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Biomedical subjects

Y Taniguchi

Publications and source records attributed to Y Taniguchi.

At least 127 records · Page 7Linked to original sources
PubMed1999

Evolution of visual pigments and related molecules.

The molecular phylogenetic tree of vertebrate visual pigments, constructed on the basis of amino acid sequence identity, suggests that the visual pigments can be classified into five groups (L, ML, MS, S and Rh) and that their genes have evolved along these five gene lines. Goldfish has a UV-sensitive visual pigment (S group) localized in miniature single cone cells. Medaka has one type of rod cell containing rhodopsin (Rh group) and four types of cone cells, each of which contains a specific visual pigment with an absorption maximum that differs from those of the others. Frogs have a violet-sensitive visual pigment (S group) in small single cone cells and a blue-sensitive visual pigment (MS group) in green rod cells. Although nocturnal and diurnal geckos have rod- and cone-based retinas, respectively, they have phylogenetically closely related visual pigments. The pigments in each line may have restricted absorption maxima. We have cloned cDNAs encoding molecules involved in the phototransduction system of visual cells, such as phosphodiesterase, opsin kinase and arrestin. We then constructed phylogenetic trees of these molecules with the deduced amino acid sequences. The resulting phylogenetic trees show that these molecules are classified into two groups; one is expressed in cones and another in rods, suggesting that rods and cones contain homologous molecules with different amino acid sequences. These differences may result in the different light responses of rods and cones.

Animals↗
PubMed1999

Estimation of cardiac output by first-pass transit of radiotracers.

To evaluate cardiac function with various tracers to be used for radionuclide scintigraphy, we examined the validity of a simplified method to measure cardiac output (CO) by modifying the equation of Stewart-Hamilton in the radionuclide study. After a bolus injection of I-123 or Tc-99m tracer, the total injection dose and count in the pulmonary artery during the first transit of the tracer were measured to calculate the CO Index. The CO Index was obtained from the integral of the first transit of radiotracers in the pulmonary artery divided by the total injected count. CO was estimated from the regression formula which was obtained by comparing the CO Index with CO measured by the Doppler echocardiographic method. There were close correlations between the CO Index and CO measured by Doppler echocardiography both in the study with I-123 (n = 13, r = 0.85, p < 0.001) and with Tc-99m (n = 17, r = 0.88, p < 0.001). The regression formula varied according to the radionuclide used for the study (CO = 2.29 x (CO Index)(0.634) for I-123 and CO = 3.18 x (CO Index)(0.518) for Tc-99m). CO measured by this method is useful for the assessment of cardiac function with various tracers in routine clinical studies, and this simple method may be utilized for assessment of organ blood flow on the basis of the microsphere model.

Cardiac Output↗
PubMed1999

Identification of novel non-insulin-dependent diabetes mellitus susceptibility loci in the Otsuka Long-Evans Tokushima fatty rat by MQM-mapping method.

The Otsuka Long-Evans Tokushima Fatty (OLETF) rat is an animal model for obese-type, non-insulin-dependent diabetes mellitus (NIDDM) in humans. We have previously identified 11 quantitative trait loci (QTLs) responsible for NIDDM susceptibility on Chromosomes (Chrs) 1, 5, 7, 8, 9, 11, 12, 14, and 16 (Nidd1-11/of for Non-insulin-dependent diabetes 1-11/oletf) by using the interval mapping method in 160 F(2) progenies obtained by mating the OLETF and the Fischer-344 (F344) rats. MQM-mapping, which was applied for QTL analysis based on multiple-QTL models, is reported to be more powerful than interval mapping, because in the process of mapping one QTL the genetic background, which contains the other QTLs, is controlled. Application of MQM-mapping in the F(2) intercrosses has led to a revelation of three novel QTLs on rat Chrs 5 (Nidd12/of), 7 (Nidd13/of), and 17 (Nidd14/of), in addition to Nidd1-11/of loci. The three QTLs, together with the Nidd1-11/of, account for a total of approximately 70% and approximately 85% of the genetic variance of the fasting and postprandial glucose levels, respectively, in the F(2). While the OLETF allele corresponds with increased glucose levels as expected for Nidd12 and 14/of, the Nidd13/of exhibits heterosis: heterozygotes showing significantly higher glucose levels than OLETF or F344 homozygotes. There is epistatic interaction between Nidd2 and 14/of. Additionally, our results indicated that the novel QTLs could show no linkage with body weight, but Nidd12/of has an interaction with body weight.

Animals↗
PubMed1999

Genetic diversity of HIV-1 group M from Cameroon and Republic of Congo.

We analyzed 57 HIV-1 isolates from Cameroon and the Republic of Congo, with respect to the env C2V3 and/or the pol integrase regions. The results indicated that the topology of the pol tree correlated well with that of the env tree for four clusters of subtype D, F G and H, suggesting that these trees reflect the true evolution of the overall genome structures of these subtypes. However, of 22 Cameroonian isolates that were classified as subtype A based on env, 20 of them diverged in their pol sequence into two lineages that were completely different from the prototypical subtype A, tentatively designated as subtypes A1 and A2. The subtype A1 isolates (6 out of 22) were related in their env C2V3 regions with prototypical subtype A strain, but in their pol regions, they formed an independent cluster that diverged from known HIV-1 subtypes so far reported (except for subtypes I and J). The subtype A2 isolates (14 out of 22), which represent the major epidemic type of HIV-1 in Cameroon, clustered distinctly in both the env and pol trees with the recently described A/G mosaic strains from Nigeria and Djibouti. These two lineages were not spreading in the neighboring Republic of Congo.

Amino Acid Sequence↗
PubMed1999

Chromosomal mapping of two RBP-J-related genes: Kyo-T and RBP-L.

We have recently isolated two genes encoding proteins which have either homology or affinity to RBP-J, a transcription factor involved in Notch signaling. Kyo-T interacts with RBP-J and possibly regulates the function of RBP-J. RBP-L has a highly homologous region with RBP-J but the function of RBP-L is unknown. Fluorescence in situ hybridization analysis of human metaphase chromosomes localized Kyo-T and RBP-L to Xq26 and 20q12-13.1, respectively.

Base Sequence↗
PubMed1999

Cathepsin Y (a novel thiol enzyme) produces kinin potentiating peptide from the component protein of rat plasma.

Rat spleen cathepsin Y (a novel enzyme) that produces bradykinin (BK) potentiating peptide (BPP) from rat plasma was isolated, characterized and its amino acid sequence was deduced from cDNA cloned by reverse transcription-polymerase chain reaction (RT-PCR). We propose the name cathepsin Y for this enzyme considering its origin, characteristics and the amino acid sequence. BPP potentiates not only BK but also lysyl-BK (lysBK) and T-kinin (TK) action on uterus contraction. The structure of BPP is Pro-Pro-Pro-Leu-Gly-Pro-Gly-Ser. The magnitude of the potentiation of BK activity by synthesized BPP was seven-fold when equivalent quantities added to BK and 23-fold when the level is doubled. The precursor proteins that produce BPP by the action of cathepsin Y are eluted into two fractions when the heated plasma was applied to a negative ion exchange column. Structure relationships between these two proteins are now under investigation. In this paper, we report on the characteristics and the amino acid sequence of rat spleen cathepsin Y, its structure and the potentiating activity of BPP, and isolation of the precursor protein.

Amino Acid Sequence↗
PubMed1999

Sintered bone implantation for the treatment of benign bone tumours in the hand.

We report the results of treatment of benign bone tumours in the hand with curettage and sintered bone implantation using bovine sintered bone (True Bone Ceramics). There were 22 patients who underwent sintered bone implantation in our department in 1984 or later. The follow-up survey period varied from 9 months to 11 years and 2 months (mean, 5.8 years). Recurrence of tumours and complications such as infection or fracture were not observed, and there were no clinical symptoms. X-rays revealed new bone formation connecting the implanted blocks to bone. Sintered bone was not absorbed, and lucent zones around the implants or other abnormal findings were not observed. Bone union was achieved in all patients who had pathological fractures before surgery.

Adolescent↗
PubMed1999

Variation of P-QRS relation during atrioventricular node reentry tachycardia.

OBJECTIVES: The main objective of this study was to characterize the phenomenon of variation in the P-QRS relation during atrioventricular node reentry tachycardia. BACKGROUND: Variation of P-QRS relation during tachycardia has been observed occasionally in atrioventricular node reentry tachycardia. However, the incidence, the characteristics and the mechanisms of this phenomenon have not been investigated previously. METHODS: Retrospective analysis was performed in 311 consecutive patients with slow-fast form and 108 patients with atypical or multiple form of atrioventricular node reentry tachycardia to examine whether variation of P-QRS relation with changes in AH, HA and AH/HA (A = atria; H = His bundle) ratio occurred during tachycardia. RESULTS: A total of 28 patients, 8 with slow-fast and 20 with atypical or multiple tachycardias, were found to manifest this phenomenon. There were 6 males and 22 females, with an average age of 38+/-16 years. In 10 patients, this phenomenon occurred transiently following electrical induction of the tachycardia. In 15 patients, changes in AH, HA and AH/HA ratio were associated with the occurrence of Wenckebach or 2:1 block proximal to the His bundle (H) recording site without interruption of the tachycardia. In nine patients, three with nonsustained tachycardia and six after administration of adenosine triphosphate, this phenomenon was observed at the termination of the tachycardia. This phenomenon was usually accompanied by a mild lengthening of the tachycardia cycle length. CONCLUSIONS: Variation of P-QRS relation with or without block may occur during atrioventricular node reentry tachycardia, especially in atypical or multiple-form tachycardias. It was postulated that decremental conduction in the distal common pathway, which exists between the distal link of the reentry circuit and the H, is primarily responsible for this phenomenon.

Adenosine Triphosphate↗
PubMed1999

IgE reactivity and cross-reactivity of Japanese monkeys (Macaca fuscata) to Japanese cedar (Cryptomeria japonica) and cypress (Chamaecyparis obtusa) pollen allergens.

BACKGROUND: The natural occurrence of Japanese cedar (Cryptomeria japonica, CJ) pollinosis has been reported in Japanese monkeys (Macaca fuscata). However, the reactivity to Japanese cypress (Chamaecyparis obtusa, CO) pollen allergens in these monkeys has not yet been reported. OBJECTIVES: The present study was designed to investigate the reactivity to CO pollen allergens in monkeys sensitized to CJ pollen allergens. METHODS: Serum samples from 40 monkeys naturally sensitized to CJ pollen allergens were collected from four troops. We measured the specific IgE to CO pollen allergens and examined the reactivity to the allergens by intradermal test. Cross-reactivity between CJ and CO pollen allergens was examined by ELISA inhibition method. Furthermore, we examined the sensitivity to the allergens by histamine release assay from leucocytes. RESULTS: All 40 monkeys had specific IgE to crude and purified major allergens (Cha o 1) of CO pollen. The monkeys showed a positive reaction to CO pollen allergens in the intradermal test. Allergenic cross-reactivity between Cha o 1 and Cry j 1 (a major allergen in CJ pollen) was also observed. Specific histamine release to both the major allergens was noted in two monkeys with CJ pollinosis. CONCLUSION: Japanese monkeys sensitized to Japanese cedar pollen allergens also demonstrate reactivity to Japanese cypress pollen allergens.

Allergens↗
PubMed1999

Major organ function under mechanical support: comparative studies of pulsatile and nonpulsatile circulation.

We examined a major organ function during 3 h biventricular assisted circulation after acute myocardial infarction model in the pig. In left ventricular circulation, the outflow cannula was placed in the ascending aorta and an inflow cannula through the mitral valve in the left ventricle. A pump (pulsatile group, Zeon Medical, Inc., Tokyo, Japan and nonpulsatile group, Nikkiso HPM-15, Nikkiso, Inc., Tokyo, Japan) was connected to each cannula. In right ventricular circulation, the outflow cannula was placed in the pulmonary artery and an inflow cannula in the right ventricle. The right ventricular circulation was supported by a nonpulsatile pump (Nikkiso HPM-15). The items measured were the regional blood flows of the cortex and medulla in the kidney, white matter and gray mater in brain, and liver; renal arterial flow; carotid arterial flow; portal vein flow; common hepatic arterial flow; arterial ketone body ratio (AKBR); and lactate/pyrubic acid (L/P). In the pulsatile group, the renal cortical blood flow increased, and the medulla blood flow decreased. On the other hand, in the nonpulsatile group, both regional blood flows decreased. That means that in the pulsatile assisted group intrarenal redistribution improved rather than in the nonpulsatile assisted group. In addition the liver regional blood flow, AKBR, and L/P showed significant differences between the pulsatile and nonpulsatile groups. On the other hand, the white matter and gray matter regional blood flows and carotid arterial flow did not show significant differences between the groups. The results of our study indicated that pulsatile circulation produced superior circulation in the kidney and liver, and microcirculation on the cell level was superior as well in early treatment of acute heart failure.

Animals↗
PubMed1999

Posterior interosseous nerve syndrome due to pseudogout.

Posterior interosseous nerve palsy associated with pseudogout of the elbow joint in a 71-year-old woman is described. Local steroid injection and administration of a nonsteroidal anti-inflammatory drug was effective in treatment.

Adrenal Cortex Hormones↗
PubMed1999

Kienböck's disease in women.

We examined 133 patients with Kienbock's disease, five of whom had bilateral disease. There were 47 women and 86 men. The mean age of patients was 42.7 years (range, 14-80 years). The frequencies of involvement of the right and left sides were approximately equal for women, but male patients tended to have right wrist joint involvement. The side of the affected wrist in the female group differed significantly from that in the male group. The age at onset for women was significantly higher than that for men. The percentage of manual workers was significantly lower among women than among men. The characteristics of Kienböck's disease in women differed from those in men and those previously reported for this disease. These findings suggest that the pathogenesis of Kienböck's disease in women differs from that in men.

Adolescent↗
PubMed1999

Localization of transforming growth factors beta1 and beta2 and epidermal growth factor in IgA nephropathy.

OBJECTIVE: The localization of transforming growth factor (TGF)-beta1. TGF-beta2 and epidermal growth factor (EGF) was investigated in IgA nephropathy, and was compared with the severity of histological damage (including tubulointerstitial lesions). MATERIALS AND METHODS: The enzyme antibody method was used to stain paraffin-embedded sections of renal tissue from 42 patients with IgA nephropathy (19 males and 23 females). RESULTS: There was a significant correlation between glomerular positivity for TGF-beta1 and TGF-beta2 and the severity of histological damage. There was also a significant correlation between positivity for TGF-beta1 and TGF-beta2 in the tubular epithelium and tubulointerstitial lesions. In contrast, there was no relationship between glomerular positivity for EGF and histological damage, although there was a significant correlation between positivity for EGF in the tubular epithelium and tubulointerstitial lesions. CONCLUSIONS: These findings suggest that TGF-beta1 and TGF-beta2 may be important in the progression of IgA nephropathy, and that the distribution of EGF may also be a useful marker for the progression of renal damage, including tubulointerstitial lesions.

Adolescent↗
PubMed1999

Effects of OK-432 on the proliferation and cytotoxicity of lymphokine-activated killer (LAK) cells.

We studied the effect of a streptococcal preparation, OK-432, on the cytotoxicity and the proliferation of lymphokine-activated killer (LAK) cells for use in adoptive immunotherapy. Peripheral blood mononuclear cells (PBMC) were derived from healthy donors and patients with malignant brain tumors. We divided PBMC into two groups; these cells then were stimulated with interleukin-2 in the presence or absence of OK-432. OK-432 was added only in the initial 3 days during the 3-week midterm culture period. Then, we compared OK-432-stimulated LAK (OK-LAK) cells with standard LAK (sLAK) cells in terms of their rate of proliferation and cytotoxicity. OK-LAK cells proliferated more rapidly than sLAK cells. The cytotoxicity of OK-LAK cells increased, whereas that of sLAK cells decreased. We also investigated the phenotypic differences between these two types of LAK cells and found that, on day 21, the OK-LAK cells consisted mostly of CD3-CD56+ NK cells, whereas the sLAK cells consisted mostly of CD3+CD56- T cells. The difference in their level of cytotoxic potential might be explained by the difference of predominant phenotype.

Antigens, CD↗
PubMed1999

An ultrashort 1-day protocol of Tc-99m tetrofosmin.

PURPOSE: This study describes a new 1-day protocol with Tc-99m tetrofosmin that requires only 100 minutes to obtain both stress and resting cardiac images by using a double-injection and subtraction method. METHODS: This procedure was performed in 48 consecutive patients. Rest-rest double injections were performed in eight patients (five men, three women; mean age, 69 +/- 9.8 years ) to evaluate count and image reproducibility (subprotocol A), and stress-rest and additional resting perfusion images (true rest) were done on a different day in 11 patients (five men, six women; mean age, 63 +/- 5.9 years) to confirm the validity of the new protocol (subprotocol B). RESULTS: Image quality scores of the resting image were excellent (35 of 48, or 72.9%), good (7 of 48, or 14.6%), fair (3 of 48, or 6.3%), and poor (3 of 48, or 6.3%). The scintigraphic findings with the new protocol corresponded closely with those of angiography in 26 of 34 cases (76.5%), with a tendency for underestimation (in 5 of 34 cases, or 14.7%) rather than overestimation (in 3 of 34 cases, or 8.8%). In subprotocol A, count reproducibility between the two resting images was excellent (r = 0.95; P < 0.0001); and in subprotocol B, the early-rest images were concordant visually and quantitatively with the true rest images (r = 0.89, P < 0.0001). CONCLUSION: Although there are some limitations, this protocol can be used as a routine stress-rest protocol.

Aged↗
PubMed1999

A Clostridium perfringens hem gene cluster contains a cysG(B) homologue that is involved in cobalamin biosynthesis.

The hem gene cluster, which consists of hemA, cysG(B), hemC, hemD, hemB, and hemL genes, and encodes enzymes involved in the biosynthetic pathway from glutamyl-tRNA to uroporphyrinogen III, has been identified by the cloning and sequencing of two overlapping DNA fragments from Clostridium perfringens NCTC8237. The deduced amino acid sequence of the N-terminal region of C. perfringens HemD is homologous to those reported for the C-terminal region of Salmonella typhimurium CysG and Clostridium josui HemD. C. perfringens CysG(B) is a predicted 220-residue protein which shows homology to the N-terminal region of S. typhimurium CysG. Disruption of the cysG(B) gene in C. perfringens strain 13 by homologous recombination reduced cobalamin (vitamin B12) levels by a factor of 200. When grown in vitamin B12-deficient medium, the mutant strain showed a four-fold increase in its doubling time compared with that of the wild-type strain, and this effect was counteracted by supplementing the medium with vitamin B12. These results suggest that C. perfringens CysG(B) is involved in the chelation of cobalt to precorrin II as suggested for the CysG(B) domain of S. typhimurium CysG, enabling the synthesis of cobalamin.

Base Sequence↗