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Biomedical subjects

K Ueno

Publications and source records attributed to K Ueno.

At least 199 records · Page 11Linked to original sources

A new method of performing continuous intraabdominal drainage after pancreaticoduodenectomy.

Dehiscence of the pancreaticoenterostomy is one of the most feared, yet common, postoperative complications following pancreaticoduodenectomy (PD). We report herein a new technique we developed for performing continuous intraabdominal suction drainage (CISD) following PD. This method of CISD involves positioning an 18 Fr sump tube beside the pancreaticoenterostomy, with a continuous suction pressure of about -20cmH2O. The fluid obtained from the sump tube is also useful for monitoring amylase levels and providing bacterial cultures to enable the early detection of dehiscence of pancreaticoenterostomy. A study was conducted on 150 patients who underwent PD for periampullary carcinoma over a 20-year period. The patients were divided into two groups according to whether or not CISD was performed: group 1 comprised 71 patients who had CISD, and group 2 79 patients who did not have CISD. Although the frequency of anastomotic dehiscence did not differ between the two groups (32% in group 1 and 25% in group 2), the mortality rate of the patients with anastomotic leakage in group 1 was lower than that in group 2 (P = 0.07). Thus, we believe that our new technique for performing CISD could improve the surgical outcome of patients following PD.

Abdomen↗

Surgical strategy for carcinoma of the pancreas head area based on clinicopathologic analysis of nodal involvement and plexus invasion.

BACKGROUND: The pattern of tumor spread, vis-à-vis nodal involvement and invasion of the extrapancreatic plexus (Plx), has not been thoroughly described for carcinoma of the pancreatic head area. METHODS: From 1973 to 1991, 110 patients (49 with carcinoma of the pancreatic head [Ph], 29 with distal bile duct cancer [Bi], and 32 with carcinoma of the papilla of Vater [Pv]) underwent pancreatectomy at Kanazawa University Hospital. Nodal involvement and Plx invasion were precisely evaluated by histopathologic examination. RESULTS: Thirty-seven (76%) of the 49 patients with Ph, 20 (69%) of the 29 with Bi, and 14 (44%) of the 32 with Pv had nodal involvement. The lymph nodes most commonly involved for Ph were the posterior pancreaticoduodenal lymph nodes (numbers 13a [superior] and 13b [inferior]), the superior mesenteric lymph nodes (number 14), the paraaortic lymph nodes (number 16), and the anterior pancreaticoduodenal lymph nodes (number 17) (13a, 51%; 13b, 47%; 14, 36.7%; 16, 18.4%; 17a, 33%; 17b, 22%). In patients with Bi, lymph nodes around the hepatoduodenal ligament (number 12) and lymph nodes numbers 13a and 14 were most commonly involved (12, 27.6%; 13a, 51.7%; 14, 34.5%). In patients with Pv, lymph node numbers 13b and 14 were most frequently involved (13b, 34.4%; 14, 15.6%). No significant correlation was noted between the tumor size and nodal involvement in these three lesions. Nodal involvement was an important prognostic factor for carcinoma of the pancreatic head area. Plx invasion in these three carcinomas was observed in 61% of patients with Ph, 29% of patients with Bi, and 3% of patients with Pv. CONCLUSIONS: Nodal involvement and Plx invasion differed significantly among carcinomas of the pancreatic head area. We believe that nodal dissection of at least group number 14 is needed for Ph, Bi, and Pv cancers. In addition, dissection of lymph nodes of number 16 and the Plx around the superior mesenteric artery and celiac axis are needed in Ph cancer. Plx dissection of the first portion of plexus pancreaticus capitalis is needed in Bi cancer.

Actuarial Analysis↗

Effects of oxygen radicals on ciliary motility in cultured human respiratory epithelial cells.

There are few reports about direct effects of specific oxygen products on ciliary function because of their instability and reactivity. We investigated the direct effects of superoxide anion (O2-) and of hydrogen peroxide (H2O2) on the ciliary function of human respiratory epithelial cells, using monolayer cell cultures, high speed video analysis of frequency (CBF), amplitude (CBA), and coordination of ciliary beats and evaluating the surface structural changes of ciliated cells at the same time. 10(-2) M H2O2 decreased ciliary beat activity. The CBF was 36.5 +/- 4.4% and the CBA was 51.0 +/- 3.8% of the baseline (time = 0) after 5 min (all p < 0.001). Catalase (2 micrograms/ml) abolished the ciliotoxic effect of H2O2. The O2- produced by reaction of xanthine (0.06 mM)-xanthine oxidase (0.04 U/ml) caused a temporary rapid increase of 26.8 +/- 1.7% in CBF and an increase of 42.5 +/- 4.1% in CBA after 15 sec (all p < 0.001). Superoxide dismutase significantly reduced these increases. Results indicated that O2- activated ciliary function with a temporary increase in O2(-)-production. This suggests that the removal of H2O2 from the O2- reaction is important in improving mucociliary clearance in excessive oxygen metabolites.

Cells, Cultured↗

Oxidation of recombinant human parathyroid hormone: effect of oxidized position on the biological activity.

PURPOSE: To determine the oxidation products of recombinant human parathyroid hormone (rhPTH) treated with H2O2, the amino acid residue oxidized, and the biological activity of the oxidation products. METHODS: Oxidized residues were determined by CNBr cleavage, trypsin digestion and subsequent fast atom bombardment mass spectrometry. The biological activity of each oxidized rhPTH was examined in rat osteosarcoma cell adenylate cyclase assay. RESULTS: Three oxidized products were isolated, namely, Met at position 8 (Met8) sulfoxide, Met at position 18 (Met18) sulfoxide and both positions Met sulfoxide. It appears that the Met8 and Met18 oxidized forms are intermediates in the generation of the Met doubly oxidized form. All oxidized forms possessed reduced biological activity, more so for oxidation at Met8 than at Met18. CONCLUSIONS: The region around Met8 is important for the activity of the parathyroid hormone.

Chromatography, High Pressure Liquid↗

Development of tissue level brain injury criteria by finite element analysis.

A three-dimensional finite element model of the direct cortical impact experiment was built and a preliminary validation against mechanical response was completed. The motion of the impactor was enforced in the model by applying the same acceleration history as that of the experimental impactor. A nonlinear contact surface algorithm was used for impactor-brain interface with the ABAQUS general purpose finite element program. The resulting motion of the impactor and the contacting node in the brain model confirmed that the impactor moved realistically and contacted the brain surface. The pressure generated in the model compared favorably with that measured by a pressure transducer in the experiment. The pattern of high shear deformation generated at the impact site in the model was similar to the pattern of contusion hemorrhage seen in the experiment. The pressure generated at the impact site propagated to the skull-brain boundary, especially, at the posterior margin of the cerebellum. Analysis of experimental data using a biomechanically validated finite element model will enable determination of tissue-level injury criteria for application in human brain models to predict head injury potential in contact, noncontact, or side impact situations.

Brain Injuries↗

Bacteriology of chronic otitis media, chronic sinusitis, and paranasal mucopyocele in Japan.

A bacteriologic study of cases of chronic otitis media, chronic sinusitis, and paranasal mucopyocele diagnosed at Gifu University Hospital was performed between 1989 and 1992. Bacteria were isolated from all of 13 samples of discharge from the ears of patients with chronic otitis media, all of 14 mucosal biopsy specimens from patients with chronic sinusitis, 8 of 10 aspirate samples from patients with chronic sinusitis, and 9 of 15 aspirates samples from patients with mucopyocele. Cultures often yielded polymicrobial growth, with an average of 3.1, 3.8, and 4.2 species per positive specimen from chronic otitis media, chronic sinusitis, and mucopyocele, respectively. The most commonly encountered anaerobes were Peptostreptococcus, Propionibacterium, and Prevotella species; the most common aerobes were Staphylococcus and Streptococcus species. One strain of Prevotella melaninogenica highly resistant to ampicillin and two strains of Peptostreptococcus resistant to cefaclor were found.

Adolescent↗

Antibiotic susceptibility profiles of Bacteroides fragilis and Bacteroides thetaiotaomicron in Japan from 1990 to 1992.

The antimicrobial susceptibility of clinical isolates of Bacteroides fragilis and Bacteroides thetaiotaomicron collected from December 1990 through November 1992 was determined by the agar dilution technique. Metronidazole, imipenem, and cefoperazone/sulbactam remained highly active against both organisms. Rates of resistance to those agents were 0, 2%, and 0.9% in B. fragilis and 0, 0.9%, and 3% in B. thetaiotaomicron, respectively. Cefoxitin and other cephamycins were active against B. fragilis; rates of resistance to these agents did not tend to increase. With the inclusion of these data, the variation of rates of resistance to several agents was summarized for each year from 1987 to 1992. Rates of resistance to imipenem decreased in 1991 and 1992 among isolates of B. fragilis (2.3% in 1991, 1.8% in 1992) and B. thetaiotaomicron (2.4% in 1991, 0 in 1992). Rates of resistance to cefoxitin in B. thetaiotaomicron varied from 10% to 38% during these 6 years, though the distributional peak of MIC values did not change. The rate of resistance to ofloxacin in B. fragilis increased from 42% in 1989 to 81% in 1992. The rate of resistance to ampicillin in B. thetaiotaomicron was 68% in 1992--approximately 30% lower than before. Mostly, however, the rates of resistance to the antimicrobial agents examined did not change significantly.

Anti-Bacterial Agents↗

Residence times of global weapons testing fallout 237Np in a grassland soil compared to 239 + 240Pu, 241Am, and 137Cs.

The vertical distribution of weapons testing fallout 237Np has been determined in an undisturbed grassland soil (Alfisol). By using a compartmental model for multi-layered soils, the mean residence half-times of 237Np in each soil layer were calculated and compared with results on weapons fallout 239 + 240Pu, 241Am and 137Cs in the same soil. The results show that the mobility of 237Np was in most soil horizons either equal or slightly enhanced as compared to that of Pu, Am, and radiocesium.

Americium↗

Cytokine stimulation during Salmonella typhimurium sepsis in Itys mice.

Cytokine production was measured in mice during Salmonella typhimurium sepsis and intoxication. In mice given live S. typhimurium (10 cfu/mouse), by intra-peritoneal injection, serum levels of tumour necrosis factor (TNF)-alpha and interleukin-6 increased steadily from day 1 until day 4. Interferon-gamma levels showed a transient peak on day 3. Interleukin-1-alpha levels were very low. There were high bacterial counts in the livers at day 3 and deaths occurred from day 4 onwards. Intraperitoneal injection of lipopolysaccharide or heat-killed bacteria also induced all of the cytokines, but their time of appearance and levels varied greatly. Cytokine induction by heat-killed bacteria was more marked. Endotoxaemia decreased with time during intoxication and increased during sepsis. Bioactive TNF, as measured by a cytotoxicity assay, was found only in mice given heat-killed bacteria.

Animals↗

Aniracetam, a pyrrolidinone-type cognition enhancer, attenuates the hydroxyl free radical formation in the brain of mice with brain ischaemia.

We demonstrate here that aniracetam has the ability to block the formation of cytotoxic hydroxyl radicals (.OH) during ischaemia-reperfusion of mouse brain. The fact that brain ischeamia for 40 min followed by reperfusion increased .OH was evidenced by detection of a peaked increase at 20 min after an ischaemic insult in the formation of 2,3-dihydroxybenzoate (DHBA) from salicylate in cerebroventricular perfusate, a means of monitoring .OH formation. A clearcut increase in dopamine was also observed during and after brain ischaemia. The ischaemia-reperfusion mice given aniracetam at an intraperitoneal dose of 30 or 100 mg kg-1 showed a smaller increase in the formation of DHBA than those given the vehicle only. Aniracetam at 100 mg kg-1 significantly suppressed the formation of DHBA by approximately 80%, becoming evident at 20 min after reperfusion and thereafter. Protection against death in mice insulted with a 40-min brain ischaemia (3/13 vs 13/25) was observed following 100 mg kg-1 aniracetam. The increase in the dopamine levels was substantially reduced following aniracetam treatment and the reduction became significant at 20 min after reperfusion and thereafter in parallel with attenuation by aniracetam of DHBA formation. This finding suggests that the inhibitory activity of aniracetam in attenuating the hydroxyl free-radical formation in ischaemic mice is probably due, at least in part, to its palliative action on the dopaminergic neurons.

Animals↗

Finite element model study of head impact based on Hybrid III head acceleration: the effects of rotational and translational acceleration.

The translational and rotational components of acceleration measured at the center of gravity of a Hybrid III dummy head were used to investigate their individual and combined effects on a two-dimensional finite element model of the human brain. Each component of acceleration generated distinct patterns of deformation. Although translational acceleration is related to pressure and rotational acceleration has a dominant effect on shear deformations, complete acceleration (combination of translation and rotation) yielded the highest values in all stresses and produced a maximum shear stress at the top of the brain.

Acceleration↗

[Evaluation of immunochromatography assay technique for detection of antibody to hepatitis B surface antigen (HBsAg)].

A new immunochromatography assay (Dainascreen Ausab Dainabot) has been recently introduced for the detection of the presence of antibody to HBsAg. To evaluate the feasibility of using the Dainascreen Ausab, we carried out comparison tests with this method and PHA. In the test of 439 sera from HB vaccinees, inhabitants in Iki Island, Nagasaki Pref., patients with autoimmune diseases and with acute hepatitis B, 154 (31.2%) were positive by Dainascreen Ausab, 145 (29.4%) were positive by PHA and 145 (29.4%) were positive by both Dainascreen Ausab and PHA. Nine (1.8%) were positive by only Dainascreen and there were none positive by only PHA. A good correlation was observed between the titer of the antibody by this method and IMx. The anti-HBs assay by this method was able to be completed within 15 minutes and the procedure was very simple. The results indicate that the sensitivity of Dainascreen is superior to PHA and that it is easy to use.

Chromatography, Thin Layer↗

[Detection of Bacteroides fragilis enterotoxin from extraintestinal clinical isolates of B. fragilis group organisms].

A total of 300 extraintestinal clinical isolates of Bacteroides fragilis group organisms were assayed for enterotoxin using HT29/C1 cells. Of the 179 strains of B. fragilis, 36 (20.0%) were positive for cell culture assay, a positivity which was neutralized by anti-B. fragilis enterotoxin serum; all 36 strains were confirmed to be enterotoxigenic B. fragilis (ETBF). Among B. fragilis isolated from blood, 18 (31%) of 59 strains were ETBF while 18 (15.0%) of 120 strains isolated from non-blood specimens were ETBF (p < 0.05). None of the 121 strains of the B. fragilis group other than B. fragilis were positive for cell culture assay. These results demonstrated that isolation of ETBF from extraintestinal clinical specimens is not uncommon and that B. fragilis enterotoxin, a metalloprotease, may play a role as a pathogenic factor in blood stream infection and sepsis.

Animals↗

MAO inhibitors, clorgyline and lazabemide, prevent hydroxyl radical generation caused by brain ischemia/reperfusion in mice.

The effects of clorgyline, the MAO-A inhibitor, and lazabemide, the MAO-B inhibitor, on the levels of the hydroxyl radicals appearing in the cerebral ventricles of mice during brain ischemia/reperfusion were examined by using a salicylate trapping method. The amount of hydroxyl radicals formed peaked at 20 min after reperfusion (approximately 150% vs. basal level). The dopamine level markedly increased shortly after the initiation of an ischemic insult and thereafter waned. By contrast, the concentration of 3,4-dihydroxyphenylacetic acid (DOPAC) level decreased during a 40-min period of ischemia, gradually returning to the preischemic basal level upon reperfusion. The ischemia reperfusion-induced hydroxyl radical generation was attenuated by 3 mg/kg of clorgyline and lazabemide. Furthermore, mice pretreated with these MAO inhibitors showed decreased DOPAC levels in comparison with those of their respective vehicle-treated control groups; recovery of the reduced DOPAC level was also delayed. In conclusion, it is likely that both type A and type B MAOs participate in the generation of hydroxyl radicals during brain ischemia/reperfusion. This finding suggests the possible use of MAO inhibitors as neuroprotective agents for treating ischemic injury.

3,4-Dihydroxyphenylacetic Acid↗

[Nephron sparing surgery of patients with renal cell carcinoma in a solitary kidney or bilateral renal cell carcinoma].

PURPOSE: The objective of this study is to evaluate the efficacy of nephron sparing surgery for renal cell carcinoma in patients with a solitary kidney or bilateral tumors. PATIENTS AND METHODS: From 1982 to 1994, a total of 12 patients with a solitary kidney or bilateral tumors underwent nephron sparing surgery. The survival and complications were examined. RESULTS: The patients were 11 males and 1 female. Three patients were in stage 1, 6 in stage 2, 2 in stage 3, and 1 in stage 4, and the mean tumor size was 3.4 cm (0.8-6.5). The complications were post-operative bleeding in one patient and slight transient renal dysfunction which didn't require hemodialysis in 3 patients. The local recurrence was observed in 1 patient (8.3%), metastasis in 3 (25%), no evidence of disease in 8 (66.7%), alive with cancer in 1 (8.3%), death due to cancer in 2 (16.7%), death due to other disease in 1 (8.3%), and the 5 year survival of all patients was 62.5%, that was almost the same as the result of 141 renal cell carcinoma patients treated with nephrectomy in our hospital. The disease free survival rate of the patients in stage 1 and 2 seems to be higher than in stage 3 and 4 with no significant difference (p = 0.0956). CONCLUSION: These results suggest that nephron sparing surgery for renal cell carcinoma in patients with a solitary kidney or bilateral tumors is a useful therapy.

Aged↗

[Multiparametric cytometric analysis of hepatocellular carcinoma and its allied lesions combining DNA ploidy analysis with morphometry using DAPI/HP double staining].

Hepatocellular carcinomas (HCC) of various differentiation, Edmondson (Edm) grade I-IV, often based upon viral infectious hepatitis transformed through regeneration, nodular and/or dysplastic adenomatous hyperplasia. Aspiration cytology, even needle biopsy for such lesions, is very difficult to interpret. We have been studying multiparametric cytologic analysis using DAPI/Hematoporphyrin (HP) staining for the cece samples provided from exactly trimmed 50-microns thick paraffin sections, employing a new software program which we developed, combining DNA ploidy and cell protein content analysis with morphometry. DAPI indicates DNA content and nuclear size and HP indicates cell protein content and cell size. From 21 cases of HCC, 43 nodules or masses including multiple lesions and nodule in nodule were analyzed. Surrounding non-neoplastic hepatic tissues were examined as the control specimens. On DNA histogram, cases with the peak over 2.4 c are identified as aneuploid (Aneupl). Cases of Edm I, or II, 6 of 8 samples showed Aneupl., all of 11 cases of Edm II, 11 cases of Edm III, and one of Edm IV showed Aneupl. Multinodular foci in the same cases and also nodule in nodule often showed different modes of Aneupl. This suggested heterogenetic carcinogeneity. Noncarcinomatous foci often showed Aneupl. modes, which may indicate malignant transformation or malignant potential.

Carcinoma, Hepatocellular↗