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Objective: To explore the value of metagenomic next-generation sequencing (mNGS) in the etiology diagnosis of bacterial meningitis in children. Methods: The etiological results of 189 children diagnosed with "bacterial meningitis" or "purulent meningitis" or "central nervous system infection" in the Children's Hospital of Fudan University from 1st January 2019 to 31st December 2020 were analyzed retrospectively. The cerebrospinal fluid (CFS) of the children with bacterial meningitis was detected by culture and mNGS respectively, and the difference of pathogen detection rate between the 2 methods was analyzed. According to the age at the time of visit, the children were divided into neonatal group (≤28 days of age) and non-neonatal group (>28 days of age), and χ2 test was used to compare the positive rate between the 2 groups. Taking CFS culture as the gold standard, the sensitivity and specificity of mNGS in the diagnosing of bacterial meningitis in children were analyzed. Results: Among these 189 children with bacterial meningitis, 116 were males and 73 were females. A total of 76 strains of pathogens were detected in blood and (or) CSF cultures, of which 50 strains (65.8%) were Gram-positive bacteria; among those, 18 strains (23.7%) of Streptococcus agalactiae, 17 strains (19.7%) of Escherichia coli and 15 strains (19.7%) of Streptococcus pneumoniae were detected with higher detection rate. The infection rate of Gram-positive bacteria in the non-neonatal group was higher than that in the neonatal group (76.0% (38/50) vs. 50.0% (13/26), χ2=5.24, P=0.020).The same CSF samples of 48 cases were tested by mNGS and culture at the same time, and the detection rate of mNGS was higher than that of CSF culture (20 cases (41.7%) vs. 12 cases (25.0%), χ2=16.45, P<0.001). The consistency of mNGS and culture results was 79.2% (38/48), and the same pathogen was detected in 11 children with both positive mNGS and CSF culture. Taking the results of CSF culture as the gold standard, the sensitivity of mNGS in the diagnosing of bacterial meningitis was 91.7%, and the specificity was 75.0%. Conclusions: The mNGS technology can improve the pathogen detection rate of bacterial meningitis in children, and has a high consistency with CSF culture. In suspected cases where the pathogen cannot be identified by traditional methods, CSF mNGS should be considered timely.
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Meningitis Bacterianas , Niño , Escherichia coli , Femenino , Bacterias Grampositivas , Secuenciación de Nucleótidos de Alto Rendimiento/métodos , Humanos , Masculino , Meningitis Bacterianas/diagnóstico , Meningitis Bacterianas/microbiología , Metagenómica/métodos , Estudios Retrospectivos , Sensibilidad y EspecificidadRESUMEN
Objective: To explore the etiologies and clinical characteristics of fever of unknown origin (FUO) and to provide clues for early diagnosis of FUO. Methods: The data about etiology, age, sex, clinical course, length of hospital stays and the expression levels of inflammatory factors in fever phase of 357 pediatric inpatients who were diagnosed with FUO in Children's Hospital of Fudan University from 1 January 2016 to 31 December 2020 were collected and retrospectively analyzed. Participants were grouped into infectious disease, inflammatory disease, malignancy and others and according to the classification of diseases and also grouped into those aged<1 year, 1-<3 years,3-<6 years, 6-<12 years and 12-<18 years. Comparisons between groups were performed using the Mann-Whitney U test, Kruskal-Wallis H test and χ² test. Results: Among the 357 patients (217 males and 140 females). The age of onset was 3.9 (1.3, 9.2) years and visiting age was 5.1 (2.0, 9.3) years. The time-consuming of diagnosis was 94 (66, 213) days. The hospital stay was 8 (6, 14) days. The most frequently identified cause of FUO was infectious diseases (163 cases, 45.7%), followed by non-infectious inflammatory diseases (133 cases, 37.2%), malignancy (21 cases, 5.9%) and others (40 cases, 11.2%). The patients at younger age were more likely to be attacked by malignancy, oncologic diagnoses, and others, nevertheless patients at older age were more likely to be attacked by non-infectious inflammatory diseases oppositely (9.8 (3.6, 11.5) vs. 3.0 (1.2, 7.0), 2.3 (1.0, 5.2), 0.9 (0.5, 1.8) years, U=41.30, 15.94, 37.08, all P<0.01);106 (65%) patients were male, and 57 (35%) patients were female. This result indicated that boys were more susceptible to infectious diseases (χ²=14.73, P<0.01). Analysis of inflammatory factors in serum among 103 patients, interleukin (IL)-6 level in 40 infectious diseases patients (9 (2, 38) ng/L) was significantly lower than those of 6 tumor patients (89 (64, 599) ng/L) and 57 non-infectious inflammatory diseases patients (25 (8, 78) ng/L, U=51.05, 15.70, both P<0.05), no significant difference was observed in IL-2, IL-4, IL-10, tumor necrosis factor α and interferon among the groups (all P>0.05). The patients grouped into those aged 1-<3 years and 3-<6 years were more likely to be attacked by infectious diseases (51.3% (59/115) and 57.1% (40/70)), while patients grouped into those aged 6-<12 years and 12-<18 years were more likely to be attacked by non-infectious inflammatory diseases (55.6% (65/117) and 72.4% (21/29)). Conclusions: Infectious disease is still the main cause of FUO in children and the boys are more susceptible to infectious diseases. However, the morbidity of non-infectious inflammatory diseases increases to number 1 in FUO of children over 6 years of age.
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Enfermedades Transmisibles , Fiebre de Origen Desconocido , Neoplasias , Anciano , Niño , Enfermedades Transmisibles/complicaciones , Femenino , Fiebre de Origen Desconocido/etiología , Humanos , Tiempo de Internación , Masculino , Neoplasias/complicaciones , Estudios RetrospectivosRESUMEN
Myostatin (MSTN) is primarily expressed in skeletal muscle and plays an important role in the regulation of muscle growth and development as well as fat deposition; however, little is known about the molecular mechanism through which MSTN regulates body fat deposition. Therefore, in this study, we sought to identify the signaling pathways through which MSTN regulates fat accumulation in pigs. MSTN knockout (MSTN-/-) pigs showed increased muscle mass, decreased fat mass, and a leaner body composition. In this study, we found that the adipose tissue of MSTN-/- pigs exhibits the characteristics of beige adipose tissue, and the mRNA expression levels of beige adipose marker genes, including UCP3, Cidea, and CD137, were significantly increased. Remarkably, the observed beige phenotype was not adipocyte autonomous but rather caused by muscle-secreted myokine interleukin (IL)-6. This occurrence results in increased AMP-activated protein kinase (AMPK) phosphorylation in adipose tissue, which subsequently activates peroxisome proliferator-activated receptor gamma coactivator 1α and the conversion of white adipocytes to beige in pigs. Therefore, we concluded that MSTN deficiency leads to increased IL-6 secretion in skeletal muscle and activates AMPK in adipocytes, thereby increasing the beige adipose tissue in MSTN-/- pigs.
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Tejido Adiposo Beige , Miostatina , Tejido Adiposo/metabolismo , Tejido Adiposo Beige/metabolismo , Tejido Adiposo Blanco/metabolismo , Animales , Técnicas de Inactivación de Genes/veterinaria , Interleucina-6/genética , Músculo Esquelético/metabolismo , Miostatina/genética , PorcinosRESUMEN
OBJECTIVE: We aim to compare the effects of stem type prosthesis implantation of the greater trochanter of the femur (GTF) and proximal femur nail anti-rotation (PFNA) for treatment of unstable intertrochanteric femoral fracture. PATIENTS AND METHODS: We retrospectively analyzed 108 patients with unstable intertrochanteric femoral fracture, including 61 cases who underwent GTF treatment and 47 cases who underwent PFNA treatment. We compared the operative time, blood loss, clinical healing and bone healing time, partial weight bearing and full weight bearing time, Harris hip score, rate of complications and rate of adverse reactions of implantation materials. RESULTS: Comparing the two groups in terms of operative time and blood loss, the differences were not statistically significant (p>0.05). The clinical and bone healing time in the GTF group were shorter than those in the PFNA group and the differences were statistically significant (p<0.05). The partial and full-weight bearing times in the GTF group were significantly shorter than those in the PFNA group. The Harris scores, one and six months after surgery, were higher than those in the PFNA group and by comparing the scores after 12 and 18 months, the differences were not statistically significant (p>0.05). The rate of complications and rate of adverse reactions of implantation material in the GTF group were lower than those in the PFNA group and the differences were statistically significant (p<0.05). CONCLUSIONS: GTF implantation is more advantageous in functional improvement and in reducing complications compared with PFNA for the treatment of unstable intertrochanteric femoral fracture.
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Clavos Ortopédicos , Fémur/cirugía , Fijación Intramedular de Fracturas/métodos , Fracturas de Cadera/cirugía , Anciano , Femenino , Curación de Fractura , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , RotaciónRESUMEN
Objective: To analyze the antimicrobial resistance profile in Chinese children. Methods: This was a prevalence survey. From January 1 through December 31, 2016, the isolates were collected from 10 tertiary children hospitals in China. Antimicrobial susceptibility testing was carried out by routine laboratory methods. The penicillin susceptibility of streptococcus pneumonia and Meropenem susceptibility of gram-negative bacteria were detected by E-test and disk diffusion method respectively. Antimicrobial susceptibility results were interpreted according to the criteria of Clinical and Laboratory Standards Institute (CLSI) Guideline 2016. The data of antimicrobial susceptibility testing of isolates from either the different patients (neonatal group and non-neonatal group) or various sources were analyzed by WHONET 5.6 software. Results: A total of 56 241 isolates were collected, of which 41.5% (23 328 isolates) were gram-positive organisms and 58.5% (32 886 isolates) gram-negative organisms. The five leading pathogens were Escherichia coli (7 995/56 214, 14.2%), Straphylococcus aureus (6 468/56 214, 11.5%), Streptococcus pneumonia (6 225/56 214, 11.1%), Haemophilus influenza (5 435/56 214, 9.7%) and Klebsiella pneumonia (4 523/56 214, 8.0%). The Meropenem resistance rates of Klebsiella pneumonia, Enterobacter cloacae, Escherichia coil, Pseudomonas aeruginosa, Acinetobacter baumonia isolates were 27.4% (326/1 189) , 8.1% (29/358) , 2.0% (27/1 362) , 19.5% (34/174) , 49.7% (230/463) in neonatal group and 15.4% (512/3 327) , 4.8% (40/841) , 2.3% (151/6 564) , 13.7% (252/1 840) , and 53.4% (860/1 611) in non-neonatal group. The Methicillin-resistant Staphylococcus aureus (MRSA) rates of neonatal group and non-neonatal group were 46.2% (649/1 404) and 33.3% (1 668/5 010) . The penicillin non-susceptible rates of Streptococcus pneumonia in the two groups were 17.6% (6/34) and 18.2% (1 121/6 158) respectively. The ß-lactamase positive rates of Haemophilus pneumonia isolates in the neonatal group and non-neonatal groups were 33.8% (47/139) and 44.4% (2 345/5 282) respectively. Conclusion: This investigation highlights the worrisome trend of antimicrobial resistance in children, especially among neonatal patients in China.
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Antibacterianos/farmacología , Farmacorresistencia Bacteriana , Staphylococcus aureus Resistente a Meticilina , Niño , China , Bacterias Gramnegativas , Haemophilus influenzae/efectos de los fármacos , Humanos , Klebsiella pneumoniae/efectos de los fármacos , Pruebas de Sensibilidad Microbiana , Pseudomonas aeruginosa/efectos de los fármacos , beta-LactamasasRESUMEN
This study aims to analyse the clinical effects of continuous blood purification (CBP) in children with severe sepsis to form a basis for CBP application in this context. One hundred and twenty children with severe sepsis treated in Binzhou Peoples Hospital, Shandong, China, from June 2013 to June 2014 were divided into two groups, a treatment and a control group, depending on parental preference. The control group was treated conventionally, and the treatment group underwent CBP in addition to conventional therapy. Cardiovascular and respiratory parameters were measured on admission and after 72 h. This study also assayed interleukin (IL)-8 and tumour necrosis factor (TNF)-α levels, and monitored clinical outcomes and prognosis. The cardiovascular and respiratory parameters of the treatment group improved to a significantly greater extent than did those of the control group (all P less than 0.05). After treatment, the levels of IL-8, IL-6, IL-10, and TNF-α declined in both groups, but more so in the treatment group (all P<0.05). The white blood cell count and C-reactive protein level fell more in the treatment than control group, with statistical significance (both P less than 0.05). CBP remarkably improved the cardiovascular and respiratory functions of children with severe sepsis, probably by eliminating factors mediating inflammation.
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Proteína C-Reactiva/metabolismo , Citocinas/sangre , Hemodiafiltración/métodos , Sepsis/sangre , Sepsis/terapia , Femenino , Humanos , Lactante , Recuento de Leucocitos , Masculino , Índice de Severidad de la EnfermedadRESUMEN
The present study shows that hip fracture women had higher serum periostin (sPostn) levels. The elevation of sPostn is associated with bone density loss, yet fracture itself may even increase sPostn levels during early healing phase. INTRODUCTION: The study aims to quantify the associations of sPostn levels with bone density loss and the possible effect on the fracture healing. METHODS: This study enrolled 261 older women with osteoporotic hip fracture and 106 age-matched women without fracture serving as controls. Clinical features, bone mineral density (BMD), and bone turnover markers including sPostn level were measured after fracture within 2 days. Follow-up sPostn levels during 1 year after 2 days were available for 128 patients. RESULTS: Initial levels of sPostn after fracture were significantly higher in patients than controls. sPostn was correlated with BMD of femoral neck (r = -0.529, P < 0.001), ß-isomerized C-terminal crosslinking of type I collagen (ß-CTX) (r = 0.403, P = 0.008), and N-terminal procollagen of type I collagen (PINP) (r = 0.236, P = 0.042) in the entire cohort. After multivariate analysis, sPostn remained as an independent risk factor for femoral neck BMD, which explained 19.1% of the variance in BMD. sPostn sampled within 7 days after fracture were acutely increasing from day 2 and then decreased and maintained at slightly high levels at 360 days. The percentage changes of sPostn positively correlated with the variation in ß-CTX (r = 0.396, P = 0.002) and PINP (r = 0.180, P = 0.033) at day 7 after fracture. CONCLUSIONS: High sPostn levels were an independent predictor of femoral neck BMD in older women presenting with an acute hip fracture. Increased sPostn levels during early healing phase may imply that Postn play a role in bone repair.
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Densidad Ósea/fisiología , Moléculas de Adhesión Celular/sangre , Fracturas de Cadera/sangre , Osteoporosis Posmenopáusica/sangre , Fracturas Osteoporóticas/sangre , Absorciometría de Fotón/métodos , Anciano , Anciano de 80 o más Años , Biomarcadores/sangre , Estudios de Casos y Controles , Moléculas de Adhesión Celular/fisiología , Femenino , Cuello Femoral/fisiopatología , Curación de Fractura/fisiología , Fracturas de Cadera/fisiopatología , Humanos , Vértebras Lumbares/fisiopatología , Osteoporosis Posmenopáusica/fisiopatología , Fracturas Osteoporóticas/fisiopatologíaRESUMEN
This study was carried out to analyze uridine diphosphate (UDP)-glucuronosyltransferase 1A1 (UGT1A1) gene mutations in neonates with unconjugated hyperbilirubinemia, from two different ethnic groups. Polymerase chain reaction and gene sequencing were used to analyze the differences in genotypes and allele frequencies of different gene mutations among the ethnic groups; this was followed by checking their correlation with the serum bilirubin level and the occurrence of unconjugated hyperbilirubinemia in neonates. Our results reveal that the UGT1A1 mutant genotype, 211G>A, is distributed differently in the case vs control groups, as well as in the Zhuang vs Han ethnic groups. Moreover, this difference is statistically significant (P < 0.05); the total serum bilirubin (TSB) and unconjugated bilirubin (UCB) levels in patients carrying the single homozygous mutation, 211G>A, were markedly higher than that in patients without the mutation (P < 0.05). Furthermore, the TSB and UCB levels were significantly different between patients carrying single or compound 211G>A heterozygous mutation, (TA)6/7, and 1941C>G/2042C>G heterozygous mutation, and patients without mutation (P > 0.05). Our findings suggest that the 211G>A mutation in the first exon may be a risk factor for unconjugated hyperbilirubinemia in Zhuang and Han neonates. The serum bilirubin levels seem to be affected by the homozygosity or heterozygosity of the UGT1A1 gene mutation; 211G>A homozygous mutation is an important factor that causes a rise in bilirubin in neonates with unconjugated hyperbilirubinemia.
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Estudios de Asociación Genética , Predisposición Genética a la Enfermedad , Glucuronosiltransferasa/genética , Hiperbilirrubinemia Hereditaria/genética , Bilirrubina/sangre , Femenino , Frecuencia de los Genes , Genotipo , Heterocigoto , Homocigoto , Humanos , Hiperbilirrubinemia Hereditaria/sangre , Hiperbilirrubinemia Hereditaria/patología , Recién Nacido , Masculino , Mutación , Polimorfismo de Nucleótido SimpleRESUMEN
This study compared the efficacy between external fixator combined with palmar T-plate internal fixation and simple plate internal fixation for the treatment of comminuted distal radius fractures. A total of 61 patients classified as type C according to the AO/ASIF classification underwent surgery for comminuted distal radius fractures. There were 54 and 7 cases of closed and open fractures, respectively. Moreover, 19 patients received an external fixator combined with T-plate internal fixation, and 42 received simple plate internal fixation. All patients were treated successfully during 12-month postoperative follow-up. The follow-up results show that the palmar flexion and dorsiflexion of the wrist, radial height, and palmar angle were significantly better in those treated with the external fixator combined with T-plate compared to those treated with the simple plate only (P < 0.05); however, there were no significant differences in radial-ulnar deviation, wrist range of motion, or wrist function score between groups (P > 0.05). Hence, the effectiveness of external fixator combined with T-plate internal fixation for the treatment of comminuted distal radius fractures was satisfactory. Patients sufficiently recovered wrist, forearm, and hand function. In conclusion, compared to the simple T-plate, the external fixator combined with T-plate internal fixation can reduce the possibility of the postoperative re-shifting of broken bones and keep the distraction of fractures to maintain radial height and prevent radial shortening.
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Fijadores Externos , Fijación de Fractura/métodos , Fracturas Conminutas/cirugía , Fijadores Internos , Fracturas del Radio/cirugía , Adulto , Anciano , Femenino , Estudios de Seguimiento , Fijación de Fractura/instrumentación , Fracturas Conminutas/fisiopatología , Humanos , Masculino , Persona de Mediana Edad , Fracturas del Radio/fisiopatología , Rango del Movimiento Articular , Recuperación de la Función , Factores de Tiempo , Resultado del TratamientoRESUMEN
Studies in the past have clearly established that CTLA4 is a susceptible gene for Graves' disease (GD). However, association studies between CTLA4 and the risk of developing Graves' ophthalmopathy (GO) in GD patients have shown conflicting results. In this study, associations of five CTLA4 single nucleotide polymorphisms (-1722A/G, -1661A/G, -318C/T, +49G/A, CT60) with GD risk and GO susceptibility in GD patients were investigated in a Chinese population. Our results showed that either +49A/G or CT60 polymorphism was associated with GD susceptibility in the Chinese population. Significant differences in the distribution of the genotypes or alleles evaluated between GD patients with and without clinically evident GO were only found for -318C/T polymorphism (P = 0.03). Multiple logistic regressions revealed that the -318T allele was negatively associated with GO under both additive and dominant genetic models (adjusted OR = 0.56, 95%CI 0.35-0.89, P = 0.014; adjusted OR = 0.51, 95%CI 0.30-0.84, P = 0.009, respectively). Stratification analysis according to gender demonstrated different scenarios concerning the role of the -318T allele in GO risk: a significant protective role for GO was only confirmed in male but not in female GD patients. Haplotype analyses showed that only the haplotypes containing the -318T allele played a protective role in GO. In conclusion, results from this study suggested that the -318T allele might play a protective role in GO susceptibility for GD patients at least in the Chinese population. However, extended analyses with larger sample size should be carried out in patients from different ethnic origins to further verify this association.
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Antígenos de Diferenciación/genética , Pueblo Asiatico/genética , Enfermedad de Graves/genética , Oftalmopatía de Graves/genética , Polimorfismo de Nucleótido Simple , Regiones Promotoras Genéticas , Adulto , Antígenos CD , Antígeno CTLA-4 , Estudios de Casos y Controles , China , Femenino , Predisposición Genética a la Enfermedad , Genotipo , Humanos , Masculino , Persona de Mediana Edad , FumarRESUMEN
To investigate the role of hyperinsulinemia/insulin resistance in vasomotor tone regulation, we studied the effects of vasoactive substances on tension and intracellular free calcium concentration ([Ca2+]i) of aortic smooth muscle derived from rats that were made hyperinsulinemic by insulin infusion and from Zucker obese rats with insulin resistance. The tension and [Ca2+]i of fura 2-loaded aortic strip preparations without endothelium were simultaneously measured by using a fluorimeter. Ten male Wistar rats received a continuous subcutaneous infusion of insulin (18 nmol x kg(-1) x day(-1)) for 2 weeks with osmotic minipumps (INS group). A control group of 10 rats received vehicle. The plasma immunoreactive insulin concentration in the INS group increased to 930 +/- 54 pmol/l. The increase in [Ca2+]i and tension by KCl and phenylephrine (PE) were lower in the INS group without alteration of the [Ca2+]i-tension relationship. The responses to serotonin (5-HT) in the INS group were similar to those in the control group. In contrast, responses to KCl, PE and 5-HT were markedly enhanced in Zucker obese rats compared with those in Zucker lean rats. The pretreatment of aortic preparations from lean rats with Bay K8644 significantly enhanced the responses to KCl to the level observed in the preparations from obese rats; however, Bay K 8644 failed to affect the responses to KCl in obese rats. These results suggest that enhanced vascular contractile responses to vasoactive substances, possibly due to altered function of the voltage-dependent Ca2+ channel in vascular smooth muscle, may play an important role in the pathogenesis of hypertension in the insulin resistance syndrome.
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Calcio/metabolismo , Hiperinsulinismo/fisiopatología , Resistencia a la Insulina , Obesidad/fisiopatología , Ácido 3-piridinacarboxílico, 1,4-dihidro-2,6-dimetil-5-nitro-4-(2-(trifluorometil)fenil)-, Éster Metílico/farmacología , Agonistas alfa-Adrenérgicos/farmacología , Animales , Aorta/fisiopatología , Agonistas de los Canales de Calcio/farmacología , Canales de Calcio/fisiología , Técnicas In Vitro , Activación del Canal Iónico , Masculino , Potenciales de la Membrana , Contracción Muscular , Músculo Liso Vascular/fisiopatología , Fenilefrina/farmacología , Cloruro de Potasio/farmacología , Ratas , Ratas Wistar , Ratas Zucker , VasodilataciónRESUMEN
To determine the mechanism of the inhibitory effect of insulin on vascular tone, contraction was measured simultaneously with endothelial and smooth muscle cytosolic Ca2+ level ([Ca2+]i) in the isolated rat aorta. Insulin (200 mU/mL) increased endothelial [Ca2+]i and decreased resting muscle tone. The removal of endothelium abolished the effects of insulin. In the aorta precontracted with norepinephrine, insulin (3 to 120 mU/mL) induced concentration-dependent inhibition of contraction. The relaxant effect followed the increase in endothelial [Ca2+]i and decrease in smooth muscle [Ca2+]i. The relaxant effect was attenuated by removal of endothelium or by the addition of 10(-5) mol/L NG-monomethyl-L-arginine but not by 10(-5) mol/L indomethacin. In the absence of endothelium, the relaxant effect of insulin followed the decrease in smooth muscle [Ca2+]i. These results suggest that insulin inhibits vascular contraction by dual mechanisms in the isolated rat aorta: (1) Insulin acts on vascular endothelium by increasing endothelial [Ca2+]i and releasing NO, which decreases smooth muscle [Ca2+]i and the Ca2+ sensitivity of the contractile elements. (2) Insulin also directly acts on smooth muscle and decreases smooth muscle [Ca2+]i.
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Aorta/fisiología , Calcio/metabolismo , Hormonas/farmacología , Insulina/farmacología , Animales , Electrofisiología , Endotelio Vascular/fisiología , Masculino , Contracción Muscular/efectos de los fármacos , Músculo Liso Vascular/fisiología , Ratas , Ratas WistarRESUMEN
BACKGROUND: We wished to investigate the possible mechanism of the protective effect of estrogen replacement on coronary atherosclerosis observed in postmenopausal women. METHODS AND RESULTS: Cytosolic Ca2+ concentration ([Ca2+]i) and contraction were measured simultaneously in fura 2-loaded porcine coronary arterial strips stimulated by the thromboxane A2 analogue U46619 and high-K+ depolarization in the presence and absence of 17 beta-estradiol. Pretreatment with 17 beta-estradiol (30 nmol/L to 30 mumol/L) inhibited the sustained elevation of [Ca2+]i and the sustained contraction induced by 300 nmol/L U46619. Higher concentrations of 17 beta-estradiol (1 to 100 mumol/L) also inhibited the U46619-induced transient increase in [Ca2+]i and contraction in the absence of extracellular Ca2+. In the strips precontracted by 90 mmol/L K+, 17 beta-estradiol (30 mumol/L) inhibited the increases in [Ca2+]i and contraction to resting levels. In contrast, 30 mumol/L 17 beta-estradiol only partially inhibited the U46619-induced sustained contraction, despite complete inhibition of the sustained increase in [Ca2+]i. Verapamil (10 mumol/L) also strongly inhibited the sustained increase in [Ca2+]i induced by 300 nmol/L U46619, with a partial inhibition of the U46619-induced sustained contraction. A subsequent addition of 30 mumol/L 17 beta-estradiol did not show an additional inhibitory effect on either the [Ca2+]i or the tension after the addition of verapamil. 17 beta-Estradiol (10 mumol/L) also inhibited the increase in [Ca2+]i and the contraction induced by cumulative addition of Ca2+ in the strips pretreated with 90 mmol/L K+. However, 17 beta-estradiol did not change the slope of the [Ca2+]i-tension curves. 17 beta-Estradiol (10 mumol/L) had no effect on the levels of cAMP and cGMP in the coronary strips. CONCLUSIONS: 17 beta-Estradiol inhibits the contraction of coronary vascular smooth muscle mainly inhibiting Ca2+ influx without changing Ca2+ sensitivity of contractile elements. The Ca2+ channel blocker-like action of 17 beta-estradiol may explain at least a part of the antiatherosclerotic effect of estrogen.
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Bloqueadores de los Canales de Calcio/farmacología , Calcio/metabolismo , Vasos Coronarios/efectos de los fármacos , Vasos Coronarios/metabolismo , Estradiol/farmacología , Tromboxano A2/farmacología , Ácido 15-Hidroxi-11 alfa,9 alfa-(epoximetano)prosta-5,13-dienoico , Animales , Arterias/efectos de los fármacos , Arterias/metabolismo , Femenino , Humanos , Membranas Intracelulares/metabolismo , Masculino , Concentración Osmolar , Potasio/farmacología , Endoperóxidos de Prostaglandinas Sintéticos/farmacología , Porcinos , Tromboxano A2/análogos & derivados , Vasoconstricción/efectos de los fármacos , Vasoconstrictores/farmacologíaAsunto(s)
Arteriosclerosis/prevención & control , Bloqueadores de los Canales de Calcio/uso terapéutico , Magnesio/uso terapéutico , Ácido 15-Hidroxi-11 alfa,9 alfa-(epoximetano)prosta-5,13-dienoico , Animales , Calcio/metabolismo , Dieta Aterogénica , Estradiol/farmacología , Masculino , Contracción Miocárdica/efectos de los fármacos , Endoperóxidos de Prostaglandinas Sintéticos/farmacología , Conejos , Ratas , Ratas Wistar , Porcinos , Tromboxano A2/análogos & derivados , Tromboxano A2/farmacología , Verapamilo/farmacologíaRESUMEN
The effect of parathyroid hormone-related protein (PTHrP) on cytosolic free Ca2+ level ([Ca2+]i) and tension in rat aortic smooth muscle was investigated with special reference to the role of production and action of cyclic AMP. Rat aortic spiral strip preparations without endothelium were treated with the acetoxymethyl ester of fura 2, and the ratio of fluorescences (R340/380), an index of [Ca2+]i, emitted from smooth muscle, was measured. The tension of the preparations was simultaneously measured. PTHrP-(1-34) produced concentration-dependent decreases both in the tension and in R340/380 increased by phenylephrine (10(-7) M). These effects were significantly inhibited by pretreatment with either PTHrP-(7-34) (10(-6) M), a PTHrP receptor antagonist, or with Rp diastereomer of adenosine cyclic 3',5'-phosphorothioate (RpcAMPS; 10(-4) M), a cyclic AMP-dependent protein kinase inhibitor. Dibutyryl cyclic AMP (10(-5)-10(-3.5 M) elicited effects similar to those of PTHrP-(1-34). PTHrP-(1-34) was found to significantly elevate aortic cAMP level, measured by specific radioimmunoassay, after 5 min incubation with PTHrP-(1-34). These results suggest that the decrease in [Ca2+]i is involved in the vasodilator action of PTHrP, and that the decreases both in tension and in [Ca2+]i might be attributed to cyclic AMP production stimulated by PTHrP.