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Biomedical subjects

H Yoshida

Publications and source records attributed to H Yoshida.

At least 1,225 records · Page 68Linked to original sources
PubMed1994

Induction of manganese superoxide dismutase by glucocorticoids in glomerular cells.

Our previous in vivo study demonstrated that methylprednisolone (MP) activates glomerular antioxidant enzymes and attenuates glomerular oxidant injuries, including those in experimental nephrosis. The present study investigates the cellular mechanism of the MP-induced activation of antioxidant enzymes and their contribution to the attenuation of cellular oxidant toxicity. When bovine glomerular endothelial cells (GECs) were treated with 10 microM MP, cellular manganese superoxide dismutase (Mn-SOD, 3.95 +/- 0.33 mu/mg protein, M +/- SE) and catalase (1.64 +/- 0.06 k/mg protein) activities were significantly (P < 0.05) elevated above control GECs (2.23 +/- 0.43 mu/mg protein and 1.06 +/- 0.09 k/mg protein, respectively). When GECs pretreated with MP (10 microM 24 hrs) were exposed to xanthine (0.1 mM)+xanthine oxidase (5 mU/ml) for four hours, levels of specific membrane lipid peroxidation products, that is, phosphatidylcholine- and phosphatidylethanolamine-hydroperoxides, remained at levels 10 to 25% of those measured in non-MP-treated (xanthine/xanthine oxidase-exposed) control cells. Moreover, the degree of cell damage following exposure to the superoxide generating system, assessed by 51Cr release, was significantly attenuated in MP-treated cells (approximately 50% of MP-non-treated controls, N = 6). Thus, MP-treated GECs with elevated antioxidant enzyme activities by MP were more resistant to the toxic effect of reactive oxygen metabolites. The mechanism of antioxidant enzyme induction by MP was studied for Mn-SOD. MP was shown to enhance Mn-SOD mRNA in bovine GECs and rat glomerular mesangial cells (GMCs) in dose-dependent manners.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Angiotensin II type 1 receptor gene abnormality in a patient with Bartter's syndrome.

Administration of a selective angiotensin I type 1 receptor (AT1) antagonist in animals not only nullifies the vasopressor action of angiotensin II, but also induces chloriduria and kaliuria, juxtoglomerular apparatus (JGA) hypertrophy and hyperreninemia, features characteristic of human Bartter's syndrome. We, therefore, explored the possibility that Bartter's syndrome may involve an AT1 abnormality. Using a pair of AT1-specific oligonucleotide primers and two different DNA polymerases (Taq and Pfu), we amplified the approximately 1 kb AT1 coding region of genomic DNA isolated from leukocytes of five patients with Bartter's syndrome by PCR and analyzed the sequence of the product. While the sequence of all clones from four patients were identical to that already reported for the normal human AT1 DNA sequence, 50% of the clones from one patient with Bartter's syndrome were found to have A-->G transition at nucleotide 931 which causes an amino acid substitution (arg-->gly) on the carboxy-terminal cytosolic tail of AT1. This mutation was not found in DNA from 50 normal controls which were screened by restriction enzyme digestion pattern of the PCR products of this region. As PCR-amplified AT1 DNA clones from four other individuals with Bartter's syndrome did not display any abnormality in the coding region, the possibility exists that Bartter's syndrome consists of multiple disease entities, where an AT1 gene abnormality represents a specific subgroup of the syndrome and/or some abnormality includes mutations outside of the coding region.

Animals↗
PubMed1994

Removal of maternal antibodies from a woman with repeated fetal loss due to P blood group incompatibility.

BACKGROUND: Plasmapheresis is intended to lower plasma antibody levels in women with blood group incompatible pregnancies. CASE REPORT: Therapeutic specific antibody removal by using antigen-positive red cells was applied to a blood group p pregnant women who had a high titer (128) of IgG anti-PP1Pk and had lost all six previous fetuses in blood group P-incompatible pregnancies. Plasma was taken from the patient with an intermittent-flow cell separator, mixed with a volume of washed and packed P-positive red cells equivalent to one-fifth of the volume of plasma, and incubated for 10 minutes in an ice water bath. The PP1Pk antibodies were removed, and the autologous plasma was transfused. Treatment by specific antibody removal was started in the seventh week of gestation, and performed one to three times a week for a total of 56 times up to the 34th week. The volume of plasma treated was 2.4 L per procedure on average and totaled 135 L. After each treatment, the antibody titer in the patient's plasma usually decreased by 1 log2, and no deleterious effect on the women was noted. The titers of IgG anti-P and anti-Pk were kept between 4 and 16 after the ninth week of gestation. At the end of the 34th week of gestation, a male infant was delivered by cesarean section. The infant did not require an exchange transfusion and is now a healthy 2-year-old boy. CONCLUSION: This therapeutic method is very useful in the management of fetomaternal P-incompatibility.

Abortion, Habitual↗
PubMed1994

Effects of alcohol consumption on antioxidant content and susceptibility of low-density lipoprotein to oxidative modification.

OBJECTIVE: The effects of moderate alcohol intake on antioxidant content of low-density lipoprotein (LDL) and the susceptibility of LDL to oxidative modification were examined in 12 healthy adult males. DESIGN: Volunteers abstained from alcohol for 3 weeks and then 12 subjects (alcohol intake group) consumed alcohol (0.5 g/kg/day) as brandy for 4 weeks; 4 subjects (control abstinence group) did not consume any alcohol for the entire study. RESULTS: In the alcohol intake group, plasma total cholesterol (TC), triglyceride (TG), phospholipids (PL), free cholesterol (FC) and apoprotein B (apoB) levels in LDL decreased significantly after alcohol intake; however, since TC/apoB, TG/apoB, PL/apoB and FC/apoB ratios did not change significantly, it is clear that LDL particle numbers decreased. Vitamin E and vitamin A levels in plasma, and vitamin E content of LDL also did not change significantly. Beta-carotene levels in plasma and in LDL decreased significantly in the alcohol intake group. In the abstinence group, lipid levels and vitamin levels did not change. Lag time before the onset of LDL oxidation and propagation rate of LDL oxidation in the alcohol intake group did not change significantly. CONCLUSIONS: Moderate alcohol intake decreases particle numbers of LDL without any changes in chemical composition, vitamin E content and susceptibility of LDL to oxidative modification. However, beta-carotene content was decreased significantly by even moderate alcohol intake.

Adult↗
PubMed1994

Topical treatment of resistant warts with glutaraldehyde.

UNLABELLED: Therapy with glutaraldehyde (GA) was used to treat twenty-five patients with selectively resistant warts. The patients were categorized as having one or more of the following conditions: 1) the location of the warts was either periungual, palmar or plantar, 2) the age of the patient was five years or younger, 3) the number of warts was two or more. RESULTS: Eighteen (72%) out of twenty-five cases were cured, and the other seven (28%) were not. The individual cure rates of the three conditions above were 80%, 60%, and 68.5% respectively. Pigmentary changes occurred immediately after the initial topical application of glutaraldehyde, and the surface of the verruca hardened. Soon afterwards some debris began to drop off of the verruca tissue little by little, and final healing was completed by less than twelve weeks without disagreeable marks. This therapy was found to be extremely useful, not only because the cure rate was high, but the following advantages were also noted: 1) no pain or pruritus, 2) no evidence of scarring or permanent pigmentary change, 3) good penetration in any location, 4) no need for special instruments or reagents except the solution, and 5) no special technique required (possible home treatment). This therapy is superior to cryotherapy (CT) in that it is useful for warts on any location, regardless of the number of lesions, and it is good for young children, although the cure rates for CT and GA are almost equal.

Administration, Topical↗
PubMed1994

Relationship between porphyria cutanea tarda (PCT) and viral hepatitis.

Recent reports have revealed the high prevalence of serological markers of viral hepatitis in porphyria cutanea tarda (PCT). We present two cases of PCT associated with hepatitis C and discuss the relationship between PCT and viral hepatitis. Case 1: A 50-year-old Japanese male noticed blisters, erosions, and fragility on sun-exposed areas of his skin in November of 1990. He had no history of excessive alcohol intake. He had been taking analgesics for eighteen years. Case 2: A 64-year-old Japanese male was referred in October of 1989 because of pigmentation on sun-exposed areas of his skin. He had been drinking alcohol excessively for 43 years. The hepatitis C virus (HCV) antibody was present in each case. Tests for the HCV antibody and hepatitis B serological markers were run in 5 other patients. HCV antibody was present in 3 of them. The two cases negative for the HCV antibody exhibited the hepatitis B antibody. We speculated that viral hepatitis infection may play an important role in precipitating PCT in cases with a history of a long term excessive intake of alcohol or chemicals.

Hepatitis C↗
PubMed1994

Detection and cloning of human papillomavirus DNA associated with recurrent respiratory papillomatosis in Thailand.

Recurrent respiratory papillomatosis (RRP) is highly prevalent in Thailand. In this study, we examined the presence of human papillomavirus (HPV) DNA in 25 RRP patients in Thailand by means of dot blot analysis and/or polymerase chain reaction. Eighty-four percent (21/25) of cases and 4% (1/25) of cases were positive for HPV-11 DNA and HPV-6 DNA, respectively. Three cases (3/25) were negative for all of the examined HPV types. No cases were positive for HPV-16 or 18. Furthermore, we isolated the recombinant HPV-11 DNA clone from a genomic library constructed with the DNA of RRP tissue. The restriction map of the cloned HPV DNA was identical with the map of known HPV-11 DNA. These results suggest at least that no specific HPV type or subtype is likely to be associated with RRP in Thailand.

Base Sequence↗
PubMed1994

Nuclear accumulation of p53 protein correlates with mutations in the p53 gene on archival paraffin-embedded tissues of human breast cancer.

Fifty invasive ductal carcinomas of the breast were analyzed by immunohistochemistry, polymerase chain reaction-single strand conformational polymorphism (PCR-SSCP) and direct sequencing after microdissection of conventional formalin-fixed, paraffin-embedded tissues. A highly significant association between the presence of p53 gene mutation and nuclear accumulation of p53 protein was found (P < 0.0001). Of 13 tumors that demonstrated p53 gene mutations, 11 (84.6%) showed nuclear accumulation of p53 protein. However, of 37 tumors in which gene mutations were not detected, only 5 (13.5%) showed nuclear accumulation of p53 protein. There was a statistically significant association between the nuclear accumulation of p53 protein and a higher histological grade (P < 0.001) or mitotic index (P < 0.01). In addition, gene mutations had a statistically significant association with a higher histological grade (P < 0.05) or mitotic index (P < 0.0001). Therefore, p53 abnormalities might be associated with an aggressive phenotype in breast cancer. We conclude that the immunohistochemical detection of nuclear p53 protein accumulation is highly associated with p53 gene mutations in archival paraffin-embedded tissues, and that this method is useful for rapid screening of p53 abnormalities.

Base Sequence↗
PubMed1994

Nucleolar organizer regions and PCNA expression in prostatic cancers.

Argyrophilic nucleolar organizer regions (AgNOR) of 79 prostatic adenocarcinomas, and an immunohistochemical stain using a monoclonal antibody against proliferating cell nuclear antigen (PCNA) of 54 prostatic adenocarcinomas, obtained by needle biopsy and transurethral resection of the prostate between 1986 and 1989, were investigated. A morphological classification was devised to count silver dots based on the relations between intra- and extra-nucleolar AgNOR (type A, B, C and D). Total AgNOR counts were significantly higher in carcinoma (4.2 +/- 1.57) than in the benign prostatic lesions (1.90 +/- 0.24). Count differences of AgNOR were evident in histological differentiation, nuclear anaplasia, and presence of nucleoli, mitosis, lymphatic invasion and vascular invasion. Higher total AgNOR counts were almost always associated with type B and C AgNOR (intranucleolar AgNOR), but were not associated with type A (nucleolus without small dot) nor type D (extra-nucleolar AgNOR). This study shows the diagnostic value of AgNOR in prostatic cancer, and the importance of morphological classification of AgNOR. The survival of patients with higher AgNOR counts (> or = 4.3) was significantly poorer than survival of those with lower AgNOR counts (< 4.3). Significantly more PCNA positive cells were identified in cancer by immunohistochemical stain and correlated with the presence of mitosis, but there was no significant difference in survival rate groups classified by PCNA positivity. It is also suggested that PCNA can be a useful marker of cell proliferation in prostatic lesions, but the AgNOR counts were diagnostically and prognostically more valuable than immunohistochemical PCNA in prostatic lesions. The correlation between AgNOR and PCNA immunoreactivity was not significant.

Adenocarcinoma↗
PubMed1994

Pyrazolopyridine derivative acts as a novel cyclooxygenase inhibitor: antiplatelet effect in aged patients with ischemic stroke.

OBJECTIVE: To examine the antiplatelet effect of a novel pyrazolopyridine derivative (KC-764) in geriatric patients with ischemic stroke. DESIGN: Randomized clinical trial of three graded dose levels. SETTING: A geriatric clinic attached to a nursing home. PATIENTS: Fifteen patients with a history of cerebral infarction with a mean age of 75 +/- 5 years (range, 65-83). Patients were divided into three groups and administered 10, 20, or 40 mg/day KC-764 for 8 weeks. MEASUREMENTS: Platelet aggregation induced by arachidonate, ADP, collagen and platelet-activating factor. Plasma or serum levels of thromboxane B2 and 6-ketoprostaglandin F1 alpha. MAIN RESULTS: Platelet aggregation was inhibited by KC-764 administration and returned to the control level after discontinuation. Although plasma thromboxane B2 levels were markedly decreased, plasma 6-ketoprostaglandin F1 alpha was not affected. However, the dose of 10 mg/day was not sufficient to maintain an effective plasma level of KC-764. There were no side effects or changes in laboratory findings. CONCLUSIONS: We confirmed that KC-764 at a dose of 20 to 40 mg/day is an effective antiplatelet agent and a good candidate for a trial to see if it is feasible for long-term use for the prevention of ischemic stroke in high-risk patients.

6-Ketoprostaglandin F1 alpha↗
PubMed1994

[A case of pediatric Chlamydia pneumoniae infection and properties of the isolate].

Chlamydia pneumoniae was isolated from the throat of a 2-year-old girl with upper respiratory illness. The isolate, Shizuoka-37, was stained with C. pneumoniae specific monoclonal antibody (RR402), as well as the genus specific antibody (Cultureset), but not with C. trachomatis specific monoclonal antibody (Micro-Trak). C. pneumoniae genome was amplified by polymerase chain reaction in the isolate. Elementary bodies (EB) of the isolate was round shaped by electron micrograph.

Child, Preschool↗
PubMed1994

Quinolone resistance mutations in the DNA gyrase gyrA and gyrB genes of Staphylococcus aureus.

A 6.4-kb DNA fragment containing the DNA gyrase gyrA and gyrB genes was cloned and sequenced from the quinolone-susceptible Staphylococcus aureus type strain ATCC 12600. An expression plasmid was constructed by inserting the cloned genes into the Escherichia coli-S. aureus shuttle vector pAT19, and deletion plasmids carrying only functional gyrA and gyrB genes were derived from this plasmid. An efficient transformation system for S. aureus RN4220 was established by using these plasmids. Quinolone-resistant mutants of S. aureus RN4220 were isolated by three-step selection with quinolones. The first- and second-step mutants were considered to be transport mutants, and the third-step mutants were divided into five groups with respect to their resistance patterns and transformation results with gyrA and gyrB genes. Sequencing analysis of the resulting mutant gyrase genes showed that they had the following point mutations: group 1, Ser-84 (TCA) to Leu (TTA) in GyrA; group 2, Ser-84 (TCA) to Ala (GCA), Ser-85 (TCT) to Pro (CCT), or Glu-88 (GAA) to Lys (AAA) in GyrA; group 3, Asp-437 (GAC) to Asn (AAC) in GyrB; group 4, Arg-458 (CGA) to Gln (CAA) in GyrB; and group 5, Ser-85 (TCT) to Pro (CCT) in GyrA and Asp-437 (GAC) to Asn (AAC) in GyrB. When the gyrA and/or gyrB mutants were transformed with the wild-type gyrA and/or gyrB plasmids, they became quinolone susceptible, but transformants with the plasmids having the same mutations on the gyrA and/or gyrB genes did not confer susceptibility. These results indicate that mutations in both gyrA and gyrB can be responsible for quinolone resistance in S. aureus.

Amino Acid Sequence↗
PubMed1994

Neonatal thymectomy diminishes renal IgA deposition in IgA nephropathy-prone ddY mice.

To understand the role of thymus-derived T cells in the development of IgA nephropathy (IgAN), we performed neonatal thymectomies on ddY mice, in which this disease occurs spontaneously. Although these thymectomized mice developed a renal lesion closely resembling that typical of IgAN, the extent of their mesangial IgA deposition was significantly milder than in control sham-operated mice. The immunological mechanisms responsible for curbing this mesangial deposition of IgA were then analyzed. The percentage of splenic T cells and the magnitude of mitogenic responses both decreased markedly in thymectomized compared with control mice. These results suggested the hypofunction of thymus-derived T cells. However, serum IgA levels were almost identical in both groups. Furthermore, sera from both groups contained similar amounts of macromolecular IgA, of the type formerly eluted from the affected glomeruli of patients with IgAN. These results strongly indicate that thymus-derived T cells or their products determine the amount of IgA deposited in the kidneys of ddY mice.

Animals↗
PubMed1994

Immunohistochemical study of c-erbB-2 oncoprotein expression in extramammary Paget's disease.

Sections of formalin-fixed, paraffin-embedded tumor tissue from 20 patients with noninvasive extramammary Paget's disease and 2 patients with invasive extramammary Paget's disease were stained immunohistochemically by means of anti-c-erbB-2 product monoclonal antibody. Membrane staining of intraepidermal tumor cells was found in only 3 of 20 cases of noninvasive extramammary Paget's disease. In the 2 invasive cases, tumor cells of invasive lesions and metastases were positive while intraepidermal tumor cells were negative.

Aged↗
PubMed1994

Vasodilatory effects of C-type natriuretic peptide on forearm resistance vessels are distinct from those of atrial natriuretic peptide in chronic heart failure.

BACKGROUND: C-type natriuretic peptide (CNP) is a newly identified peptide that is structurally related to atrial natriuretic peptide (ANP). Although it has been suggested that CNP is released from the endothelium for the regulation of local vascular tone, no data are available concerning the vasodilatory response to CNP in humans. METHODS AND RESULTS: Strain-gauge plethysmography was used to determine the vasodilatory effects of intra-arterially infused CNP compared with the effects of ANP infusion in 11 patients with chronic heart failure (CHF) and 11 age-matched healthy controls. Graded doses of CNP and ANP (8, 16, 32, and 48 pmol.min-1.dL-1 tissue volume) were administered randomly into the nondominant brachial artery, and forearm blood flow (FBF) was measured. No significant changes in systemic blood pressure and heart rate were found during the study. Both the absolute and percent FBF responses to ANP relative to the baseline value were significantly lower in CHF patients than in healthy controls (P < .01), whereas the responses to CNP were similar. The calculated forearm spillover of cyclic GMP (cGMP) was significantly lower in CHF patients receiving the highest dose of ANP (P < .02), whereas changes in cGMP spillover after the equimolar dose of CNP were significantly higher (P < .02), despite the lesser potency of CNP. CONCLUSIONS: In patients with CHF the peripheral vasodilatory effect of ANP is attenuated, but CNP-induced peripheral vasorelaxation is preserved, with CNP being less potent for equimolar doses.

Atrial Natriuretic Factor↗
PubMed1994

Assessment of quantitative exercise thallium-201 emission computed tomography in patients with vasospastic angina--value of washout rate analysis.

This study was performed to assess the value of washout rate analysis of quantitative exercise thallium-201 emission computed tomography in vasospastic angina patients without significant coronary stenosis. Quantitative analysis of both thallium-201 perfusion and washout rate before and after drug treatment was performed in 48 patients with vasospastic angina and no significant coronary artery stenosis. All of the patients attained more than 90% of their age-predicted heart rate during each exercise test. Before drug treatment, 26 patients exhibited exercise-induced ischemia (perfusion defects on stress polar map), 17 did not exhibit exercise-induced ischemia (normal stress and washout rate polar maps), and the remaining 5 patients showed no perfusion defects, but did show extensive abnormal washout rates. On coronary angiography, multivessel coronary spasm was documented in 12 of the 26 patients with exercise-induced ischemia, in 7 of the 17 patients without exercise-induced ischemia and in 4 patients with an extensive abnormal washout rate and a normal stress polar map. In the 17 patients without exercise-induced ischemia, the mean washout rate was significantly decreased (p < 0.05) in association with a significant decrease in the double product (p < 0.05) after drug treatment. Of the 26 patients with exercise-induced ischemia, 18 (group 1) showed an increase in the mean washout rate with improved perfusion defect after drug treatment. The remaining 8 patients (group 2) showed a decrease in the mean washout rate with improved perfusion defect after drug treatment, which increased significantly on repeat exercise test performed after additional increased doses of antianginal drugs were administered (p < 0.01). The number of patients with multivessel coronary spasm was significantly high in group 2 (p < 0.01). Thirteen patients showed an extensive abnormal washout rate before drug treatment, including 8 patients with exercise-induced ischemia and 5 patients with no perfusion defects, who showed an increased mean washout rate after drug treatment (p < 0.05). These findings indicate that washout rate analysis aids in the diagnosis in vasospastic angina patients with exercise-induced ischemia. Some patients with exercise-induced ischemia can not be detected by thallium-201 perfusion analysis alone, especially those with multivessel coronary spasm and when this procedure is performed after drug treatment. In addition, a high frequency of abnormal washout rate in vasospastic angina may result not only from exercise-induced ischemia due to main epicardial coronary artery spasm, but also from microspasm, or impairment of microcirculation or myocyte.

Aged↗
PubMed1994

Effects of angiotensin II on isolated rabbit afferent arterioles.

We examined the effects of angiotensin II (Ang II) on isolated rabbit afferent arterioles to assess the direct effect of Ang II at the resistance vessel level in the kidney. We microdissected the superficial afferent arteriole from the kidney of New Zealand White rabbits. The afferent arteriole was cannulated with a micropipette system, and the intraluminal pressure was set at 80 mmHg. Ang II did not change the lumen diameter of the afferent arterioles. After the afferent arterioles were pretreated with aspirin DL-lysine or indomethacin, Ang II (10(-7) M) caused transient vasoconstriction in the afferent arterioles. Ang II (10(-7) M) caused persistent constriction in the afferent arterioles pretreated with NG-nitro-L-arginine (10(-4) M). Physiological doses of Ang II decreased the lumen diameter of the isolated afferent arterioles pretreated with NG-nitro-L-arginine and aspirin DL-lysine. Dup753 (10(-6) M), an AT1-receptor antagonist, abolished the vasoconstrictor effects of Ang II. These findings suggest that the isolated rabbit afferent arteriole has AT1 receptors, and the vasoconstrictor response of Ang II is counteracted by vasodilatory prostaglandins and nitric oxide.

Angiotensin II↗