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Biomedical subjects

H Kudo

Publications and source records attributed to H Kudo.

At least 19 recordsLinked to original sources
PubMed2006

Comparison of two types of ulnar component in type-5 Kudo total elbow arthroplasty in patients with rheumatoid arthritis: a long-term follow-up.

The purpose of this study was to assess the long-term results (more than ten years) of two types of cemented ulnar component with type-5 Kudo total elbow arthroplasty in a consecutive series of 56 patients (60 elbows) with rheumatoid arthritis, and to compare the results in elbows above and below a Larsen grade IV. There was no radiolucency around the humeral component. Patients in whom a metal-backed ulnar component and a porous-coated stem were used had better clinical results and significantly less progression of radiolucent line formation around the ulnar component. They also had a significantly better long-term survival than patients with an all-polyethylene ulnar component. The clinical results of arthroplasty using all-polyethylene ulnar components were inferior, regardless of the degree of joint destruction. We conclude that the type-5 Kudo total elbow arthroplasty with cementless fixation of the porous-coated humeral component and cemented fixation of a metal-backed ulnar component is acceptable and well-tolerated by rheumatoid patients.

Adult↗
PubMed2006

Kudo type-5 total elbow arthroplasty in mutilating rheumatoid arthritis: a 5- to 11-year follow-up.

We studied 11 patients (14 elbows) with gross rheumatoid deformity of the elbow, treated by total arthroplasty using the Kudo type-5 unlinked prosthesis, and who were evaluated between five and 11 years after operation. Massive bone defects were augmented by autogenous bone grafts. There were no major complications such as infection, subluxation or loosening. In most elbows relief from pain and stability were achieved. The results, according to the Mayo Elbow Performance Score, were excellent in eight, good in five and fair in one. In most elbows there was minimal or no resorption of the grafted bone. There were no radiolucent lines around the stems of the cementless components. This study shows that even highly unstable rheumatoid elbows can be replaced successfully using an unlinked prosthesis, with augmentation by grafting for major defects of bone.

Adult↗
PubMed2005

Overexpression of glucose transporter 1 in esophageal squamous cell carcinomas: a marker for poor prognosis.

SUMMARY: Recently, Glut1 (human erythrocyte glucose transporter) expression has been demonstrated in various tumors. The aim of this study is to evaluate the prognostic utility of Glut1 expression in esophageal carcinomas. We studied Glut1 expression by immunohistochemistry of paraffin sections from 63 esophageal squamous cell carcinomas. All 63 carcinomas expressed Glut1. The mean percentage of positively stained tumor cells was 77.8% (median, 84.7%). There were two staining patterns in positive cells: 'strongly positive' and 'weakly positive'. The percentage of 'strongly positive' cells (%Glut1-SP) ranged from 0% to 95.6% (mean, 32.3%; median, 27.4%). The 5-year survival rate for patients with a high %Glut1-SP (> 30%) was significantly lower than that for patients with a low %Glut1-SP (< 30%) (P < 0.01). Statistical analysis revealed that the relative risk of death for patients with high %Glut1-SP was 2.02 times that for patients with low %Glut1-SP (P = 0.064), suggesting a possible independent predictive value for %Glut1-SP.

Adult↗
PubMed2004

Investigation of saddle trajectories for cardiac CT imaging in cone-beam geometry.

This paper investigates cone-beam tomography for a wide class of x-ray source trajectories called saddles. In particular, a mathematical analysis of the number of intersections between a saddle and an arbitrary plane is given. This analysis demonstrates that axially truncated cone-beam projections acquired along a saddle can be used for exact reconstruction at any point in a large volume. The reconstruction can be achieved either using a new algorithm presented herein or using a formula recently introduced by Katsevich (2003 Int. J. Math. Math. Sci. 21 1305-21). The shape of the reconstructed volume and the properties of saddles make saddles attractive for cardiac imaging. Three examples of saddles are presented with a discussion of implementation on devices similar to modern C-arm systems and multislice CT scanners. Reconstruction with one of these saddles has been tested using computer-simulated data, with and without truncation. The imaged phantom for the truncated data is a FORBILD head phantom (representing the heart) that has been modified and embedded inside the FORBILD thorax phantom. The non-truncated data were generated by excluding the thorax. The reconstructed images demonstrate the accuracy of the mathematical results.

Algorithms↗
PubMed2004

Immunohistochemical demonstration of salmon olfactory glutathione S-transferase class pi (N24) in the olfactory system of lacustrine sockeye salmon during ontogenesis and cell proliferation.

In mammals, glutathione S-transferase (GST) in the olfactory epithelium is involved in assistance of the olfactory reception by the xenobiotic metabolism. We previously reported the protein and gene expressions of salmon olfactory GST class pi (soGST) in the olfactory receptor cells (ORCs) of the salmonid fish. However, the chronological appearances of soGST in ORCs during ontogeny and cell proliferation are still unknown in this species. In this study, we performed immunohistochemistry of soGST using an antibody specific to soGST in the olfactory system (olfactory placode, olfactory pit, olfactory epithelium, olfactory nerve and olfactory bulb) of lacustrine sockeye salmon ( Oncorhynchus nerka) embryos and 5-bromo-2'-deoxyuridine (BrdU) experimental fish. The projection of olfactory nerve bundles from the olfactory pit to the presumptive olfactory bulb was identified at embryonic day 28 after fertilization. The olfactory cilia were first detected on the apical surface of ORCs at day 43. soGST-immunoreactivity was first detected within the olfactory pit cells at day 55. At 58 day, the number of soGST-immunoreactive cells increased markedly in the olfactory epithelia, and soGST-immunoreactive fibers were observed in the olfactory nerves and olfactory bulbs. By in vivo uptake of BrdU in 1-year-old fish, we observed for the first time at day 7 after labeling that the olfactory epithelia showed ORCs in which both soGST-immunoreactivity and BrdU coexisted. These results indicate that soGST is synthesized in the mature ORCs of lacustrine sockeye salmon after cell formation and differentiation.

Animals↗
PubMed2004

Topographic effects on adhesive force mapping of stretched DNA molecules by pulsed-force-mode atomic force microscopy.

Adhesive interaction between a tip and a sample surface was examined on a microscopic scale by pulsed-force-mode atomic force microscopy (PFM-AFM). The signal measured by monitoring pull-off force is influenced by various factors such as topography, elasticity, electrostatic charges, and adsorbed water on surfaces. Here, we focus on the topographic effects on the adhesive interaction. To clarify the topographic influence, the adhesive force measurement of a stretched DNA molecule with a smaller radius of curvature than that of a tip was carried out at low relative humidity (RH) with an alkanethiol-modified tip. The experimental conditions such as low RH and the use of the alkanethiol-modified tip were required to minimise the influence of water capillary force on hydrated DNA strands. The hydrophobic modification of a substrate surface was also important to minimise the adsorbed water effect. The DNA molecules were stretched on the substrate surfaces by an immobilisation process called a dynamic molecular combing method. The two-component vapour-phase surface modification with an alkylsilane mixed with a silane derivative containing an amino end group enhanced the DNA adsorption due to the electrostatic interaction. The experimental results for the topographic effects on the adhesive force mapping were reproducible.

Adhesiveness↗
PubMed2004

Observation of removal of an Fmoc protecting group by scanning tunneling microscopy.

We demonstrate here by imaging successive surface reactions in self-assembled monolayers (SAMs) on Au(111) at molecular scale with a scanning tunneling microscope (STM): (i) SAM matrices formation with 1-octanethiol on Au(111) in ethanol, (ii) insertion of N-Fmoc-aminooctanethiol into the SAM matrices in ethanol, and (iii) removal of the Fmoc protecting group with tris(2-aminoethyl)amine (TAEA). The total reaction is formation of SAMs containing a small amount of NH2 terminated molecules in the CH3 terminated SAM matrices. After the reaction of the protecting group with TAEA, STM imaging revealed the decrease in heights of the inserted molecules on average. We attributed this observation to removal of the protecting group by taking account of a convolution of electronic and topographic contributions to observed STM heights. Apparent areas of the terminal groups, however, became larger on removal. The increase in the areas was attributed to water adsorption to the NH2 terminal group under air.

Journal Article↗
PubMed2003

Uni-axial cyclic stretch induces Cbfa1 expression in spinal ligament cells derived from patients with ossification of the posterior longitudinal ligament.

Ossification of the posterior longitudinal ligament of the spine (OPLL) is characterized by ectopic bone formation in the spinal ligaments. Mechanical stress, which acts on the posterior ligaments, is thought to be an important factor in the progression of OPLL. To clarify this mechanism, we investigated the effects of in vitro cyclic stretch (120% peak to peak, at 0.5 Hz) on cultured spinal ligament cells derived from OPLL (OPLL cells) and non-OPLL (non-OPLL cells) patients. The mRNA expressions of Cbfa1 (an osteoblast-specific transcription factor), type I collagen, alkaline phosphatase (ALP), osteocalcin and integrin beta1 (a mechanotransducer) were increased by cyclic stretch in OPLL cells, whereas no change was observed in non-OPLL cells. The effects of cyclic stretch on the spinal ligament tissues derived from OPLL and non-OPLL patients were also analyzed by immunohistochemistry using an antibody against Cbfa1. The expression of Cbfa1 was increased by cyclic stretch at the center of the spinal ligament tissues of OPLL patients, whereas no change was observed in the tissues of non-OPLL patients. Furthermore, U0126, a specific inhibitor of MAPK kinase (MEK), suppressed the stretch-induced mRNA expressions of Cbfa1, ALP and type I collagen in OPLL cells. These results suggest that in OPLL cells, mechanical stress is converted by integrin beta1 into intracellular signaling and that Cbfa1 is activated through the MAP kinase pathway. Therefore, we propose that mechanical stress plays a key role in the progression of OPLL through an increase in Cbfa1 expression.

Aged↗
PubMed2003

Validity of simple mucosal biopsy criteria combined with endoscopy predicting patients with ulcerative colitis ultimately requiring surgery: a multicenter study.

BACKGROUND: Recent mucosal biopsy criteria combined with endoscopy effectively differentiate patients with ulcerative colitis ultimately requiring surgery (UC-S) from those receiving medication alone (UC-M). However, the criteria were inconvenient in practical use because of the need for complicated calculations, and the validity has not been verified in other institutes where the indications for surgery may differ. The aims of this multicenter study were to propose simple criteria in which calculation can be performed by mental arithmetic and to measure their validity. METHODS: Based on the above original criteria, we constructed simple criteria in which coefficients and constant were simplified to integral numbers. The criteria consisted of the diagnostic categories, highest-risk, high-risk, unpredictable, low-risk, and lowest-risk of surgery. The validity of these proposed criteria was evaluated in 121 patients with UC-S and 186 with UC-M from 11 institutes. RESULTS: The categories of high-risk and low-risk had sensitivities exceeding 86.0% and specificities exceeding 95.2%, and the validities were maintained at high levels in most individual institutes. There was little difference in validity between the proposed and original criteria when testing using the same patients. CONCLUSIONS: Despite simplified coefficients and constant, the proposed criteria reliably predicted the eventual clinical outcome of patients with ulcerative colitis and would be helpful in determining the necessity of surgery.

Adolescent↗
PubMed2002

Secretory carcinoma of the breast: a tumour analogous to salivary gland acinic cell carcinoma?

AIMS: Acinic cell-like breast carcinoma is a newly recognized entity, and few acinic cell-like breast carcinoma cases have been reported. All reported acinic cell-like breast carcinomas were counterparts of the solid type of acinic cell carcinoma of the salivary gland. We report here three cases of secretory breast carcinoma with acinic cell differentiation, and discuss the similarity between secretory breast carcinoma and acinic cell carcinoma of the salivary gland. METHODS AND RESULTS: The cases were histologically identical to acinic cell carcinoma of the salivary gland: papillary-cystic type in case 1, a mixture of papillary-cystic, microcystic and follicular type in case 2, and microfollicular type in case 3. Immunohistochemically, the tumour cells were positive for salivary-type amylase, lysozyme, S100 protein and alpha 1-antitrypsin, and negative or less reactive for gross cystic disease fluid protein-15 and oestrogen receptor. All three cases did not reveal metastasis or recurrence. CONCLUSIONS: These cases were typical of secretory breast carcinoma, and were clinically, histologically and immunohistochemically analogous to acinic cell carcinoma of the salivary gland. We emphasize that secretory breast carcinoma and acinic cell carcinoma of the salivary gland may be identical lesions.

Adult↗
PubMed2002

Biopsy pathology predicts patients with ulcerative colitis subsequently requiring surgery.

BACKGROUND: The clinical course of patients with ulcerative colitis (UC) is unpredictable, and 17%-38% ultimately require surgery. We hypothesized that mucosal histology may differ between patients requiring surgery and those receiving medication alone. The aim of this study was to elucidate comprehensive criteria consisting of specific histologic features enabling the prediction of failure to medical treatment. METHODS: We studied colorectal biopsy specimens from 67 patients ultimately requiring surgery (UC-S) and 90 receiving medication alone for more than 3 years (UC-M), and conducted multiple logistic regression analysis on 70 histologic features together with endoscopic disease extent and patient age. The analysis constructed an equation finding probability of UC-S (P(UC-S)). Based on a receiver-operating characteristic curve, we selected four cut-off values of P(UC-S), and determined criteria of five categories: highest-risk, higher-risk, unpredictable, lower-risk and lowest-risk of surgery. Sensitivity and specificity of criteria were evaluated in a 2 x 5 table. RESULTS: Statistically significant features predicting UC-S were deep ulceration (X1), frequent crypt abscesses (X2), focal and segmental mononuclear cell infiltration (X3 and X4), paucity of eosinophils (X5: eosinophil infiltration) and wide extent of the disease (X6). The regression equation was as follows: logitP(UC-S) = -16.26 + 3.20X1 + 4.83X2 + 11.65X3 + 5. 10X4 - 5.59X5 + 5.53X6. Higher-risk and lower-risk showed sensitivity exceeding 91.0% and specificity exceeding 98.5% in predicting the outcome. CONCLUSIONS: Our criteria incorporating specific histologic features and endoscopic disease extent reliably predict eventual clinical outcome, and are expected to prove useful in determining the necessity of surgery.

Adult↗
PubMed2002

NOS and COX isoforms and abnormal microvessel responses to CO2 and H+ in hyperoxia-injured lungs.

The aim of the present study was to compare microvessel responses to hypercapnic and isocapnic acidosis in hyperoxia-injured lungs and to assess the role of constitutive and inducible forms of nitric oxide synthase (NOS) and cyclo-oxygenase (COX). Real-time confocal luminescence microscopy was used to measure changes in the diameter of acinar arterioles, venules and capillaries in response to stimulation with hypercapnic and isocapnic acidosis in isolated rat lungs injured by 90% oxygen exposure for 48 h. Observations were made with and without inhibition of constitutive (endothelial constitutive NOS (ecNOS) and COX-1) and inducible isoforms (iNOS and COX-2) of NOS and COX. Upregulation of NOS was assessed by measuring enzyme levels in lung homogenates by Western blot analysis and enhancement of the COX-related pathway was judged from perfusate concentrations of 6-ketoprostaglandin F1alpha. ecNOS and COX-1, but not iNOS and COX-2, were upregulated in hyperoxia-injured lungs. The nitric oxide produced by ecNOS attenuated COX-1 activity in injured arterioles and venules, but carbon dioxide enhanced it, leading to paradoxical dilatation of these microvessels under hypercapnic conditions with ecNOS inhibition. Although a high hydrogen ion concentration was unnecessary for excitation of COX-1, venule constriction in response to H+ was enhanced by COX-1 inhibition. Constitutive, but not inducible, isoforms of cyclo-oxygenase and nitric oxide synthase play an important role in abnormal microvessel responses to carbon dioxide and hydrogen ions in hyperoxia-injured lungs.

Acidosis, Respiratory↗
PubMed2002

Disorganization of honey-comb immunoreactive pattern of desmin and plectin in rat atrophic soleus muscle fiber induced by hindlimb suspension.

Immunoreactivity for desmin, plectin and alpha-actinin was investigated in rat atrophic soleus muscle fibers induced by hindlimb suspension between 1 and 4 weeks (hindlimb suspension group, HSG), and compared with that of the control group (CG). Some of the HSG for 4 weeks were allowed unrestricted cage activity for 2 weeks as the recovery group (RG). In the cross-sectioned muscle fibers of the CG, desmin and plectin showed honey-comb immunoreactive patterns extending throughout the sarcoplasm. Superimposed images by double immunofluorescence labeling showed overlapping of both immunoreactivities. In the longitudinally sectioned profiles, superimposed images of alpha-actinin and desmin were overlapped at the level of Z-discs. The focal disorganization of the above honeycomb immunoreactive patterns, followed by the reduction of the cross-sectional area (CSA) of atrophic soleus muscle fibers and the appearance of Z-streaming, uniquely arose in the HSG from the first week and extended throughout the sarcoplasm in proportion to the suspension period. Such honey-comb patterns of both desmin and plectin were already restored in the RG at 2 weeks, followed by the disappearance of Z-streaming, prior to the recovery of the CSA. These findings indicate that the disorganization of topological and structural relationships of desmin and plectin with Z-discs surrounding individual myofibrils is primarily evoked, which leads to Z-streaming of atrophic soleus muscle fibers, and that the restoration of the muscle activity results in an early arrangement recovery of desmin and plectin around myofibrils.

Animals↗
PubMed2002

Enhanced expression of endothelin-1 and endothelin-converting enzyme-1 in acute hypoxic rat aorta.

Deeply anesthetized male Wistar rats were perfused by Hanks' balanced salt solution bubbled with either 95%air and 5%CO2 (normoxic group) or 95%N2 and 5%CO2 (hypoxic group) from the thoracic aorta for 30 min, and the isolated abdominal aortae from both groups were used for electron microscopy, immunocytochemistry of endothelin (ET)-1 and ET-converting enzyme (ECE)-1, and in situ hybridization of preproET-1 mRNA. A remarkable increase in the number of Weibel-Palade (WP) bodies, storage sites of ET-1 and ECE-1, occurred in the hypoxic group when compared to the normoxic group. Immunoreactivities for ET-1 and ECE-1, and signals for preproET-1 mRNA were seen along the endothelia of both groups, but the intensities were significantly elevated in the hypoxic group. The increase in the number of ECE-1 immunoreactive gold particles was noticed especially in WP bodies in the hypoxic group. These findings indicate the enhancement of preproET-1 synthesis in the aortic endothelial cells as well as the acceleration of ET-1 processing in increased WP bodies in such cells in an experimentally hypoxic condition of the rat aortae.

Acute Disease↗
PubMed2001

Splenomegaly induced by recombinant human granulocyte-colony stimulating factor in rats.

Spontaneous ruptures of the spleen have been observed in donors and patients with malignancy during mobilization of peripheral blood stem cells. Thus, we investigated the morphological and histological alteration of the spleen, and mRNA expression levels and activities of the DNA-synthesizing enzymes thymidylate synthase (TS) and thymidine kinase (TK) in the splenic cells, of rats treated with recombinant human granulocyte-colony stimulating factor (rhG-CSF). Daily injections of rhG-CSF for 5 or 7 days slightly enhanced the splenic weight. Single or 3-day treatment with rhG-CSF markedly enhanced the number of granulocytes in peripheral blood. Expression levels of TS and TK mRNA in the splenic cells were significantly increased 6 hours after rhG-CSF treatment. Early expression of TS and TK mRNA in the splenic cells may indicate a reseeding of hematopoietic cells from the bone marrow. Daily injections with rhG-CSF enhanced the TS and TK activities in the splenic cells. As continuous elevations of DNA-synthesizing enzyme activity and spleno-megaly are suggestive of a possible splenic rupture, the monitoring of peripheral granulocytes and splenic size is necessary during the rhG-CSF treatment.

Animals↗
PubMed2001

Spatial distribution and histogenesis of colorectal Paneth cell metaplasia in idiopathic inflammatory bowel disease.

BACKGROUND AND AIM: Colorectal Paneth cell metaplasia (PCM) is known to be a sign of idiopathic inflammatory bowel disease (IBD), although its distribution and histogenesis are not fully understood. Objectives of this research were to investigate the spatial distribution of PCM in IBD and other forms of colitis (non-IBD), and to find stimuli causing PCM. METHODS: We studied multiple biopsy specimens from 181 patients with ulcerative colitis (UC), 159 with Crohn's disease (CD), 448 with non-IBD, and 78 normal controls. Paneth cell metaplasia frequency, at each colorectal site, was evaluated to find possible differences among diseases, phases of activity, and extents of disease. RESULTS: In non-IBD and controls, PCM was rarely (0-1.9%) seen at distal sites, but frequently (up to 48.7%) found at the ascending colon and cecum (P < 0.001). Paneth cell metaplasia frequency was significantly higher in IBD than in non-IBD patients and controls at distal sites (P < 0.001), but did not differ significantly between UC and CD, or among active, resolving, and quiescent phases. In UC, proctitis and left-sided colitis rarely displayed PCM at unaffected sites. Multiple logistic regression analysis revealed that PCM was positively associated with crypt distortion and mononuclear cell infiltration (P < 0.005), but negatively or not significantly associated with crypt atrophy, mucin depletion, acute inflammation, or phase of activity. CONCLUSIONS: Paneth cell metaplasia is a non-specific phenomenon in the proximal colon, but distal PCM, which occurs exclusively in affected mucosa, is a useful marker indicating IBD, even in the inactive phase. Regression analysis suggests that repair and regeneration may be the most potent stimuli causing PCM.

Adult↗
PubMed2001

Observer variation of diagnoses based on simple biopsy criteria differentiating among Crohn's disease, ulcerative colitis, and other forms of colitis.

BACKGROUND AND AIM: Simple mucosal biopsy criteria proposed by authors reliably differentiate idiopathic inflammatory bowel disease (IBD) from other forms of colitis (non-IBD) and Crohn's disease involving the colon (CD) from ulcerative colitis (UC). The aim of this study is to investigate the reproducibility of these criteria. METHODS: Three established pathologists and two medical students blindly examined 20 sets of multiple biopsy slides from patients with CD, 20 from those with UC, and 20 from those with non-IBD. The students had been given instructions on histological definitions using another 15 sets previously. Each observer evaluated 10 histological items required in the criteria and determined categorical diagnoses such as definite IBD and probable UC. Interobserver agreement for the individual histological items was measured by using kappa analysis and Pearson's correlation, while it was measured for categorical diagnoses with the use of Spearman's rank correlation. RESULTS: All of the individual histological items expressed excellent or fair-to-good agreement among the five observers, although two items associated with the criteria for CD and UC had poor agreements among the students. With regard to categorical diagnoses based on the criteria for IBD and non-IBD, and those for CD and UC, coefficients for Spearman's rank correlation exceeded 0.92 and 0.86 among the pathologists, and 0.76 and 0.74 among the students, respectively; all of the coefficients were statistically significant (P < 0.05). CONCLUSIONS: The simple criteria were sufficiently reproducible and would help most pathologists to make an automated and objective diagnosis.

Biopsy↗