Ultrastructural study of human uterine epithelium from a patient with a confirmed pregnancy

Scanning and transmission electron microscopy have been used to study the uterine epithelial cells from a pregnant human uterus approximately 8 days after ovulation. The ultrastructural appearance of the epithelial cells generally conforms with that previously described as showing receptivity, although some significant regional variability exists.     

The fine structure of atypical ciliated cells in the human gastric epithelium

Gastric mucosa obtained from the body and pyloric portions of the human stomach were observed by light and transmission electron microscopy. Ciliated cells were found in two of 18 subjects examined, one patient with gastric ulcer and the other one with gastric adenocarcinoma. The ciliated cells were found in epithelia at sites away from the main lesions. The tissues containing ciliated cells showed intestinal metaplasia combined with mild chronic gastritis in both cases. The epithelial layer facing the gastric lumen was composed of columnar cells with numerous uniform microvilli and goblet cells. This epithelium extended to the superficial parts of the tubules surrounded by the lamina propria. The deeper portions of the tubules were composed of mucous secretory, endocrine, and rarely ciliated cells. These ciliated cells were provided with numerous cilia the numbers of which varied considerably from cell to cell. This was in contrast to the primary cilium which is usually single. The central part of the apical cell membrane was sometimes concave in the area from where cilia tended to arise. It was also observed that numerous basal bodies as well as mucus-like granules were contained in the same cell. The axonemal pattern was different from that of ordinary cilia and showed 9 + 0 and 8 + 1 patterns. In longitudinal sections it was found that one peripheral doublet was displaced to the center of the axoneme as it left the basal body.     

Ultrastructural morphometric analysis of the uterine epithelium during early pregnancy in the sheep

Stereological techniques were used to quantify ultrastructural changes in the caruncular epithelium during the pre- (Day 13), peri- (Day 16) and post- (Days 19 and 22) attachment periods of placentation. Tissues from Day-13 non-pregnant ewes were used as controls. Uteri for stereological evaluation were perfused via the uterine artery with 3% glutaraldehyde and separated into proximal, middle and distal regions. Tissues from caruncular areas were processed for electron microscopy. Volume fractions (Vv) of nuclei, mitochondria, lipid and cytoplasmic granules were estimated by point-counting volumetry. Surface areas per unit tissue volume (Sv) of mitochondrial membranes and cristae, Golgi, plasmalemma, endoplasmic reticulum and nuclear membranes were estimated by line-intersection counting. The only significant difference between pregnant and non-pregnant uterine epithelium at Day 13, a time before attachment, was a lower Sv of smooth endoplasmic reticulum (SER) in tissue from pregnant ewes. This value returned to control (non-pregnant Day 13) levels at Day 16, and was again significantly reduced at Days 19 and 22. The Vv of lipid decreased significantly at Day 16 and remained at reduced levels thereafter. These changes may reflect the effects of conceptus products on lipid storage and mobilization. The Sv of rough endoplasmic reticulum (RER) significantly increased on Day 16 of gestation, and remained elevated on Day 19. These results may reflect increased synthesis of protein for export at these times. In general, several of the values measured which may be indicative of cellular metabolism were reduced at Day 22 of pregnancy, perhaps suggesting diminished metabolism by the uterine epithelium after attachment of the trophoblast.(ABSTRACT TRUNCATED AT 250 WORDS)     

The circulatory bed of the human uterine tube

By means of combined morphological methods blood vessels have been studied in 54 uterine tubes of child-birth women. The main pathways for carrying and distribution of blood to corresponding parts of the tube are sector arteries. They are situated in the subserous tela along the anterior and posterior semicircles of the organ. The microcirculatory bed (MCB) of the uterine tube is presented by serous, subserous, muscular and mucosal plexuses. The MCB of the serous tunic is characterized by vascular compositions--modules. Angioarchitectonics of the mucosal tunic is determined with differences in vascularization of complex and simple folds. Organospecific for small arteries and veins of the tubes is presence of vascular mechanisms, regulating the blood stream (intimal cushions, muscular-elastic constrictors, valves and others). Blood capillaries of the mucosal tunic possess a number of ultrastructural peculiarities: thickened peripheral part of endotheliocyte cytoplasm, that contains fenestrae; wide continuous basal membrane with pericytes in its duplication; three types of pericytic-endothelial contacts etc.     

Ultrastructural study of the boar seminiferous epithelium: changes in cryptorchidism

The present study compares the ultrastructural features of Sertoli cells and germ cells between scrotal testes of healthy boars and abdominal testes of unilateral and bilateral cryptorchid boars. In healthy boars, spermatogonia are flat cells lying in close association with the basal lamina. As differentiation progresses, spermatogonia acquire an oval profile and lose their contact with the basal lamina. Spermatocytes are round cells moving from the basal compartment of the seminiferous epithelium to the luminal compartment. Spermatids exhibit complex morphological changes leading to the formation of spermatozoa. Sertoli cells extend from the basal lamina to the tubular lumen. The nucleus encloses fine euchromatin and one or two nucleoli; the nuclear envelope has a few deep infoldings. The lateral cell membranes form junctional specializations that constitute the blood-testis barrier. The cytoplasm encloses smooth endoplasmic reticulum, vesicles, aggregates, and scattered mitochondria. The seminiferous epithelium of abdominal testes from unilateral and bilateral cryptorchid boars contains few spermatogonia with an abnormal appearance; the alteration in germ cell number is more severe in the bilateral disease. In unilateral cryptorchid boars, spermatogonia appear as either large pyramidal cells or roundish cells; in bilateral cryptorchid boars, spermatogonia show roundish profiles and degenerative patterns. Abdominal testes of both unilateral and bilateral cryptorchid boars are constituted by immature Sertoli cells that show abnormal cytoplasmic content, defective development of the blood-testis barrier, and atypical nuclear appearance; in bilateral cryptorchid boars, immature Sertoli cells exhibit degenerative signs. At postpubertal age, unilateral and bilateral cryptorchidism induce total arrest of spermatogenesis at spermatogonial stage as a result of an abnormal differentiation of the Sertoli cells. Moreover, the degeneration of abdominal testes initiates earlier in bilateral cryptorchidism than in unilateral cryptorchidism.     

Ultrastructural study of bronchial epithelium in chronic respiratory diseases.

The fine structure of bronchial epithelium in thirty-six patients, thirty-one men and five women, suffering from chronic obstructive pneumonopathy or bronchial carcinoma was studied. No remarkable alterations were found with electron microscopy, in most non-smokers in contrast to the smokers who presented destruction of the epithelial cells and loss of the cilia or many pathological cilia with an abnormal microtubular configuration and irregular orientation. The severity, however, of the alterations was not related to the severity of smoking and to the presence of bronchial cancer.     

Ultrastructural alterations in ciliated protozoa under heavy metal exposure

Transmission electron microscopy was used to study the ultrastructural changes induced by exposure to Cd or Zn in three species of ciliated protozoa: Colpoda steinii, Cyrtolophosis elongata and Drepanomonas revoluta. The main cytoplasmic alterations were partial mitochondrial degeneration, cytoplasmic vacuolisation, accumulation of membranous debris and autophagosome formation. At the nuclear level we detected nucleolar fusion in the macronucleus, and micronuclear membrane modifications. We compared these modifications with those coinciding with ciliate encystment (a differentiation process induced by environmental nutritional stress) and with changes in eukaryotic cells treated with staurosporine, a potent protein kinase inhibitor considered to be an apoptosis inducer. Exposure to heavy metals also coincided with the appearance of electron-dense accumulations in the cytoplasm, which might be related to metallothionein-mediated detoxification. The results are compared with previously reported data from ciliates and microalgae treated with heavy metals.     

Ultrastructural and histochemical studies on the epithelium revestment layer in the tube feet of the starfish Asterina stellifera

The “cuticle,” which revests the starfish tube foot, has been studied by electron microscopy and the findings correlated with histochemical observations. The “cuticle” is composed by two distinct zones; an outer zone including numerous microvilli, which extend from the inner zone into and through a fibrillar substance distinctly organized in two layers. These microvilli protrude slightly beyond the outer surface, where their tips give rise tonumerous extremely delicate fibrils. The second inner zone, of quite variable thickness and condensation of material, presents a coarser fibrous matrix where organelles and inclusions can be found. The whole cuticular complex does not derive from the majority of the epithelial cells, but is probably an extension of a special kind of T-shaped cells appearing at intervals, the “cuticle” forming a syncytial surface. Histochemical investigations indicate that the “cuticle” contains a combination of neutral and acid mucopolysaccharide, with a marked neutral predominance, the outer one displaying also an extremely thin coat of acid mucopolysaccharide with the sulfate group. The ordered arrangement of the microvilli suggests that this situation is imposed by the strong bond existing between the microvilli and the ouble mucopolysaccharide layers which would act as a cementing substance stabilizing the entire apical surface of the cell.     

Infection of ciliated cells by human parainfluenza virus type 3 in an in vitro model of human airway epithelium

We constructed a human recombinant parainfluenza virus type 3 (rPIV3) that expresses enhanced green fluorescent protein (GFP) and used this virus, rgPIV3, to characterize PIV3 infection of an established in vitro model of human pseudostratified mucociliary airway epithelium (HAE). The apical surface of HAE was highly susceptible to rgPIV3 infection, whereas only occasional cells were infected when virus was applied to the basolateral surface. Infection involved exclusively ciliated epithelial cells. There was little evidence of virus-mediated cytopathology and no spread of the virus beyond the ciliated cell types. Infection of ciliated cells by rgPIV3 was sensitive to a neuraminidase specific for alpha2-6-linked sialic acid residues, but not to a neuraminidase that cleaves alpha2-3- and alpha2-8-linked sialic acid residues. This provided evidence that rgPIV3 utilizes alpha2-6-linked sialic acid residues for initiating infection, a specificity also described for human influenza viruses. The PIV3 fusion (F) glycoprotein was trafficked exclusively to the apical surface of ciliated cells, which also was the site of release of progeny virus. F glycoprotein localized predominately to the membranes of the cilial shafts, suggesting that progeny viruses may bud from cilia per se. The polarized trafficking of F glycoprotein to the apical surface also likely restricts its interaction with neighboring cells and could account for the observed lack of cell-cell fusion. HAE derived from cystic fibrosis patients was not more susceptible to rgPIV3 infection but did exhibit limited spread of virus due to impaired movement of lumenal secretions due to compromised function of the cilia.     

Topology and planar polarity of the Xenopus embryonic ciliated epithelium

The effect of mechanical stress on the topology and planar polarity (PP) of the Xenopus embryonic ciliated epithelium was studied. It was found that the explantation of different sections of the blastocoel roof of the early gastrula disrupted the normal orientation of rows of ciliated cells (CCs) and led to the partition of zones with a single PP into several sections with different polarity or to the occurrence of chaotic patterns. Mechanical stretching of explants increased the order of their PP and oriented it predominantly perpendicular to the stretching axis. Changes in mechanical stress had no significant effect on the ciliated epithelium topology.