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1.
Clin Radiol ; 75(3): 238.e11-238.e19, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31679815

RESUMO

AIM: To propose a pharmacokinetic non-linear analysis method to determine contrast medium (CM) dose for computed tomography (CT) hepatic enhancement to improve body size dependency and validate the proposed CM dose determination method through a clinical study. MATERIALS AND METHODS: Enhancement data of 105 patients who underwent hepatic dynamic CT with a fixed CM dose were analysed. From the analysis results, CM doses as a function of each of four body size indices (body weight [BW], lean body weight [LBW], blood volume [BV], and body surface area [BSA]) for achieving improved body size dependency were determined (proposed method), and the body size dependencies were simulated using the enhancement data from 105 patients. The proposed method was validated with a two-arm clinical study on BW. Body size dependency was evaluated using p-value of correlation coefficient between Body size indices and enhancements (p<0.05: significant dependency) and mean absolute error (MAE). RESULTS: The simulation showed that significant body size dependencies not considered by the conventional method can be improved by the proposed method. MAEs of BW, LBW, and BV were also significantly reduced (p<0.05). The clinical study with BW demonstrated a similar improvement to that in the simulation result. MAE was also significantly reduced (p<0.001). CONCLUSION: The proposed method demonstrated more improved BW, LBW, and BV dependence compared to the conventional method. Through the two-arm clinical study, the proposed method using BW only, without height information, is a suitable index for improving body size dependency.


Assuntos
Tamanho Corporal , Meios de Contraste/administração & dosagem , Meios de Contraste/farmacocinética , Iopamidol/administração & dosagem , Iopamidol/farmacocinética , Fígado/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
2.
Neth Heart J ; 28(Suppl 1): 78-87, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32780336

RESUMO

Dutch researchers were among the first to perform clinical studies in bare metal coronary stents, the use of which was initially limited by a high incidence of in-stent restenosis. This problem was greatly solved by the introduction of drug-eluting stents (DES). Nevertheless, enthusiasm about first-generation DES was subdued by discussions about a higher risk of very-late stent thrombosis and mortality, which stimulated the development, refinement, and rapid adoption of new DES with more biocompatible durable polymer coatings, biodegradable polymer coatings, or no coating at all. In terms of clinical DES research, the 2010s were characterised by numerous large-scale randomised trials in all-comers and patients with minimal exclusion criteria. Bioresorbable scaffolds (BRS) were developed and investigated. The Igaki-Tamai scaffold without drug elution was clinically tested in the Netherlands in 1999, followed by an everolimus-eluting BRS (Absorb) which showed favourable imaging and clinical results. Afterwards, multiple clinical trials comparing Absorb and its metallic counterpart were performed, revealing an increased rate of scaffold thrombosis during follow-up. Based on these studies, the commercialisation of the device was subsequently halted. Novel technologies are being developed to overcome shortcomings of first-generation BRS. In this narrative review, we look back on numerous devices and on the DES and BRS trials reported by Dutch researchers.

6.
Clin Genet ; 87(4): 356-61, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24697219

RESUMO

Eukaryotic elongation factor 1, alpha-2 (eEF1A2) protein is involved in protein synthesis, suppression of apoptosis, and regulation of actin function and cytoskeletal structure. EEF1A2 gene is highly expressed in the central nervous system and Eef1a2 knockout mice show the neuronal degeneration. Until now, only one missense mutation (c.208G > A, p.Gly70Ser) in EEF1A2 has been reported in two independent patients with neurological disease. In this report, we described two patients with de novo mutations (c.754G > C, p.Asp252His and c.364G > A, p.Glu122Lys) in EEF1A2 found by whole-exome sequencing. Common clinical features are shared by all four individuals: severe intellectual disability, autistic behavior, absent speech, neonatal hypotonia, epilepsy and progressive microcephaly. Furthermore, the two patients share the similar characteristic facial features including a depressed nasal bridge, tented upper lip, everted lower lip and downturned corners of the mouth. These data strongly indicate that a new recognizable disorder is caused by EEF1A2 mutations.


Assuntos
Transtorno Autístico/genética , Epilepsia/genética , Face/anormalidades , Deficiência Intelectual/genética , Fator 1 de Elongação de Peptídeos/genética , Sequência de Bases , Variações do Número de Cópias de DNA , Feminino , Humanos , Dados de Sequência Molecular , Mutação de Sentido Incorreto/genética , Linhagem , Análise de Sequência de DNA , Síndrome
7.
Opt Express ; 22(2): 2051-9, 2014 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-24515214

RESUMO

We demonstrate a robust 3-dB directional coupler which has a narrow silicon wire core and a wide gap. Sensitivity to the gap variation is decreased to one tenth that of a conventional directional coupler. Better spectral stability due to the enhanced robustness to waveguide geometrical fluctuations was experimentally verified.

9.
Opt Express ; 21(6): 6889-94, 2013 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-23546071

RESUMO

n-channel body-tied partially depleted metal-oxide-semiconductor field-effect transistors (MOSFETs) were fabricated for large current applications on a silicon-on-insulator wafer with photonics-oriented specifications. The MOSFET can drive an electrical current as large as 20 mA. We monolithically integrated this MOSFET with a 2 × 2 Mach-Zehnder interferometer optical switch having thermo-optic phase shifters. The static and dynamic performances of the integrated device are experimentally evaluated.


Assuntos
Interferometria/instrumentação , Refratometria/instrumentação , Processamento de Sinais Assistido por Computador/instrumentação , Silício/química , Transistores Eletrônicos , Condutividade Elétrica , Desenho de Equipamento , Análise de Falha de Equipamento , Temperatura Alta , Fótons , Integração de Sistemas
10.
Endoscopy ; 45(1): 67-70, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23208779

RESUMO

The aims of this study were to compare the detection rates of gastrointestinal follicular lymphoma lesions by video capsule endoscopy (VCE) and double-balloon endoscopy (DBE), and to determine the pathologic diagnostic yields of DBE-directed biopsies. A total of 27 consecutive patients were enrolled. No significant difference in detection rates was observed in 12 patients who underwent total enteroscopy at both VCE and DBE. Pathologic diagnostic yields stratified by location were 91 % in the proximal duodenum at esophagogastroduodenoscopy, 88 % in the jejunum at antegrade DBE, 52 % in the ileum at retrograde DBE, and 57 % in the terminal ileum at colonoscopy. VCE and DBE were helpful in determining treatment in 44 % of patients.


Assuntos
Endoscopia por Cápsula , Endoscopia Gastrointestinal/métodos , Neoplasias Gastrointestinais/diagnóstico , Linfoma Folicular/diagnóstico , Idoso , Idoso de 80 Anos ou mais , Distribuição de Qui-Quadrado , Feminino , Neoplasias Gastrointestinais/patologia , Neoplasias Gastrointestinais/terapia , Humanos , Imuno-Histoquímica , Linfoma Folicular/patologia , Linfoma Folicular/terapia , Masculino , Pessoa de Meia-Idade , Estatísticas não Paramétricas
11.
Opt Express ; 20(24): 27083-93, 2012 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-23187564

RESUMO

In this work, we report the experimental observation of supercontinua generation in two kinds of suspended-core microstructured soft-glass optical fibers. Low loss, highly nonlinear, tellurite and As2S3 chalcogenide fibers have been fabricated and pumped close to their zero-dispersion wavelength in the femtosecond regime by means of an optical parametric oscillator pumped by a Ti:Sapphire laser. When coupled into the fibers, the femtosecond pulses result in 2000-nm bandwidth supercontinua reaching the Mid-Infrared region and extending from 750 nm to 2.8 µm in tellurite fibers and 1 µm to 3.2 µm in chalcogenide fibers, respectively.


Assuntos
Lasers , Luz , Fibras Ópticas , Sulfetos/química , Telúrio/química , Desenho de Equipamento , Dinâmica não Linear
12.
Eur J Clin Microbiol Infect Dis ; 30(1): 117-20, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20820834

RESUMO

We report the systemic cytokine and chemokine response in children with the 2009 pandemic influenza A (H1N1) virus infection. In patients with pneumonia, the serum levels of IFN-γ and IL-5 were significantly higher than those in patients without pneumonia. This tendency was also present for IL-6, IL-8, IL-10, IL-13, and MCP-1 in patients with pneumonia. Among patients with pneumonia, the levels of MCP-1 were significantly higher in the group of patients with pneumonia with severe respiratory failure than patients with mild pneumonia.


Assuntos
Citocinas/sangue , Vírus da Influenza A Subtipo H1N1/imunologia , Influenza Humana/imunologia , Criança , Pré-Escolar , Feminino , Humanos , Influenza Humana/complicações , Masculino , Pneumonia/imunologia , Pneumonia/patologia
13.
J Clin Pharm Ther ; 36(3): 412-5, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21463348

RESUMO

WHAT IS KNOWN AND OBJECTIVE: Adrenoleukodystrophy (ALD) is an X-linked disorder and characterized by the accumulation of saturated very long-chain fatty acids. Treatment is still unsatisfactory. Our objective is to report on the effect of the free-radical scavenger, edaravone, in a patient with ALD. CASE SUMMARY: The patient was given edaravone intravenously twice. D-ROM in cerebral spinal fluid decreased dramatically, and a shortening of neuronal transmission time as estimated on somatosensory evoked potential was observed. After terminating the treatment, his symptoms progressively reappeared. WHAT IS NEW AND CONCLUSION: This is the first report of the use of edaravone in ALD. The drug is apparently effective in improving symptoms of ALD and should be evaluated more formally.


Assuntos
Adrenoleucodistrofia/tratamento farmacológico , Antipirina/análogos & derivados , Sequestradores de Radicais Livres/uso terapêutico , Adrenoleucodistrofia/líquido cefalorraquidiano , Antipirina/efeitos adversos , Antipirina/uso terapêutico , Criança , Edaravone , Potenciais Somatossensoriais Evocados/efeitos dos fármacos , Sequestradores de Radicais Livres/efeitos adversos , Humanos , Masculino , Neurônios/efeitos dos fármacos , Espécies Reativas de Oxigênio/líquido cefalorraquidiano , Transmissão Sináptica/efeitos dos fármacos , Extremidade Superior/inervação
14.
Water Sci Technol ; 61(1): 119-26, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20057097

RESUMO

Anaerobic ammonium oxidation (anammox) is a novel nitrogen pathway catalyzed by anammox bacteria which are obligate anaerobic chemoautotrophs. In this study, enrichment culture of marine anammox bacteria (MAAOB) from the samples related to seawater was conducted. Simultaneous removal of ammonium and nitrite was confirmed in continuous culture inoculated with sediment of a sea-based waste disposal site within 50 days. However, no simultaneous nitrogen removal was observed in cultures inoculated with seawater-acclimated denitrifying sludge or with muddy sediment of tideland even during 200 days. Nitrogen removal rate of 0.13 kg/m(3)/day was achieved at nitrogen loading rate of 0.16 kg/m(3)/day after 320th days in the culture inoculated with the sediment of waste disposal site. The nitrogen removal ratio between ammonium nitrogen and nitrite nitrogen was 1:1.07. Denaturing gradient gel electrophoresis (DGGE) analysis indicated that an abundance of the bacteria close to MAAOB and coexistence of ammonium oxidizing bacteria and denitrifying bacteria in the culture.


Assuntos
Bactérias Anaeróbias/isolamento & purificação , Água do Mar/microbiologia , Aclimatação , Azoarcus/genética , Azoarcus/isolamento & purificação , Bactérias Anaeróbias/genética , Bactérias Anaeróbias/crescimento & desenvolvimento , Reatores Biológicos , DNA Bacteriano/genética , DNA Bacteriano/isolamento & purificação , Flavobacterium/genética , Flavobacterium/isolamento & purificação , Cinética , Nitritos/análise , Nitrosomonas/genética , Nitrosomonas/isolamento & purificação , Oxirredução , Compostos de Amônio Quaternário/análise , Compostos de Amônio Quaternário/química , RNA Bacteriano/genética , RNA Ribossômico 16S/genética , Rhizobium/genética , Rhizobium/isolamento & purificação
15.
Science ; 270(5241): 1491-4, 1995 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-7491495

RESUMO

The phosphorylation of the human estrogen receptor (ER) serine residue at position 118 is required for full activity of the ER activation function 1 (AF-1). This Ser118 is phosphorylated by mitogen-activated protein kinase (MAPK) in vitro and in cells treated with epidermal growth factor (EGF) and insulin-like growth factor (IGF) in vivo. Overexpression of MAPK kinase (MAPKK) or of the guanine nucleotide binding protein Ras, both of which activate MAPK, enhanced estrogen-induced and antiestrogen (tamoxifen)-induced transcriptional activity of wild-type ER, but not that of a mutant ER with an alanine in place of Ser118. Thus, the activity of the amino-terminal AF-1 of the ER is modulated by the phosphorylation of Ser118 through the Ras-MAPK cascade of the growth factor signaling pathways.


Assuntos
Proteínas Quinases Dependentes de Cálcio-Calmodulina/metabolismo , Receptores de Estrogênio/metabolismo , Serina/metabolismo , Ativação Transcricional , Sequência de Aminoácidos , Animais , Linhagem Celular , Ativação Enzimática , Fator de Crescimento Epidérmico/farmacologia , Estradiol/análogos & derivados , Estradiol/farmacologia , Antagonistas de Estrogênios/farmacologia , Humanos , Quinases de Proteína Quinase Ativadas por Mitógeno , Dados de Sequência Molecular , Mutação , Fosforilação , Alcamidas Poli-Insaturadas , Proteínas Quinases/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Proteínas Proto-Oncogênicas c-raf , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Receptores de Estrogênio/química , Receptores de Estrogênio/genética , Proteínas Recombinantes de Fusão/metabolismo , Somatomedinas/farmacologia , Tamoxifeno/análogos & derivados , Tamoxifeno/farmacologia , Ativação Transcricional/efeitos dos fármacos , Transfecção
16.
J Neonatal Perinatal Med ; 12(3): 295-300, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30883365

RESUMO

BACKGROUND: The efficacy of macrolide treatment on gastrointestinal motility and acquirement of feeding tolerance in extremely low birth weight (ELBW) infants are controversial. This study aimed to evaluate clinical effects of parenterally administered erythromycin (EM) and clarithromycin (CAM) on gastrointestinal motility in ELBW infants. METHODS: ELBW infants treated in Tokyo Medical University Hospital were retrospectively studied. Several outcomes of ELBW infants treated with EM or CAM were compared with those recognized before initiation of the medication, as well as with those of patients with no macrolide treatment. The primary outcomes included average gastric residual volume that was evaluated 3 hours after enteral feeding. Secondary outcomes were the number of patients who developed feeding intolerance, stool frequency, and other adverse events, such as respiratory comorbidities and pyloric stenosis. RESULTS: Among a total of 53 infants, 20 and 13 were treated with EM and CAM, respectively, whereas 20 infants were not administered macrolides. The gastric residual volume was significantly decreased after initiation of medication compared with before medication in the EM group, whereas that of the untreated group showed no change. When the EM and CAM groups were combined, the gastric residual volume was also significantly decreased after treatment compared with before treatment. An increase in stool frequency and pyloric stenosis were not observed in the groups. CONCLUSION: EM might be effective for acquiring feeding tolerance in ELBW infants. A future prospective study with a larger population is required to determine the efficacy of CAM.


Assuntos
Claritromicina/administração & dosagem , Eritromicina/administração & dosagem , Fármacos Gastrointestinais/administração & dosagem , Motilidade Gastrointestinal/efeitos dos fármacos , Recém-Nascido de Peso Extremamente Baixo ao Nascer/fisiologia , Claritromicina/farmacologia , Nutrição Enteral/métodos , Eritromicina/farmacologia , Feminino , Intolerância Alimentar/congênito , Intolerância Alimentar/fisiopatologia , Fármacos Gastrointestinais/farmacologia , Humanos , Recém-Nascido , Recém-Nascido Prematuro , Masculino , Estudos Retrospectivos , Resultado do Tratamento
17.
Bone Joint J ; 101-B(9): 1151-1159, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31474143

RESUMO

AIMS: We analyzed the long-term outcomes of patients observed over ten years after resection en bloc and reconstruction with extracorporeal irradiated autografts. PATIENTS AND METHODS: This retrospective study included 27 patients who underwent resection en bloc and reimplantation of an extracorporeal irradiated autograft. The mean patient age and follow-up period were 31.7 years (9 to 59) and 16.6 years (10.3 to 24.3), respectively. The most common diagnosis was osteosarcoma (n = 10), followed by chondrosarcoma (n = 6). The femur (n = 13) was the most frequently involved site, followed by the tibia (n = 7). There were inlay grafts in five patients, intercalary grafts in 15 patients, and osteoarticular grafts in seven patients. Functional outcome was evaluated with the Musculoskeletal Tumor Society (MSTS) scoring system. RESULTS: There were no recurrences in the irradiated autograft and the autograft survived in 24 patients (88.9%). Major complications included nonunion (n = 9), subchondral bone collapse (n = 4), and deep infection (n = 4). Although 34 revision procedures were performed, 25 (73.5%) and four (11.8%) of these were performed less than five years and ten years after the initial surgery, respectively. The mean MSTS score at the last follow-up was 84.3% (33% to 100%). CONCLUSION: Considering long-term outcomes, extracorporeal irradiated autograft is an effective method of reconstruction for malignant musculoskeletal tumours Cite this article: Bone Joint J 2019;101-B:1151-1159.


Assuntos
Neoplasias Ósseas/radioterapia , Neoplasias Ósseas/cirurgia , Osso e Ossos/cirurgia , Salvamento de Membro/métodos , Reimplante , Transplante Autólogo/métodos , Adolescente , Adulto , Autoenxertos/efeitos da radiação , Osso e Ossos/efeitos da radiação , Criança , Seguimentos , Sobrevivência de Enxerto , Humanos , Pessoa de Meia-Idade , Radioterapia/métodos , Procedimentos de Cirurgia Plástica/métodos , Recuperação de Função Fisiológica , Estudos Retrospectivos , Transplante Autólogo/efeitos adversos , Adulto Jovem
18.
Lipids ; 43(1): 37-43, 2008 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-17985168

RESUMO

Disorders of the metabolism of essential fatty acids (EFAs) are related to atopic dermatitis (AD). Concentrations of dihomo-gamma-linolenic acid (DGLA), an EFA, in the serum of AD patients are lower than those in healthy volunteers. Recently we developed a fermented DGLA oil, and examined whether oral administration of DGLA prevents development of dermatitis in NC/Nga mice, which spontaneously develop human AD-like skin lesions. NC/Nga mice were fed a diet either containing or not containing DGLA for 8 weeks under in air-uncontrolled conventional circumstances. Clinical skin severity scores were significantly lower in mice fed DGLA than in mice not fed it. Scratching behavior and plasma total IgE levels were also reduced in the DGLA group, in association with histological improvement. DGLA suppressed clinical severity of skin lesions dose-dependently, with an increase in DGLA contents in phospholipids of skin, spleen, and plasma. Discontinuation of DGLA administration resulted in the onset of dermatitis and a decrease in DGLA contents in skin, spleen, and plasma. These findings indicate that oral administration of DGLA effectively prevents the development of AD in NC/Nga mice, and that DGLA in phospholipids is a compound of key importance in the development and prevention of dermatitis.


Assuntos
Ácido 8,11,14-Eicosatrienoico/administração & dosagem , Dermatite Atópica/prevenção & controle , Administração Oral , Animais , Dieta , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Feminino , Imunoglobulina E/sangue , Masculino , Camundongos , Camundongos Endogâmicos , Índice de Gravidade de Doença , Pele/efeitos dos fármacos , Pele/patologia , Testes Cutâneos
19.
Transplant Proc ; 40(7): 2285-8, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18790213

RESUMO

BACKGROUND: Currently the long-term outcome among recipients of ABO-incompatible renal transplantations is excellent in Japan. However, previous reports have documented poor outcomes in patients with high (> 1:256) anti-A/B antibody titers pretreatment. The immunosuppressive protocol for ABO-incompatible high-titer renal transplantation has remained a medical challenge. METHODS: We treated 3 patients with high (> 1:512) anti-A/B antibody titers prior to ABO-incompatible renal transplantation. Our immunosuppressive protocol was initiated 1 month prior to surgery and included mycophenolate mofetil (1 g/d) and low-dose steroid (methylprednisolone [8 mg/d]). Two doses of the anti-CD20 antibody rituximab, (150 mg/m2) were administered 2 weeks before and on the day of transplantation. We performed antibody removal with 6 to 8 sessions of plasmapheresis (plasma exchange or double-filtration plasmapheresis) before transplantation. Splenectomy was also performed on the day of transplantation. Postoperative immunosuppression followed the same regimen as ABO-compatible cases, in which calcineurin inhibitors were initiated 3 days before transplantation combined with 2 doses of basiliximab. RESULT: With this protocol, the anti-A/B antibody was reduced to below 1:16 in all cases. All 3 patients underwent successful transplantation with a mean current serum creatinine of 1.32 mg/dL (range, 1.22-1.50 mg/dL). There were no episodes of antibody-mediated rejection. No serious complications or side effects were encountered. CONCLUSIONS: A preconditioning protocol consisting of rituximab infusions, splenectomy, plasmapheresis, and pharmacologic immunosuppression enabled ABO-incompatible renal transplantation in patients with high (> 1:512) anti-A/B antibody titer.


Assuntos
Sistema ABO de Grupos Sanguíneos/imunologia , Incompatibilidade de Grupos Sanguíneos , Transplante de Rim/efeitos adversos , Adulto , Feminino , Humanos , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Imunossupressores/uso terapêutico , Transplante de Rim/imunologia , Masculino , Pessoa de Meia-Idade , Esplenectomia , Resultado do Tratamento
20.
J Clin Invest ; 70(1): 135-40, 1982 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-6282936

RESUMO

Effect of metabolic acidosis on two distinct 25-hydroxyvitamin D(3)-1alpha-hydroxylase (1alpha-hydroxylase) systems was studied in the kidneys of vitamin D-deficient rats; one is localized in the proximal convoluted tubule (PCT), is activated in vitamin D deficiency, and is regulated primarily by parathyroid hormone (PTH) via cyclic AMP; the other is localized in the proximal straight tubule (PST), is latent in vitamin D deficiency, and is selectively stimulated by calcitonin via a cyclic AMP-independent mechanism. The 1alpha-hydroxylase activities were measured in the PCT and PST microdissected from the kidney of vitamin D-deficient rats with or without metabolic acidosis of varying duration. The 1alpha-hydroxylase activity decreased in the PCT from 0.74+/-0.07 fmol/mm per h to 0.24+/-0.02 at day 3 of metabolic acidosis without a further decline at day 7. Neither metabolic acidosis of 16 h duration nor reduction of the incubation medium pH from 7.4 to 7.0 affected the enzyme activity in the PCT. To examine the underlying mechanism for the suppression of 1alpha-hydroxylase activity, PTH, cyclic AMP, or calcitonin was given to rats with metabolic acidosis of 3 d duration. Although PTH failed to augment the suppressed 1alpha-hydroxylase activity in the PCT, cyclic AMP restored it to the level of control rats. The 1alpha-hydroxylase activity in the PST remained undetectable in control rats and in acidotic rats with or without PTH or cyclic AMP treatments. However, calcitonin stimulated the 1alpha-hydroxylase activity in the PST equally from undetectable to 0.75+/-0.09 fmol/mm per h in control and to 0.78+/-0.10 in acidotic rats. The data suggests that metabolic acidosis suppresses 1alpha-hydroxylase only in the PCT by inhibiting PTH-dependent adenylate cyclase, and that cellular events beyond cyclic AMP in the PCT and the events responsive to calcitonin in the PST are unaffected. The results show the definite advantage of using defined single nephron segments to study the hormonal and ionic control of the 1alpha-hydroxylase system in the kidney.


Assuntos
Acidose/metabolismo , Rim/metabolismo , Esteroide Hidroxilases/metabolismo , 25-Hidroxivitamina D3 1-alfa-Hidroxilase , Acidose/induzido quimicamente , Acidose/complicações , Animais , Bicarbonatos/sangue , Calcitonina/farmacologia , Cálcio/sangue , AMP Cíclico/farmacologia , Concentração de Íons de Hidrogênio , Túbulos Renais Proximais/metabolismo , Masculino , Hormônio Paratireóideo/farmacologia , Fosfatos/sangue , Ratos , Deficiência de Vitamina D/complicações , Deficiência de Vitamina D/metabolismo
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