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Biomedical subjects

H Uchida

Publications and source records attributed to H Uchida.

At least 163 records · Page 9Linked to original sources

Induction of apoptosis in normal human renal tubular epithelial cells by Escherichia coli Shiga toxins 1 and 2.

The cytotoxicity of Shiga toxin (Stx) 1 and Stx2 produced by Escherichia coli to human renal cortical epithelial cells (HRCEC) in primary culture was investigated. HRCEC express CD24, the marker of renal distal tubules, as well as globotriaosyl ceramide/CD77, the receptor for Stxs. Binding of Stxs to HRCEC was confirmed by positive staining with specific antibodies to Stxs. Treatment of HRCEC with Stxs induced rapid cell death, which was reversed in the presence of neutralizing antibody specific for Stx. DNA fragmentation was found to be accompanied by Stx-mediated cell death in HRCEC, indicating that apoptosis was part of the process. These data and previous reports indicate that a variety of renal cell types, including tubular epithelial cells as well as glomerular capillary endothelial cells, may be targets for Stx-mediated apoptosis, which could contribute to the pathogenesis of hemolytic-uremic syndrome caused by Stx-producing E. coli infection.

Adult↗

Genetic alterations of mixed hyperplastic adenomatous polyps in the colon and rectum.

Some mixed hyperplastic adenomatous polyps (MHAPs) contain dysplastic lesions or even carcinomas. These polyps are considered to be different from ordinary hyperplastic polyps and may have a preneoplastic potential. We investigated APC and K-ras mutations in MHAPs of the colon and rectum, and also in colorectal adenomas and hyperplastic polyps to identify molecular differences between MHAPs, adenomas and hyperplastic polyps, using direct sequencing of mutation cluster regions (MCR) in APC and K-ras. No APC mutations were identified in 12 MHAPs and 8 hyperplastic polyps, whereas 10 of 27 (37.0%) adenomas showed somatic mutations. K-ras mutations were identified in one of 12 (8.3%) MHAPs, one of 8 (12.5%) hyperplastic polyps, and 10 of 27 (37.0%) adenomas. p53 mutation was found in a carcinoma arising in an MHAP. Mutations other than APC mutations may play a role in the development of MHAPs.

Adenoma↗

[In vitro specific binding of Shiga toxin 1 and 2 by TAK-751S (Gb3 analog)].

TAK-751S is a synthetic trisaccharide coupled to Chromosorb P using a spacer sequence of 8-methoxycarboyloctyl (MCO). Its chemical structure is similar to a human receptor (Gb3) of Stx produced by enterohemorrhagic Escherichia coli (EHEC). In vitro efficacy of TAK-715S was studied by using ACHN cultured cell assay, which is sensitive and specific for measuring low level of Stx. Under various conditions, TAK-715S was mixed with purified Stx1 and Stx2, and residual free toxins in the solution were measured by using ACHN cells. TAK-715S was demonstrated to bind specifically to Stx1 and Stx2 under the condition similar to a human intestine while Chromsorb P did not bind to any Stx. The binding activity was stable in the presence of various processed foods, fresh vegetables and fruits. Antibiotics such as fosfomycin, kanamycin and norfloxacin did not disturb its binding capability. Minimum inhibitory concentrations of these antibiotics against Staphylococcus aureus FDA209P or E. coli NIHJ JC-2 neither changed after incubating with TAK-751S for 60 min at 37 degrees C. These results suggest that TAK-751S can be given orally with various foods and antibiotics for the elimination of Stx1 and Stx2 in the gut of patients with EHEC infections.

Adsorption↗

Effects of a novel antihypertensive drug, cilnidipine, on catecholamine secretion from differentiated PC12 cells.

Effects of a novel dihydropyridine type of antihypertensive drug, cilnidipine, on the regulation of the catecholamine secretion closely linked to the intracellular Ca2+ were examined using nerve growth factor (NGF)-differentiated rat pheochromocytoma PC12 cells. By measuring catecholamine secretion with high-performance liquid chromatography coupled with an electrochemical detector, we showed that high K+ stimulation evoked dopamine release from PC12 cells both before and after NGF treatments. Cilnidipine depressed dopamine release both from NGF-treated and untreated PC12 cells in a concentration-dependent manner. In contrast, inhibition by nifedipine was markedly decreased in the differentiated PC12 cells. With intracellular Ca2+ concentration ([Ca2+]i) measurements using fura 2, the elevation of high K+-evoked [Ca2+]i was separated into nifedipine-sensitive and -resistant components. The nifedipine-resistant [Ca2+]i increase was also blocked by cilnidipine, as well as omega-conotoxin-GVIA. By the use of the conventional whole-cell patch-clamp technique, the compositions of the high-voltage-activated Ca2+ channel currents in the NGF-treated PC12 cells were divided into types: L-type, N-type, and residual current components. It was also estimated that cilnidipine at 1 and 3 micromol/L strongly blocked the N-type current without affecting the residual current. These results suggest that cilnidipine inhibits catecholamine secretion from differentiated PC12 cells by blocking Ca2+ influx through the N-type Ca2+ channel, in addition to its well-known action on the L-type Ca2+ channel.

Animals↗

The 20-kilodalton (kDa) human growth hormone (hGH) differs from the 22-kDa hGH in the complex formation with cell surface hGH receptor and hGH-binding protein circulating in human plasma.

In spite of recent advance in understanding of the stoichiometry of 22-kDa human GH (22K-hGH) with cell surface hGH receptor (hGHR) and hGH-binding protein (hGH-BP) circulating in human plasma, that of 20-kDa hGH (20K-hGH) is poorly understood. To clarify this, mouse pro-B Ba/F3 cells stably expressing the full-length hGHR (Ba/F3-hGHR) and both recombinant and native hGH-BP were used in this study. Cell proliferation assay revealed that the two hGH isoforms increased Ba/F3-hGHR cells to the same extent in a dose-dependent manner at 0.1 pM-10 nM. However, the self-inhibition observed in 20K-hGH at 5 microM was significantly less than that in 22K-hGH. Furthermore, addition of 1 and 10 nM recombinant hGH-BP caused a slight inhibition in 20K-hGH, but a drastic inhibition in 22K-hGH. Gel filtration chromatography of mixtures of 20K-hGH with recombinant hGH-BP clearly demonstrated that 20K-hGH formed a 1:2 (hGH:hGH-BP) complex efficiently but no detectable 1:1 complex in any conditions. Supporting data were also obtained with native hGH-BP. Computer-aided homology modeling of 20K-hGH has provided speculative data that the conformational change caused by deletion of 15 residues may occur only in the loop between helix 1 and helix 2, resulting in the reduction of its site 1 affinity. In conclusion, 20K-hGH possesses a unique property for forming a 1:2 complex to the same extent as 22K-hGH but has difficulty in forming a 1:1 complex, which might be attributed to the conformational change restricted to its site 1 region.

Animals↗

Effects of endoluminal stent-grafts on acute aortic dissection in dogs.

Acute aortic dissection is a life-threatening condition, and may be treated with aggressive hypotensive drug therapy, but emergency surgery is often necessary. We evaluated the effectiveness of stent-grafts for the treatment of acute aortic dissection. Aortic dissection was surgically created in the descending thoracic aorta in 20 adult mongrel dogs. A stent-graft was inserted in the entry position. The tested animals were divided into 4 groups based on re-entry type and blood pressure alteration rate (AR) after acute aortic dissection. After insertion of the stent, the following results were observed: a) AR improved; b) proximal descending aorta and superior mesenteric arterial flows increased; c) cardiac function improved; and d) the dissecting aortic diameter decreased in the presence of pressure gradient group. From these results, insertion of a stent-graft to treat acute aortic dissection was judged to be effective.

Acute Disease↗

Comparison of the nucleotide sequence and secondary structure of the 5.8S ribosomal RNA gene of Chlamydomonas tetragama with those of green algae.

We have determined the nucleotide sequence of a PCR product corresponding to the 5.8S ribosomal RNA gene in Chlamydomonas tetragama and compared the obtained sequence with those of one red and eleven green algae. A phylogenetic tree based on the 5.8S rDNAs and comparison of their predicted secondary RNA structure, with attention to a region which has been proposed to base-pair with an internal guide sequence of an intron in the large subunit chloroplast rRNA, suggested that C. tetragama was not closely related with Chlamydomonas reinhardtii. These results support the previous idea that the genus Chlamydomonas is heterogenous.

Animals↗

Spinal meningeal melanocytoma presenting with superficial siderosis of the central nervous system. Case report and review of the literature.

Meningeal melanocytoma is a benign melanocytic tumor that originates most frequently from the melanocytes in the posterior fossa or along the spinal cord. This tumor generally occurs as an extraaxial mass that compresses adjacent neural structures to produce various neurological signs. The authors describe an unusual case in which a patient with a meningeal melanocytoma located at the thoracic spinal cord presented with superficial siderosis of the central nervous system (CNS). Extensive neuroradiological studies identified the presence of a spinal cord tumor, and postsurgical histological examination revealed the meningeal melanocytoma as a bleeding source. After surgery, lumbar puncture demonstrated normalization of the patient's cerebrospinal fluid; however, no neurological improvement occurred. The neurological deficits seem irreversible. Meningeal melanocytoma is biologically benign and can be cured by complete surgical resection; therefore, this tumor should be included in the differential diagnosis of pigmented lesions of the CNS. The authors reviewed 14 cases of well-documented meningeal melanocytoma in the literature and discuss the clinical, radiological, and pathological features of the present case to emphasize the importance of early diagnosis and identification of the source of bleeding in patients with superficial siderosis.

Brain Diseases↗

Three-dimensional power Doppler sonography of tumor vascularity.

The purpose of this study was to assess the value of routine clinical examination using three-dimensional power Doppler sonography of intratumoral blood flow. Twenty-two hepatocellular carcinomas, seven cases of hepatic metastasis, four hepatic hemangiomas, six renal cell carcinomas, two cases of hepatic focal nodular hyperplasia, and one case of splenic metastasis were included in the study. Three-dimensional images were reconstructed by maximum intensity projection method using cine-loop data on a built-in computer in a LOGIQ 500 and a LOGIQ 700 from GE Yokogawa Medical Systems. The three-dimensional images obtained were viewed multidirectionally on a monitor screen. Three-dimensional representations of intratumoral blood flow became available for all tumors approximately 5 s to 30 s after scanning. In every case, the entire vasculature of the tumor was appreciated more easily from three-dimensional images than from cross-sectional two-dimensional images. These three-dimensional images of intratumoral blood flows corresponded to the tumor vessels that could be visualized by angiography at the early arterial phase. Differential diagnosis of hepatic tumors based on distinct difference in their intratumoral vascular structures was performed. Our results suggest that three-dimensional power Doppler sonography can be used for routine clinical examination of tumor vascularity and may provide improved diagnostic information.

Carcinoma, Hepatocellular↗

Intrarenal varices: demonstration by color Doppler sonography.

Idiopathic intrarenal varices are a rare disease, and only a few cases have been reported. We encountered a patient with intrarenal varices in whom color Doppler sonography was useful for diagnosing and demonstrating this disease, especially with 3D reconstruction of blood flow, which we began using recently.

Female↗

[Treatment of hepatocellular carcinoma by segmental SMANCS Lipiodol-TAE].

Segmental SMANCS Lipiodol TAE (Seg. SMANCS Lp-TAE) using SMANCS was used to treat HCC in 58 patients and was evaluated in comparison with Seg. Lp-TAE using Epirubicin performed in 50 patients with respect to the course of atrophy of the embolized area, recurrence rate and side effects. On serial CT (Lp-CT) performed after TAE, in cases with P type in which the tumor is present in the periphery of the embolized area and showing Type I homogeneous accumulation of Lp within the tumor, the incidence of atrophy in the embolized area including the tumor was high and the recurrence rate was low. Although no significant difference in the recurrence rate was noted between the groups in which SMANCS and EPI were used, there were more cases with marked atrophy and a lower recurrence rate in the former. No difference was found in post-procedural side effects such as fever between the two groups, while hypotension was rarely observed during the procedure in the group in which SMANCS was used and was easily managed with intravenous steroids. The present results suggest that Seg. SMANCS Lp-TAE is an effective local treatment for HCC limited to a subsegment or segment.

Aged↗

[Comparative studies on activities of antimicrobial agents against causative organisms isolated from patients with urinary tract infections (1996). I. Susceptibility distribution].

The frequencies of isolation and susceptibilities to antimicrobial agents were investigated on 680 bacterial strains isolated from patients with urinary tract infections (UTIs) in 10 hospitals during the period of June 1996 to May 1997. Of the above bacterial isolates, Gram-positive bacteria accounted for 30.4% and a majority of them were Enterococcus faecalis. Gram-negative bacteria accounted for 69.6% and most of them were Escherichia coli. Susceptabilities of several isolated bacteria to antimicrobial agents were as followed; 1. Enterococcus faecalis Ampicillin (ABPC) showed the highest activity against E. faecalis isolated from patients with UTIs. Its MIC90 was 1 microgram/ml. Imipenem (IPM) and vancomycin (VCM) were also active with the MIC90S of 2 micrograms/ml. The others had low activities with the MIC90S of 16 micrograms/ml or above. 2. Staphylococcus aureus including MRSA Arbekacin (ABK) and VCM showed the highest activities against both S. aureus and MRSA isolated from patients with UTIs. The MIC90S of them were 1 or 2 micrograms/ml. The others except minocycline (MINO) had low activities with the MIC90S of 32 micrograms/ml or above. 3. Staphylococcus epidermidis ABK and VCM showed the strongest activities against S. epidermis isolated from patients with UTIs. The MICs for all strains were equal to or lower than 2 micrograms/ml. Cefazolin (CEZ), cefotiam (CTM) and cefozopran (CZOP) were also active with the MIC90S of 4 micrograms/ml. Compared with antimicrobial activities of cephems is 1995, the MIC90S of them had changed into a better state. They ranged from 4 micrograms/ml 16 micrograms/ml in 1996. 4. Streptococcus agalactiae All drugs except MINO were active against S. agalactiae. ABPC, CZOP, IPM, and clarithromycin (CAM) showed the highest activities. The MICs for all strains were equal to or lower than 0.125 micromilligrams. Tosufloxacin (TFLX) and VCM were also active with the MIC90S of 0.5 micromilligrams. 5. Citrobacter freundii Gentamicin (GM) showed the highest activity against C. freundii isolated from patients with UTIs. Its MIC90 was 0.5 micrograms/ml. IPM and amikacin (AMK) were also active with the MIC90S of 1 microgram/ml and 2 micrograms/ml, respectively. Cefpirome (CPR) and CZOP were also active with the MIC90S of 8 micrograms/ml. The MIC90S of the others were 16 micrograms/ml or above. 6. Enterobacter cloacae IPM showed the highest activity against E. cloacae. The MICs for all strains were equal to or lower than 0.5 microgram/ml. The MIC90S of ciprofloxacin (CPFX) and TFLX were 1 microgram/ml, the MIC90 of AMK was 2 micrograms/ml, the MIC90S of CZOP, GM and ofloxacin (OFLX) were 4 micrograms/ml. The MIC50S of cephems except CEZ, cefmetazole (CMZ) and cefaclor (CCL) had changed into a better state in 1996, compared with those in 1995. 7. Escherichia coli All drugs except penicillins and MINO were active against E. coli. Particularly CPR, CZOP and IPM showed the highest activities against E. coli. The MIC90S of them were 0.125 microgram/ml or below. Among E. coli strains, those with low susceptibilities to cephems except CEZ, cefoperazone (CPZ), latamoxef (LMOX) and CCL have increased in 1996, compared with those in 1995. 8. Klebsiella pneumoniae K. pneumoniae was susceptible to all drugs except penicillins, with the MIC90S of 2 micrograms/ml or below. CPR had the strongest activity, the MICs for all strains were equal to or lower than 0.25 microgram/ml. Flomoxef (FMOX), cefixime (CFIX), CZOP and carumonam (CRMN) were also active with the MIC90S of 0.125 microgram/ml or below. 9. Pseudomonas aeruginosa All drugs except quinolones were not so active against P. aeruginosa with the MIC90S were 32 micrograms/ml or above. Quinolones were more active in 1996 than 1995. The MIC90S of them were between 4 micrograms/ml and 8 micrograms/ml, and the MIC50S of them were between 1 microgram/ml and 2 micrograms/ml. 10. Serratia marcescens GM showed the highest activity against S. marcescens. Its MIC90 was 1 micro

Anti-Bacterial Agents↗

[Comparative studies on activities of antimicrobial agents against causative organisms isolated from patients with urinary tract infections (1996). II. Background of patients].

Clinical background was investigated on patients with urinary tract infections (UTIs) from whom 752 bacterial strains were isolated in 10 hospitals during the period from June, 1996 through May, 1997. 1. Distribution of age and sex of patients and type of infections. Among males, those with ages 40 years or older were more frequent, the higher the ages of them. Among females, those with ages in the 60's were the most frequent (24.6%), and those with ages in the 20's, 40's and 50's were about 13%. With regard to type of infections, more than a half of infections among males with ages 30 years or older were of complicated types, but most of infections among females were of uncomplicated types, especially among females of ages less than 60 years. 2. Ages of patients and types of pathogens. The higher the ages of patients, the lesser became the isolation frequencies of Escherichia coli, but the higher were those of Pseudomonas aeruginosa and Klebsiella spp. 3. Effect of antibiotic use on isolation frequencies of pathogens. Use of antibiotics decreased pathogens isolated from patients with uncomplicated UTIs drastically (231 isolates before antibiotics compared to 60 after). Even isolated pathogens from patients with complicated UTIs decreased drastically with the use of antibiotics when indwelling catheters were not in use (193 isolates before antibiotics compared to 75 after), but when indwelling catheters were in use, antibiotics apparently failed to decrease the isolation frequency. 4. Surgical procedures and types of causative organisms for UTIs. From cases of uncomplicated UTIs, E. coli was the most frequently isolated, followed by Enterococcus Faecalis and Klebsiella spp. E. coli was the most frequently isolated organism from complicated UTIs without indwelling catheters. When a surgical procedures were not done, E. coli was isolated most frequently. From cases of complicated UTIs with indwelling catheters, P. aeruginosa, E. coli and E. faecalis were the organisms that were mainly isolated, with isolation frequencies of 23.2%, 15.2, 12.2, respectively. When no surgical procedures were used, isolation frequencies of P. aeruginosa, E. faecalis and Enterobacter spp. were 17.2%, 13.8%, 13.8%, respectively.

Adolescent↗

[Circulatory collapse during laparoscopic cholecystectomy].

A 52 year-old female without any cardiac disease underwent laparoscopic cholecystectomy. Anesthesia was induced with thiamylal and maintained with nitrous oxide and isoflurane. Epidural anesthesia was also used during surgery. When the intraabdominal insufflation was performed in reverse-trendelenburg position 15 minutes after the start of incision, the heart rate suddenly decreased from 75 to 49 bmp with a fall in blood pressure. Her hemodynamic state recovered immediately after the release of intraabdominal pressure and the administration of ephedrine with a rapid infusion of Hespander. The circulatory collapse did not occur when the second insufflation was tried carefully. The circulatory collapse was probably due to the vagal reflex. The decrease in cardiac preload during the reverse trendelenburg position and the epidural administration of local anesthetics may have caused or worsened the circulatory collapse. In anesthetic managements of laparoscopic cholecystectomy using general anesthesia with epidural anesthesia, prophylactic hydrogenation and prevention of parasympathetic domination are important to minimize the vagal reflex.

Anesthesia, Epidural↗

[Comparative studies on activities of antimicrobial agents against causative organisms isolated from patients with urinary tract infections (1996), III. Secular changes in susceptibility].

Susceptibilities to various antimicrobial agents were examined for Enterococcus faecalis, Staphylococcus aureus, Escherichia coli, Klebsiella spp., and Pseudomonas aeruginosa that were isolated from patients with urinary tract infections (UTIs) in 10 hospitals during June 1996 to May 1997, and the results were compared with those obtained during the same period in earlier years. 1. E. faecalis Among E. faecalis strains, those with high susceptibilities to ampicillin and minocycline appeared to have decreased in the latest study period. 2. S. aureus To almost antimicrobial agents, S. aureus isolated from uncomplicated UTIs showed low susceptibilities. But the MIC50s of those agents for S. aureus from complicated UTIs have changed better state. Particularly, the MIC50s of imipenem and clindamycin were 0.125 microgram/ml or below in the latest period for the first time in our history. 3. E. coli The susceptibilities to piperacillin and quinolones of E. coli isolated from uncomplicated UTIs were better than those isolated from complicated UTIs. 4. Klebsiella spp. The susceptibilities to almost antimicrobial agents of Klebsiella spp. have been better during the latest period, compared to those during period of 1995-1996, but to ofloxacin and ciprofloxacin have appeared to have been lower. 5. P. aeruginosa The susceptibilities to quinolones of P. aeruginosa have been better during the latest period compared those during periods of 1995-1996. But, the susceptibilities to cefozopran, carbapenems and monobactams of P. aeruginosa isolated from complicated UTIs appeared to have been lower. These susceptibility changes should be utilized in determining clinical treatments.

Anti-Bacterial Agents↗

[A case of adenoid cystic carcinoma presenting with stridor and which was treated by reversed gamma type stent placement].

A 66-year-old man was admitted to Saiseikai Suita Hospital with stridor and dyspnea. The flow-volume curve showed central airway obstruction pattern. Although a P-A chest roentogenogram was normal, chest tomogram demonstrated a tumor shadow in the lower portion of the trachea. Chest CT examination demonstrated a tumor arising from the posterior wall of the lower portion of the trachea and stenosis with wall thickening extending from the lower portion of the trachea to both main bronchi. Bronchofiberscopic examination revealed polypoid tumors obstructing the lower portion of the tracheal lumen, and biopsy was subsequently performed. On the night immediately after the bronchofiberscopic examination, the patent suddenly choked, and emergency intubation was performed. Adenoid cystic carcinoma was diagnosed on biopsy and we decided to place a spiral Z-stent. A reversed gamma-type stent placement was used. The first spiral Z-stent extended from the trachea to the right main bronchus and the second spiral Z-stent was placed in the left main bronchus through the first stent. Following the spiral Z-stent placement radiotherapy was performed. Spiral Z-stent placement resulted in dilation of the stenotic trachea and both main bronchi.

Aged↗

[Diagnostic capabilities of a classification program of the Heidelberg retina tomograph for early glaucomatous changes].

We investigated the diagnostic capabilities of a new glaucoma diagnostic softwave (classification program) of the Heidelberg retina tomograph for early glaucoma. Thirty eyes of 30 patients with early glaucoma (average visual field mean deviation = -3.7 dB) and 30 eyes of 30 normal subjects were enrolled. The criterion for early glaucomatous change was a visual field defect appearing earlier than Aulhorn classification stage II without considering the disc configuration. The diagnostic ability of three glaucoma specialists for the same eyes was evaluated using the Heidelberg retina tomograph analysis map. The agreement of two or three glaucoma specialists was accepted as the final judgment. Sensitivity, specificity, and diagnostic precision were calculated for all evaluations. The agreement between the classification program and glaucoma specialists was calculated with kappa statistics. Sensitivity, specificity, and diagnostic precision of the classification program were 80%, 83% and 82%, respectively. Those of the by glaucoma specialists were 83%, 90% and 87%, respectively. The agreement between the classification program and glaucoma specialists was excellent (kappa 0.73, % agreement 86.7%). The classification program will aid the diagnosis of early glaucomatous damage with high sensitivity and specificity.

Adult↗

[Clinical study on chlormadinone acetate alone followed by combination with LH-RH analogue for prostatic cancer: effects on lipid metabolism].

Twenty-four previously untreated patients with a diagnosis of prostatic cancer were treated with chlormadinone acetate (CMA) alone (100 mg/day) for 4 weeks, and luteinizing hormone-releasing hormone analogue (LH-RHa) was added for the next 24 weeks. Marked decreases in blood LH, testosterone (T), prostate specific antigen (PSA), gamma-seminoprotein (gamma-Sm), and prostatic acid phosphatase (PAP) were observed after a single dose of CMA. T levels were significantly increased 3 days after the initial dose of LH-RHa, and did not return to the pretreatment level. There were no significant increases in any of the markers, nor were there any flare-up cases. Triglyceride levels, which were slightly elevated before the start of treatment, were significantly decreased 24 weeks after the completion of combined therapy. PSA was evaluated as partial response (PR) or better in 86.7% of the patients. Overall evaluation showed PR or better in 75.0% of the patients. These findings suggest that prior administration of CMA followed by combined administration with LH-RHa is useful in the treatment of prostatic cancer. No negative effects on lipid metabolism were observed at any time during the treatment period.

Aged↗