PubMed Health⌕ Search

Biomedical subjects

T Kudoh

Publications and source records attributed to T Kudoh.

At least 73 records · Page 4Linked to original sources
PubMed1995

Large-scale screening for human parvovirus B19 DNA in clinical specimens by dot blot hybridization and polymerase chain reaction.

Large-scale screening for human parvovirus B19 (B19) DNA in serum samples was carried out by both dot blot hybridization and the polymerase chain reaction (PCR). Dot blot hybridization was undertaken with a digoxigenin-labeled DNA probe. Serum samples from four patients were pooled and tested by a dot blot hybridization assay. When a dot was positive, each of the four samples was tested separately to identify the positive sample. The PCR template was the DNA extracted from mixed serum samples from 10 patients. When B19 DNA was positive by PCR, each of the ten samples was tested separately. A total of 7,969 serum samples were tested by dot blot hybridization and 15 samples (11 patients) were positive for B19 DNA; 7,038 serum samples were tested by PCR and 71 samples (50 patients) were positive. Large-scale screening for B19 DNA by PCR suggested a broader spectrum of clinical manifestations associated with B19 infection.

Base Sequence↗
PubMed1995

Assessment of coronary vasodilator reserve by N-13 ammonia PET using the microsphere method and Patlak plot analysis.

UNLABELLED: Noninvasive quantification of regional myocardial blood flow (MBF) has been successfully achieved with N-13 ammonia. The microsphere method as a simple method for quantifying regional myocardial blood flow was reevaluated in comparison with Patlak graphical analysis. In addition coronary vasodilator reserve (CVR) was estimated by both methods. METHODS: Dynamic N-13 ammonia PET studies were performed in 10 healthy volunteers and 10 patients with coronary artery disease at baseline and after dipyridamole infusion (0.56 mg/kg). MBF was estimated by the microsphere method at various times and by Patlak graphical analysis. In order to reduce the noise level in the microsphere method, MBF estimates were also performed after data in 10-40 seconds were averaged. RESULTS: In the studies on normal subjects MBF (ml/min/g) determined by the microsphere method significantly differs from time to time. However, MBF determined by the modified microsphere method [with average (Extraction fraction) x MBF values obtained between 100 and 120 sec] linearly correlated well with MBF by Patlak graphical analysis (r = 0.97, slope = 0.98, intercept = 0.20). In the studies on patients with coronary artery disease a good agreement of the MBF estimates was also observed (r = 0.97, slope = 0.98, intercept = 0.22). In the studies on the normal subjects and patients with coronary artery disease, CVR obtained by the modified microsphere method after correcting the overestimated MBF values also correlated well with that by Patlak graphical analysis (r = 0.90, slope = 1.14, intercept = -0.15, and r = 0.92, slope = 0.82, intercept = 0.25, respectively). CONCLUSION: The modified microsphere method is a very simple and reliable approach for quantifying MBF with N-13 ammonia PET which is comparable to Patlak graphical analysis. It also makes possible CVR assessment as accurate as Patlak graphical analysis.

Adult↗
PubMed1995

Incidence of human parvovirus B19 DNA detection in blood donors.

1000 serum samples from blood donors were tested for human parvovirus B19 (B19) DNA by a nested PCR assay: six samples were positive for B19 DNA. The frequency was 1/167 (0.6%), considerably higher than previous surveys (0.004-0.03%). Five of the six samples were also positive for anti-B19 IgM, indicating an acute phase of infection. It is recommended to screen for B19 DNA in blood products to prevent transfusion mediated viral infection for those susceptible such as immunocompromised patients and pregnant women.

Antibodies, Viral↗
PubMed1995

[Serological diagnosis for human parvovirus B19 infection by an enzyme immunoassay kit with recombinant antigens synthesized in a baculovirus expression system].

Propagation of human parvovirus B19 (B19) in cell cultures are not applicable to the source of viral antigens for serological assays at present. Enzyme immunoassay (EIA) kits with recombinant B19 capsids by E. coli or baculovirus expression system have been developed. We tested serum samples from the patients with erythema infectiosum and aplastic crisis by EIA kit with recombinant antigens synthesized in a baculovirus expression system (Denka Seiken Co., Tokyo, Japan). The antigens used in the kit are self-assembled recombinants containing both VP-1 and VP-2 with the same proportion as found in native B19 capsids. B19 IgM is detected by antibody capture methods and IgG by indirect methods. All of the samples were positive for B19 DNA by nested PCR. Thirty-six (97%) of the 37 patients with erythema infectiosum and all (100%) of the 4 patients with aplastic crisis were positive for B19 IgM. The EIA kit with recombinant antigens synthesized in a baculovirus expression system has proved to be reliable and useful for the diagnosis of B19 infection.

Antibodies, Viral↗
PubMed1995

Motion correction in exercise first-pass radionuclide ventriculography without an external point source.

UNLABELLED: Exercise first-pass radionuclide ventriculography provides valuable diagnostic and prognostic information in patients with coronary artery disease. In this procedure, motion correction of the images is commonly performed using a second external point source attached to the chest wall during exercise (dual-isotope method). Recently, a motion correction algorithm without an external point source (single-isotope method) was developed and the results compared with those of the dual-isotope method. METHODS: To examine the accuracy of the motion correction method, a phantom study was performed using a moving cardiac phantom with a motion speed of up to 169 cycle/min and motion amplitude up to 6 cm. Count fluctuation in the phantom region by motion was calculated as a coefficient of variation (CV). In the clinical study, time-activity curves of the left ventricular phase were created for quantitative assessment of variation as CV values of the ejection fraction in the central five cardiac cycles after correction by the two methods during exercise radionuclide ventriculography in 17 patients. RESULTS: In the moving phantom, both the single- and dual-isotope methods reduced the CV values less than 10%. In the clinical study, the single-isotope method provided less CV value of ejection fraction (9.8% +/- 5.6%) than the dual-isotope method (24.8% +/- 10.5%) (p < 0.01), indicating less individual variation of ejection fraction values. CONCLUSION: These data indicate that object motion can be accurately corrected in the moving phantom by both single- and dual-isotope methods. In clinical studies, the single-isotope method is more accurate.

Algorithms↗
PubMed1995

[Assessment of left ventricular wall thickening with gated 99mTc-MIBI SPECT--value of normal file].

The wall thickening was assessed by regional count increase from end-diastole (ED) to end-systole (ES) in gated 99mTc-MIBI SPECT. The wall thickening index was calculated as (ES count--ED count)/ED count x 100 (% thickening). Gated SPECT was performed three hours after injection of 600 MBq of 99mTc-MIBI in 20 normal subjects to create normal files (ED, ES perfusion maps and % thickening map). In normal ED and ES perfusion maps, distribution in anterior and lateral regions were higher than other regions, indicating heterogeneous perfusion. In addition, the % thickening in apex was higher than anterior and lateral and septal regions, suggesting heterogeneous % thickening in normal subjects. Furthermore, the % thickening was different between male and female. We conclude that quantitative analysis of regional thickening can be performed by gated 99mTc-MIBI SPECT with normal files.

Adult↗
PubMed1994

Molecular cloning of a mouse counterpart for human TGF-beta type I receptor.

TGF-beta is a multifunctional polypeptide which is involved in the regulation of cell growth, differentiation, and immunomodulation. Its signaling receptors on the cell surface are postulated to be the type I (TGF beta RI) and type II receptors (TGF beta RII). Previously, TGF beta RII has been cloned and was found to be a receptor type serine/threonine kinase (RSK). In an attempt to isolate novel RSKs expressed in mouse ES cells, we obtained a clone designated as ESK2, which was very closely related to human TGF beta RI. The amino acid sequence of the intracellular domain is completely identical and the transmembrane domain is identical except for one residue. The extracellular domain is 90% homologous with a deletion and an insertion of four amino acid residues. ESK2 also binds to TGF-beta in the presence of TGF beta RII, indicating that ESK2 is the mouse counterpart for human TGF beta RI.

Amino Acid Sequence↗
PubMed1994

Human parvovirus B19-induced aplastic crisis in iron deficiency anemia.

Human parvovirus B19 (HPVB19) infects and replicates in erythroid progenitor cells. Its specific cytotoxic effect on these cells results in aplastic crises in patients with congenital hemolytic anemias. Aplastic crisis due to HPVB19 infection in a healthy girl revealed occult iron deficiency anemia. The condition is characterized by a high serum iron level in the aplastic phase and rapid recovery after administration of iron. Temporary HPVB19-induced red blood cell aplasia could occur in patients with other anemias, particularly those with non-inherited form of hemolysis.

Adolescent↗
PubMed1994

Minocycline-induced hemolytic anemia.

A case of drug-induced immune hemolytic anemia is described. A 2 year old boy exhibited sudden anemia and hemoglobinuria after administration of minocycline (MINO). The specific immunoglobulin G antibody against MINO was demonstrated in the patient's serum by western blotting. This is a rare example where anti-minocycline immune complex-mediated hemolysis was responsible for an intravascular hemolytic process.

Anemia↗
PubMed1994

[Effect of intravesical bacillus Calmette-Guérin on N-butyl-N-(4-hydroxybutyl)-nitrosamine induced urinary bladder carcinogenesis in rats].

The effect of intravesical Bacillus Calmette-Guérin (BCG) on N-butyl-N-(4-hydroxybutyl)-nitrosamine (BBN) induced urinary bladder carcinogenesis was pathologically evaluated. As a suppressive study of BCG on initiation, F344 female rats given 0.05% BBN orally for 6 weeks had intravesical instillation of either BCG or saline 3 times during BBN administration (Group A). As an inhibitory study of BCG on promotion, F344 female rats given the same strength BBN for 10 weeks had intravesical instillation of either BCG or saline 4 times starting at 7th week of BBN administration (Group B). The bladders were extirpated at 18th or 36th week after BBN administration in Group A and at 10th or 18th week in Group B. The lesions in the bladder were classified into 4 pathological findings; simple hyperplasia, papillary or nodular hyperplasia, papilloma and transitional cell carcinoma. The incidence of the lesions and the number of the lesions per 10 cm basement membrane were observed. BCG did not inhibit the growth of transitional cell carcinoma in Group A nor in Group B, rather partly promoted carcinogenesis. These results indicate that BCG have no inhibitory effect on carcinogenesis. We concluded that prophylactic effect of intravesical BCG is not due to inhibition of carcinogenesis but elimination of residual tumors by strong antitumor effect of BCG.

Administration, Intravesical↗
PubMed1993

Species specificity of pharmacological characteristics of CCK-B receptors.

Novel CCK-B receptor antagonists, tetronothiodin and L-156,586, showed different affinities for CCK-B receptors in brain membranes from human, rat, guinea pig and mouse. [125I]CCK-8 bound to these membranes with a similar affinity. However, tetronothiodin was most potent in rat (IC50 = 3.6 nM), followed by guinea pig (96 nM), human (210 nM) and mouse (280 nM). L-156,586 bound with highest affinity to membranes from guinea pig (11 nM), and with lowest affinity to membranes from mouse (220 nM). These results suggest the existence of species specificity of CCK-B receptors, and that these two compounds are useful tools for discrimination between these receptors.

Aged↗
PubMed1993

Thrombocytopenia induced by human parvovirus B19 infections.

Human parvovirus B19 (B19) has a remarkable tissue-tropism for erythroid elements--from erythroid precursors (BFU-E, CFU-E) to erythroblasts. B19 is thought to be incapable of propagating in cells other than erythroid progenitors. Leukocytopenia and thrombocytopenia sometimes occur in addition to erythrocytopenia in patients with B19 infection. We retrospectively investigated the possible cause of thrombocytopenia by B19 infection in 23 patients with thrombocytopenia admitted to our hospital in the past 5 years. Two patients were found to be infected by B19. Mild thrombocytopenia in both cases was thought to be an early event in B19 infection.

Child↗
PubMed1993

Retrospective study on the influence of human parvovirus B19 infection among children with malignant diseases.

Human parvovirus B19 (B19) is a known cause of erythema infectiosum (fifth disease) and aplastic crisis in patients with hemolytic anemias. When patients with malignant diseases are infected by B19 during chemotherapy, erythroid suppression of bone marrow sometimes occurs. We performed a retrospective investigation of B19 infection among 95 children with malignant diseases in our hospital during the past 14 years. By the method of dot blot hybridization, 9 of 95 patients were found to be positive for B19 DNA during chemotherapy. All 9 patients had reticulocytopenia at the time B19 DNA was detected in their serum samples. Neutropenia and thrombocytopenia were not found. Seven of them had only transient reticulocytopenia. Serum samples from 2 other patients were positive for B19 DNA for a longer time. They suffered from persistent anemia for about 2 and 13 month, respectively. The years when B19 DNA was detected from the 9 patients corresponded to the prevalence of erythema infectiosum in Japan.

Child↗
PubMed1993

Tetronothiodin, a novel cholecystokinin type-B receptor antagonist produced by Streptomyces sp. NR0489. II. Isolation, characterization and biological activities.

A novel cholecystokinin type-B receptor antagonist named tetronothiodin has been isolated by column chromatography and preparative HPLC from the fermentation broth of Streptomyces sp. NR0489. Tetronothiodin inhibited the binding of CCK8 (C-terminal octapeptide of cholecystokinin) to rat cerebral cortex membranes (CCK type-B receptors) with an IC50 of 3.6 nM, whereas it did not inhibit CCK8 binding to rat pancreatic membranes (CCK type-A receptors). It also inhibited CCK8 induced Ca2+ mobilization in GH3 cells, a rat anterior pituitary cell line, but was without effect on the basal cytosolic Ca2+ concentration. This finding indicated tetronothiodin was an antagonist of CCK type-B receptors.

Animals↗
PubMed1993

Technetium-99m(V)dimercaptosuccinic acid uptake in intra-abdominal massive deposit of amyloid protein.

Technetium-99m(V)dimercaptosuccinic acid (DMSA) scintigraphy was performed in two patients with pathologically confirmed primary amyloidosis. Both patients had tumor-like deposits of AL-type amyloid in the abdomen. Marked uptake of the tracer by the amyloid deposits was noted. Technetium-99m-(V)DMSA scintigraphy appears to be useful in detecting the distribution of amyloid deposits and in determining the appropriate site for biopsy.

Abdomen↗