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Biomedical subjects

K Konishi

Publications and source records attributed to K Konishi.

At least 55 records · Page 3Linked to original sources
PubMed2000

Long-term postoperative functional evaluation of pylorus preservation in Imanaga pancreatoduodenectomy.

Our purpose was to determine whether pylorus-preservation in the Imanaga (PpPDI) method minimizes postoperative impairment of gastrointestinal function. Nine patients who had undergone PpPDI (postoperative years: 5.7 +/- 2.6) and nine patients who had undergone conventional Imanaga pancreatoduodenectomy (PDI) (postoperative years: 6.8 +/- 2.0) were evaluated for symptoms, nutritional parameters, and physiologic function of the biliary tract and residual stomach using gastric emptying and hepatobiliary scintigraphy. The body weight recovered to 99.3% +/- 3.8% of pre-illness body weight in PpPDI, showing a significantly better recovery than in patients after the PDI procedure (91.0% +/- 6.4%, P < 0.05). The mean gastric emptying half-time (GET1/2) in the upright position after PDI was significantly shorter (42.3 min) than after PpPDI (80.8 min, P < 0.05). Mixture of food with bile was conserved better in the PpPDI group than in the PDI group. In the long term, the pylorus-preserving Imanaga-type procedure minimizes disruption of gastric function and asynchrony between ingested food and bile.

Adult↗
PubMed2000

Tubular osteopontin expression in human glomerulonephritis and renal vasculitis.

Tubulointerstitial change is a common histopathologic feature of acute and chronic glomerular diseases and is more closely correlated than glomerular damage with renal function and subsequent outcome. Monocyte infiltration is presumed to be initiated by chemoattractants and has a pivotal role in tubulointerstitial changes. Osteopontin (OPN) is a candidate as such a chemoattractant and has been shown to recruit monocytes into the interstitium of animal models of renal diseases. In this study, we investigated OPN expression by immunostaining and its correlation with clinical and histopathologic parameters in patients with immunoglobulin A (IgA) nephropathy, diffuse proliferative lupus nephritis (DPLN), and myeloperoxidase-antineutrophil cytoplasmic autoantibody-associated microscopic polyangiitis (MMP). Twenty patients with IgA nephropathy, 12 patients with DPLN, and 14 patients with MMP were studied. OPN expression, which was constitutively observed on the apical membrane of distal tubules, was upregulated in the cytoplasm of proximal and distal tubular epithelium parallel to the degree of interstitial mononuclear cell infiltration in patients with IgA nephropathy, as well as those with DPLN. CD68(+) monocyte infiltration significantly correlated with the degree of OPN expression in the tubular epithelium. Conversely, there was no apparent induction of OPN in the proximal and distal tubular epithelium of patients with MMP despite remarkable monocyte infiltration. In conclusion, these data suggest that inducible expression of OPN in the tubular epithelium seems to be associated with interstitial monocyte infiltration and subsequent tubulointerstitial changes in some forms of human renal diseases.

Biopsy↗
PubMed2000

Delayed-feedback control of spatial bifurcations and chaos in open-flow models

A delayed-feedback control scheme is presented for suppressing spatial bifurcation and chaotic behavior in open-flow models. It is shown that spatial bifurcation and chaotic behavior never occur when the delayed-feedback controller is designed such that the following two conditions are satisfied: all the poles of the transfer function of each site are inside a unit circle and the H(infinity) norm of the transfer function is less than 1. We provide a simple systematic procedure for design of the delayed-feedback controller. It is confirmed that our theoretical results agree well with the numerical simulations.

Journal Article↗
PubMed2000

Spatiotemporal stability of one-way open coupled nonlinear systems

The present paper investigates the spatiotemporal stability of homogeneous solutions in one-way open coupled nonlinear systems. We show that the H(infinity) norm concept, which has been used as an important index in the field of robust control theory, allows us to grasp the mechanism of spatial instability in coupled systems. Spatial instability occurs only when the H(infinity) norm of the transfer function of each site is greater than 1. It is shown that numerical simulations for one-way open coupled double scroll circuits are in good agreement with our theoretical results.

Journal Article↗
PubMed2000

Enzymatic properties of dipeptidyl aminopeptidase IV produced by the periodontal pathogen Porphyromonas gingivalis and its participation in virulence.

Porphyromonas gingivalis is a major pathogen associated with adult periodontitis. We cloned and sequenced the gene (dpp) coding for dipeptidyl aminopeptidase IV (DPPIV) from P. gingivalis W83, based on the amino acid sequences of peptide fragments derived from purified DPPIV. An Escherichia coli strain overproducing P. gingivalis DPPIV was constructed. The enzymatic properties of recombinant DPPIV purified from the overproducer were similar to those of DPPIV isolated from P. gingivalis. The three amino acid residues Ser, Asp, and His, which are thought to form a catalytic triad in the C-terminal catalytic domain of eukaryotic DPPIV, are conserved in P. gingivalis DPPIV. When each of the corresponding residues of the enzyme was substituted with Ala by site-directed mutagenesis, DPPIV activity significantly decreased, suggesting that these three residues of P. gingivalis DPPIV are involved in the catalytic reaction. DPPIV-deficient mutants of P. gingivalis were constructed and subjected to animal experiments. Mice injected with the wild-type strain developed abscesses to a greater extent and died more frequently than those challenged with mutant strains. Mice injected with the mutants exhibited faster recovery from the infection, as assessed by weight gain and the rate of lesion healing. This decreased virulence of mutants compared with the parent strain suggests that DPPIV is a potential virulence factor of P. gingivalis and may play important roles in the pathogenesis of adult periodontitis induced by the organism.

Amino Acid Sequence↗
PubMed2000

Inhibitory effect of sanguiin H-11 on chemotaxis of neutrophil.

Neutrophil is accumulated by chemoattractants at inflammatory sites. In order to find a new substance to regulate the chemotaxis of neutrophil, we examined the effects of purified tannins and related compounds (33 species). Among those studied, sanguiin H-11, purified from the plant Sanguisorba officinalis, was the most potent inhibitor of rat cytokine induced neutrophil chemoattractant-1 (CINC-1, a counterpart of human GRO (melanoma growth-stimulating activity)) dependent chemotaxis in rat neutrophils. Sanguiin H-11 inhibited platelet-activating factor- and N-formylmethionyl-leucyl-phenylalanine-dependent chemotaxis of neutrophil in addition to CINC-1-dependent reactions. Sanguiin H-11 also inhibited chemokinesis of neutrophil, but did not drastically affect the increase of intracellular free [Ca2+] level or degranulation monitored by the secretion of elastase, following chemoattractant stimulation. These results indicated that sanguiin H-11 is a potent inhibitor of chemoattractant-dependent and independent neutrophil movement.

Animals↗
PubMed2000

A facile synthesis of 2-deoxy-2,3-didehydroneuraminic acid derivatives.

The 2-thio- or 2-selenoglycosides of N-acetylneuraminic acid methyl ester were transformed by successive treatment with dimethyl(methylthio)sulfonium triflate (DMTST) and 1,8-diazabicyclo[5.4.0]-7-undecene (DBU) to give the corresponding methyl 2-deoxy-2,3-didehydroneuraminates in excellent yields. Their acids and their analogues are sialidase inhibitors of pharmaceutical interest.

Enzyme Inhibitors↗
PubMed2000

Prediction of crude fat content of longissimus muscle of beef using the ratio of fat area calculated from computer image analysis: comparison of regression equations for prediction using different input devices at different stations.

Crude fat content of longissimus (ribeye) muscle of beef cattle was predicted from a ratio of fat area (RFA) to area of ribeye muscle calculated from computer image analysis (CIA). Cross sections of 64 ribeyes taken from the 6-7th rib from cattle at experiment station A and cross sections of 94 ribeyes taken from the 6-7th rib from cattle at Experiment Station B were used in this study. Slices (1 to 1.5 cm in thickness) of just the Longissimus dorsi were homogenized and sampled for chemical estimation of crude fat content using petroleum ether. Crude fat content as determined from chemical analysis was used as the true estimate of fat content. A CCD (charge-coupled device) camera was used as the input device at Experiment Station A, and a single-lens reflex camera was used at Experiment Station B to photograph ribeyes for CIA. The contour comparison method, which assigns a threshold value for each marbling particle, was used to obtain accurate binarization in this study. Minimum and maximum of chemical measurements of crude fat were 2.1 and 39.8%, and for CIA calculation of the RFA were 6.1 and 56.8%, respectively. This range covered almost the complete range of the beef marbling standard used in carcass grading in Japan. The equation for the regression of the crude fat content (Y) on RFA (X) calculated from CIA for all of the data was Y = .793X-3.04 with r2 = .96. Regression equations for prediction of crude fat percentage from RFA taking into consideration the effect of experiment station were Y = .741X-2.22 with r2 = .91 for Experiment Station A, and Y = .782X-2.54 with r2 = .91 for Experiment Station B. Analysis of covariance showed that the effects of experiment stations on intercepts and slopes were not significant (P > .10). The ranges of differences between actual and predicted crude fat content from the prediction equation that was calculated without consideration of the effect of station were -6.4 to 4.0%. CIA of cross sections of the ribeye muscle seems to have potential for prediction of crude fat content.

Adipose Tissue↗
PubMed2000

Developmental changes in enzyme activities and in morphology of rat cortex mitochondria.

Development of mitochondria in rat brain cortex was investigated in terms of mitochondrial respiratory enzyme activities, and structural and numerical developments of mitochondria. Measurements of succinate-O2 and NADH-O2 oxidoreductase activities of mitochondria resulted in simultaneous changes of activities in postnatal rat. Both oxidoreductase activities were still low at 0-5 days old, increased until 15 days, decreased slightly at 21 days and drastically in adult mitochondria. In morphological study, the cross-sectional area of mitochondrion per cell increased gradually until 21 days old, but decreased drastically in adult. The area of a mitochondrion at 5 days increased about 1.5-fold in comparison with that at 0 days, and maintained at 15 and 21 days. However, the values of area of one mitochondrion from 10 days and adult are about half of a maximum value (21 days). Numbers of mitochondrion per cell were still low at 0-5 days, and high constantly (about twice) at 10-21 days. These findings suggest that the organelle division of mitochondria may be carried out at 5-10 days postnatal. The number of adult rat mitochondria decreased slightly. The small and undeveloped mitochondria were observed at 0 day postnatal by use of transmission electron microscopy (TEM). However, during development from 5 days postnatal, larger and elongated mitochondria were observed, and the maximal complexity of structure of cristae is observed at 15 days and 21 days by TEM. In adult cortex, the small mitochondria were also observed with compact and dense cristae. Our results indicate that the changes of activities of mitochondrial respiratory enzymes in rat cortex is good correlated with the structural maturation of mitochondria.

Animals↗
PubMed2000

[Surgery for intrathoracic recurrence of non-small cell lung cancer].

In this study, we defined a solitary lung nodle in the same histology which could be traced its' origin from carcinoma in situ or was found over than two years' follow up as a second primary lung cancer. These cases were excluded. Eighteen cases underwent second surgery for intrathoracic recurrence. Fourteen cases were male and four cases were female. Their ages ranged from 23 to 75 (average 59.6) years. The histology were adenocarcinoma in 9 cases, squamouscarcinoma in 7, adenosquamous carcinoma in 1, large cell carcinoma in 1. The initial surgical procedures were lobectomy in 17, partial resection in 1. The initial stage were I in 13, II in 2, IIIA in 1. Pulmonary recurrence were found in 10, bronchial stump recurrence were found in 4, pulmonary hilus lymph node recurrence were found in 2, mediastinal lymph node recurrence were found in 2, pulmonary stump recurrence was found in 1. The second surgical procedures were completion pneumonectomy in 7, completion lobectomy in 1, lobectomy with segmentectomy in 1, segmentectomy or partial resection in 7, mediastinal dissection in 2. The overall 5-year survival rate of the patients with recurrence after reoperation was 31.8%. An aggressive surgical approach for recurrent lung cancer should be recommended.

Adult↗
PubMed2000

Effect of sulfated colominic acid on enteric virus (rotavirus, poliovirus and coxsackievirus) infections in vitro.

Sulfated colominic acid exhibited suppressive effects on SA11 (simian rotavirus)- and MO (human rotavirus)-infections, but not on Wa (human rotavirus)-, Sabin 1 (poliovirus 1)-, and Nancy (coxsackie B3 virus)-infections, in vitro. The infection of SA11 was found to be inhibited by mixed treatment and early posttreatment with sulfated colominic acid, but not by pretreatment, by plaque assay and multiple growth assay. The results were confirmed by the infectivity titer, RNA polyacrylamide gel electrophoresis, and electron microscopic analysis. The mechanism of the suppressive effect was suggested to be adsorption inhibition at an early stage of the infection.

Cells, Cultured↗
PubMed1999

Intussusception of a mucocele of the appendix secondary to an obstruction by endometriosis: report of a case.

We treated a patient with a complete invagination of the cecum which contained a mucocele of the appendix secondary to an obstruction by endometriosis. Preoperatively, a barium enema showed a crab's claw-like area without filling in the oral side of the transverse colon. An emergency laparotomy was performed and revealed a mucocele of the appendix to have induced appendicecal invagination; however, no colonic invagination was observed. An appendicecal resection was thus done. Pathologically, the resected specimen was a mucosal hyperplasia with mucin-secreting lesions of the appendix. The theories regarding the pathogenesis of appendicecal mucocele are reviewed and discussed.

Adult↗
PubMed1999

Glutamate toxicity induced degeneration of outer hair cells with a temporal increase of nitric oxide production in the guinea pig cochlea.

The aim of this study was to examine the roles of glutamate (GLU) toxicity and involvement of nitric oxide (NO) in the pathogenesis of cochlear degeneration. We examined guinea pig cochleae following chronic exposure to GLU. Trypan blue extrusion and transmission electron microscopy were performed to evaluate degeneration in the organ of Corti. In parallel, nitric oxide synthase (NOS) activity was demonstrated by histochemical staining of NADPH diapholase. GLU treatment caused time-dependent degeneration of outer hair cells (OHCs) in conjunction with a temporal increase of NOS activity in the organ of Corti. This suggests that GLU may be involved in OHC degeneration under toxic conditions, with NO production possibly playing a role in this process.

Animals↗
PubMed1999

Determination of antibodies to TT virus (TTV) and application to blood donors and patients with post-transfusion non-A to G hepatitis in Japan.

Recently, a nonenveloped single-stranded DNA virus named TT virus (TTV) has been reported in association with non-A to G post-transfusion as well as sporadic acute and chronic liver disease. A method was developed for the detection of antibody to TTV (anti-TTV) by means of immune precipitation and detection of TTV DNA by the polymerase chain reaction. The test serum was incubated with TTV, recovered from feces of a carrier, and after incubation, the formed immune complexes were precipitated with goat antiserum to human IgG. TTV DNA was sought for by the polymerase chain reaction in both precipitate and supernatant. The detection of TTV DNA in the precipitate, but not in the supernatant, was considered to represent anti-TTV in the test serum. Of the 44 healthy blood donors in Japan, anti-TTV was detected in one of the six (17%) with TTV DNA and 11 of the 38 (29%) without TTV DNA. In the two patients with post-transfusion non-A to G hepatitis, free anti-TTV developed as they cleared TTV in serum. Anti-TTV complexed with TTV in serum, detectable by precipitating sera with goat anti-human IgG and testing for TTV DNA, elicited while the patients had elevated alanine transaminase levels. The determination of anti-TTV would be useful for detecting resolved infection in surveys for exposure to TTV in the general population, and for establishing the mechanism of liver injury associated with TTV infection.

Adult↗
PubMed1999

Clinical assessment of collagen cross-linked N-telopeptides as a marker of bone metabolism in patients with primary hyperparathyroidism.

This study assesses the clinical usefulness of collagen cross-linked N-telopeptides (NTx), a new marker for bone resorption, as a marker for primary hyperparathyroidism. The study was conducted on 114 patients who had undergone parathyroidectomy for primary hyperparathyroidism. Urine NTx levels were longitudinally determined by ELISA. Longitudinal serum bone Gla protein (BGP) determinations and dual energy X-ray absorptiometry (DEXA) examinations were also performed before and after parathyroidectomy. Before parathyroidectomy, the mean urine NTx level in primary hyperparathyroidism was 149.0 +/- 116.8 pmol BCE/mumol Cr (normal: < 55 pmol BCE/mumol Cr), and the positive rate was 88.5%. The mean BGP level was 33.5 +/- 59.1 ng/mL (normal: 12.7 ng/mL), and the positive rate was 77.7%. The NTx positive rate was higher than the BGP positive rate. NTx values were significantly correlated with bone mineral density (P < 0.002) and BGP values (P < 0.005). Two weeks after parathyroidectomy the NTx levels had already decreased significantly to 65.1 pmol BCE/mumol Cr (P < 0.001), and by one month postoperatively they had fallen to 55.9 pmol BCE/mumol Cr, reaching the normal range much sooner than BGP. The NTx normalization rate two weeks postoperatively was 37%, and by 12 months postoperatively it was normal in 83% of patients. BGP levels decreased more gradually than the NTx levels, and only became normal in 9% of cases two weeks postoperatively, as opposed to 74% by 12 months. It is concluded that NTx reflects bone turnover in primary hyperthyroidism, and that it is an excellent marker for bony lesions before and after parathyroidectomy.

Biomarkers↗