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A Kuroda

Publications and source records attributed to A Kuroda.

At least 91 records · Page 5Linked to original sources
PubMed1993

Molecular cloning of a sporulation-specific cell wall hydrolase gene of Bacillus subtilis.

Southern hybridization analysis of Bacillus subtilis 168S chromosomal DNA with a Bacillus licheniformis cell wall hydrolase gene, cwlM, as a probe indicated the presence of a cwlM homolog in B. subtilis. DNA sequencing of the cwlM homologous region showed that a gene encoding a polypeptide of 255 amino acids with a molecular mass of 27,146 Da is located 625 bp upstream and in the opposite direction of spoVJ. The deduced amino acid sequence of this gene (tentatively designated as cwlC) showed an overall identity of 73% with that of cwlM and of 40% with the C-terminal half of the B. subtilis vegetative autolysin, CwlB. The construction of an in-frame cwlC-lacZ fusion gene in the B. subtilis chromosome indicated that cwlC is induced at 6 to 7 h after sporulation (t6 to t7). The spoIIIC (sigma K) mutation and earlier sporulation mutations greatly reduced the expression of the cwlC-lacZ fusion gene. Northern hybridization analysis using oligonucleotide probes of the cwlC region indicated that a unique cwlC transcript appeared at t7.5 and t9. Transcriptional start points determined by primer extension analysis suggested that the -10 region is very similar to the consensus sequence for the sigma K-dependent promoter. Insertional inactivation of the cwlC gene in the B. subtilis chromosome caused the disappearance of a 31-kDa protein lytic for Micrococcus cell walls, which is mainly located within the cytoplasmic and membrane fractions of cells at t9. The CwlC protein hydrolyzed both B. subtilis vegetative cell walls and spore peptidoglycan.

Amino Acid Sequence↗
PubMed1993

High-level transcription of the major Bacillus subtilis autolysin operon depends on expression of the sigma D gene and is affected by a sin (flaD) mutation.

Transcription of the major Bacillus subtilis autolysin gene (cwlB) was investigated. Deletion of the region upstream of the gene cluster lppX-cwbA-cwlB led to a loss of promoter activity. Primer extension analysis suggested that the cwlB operon is transcribed by E sigma D and E sigma A, the former transcripts being predominants at the exponential growth phase. Expression of the lppX-lacZ fusion gene was reduced by about 90% in a sigD-null mutant. A sin (flaD1) mutation caused a severe defect in transcription of the lppX-cwbA-cwlB operon. The sin (flaD1) mutation also reduced expression of a sigD-lacZ fusion gene constructed in the B. subtilis chromosome. Since the sigD-null mutant exhibits motility and autolysin deficiencies and filamentation, similar phenotypes in the sin (flaD1) mutant may be caused by reduction in expression of the sigma D protein.

Amino Acid Sequence↗
PubMed1993

Selectivity of human T lymphotropic virus type-1 (HTLV-1) and HTLV-2 infection among different populations in Brazil.

A seroprevalence study for human T lymphotropic virus type-1 (HTLV-1) and HTLV-2 was conducted in Sao Paulo, Brazil among 2,312 individuals that included following groups: 1,148 volunteer blood donors, 37 patients with tropical spastic paraparesis (TSP), 53 with lymphoproliferative disorders, 171 with a history of multiple blood transfusions, 268 human immunodeficiency virus type-1 (HIV-1) seropositive subjects, and 635 Amazonian Indians. Antibodies to HTLV-1/2 were screened by enzyme-linked immunosorbent assay (ELISA) and confirmed by Western blot and/or radioimmunoprecipitation. The differentiation of HTLV-1 and HTLV-2 was achieved using a synthetic recombinant peptide (rgp46) ELISA. We confirmed the presence of HTLV-1 infection in Brazil, both in blood donors (0.4%) and in patients exposed to blood transfusions (2.9%), as well as the occurrence of HTLV-1-associated TSP (11 patients, or 30% of all TSP cases) and adult T cell leukemia/lymphoma (two cases, or 3.5% of all hematologic malignancies). The HIV-1 infected individuals were shown to be coinfected (8.9%) with either HTLV-1 or HTLV-2. All HIV-1 and HTLV-2 coinfected individuals were intravenous drug abusers. In addition, we also demonstrated the presence of HTLV-2 (4.7%), and HTLV-1/2 (0.8%) in tribes of Amazonian Indians who lived in the eastern Amazon basin (southeastern State of Para). The selectivity of these retroviral infections in particular groups is emphasized, as well as the need for HTLV-1/2 screening of all blood donors in Brazil as a public health measure.

Adolescent↗
PubMed1993

Differential sensitivity of rat cardiac sarcolemma and mitochondria to damage induced by lipid peroxidation.

It is well known that the sarcolemma is the organelle most susceptible to lipid peroxidative attack in the isolated membrane preparations. To determine whether this also occurs in the intact heart, we studied the effect of cumene hydroperoxide, an agent capable of initiating lipid peroxidation, on the ultrastructure and lanthanum (La) staining of isolated rat hearts perfused with HEPES buffer (pH 7.4) containing: 140 mM NaCl, 5 mM KCl, 1 mM MgCl2, 3 mM HEPES, 1.5 mM CaCl2 and 11 mM glucose. No ultrastructural alterations or intracellular deposits of La were observed in myocytes of rats perfused with HEPES buffer. Perfusion with cumene hydroperoxide (0.5 mM) for 30 min induced a release of malondialdehyde-like substance in the perfusate and a spectrum of myocardial ultrastructural alterations. La was always observed only outside the sarcolemma in myocytes with moderate damage consisting of clearing of the mitochondrial matrix and slight margination of chromatin in the nuclei. Intracellular La was found in myocytes with severe and irreversible damages consisting of fragmentation of cristae and electron-dense amorphous particles in mitochondria. La was deposited on the outer surface of the mitochondrial membranes, lipid droplets and myofilaments. These data suggest that mitochondria are more susceptible than is the sarcolemma to lipid peroxidation induced by cumene hydroperoxide in the beating rat heart.

Animals↗
PubMed1993

Cystopancreaticostomy and longitudinal pancreaticojejunostomy as a simpler technique of combined drainage operation for chronic pancreatitis with pancreatitis with pancreatic pseudocyst causing persistent cholestasis.

A simpler combined drainage operation for a patient with chronic pancreatitis and chronic pseudocyst is described in the following conditions: the pancreatic duct was markedly dilated, the cyst was located directly behind the main pancreatic duct in the head of the pancreas and separate from the duodenum and the cyst caused persistent CBD stricture and cholestasis mainly by its compressive effect. The pancreatic duct was opened anteriorly throughout its length. A second incision was made in the posterior wall of the main pancreatic duct into the cyst and the edge of the opening was sutured for hemostasis. The opened pancreas was anastomosed to a Roux-en-Y jejunal limb according to the ordinary method of longitudinal pancreaticojejunostomy. This technique, cystopancreaticostomy and pancreaticojejunostomy, may provide a simpler and effective operative strategy for patients with chronic pancreatitis and pseudocyst in similar conditions.

Cholestasis↗
PubMed1993

Clinicopathological characteristics of hepatic hilar bile duct carcinoma.

We reviewed thirty cases of hepatic hilar bile duct carcinoma found in 5,800 consecutive autopsy cases, mainly of the aged, and analysed their clinicopathological characteristics. Eleven cases had a record of tumor resection (8 men, 3 women, mean age 75.1 years). At operation, the gross type was mainly infiltrative in all eleven cases, and the stage was II, III or IV in as many as ten cases. Cholecystectomy and bile duct resection were performed in all cases except one in whom additional hepatic lobectomy was performed. In none of the cases was the operation curative. The main cause of non-curability was residual carcinoma on the surgical cut or ablated surface due to longitudinal or lateral cancerous interstitial spread. This was confirmed by the fact that local relapse of carcinoma, either in the hepatic hilus or hepatoduodenal ligament, was found in all the cases at autopsy. This fact also indicates the difficulty in achieving complete resection of carcinoma in this part. On the other hand, a relatively "benign" aspect of hepatic hilar bile duct carcinoma was suggested as follows: 1. Most of the cases were well-differentiated adenocarcinoma. 2. Although there was no case of curative resection, three out of of nine cases (excluding the cases of death during operation) survived more than two years. 3. Distant metastasis found at autopsy was relatively rare, being seen in four of these eleven cases. In the light of these data an operation, even though palliative, is considered to be justified.

Adenocarcinoma↗
PubMed1992

Characterization of the Bacillus subtilis CwbA protein which stimulates cell wall lytic amidases.

The Bacillus subtilis cell wall binding protein, CwbA, stimulated the cell wall lytic activities of the B. subtilis and B. licheniformis autolysins (CwlA and CwlM, respectively) in addition to that of the major B. subtilis autolysin (CwlB). Even though the substrate for the enzyme reaction was changed from B. subtilis cell wall containing a teichoic acid to Micrococcus luteus cell wall containing a teichuronic acid, the stimulatory effect of CwbA on CwlA activity was observed.

Bacillus subtilis↗
PubMed1992

Genetic structure, isolation and characterization of a Bacillus licheniformis cell wall hydrolase.

A DNA fragment containing the gene for a cell wall hydrolase of Bacillus licheniformis was cloned into Escherichia coli. Sequencing of the fragment showed the presence of an open reading frame which encodes a polypeptide of 253 amino acids with a molecular mass of 27,513. The gene was designated as cwlM, for cell wall lysis. The deduced amino acid sequence indicated that there is a repeated sequence consisting of 33 amino acid residues in the C-terminal region. Deletion of the C-terminal region did not lead to any loss of cell wall lytic activity. The gene product purified from E. coli cells harboring a cwlM-bearing plasmid exhibited a M(r) value of 29 kDa on SDS-polyacrylamide gels, and characterization of the specific substrate bond cleaved by CWLM indicated that the enzyme is an N-acetylmuramoyl-L-alanine amidase (EC 3.5.1.28). The enzyme hydrolyzed the cell wall of Micrococcus luteus more efficiently than those of B. licheniformis and B. subtilis, but the truncated CWLM (lacking the C-terminal region) had lost this preference. CWLM prepared from B. subtilis cells harboring a plasmid containing cwlM had a similar M(r) value to that from E. coli. Amino acid sequence homologies between CWLM and other amidases, and their protein structures are discussed.

Amino Acid Sequence↗
PubMed1992

Molecular cloning and sequencing of the upstream region of the major Bacillus subtilis autolysin gene: a modifier protein exhibiting sequence homology to the major autolysin and the spoIID product.

The upstream region of the N-acetylmuramoyl-L-alanine amidase gene (cwlB; a major Bacillus subtilis autolysin) was cloned into Escherichia coli by chromosome walking. Sequencing of the region showed the presence of two open reading frames, one (designated as cwbA) which starts at a UUG codon and encodes a polypeptide of 705 amino acids with an M(r) of 76,725, and the other (designated as lppX), upstream of cwbA, comprising 102 amino acids and having a signal sequence characteristic of a lipoprotein. Purification of the CwbA protein and determination of its N-terminal amino acid sequence revealed that it contains a presumed signal peptide which is processed after Ala at position 25 from the N-terminal, and that the M(r) of the mature form is 75,000. The amino acid sequences of the N-terminal and C-terminal regions of CwbA were found to be highly homologous with those of the cell wall binding domain of CwlB and the spoIID gene product, respectively. CwbA stimulated the major autolysin activity approximately threefold in vitro. These data indicate that CwbA is the modifier protein of the major autolysin reported by Herbold, D. R. & Glaser, L. (1975; Journal of Biological Chemistry 250, 1676-1682). In-frame fusion between the lppX and lacZ genes demonstrated that lppX is translated in vivo and expressed during the exponential growth phase.

Amino Acid Sequence↗
PubMed1992

No significant correlation between histologic changes of the papilla of Vater and juxtapapillary diverticulum. Special reference to the pathogenesis of gallstones.

The aim of this study was to investigate the significance of histologic changes of the papilla of Vater in cases with a juxtapapillary diverticulum, with special reference to the pathogenesis of gallstones. Three hundred and sixty-two autopsy cases, mainly of aged people, were analyzed. The incidence of both diverticulum and gallstone increased with age. The presence of diverticulum was associated with a significant increase of gallstones (49% versus 20%; P < 0.01). Analysis by the type of gallstones showed a significantly higher incidence of bilirubinate in cases with juxtapapillary diverticula. Stones both in the gallbladder and in the extrahepatic bile ducts were more prevalent in cases with diverticula as compared with the cases without diverticula. No significant relationship was found between juxtapapillary diverticula and the degree of histologic changes in the papilla of Vater, such as inflammatory cellular infiltration, fibrous proliferation, glandular proliferation, or muscular hypertrophy and proliferation of the sphincter of Oddi. These facts imply that juxtapapillary diverticula are not involved in the formation of gallstones via histologic changes of the papilla of Vater, whereas diverticula may play an important role in the pathogenesis of gallstones, especially of bilirubin stones.

Aged↗
PubMed1992

[Small cell carcinoma of urinary bladder. A case report].

A 57-year-old male patient was admitted because of a severe lumbar pain and gross hematuria. The rectal examination revealed a fist-sized soft tissue mass in the small pelvic space. A huge non-papillary tumor, which occupied the intravesical space, was found on cystoscopic examination. CEA IAP, TPA, CA19-9 and NSE were abnormally elevated in the serum. The pelvic CT scan shown an enormous polypoid tumor arising from the anterior vesical wall, while no abnormal lesion was found in the head, neck, chest and abdominal CT scans. The bone scintigraphy revealed multiple abnormal accumulations. The transurethral biopsy of the tumor was carried out. The pathological examination revealed homogeneous and small tumor cells arranged in sheet and solid patterns, which were positive for the anti-NSE stain and anti-NF stain, but negative for Grimelius stain. The final diagnosis was small cell undifferentiated carcinoma of the urinary bladder. The patient died of cancer five months after diagnosis.

Carcinoma, Small Cell↗
PubMed1992

[Surgical and non-surgical treatments of gallstones].

Comparisons were made of therapeutic modalities for gallstones. Four-hundred thirty-five patients with gallstones were operated on with the mortality rate of 0.7%. Extracorporeal shock-wave lithotripsy (ESWL) was performed in 84 patients with gallbladder stones. Complete stone disappearance rate at 1 year was 31% in patients with one to three radio-lucent stones not larger than 3cm in diameter and 57% in solitary stones up to 2cm with the US pattern of Ia or Ib. There was no major complication. Endoscopic sphincterotomy (EST) was performed in 131 patients with common bile duct stones. The success rate was for stone extraction, was 97%. Immediate complications occurred in 8% cases, yielding the mortality rate of 0.8%. Common bile duct stones recurred in 2 of 113 patients (3%). Acute cholecystitis was experienced in 2 of 43 patients with the gallbladder left in situ; 2 of 12 with and none of 31 without gallbladder stones. In conclusion, ESWL is a safe and effective treatment in selected patients. EST can be the first-choice modality in the treatment of not only the post-cholecystectomy cases but also the patients with the gallbladder without stones.

Adult↗
PubMed1992

[Microspectrophotometric analysis of DNA content in duct epithelial proliferation and invasive carcinoma of the pancreas].

Nuclear DNA content of 131 pancreatic duct epithelial lesions, including 10 normal ducts, 30 intraductal proliferations with mild atypia (groups I-II), 30 with moderate atypia (group III), 24 with severe atypia (group IV), 14 of carcinoma in situ (group V), and 23 invasive carcinomas, was analyzed using microspectrophotometry. DNA histograms were classified into diploid, polyploid and aneuploid patterns. All of normal duct epithelia showed diploidy. Polyploid patterns were observed in 3 (10%) lesions of groups I-II, 17 (56.7%) of group III, 14 (58.4%) of group IV, 7 (50%) of group V, and 6 (26.1%) of invasive carcinomas, and aneuploid patterns were observed in 0%, 10%, 33.3%, 50% and 73.9%, respectively. This distribution of ploidy patterns revealed a gradual shift to the main ploidy from diploid to polyploid followed by aneuploid in proportion to the increase of the degree of epithelial atypia. The frequencies of polyploid cells in each lesion were determined. Their averages were 0.2% in groups I-II, 1.9% in group III, 3.4% in group IV, 4.4% in group V, and 6.7% in invasive carcinoma. The S+G2M phase fractions were significantly higher in proliferative epithelia than in normal. The results of this study suggest that duct epithelial proliferations of the pancreas have "genetic instability" leading to a serial clonal evolution and play a significant role in the progression of pancreatic duct cell carcinoma.

Carcinoma in Situ↗
PubMed1991

Purification and characterization of a cell wall hydrolase encoded by the cwlA gene of Bacillus subtilis.

A cell wall hydrolase of Bacillus subtilis was prepared from Escherichia coli cells harboring a plasmid containing the B. subtilis cwlA gene and purified by hydroxyapatite column chromatography and HPLC through TSK-gel G3000SWXL. In contrast to the molecular mass of 29,919 Da deduced from its nucleotide sequence, the purified CWLA is a 23 kDa protein. Characterization of the specific substrate bond cleaved by CWLA indicated the enzyme is an N-acetylmuramyl-L-alanine amidase. A 32-kDa precursor protein was detected on zymography of a crude cell homogenate. Some of the enzymatic properties of CWLA are also described.

Bacillus subtilis↗
PubMed1991

Clinical pathology of endocrine tumors of the pancreas. Analysis of autopsy cases.

A clinicopathological analysis of endocrine tumors of the pancreas, using 800 autopsy cases (422 men, 378 women, mean age 78.7) was accomplished. The results were: (1) Endocrine tumors and similar lesions were found in 3% or 24 cases (25 lesions). Twenty lesions (20 cases) were found to be tumors and five lesions (five cases) were determined to be hyperplasia of Langerhans islets. (2) Incidence of tumor was 10% (6/60) in individuals having histological studies of all sections of the pancreas, and 1.6% (12/738) in individuals having histological studies of three random sections of the pancreas. (3) None of the cases with tumors and hyperplastic lesions showed symptoms of hormone production. (4) Immunohistochemical analysis revealed hormone production in all 20 tumor cases and multiple hormone production was found in 14 of these (70%). (5) Ductular or tubular structures were found in or adjacent to the tumors in 12 cases (60%) and hyperplasia in one case (20%). Langerhans islets, 500 microns or larger in size, were found in three lesions of the tumor (15%). Langerhans islets with the mean diameter of normal islets + 2 SD or larger also were found around five tumors (25%) and three hyperplasias (60%). The above findings suggest that endocrine tumors of the pancreas are prevalent and that they do not produce symptoms of excessive hormone production even though they do continue to produce hormones. Some of the endocrine tumors or hyperplasias develop from totipotent stem cells of the duct epithelia, and factors promoting the growth of Langerhans islets might exist.

Aged↗
PubMed1991

Characterisation of beta 1 and beta 2 adrenoceptor subtypes in the atrioventricular node of diabetic rat hearts by quantitative autoradiography.

STUDY OBJECT: The aim was to determine whether the changes in beta adrenoceptors might be involved in the conduction system of diabetic rat hearts. DESIGN: beta Adrenoceptors in the atrioventricular node of diabetic hearts and controls were characterised by quantitative autoradiography. EXPERIMENTAL MATERIAL: The experiments were performed in five male Wistar rats injected with streptozotocin (65 mg.kg-1) to induce diabetes and in five rats injected with vehicle alone. MEASUREMENTS AND MAIN RESULTS: 125I-iodocyanopindolol binding sites decreased by 25% in atrioventricular node of diabetic hearts compared to control hearts without a significant change in the affinity. The selective beta 1 adrenoceptor antagonist CGP20712A (100 nmol.litre-1) displaced about 30% and 50% of the total atrioventricular node binding sites in diabetic and control hearts, respectively. CONCLUSIONS: These data support the concept that a decrease in beta adrenoceptors, mainly of the beta 1 subtype, in the atrioventricular node may play an important role in the cardiac conduction disturbance of diabetic animals.

Animals↗
PubMed1991

Immunohistochemical study of the distribution of pancreastatin in endocrine tumors of the pancreas and in normal pancreatic tissue: analysis of autopsy cases.

Using sixteen cases (sixteen lesions) of endocrine tumor of the pancreas, found in 1,300 consecutive autopsy cases (661 men and 639 women; mean age, 79.0 years), we examined distribution patterns of pancreastatin (PST) in these endocrine tumors and in normal tissues around them, using immunohistochemical staining. In addition, the distribution patterns of PST was compared with those of insulin (INS), glucagon (GLU), somatostatin (SOM), and pancreatic polypeptide (PP), in these tissues. Normal islets of Langerhans were stained completely and evenly for PST. Two endocrine tumors did not stain for PST at all, six were partially stained, and eight were stained as densely as normal islets, or even more densely. Acinar cells were only partially stained for PST in 11 cases and showed scattered staining in three cases. Epithelial cells of ducts or ductuli were partially stained for PST in 10 cases and showed scattered staining in three cases. Distribution patterns of PST coincided with that of INS in 56% (9/16) of cases, GLU in 81% (13/16), SOM in 31% (5/16), and PP in 31% (5/16). In the eight tumors that were stained at least as densely for PST as normal islets, the staining pattern did not coincide with that of INS in any case (0%), coincided with that of GLU in all 8 cases (100%), and coincided with those of SOM and PP in one case each (13%). Therefore, the distribution of GLU-producing cells (A cells) coincided most closely with that of PST. It is concluded that most PST is secreted from A cells in human pancreas.

Adenoma, Islet Cell↗