Biomedical subjects

Satoshi Fukumoto

Publications and source records attributed to Satoshi Fukumoto.

26 records · Page 2Linked to original sources

PubMed2003

Adenocarcinoma arising in a tubular duplication of the jejunum.

To our knowledge, only five cases of malignant changes in small-bowel duplication have been reported previously in the English-language literature, and these were found only in ileal duplications. We describe a unique case of adenocarcinoma arising in a tubular duplication of the jejunum; this is the oldest patients in whom malignant tumor of alimentary tract duplication has been reported. A 73-year-old man was admitted to our hospital because of lower abdominal pain. Computed tomography (CT) and ultrasonography showed two abdominal masses; one, about 5 cm in size, was observed in the upper abdomen, the superior mesenteric artery (SMA) and the other, which was a well-demarcated heterogeneous mass, was revealed in the lower abdomen. Laparotomy revealed the mass in the upper abdomen involved the SMA and transverse colon, while the mass in the lower abdomen was of white globular form, ping-pong ball size, in the jejunal serosa approximately 40 cm on the anal side from Treiz's ligament. Transverse colostomy and a partial jejunectomy were performed, and the tumor was resected. Histologically, the diagnosis was adenocarcinoma arising in a tubular duplication of the jejunum. The patient died of necrosis and perforation of the intestine due to obstruction of the SMA 7 months after the surgery. Autopsy revealed that the upper abdominal mass consisted of metastatic foci associated with the lymph node of the SMA.

Adenocarcinoma↗

PubMed2003

Short-chain fatty acids stimulate colonic transit via intraluminal 5-HT release in rats.

We studied whether physiological concentration of short-chain fatty acids (SCFAs) affects colonic transit and colonic motility in conscious rats. Intraluminal administration of SCFAs (100-200 mM) into the proximal colon significantly accelerated colonic transit. The stimulatory effect of SCFAs on colonic transit was abolished by perivagal capsaicin treatment, atropine, hexamethonium, and vagotomy, but not by guanethidine. The stimulatory effect of SCFAs on colonic transit was also abolished by intraluminal pretreatment with lidocaine and a 5-hydroxytryptamine (HT)(3) receptor antagonist. Intraluminal administration of SCFAs provoked contractions at the proximal colon, which migrated to the mid- and distal colon. SCFAs caused a significant increase in the luminal concentration of 5-HT of the vascularly isolated and luminally perfused rat colon ex vivo. It is suggested that the release of 5-HT from enterochromaffin cells in response to SCFAs stimulates 5-HT(3) receptors located on the vagal sensory fibers. The sensory information is transferred to the vagal efferent and stimulates the release of acetylcholine from the colonic myenteric plexus, resulting in muscle contraction.

Animals↗

PubMed2002

Deformation of lipid droplets in fixed samples.

Nile red, Sudan III, and oil red O have been used to stain lipid droplets (LDs) for fluorescence microscopy. We noticed that LDs labeled by Nile red are different in appearance from those stained by the latter two dyes. To understand the cause of the difference, we used sequential labeling procedures (first LD stain-photography-quenching-second LD stain-photography), and examined the effect of several factors. Immunofluorescence labeling for adipose differentiation-related protein (ADRP), an LD marker, was also observed comparatively with the lipid stains. As a result, we found that ethanol and isopropanol used for Sudan III and oil red O staining, respectively, and glycerol used for mounting, cause fusion of adjacent LDs even in glutaraldehyde-fixed samples. By the same treatment, immunofluorescence labeling for ADRP was dislocated to the rim of large LDs that were formed as a result of the artifactual fusion. The result indicates that the LD structure can be better observed with Nile red than with Sudan III or oil red O.

Adipose Tissue↗

PubMed2002

Overexpression of ganglioside GM1 results in the dispersion of platelet-derived growth factor receptor from glycolipid-enriched microdomains and in the suppression of cell growth signals.

To investigate the molecular mechanisms of gangliosides for the regulation of cell proliferation, Swiss 3T3 cells were transfected with GM2/GD2 synthase and GM1 synthase cDNAs, resulting in the establishment of GM1-expressing (GM1(+)) lines. Compared with the vector control (GM1(-)) cell lines, GM1(+) cells exhibited reduced cell proliferation by stimulation with platelet-derived growth factor (PDGF). In accordance with the reduced cell growth, GM1(+) cells showed earlier decreases in the phosphorylation levels of PDGF receptor and less activation of MAP kinases than GM1(-) cells. To analyze the effects of GM1 expression on the PDGF/PDGF receptor (PDGFR) signals, the glycolipid-enriched microdomain (GEM) was isolated and the following results were obtained. (i) PDGFR predominantly distributed in the non-GEM fraction in GM1(+) cells, while it was present in both GEM and non-GEM fractions in GM1(-) cells. (ii) Activation of PDGFR as detected by anti-phosphotyrosine antibody occurred almost in parallel with existing amounts of PDGFR in each fraction. (iii) GM1 binds with PDGFR in GEM fractions. These findings suggested that GM1 regulates signals via PDGF/PDGFR by controlling the distribution of PDGFR in- and outside of GEM, and also interacting with PDGFR in the GEM fraction as a functional constituent of the microdomain.

3T3 Cells↗

PubMed2001

b-series Ganglioside deficiency exhibits no definite changes in the neurogenesis and the sensitivity to Fas-mediated apoptosis but impairs regeneration of the lesioned hypoglossal nerve.

The polymorphic carbohydrate structures of gangliosides play regulatory roles. In particular, b-series gangliosides, all of which contain alpha-2,8 sialic acids, have been considered to be critical in various biological events such as adhesion, toxin binding, neurite extension, cell growth, and apoptosis. To clarify the physiological functions of b-series gangliosides in vivo, we have established a gene knockout mouse of GD3 synthase. Although all b-series structures were deleted in the mutant mice, they showed an almost complete nervous tissue morphology with no apparent abnormal behavior. Moreover, no differences in Fas-mediated apoptotic reaction of lymphocytes between wild type and the mutant mice were detected. However, the mutant mice exhibited clearly reduced regeneration of axotomized hypoglossal nerves compared with the wild type, suggesting that b-series gangliosides are more important in the repair rather than in the differentiation of the nervous system and apoptotic process induced via Fas.

Animals↗

PubMedDate not supplied

Laparoscopy-assisted colon resection for mucosa-associated lymphoid tissue (MALT) lymphoma in the cecum.

Colonic MALToma (mucosa-associated lymphoid tissue lymphoma) has not been well investigated compared to stomach MALToma which is related to Helicobacter pylori infection. We report the uncommon case of MALToma in the cecum initially identified as submucosal tumor, successfully treated by laparoscopy-assisted resection with systemic lymphadectomy. As the metastatic ability and sensitivity against chemotherapy of colonic MALToma is not known, temporally, this treatment seems to be the best choice.

Adult↗

PubMedDate not supplied

Tape ligature of cystic duct and fundus-down approach for safety laparoscopic cholecystectomy: outcome of 500 patients.

It is important to identify the structure of Calot's triangle at the time of cystic duct isolation to decrease intraoperative bile duct injury. Isolation of the cystic duct is the first dangerous technique in laparoscopic cholecystectomy. In conventional open cholecystectomy, the fundus-down approach (retrograde) is a more common procedure than the approach in the reverse direction. Similarly, the fundus-down approach is safe and has benefits of reducing common bile duct injury. We report the easy and safe contrivance for laparoscopic cholecystectomy with taping of the cystic duct followed by resection of the gallbladder with the fundus-down approach, performed for 500 patients. The identified cystic duct was ligatured temporarily with Teflon tape. Then, fundus of the gallbladder was isolated with the fundus-down approach except for Calot's triangle. The tape was used for pulling down the cystic duct and Calot's triangle was easily visible. The cystic duct was cut off only after the confirmation of no bile duct injury. Thanks to this tape procedure, there was no bile duct injury in our 500 cases. We recommend this tape ligature of the cystic duct with the fundus-down approach to decrease the incidence of common bile duct injury.

Adolescent↗

PubMedDate not supplied

Lymphadenectomy along the middle colic artery in laparoscopic resection of transverse colon.

BACKGROUND/AIMS: Although laparoscopic-assisted colectomy has been replacing open colectomy, dissection of lymph nodes along the main artery is sometimes difficult and dangerous in laparoscopic-assisted colectomy, especially, lymph nodes at the origin of the middle colic artery in laparoscopic resection of the transverse colon. METHODOLOGY: After the isolation of colon, meso-colon in both ends was excised. Then, the colon was rotated clockwise 90 degrees by centering at the base of the meso-colon. This procedure made it easier to isolate the anterior and posterior leaf of the meso-colon at its base. The middle colic artery was divided at the root with the dissection of lymph nodes around the base of the meso-colon. RESULTS: Successful lymphadenectomy of the lymph node along the origin of the middle colic artery was performed. Twelve patients with early transverse colon cancer underwent laparoscopic transverse colon resection using this method. CONCLUSIONS: This method may contribute to the easy and safe laparoscopic transverse colectomy by improving the limited view of the laparoscope and raises the possibility for laparoscopic resection of advanced colon cancer.

Aged↗