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1.
Crit Care ; 27(1): 417, 2023 10 31.
Artigo em Inglês | MEDLINE | ID: mdl-37907989

RESUMO

BACKGROUND: Sepsis is one of the leading causes of death. Treatment attempts targeting the immune response regularly fail in clinical trials. As HCMV latency can modulate the immune response and changes the immune cell composition, we hypothesized that HCMV serostatus affects mortality in sepsis patients. METHODS: We determined the HCMV serostatus (i.e., latency) of 410 prospectively enrolled patients of the multicenter SepsisDataNet.NRW study. Patients were recruited according to the SEPSIS-3 criteria and clinical data were recorded in an observational approach. We quantified 13 cytokines at Days 1, 4, and 8 after enrollment. Proteomics data were analyzed from the plasma samples of 171 patients. RESULTS: The 30-day mortality was higher in HCMV-seropositive patients than in seronegative sepsis patients (38% vs. 25%, respectively; p = 0.008; HR, 1.656; 95% CI 1.135-2.417). This effect was observed independent of age (p = 0.010; HR, 1.673; 95% CI 1.131-2.477). The predictive value on the outcome of the increased concentrations of IL-6 was present only in the seropositive cohort (30-day mortality, 63% vs. 24%; HR 3.250; 95% CI 2.075-5.090; p < 0.001) with no significant differences in serum concentrations of IL-6 between the two groups. Procalcitonin and IL-10 exhibited the same behavior and were predictive of the outcome only in HCMV-seropositive patients. CONCLUSION: We suggest that the predictive value of inflammation-associated biomarkers should be re-evaluated with regard to the HCMV serostatus. Targeting HCMV latency might open a new approach to selecting suitable patients for individualized treatment in sepsis.


Assuntos
Infecções por Citomegalovirus , Sepse , Humanos , Citomegalovirus , Infecções por Citomegalovirus/complicações , Imunidade , Interleucina-6 , Sepse/complicações
2.
J Craniomaxillofac Surg ; 51(9): 528-535, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37460350

RESUMO

INTRODUCTION: The aim of this study was to investigate the orthodontic treatment needs (OTN) of children with RS treated with the TPP in infancy compared to age- and sex-matched controls. METHODS: The aim of this study was to investigate the orthodontic treatment needs (OTN) of children with RS treated with the TPP in infancy compared to age- and sex-matched controls. RESULTS: In 21 children with RS (n = 23; 19 non-syndromic, 4 syndromic; average age 9.9 years) showed high OTN, which was significantly higher than in controls (n = 21). The latter of 9 controls had minor OTN, followed by 8 participants with borderline OTN. Regarding the intraoral picture, patients with RS had an increased open bite tendency. Without considering the presence of a cleft palate, 16 children with RS had high or very high OTN, compared to 4 of controls. CONCLUSIONS: Patients with RS have significantly higher OTN than healthy controls, independent of cleft occurrence. RS is associated with dental anomalies and special skeletal growth patterns, both increasing malocclusion and negatively affecting dentoalveolar growth. This should raise awareness for identifying these needs and provide a comprehensive orthodontic treatment, where functional rehabilitation should be favored over aesthetic results.

3.
J Craniomaxillofac Surg ; 44(5): 597-607, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26924432

RESUMO

Juvenile idiopathic arthritis is the most common inflammatory rheumatic disease of childhood and represents a series of chronic inflammatory arthritides of unknown cause. Involvement of the temporomandibular joint has been reported in up to 87% of children with juvenile idiopathic arthritis when based on magnetic tomography imaging; it can be asymptomatic and may lead to severe long term complications. In this review a summary of the contemporary literature of imaging of the temporomandibular joint in children with juvenile idiopathic arthritis will be provided, including ultrasound which is a valuable method for guided joint injections, but does not necessarily allow detection of acute inflammation, cone beam computed tomography, which has emerged as a feasible and accurate low-dose alternative as compared to conventional computed tomography to detect destructive change, and magnetic resonance imaging which is considered the method of choice for assessing acute, inflammatory change, although the lack of normative standards remains a challenge in children.


Assuntos
Artrite Juvenil/diagnóstico por imagem , Transtornos da Articulação Temporomandibular/diagnóstico por imagem , Articulação Temporomandibular/diagnóstico por imagem , Artrite Juvenil/classificação , Artrite Juvenil/complicações , Diagnóstico por Imagem/métodos , Humanos , Articulação Temporomandibular/anatomia & histologia , Transtornos da Articulação Temporomandibular/etiologia
4.
J Craniomaxillofac Surg ; 42(8): 1802-7, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25033739

RESUMO

INTRODUCTION: Juvenile idiopathic arthritis (JIA) is characterized by a progressive destruction of the joints. The temporomandibular joints (TMJ) are especially likely to be affected. The often undetected arthritis in the TMJ in particular can cause significant destruction and craniofacial developmental abnormalities. The aim of this study was to analyze the destructive impact of JIA on TMJ and mandibular development. MATERIAL AND METHODS: We analyzed a total of 92 joints and mandibular rami using digital cone-beam tomography (CBT) and compared 23 consecutively treated JIA patients with 23 healthy controls, matched for age and gender. We evaluated ramus length, vertical depth of the articular fossa, anterior-posterior dimensions of the mandibular head and condylar process. The statistical analysis was performed using non-parametric Wilcoxon and Kruskal-Wallis Rank Sum tests. RESULTS: The JIA patients exhibited significantly more pronounced asymmetries. However, we were unable to detect significant differences in the metric measuring distances. The different JIA subtypes exerted no statistically significant influence. CONCLUSIONS: The possible destruction arising as a result of JIA concerns the TMJ and the length of the mandibular ramus. These craniofacial anomalies demonstrate the central importance of sufficiently early detection and timely treatment in the prevention of such growth disturbances.


Assuntos
Artrite Juvenil/diagnóstico por imagem , Mandíbula/diagnóstico por imagem , Transtornos da Articulação Temporomandibular/diagnóstico por imagem , Articulação Temporomandibular/diagnóstico por imagem , Adolescente , Estudos de Casos e Controles , Cefalometria/métodos , Criança , Tomografia Computadorizada de Feixe Cônico/métodos , Diagnóstico Precoce , Feminino , Humanos , Processamento de Imagem Assistida por Computador/métodos , Masculino , Côndilo Mandibular/diagnóstico por imagem , Desenvolvimento Maxilofacial/fisiologia , Osso Temporal/diagnóstico por imagem
5.
J Orofac Orthop ; 73(2): 126-37, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22383061

RESUMO

AIMS: Three-dimensional (3D) integration of a maxillary model into a facial model has only been possible by a complex procedure using face bow transfer after taking impressions of certain maxillary and facial parts. In this study, we aimed to develop a method for integrating a scanned maxillary model into a scan-realized facial model. MATERIAL AND METHODS: A total of 19 patients with the medical indication for cone-beam computed tomography (CBCT) and orthodontic treatment were included in this study. Facial and maxillary scans were also taken. The construction of the integrated surface model required 10 steps. This integration procedure was evaluated by taking ten 3D dentofacial linear segment measurements in the integrated scan and the CBCT. These results were analyzed using descriptive statistics. RESULTS: All measurements demonstrated good intra-individual reliability. We observed almost perfect congruence between integrated scan and CBCT in vertical distances, while the sagittal measurements revealed more, yet clinically acceptable, deviations possibly caused by different error sources in either of the two methods. CONCLUSION: This new method is suitable for generating 3D integrated surface-scan models which can be used for growth and therapy control studies in orthodontics and other disciplines in the dentofacial fields. Since this method does not require ionizing radiation, it is highly recommendable as an application for children and adolescent patients.


Assuntos
Tomografia Computadorizada de Feixe Cônico/métodos , Face/diagnóstico por imagem , Interpretação de Imagem Assistida por Computador/métodos , Imageamento Tridimensional/métodos , Maxila/diagnóstico por imagem , Modelos Dentários , Ortodontia Corretiva , Fotogrametria/métodos , Adolescente , Cefalometria/métodos , Criança , Aparelhos de Tração Extrabucal , Feminino , Humanos , Modelos Lineares , Masculino , Projetos de Pesquisa , Software
7.
Brain Res ; 1096(1): 30-9, 2006 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-16764836

RESUMO

Adenosine is a ubiquitous neuromodulator and homeostatic regulator that exerts its physiologic actions through activation of A(1), A(2A), A(2B) and A(3) adenosine receptor subtypes. In the central nervous system, adenosine's action in neurons is manifested in its modulation of tonic inhibitory control. Adenosine released in the brain during hypoxia has critical depressant effects on breathing in fetal and newborn mammals, an action suggested to be mediated by A(2A) receptors in the posteromedial thalamus. In an effort to more accurately define the spatial distribution of adenosine A(2A) receptors in fetal sheep diencephalon, we have used a receptor autoradiographic technique utilizing an iodinated radioligand [(125)I]ZM 241385, which has greater sensitivity and resolution than the tritiated compound. The distribution of ligand binding sites in the fetal sheep diencephalon indicated that the highest levels of binding were in select thalamic nuclei, including those implicated in hypoxic depression of fetal breathing, and the pineal. Given the high density of labeled A(2A) receptors in the pineal, these sites were characterized more fully in homogenate radioligand binding assays. These data indicate that [(125)I]ZM 241385 binding sites display a pharmacological signature consistent with that of adenosine A(2A) receptors and are expressed at similar levels in fetal, lamb and adult ovine brain. The adenosine A(2A) receptor pharmacologic signature of the [(125)I]ZM 241385 binding site in pineal cell membranes generalized to the site characterized in membranes derived from other portions of the lamb thalamus, including the sector involved in hypoxic inhibition of fetal breathing. These results have important implications for the functional roles of adenosine A(2A) receptors in the thalamus and pineal of sheep brain.


Assuntos
Glândula Pineal/metabolismo , Receptor A2A de Adenosina/metabolismo , Triazinas/metabolismo , Triazóis/metabolismo , Adenosina/metabolismo , Adenosina/fisiologia , Algoritmos , Animais , Autorradiografia , Sítios de Ligação/efeitos dos fármacos , Ligação Competitiva/efeitos dos fármacos , Encéfalo/embriologia , Encéfalo/metabolismo , Química Encefálica/fisiologia , Interpretação Estatística de Dados , Diencéfalo/embriologia , Diencéfalo/metabolismo , Feminino , Técnicas In Vitro , Radioisótopos do Iodo , Membranas/metabolismo , Gravidez , Receptores Acoplados a Proteínas G/metabolismo , Ovinos , Núcleos Talâmicos/citologia , Núcleos Talâmicos/metabolismo
8.
Placenta ; 22(6): 591-6, 2001 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-11440548

RESUMO

Placental calcification commonly increases with gestational age. The mechanism of apatite mineralization probably involves one of three known mechanisms of tissue calcification: physiological (like bone), dystrophic (ischaemia-related) or metastatic (mineralization in a supersaturated environment). This study was designed to determine the mechanism of calcification by examining (1) the mineral content of placental calcifications in comparison to other physiological and pathological apatites, and (2) the expression of bone morphogenetic proteins (BMPs), which are important in physiological calcification, across gestational age. By energy-dispersive x-ray analysis (EDXA), the Ca/P weight ratio for apatitic mineral from mature calcifications was 2.00+/-0.05 (s.e.), which is similar to that for stones formed in a metastatic, supersaturated environment and lower than that observed in physiological calcification. Biologically active BMP, which was determined by bioassay, was demonstrated in mature and postmature placentae. The BMPs PLAB, PDF and related protein INSL-4 were identified by semiquantitative reverse transcriptase polymerase chain reaction (RT-PCR), but their mRNA expression was independent of gestational age (7-41 weeks of gestation). We conclude that (1) the identified BMPs were not related directly to placental calcification, which argues against physiological calcification, and (2) the chemical composition of the apatitic mineral was suggestive of rapid formation in a supersaturated environment, which is consistent with a metastatic mechanism of calcification.


Assuntos
Calcinose/metabolismo , Doenças Placentárias/metabolismo , Placenta/química , Animais , Bioensaio , Northern Blotting , Proteínas Morfogenéticas Ósseas/análise , Proteínas Morfogenéticas Ósseas/genética , Calcinose/etiologia , Cálcio/análise , Microanálise por Sonda Eletrônica , Feminino , Idade Gestacional , Humanos , Camundongos , Camundongos Nus , Minerais/análise , Fósforo/análise , Gravidez , Gravidez Prolongada , RNA Mensageiro/análise , Ratos , Ratos Sprague-Dawley , Reação em Cadeia da Polimerase Via Transcriptase Reversa
9.
J Appl Physiol (1985) ; 91(1): 343-50, 2001 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-11408450

RESUMO

This study was designed to determine the adenosine (Ado) receptor subtype that mediates the depressant effects of Ado on fetal breathing and rapid eye movements (REM). In chronically catheterized fetal sheep (>0.8 term), intra-arterial infusion of N(6)-cyclopentyladenosine (CPA), an Ado A(1)-receptor agonist, increased the incidence of high-voltage electrocortical (ECoG) activity while virtually abolishing low-voltage activity, REM, and breathing. These effects were blocked by 9-cyclopentyl-1,3-dipropylxanthine (DPCPX), an Ado A(1)-receptor antagonist. Infusion of DPCPX alone increased breath amplitude but had no significant effect on inspiratory duration, breath interval, incidence of REM, or incidence of low-voltage activity. Ado A(2A)-receptor blockade with ZM-241385 increased the incidence of low-voltage ECoG activity, REM, and breathing but had no effect on breath amplitude or respiratory cycle. Both DPCPX and ZM-241385 eliminated the inhibitory effects of Ado on REM and breathing. We conclude that 1) Ado A(1) receptors tonically inhibit fetal respiratory drive, 2) Ado A(2A) receptors tonically inhibit REM-like behavioral state, and 3) both Ado A(1) and A(2A) receptors mediate the depressant effects of Ado on REM and breathing.


Assuntos
Feto/fisiologia , Receptores Purinérgicos P1/fisiologia , Fenômenos Fisiológicos Respiratórios , Fases do Sono/fisiologia , Adenosina/análogos & derivados , Adenosina/farmacologia , Animais , Agonistas do Receptor Purinérgico P1 , Antagonistas de Receptores Purinérgicos P1 , Ovinos/embriologia , Triazinas/farmacologia , Triazóis/farmacologia , Xantinas/farmacologia
10.
Am J Physiol Heart Circ Physiol ; 280(1): H83-9, 2001 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11123221

RESUMO

Nonselective adenosine (ADO) receptor antagonists block hypoxia-induced bradycardia and hypertension in fetal sheep. This study was designed to determine the ADO receptor subtype that is involved in these cardiovascular responses. In chronically catheterized fetal sheep (>0.8 term), fetal hypoxemia was induced by having the ewe breathe a hypoxic gas mixture (9% O(2)-3% CO(2)-88% N(2)) for 1 h. Intra-arterial infusion of ZM-241385, an antagonist highly selective for ADO A(2A) receptors, to eight fetuses during normoxia significantly increased mean arterial pressure (MAP) from 42.5 +/- 2.0 to 46.1 +/- 2.0 mmHg without altering heart rate (HR). Infusion of a selective antagonist of ADO A(1) receptors [1, 3-dipropyl-8-cyclopentylxanthine (DPCPX)] elevated MAP and HR only after the infusion was terminated, although administration of the vehicle for ZM-241385 or DPCPX had no effect on MAP or HR. Isocapnic hypoxia with infusion of DPCPX or the vehicle for DPCPX or ZM-241385 produced a transient fall in HR, a rise in MAP, and a decrease in plasma volume. In contrast, ADO A(2A) receptor blockade abolished the hypoxia-induced bradycardia and hypertension and blunted the decline in plasma volume. We conclude that fetal ADO A(2A) receptors: 1) modulate AP during normoxia, and 2) mediate cardiovascular responses during acute O(2) deficiency.


Assuntos
Pressão Sanguínea , Hipóxia Fetal/fisiopatologia , Frequência Cardíaca , Receptores Purinérgicos P1/fisiologia , Adenosina/análogos & derivados , Adenosina/farmacologia , Animais , Gasometria , Feminino , Concentração de Íons de Hidrogênio , Fenetilaminas/farmacologia , Gravidez , Agonistas do Receptor Purinérgico P1 , Antagonistas de Receptores Purinérgicos P1 , Receptor A2A de Adenosina , Ovinos , Triazinas/farmacologia , Triazóis/farmacologia , Xantinas/farmacologia
11.
Am J Physiol Regul Integr Comp Physiol ; 278(4): R831-7, 2000 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10749769

RESUMO

The effects of diencephalic lesions on respiratory responses to intra-arterially infused adenosine (ADO) were determined in chronically catheterized fetal sheep (>0.8 term). These studies were designed to test the hypothesis that the inhibitory effects of ADO on fetal breathing, like those of hypoxia, are mediated by the parafascicular nuclear complex (Pf) of the posteromedial thalamus. ADO inhibited breathing [control (C): 26 +/- 2.6, ADO: 4 +/- 1 min/h] in normal fetuses and in a fetus with a lesion that virtually destroyed the thalamus but left intact most of Pf. Neuronal lesions in the diencephalon, produced by injecting ibotenic acid, abolished the inhibitory effects of ADO on breathing (C: 31 +/- 5.1, ADO: 30 +/- 4.5 min/h) when the lesions encompassed Pf or the sector immediately rostral to Pf that retained the capacity to regulate hypoxic inhibition. Smaller lesions created by the insertion of needles also eliminated the depressant effects of ADO when disruptions were within Pf or a rostral component of the thalamic cortical activating system. It is concluded that 1) a medial thalamic sector is critically involved in ADO-induced apnea and 2) ADO-dependent and ADO-independent mechanisms mediate hypoxic inhibition.


Assuntos
Adenosina/farmacologia , Hipóxia/fisiopatologia , Inibição Neural/fisiologia , Respiração , Tálamo/fisiopatologia , Vasodilatadores/farmacologia , Animais , Pressão Sanguínea , Cateterismo , Líquido Cefalorraquidiano , Circulação Cerebrovascular/efeitos dos fármacos , Denervação , Agonistas de Aminoácidos Excitatórios , Feminino , Feto/fisiopatologia , Gliose/induzido quimicamente , Gliose/patologia , Ácido Ibotênico , Microinjeções , Necrose , Gravidez , Prosencéfalo/cirurgia , Ovinos , Sono REM/fisiologia , Tálamo/irrigação sanguínea , Tálamo/patologia
12.
Am J Physiol ; 276(6): R1805-11, 1999 06.
Artigo em Inglês | MEDLINE | ID: mdl-10362763

RESUMO

8-Phenyltheophylline (PT), a potent and specific inhibitor of adenosine receptors, was infused intra-arterially into unanesthetized fetal sheep to determine the role of adenosine in hypoxic inhibition of fetal breathing. PT in normoxic fetuses increased heart rate and the incidence of low-voltage electrocortical activity, rapid eye movements (REM), and breathing. Mean breath amplitude increased by 44%. Hypoxia (preductal arterial PO2 = 14 Torr) induced a metabolic acidemia, a transient bradycardia, and hypertension while virtually eliminating REM and breathing. PT administration during hypoxia enhanced the metabolic acidemia, blocked the bradycardia and hypertension, increased the incidence of REM and breathing, and elevated mean breath amplitude. The results indicate that 1) adenosine is involved in fetal glycolytic and cardiovascular responses to hypoxia, 2) activation of central adenosine receptors mediates about one-half the inhibitory effects of hypoxia on REM and breathing, and 3) the depression of breathing may critically depend on a hypoxia-induced reduction in phasic REM sleep.


Assuntos
Hipóxia Fetal/fisiopatologia , Feto/fisiologia , Coração/embriologia , Antagonistas de Receptores Purinérgicos P1 , Respiração , Ácidos/sangue , Adenosina/farmacologia , Animais , Córtex Cerebral/embriologia , Hipóxia Fetal/sangue , Hipóxia Fetal/complicações , Hipóxia Fetal/metabolismo , Feto/metabolismo , Frequência Cardíaca/efeitos dos fármacos , Frequência Cardíaca/fisiologia , Hipertensão/etiologia , Hipertensão/prevenção & controle , Injeções Intra-Arteriais , Oxigênio/sangue , Pressão Parcial , Valores de Referência , Ovinos/embriologia , Sono REM/efeitos dos fármacos , Teofilina/análogos & derivados , Teofilina/farmacologia
13.
Am J Obstet Gynecol ; 180(5): 1272-7, 1999 May.
Artigo em Inglês | MEDLINE | ID: mdl-10329889

RESUMO

OBJECTIVE: This study was designed to determine the role of adenosine in the hypoxic release of corticotropin in fetal sheep. STUDY DESIGN: The adenosine receptor antagonist 8-phenyltheophylline or the vehicle was infused intra-arterially to chronically catheterized fetal sheep (>0.8 term) during an hour of fetal hypoxemia (Pa O 2 congruent with 14 mm Hg). Control studies were also performed in which 8-phenyltheophylline or the vehicle was administered to normoxic fetuses. RESULTS: 8-Phenyltheophylline abolished hypoxia-induced bradycardia and hypertension and produced a nearly 5-fold greater rise in fetal plasma concentrations of corticotropin and approximately a 3-fold greater increase in plasma cortisol levels. During normoxia 8-phenyltheophylline increased plasma cortisol concentrations by 2-fold without altering corticotropin levels, mean arterial blood pressure, or heart rate. CONCLUSION: Adenosine blunts fetal corticotropin release during hypoxia, which in turn reduces cortisol secretion. At lower corticotropin concentrations, adenosine also appears to dampen the cortisol response through direct effects on the adrenals.


Assuntos
Adenosina/fisiologia , Hormônio Adrenocorticotrópico/sangue , Hipóxia Fetal/fisiopatologia , Hidrocortisona/sangue , Antagonistas de Receptores Purinérgicos P1 , Teofilina/análogos & derivados , Animais , Pressão Sanguínea/efeitos dos fármacos , Bradicardia/tratamento farmacológico , Bradicardia/etiologia , Feminino , Sangue Fetal/metabolismo , Hipóxia Fetal/complicações , Frequência Cardíaca Fetal/efeitos dos fármacos , Concentração de Íons de Hidrogênio , Hipertensão/tratamento farmacológico , Hipertensão/etiologia , Cinética , Oxigênio/administração & dosagem , Oxigênio/sangue , Gravidez , Ovinos , Teofilina/administração & dosagem , Teofilina/farmacologia , Teofilina/uso terapêutico
14.
Am J Physiol ; 274(1): R152-9, 1998 01.
Artigo em Inglês | MEDLINE | ID: mdl-9458912

RESUMO

CGS-21680 (CGS), a highly selective adenosine A2a receptor agonist, may excite the fetal carotid bodies. This study was designed to determine 1) whether CGS stimulates fetal breathing and 2) whether sinoaortic denervation abolishes CGS-induced tachycardia. In eight intact fetuses (> 0.8 term), intra-arterial CGS infusion (6 micrograms.min-1.kg estimated fetal wt-1) increased mean arterial PCO2 by 3-7 Torr, reduced fetal arterial PO2 by 2-5 Torr, and produced a mild metabolic acidemia. Heart rate increased from 154 +/- 7 (control) to 249 +/- 12 beats/min, but mean arterial pressure was not significantly affected. CGS initially increased the frequency, amplitude, and incidence of fetal breathing, but this hyperpnea was followed by prolonged respiratory depression that was not reversed with blockade of adenosine A1 receptors. Denervation of both carotid bodies together with interruption of the vagi abolished the hyperpnea without altering the respiratory depression or the maximum rise in heart rate. We conclude that CGS induces 1) tachycardia by a mechanism independent of the peripheral arterial chemoreceptors, 2) hyperpnea by stimulating peripheral adenosine A2a receptors, and 3) respiratory depression by activating central A2a receptors.


Assuntos
Adenosina/análogos & derivados , Feto/fisiologia , Hemodinâmica/efeitos dos fármacos , Fenetilaminas/farmacologia , Agonistas do Receptor Purinérgico P1 , Respiração/efeitos dos fármacos , Nó Sinoatrial/inervação , Adenosina/farmacologia , Animais , Anti-Hipertensivos/farmacologia , Pressão Sanguínea/efeitos dos fármacos , Dióxido de Carbono/sangue , Corpo Carotídeo/embriologia , Células Quimiorreceptoras/fisiologia , Eletroencefalografia , Eletroculografia , Feminino , Feto/efeitos dos fármacos , Frequência Cardíaca Fetal/efeitos dos fármacos , Denervação Muscular , Oxigênio/sangue , Pressão Parcial , Gravidez , Receptor A2A de Adenosina , Ovinos , Nó Sinoatrial/embriologia , Traqueia/embriologia , Nervo Vago/embriologia
16.
Brain Res ; 759(2): 309-12, 1997 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-9221954

RESUMO

Hypoxia increases brain adenosine concentrations, which provides neuroprotection through activation of central adenosine A1 receptors. This study was carried out to determine whether PD 81,273, which increases adenosine's binding to A1 receptors, would reduce hypoxia-induced brain injury. PD 81,273 (3 mg/kg, i.p.) decreased by about 50% the weight loss of the left cerebral hemisphere caused by hypoxia-ischemia in neonatal rats. Thus, enhancing adenosine's binding to the A1 receptor decreases hypoxic brain damage.


Assuntos
Lesões Encefálicas/metabolismo , Isquemia Encefálica/metabolismo , Hipóxia/metabolismo , Agonistas do Receptor Purinérgico P1 , Tiofenos/farmacologia , Animais , Animais Recém-Nascidos/fisiologia , Ratos , Ratos Sprague-Dawley
17.
Brain Res ; 778(2): 439-42, 1997 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-9459565

RESUMO

Microdialysis was performed to determine whether hypoxia increases fetal brain adenosine (ADO) concentration through dephosphorylation of extracellular 5'-adenosine monophosphate (5-AMP). Hypoxia (fetal PaO2 approximately 14 Torr) increased fetal brain ADO levels approximately two-fold when the probes were perfused with synthetic cerebrospinal fluid (CSF) containing inhibitors of the nucleoside transporter but not with this solution plus a blocker of ecto-5'-nucleotidase (AOPCP). The hypoxia-induced rise in fetal brain ADO concentrations depends critically upon the hydrolysis of extracellular 5'-AMP.


Assuntos
Monofosfato de Adenosina/metabolismo , Hipóxia Fetal/metabolismo , Respiração/fisiologia , Difosfato de Adenosina/análogos & derivados , Difosfato de Adenosina/antagonistas & inibidores , Difosfato de Adenosina/metabolismo , Animais , Líquido Cefalorraquidiano , Inibidores Enzimáticos/metabolismo , Feminino , Microdiálise , Gravidez , Ovinos , Tálamo/química , Tálamo/enzimologia
18.
J Physiol ; 488 ( Pt 3): 761-6, 1995 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-8576865

RESUMO

1. In seven unanaesthetized fetal sheep (> 80% term), isocapnic hypoxia (arterial partial pressure of O2, Pa,O2, approximately 15 mmHg) was induced for 1 h by lowering maternal inspired PO2. Fetal hypoxia was also produced during intra-arterial administration of the adenosine receptor antagonist 8-(p-sulphophenyl)-theophylline (8-SPT). The fetal 8-SPT infusion was begun just prior to hypoxia and was stopped when fetal Pa,O2 was returned to normal. 2. Hypoxia induced a progressive fetal acidosis, a rise in mean arterial pressure, a transient fall in heart rate and a decrease in breathing movements. 8-SPT significantly reduced the metabolic acidosis and abolished the hypertension and bradycardia without altering hypoxic inhibition of fetal breathing. Administration of the vehicle for 8-SPT during hypoxia did not significantly affect the normal fetal metabolic and cardiovascular responses to acute O2 deprivation. 3. It is concluded that adenosine mediates the fetal bradycardia and hypertension produced by hypoxia, indicating that adenosine modulates fetal autonomic responses to acute oxygen deficiency. Secondly, adenosine contributes to fetal metabolic acidaemia, suggesting that adenosine also modulates fetal glycolytic responses to hypoxia.


Assuntos
Adenosina/fisiologia , Feto/fisiologia , Hipóxia/metabolismo , Acidose/fisiopatologia , Animais , Pressão Sanguínea/fisiologia , Feminino , Feto/química , Glicólise/fisiologia , Frequência Cardíaca/fisiologia , Hipóxia/fisiopatologia , Gravidez , Antagonistas de Receptores Purinérgicos P1 , Ovinos , Teofilina/análogos & derivados , Teofilina/farmacologia , Trometamina/farmacologia
19.
Am J Physiol ; 269(1 Pt 2): H282-7, 1995 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-7631858

RESUMO

The effects of adenosine on atrial natriuretic peptide (ANP) secretion were determined in chronically catheterized fetal sheep (> 0.8 term). Adenosine was infused into the the right jugular vein for 1 h at 8 +/- 0.4 (5 fetuses), 160 +/- 8 (6 fetuses), and 344 +/- 18 micrograms.min-1.kg estimated fetal wt-1. Fetal arterial blood gases and pH were generally unaffected by adenosine, although mean arterial CO2 tension increased transiently by 2-5 Torr and pH fell progressively during the highest rate of infusion. During the intermediate and high infusion rates, fetal hemoglobin concentrations increased by 11-13% and mean fetal heart rate rose by 18% from a control value of approximately 167 beats/min. Mean arterial pressure was not affected during adenosine infusion. Adenosine significantly increased fetal plasma ANP levels, with maximum concentrations 1.80, 2.36, and 2.51 times greater than control means (142-166 pg/ml) for the respective infusion rates of 8, 160, and 344 micrograms.min-1.kg estimated fetal wt-1. In seven fetuses, reducing fetal arterial O2 tension by approximately 9-10 Torr from a control of 23 +/- 1.3 Torr increased plasma ANP concentrations approximately 2.4 times the control mean of 176 pg/min. Adenosine-receptor blockade with 8-(p-sulfophenyl)-theophylline reduced by 50% the maximum hypoxia-induced rise in plasma ANP concentrations. It is concluded that adenosine causes a dose-dependent rise in fetal plasma ANP concentrations and modulates fetal ANP release during hypoxia.


Assuntos
Adenosina/farmacologia , Fator Natriurético Atrial/sangue , Sangue Fetal/metabolismo , Hipóxia/sangue , Animais , Pressão Sanguínea , Gases/sangue , Frequência Cardíaca , Hemoglobinas/análise , Concentração de Íons de Hidrogênio , Hipóxia/fisiopatologia , Antagonistas de Receptores Purinérgicos P1 , Ovinos , Teofilina/análogos & derivados , Teofilina/farmacologia
20.
J Appl Physiol (1985) ; 77(6): 2734-9, 1994 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-7896614

RESUMO

Because hypoxic inhibition of fetal breathing may be caused by a rise in central adenosine levels, the effects of O2 deficiency on fetal brain adenosine concentrations were determined at levels of hypoxia that inhibited fetal breathing. Under halothane anesthesia, the brains of fetal sheep (0.8 term) were implanted with guide cannulas exteriorized through a Silastic rubber window in the uterus and flank of the ewe. At least 4 days after surgery, a microdialysis probe was inserted into a cannula with the membrane tip placed in the rostral brain stem. During 1 h of isocapnic hypoxia, mean fetal arterial PO2 was reduced from 24.0 +/- 0.9 Torr (control) to 13 +/- 0.6 Torr and arterial pH fell progressively from 7.354 +/- 0.007 to 7.273 +/- 0.023. Hypoxia decreased the incidence of fetal breathing movements from 33 +/- 5.2 to 5 +/- 2.2 min/h, with a normal incidence (29 +/- 3.5 min/h) during the hour after arterial PO2 returned to control values. Adenosine concentrations in microdialysis perfusate under control conditions averaged approximately 35 nM, increased up to 2.3-fold during the hour of O2 deficiency, and fell toward control values when normoxia was restored. We conclude that fetal brain adenosine levels are increased at levels of O2 deficiency that inhibit fetal breathing, which are results consistent with a role for adenosine in hypoxic inhibition of fetal breathing.


Assuntos
Adenosina/metabolismo , Encéfalo/embriologia , Feto/fisiologia , Hipóxia/fisiopatologia , Respiração , Animais , Artérias , Sistema Cardiovascular/fisiopatologia , Feminino , Movimento Fetal , Gases/sangue , Concentração Osmolar , Oxigênio/sangue , Pressão Parcial , Ovinos
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