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Biomedical subjects

Y Yoshida

Publications and source records attributed to Y Yoshida.

At least 127 records · Page 7Linked to original sources

Characteristics of patients complaining of halitosis and the usefulness of gas chromatography for diagnosing halitosis.

OBJECTIVE: The purpose of this study was to examine the characteristics of patients complaining of halitosis and to evaluate the diagnostic accuracy of 3 methods of measuring halitosis. STUDY DESIGN: The actual degree of halitosis was determined through use of an organoleptic test in 155 patients aged 46 +/- 17 years (mean +/- SD). The volatile sulfur compounds (VSCs) were determined with gas chromatography and with sulfide monitoring. RESULTS: The organoleptic test revealed that 55% of the subjects had either no mouth odor or slight mouth odor. There was a significant correlation between the organoleptic score and the total VSC level as determined through use of other methods. The critical discrimination value of the total VSC level was calculated to be 0.057 ppm for gas chromatography and 0.117 ppm for sulfide monitoring; high sensitivity and specificity were obtained when the gas chromatography value was used. The amount of tongue coating was significantly greater in the halitosis-positive group than in the halitosis-negative group, whereas there was no difference in salivary flow rate between the 2 groups. CONCLUSION: These results indicate that determining VSCs with gas chromatography is a useful means of diagnosing halitosis.

Chi-Square Distribution↗

Successful endovascular repair of juxtarenal and suprarenal aortic aneurysms with a branched stent graft.

This case report describes a new technique for repairing pararenal aortic aneurysms with a transluminally placed triple-branched stent graft with sidearms extending into the superior mesenteric artery and renal arteries. Endovascular repair with the branched stent graft was attempted in two patients with a pararenal aortic Aneurysm. Stent grafting was technically successful in both patients. Although postoperative transient renal function impairment and paralytic ileus occurred in patient 2, these complications were gradually resolved in the perioperative period. A substantial shrinkage of the aneurysm was revealed by means of computed tomographic measurements in patient 1. In both patients, complete exclusion of the aneurysm and patency of the bilateral renal arteries and the superior mesenteric artery were confirmed by means of follow-up computed tomographic images at 2 years. This minimally invasive approach for pararenal aortic aneurysms appears to be a viable therapeutic option for patients who are at high risk for open surgery.

Aged↗

Reduction of intraocular pressure by topical administration of an inhibitor of the Rho-associated protein kinase.

PURPOSE: Rho-associated coiled coil-forming protein kinase (ROCK) is a downstream target of a small GTPase, Rho. The kinase has been reported to regulate actomyosin-based contractility of smooth muscles by modulation of myosin phosphatase activity. Contractility of ciliary muscle could be implicated in regulation of intraocular pressure while that of ocular vessels could affect blood flow to retina. The present study has been performed to investigate the effect of a ROCK inhibitor on intraocular pressure in rabbits. METHODS: An inhibitor of ROCK, Y-27632, was dissolved in an ophthalmic solution and topically administered to the eye of a Japanese white rabbit. Intraocular pressure was measured by pneumatonography (n = 12, 24 eyes). Constriction of ciliary muscle was measured by the Magnus method using 12 eyes. RESULTS: Topical application of 0.1 and 0.03% Y-27632 significantly decreased the intraocular pressure, with maximum decreases of 5.3 and 4.3 mm Hg after 90 minutes compared with the control eye. Y-27632 inhibited the carbachol-induced constriction of rabbit ciliary muscle. CONCLUSIONS: The ROCK inhibitor reduced intraocular pressure in rabbits by topical instillation. The inhibitor relaxed the excised ciliary muscle which was previously constricted by carbachol suggesting that the inhibitor acts to increase the uveoscleral outflow. Our results suggest that the ROCK inhibitor is a promising treatment for glaucoma therapy in the next generation.

Administration, Topical↗

The amino acid residues affecting the activity and azole susceptibility of rat CYP51 (sterol 14-demethylase P450).

The amino acid residues affecting the function of rat sterol 14-demethylase P450 (CYP51) were examined by means of point mutation. Forty-five mutants with respect to 27 amino acid sites were constructed and expressed in Escherichia coli. Substitution of highly conserved Y131, E369, R372, or R382 decreased the expression of CYP51 protein, indicating some structural importance of these residues. Substitution of H314, T315, or S316 caused considerable effects on the catalytic activity, and T315 was identified as the "conserved threonine" of CYP51. H314 was important for maintenance of the activity of CYP51 and was a characteristic residue of this P450, because the position corresponding to this residue is occupied by an acidic amino acid in most other P450 species. A144 was identified as a residue affecting the interaction of CYP51 with ketoconazole. Substitution of A144 with I, which occupies the corresponding position in fungal CYP51, enhanced the ketoconazole susceptibility of rat CYP51 with little change in the catalytic activity, indicating an important role of this residue in determination of the ketoconazole susceptibility of CYP51. Alteration of the catalytic activity was caused by the substitution at some other sites, whereas substitution of a few highly conserved amino acids caused little alteration of the activity of CYP51.

Amino Acid Substitution↗

Gonadotropin-dependent expression of sterol 14-demethylase P450 (CYP51) in rat ovaries and its contribution to the production of a meiosis-activating steroid.

Immunohistochemical analysis showed that sterol 14-demethylase P450 (CYP51) is expressed in mature follicles and corpus lutea of rat ovaries. In follicles, CYP51 is expressed in granulosa and theca cells but not in oocytes. The ovarian CYP51 activity of hypophysectomized rats is very low and induced by pregnant mares' serum gonadotropin (PMSG) treatment together with ovarian growth. The expression of CYP51 first increases in growing follicles and then appears in the corpus lutea after luteinization. The former event may be due to the follicular-stimulating hormone action of PMSG, and the latter may be caused by the luteinizing hormone effect of PMSG. Sterol analysis indicated that the product of the CYP51-mediated lanosterol 14-demethylation, 4,4-dimethylcholesta-8,14,24-trienol, which has been identified as a meiosis-activating steroid (MAS) in mammals [Byskov et al. (1995) Nature 374, 559-562], accumulates (about 10 pmol/mg of ovary) in mature rat ovaries, and the content is enough to activate the resumption of meiosis. These lines of evidence suggest that the expression of ovarian CYP51 is dependent on gonadotropins, and ovarian CYP51 activity is enough for accumulating MAS. Serum insulin does not affect the ovarian CYP51 level, although it is essential for hepatic CYP51 expression. These findings indicate that expression of CYP51 is regulated differently among organs.

Animals↗

Inhibition of progression of heart failure and expression of TGF-beta 1 mRNA in rats with heart failure by the ACE inhibitor quinapril.

The cardioprotective effects of quinapril, an angiotensin-converting enzyme inhibitor, were studied in a rat model of heart failure. Twenty-six rats were divided into two groups: one given 20 mg/kg/day quinapril (n = 11), and controls given 0.5% methylcellulose (n = 15). After oral administration for 1 month, quinapril reduced heart weight (from 1.28+/-0.05 to 0.87+/-0.02 g; p < 0.05) without changing body weight. Quinapril lowered left ventricular end-diastolic pressure (from 14.1+/-2.0 to 6.6+/-1.5 mmHg; p < 0.05) and central venous pressure (from 2.7+/-0.9 to 0.7+/-0.4 mmHg), and increased +/- dP/dt (from +2409+/-50 to +3569+/-169 mmHg/s, and from -2318+/-235 to -3960+/-203 mmHg/s; both p < 0.01). The area of myocardial fibrosis was markedly reduced by quinapril (6+/-3%) as compared with controls (29+/-6%; p < 0.01). Expression of transforming growth factor (TGF)-beta1 mRNA was markedly increased in controls as compared with age-matched normal rats. The increase in level of TGF-beta1 mRNA was significantly suppressed by quinapril (from 17.1+/-6.2 to 9.00+/-2.40; p < 0.05). These observations indicated that quinapril has cardioprotective effects on heart failure, and that the beneficial effects may be partly explained by attenuation of fibrotic response through suppression of TGF-beta1 mRNA expression.

Administration, Oral↗

A comparison of complete genome sequences of the attenuated RC-HL strain of rabies virus used for production of animal vaccine in Japan, and the parental Nishigahara strain.

In order to establish the molecular basis of the pathogenicity of the attenuated RC-HL strain of rabies virus used for the production of animal vaccine in Japan, the complete genome sequence of this strain was determined and compared with that of the parental Nishigahara strain which is virulent for adult mice. The viral genome of both strains was composed of 11,926 nucleotides. The nucleotide sequences of the two genomes showed a high homology of 98.9%. The homology of the G gene was lower than those of N, P, M and L genes at both nucleotide and deduced amino acid levels, and the percentage of radical amino acid substitutions on the G protein was the highest among the five proteins. These findings raise the possibility that the structure of the G protein is the most variable among the five proteins of the two strains. Furthermore, we found two clusters of amino acid substitutions on the G and L proteins. The relevance of these clusters to the difference in the pathogenicity between the two strains is discussed.

Amino Acid Sequence↗

Association of ANA, a member of the antiproliferative Tob family proteins, with a Caf1 component of the CCR4 transcriptional regulatory complex.

A 35-kDa protein, ANA, belongs to an emerging family of antiproliferative proteins consisting of Tob, Tob2, ANA / BTG3, PC3B, PC3 / TIS21 / BTG2, and BTG1. All of these, except ANA and PC3B, have been shown to interact with the CCR4 transcription factor-associated protein Caf1. Here we show that ANA also associates with Caf1, ANA being the preferred partner of Caf1 among the Tob family proteins. Although ANA is likely to interact with Caf1 at its amino-terminal half, which is conserved among the family members, our data suggest that the carboxyl-terminal half of ANA plays a role in the interaction. Finally, in situ hybridization experiments revealed that expression of Caf1 overlaps at least in part with that of ANA. Thus, ANA could function through its interaction with Caf1.

Animals↗

[Tsutsugamushi disease (scrub typhus) in Japan: epidemiological aspects].

Epidemiological aspects of tsutsugamushi disease (scrub typhus) in Japan in 1998 were analyzed using questionnaires. Four hundred and sixteen scrub typhus cases were reported in 24 prefectures in 1998. The annual number of the patients in 1998 was similar to those in the preceding three years. There was no sex difference. The patients at the age of 51 or greater accounted for 72% of the total cases. Patients engaged in farming and forestry accounted for 32% and 14% cases, respectively. Fifty-six, 21 and 19% were reported in Kyusyu, Kanto and Tohoku-Hokuriku districts, respectively, 96% of the total cases being reported in these 3 districts. Most cases were reported from April through June with some from October through December in Tohoku-Hokuriku districts, while most cases were reported from October through December in other districts, including Kyusyu and Kanto districts. Thus, there was a difference in epidemic seasons among the districts. Serotypes of scrub typhus rickettsia were analyzed by serum antibody titers in the Kyusyu district. The novel Kawasaki and Kuroki types were major strains; however, no geographical difference was seen within the Kyusyu district. Interestingly, 24 cases were diagnosed only by the new serotypes not by the classical serotypes (Kato, Karp and Gilliam) in serological tests. This result suggests that further investigations are required to determine the prevalent serotypes in each district and to improve the serological tests. This was the first comprehensive report of epidemiology of scrub typus in entire Japan. Information obtained in the present study provides deep insight into prediction, diagnosis, treatment and prevention of scrub typhus in Japan.

Adolescent↗

[Tsutsugamushi disease (scrub typhus) in Japan: clinical features].

Clinical features of tsutsugamushi disease (scrub typhus) were analyzed, based on 416 cases reported in Japan in 1998. Three major clinical symptoms: eschar, fever and rash were found in 87%, 98% and 92% of the cases, respectively. Elevated levels of CRP, GOT, GPT and LDH were observed in 96%, 85%, 78% and 91%, respectively. These clinical and laboratory findings were observed in the majority of the cases and considered important for diagnosis. Disseminated intravascular coagulation developed in 21 cases, indicating that scrub typhus can be life threatening. Lymphadenopathy was observed in 51% of the cases. Enlarged lymph nodes were limited to the local sites in 75% of these lymphadenopathy cases and most of these sites were adjacent to eschars. Most eschars were scabbed and located in the abdomen and the lower half of the body, especially the feet. This suggests that these parts are frequently exposed to tsutsugamushi mites. Furthermore, the skin is soft in these parts and covered by cloth. These factors may make it possible for mites to keep biting without being noticed for several hours, long enough for rickettsial transmission. Interestingly, eschar and rash were absent in 14% and 8% of the cases, respectively. This result suggests that the cases without the unique symptoms may have been misdiagnosed as common cold or other febrile illnesses. One hundred and fifty-four suspected cases were not scrub typhus cases by the serological tests. The three major clinical symptoms were present in approximately a half of these negative cases, eschar being observed in approximately 70%. This may suggest the presence of new type of scrub typhus can not be diagnosed by the present laboratory tests. Clinical features of scrub typhus in Japan were well revealed, and information obtained in the present study is useful for improving clinical diagnosis. It should, however, be stressed that there were cases that could not be correctly diagnosed only by the clinical symptoms, suggesting that it is important to improve the serological tests.

Diagnosis, Differential↗

Identification of Actinobacillus actinomycetemcomitans serotypes by multiplex PCR.

Oligonucleotide primers specific for gene clusters involved in the biosynthesis of serotype-specific polysaccharide antigens were designed to identify Actinobacillus actinomycetemcomitans serotypes a to e using the multiplex PCR. This method may be useful for serotype-specific genotyping rapidly and directly from clinical samples containing various organisms.

Actinobacillus Infections↗

Enhanced expression of plasminogen activator inhibitor 1 in patients with nephrotic syndrome.

Hypercoagulability is present in patients with nephrotic syndrome. However, alterations in coagulation and fibrinolysis reflected in the glomeruli and urine are not fully understood. We examined plasma and urine concentrations of tissue-type plasminogen activator (tPA) and type 1 plasminogen activator inhibitor (PAI-1) in 33 patients with nephrotic syndrome (nephrotic group). We compared these concentrations with the concentrations in 30 nonnephrotic patients with chronic glomerulonephritis (nonnephrotic group) and with the concentrations in 30 healthy volunteers (control group). We also examined fibrin/fibrinogen degradation products in serum and urine and plasma D-dimers. The expression of tPA and PAI-1 was examined in isolated glomeruli using RT-PCR methods. Deposition of fibrinogen/fibrin-related antigen was observed by direct immunofluorescence. The incidence of fibrinogen/fibrin-related antigen deposition in the nephrotic group was significantly higher than that in the nonnephrotic group. The concentrations of fibrin/fibrinogen degradation products in serum and urine and of plasma D-dimers were significantly elevated in the nephrotic group as compared with the nonnephrotic and control groups. The plasma concentrations of tPA in the nephrotic group were significantly higher than those in the control group. The urinary excretion of tPA in the nephrotic group was also significantly higher than in the nonnephrotic and control groups. The urinary excretion of PAI-1 in the nephrotic group was higher than that in the control group. The ratio of PAI-1 mRNA to tPA mRNA in glomeruli was increased in the nephrotic group as compared with the nonnephrotic group. These results indicate that the fibrinolytic activity is increased in patients with nephrotic syndrome despite urinary losses of tPA. However, a relatively enhanced expression of PAI-1 may be involved in the intraglomerular fibrinogen/fibrin-related antigen deposition seen in nephrotic syndrome.

Adolescent↗

Significance of ACE genotypes and medical treatments in childhood focal glomerulosclerosis.

BACKGROUND: There is little information on the significance of angiotensin-converting enzyme (ACE) genotypes and medical treatments in children with primary focal segmental glomerulosclerosis (FSGS). METHODS: A multicenter retrospective study was performed on the role of ACE genotypes and medical treatments in 43 Japanese children with FSGS (20 males and 23 females), including 17 children who progressed to end-stage renal failure during the mean observation period of 6.9 +/- (SD) 5.0 years. RESULTS: The incidence of the D allele of the ACE gene was higher in the whole group of 43 children with FSGS and in a subgroup of 28 steroid-resistant FSGS children (p < 0.05) than in the 130 children of the healthy control group (0.48, 0.48, and 0.33, respectively). ACE genotypes did not affect renal survival in the whole FSGS group nor in the steroid-resistant subgroup. Among the 28 steroid-resistant children, treatment with ciclosporin was effective in delaying the development of end-stage renal failure (p = 0.044), independently of other treatment regimens. CONCLUSION: The present study of Japanese children with FSGS showed that the D allele of the ACE gene is associated with the development of FSGS, but not associated with the progression of FSGS which was greatly ameliorated with ciclosporin, irrespective of ACE genotypes.

Angiotensin-Converting Enzyme Inhibitors↗

Thyroarytenoid muscle: functional subunits based on morphology and muscle fiber typing in cats.

Using parvalbumin immunohistochemistry to determine the distribution of muscle fiber types in the feline thyroarytenoid muscle (TA), we clearly distinguished the vocalis (with predominance of "slow" type 1 fibers) from the external TA (in which "fast" type 2 fibers predominated, especially in its rostral part). Reconstruction of serial frontal sections of the TA allowed the stereoscopic study of each division. The existence of a rudimentary laryngeal ventricle separating the true and false vocal folds in cats was demonstrated anatomically and histologically, and its relationships to each division of the TA were established. Our results suggest that the vocalis, fitted for enduring activities, is suited for voice control. The fast, rostral part of the external TA seems suited to laryngeal sphincteric demands, while its caudal counterpart may act in both functions. The anatomic individualization of the divisions of the TA may suggest that they play distinct physiological roles and may imply that they should not be considered a single functional unit.

Animals↗

Adhesion to and decalcification of hydroxyapatite by carboxylic acids.

Fundamental to the processes of decalcification of or adhesion to mineralized tissues is the molecular interaction of acids with hydroxyapatite. This study was undertaken to chemically analyze the interaction of 1 mono-, 2 di-, 1 tri-, and 2 polycarboxylic acids with hydroxyapatite in an attempt to elucidate the underlying mechanism. Maleic, citric, and lactic acid decalcified hydroxyapatite, in contrast to oxalic acid and the two polycarboxylic acids that were chemically bonded to hydroxyapatite. Solubility tests showed that the calcium salts of the former were very soluble, whereas those of the latter could hardly be dissolved in the respective acid solutions. Based on these data, an adhesion/decalcification concept was advanced that predicts that carboxylic acids, regardless of concentration/pH, either adhere to or decalcify hydroxyapatite, depending on the dissolution rate of the respective calcium salts in the acid solution. This contrasting behavior of organic acids most likely results from their differential structural conformations.

Acrylic Resins↗