RESUMO
While the vast majority of cellular DNA in eukaryotes is contained in long linear strands in chromosomes, we have long recognized some exceptions like mitochondrial DNA, plasmids in yeasts, and double minutes (DMs) in cancer cells where the DNA is present in extrachromosomal circles. In addition, specialized extrachromosomal circles of DNA (eccDNA) have been noted to arise from repetitive genomic sequences like telomeric DNA or rDNA. Recently eccDNA arising from unique (nonrepetitive) DNA have been discovered in normal and malignant cells, raising interesting questions about their biogenesis, function and clinical utility. Here, we review recent results and future directions of inquiry on these new forms of eccDNA.
Assuntos
DNA Circular/genética , DNA Mitocondrial/genética , DNA de Neoplasias/genética , Neoplasias/genética , Células Neoplásicas Circulantes/química , Animais , Cromossomos Humanos/química , Cromossomos Humanos/metabolismo , DNA de Cloroplastos/química , DNA de Cloroplastos/genética , DNA de Cloroplastos/metabolismo , DNA Circular/química , DNA Circular/metabolismo , DNA de Cinetoplasto/química , DNA de Cinetoplasto/genética , DNA de Cinetoplasto/metabolismo , DNA Mitocondrial/química , DNA Mitocondrial/metabolismo , DNA de Neoplasias/química , DNA de Neoplasias/metabolismo , Células Eucarióticas/química , Células Eucarióticas/metabolismo , Humanos , Kinetoplastida/genética , Kinetoplastida/metabolismo , Neoplasias/metabolismo , Neoplasias/patologia , Células Neoplásicas Circulantes/metabolismo , Plantas/genética , Plantas/metabolismo , Plasmídeos/química , Plasmídeos/metabolismo , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Telômero/química , Telômero/metabolismoRESUMO
Histone mRNA levels are cell cycle regulated, and the major regulatory steps are at the posttranscriptional level. A major regulatory mechanism is S-phase restriction of Stem-loop binding protein (SLBP) which binds to the 3' end of histone mRNA and participates in multiple steps of histone mRNA metabolism, including 3' end processing, translation and regulation of mRNA stability. SLBP expression is cell cycle regulated without significant change in its mRNA level. SLBP expression is low in G1 until just before S phase where it functions and at the end of S phase SLBP is degraded by proteasome complex depending on phosphorylations on Thr60 and Thr61. Here using synchronized HeLa cells we showed that SLBP production rate is low in early G1 and recovers back to S phase level somewhere between early and mid-G1. Further, we showed that SLBP is unstable in G1 due to proteasome mediated degradation as a novel mechanism to keep SLBP low in G1. Finally, the S/G2 stable mutant form of SLBP is degraded by proteasome in G1, indicating that indicating that the SLBP degradation in G1 is independent of the previously identified SLBP degradation at S/G2. In conclusion, as a mechanism to limit histone production to S phase, SLBP is kept low in G1 phase due to cooperative action of translation regulation and proteasome mediated degradation which is independent of previously known S/G2 degradation.
Assuntos
Proteínas Nucleares/genética , Complexo de Endopeptidases do Proteassoma/genética , Biossíntese de Proteínas , Proteólise , Fatores de Poliadenilação e Clivagem de mRNA/genética , Fase G1/genética , Regulação da Expressão Gênica , Células HeLa , Histonas/genética , Histonas/metabolismo , Humanos , Proteínas Nucleares/metabolismo , Fosforilação/genética , Complexo de Endopeptidases do Proteassoma/metabolismo , Ligação Proteica , RNA Mensageiro/genética , Fatores de Poliadenilação e Clivagem de mRNA/metabolismoRESUMO
PURPOSE: Metastatic renal cell carcinoma (mRCC) bears a poor prognosis. We investigated the prognostic significance of some hematologic parameters of patients with mRCC. METHODS: We retrospectively reviewed the records of 53 patients with mRCC . The mean follow up time was 34 months (range 5-142).We assessed the prognostic value of hematologic parameters (leukocytes ,neutrophils, lymphocytes, platelets, neutrophil to lymphocyte ratio/NLR, platelet to lymphocyte ratio/PLR), and other clinical parameters with univariate and multivariate analysis. RESULTS: Memorial Sloan-Kettering Cancer Center (MSKCC) risk group , lung metastases, sunitinib treatment, lymphocyte count, NLR, and anemia significantly correlated with median overall survival (OS) on univariate analysis. The median OS in patients with a NLR < 3.4 was 32.2 months , significantly higher than the 13.9 months in patients with a ratio ≥ 3.4 (p = 0.006). Multivariate analysis revealed that MSKCC risk group and the NLR were independent predictors of OS. CONCLUSION: Hematologic parameters may be associated with OS in mRCC. However, further studies are needed to establish their routine use.
Assuntos
Plaquetas , Carcinoma de Células Renais/sangue , Carcinoma de Células Renais/secundário , Neoplasias Renais/sangue , Neoplasias Renais/patologia , Linfócitos , Neutrófilos , Adulto , Idoso , Antineoplásicos/uso terapêutico , Carcinoma de Células Renais/mortalidade , Carcinoma de Células Renais/terapia , Feminino , Humanos , Indóis/uso terapêutico , Estimativa de Kaplan-Meier , Neoplasias Renais/mortalidade , Neoplasias Renais/terapia , Contagem de Linfócitos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Contagem de Plaquetas , Valor Preditivo dos Testes , Prognóstico , Modelos de Riscos Proporcionais , Inibidores de Proteínas Quinases/uso terapêutico , Pirróis/uso terapêutico , Estudos Retrospectivos , Fatores de Risco , Sunitinibe , Fatores de TempoRESUMO
BACKGROUND: The pandemic of the new type of corona virus infection 2019 [Covid-19] also affect people with Multiple Sclerosis (pwMS). Currently, the accumulating information on the effects of the infection regarding the demographic and clinical characteristics of the disease, as well as outcomes within different DMTs¸ enable us to have better practices on the management of the Covid-19 infection in pwMS. OBJECTIVE: To investigate the incidence of coronavirus disease 2019 (Covid-19) and to reveal the relationship between the demographic-clinical and therapeutic features and the outcome of Covid-19 infection in a multi-center national cohort of pwMS. METHODS: The Turkish Neurological Society-MS Study Group in association with the Italian MuSC-19 Study Group initiated this study. A web-based electronic Case Report Form (eCRF) of Study-MuSC-19 were used to collect the data. The demographic data and MS histories of the patients were obtained from the file tracking forms of the relevant clinics. RESULTS: 309 MS patients with confirmed Covid-19 infection were included in this study. Two hundred nineteen (219) were females (70.9%). The mean age was 36.9, ranging from 18 to 66, 194 of them (62.8%) were under 40. The clinical phenotype was relapsing-remitting in 277 (89.6%) and progressive in 32 (10.4%). Disease duration ranged from 0.2 years to 31.4 years. The median EDSS was 1.5, ranging from 0 to 8.5. The EDSS score was<= 1 in 134 (43%) of the patients. 91.6% of the patients were on a DMT, Fingolimod was the most frequently used drug (22.0%), followed by Interferon (20.1%). The comorbidity rate is 11.7%. We were not able to detect any significant association of DMTs with Covid-19 severity. CONCLUSION: The Turkish MS-Covid-19 cohort had confirmed that pwMS are not at risk of having a more severe COVID-19 outcome irrespective of the DMT that they are treated. In addition, due to being a younger population with less comorbidities most had a mild disease further highlight that the only associated risk factors for having a moderate to severe COVID-19 course are similar with the general population such as having comorbid conditions and being older.
Assuntos
COVID-19 , Esclerose Múltipla , Adulto , Estudos de Coortes , Feminino , Cloridrato de Fingolimode , Humanos , SARS-CoV-2RESUMO
Garlic has long been used for medicinal purposes. It has been shown that different forms of garlic have significant antioxidant effects. The strong flavor, odor and unwanted gastrointestinal side effects of fresh garlic has rendered the use of commercial garlic supplements as a preferable option. To investigate the effects of garlic supplementation on serum total antioxidant capacity and lipid parameters, 17 healthy volunteers were administered four standardized commercial garlic tablets every day for 30 days. Blood samples were taken at day 1 (before the first administration of tablets [control] and at 3 h after the administration of tablets), 15 and 30 days, respectively. Total antioxidant capacity (TAC), total cholesterol, low density lipoprotein cholesterol (LDL cholesterol), high density lipoprotein cholesterol (HDL cholesterol) and triglyceride (TG) were measured in sera. Serum TAC was increased significantly at 30 days compared with 15 days, 3 h and control. There was also a significant increase in serum TAC at 15 days compared with 3 h and control. Total cholesterol, LDL cholesterol, HDL cholesterol and TG were not found to be significantly different between control, 3 h, 15 and 30 days. These data suggest that garlic, used as a dietary supplementation, may be beneficial in increasing the antioxidant capacity of the body.
Assuntos
Antioxidantes/metabolismo , HDL-Colesterol/sangue , LDL-Colesterol/sangue , Suplementos Nutricionais , Alho , Triglicerídeos/sangue , Adulto , Feminino , Humanos , Masculino , Adulto JovemRESUMO
Hepatitis A is a worldwide vaccine-preventable infection. Recommendation of vaccination depends on the endemicity of the disease. The World Health Organization recommends universal hepatitis A vaccination in intermediate areas; however, there is no need of mass vaccination in high and low endemicity regions. Therefore, most of the countries are using a vaccination policy according to the endemicity characteristic representing the whole of the country. The endemicity of this infection varies due to sanitary and hygiene conditions and socioeconomic differences among the countries and in various regions of the same country. A sample of 1173 persons between the age of 0 and 91 years from nine randomly selected medical centres from five different geographical centres of Turkey were tested for the level of anti-hepatitis A virus (anti-HAV) immunoglobulin-G antibodies using an enzyme-linked immunosorbent assay. The overall prevalence of anti-HAV antibodies was 64.4% (1142/1173). While the rate of sero-positivity was over 80% in the 5-9 age group and more than 90% after 14 years of age in south-eastern and eastern regions, it was lower than 50% at the age of 5-9 years in central and western regions and remains under 80% in those areas. We conclude that the differences observed in HAV sero-positivity among various geographical regions in Turkey support a universal HAV immunization policy for children currently living in regions of intermediate endemicity.
Assuntos
Diretrizes para o Planejamento em Saúde , Anticorpos Anti-Hepatite A/sangue , Vacinas contra Hepatite A/administração & dosagem , Vírus da Hepatite A Humana/imunologia , Hepatite A/epidemiologia , Vacinação , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Feminino , Geografia , Hepatite A/imunologia , Hepatite A/prevenção & controle , Humanos , Imunoglobulina G/sangue , Lactente , Masculino , Pessoa de Meia-Idade , Estudos Soroepidemiológicos , Turquia/epidemiologiaRESUMO
OBJECTIVE: To evaluate changes in perceptual and several acoustic parameters of voice in patients with Parkinson's disease (PD) and to find out any relation with these parameters and motor components of Unified Parkinson's Disease Rating Scale (UPDRS) in this patient group. MATERIALS AND METHODS: Twenty patients with PD (12 male and 8 female) were given objective and subjective voice tests and results were compared with those of 20 age- and sex-matched controls. Patient's perceptual voice analysis was assessed using GRBAS scale including Grade of Dysphonia, Roughness, Breathiness, Asthenia and Strain items. Measurements for objective voice analysis, acoustic assessment tests including frequency perturbation [jitter (jitt)%], intensity perturbation [shimmer (shim)%], noise to harmonic ratio (NHR), fundamental frequency (F0), variability of fundamental frequency (vF0), diadochokinetic rate (DDK) and maximum phonation time (MPT) were used. An assessment of disability caused by voice disorders was scored according to the Voice Handicap Index (VHI) by the patient. All subjects also underwent videolaryngostroboscopic (VLS) examination. Motor components of UPDRS and acoustic parameters of voice were investigated for any correlations. RESULTS: Compared with controls, roughness (P = 0.15), breathiness (P = 0.004) and asthenia (P = 0.031) values of males and breathiness (P = 0.043) and asthenia (P = 0.023) values of females were higher in patients with PD. Mean VHI scores of patients with PD were higher for both male and female patients (P = 0.0001 for male, P = 0.002 for female). The mean values for MPT (P = 0.02) and DDK (P = 0.025) were shorter in patients with PD. Jitt%, shim% and mean F0 values were similar among the two groups. But mean vF0 values were significantly higher in male patients with PD (P = 0.05). On VLS examination, non-closure glottic pattern was found to be more frequent in the PD group. CONCLUSION: Although it is well known that pathophysiological changes in PD affect the voice, the present study found only few significant correlations between motor component of UPDRS and voice parameters.
Assuntos
Transtornos dos Movimentos/complicações , Doença de Parkinson/complicações , Distúrbios da Voz/diagnóstico , Distúrbios da Voz/etiologia , Idoso , Avaliação da Deficiência , Feminino , Rouquidão/diagnóstico , Rouquidão/etiologia , Rouquidão/fisiopatologia , Humanos , Laringe/fisiopatologia , Masculino , Pessoa de Meia-Idade , Transtornos dos Movimentos/fisiopatologia , Músculo Esquelético/inervação , Músculo Esquelético/fisiopatologia , Doença de Parkinson/fisiopatologia , Fonação , Caracteres Sexuais , Distúrbios da Voz/fisiopatologiaRESUMO
In eukaryotes, bulk histone expression occurs in the S phase of the cell cycle. This highly conserved system is crucial for genomic stability and proper gene expression. In metazoans, Stem-loop binding protein (SLBP), which binds to 3' ends of canonical histone mRNAs, is a key factor in histone biosynthesis. SLBP is mainly expressed in S phase and this is a major mechanism to limit bulk histone production to the S phase. At the end of S phase, SLBP is rapidly degraded by proteasome, depending on two phosphorylations on Thr 60 and Thr 61. Previously, we showed that SLBP fragment (aa 51-108) fused to GST, is sufficient to mimic the late S phase (S/G2) degradation of SLBP. Here, using this fusion protein as bait, we performed pull-down experiments and found that DCAF11, which is a substrate receptor of CRL4 complexes, binds to the phosphorylated SLBP fragment. We further confirmed the interaction of full-length SLBP with DCAF11 and Cul4A by co-immunoprecipitation experiments. We also showed that DCAF11 cannot bind to the Thr61/Ala mutant SLBP, which is not degraded at the end of S phase. Using ectopic expression and siRNA experiments, we demonstrated that SLBP expression is inversely correlated with DCAF11 levels, consistent with the model that DCAF11 mediates SLBP degradation. Finally, we found that ectopic expression of the S/G2 stable mutant SLBP (Thr61/Ala) is significantly more toxic to the cells, in comparison to wild type SLBP. Overall, we concluded that CRL4-DCAF11 mediates the degradation of SLBP at the end of S phase and this degradation is essential for the viability of cells.
Assuntos
Proteínas de Transporte/metabolismo , Proteínas Nucleares/metabolismo , Proteólise , Fase S , Fatores de Poliadenilação e Clivagem de mRNA/metabolismo , Sequência de Aminoácidos , Morte Celular , Proteínas Culina/metabolismo , Fase G2 , Técnicas de Silenciamento de Genes , Células HeLa , Humanos , Proteínas Mutantes/metabolismo , Proteínas Nucleares/química , Fosforilação , Complexo de Endopeptidases do Proteassoma/metabolismo , Ligação Proteica , Interferência de RNA , Fatores de Poliadenilação e Clivagem de mRNA/químicaRESUMO
Several studies suggest that soluble Amyloid ß (Aß) oligomer-induced aberrant neuronal cell cycle re-entry is the initial trigger for a significant part of the neuronal degeneration and loss in Alzheimer's disease (AD). In this study, we investigated the role of Ras, which is a well-known protooncoprotein, in soluble Aß oligomer-induced aberrant neuronal cell cycle activation and subsequent cell loss using retinoic acid differentiated human SH-SY5Y neuroblastoma cells as model system. In line with previous literature, we showed that in vitro preparations of soluble Aß42 oligomers triggered cell cycle activation but not cell proliferation. As a new finding, we showed that Farnesylthiosalicylic acid (FTS), a specific chemical Ras inhibitor, prevented soluble Aß42 oligomer preparation-induced cell cycle activation. Moreover, we showed that the expression of dominant negative mutant H-Ras (S17N) prevented soluble Aß42 oligomer preparation-induced cell cycle activation, confirming the specific role of Ras in this pathway. As a possible better mimic of the situation in the AD brain, we prepared soluble oligomers from Aß42 : Aß40 (3:7) peptide mixture and showed that this oligomer preparation similarly induced cell cycle activation which was also inhibited by the Ras inhibitor. Finally, we showed that FTS prevented soluble Aß42 oligomer preparationinduced cell death in our retinoic acid differentiated SH-SY5Y cells. Overall, our results strongly suggest that Ras activity is required for soluble Aß oligomer-induced aberrant neuronal cell cycle reentry and subsequent neuronal loss, which are considered important mechanisms in AD pathogenesis.
Assuntos
Peptídeos beta-Amiloides/farmacologia , Ciclo Celular/efeitos dos fármacos , Morte Celular/efeitos dos fármacos , Inibidores Enzimáticos/farmacologia , Farneseno Álcool/análogos & derivados , Fragmentos de Peptídeos/farmacologia , Salicilatos/farmacologia , Proteínas ras/metabolismo , Diferenciação Celular , Linhagem Celular Tumoral , Relação Dose-Resposta a Droga , Farneseno Álcool/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Proteínas Associadas aos Microtúbulos/metabolismo , Neuroblastoma/patologia , Neurônios/efeitos dos fármacos , Fatores de TempoRESUMO
We have recently shown that expression of the GLUT1 glucose transporter isoform is augmented in cells exposed to cobalt chloride [Co(II)], an agent that stimulates the expression of hypoxia-responsive genes (Behrooz, A., Ismail-Beigi, F., 1997. J. Biol. Chem. 272, 5555-5562.). Here, we examine the effect of Co(II) on glycemia and tissue GLUT1 mRNA content of normal and diabetic rats. The addition of 2 mM Co(II) in the drinking water reduced the glycemia of streptozotocin-induced diabetic rats by day 3 from 32.3 +/- 2.1 to 21.0 +/- 1.9 mM (non-fasting). Co(II) resulted in no change in serum insulin levels of normal or diabetic rats. Treatment with 4 mM Co(II) was more effective than 2 mM Co(II) in reducing the glycemia of diabetic rats, while 6 mM Co(II) was associated with severe toxicity. GLUT1 mRNA content increased significantly in ventricular myocardium, renal cortex, skeletal muscle, cerebrum and liver of normal and diabetic rats treated with 2 mM cobalt chloride (ranging from 1.3- to 2.9-fold in the different tissues). It is concluded that: (1) treatment with Co(II) decreases the glycemia of diabetic rats, and (2) the glycemia-lowering effect of Co(II) is associated with, and may be mediated by, enhanced expression of GLUT1 mRNA.
Assuntos
Glicemia/metabolismo , Cobalto/farmacologia , Diabetes Mellitus Experimental/genética , Regulação da Expressão Gênica/efeitos dos fármacos , Proteínas de Transporte de Monossacarídeos/genética , Animais , Peso Corporal/efeitos dos fármacos , Diabetes Mellitus Experimental/sangue , Ingestão de Líquidos , Transportador de Glucose Tipo 1 , Insulina/sangue , Masculino , Especificidade de Órgãos , RNA Mensageiro/análise , Ratos , Ratos Sprague-DawleyRESUMO
Beta thalassemia, characterized by the deficiency or the absence of beta globulin production, is the most widespread inherited disorder in the world and is also common in Turkey. To determine the prevalence of carriers for beta thalassemia, we screened the couples before their marriage. For this aim, from 1994 to 1999, a total of 14.200 people were screened. The complete blood count and red blood cell indices (hemoglobin: Hb, hematocrite: Hct, median corpusculer volume: MCV, median corpusculer hemoglobin: MCHb, median corpusculer hemoglobin concentration: MHbC, concentration were measured by automated cell counter on the same day of collection. Then for the samples with MCV values of 78 fL or below, hemoglobin electrophoresis were employed. Testing for beta thalassemia was carried out by the conventional cellulose asetate electropheresis at pH 8.4. People who have elevated HbA2 (≥ 3.5%) were accepted as beta-thalassemia carrier or patient. We detected 3300 people with MCV levels of 78 fL or below and 311 cases of beta thalassemia carrier and 11 cases of beta thalassemia. The prevalence of carriers for beta thalassemia in Denizli was 2.2%. This result indicated that the people with anemia in our region should be investigated for the existence of hemoglobinopathy.
RESUMO
OBJECTIVES: To investigate the role of diffusion-weighted MRI (DWI) in the diagnosis of urinary bladder (UB) tumours by means of measuring apparent diffusion coefficient (ADC) values. METHODS: A total of 83 people aged between 18 and 86 years were included in the study: 63 patients with UB pathology (46 malignant, 17 benign) constituted the case group; 20 individuals without any UB pathology constituted the control group. DWI was applied to all individuals. The ADC values were measured based on the tissue of the UB mass entities and normal UB wall in the control group. RESULTS: The mean ADC value in the UB carcinoma group was significantly lower than that in the control group: 1.0684 ± 0.26 × 10(-3) mm(2) s(-1) and 2.010 ± 0.11 × 10(-3) mm(2) s(-1), respectively (p<0.01). There was a significant difference among the mean ADC values of different grades of malignant tumours, corresponding to 0.9185 ± 0.20 mm(2) s(-1) and 1.281 ± 0.18 mm(2) s(-1) in high-grade and low-grade malignant UB carcinomas, respectively (p<0.01). The ADC value in the carcinoma group was significantly lower than that in the benign lesion group: 1.0684 ± 0.26 × 10(-3) mm(2) s(-1) and 1.803 ± 0.19 × 10(-3) mm(2) s(-1), respectively (p<0.01). All 46 malignant lesions displayed a restriction in diffusion; 4 of the 17 benign lesions displayed a mild restriction in diffusion. The sensitivity, specificity and accuracy of DWI in the diagnosis of malignant UB lesions was 100%, 76.5% and 93.65%, respectively. CONCLUSION: DWI can be beneficial in the differentiation of benign and malignant UB lesions, as well as of high-grade and low-grade UB carcinomas, using quantitative ADC measurements.
Assuntos
Carcinoma/diagnóstico , Imagem de Difusão por Ressonância Magnética , Papiloma/diagnóstico , Hiperplasia Prostática/diagnóstico , Neoplasias da Próstata/diagnóstico , Neoplasias da Bexiga Urinária/diagnóstico , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma/patologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Papiloma/patologia , Estudos Prospectivos , Hiperplasia Prostática/patologia , Neoplasias da Próstata/patologia , Neoplasias da Bexiga Urinária/patologia , Adulto JovemRESUMO
S phase is characterized by the replication of DNA and assembly of chromatin. This requires the synthesis of large amounts of histone proteins to package the newly replicated DNA. Histone mRNAs are the only mRNAs that do not have polyA tails, ending instead in a conserved stemloop sequence. The stemloop binding protein (SLBP) that binds the 3' end of histone mRNA is cell cycle regulated and SLBP is required in all steps of histone mRNA metabolism. Activation of cyclin E/cdk2 prior to entry into S-phase is critical for initiation of DNA replication and histone mRNA accumulation. At the end of S phase SLBP is rapidly degraded as a result of phosphorylation of SLBP by cyclin A/cdk1 and CK2 effectively shutting off histone mRNA biosynthesis. E2F1, which is required for expression of many S-phase genes, is regulated in parallel with SLBP and its degradation also requires a cyclin binding site, suggesting that it may also be regulated by the same pathway. It is likely that activation of cyclin A/cdk1 helps inhibit both DNA replication and histone mRNA accumulation, marking the end of S phase and entry into G(2)-phase.
Assuntos
Ciclina A/metabolismo , Replicação do DNA , Histonas/genética , RNA Mensageiro/metabolismo , Fase S/genética , Ciclina A/genética , Fator de Transcrição E2F1/genética , Fator de Transcrição E2F1/metabolismo , Regulação da Expressão Gênica , Células HeLa , HumanosRESUMO
We report on a 5-year-old boy presenting with tethered cord, diastometamyelia, spinal dysraphism, terminal lipoma, spinal epidermoid, and dermal sinus tract with CT, conventional MRI, and diffusion-weighted MRI findings. To the best of our knowledge, our case has the property to be the first case in the literature showing the association of these pathologies all together.
Assuntos
Cisto Epidérmico/diagnóstico , Lipoma/diagnóstico , Defeitos do Tubo Neural/diagnóstico , Espinha Bífida Oculta/diagnóstico , Medula Espinal/anormalidades , Disrafismo Espinal/diagnóstico , Siringomielia/diagnóstico , Pré-Escolar , Humanos , Imageamento por Ressonância Magnética , Masculino , Tomografia Computadorizada por Raios XRESUMO
Histone mRNA levels are cell cycle regulated, and a major regulatory mechanism is restriction of stem-loop binding protein (SLBP) to S phase. Degradation of SLBP at the end of S phase results in cessation of histone mRNA biosynthesis, preventing accumulation of histone mRNA until SLBP is synthesized just before entry into the next S phase. Degradation of SLBP requires an SFTTP (58 to 62) and KRKL (95 to 98) sequence, which is a putative cyclin binding site. A fusion protein with the 58-amino-acid sequence of SLBP (amino acids 51 to 108) fused to glutathione S-transferase (GST) is sufficient to mimic SLBP degradation at late S phase. Using GST-SLBP fusion proteins as a substrate, we show that cyclin A/Cdk1 phosphorylates Thr61. Furthermore, knockdown of Cdk1 by RNA interference stabilizes SLBP at the end of S phase. Phosphorylation of Thr61 is necessary for subsequent phosphorylation of Thr60 by CK2 in vitro. Inhibitors of CK2 also prevent degradation of SLBP at the end of S phase. Thus, phosphorylation of Thr61 by cyclin A/Cdk1 primes phosphorylation of Thr60 by CK2 and is responsible for initiating SLBP degradation. We conclude that the increase in cyclin A/Cdk1 activity at the end of S phase triggers degradation of SLBP at S/G(2).
Assuntos
Proteína Quinase CDC2/metabolismo , Ciclina A/metabolismo , Proteínas Nucleares/metabolismo , Fase S , Fatores de Poliadenilação e Clivagem de mRNA/metabolismo , Proteína Quinase CDC2/genética , Caseína Quinase II/metabolismo , Células HeLa , Humanos , Fosforilação , Interferência de RNA , Treonina/metabolismoRESUMO
Chorea is a rare complication of polycythaemia vera. Polycythaemic chorea occurs predominantly in females and usually in generalised form. We present a 66-year-old woman with acute onset hemichorea-ballism with no vascular pathology in the basal ganglia region. A clear relationship was observed between the onset of chorea and worsening of haematological parameters in the patient. After repeated phlebotomies the patient's clinical status was improved. Polycythaemic chorea must be considered, especially in the elderly, as early diagnosis leads to effective treatment and prevention of complications.
Assuntos
Coreia/etiologia , Policitemia Vera/complicações , Doença Aguda , Idoso , Antidiscinéticos/administração & dosagem , Coreia/tratamento farmacológico , Antagonistas de Dopamina/administração & dosagem , Feminino , Haloperidol/administração & dosagem , Humanos , Flebotomia , Policitemia Vera/terapia , Sulpirida/administração & dosagemRESUMO
To determine the role of 'translocation' vs. 'activation' of Glut1 in the stimulation of glucose transport in response to inhibition of oxidative phosphorylation, we measured the abundance of myc-tagged Glut1 in plasma membrane of stably transfected Clone 9 cells, a rat liver cell line expressing only the Glut1 isoform. The myc epitope-tag is located between Ile56 and Pro57 in the putative first extracellular loop of Glut1. Under basal conditions, transfected cells expressed approximately 3 fold higher levels of Glut1 and exhibited a approximately 3 fold higher rate of glucose transport than non-transfected cells. To delineate the mechanism mediating the stimulation of glucose transport by a azide we employed two strategies: (1) mild cell surface biotinylation followed by isolation of plasma membranes and quantitation of Glut1 sites in Western blots employing anti-Glut1 and anti-myc antibodies, and (2) quantitative immunofluorescence of myc epitopes in plasma membrane sheets. The rate of glucose transport increased 2.9 +/- 0.5 fold in transfected cells exposed to 5 mM azide for 1 h. Exposure to azide, however, resulted in no significant increase in Glut1 content of plasma membranes using anti-Glut1 or anti-myc antibodies in Western blots (1.0 +/- 0.1 and 0.9 +/- 0.2 fold, respectively; azide/control), and was associated with no detectable increase in immunofluorescence using either anti-Glut1 or anti-myc antibodies (p > 0.1 for both measurements). Treatment of cells with cobalt chloride (employed as a positive control) resulted in marked increases in glucose transport, cell and plasma membrane Glut1 content, and immunofluorescence of plasma membrane sheets (8-10 fold increase in each parameter). We conclude that the stimulation of glucose transport by azide results mainly from activation of Glut1 transporters pre-existing in the plasma membrane.
Assuntos
Genes myc , Glucose/metabolismo , Proteínas de Transporte de Monossacarídeos/metabolismo , Animais , Azidas/farmacologia , Transporte Biológico , Western Blotting , Células Clonais , Cobalto/farmacologia , Imunofluorescência , Transportador de Glucose Tipo 1 , Fosforilação Oxidativa , RatosRESUMO
Starfish oocytes, eggs, and embryos are popular models for studying meiotic maturation, fertilization, and embryonic development. Their large (170- to 200-microm) oocytes are obtainable in copious amounts and are amenable to manipulations that mammalian oocytes are not. The most formidable obstacle to working with marine oocytes is their seasonal availability, yet a successful means of preserving them for use during the nonreproductive season has not been reported. The aim of this study was to investigate the response of starfish oocytes to freezing with rapid and slow cooling rates under a variety of conditions to develop a cryopreservation protocol for these cells. Cryomicroscopic observation revealed that starfish oocytes in isotonic medium undergo intracellular ice formation (IIF) at very high subzero temperatures, such that the mean difference between the temperature of extracellular ice formation (T(EIF)) and IIF (TI(IF)) was less than 3 degrees C and the average T(IIF) was approximately between -4 and -6 degrees C. Neither partial cellular dehydration nor addition of the cryopreservative dimethyl sulfoxide significantly depressed the T(IIF). Under some conditions, we observed ice nucleation at multiple locations within the cytoplasm, suggesting that several factors contribute to the unusually high T(IIF) during controlled-rate freezing and thus vitrification may be a more suitable method for cryopreserving these cells.
Assuntos
Criopreservação/métodos , Oócitos , Estrelas-do-Mar , Animais , Crioprotetores , Dessecação , Dimetil Sulfóxido , Feminino , Liofilização , Gelo , Técnicas In Vitro , Líquido Intracelular/metabolismo , Oócitos/metabolismo , Água do Mar , Estrelas-do-Mar/citologia , Estrelas-do-Mar/metabolismo , TemperaturaRESUMO
The information about the vitality of the plaque is limited. Only motile bacteria can be distinguished as alive. Vital staining allows to differentiate between living nonmotile rods and dead, previously motile rods. With increasing severity of the periodontal destruction, the proportion of alive respectively motile rods and vibrions increases. The vital staining shows very clearly the relation between destruction and living rods.