RESUMO
OBJECTIVES: In 2011, a consensus was reached defining "late presenters" (LPs) as individuals presenting for care with a CD4 count < 350 cells/µL or with an AIDS-defining event, regardless of CD4 count. However, a transient low CD4 count is not uncommon in recent infections. The objective of this study was to investigate how measurements of late presentation change if the clinical stage at the time of diagnosis is taken into account. METHODS: Case surveillance data for newly diagnosed patients in Belgium in 1998-2012 were analysed, including CD4 count at diagnosis, the presence of AIDS-defining events, and recent infections (< 6 months) as reported by clinicians in the case of acute illness or a recent negative test. First, proportions of LPs were calculated according to the consensus definition. Secondly, LPs were reclassified as "nonlate" if infections were reported as recent. RESULTS: A total of 7949 HIV diagnoses were included in the study. Recent infections were increasingly reported over time, accounting for 8.2% of new infections in 1998 and 37.5% in 2012. The consideration of clinical stage significantly modified the proportion of LPs: 18.2% of men who have sex with men (MSM) diagnosed in 2012 would be classified as LPs instead of 30.9% using the consensus definition (P < 0.001). The proportion of patients misclassified as LPs increased significantly over time: 5% in MSM in 1998 vs. 41% in 2012. CONCLUSIONS: This study suggests that low CD4 counts in recent infections may lead to overestimation of late presentation when applying the consensus definition. The impact of transient CD4 count on late presentation estimates should be assessed and, if relevant, the introduction of clinical stage in the definition of late presentation should be considered.
Assuntos
Infecções por HIV/diagnóstico , Infecções por HIV/epidemiologia , Bélgica/epidemiologia , Contagem de Linfócito CD4 , Consenso , Diagnóstico Tardio/estatística & dados numéricos , Infecções por HIV/patologia , Homossexualidade Masculina/estatística & dados numéricos , Humanos , Masculino , Fatores de RiscoRESUMO
OBJECTIVES: The aim of the study was to test the antiviral efficacy of a triple nucleoside reverse transcriptase inhibitor (NRTI) regimen, with potential beneficial metabolic effects, as maintenance therapy after induction with dual NRTIs and a boosted protease inhibitor (PI). METHODS: An open-label, noninferiority study was carried out. Antiretroviral therapy (ART)-naïve patients with CD4 count ≤ 350 cells/µL and HIV-1 RNA >30000 copies/mL (n=207) were treated with zidovudine/lamivudine and lopinavir/ritonavir. After achieving HIV-1 RNA <50 copies/mL on two consecutive occasions between weeks 12 and 24 after baseline, 120 patients (baseline: median HIV-1 RNA 5.19 log10 copies/mL; median CD4 count 180 cells/µL) were randomized to receive abacavir/lamivudine/zidovudine (ABC/3TC/ZDV) (n=61) or to continue the PI-based ART (n=59). RESULTS: For the proportions of patients (intention-to-treat; missing=failure) with HIV-1 RNA <400 copies/mL (PI group, 66%; ABC/3TC/ZDV group, 71%) and <50 copies/mL (PI group, 63%; ABC/3TC/ZDV group, 62%) at 96 weeks, switching to ABC/3TC/ZDV was noninferior compared with continuing the PI regimen; the difference in failure rate (ABC/3TC/ZDV minus PI) was -4.4 percentage points [95% confidence interval (CI) -21.0 to +12.3 percentage points] and +0.4 percentage points (95% CI -16.9 to +17.7 percentage points), respectively. In the per protocol analysis, the difference in virological failure for HIV-1 RNA >400 copies/mL (0 of 39 patients in the PI group and two of 45 patients in the NRTI group) and for HIV-1 RNA >50 copies/mL (two of 39 and three of 45 patients, respectively) was +4.4 percentage points (95% CI -2.1 to +11.0 percentage points) and +1.5 percentage points (95% CI -8.6 to +11.7 percentage points), respectively, also showing noninferiority. Serum lipids significantly improved in the NRTI group, but not in the PI arm. CONCLUSIONS: A single-class NRTI regimen after successful induction with standard ART had similar antiviral efficacy compared to continuation of a PI-based regimen at 96 weeks after baseline, with improved serum lipids.
Assuntos
Fármacos Anti-HIV/administração & dosagem , Didesoxinucleosídeos/administração & dosagem , Infecções por HIV/tratamento farmacológico , Lamivudina/administração & dosagem , Zidovudina/administração & dosagem , Adulto , Idoso , Bélgica/epidemiologia , Contagem de Linfócito CD4 , Protocolos Clínicos , Progressão da Doença , Esquema de Medicação , Combinação de Medicamentos , Quimioterapia Combinada , Feminino , Infecções por HIV/imunologia , Inibidores da Protease de HIV , HIV-1/imunologia , Humanos , Lipídeos , Masculino , Pessoa de Meia-Idade , Países Baixos/epidemiologia , Estudos Prospectivos , RNA Viral/efeitos dos fármacos , Resultado do Tratamento , Carga ViralRESUMO
Klebsiella pneumoniae infections show particular features depending on the geographical localization as well as comorbidity factors. We are presenting the case of a european patient with diabetes mellitus who presented a septicaemia, a meningitis as well as an hepatic abscess due to a K. pneumoniae and whose evolution was excellent under antibiotics. Usually described among Asian patients, the primary hepatic K. pneumoniae abscess, which is a clinical entity recently described, can give rise to potentially serious and multiple septic metastasis. We also discuss the diagnostic and therapeutic attitudes related to this infection.
Assuntos
Complicações do Diabetes/microbiologia , Infecções por Klebsiella/etiologia , Klebsiella pneumoniae , Abscesso Hepático Piogênico/complicações , Meningite/etiologia , Sepse/etiologia , Complicações do Diabetes/diagnóstico por imagem , Humanos , Abscesso Hepático Piogênico/diagnóstico por imagem , Masculino , Meningite/microbiologia , Pessoa de Meia-Idade , RadiografiaRESUMO
Intra-abdominal infection is a common cause of severe sepsis in a hospital setting and remains associated with a significant morbidity, mortality and resource use. Early adequate surgery or drainage remain the cornerstones of intra-abdominal infection management and impact on patients outcome. Concomitant early and adequate empiric antimicrobial therapy further influences patients morbidity and mortality. Multiple empirical regimens have been proposed in this setting, but rarely supported by well designed, randomized-controlled studies. The current manuscript summarizes the recommendations of the Infection Disease Advisory Board on the management of intra-abdominal infections. Empiric antimicrobial therapy for the most common causes of abdominal infections is proposed. In addition, particular attention has been paid on antibiotic treatment duration.
Assuntos
Cavidade Abdominal , Anti-Infecciosos/uso terapêutico , Infecções Bacterianas/tratamento farmacológico , Abscesso Abdominal/diagnóstico , Abscesso Abdominal/tratamento farmacológico , Abscesso Abdominal/microbiologia , Anti-Infecciosos/administração & dosagem , Infecções Bacterianas/diagnóstico , Infecções Bacterianas/microbiologia , Candidíase/diagnóstico , Candidíase/tratamento farmacológico , Esquema de Medicação , Humanos , Guias de Prática Clínica como Assunto , Terminologia como AssuntoRESUMO
The implementation of a quality program in the field of the infectious diseases requires the prior definition of criteria (efficacy, low toxicity, low cost, less emergence of resistant strains) but also the target (the patient it-self, his or her community, the health system as a whole). A lot of tools are questioned: antimicrobial policy (escalation/streamlining, restricted formularies, antibiotics rotation), guidelines, relational tools (booklets and CME, prescription's formularies, computer's help and the Web) but also the role of an infectious diseases specialist and an antimicrobial management team. Finally, we outline some processes of evaluation.
Assuntos
Infecção Hospitalar/prevenção & controle , Hospitalização , Infecções/terapia , Antibacterianos/uso terapêutico , Humanos , Guias de Prática Clínica como Assunto , Qualidade da Assistência à SaúdeRESUMO
Being faced with the risks of emergence and spread of antibiotic multiresistant bacterial strains in the hospital, it is a joint responsibility of all medical specialities and hospital management to promote the protection of the microbial ecology. Strategies to optimize antimicrobial use and practical approaches are discussed here. The need of mobilization of the entire hospital community and implementation of infectious diseases consultants is emphasized, as recommended by the "Groupement pour le Dépistage, l'Etude et la Prévention des Infections Hospitalières" (GDEPIH).
Assuntos
Resistência Microbiana a Medicamentos , Uso de Medicamentos/normas , Fidelidade a Diretrizes/normas , Hospitais , Guias de Prática Clínica como Assunto , Padrões de Prática Médica/normas , Infecção Hospitalar/microbiologia , Infecção Hospitalar/prevenção & controle , Humanos , Política Organizacional , Seleção de PacientesRESUMO
OBJECTIVE: The 'HICPAC guidelines', published in the USA in 1995 stressed the crucial role of restrictive usage of glycopeptides in the strategy to limit the emergence and spread of resistant enterococci. Because controversy still remains in Belgium on the necessity and feasability of restricting glycopeptide usage, the infectious diseases advisory board (IDAB) developed a consensus statement on the judicious use of glycopeptides in Belgium. METHODS: The literature on the indications for glycopeptide treatment was reviewed, categorized and discussed by a working party of the IDAB.Consequently, the IDAB reached consensus on the warranted indications for glycopeptide use in Belgium. RESULTS: The opinion of the IDAB-members is reported in a consensus statement specifying the indications for treatment and for prophylaxis with glycopeptide antimicrobials, as well as the situations where glycopeptides should not be used, taking into account the specific epidemiology of bacterial resistance, the availability of antibiotics and the common prescribing practices in Belgium. CONCLUSIONS: The IDAB concludes that restrictive usage of glycopeptides must also be a priority in Belgium. Guidelines on the judicious use of these antibiotics adapted to the national situations must contribute to this objective.
Assuntos
Antibacterianos/uso terapêutico , Bactérias Gram-Positivas/efeitos dos fármacos , Infecções por Bactérias Gram-Positivas/tratamento farmacológico , Antibacterianos/farmacologia , Antibioticoprofilaxia , Bélgica , Resistência Microbiana a Medicamentos , Resistência a Múltiplos Medicamentos , Humanos , MEDLINE , Testes de Sensibilidade Microbiana , Teicoplanina/farmacologia , Resultado do Tratamento , Resistência a VancomicinaRESUMO
Transferrin receptor density was investigated in human colorectal surgical specimens. Crude membranes were prepared from 23 cancer tumors (adenocarcinoma or malignant villous tumor) and 3 non-cancer tumors (polyadenoma or villous tumor) and 26 adjacent control mucosa. Contrary to non-cancer tumors, Scatchard analysis of 125I-transferrin binding data evidenced higher maximal transferrin binding capacity and lower dissociation constant in cancer tissues (Bmax cancer 1.828+/-0.320 nmol/g, Kd 24.1+/-4.7 nM), as compared to paired control colonic mucosa (Bmax contol 0.851+/-0.182 nmol/g, Kd 30.7+/-7.3 nM), paired t-tests: Bmax p<0.001, Kd p<0.05). As the cancer/control Bmax ratio was 2.6+/-0.4,transferrin carrier constructs should be proposed for cancer imaging or therapy.
Assuntos
Neoplasias Colorretais/metabolismo , Receptores da Transferrina/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores , Neoplasias Colorretais/diagnóstico , Neoplasias Colorretais/terapia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Ligação Proteica , Ensaio Radioligante , Receptores da Transferrina/química , Transferrina/química , Transferrina/metabolismoRESUMO
Fundamental research performed in the author's laboratory led to the understanding of mechanisms of the mineralocorticoid biosynthetic pathway. Sensitive assays were then developed to allow measurement of the different mineralocorticoid metabolites in several biological fluids. Using these methods biological markers that contribute to the differential diagnosis between benign and malignant adrenal tumors were identified. In the present paper we report that the exploration of the entire mineralocorticoid pathway in the plasma of patients during basal state and after stimulation and/or inhibition test is a powerful tool to predict or validate diagnosis of adrenal malignancy. Moreover, mineralocorticoid exploration can help differentiate between two different types of malignancy, ie malignant cortical adrenaloma and metastases of other cancer. The biochemical mechanisms leading to the atypical mineralocorticoid metabolism in the case of malignant cortical adrenaloma are now under study.
Assuntos
Neoplasias do Córtex Suprarrenal/diagnóstico , Neoplasias das Glândulas Suprarrenais/diagnóstico , Adenoma Adrenocortical/diagnóstico , Aldosterona/biossíntese , Biomarcadores Tumorais , Feocromocitoma/diagnóstico , Neoplasias do Córtex Suprarrenal/metabolismo , Neoplasias das Glândulas Suprarrenais/metabolismo , Adenoma Adrenocortical/metabolismo , Adulto , Idoso , Corticosterona/biossíntese , Diagnóstico Diferencial , Feminino , Humanos , Hidroxicorticosteroides/biossíntese , Masculino , Pessoa de Meia-Idade , Mineralocorticoides/biossíntese , Feocromocitoma/metabolismoRESUMO
In this limited series of 23 patients suffering from severe or life-threatening intra-abdominal infection, piperacillin + tazobactam, together with adequate surgical drainage and resections, cured 78% of our patients and eradicated almost all the pathogens. Side effects included essentially eosinophilia and elevation of transaminases but was never severe. Piperacillin + tazobactam seem thus to be an acceptable treatment, associated with correct surgical drainage. This regimen has to be compared in appropriate trial versus gold standard therapy, such as imipenem, a beta-lactam with aminoglucoside and imidazole or clindamycin or with broad spectrum beta-lactam and other inhibitors or beta-lactamases, but our rate of cure is impressive in such a population.
Assuntos
Quimioterapia Combinada/uso terapêutico , Infecções por Bactérias Gram-Negativas/tratamento farmacológico , Infecções por Bactérias Gram-Positivas/tratamento farmacológico , Ácido Penicilânico/análogos & derivados , Piperacilina/administração & dosagem , Abdome/cirurgia , Adulto , Idoso , Drenagem , Eosinofilia/induzido quimicamente , Feminino , Infecções por Bactérias Gram-Negativas/cirurgia , Infecções por Bactérias Gram-Positivas/cirurgia , Humanos , Masculino , Pessoa de Meia-Idade , Ácido Penicilânico/administração & dosagem , Ácido Penicilânico/efeitos adversos , Piperacilina/efeitos adversos , Tazobactam , Inibidores de beta-LactamasesRESUMO
The possible modulations by morphine and various opioids of the spinal release of cholecystokinin-like material (CCKLM) evoked by 30 mM K+ was studied in vitro, using slices of the dorsal part of the rat lumbar enlargement superfused with an artificial cerebrospinal fluid. Addition of the mu agonist, DAGO (0.1-10 microM), to the perfusing fluid produced a concentration-dependent decrease in the peptide release, which could be prevented by the preferential mu antagonist, naloxone. Complex modulations were induced by the delta agonist, DTLET, as this drug inhibited CCKLM release when added at 10 nM-3 microM to the perfusing fluid, but enhanced it at 10 microM. Both effects were preventable by the delta antagonists naltrindole and ICI 154129, suggesting that delta receptors, possibly of different subtypes, mediated the inhibition and stimulation by DTLET. Morphine also exerted a biphasic effect, as the alkaloid decreased CCKLM release at 0.01-0.1 microM and enhanced it at 10 microM. Morphine-induced inhibition was preventable by naloxone, whereas its stimulatory effect could be blocked by naltrindole and ICI 154129. Although inactive on its own on CCKLM release, the selective kappa 1 agonist U 50488H (1 microM) prevented the inhibitory effects of both DAGO (10 microM) and morphine (0.1 microM), suggesting the existence of interactions between kappa 1 and mu receptors within the dorsal zone of the rat spinal cord. These data indicate that low concentrations of morphine exert an inhibitory influence on spinal CCKergic neurons that depends on the stimulation of mu opioid receptors. The excitatory influence of 10 microM morphine likely results from the simultaneous stimulation of mu, delta and kappa receptors, as the inhibitory effect of mu receptor stimulation can be masked by that of kappa 1 receptors, allowing only the expression of a delta-dependent excitatory effect similar to that induced by 10 microM DTLET.
Assuntos
Colecistocinina/metabolismo , Morfina/farmacologia , Receptores Opioides delta/fisiologia , Receptores Opioides mu/fisiologia , Medula Espinal/metabolismo , (trans)-Isômero de 3,4-dicloro-N-metil-N-(2-(1-pirrolidinil)-ciclo-hexil)-benzenoacetamida , Animais , Ala(2)-MePhe(4)-Gly(5)-Encefalina , Encefalinas/farmacologia , Masculino , Antagonistas de Entorpecentes , Oligopeptídeos/farmacologia , Pirrolidinas/farmacologia , Radioimunoensaio , Ratos , Ratos Sprague-Dawley , Receptores Opioides/agonistasRESUMO
The role of endothelin, a powerful vasoconstrictor, was studied in coronary spasm. A methylergonovine stress test was performed in patients with normal coronary angiography. Patients who developed spasm (Group I, n = 6) were compared with those who did not (Group II, n = 6). Plasma endothelin was measured at 8, 11 a.m., 2 p.m., 4, 7, 9, 11 p.m. and 1 a.m. The stress test was carried out at 17 hours and an additional endothelin measurement was performed during spasm in positive cases. The clinical characteristics of the two groups were comparable especially with regards to cardiovascular risk factors. Except for the value recorded during coronary spasm, the plasma endothelin levels were significantly higher in the group with coronary spasm. A time-dependent variation was observed in both groups with higher endothelin levels in the morning. In group I the plasma endothelin levels were higher under basal conditions and during spasm in patients with spastic angina.
Assuntos
Vasoespasmo Coronário/sangue , Endotelinas/sangue , Adulto , Idoso , Vasoespasmo Coronário/induzido quimicamente , Feminino , Humanos , Masculino , Metilergonovina , Pessoa de Meia-IdadeRESUMO
The mechanisms for isoproterenol-induced atrial natriuretic peptide (ANP) release were studied in superfused rabbit sliced right atria. Addition of 1 microM norepinephrine to this preparation induced a significant monophasic twofold rise in ANP release. This effect was abolished by 1 microM propranolol and mimicked by 1 microM isoproterenol. Furthermore, addition of 200 microM 3-isobutyl-1-methylxanthine (IBMX) to the superfusing medium potentiated isoproterenol effect 31%. In addition, superfusion of slices with 0.5 mM N6,2-O-dibutyryladenosine 3',5'-cyclic monophosphate [(Bu)-2cAMP] enhanced ANP release in the same manner as the beta-agonist. After isoproterenol stimulation, adenosine 3',5'-cyclic monophosphate (cAMP) concentration in effluents increased significantly. ANP secretory response to isoproterenol was unaffected by extracellular calcium concentration or 1 mM ethylene glycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid (EGTA). Finally, 10 microM indomethacin significantly reduced isoproterenol-stimulated ANP release. It is concluded that 1) norepinephrine-induced ANP release is mediated by its beta-agonist activity, 2) isoproterenol-stimulated release appears to be mediated by cAMP, 3) isoproterenol effect does not require extracellular calcium, and 4) prostaglandins may be involved in this beta-adrenergic effect.
Assuntos
Fator Natriurético Atrial/metabolismo , Isoproterenol/farmacologia , Miocárdio/metabolismo , Animais , Cálcio/farmacologia , AMP Cíclico/metabolismo , Átrios do Coração , Técnicas In Vitro , Norepinefrina/farmacologia , Perfusão , CoelhosRESUMO
Heart failure is usually characterized by a relative insensitivity to atrial natriuretic factor (ANF). Downregulation of ANF receptors has been reported but remains controversial. Renal response to ANF infusion, glomerular ANF receptors, and guanosine 3',5'-cyclic monophosphate (cGMP) production have been studied in rabbits with congestive heart failure (CHF) after traumatic aortic regurgitation and abdominal aortic stenosis. Diuresis and natriuresis induced by ANF infusions were significantly decreased in CHF animals. Plasma cGMP was higher in CHF rabbits before ANF administration than in controls (37.6 +/- 7.2 vs. 17.1 +/- 3.9 pmol/ml, P < 0.02) and increased to a same level after ANF in both groups (48.8 +/- 4.2 vs. 52.5 +/- 2.8 pmol/ml, NS). No difference was found in glomerular ANF receptor density (436 +/- 54 vs. 425 +/- 57 fmol/mg protein, NS) nor in affinity between the two groups (dissociation constant; 240 +/- 24 vs. 347 +/- 49 pM, NS). Moreover, in vitro glomerular cGMP production in response to exogenous ANF was preserved. In conclusion, despite a blunted renal response to ANF in vivo, glomerular ANF receptors were unchanged in this model, and no defect in cGMP production in response to ANF was found. This suggests the existence of an intracellular defect beyond the second messenger.
Assuntos
Insuficiência Cardíaca/metabolismo , Glomérulos Renais/metabolismo , Receptores do Fator Natriurético Atrial/metabolismo , Animais , Fator Natriurético Atrial/sangue , Fator Natriurético Atrial/farmacologia , Ligação Competitiva , GMP Cíclico/sangue , GMP Cíclico/metabolismo , Feminino , Insuficiência Cardíaca/fisiopatologia , Hemodinâmica/efeitos dos fármacos , Rim/efeitos dos fármacos , CoelhosRESUMO
A provocation test using methylergometrine was carried out in patients with a normal coronary angiogram. Patients exhibiting spasm (Group 1, n = 6) were compared with non-spasm patients (Group II, n = 6). The endothelin concentration was determined in all cases at 0800, 1100, 1400, 1600, 1900, 2100, 2300 and 0100 h. The provocation test was carried out at 1700 h and an additional determination was made during spasm if the test was positive. The two groups had similar clinical characteristics and did not differ in terms of risk factors. Apart from the value recorded during spasm, the endothelin plasma level was significantly higher in Group I. A time x measurement interaction was noted in both groups, with a higher endothelin level in the morning. The endothelin level increased significantly during spasm in Group I patients. The plasma concentration of endothelin appeared to be higher in the basal state and during spasm in patients exhibiting spastic angina.
Assuntos
Vasoespasmo Coronário/sangue , Endotelinas/sangue , Adulto , Idoso , Angiografia Coronária , Vasoespasmo Coronário/diagnóstico por imagem , Diagnóstico Diferencial , Relação Dose-Resposta a Droga , Eletrocardiografia Ambulatorial/efeitos dos fármacos , Feminino , Humanos , Masculino , Metilergonovina , Pessoa de Meia-IdadeRESUMO
In order to find a biochemical marker to assist the physician in the difficult differential diagnosis between malignant and nonmalignant adrenal tumors, plasma levels of the mineralocorticosteroids (deoxycorticosterone, 18-hydroxydeoxycorticosterone, corticosterone, 18-hydroxycorticosterone, and aldosterone) were determined. The same method (RIA which is preceded by a crucial separation step) was used to measure all these steroids including aldosterone. The subjects included 15 adults presenting various clinical signs of adrenocortical tumors (histopathologically: 6 with adrenal carcinoma, 1 with a history of adrenal carcinoma, 1 with adrenal metastasis from other forms of cancer, 6 with adenoma, and 1 with hyperplasia). The results show that both presurgery and during a recurrence of adrenal carcinoma, hypoaldosteronism occurs which contrasts with the normal or even elevated levels of some aldosterone precursors. In the 7 cases of adrenal cortical carcinoma, this dysfunction of the aldosterone pathway was detected regardless of the impairment of the other steroidogenesis pathways, whereas it was never found with a nonmalignant tumor. Despite the limited number of cases so far available, these findings suggest that detection of abnormalities of the aldosterone pathway, and particularly the detection of hypoaldosteronism by an assay method involving a crucial steroid separating step, could contribute to a differential diagnosis between benign and malignant adrenocortical tumor and between adrenal metastasis and other forms of cancer.
Assuntos
Neoplasias das Glândulas Suprarrenais/diagnóstico , Biomarcadores Tumorais/sangue , Hipoaldosteronismo/sangue , Mineralocorticoides/sangue , 18-Hidroxicorticosterona/sangue , Neoplasias das Glândulas Suprarrenais/sangue , Neoplasias das Glândulas Suprarrenais/patologia , Adulto , Aldosterona/sangue , Corticosterona/sangue , Desoxicorticosterona/análogos & derivados , Desoxicorticosterona/sangue , Feminino , Humanos , Hipoaldosteronismo/etiologia , Masculino , Radioimunoensaio , Valores de ReferênciaRESUMO
To investigate the role of calcitonin gene-related peptide (CGRP) in cardiac failure, a sensitive and specific radioimmunoassay was developed to study plasma levels of CGRP in 37 normal subjects and 41 patients with heart failure (HF). The mean plasma levels of CGRP were 294.3 pg.ml-1 (SEM: 41.4) in normal subjects and 121.2 pg.ml-1 (SEM: 21.2) in HF patients. The significant decrease observed in HF patients suggests that CGRP is involved in the pathogenesis of heart failure via a direct effect or via modulation of sympathetic nervous activity.
Assuntos
Peptídeo Relacionado com Gene de Calcitonina/sangue , Insuficiência Cardíaca/sangue , Peptídeo Relacionado com Gene de Calcitonina/fisiologia , Feminino , Coração/inervação , Insuficiência Cardíaca/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Norepinefrina/sangue , Radioimunoensaio , Sistema Nervoso Simpático/fisiopatologiaRESUMO
Superfusion of slices of the dorsal zone of the lumbar enlargement of the rat spinal cord with an artificial cerebrospinal fluid allowed the collection of cholecystokinin-like material (CCKLM) whose Ca(2+)-dependent release could be evoked by tissue depolarization with 30 mM K+. Studies on the possible influence of GABA and related agonists on this process showed that the amino acid, the GABAA agonist, muscimol, and the GABAB agonist, baclofen, inhibited the K(+)-evoked release of CCKLM from the rat spinal cord in a concentration-dependent manner. Maximal inhibition did not exceed -40% with either agonist. Furthermore, the effects of GABAA and GABAB receptor stimulation were not additive. Whereas the effects of muscimol (10 microM) and baclofen (1 microM) could be completely antagonized by bicuculline (1 microM) and phaclofen (10 microM), respectively, complete blockade of the inhibition by GABA (1 microM) could only be achieved in the presence of both antagonists. These data indicate that both GABAA and GABAB receptors are involved in the negative influence of GABA onto CCK-containing neurones within the dorsal horn of the rat spinal cord. Apparently, these receptors are not located on CCK-containing neurones themselves, since the inhibitory effect of GABA on the K(+)-evoked release of CCKLM could be completely prevented by tetrodotoxin (1 microM). As CCK acts centrally as an endogenous opioid antagonist, such a GABA-inhibitory control of spinal CCK-containing neurones might participate in the analgesic action of the amino acid via the intrathecal route.
Assuntos
Colecistocinina/metabolismo , Receptores de GABA-A/efeitos dos fármacos , Medula Espinal/efeitos dos fármacos , Ácido gama-Aminobutírico/farmacologia , Animais , Baclofeno/farmacologia , Cromatografia Líquida de Alta Pressão , Técnicas In Vitro , Masculino , Muscimol/farmacologia , Perfusão , Radioimunoensaio , Ratos , Ratos Sprague-Dawley , Receptores de GABA-A/metabolismo , Medula Espinal/metabolismoRESUMO
Possible interactions between Met-enkephalin and cholecystokinin (CCK)-containing neurons in the rat substantia nigra were investigated by looking for the effects of various opioid receptor ligands and inhibitors of enkephalin-degrading enzymes on the K(+)-evoked overflow of CCK-like material (CCKLM) from substantia nigra slices. The delta-opioid agonists D-Pen2, D-Pen5-enkephalin (50 microM) and Tyr-D-Thr-Gly-Phe-Leu-Thr (DTLET; 3 microM) enhanced, whereas the mu-opioid agonists Tyr-D-Ala-Gly-MePhe-Gly-ol (DAGO; 10 microM) and MePhe3, D-Pro4-morphiceptin (PL 017; 10 microM) decreased, the K(+)-evoked release of CCKLM. By contrast, the kappa-opioid agonist U-50488 H (5 microM) was inactive. The stimulatory effect of DTLET could be prevented by the delta antagonist ICI-154129 (50 microM), but not by the mu antagonist naloxone (1 microM). Conversely, the latter drug, but not ICI-154129, prevented the inhibitory effect of DAGO and PL 017. A significant increase in CCKLM overflow was observed upon tissue superfusion with the peptidase inhibitors kelatorphan or bestatin plus thiorphan. This effect probably resulted from the stimulation of delta-opioid receptors by endogenous enkephalins protected from degradation, because it could be prevented by ICI-154129 (50 microM). Furthermore the peptidase inhibitors did not enhance CCKLM release further when delta-opioid receptors were stimulated directly by DTLET (3 microM). These data indicate that opioids acting on delta and mu receptors may exert an opposite influence, i.e., excitatory and inhibitory, respectively, on CCK-containing neurons in the rat substantia nigra.(ABSTRACT TRUNCATED AT 250 WORDS)