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F Sasaki

Publications and source records attributed to F Sasaki.

At least 217 records · Page 12Linked to original sources
PubMed1986

[Surgical treatment of chronic constipation with megarectum in children].

In this paper, a new operative procedure for patients with chronic constipation with megarectum and its results are presented. Nine cases of idiopathic chronic constipation and one case of short aganglionosis showing megarectum underwent this operation. An incision was placed on the dentate line at 6 o'clock and the internal sphincter muscle was identified. The incision was extended to this muscle. The blunt division between the internal and external sphincter muscles was orally advanced 5 cm from the dentate line. The all layers of anus and lower part of rectum in length of 5 cm were clamped by 2 forceps in width of 1 cm. The mucosal and muscular layers were bilaterally cut in the outer side of the forceps. The rectum on the top of the forceps was pulled through to the dentate line and was anastomosed there; i.e. the posterior part of the anus was replaced by the rectal wall. Bowel habits of operated patients were evaluated at 1 to 3 years after the operation. Complete cure was obtained in 7 cases (including 1 case with aganglionosis). Three cases improved but needed sometimes suppositories. This procedure, sphinctero-myectomy and-plasty may be an operation of choice for chronic constipation with megarectum.

Adolescent↗
PubMed1986

[New surgical technic in megarectum].

The sphinctero-myectomy as a surgical treatment of megarectum has been generally advocated, but its results are not always satisfactory. In this paper, a new surgical treatment will be presented. Ten cases with idiopathic chronic constipation presenting megarectum in barium enema underwent this operation. After anal dilatation, incision was made in width of 2 cm at 6 o'clock on the dentate line. The blunt split between internal and external sphincter muscles was advanced to 6 cm orally. The all layers of superior part of anus and lower part of rectum in length of 5 cm were clumped by two forceps in width of 1 cm. Then the all layers in outer side of forceps were cut bilaterally. The rectum on the top of the forceps was pulled through to the dentate line and was anastomosed there. The operative results were evaluated more than one year after the operation. Complete cure was noticed in 7 cases and marked improvement in 3 cases. Our procedure, named as sphinctero-myectomy and plasty can be operation of choice for chronic constipation with megarectum.

Adolescent↗
PubMed1985

Network and lamellar structures in the tail muscle fibers of the metamorphosing anuran tadpole.

Networks of regularly arranged tubular units and lamellar structures were observed in the degenerating tail muscle fibers of spontaneously metamorphosing anuran tadpoles. These networks appeared to be similar to those previously found in the skeletal muscle of other animals under abnormal conditions. They stained clearly with ruthenium red (RR) and a continuity with the transverse tubular system (T tubules) of triads was clearly observed. The diameter of the tubular unit, 20-25 nm, was almost equal to that of the T tubules of the intact tail muscle fibers, indicating the network structures were probably formed by T tubules connecting together. In the early stages of metamorphosis, networks in the tetragonal configuration were observed within the end region of the muscle fibers. At the climax of metamorphosis, well-developed networks in which the tubular units were arranged in a hexagonal pattern were seen in various regions of the fibers. Other observed lamellar structures may originate from lateral elements of the triads. The formation of the network structure is discussed.

Animals↗
PubMed1985

Scanning electron microscopy of macrophages in the tail musculature of the metamorphosing anuran tadpole, Rana japonica.

Scanning electron microscopy was used to investigate the morphological changes of the tail musculature of the metamorphosing anuran tadpole, attention being focused on phagocytosis by macrophages. Muscle fibers were stained en bloc with silver and freeze-fractured during dehydration, or torn after drying. Samples were sputter-coated with gold-palladium and observed in both secondary electron- and back-scattered electron modes with a scanning electron microscope. Various cells were identified by the methods of secondary electron- and back-scattered electron images. Some macrophages lying between muscle fibers at prometamorphic stages possessed numerous finger-like projections and well-developed ruffles. During degeneration of muscle fibers macrophages collected in the degenerating region and invaded the space between the disordering myofibrils. In advanced stages the numbers of macrophages clearly increased on or around the degenerating muscle fibers. At the climactic stage fragmented muscles were entrapped and then engulfed by the macrophages. With the completion of phagocytosis, the macrophages became globular with reduction of the ridge-like ruffles. Macrophages may play a role not only in scavenging the fragmented muscle fibers, but also using their long processes in active formation of the fragments.

Animals↗
PubMed1985

Acetylcholinesterase activity in nerve endings of tails of Rana japonica and R. catesbeiana during metamorphosis.

In anuran tadpole tails, the myelinated motor nerve fibers branch in the myoseptum to innervate both red and white muscle fibers at, or near, their ends. There are no significant ultrastructural differences between the nerve endings of the two types of muscle fibers. Intense acetylcholinesterase reaction product was observed in synaptic clefts and junctional folds, as well as in transverse tubules. As metamorphosis proceeded, the junctional folds of the nerve endings disappeared, however, acetylcholinesterase reaction product was still observed in the synaptic clefts. As muscle fibers began to degenerate, nerve endings began to separate from them. However, after nerve endings were completely separated from the surfaces, degenerated muscle fibers, synaptic and cored vesicles were still well preserved although no acetylcholinesterase reaction product was found. It seems clear that the mechanism of the muscle degeneration in the tadpole tail during metamorphosis is not the result of the degeneration of its nerve endings.

Acetylcholinesterase↗
PubMed1984

The ultrastructure of oral (buccopharyngeal) membrane formation and rupture in the anuran embryo.

The ultrastructure of the oral (buccopharyngeal) membrane was examined by transmission and electron microscopy in the anuran, Rana japonica, embryo. The stomodeum is recognizable on the ventral surface anterior to the neural folds as the neural folds are beginning to close (neural tube stage). The stomodeum is gradually enlarged and deepened as development proceeds. At the neural tube stage, the oral membrane is 5-7 cell layers thick and the stomodeal ectodermal cells are cuboidal and the foregut endodermal cells are cuboidal or columnar. Desmosomes and basal lamina could not be found between the ectodermal and endodermal epithelia. The oral membrane gradually thins between the neural tube and hatching stages. At the hatching stage, the oral membrane becomes two or three cell layers thick and each cell is flattened. Many perforations of the oral membrane after hatching and the oral membrane appears "net-like." Necrotic cells occur in the oral membrane and these cells contain many autophagic vacuoles. ACPase-positive lysosomes, Golgi regions, and autophagic vacuoles were present in the oral membrane. At the asymmetrical trunk stage, a large part of the oral membrane disappears and only remnants are left.

Animals↗
PubMed1984

Satellite cells in the tail muscles of the urodelan larvae during development.

The incidence and ultrastructure of satellite cells in the tail muscles of urodelan larvae were examined during development during which the number of satellite cells is gradually reduced. They are found more frequently in red than in the white fibres in all four stages examined (stage 53, 64, 66+ and juvenile). As development proceeds, intercellular space between satellite cell and muscle fibre is in general gradually extended and is mostly filled with basal lamina. Small muscle cells, satellite fibres, which are situated under the basal lamina of the parent fibre, are morphologically similar to satellite cells but contain a small amount of myofibrils. Three types of satellite fibres are distinguishable on the basis of differences in K2-EDTA-treated ATPase activity, width of Z line, and parent fibre type. Neuromuscular junctions are visible in satellite fibres.

Animals↗