Biomedical subjects

T Kitano

Publications and source records attributed to T Kitano.

At least 37 records · Page 2Linked to original sources

PubMed2000

Evolutionary history of the Rh blood group-related genes in vertebrates.

Rh and its homologous Rh50 gene products are considered to form heterotetramers on erythrocyte membranes. Rh protein has Rh blood group antigen sites, while Rh50 protein does not, and is more conserved than Rh protein. We previously determined both Rh and Rh50 gene cDNA coding regions from mouse and rat, and carried out phylogenetic analyses. In this study, we determined Rh50 gene cDNA coding regions from African clawed frog and Japanese medaka fish, and examined the long-term evolution of the Rh blood group and related genes. We constructed the phylogenetic tree from amino acid sequences. Rh50 genes of African clawed frog and Japanese medaka fish formed a cluster with mammalian Rh50 genes. The gene duplication time between Rh and Rh50 genes was estimated to be about 510 million years ago based on this tree. This period roughly corresponds to the Cambrian, before the divergence between jawless fish and jawed vertebrates. We also BLAST-searched an amino acid sequence database, and the Rh blood group and related genes were found to have homology with ammonium transporter genes of many organisms. Ammonium transporter genes can be classified into two major groups (amt alpha and amt beta). Both groups contain genes from three domains (bacteria, archaea, and eukaryota). The Rh blood group and related genes are separated from both amt alpha and beta groups.

Amino Acid Sequence↗

PubMed2000

Unwashed shed blood infusion causes deterioration in right ventricular function after coronary artery surgery.

We investigated right ventricular function after infusion of unwashed shed blood collected from mediastinal and chest tube drainage. Changes in thromboxane B2 (TXB2) and 6-keto-PGF1 alpha, which are stable metabolites of thromboxane A2 (TXA2) and prostacyclin respectively, were also investigated. The amount of infused shed blood was 484 +/- 76 ml (mean +/- SD). Right ventricular ejection fraction decreased rapidly after the infusion and did not return to its original level until 120 minutes later (P < 0.05). Mean pulmonary artery pressure rose after infusion of the shed blood (P < 0.05). The TXB2 level in the unwashed shed blood was about 20,000 times higher than the preoperative plasma level. The plasma TXB2 level at 30 minutes after the infusion was significantly elevated (P < 0.05), and at 120 minutes it had returned to the original level. Unwashed shed blood may contain vasoactive substances that induce the release of TXA2 and increase right ventricular afterload.

6-Ketoprostaglandin F1 alpha↗

PubMed2000

Evolution of the ABO blood group gene in Japanese macaque.

We determined 5 sequences of Japanese macaque ABO blood group gene exon 7 (ca. 0.5 kb) and 2 sequences for exon 5 and intron 6 (ca. 1.7 kb). We compared those data with published sequences of other Old World monkey species, and the results suggest that alleles A and B were polymorphic in the ancestral species of macaques, and that B type allele evolved independently in macaque and baboon lineages.

ABO Blood-Group System↗

PubMed2000

Dexa-measured bone density changes over time after intertrochanteric hip fractures.

The local bone density after an intertrochanteric hip fracture changes over time. In this study, bone density was measured in proximal femur and third lumbar vertebrae in patients treated for an intertrochanteric hip fracture at various periods. There were 60 patients (mean age 71.4 years) and 50 control patients (mean age 62.4 years). Bone density measurements were performed with Dual energy X-ray absorptiometry (DEXA). Bilateral measurements of the greater trochanter, lesser trochanter and femoral diaphysis as well as the third lumbar vertebrae were performed. Each area showed different course of change. The bone density of the greater trochanter and the lesser trochanter in the injured side increased after three months as compared with the control. After three years, the bone density of the greater trochanter decreased. The bone density of the femoral diaphysis and the third vertebrae gradually decreased over time. The authors suggest that bone density changes under the influence of callus formation, bone remodeling, decrease in daily activity, and use of ambulatory aids, etc.

Absorptiometry, Photon↗

PubMed1999

An analysis of subjective complaints in a population living in a methylmercury-polluted area.

The aim of this study is to document subjective complaints, to analyze the structure of a population living in a methylmercury-polluted area, and to investigate the relationship between the subjective complaints and methylmercury pollution. A total of 1304 adults in the polluted area, who were living in the methylmercury-polluted area near Minamata City in Kumamoto Prefecture, Japan, and 446 age-matched adults in a nonpolluted area were interviewed. Comparison of prevalence, factor analysis, and cluster analysis were conducted using data drawn from a questionnaire survey about 64 subjective complaints. The population in the polluted area had more various complaints than that living in the nonpolluted area. The factor analysis proposed four factors: nonspecific, sensory, arthritic, and muscular. Each of the four factor scores was significantly higher in the population in the polluted area. Subjects who had more complaints were classified into three clusters using cluster analysis. It is possible that not only neurological subjective complaints but also nonspecific complaints of the population in the polluted area might be influenced by past methylmercury exposure.

Adult↗

PubMed1999

Axillofemoral bypass for recurrent atypical coarctation of the thoracic aorta. Woman in childbearing age.

Various surgical techniques for recurrent atypical coarctation have been described, and extra-anatomic bypass with a thoracotomy or a sternotomy approach has been widely recommended. We report a case where axillofemoral bypass has been used to treat a 28-year-old woman with recurrent atypical coarctation. Ordinarily, she had not suffered greatly from hypertension, but she experienced repeated miscarriages most probably owing to uncontrolled hypertension over 200 mmHg during pregnancy. We chose an axillofemoral bypass for extra-anatomic bypass to manage intractable hypertension during pregnancy. Postoperatively, her hemodynamics improved substantially, particularly during pregnancy, and two children were successfully delivered. The patient remains in excellent condition 74 months after operation. We suggest that an axillofemoral bypass will become an option among surgical techniques for recurrent coarctation under individual circumstances.

Adult↗

PubMed1999

Evolution of Rh blood group genes have experienced gene conversions and positive selection.

There are two tightly linked loci (D and CE) for the human Rh blood group. Their gene products are membrane proteins having 12 transmembrane domains and form a complex with Rh50 glycoprotein on erythrocytes. We constructed phylogenetic networks of human and nonhuman primate Rh genes, and the network patterns suggested the occurrences of gene conversions. We therefore used a modified site-by-site reconstruction method by using two assumed gene trees and detected 9 or 11 converted regions. After eliminating the effect of gene conversions, we estimated numbers of nonsynonymous and synonymous substitutions for each branch of both trees. Whichever gene tree we selected the branch connecting hominoids and Old World monkeys showed significantly higher nonsynonymous than synonymous substitutions, an indication of positive selection. Many other branches also showed higher nonsynonymous than synonymous substitutions; this suggests that the Rh genes have experienced some kind of positive selection.

Animals↗

PubMed1999

The effects of circulating interleukin-8 and adhesion molecules on pulmonary dysfunction in pediatric orthotopic liver transplantation.

We investigated the effects of circulating inflammatory cytokines and adhesion molecules induced by ortho-topic liver transplantation (OLT) on pulmonary function. Although the plasma interleukin-8 (IL-8) levels increased gradually, peaking at the end of the operation, these increases were considered minimal. The baseline endothelial adhesion molecule (E-selectin) level was several times higher than the normal value, but after reperfusion of the new transplanted liver, the plasma E-selectin concentrations decreased to within the normal range and remained almost normal during the postoperative period. Similar changes were observed in the plasma levels of other types of adhesion molecules. Although PaO(2)/FIO(2) showed a significant inversed correlation with the peak IL-8 concentration, after the exclusion of two patients, one of whom died and one of whom rejected the transplanted liver, no correlation was able to be found between the PaO(2)/FIO(2) ratio and the maximum IL-8 concentration. Furthermore, there was no correlation between the adhesion moleclues and PaO(2)/FIO(2). These results suggest that IL-8 exerts only a slight effect on respiratory function following successful pediatric liver transplantation, and that circulating adhesion molecules do not affect perioperative lung function.

Adolescent↗

PubMed1999

[Effects of allopurinol for oxidative injury of cisplatin-induced nephrotoxicity in mice].

The effects of allopurinol (Allop) on the lipid peroxidation in the nephrotoxicity of an antitumor drug, cisplatin (CDDP) were studied in mice. CDDP was administered intraperitoneally to two groups (CDDP + Allop group and CDDP + CMC-Na group) at single doses of 10 mg/kg, and mice were sacrificed 3 days after CDDP administration. The body weights of the CDDP-administered group gradually decreased to approximately 78% of the values of the control group (saline + Allop group and saline + CMC-Na group) within 3 days. Plasma urea nitrogen and creatinine, especially in the CDDP + Allop group, increased after 3 days. Lipid peroxides in the blood and kidney were monitored by measuring the production of malondialdehyde (MDA), which increased in the CDDP + CMC-Na group. On the other hand, MDA levels in the CDDP + Allop group increased in the kidney but remained unchanged in the blood. Changes were observed in tissue glutathione (reduced form, GSH; oxidized form, GSSG) levels in the CDDP + Allop group but not in the CDDP + CMC-Na group. Histomorphological examination demonstrated the degeneration of the proximal tubuli in the CDDP-administered groups. Especially in the CDDP + Allop group, the increase of mesangium cells in the glomeruli was observed. From these results, it was suggested that Allop was not able to inhibit CDDP-induced lipid peroxidation in the kidney, and the kidney function became more severely impaired by the administration of Allop.

Allopurinol↗

PubMed1999

Suppression of P450 aromatase gene expression in sex-reversed males produced by rearing genetically female larvae at a high water temperature during a period of sex differentiation in the Japanese flounder (Paralichthys olivaceus).

The phenotypic sex of many teleost fishes including flounders can be experimentally altered by treating embryos or larvae with varied temperatures or sex-steroid hormones. To analyse the sex determination mechanism, especially the role of cytochrome P450 aromatase (P450arom), an enzyme that catalyses the conversion of androgens to estrogens, in temperature-dependent gonadal sex differentiation in the Japanese flounder, we generated two populations of larvae, both having XX (genetic females) but each growing up to display all phenotypic females or males, by rearing the larvae at normal (18 degrees C) or high (27 degrees C) water temperatures from days 30 to 100 after hatching respectively. The larvae (XX) were produced artificially by mating normal females (XX) with gynogenetic diploid males (XX) which had been sex-reversed to phenotypic males by 17alpha-methyltestosterone. To study the role of P450arom in sex determination in the flounder, we first isolated a P450arom cDNA containing the complete open reading frame from the ovary. RT-PCR showed that P450arom mRNA was highly expressed in the ovary and spleen but weakly in the testis and brain. Semi-quantitative analyses of P450arom mRNA in gonads during sex differentiation showed that there was no difference in the levels of P450arom mRNA between the female and male groups when the gonad was sexually indifferent (day 50 after hatching). However, after the initiation of sex differentiation (day 60), the mRNA levels increased rapidly in the female group, whereas they decreased slightly in the male group. Similarly, estradiol-17beta levels rose remarkably in the female group, yet remained constant in the male group. These results suggest that induction of sex reversal of genetically female larvae to phenotypic males by rearing them at a high water temperature caused a suppression of P450arom gene expression. Furthermore, we suggest that the maintenance of P450arom mRNA at very low levels is a prerequisite for testicular differentiation, while the increased levels are indispensable for ovarian differentiation.

Amino Acid Sequence↗

PubMed1999

Differences in the effect of iron-deficient diet on tissue weight, hemoglobin concentration and serum triglycerides in Fischer-344, Sprague-Dawley and Wistar rats.

This study was designed to examine the differences in the effect of an iron-deficient diet on iron metabolism in Fischer-344 (FC), Sprague-Dawley (SD) and Wistar (WT) rats based on hemoglobin (Hb), hematocrit (Hct), serum iron levels, growth rate and organ weight. Hb concentration was higher in FC rats (14 mg/100 mL) on the initial day than in SD (10) and WT (10) rats. Although the Hb level was significantly decreased in FC rats fed an iron-deficient (ID, 8 mg/kg) diet for 33 d compared to the FC rats fed an iron-adequate (IA, 50 mg/kg) diet, the relative concentration of Hb was high in FC rats fed the ID diet as compared to the SD and WT rats fed the same diet. A similar relationship was detected between Hct and serum iron concentrations. Although serum triglycerides (TG) were significantly increased in each rat strain fed the ID diet as compared to the IA diet, the percentage of the value for the IA diet was lowest in FC rats (119%) fed the ID diet as compared to the SD (328) and WT (394) rats fed the same diet. Retroperitoneal fat pad was decreased in FC, SD and WT rats fed the ID diet as compared to the IA diet. SD rats were particularly sensitive to the reduction of retroperitoneal fat pad. The results suggested that rat strains responded differently to dietary iron inadequacy, and that FC rats were less sensitive to an iron-deficient diet as compared to the SD and WT rats.

Adipose Tissue↗

PubMed1999

[Mercury (Hg)].

Explore the source record for details and available documents.

Humans↗

PubMed1998

Measurements of zeta potentials of particulate biomaterials in protein-rich hyaluronan solution with changes in pH and protein constituents.

This study was undertaken to determine the zeta potentials of particulate biomaterials in three types of protein-rich hyaluronan solution with changes in pH; a microelectrophoretic method was used. For the purpose of determining the pH value of synovial fluid in various inflammatory conditions, we collected synovial fluid samples from joints with osteoarthritis (OA), rheumatoid arthritis (RA), and those undergoing revisions arthroplasties. The mean values of the pH in the synovial fluid from joints with OA, RA, and revision arthroplasty were shown to be 7.9, 7.5, and 8.1, respectively. The pH-zeta potential curves obtained differed, depending on the biomaterial and the medium. Addition of gamma-globulin to the medium reduced the absolute value of the zeta potentials of some of the biomaterials. The findings of this study suggest that the electrophoretic behaviors of the particulate biomaterials tested in this study are affected by the protein constituents of and pH changes in protein-rich synovial fluid. The values we obtained will be useful as reference standards and will also aid in the study of the surface phenomena of biomaterials.

Biocompatible Materials↗

PubMed1998

Conserved evolution of the Rh50 gene compared to its homologous Rh blood group gene.

We have sequenced the complete coding region of the Rh blood group gene for mouse and rat and that of Rh-related 50 kD glycoprotein (Rh50) for mouse, rat, and crab-eating macaque. Phylogenetic analyses of Rh and Rh50 amino acid sequences indicate that the Rh50 gene has been evolving about two times more slowly than the Rh blood group gene in both primates and rodents. This conservative nature of the Rh50 gene suggests its relative importance to the Rh blood group gene. The time of gene duplication that produced the Rh and Rh50 genes was estimated to be about 240-310 million years ago. We also conducted window analyses of synonymous and nonsynonymous nucleotide substitutions for those two genes. Some peaks where nonsynonymous substitutions are higher than synonymous ones were located on outer membrane regions. This suggests the existence of positive Darwinian selection on Rh and Rh50 genes through host-parasite interactions.

Animals↗

PubMed1998

Diversity and complexity of ceramide signalling in apoptosis.

Sphingolipid ceramide has emerged as a lipid messenger of cell functions including differentiation and apoptosis. Diverse kinds of stresses (ultraviolet, irradiation, heat shock and hypoxia) and biological factors (TNF-alpha, IFN-gamma and Fas antibody) require ceramide generation to execute apoptosis. The review summarises the diversity and complexity of up- and downstream of ceramide signalling in apoptosis and clinical implications of ceramide-induced apoptosis.

Animals↗

PubMed1998

Decreased hydration state of the stratum corneum and reduced amino acid content of the skin surface in patients with seasonal allergic rhinitis.

Recent studies of the stratum corneum (SC) in patients with atopic dermatitis (AD) have disclosed various functional impairments even in clinically unaffected skin. However, it has not been clear whether the presence of atopic background itself has any influence on the function of the SC. In this study, we conducted functional studies of the SC in the mid-portion of the flexor surface of the forearm of 49 skin lesion-free patients with allergic rhinitis to Japanese cedar pollen (atopic respiratory disease; ARD) in early spring, their disease-active season, by comparing the findings obtained with those in 28 patients with AD and 57 age-matched healthy control subjects. The results showed that the patients with ARD had significantly lower skin surface hydration levels assessed by high-frequency conductometry than those of the healthy control subjects. These levels were, however, not as low as those noted in moderately or severely affected patients with AD. Moreover, by measuring the amounts of water-soluble amino acids contained in the superficial portions of the SC, we found that these are also decreased at a marginal level (P = 0.051) in patients with ARD compared with levels in healthy control subjects. In contrast, the water barrier function of the SC evaluated by measurements of transepidermal water loss in patients with ARD was not different from that of the healthy control subjects. These results suggest that, although their skin appears normal clinically, the SC of the patients with ARD has functional deficiency in water-holding capacity.

Adult↗

PubMed1998

Effect of dietary magnesium level on nephrocalcinosis and growth in rats.

We studied the extent of kidney calcification by varying dietary levels of Mg, based on pathological examinations and calcium (Ca) and magnesium (Mg) balance tests. AIN-76 diets containing varying levels of Mg--0.3 (-M), 1.3 (1/20M), 2.4 (1/10M), 9.2 (1/5M), 19 (control), 38 (2M), 102 (5M), and 187 (10M) mmol/kg diet--were fed to 3-week-old male Fischer-344 rats for 14d. Although the magnitude of abnormality was highest in kidney of rats fed the -M diet, the damage was normalized as the dietary level of Mg increased, with increasing serum Mg concentration and urinary excretion of Mg. We found almost no deposition of Ca in rats fed the 10M diet. The mechanism by which the high dietary Mg induces these effects most likely involves a competition between Mg and Ca for reabsorption in proximal and/or distal tubules, since these diets increased the urinary excretion of Ca. However, these high Mg diets decreased food intake and body weight gain compared with the control diet, although these indices were not decreased in rats fed the 2M diet. The results suggest that a dietary magnesium level approximately twice the normal level effectively reduces kidney calcification while maintaining normal growth in rats.

Animal Feed↗

PubMed1998

Increased lung uptake of iodine-123-MIBG in diabetics with sympathetic nervous dysfunction.

UNLABELLED: Scintigraphy with 123I-MIBG and 201TI was compared in patients with various diseases including diabetes mellitus, with and without sympathetic nervous dysfunction. This study was done to assess lung uptake of these tracers semiquantitatively. METHODS: Thirty-eight patients with diabetes mellitus, seven patients with dilated cardiomyopathy (DCM), 12 patients with hypertrophic cardiomyopathy (HCM) and eight healthy subjects were studied. Sympathetic nervous dysfunction was observed in 13 of the 38 diabetic patients. Simultaneous imaging with 123I-MIBG and 201TI was performed. The ratio of lung to total injected dose count and washout rate in the lung were calculated from dynamic images acquired in the initial 2 min and static images acquired at 15 min and at 4 hr after injection of the tracers. RESULTS: Lung uptake of 123I-MIBG at 4 hr was significantly increased in the diabetic group as compared with those in the other groups. In diabetic patients with sympathetic nervous dysfunction, the lung uptake ratio of 123I-MIBG at 4 hr was significantly higher than that in the diabetic patients without sympathetic nervous dysfunction, due to decreased clearance of 123I-MIBG from the lung. On the other hand, increased lung uptake of 201TI was observed in DCM patients at both 15 min and 4 hr. There was no significant difference between lung uptake of 201TI in diabetic patients and that in healthy subjects. CONCLUSION: Lung uptake of 123I-MIBG was increased and lung washout of 123I-MIBG was decreased in diabetic patients with sympathetic nervous dysfunction, while lung uptake of 201TI was not altered. lodine-123-MIBG scintigraphy of the lung may provide information on sympathetic nervous activity in diabetic patients. It is a promising method for studying the kinetics of norepinephrine in the lung because MIBG is taken up in the lung by the same mechanism as norepinephrine.

3-Iodobenzylguanidine↗