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1.
Eur Rev Med Pharmacol Sci ; 26(13): 4550-4556, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35856343

RESUMO

Conventional open thyroidectomy is still considered the gold standard for thyroid surgery. Transoral endoscopic thyroidectomy vestibular approach (also known as TOETVA) is often considered to be more advantageous than the other approaches, such as minimally invasive video assisted thyroidectomy, thyroidectomy via breast/axillary/retroauricular access, bilateral axillo-breast approach and axillo-bilateral breast approach. In this scoping review, we discuss the risks and the benefits of this surgical approach and its medico-legal and ethical implications, particularly focusing on the importance of practice on cadavers. Currently, there is little scientific evidence supporting TOETVA, since there are few papers on the comparison with the traditional open thyroidectomy that have been published and thus little data on the long-term outcomes of TOETVA are available. Since the better cosmetic outcome currently represents the main indication for this surgical technique, substantial medico-legal and ethical issues arise. Moreover, practice on cadavers can help surgeons to develop the technical and non-technical skills required to perform efficiently and safely this new surgical procedure.


Assuntos
Glândula Tireoide , Tireoidectomia , Cadáver , Endoscopia , Humanos , Glândulas Paratireoides , Glândula Tireoide/cirurgia , Tireoidectomia/métodos
3.
Eur Rev Med Pharmacol Sci ; 25(15): 4999-5005, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34355371

RESUMO

We report a case of unusual and unexplained cardiac death in an 18-years old female patient with congenital neurosensorial deafness. The fatal event was characterized by an initial syncopal episode, associated with a wide QRS tachycardia (around 110 bpm) but stable hemodynamic conditions. The patient, however, subsequently developed severe hypotension and progressive bradyarrhythmias until asystole and lack of cardiac response to resuscitation maneuvers and ventricular pacing.


Assuntos
Morte , Adolescente , Bradicardia/diagnóstico , Surdez/diagnóstico , Eletrocardiografia , Feminino , Humanos , Síncope/diagnóstico , Taquicardia/diagnóstico
4.
Eur Rev Med Pharmacol Sci ; 25(3): 1738-1742, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33629343

RESUMO

OBJECTIVE: Since the beginning of the COVID-19 pandemic it has been recommended that chemical disinfectants are used to protect surfaces. This study aimed to determine whether the number of exposure calls related to household disinfectants (HD) received between January 30, 2020 to May 18, 2020 varied from the same time period in the previous year. MATERIALS AND METHODS: A retrospective review of the poison control center database from the Fondazione Universitario Policlinico Agostino Gemelli IRCCS, Rome, Italy, was conducted. Calls from Italian citizens, hospitals, and general practitioners received during the same time period in 2019 and 2020 were compared. RESULTS: The center received 1972 exposure calls during the study period. A 5% increase in calls regarding exposure to HDs was noted from 2019 to 2020 (9.8% to 15.2%, p<0.001). The majority of enquiries regarded bleach-containing products, hand sanitizers, ethanol, and hydrogen peroxide. Most calls were received from patients in their homes (n, 259; prevalence, 86%; increase, 107%) and concerned accidental exposure (n, 280; prevalence, 93%; increase, 76%), while cases of intentional exposure decreased (n, 14; prevalence, 5%; decrease, 33%). The main route of exposure was ingestion (n, 170; prevalence, 57%; increase, 45%), but the highest increase was observed in inhalation cases (n, 82; prevalence, 27%; increase, 122%). CONCLUSIONS: As the incidence of enquiries regarding products that can represent an important health hazard, when improperly used, increased in 2020 suggests that the COVID-19 public health messaging on the proper use of HDs should be improved.


Assuntos
COVID-19/prevenção & controle , Desinfetantes/intoxicação , Desinfecção , Habitação/normas , Centros de Controle de Intoxicações/estatística & dados numéricos , SARS-CoV-2 , COVID-19/transmissão , Humanos , Itália , Estudos Retrospectivos , SARS-CoV-2/efeitos dos fármacos
6.
J Eur Acad Dermatol Venereol ; 33(6): 1020-1028, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30767283

RESUMO

Alopecia neoplastica (AN) from visceral tumours is a rare form of cutaneous metastasis in which internal malignancies spread to the scalp. The diagnosis of AN may be very challenging, especially when its onset precedes the diagnosis of the primary tumour. We aimed to improve the knowledge on AN, highlighting that in case of scarring localized alopecia, a differential diagnosis with metastasis should always be considered. We performed a systematic review to describe the main demographic and clinical features associated with AN from visceral malignancies; a survival analysis was also performed. In 118 reports, accounting for 123 patients, we found that women were more affected by AN than men (53.7% vs. 46.3%). The most frequent site of the primary tumour was the gastrointestinal tract (24.4%), followed by breast (17.9%), kidney (8.1%), lung (7.3%), thyroid (7.3%), uterus (6.5%), central nervous system (6.5%), liver (3.3%) and other anatomic areas for 18.7% of cases. Furthermore, in more than half of the cases (66.1%), AN lesions were single and were mainly diagnosed after the primary visceral tumour (71.5%). Finally, survival analysis highlighted a lower progression-free survival in men; while, no significant differences in overall survival were reported among genders. In conclusion, metastatic skin disease should always be taken into consideration when dealing with patients with localized scarring alopecia.


Assuntos
Neoplasias Abdominais/complicações , Alopecia/complicações , Neoplasias Cutâneas/secundário , Neoplasias Abdominais/patologia , Humanos
7.
Int J Legal Med ; 132(4): 1225-1230, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29052041

RESUMO

We performed external autopsies and examinations on two inmates who had committed suicide by hanging themselves with their underwear and using the window bars of their cells as ligature points after they had been placed in solitary confinement. In one case, the inmate had even been deprived of her clothing (with the exception to her underwear). Underwear has been rarely described as a means for self-harm and, to the best of our knowledge, no previous study has focused on cases of prison suicides committed using this garment, even though it is available to every inmate. The two cases were very similar; both inmates were young, physically aggressive and in their first week at a new facility; both had been affected by mental disorders, had been prescribed psychotropic medications and had histories of psychiatric hospitalisation. In each case, the psychiatric evaluations had highlighted significant suicidal risk. We discuss these two cases in an attempt to describe the complexity of and contradictions within the management of suicidal inmates at correctional facilities. We aim to propose new strategies and emphasise the need to introduce evidence-based standardised protocols over inhumane, ineffective and simplistic punitive measures in the management of these individuals.


Assuntos
Transtornos Mentais/complicações , Prisioneiros/psicologia , Punição , Isolamento Social , Suicídio , Adulto , Asfixia/patologia , Feminino , Humanos , Masculino , Lesões do Pescoço/patologia , Adulto Jovem
8.
Int J Lab Hematol ; 40(2): 201-208, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29205868

RESUMO

INTRODUCTION: The high-throughput era remarkably changed molecular laboratory practice. Actually, the increasing number of processed samples requires to reduce the risk of operator biases, by automating or simplifying as much as possible both the analytical and the pre-analytical phases. Minimal residual disease (MRD) studies in hematology often require a simultaneous processing of many bone marrow and peripheral blood samples from patients enrolled in prospective, multicenter, clinical trials, monitored at several planned time points. METHODS: In this study, we demonstrate that red blood cell lysis (RBL) pre-analytical procedure can replace the time-consuming Ficoll stratification as cell recovering step. Here, we show a MRD comparison study using both total white blood cells and mononuclear cells recovered by the 2 procedures from 46 follicular lymphoma (FL), 15 multiple myeloma (MM), and 11 mantle cell lymphoma (MCL) patients enrolled in prospective clinical trials. RESULTS: The experiments were performed in the 4 laboratories of the Fondazione Italiana Linfomi (FIL) MRD Network and showed superimposable results, in terms of good correlation (R = 0.87) of the MRD data obtained by recovering blood cells by the 2 approaches. CONCLUSION: Based on these results, the FIL MRD Network suggests to optimize the pre-analytical phases introducing RBL approach for cell recovery in the clinical trials including MRD analysis.


Assuntos
Ficoll , Hemólise , Neoplasia Residual/diagnóstico , Ensaios Clínicos como Assunto , Diatrizoato , Humanos , Leucócitos , Leucócitos Mononucleares , Métodos
11.
Int J Lab Hematol ; 37(6): 766-73, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26189968

RESUMO

INTRODUCTION: Philadelphia-negative chronic myeloproliferative neoplasms (MPNs) are clonal disorders that present JAK2(V617F) mutation in 50-95% of cases. The main objective of this study was the comparison of two PCR methods, real-time (qPCR) and droplet digital PCR (DD-PCR) for detection of the JAK2(V617F) mutation, to assess analytic sensitivity, specificity, and feasibility of the two methods. METHODS: Ninety-nine patients with MPN of 225 presenting the JAK2(V617F) mutation by qPCR have been evaluated by DD-PCR also. RESULTS: We demonstrated an absolute concordance in terms of specificity between the two methods, DD-PCR showing a higher sensitivity (half a log higher than qPCR). As expected, a progressive increase of mutant allele burden was observed from essential thrombocythemia (ET) to polycythemia vera (PV) and primary myelofibrosis (PMF) to secondary myelofibrosis (SMF). CONCLUSION: In conclusion, our study showed that DD-PCR could represent a new and promising technological evolution for detection of JAK2 mutation in MPNs.


Assuntos
Janus Quinase 2/genética , Mutação , Transtornos Mieloproliferativos/diagnóstico , Transtornos Mieloproliferativos/genética , Reação em Cadeia da Polimerase em Tempo Real/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Alelos , Doença Crônica , Feminino , Proteínas de Fusão bcr-abl/genética , Humanos , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase em Tempo Real/normas , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Adulto Jovem
12.
G Ital Dermatol Venereol ; 150(1): 51-71, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25516220

RESUMO

The most recent pediatric vasculitis classifications (EULAR/PRINTO/PRES) have proposed the use of an integration of clinical signs and symptoms, laboratory data, imaging and pathologic data. Pediatric vasculitis represent a peculiar clinical-diagnostic model, compared to the corresponding adult pathology chapter, and in particular, dermatopathologic aspects of these diseases identify more specific issues, made contingent by crucial variables such as duration of vasculitis lesion, site of the biopsy, proper biopsy depth, and possibility to correlate histopathological findings with immunopathological results. Possible additional diagnostic difficulties may arise from the fact that, in children, the same systemic disease, such as lupus erythematosus, may present with different clinical manifestations, with histopathological features of a precise type of vasculitis specific for that type of clinical manifestation. Examples are provided by hypocomplementemic urticarial vasculitis, cryoglobulinemic purpura, lymphocytic vasculitis of livedoid lesions. This paper describes the cutaneous histopathological findings of some vasculitis related pediatric diseases, be they pertaining to a systemic vasculitis with corresponding cutaneous vasculitis, to a systemic vasculitis with sporadic cutaneous vasculitic involvement, and to a systemic vasculitis without cutaneous vasculitic involvement. Type and level of histopathological vasculitic involvement, caliber of the vessel, type of vasculitis associated infiltrate, are likewise reliable integration in the complex diagnostic path of vasculitis in childhood. On the basis of these criteria dermatopathologists should be confident in identifying the type of the vasculitis and relate them to a specific pediatric disease.


Assuntos
Dermatopatias Vasculares/patologia , Vasculite Sistêmica/patologia , Vasculite/patologia , Fatores Etários , Biópsia , Criança , Humanos , Dermatopatias Vasculares/classificação , Dermatopatias Vasculares/diagnóstico , Vasculite Sistêmica/classificação , Vasculite Sistêmica/diagnóstico , Vasculite/classificação , Vasculite/diagnóstico
13.
Int J Immunopathol Pharmacol ; 27(1): 127-30, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24674688

RESUMO

Pompholyx is a common eruption of small vesicles on the palms, soles, and/or lateral aspects of the fingers. It has a multifactorial etiology, including genetic determinants, allergy to metals, and id reaction; rarely it is a drug-related side effect. We report a paediatric case of pompholyx of the hands related to the intravenous immunoglobulin (IVIG) therapy for Clinically Isolated Syndrome (CIS). A 10-year-old boy, received an IVIG therapy (Venital, Kedrion Spa, Italy) at a dose of 400 mg/kg daily for five days. The fifth day of IVIG infusion, a symmetrical vesicular eruption appeared on the palms of the hands and on lateral aspects of the fingers. The lesions improved with application of topical steroids in few days. The mechanism of induction of pompholyx by IVIG therapy is unknown. A review of the Literature suggests the hypothesis that dyshidrotic eczematous reactions may be related not only to the type of IVIG, to the dose and the rates of infusion, but also to an allergic response to excipients and preservatives contained in the drug, probably elicited by an underlying neurological disease in some cases.


Assuntos
Doenças Desmielinizantes/tratamento farmacológico , Eczema Disidrótico/induzido quimicamente , Imunoglobulinas Intravenosas/efeitos adversos , Administração Cutânea , Corticosteroides/administração & dosagem , Corticosteroides/uso terapêutico , Criança , Eczema Disidrótico/diagnóstico , Eczema Disidrótico/tratamento farmacológico , Eczema Disidrótico/imunologia , Humanos , Imunoglobulinas Intravenosas/administração & dosagem , Imunoglobulinas Intravenosas/uso terapêutico , Masculino , Resultado do Tratamento
14.
Pharmacogenomics J ; 14(4): 328-35, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24589908

RESUMO

The aim of the study was to investigate any possible influence of polymorphisms of transmembrane transporters human organic cation transporter 1 (hOCT1), ABCB1, ABCG2 on imatinib pharmacokinetics in 33 men and 27 women (median age and range, 56 and 27-79 years, respectively) affected by chronic myeloid leukemia. A population pharmacokinetic analysis was performed to investigate imatinib disposition in every patient and the role of transporter polymorphisms. Results showed that the α1-acid glycoprotein and the c.480C>G genotype of hOCT1 had a significant effect on apparent drug clearance (CL/F) being responsible, respectively, for a 20% and 10% decrease in interindividual variability (IIV) of CL/F (from 50.1 up to 19.6%). Interestingly, 25 patients carrying at least one polymorphic c.480 G allele had a significant lower CL/F value with respect to the 35 c.480CC individuals (mean±s.d., 9.6±1.6 vs 12.1±2.3 l h(-1), respectively; P<0.001). In conclusion, the hOCT1 c.480C>G SNP may significantly influence imatinib pharmacokinetics, supporting further analyses in larger groups of patients.


Assuntos
Antineoplásicos/farmacocinética , Benzamidas/farmacocinética , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Transportador 1 de Cátions Orgânicos/genética , Piperazinas/farmacocinética , Polimorfismo de Nucleotídeo Único , Pirimidinas/farmacocinética , Subfamília B de Transportador de Cassetes de Ligação de ATP/genética , Adulto , Idoso , Benzamidas/uso terapêutico , Feminino , Genótipo , Haplótipos , Humanos , Mesilato de Imatinib , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Masculino , Taxa de Depuração Metabólica , Pessoa de Meia-Idade , Piperazinas/uso terapêutico , Pirimidinas/uso terapêutico
15.
G Ital Dermatol Venereol ; 148(4): 371-85, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23900159

RESUMO

This paper will give a comprehensive view of the most frequent panniculitides seen in childhood, with emphasis on the types exclusively found in infancy, and for all other types of panniculitides also found in adults. Aim of this paper is also to analyze the clinical differences between panniculitis in childhood and in adulthood, and to give reliable histopathologic criteria for a specific diagnosis. A review of the literature is here integrated by authors' personal contribution. Panniculitides in children is a heterogeneous group of diseases, as well as in adult life, characterized by inflammation of the subcutaneous fat. Only very few types of panniculitis are exclusively found in childhood, such as Sclerema neonatorum and subcutaneous fat necrosis of the newborn, while the vast majority of the other types may be found both in paediatric age and in adults. Furthermore, this paper will consider in detail panniculitis according to their frequency, such as Erythema nodosum, Lupus panniculitis, Cold panniculitis, panniculitis in Behçet disease, and poststeroid panniculitis. It will also describe rare forms of panniculitis, such as Eosinophilic panniculitis (a pathological entity debated by many authors), Subcutaneous panniculitis T-cell lymphoma, and the different forms of the so call "Lipophagic panniculitis", encompassing respectively the febrile relapsing panniculitis of Weber-Christian disease and the non-relapsing form of Rothmann-Makai disease. For each type of panniculitis considered concise information will be given about epidemiology, etiology, clinical findings, laboratory data, prognosis and therapy, while histopathologic findings will be described in detail.


Assuntos
Paniculite/patologia , Corticosteroides/efeitos adversos , Idade de Início , Síndrome de Behçet/complicações , Celulite (Flegmão)/sangue , Celulite (Flegmão)/epidemiologia , Celulite (Flegmão)/patologia , Celulite (Flegmão)/terapia , Criança , Pré-Escolar , Temperatura Baixa/efeitos adversos , Diagnóstico Diferencial , Eosinofilia/sangue , Eosinofilia/epidemiologia , Eosinofilia/patologia , Eosinofilia/terapia , Eritema Nodoso/sangue , Eritema Nodoso/diagnóstico , Eritema Nodoso/epidemiologia , Eritema Nodoso/patologia , Eritema Nodoso/terapia , Necrose Gordurosa/sangue , Necrose Gordurosa/epidemiologia , Necrose Gordurosa/patologia , Necrose Gordurosa/terapia , Granuloma Anular/sangue , Granuloma Anular/epidemiologia , Granuloma Anular/patologia , Granuloma Anular/terapia , Humanos , Lactente , Recém-Nascido , Linfoma Cutâneo de Células T/sangue , Linfoma Cutâneo de Células T/epidemiologia , Linfoma Cutâneo de Células T/patologia , Linfoma Cutâneo de Células T/terapia , Paniculite/classificação , Paniculite/diagnóstico , Paniculite/epidemiologia , Paniculite/etiologia , Paniculite/terapia , Paniculite Nodular não Supurativa/sangue , Paniculite Nodular não Supurativa/epidemiologia , Paniculite Nodular não Supurativa/patologia , Paniculite Nodular não Supurativa/terapia , Esclerema Neonatal/sangue , Esclerema Neonatal/epidemiologia , Esclerema Neonatal/patologia , Esclerema Neonatal/terapia , Gordura Subcutânea/patologia , Deficiência de alfa 1-Antitripsina/complicações
16.
G Ital Dermatol Venereol ; 148(4): 435-41, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23900165

RESUMO

Aim of this work was to define the histopathological features of post-surgical panniculitis. Dermal and hypodermal changes will be analyzed in detail, to understand the cascade of events that characterize the tissue response to surgical trauma. Cutaneous re-excision specimens of cases of basal cell carcinoma, squamous cell carcinoma, and melanoma consecutively seen from January 1, 2011 to June 30, 2011 at the Department of Dermatology, University of Pavia, were included in this study. Only the cases in which the first surgical procedure included the subcutaneous fat, were considered. In addition, the time elapsed from the first surgical procedure and the re-excision had to be included in a period of time from one to three months. All the specimens were stained with hematoxylin and eosin. Thirty cutaneous re-excision specimens were studied. Histopathologic examination revealed changes of epidermis, ranging from slight atrophy to moderate hyperplasia. In two cases focal ulceration was seen, with transfollicular elimination of foreign body material. The main dermal changes observed were the: 1) scar with well defined vertical orientation along the dermal suture line; 2) rounded cicatricial areas with radial branching septa of scarring tissue; 3) foreign body granuloma formation; 4) alignment of hystiocytes at the dermo-hypodermal border; 5) traumatic neuromas. The subcutaneous fat changes included: 1) lobular panniculitis with consistent presence of foam cells; 2) striking anisocytosis with pseudocystic degeneration and necrosis of adipocytes; 3) eritrocyte extravasation, mainly at the dermo-hypodermal border; 4) deep seated phlebitis. Post-surgical panniculitis is a lobular foam cell panniculitis characterized by simultaneous dermal and hypodermal changes, expression of the multi-faceted tissue response to a surgical trauma. This type of peculiar lipophagic response puts post-surgical panniculitis into the wider chapter of lipophage tissue response seen in atherosclerosis, glomerulosclerosis and some infectious models such as Mycobacterium tuberculosis and Chlamydia pneumoniae infections. Furthermore it may be seen as a reliable and convenient model for laboratory investigation on foam cell tissue response.


Assuntos
Células Espumosas/fisiologia , Paniculite/etiologia , Fagocitose , Complicações Pós-Operatórias/etiologia , Carcinoma Basocelular/cirurgia , Carcinoma de Células Escamosas/cirurgia , Cicatriz/etiologia , Cicatriz/patologia , Derme/lesões , Epiderme/lesões , Células Espumosas/patologia , Granuloma de Corpo Estranho/etiologia , Granuloma de Corpo Estranho/patologia , Histiócitos/patologia , Humanos , Melanoma/cirurgia , Modelos Biológicos , Necrose , Paniculite/patologia , Neoplasias Cutâneas/cirurgia , Gordura Subcutânea/lesões , Gordura Subcutânea/patologia , Cicatrização
17.
Neuroscience ; 223: 1-11, 2012 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-22863673

RESUMO

In this study we show that high frequency stimulation (HFS, 100Hz) of afferent fibers to the medial vestibular nucleus (MVN) can induce opposite long-term modifications of synaptic responses in the type B neurons depending upon the stimulation pattern. Long burst stimulation (LBS: 2s) and short burst stimulation (SBS: 0.55s) were applied with different burst number (BN) and inter-burst intervals (IBI). It results that both LBS and SBS can induce either N-methyl-d aspartate receptors (NMDARs)-mediated long-term potentiation (LTP) or long-term depression (LTD), depending on temporal organization of repetitive bursts. In particular, the IBI plays a relevant role in guiding the shift from LTP to LTD since by using both LBS and SBS LTP is induced by shorter IBI than LTD. By contrast, the sign of long-term effect does not depend on the mean impulse frequency evaluated within the entire stimulation period. Therefore, the patterns of repetitive vestibular activation with different ratios between periods of increased activity and periods of basal activity may lead to LTP or LTD probably causing different levels of postsynaptic Ca(2+). On the whole, this study demonstrates that glutamatergic vestibular synapse in the MVN can undergo NMDAR-dependent bidirectional plasticity and puts forward a new aspect for understanding the adaptive and compensatory plasticity of the oculomotor responses.


Assuntos
Vias Aferentes/fisiologia , Estimulação Elétrica , Potenciação de Longa Duração/fisiologia , Depressão Sináptica de Longo Prazo/fisiologia , Neurônios/fisiologia , Sinapses/fisiologia , Núcleos Vestibulares/citologia , Análise de Variância , Animais , Animais Recém-Nascidos , Biofísica , Potenciais Pós-Sinápticos Excitadores/fisiologia , Técnicas In Vitro , Masculino , Técnicas de Patch-Clamp , Ratos , Fatores de Tempo
18.
Neuroscience ; 192: 67-73, 2011 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-21749911

RESUMO

In the hippocampal formation many neuromodulators are possibly implied in the synaptic plasticity such as the long-term potentiation (LTP) induced by high-frequency stimulation (HFS) of afferent fibers. We investigated the involvement of locally synthesized neural 17ß-estradiol (nE(2)) in the induction of HFS-LTP in hippocampal slices from male rats by stimulating the Schaffer collateral fibers and recording the evoked field excitatory postsynaptic potential (fEPSP) in the CA1 region. We demonstrated that either the blockade of nE(2) synthesis by the aromatase inhibitor letrozole, or the antagonism of E(2) receptors (ERs) by ICI 182,780 did not prevent the induction of HFS-LTP, but reduced its amplitude by ∼60%, without influencing its maintenance. Moreover, letrozole and ICI 182,780 did not affect the first short-term post-tetanic component of LTP and the paired-pulse facilitation (PPF). These findings demonstrate that nE(2) plays an important role in the induction phase of HFS-dependent LTP. Since the basal responses were not affected by the blocking agents, we suggest that the synthesis of nE(2) is induced or enhanced by HFS through aromatase activation. In this context, the local production of nE(2) seems to be a very effective mechanism to modulate the amplitude of LTP.


Assuntos
Região CA1 Hipocampal/metabolismo , Estradiol/metabolismo , Potenciação de Longa Duração/fisiologia , Neurônios/metabolismo , Animais , Inibidores da Aromatase/farmacologia , Região CA1 Hipocampal/efeitos dos fármacos , Antagonistas de Estrogênios/farmacologia , Potenciais Pós-Sinápticos Excitadores/fisiologia , Potenciação de Longa Duração/efeitos dos fármacos , Masculino , Neurônios/efeitos dos fármacos , Técnicas de Cultura de Órgãos , Ratos , Ratos Wistar
19.
Neuroscience ; 187: 1-14, 2011 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-21539898

RESUMO

Using intracellular recordings, we investigated the effects of high frequency stimulation (HFS) of the primary vestibular afferents on the evoked excitatory postsynaptic potential (EPSP) and intrinsic excitability (IE) of type-A and type-B neurons of the medial vestibular nucleus (MVN), in male rat brainstem slices. HFS induces long-term potentiation (LTP) of both EPSP and IE, which may occur in combination or separately. Synaptic LTP is characterized by an increase in the amplitude, slope and decay time constant of EPSP and IE-LTP through enhancements of spontaneous and evoked neuron firing and of input resistance (Rin). Moreover, IE-LTP is associated with a decrease in action potential afterhyperpolarization (AHP) amplitude and an increase in interspike slope steepness (ISS). The more frequent effects of HFS are EPSP-LTP in type-B neurons and IE-LTP in type-A neurons. In addition, the development of EPSP-LTP is fast in type-B neurons but slow in type-A, whereas IE-LTP develops slowly in both types. We have demonstrated that activation of N-methyl-d aspartate receptors (NMDARs) is only required for EPSP-LTP induction, whereas metabotropic glutamate receptors type-1 (mGluR1) are necessary for IE-LTP induction as well as the full development and maintenance of EPSP-LTP. Taken together, these findings demonstrate that brief and intense activation of vestibular afferent input to the MVN neurons may provoke synaptic LTP and/or IE-LTP that, induced in combination or separately, may assure the different selectivity of the MVN neuron response enhancement to the afferent signals.


Assuntos
Potenciais Pós-Sinápticos Excitadores/fisiologia , Potenciação de Longa Duração/fisiologia , Neurônios/fisiologia , Sinapses/fisiologia , Núcleos Vestibulares/fisiologia , Vias Aferentes/fisiologia , Animais , Estimulação Elétrica , Masculino , Técnicas de Cultura de Órgãos , Técnicas de Patch-Clamp , Ratos , Ratos Wistar , Transmissão Sináptica/fisiologia
20.
Neuroscience ; 171(3): 666-76, 2010 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-20884332

RESUMO

In brainstem slices of young male rat, we investigated the influence of the neuroactive steroid testosterone (T) on the synaptic responses by analyzing the field potential evoked in the medial vestibular nucleus (MVN) by vestibular afferent stimulation. T induced three distinct and independent long-term synaptic changes: fast long-lasting potentiation (fLP), slow long-lasting potentiation (sLP) and long-lasting depression (LD). The fLP was mediated by 17ß-estradiol (E(2)) since it was abolished by blocking the estrogen receptors (ERs) or the enzyme converting T to E(2). Conversely, sLP and LD were mediated by 5α-dihydrotestosterone (DHT) since they were prevented by blocking the androgen receptors (ARs) or the enzyme converting T to DHT. Therefore, the synaptic effects of T were mediated by its androgenic or estrogenic metabolites. The pathways leading to estrogenic and androgenic conversion of T might be co-localized since, the occurrence of fLP under block of androgenic pathway, and that of sLP and LD under estrogenic block, were higher than those observed without blocks. In case of co-localization, the effect on synaptic transmission should depend on the prevailing enzymatic activity. We conclude that circulating and neuronal T can remarkably influence synaptic responses of the vestibular neurons in different and opposite ways, depending on its conversion to estrogenic or androgenic metabolites.


Assuntos
Androgênios/fisiologia , Estrogênios/fisiologia , Neurônios/metabolismo , Transmissão Sináptica/fisiologia , Testosterona/fisiologia , Núcleos Vestibulares/metabolismo , Androgênios/farmacologia , Animais , Estrogênios/farmacologia , Masculino , Neurônios/efeitos dos fármacos , Técnicas de Cultura de Órgãos , Ratos , Ratos Wistar , Transmissão Sináptica/efeitos dos fármacos , Testosterona/farmacologia , Núcleos Vestibulares/citologia , Núcleos Vestibulares/efeitos dos fármacos
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