Morphofunctional organization of the male reproductive system of the catfish Iheringichthys labrosus (Lütken, 1874) (Siluriformes:Pimelodidae)

An anatomical, histological and ultrastructural study was made of the reproductive system and spermatogenesis of Iheringichthys labrosus. The testis are digitiform and consist of a sperm atogenic cranial region, a spermatogenic/secretory medial (transition) region, and a strictly secretory caudal region. The cranial region represents 66% of the total length of the maturing testis and its fringes or lobes have a length of 5.59 + 0.73 mm. The medial and caudal regions represent each 17% of the testicular length and their fringes have a length of 5.37 +/- 0.69 mm and 3.12 +/- 0.38 mm, respectively. Histologically, the cranial region of the testis is made up of seminiferous tubules with spermatogenic cells contained in cysts. These cells undergo synchronous development, inside the cysts where spermatogenesis is completed. The secretory caudal region does not constitute an individualized gland. Ultrastructurally, its secretory cells have a vesiculous nucleus and a cytoplasm with abundant dilated cisternae of rough endoplasmic reticulum. The caudal region produces a glycoproteic secretion and exhibits variable electron density during maturation. During the resting period, these cells are poor in synthesis organelles. The spermatozoa are of the primitive type, with a round head (1.56 +/- 0.11 microm), a rudimentary middle piece, and a long flagellum with a 9 + 2 axonemal arrangement.     

Surface changes during development and involution of the cement gland of Xenopus laevis

Summary The cement gland was studied from stage 17, when the anlage is established, to stage 49, shortly before its disappearance. At early stages, the apical membrane is covered by small microvilli that are more abundant than in the surrounding epiblast cells. Vesicular protrusions along the cell boundaries are also more numerous in the gland cells.When the gland reaches maturity, the apical membranes of gland cells differentiate into two regions. In the cranial, kidney-shaped region, the membranes are very narrow and protrude above the level of cell boundaries. Long and slender villi raise from the surface adjacent to cell boundaries. Apical surfaces in the caudal portion are larger and flattened. Cell boundaries are lined with shorter and thicker surface projections. At these stages, the bordering cells are covered with secretion vesicles.During involution the number of cells is progressively reduced. The area of the caudal portion increases relative to the area of the cranial portion. Apical surfaces become more flattened. Surface projections become much shorter and invade the whole of the apical surface. Bordering cells lose their secretion vesicles and their apical surface becomes ruffled with numerous short wrinkles. The significance of the apical structures and their evolution is discussed.     

Pulmonary immunoreactive calcitonin in the African green monkey (Cercopithecus aethiops): Anatomic distribution

The hormone calcitonin, which occurs predominantly within the C cells of the mammalian thyroid gland, is also found within the pulmonary endocrine cells of the epithelium of the tracheobronchial tree. A study was made of the distribution of immunoreactive calcitonin (iCT) in the African green monkey. Using two different region-specific antisera, the total respiratory iCT comprised 2.5% and 5.8% of the total thyroid iCT. The mean concentration of iCT in the right lung exceeded that in the left, and the mean concentration of the right middle or right upper lobe exceeded that of all other lobes. Embryologically, the ultimobranchial bodies contribute their iCT-producing C cell primordia to the thyroid gland near the level of the primitive laryngotracheal cleft and shortly after the early arborization of the bronchial tree. In monkeys and most other mammals, the right main stem bronchus is larger and develops earlier than the left. The data suggest an early migration of cells from the ultimobranchial bodies to the bronchi, eventually giving rise to the iCT-containing pulmonary endocrine cells.     

A histochemical study of aldehyde fuchsin-positive material and "high-esterase cells" in the pineal gland of the Mongolian gerbil.

The pineal gland of the Mongolian gerbil consists of a superficial gland, stalk and deep pineal. The deep pineal differentiates postnatally. Histochemical studies of the superficial pineal gland indicate that it may be involved in the secretion of protein. Presumptive secretory material visualized by aldehyde fuchsin (AF) and chrome hematoxylin was observed along the course of blood vessels and among the pinealocytes. The distribution and texture of the AF-positive material was distinctive. It did not correspond to the pattern and texture of material stained with PAS, Sudan Black or acid orcein. Staining with AF was markedly reduced after incubation with trypsin, indicating that the AF-positive material is at least partially protein. The amount of stainable material increased with age. The AF-positive material was observed in what appeared to be interstitial or glial cells and processes, and in the processes of perivascular cells. Cells and fibrous processes with high non-specific esterase activity ("high-esterase cells") were observed among the pinealocytes and along the course of blood vessels. The distribution of the "high-esterase cells" and the morphology and texture of their esterase-containing processes were remarkably similar to the morphology and distribution of the material that stained with AF. It may be that the "high-esterase cells" contain AF-positive material. The "high-esterase cells" hydrolyzed both alpha-naphthyl acetate and alpha-naphthyl butyrate. The pinealocytes hydrolyzed only alpha-naphthyl acetate. The "high-esterase cells" appear to form a distinct class of cells within the superficial pineal gland. They are tentatively identified as a type of glial cell.     

Cervical changes in estrogen receptor alpha,oxytocin receptor,LH receptor,and cyclooxygenase-2 depending on the histologic compartment,longitudinal axis,and day of the ovine estrous cycle

The aim was to investigate the histologic distribution of estrogen receptor α (ERα), oxytocin receptor (OxR), LH receptor (LHR), and cyclooxygenase-2 (COX-2) in the cervix of the ewe during the estrous cycle. Immunohistochemistry was performed in the cranial and caudal cervix of Corriedale ewes on Day 1 (n = 6), 6 (n = 5), or 13 (n = 6) after estrous detection (Day 0). The ERα proportional score (%ERα nuclei) was lower in the cranial cervix than in the caudal cervix, whereas the OxR and COX-2 immunostaining areas (%areas) were greater in the cranial cervix than in the caudal cervix (P < 0.04). The %ERα nuclei decreased from Days 1 to 13 in luminal epithelia, but increased from Days 1 to 6 or remained unchanged in stromata (P < 0.003). The %OxR area was higher on Day 6 than on Days 1 and 13 in the superficial glandular epithelium, and increased from Days 1 to 13 in the deep glandular epithelium (P < 0.04). The %LHR area increased during the estrous cycle in luminal epithelia and fold stroma (P < 0.004). The %COX-2 area was restricted to epithelia, and it was lower on Day 1 than on Days 6 and 13 in luminal epithelia (P < 0.05). Differences in ERα, OxR, LHR, and COX-2 between cranial and caudal cervical zones indicate different physiological functions, and their cyclic variations in the cervical epithelia, in contrast to little or no variations in the stroma, suggest a hormone-responsive driving role of epithelia in cervical function.     

Comparative anatomical studies of thyroid and thymic arteries: I. Rat (Rattus norvegicus albinus)

The thyroid and thymic arteries were investigated in 50 male and 50 female rats. In more than 70% of the animals, on both sides the cranial thyroid artery forms a common trunk with the ascending pharyngeal artery. The caudal thyroid artery arises not from the deep cervical but from the pericardiacophrenic artery. It may be replaced, however, by a branch of some other artery, such as the brachiocephalic, subclavian, vertebral, or ascending cervical, suggesting a shift of its origin from the internal thoracic artery to the thyrocervical trunk as in man. All the thoracic lobes of the thymus are supplied directly by a thymic branch of the internal thoracic artery or indirectly by a branch of the pericardiacophrenic artery. More than half of the specimens have a cervical thymic lobe of variable size, which is supplied by a branch of the cranial thyroid, external carotid, and/or occipital arteries. Some of these thymic arteries, except those from the external carotid and occipital arteries, reach the thoracic lobe. The thoracic lobes lacking a cervical lobe may be supplied by the thymic branch arising only from the cranial thyroid artery. Other anomalous arteries supplying the thoracic lobe are derived from the superficial cervical and/or the right common carotid arteries. These results show that the thymic arteries of rats are basically similar to those of man, although they display a clear difference in their frequency and origin.     

Structure of the female gonoduct of the viviparous teleost Poecilia reticulata (Poeciliidae) during nongestation and gestation stages

Female teleosts do not have oviducts because Müllerian ducts do not develop. Instead, the caudal region of the ovary, the gonoduct, connects to the exterior. Because of the lack of oviducts in viviparous teleosts, the embryos develop in the ovary, as an intraovarian gestation, unique in vertebrates. This is the first study to address the histology of the gonoduct in a viviparous teleost. The gonoduct of Poecilia reticulata was analyzed during previtellogenesis, vitellogenesis, and gestation. The gonoduct lacks germinal cells. From deep to superficial, the wall has simple cuboidal or columnar epithelium, loose connective tissue, longitudinal layer of smooth muscle, and visceral peritoneum. Cells of the immune system occur in the lumen and in the mucosa. The gonoduct was divided in three regions: 1) cephalic, 2) middle, and 3) caudal. At the initial part of each region, thin mucosal folds extend into the lumen. The cephalic region forms a tubular structure with light and irregular folds. The middle region has a wider lumen and is more irregular due to ventral invaginations and irregular and short mucosal folds; beneath the epithelium there are melano‐macrophage centers. The caudal region is delimited from the middle region by folds; however, they are thinner than these of the other regions. Ventral invaginations form exocrine glands, and the smooth muscle is thicker than in the other regions. During gestation, cells of the immune system are abundant; melano‐macrophage centers become larger and the glands exhibit desquamated cells. These observations suggest roles of the gonoduct in reducing the diameter of the lumen; receiving sperm during vitellogenesis; producing secretions, more abundant during vitellogenesis; and in immunological activity throughout the reproductive cycle. The ciliated epithelium and the thick muscle of the caudal region may be involved during birth. J. Morphol. 275:247–257, 2014. © 2013 Wiley Periodicals, Inc.     

Helodermin-like peptides in noradrenaline cells of adrenal medulla

Helodermin, a VIP/secretin-like peptide, was first isolated from the venom of the lizard Gila monster. Small amounts of helodermin-like peptides have since been detected in many mammalian tissues. Notably high concentrations were demonstrated in the thyroid gland, and immunocytochemical studies revealed intense helodermin-like immunostaining in thyroid C cells and medullary thyroid carcinoma cells. In the present study, we examined the adrenal gland of mouse, rat and pig for the presence of helodermin-like peptides. Using an antiserum raised against lizard helodermin immunostaining was observed in the noradrenaline-producing cells of the adrenal medulla in all 3 species. Radioimmunoassay revealed high concentrations of helodermin-like peptides in the mouse and rat adrenal. The concentrations in the pig adrenal could not be determined because of a non-parallel dilution curve. Upon high-performance liquid chromatography, the immunoreactive material in extracts of mouse and rat adrenals eluted in one major peak, close to the elution position of lizard helodermin.     

Lateral line morphology and cranial osteology of the Rubynose Brotula,Cataetyx rubrirostris

Cranial osteology, canal neuromast distribution, superficial neuromast distribution and innervation, and cephalic pore structure were studied in cleared and stained specimens of the deep sea brotulid Cataetyx rubrirostris. The cranial bone structure of C. rubrirostris is similar to other brotulids (Dicrolene sp.) and zoarcids (Zoarces sp.), except for an unusual amount of overlapping of the bones surrounding the cranial vault. The superficial neuromasts are innervated by the anterodorsal, anteroventral, middle and posterior lateral line nerves and are organized similarly to those of the blind ophidioid cave fish Typhliasina pearsei. The cephalic pores open into a widened lateral line canal system. The canal is compartmentalized into a series of neuromast‐containing chambers that probably amplify signals received by the system. J. Morphol. 241:265–274, 1999. © 1999 Wiley‐Liss, Inc.     

Regional load bearing of the canine acetabulum

OBJECTIVE: To determine the load bearing areas of the canine acetabulum. MATERIALS AND METHODS: A kinematic study of four healthy dogs was used to determine the orientation of the femur to the pelvis at mid-stance. Femora and pelves from 10 canine cadavers were loaded with the physiological canine hip reaction force and angle being replicated. Impression material placed within the acetabulum was extruded from areas of load bearing. Digital images before and after loading were used to assess if six different regions of the acetabulum were fully, partially or non-load bearing. RESULTS: All areas of the acetabulum were partially or fully load bearing. The cranial and caudal thirds of the acetabulum were 7.9 and 13.1 times more likely to be fully load bearing than the central third, respectively. There was a significant difference in load bearing between the axial, middle and abaxial thirds of the acetabulum in all tests, with the middle and abaxial thirds 72.4 and 351 times more likely to be fully load bearing than the axial third, respectively. CONCLUSION: The cranial and caudal thirds and the middle and abaxial thirds of the canine acetabulum are fully load bearing. CLINICAL RELEVANCE: The caudal third of the canine acetabulum is loaded and therefore recommendations that fractures in this area be managed conservatively need to be reconsidered.     

C cells in normal thyroid aspirates.

OBJECTIVE: To quantify C cells in normal thyroid aspirates. STUDY DESIGN: Smears of 18 glands from patients with no thyroid disease, 8 women and 10 men aged on average 52.8 years, were analyzed. Five samples were aspirated from the upper, middle and lower thirds of each lateral lobe and from the isthmus. Smears were stained with anticalcitonin monoclonal antibody. RESULTS: C cells were detected in all specimens, ranging in number from 3 to 19 per gland, with 53.4% of the cells in the right lobe, 42.8% in the left lobe and 3.7% in the isthmus. The aspirates from the right lobe had 0-13 cells in the upper third, 0-9 in the middle third and 0-3 in the lower third. In the left lobe aspirates there were 0-7 cells in the upper third, 0-6 in the middle third and 0-2 in the lower third. One to two C cells were observed in the isthmus in only four cases. CONCLUSION: It is possible to determine the presence of C cells in normal thyroids and confirm studies conducted on histologic material; the cells were more frequently detected in the middle and upper third and mainly on the right side. They were rare in the isthmus. The search for C cells in thyroid aspirates is of great importance because it permits one to confirm rapidly, precisely and minimally invasively cases suspected of C cell hyperplasia, a preneoplastic condition that precedes the development of medullary carcinoma. In addition, the method shows numerical changes in these cells in such conditions as Hashimoto's thyroiditis and colloid goiter, in which the present results could serve as a control.     

Cholinergic nerves in the thyroid gland

Summary The cholinergic innervation of the thyroid gland has been studied in the human. AChE positive nerve fibers are localized in the wall of the thyroid artery, arranged in two plexuses, a superficial (adventitial) and a deep one (medial). The glandular tissue is provided with cholinergic nerve fibers, localized between and around thyroid follicles. The present results suggest that the endocrine activity of the thyroid gland is also under the control of the autonomic nervous system.     

Dynamics of postnatal histogenesis of the thyroid in normal rats and after sympathectomy

The changes of the thyroid gland and neurocytes of the cranial sympathetic ganglia were followed in rats of different ages after guanethidine injections with the use of radioimmunological assay, electron microscopy and morphometry. The injection of 15 mg of the drug per kg of body weight within the first two weeks after birth caused the death of over 80% of the cells in the sympathetic ganglion. In the sympathectomized 15-day- and 1-month-old rats the functional activity of the thyroid gland was markedly reduced. Later on, intrathyroid hormonogenesis somewhat increases due, apparently, to partial recovery of the organ adrenergic innervation and increase in the production of thyrotropic hypophysial hormone and calcitonin.     

The relative importance of the deep and superficial vascular systems for delay of the transverse rectus abdominis musculocutaneous flap as demonstrated in a rat model

The use of some form of delay maneuver for "high-risk" patients before transfer of the superior pedicled lower transverse rectus abdominis musculocutaneous (TRAM) flap for breast reconstruction has augmented the rate of success in both the experimental and clinical arenas. A common method of vascular delay has been the bilateral division of both the superficial inferior epigastric and deep inferior epigastric vessels. Whether all of these must be divided to adequately effect the delay is unknown. For that matter, the relative importance of the superficial versus the deep vascular systems is unclear. To investigate this uncertainty, a delay was attempted in 61 Sprague-Dawley rats by division of either the superficial inferior epigastric or deep cranial epigastric vessels (the latter is the homologue to the human deep inferior epigastric) in unilateral or bilateral fashion. Division of the contralateral superficial inferior epigastric vessel resulted in significantly greater TRAM flap survival than either ipsilateral or bilateral superficial inferior epigastric vessel division (p = 0.0034 or p = 0.0093, respectively). Division of the ipsilateral or bilateral deep cranial epigastric vessel resulted in significantly greater flap survival than just contralateral deep cranial epigastric vessel division (p = 0.0034 or p = 0.006, respectively). No significant difference was observed between the group having contralateral superficial inferior epigastric or groups with ipsilateral deep cranial epigastric division, implying that either alone would be efficacious to achieve the desired delay effect. This would allow the other vascular system to be retained intact for later potential salvage maneuvers as needed.     

Morphometric and stereological study of the seminal vesicle of the guinea pig.

The seminal vesicle of the guinea pig has been widely used as a model for the study of hormonal action on the male accessory sex organ, but there have been few attempts to quantify their cellular and tissue components. In the present study, the seminal vesicle of the guinea pig was described in the form of a morphometric model. Tissue samples were taken from the distal, middle and proximal regions of the gland and processed for light microscopy. Using a combination of a stereological point-counting technique and direct measurement, the relative volumes of different components (lumen, epithelium, lamina propria and fibromuscular layer) were determined. The relative numbers of the secretory cells and basal cells were also estimated. Following the estimation of the average size of the seminal vesicle, the relative volume of different components and the relative number of secretory cells were transformed into absolute data on a per average seminal vesicle basis. Similarly, the average sizes of the secretory cells and nuclei were also determined. The quantitative data generated from the present study will serve as a baseline for further studies of the seminal vesicle of the guinea pig. The techniques used in the present study are easy to apply, and data generated were objective and reproducible.     

Microvasculature of the thyroid gland in the common tree shrew (Tupaia glis): microvascular corrosion cast/scanning electron microscopy study.

A thyroid vascular cast of the common tree shrew (Tupaia glis) was obtained by injection of Batson's No. 17 plastic mixture into the ascending aorta. The cast was studied under the scanning electron microscope. It was found that each half of the gland is supplied by a large superior and a rather small inferior thyroid artery. After plunging into the gland, the arteries divide into smaller branches that are the interlobular, intralobular and follicular arteries (afferent vessels). The basket-like capillaries arising from the follicular arteries and encapsulating thyroid follicles are of large diameter and are arranged in a single layer. The follicular side of the capillary casts was observed to contain numerous small and some large projecting knobs compatible with the presence of fenestrations in the endothelial cells. On the other hand, endothelial nuclear imprints were found mainly on the stromal surface of the follicular capillary casts. Transfollicular capillaries connecting the adjacent follicular capillary networks were also observed. Blood from the follicular capillaries either drains into the follicular veins (efferent vessels) or abruptly drains into the intralobular veins before proceeding to intralobular and interlobular veins, respectively. The interlobular veins are collected into a few small superior, a few larger middle and a few even larger inferior thyroid veins. These veins drain directly into the laryngeal vein lying adjacent to the deep surface of the thyroid gland before joining the jugular vein. Venous valves were identified outside the thyroid gland. In addition, the glomerular capillary island of the parathyroid gland was often seen at the cranioanterolateral and sometimes at the cranioposterolateral aspect of the thyroid gland.     

Effect of superior cervical ganglionectomy on monoamine content in the epithalamic area of the Mongolian gerbil (Meriones unguiculatus): A fluorescence histochemical study

Summary Extirpation of the superior cervical ganglion was performed in a series of Mongolian gerbils. One or two weeks after the ganglionectomy the animals were injected with a monoamine oxidase inhibitor. Subsequently perfusion fixation was performed using the glyoxylic acid-paraformal-dehydemagnesium method (Lorén et al., 1976) for fluorescence histochemical investigation of the monoamines of the pineal complex. In the ganglionectomized animals all of the blue-fluorescent sympathetic fibers in the pineal complex (superficial pineal gland, deep pineal gland and the pineal stalk) completely disappeared. The yellow indolamine fluorescence of the cells in the superficial pineal and the deep pineal, as well as in the pineal stalk, was markedly reduced after ganglionectomy. No change in the morphology or number of sympathetic fibers in the medial habenular nucleus was observed. These results indicate that the presence of sympathetic nerve fibers with perikarya in the superior cervical ganglion is necessary for maintaining a high indolamine content in all three parts of the pineal complex. In addition, the results also indicate that the deep pineal gland is a functional part of the pineal complex. The presence of a functionally active deep pineal, bordering the pineal recess, suggests that part of the pineal hormones might be secreted into the cerebrospinal fluid.This work was supported by the Carlsberg Foundation, the Swedish Natural Science Research Council, grant no. 2126-100, and the Danish Medical Research Council, grant no. 512-7134     

Cytochemical localisation of acid phosphatase in the phagocytising conjunctival epithelium of the guinea pig

Summary The ultrastructural localisation of acid phosphalase activity was investigated on the guinea pig conjunctival epithelium incubated in vivo with a suspension of latex spheres. Deposits of acid phosphatase reaction product were concentrated on the elements of GERL, the phagocytic vacuoles, and the cell membrane. Acid phosphatase activity in GERL was intense in basal and suprabasal cells and decreased towards the superficial cells. Phagosomes containing latex spheres and reaction product of acid phosphatase were observed mainly in the centrospheral region of the superficial and intermediate epithelial cells. Acid phosphatase activity in phagocytising cells was not increased as compared to that in non-phagocytising cells. The observations indicate that existing acid phosphatase in unstimulated conjunctival epithelial cells is released into heterophagosomes brought within the lysosomal compartment. The number of secondary phagosomes seems to be increased by intercellular transport of latex spheres to the acid phosphatase rich cells in the deep layers of the epithelium.     

Cytochemical localisation of acid phosphatase in the phagocytising conjunctival epithelium of the guinea pig

The ultrastructural localisation of acid phosphatase activity was investigated on the guinea pig conjunctival epithelium incubated in vivo with a suspension of latex spheres. Deposits of acid phosphatase reaction product were concentrated on the elements of GERL, the phagocytic vacuoles, and the cell membrane. Acid phosphatase activity in GERL was intense in basal and suprabasal cells and decreased towards the superficial cells. Phagosomes containing latex spheres and reaction product of acid phosphatase were observed mainly in the centrospheral region of the superficial and intermediate epithelial cells. Acid phosphatase activity in phagocytising cells was not increased as compared to that in non-phagocytising cells. The observations indicate that existing acid phosphatase in unstimulated conjunctival epithelial cells is released into heterophagosomes brought within the lysosomal compartment. The number of secondary phagosomes seems to be increased by intercellular transport of latex spheres to the acid phosphatase rich cells in the deep layers of the epithelium.     

Changes in the histomorphology of the canine cervix through the oestrous cycle

The importance of canine reproduction is steadily increasing and little is known about the canine cervix so far. The aim of this study was to describe the histomorphology of the canine cervix and to determine its correlation to the stage of oestrous cycle and to circulating concentrations of progesterone (P4) and estradiol-17beta (E2), respectively. Ovariohysterectomy (OHE) was performed in 33 non-pregnant, healthy, intact bitches in defined stages of oestrous cycle (proestrus N = 5, estrus N = 7, early diestrus N = 5, late diestrus N = 11, anestrus N = 5). The entire cervix was collected for histological evaluation of the epithelial layer (number of layers, thickness), the stroma (number of layers, thickness, density, structure, and distribution of elastic fibres) and the average area and density of cervical glands as well as blood vessels. These parameters were evaluated in all the three parts of the cervix (cranial, middle, and caudal or vaginal part). The cervix showed the typical structure with a superficial epithelium, a lamina propria with cervical glands and vascular structures and a tunica muscularis below. Folds in the superficial epithelium were only observed in 54% females (N = 18). Epithelial thickness (P < 0.0001), number of glands (P < 0.05), mean area of glands (P < 0.0001), mean area of venous vessels (P < 0.0001), number of arterial vessels (P = 0.02), number of mast cells and number of eosinophilic granulocytes per mm² (P < 0.01) were significantly influenced by the stage of cycle. The following factors were significantly influenced by the localisation: number of epithelial layers (P < 0.0001), thickness of stroma (P < 0.0001) and mean number of glands (P < 0.01). Only mean area of venous vessels was significantly influenced by the stage of cycle and the localisation (P < 0.01). Besides, P4 was significantly correlated to number of glands per mm² (P < 0.0001), mean area of venous vessels (P < 000.1) and number of mast cells (P < 0.01).This study provided detailed information about the histomorphological structure of the cervix in non-pregnant bitches and showed that the cervix undergoes cyclic changes during the canine oestrous cycle, in particular in association with circulating progesterone concentration.