumors varied in appearance and were comprised of sheets and nests of round to polygonal cells with distinct borders. Nuclei were hyperchromatic, pleomorphic, and centrally to eccentrically located and often contained single nucleoli. Occasional multinucleated giant cells were observed. Tumors were pale pink and homogeneous with trichrome stain and negative with toluidine blue. Three tumors had positive to weakly positive immunoreactivity for desmin, and 1 was positive for alpha smooth muscle actin. Expression of S-100, wide-spectrum cytokeratin, and neuron-specific enolase was negative for all tumors. Ultrastructurally, prominent electron-dense cytoplasmic granules were abundant and contained secondary lysosomes with heterogeneous lysosomal contents. The characteristics of these uterine granular cell tumors were suggestive of a myogenic origin.
B6C3F1 mouse; cytoplasmic granules; granular cell tumor; immunohistochemistry; secondary lysosomes; ultrastructure; uterus
Aim of work:
To demonstrate the bleomycin induced histological changes in the lung and the possible protective and/or therapeutic effect of stem cell therapy.
Materials and methods:
Study was carried out on 36 adult male albino rats, classified into 4 groups: group I (control), group II (bleomycin treated group), group III (early stem cell treated group: immediately after bleomycin), group IV (late stem cell treated group: 7 days after bleomycin). Sections were taken at the 14th day of experiment. stained with Hematoxylin and Eosin, Masson’s trichrome, immunohistochemichal stains for α-SMA & PCNA. Sections were examined by light & immunofluroscent microscopy. Area percent of collagen fibers, area percent & optical density of α-SMA immunopositive cells were measured as well as the number of H&E and PCNA stained pneumocytes type II was counted.
Group II showed, thickening of septa, extravasation of blood, dividing pneumocytes type II cells with acinar formation, cellular infiltration, fibroblast cells, almost complete loss of normal lung architecture in certain fields, consolidation and replacement of the lung tissue with fibrous tissue in other fields. Restoring of lung tissue with significant decrease in mean area % of collagen fibers, α-SMA immunopositive cells were detected in group III.
Early treatment with bone marrow derived mesenchymal stem cells (BMSCs) immediately after bleomycin administration showed a significant reduction in fibrotic changes, however the late treatment with BMSCs (7 days) after bleomycin administration showed non significant results.
Bleomycin; BMSCs; α-SMA; PCNA; Lung fibrosis; PKH26
The nasopalatine region is composed of structures such as the vomeronasal organ and
nasopalatine duct. The nasopalatine duct may provide the communication of the mouth
to the nasal cavity in human fetuses and can be obliterated in an adult human.
Knowledge on the development of the nasopalatine region and nasopalatine duct in
humans is necessary for understanding the morphology and etiopathogenesis of lesions
that occur in this region.
The aim of the present study was to describe the morphological aspects of the
nasopalatine region in human fetuses and correlate these aspects with the
development of pathologies in this region.
Material and Methods:
Five human fetuses with no facial or palatine abnormalities were used for the
acquisition of specimens from the nasopalatine region. After demineralization, the
specimens were histologically processed. Histological cuts were stained with
methylene blue to orient the cutting plane and hematoxylin-eosin for the
descriptive histological analysis.
The age of the fetuses was 8.00, 8.25, 9.00 and 9.25 weeks, and it was not
possible to determine the age in the last one. The incisive canal was observed in
all specimens as an opening delimited laterally by the periosteum and connecting
oral and nasal cavity. The nasopalatine duct is an epithelial structure with the
greatest morphological variation, with either unilateral or bilateral occurrence
and total patent, partial patent and islet forms. The vomeronasal organ is a
bilateral epithelized structure located alongside the nasal septum above the
incisive canal in all the fetuses.
The incisive canal, nasopalatine duct and vomeronasal organ are distinct anatomic
structures. The development of nasopalatine duct cysts may occur in all forms of
the nasopalatine duct.
Morphogenesis; Maxilla; Vomeronasal organ; Palate; Incisive papilla
To investigate the distribution and activity of phosphodiesterase 5 (PDE5) in the urethra.
Materials and Methods
Rat tissues were examined for expression of PDE5 and alpha-smooth muscle actin (SMA). Urethral PDE5 activity was examined by tissue bath in the presence of sildenafil.
Anti-SMA antibody stained all known smooth muscles in all tested tissues. It also revealed the presence of a small amount of smooth muscle fibers in the levator ani muscle. Anti-PDE5 antibody stained the smooth muscles in the penis and bladder but not the striated leg muscle. However, it stained predominantly the striated muscle in the urethra and levator ani muscle. In the urethra, the amount of PDE5 in the striated muscle was 6 times as high as in the smooth muscle. Within the urethral striated muscle, PDE5 expression was localized to the Z-band striations. Intermingling of the smooth and striated muscles were clearly visible on both the inner and outer rims of the circularly arranged striated muscle layer. Relaxation of pre-contracted urethral tissues by sodium nitroprusside (SNP) was enhanced by sildenafil, indicating the presence of PDE5 activity, which was primarily located in the striated muscle as judged by PDE5 staining.
PDE5, despite its presumed smooth muscle specificity, was predominantly expressed in the striated muscle of the urethra and the levator ani muscle. These results are consistent with earlier studies in which these striated muscles were found to be developmentally related to smooth muscle. They also suggest that these striated muscles are possibly regulated by PDE5.
Fetal development of the cartilage of the pharyngotympanic tube (PTT) is characterized by its late start. We examined semiserial histological sections of 20 human fetuses at 14-18 weeks of gestation. As controls, we also observed sections of 5 large fetuses at around 30 weeks. At and around 14 weeks, the tubal cartilage first appeared in the posterior side of the pharyngeal opening of the PTT. The levator veli palatini muscle used a mucosal fold containing the initial cartilage for its downward path to the palate. Moreover, the cartilage is a limited hard attachment for the muscle. Therefore, the PTT and its cartilage seemed to play a critical role in early development of levator veli muscle. In contrast, the cartilage developed so that it extended laterally, along a fascia-like structure that connected with the tensor tympani muscle. This muscle appeared to exert mechanical stress on the initial cartilage. The internal carotid artery was exposed to a loose tissue facing the tubal cartilage. In large fetuses, this loose tissue was occupied by an inferior extension of the temporal bone to cover the artery. This later-developing anterior wall of the carotid canal provided the final bony origin of the levator veli palatini muscle. The tubal cartilage seemed to determine the anterior and inferior margins of the canal. Consequently, the tubal cartilage development seemed to be accelerated by a surrounding muscle, and conversely, the cartilage was likely to determine the other muscular and bony structures.
Pharyngotympanic tube cartilage; Levator veli palatini muscle; Internal carotid artery; Tensor tympani muscle; Human fetuses
To analyze the quantity and distribution of intramuscular nerves within the striated urogenital sphincter and test the hypothesis that decreased nerve density is associated with decreased striated sphincter muscle and cadaver age.
Thirteen cadaveric urethras (mean age 47 years, range 15–78 years) were selected for study. A sagittal histologic section was stained with S100 stain to identify intramuscular nerves. The number of times that a nerve was seen within the striated urogenital sphincter (nerve number) was counted. The number of axons within each nerve fascicle was also counted. Regression analysis of nerve density against muscle cell number and age was performed.
Remarkable variation was found in the quantity of intramuscular nerves in the striated urogenital sphincter of the 13 urethras studied. The number of nerves ranged from 72 to 543, a sevenfold variation (mean 247.1 ± standard deviation 123.2), and the range of number of axons was 431 to 3523 (2201 ± 1152.6). The larger nerve fascicles were seen predominantly in the distal (13.1 ± 5.7 axons per nerve) compared with the proximal part of the striated urogenital sphincter (1.2 ± 2). Reduced nerve density throughout the striated urogenital sphincter correlated with fewer muscle cells (P = .02). Nerve density also decreased with advancing age (P = .004).
Remarkable variation in the quantity of intramuscular nerves was found. Women with sparse intramuscular nerves had fewer striated muscle cells. Intramuscular nerve density declined with age.
A new surgical procedure, the proximal levator technique, achieves recession of the retracted upper eyelid in Graves' ophthalmopathy by sectioning the levator muscle proximal to Whitnall's ligament and fixing eyelid position with sutures that permit postoperative adjustment. This technique deserves further study. Enlargement of the proximal levator muscle in Graves' eye disease is shown on orbital CT scans and is found at surgery when the proximal levator technique is employed. Histologic and morphometric studies demonstrate increased levator muscle fiber size as well as increased extracellular volume. These findings suggest that levator muscle hypertrophy is important in the pathogenesis of upper eyelid retraction in Graves' ophthalmopathy.
The function of the anal sphincters has been studied by obtaining continuous recordings of the pressure in the anal canal and the electromyographic activity in the striated sphincter muscles during expansion of the ampulla recti by means of an air balloon. Ten healthy subjects were examined before and after the striated muscles had been entirely paralysed by bilateral pudendal block, making it possible to record the activity from the internal sphincter alone. The results show that the internal sphincter contributes about 85% of the pressure in the anal canal at rest but only about 40% after a sudden substantial distension of the rectum. During constant substantial rectal distension, the internal sphincter accounts for about 65% of the anal pressure. It is concluded that the internal sphincter in the adult is chiefly responsible for anal continence at rest. In the event of sudden substantial distension of the rectum, continence is maintained by the striated sphincter muscles, whereas both sphincter systems probably have an important function during constant distension of the rectum.
To re-examine the anatomy of the perineal membrane and its anatomical relationships in whole-pelvis and histological serial section as well as gross anatomical dissection.
Serial trichrome-stained histologic sections of 5 female pelvic specimens (0 to 37 years old) were examined. Specimens included the urethra, perineal membrane, vagina and surrounding structures. Macroscopic whole pelvis sections of 3 adults 28 to 56 years in axial, sagittal and coronal sections were also studied. Dissections of 6 female cadavers 48 to 90 years were also performed.
The perineal membrane is composed of 2 regions, one dorsal and one ventral. The dorsal portion consists of bilateral transverse fibrous sheets that attach the lateral wall of the vagina and perineal body to the ischiopubic ramus. This portion is devoid of striated muscle. The ventral portion is part of a solid 3-dimensional tissue mass in which several structures are embedded. It is intimately associated with the compressor urethrae and the urethrovaginal sphincter muscle of the distal urethra with the urethra and its surrounding connective. In this region the perineal membrane is continuous with the insertion of the arcus tendineus fascia pelvis. The levator ani muscles are connected with the cranial surface of the perineal membrane. The vestibular bulb and clitoral crus are fused with the membrane's caudal surface.
The structure of the perineal membrane is a complex 3-dimensional structure with two distinctly different dorsal and ventral regions; not a simple trilaminar sheet with perforating viscera.
perineal membrane; urogenital diaphragm; pelvic floor dysfunction; pelvic organ prolapse; anatomy; female
Background: We previously reported that the supratarsal Mueller's muscle is innervated by both sympathetic efferent fibers and trigeminal proprioceptive afferent fibers, which function as mechanoreceptors-inducing reflexive contractions of both the levator and frontalis muscles. Controversy still persists regarding the role of the mechanoreceptors in Mueller's muscle; therefore, we clinically and histologically investigated Mueller's muscle. Methods: We evaluated the role of phenylephrine administration into the upper fornix in contraction of Mueller's smooth muscle fibers and how intraoperative stretching of Mueller's muscle alters the degree of eyelid retraction in 20 patients with aponeurotic blepharoptosis. In addition, we stained Mueller's muscle in 7 cadavers with antibodies against α-smooth muscle actin, S100, tyrosine hydroxylase, c-kit, and connexin 43. Results: Maximal eyelid retraction occurred approximately 3.8 minutes after administration of phenylephrine and prolonged eyelid retraction for at least 20 minutes after administration. Intraoperative stretching of Mueller's muscle increased eyelid retraction due to its reflexive contraction. The tyrosine hydroxylase antibody sparsely stained postganglionic sympathetic nerve fibers, whereas the S100 and c-kit antibodies densely stained the interstitial cells of Cajal (ICCs) among Mueller's smooth muscle fibers. A connexin 43 antibody failed to stain Mueller's muscle. Conclusions: A contractile network of ICCs may mediate neurotransmission within Mueller's multiunit smooth muscle fibers that are sparsely innervated by postganglionic sympathetic fibers. Interstitial cells of Cajal may also serve as mechanoreceptors that reflexively contract Mueller's smooth muscle fibers, forming intimate associations with intramuscular trigeminal proprioceptive fibers to induce reflexive contraction of the levator and frontalis muscles.
The molecular characterization of muscular dystrophies and myopathies in humans has revealed the complexity of muscle disease and genetic analysis of muscle specification, formation and function in model systems has provided valuable insight into muscle physiology. Therefore, identifying and characterizing molecular mechanisms that underlie muscle damage is critical. The structure of adult Drosophila multi-fiber muscles resemble vertebrate striated muscles 1 and the genetic tractability of Drosophila has made it a great system to analyze dystrophic muscle morphology and characterize the processes affecting muscular function in ageing adult flies 2. Here we present the histological technique for preparing paraffin-embedded and frozen sections of Drosophila thoracic muscles. These preparations allow for the tissue to be stained with classical histological stains and labeled with protein detecting dyes, and specifically cryosections are ideal for immunohistochemical detection of proteins in intact muscles. This allows for analysis of muscle tissue structure, identification of morphological defects, and detection of the expression pattern for muscle/neuron-specific proteins in Drosophila adult muscles. These techniques can also be slightly modified for sectioning of other body parts.
The aim of this study was to explore whether alendronate sodium regulates tissue remodeling by controlling the transforming growth factor (TGF)-β1-induced epithelial-mesenchymal transition (EMT) and bone morphogenetic protein (BMP)-7-induced mesenchymal-epithelial transition (MET) in CCl4-induced hepatic fibrosis in mice. A mouse model of CCl4-induced hepatic fibrosis was evaluated using the hematoxylin and eosin (HE) and Masson’s trichrome staining histological methods. The activities of serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were measured using an automated biochemical analyzer. The expression of TGF-β1, α-smooth muscle actin (α-SMA), BMP-7 and E-cadherin in the hepatic tissue was detected using immunohistochemistry. The mRNA and protein levels of TGF-β1, α-SMA, BMP-7, fibroblast-specific protein 1 (FSP1), E-cadherin and N-cadherin were detected using RT-PCR and western blot analysis. Immunohistochemical and molecular biochemical examination revealed that alendronate sodium significantly arrested the progression of hepatic fibrosis. Alendronate sodium caused significant amelioration of liver injury and reduced the activities of serum ALT and AST (P<0.001). Furthermore, alendronate sodium markedly reduced TGF-β1 and α-SMA mRNA expression and increased BMP-7 and E-cadherin in the mouse liver tissue (P<0.001). Alendronate sodium significantly arrested the progression of hepatic fibrosis. The underlying mechanism was associated with changes in the redox state, which remains variable in liver fibrosis, and depends on the balance between TGF-β/smad- and BMP-7-modulated mechanisms which regulate EMT and MET in multifunctional progenitors.
alendronate sodium; transforming growth factor-β1; bone morphogenetic protein-7; epithelial mesenchymal transition; liver fibrosis
Hassall's corpuscles (HC) are commonly used as diagnostic features for identifying human thymus and are still present in thymuses undergoing fatty degeneration in young adults. However, few studies have been performed on human fetuses.
A cross-sectional study was done, to study the morphology of HC in human fetuses.
Materials and Methods:
Twenty-eight thymuses were collected from fetuses of gestational age ranging from 11 to 40 weeks. Thymuses were processed by paraffin embedding methods and hematoxylin and eosin staining.
The size of HC varied from very small (100 microns) to very large corpuscles (> 900 microns). A high level of polymorphism was also observed, from round to unusual or odd shapes corpuscles. The degenerated reticulo-epithelial cells represented the starting point in HC formation. The growth of HC was rapid, especially near 28 weeks, and the level of HC polymorphism was significantly greater after 28 weeks of gestation. In advanced stages of gestation, the increase in size of some corpuscles reduced the spaces between them, and some patterns strongly supported the hypothesis that some HC had fused in a single and larger corpuscle.
The rapid rise in number and size of HC around 28 weeks of gestation would fit with their role in the negative selection process of thymocytes.
Fetuses; gestation; Hassall's corpuscles; polymorphism; reticulo-epithelial cells
Angioleiomyoma is a benign soft-tissue tumor originating from vascular smooth muscle, and is rare in the head and neck. The present study retrospectively examined a cohort of patients with head and neck angioleiomyoma treated at the West China Hospital of Stomatology, and also subjected archived tissues to modern immunohistochemical analysis. In total, 21 patients were treated for angioleiomyoma between 1978 and 2012 at the West China Hospital of Stomatology, Sichuan University (Chengdu, Sichuan, China). Medical records were examined and paraffin block sections were cut and stained with hematoxylin and eosin, Masson’s trichrome stain and Van Gieson stain, prior to being subjected to immunohistochemical analysis to re-evaluate and confirm the diagnoses. Angioleiomyomas were found to account for only 0.18% of the benign head and neck tumors in the patients presenting to the hospital over the past 34 years. The diagnosis was more common in males (male:female ratio, 1.625:1) and the mean age at diagnosis was 42.5 years. The most common sites were the buccal mucosa, parotid gland and palate. More than half of the tumors (61.9%) were >2 cm in diameter. Five tumors presented with pain and/or tenderness. The histological subtype was reported as solid in five cases, venous in six, cavernous in nine and venous-cavernous in one. Three tumors exhibited nerve neurofibrils. All tumors were excised with no subsequent recurrence. Cytological and imaging examinations were not useful for pre-operative diagnosis. Angioleiomyoma is a benign tumor that causes limited morbidity. Surgical excision is the only effective treatment and recurrence is rare. The present study revealed that nerves were present in a small proportion (14.3%) of tumors. It was hypothesized that the compression of nerves accompanying numerous blood vessels in the tumor may cause pain, particularly in venous- and cavernous-type angioleiomyomas.
angioleiomyomas; head and neck region; retrospective study; nerve; immunohistochemical analysis
Intranodal palisaded myofibroblastoma (IPM) is a benign mesenchymal neoplasm originating from smooth muscle cells and myofibroblasts. It is characterized by spindle cells, amianthoid fibers, and by the proliferation of hemosiderin-containing histiocytes in the lymph node. A nodular lesion was excised from the inguinal region of an 80-year-old male patient. Macroscopic examination of a section of the lesion demonstrated a solid appearance with hemorrhagic areas. Microscopic examination revealed spindle cell proliferation, amianthoid fibers, hemosiderin pigment, and extravasated erythrocytes. Nuclei of the spindle cells displayed a palisaded appearance. Compressed lymphoid tissue was observed around the lesion. With Masson's trichrome, spindle cells stained as smooth muscle, whereas collagen staining was observed in homogeneous eosinophilic accumulations. Neoplastic cells were identified by the presence of vimentin and SMA. The Ki67 index was less than 1%. In light of these results, the case was diagnosed as "intranodal palisaded myofibroblastoma." IPM is an uncommon neoplasm originating from the stromal component of the lymph node. Although IPM is benign, it is frequently confused with metastatic lesions.
To examine histological aspects of the ligaments between the middle ear and temporomandibular joint and suppose a theoretical role of their structural characteristics on mobility of mallear ossicle.
The ligaments were obtained by microdissection of middle cranial fossa on both sites of 15 cadavers fixed in formalin solution and were sectioned longitudinally (7–10 μm thickness). The sections were stained with Verhoff’s Van Gieson’s stain (VVG) for demonstration of elastic fibers and visualized at X2.5 and X10 magnifications under light microscopy.
Anterior mallear ligament (AML) and sphenomandibular ligaments (SML) were consisted of collagen fibres in analyzed specimens. The discomallear ligament (DML) was constituted of rich collagenous fibres. One specimen of DML harvested between petrotympanic fissure and retrodiscal-capsular intersection site contained elastic fibers dispersed in cotton-bowl appearance between collagen fibers. In the light of functional tests performed in previous studies, it could be extrapolated that presence of elastic fibers in the DML may prevent excessive forces conducted to mallear head by elongation of elastic fibers.
Collagenous fibres have no ability to stretch along their axis which may lack compensatory mechanism to prevent mallear head mobility.
Anterior mallear ligament; Discomallear ligament; Sphenomandibular ligament; Collagen fibres; Elastic fibres; Malleus
Detailed knowledge of the anatomy of the rhabdosphincter and adjacent tissues is mandatory during urologic surgery to ensure reliable oncologic and functional outcomes. To characterize the levator ani (LA) function for the urethral sphincter, we described connective tissue morphology between the LA and urethral rhabdosphincter. The interface tissue between the LA and rhabdosphincter area in males contained abundant irregularly arrayed elastic fibers and smooth muscles. The male rhabdosphincter was positioned alongside the LA to divide the elevation force and not in-series along the axis of LA contraction. The male perineal membrane was thin but solid and extends along the inferior margin or bottom of the rhabdosphincter area. In contrast, the female rhabdosphincter, including the compressor urethrae and urethrovaginal sphincter muscles, was embedded in the elastic fiber mesh that is continuous with the thick, multilaminar perineal membrane. The inferomedial edge of the female LA was attached to the upper surface of the perineal membrane and not directly attached to the rhabdosphincter. We presented new diagrams showing the gender differences in topographical anatomy of the LA and rhabdosphincter.
By sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunodiffusion, we identified paramyosin in two smooth invertebrate "catch" muscles (Mytilus anterior byssus retractor and Mercenaria opaque adductor) and five invertebrate striated muscles (Limulus telson levator, Homarus claw muscle, Balanus scutal depressor, Lethocerus air tube retractor, and Aequipecten striated adductor). We show that (a) the paramyosins in all of these muscles have the same chain weights and (b) they are immunologically similar. We stained all of these muscles with specific antibody to Limulus paramyosin using the indirect fluorescent antibody technique. Paramyosin was localized to the A bands of the glycerinated striated muscles, and diffus fluorescence was seen throughout the glycerinated fibers of the smooth catch muscles. The presence of paramyosin in Homarus claw muscle, Balanus scutal depressor, and Lethocerus air tube retractor is shown here for the first time. Of the muscles in this study, Limulus telson levator is the only one for which the antiparamyosin staining pattern has been previously reported.