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1.
J Sex Med ; 12(3): 827-34, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25630365

RESUMO

INTRODUCTION: Priapism is rare-presenting feature in male patients with chronic myeloid leukemia (CML). Several hypotheses for pathogenesis have been described. Management has been controversial; some authors described resolution following priapism-specific interventions, and others recommended addition of CML-specific therapy or even CML-specific therapy alone. AIM: In this report, we describe presentation and management of a man with refractory priapism that was the first presenting manifestation of CML. We also report, for the first time, the pathology sections of the sinusoidal tissue in such cases. Literature is reviewed for similar cases and their outcome. METHODS: A 21-year-old male patient presented with painful priapism that started 6 days earlier and failed aspiration-irrigation. CBC revealed marked leucocytosis. Oncology care diagnosed CML, and treatment with Imatinib was commenced with prior semen cryopreservation. Following remission, a penile prosthesis was implanted, assisted by optical corporotomy. Sinusoidal tissue biopsy was stained by hematoxylin/eosin (H&E) and CD34. MAIN OUTCOME MEASURES: Pathology sections of cavernous tissue following CML-induced priapism. RESULTS: The penile implant survived without complications. H&E examination of the sinusoidal tissue biopsy revealed leukemic infiltration associated with vascular endothelial damage. CD34 staining showed the mixed picture of leukemic infiltrates, intact vascular endothelium with lumena showing leukemic cells, alternating with destroyed vessels, and no vascular lumena and ruminants of endothelial cells. CONCLUSION: Priapism can be the first manifestation of previously undetected CML. The pathological picture of sinusoidal tissue in such cases is presented. In the case at hand, a complete blood picture was helpful in early diagnosis of CML and early initiation of targeted chemotherapy along with the corporal irrigation/aspiration or shunt surgery. It is therefore recommended to have a CBC examined at presentation of any case of ischemic priapism of unknown etiology, early initiation of CML therapy along with aspiration/irrigation, preferably cryopreserving a semen sample before CML therapy.


Assuntos
Antineoplásicos/uso terapêutico , Benzamidas/uso terapêutico , Endotélio Vascular/patologia , Leucemia Mielogênica Crônica BCR-ABL Positiva/complicações , Leucemia Mielogênica Crônica BCR-ABL Positiva/diagnóstico , Prótese de Pênis , Piperazinas/uso terapêutico , Priapismo/etiologia , Pirimidinas/uso terapêutico , Criopreservação , Humanos , Mesilato de Imatinib , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Leucemia Mielogênica Crônica BCR-ABL Positiva/patologia , Masculino , Priapismo/tratamento farmacológico , Priapismo/patologia , Preservação do Sêmen , Resultado do Tratamento , Adulto Jovem
2.
Int J Neurosci ; 120(5): 386-95, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20402579

RESUMO

The arcuate nucleus (ARC) modulates both satiety and hunger signals at the lateral and medial sites, respectively, though these competing responses may be both mediated by serotonin (5-HT). We sought to determine region-specific effects of 5-HT on ARC neurons. Electrical activities in rat hypothalamic slices were simultaneously recorded with an extracellular multielectrode array. 5-HT effects on the ARC were region-specific: primary inhibition of medial ARC and stimulation of lateral ARC neurons. 5-HT primarily inhibited ventromedial nucleus neurons. These results suggest ARC region-specific responses to 5-HT consistent with the anatomical location of lateral ARC anorexigenic proopiomelanocortin neurons and medial ARC orexigenic neuropeptide Y neurons.


Assuntos
Potenciais de Ação/fisiologia , Núcleo Arqueado do Hipotálamo/fisiologia , Serotonina/fisiologia , Núcleo Hipotalâmico Ventromedial/fisiologia , Potenciais de Ação/efeitos dos fármacos , Animais , Núcleo Arqueado do Hipotálamo/efeitos dos fármacos , Cálcio/metabolismo , Interações Medicamentosas , Fenfluramina/farmacologia , Técnicas In Vitro , Masculino , Piperazinas/farmacologia , Piridinas/farmacologia , Ratos , Ratos Sprague-Dawley , Ritanserina/farmacologia , Serotonina/farmacologia , Antagonistas da Serotonina/farmacologia , Inibidores Seletivos de Recaptação de Serotonina/farmacologia , Núcleo Hipotalâmico Ventromedial/efeitos dos fármacos
3.
Strahlenther Onkol ; 185(4): 222-30, 2009 Apr.
Artigo em Alemão | MEDLINE | ID: mdl-19370424

RESUMO

BACKGROUND: Postoperative radiotherapy after breast cancer surgery effectively reduces local relapses. A survival benefit after breast conservation, however, has only been proven recently which was in part due to excessive cardiac mortality of patients who had been treated with radiotherapy in the past. MATERIAL AND METHODS: The literature on postoperative radiotherapy for breast cancer was reviewed with regard to cardiac toxicity as the basis for hypothesis generation. RESULTS: From numerous publications on cardiac toxicity of breast cancer radiotherapy, the following pattern emerges: in series where a high radiation dose was applied to a significant percentage of the heart (postmastectomy and postlumpectomy series) cardiac toxicity/mortality was increased versus a nonexposed cohort or for left over right disease. If, however, a relevant exposure of cardiac muscle could be more or less excluded based on the technique used (mainly more recent postlumpectomy radiotherapy), no cardiac toxicity was observed. Series for which individual dose exposure varied or could not be clarified also came to varying conclusions. Also due to retrospectively unclear dose distributions, an exact quantification of tolerance doses/effects of different geographic dose distribution patterns could not be performed to date. A particularly difficult question to answer is the threshold volume for clinically relevant cardiotoxicity with tangential radiotherapy at prescription doses. As a consequence, this precludes an estimate in which situations multifield intensity-modulated radiotherapy (IMRT) with its characteristic dose distribution pattern of a larger volume exposed to intermediate doses and higher mean/median heart doses (as shown in Figure 1) might be preferable. CONCLUSION: This review updates the database on cardiac toxicity of breast cancer radiotherapy with special emphasis regarding the issues related to the clinical use of IMRT. Multifield IMRT may reduce the cardiac risk for a small subset of patients at excessive risk with conventional tangential radiotherapy due to unfavorable thoracic geometry, for whom partial-breast radiotherapy is not an option. Due to further concern about the effects of intermediate doses to larger heart volumes, potentially increased contralateral cancer risk and the long latency of clinically apparent toxicity, the introduction of breast IMRT should be closely followed. Accompanying functional studies may have the potential to detect cardiac toxicity at an earlier time.


Assuntos
Neoplasias da Mama/mortalidade , Neoplasias da Mama/terapia , Cardiopatias/epidemiologia , Cardiopatias/prevenção & controle , Mastectomia/mortalidade , Radioterapia Conformacional/mortalidade , Comorbidade , Feminino , Humanos , Incidência , Mastectomia/estatística & dados numéricos , Medição de Risco/métodos , Fatores de Risco , Resultado do Tratamento
4.
Int J Clin Pharm ; 40(6): 1539-1547, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30167970

RESUMO

Background Cisplatin-induced nephrotoxicity still occurs despite the intensive hydration approach adapted to prevent its occurrence. Objective Evaluation of the effect of acetazolamide (ACTZ) on minimizing cisplatin-induced nephrotoxicity compared to mannitol when added to hydration regimen. Setting Nasser Institute Cancer Center (NICC), Cairo, Egypt. Method A total of 35 patients planned to receive cisplatin were divided into two groups: 20 patients received mannitol and 15 patients received ACTZ. Both groups received standard hydration measures as well for prevention of cisplatin-induced nephrotoxicity. Main outcome measure Patients' kidney function was assessed using serum creatinine, creatinine clearance and blood urea nitrogen. Kidney injury was assessed using RIFLE criteria. Patients' liver function tests and hematological parameters were also monitored. Results Patients in the mannitol group showed higher risk of developing kidney injury (30%) whereas those in the ACTZ group showed lower risk (8.9%), relative risk (RR) 0.269, 95% CI 0.108-0.815. No statistically significant difference occurred between the two groups concerning liver function tests or hematological parameters. Conclusion Use of ACTZ in addition to intensive hydration may have more beneficial effect on minimizing cisplatin-induced nephrotoxicity compared to mannitol plus intensive hydration approach. A large multicenter randomized clinical trials is recommended to confirm study results and to assess effect of ACTZ on tumor response.


Assuntos
Acetazolamida/uso terapêutico , Antineoplásicos/efeitos adversos , Cisplatino/efeitos adversos , Diuréticos/uso terapêutico , Nefropatias/induzido quimicamente , Nefropatias/tratamento farmacológico , Manitol/uso terapêutico , Acetazolamida/efeitos adversos , Injúria Renal Aguda/epidemiologia , Adulto , Idoso , Diuréticos/efeitos adversos , Feminino , Humanos , Testes de Função Renal , Testes de Função Hepática , Masculino , Manitol/efeitos adversos , Pessoa de Meia-Idade , Projetos Piloto
5.
J Matern Fetal Neonatal Med ; 18(2): 123-7, 2005 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16203598

RESUMO

OBJECTIVE: Sweet taste responsiveness is reduced in adult rats and humans following continued oral sucrose. We have previously demonstrated that sublingual sucrose stimulates near term ovine fetal swallowing, suggesting intact taste responsiveness. We sought to determine if prolonged oral sucrose infusion to the near term ovine fetus will evoke adaptation, as manifested by reduced swallowing stimulation. METHODS: Time-dated pregnant ewes and fetuses (n = 4) were chronically prepared with fetal vascular and sublingual catheters, and electrocorticogram and esophageal electromyogram electrodes and studied at 129 +/- 1 d gestation. Following an initial 2 h basal period, sucrose (2.5%) was infused sublingually (0.25 ml/min) to the fetus for 8 h. Fetal swallowing activity, blood pressure and heart rate were continuously recorded while maternal and fetal arterial blood samples were taken at timed intervals. RESULTS: During the basal period, fetal swallowing averaged 0.9 +/- 0.1 swallows/min. Fetal swallowing increased significantly following sublingual 2.5% sucrose infusion and remained significantly elevated at 2, 4, 6 and 8 h after initiation of sucrose infusion (1.3 +/- 0.1, 1.2 +/- 0.1, 1.3 +/- 0.1, 1.3 +/- 0.1 swallows/min; p < 0.001). There were no significant changes in fetal cardiovascular or arterial blood parameters. CONCLUSIONS: Although oral sucrose significantly stimulates near term ovine fetal ingestive behavior, sweet taste adaptation or habituation does not occur, in contrast to that observed in adult animals and human. The lack of taste adaptation in the fetus/newborn may facilitate increased neonatal food intake and accelerated growth.


Assuntos
Deglutição/efeitos dos fármacos , Feto/fisiologia , Sacarose/administração & dosagem , Adaptação Fisiológica , Administração Sublingual , Animais , Gasometria , Pressão Sanguínea , Deglutição/fisiologia , Eletromiografia , Esôfago/fisiologia , Feminino , Frequência Cardíaca , Gravidez , Ovinos , Estimulação Química
6.
Physiol Behav ; 79(1): 79-88, 2003 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-12818712

RESUMO

Fetal swallowing has important roles in fetal gastrointestinal development, and perhaps fetal somatic growth and maturation. Ingestive behavioral responses must develop in utero to provide for acquisition of water and food intake during the neonatal period. At birth, the rat, ovine and human fetus have developed mechanisms to acquire food via intact mechanisms of taste, suckling and swallowing. Our preliminary studies suggest that in sheep and likely in human fetuses, putative orexic-mediated ingestive responses are present near term gestation. We hypothesize that both orexic (appetite) and satiety mechanisms develop during the last third of gestation and the related neurotransmitters involved in this process are functional. The potential in utero imprinting of orexic mechanisms may influence infant, childhood and ultimately adult appetite "set-points". Thus, dysfunctional appetite, and perhaps obesity, may result from maternal environmental influences during critical stages of development.


Assuntos
Apetite/fisiologia , Deglutição/fisiologia , Ingestão de Alimentos/fisiologia , Desenvolvimento Embrionário e Fetal/fisiologia , Animais , Animais Recém-Nascidos , Período Crítico Psicológico , Sistema Digestório/embriologia , Ingestão de Líquidos/fisiologia , Feminino , Idade Gestacional , Humanos , Hipotálamo/embriologia , Fixação Psicológica Instintiva/fisiologia , Recém-Nascido , Leptina/fisiologia , Neuropeptídeo Y/fisiologia , Gravidez , Efeitos Tardios da Exposição Pré-Natal , Ratos , Ovinos
7.
Radiother Oncol ; 102(2): 268-73, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22100654

RESUMO

PURPOSE/OBJECTIVE(S): IMRT allows dose escalation for large lung tumors, but respiratory motion may compromise delivery. A treatment plan that modulates fluence predominantly in the transversal direction and leaves the fluence identical in the direction of the breathing motion may reduce this problem. MATERIALS/METHODS: Planning-CT-datasets of 20 patients with Stage I-IV non small cell lung cancer (NSCLC) formed the basis of this study. A total of two IMRT plans and one 3D plan were created for each patient. Prescription dose was 60 Gy to the CTV and 70 Gy to the GTV. For the 3D plans an energy of 18 MV photons was used. IMRT plans were calculated for 6 MV photons with 13 coplanar and with 17 noncoplanar beams. Robustness of the used method of anisotropic modulation toward breathing motion was tested in a 13-field IMRT plan. RESULTS: As a consequence of identical prescription doses, mean target doses were similar for 3D and IMRT. Differences between 3D and 13- and 17-field IMRT were significant for CTV Dmin (43 Gy vs. 49.1 Gy vs. 48.6 Gy; p<0.001) and CTV D(95) (53.2 Gy vs. 55.0 Gy vs. 55.4 Gy; p=0.001). The D(mean) of the contralateral lung was significantly lower in the 17-field plans (17-field IMRT vs. 13- vs. 3D: 12.5 Gy vs. 14.8 Gy vs. 15.8 Gy: p<0.05). The spinal cord dose limit of 50 Gy was always respected in IMRT plans and only in 17 of 20 3D-plans. Heart D(max) was only marginally reduced with IMRT (3D vs. 13- vs. 17-field IMRT: 38.2 Gy vs. 36.8 Gy vs. 37.8 Gy). Simulated breathing motion caused only minor changes in the IMRT dose distribution (~0.5-1 Gy). CONCLUSIONS: Anisotropic modulation of IMRT improves dose delivery over 3D-RT and renders IMRT plans robust toward breathing induced organ motion, effectively preventing interplay effects.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/radioterapia , Neoplasias Pulmonares/radioterapia , Radioterapia Conformacional/métodos , Radioterapia de Intensidade Modulada/métodos , Idoso , Idoso de 80 Anos ou mais , Anisotropia , Carcinoma Pulmonar de Células não Pequenas/diagnóstico por imagem , Carcinoma Pulmonar de Células não Pequenas/patologia , Feminino , Humanos , Neoplasias Pulmonares/diagnóstico por imagem , Neoplasias Pulmonares/patologia , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Dosagem Radioterapêutica , Planejamento da Radioterapia Assistida por Computador/métodos , Respiração , Tomografia Computadorizada por Raios X , Resultado do Tratamento
8.
Ann Saudi Med ; 31(2): 158-62, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21403412

RESUMO

BACKGROUND AND OBJECTIVES: Prior to the mid-1980s, the treatment of choice for anal cancer was abdominoperineal resection. Currently, combined chemoradiation is the standard of care. Or objective was to analyze results of treatment for anal canal carcinoma treated with combined chemoradiation. DESIGN AND SETTING: Retrospective review of data in local cancer registry at King Faisal Specialist Hospital and Research Centre (KFSHRC) from a 12-year period (1993 to 2005). METHODS: We identified patients with confirmed diagnosis of anal canal squamous cell carcinoma. RESULTS: Of 40 patients identified, 33 were considered eligible for our analysis. All patients were treated by concurrent chemoradiation with mandatory treatment break (MTB) There were 10 (30%) local recurrences. Five-year progression-free survival (PFS) was 50.9%; overall survival (OS) at 5 years was 73.4%. Patients with stage II disease had a median PFS period of 10 years, with no relapses until their last follow-up. There was no statistically significant difference in PFS between patients with stage IIIA disease and those with stage IIIB disease-44.7% and 45%, respectively (P=.8). Five-year PFS according to 'T' stages was as follows: T1, 66%; T2, 71%; T3, 59%; T4, 30% (P>.05). The 5-year colostomy-free survival (CFS) for all patients was 74%. Distant metastases were observed in 4 patients. CONCLUSION: Combined chemoradiation in treatment of anal cancer is effective in terms of local control and sphincter preservation. Five-year estimates of PFS, OS, as well as CFS, in patients treated with a MTB were surprisingly comparable to those determined in most non-MTB series. However, we reported a higher local failure rate, for which we are reevaluating our treatment protocol.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias do Ânus/terapia , Carcinoma de Células Escamosas/terapia , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias do Ânus/fisiopatologia , Carcinoma de Células Escamosas/fisiopatologia , Terapia Combinada , Intervalo Livre de Doença , Feminino , Seguimentos , Hospitais Especializados , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia , Estadiamento de Neoplasias , Sistema de Registros , Estudos Retrospectivos , Arábia Saudita , Sobrevida , Resultado do Tratamento
9.
Int J Radiat Oncol Biol Phys ; 74(1): 73-80, 2009 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-18973977

RESUMO

PURPOSE: Three-dimensional (3D) treatment planning has reduced the cardiac dose in postoperative radiotherapy for breast cancer; however, the overall cardiac toxicity is still an issue because of more aggressive adjuvant treatment. Toxicity models have suggested that a reduction of the heart volume treated to high doses might be particularly advantageous. We compared aperture-based multifield intensity-modulated radiotherapy (IMRT) plans to 3D-planned tangent fields using dose-volume histograms, cardiac toxicity risk, and the robustness to positioning errors. METHODS AND MATERIALS: For 14 computed tomography data sets of patients with left-sided breast cancer (unfavorable thoracic geometry), a 3D treatment plan and an IMRT plan were created. The dose-volume histograms were evaluated for the target and risk organs. Excess risk of cardiac mortality was calculated for both approaches using a relative seriality model. Positioning errors were simulated by moving the isocenter. RESULTS: IMRT reduced the maximal dose to the left ventricle by a mean of 30.9% (49.14 vs. 33.97 Gy). The average heart volume exposed to >30 Gy was reduced from 45 cm(3) to 5.84 cm(3). The mean dose to the left ventricle was reduced by an average of 10.7% (10.86 vs. 9.7 Gy), and the mean heart dose increased by an average of 24% (from 6.85 to 8.52 Gy). The model-based reduction of the probability for excess therapy-associated cardiac death risk was from 6.03% for the 3D plans to 0.25% for the IMRT plans. CONCLUSION: Aperture-based IMRT for left-sided breast cancer significantly reduces the maximal dose to the left ventricle, which might translate into reduced cardiac mortality. Biological modeling might aid in deciding to treat with IMRT but has to be validated prospectively.


Assuntos
Neoplasias da Mama/radioterapia , Coração/efeitos da radiação , Lesões por Radiação/prevenção & controle , Planejamento da Radioterapia Assistida por Computador/métodos , Algoritmos , Carga Corporal (Radioterapia) , Neoplasias da Mama/patologia , Feminino , Coração/anatomia & histologia , Humanos , Imageamento Tridimensional/métodos , Lesões por Radiação/mortalidade , Dosagem Radioterapêutica , Radioterapia Conformacional/métodos , Radioterapia de Intensidade Modulada
10.
J Soc Gynecol Investig ; 12(7): 504-9, 2005 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16202927

RESUMO

BACKGROUND: In adult rats, N-methyl-D-aspartate (NMDA) receptors have been implicated in the central control of body fluid homeostasis, as intracerebroventricular (ICV) injection of NMDA receptor antagonists suppresses stimulated drinking behavior. Fetal swallowing occurs at a significantly higher rate as compared to adult drinking, contributing to amniotic fluid volume regulation and fetal gastrointestinal development. The aim of present study was to determine the role of central NMDA receptors in the modulation of fetal swallowing activity. METHODS: Eight time-dated pregnant ewes and fetuses were chronically prepared with fetal vascular and ICV catheters, electrocorticogram (ECoG), and esophageal electromyogram electrodes and studied at 130 +/- 1 days' gestation. Following an initial 2-hour baseline period (time 2 h), the NMDA receptor antagonist, dizocipline (1 mg), was injected ICV. At time 4 h, the dose of dizocipline was repeated, together with angiotensin II (AngII, 6.4 microg). Fetal swallowing was monitored for 2 hours after each injection. Four of these fetuses also received an identical control study (on an alternate day) in which dizocipline was replaced with artificial cerebrospinal fluid (aCSF). RESULTS: ICV dizocipline injection nearly abolished spontaneous fetal swallowing activities (0.6 +/- 0.1 to 0.2 +/- 0.1 swallows/min; P < .001). ICV AngII in the presence of dizocipline did not demonstrate a dipsogenic effect on fetal swallowing (0.1 +/- 0.1; P < .001). In the control study, ICV injection of aCSF did not change fetal swallowing activity (1.0 +/- 0.1 swallows/min), while ICV AngII resulted in a significant increase in fetal swallowing (2.0 +/- 0.1 swallows/min; P < .001). CONCLUSIONS: This study demonstrates that central NMDA-glutamate receptor-mediated activity contributes to the high rate of spontaneous and AngII-stimulated fetal swallowing. We speculate that reduced NMDA receptor expression within the forebrain dipsogenic neurons may account for observed differences in drinking activities between the fetus/neonate and the adult.


Assuntos
Angiotensina II/fisiologia , Deglutição/fisiologia , Feto/fisiologia , Receptores de N-Metil-D-Aspartato/fisiologia , Animais , Maleato de Dizocilpina/farmacologia , Antagonistas de Aminoácidos Excitatórios/farmacologia , Feminino , Homeostase , Gravidez , Ovinos , Equilíbrio Hidroeletrolítico
11.
Am J Physiol Regul Integr Comp Physiol ; 288(4): R1014-20, 2005 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15550618

RESUMO

Swallowed volumes in the fetus are greater than adult values (per body weight) and serve to regulate amniotic fluid volume. Central ANG II stimulates swallowing, and nonspecific ANG II receptor antagonists inhibit both spontaneous and ANG II-stimulated swallowing. In the adult rat, AT1 receptors mediate both stimulated drinking and pressor activities, while the role of AT2 receptors is controversial. As fetal brain contains increased ANG II receptors compared with the adult brain, we sought to investigate the role of both AT1 and AT2 receptors in mediating fetal swallowing and pressor activities. Five pregnant ewes with singleton fetuses (130 +/- 1 days) were prepared with fetal vascular and lateral ventricle (LV) catheters and electrocorticogram and esophageal electromyogram electrodes and received three studies over 5 days. On day 1 (ANG II), following a 2-h basal period, 1 ml artificial cerebrospinal fluid (aCSF) was injected in the LV. At time 4 h, ANG II (6.4 microg) was injected in the LV, and the fetus was monitored for a final 2 h. On day 3, AT1 receptor blocker (losartan 0.5 mg) was administered at 2 h, and ANG II plus losartan was administered at 4 h. On day 5, AT2 receptor blocker (PD-123319; 0.8 mg was administered at 2 h and ANG II plus PD-123319 at 4 h. In the ANG II study, LV injection of ANG II significantly increased fetal swallowing (0.9 +/- 0.1 to 1.4 +/- 0.1 swallows/min; P < 0.05). In the losartan study, basal fetal swallowing significantly decreased in response to blockade of AT1 receptors (0.9 +/- 0.1 to 0.4 +/- 0.1 swallows/min; P < 0.05), while central injection of ANG II in the presence of AT1 receptor antagonism did not increase fetal swallowing (0.6 +/- 0.1 swallows/min). In the PD-123319 study, basal fetal swallowing did not change in response to blockade of AT2 receptor (0.9 +/- 0.1 swallows/min), while central injection of ANG II in the presence of AT2 blockade significantly increased fetal swallowing (1.5 +/- 0.1 swallows/min; P < 0.05). ANG II caused significant pressor responses in the control and PD-123319 studies but no pressor response in the presence of AT1 blockade. These data demonstrate that in the near-term ovine fetus, AT1 receptor but not AT2 receptors accessible via CSF contribute to dipsogenic and pressor responses.


Assuntos
Pressão Sanguínea/fisiologia , Deglutição/genética , Deglutição/fisiologia , Feto/fisiologia , Receptor Tipo 1 de Angiotensina/genética , Receptor Tipo 1 de Angiotensina/fisiologia , Angiotensina II/fisiologia , Animais , Antiarrítmicos/farmacologia , Gasometria , Química Encefálica/genética , Química Encefálica/fisiologia , Ingestão de Líquidos/fisiologia , Eletromiografia , Feminino , Imidazóis/farmacologia , Losartan/farmacologia , Gravidez , Piridinas/farmacologia , Receptor Tipo 2 de Angiotensina/fisiologia , Ovinos
12.
Am J Physiol Regul Integr Comp Physiol ; 282(5): R1521-7, 2002 May.
Artigo em Inglês | MEDLINE | ID: mdl-11959696

RESUMO

Spontaneous fetal swallowing occurs at a markedly higher rate compared with spontaneous adult drinking activity. This high rate of fetal swallowing is critical for amniotic fluid volume regulation. Central NO is critical for maintaining the normal rate of fetal swallowing, as nonselective inhibition of NO (with central N(G)-nitro-L-arginine methyl ester) suppresses spontaneous and angiotensin II (ANG II)-stimulated swallowing. We sought to differentiate the contributions of central endothelial vs. neuronal NO in the regulation of spontaneous and stimulated fetal swallowing, using a selective neuronal NO synthase (nNOS) inhibitor. Six time-dated pregnant ewes and fetuses were chronically prepared with fetal vascular and intracerebroventricular (i.c.v.) catheters and electrocorticogram (ECoG) and esophageal electromyogram electrodes and studied at 130 +/- 1 days of gestation. After an initial 2-h baseline period (0-2 h), the selective nNOS inhibitor N-propyl-L-arginine (NPLA) was injected i.c.v. (2-4 h). At 4 h, the dose of NPLA was repeated, together with ANG II, and fetal swallowing was monitored for a final 2 h. Four fetuses also received an identical control study (on an alternate day) in which NPLA was replaced with artificial cerebrospinal fluid (aCSF). Suppression of nNOS by i.c.v. NPLA significantly reduced mean (+/- SE) spontaneous fetal swallowing (1.35 +/- 0.12 to 0.50 +/- 0.07 swallows/min; P < 0.001). Injection of ANG II in the presence of NPLA had no dipsogenic effect on fetal swallowing (0.68 +/- 0.09 swallows/min). In the aCSF study, i.c.v. aCSF did not change fetal swallowing (0.93 +/- 0.10 vs. 0.95 +/- 0.09 swallows/min), whereas i.c.v. ANG II resulted in a significant increase in the rate of fetal swallowing (2.0 +/- 0.04 swallows/min; P = 0.001). We speculate that the suppressive dipsogenic effects of central NPLA indicate that spontaneous and ANG II- stimulated fetal swallowing is dependent on central nNOS activity.


Assuntos
Angiotensina II/farmacologia , Deglutição/efeitos dos fármacos , Deglutição/fisiologia , Feto/fisiologia , Neurônios/metabolismo , Óxido Nítrico/fisiologia , Animais , Arginina/análogos & derivados , Arginina/farmacologia , Pressão Sanguínea/efeitos dos fármacos , Sistema Cardiovascular/embriologia , Córtex Cerebral/embriologia , Eletroencefalografia , Eletromiografia , Desenvolvimento Embrionário e Fetal , Inibidores Enzimáticos/farmacologia , Esôfago/embriologia , Sangue Fetal/fisiologia , Idade Gestacional , Óxido Nítrico Sintase/antagonistas & inibidores , Óxido Nítrico Sintase Tipo I , Ovinos/embriologia
13.
Am J Obstet Gynecol ; 189(4): 949-52, 2003 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-14586332

RESUMO

OBJECTIVE: In adults, nutrient intake is controlled by opposing actions of appetite stimulants (eg, neuropeptide Y [NPY]) and suppressors (eg, leptin). Because NPY may exert a preferential role in mediating adult carbohydrate intake, we sought to determine the effect of central NPY on near-term fetal carbohydrate ingestion. STUDY DESIGN: Five pregnant ewes and fetuses were prepared with fetal vascular, sublingual, and intracerebroventricular catheters, electrocorticogram, and esophageal electromyogram electrodes and studied at 131+/-2 days' gestation. After a 2-hour baseline period, 10% sucrose was infused sublingually for the duration of the study. At 4 hours' time, NPY was injected into the fetal cerebral ventricles and fetal swallowing monitored for an additional 6 hours. RESULTS: During the basal period, mean (+/-SEM) swallowing averaged 0.8+/-0.1 swallows per minute. Fetal swallowing increased significantly in response to sublingual sucrose (1.3+/-0.1 swallows/min, P=.001), and further significantly increased at 4 to 6 hours after NPY injection into the cerebral ventricles (1.8+/-0.3, P=.001). CONCLUSION: These results indicate central NPY stimulation of fetal ingestion beyond that resulting from sublingual 10% sucrose. The in utero development of NPY-induced ingestive behavior may be in preparation for high neonatal caloric intake.


Assuntos
Ventrículos Cerebrais/efeitos dos fármacos , Feto/fisiologia , Neuropeptídeo Y/administração & dosagem , Sacarose , Animais , Feminino , Injeções Intraventriculares , Gravidez , Carneiro Doméstico , Estimulação Química
14.
Am J Obstet Gynecol ; 187(4): 898-901, 2002 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-12388973

RESUMO

BACKGROUND: Dipsogen-mediated ingestion matures acutely in late gestation because the preterm fetus may demonstrate absent responses to putative dipsogens. Although central appetite-mediated ingestive behavior is functional near term, it is unknown whether peripheral mechanisms for stimulation of appetite also are functional. In the adult, sweet taste stimulates and potentiates ingestive behavior. We sought to determine whether oropharyngeal sucrose exposure stimulates ingestive behavior in the near-term ovine fetus. STUDY DESIGN: Time-dated pregnant ewes with near-term singleton fetuses (n = 6) were chronically prepared with fetal vascular and sublingual catheters and esophageal electromyogram electrodes and studied at 129 +/- 1 days of gestation. After an initial 2-hour baseline period, successive solutions of distilled water and 2.5%, 10%, and 40% sucrose were infused sublingually (0.25 mL/min), each for 2 hours. Maternal and fetal arterial blood samples were drawn at timed intervals. RESULTS: During the basal period, fetal swallowing averaged 0.9 +/- 0.1 swallows per minute. Swallowing did not change in response to distilled water (0.9 +/- 0.2 swallows per minute) but significantly increased after sublingual infusion of 2.5% sucrose (1.3 +/- 0.1 swallows per minute), 10% sucrose (1.8 +/- 0.1 swallows per minute), and 40% sucrose (1.3 +/- 0.1 swallows per minute, P =.001). There were no significant changes in other fetal or maternal parameters. CONCLUSIONS: The stimulation of fetal swallowing in response to sublingual sucrose infusion suggests that taste-mediated ingestive behavior is functional in the near-term fetus and that both central and systemic appetite mechanisms are intact near term. Fetal swallowing increased in response to an increase in sucrose concentration to peak at 10% and then decreased with further rises in concentration, possibly mediated by aversive fetal reaction to a high-intensity sucrose concentration.


Assuntos
Deglutição/efeitos dos fármacos , Comportamento Alimentar/efeitos dos fármacos , Feto/fisiologia , Ovinos/embriologia , Sacarose/farmacologia , Administração Sublingual , Animais , Sangue/metabolismo , Fenômenos Fisiológicos Cardiovasculares , Sistema Cardiovascular/embriologia , Cateterismo , Relação Dose-Resposta a Droga , Eletromiografia , Feminino , Sangue Fetal/metabolismo , Idade Gestacional , Concentração Osmolar , Gravidez , Soluções/administração & dosagem , Soluções/farmacologia , Sacarose/administração & dosagem
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