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A Kuroda

Publications and source records attributed to A Kuroda.

At least 73 records · Page 4Linked to original sources
PubMed1995

Analysis of small cystic lesions of the pancreas.

UNLABELLED: There have been few reports on (1) the nature and pathogenesis of small cystic lesions of the pancreas, (2) their incidence, age distribution, and location, and (3) their significance as potential precursors of intraductal papillary tumors, mucinous cystic tumors, and duct cell carcinomas. MATERIALS: Epithelial growth of small cystic lesions in 300 consecutive autopsy cases and in seven cases of small duct cell carcinoma from among 2300 elderly autopsy cases, was evaluated by histopathological analysis. One hundred eighty-six cystic lesions were found in 73 of 300 autopsy cases (24.3%). The incidence of cystic lesions increased with age. Cystic lesions were equally distributed throughout the pancreas. Epithelial atypia was histologically classified into five groups: normal epithelium; papillary hyperplasia without atypia; atypical hyperplasia; carcinoma in situ; and invasive carcinoma. The incidence of each group was 47.5, 32.8, 16.4, 3.4, and 0%, respectively. Epithelia of atypical hyperplasia or carcinoma in situ were more prevalent in small cystic lesions (less than 4 mm in diameter) than in larger lesions (chi-square test, p < 0.05). Epithelia of dilated ductular branches adjacent to cystic lesions showed a similar degree of atypia as the epithelia of the cystic lesions themselves (p < 0.01). Epithelial atypia of the main pancreatic duct was mild in all of the cases but two, and was not related to that of the cystic lesion. Among the seven cases of small duct cell carcinoma, two cases had small cancerous cystic lesions, 4.1 and 5.3 mm in diameter, within the tumor. Small cystic lesions appear to have the potential to progress to malignancy but definitive evidence has not been demonstrated. Additional studies, including molecular biological examinations, are necessary to fully understand the biology of these lesions.

Aged↗
PubMed1995

Nucleotide sequence and regulation of a new putative cell wall hydrolase gene, cwlD, which affects germination in Bacillus subtilis. .

DNA sequencing of a region upstream of the mms223 gene of Bacillus subtilis showed the presence of two open reading frames, orf1 and orf2, which may encode 18- and 27-kDa polypeptides, respectively. The predicted amino acid sequence of the latter shows high similarity to a major autolysin of B. subtilis, CwlB, with 35% identity over 191 residues, as well as to other autolysins (CwlC, CwlM, and AmiB). The gene was tentatively named cwlD. Bright spores produced by a B. subtilis mutant with an insertionally inactivated cwlD gene were committed to germination by the addition of L-alanine, and spore darkening, a slow and partial decrease in A580, and 72% dipicolinic acid release compared with that of the wild-type strain were observed. However, degradation of the cortex was completely blocked. Spore germination of the cwlD mutant measured by colony formation after heat treatment was less than 3.7 x 10(-8). The germination deficiency of the cwlD mutant was only partially removed when the spores were treated with lysozyme. Analysis of the chromosomal transcription of cwlD demonstrated that a transcript (RNA2) appearing 3 h after initiation of sporulation may have originated from an internal sigma E-dependent promoter of the cwlD operon, and a longer transcript (RNA1) appearing 4.5 h after sporulation may have originated from a sigma G-dependent promoter upstream of the orf1 gene. The cwlD mutant harboring a B. subtilis vector plasmid containing the intact cwlD gene recovered germination at a frequency 26% of the wild-type level.

Alanine↗
PubMed1995

Molecular cloning and characterization of a chemotactic transducer gene in Pseudomonas aeruginosa.

A Pseudomonas aeruginosa mutant, defective in taxis toward L-serine but responsive to peptone, was selected by the swarm plate method after N-methyl-N'-nitrosoguanidine mutagenesis. The mutant, designated PCT1, was fully motile but failed to show chemotactic responses to glycine, L-serine, L-threonine, and L-valine. PCT1 also showed weaker responses to some other commonly occurring L-amino acids than did the wild-type strain PAO1. A chemotactic transducer gene, denoted pctA (Pseudomonas chemotactic transducer A), was cloned by phenotypic complementation of PCT1. Nucleotide sequence analysis showed that the pctA gene encodes a putative polypeptide of 629 amino acids with a calculated mass of 68,042. A hydropathy plot of the predicted polypeptide suggested that PctA may be an integral membrane protein with two potential membrane-spanning regions. The C-terminal domain of PctA showed high homology with the enteric methyl-accepting chemotaxis proteins (MCPs). The most significant amino acid sequence similarity was found in the region of MCPs referred to as the highly conserved domain. The pctA gene was inactivated by insertion of a kanamycin resistance gene cassette into the wild-type gene, resulting in the same observed deficiency in taxis toward L-amino acids as PCT1. In vivo methyl labeling experiments with L-[methyl-3H]methionine showed that this knockout mutant lacked an MCP with a molecular weight of approximately 68,000.

Amino Acid Sequence↗
PubMed1995

Large cholesterol polyps of the gallbladder: diagnosis by means of US and endoscopic US.

PURPOSE: To identify ultrasonographic (US) features of large cholesterol polyps (> 10 mm in diameter) of the gallbladder in the differential diagnosis of polypoid lesions. MATERIALS AND METHODS: Sixty-seven patients underwent US (n = 67) and endoscopic US (n = 33). Fourteen patients had large cholesterol polyps. Findings in these patients were compared with those in patients with small cholesterol polyps (< or = 10 mm in diameter; n = 34) or other polypoid lesions (n = 19). RESULTS: US demonstrated the large cholesterol polyps as pedunculated masses with granular surfaces. In 94% of patients, all small cholesterol polyps were echogenic whereas the large cholesterol polyps tended to have decreased echogenicity. Endoscopic US showed complete or partial aggregation of echogenic spots in all cholesterol polyps-but not in other polypoid lesions, which included carcinomas. CONCLUSION: Aggregation of echogenic spots seems to be a US feature characteristic of both large and small cholesterol polyps. Routine use of endoscopic US is recommended for differential diagnosis of polypoid lesions because of its high resolution.

Adenocarcinoma↗
PubMed1995

Diagnosis of acute pancreatitis: value of endoscopic sonography.

OBJECTIVE: The aim of this study is to assess the diagnostic usefulness of endoscopic sonography in acute pancreatitis. SUBJECTS AND METHODS: Twenty-three patients with clinically diagnosed acute pancreatitis (edematous pancreatitis in 16 and necrotizing pancreatitis with heterogeneous enhancement of the pancreas on contrast-enhanced CT scans in seven) prospectively underwent endoscopic sonography. We studied visualization of the pancreas and the extrahepatic bile duct, capability of differentiation between edematous and necrotizing pancreatitis, and detectability of common bile duct stones and compared the results of endoscopic sonography with those of conventional sonography, CT, and ERCP. In 25 normal subjects, we performed endoscopic sonography to determine the size of the pancreas. RESULTS: Endoscopic sonography could be performed at the bedside noninvasively and repeatedly. Normal pancreas size was defined from the results of normal subjects. Endoscopic sonography adequately showed the whole length of the pancreas and the extrahepatic bile duct in all cases. On endoscopic sonography, the pancreas was enlarged in 10 of 16 patients with edematous pancreatitis and in all seven patients with necrotizing pancreatitis. In edematous pancreatitis, the echogenicity of the pancreas was normal (four patients) or diffusely hypoechoic (12 patients). In all seven patients with necrotizing pancreatitis, endoscopic sonography showed a pancreatic focal hypoechoic mass with or without interspersed echogenic spots. Endoscopic sonography could differentiate edematous and necrotizing pancreatitis as well as CT could. Conventional sonography depicted the pancreas in only 61% of patients. Endoscopic sonography was highly sensitive in depicting inflammatory peripancreatic spread compared with CT. Endoscopic sonography was more sensitive (100%) than conventional sonography (43%) and CT (57%) for detecting bile duct stones in biliary pancreatitis. CONCLUSION: This study suggests that endoscopic sonography may be useful for the diagnosis of acute pancreatitis, particularly in cases of biliary pancreatitis.

Acute Disease↗
PubMed1995

Interleukin 10 cooperates with interleukin 4 to suppress inflammatory cytokine production by freshly prepared adherent rheumatoid synovial cells.

OBJECTIVE: Inflammatory cytokines have been implicated as important mediators of inflammation in rheumatoid arthritis (RA). We investigated whether interleukin 4 (IL-4) and interleukin 10 (IL-10) suppress the production of inflammatory cytokines by freshly prepared adherent rheumatoid synovial cells. METHODS: Adherent synovial cells were obtained from the rheumatoid synovium by collagenase digestion. The levels of IL-1 beta, tumor necrosis factor-alpha (TNF-alpha), IL-6, and IL-8 in culture supernatants were measured by ELISA. The gene expression of IL-6 and IL-8 were determined by Northern blot analysis. RESULTS: Freshly prepared rheumatoid synovial cells spontaneously produced large amounts of IL-6 and IL-8. However, the amounts of IL-1 beta and TNF-alpha produced were approximately 1000-fold less than those of IL-6 and IL-8. IL-4 alone inhibited the production of IL-1 beta, IL-6, and IL-8 by 32, 35, and 50%, respectively. IL-10 alone was less potent than IL-4 in suppressing these cytokines. Of note, the combination of IL-4 and IL-10 cooperatively exerted potent suppressive effects on the production of IL-1 beta, IL-6, and IL-8 by 74.3, 69, and 77%, respectively. The suppressive effects of the combination of IL-4 and IL-10 on IL-6 and IL-8 were also observed at the levels of mRNA. CONCLUSION: These results suggest that combination of IL-4 and IL-10 may be capable of suppressing the production of inflammatory cytokines at rheumatoid inflammatory joints.

Aged↗
PubMed1994

Lysis of endothelial cells by autologous lymphokine-activated killer cells.

The mechanisms of lysis of endothelial cells derived from human umbilical vein (HUVEC) by autologous lymphokine-activated killer (LAK) cells, generated from cord blood lymphocytes of the same donor, were investigated. Freshly isolated HUVEC as well as HUVEC cultured for several passages were efficiently lysed by autologous LAK cells, and their susceptibility to the LAK cells was almost the some as that of allogenic HUVEC. Complement-depletion experiments revealed that the lysis was mainly dependent on CD16+ natural killer (NK) LAK cells. pretreatment of HUVEC with recombinant interferon gamma (rIFN gamma) for 24 h made them resistant to lysis by autologous LAK cells, while pretreatment with either rIL-1 beta. rTNF alpha, or acidic or basic fibroblast growth factor did not alter the lytic sensitivity of HUVEC. The resistance of rIFN gamma-treated HUVEC was specific to lysis by CD16+ NK LAK cells, and their lysis by CD3+ T-LAK cells was not significantly altered. Moreover, in comparison with control HUVEC or rIL-1 beta-treated HUVEC, rIFN gamma-treated HUVEC had a significantly less potent inhibitory effect on the lysis of untreated HUVEC, when used as an unlabeled target. This suggests that rIFN gamma treatment may down-regulate the recognition of some molecules on HUVEC by rIL-2-activated NK cells. These data suggest that damage of the endothelium during LAK therapy is mainly dependent on LAK cells with a NK phenotype that can specifically recognize a certain molecule on autologous endothelial cells.

CD3 Complex↗
PubMed1994

Intracellular action of an exogenous low-molecular-weight synthetic protease inhibitor, E3123, in cerulein-induced acute pancreatitis in rats.

The intracellular distribution and action of a new synthetic protease inhibitor, E3123, were studied in cerulein-induced acute pancreatitis in rats. Acute pancreatitis was induced by a 4-h iv infusion of a supramaximal dose of cerulein, and was treated by prophylactic (pretreatment) or therapeutic (posttreatment) continuous administration of E3123. Pancreatic edema and hyperamylasemia were ameriolated only by prophylactic treatment. A subcellular fractionation study showed that the activities of cathepsin-B and trypsin in the zymogen granule-enriched fraction of the cerulein-pancreatitis group were remarkably increased. Both prophylactic and therapeutic treatment significantly prevented the elevation of these enzyme activities. These effects were accompanied by amelioration of pancreatic histopathological features, including intracellular vacuolization and fat necrosis. A microscopic autoradiographic study using 3H-labeled E3123 showed diffuse intracellular distribution of E3123, and the radioactivity of 3H-E3123 in the posttreatment group was three times greater than that in the pretreatment group. This study provides the first experimental evidence that, even when administered therapeutically, exogenous protease inhibitors are transported into pancreatic acinar cells, thereby reducing the severity of early intracellular alterations in cerulein-induced acute pancreatitis.

Acute Disease↗
PubMed1994

Different clinicopathologic findings in two histologic types of carcinoma of papilla of Vater.

The aim of this study was to investigate the differences between the clinicopathological findings in two histologic types of carcinoma of the papilla of Vater. We histologically classified carcinoma of the papilla into two types: 1) an intestinal type that resembles tubular adenocarcinoma of the stomach or colon, and 2) a pancreaticobiliary type that is characterized by papillary projections with scant fibrous cores. We examined 53 cases of resected carcinoma of the papilla. The intestinal-type carcinomas were similar to the intestinal mucosa in that they had lysozyme-containing, Paneth or argyrophil cells, as demonstrated by the immunohistochemically positive stainings for the anti-lysozyme antibody. Although both the sizes of the two types of carcinomas and the age distributions of cases with the two types of carcinoma were almost the same, the prognosis of the cases with the intestinal type was much better than that of the cases with the pancreaticobiliary type. Histological lymph node metastasis was found significantly more often in the pancreaticobiliary type. This result was supported by the fact that small carcinomas of the intestinal type showed little or no invasion into the surrounding interstitium, as opposed to the pancreaticobiliary type, which had a strong infiltrative tendency. The pathogenesis of carcinoma of the papilla of Vater should be further evaluated, taking into consideration the existence of these two histologic types.

Adult↗
PubMed1994

Alpha 1-adrenoceptors in the conduction system of rat hearts.

1. We have characterized alpha 1-adrenoceptor in the conduction systems of the rat heart by quantitative autoradiography. 2. Consecutive 20 micron thick sections from a single rat heart containing the sinoatrial (SA) node and atrioventricular (AV) node were incubated with increasing concentrations of [3H]-prazosin with or without 10 microM phentolamine. After exposure to 3H-Ultrofilm, optical densities corresponding to the SA node and AV node were determined by computerized densitometry after comparison with 3H standards. 3. The SA node and AV node were stained heavily for cholinesterase and they contained a higher concentration of alpha 1-adrenoceptors than the adjacent myocardium without a significant change in the affinity. 4. These results support the hypothesis that alpha 1-adrenoceptors may play an important role not only in inotropism but also in chronotropism of rat hearts.

Animals↗
PubMed1994

Effect of degS-degU mutations on the expression of sigD, encoding an alternative sigma factor, and autolysin operon of Bacillus subtilis.

Primer extension analysis of transcripts of the Bacillus subtilis autolysin (cwlB) operon indicated that SigD-dependent transcripts from the Pd promoter are missing in the degU32(Hy) and degS200 (Hy) mutants. The degU32(Hy) mutation caused a 99% reduction in the expression of a sigD-lacZ translational fusion gene constructed in the B. subtilis chromosome. The phosphorylated form of the DegU protein seems to be a regulator for expression of the sigD gene.

Bacillus subtilis↗
PubMed1994

IgE antibody production is associated with suppressed interferon-gamma levels in mesenteric lymph nodes of rats infected with the nematode Nippostrongylus brasiliensis.

IgE and IgG2a antibody production and interferon (IFN)-gamma secretion were studied in rats infected with the gut nematode Nippostrongylus brasiliensis by in vitro cultivation of mononuclear cells obtained from spleen (SPL), mesenteric lymph nodes (MLN) and pulmonary hilar lymph nodes (PLN). The highest levels of IgE were detected in the culture supernatants of MLN cells after infection: IgE levels were modest in PLN and negligible in SPL. In contrast, the highest levels of IgG2a were produced by PLN cells, followed by MLN and SPL cells. These results indicate that the MLN is the most significant site for IgE production in nematode infection, while IgG2a production is more marked in PLN. In naive rats, the spontaneous secretion of IFN-gamma was highest in PLN cells, followed by MLN and SPL cells. After the infection, IFN-gamma levels were significantly decreased in MLN and PLN. Suppression of IFN-gamma secretion was also observed in concanavalin A (ConA)-stimulated MLN and PLN cells from infected rats. In MLN, the ratio of CD4+ to CD8+ T cells was increased after the infection. Stimulation with an allergen-rich, excretory-secretory (ES) substance of the nematode enhanced ongoing IgE production, and suppressed IFN-gamma secretion by MLN and PLN cells. In contrast, an allergen-poor, adult worm extract potentiated IFN-gamma secretion. These results show that nematode-induced IgE antibody response is associated with the suppressed production and/or secretion of IFN-gamma, particularly in the MLN, and that some molecules in the ES substance may trigger these immune responses.

Animals↗
PubMed1993

Bacillus subtilis mutant deficient in the major autolytic amidase and glucosaminidase is impaired in motility.

The purified autolytic endo-beta-N-acetylglucosaminidase of Bacillus subtilis AC327 was cleaved with cyanogen bromide, and the N-terminal amino acid sequence of one of the peptide fragments was determined. Then, a DNA fragment containing a part of the glucosaminidase gene was cloned into Escherichia coli JM109 using synthetic oligonucleotides as probes whose sequences had been deduced from the N-terminal amino acid sequence. Zymographic analysis showed that the resultant glucosaminidase-deficient strain lacked a 35-kDa lytic band in addition to a 90-kDa lytic one corresponding to the glucosaminidase. A double mutant strain deficient in the major two autolysins (amidase and glucosaminidase) exhibited greatly impaired motility on a swarm plate whereas the single mutant strains were motile.

Acetylglucosaminidase↗
PubMed1993

Transendothelial migration activity of lymphokine-activated killer (LAK) cells.

With an in vitro static system using HUVEC (human umbilical vein-derived endothelial cells) cultured on type I collagen gel, we investigated the transendothelial migration activities of I1-2 activated killer (LAK) cells. Our results indicate that in comparison with unstimulated T cells, LAK cells exhibit strong transendothelial migration activity, as well as increased adhesiveness to HUVEC. Pretreatment of HUVEC for 24 h with rINF-gamma, rTNF-alpha and rIL-1 beta enhanced the LAK cell migration. The increase in the percentage of migration of LAK cells was greater than that of the percentage of adhesion but significantly less than the increase in the percentage of migration of resting T cells. The results of blocking studies using mAb strongly suggest that the enhanced migration of LAK cell was probably attributed to nonspecifically increased binding to HUVEC and markedly enhanced chemokinetic activity that was dependent primarily on the LFA-1 molecule. Among LAK cells, there were considerable differences in the migration activities of the various phenotypes. CD8+T-LAK migrated preferentially to CD4+T-LAK. CD16+ NK-LAK showed increased adhesion but somewhat decreased migration activities. However, rINF-gamma treatment of HUVEC for 24 h promoted vigorous migration of CD16+ NK-LAK, which suggests that endothelium regulate the migration of LAK cells. Based on these observations, we proposed that LAK cells, if transferred into tumor feeding vessels, can migrate into tumor tissue in considerable numbers and efficiently make contact with individual tumor cells to produce preferable clinical effects.

Cell Adhesion↗
PubMed1993

Molecular cloning, sequence analysis, and characterization of a new cell wall hydrolase, CwlL, of Bacillus licheniformis.

We have cloned a DNA fragment containing the gene for a cell wall hydrolase from Bacillus licheniformis FD0120 into Escherichia coli. Sequencing of the fragment showed the presence of an open reading frame (ORF; designated as cwlL), which is different from the B. licheniformis cell wall hydrolase gene cwlM, and encodes a polypeptide of 360 amino acids with a molecular mass of 38,994. The enzyme purified from the E. coli clone is an N-acetylmuramoyl-L-alanine amidase, which has a M(r) value of 41 kDa as determined by SDS-polyacrylamide gel electrophoresis, and is able to digest B. licheniformis, B. subtilis and Micrococcus luteus cell walls. The nucleotide and deduced amino acid sequences of cwlL are very similar to those of ORF3 in the putative operon xpaL1-xpaL2-ORF3 in B. licheniformis MC14. Moreover, the amino acid sequence homology of CwlL with the B. subtilis amidase CwlA indicates two evolutionarily distinguishable regions in CwlL. The sequence homology of CwlL with other cell wall hydrolases and the regulation of cwlL are discussed.

Amino Acid Sequence↗
PubMed1993

Treatment of choledocholithiasis in patients with liver cirrhosis. Surgical treatment or endoscopic sphincterotomy?

OBJECTIVE: The clinical features of choledocholithiasis were analyzed in cirrhotic patients. The outcomes of surgical treatment and endoscopic sphincterotomy (EST) in this situation were compared and the risk factors predictive of an increased mortality rate were identified. SUMMARY BACKGROUND DATA: In cirrhotic patients, high risk for gallbladder stones in cholecystectomy has been established. Common bile duct stones can often exacerbate liver dysfunction and might be more difficult to treat. METHODS: Among 16 cirrhotic patients with choledocholithiasis, 9 underwent choledocholithotomy and T-tube placement (surgery group) and 7 underwent EST (EST group). Pretreatment clinical data were comparable between groups. RESULTS: Among 16 patients, 15 had biliary tract symptoms and 7 had cholangitis. The surgery group had excessive intraoperative hemorrhage (1576 mL) and a high morbidity rate (66.7%). The mortality rate was 44.4%: 0% in Child A or B classification patients and 80% in Child C patients. The common causes of death were liver failure, postoperative hemorrhage, and sepsis. The EST group had no complications related to procedures, but there was one death (14.3%) due to preexisting liver failure. Hepatic dysfunction, coagulopathy, and cholangitis were factors predictive of an increased mortality rate. CONCLUSIONS: Choledocholithiasis in cirrhotic patients should be treated by EST after liver function and general condition are improved by medical management, except in emergency cases.

Adult↗
PubMed1993

Functional analysis of TCR gamma delta+ T cells in tumour-infiltrating lymphocytes (TIL) of human pancreatic cancer.

In six patients with advanced pancreatic carcinoma, TIL and tumour-draining lymphocytes (TDL) were isolated from primary pancreatic tumour and regional lymph nodes. In comparison with TDL and peripheral blood lymphocytes (PBL), TIL contained a comparatively higher percentage of TCR gamma delta+ cells, although they were still a small fraction. By 2 weeks culture with rIL-2 and immobilized OKT-3 antibody, the TCR gamma delta+ cells in TIL were preferentially expanded at the early culture periods, although it was temporary. In four cases, the TCR gamma delta+ and CD8+ TCR alpha beta+ TIL were separated by negative sorting using flowcytometry. All the TCR gamma delta+ TIL were CD4-, CD8- (double negative), and one of the TIL lines was mostly composed of delta TCS1+ cells, while the others were delta TCS1-. In comparison with CD8+ TCR alpha beta+ TIL, all the TCR gamma delta+ TIL exhibited much stronger lytic activity against freshly isolated autologous pancreatic cancer cells. However, all the gamma delta+ TIL also exhibited a strong non-MHC-restricted cytotoxicity, and there was no correlation between the lytic pattern and the percentage of delta TCS1+ cells. These data suggest that the TCR gamma delta+ T cells can proliferate vigorously in a certain condition, and if successfully expanded in vitro they might be helpful material for effective adoptive immunotherapy.

Aged↗