[Characteristics of ATPase activity in the sarcolemma of longitudinal and circular muscles of the canine ileum]. / Kharakteristika ATFaznoi aktivnosti sarkolemmy prodol'noi i tsirkuliarnoi muskulatury podvzdoshnoi kishki sobaki.

The subcellular fraction enriched in sarcolemmal vesicles was isolated from the longitudinal muscle (LM) and the circular muscle (CM) of the canine ileum by sucrose density gradient centrifugation. Treatment of the LM and CM membranes with sodium dodecylsulfate (0.2 mg/kg protein) led to a 3-fold increase in Na,K-ATPase activity (up to 24 and 39 mumol Pi/mg protein/h, respectively) and to a 90-95% inactivation of Mg-ATPase which was 2 and 8 times (for the CM and the LM, respectively) more active than Na,K-ATPase in the untreated sarcolemma. A specific inhibition of Na,K-ATPase activity by acetylcholine (Ach) and serotonin (ST) was observed which could de blocked in the presence of muscarinic and serotonin receptor antagonists. Sensitivity of the enzyme to ST was more than one order of magnitude higher than to Ach (IC50 = 10(-8) vs 1.2 x 10(-7) M). The inhibition of Na,K-ATPase activity by the neurotransmitters was more pronounced in the LM membranes (30-40%) than in the CM ones (10-20%). These data indicate that cell membranes of the LM and CM differ both in specific ATPase activities and the responsiveness of Na,K-ATPase to the receptor-mediated effects of Ach and ST.

[Ultrastructure of squamous epithelium in esophageal dysplasia and squamous cell cancer]. / Ul'trastruktura ploskogo épiteliia pri displazii i ploskokletochnom rake pishchevoda.

Electron microscopic examination of the oesophageal squamous cell carcinoma revealed the presence in the tumour of both undifferentiated and differentiated squamous cells. Keratinocytes appeared and the signs of keratinization were more pronounced in the cytoplasm of differentiated cells. Dysplastic changes were observed at the periphery of the primary node. Two main variants of dysplasia (dark-cell and clear-cell) were distinguished, this at the ultrastructural level being the reflection of the direction of differentiation and the degree of cell maturity in the dysplastic foci. With the exception of few cases with a cell polymorphism in the foci of a severe dysplasia, dysplastic changes of the squamous epithelium were characterized by a monotonous ultrastructural cell composition. The dysplastic cells were distinguished by a degree of differentiation and high synthetic activity.

[Ultrastructure of the esophageal mucus glands in normal conditions and in esophageal cancer]. / Ul'trastruktura slizistykh zhelez pishchevoda v norme i pri rake pishchevoda.

The ultrastructure of the glandular apparatus and epithelium of the excretory ducts of esophageal mucous glands proper normally and in esophageal carcinoma was studied electron microscopically. Acinar cells were represented by two kinds, "Dark" and "clear" cells reflecting alternating activity of the secretory cells. The ultrastructural features of the reserve cells of excretory ducts such as hypertrophy of the nucleus, scalloped nuclear membrane, high electron density of the nucleus and cytoplasm, abundance of ribosomes and polysomes allow them to be considered as low differentiated highly active cambial elements. In esophageal carcinoma, reserve cell proliferates of the excretory ducts were found to have granule-containing cells possibly related to the system of serotoninocytes. The reserve cells showed ultrastructural changes with signs of dysplasia.

[Ultrastructural changes in tissues in postburn cicatricial esophageal stenosis during bougienage and prolonged intubation]. / Ul'trastrukturnye izmeneniia tkanei v posleozhogovykh rubtsovykh suzheniiakh pishchevoda pri buzhirovanii i dlitel'noi intubatsii.

The ultrastructure of tissues in postburn esophageal strictures was studied in 24 patients varying in ages from 23 to 70 years with the postburn period ranging from 1 1/2 months to 36 years. Biopsy samples for the study were collected during fibroesophagoscopies before treatment, after bougienage and longterm intubation with the Tkachenko tube. Before treatment, pathologically altered granulation tissue forming the surface of ulcerated esophageal strictures was found to contain such mature forms of fibroblasts as collagenoblasts with moderate collagen-producing activity, myofibroblasts, and fibrocytes. Mechanical effects of bougienage and intubation of the esophagus stimulated formation of young granulation tissue in the area of ulcerated strictures, intubation of the strictures stimulating both biosynthesis and catabolism of collagen. Mature forms of fibroblasts of young granulation tissue formed in bougienage were represented by collagenoblasts with intensive collagen-producing activity, myofibroblasts, fibrocytes, and after long-term esophageal intubation also by fibroclasts.

[Ultrastructure of esophageal epithelium under normal conditions and in dysplastic foci]. / Ul'trastruktura épiteliia pishchevoda v norme i v ochagakh displazii.

Electron microscopic examinations of the ultrastructure of normal esophageal epithelium of an adult man revealed submicroscopic features of each epithelial layer. A specific structure of epithelial cells is represented by tonofibrils. Glycogen is found only in the prickle-cell and superficial layers. In the latter there were some signs of incomplete keratinization. Hyperplasia of the prickle-cell and superficial layers epithelium was accompanied by accumulation of glycogen and marked parakeratosis with disintegration of the nucleus, formation of keratin fibrils, and destruction of desmosomal bonds. Dysplastic changes in the esophageal epithelium were heterogenous and presented a whole set of ultrastructural rearrangements. We distinguish two variants of dysplasia. In the "dark-cell" variant there were hypertrophy and hyperchromia of the nucleus, deep invaginations of the nuclear membrane, swelling of the mitochondria, appearance of myelin-like structures in the matrix, increased number of free ribosomes, polysomes, and lipids, formation of tonofibrillar-keratohyaline complexes, increased number of cytoplasmic processes. The "clear-cell" variant was characterized by nuclear hypertrophy, marked dilation of cisterns of the rough endoplasmic reticulum, extensive vesicle formation, keratohyaline granules, few cytoplasmic outgrowths, dilation of the intercellular space.