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Biomedical subjects

H Kudo

Publications and source records attributed to H Kudo.

At least 73 records · Page 4Linked to original sources
PubMed1999

No psychological emergence reactions in schizophrenic surgical patients immediately after propofol, fentanyl, and ketamine intravenous anesthesia.

PURPOSE: We attempted to determine the frequency of adverse psychological events after total intravenous anesthesia with propofol-fentanyl-ketamine (PFK) in surgical schizophrenic patients. METHODS: PFK was used in 25 schizophrenic patients undergoing various surgical procedures from 1995 to 1997. Adverse events occurring during and after anesthesia were recorded. Psychiatric follow-up was also done during the first 3 postoperative weeks at least. RESULTS: One patient died postoperatively of airway obstruction from concomitant severe malignant thyroid disease, but in the remaining patients neither respiratory nor cardiovascular states during or after anesthesia became unstable. None of the patients developed adverse psychological emergence reactions immediately after anesthesia. Two patients undergoing major surgical procedures exhibited delirium in the early postoperative days despite taking their routine antipsychotic drugs postoperatively. CONCLUSIONS: We suggest that PFK maintains stable respiratory and cardiovascular states, and causes no psychological emergence reactions in schizophrenic surgical patients. However, adverse psychological events may occur postoperatively, probably due to continued psychic stress. We therefore recommend appropriate perioperative management and further psychological studies for such patients.

Journal Article↗
PubMed1999

Salmonid olfactory system-specific protein (N24) exhibits glutathione S-transferase class pi-like structure.

A salmonid olfactory system-specific protein (N24) that has been identified in lacustrine sockeye salmon (Oncorhynchus nerka) was characterized by biochemical and molecular biological techniques. N24 is a homodimer, and the intact molecular mass is estimated as approximately 43.3 kDa by gel filtration. Furthermore, N24 was located only in the cytosolic fraction of the olfactory tissues as determined by subcellular fractionation. cDNA encoding the lacustrine sockeye salmon N24 was isolated and sequenced. This cDNA contained a coding region encoding 216 amino acid residues and the molecular mass of this protein is calculated to be 242,224.77. The protein and nucleotide sequencing demonstrates the existence of a remarkable homology between N24 and glutathione S-transferase (GST; EC 2.5.1.18) class pi enzymes. Northern analysis showed that N24 mRNA with a length of 950 bases is expressed in lacustrine sockeye salmon olfactory epithelium. Olfactory receptor cells showed strong hybridization signals for N24 mRNA in the olfactory epithelium. N24 demonstrated glutathione binding activity in affinity-purified GST column experiments. The present study describes for the first time cDNA cloning of GST in fish olfactory epithelium.

Animals↗
PubMed1999

Morphologic criteria applicable to biopsy specimens for effective distinction of inflammatory bowel disease from other forms of colitis and of Crohn's disease from ulcerative colitis.

BACKGROUND: Inflammatory bowel disease (IBD)--and Crohn's disease (CD) and ulcerative colitis (UC) in particular--could be more reliably diagnosed by using biopsy criteria incorporating the colorectal distribution of specific histologic features. The aim of this study was to elucidate criteria distinguishing IBD from other forms of colitis (non-IBD), and CD from UC on the basis of multiple colorectal biopsies. METHODS: We examined multiple biopsy specimens (mean, 6.1) from 299 consecutive Japanese subjects with active colitis and performed multiple logistic regression analyses on 70 histologic features, from which 2 equations were constructed for the probabilities (P(IBD) and P(CD)) of a) IBD (versus non-IBD), and b) CD (versus UC), respectively, being present. On the basis of a receiver-operating characteristic curve, we determined four cut-off values for P(IBD) and constructed the criteria, consisting of the five categories 'definite IBD', 'probable IBD', 'unknown', 'probable non-IBD', and 'definite non-IBD'. The criteria for CD versus UC were constructed in a similar manner. Their validities were evaluated using 132 Canadian subjects. RESULTS: The statistically significant histologic features were as follows: for IBD, crypt architectural abnormalities, basal plasmacytosis with severe chronic inflammation, and distal Paneth cell metaplasia; for CD, segmental crypt architectural abnormalities and mucin depletion, mucin preservation at the active sites, and focal chronic inflammation without crypt atrophy. In the categories of probable IBD and probable non-IBD, both sensitivities and specificities exceeded 97%. Probable CD and probable UC showed high specificities of more than 97%, and their sensitivities were 94% and 89%, respectively. Kappa statistics showed these criteria to be sufficiently reproducible. CONCLUSIONS: Specific histological features together with their distribution can reliably diagnose IBD, distinguish CD from UC, and provide an estimate of the probability of the underlying disease being present.

Adult↗
PubMed1999

Analysis of stability and catalytic properties of two tryptophanases from a thermophile.

Two tryptophanases, Tna1 and Tna2, both of which were cloned from the thermophile Symbiobacterium thermophilum, differ in their enzymatic properties, such as thermal stability, catalytic efficiency and activation energy of catalysis, despite the great similarity (92%) in their amino acid sequences. Chimeric tryptophanases were constructed by recombination of the two genes to try to elucidate the molecular basis for the difference. The stability of each chimeric enzyme was roughly proportional to the content of amino acid residues from Tna1. Three regions, tentatively named regions 2, 4 and 5, which contained the amino acid residues 70-129, 192-298 and 299-453, respectively, were especially important for the increase in thermal stability. Site-directed mutagenesis revealed that V104 in region 2 and Y198 in region 4 of Tna1 were involved in the increase in thermal stability of Tna1. Amino acid residues contributing to the higher catalytic efficiency of Tna1 were similarly analyzed, using the chimeric tryptophanases, and found to be located in region 5. Site-directed mutagenesis revealed that I383 and G395 in Tna1, which were presumably located close to the putative active center, played an active role in the increase of catalytic efficiency of Tna1. The activation energy of catalysis was proportional to the content of amino acid residues from Tna2, suggesting the amino acid residues responsible for the difference were dispersed over the whole molecule.

Amino Acid Sequence↗
PubMed1999

Nitric oxide differentially attenuates microvessel response to hypoxia and hypercapnia in injured lungs.

The issue of whether the acinar microvessel response to alveolar hypoxia and hypercapnia is impaired in injured lungs has not been vigorously addressed, despite the importance of knowing whether it is or not when treating patients with serious lung injury in terms of permissive hypercapnia. Applying a real-time laser confocal luminescence microscope, we studied hypoxia- and hypercapnia-induced changes in the diameter of the intra-acinar arterioles, venules, and capillaries of isolated rat lungs harvested from animals exposed for 48 h to 21% O(2) (group N) or 90% O(2) (group H). Measurements were made with and without inhibition of nitric oxide (NO) synthase (NOS) by N(omega)-nitro-L-arginine methyl ester or of cyclooxygenase (COX) by indomethacin at different basal vascular tones evoked by thromboxane A(2) (TXA(2)) analog. Hypoxia in the absence of TXA(2) contracted arterioles in group N but not in group H. Attenuated hypoxia-induced arteriole constriction was restored almost fully by inhibiting NOS and partially by inhibiting COX. Hypercapnia induced venule dilation in group N, but did not dilate venules in group H, irrespective of TXA(2). NOS inhibition in hypercapnia unexpectedly enhanced venule and arteriole dilation in group H. These responses no longer occurred when NOS and COX were inhibited simultaneously. In conclusion, microvessel reactions to hypoxia and hypercapnia are abnormal in hyperoxia-injured acini, in which NO directly attenuates hypoxia-induced arteriole constriction, whereas COX inhibited by excessive NO impedes hypercapnia-induced microvessel dilation.

Animals↗
PubMed1999

Total elbow arthroplasty with use of a nonconstrained humeral component inserted without cement in patients who have rheumatoid arthritis.

BACKGROUND: Most total elbow prostheses that are currently in use require cement for fixation of each component. We developed a new (type-5) prosthesis that does not need cement for fixation. METHODS: The humeral component is made of cobalt-chromium alloy, and its stem is porous-coated with a plasma spray of titanium alloy. There are two options for the ulnar component: an all-polyethylene type and a metal-backed type with a porous-coated stem. Forty-three elbows in thirty-seven patients who had rheumatoid arthritis were treated with total elbow replacement arthroplasty with use of the type-5 prosthesis. The humeral component was implanted without cement in all elbows, whereas the ulnar component was implanted without cement in eleven elbows and was fixed with cement in the remaining thirty-two. The elbows were followed for an average of three years and ten months (range, two years and six months to five years and six months). RESULTS: The clinical results were assessed according to a modification of the Mayo Clinic Performance Index. At the time of the latest follow-up, the overall result was excellent for six elbows, good for thirty-one, and fair for six. All elbows had been rated as poor before the operation. There was almost complete relief of pain in twenty-nine elbows and mild or occasional pain in the remaining fourteen. Flexion increased markedly, from an average of 104 degrees preoperatively to an average of 133 degrees postoperatively; this difference was highly significant (p < 0.001, Student t test). In contrast, extension (flexion contracture) worsened slightly, from an average of 38 degrees preoperatively to an average of 42 degrees postoperatively; this difference was significant (p < 0.05). There was one postoperative dislocation of the elbow, and ectopic bone formed in another, with recurrence of ankylosis. Both elbows had a reoperation, and a good result eventually was obtained. There were no instances of postoperative infection or neuropathy of the ulnar nerve. Radiographically, there were no radiolucent lines at the bone-metal interface of any of the humeral or ulnar stems that had been implanted without cement, suggesting solid fixation by osseointegration. CONCLUSIONS: The results of total elbow arthroplasty with use of this prosthesis appear promising. There was a high rate of relief of pain as well as of restoration of adequate function in patients in whom the elbow was severely affected by rheumatoid arthritis.

Adult↗
PubMed1998

Response of intra-acinar pulmonary microvessels to hypoxia, hypercapnic acidosis, and isocapnic acidosis.

To elucidate the differential reactivity of pulmonary microvessels in the acini to hypoxia, excessive CO2, and increased H+, we investigated changes in the diameter of precapillary arterioles, postcapillary venules, and capillaries in isolated rat lungs on exposure to normocapnic hypoxia (2% O2), normoxic hypercapnia (15% CO2), and isocapnic acidosis (0.01 mol/L HCl). Microvascular diameters were precisely examined using a real-time confocal laser scanning luminescence microscope coupled to a high-sensitivity camera with an image intensifier. Measurements were made under conditions with and without indomethacin or N(omega)-nitro-L-arginine methyl ester to assess the importance of vasoactive substances produced by cyclooxygenase (COX) or NO synthase (NOS) as it relates to the reactivity of pulmonary microvessels to physiological stimuli. We found that acute hypoxia contracted precapillary arterioles that had diameters of 20 to 30 microm but did not constrict postcapillary venules of similar size. COX- and NOS-related vasoactive substances did not modulate hypoxia-elicited arteriolar constriction. Hypercapnia induced a distinct venular dilatation closely associated with vasodilators produced by COX but not by NOS. Arterioles were appreciably constricted in isocapnic acidosis when NOS, but not COX, was suppressed, whereas venules showed no constrictive response even when both enzymes were inhibited. Capillaries were neither constricted nor dilated under any experimental conditions. These findings suggest that reactivity to hypoxia, CO2, and H+ is not qualitatively similar among intra-acinar microvessels, in which COX- and NOS-associated vasoactive substances function differently.

6-Ketoprostaglandin F1 alpha↗
PubMed1998

Induction of apoptosis, p53 and heme oxygenase-1 by cytotoxic prostaglandin delta12-PGJ2 in transformed endothelial cells.

Delta12-prostaglandin (PG)J2, which has been reported to have potent growth inhibitory activity in various tumor cells, induced apoptosis at 5 microg/ml culture medium in transformed mouse endothelial (F2) cells. Immunoblot analysis using anti-p53 or anti-WAF1 antibodies demonstrated that these two proteins had increased following delta12-PGJ2 treatment in F2 cells. Western blotting analysis using anti-heme oxygenase-1 (heat shock protein (HSP)32) antibody also revealed that delta12-PGJ2 induced HSP32 formation in F2 cells. HSP32 was also induced by heat shock treatment at 43 degrees C for 90 min. In contrast, HSP72 was not induced by heat shock or by delta12-PGJ2 treatment. In agreement with these findings, HSP32 immunofluorescence in the cytoplasm of F2 cells was intensified by delta12-PGJ2 treatment. More intense HSP32 immunoreactivity was similarly observed after heat shock treatment. These results suggest that delta12-PGJ2 caused the apoptotic cell death of F2 cells, which involved a certain process required for p53 or HSP32 induction.

Animals↗
PubMed1998

Cone-beam filtered-backprojection algorithm for truncated helical data.

This paper investigates 3D image reconstruction from truncated cone-beam (CB) projections acquired with a helical vertex path. First, we show that a rigorous derivation of Grangeat's formula for truncated projections leads to a small additional term compared with previously published similar formulations. This correction term is called the boundary term. Next, this result is used to develop a CB filtered-backprojection (FBP) algorithm for truncated helical projections. This new algorithm only requires the CB projections to be measured within the region that is bounded, in the detector, by the projections of the upper and lower turns of the helix. Finally, simulations with mathematical phantoms demonstrate that: (i) the boundary term is necessary to obtain high-quality imaging of low-contrast structures and (ii) good image quality is obtained even with large values of the pitch of the helix.

Algorithms↗
PubMed1998

Fast and stable cone-beam filtered backprojection method for non-planar orbits.

We propose a new cone-beam shift-variant filtered backprojection (FBP) method for non-planar orbit data acquisitions. The new method is exact, fast and stable to discretization errors. It is based on the hybrid FBP framework whose key feature is to combine the shift-variant filtering with the ramp filtering to produce the filtered projections. We show that an adequate combination of the two filterings allows us to minimize contributions of the time-consuming and numerically unstable shift-variant filtering. We demonstrate the performances of the new method by simulation studies. We also apply the new method to real x-ray data acquired from our experimental system of monochromatic computed tomography.

Computer Simulation↗
PubMed1998

Lacustrine sockeye salmon return straight to their natal area from open water using both visual and olfactory cues.

Mechanisms of the amazing ability of salmon to migrate a long distance from open water to natal streams for spawning are still unknown. Lacustrine sockeye salmon (Oncorhynchus nerka) in Lake Toya offers an excellent model system for studying the orientation mechanism in open water, because mature fish return to the natal area with a high degree of accuracy. First we examined the percentage of fish returning to the natal area after they were released 7 km south of the natal area. Forty percent of control male mature fish and 25% of the fish blinded by injection of a mixture of carbon toner and corn oil into the eyeball were captured in the natal area within 5 days. Forty-four percent of fish with brass rings (control) and 31% of fish with NdFe magnetic rings which interfere with the magnetic cue were captured in the natal area within 3 days. These experiments suggested that, although the number of blinded fish captured in the natal area was less than that of the controls, the difference was not statistically significant. In the fish captured in the natal area within 3 or 5 days, fish which found the natal area using their olfactory cue after random swimming for a long time and returned to that area may be included. Hence we tracked fish telemetrically using an ultrasonic tracking system, and found that mature males released at a long distance (3.6 or 6.8 km) from the natal area swam straight to the vicinity of the natal area. Interference of the magnetic cue by the attachment of a magnetic ring did not affect their direct return. Blockage of the visual cue caused them to move randomly. These data suggest that lacustrine sockeye salmon return straight to the vicinity of the natal area using their visual cue and finally reach the exact homing point using their olfactory cue.

Animals↗
PubMed1998

Immunolocalization of fibronectin and its receptors integrin alpha 3 and alpha 5 subunits in the rat limb development.

In the rat hind limb bud aged between prenatal days 14 and 16, immunoreactions of fibronectin in the apical ectodermal ridge were localized on the plasma membranes of epidermal cells and cytoplasmic projections of the underlying mesenchymal cells, which are in contact with the basal lamina. Those of integrin alpha 3 and alpha 5 subunits also appeared on such areas. Definite immunoreactions of fibronectin and both integrin subunits were seen in cell to cell contact areas of mesenchymal cells which are associated with the marginal vein, or with each other forming solid cell cords, and appeared on the basal plasma membrane of endothelial cells of the growing capillaries arising from the marginal vein. These findings suggest that fibronectin may work as a ligand for alpha 3 beta 1 and/or alpha 5 beta 1 integrins expressed by the mesenchymal and vasoformative cells in developing limb bud.

Animals↗
PubMed1998

Additive effects of medroxyprogesterone acetate and 5-fluorouracil derivative on 7,12-dimethylbenz[a]anthracene-induced rat mammary tumors.

Chronic oral administration of 1-(2-tetrahydrofuryl)-5-fluorouracil in combination with uracil suppressed thymidylate synthetase (TS) gene expression followed by reduction of TS activity in rat mammary tumors induced with 7,12-dimethylbenz[a]anthracene. Addition of medroxyprogesterone acetate (MPA) to the anticancer drug caused an additional decrease in TS and thymidine kinase activities in the tumor growth and restoration of bone loss. These results suggest that the simultaneous administration of MPA and anticancer drugs causes increased inhibition of mammary tumor growth and also diminishes the bone loss.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1998

The role of endothelin-1 in regulation of rat mesenteric microcirculation.

Immunocytochemistry of endothelin-1 (ET-1) and the ETA receptor, and scanning electron microscopy using cast resin after treatment with ET-1, were carried out in the rat mesenteric microvasculature. Immunoreaction of ET-1 was preferentially seen along the endothelium of the proximal portion of the anterior mesenteric artery, the endothelial cells of which contain abundant Weibel-Palade (WP) bodies. However, the arterioles and small veins distal to the artery showed little immunoreactivity but showed heavy immunoreaction of ETA receptors in the media. By scanning electron microscopy after treatment with ET-1, the mesenteric microvasculature became slightly narrower compared to the control exhibited of localized constricted areas, especially in the region of the small veins. Light microscopy of such areas revealed localized thickening of the medial muscle cells. Because the release of ET-1 from endothelial cells depends in part on extracellular discharge of the WP bodies, the results indicate that ET-1, discharged from the proximal portion of the anterior mesenteric artery, induces vasoconstriction of the arterioles and small veins, mediated by ETA receptors. The localized thickening in areas in the media of the small veins may participate in the maintenance of blood flow through the portal circulation.

Animals↗
PubMed1998

A quantitative immunohistochemical evaluation of inflammatory cells at the affected and unaffected sites of inflammatory bowel disease.

Levels of T lymphocytes, histiocytes and mast cells have been reported to be increased in the affected mucosa of Crohn's disease (CD) and ulcerative colitis (UC), but the colorectal distribution of these cells is not fully understood. We hypothesized that differences in cell densities between CD and UC would be characteristic, not only in the affected, but also in the unaffected mucosa. The aims of the present study were to clarify whether there were any differences in cell densities in CD, UC and infectious colitis (IC) in the affected mucosa and between CD and UC in the unaffected mucosa. Using mouse monoclonal antibodies recognizing memory T cells (OPD4), cytotoxic/suppressor T cells (C8/144B), histiocytes (PG-M1) and mast cells (AA1), we evaluated mucosal cell densities in biopsy specimens from both endoscopically affected and unaffected sites of CD (n = 12) and UC (n = 15) and from affected sites of IC (n = 10). Ten normal controls were also examined. At affected sites, all cells were significantly more abundant in UC than in the other conditions, except that the density of PG-M1+ in CD was similar to that seen in UC. Although the densities of OPD4+ and C8/144B+ cells at unaffected sites were slightly higher in both CD and UC and in UC, respectively, there was no significant difference in cell densities between CD and UC. The ratio of OPD4+ cell density at affected sites to that at unaffected sites was appreciably higher in UC than in CD. The results suggest that a common feature of UC and CD is an increase in PG-M1+ cells at the affected mucosa but that the other inflammatory cells studied are more abundant, particularly in UC, and that the difference between UC and CD is conspicuous when comparing the OPD4+ cell density of the affected mucosa with that of the unaffected mucosa.

Adult↗
PubMed1998

Immunocytochemistry of fibronectin and endothelin-1 in the cavernous body of postnatal rabbit penises.

The differentiating cavernous body (CB) of postnatal rabbit penises was examined with a special reference to immunolocalizations for fibronectin (FN) and endothelin-1 (ET-1). At postnatal day 1, the CBs were embedded by an abundance of mesenchymal cells (MCs), and some of them were closely associated with endothelial cells of preexisting capillaries. Our electron micrographs indicated that such MCs are successively incorporated into the capillary endothelium as vasoformative cells. At this period, vascular sprouts of the helicine artery (HA), which were associated with the MCs, arose from the deep penile artery, and the transformation of such cells to endothelial and medial muscle ones was also indicated, and some MCs appeared to differentiate to epithelioid cells in the media. Immunoreactions for FN were preferentially localized in the rough endoplasmic reticulum (rER) and along the plasma membrane of such vasoformative MCs, and on the extracellular matrix components which connect these MCs with sprouts of both growing capillaries and HA. These findings suggest that FN, which is produced in the rER of the MCs, plays a crucial role in the mechanical linkage during the incorporation of vasoformative MCs into these penile vessels. Immunoreactions for ET-1 were preferentially localized on Weibel-Palade bodies in endothelial cells of the HA, implying the involvement of this peptide in the regulation of the local blood flow in this vessel.

Animals↗
PubMed1998

Differential contribution of various adhesion molecules to leukocyte kinetics in pulmonary microvessels of hyperoxia-exposed rat lungs.

To elucidate the differential role of various adhesion molecules in distorting leukocyte behavior in the microvasculature of hyperoxia-exposed rat lungs, we investigated fluorescein-labeled leukocyte and erythrocyte kinetics in isolated lungs taken from the animals exposed to 90% O2 for 48 h under conditions in which endothelial intercellular adhesion molecule-1 (ICAM-1) and P-selectin were inhibited by appropriate monoclonal antibodies (1A29 for ICAM-1 and ARP2-4 for P-selectin), while leukocyte L-selectin was restrained with fucoidin. Measurements of blood cell kinetics were made by a confocal laser luminescence microscope coupled with a high-speed video camera. In addition, we histologically examined leukocyte accumulation within the alveolar septa and ICAM-1 as well as P-selectin expressions in the lung. We found that P-selectin expression was sparsely enhanced only in arterioles, whereas ICAM-1 was significantly induced in both venules and capillaries. Firm adhesion of leukocytes was not identified in arterioles and venules, whereas leukocyte rolling was evident in both the vessels. Arteriolar rolling was regulated via a P-selectin- and ICAM-1-independent but L-selectin-dependent mechanism, whereas venular rolling was mediated via a P-selectin-independent but ICAM-1- and L-selectin-dependent pathway. Leukocyte sequestration within capillaries was augmented by an ICAM-1-related mechanism. These findings may suggest that, in hyperoxia-exposed lungs, induction of adhesion molecules and their obstacles to leukocyte behavior are qualitatively different among arterioles, venules, and capillaries.

Animals↗