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2.
Ann Med Surg (Lond) ; 78: 103914, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35734695

RESUMO

Introduction: The terrible triad of the elbow (TTE) is a lesion associating a dislocation of the elbow, a fracture of the radial head, and a fracture of the coronoid process, with a high potential of complication. The treatment is based on the restoration of bone lesions and external capsular ligament repair. The systematic repair of the medial collateral ligament (MCL) is still debated in the literature. The aim of this study is to evaluate the clinical and functional results of the surgical treatment in a real-world series from Easter Morocco. Patients and methods: This was a retrospective study of 6 cases of TTE operated by isolated external approach or combined approach (internal or anterior) of the elbow in the department of Traumatology-Orthopedics of the Mohammed VI University Hospital (Oujda Morocco), over a period of 7 years from 2013 to 2020. Radial head and coronoid process fractures were classified according to the Mason and Morrey-Regan classifications, respectively. The following clinical parameters were evaluated: Mayo Clinic Elbow Performance Score (MEPS), Quick Disabilities of the Arm, Shoulder and Hand (DASH), Visual Analog Scale (VAS), and arc of mobility in flexion-extension and prono-supination. Results: 6 male patients treated between May 2013 and December 2020 were included. The median follow-up was 48 months. All patients had frontal and lateral standard X-ray of over and under joints, and computed tomography (CT)-scan was delivered for 5 cases. The elbow dislocation was posterolateral in five cases, and posteromedial in only one patient. Radial head fractures were classified as type I in one case, type II in two cases, and type III in three cases. Coronoid fractures were type I in three cases, type II in one case, and type III in two cases. At the last follow up, the mean MEPS, Quick DASH, and VAS was 81, 28, 0.8, respectively. The mean arc of mobility in flexion was 120° and it was deficient by 20° in extension. In addition, the mean arc of mobility in protonation was 80°, while in supination it was 75°. Regarding complications, we noticed an instability of the elbow on valgus in a single case, elbow stiffness with heterotopic ossification in a single case, ulnar nerve damage in a single case during medial collateral ligament anchoring, and elbow hygroma in one single case. Conclusion: The surgical management of TTE can provide good and long-term functional results after restoration of the stabilization of bone structures and the lateral ligament complex, without the need to repair the medial collateral ligament.

3.
Cureus ; 14(3): e23683, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35505755

RESUMO

Introduction The aim of this study was to compare epidemiological characteristics of breast cancer in young adolescent women (YAW) versus older women (OW). Methods This was a cross-sectional prospective observational study, conducted in Ward 3, Jinnah Postgraduate Medical Center, Karachi, Pakistan, from September 2021 to February 2022. A total of 120 female patients were recruited in this study from the Outpatient Department of Jinnah Postgraduate Medical Center, out of which 22 patients were below the age of 40 years and 98 were above 40 years. For breast cancer diagnosis, we used the triple assessment method involving clinical examination, radiology, and histopathology. Diagnosed patients were further evaluated for hormonal status and metastatic workup. Results were noted on a performa, and differences between both age groups were analyzed. Results Out of 120 patients, 22 were younger than 40 years and 98 were older than 40 years. YAW used to present late after the appearance of symptoms. Patients of both age groups mostly presented with breast lumps (68.18% in YAW and 81.6% in OW). YAW presented with larger sizes of lumps and with more nodal involvement as compared to OW. BI-RADS IV (Breast Imaging Reporting and Data System Category IV) was the most commonly observed (27.27% in YAW and 48.97% in OW) mammographic finding in both age groups. Invasive ductal carcinoma was the most common histological type in both age groups (72.73% in YAW and 76.53% in OW). The triple-negative disease was more commonly found in YAW than OW (40.91% in YAW vs 21.43% in OW). We found that usually YAW presented at advanced stages (stages III and IV, 54.55%) and higher grades (grade III, 63.63%). Conclusion Breast cancer in young patients is rare but more aggressive with higher grades, advanced stages, and poor prognostic features. Heredity is mainly the risk factor in young breast cancer patients. There should be proper screening programs for high-risk group for early diagnosis and prompt treatment. Other age-specific concerns such as psychological impact of disease should be addressed as well.

4.
Med J Malaysia ; 75(4): 400-402, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32724002

RESUMO

In Malaysia, COVID-19 pandemic recorded considerable number of cases. Many hospitals have been converted into COVID-19 centres to manage these cases. The Penang General Hospital was designated as a hybrid hospital to manage both COVID-19 and non-COVID-19 cases. Consequently, services across specialties, including urology have been affected. Triage of referrals was necessary to ensure optimum patient care, thus we designed a triage system to address this situation. A record screening system of patients was also implemented to limit outpatient appointments. We share this early experience in managing urology patients during this pandemic.


Assuntos
Betacoronavirus , Infecções por Coronavirus/epidemiologia , Pneumonia Viral/epidemiologia , Encaminhamento e Consulta , Triagem , Urologia , Assistência Ambulatorial , COVID-19 , Humanos , Pandemias , SARS-CoV-2
5.
Heliyon ; 4(3): e00567, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29560476

RESUMO

Recently, researchers have started to pay more attention to a usually ignored topic: audience perceptions. Legitimacy, for example, is no longer modeled as the number of organizations in a population. It is now thought to be dependent on how audience members perceive these organizations. This paper will study how the newspaper industry in Lebanon emerged. The paper studies the period 1851-1879, building on the theoretic formulation of Hannan et al. (2007). The concept of cluster formation will also be introduced in order to help answer the question of whether unified identity projection is a necessary condition for successful legitimation and emergence. So far, research has produced diverging results as to the necessary conditions for successful legitimation. Cluster Analysis is used to show that in the case of the Lebanese newspaper industry, successful emergence was attained without the need to project a unified identity. In fact, the analysis clearly shows that there were two separate groups of clusters that had emerged by the end of the period. The nature of these two clusters will be investigated by looking at the category spanning activities of the newspapers that were members of the clusters.

6.
Eur J Trauma Emerg Surg ; 40(3): 387-93, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26816076

RESUMO

PURPOSE: Management practices associated with war-related amputations in countries at war may be different from the recommendations of occidental Health Force Services due to the high numbers of wounded persons to treat in precarious conditions. This observational retrospective study documents the current management of local lower extremity amputees in Afghanistan. Surgical practices, with or without delayed primary closure (DPC), and prosthetic rehabilitation issues are analyzed. METHODS: This retrospective study was conducted in the National Military Hospital (NMH) of Kabul from May 2011 to November 2011. Fifty-four Afghan patients who underwent a lower extremity combat-related amputation were included. Ten of them sustained a bilateral amputation. RESULTS: Injuries were caused by improvised explosive devices (IEDs) or mines in 48 cases, bullets in three cases, and exploding shell fragments in three cases. Of the 64 amputations studied, 46 were open length preserving amputations and primary closure (PC) was applied in 18 cases. Patients were reviewed with a mean follow-up of 5.4 months (range 1-28 months). In the DPC group, secondary closure was performed with a mean time of 18.7 days (range 4-45 days) from injury. The proportion of infectious complications seemed to be higher in the PC group (5/18) than in the DPC group (3/46), but it was only a statistical trend (p = 0.1). Forty-three patients were not prosthetic fitted at the last follow-up. CONCLUSION: This study supports the surgical strategy of a two-stage procedure for lower limb amputations in countries at war, but underlines the problems of late secondary closure and prosthetic fitting related to decreased sanitary conditions.

7.
Chir Main ; 31(5): 266-8, 2012 Oct.
Artigo em Francês | MEDLINE | ID: mdl-23084653

RESUMO

Wartenberg's sign, or permanent abduction of the little finger, occurs in the context of sequelae of ulnar nerve palsy. Its presence alone is rarely reported in the literature and is due to avulsion of the insertion of the third volar interosseous muscle. Several surgical techniques to correct this sign are reported in the literature. The authors report the case of a Wartenberg's sign without ulnar nerve palsy due to traumatic avulsion of the third volar interosseous muscle that was treated by a transfer of the extensor digiti minimi onto the radial side of the extensor digitorium communis according to technique of Bellan et al. After 1-year follow-up, result was good with no recurrence of any deformities and a normal active extension.


Assuntos
Deformidades Adquiridas da Mão/cirurgia , Músculo Esquelético/cirurgia , Transferência Tendinosa , Neuropatias Ulnares/cirurgia , Adulto , Seguimentos , Deformidades Adquiridas da Mão/etiologia , Humanos , Masculino , Articulação Metacarpofalângica/inervação , Articulação Metacarpofalângica/cirurgia , Procedimentos Ortopédicos/métodos , Técnicas de Sutura , Transferência Tendinosa/métodos , Resultado do Tratamento , Neuropatias Ulnares/etiologia
9.
Horm Metab Res ; 39(7): 515-8, 2007 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-17611905

RESUMO

OBJECTIVE: The aim of this study was to investigate the gender specific correlations of stress related tissues [adrenal gland volume (AV), visceral fat] and alimentary dependent fat compartments with cortisol concentrations in healthy male and female subjects. METHODS: Fourteen men and 13 women were examined. Fat compartments [whole body fat, visceral adipose tissue (VAT) and subcutaneous adipose tissue (SCAT)] were determined using whole body MRI. Adrenal gland volume was assessed by a 3D MR data set. The salivary cortisol was determined at 9 AM and 4 PM. RESULTS: Men had significantly more visceral fat and less subcutaneous fat than women. Adrenal gland size correlated significantly with the visceral and subcutaneous fat in women (r=0.7, p=0.008), but not in men (r=0.2, p=0.4). There was a negative correlation between the decrease of cortisol between 9 AM and 4 PM with VAT (r=-0.451, p=0.027) in the whole group. DISCUSSION: The high correlation between the adrenal gland volume and VAT in women underlines the link between hypothalamic-pituitary-adrenal (HPA) axis, stress, and circadian cortisol rhythm, respectively, and an increased abdominal fat volume. The lack of correlation between visceral fat and adrenal volume in men points to an additional influence of sex hormones.


Assuntos
Glândulas Suprarrenais/anatomia & histologia , Distribuição da Gordura Corporal , Imageamento por Ressonância Magnética , Caracteres Sexuais , Imagem Corporal Total , Tecido Adiposo/anatomia & histologia , Adulto , Feminino , Saúde , Humanos , Masculino , Pessoa de Meia-Idade , Tamanho do Órgão
10.
Head Neck ; 29(9): 851-6, 2007 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17427964

RESUMO

BACKGROUND: Our aim was to determine the surgical characteristics of an elderly cohort of patients undergoing resection of head and neck skin neoplasms. METHODS.: All cases of patients with head and neck skin neoplasms (excluding malignant melanoma) who underwent surgical resection in a regional referral center over a 10-year period were retrospectively reviewed. The study group comprised 152 patients (208 cases) aged >or=80 years. They were compared with 311 patients (430 cases) aged <80 years. RESULTS: Elderly patients had higher Charlson comorbidity index, American Society of Anesthesiologists' physical status scores, dementia, and aspirin intake (all p < .05). They also had a higher incidence of scalp involvement and lower incidence of nasal involvement (both p < .05). Elderly patients had a larger lesion size at presentation and required sacrifice of a greater area of skin (both p < .05). However, they also underwent more local anesthetic procedures, although the need for local flap or skin graft repair was not increased. Two elderly patients had intraoperative tachyarrythmias induced by local anesthesia. However, no patient died within 30 days of surgery, and wound complication rate and disease-free survival were comparable to younger patients. CONCLUSION: With careful attention to comorbid illness and perioperative monitoring, surgical resection of head and neck skin neoplasms is safe in the elderly. Lesions are more advanced at presentation and hence require sacrifice of a larger area of skin to obtain macroscopic clearance. Yet for the majority of lesions, local anesthesia is adequate and surgical resection and simple skin closure can be accomplished without the need for complex flap or skin graft reconstructions.


Assuntos
Neoplasias de Cabeça e Pescoço/cirurgia , Idoso de 80 Anos ou mais , Anestesia Geral , Anestesia Local , Carcinoma Basocelular/cirurgia , Carcinoma de Células Escamosas/cirurgia , Comorbidade , Feminino , Neoplasias de Cabeça e Pescoço/epidemiologia , Humanos , Masculino , Neoplasias Nasais/cirurgia , Procedimentos de Cirurgia Plástica , Estudos Retrospectivos , Couro Cabeludo , Neoplasias Cutâneas/cirurgia
11.
J Neurol Neurosurg Psychiatry ; 78(2): 152-6, 2007 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-16891384

RESUMO

BACKGROUND: Tinnitus has been shown to respond to modulations of cortical activity by high-frequency and low-frequency repetitive transcranial magnetic stimulation (rTMS). OBJECTIVE: To determine the tinnitus-attenuating effects of a 2-week daily regimen of rTMS, navigated to the maximum of tinnitus-related increase in regional cerebral blood flow. METHODS: Six patients with chronic tinnitus were enrolled in this sham-controlled crossover study and treated with 2x2 weeks of suprathreshold 1 Hz rTMS (30 min) applied to the region with maximal tinnitus-related increase in regional cerebral blood flow delineated by functional imaging with [15O]H2O positron emission tomography and a control area. Tinnitus-related distress was assessed before and after each treatment and 2 weeks after the end of the 4-week course of stimulation using a validated tinnitus questionnaire. Additional self-assessment scores of tinnitus change, loudness and annoyance were obtained. RESULTS: In five of six patients, rTMS induced greater reduction of the tinnitus questionnaire score than sham stimulation. In two patients, all parameters measured (tinnitus change score, tinnitus loudness, tinnitus annoyance) showed unequivocal improvement. At the group level, the degree of response in the tinnitus questionnaire score was correlated with tinnitus-associated activation of the anterior cingulate cortex. Two weeks after the final stimulation, tinnitus had returned to baseline in all patients but one. CONCLUSION: Tinnitus can be attenuated by low-frequency rTMS navigated to each person's maximum tinnitus-related cortical hyperactivity. The effects are only moderate; interindividual responsiveness varies and the attenuation seems to wear off within 2 weeks after the last stimulation session. Notably, tinnitus-related anterior cingulate cortex activation seems to predict the response to rTMS treatment.


Assuntos
Zumbido/terapia , Estimulação Magnética Transcraniana , Idoso , Doença Crônica , Estudos Cross-Over , Feminino , Giro do Cíngulo/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Tomografia por Emissão de Pósitrons , Recidiva , Estimulação Magnética Transcraniana/métodos , Resultado do Tratamento
12.
J Neuroimmunol ; 183(1-2): 43-9, 2007 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-17184847

RESUMO

Infection with a high dose of Leishmania major has been shown to induce hyperalgesia in BALB/c mice accompanied by a sustained upregulation of Interleukin-1beta (IL-1beta) and an early upregulation of Interleukin-6 (IL-6). On the other hand, Interleukin 10 (IL-10) has been demonstrated to be hypoalgesic in other models such as rats exposed to UV rays. In this study, we injected BALB/c mice with a high dose of Leishmania major and treated them with IL-10 (15 ng/animal) for six consecutive days. Hyperalgesia was assessed using thermal pain tests and the levels of IL-1beta and IL-6 were also assessed at different post-infection days. Our results show that IL-10 can reduce the Leishmania major-induced hyperalgesia during the treatment period through a direct effect on the levels of IL-1beta which seems to play an important role in this hyperalgesia induction since its level was reduced during the period of IL-10 injection and was increased again when this treatment was stopped. On the contrary IL-10 has no direct effect on the levels IL-6 which seems to have no direct role in the induced hyperalgesia.


Assuntos
Hiperalgesia/tratamento farmacológico , Interleucina-10/uso terapêutico , Interleucina-1beta/metabolismo , Leishmania major , Leishmaniose Cutânea/complicações , Análise de Variância , Animais , Feminino , Hiperalgesia/etiologia , Interleucina-6/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Tempo de Reação/efeitos dos fármacos
13.
Arch Otolaryngol Head Neck Surg ; 132(11): 1237-41, 2006 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17116821

RESUMO

OBJECTIVE: To determine whether the antiplatelet agent aspirin increases hemorrhagic risk in patients undergoing surgical resection of cutaneous head and neck lesions. DESIGN: Retrospective cohort study. SETTING: Regional referral center. Patients All cases of cutaneous head and neck lesions surgically resected during a 10-year period were included. MAIN OUTCOME MEASURES: Outcome measures were incidence of significant postoperative hemorrhage, defined as postoperative hematoma or hemorrhage necessitating surgical reexploration; and total postoperative hemorrhage, defined as any hemorrhage lasting longer than 4 hours despite external pressure, requiring medical review, and resulting in prolongation of the patient's hospital stay or readmission to the hospital. RESULTS: Seven hundred eleven patients (974 cases) were eligible for inclusion, of whom 320 were receiving aspirin therapy at the time of surgery. The incidence of significant postoperative hemorrhage in the aspirin and nonaspirin groups was 5 (1.6%) and 0, respectively (P = .004), and aspirin use was the only risk factor for significant postoperative hemorrhage. The incidence of total postoperative hemorrhage in the aspirin and nonaspirin groups was 7 (2.2%) and 1 (0.1%), respectively (P = .002). At multivariate analysis, aspirin use and local flap reconstruction were independent risk factors for total postoperative hemorrhage. Cases receiving aspirin therapy who also underwent local flap reconstruction were at exponential (124-fold) increased risk of total postoperative hemorrhage compared with cases with neither risk factor. CONCLUSIONS: Aspirin intake at the time of surgery to resect cutaneous head and neck lesions confers a small but statistically increased risk of postoperative hemorrhage. This risk is particularly pronounced in patients undergoing local flap reconstruction.


Assuntos
Aspirina/efeitos adversos , Neoplasias de Cabeça e Pescoço/cirurgia , Inibidores da Agregação Plaquetária/efeitos adversos , Hemorragia Pós-Operatória/induzido quimicamente , Neoplasias Cutâneas/cirurgia , Idoso , Estudos de Coortes , Feminino , Humanos , Masculino , Análise Multivariada , Estudos Retrospectivos , Fatores de Risco , Retalhos Cirúrgicos
14.
Exp Parasitol ; 113(3): 168-73, 2006 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16516198

RESUMO

Neural involvement was traditionally associated with leprosy. However, more recent studies have shown the presence of a persistent hyperalgesia in cutaneous leishmaniasis caused by the infection of BALB/c mice with a high dose of Leishmania major. In this study, we report the presence of hyperalgesia within the first two weeks of infection caused by a low dose of the parasite. Using BALB/c mice, we demonstrate the presence of hyperalgesia during the first 10 days of infection as assessed by thermal pain tests. After 10 days these decreased pain thresholds start to recover resulting in similar levels to those in uninfected controls during the third week of infection. This hyperalgesia is accompanied by a sustained upregulation of interleukin-1beta (IL-1beta) and an early upregulation of interleukin-6 (IL-6) which is restored to normal levels after five days of infection. In conclusion, this study shows that, during early infection, the low dose of L. major causes hyperalgesia accompanied by an upregulation of IL-1beta and IL-6 and that these effects are reversed within the first two weeks of infection.


Assuntos
Hiperalgesia/parasitologia , Interleucina-1/metabolismo , Interleucina-6/metabolismo , Leishmania major/patogenicidade , Leishmaniose Cutânea/fisiopatologia , Animais , Feminino , Leishmania major/imunologia , Leishmaniose Cutânea/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Regulação para Cima
15.
Dalton Trans ; (19): 3106-9, 2004 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-15452639

RESUMO

The apatite-type phases, La(9.33+x)(Si/Ge)(6)O(26+3x/2), have recently been attracting considerable interest as potential electrolytes for solid oxide fuel cells. In this paper we report results from a range of doping studies in the Si based systems, aimed at determining the key features required for the optimisation of the conductivities. Systems examined have included alkaline earth doping on the rare earth site, and P, B, Ga, V doping on the Si site. By suitable doping strategies, factors such as the level of cation vacancies and oxygen excess have been investigated. The results show that the oxide ion conductivities of these apatite systems are maximised by the incorporation of either oxygen excess or cation vacancies, with the former producing the best oxide ion conductors. In terms of samples containing cation vacancies, conductivities are enhanced by doping lower valent ions, Ga, B, on the Si site. The presence of higher valent ions on these sites, e.g. P, appears to inhibit the incorporation of excess oxygen within the channels, and so limits the maximum conductivity that can be obtained. Overall the results suggest that the tetrahedral sites play a key role in the conduction properties of these materials, supporting recent modelling studies, which have suggested that these tetrahedra aid in the motion of the oxide ions down the conduction channels by co-operative displacements.

16.
Saudi Med J ; 23(6): 672-4, 2002 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-12070545

RESUMO

OBJECTIVE: This study is aimed at determining the incidence of surgical site infections, with antibiotic use. Furthermore, to correlate infection with type of operations, length of intervention, number of stitches, pre-operative hospitalization, age and sex of the patient. METHODS: All Yemeni patients (N=601) who underwent surgical intervention, with preoperative antibiotic prophylaxis, at Al-Kuwait University Hospital, Sana'a, Republic of Yemen, during 1st August 2000 through to 30th November 2000 were followed up until stitch removal or discharge. Data was registered in a spreadsheet and processed statistically by statistical package for social sciences 10.0. RESULTS: Overall incidence of surgical site infections was 2.2%, 0.5% in clean operation, 2.8% in clean contaminated, 9.1% in contaminated and 2.3% in dirty operations. Surgical site infections were found positively correlated with duration of operation (P=0.015) and number of stitches (P=0.017), but insignificantly associated with sex, age, type of operation and pre-operative hospitalization. CONCLUSION: In conclusion, surgical site infections, with antibiotic use, were found low. Higher number of stitches and longer duration of operation were the risk factors.


Assuntos
Antibioticoprofilaxia , Procedimentos Cirúrgicos Operatórios/métodos , Infecção da Ferida Cirúrgica/prevenção & controle , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Feminino , Hospitais Universitários , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Iêmen
17.
J Mol Neurosci ; 17(3): 303-10, 2001 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11859926

RESUMO

As has been previously described, tetanus toxin (TeTx) and its H(C) fragment inhibit the sodium-dependent 5-hydroxytryptamine (5-HT) uptake in rat-brain synaptosomes, probably through a kinase mechanism affecting the 5-HT transporter. Now, the inhibition of 5-HT uptake in neurons in primary culture by TeTx in a dose-dependent manner is described in this work. This effect is also produced by the nontoxic C-terminal fragment of the TeTx heavy chain (H(C)-fragment), indicating that 5-HT uptake inhibition is a consequence of the toxin binding to the plasmatic membrane and not to its catalytic activity. This conclusion is supported by the fact that the 5-HT accumulation was not inhibited by the light chain of TeTx or the toxoid, and was even potentiated by botulinum neurotoxin A. These results correlate with the activation of phosphoinositide-phospholipase C activity in the cultures used in this study, this activity only being enhanced by TeTx and by its Hc-fragment. On the other hand, the use of tyrosine phosphorylation modulators indicates that both Na3VO4 and basic fibroblast growth factor (bFGF) produce an enhancement of 5-HT uptake in this system, which is also sensitive to TeTx inhibition. On the other hand, genistein alone is able to reduce the 5-HT transport in cultured neurons, and this effect did not appear to be additive to that elicited by TeTx. This result suggests that TeTx and genistein may share some events in their respective mechanisms of action. Furthermore, the incubation at different concentrations of 12-O-tetradecanoylphorbol 13-acetate (TPA) confirms the involvement of protein kinase C (PKC) in 5-HT transport modulation in rat-brain neuronal primary cultures. In summary, we shall demonstrate in this work that TeTx induces, through its Hc fragment, an inhibition of both basal and stimulated serotonin uptakes in primary neuronal cultures, in parallel to the activation of phosphoinositide-phospholipase C activity and PKC activation.


Assuntos
Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Proteínas de Transporte/metabolismo , Glicoproteínas de Membrana/metabolismo , Proteínas de Membrana Transportadoras , Proteínas do Tecido Nervoso/metabolismo , Neurotoxinas/farmacologia , Serotonina/metabolismo , Toxina Tetânica/farmacologia , Animais , Transporte Biológico/efeitos dos fármacos , Encéfalo/citologia , Proteínas de Transporte/efeitos dos fármacos , Técnicas de Cultura de Células , Relação Dose-Resposta a Droga , Ativação Enzimática/efeitos dos fármacos , Glicoproteínas de Membrana/efeitos dos fármacos , Proteínas do Tecido Nervoso/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Fosforilação/efeitos dos fármacos , Proteína Quinase C/metabolismo , Ratos , Proteínas da Membrana Plasmática de Transporte de Serotonina , Fosfolipases Tipo C/metabolismo , Tirosina/metabolismo
18.
FEBS Lett ; 486(2): 136-42, 2000 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-11113454

RESUMO

Tetanus toxin (TeTx) modifies Na(+)-dependent, high-affinity 5-hydroxytryptamine (5-HT, serotonin) uptake in a synaptosomal-enriched P(2) fraction from rat brain. The effect corresponds to a rapid and non-competitive uptake inhibition, and it is preceded by induction of phospholipase C (PLC) activity and translocation and down-regulation of the classical protein kinase C (PKC-alpha, -beta and -gamma) isoforms. The effects on serotonin transport and on cPKC activation were similar to the effects exhibited by phorbol ester 12-O-tetradecanoylphorbol 13-acetate (TPA). Moreover, after treatment with TeTx, an increase in Ser- and Tyr-specific phosphorylation was found. Activation of PKC by both TeTx and TPA results in a loss of transport capacity and serotonin transporter (SERT) phosphorylation, which are abolished by coapplication of the specific PKC inhibitor bisindolylmaleimide-1. Since a specific PLCgamma1 phosphorylation prior to TeTx's inducing SERT phosphorylation was found, the studies suggest that part of the action of TeTx consists of modifying the signal cascade initiated in tyrosine kinase receptors on nerve tissue previous to its cellular internalization, resulting in transporter phosphorylation.


Assuntos
Proteínas de Transporte/metabolismo , Glicoproteínas de Membrana/metabolismo , Proteínas de Membrana Transportadoras , Proteínas do Tecido Nervoso/metabolismo , Serotonina/metabolismo , Toxina Tetânica/metabolismo , Animais , Transporte Biológico , Encéfalo/metabolismo , Relação Dose-Resposta a Droga , Ativação Enzimática , Inibidores Enzimáticos/metabolismo , Indóis/metabolismo , Isoenzimas/metabolismo , Marcação por Isótopo , Maleimidas/metabolismo , Fosfolipase C gama , Fosforilação , Proteína Quinase C/antagonistas & inibidores , Proteína Quinase C/metabolismo , Proteína Quinase C beta , Proteína Quinase C-alfa , Ratos , Ratos Sprague-Dawley , Serina/metabolismo , Proteínas da Membrana Plasmática de Transporte de Serotonina , Sinaptossomos/metabolismo , Toxina Tetânica/farmacologia , Acetato de Tetradecanoilforbol/metabolismo , Acetato de Tetradecanoilforbol/farmacologia , Trítio , Fosfolipases Tipo C/metabolismo , Tirosina/metabolismo
19.
J Neurochem ; 72(5): 1991-8, 1999 May.
Artigo em Inglês | MEDLINE | ID: mdl-10217276

RESUMO

Clostridium neurotoxins produce inhibition of both basal and K(+)-evoked serotonin release in rat brain synaptosomes. To produce these effects, tetanus toxin (TeTx), as well as botulinum neurotoxin type A (BoNT/A), added to brain synaptosomes, must be incubated at 37 degrees C over a long interval (hours). This serotonin exocytosis inhibition was abolished with previous treatment with specific Zn2(+)-metalloprotease inhibitors. Nevertheless, a short incubation time produces different behavior of the indicated neurotoxins: TeTx significantly blocks the sodium-dependent, high-affinity serotonin uptake, whereas a small increase of this uptake was found with BoNT/A. Both Zn2(+)-metalloprotease active fragments, light chains of TeTx and BoNT/A, are unable to reproduce the block of the serotonin uptake, whereas the C-terminal portion of the TeTx heavy chain (Hc-TeTx), which binds specifically to the target tissue, inhibited the serotonin uptake in a dose-dependent manner. The IC50 of Hc-TeTx ranges from 0.62 to 2.08 nM. Binding of [3H]imipramine and [3H]serotonin did not change after toxin treatments, which indicates that these clostridium neurotoxins do not act on the serotonin high-affinity site at the serotonin transporter or at other serotonin high-affinity sites. These results could indicate that TeTx and Hc-TeTx bind to different targets than BoNT/A in the plasma membrane.


Assuntos
Toxinas Botulínicas Tipo A/farmacologia , Encéfalo/metabolismo , Neurotoxinas/farmacologia , Antagonistas da Serotonina/farmacologia , Serotonina/metabolismo , Sinaptossomos/metabolismo , Toxina Tetânica/farmacologia , Animais , Toxinas Botulínicas Tipo A/química , Encéfalo/efeitos dos fármacos , Relação Dose-Resposta a Droga , Masculino , Fragmentos de Peptídeos/farmacologia , Ratos , Ratos Sprague-Dawley , Sinaptossomos/efeitos dos fármacos , Toxina Tetânica/química
20.
Biochem Pharmacol ; 57(1): 111-20, 1999 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-9920291

RESUMO

Tetanus toxin (TeTx) is a powerful clostridial neurotoxin that inhibits Ca2+-dependent neurotransmitter secretion as do the botulinum neurotoxins (BoNTs). We found that TeTx (but not BoNT/A) produced a specific time- and dose-dependent inhibition of Na+-dependent [3H]5-hydroxytryptamine (serotonin, 5-HT) uptake in rat CNS synaptosomes. This effect was found in all CNS tryptaminergic areas, being maximal in the hippocampus and occipital cortex. TeTx produced the maximum reduction in [3H]5-HT uptake after 30 min of preincubation, being significant also at lower doses (10(-12) M) or shorter incubation times (10 min). Serotonin transport inhibitors such as fenfluramine (IC50, 11.0 +/- 0.9 microM), paroxetine (IC50, 33.5 +/- 0.1 microM), and imipramine (IC50, 89.9 +/- 5.7 microM) were 3 or 4 orders of magnitude less potent than TeTx (IC50, 8.7 +/- 1.0 nM). Of the two fragments of TeTx, (the C-terminal portion of the neurotoxin heavy chain, which is responsible for the binding to the nerve tissue) was consistently more effective than the L-H(N) fragment (the light neurotoxin chain disulfide linked to the N-terminal portion of the heavy chain, which is responsible for the toxic metalloprotease action) as inhibitor of [3H]5-HT uptake in synaptosomal preparations (56 +/- 5% and 95 +/- 3% with respect to control, respectively). Antagonism of the toxin-induced [3H]5-HT uptake blockade could not be reversed by zinc chelators but did have the ability to antagonize the TeTx inhibition of basal and K+-evoked [3H]5-HT release in rat synaptosomes. The reduction in serotonin accumulation induced by TeTx could be responsible for some tetanic symptoms that have been related to the serotonergic system.


Assuntos
Encéfalo/metabolismo , Inibidores Seletivos de Recaptação de Serotonina/farmacologia , Serotonina/metabolismo , Sódio/farmacologia , Sinaptossomos/metabolismo , Toxina Tetânica/farmacologia , Animais , Transporte Biológico/efeitos dos fármacos , Toxinas Botulínicas/farmacologia , Captopril/farmacologia , Fenfluramina/farmacologia , Imipramina/farmacologia , Cinética , Masculino , Especificidade de Órgãos , Paroxetina/farmacologia , Fenantrolinas/farmacologia , Ratos , Ratos Sprague-Dawley , Sinaptossomos/efeitos dos fármacos , Temperatura , Trítio
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