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Biomedical subjects

H Kudo

Publications and source records attributed to H Kudo.

At least 91 records · Page 5Linked to original sources
PubMed1998

Impaired hypoxic vasoconstriction in intraacinar microvasculature in hyperoxia-exposed rat lungs.

To assess the effects of exposure of the lung to hyperoxic conditions on reactivity of pulmonary microcirculation to hypoxic stimulation, we measured hypoxia-elicited overall pulmonary pressor changes (HPV) and microvascular diameter changes in intraacinar arterioles, venules, and capillaries in isolated perfused rat lungs exposed to a hyperoxic environment (90% O2). To estimate the importance of vasoactive prostaglandins and nitric oxide (NO) for HPV modification, we examined the roles of constitutive and inducible forms of cyclooxygenase (COX-1 and COX-2) and those of NO synthase (eNOS and iNOS). Indomethacin was used for inhibiting both COX-1 and COX-2, while NS-398 was used as a selective inhibitor of COX-2. Both eNOS and iNOS were suppressed by L-NAME, whereas iNOS alone was inhibited by aminoguanidine. Microvascular diameter was measured with a real-time confocal laser scanning luminescence microscope. We found that (1) exposure to hyperoxia caused overall HPV and arteriolar constriction to be attenuated; (2) the blunted HPV was restored by L-NAME but not by aminoguanidine, indomethacin, or NS-398; and (3) arteriolar constriction was improved by either L-NAME, aminoguanidine, or indomethacin but only slightly by NS-398. In conclusion, attenuation of overall HPV in hyperoxia-exposed lungs is explicable mainly by excessive NO generated via eNOS, while impaired arteriolar constriction is caused by NO yielded by eNOS and iNOS as well as by vasodilating prostaglandin(s) produced by COX-1.

Animals↗
PubMed1998

Non-constrained elbow arthroplasty for mutilans deformity in rheumatoid arthritis: a report of six cases.

Six highly unstable elbows with severe bone loss due to rheumatoid arthritis were replaced by a non-constrained, unlinked prosthesis. Bone defects were filled with autogenous bone grafts. The mean follow-up was 4.5 years (2 to 8). The clinical results were excellent in four elbows and good in two, with good varus-valgus stability in all. Radiological follow-up showed no appreciable signs of loosening, and the bone grafts had retained most of their original size, with minimal resorption. There were no major complications such as dislocation, skin necrosis, infection or ulnar neuropathy. The study has shown that the so-called mutilans elbow can be successfully replaced using a properly selected type of non-constrained, unlinked prosthesis with bone grafting of the major defects.

Alloys↗
PubMed1998

Do adhesion molecules importantly regulate leukocyte kinetics within intraacinar microvessels of the lung?

Precise assessment of blood cell kinetics in the pulmonary microcirculation is extremely difficult because pulmonary microvascular architecture contains arterioles, venules and capillaries in an exceedingly intricate and densely convoluted fashion. Conventional epiluminescence microscopy may not be suitable for investigation of blood cell kinetic in the pulmonary microcirculation, in which arterioles, venules and capillary networks are not located in the same plane. To overcome these impediments, we recently developed a real-time confocal laser luminescence microscope with a high-speed analysis component having the capacity to yield confocal-images of rapidly moving cells at a rate of 1,000 frames/sec and at sufficiently high magnification. In the current review, we will first introduce the details of our newly developed observation system constructed with a view to estimation of blood cell dynamics in the intraacinar microcirculation of the lung. Applying this novel method to isolated perfused rat lungs, we will secondly address the issue of whether or not leukocyte-endothelium interactions in the pulmonary microcirculation qualitatively differ from those serving in the systemic microcirculation. We will particularly shed light on possible roles of endothelial ICAM-1, endothelial P-selectin and leukocyte L-selectin in distorting leukocyte kinetics in the intraacinar microvessels under a variety of diseased conditions, including prolonged exposure to a hyperoxic environment inducing a significant upregulation of ICAM-1 as well as P-selectin on the pulmonary microvascular endothelium, and stimulation of leukocytes by an IL-8 analog causing downregulation of leukocyte L-selectin but inverse upregulation of CD18-related integrins.

Animals↗
PubMed1998

Intraosseous meningioma with a dural defect.

A 56-year-old female presented with a rare intraosseous meningioma associated with an unusual dural defect caused by invasion of the tumor. The underlying dura mater is normal or thickened in most cases of intraosseous meningiomas. Most intraosseous meningiomas are benign histologically, but they should be extirpated before invasion into the subdural space occurs.

Dura Mater↗
PubMed1998

[Cone sensitivity measurements in diabetic retinopathy].

We made cone sensitivity measurements and hue discrimination measurements in 58 eyes of 34 diabetic patients with and without diabetic retinopathy including preproliferative retinopathy. The same measurements were performed in 8 eyes of 8 subjects to compare them. In this study, we were able to make the measurements in a short time and comfortably for the patients because we only needed to measure peak sensitivities of spectral sensitivity curves in three cones. There was significant correlation between short wave length sensitive-cone pathway sensitivity and retinopathy levels determined by fluorescein angiography. The cone sensitivity measurements that we used in this study were simple and sensitive. Our results suggested that the measurements were useful for detection of visual functional disturbances, determination of retinopathy levels, and prognosis.

Adult↗
PubMed1998

[5-S-cysteinyldopa as a tumor marker for primary uveal malignant melanoma].

The clinical significance of 5-S-cysteinyldopa (5-S-CD), a major intermediate in melanin synthesis, was evaluated as a potential diagnostic tumor marker for uveal melanoma. Serum concentrations of 5-S-CD in 6 out of 7 patients with uveal melanoma in the absence of extraocular metastases were close to those of controls. In contrast, serum concentrations of 5-S-CD were found to be elevated in 3 patients with systemic metastases of melanoma. In addition, 5-S-CD in intraocular fluids, including both aqueous and vitreous humor, was elevated in patients with uveal melanoma regardless of the presence or absence of systemic metastases. These results suggest that 5-S-CD in the intraocular fluid may serve as a useful biochemical marker for the diagnosis of uveal melanoma.

Adult↗
PubMed1998

[In vitro antibacterial activity of vancomycin in combination with panipenem against carbapenem-resistant MRSA].

The synergistic relationship between vancomycin (VCM) and carbapenem (CRB) has been reported in antibacterial activity against CRB-resistant strains of MRSA. The purpose of this study is to investigate the antibacterial activity against CRB-resistant MRSA using VCM, panipenem (PAPM), and a combination of both. 8 strains of CRB-resistant MRSA were used to examine the effects of these antibiotics by the broth microdiluton technique. The effect of pH (pH 6, 7, 8) on MIC of VCM alone was not observed in 7 out of 8 strains; MICs were between 1.0-2.0 micrograms/ml. PAPM alone, however, showed an enhancing tendency in alkaline condition in 6 out of 8 strains. There was no influence of pH on MICs in the combination use of VCM and PAPM, showing additive effect in 1 strain and synergistic in 6 strains. Killing-curves against PAPM-resistant MRSA were examined under the following drug combinations; 1/4 MIC of VCM (0.5 micrograms/ml) plus 1/4 MIC of PAPM (16 micrograms/ml), and 1/4 MIC of VCM plus 1/8 MIC of PAPM (8 micrograms/ml). The former drug combination showed synersistic effect; decrease from 1.05 x 10(5) to 6.45 x 10(4) CFU/ml after 6 hours' incubation and to less than 10 CFU/ml after 24 hours. The latter drug combination showed synergistic activity (2.68 x 10(2) CFU/ml) after 24 hours' incubation, but lost antibacterial activity after 48 hours. In conclusion, PAPM in combination with VCM showed synergistic effects on CRB-resistant MRSA. This combination therapy should be evaluated for the treatment of MRSA infection in patients with renal dysfunction.

Carbapenems↗
PubMed1998

[Effective splenectomy in a patient with HIV-associated thrombocytopenia].

A 31-year-old man presented with a 3-month history of petechial hemorrhages. Physical examination revealed no splenomegaly. The patient's platelet count was 1.0 x 10(9)/l and bone marrow aspiration showed an elevated number of megakaryocytes. A diagnosis of HIV-associated thrombocytopenia was made on the basis of HIV seropositive results. The CD4 cell count was 400 x 10(6)/l. No opportunistic infections indicating AIDS were detected. Initially the patient was treated with predonisolone, but showed only a transient response. He also failed to respond to zidovudine, lamivudine, or indinavir. Following splenectomy, however, his platelet count rose above 80 x 10(9)/l (normal level: 150-350 x 10(9)/l).

Adult↗
PubMed1997

Construction of a Fibrobacter succinogenes genomic map and demonstration of diversity at the genomic level.

The genomic cleavage map of the type strain Fibrobacter succinogenes S85 was constructed. The restriction enzymes AscI, AvrII, FseI, NotI, and SfiI generated DNA fragments of suitable size distribution that could be resolved by pulsed-field gel electrophoresis (PFGE). An average genome size of 3.6 Mb was obtained by summing the total fragment sizes. The linkages between the 15 AscI fragments of the genome were determined by combining two approaches: isolation of linking clones and cross-hybridization of restriction fragments. The genome of F. succinogenes was found to be represented by the single circular DNA molecule. Southern hybridization with specific probes allowed the eight genetic markers to be located on the restriction map. The genome of this bacterium contains at least three rRNA operons. PFGE of the other three strains of F. succinogenes gave estimated genome sizes close to that of the type strain. However, RFLP patterns of these strains generated by AscI digestion are completely different. Pairwise comparison of the genomic fragment distribution between the type strain and the three isolates showed a similarity level in the region of 14.3% to 31.3%. No fragment common to all of these F. succinogenes strains could be detected by PFGE. A marked degree of genomic heterogeneity among members of this species makes genomic RFLP a highly discriminatory and useful molecular typing tool for population studies.

Animals↗
PubMed1997

A prospective randomized comparison between long and discontinuous-long protocols of gonadotropin-releasing hormone agonist for in vitro fertilization.

OBJECTIVE: To investigate the efficacy of a discontinuous-long protocol in an IVF program. DESIGN: Prospective randomized study. SETTING: University hospital. PATIENT(S): One hundred thirty-seven IVF cycles of 92 patients in an outpatient IVF program from April 1995 to December 1995. INTERVENTION(S): In the discontinuous-long protocol group (n = 68), GnRH agonist (GnRH-a) was administered from the luteal phase until cycle day 7, when pure FSH administration was begun. In the long protocol group (n = 69), GnRH-a was administered until the day before hCG administration. MAIN OUTCOME MEASURE(S): Serum LH and ovarian steroid hormone levels, and IVF outcome. RESULT(S): The period and the total dosage of hMG were increased in the discontinuous-long protocol group. Although the fertilization rate was similar under both protocols, the number of embryos transferred was smaller and the cancellation rate was higher in the discontinuous-long protocol group because of the greater failure of oocyte retrieval and fertilization. Serum E2 levels in the late follicular phase were lower in the discontinuous-long protocol group. CONCLUSION(S): Early discontinuation of GnRH-a is not beneficial because of its adverse effects on follicular development.

Adult↗
PubMed1997

Uneventful total intravenous anaesthesia with ketamine for schizophrenic surgical patients.

Ketamine has been considered to be contraindicated for schizophrenic patients because it may induce psychological emergence reactions and psychiatric deterioration. Total intravenous anaesthesia (TIVA) with ketamine combined with droperidol and fentanyl (DFK) has been used in 14 schizophrenic patients undergoing various surgical procedures. Two patients died post-operatively of concomitant severe disease rather than from schizophrenia related pathophysiology or anaesthetic complication. One patient showed transient mild anxiety in the early post-operative period soon relieved by the patient's routine medication. However, no patient developed exacerbations of psychosis or psychological emergence reactions during the first post-operative month. The cardiovascular state during and after DFK remained stable in all cases. It is concluded that ketamine when combined with droperidol and fentanyl is a satisfactory anaesthetic for patients with schizophrenia.

Adjuvants, Anesthesia↗
PubMed1997

An autopsy case of angioimmunoblastic T-cell lymphoma with a high content of epithelioid cells in the lymph node: immunohistochemical and genomic analyses.

A 79-year-old female developed red papulonodular eruptions on her extremities, facial erythema, generalized lymphadenopathy and high fever. Histopathology of an affected lymph node showed the features of angioimmunoblastic T-cell lymphoma with a high content of epithelioid cells. She died about two years after the onset despite therapy. Genomic Southern blotting and immunostaining of the lymph nodes were performed twice. In August of 1993, Southern blotting did not show any rearrangement of the immunoglobulin or the T-cell receptor (TCR) gene. Small or medium-sized lymphoid cells were positive for CD4 or CD8 (CD4:CD8 = 2:1). However, in September of 1994 (at autopsy), rearrangements of TCK C beta 1, J beta 2 and J gamma genes were observed. Small or medium-sized lymphoid cells were positive for CD4, but negative for CD8. Several large cells were positive for Latent Membrane Protein 1 (LMP1) of the Epstein-Barr virus (EBV). Our results proved that selective oligoclonal proliferation of tumor cells (probably CD4+) accompanied the disease progress.

Aged↗
PubMed1997

Effects of active vasoconstriction and total flow on perfusion distribution in the rabbit lung.

We analyzed the effects of hypoxic vasoconstriction and total flow on the distribution of pulmonary perfusion in 38 isolated left rabbit lungs perfused under zone 3 conditions. Lungs were suspended in an upright position, oriented to the apicobasal line. Distributions of regional perfusion rates (RPR) along the vertical and horizontal axes were determined using nonradioactive microspheres labeled with heavy metal elements, which were detectable with X-ray fluorescence spectrometry. Changing the O2 concentration of a respirator and an extracorporeal membrane oxygenator independently, respective influences of active vasoconstriction induced by alveolar hypoxia and pulmonary artery hypoxia (PA hypoxia) on the RPR distribution were examined at a flow rate of 0.4 ml x min(-1) x g wet lung tissue(-1). To analyze the effects of changes in total flow, we investigated the RPR distribution at a perfusion rate of 1.2 ml x min(-1) x g wet lung tissue(-1). The RPR distribution in the absence of hypoxia was inhomogeneous and was augmented in the lower lung fields, whereas alveolar hypoxia shifted the RPR upward and significantly diminished the RPR in the lung base. RPR distributions along the horizontal axes under alveolar hypoxia conditions demonstrated that remarkable hypoxic pulmonary vasoconstriction (HPV) takes place in medial regions at the lung base. PA hypoxia altered the RPR distribution in qualitatively the same manner as alveolar hypoxia. Increased flow rate augmented the RPR in the lung, except in the dorsobasal region. These results suggest that the occurrence of HPV and the vascular conductance are not uniform throughout the lung.

Animals↗
PubMed1997

Diversity in distribution of Na+.K+ATPase of the choroid epithelium of prenatal rats; an immunocytochemical study.

The differentiating choroid plexus in rats at ages ranging from prenatal day 16 to postnatal day 3 was investigated with a special emphasis on the immunolocalization of Na+.K+ATPase in the choroid epithelium and neocapillarization of the choroid stroma. Immunoreactions for Na+.K+ATPase were localized on the apical plasma membrane of the simple choroid epithelium throughout the stages examined, but it also appeared on the basolateral plasma membrane till prenatal day 18, prior to the formation of the tight junctions as seen from both a marker experiment using lanthanum chloride and immunoreactions for tight junction-associated protein (ZO-1). This suggests that a polarity of the enzyme localization to the apical plasma membrane may take place after the establishment of the blood-cerebrospinal fluid barrier. Mesenchymal cells in the choroid stroma immunoreacted to the laminin antibody and occasionally contacted each other--forming solid cell cords--or endothelial cells of the preexisting capillaries. The contact areas immunoreacted to this antibody. Since there were few or no mitotic figures of the endothelial cells, the involvement of laminin in a mechanical linkage between the adjacent vasoformative mesenchymal cells as well as the endothelial lining in a manner suggestive of vasculogenesis was indicated.

Animals↗
PubMed1997

Characterization of bovine heart sulfotransferase catalyzing the sulfation of tyrosine-containing peptides.

Using [35S]PAPS as the sulfate donor, we have detected a sulfotransferase from bovine heart which catalyzes the sulfation of tyrosine-containing peptides. The enzyme displayed optimal activity at pH 5.75 and 35 degrees C in a one-hour reaction. The addition of 10 mM Mn2+ or Co2+ to the reaction mixture increased the sulfotransferase activity by 3.4- and 3.5-fold, respectively. In contrast, the maximum increment stimulated by Mg2+ was only 1.75-fold at 15 mM concentration, and instead of exerting an enhancement effect, Ca2+ was found to be a potent inhibitor. The addition of 50 mM NaF to the reaction mixture resulted in an increase in sulfotransferase activity of 3.3-fold. The K(m) for 3'-phosphoadenosine 5'-phosphosulfate (PAPS) was determined to be 2 microM at a constant 0.5 mM Boc-Glu-Asp-Tyr-Val. Among the 10 peptides tested as substrates, Boc-Glu-Asp-Tyr-Val and Boc-Asp-Asp-Tyr-Val provided the highest activities.

Amino Acid Sequence↗
PubMed1997

[Bilateral leg ulcers with pathologic evidence of small vessel vasculitis by skin biopsy during hydroxyurea therapy of chronic myelogenous leukemia].

We report a 45-year-old male with chronic myelogenous leukemia (CML) who experienced skin ulcers of the left lateral malleolus and dorsum of both feet. He had been treated with hydroxyurea (HU) for 2 years. His leg ulcers improved after HU was discontinued. Skin biopsy of the ulcerated lesion revealed that the lesion is compatible with small vessel vasculitis, but circulating immune complexes (C1q, anti-C3d antibody) were negative. Although the precise mechanism of the skin ulcer is unknown, we must take into consideration the skin changes were secondary to hydroxyurea therapy in myeloproliferative disorders.

Antineoplastic Agents↗
PubMed1997

Leukocyte kinetics in the pulmonary microcirculation: observations using real-time confocal luminescence microscopy coupled with high-speed video analysis.

To quantitatively assess blood cell kinetics in the intact pulmonary microcirculation, in which arterioles, venules, and capillaries are exceedingly intricate and densely convoluted, we recently developed a real-time confocal laser luminescence microscope with a high-speed analysis component. The system has the capacity to yield confocal images of rapidly moving cells at a rate of 1000 frames/second and at sufficiently high degrees of magnification. Applying this novel method to isolated perfused rat lungs, we estimated the endothelial distributions of constitutively expressed intercellular adhesion molecule-1 (ICAM-1) and P-selectin and also studied leukocyte hemodynamic behavior in the pulmonary microvasculature under conditions in which ICAM-1, P-selectin, and L-selectin were inhibited, respectively, by 1A29 (monoclonal antibody to rat ICAM-1), ARP2-4 (monoclonal antibody to rat P-selectin), and fucoidin (competitive inhibitor of both P- and L-selectin). The results were compared with those obtained with a nonconfocal microscope using conventional epiluminescence. Intertwined microvessel networks in the lung were clearly distinguishable in confocal images but not in conventional nonconfocal views. ICAM-1 was perceptibly expressed along venular and capillary but not arteriolar endothelium, whereas P-selectin was undetectable in all microvessels examined. Leukocytes were not firmly adhered to venular or arteriolar endothelial cells. Leukocyte rolling was recognized more frequently along arteriolar walls than along venular walls and was suppressed in arterioles by L-selectin inhibition but not by either ICAM-1 or P-selectin inhibition. In capillaries, transient and sustained arrest of leukocytes occurred at physiologic shear rates. Inhibition of ICAM-1 or P-selectin had no remarkable effect upon either transient or sustained entrapment of leukocytes in capillaries. In conclusion, physiologic and biologic characteristics of pulmonary microvessels appear to be quite different from those of the systemic microcirculation.

Animals↗