Search PubMed⌕ Search

Biomedical subjects

H Uchida

Publications and source records attributed to H Uchida.

At least 109 records · Page 6Linked to original sources
PubMed1999

Rapid growth of residual colonic tumor after incomplete mucosal resection.

We report an 89-year-old man with colon cancer that developed rapidly after an incomplete endoscopic mucosal resection (EMR), and discuss the adverse effect of this maneuver on the tumor biology. A sessile polyp, 15 mm in size, was detected at the hepatic flexure. EMR was performed immediately. Histological examination showed well differentiated adenocarcinoma with an adenomatous component invading the submucosal layer. There was vascular invasion (positive on elastica van Gieson staining) and the surgical margin was positive for cancer. A right hemicolectomy was performed. The surgical specimen showed the residual tumor, 22 mm in diameter. The relevant histopathological findings of the surgical specimen were: well differentiated adenocarcinoma, with partly mucinous carcinoma and a tubular adenomatous component, depth muscularis propria (mp), lymph node (LN) (0/9). Most of the submucosally invasive cancer was resected by the initial EMR, but the small residual tumor showed rapid growth within only 3 months after the EMR. It was assumed that the residual tumor cells had acquired more malignant characteristics after EMR. In regard to EMR we propose that: (1) except for patients who are at high risk for a major operation, EMR should be avoided for carcinoma with massive submucosal invasion, (2) colonic resection should be performed immediately when histology shows a positive surgical margin for carcinoma, and (3) patients operated after an incomplete EMR should be watched very carefully for the detection of recurrence.

Adenocarcinoma↗
PubMed1999

Severe complications of ulcerative colitis after high-dose prednisolone and azathioprine treatment.

We report a rare case of ulcerative colitis (UC) associated with methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa infections in multiple organs, and with compressive fracture from osteoporosis after the administration of high-dose prednisolone and azathioprine. A 25-year-old man had been treated with high-dose prednisolone for UC. He suddenly experienced severe lumbago, which prevented him from walking. Plain X-ray demonstrated compressive fractures of the thoracic and the lumbar vertebrae, which were thought to be due to osteoporosis as a side effect of the high-dose prednisolone. At this admission, in another hospital, he also had a bloody discharge from the rectum, and azathioprine was started; however, the patient's condition still did not show any improvement. The total doses of azathioprine and prednisolone he had received were 3150 mg and more than 15,000 mg, respectively. Considering the presence of the serious complications, surgical intervention was the treatment selected. Culture study revealed MRSA in the feces and nasal cavity, and P. aeruginosa in the feces and urine. Vancomycin hydrochloride and gentamicin were administered, and were effective, with a subsequent negative culture study. Subtotal colectomy with mucus fistula was performed. After the operation, culture studies remained negative. Major steroid side effects such as bone fracture and osteoporosis should be considered as an indication for surgery in UC patients. MRSA and P. aeruginosa are a menace, especially for UC immunosuppressed patients on steroid or immunosuppressive therapy. When these bacteria are detected, there should be prompt and adequate antimicrobial therapy against the organisms and the immunosuppressive therapy should be immediately discontinued. We conclude that surgical therapy should be considered in the earlier stage for patients with intractable UC, rather than continuing long-term administration of steroid or azathioprine, which may lead to serious complications.

Adult↗
PubMed1999

Peripapillary atrophy in primary angle-closure glaucoma: a comparative study with primary open-angle glaucoma.

PURPOSE: To investigate the characteristics of peripapillary atrophy in primary angle-closure glaucoma and to compare peripapillary atrophy in primary angle-closure glaucoma with that in primary open-angle glaucoma. METHODS: Twenty-one eyes (of 21 patients) with chronic primary angle-closure glaucoma that had no evidence of an acute attack or combined-mechanism glaucoma and 31 eyes (31 patients) with primary open-angle glaucoma were enrolled in this study. The cup-to-disk area ratio and the visual field mean deviation were matched in both groups. The prevalence of peripapillary atrophy and peripapillary atrophy-to-disk area ratio of eyes with primary angle-closure glaucoma and eyes with primary open-angle glaucoma were compared. The correlation between the peripapillary atrophy area and the cup-to-disk area ratio or the mean deviation was also evaluated. RESULTS: Eight (38%) of 21 eyes with primary angle-closure glaucoma and 21 (68%) of 31 eyes with primary open-angle glaucoma had peripapillary atrophy. The peripapillary atrophy-to-disk area ratio averaged 0.16 in primary angle-closure glaucoma and 0.41 in primary open-angle glaucoma. There were statistically significant differences regarding the prevalence of peripapillary atrophy (P = .048) and peripapillary atrophy-to-disk area ratio (P = .005) between the two groups. There was no significant correlation between the peripapillary atrophy area and the cup-to-disk area ratio or the mean deviation in primary angle-closure glaucoma. In contrast, the peripapillary atrophy-to-disk area ratio significantly correlated with the cup-to-disk area ratio (P = .003) and the mean deviation (P = .0001) in primary open-angle glaucoma. CONCLUSIONS: The peripapillary atrophy in primary angle-closure glaucoma has a different relationship to the structural and functional optic disk changes than that in primary open-angle glaucoma. Different mechanisms seem to be involved in the development of the optic disk damage in the two types of glaucoma.

Adult↗
PubMed1999

Experimental small bowel transplantation using newborn intestine in rats: II. Revascularization of newborn intestine is independent of vascular endothelial growth factor.

BACKGROUND: Fetal and newborn intestine often are revascularized after subcutaneous transplantation without surgical vascular anastomosis. However, the mechanism of this ability remains unclear. METHODS: First, the ability of natural revascularization in newborn organs was tested. Newborn organs in whole (liver, kidney, heart, intestine, spleen, and pancreas) were grafted i nto the subcuta neous tissue of the adult rat and evaluated histopathologically 2 weeks after transplantation. Second, expression of vascular endothelial growth factor (VEGF) mRNA in the intestinal graft was determined before and after transplantation. Finally, we tested whether the free graft survival of newborn intestine was interrupted by TNP-470, an antiangiogenic agent. RESULTS: Spleen and intestine were revascularized at a higher rate (91.6%, 75%, respectively), and kidney and heart grafts survived at a lower rate (41.7%, 25%, respectively). But all of liver and pancreas grafts failed to be revascularized. VEGF mRNA was not induced in the course of revascularizing. Furthermore, TNP-470 did not interfere with neovascularization of the newborn intestinal graft in vivo. CONCLUSIONS: Each organ had an organ-specific angiogenic activity. Neovascularization of intestinal graft was not dependent on VEGF expression.

Angiogenesis Inhibitors↗
PubMed1999

Experimental small bowel transplantation using newborn intestine in rats: I. Lipid absorption restored after transplantation of nonvascularized graft.

BACKGROUND/PURPOSE: Utilizing the characters of neovascularized activity of newborn organs, the authors developed a rat model of small bowel transplantation with a free graft of newborn intestine into the recipient's omentum. METHODS: Segmental intestine from newborn rats were grafted into the omentum without vascular anastomosis in a syngeneic combination (n = 19). The transplanted intestine was examined morphologically and electrophysiologically 4 weeks after grafting. Then, recipients' small intestine was totally substituted by the transplanted newborn intestine, and recipients' survival was recorded after orthotopical reconstruction. During the experimental periods, feces of these rats were collected, and total lipid excretion was measured. The short-gut rats, whose small bowel was totally resected, served as a control (n = 12). RESULTS: Thirteen of 19 grafts (68.4%) were judged as a histologically mature intestine. They showed typical slow waves that were identical to those of native small intestine. After all of the mature grafts were interposed, six recipients (46.2%) survived longer than 15 weeks. Control short gut animals severely lost weight and died except for one. CONCLUSION: Newborn intestinal transplantation could restore severe weight loss in the short-gut rats and save them.

Animals↗
PubMed1999

Localized wedge-shaped defects of retinal nerve fiber layer and disc hemorrhage in glaucoma.

OBJECTIVE: To evaluate frequencies of localized wedge-shaped defects of the retinal nerve fiber layer (RNFL) in eyes with and without disc hemorrhage in normal-tension glaucoma (NTG) and primary open-angle glaucoma (POAG). This study also aims to define a topographic correlation between disc hemorrhage and localized RNFL defects in POAG. DESIGN: Cross-sectional study. PARTICIPANTS AND CONTROLS: The authors studied 83 eyes of 83 patients with NTG (male/female = 23/60; age, 58.8+/-12.9 years) and 20 eyes of 20 patients with POAG (male/female = 9/11; age, 61.6+/-11.4 years); subjects in both groups had developed new disc hemorrhage at the time of enrollment. The authors randomly selected 45 eyes of 45 patients with NTG (male/female = 20/25; age, 62.0+/-9.3 years) and 24 eyes of 24 patients with POAG (male/female = 13/11; age, 56.3+/-14.5 years) with no history of disc hemorrhage during the follow-up period of more than 2 years. METHODS: Visual field in the patients with POAG was matched to that of the patients with NTG regarding global indices for both the hemorrhage and the nonhemorrhage groups. Localized wedge-shaped defects of RNFL were identified by scanning laser ophthalmoscopy using an argon-blue laser. MAIN OUTCOME MEASURES: The frequency of localized RNFL defects and the relationship between the locations of disc hemorrhages and localized RNFL defects were determined. RESULTS: Localized wedge-shaped defects of RNFL occurred significantly more often in the hemorrhage group than in the nonhemorrhage group in both NTG (Fisher's exact probability test, P < 0.0001) and POAG (P < 0.05) patients. Regardless of the presence of disc hemorrhage, there was no significant difference in the frequency of localized RNFL defects between patients with NTG and those with POAG. Most disc hemorrhages were present in the vicinity of the border between localized RNFL defects and relatively healthy-looking RNFL in both patients with POAG and those with NTG. CONCLUSION: Disc hemorrhage is associated with localized damage of RNFL in both NTG and POAG.

Cross-Sectional Studies↗
PubMed1999

Nonclostridial gas gangrene due to Streptococcus anginosus in a diabetic patient.

Streptococcus anginosus was recently identified as a distinct species from the other members of Streptococcus milleri group (Streptococcus constellatus, Streptococcus intermedius). We report a rare case of nonclostridial gas gangrene caused by S. anginosus. A 62-year-old diabetic woman was admitted with gas gangrene of the perineal area. She had been taking her oral hypoglycemia medication regularly for 10 years, but the diabetes was inadequately controlled. She was treated with surgical debridement of the necrotic tissue, insulin injection, and antibiotic therapy, and had a satisfactory clinical course.

Diabetes Mellitus, Type 2↗
PubMed1999

Twin-tube endografts for aortic aneurysms: an experimental feasibility study.

PURPOSE: To explore feasibility of twin-tube endografts (TTEGs) for treatment of abdominal aortic aneurysm (AAA). MATERIALS AND METHODS: AAAs were created in six dogs by overdilation of Palmaz stents. TTEGs made of seven 9.5-mm-diameter Gianturco Rösch Z (GRZ) stents and covered with PTFE were deployed simultaneously from both femoral arteries through 10-F sheaths to exclude the AAA. Follow-up aortography was performed immediately and at 2, 4, and 8 weeks. Two dogs were killed at 4 weeks and four were killed at 8 weeks. Gross and histologic examinations were performed. RESULTS: AAA creation and TTEG placement were successful in all six dogs. TTEGs completely excluded AAAs in five dogs. Minor temporary perigraft leak was seen in one dog immediately after stent placement. Four dogs had TTEGs patent to termination at 8 weeks. In two dogs with oversized TTEGs, one of the twin endografts occluded at 2 weeks. At autopsy, TTEGs were formed in semicircular shape and histology did not show any significant inflammatory reaction. CONCLUSION: TTEGs show promise for treatment of AAA, with the potential of reducing the introductory sheath size. Further experimental studies, particularly with TTEGs extended into iliac arteries, are warranted.

Angiography↗
PubMed1999

Identification and selective perfusion of the spinal cord-feeding arteries by intrathecal pO2 monitoring for spinal cord protection.

OBJECTIVES: to study whether spinal cord-feeding arteries could be identified by the changes in the intrathecal pO2 (I-pO2), and to examine whether selective perfusion of feeding arteries identified by this method could protect the spinal cord against ischaemia. DESIGN: controlled animal experiments. MATERIALS AND METHODS: in experiment 1, using 16 mongrel dogs, 18 segmental arteries were cannulated through which oxygenated saline was injected and the I-pO2 change was observed. When the I-pO2 increase was more than 0.5 mmHg, the artery was considered to be a spinal cord-feeding artery. In experiment 2, involving 10 dogs, the segmental arteries identified as spinal cord-feeding arteries were perfused with arterial blood and the recovery of I-pO2 and evoked spinal potentials (ESP) was examined. RESULTS: of 208 segmental arteries examined, 176 (84.6%) arteries were correctly judged and 32 (15.4%) were not. It was observed that the I-pO2 recovered from 13.9 to 30.5 mmHg and the ESP recovered from 20.9% and 8.2% to 66.5% and 44.7% of each control for the first negative (N1) and second negative (N2) components, respectively. CONCLUSION: spinal cord-feeding arteries were successfully identified using the I-pO2 monitoring method. Perfusion of these arteries with arterial blood improved the I-pO2 and ESP, which were significantly depressed by ischaemia.

Animals↗
PubMed1999

Shiga toxins induce apoptosis in pulmonary epithelium-derived cells.

The effect of Shiga toxins (Stxs) produced by Escherichia coli on human lung epithelial cells was investigated. Specific antibodies for Stxs positively stained lung tissue from a patient who died of hemolytic uremic syndrome associated with Stx-producing E. coli (STEC) infection, indicating the deposition of Stxs in the lung. Binding experiments with normal lung tissue revealed apparent Stx binding to both vascular endothelium and to portions of the pulmonary epithelium. CD77-positive lung carcinoma cell lines, which are derived from lung epithelium, showed binding to Stx and a high susceptibility to Stxs, as determined by MTT assay. Consistent with our previous reports on renal tubular epithelium, apoptosis is involved in the Stx-mediated cytotoxicity of these lines. These data indicate that lung epithelium is another target for Stxs, and Stx-mediated injury to lung epithelial cells is thought to play an important role in the pathogenesis of pulmonary involvement associated with STEC infection.

Antigens, CD↗
PubMed1999

Platelet hyporeactivity in young infants during cardiopulmonary bypass.

UNLABELLED: Platelet dysfunction is one of the most important factors contributing to a postoperative hemorrhagic diathesis in children with congenital heart disease undergoing operations requiring cardiopulmonary bypass (CPB). However, very little is known about the influence of CPB on platelets in neonates and young infants. We studied 16 patients--8 young infants (<2 mo old) and 8 children (>12 mo old)--with congenital heart disease undergoing CPB. Surface density of an important platelet adhesive receptor, glycoprotein Ib, and degree of platelet activation, indicated by p-selectin positivity, were measured by whole blood flow cytometry in samples obtained at seven time points during the operations. We found that the percentage of p-selectin-positive platelets increased significantly in children, but not in young infants, during CPB. The young infant group exhibited a significantly smaller reduction of glycoprotein Ib than the child group during CPB (21.0% +/- 12.0% vs 32.7% +/- 18.1%; P < 0.05). Lack of CPB-induced increase of p-selectin and a smaller decrease of glycoprotein Ib in young infants in the current study suggest reduced platelet reactivity in young infants and neonates during CPB. The clinical significance of the reduced platelet reactivity in young infants and neonates remains to be determined. IMPLICATIONS: Platelets of young infants are less reactive than those of children during cardiopulmonary bypass, as determined by the cardiopulmonary bypass-induced alterations in platelet membrane adhesive receptors.

Age Factors↗
PubMed1999

Characterization of Chlamydomonas reinhardtii zygote-specific cDNAs that encode novel proteins containing ankyrin repeats and WW domains.

Genes that are expressed only in the young zygote are considered to be of great importance in the development of an isogamous green alga, Chlamydomonas reinhardtii. Clones representing the Zys3 gene were isolated from a cDNA library prepared using zygotes at 10 min after fertilization. Sequencing of Zys3 cDNA clones resulted in the isolation of two related molecular species. One of them encoded a protein that contained two kinds of protein-to-protein interaction motifs known as ankyrin repeats and WW domains. The other clone lacked the ankyrin repeats but was otherwise identical. These mRNA species began to accumulate simultaneously in cells beginning 10 min after fertilization, and reached maximum levels at about 4 h, after which time levels decreased markedly. Genomic DNA gel-blot analysis indicated that Zys3 was a single-copy gene. The Zys3 proteins exhibited parallel expression to the Zys3 mRNAs at first, appearing 2 h after mating, and reached maximum levels at more than 6 h, but persisted to at least 1 d. Immunocytochemical analysis revealed their localization in the endoplasmic reticulum, which suggests a role in the morphological changes of the endoplasmic reticulum or in the synthesis and transport of proteins to the Golgi apparatus or related vesicles.

Amino Acid Sequence↗
PubMed1999

In vitro anti-human immunodeficiency virus activities of Z- and E-methylenecyclopropane nucleoside analogues and their phosphoro-L-alaninate diesters.

Nucleoside analogues with a Z- or an E-methylenecyclopropane moiety were synthesized and examined for activity against human immunodeficiency virus type 1 (HIV-1) in vitro. The addition of a methyl phenyl phosphoro-L-alaninate moiety to modestly active analogues resulted in potentiation of their anti-HIV-1 activity. Two such compounds, designated QYL-685 (with 2,6-diaminopurine) and QYL-609 (with adenine), were most potent against HIV-1 in vitro, with 50% inhibitory concentrations of 0.034 and 0.0026 microM, respectively, in MT-2 cell-based assays. Both compounds were active against zidovudine-resistant, didanosine-resistant, and multi-dideoxynucleoside-resistant infectious clones in vitro. Further development of these analogues as potential therapies for HIV-1 infection is warranted.

Anti-HIV Agents↗