PubMed Health⌕ Search

Biomedical subjects

G Kobayashi

Publications and source records attributed to G Kobayashi.

At least 37 records · Page 2Linked to original sources
PubMed1999

Diagnosis of the depth of invasion of gallbladder carcinoma by EUS.

BACKGROUND: The prognosis of gallbladder carcinoma is dismal and relates to the depth of invasion as expressed by the T factor in TNM staging. We evaluated the utility of endoscopic ultrasound (EUS) in the diagnosis of the depth of invasion of gallbladder cancer. METHODS: Thirty-nine patients who underwent both EUS and surgery were included in this study. The EUS images were classified according to the relation between tumor echo pattern and gallbladder-wall structure, and the resulting types were compared with depth of invasion as determined histologically. Based on the results, a set of diagnostic criteria is proposed. RESULTS: The EUS images were classified into four categories. Type A is a pedunculated mass with a fine-nodular surface and intact neighboring wall. Type B is a broad-based mass with an irregular surface and intact outer hyperechoic layer of the adjacent wall. In type C, the outer hyperechoic layer is irregular due to a mass echo, whereas, in type D, the outer hyperechoic layer is disrupted by a mass echo. Each of the four categories of EUS images correlated well with the histologic depth of invasion. CONCLUSION: EUS is useful in the T staging of gallbladder cancer.

Adult↗
PubMed1999

Extractive acetone-butanol-ethanol fermentation using methylated crude palm oil as extractant in batch culture of Clostridium saccharoperbutylacetonicum N1-4 (ATCC 13564).

The possibility of employing methylated crude palm oil (CPOE) as an extraction solvent to reduce end-product inhibition and to enhance solvent productivity in acetone-butanol-ethanol (ABE) fermentation was evaluated using oleyl alcohol as the standard butanol extractant. Fermentation was carried out at an initial glucose concentration of 90 g/l. CPOE did not inhibit the growth of the fermentative organism. Without solvent extraction, butanol production ceased after 30 h at a concentration of 15.4 g/l limiting cell growth to 3.98 g/l and glucose consumption to 62%. Applying CPOE as the extraction solvent, about 47% of the total butanol produced was extracted, glucose consumption was increased to 83% and relatively high glucose consumption rates and solvent productivities were obtained. Butanol production increased to 20.9 g/l; total ABE solvents and yield also increased from 21.2 g/l and 38% (in conventional fermentation) to 29.8 g/l and 40.4%, respectively.

Journal Article↗
PubMed1998

The gene encoding dipeptidyl aminopeptidase BI from Pseudomonas sp. WO24: cloning, sequencing and expression in Escherichia coli.

We have isolated the dipeptidyl aminopeptidase BI (DAP BI) gene from the plasmid library of Pseudomonas sp. WO24 chromosomal DNA by the enzymatic plate assay using a chromogenic substrate. The DAP BI gene, designated dap b1, was further subcloned and sequenced. Sequence analysis of an approx. 3-kb fragment revealed an open reading frame of 2169 nucleotides, which was assigned to the dap b1 gene by N-terminal and internal amino acid sequences. The predicted amino acid sequence of DAP BI containing a serine protease Gly-X-Ser-X-Gly consensus motif displays extensive homologies to the several proteases belonging to the prolyl oligopeptidase family, a novel serine protease family possessing the catalytic triad with a specific array of Ser, Asp and His in this order, which is the hallmark of the member of this family including DAP IV. The dap b1 gene was expressed in Escherichia coli and the expressed enzyme was purified about 230-fold with 2.6% recovery from the cell-free extracts. The enzymatic properties such as molecular mass, substrate specificity and effect of inhibitor were similar to the native enzyme from Pseudomonas sp. WO24.

Amino Acid Sequence↗
PubMed1998

[Surgical treatment for a 16-year-old girl with anomalous origin of the right pulmonary artery from ascending aorta].

Anomalous origin of the right pulmonary artery is a rare congenital malformation and is usually fatal without early surgical correction. A 16-year-old patient, who had received no previous treatment, demonstrated abnormal findings on ECG. On cardiac catheterization, the pressure in the normally arising left pulmonary artery was found to be greater than the systemic level. Bidirectional shunting across a patent ductus was identified and aortography revealed that the right pulmonary artery arose from the posterior wall of the proximal ascending aorta. The presence of severe pulmonary vascular obstructive disease was anticipated and right lung biopsy was performed. The index of pulmonary vascular disease rating was 2.8 and the Heath-Edwards classification was grade 3. Consequently, we considered that corrective right pulmonary circulation could be maintained after correction, and total correction was performed. The postoperative course was uneventful and the pulmonary artery pressure reduced significantly. Discussion focuses on the surgical indications for such infrequent older cases and we conclude that preoperative lung biopsy is useful in identifying severe pulmonary vascular disease and evaluating indications for surgery.

Adolescent↗
PubMed1998

ERCP for intradiverticular papilla: two-devices-in-one-channel method. Endoscopic Retrograde Cholangiopancreatography.

BACKGROUND: The prevalence of biliopancreatic disorders is high in patients with periampullary diverticula. However, endoscopic retrograde cholangiopancreatography (ERCP) in patients with the papilla deep inside duodenal diverticula is difficult. METHODS: Two patients were included in this study, each with the papilla deep inside a diverticulum and in whom an initial ERCP was unsuccessful. A biopsy forceps to pinch the duodenal mucosa distal to the papilla and pull the papilla out of the diverticulum and a cannula were inserted into the working channel of a duodenoscope together (the two-devices-in-one-channel method). With coordination of the two instruments, cannulation of the bile duct was attempted. RESULTS: In both patients ERCP was successful using this procedure and no complications followed. CONCLUSIONS: The two-devices-in-one-channel method is useful when performing ERCP in patients with the papilla inside juxtapapillary diverticula.

Aged↗
PubMed1998

Gradual loss of IgG antibodies against GB virus C/hepatitis G virus in a patient with AIDS.

GB virus C/hepatitis G virus (GBV-C/HGV) is a positive-sense, single-stranded RNA virus belonging to the family Flaviviridae and is distantly related to hepatitis C virus (HCV). GBV-C/HGV can be transmitted by the parenteral and the sexual route. Among individuals infected with human immunodeficiency virus type 1 (HIV-1) by the sexual route, we and others have demonstrated a high prevalence of GBV-C/HGV infection. Recently, Woolley and colleagues reported that AIDS patients co-infected with GBV-C/HGV had a significantly lower mean CD4 cell count than AIDS patients without GBV-C/HGV infection, suggesting that GBV-C/HGV antibody may be lost with progression to AIDS. To our knowledge no data are available on the loss of antibody against GBV-C/HGV in AIDS patients. We now report on an HIV-infected patient who exhibited gradual loss of IgG antibodies against GBV-C/HGV, as well as HCV, with progression of HIV disease.

AIDS-Related Opportunistic Infections↗
PubMed1997

The central region of RepE initiator protein of mini-F plasmid plays a crucial role in dimerization required for negative replication control.

The RepE protein (251 residues, 29 kDa) of mini-F plasmid, mostly found as dimers, plays a key role in mini-F replication. Whereas monomers bind to the origin to initiate replication, dimers bind to the repE operator to repress its own transcription. Among the host factors required for mini-F replication, a set of molecular chaperones (DnaK, DnaJ and GrpE) is thought to facilitate monomerization of RepE dimers. To further understand the structural basis of functional differentiation between the two forms of RepE, we examined the region(s) critical for dimerization by isolation and characterization of RepE mutants that were defective in autogenous repressor function. Such mutations were isolated from two separate regions of RepE, the central region (residues 111 to 161) and the C-terminal region (residues 195 to 208). The central region overlapped the region where the chaperone-independent copy-up mutations were previously isolated (residues 93 to 135). Likewise the mini-F mutant plasmids, carrying the mutations in the central region, could replicate in a dnaK null mutant host. One of them, S111P (111th serine changed to proline), showed a very high origin-binding activity vis-à-vis a severely reduced operator-binding activity, much like the RepE54 (R118P) mutant previously shown to form only monomers. Gel filtration and chemical crosslinking studies with purified RepE revealed that S111P primarily formed monomers, whereas other mutant proteins formed mostly dimers. On the other hand, analysis of deletion mutants revealed that the N-terminal 42 and the C-terminal 57 residues were dispensable for dimerization. Thus, the region spanning residues 93 to 161 of RepE (including Ser111 and Arg118) appeared to be primarily involved in dimerization, contributing to the negative regulation of plasmid replication.

Bacterial Proteins↗
PubMed1997

Superficial elevated-type early gallbladder carcinoma treated by laparoscopic cholecystectomy.

A 60-year-old woman was admitted to our department for detailed examination of a polypoid lesions of the gallbladder detected at the time of a mass survey by ultrasound. Endoscopic ultrasonography (EUS) demonstrated a broad-based mass lesion, about 10 mm in size, with an irregular surface, at the peritoneal side of the body of the gallbladder. The layer structure of the gallbladder wall had not been destroyed by the mass. Computed tomography showed no direct invasion of the liver or other evidence of metastasis. Type-IIa (superficial elevated-type) early gallbladder cancer was suspected and laparoscopic cholecystectomy was performed. Histologically, the tumor proved to be a papillo-tubular adenocarcinoma, 9 x 8 mm in size, confined to the mucosa and without lymphatic permeation, vascular involvement, perineural invasion, or other signs of metastasis. Laparoscopic cholecystectomy for gallbladder cancer can be indicated only when a lesion is a pedunculated protruded-type (type-Ip) cancer, or a broad-based cancer 10 mm or less in size located on the peritoneal side with no destruction of the layer structure of the wall demonstrated by EUS. This strategy is justified only with precise evaluation of the lesion by EUS.

Adenocarcinoma↗
PubMed1997

[Comparison of echograms by a microscanner and histological findings of the common bile duct, in vitro study].

To confirm the relationship between the layer structure of the common bile duct by a microscanner (MS) and its histological features, we performed a study using the pinning method with needles and catgut. The locations of 67 needles inserted at random depths in 29 slices of the resected common bile duct from 18 patients were confirmed both by a MS and a microscope. The wall of the common bile duct was delineated as a two- (42 points) or three-layer structure (25 points); "low and high" or "high, low, and high echoic layers" from the mucosal side. A fibrotic layer (ss 1) was often (56/67 points, 16/18 patients) seen in the subserosa (ss) containing nerves and vessels larger than 100 mu in diameter. Among the 51 needle echoes demonstrated in the inner hypoechoic layer, 2 were located in the mucosa (m), 12 in the fm, 19 in the af, 17 in the ss 1, and 1 in the fatty layer of the ss (ss 2). Five of the 6 needles in the outer hyperechoic layer were in the ss 2, and 1 was in the pancreatic parenchyma (pa). Four of the 8 needles at the border between the inner hypoechoic layer and the outer hyperechoic layer histologically corresponded to fm, af, ss 1, and pa, respectively, and the other four corresponded to ss 2. From these results, we conclude that the inner hypoechoic layer contains not only m, fm, and af, but also ss 1. Therefore, this should be kept in mind for the preoperative assessment of the depth of bile duct carcinoma by MS.

Bile Duct Neoplasms↗
PubMed1996

Two types of novel dipeptidyl aminopeptidases from Pseudomonas sp. strain WO24.

Two kinds of dipeptidyl aminopeptidase I (DAP I [cathepsin C])-like activities which hydrolyze Gly-Phe-p-nitroanilide (Gly-Phe-pNA) were detected in Pseudomonas sp. strain WO24. They were purified and characterized. The isolated enzymes, named DAP BII and DAP BIII, were revealed to be homogeneous by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and isoelectric focusing. DAP BII was estimated to have a molecular mass of 150,000 Da by gel filtration and a subunit size of 73,000 Da by SDS-PAGE, indicating it to be a homodimer. The molecular mass of DAP BIII was evaluated to be approximately 60,000 Da by gel filtration and 69,000 Da by SDS-PAGE, indicating that it is monomeric. The isoelectric points of DAP BII and DAP BIII were 6.1 and 5.0, and their optimal pHs were 8.0 and 8.5 to 9.0, respectively. The result of peptide mapping for DAP BII and DAP BIII showed that these enzymes consist of different components. Both enzymes were completely inhibited by diisopropylphosphofluoride but not by general thiol inhibitors, indicating that they are serine proteases. DAP BII and DAP BIII hydrolyzed Gly-Phe-pNA but not Gly-Arg-pNA, both of which are model substrates for mammalian DAP I. Despite these shared activities toward DAP I, DAP BII released dipeptides from Ala-Ala-pNA and Lys-Ala-4-methylcoumarinamide (a substrate for DAP II), whereas DAP BIII did not hydrolyze either of these compounds and was presumed to prefer substrates composed of bulky, hydrophobic amino acids at P1 and P1' positions. In addition, DAP BII showed no endopeptidase activity, whereas DAP BIII possessed the activity on N-terminally blocked peptide derivatives besides exopeptidase activity. Assays performed with bioactive peptides such as angiotensin I and neuromedin N as substrates indicate that DAP BII has a considerably broader substrate specificity than DAP BIII and is able to hydrolyze an X-Pro bond, an imido bond that few peptidases and no known DAPs can cleave. These characteristics, namely, substrate specificities, molecular mass, pI, peptide mapping, pH optimum, and effect of inhibitors, suggested that the two DAPs purified in this work are distinct enzymes and do not belong to any of the previously reported DAP classes.

Bacterial Proteins↗
PubMed1996

[Diagnosis of superficial-type early carcinoma of the gallbladder by endoscopic ultrasonography--comparison with ultrasonography].

The detectability of superficial-type carcinoma of the gallbladder by ultrasonography (US) and endoscopic ultrasonography (EUS) were investigated. Eight patients with such carcinoma of the gallbladder were reviewed. They had undergone both US and EUS previous to surgery. The tumor was detected in 3 patients by US, 2 patients with IIa + IIb-type carcinoma and 1 patient with IIa-type carcinoma. Those lesions were visualized as localized thickening of the gallbladder wall or as broad-based tumor. In 2 patients, lesions were not initially detected by US, but were shown by US after the examination by EUS. The tumor was detected by EUS also in 1 case of IIb + IIa-type carcinoma besides those 3 patients mentioned above. All four of these lesions were visualized as broad-based tumor by EUS. It was difficult to detect pure IIb-type or small IIa-type carcinoma even by EUS. In patients with concomitant acute cholecystitis or gallbladder stone, it was difficult to evaluate the abnormal findings of the gallbladder wall.

Aged↗
PubMed1996

[Ultrasonographic study of rectal carcinoid tumors].

To compare intraluminal ultrasonographic (ILUS) findings with histological findings of rectal carcinoid tumors, 35 patients with rectal carcinoid tumors were reviewed. The results were as follows: 1) The rectal wall was visualized as a seven- or nine-layer structure by means of ILUS in 81% of the patients. 2) The possibility that the thin hyperechoic third layer above the tumor on ILUS corresponds to the muscularis mucosae and fibrointerstitium above the tumor histologically. 3) In cases with relatively high internal echoes, the amount of fibrointerstitium exceeded that of tumor cells histologically. 4) In cases with nonuniform internal echo patterns, tumor cells were separated by thick fibrointerstitium forming nodular nests.

Carcinoid Tumor↗
PubMed1996

[A clinico-pathological study of early gallbladder carcinoma].

We performed a clinico-pathological study on cases with early gallbladder carcinoma to elucidate its morphological characteristics. Thirty cases (33 lesions) were included, invasion was confined to the mucosa in 24 of these cases and involvement of both the mucosa and muscularis propria was seen in 6 cases. The results are as follows: 1) In all cases with I p-type cancer, the depth of invasion was limited to the mucosa. 2) In I s cases in which the tumor had a broad base, 10mm in size or less, the depth of invasion was up to the muscularis propria. 3) In cases with II a-type carcinoma in which the base was less than 15mm in size, no involvement of the subserosa was observed. In conclusion, it is suggested that with lesions diagnosed by imaging modalities as I p-type cancers, broad-based tumors with a base of 10mm or less, or II a-like lesions with a base less than 15mm, there is a high probability that the depth of invasion is limited to the mucosa or up to the muscularis propria.

Adult↗