144 research outputs found

    Identification of vasopressin and determination of its corticomedullary levels in rat kidney tissue

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    Identification of vasopressin and determination of its corticomedullary levels in rat kidney tissue. To investigate the kidney tissue level of arginine vasopressin (AVP), tissue AVP was extracted, identified and assayed. Rat kidney tissue was separated into the papilla (P), medulla (M), and cortex (C). After homogenization, AVP was extracted with acetone and determined by radioimmunoassay. Fractionation of the tissue extract by Sephadex G25 column chromatography showed that the peak of immunoreactive AVP was identical to that of synthetic AVP. There was good correlation between bioassayable and immunoassayable AVP for the tissue extracts. Tissue AVP concentrations (pg/g wet weight) after 36hr of dehydration were: P, 164.3 ± 13.0; M, 93.8 ± 8.4; and C. 28.9 ± 3.9 with a plasma AVP (pg/ml) of 11.7 ± 1.0 (mean ± SE, N = 18). Thus, the papilla/plasma AVP concentration ratio was high. When l25I-AVP was administered, the papilla/plasma ratio was very low. Under water diuresis, the tissue AVP level was very low. The kidney tissue level of dDAVP, which was administered exogenously, was much higher than that of AVP when compared at similar plasma levels. Thus, the present study demonstrated the existence of a corticomedullary concentration gradient of AVP with a medullary level much higher than the plasma level. The accumulation of AVP seemed to result from receptor-mediated processes, since, 125I-AVP, which is biologically inactive and does not bind to hormone receptors, showed only a slight accumulation. The higher tissue level of dDAVP suggested that the tissue level was determined by the balance between accumulation and inactivation. since dDAVP is known to be scarcely inactivated in the kidney.Identification de la vasopressine et dĂ©termination de ses niveaux cortico-mĂ©dullaires dans le tissu rĂ©nal de rat. Explorer le niveau tissulaire rĂ©nal d'arginine vasopressine (AVP), l'AVP tissulaire a Ă©tĂ© extraite, identifiĂ©e et dosĂ©e. Le tissu rĂ©nal a Ă©tĂ© sĂ©parĂ© en papille (P), medulla (M), et cortex (C). AprĂšs homogĂ©nĂ©isation, l*AVP a Ă©tĂ© extraite avec de l'acĂ©tone et dĂ©terminĂ©e par dosage radioimmunologique. Le fractionnement de l'extrait tissulaire sur colonne de chromatographic de SĂ©phadex G25a montrĂ© que le pic d'AVP immunorĂ©active Ă©tait identique Ă  celui de l'AVP synthĂ©tique. Il y avait une bonne corrĂ©lation entre l'AVP dosable biologiquement et immunologiquement dans ces extraits tissulaires. Les concentrations tissulaires d'AVP (pg/g de poids humide) aprĂšs 36 heures de dĂ©shydratation Ă©taient: P, 164,3 ± 13.0; M, 93,8 ± 8.4; et C, 28,9 ± 3.9 avec une AVP plasmatique (pg/ml) de 11,7 ± 1,0 (moyenne ± se, N = 18). Ainsi, le rapport de concentration d'AVP papille/plasma Ă©tait Ă©levĂ©. Quand de l'125I-AVP Ă©tait administrĂ©e, le rapport papille/plasma Ă©tait trĂšs bas. Lors d'une diurĂšse aqueuse, le niveau d'AVP tissulaire Ă©tait trĂšs bas. Le niveau tissulaire rĂ©nal de dDAVP, qui avait Ă©tĂ© administrĂ© de façon exogĂšne, Ă©tait bien plus Ă©levĂ© que celui de l'AVP par rapport a un niveau plasmatique identique. Ainsi, cette Ă©tude a dĂ©montrĂ© l'existence d'un gradient de concentration cortico-mĂ©dullaire d'AVP avec un niveau mĂ©dullaire bien plus Ă©levĂ© que le niveau plasmatique. L'accumulation d'AVP a semblĂ© rĂ©sulter de processus ayant un rĂ©cepteur pour mĂ©diateur puisque 125I-AVP, qui est biologiquement inactive et ne se lie pas aux rĂ©cepteurs hormonaux, n'a prĂ©sentĂ© qu'une discrĂšte accumulation. Le niveau tissulaire plus Ă©levĂ© de dDAVP suggĂ©rait que le niveau tissulaire Ă©tait dĂ©terminĂ© par un Ă©quilibre entre l'accumulation et Linactivation la dDAVP Ă©tant connue pour ĂȘtre faiblement inactivĂ©e par le rein

    Evolution of pore structure in microporous silica membranes:sol-gel procedures and strategies

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    Silica membranes exhibiting excellent molecular sieving capability, which would find applications in fuel‐cell electric vehicles with on‐board hydrogen generation, for example, are the aim of the sol‐gel strategies outlined here. It is shown that optimization of the sol‐gel synthesis parameters is important in order to achieve membranes with minimum defects and hence high selectivity. The preparation of the supported membranes is described and the gas permeation behavior of membranes made from different sol compositions reported

    Rapid diagnosis of lyme disease: Flagellin gene-based nested polymerase chain reaction for identification of causative Borrelia species

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    AbstractObjective: Each of Borrelia burgdorferi sensu stricto, Borrelia garinii, and Borrelia afzelii has characteristic restriction sites in its flagellin gene. The authors focused on this gene and developed a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis for rapid diagnosis of Lyme disease.Methods: External and internal primer sets were designed for nested PCR to amplify an approximately 580 by fragment of the flagellin gene that includes species-specific restriction sites. DNA extracted from tissue samples of mice and humans were used as templates for PCR. The amplicons obtained were digested with HapII, HhaI, CelII HincII, or Ddel endonuclease.Results: In mice experimentally infected with each of B. burgdorferi sensu stricto, B. garinii, and B. afzelii, borrelial DNA was detected irrespective of differences in the causative species. However, RFLP of the amplicons was able to identify the species. Skin biopsy samples from 11 Japanese patients with erythema migrans were subjected to both PCR and culture tests. Borrelial infections were detected in seven cases (64%) by PCR and eight cases (73%) by culture. All PCR-positive samples were also positive by culture. The causative species in human infections was easily identified as B. garinii by RFLP analysis of the amplicons.Conclusion: The nested PCR-RFLP system appears to be an easy and reliable diagnostic tool for the detection and species identification of borreliae in human cutaneous biopsies

    Clinical Study in 11 Cases of Endobronchial Foreign Body

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    We report 11 cases of endobronchial foreign body. From January 1982 through December 1994, a total of 11 cases were diagnosed roentogenographically and bronchoscopically at our hospital. These patients consisted of 10 men and 1 woman with a mean age of 58.5 years (range 33 to 77 years). Symptoms on presenting were usually cough, sputum, or chest pain. The foreign bodies were inorganic in 10 cases and of organic origin in 1 case. Three patients were not aware that they had aspirated a foreign body. In 9 patients, the endobronchial foreign bodies were successfully removed endoscopically. One patient spontaneously expectorated the foreign body before bronchoscopy. One patient underwent thoracotomy because the foreign body could not be removed bronchoscopically. There were no severe complications during or after the endoscopic removal of the foreign bodies, but in one patient extraction of the foreign body caused pneumonia after bronchoscopy. In conclusion, flexible bronchoscopy is useful for the diagnosis and treatment of endobronchial foreign bodies

    Clinical impact of aortic valve replacement in patients with moderate mixed aortic valve disease

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    BackgroundInformation is scarce regarding the clinical implications of aortic valve replacement (AVR) for patients suffering from moderate mixed aortic valve disease (MAVD), characterized by a combination of moderate aortic stenosis (AS) and regurgitation (AR). The objective of this retrospective study was to explore the clinical effects of AVR in individuals with moderate MAVD.MethodsWe examined the clinical data from patients with moderate MAVD and preserved left ventricular ejection fraction, who had undergone echocardiography in the period spanning from 2010 to 2018. Moderate AS was defined as aortic valve area index of 0.60–0.85 cm2/m2 and peak velocity of 3.0–4.0 m/s. Moderate AR was defined as a vena contracta width of 3.0–6.0 mm. The primary endpoint was a composite of all-cause death and heart failure hospitalization.ResultsAmong 88 patients (mean age, 74.4 ± 6.8 years; 48.9%, men), 44 (50.0%) required AVR during a median follow-up period of 3.3 years (interquartile range, 0.5–4.9). Mean values of specific aortic valve variables are as follows: aortic valve area index, 0.64 ± 0.04 cm2/m2; peak velocity, 3.40 ± 0.30 m/s; and vena contracta width, 4.1 ± 0.7 mm. The primary endpoint occurred in 32 (36.4%) patients during a median follow-up duration of 5.3 years (interquartile range, 3.2–8.0). Multivariable analysis revealed that AVR was significantly associated with the endpoint (hazard ratio, 0.248; 95% confidence interval, 0.107–0.579; p = 0.001) after adjusting for age, B-type natriuretic peptide, and the Charlson comorbidity index. Patients who underwent AVR during follow-up had significantly lower incidence rates of the endpoint than those managed with medical treatment (10.2% vs. 44.1% at 5 years; p < 0.001).ConclusionsApproximately half of the patients diagnosed with moderate MAVD eventually necessitated AVR throughout the period of observation, leading to positive clinical results. Vigilant tracking of these patients and watchful monitoring for signs requiring AVR during this time frame are essential

    R26-WntVis reporter mice showing graded response to Wnt signal levels

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    The canonical Wnt signaling pathway plays a major role in the regulation of embryogenesis and organogenesis, where signal strength-dependent cellular responses are of particular importance. To assess Wnt signal levels in individual cells, and to circumvent the integration site-dependent bias shown in previous Wnt reporter lines, we constructed a new Wnt signal reporter mouse line R26-WntVis. Heptameric TCF/LEF1 binding sequences were combined with a viral minimal promoter to confer a graded response to the reporter depending on Wnt signal strengths. The histone H2B-EGFP fusion protein was chosen as the fluorescent reporter to facilitate single-cell resolution analyses. This WntVis reporter gene was then inserted into the ROSA26 locus in an orientation opposite to that of the endogenous gene. The R26-WntVis allele was introduced into Wnt3a−/− and Wnt3avt/− mutant mouse embryos and compared with wild-type embryos to assess its performance. The R26-WntVis reporter was activated in known Wnt-dependent tissues and responded in a graded fashion to signal intensity. This analysis also indicated that the major Wnt activity early in embryogenesis switched from Wnt3 to Wnt3a around E7.5. The R26-WntVis mouse line will be widely useful for the study of Wnt signal-dependent processes

    Roles of DRB1*1501 and DRB1*1502 in the pathogenesis of aplastic anemia

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    金æČąć€§ć­ŠćŒ»ć­Šéƒšé™„ć±žç—…é™ąć†…ç§‘Objective: Although a number of reports have documented a significantly increased incidence of HLA-DR15 in aplastic anemia (AA), the exact role of HLA-DR15 in the immune mechanisms of AA remains unclear. We herein clarify the difference between DRB1*1501 and DRB1*1502, the two DRB1 alleles that determine the presentation of HLA-DR15, in the pathophysiology of AA. Materials and Methods: We investigated the relationships of the patients* HLA-DRB1 allele with both the presence of a small population of CD55-CD59- (PNH-type) blood cells and the response to antithymocyte globulin (ATG) plus cyclosporin (CsA) therapy in 140 Japanese AA patients. Results: Of the 30 different DRB1 alleles, only DRB1*1501 (33.6% vs 12.8%, pc < 0.01) and DRB1*1502 (43.6% vs 24.4%, pc < 0.01) displayed significantly higher frequencies among the AA patients than among a control. AA patients possessing HLA-DR15 tended to be old, and especially, the frequency of DRB1*1502 in patients 40 years of age and older (52.4%) was markedly higher than that in those younger than 40 years old (16.2%, pc < 0.01). Only DRB1*1501 was significantly associated with the presence of a small population of PNH-type cells and it also showed a good response to ATG plus CsA therapy in a univariate analysis. A multivariate analysis showed only the presence of a small population of PNH-type cells to be a significant factor associated with a good response to the immunosuppressive therapy (p < 0.01). Conclusions: Although both DRB1*1501 and DRB1*1502 contribute to the development of AA, the methods of contribution differ between the two alleles. © 2007 International Society for Experimental Hematology
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