OBJECTIVE: To observe the changes of cell gap junction ultrastructure of gastric epithelial cells in patients with gastric cancer(GC) and precancerous lesion(PL),and to investigate the relation between these changes and H.pylori infection. METHODS: Seventy patients with GC, 88 with PL, and 33 with chronic superfial gastritis (CSG) were studied. H.pylori was detected by rapid urease test,basic fuchsin stain and 14C-urea breath test. The CagA gene of H.pylori was determined by polymerase chain reaction(PCR).The cell gap junction ultrastructure was observed under transmission electronic microscope. RESULTS: Length of junction/unit perimeter of gastric epithelial cells in patients with PL was smaller than that in CSG patients, and the smallest width of the intercellular space was bigger than that in CSG patients. The number of cell junction, the number of junction/unit perimeter, and the length of junction/unit perimeter in patients with GC were all smaller than those in patients with CSG or PL, and its smallest width of the intercellular space was bigger than that in patients with CSG. In patients with GC, the number of cell junction, the number of junction/unit perimeter and the length of junction/unit perimeter in CagA+ H.pylori group were smaller than those in CagA(-) H.pylori group, and its smallest width of the intercellular space was bigger than that in CagA(-) H.pylori group. In PL patients, the intercellular space decreased, and the length of cell junction of gastric epithelial cells became bigger after H.pylori eradication. The length of junction/unit perimeter in patients of H.pylori eradication was bigger than that in patients without eradication, and the smallest width of the intercellular space was smaller than that in patients without eradication. CONCLUSION The changes of cell gap junction of gastric epithelial cells in patients with GC and PL are associated with H.pylori infection especially CagA+ H.pylori infection. Eradication of H.pylori can promote the formation of cell junction.
Adenocarcinoma ; microbiology ; ultrastructure ; Epithelial Cells ; ultrastructure ; Female ; Gastric Mucosa ; ultrastructure ; Helicobacter Infections ; pathology ; Helicobacter pylori ; Humans ; Intercellular Junctions ; ultrastructure ; Male ; Precancerous Conditions ; microbiology ; ultrastructure ; Stomach Neoplasms ; microbiology ; ultrastructure

OBJECTIVEIt is well known that glioma stem cells-progenitors (GSCP) proliferate indefinitely and hardly differentiate in vitro, however, the reasons remain unknown. The aim of this study was to explore the ultrastructural basis of GSCP.

METHODSGSCP, kept by our laboratory, were collected, embedded, and cut into ultrathin sections and observed under the transmission electron microscope.

RESULTSA single GSCP usually had relatively well developed mitochondria, Golgi apparatuses, ribosomes, and undeveloped rough endoplasmic reticulum, but seldom lysosomes and no typical autophagosomes were found, and the nuclear-cytoplasmic ratio was high. The nuclei frequently contained huge amounts of euchromatin and a small quantity of heterochromatin, and in most nuclei there were only one nucleolus, however, two or more nucleoli were also common. Typical apoptotic cells could hardly be found in tumor-spheres, and between neighboring cells in tumor-spheres there were incompletely developed desmosomes or intermediate junction.

CONCLUSIONThe ultrastructural features of glioma stem cells-progenitors showed that BTSCP were very primitive and the lack of autophagy and the underdevelopment of some other cellular organelles are probably the reasons for the differential inhibition of GSCPs.

Brain Neoplasms ; ultrastructure ; Cell Line, Tumor ; Cell Membrane ; ultrastructure ; Cell Nucleus ; ultrastructure ; Chromatin ; ultrastructure ; Cytoplasm ; ultrastructure ; Glioma ; ultrastructure ; Humans ; Intercellular Junctions ; ultrastructure ; Microscopy, Electron, Transmission ; Mitochondria ; ultrastructure ; Neoplastic Stem Cells ; ultrastructure

OBJECTIVESTo observe the detrusor ultrastructure in BPH patients and to investigate the relationship between detrusor instability and ultrastructure.

METHODSThe patients were divided into groups of detrusor instability(DI) and detrusor stability(DS) according to urodynamics examination. The structure of the detrusor were observed by light microscopy and transmission electron microscopy(TEM).

RESULTSThe intercellular intermediate junctions and cytoplasmic process junctions in DS were 11.34 +/- 3.23 and 4.26 +/- 1.78 respectively. The intercellular intermediate junctions decreased obviously (3.12 +/- 1.47, P < 0.01) instead of a large amount of cytoplasmic process junctions (26.37 +/- 7.14, P < 0.01) in DI.

CONCLUSIONSThere is a close relevance between intercellular junctions and DI. The observation of the ultrastructure of the detrusor is helpful for the diagnosis of BPH with DI and for the clinical treatment.

Aged ; Aged, 80 and over ; Humans ; Intercellular Junctions ; ultrastructure ; Male ; Microscopy, Electron ; Middle Aged ; Muscle, Smooth ; ultrastructure ; Prostatic Hyperplasia ; pathology ; Urinary Bladder ; ultrastructure

OBJECTIVETo investigate the effect of Helicobacter pylori-encoded CagA on biological behavior of gastric adenocarcinoma AGS cells.

METHODSWith experiment-control system of the wild-type CagA positive strain and isogenic CagA negative mutant strain of Helicobacter pyroli (Hp) were used as control and experimental groups, respectively. The cell contact, migration and invasion were examined by light and electron microscopy and invasion assay.

RESULTSThe AGS cells infected by Hp strain with positive wild-type CagA showed more severely changed tight junction, wider intercellular space, loss of cell contacts, and higher migrating and invasive ability.

CONCLUSIONHp CagA may lead to loss of cell contacting and higher migrating and invading ability of gastic cells, and accelerates the malignant progress of tumor.

Adenocarcinoma ; microbiology ; pathology ; ultrastructure ; Antigens, Bacterial ; genetics ; Bacterial Proteins ; genetics ; Cell Line, Tumor ; Cell Movement ; Extracellular Space ; Helicobacter pylori ; genetics ; pathogenicity ; Humans ; Intercellular Junctions ; ultrastructure ; Mutation ; Stomach Neoplasms ; microbiology ; pathology ; ultrastructure

PURPOSE: To investigate the morphological characteristics of keratocytes and the interconnection of keratocytes with adjacent keratocytes using the flat preparation method and scanning electron microscopy with a frontal section of the human corneal stroma. METHODS: The thin, corneal collagen lamellae were carefully dissected from the cornea (n=7), which had been stained by the flat preparation method. The remaining tissue was fixed in 3% glutaraldehyde and observed by transmission electron microscopy following the frontal section. RESULTS: The flat preparation revealed the corneal fibroblasts between the lamellae of the collagen fibers and showed that the ramifying cellular processes of the keratocytes were in contact with the cytoplasmic processes or cell bodies of neighboring fibroblasts. Two types of discrete subpopulations of keratocytes were identified: a smaller, cellular type of keratocyte with spindle-shaped nucleus with heterochromatin, and a larger, cellular type with a large indented nucleus with relatively scanty cytoplasm. Collagen fibers ran parallel to each other toward the fenestration of the cytoplasmic wall of the keratocyte. CONCLUSIONS: These flat preparation method results showed that the keratocytes within the corneal stroma are interconnected with the adjacent keratocytes, which indicates the presence of a functional communicating network through the keratocyte circuits within the stroma. A smaller, cellular type of keratocyte with spindle-shaped nucleus was morphologically differentiated from a larger, cellular type with a large, indented nucleus by flat preparation and transmission electron microscopy.
Middle Aged ; Microscopy, Electron, Transmission ; Microscopy, Electron, Scanning ; Intercellular Junctions/*ultrastructure ; Infant ; Humans ; Corneal Stroma/*cytology/pathology ; Child, Preschool ; Child ; Cell Size ; Aged ; Adult ; Adolescent

Actin can be found in all kinds of eukaryotic cells, maintaining their shapes and motilities, while its dynamics in sperm cells is understood less than their nonmuscle somatic cell counterparts. Spermatogenesis is a complicated process, resulting in the production of mature sperm from primordial germ cell. Significant structural and biochemical changes take place in the seminiferous epithelium of the adult testis during spermatogenesis. It was proved that all mammalian sperm contain actin, and that F-actin may play an important role during spermatogenesis, especially in nuclear shaping. Recently a new model for sperm head elongation based on the acrosome-acroplaxome-manchette complex has been proposed. In Drosophila, F-actin assembly is supposed to be very crucial during individualization. In this mini-review, we provide an overview of the structure, function, and regulation characteristics of actin cytoskeleton, and a summary of the current status of research of actin-based structure and movement is also provided, with emphasis on the role of actins in sperm head shaping during spermiogenesis and the cell junction dynamics in the testis. Research of the Sertoli ectoplasmic specialization is in the spotlight, which is a testis-specific actin-based junction very important for the movement of germ cells across the epithelium. Study of the molecular architecture and the regulating mechanism of the Sertoli ectoplasmic specialization has become an intriguing field. All this may lead to a new strategy for male infertility and, at the same time, a novel idea may result in devising much safer contraception with high efficiency. It is hoped that the advances listed in this review would give developmental and morphological researchers a favorable investigating outline and could help to enlarge the view of new strategies and models for actin dynamics during spermatogenesis.
Acrosome ; physiology ; Actins ; chemistry ; physiology ; Animals ; In Vitro Techniques ; Intercellular Junctions ; physiology ; Male ; Sertoli Cells ; physiology ; ultrastructure ; Sperm Motility ; physiology ; Spermatogenesis ; physiology ; Testis ; cytology ; physiology

The integrity of blood vessels controls vascular permeability and extravasation of blood cells, across the endothelium. Thus, the impairment of endothelial integrity leads to hemorrhage, edema, and inflammatory infiltration. However, the molecular mechanism underlying vascular integrity has not been fully understood. Here, we demonstrate an essential role for A-kinase anchoring protein 12 (AKAP12) in the maintenance of endothelial integrity during vascular development. Zebrafish embryos depleted of akap12 (akap12 morphants) exhibited severe hemorrhages. In vivo time-lapse analyses suggested that disorganized interendothelial cell-cell adhesions in akap12 morphants might be the cause of hemorrhage. To clarify the molecular mechanism by which the cell-cell adhesions are impaired, we examined the cell-cell adhesion molecules and their regulators using cultured endothelial cells. The expression of PAK2, an actin cytoskeletal regulator, and AF6, a connector of intercellular adhesion molecules and actin cytoskeleton, was reduced in AKAP12-depleted cells. Depletion of either PAK2 or AF6 phenocopied AKAP12-depleted cells, suggesting the reduction of PAK2 and AF6 results in the loosening of intercellular junctions. Consistent with this, overexpression of PAK2 and AF6 rescued the abnormal hemorrhage in akap12 morphants. We conclude that AKAP12 is essential for integrity of endothelium by maintaining the expression of PAK2 and AF6 during vascular development.
A Kinase Anchor Proteins/*genetics/metabolism ; Animals ; Blood Vessels/abnormalities/*embryology/metabolism ; Cell Cycle Proteins/genetics/metabolism ; Down-Regulation ; Embryo, Nonmammalian/abnormalities/*blood supply/embryology/metabolism ; Gene Deletion ; *Gene Expression Regulation, Developmental ; Hemorrhage/*embryology/genetics/metabolism ; Human Umbilical Vein Endothelial Cells ; Humans ; Intercellular Junctions/genetics/metabolism/ultrastructure ; Kinesin/genetics/metabolism ; Myosins/genetics/metabolism ; Zebrafish/*embryology/genetics ; p21-Activated Kinases/genetics/metabolism

BACKGROUNDGastroesophageal reflux disease (GERD) is a common disorder. Dilation of intercellular spaces of esophageal epithelium has been revealed at transmission electron microscopy both in the rabbit acid-perfused esophagus and in esophageal biopsies from GERD patients. This study aimed to observe the changes of the intercellular spaces of squamous epithelium of lower esophagus in patients with GERD and the changes of intercellular spaces of patients with erosive esophagitis (EE) before and after omeprazole treatment.

METHODSOutpatients having GERD symptoms for more than 3 months and volunteers were collected. All of them underwent gastroendoscopy and 24-hour ambulatory pH monitoring. Biopsies were taken from the lower esophagus (2 cm above Z-line) for electron microscope examination. Five healthy volunteers, six non-erosive reflux disease (NERD) patients, and five EE patients were enrolled. Intercellular spaces of GERD patients and controls were calculated. Then we selected 20 patients with EE diagnosed by gastroendoscopy. All of them were treated with omeprazole (Losec, 20 mg bid) for 4 weeks then underwent gastroendoscopy again. Biopsies were taken from 2 cm above Z-line for electron microscope examination. All the patients completed the questionnaire about reflux symptoms before and after treatment.

RESULTSIntercellular spaces of esophageal epithelial cell in volunteers, NERD patients and EE patients were (0.37 +/- 0.07) microm, (1.31 +/- 0.08) microm, and (1.33 +/- 0.14) microm, respectively, with significant differences between the control group and the NERD group (P = 0.000). In the 20 EE patients, the mean intercellular space before treatment was (1.14 +/- 0.15) microm. After treatment the intercellular space was (0.51 +/- 0.18) microm, a significant difference compared with pre-treatment measurements (P = 0.000).

CONCLUSIONSDilated intercellular spaces (DIS) were seen in both NERD and EE cases. The dilated intercellular spaces of esophageal epithelium in EE patients could be recovered after a short time of treatment with omeprazole.

Adult ; Anti-Ulcer Agents ; pharmacology ; therapeutic use ; Esophageal pH Monitoring ; Esophagitis, Peptic ; drug therapy ; pathology ; Extracellular Space ; drug effects ; Female ; Gastroesophageal Reflux ; drug therapy ; pathology ; Gastroscopy ; Humans ; Intercellular Junctions ; drug effects ; ultrastructure ; Male ; Microscopy, Electron, Transmission ; Middle Aged ; Omeprazole ; pharmacology ; therapeutic use