RESUMO
Tumor hypoxia may play a fundamental role in determining the radiotherapy outcome for several cancer types. Functional imaging with hypoxia specific radiotracers offers a way to visualize and quantify regions of increased radioresistance, which may benefit from dose escalation strategies. Conversion of the uptake in positron emission tomography (PET) images into oxygenation maps offers a way to quantitatively characterize the microenvironment. However, normalization of the uptake with respect to a well-oxygenated reference volume (WOV), which should be properly selected, is necessary when using conversion functions. This study aims at assessing the sensitivity of quantifying tumor oxygenation based on 18F-fluoromisonidazole (FMISO) PET with respect to the choice of the location and the oxygenation level of the WOV in head and neck cancer patients. WOVs varying not only in shape and location but also with respect to the assigned pO2 level were considered. pO2 values other than the standard 60 mmHg were selected according to the specific tissue type included in the volume. For comparison, the volume which would be considered as hypoxic based on a tissue-to-muscle ratio equal to 1.4 was also delineated, as conventionally done in clinical practice. Hypoxia mapping strategies are found highly sensitive to selection of the location of well-oxygenated region, but also on its assigned oxygenation level, which is crucial for hypoxia-guided adaptive dose escalation strategies.
Assuntos
Neoplasias de Cabeça e Pescoço , Oximetria/instrumentação , Oximetria/normas , Oxigênio , Tomografia por Emissão de Pósitrons , Hipóxia Tumoral , Neoplasias de Cabeça e Pescoço/fisiopatologia , Humanos , Misonidazol/análogos & derivados , Misonidazol/metabolismo , Oxigênio/metabolismo , Microambiente TumoralRESUMO
OBJECTIVE: The aim of this study was to explore the influence of maternal eating behaviour on a clinical population of young women compared with a non-clinical one. METHODS: A group of 59 young women (age 16-30 yr) attending a weight-loss Clinic and their mothers (n=59; age 37-64 yr) were enrolled. They were compared with a group of female students (n=59; age 18-36 yr) and their mothers (n=59; age 41-67 yr). Body weight and height were measured and body mass index (BMI) calculated. Eating behaviour was assessed by using the Eating Disorders Inventory (EDI), Eating Inventory (EI) and Eating Attitude Test 26 (EAT-26). RESULTS: The EDI-2 scales significantly different between the groups were drive for thinness, bulimia, body dissatisfaction, inadequacy, enteroceptive awareness and insecurity. The EI scales values were all different between the groups and consistently higher in the clinical populations. The differences between groups were even more striking for the EAT-26 scales; the clinical young women had the highest scores. The daughter-mother correlation for each scale in the clinical and non-clinical groups showed that the EDI-2 scales assessing eating behaviour, drive for thinness, bulimia and body dissatisfaction, were significantly related in the non clinical group but not in the clinical group. On the other side, the clinical group showed correlation for the scales assessing psychopathological traits such as perfectionism, interpersonal disrupt, enteroceptive awareness, impulsivity and insecurity. For EI scales the correlation was significant for disinhibition in the non clinical group. A correspondence was observed for dieting in the non clinical group and for food preoccupation in the clinical group. EDI-2, EI and EAT-26 scales assessing eating behaviour were strongly predictive of BMI in both groups. CONCLUSIONS: Maternal eating behaviour influences the young women; in particular mothers-daughters of the clinical group showed some problems, for which they still had to grow up and stand out. Finally, the control population revealed some eating disorders as well.
Assuntos
Imagem Corporal , Comportamento Alimentar/psicologia , Transtornos da Alimentação e da Ingestão de Alimentos/psicologia , Mães/psicologia , Adolescente , Adulto , Idoso , Aconselhamento , Feminino , Humanos , Modelos Logísticos , Pessoa de Meia-Idade , Inquéritos e Questionários , Mulheres/psicologiaRESUMO
Vascular endothelial growth factor (VEGF) is a potent stimulator of angiogenesis, associated with unfavorable clinical characteristics in breast cancer. The aim of this study was to evaluate different angiogenic markers in endocrine-positive breast cancer patients. The authors analyzed serum and tumor samples from 71 patients with endocrine-positive operable primary breast cancer to determine the expression and the possible relationship between circulating serum VEGF levels, tumor VEGF expression, microvessel density (MVD), and other immunohistochemical parameters. Basal VEGF serum levels were significantly higher in breast cancer patients than in healthy controls. A significant correlation was observed between basal VEGF serum concentrations, microvessel density (p = 0.01) and p53 status (p = 0.004). Intratumoral VEGF expression was significantly associated with neoplastic embolization (p = 0.041) and circulating VEGF levels (p = 0.047). The results confirm that in primary endocrine-positive breast cancer serum VEGF levels are elevated and show a positive relationship with tumor VEGF and p53 overexpression.
Assuntos
Neoplasias da Mama/sangue , Proteína Supressora de Tumor p53/biossíntese , Fator A de Crescimento do Endotélio Vascular/sangue , Fator A de Crescimento do Endotélio Vascular/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias da Mama/irrigação sanguínea , Neoplasias da Mama/patologia , Progressão da Doença , Feminino , Humanos , Imuno-Histoquímica , Pessoa de Meia-Idade , Células Neoplásicas Circulantes/patologia , Neovascularização Patológica/metabolismo , Receptores de Estrogênio/metabolismoRESUMO
The behavioural factors that drive a normal weight woman to embark on a diet and to look for nutritional support in weight loss clinics are still not completely understood. A pilot cross-sectional study was carried out in 70 young (age range: 18-35 yr), normal weight women attending a weight loss clinic in South of Italy (Naples). They were compared to a population of 94 normal weight students (age range:17-23 yr) who had never attended a weight loss clinic. Subjects with eating disorders have been excluded. Weight and height were measured and body mass index (BMI) was calculated. Eating behaviour was assessed using a validated Italian version of the Eating Disorders Inventory (EDI) questionnaire. The two groups were matched for BMI (22.4 vs 22.1 kg/m2), smoking and physical activity. Students were more educated and less likely to be on a diet at the time of the study. Students had statistically significant lower scores for drive for thinness, body dissatisfaction, inadequacy and interpersonal disrupt. The bulimia scale was the only significant predictor (p<0.05) of BMI in the patients' group; body dissatisfaction (p<0.05) predicted BMI in the control group. This study has shown that weight concern and health awareness are not the only factors that lead a normal weight woman to look for nutritional counselling but there is an underlying substrate of psychological and social distress behind the request, which should be properly assessed before starting any nutritional therapy in the clinical practice.
Assuntos
Dieta Redutora/psicologia , Redução de Peso , Adolescente , Adulto , Imagem Corporal , Índice de Massa Corporal , Tamanho Corporal , Bulimia , Estudos Transversais , Escolaridade , Transtornos da Alimentação e da Ingestão de Alimentos/diagnóstico , Feminino , Humanos , Relações Interpessoais , Análise Multivariada , Projetos Piloto , Valores de Referência , Análise de Regressão , Inquéritos e QuestionáriosRESUMO
AIM: Knowledge of axillary lymph node status is a key aid to staging and prognosis and it represents a guideline for adjuvant therapy in breast cancer. Despite the morbidity it causes, complete axillary dissection was long the mainstay of treatment. Sentinel lymph node biopsy has proved so reliable in the evaluation of node involvement that axillary node dissection is now generally performed when sentinel node biopsy tests negative. METHODS: In this 3-phase study, 50 patients were enrolled to evaluate the learning curve of sentinel node biopsy (phase 1, September 1997-January 1998); 256 patients (age range 27-81 years) with infiltrative breast cancer (T <3 cm, clinical N0) underwent level 1 lymph node dissection when the sentinel node tested negative at histopathology (phase 2, February 1998-March 2001); 221 patients with T <3 cm underwent dissection of the sentinel node when it tested negative for metastasis (phase 3, April 2001-March 2005). RESULTS: The sentinel node was preoperatively detected in 98.6% of cases after peritumoral and intradermic injection of the radionuclide tracer and intraoperatively in 99% (90% with radio-guided surgery, 10% with vital staining). The sentinel node was positive in 15% of patients with T1 and metastatic in 65%. CONCLUSIONS: Our results are in line with the published data; therefore, the study will go forward to examine the role of the micrometastasis in the sentinel node and of in-transit tumoral cells.
Assuntos
Neoplasias da Mama/patologia , Neoplasias da Mama/cirurgia , Excisão de Linfonodo , Linfonodos/patologia , Linfonodos/cirurgia , Biópsia de Linfonodo Sentinela , Adulto , Idoso , Idoso de 80 Anos ou mais , Axila/cirurgia , Neoplasias da Mama/diagnóstico por imagem , Carcinoma Ductal de Mama/patologia , Carcinoma Ductal de Mama/cirurgia , Corantes , Feminino , Humanos , Linfonodos/diagnóstico por imagem , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Cintilografia , Compostos Radiofarmacêuticos , Estudos Retrospectivos , Sensibilidade e Especificidade , Biópsia de Linfonodo Sentinela/educação , Agregado de Albumina Marcado com Tecnécio Tc 99mRESUMO
UNLABELLED: Our objective was to investigate the potential risk factors associated with cytomegalovirus (CMV) infection. PATIENTS AND METHODS: From January 1999 to December 2001, 163 liver transplantations were performed in 154 patients. The study inclusion criteria were absence of retransplantation and survival of more than 6 months. One hundred fifteen patients met the inclusion criteria. We determined variables such as age, gender, and number of hemecomponents as well as serum IgG CMV status of donors and recipients. We recorded the immunosuppression used by each patient. CMV infection was detected by positive antigenemia. RESULTS: Recipient mean age was 50 years. The etiology of cirrhosis was viral (n = 57; 49.6%), alcoholic (n = 20; 17.4%), virus and alcohol (n = 15; 13.0%), cryptogenic (n = 14; 12.2%), or other causes (n = 9; 7.8%). CMV infection was positive in 75 patients (65.8%). There was no relation between infection and age, gender, or CMV IgG donor recipient status, or the number of hemecomponent units. The risk was 3.8-fold higher for patients receiving a three-drug compared with a two-drug regimen. When cyclosporine was used instead of tacrolimus, the risk of CMV infection was 4.3-fold higher. Logistic regression analysis revealed cyclosporine (OD=5.8) and a three-drug regimen (OD=6.7) to have stronger associations with CMV infection. CONCLUSION: The use of cyclosporine (OD=5.8) and a three-drug regimen (OD=6.7) are risk factors for CMV infection.
Assuntos
Infecções por Citomegalovirus/epidemiologia , Transplante de Fígado/efeitos adversos , Complicações Pós-Operatórias/virologia , Ciclosporina/efeitos adversos , Ciclosporina/uso terapêutico , Citomegalovirus/isolamento & purificação , Feminino , Humanos , Imunoglobulina G/sangue , Imunossupressores/efeitos adversos , Imunossupressores/uso terapêutico , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de RiscoRESUMO
UNLABELLED: Cytomegalovirus (CMV) is one of the most common and serious opportunistic infections in solid organ transplant patients. In different series the incidence of CMV infection ranges from 25% to 85%. An indirect effect of infection includes reduced long-term patient and allograft survival. Our objective was to determine the relationship between CMV infection and patient survival after orthotopic liver transplantation. PATIENTS AND METHODS: From January 1999 to December 2001, 163 orthotopic liver transplantations were performed in 154 patients. The inclusion criteria for this analysis were the absence of retransplantation and survival of more than 6 months. One hundred fifteen patients met the inclusion criteria. CMV infection was detected by positive antigenemia. RESULTS: CMV infection occurred in 65.8% of patients after orthotopic liver transplantation. Their 5-year survival was 85%, with no difference observed between patients with or without infection (P = .8). CONCLUSION: CMV infection did not interfere with patient survival after orthotopic liver transplantation.
Assuntos
Infecções por Citomegalovirus/epidemiologia , Transplante de Fígado/fisiologia , Complicações Pós-Operatórias/virologia , Infecções por Citomegalovirus/mortalidade , Infecções por Citomegalovirus/fisiopatologia , Humanos , Transplante de Fígado/mortalidade , Seleção de Pacientes , Complicações Pós-Operatórias/mortalidade , Estudos Retrospectivos , Análise de Sobrevida , SobreviventesRESUMO
The Authors report their experience about 127 ductal carcinoma in situ (DCIS) of the breast. Guidelines for surgical treatment are: radiological or clinical diagnosis, tumor's extension, histological classification, grading and margin status. At the present the Authors prefer breast conserving surgery with tumor margin's study. They report their experience in the last seven years about sentinel node biopsy. Radiotherapy and endocrine therapy are indicated for selected patients; local recurrence after DCIS therapy is 8,1% on a 6,1 years follow-up.
Assuntos
Neoplasias da Mama/cirurgia , Carcinoma Intraductal não Infiltrante/cirurgia , Adulto , Idoso , Neoplasias da Mama/diagnóstico , Neoplasias da Mama/terapia , Carcinoma Intraductal não Infiltrante/diagnóstico , Carcinoma Intraductal não Infiltrante/terapia , Feminino , Seguimentos , Humanos , Mastectomia Segmentar/métodos , Pessoa de Meia-Idade , Terapia Neoadjuvante/métodos , Recidiva Local de Neoplasia , Guias de Prática Clínica como Assunto , Estudos Retrospectivos , Resultado do TratamentoRESUMO
Breast-conserving surgery is the treatment of choice for the breast cancer T < 3 cm. The local recurrence is a problem of diagnosis and consequent treatment. We enrolled, from 1987 to 2004, 1504 breast cancer. In 803 (53.4%) tumor with T < 3 cm we performed conserving surgery. The sentinel lymph node (SN) technique induce to limit the axillary dissection in patients T1a-b to the SN only if non metastatic and located to the first level, the dissection of the 1st level of the axilla in patients T1c-T2 < 3 cm and SN negative, complete axillary dissection in patients with metastatic SN or located to the 2nd level. Our percentage of local recurrence in the follow-up was 3.5% at 5 years and 6% at 10 years.
Assuntos
Neoplasias da Mama/cirurgia , Carcinoma in Situ/cirurgia , Carcinoma Ductal de Mama/cirurgia , Carcinoma Lobular/cirurgia , Mastectomia Segmentar , Axila , Mama/patologia , Neoplasias da Mama/patologia , Carcinoma in Situ/patologia , Carcinoma Ductal de Mama/patologia , Carcinoma Lobular/patologia , Ensaios Clínicos como Assunto , Feminino , Seguimentos , Humanos , Excisão de Linfonodo , Metástase Linfática , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/diagnóstico , Recidiva Local de Neoplasia/cirurgia , Estadiamento de Neoplasias , Biópsia de Linfonodo Sentinela , Fatores de TempoRESUMO
OBJECTIVE: To investigate the presence of syntactic impairments in native language in Parkinson's disease. METHODS: Twelve bilingual patients, with Friulian as their first language (L1) and Italian as their second (L2), with Parkinson's disease and 12 normal controls matched for age, sex, and years of schooling, were studied on three syntactic tasks. RESULTS: Patients with Parkinson's disease showed a greater impairment of L1 than L2. CONCLUSIONS: These findings provide evidence of greater basal ganglia involvement in the acquisition and further processing of grammar in L1 v L2 possibly due to a major involvement of procedural memory in representing L1 grammar.
Assuntos
Transtornos da Linguagem/etiologia , Transtornos da Linguagem/psicologia , Linguística , Doença de Parkinson/complicações , Doença de Parkinson/psicologia , Gânglios da Base/patologia , Estudos de Casos e Controles , Feminino , Humanos , Transtornos da Linguagem/etnologia , Masculino , Pessoa de Meia-Idade , Doença de Parkinson/etnologiaRESUMO
Situs viscerum inversus is a rare condition, in which the organs are transposed from their normal location in the opposite side of the body. The inversion of L-R asymmetry may be complete (SVI totalis) or partial (SVI partialis), whereby transposition is confined to either the abdominal or thoracic viscera. The authors report a case of videolaparocholecystectomy for cholelithiasis successfully performed on a 41-year-old Caucasian woman with situs viscerum inversus totalis. The patient was discharged on the 2nd postoperative day. The symptomatology disappeared right after the intervention, and still now, after a follow-up of six months, is absent. The procedure was safely performed on the patient with no particular difficulties, except for the reverse position of the angle between the operating and exposing trocars, which led to a difficult approach to the Calot triangle when using the right hand of the surgeon.
Assuntos
Colecistectomia Laparoscópica , Situs Inversus/cirurgia , Adulto , Colelitíase/complicações , Feminino , Humanos , Situs Inversus/complicações , Situs Inversus/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Resultado do TratamentoRESUMO
AIM: New models of care are proposed to reduce the costs of traditional hospitalization and to improve the utilization of resources in surgery. Day surgery is widely employed in breast surgery. In this study we report the conversion rate and causes in ordinary hospitalization and we identify some contraindications related to breast surgery in day surgery. METHODS: A cohort study was performed on 306 patients operated on between July 1999 and December 2001 for breast lesions with uncertain interpretation at the clinical and/or instrumental examination. Those patients who lived at a distance of less than 50 km from the hospital, had a telephone, a suitable house, direct family support and, if necessary, could benefit from home health care in addition to hospitalization, were considered as eligible to day surgery. The kind of anesthesia and hospital admission were established after clinical, psycho-emotional, and socio-familiar evaluation of the patients by the surgeon and the anesthetist. RESULTS: A total of 250 excisional biopsies and 56 biopsies with a Mammotome were performed. Surgery was performed under local anesthesia in 278 patients and general anesthesia in 28 subjects. Observation exceeding 24 hours was only necessary in 10 patients reporting hypotension syndrome and anxiety. The conversion rate in ordinary hospitalization was 0.3%. Postoperative morbidity was 1%. CONCLUSION: Day surgery is an effective model of care in breast surgery for diagnostic and therapeutic purposes without axillary dissection. A good selection of patients, perfect interdisciplinary collaboration, and an efficient structural organization are necessary to control the complication and conversion rates of traditional hospitalization.
Assuntos
Procedimentos Cirúrgicos Ambulatórios , Doenças Mamárias/cirurgia , Biópsia , Doenças Mamárias/patologia , Neoplasias da Mama/cirurgia , Feminino , Humanos , Masculino , Estudos Retrospectivos , Resultado do TratamentoRESUMO
The aim of the study was to investigate risk factors associated with cytomegalovirus (CMV)-positive antigenemia in orthotopic liver transplant (OLT) patients. Sixty-nine patients undergoing OLT during 2001 were retrospectively evaluated for CMV antigenemia during a follow-up of 6 months after transplantation for demographic variables, pretransplant donor and recipient CMV serologic status, etiology of liver disease, number of blood transfusions, and type of immunosuppression. Among the 69 patients who underwent 71 OLT in this period, 43 met study criteria. Mean age was 49.7 +/- 10.8 years and 60.5% were men. End-stage liver disease was the indication for liver transplant, except in one case. The most prevalent etiology of liver disease was hepatitis C and/or alcohol in 66% of the cases. CMV-positive status was recorded in 74% of donors and 95% of recipients. None of the CMV-negative recipients received a positive donor allograft. CMV-positive antigenemia was 84% with 12% having two episodes of infection. There was no correlation between CMV infection and age, gender, etiology of liver disease, or number of blood transfusions. However, all patients using cyclosporine had CMV-positive antigenemia compared with 61% using tacrolimus (P <.032). In this study, the incidence of CMV infection after OLT in adult patients was slightly higher than reported in literature. No risk factor was associated with CMV antigenemia; however, this study suggests a higher probability of CMV infection among patients treated with cyclosporine.
Assuntos
Infecções por Citomegalovirus/epidemiologia , Infecções por Citomegalovirus/imunologia , Transplante de Fígado , Complicações Pós-Operatórias/virologia , Antígenos Virais/sangue , Feminino , Seguimentos , Humanos , Hepatopatias/classificação , Hepatopatias/etiologia , Hepatopatias/cirurgia , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Fatores de TempoRESUMO
Kdc1 is a novel K+-channel gene cloned from carrot roots, and which is also present in cultured carrot cells. We investigated the characteristics of the ionic current elicited in Xenopus oocytes coinjected with KDC1 (K+-Daucus carota 1) and KAT1 (from Arabidopsis thaliana) RNA. Expressed heteromeric channels displayed inward-rectifying potassium currents whose kinetics, voltage characteristics, and inhibition by metal ions depended on KDC1:KAT1 ratios. At low KDC1:KAT1 ratios, Zn2+ inhibition of heteromeric K+ current was less pronounced compared to homomeric KAT1 channels, while at higher KDC1:KAT1 ratios, the addition of Zn2+ even produced an increase in current. Under the same conditions, the Ni2+ inhibition of the current was also reduced, but no current increase was observed. These effects might be explained by the unusual amino acid composition of the KDC1 protein in terms of histidine residues that are absent in the pore region, but abundant (four per subunit) in the proximity of the pore entrance. Channels like KDC1 could be at least partially responsible for the higher resistance of carrot cells in the presence of metals.
Assuntos
Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Canais de Potássio Corretores do Fluxo de Internalização , Canais de Potássio/genética , Canais de Potássio/metabolismo , Animais , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis , Cátions/farmacologia , Daucus carota/genética , Daucus carota/metabolismo , Feminino , Genes de Plantas , Técnicas In Vitro , Oócitos/metabolismo , Técnicas de Patch-Clamp , Proteínas de Plantas/química , Raízes de Plantas/metabolismo , Canais de Potássio/química , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , XenopusRESUMO
The concept of sentinel node biopsy, initially introduced for melanoma, has also been used for breast cancer since the 90's, in that, with the increasingly, widespread use of mammographic screening and of other minimally invasive diagnostic procedures, smaller and smaller cancers are now being diagnosed. For these cancers axillary dissection often constitutes overtreatment. For cancers at an initial stage with a low risk of axillary metastases investigation of sentinel lymph nodes enables us the surgeon to assess the axillary lymph-node status and avoid axillary dissection which is responsible for a certain amount of morbidity. Sentinel nodes can be sought using colorimetric or radioisotope methods. To date there is no common consensus of opinion as to which is the better procedure and the respective indications. Both methods allow detection of sentinel nodes in roughly 90% of cases and the combination of the two yields 100% detection rates. It is widely accepted that sentinel node biopsy should be reserved for unifocal tumours which have not been treated previously and which measure less than 15 mm in diameter. The advantages of the procedure are substantial provided it is performed correctly by surgeons properly trained in its use. The learning curve is relatively brief and is based on no more than 30-40 cases.
Assuntos
Neoplasias da Mama/cirurgia , Humanos , Biópsia de Linfonodo Sentinela/educação , Biópsia de Linfonodo Sentinela/métodosRESUMO
STUDY AIM: The aim of this prospective multicentric non-randomised trial was to report the complications of the central venous catheter insertion with different techniques and to assess the advantages of the low lateral approach to the internal jugular vein, according to the technique originally described by Jernigan et al, with our own modifications. PATIENTS AND METHOD: From January 1993 to August 1997, 2,290 CVC (2,286 by percutaneous puncture and 4 by surgical approach) were placed. The following complications were analysed prospectively: pneumothorax, accidental arterial puncture, more than two punctures of the same vein, necessity to shift to another venous approach, complete failure, malposition of catheter. RESULTS: The veins the most frequently used were internal jugular vein (48.7%), femoral vein (27%) and subclavian vein (24.2%). Internal jugular vein was punctured especially by low lateral approach (75%) and subclavian vein by infraclavicular approach (92%). With these two placements, the rate of pneumothorax was 0% and 3.1% respectively (p < 0.001), the rate of accidental arterial puncture was 1% and 2.7% respectively (p < 0.03) and the rate of more than two consecutive punctures was 3.1% and 6.3% respectively (p < 0.008). CONCLUSION: On our experience, we advocate the low lateral approach to the internal jugular vein as first choice technique for venipuncture in both adults and children for both short and long-term central venous approach, because it is associated to high rate of outcome and to low rate of complications in comparison with other techniques.
Assuntos
Cateterismo Venoso Central/efeitos adversos , Cateterismo Venoso Central/métodos , Adulto , Criança , Veia Femoral , Humanos , Veias Jugulares , Flebotomia , Pneumotórax/etiologia , Estudos Prospectivos , Fatores de Risco , Veia Subclávia , Fatores de TempoRESUMO
Potassium is an essential nutrient which plays an important role in many aspects of plant growth and development. Plants have developed a number of highly specific mechanisms to take up potassium from the soil; these include the expression of K(+) transporters and potassium channels in root cells. Despite the fact that root epidermal and hair cells are in direct contact with the soil, the role of these tissues in K(+) uptake is not well understood. Here we report the molecular cloning and functional characterization of a novel potassium channel KDC1 which forms part of a new subfamily of plant K(in) channels. Kdc1 was isolated from carrot root RNA and in situ hybridization experiments show Kdc1 to be highly expressed in root hair cells. Expressing the KDC1 protein in Chinese hamster ovary cells identified it as a voltage and pH-dependent inwardly rectifying potassium channel. An electrophysiological analysis of carrot root hair protoplasts confirmed the biophysical properties of the Kdc1 gene product (KDC1) in the heterologous expression system. KDC1 thus represents a major K(+) uptake channel in carrot root hair cells.
Assuntos
Daucus carota/metabolismo , Proteínas de Plantas/química , Proteínas de Plantas/genética , Raízes de Plantas/metabolismo , Canais de Potássio/química , Canais de Potássio/genética , Sequência de Aminoácidos , Animais , Northern Blotting , Células CHO , Clonagem Molecular , Cricetinae , Eletrofisiologia , Proteínas de Fluorescência Verde , Concentração de Íons de Hidrogênio , Hibridização In Situ , Íons , Proteínas Luminescentes/metabolismo , Dados de Sequência Molecular , Filogenia , Proteínas de Plantas/biossíntese , Potássio/metabolismo , Canais de Potássio/biossíntese , Protoplastos/metabolismo , Proteínas Recombinantes de Fusão/metabolismo , Homologia de Sequência de Aminoácidos , Temperatura , Fatores de Tempo , TransfecçãoRESUMO
The authors describe a rare case of peritoneal mesothelioma. Cytological, histological and immunohistochemical characterization of the tumor allowed the differential diagnosis from papillary carcinoma and suggested the diagnosis of leiomyoid mesothelioma.
Assuntos
Carcinoma Papilar/secundário , Mesotelioma/patologia , Neoplasias Peritoneais/patologia , Idoso , Ascite , Líquido Ascítico/patologia , Biomarcadores/análise , Biomarcadores Tumorais/análise , Biópsia , Carcinoma Papilar/patologia , Diagnóstico Diferencial , Evolução Fatal , Feminino , HumanosRESUMO
The Arabidopsis thaliana potassium channel KAT1 was expressed and characterized in Chinese hamster ovary cells. KAT1-GFP fusion protein was successfully targeted to the plasma membrane and electrophysiological analysis revealed functional expression of KAT1 only in cells cultured at 30 degrees C. The main biophysical characteristics of KAT1 are similar to those described for the channel expressed in other systems. CHO cells represent an advantageous expression system and may be the system of choice to study the expression, assembly, function, and regulation of plant potassium channels in general.
Assuntos
Canais de Potássio Corretores do Fluxo de Internalização , Canais de Potássio/biossíntese , Temperatura , Animais , Arabidopsis/metabolismo , Proteínas de Arabidopsis , Células CHO , Membrana Celular/metabolismo , Cricetinae , Eletrofisiologia , Proteínas de Fluorescência Verde , Proteínas Luminescentes/metabolismo , Microscopia de Fluorescência , Proteínas de Plantas , Proteínas Recombinantes de Fusão/metabolismo , TransfecçãoRESUMO
Polyclonal antibodies raised against rat vesicle associated membrane protein-2 (VAMP-2) recognized, in carrot (Daucus carota) microsomes, two major polypeptides of 18 and 30 kD, respectively. A biochemical separation of intracellular membranes by a sucrose density gradient co-localized the two polypeptides as resident in light, dense microsomes, corresponding to the endoplasmic reticulum-enriched fractions. Purification of coated vesicles allowed us to distinguish the subcellular location of the 18-kD polypeptide from that of 30 kD. The 18-kD polypeptide is present in the non-clathrin-coated vesicle peak. Like other VAMPs, the carrot 18-kD polypeptide is proteolyzed by tetanus toxin after separation of coatomers. Amino acid sequence analysis of peptides obtained by digestion of the 18-kD carrot polypeptide with the endoproteinase Asp-N confirms it to be a member of the VAMP family, as is suggested by its molecular weight, vesicular localization, and toxin-induced cleavage.