Biomedical subjects

K Uchida

Publications and source records attributed to K Uchida.

At least 397 records · Page 22Linked to original sources

PubMed1999

[Implication of health checkups of students from developing countries in Japan].

We investigated the prevalence of peripheral blood abnormalities, parasitic infestation, and hepatitis virus infection, by using the results of the primary screening health checkups for 423 students (male: 317, female: 106, average age +/- SD: 34.2 +/- 5.5 year-old) from abroad. Most of them were from Southeast Asia, Africa, Central and South America, and other developing countries in tropical or subtropical areas. Thalassemia-like hematological disorders, showing microcytic peripheral red blood cells without any anemia, were seen in 7.6 percent of the students, and intestinal parasites were revealed in 12.7 percent of them. The positive rate for anti-hepatitis A virus antibodies (84.3%) and the exposure rate of hepatitis B viruses (35.3%) were similar to previous reports. Compared with the positive rate for anti-hepatitis C virus antibodies (anti-HCVAb) of students from other regions (1.5%), a significantly high seropositivity for anti-HCVAb was encountered in Egyptian participants (21.1%). In recent years, population shifts and rapid transportation have facilitated the spread of certain infectious diseases from endemic to non-endemic areas. International preventive strategies, education of people regarding infectious diseases, and sufficient medical staffs for this purpose are urgently recommended.

Adult↗

PubMed1999

[Pulmonary thromboembolism accompanied by abnormal plasminogen].

A 38-year-old man was admitted to our hospital because of sudden chest pain and bloody sputum. Lung perfusion scintigraphy disclosed segmental defects in both lungs. An enhanced thin-section computed tomographic scan of the chest showed a low-density area in the right main pulmonary artery. These findings yielded a diagnosis of pulmonary thromboembolism. Serum plasminogen activity was low, not only in the patient but in his elder brother and daughter. Gene analysis revealed a point mutation at exon 15 of the plasminogen gene, suggesting abnormal plasminogen. Abnormal plasminogen is more prevalent in Japan than in the USA or Europe, and is usually asymptomatic. Thromboembolism in patients with abnormal plasminogen is very rare. Further studies are needed to elucidate the relationship between plasminogen abnormalities and pulmonary thromboembolism.

Adult↗

PubMed1999

[A case of renal capsular leiomyoma].

A 50-year-old woman was admitted for the treatment of retroperitoneal tumor. Enhanced comtuted tomography showed a low density mass between the left kidney and psoas muscle. Magnetic resonance imaging revealed a high intensity and homogeneous mass on T1-weighted sequence, and a low intensity and heterogeneous mass on T2-weighted sequence. Surgical exploration revealed that the tumor was adherent to the left kidney and en bloc excision of the tumor and the left kidney was performed. Histopathological diagnosis was leiomyoma originating from the renal capsule.

Female↗

PubMed1999

Phylogenic analysis of echovirus type 30 isolated from a large epidemic of aseptic meningitis in Japan during 1997-1998.

During 1997 to 1998, a nationwide epidemic of aseptic meningitis occurred in Japan. More than 4,500 isolates from patients with aseptic meningitis were identified as echovirus type 30. To investigate the character of these isolates, we examined the nucleotide sequences of thirty-seven geographical representatives and compared them with 50 strains isolated during the past 20 years. The phylogenic analysis used partial sequences from either the VP1 or VP4-VP2 region of the viral capsid. This analysis revealed that the isolates were divided into six genomic groups. All isolates identified during 1997-1998 belonged to only two genomic groups; these two groups are thought to be the causative viral agents involved in the recent epidemic.

Enterovirus B, Human↗

PubMed1999

[5-FU sensitivity and thymidylate synthase in gastric cancer].

The relationship of 5-FU-sensitivity to thymidylate synthase (TS) was investigated in a total of 82 gastric cancers of stage III or IV. The sensitivity test was done by Histoculture Drug Response Assay and TS expression was stained immunohistochemically using anti-TS antibody. Sensitivity to 5-FU of more than 50% of the inhibitory index (high sensitivity) was observed in 28.1% of the materials, less than 50% (low sensitivity) in 71.9% and less than 20% in 50.0%. The expression of TS was found in 25.6% of the patients. The incidence of positive TS expression was 34.5% in the high sensitivity group, against 22.0% in the low sensitivity group, with no statistical difference between them. No particular relationship was found between 5-FU-sensitivity group and TS expression rate when the tumor-histology was divided into high and low differentiation. In the present study, the ratio of patients negative for TS among the high 5-FU-sensitivity group both was 65.2%, both of which have been reported as producing high survival rates. In contrast, the ratio of patients positive for TS in the low 5-FU-sensitivity group was 22.0%. From these results, TS is considered to be responsible for approximately 40-50% of either high or low 5-FU-sensitivity, respectively, when the lower TS expression in the present study was taken into consideration and corrected.

Antimetabolites, Antineoplastic↗

PubMed1999

Histological factors of 1-h biopsy influencing the delayed renal function and outcome in cadaveric renal allografts.

The morphological characteristics of a kidney biopsy specimen taken 1 h after reperfusion of blood into the graft (1-h biopsy) during a cadaveric transplant operation were studied. The aim of the 1-h biopsy is to evaluate the pre-transplant risk factors for the delayed graft function, assess the renal function of the graft, and predict long-term graft survival. The total number of 1-h biopsies was 113, consisting of 86 male and 27 female donors. The mean age of the donors is 39.5 +/- 17.3 yr. Arteriosclerosis (AS) and tubulo-interstitial injury (TI) were both estimated using a semi-quantitative scale. AS score was graded into four categories, according to the severity of the thickening of interlobular artery: 0: none, 1: mild, 2: moderate and 3: severe. No biopsy revealed severe AS of grade 3. The TI score was graded from 0 to 5, according to the morphological injury: 0: none, 1-2 non-specific tubulo-interstitial injury (NSTI), and 3-5 compatible with acute tubular necrosis (ATN) in terms of pathological diagnosis. The mean ages of donors showing as AS of score 0, 1, and 2 were 30.6 +/- 14.6, 49.7 +/- 13.5, and 56.9 +/- 6.30, respectively. The mean donor age of the AS 1 group and AS 2 group was significantly lower than for the AS 0 group. The lowest serum creatinine values after operation (best Cr) of recipients with AS scores of 0, 1, and 2 were 1.31 +/- 0.45, 1.60 +/- 0.70, and 1.84 +/- 0.71 mg/dL, respectively; the best Cr of AS scores of 1 and 2 was significantly higher than in the AS score 0 group. The mean creatinine level at the final point of the AS 0 group was significantly lower than in the combined AS 1 and AS 2 group (serum creatinine 1.44 +/- 1.03 vs 1.87 +/- 1.53 mg/dL: p < 0.01). The duration of severe hypotension less than 50 mmHg or 80 mmHg was significantly shorter in the NSTI group than in the ATN group (less than 50 mmHg was 29.7 +/- 124 vs 72.5 +/- 174, less than 80 mmHg 105 +/- 234 vs 193 +/- 261 min: p < 0.01). The post-operative (po) day expressing diuresis in excess of 1000 mL of urine per d was 8.28 +/- 17.5 and 13.7 +/- 23.3 (p < 0.01) in the NSTI and ATN group, respectively. The po-d of the last hemodialysis and the po-d showing serum creatinine less than 2.0 mg/dL in NSTI and ATN group was 7.74 +/- 17.4 and 13.3 +/- 23.2 (p < 0.01), and 25.0 +/- 30.5 and 38.0 +/- 35.2 (p < 0.01), respectively. We concluded that 1-h renal biopsy is useful for assessing the outcome of renal allograft. AS of a donor kidney is one of the most important risk factors for both short and long-term outcome of the graft. The TI score was useful to predict the outcome of delayed graft function.

Adult↗

PubMed1999

Case study of paired cadaver renal allografts from the same donor: influence of local DIC kidney and concomitant acute rejection on early graft outcome.

We report the clinical course of 2 recipients whose renal allografts were obtained from the same cadaver donor after cardiac arrest. The recipients showed different outcomes after transplantation. Graft biopsy after reperfusion revealed disseminated intravascular coagulation (so-called DIC kidney) and severe acute tubular necrosis (ATN) in both recipients. While one graft showed primary nonfunction, the other graft became functional after a post-operative anuric period. Serial graft biopsies performed during the oligo-anuric period revealed recovery of ATN and no intra-glomerular fibrin thrombi, but development of acute rejection was detected in both recipients. The left kidney graft showed more severe local DIC kidney than the right kidney, as well as more severe acute rejection in the oligo-anuric period. Despite aggressive anti-rejection therapy, the left kidney graft showed primary nonfunction. Therefore, severe acute rejection leading to primary nonfunction might have been related to more severe ischemic injury and more extensive local DIC kidney in the left kidney.

Adult↗

PubMed1999

Electron microscopic peritubular capillary lesions: a new criterion for chronic rejection.

Typical chronic rejection showing prominent glomerular and/or arterial lesions is less common in renal allograft patients treated with cyclosporin A (CsA). We investigated the value of peritubular capillary lesions as a criterion for chronic rejection in the CsA era. A total of 129 renal graft biopsies, taken from recipients showing graft dysfunction after more than 2 months post-operatively, were examined by electron microscopy, and peritubular capillary lesions were studied, especially multi-layered basement membrane lesions (MLPTC). Eighty-two biopsy specimens taken from non-transplantation patients were also studied as a control. Five biopsies (6%) showed mild and atypical MLPTC in the control group. Of the 129 allograft biopsies, MLPTC was seen in 55 (42.6%). The prevalence showed no significant relationship to the interval from operation to biopsy. MLPTC was either typical (n = 10) or incomplete (n = 45). Concomitant membrane disruption, edema and lymphocyte infiltration of the subendothelial space, reflecting acute cellular rejection, were occasionally noted in both groups. Incomplete MLPTC often developed within 1 yr after surgery, in association with acute rejection. It was found in 26-50% of biopsies at any time up to 5 yr post-operatively. The incidence of typical MLPTC was 5.7-12.8% over 1 yr post-operatively. These findings suggest that the development of chronic rejection is closely related to relapsing acute tubulo-interstitial allograft rejection which is often clinically silent. We concluded that MLPTC is useful as a specific criterion for chronic rejection.

Basement Membrane↗

PubMed1999

A case of IgA nephropathy after ABO-incompatible living kidney transplantation.

A 39-yr-old Japanese man underwent living related kidney transplantation. Because the graft was ABO-incompatible, he was treated with double filtration plasmapheresis before transplantation and his immunosuppressive therapy was stronger than usual. However, immunoglobulin A nephropathy, accompanied by cellular crescents and necrotizing lesions, developed after 18 months. To our knowledge, the association of IgA nephropathy with ABO-incompatible kidney transplantation has not been reported previously.

ABO Blood-Group System↗

PubMed1999

Swelling and flow properties of tubular poly(vinyl alcohol) gels.

Swelling and flow properties of tubular poly(vinyl alcohol) (PVA) hydrogels prepared with the cooling method were investigated using an inflation testing method. When the tubular hydrogel in liquid paraffin was inflated by using liquid paraffin as a pressure transmitting medium, namely in the case that the liquids inside and outside the gel are both liquid paraffin (P/P combination), the gel showed a slight volume change determined by Poisson's ratio of the gel. When the gel in water was inflated by liquid paraffin (P/W combination), the gel swelled to large extent compared with the case of P/P. The hydrogel in W/W combination, namely in the situation that the gel was immersed in water and also inflated by water, showed a very large volume change if the comparison was done at the same pressure. The origin of the volume change in P/P, P/W and W/W combinations is discussed. The volume change in P/P was governed by the Poisson ratio as a material constant (mu 0) of the PVA gels, and the gels swelled by the change in the application of pressure (or deformation) in P/W. The volume change in W/W was closely related to the flow of solvent in the gel.

Gels↗

PubMed1999

[Prostate cancer].

Although the incidence of latent or incidental cancer of the prostate is quite similar among Japanese and Americans, the incidence of clinically manifest prostate cancer and the mortality rates of prostate cancer are significantly higher in the latter. But, recently, the incidence of clinical cancer in Japan has been increasing exponentially, and the change in dietary habits is considered to be a major cause of this increase. Comparing the histological differences of prostate cancer between the Japanese and the Americans, the cribriform pattern is predominant in Japanese clinically significant cancer. On the other hand, a simple glandular pattern is predominant in American clinically significant cancer. These differences between Japanese and American prostate cancer suggest that each prostate cancer arises from different sources. For the organ-confined prostate cancer (stage A2 and B); radical prostatectomy has been considered the definitive treatment. But radiotherapy is now considered another radical treatment for localized prostate cancer which results in reduced morbidity. A heavy particle beam and brachytherapy are an even more radical modality that can deliver a greater dose of radiation to a localized lesion without affecting the surrounding normal tissue. For locally advanced prostate cancer (stage C); For the purpose of downstaging and radical treatment of locally advanced prostate cancer, combination of neoadjuvant hormonal therapy and radical prostatectomy has been expected. This regimen resulted in a significant decrease of positive surgical margins, but did not result in decrease of PSA failure. The impact on patient survival will be determined by the long-term follow-up. For advanced prostate cancer (stage D); In the study of the comparison of bilateral orchiectomy with or without flutamide in stage D2 prostate cancer, neither significant improvement of combination group on progression-free survival nor overall survival has been shown. From this result, the true efficacy of MAB is not certain.

Androgen Antagonists↗

PubMed1998

Human erythrocyte bisphosphoglycerate mutase: inactivation by glycation in vivo and in vitro.

2,3-Bisphosphoglycerate mutase (BPGM) [EC 5.4.2.4] is a multifunctional enzyme that catalyzes both the synthesis and the degradation of 2,3-diphosphoglycerate (2,3-DPG) and contains three types of activities in that it functions as a 2,3-DPG synthetase, a phosphoglycerate mutase and a 2,3-DPG phosphatase. In humans, BPGM occurs only in erythrocytes and plays a pivotal role in the dissociation of oxygen from hemoglobin via 2,3-DPG. The present study shows that the specific activity of BPGM in erythrocytes of diabetic patients is decreased, compared to normal controls as judged by 2,3-DPG synthetase activity and immunoreactive contents. To understand the mechanism by which the enzyme is inactivated, the enzyme was purified from pooled erythrocytes from diabetic patients and subjected to a boronate affinity column. The flow through fraction was active while the bound fraction was completely inactive. The bound fraction was reactive to an anti-hexitollysine antibody, indicating that the enzyme had undergone glycation and inactivation. The primary glycated site of the enzyme was found to be Lys158 as judged by amino acid sequencing and the reactivity with an anti-hexitollysine IgG, after reverse-phase HPLC of the lysyl-endopeptidase-digested peptides. Extensive glycation of recombinant BPGM in vitro indicated that the glycation sites were Lys2, Lys4, Lys17, Lys42, Lys158, and Lys196. From these results, the loss of enzymatic activity appears to be due to the glycation of Lys158 which may be located in the vicinity of the substrate binding site.

Aged↗

PubMed1998

Ba2+ selectively inhibits receptor-mediated contraction of the esophageal muscularis mucosae.

The aim of the present study was to examine the effect of Ba2+ on acetylcholine- and KCl-induced contractions of the guinea-pig esophageal muscularis mucosae. When the muscularis mucosae was pretreated with nicardipine (1 microM), Ba2+ (0.1-30 mM) markedly inhibited the acetylcholine (3 microM)-induced tone, and at 10-30 mM the tone returned to its basal level. In contrast, Ba2+ (0.1-30 mM) slightly increased the KCl (60 mM)-induced tone. Moreover, the Ba2+ (30 mM)-increased KCl tone was completely inhibited by treatment with nicardipine (0.3-1 microM). In conclusion, Ba2+ both selectively inhibits receptor-mediated contraction of the muscularis mucosae and itself permeates through voltage-dependent Ca2+ channels.

Acetylcholine↗

PubMed1998

Generation of protein carbonyls by glycoxidation and lipoxidation reactions with autoxidation products of ascorbic acid and polyunsaturated fatty acids.

Accumulation of carbonyl derivatives of proteins (protein carbonyl) is taken as a biomarker of oxidative protein damage in aging and in various diseases. We detected protein carbonyls in situ in human diabetic arteriosclerotic tissues and characterized the formation of protein carbonyls. Protein carbonyls were identified in the thickened intima of arterial walls and co-localized with protein adducts formed by carbonyl amine chemistry between protein and carbonyl compounds derived from autoxidation of carbohydrates, lipids, and ascorbate, i.e. advanced glycation end products or glycoxidation products, such as carboxymethyllysine (CML) and pentosidine, and lipoxidation products, such as malondialdehyde (MDA) and 4-hydroxy-nonenal (HNE). In vitro incubation of proteins with ascorbic acid accelerated the production of protein carbonyls as well as CML and pentosidine, and incubation with arachidonate accelerated the production of protein carbonyls as well as CML, MDA, and HNE. By contrast, incubation of proteins with glucose resulted in the production of CML and pentosidine, but not protein carbonyls. Schiff base inhibitors, (+/-)-2-isopropylidenehydrazono-4-oxo-thiazolidin-5-ylace tanilide and aminoguanidine, inhibited the production of protein carbonyls after incubation with ascorbate and arachidonate. The present study suggests that ascorbate and polyunsaturated fatty acids, but not glucose, represent potential sources of protein carbonyls, and that both the glycoxidation and lipoxidation reactions contribute to protein carbonyl formation in aging and various diseases.

Arachidonic Acid↗

PubMed1998

An alternative form of poly(ADP-ribose) polymerase in Drosophila melanogaster and its ectopic expression in rat-1 cells.

We here report an alternatively spliced form of PARP lacking exon 5 of the Drosophila PARP gene encoding the auto-modification domain. The alternative form of PARP (PARP II) consists 804 amino acids with a molecular weight of 92.3 kDa. The deduced amino acid sequence of PARP II was completely matched to that of PARP I encoded by a full-length Drosophila PARP cDNA, except it lacks the region corresponding to the auto-modification domain. To examine the function of PARP II, stable transformants of Rat-1 cells in which PARP II was ectopically expressed by MMTV-LTR were isolated and characterized. After induction with dexamethasone, PARP II transformants showed slower growth and showed morphological changes with loss of spindled shape compared to cells transformed with the vector or PARP I. The PARP II-transformed cells incorporated propidium iodide after induction; however, Annexin V and TUNEL analysis indicated these changes were not due to apoptosis.

Amino Acid Sequence↗

PubMed1998

Identification and cloning of two novel allergens from the lipophilic yeast, Malassezia furfur.

Two novel allergens, designated Mal f 2 and Mal f 3 according to the WHO/IUIS Allergen Nomenclature Subcommittee recommendation, were isolated from the lipophilic yeast Malassezia furfur cell extracts and the genes coding for those were cloned. Mal f 2 and Mal f 3 had apparent molecular weights of 21 kDa and 20 kDa, respectively, on SDS-PAGE under reducing conditions. The identified cDNA clone of Mal f 2 encoded an open reading frame of 177 amino acid residues. Fifty-one percent identity was found between the Mal f 2 and Mal f 3 sequences. Comparison of the Mal f 2 and Mal f 3 sequences with known protein sequences revealed that they had sequence homology with two peroxisomal membrane proteins of Candida boidinii and an Aspergillus fumigatus allergen, Asp f 3. In RAST, both Mal f 2- and Mal f 3-specific IgE antibodies could be detected in approximately 70 % of sera from M. furfur sensitized patients with atopic dermatitis.

Allergens↗

PubMed1998

Acrolein is a product of lipid peroxidation reaction. Formation of free acrolein and its conjugate with lysine residues in oxidized low density lipoproteins.

Lipoprotein peroxidation, especially the modification of apolipoprotein B-100, has been implicated to play an important role in the pathogenesis of atherosclerosis. However, there have been few detailed insights into the chemical mechanism of derivatization of apolipoproteins during oxidation. In the present study, we provide evidence that the formation of the toxic pollutant acrolein (CH2=CH-CHO) and its conjugate with lysine residues is involved in the oxidative modification of human low density lipoprotein (LDL). Upon incubation with LDL, acrolein preferentially reacted with lysine residues. To determine the structure of acrolein-lysine adduct in protein, the reaction of acrolein with a lysine derivative was carried out. Employing Nalpha-acetyllysine, we detected a single product, which was identified to be a novel acrolein-lysine adduct, Nalpha-acetyl-Nepsilon-(3-formyl-3,4-dehydropiperidino )lysine. The acid hydrolysis of the adduct led to the derivative that was detectable with amino acid analysis. It was revealed that, upon in vitro incubation of LDL with acrolein, the lysine residues that had disappeared were partially recovered by Nepsilon-(3-formyl-3, 4-dehydropiperidino)lysine. In addition, we found that the same derivative was detected in the oxidatively modified LDL with Cu2+ and that the adduct formation was correlated with LDL peroxidation assessed by the consumption of alpha-tocopherol and cholesteryl ester and the concomitant formation of cholesteryl ester hydroperoxide. Enzyme-linked immunosorbent assay that measures free acrolein revealed that a considerable amount of acrolein was released from the Cu2+-oxidized LDL. Furthermore, metal-catalyzed oxidation of arachidonate was associated with the formation of acrolein, indicating that polyunsaturated fatty acids including arachidonate represent potential sources of acrolein generated during the peroxidation of LDL. These results indicate that acrolein is not just a pollutant but also a lipid peroxidation product that could be ubiquitously generated in biological systems.

Acrolein↗

PubMed1998

Colocalization of Bcl-2 and 4-hydroxynonenal modified proteins in microglial cells and neurons of rat brain following transient focal ischemia.

Bcl-2 has a role in suppressing the production of reactive oxygen species and lipid peroxidation. To explore the in situ localization of 4-hydroxy-2-nonenal (HNE)-modified proteins and the Bcl-2 oncoprotein, we used double immunofluorescence labeling and confocal imaging in the rat brain after 3 h of middle cerebral artery (MCA) occlusion followed by reperfusion. Immunoreactivity for HNE or Bcl-2 was not detected at 1 h, but appeared in some intact neurons in the boundary between the infarcted and non-infarcted zones at 12 h. At 48 h, HNE-positive microglia were colocalized with Bcl-2 in the infarcted area and the boundary zone. Bcl-2 may play an important role in the antioxidant system promoting survival of the neurons and activated microglia following reperfusion injury.

Aldehydes↗