RESUMO
In mammals, pituitary adenylate cyclase-activating polypeptide (PACAP) and vasoactive intestinal peptide (VIP) are involved in cardiovascular and respiratory regulation. Several studies have demonstrated the presence of PACAP, VIP and their receptors in various tissues of teleost fish, including the brain, but little is known about their respiratory and cardiovascular effects. The present study was undertaken to compare the central and peripheral actions of graded doses (25-100 pmol) of trout PACAP and trout VIP on ventilatory and cardiovascular variables in the unanaesthetized rainbow trout. Compared with vehicle, only intracerebroventricular injection of PACAP significantly (P<0.05) elevated the ventilation frequency and the ventilation amplitude, but both peptides significantly increased the total ventilation (total ventilation). However, the maximum hyperventilatory effect of PACAP was approximately 2.5-fold higher than the effect of VIP at the 100 pmol dose (PACAP, (total ventilation)=+5407+/-921 arbitrary units, a.u.; VIP, (total ventilation)=+2056+/-874 a.u.; means +/- s.e.m.). When injected centrally, only PACAP produced a significant increase in mean dorsal aortic blood pressure (P(DA)) (100 pmol: +21%) but neither peptide affected heart rate (f(H)). Intra-arterial injections of either PACAP or VIP were without effect on the ventilatory variables. PACAP was without significant action on P(DA) and f(H) while VIP significantly elevated P(DA) (100 pmol: +36%) without changing f(H). In conclusion, the selective central hyperventilatory actions of exogenously administered trout PACAP, and to a lesser extent VIP, suggest that the endogenous peptides may be implicated in important neuroregulatory functions related to the central control of ventilation in trout.
Assuntos
Consumo de Oxigênio/efeitos dos fármacos , Polipeptídeo Hipofisário Ativador de Adenilato Ciclase/farmacologia , Truta/metabolismo , Peptídeo Intestinal Vasoativo/farmacologia , Sequência de Aminoácidos , Análise de Variância , Animais , Pressão Sanguínea/efeitos dos fármacos , Cromatografia Líquida de Alta Pressão , Relação Dose-Resposta a Droga , Eletrocardiografia , Frequência Cardíaca/efeitos dos fármacos , Dados de Sequência Molecular , Polipeptídeo Hipofisário Ativador de Adenilato Ciclase/genética , Polipeptídeo Hipofisário Ativador de Adenilato Ciclase/metabolismo , Peptídeo Intestinal Vasoativo/genética , Peptídeo Intestinal Vasoativo/metabolismoRESUMO
Although in most vertebrate species urotensin-II (UII) is synthesized in neurons of the central nervous system, little is known regarding the physiological actions of UII in the brain. We have investigated the effects of intracerebroventricular (ICV) administration of synthetic trout UII (1, 5, and 50 pmol) on total motor activity (ACT), ventilatory frequency (VF), ventilatory amplitude (VA), and heart rate (HR) in the unanesthetized trout. ICV injection of UII increased ACT in a dose-dependent manner, and the maximal effect was observed at a dose of 5 pmol. At doses of 1 and 5 pmol, UII did not affect VF, VA, or HR. At the highest dose tested (50 pmol), UII not only increased ACT, but also significantly activated VF, VA, and HR. In contrast, ICV injection of synthetic trout angiotensin-II (5 pmol) did not produce any effect on ACT, VF, or VA, but sharply increased HR. These data provide the first evidence that UII can act centrally to induce motor activity in a nonmammalian vertebrate species.
Assuntos
Frequência Cardíaca/fisiologia , Atividade Motora/fisiologia , Oncorhynchus mykiss/fisiologia , Urotensinas/administração & dosagem , Animais , Frequência Cardíaca/efeitos dos fármacos , Injeções Intraventriculares , Atividade Motora/efeitos dos fármacos , Ventilação Pulmonar/efeitos dos fármacos , Ventilação Pulmonar/fisiologia , Fatores de Tempo , Urotensinas/fisiologiaRESUMO
We present a very rare case of an intrasellar cavernous hemangioma mimicking, clinically and neuroradiologically, the presence of a nonfunctioning pituitary adenoma. It was possible to diagnose this benign, congenital vascular malformation only through a histological examination.
Assuntos
Hemangioma Cavernoso/cirurgia , Neoplasias Hipofisárias/cirurgia , Adulto , Hemangioma Cavernoso/patologia , Humanos , Hipofisectomia , Masculino , Necrose , Recidiva Local de Neoplasia/cirurgia , Hipófise/patologia , Neoplasias Hipofisárias/patologia , ReoperaçãoRESUMO
In a patient with thrombosis of the central retinal artery, plain skull radiographs showed an enlarged sella turcica and computerized tomography revealed ventricular dilatation. Neuroradiological examination demonstrated stenosis of the Sylvian aqueduct and an unusual type of empty sella due to intrasellar persistence of the recessus infundibuli and the presence of an intrasellar arachnoidocele. The former anomaly has been reported in only three cases; in none of them was it associated with the latter abnormality.
Assuntos
Ventrículos Cerebrais/anormalidades , Síndrome da Sela Vazia/etiologia , Aracnoide-Máter/diagnóstico por imagem , Encefalopatias/complicações , Encefalopatias/diagnóstico por imagem , Cistos/complicações , Cistos/diagnóstico por imagem , Síndrome da Sela Vazia/diagnóstico por imagem , Humanos , Hidrocefalia/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Hipófise/diagnóstico por imagem , Sela Túrcica/diagnóstico por imagem , Tomografia Computadorizada por Raios XRESUMO
Gigantism, an extremely rare condition, develops before puberty or in subjects in whom puberty is not yet completed. Hypersecretion of somatotropic hormone results in a tremendous surge in growth (our patient was 2.36 m tall). Among other clinical symptoms disabling peripheral neuropathy predominates and changes in nerve conduction velocity are not merely due to the increase in height. The increase in growth hormone concentrations combined with hypogonadotrophic hypogonadism with normal prolactinaemia is associated with peculiar cutaneous symptoms and with low levels of sex hormone-binding protein.
Assuntos
Adenoma/metabolismo , Gigantismo/etiologia , Hormônio do Crescimento/metabolismo , Doenças do Sistema Nervoso Periférico/etiologia , Neoplasias Hipofisárias/metabolismo , Adenoma/complicações , Adulto , Gigantismo/fisiopatologia , Humanos , Hipogonadismo/etiologia , Perna (Membro)/inervação , Masculino , Neoplasias Hipofisárias/complicações , Fatores de TempoRESUMO
The authors report the cases of two patients who were severely disabled due to signs and symptoms of vertebrobasilar insufficiency caused by unilateral segmental occlusion of one vertebral artery. The patency of the occluded vertebral artery beyond C3 was demonstrated by a faint angiographic injection through anastomic ascending cervical arteries which provided insufficient blood supply. The opposite vertebral artery was abnormal in both cases: a proximal kinking with intracranial atheromatous stenosis in the first and an atheromatous ostial stenosis in the second one. A venous by pass from the external carotid artery (end to end anastomosis) to the C1-C2 portion of the vertebral artery (en to side anastomosis) was performed through an incision from the tip of the mastoid process along the S.C.M. the division of which was unnecessary. Post operatively the signs and symptoms disappeared immediately. The stability of this result is attested by a follow up period of 13 months in the first case and 9 months in the second one. A control angiogram demonstrated a good supply to the vertebro-basilar system through the bypass, the excellent permeability of which was further confirmed by repeated Doppler ultrasound examinations. The indication of this technique is discussed.
Assuntos
Arteriopatias Oclusivas/cirurgia , Artéria Vertebral/cirurgia , Idoso , Artéria Carótida Externa/cirurgia , Humanos , Masculino , Pessoa de Meia-Idade , Veias/transplanteRESUMO
A rare anomaly of the A1 portion of both ACA associated with a saccular aneurysm of the basilar bifudcation is presented. Based upon this case and eigth other cases in the literature, the anatomical and radiological features of the anomaly are precised : the anomalous artery comes from the internal carotid artery right over the cavernous sinus, very close to the origin of the ophtalmic artery; it rums medailly below the inferior aspect of the optic nerve, thus being projected under the plane of the optic canal on oblique angiograms; finally, it crosses the anterior edge of the optic chiasm up to the interhemispheric fissure. By itself the anomaly is asymptomatic but it should not be considered as a mere curiosity since it has most often been found associated with a variety of cerebral vasculature anomalies and in particular with encor more saccular aneurysms of the circle of Willis.
Assuntos
Círculo Arterial do Cérebro/anormalidades , Encéfalo/irrigação sanguínea , Artéria Carótida Interna/anormalidades , Artérias Cerebrais/anormalidades , Feminino , Humanos , Pessoa de Meia-Idade , FenótipoRESUMO
The present study was undertaken to determine the central and peripheral actions of trout angiotensin III (ANG III) on heart rate (HR) and mean dorsal aortic blood pressure (P(DA)) in the unanaesthetized rainbow trout. Intracerebroventricular injection of ANG III (5-100 pmol) produced a significant and dose-dependent increase in HR without significant change in P(DA). In contrast, when injected peripherally ANG III (5-50 pmol) evoked a significant and dose-dependent increase in P(DA). The hypertensive responses were accompanied by a bradycardia that reached significance only for the highest dose of ANG III tested. In conclusion, our results have shown that ANG III has potent and contrasting cardiovascular actions depending on whether its site of action is the brain or the peripheral circulation. Endogenous ANG III may have important physiological functions in teleost fishes.
Assuntos
Angiotensina III/farmacologia , Sistema Cardiovascular/efeitos dos fármacos , Truta , AnimaisRESUMO
Despite the indisputable role of immunoglobulin (Ig)A in the pathogenesis of primary Sjögren syndrome (pSS), the causative abnormality remains largely unknown. As an extension of our report that IgA is oversialylated in this disease, the thrust of the present study was to measure the sialyltransferase (ST) activity in B lymphocytes. ST containing lysates of B cells from 17 pSS patients and 10 controls, were obtained using a combination of detergents, and incubated with affinity purified IgA that had been previously desialylated. The deposition of cytidine 5' monophosphate sialic acid (SA) by ST from B cells onto IgA was detected by two ELISA based upon the use of biotinylated lectins (Sambucus nigra agglutinin which is specific for alpha2-6 SA and Maackia amurensis which is specific for alpha2-3 SA). In parallel, the amount of SA on IgA from ten of the 17 patients and eight of the 10 controls was assayed using the same method. An excess of alpha2-3 and alpha2-6 SA on IgA was found in those patients with excessive activity of alpha2-3 and alpha2-6 ST. Thus, IgA hypersialylation in pSS patients may result from undue activity of ST.
Assuntos
Linfócitos B/enzimologia , Sialiltransferases/sangue , Síndrome de Sjogren/enzimologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Linfócitos B/imunologia , Fracionamento Celular , Ativação Enzimática/imunologia , Feminino , Humanos , Imunoglobulina A/sangue , Masculino , Pessoa de Meia-Idade , Ácido N-Acetilneuramínico/sangue , Análise de Regressão , Síndrome de Sjogren/imunologia , beta-D-Galactosídeo alfa 2-6-Sialiltransferase , beta-Galactosídeo alfa-2,3-SialiltransferaseRESUMO
The blink reflex (BR) study has been carried out on 40 severe head injury cases (average age 24.3 years). The recording was conducted several times between the 2nd and the 12th day and was repeated during the first month and beyond in prolonged comas. 23 patients did not respond even to high intensity stimuli. 17 patients displayed delayed and low amplitude latency responses: one of the components, early R1 or late R2 could be missing. The existence of a detectable focalized hemispheric lesion had no effect on the disappearance of the delayed lateral response. No BR was observed in mesencephalic, protubering comas and in 4 cases of subcortical and diencephalic comas. BR was observed in subcortical or diencephalic comas and in 5 cases of mesencephalic comas. The evolution of patients who did not display any electrical response during the first recording was unfavourable in 15 cases. Among the 5/8 remaining comatose cases, the BR was missing on the 2nd day and back on the 7th day. Among the 17 patients who displayed BR their evolution proved to be very favourable or favourable in 13 cases. In all the patients who survived beyond a month the response latencies proved normal, yet their amplitude was considerably lowered. The lack of BR is temporary but it is an element of unfavourable prognosis if it persists beyond a span of 8 days.
Assuntos
Piscadela , Lesões Encefálicas/complicações , Coma/diagnóstico , Adolescente , Adulto , Lesões Encefálicas/diagnóstico , Criança , Eletroencefalografia , Potenciais Evocados , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Tempo de ReaçãoRESUMO
Serum IgG and IgA are glycoprotein and significant glycoform abnormalities have been established in primary Sjögren's syndrome. The proportion of asialylated IgG is abnormally high in the patients, whereas IgA1 and IgA2 appear to be over-sialylated. This peculiarity might explain the defective binding of IgA to asialoglycoreceptors. Furthermore, the activity of alpha 2,6 sialyl transferase is higher in the IgA-producing B cells from the patients than in the controls, whereas the alpha 2,3 sialyl transferase operates in the former cells but not in the latter. The mechanism of this enzyme dysregulation warrants elucidation.
Assuntos
Imunoglobulina A/sangue , Imunoglobulina G/sangue , Síndrome de Sjogren/imunologia , Linfócitos B/imunologia , Humanos , Sialiltransferases/sangue , Síndrome de Sjogren/diagnósticoRESUMO
The cardiovascular effects of centrally and peripherally administered synthetic trout urotensin (U)-I, a member of the corticotropin-releasing hormone family of neuroendocrine peptides, were investigated in unanesthetized rainbow trout Oncorhynchus mykiss. Intracerebroventricular injections of U-I (5.0 and 12.5 pmol) produced a sustained increase in mean dorsal aortic blood pressure (P(DA)) without significant change in heart rate (HR). This elevation in P(DA) was associated with an increase in cardiac output, but systemic vascular resistance did not change. Intra-arterial injection of U-I (12.5-500 pmol) evoked a dose-dependent increase in P(DA), but in contrast to the hemodynamic effects of centrally administered U-I, the hypertensive effect was associated with an increase in systemic vascular resistance and an initial fall in cardiac output. HR did not change or underwent a delayed increase. Pretreatment of trout with prazosin, an alpha-adrenoreceptor antagonist, completely abolished the rise in arterial blood pressure after intra-arterial administration of U-I, which was replaced by a sustained hypotension and tachycardia. Trout U-I produced a dose-dependent (pD(2) = 7.74 +/- 0.08) relaxation of preconstricted rings of isolated trout arterial vascular smooth muscle, suggesting that the primary action of the peptide in the periphery is vasorelaxation that is rapidly reversed by release of catecholamines. Our results suggest that U-I may regulate blood pressure in trout by acting centrally as a neurotransmitter and/or neuromodulator and peripherally as a neurohormone functioning either as a locally acting vasodilator or as a potent secretagogue of catecholamines.