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1.
Front Neurol ; 15: 1338291, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38333604

RESUMO

Introduction: Acute amnestic syndrome is an uncommon clinical presentation of neurological disease. Differential diagnosis encompasses several syndromes including Wernicke-Korsakoff and transient global amnesia (TGA). Structural lesions of the fornix account for a minority of cases of acute amnestic syndromes. Etiology varies from iatrogenic injury to ischemic, inflammatory, or neoplastic lesions. A prompt diagnosis of the underlying pathology is essential but challenging. The aim of this review is to systematically review the existing literature regarding cases of acute amnestic syndrome associated with non-iatrogenic lesions of the fornix. Methods: We performed a systematic literature search on PubMed, Scopus, and Web of Science up to September 2023 to identify case reports and case series of patients with amnestic syndrome due to fornix lesions. The systematic review was conducted according to PRISMA guidelines. The research was limited to articles written in English. Cases of fornix damage directly ascribable to a surgical procedure were excluded. Results: A total of 52 publications reporting 55 cases were included in the review. Focusing on acute/subacute onset, vascular etiology was highly prevalent, being responsible for 78% of cases, 40/55 (74%) of which were due to acute ischemic stroke. The amnestic syndrome was characterized by anterograde amnesia in all patients, associated with retrograde amnesia in 27% of cases. Amnesia was an isolated presentation in most cases. Up to two thirds of patients had persistent memory deficits of any severity at follow-up. Discussion: Acute amnestic syndrome can be rarely caused by fornix lesions. In most cases of acute/subacute presentation, the etiology is ischemic stroke, mainly caused by strokes involving the subcallosal artery territory. The differential diagnosis is challenging and a distinction from common mimics is often difficult on a clinical basis. A high index of suspicion should be maintained to avoid misdiagnosis and provide adequate acute treatment to patients with time-dependent disease, also employing advanced neuroimaging. More research is needed to better understand the outcome and identify prognostic factors in patients with amnestic syndrome due to fornix lesions.

2.
Eur J Neurol ; 27(12): 2641-2645, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32905639

RESUMO

BACKGROUND AND PURPOSE: Comorbidity of acute ischaemic stroke with Covid-19 is a challenging condition, potentially influencing the decision of whether to administer intravenous thrombolysis (IVT). We aimed to assess the 1-month outcome in ischaemic stroke patients with Covid-19 infection who received IVT alone or before thrombectomy (bridging therapy). METHODS: As a collaboration initiative promoted by the Italian Stroke Organization, all Italian stroke units (n = 190) were contacted and invited to participate in data collection on stroke patients with Covid-19 who received IVT. RESULTS: Seventy-five invited centers agreed to participate. Thirty patients received IVT alone and 17 received bridging therapy between 21 February 2020 and 30 April 2020 in 20 centers (n = 18, Northern Italy; n = 2, Central Italy). At 1 month, 14 (30.4%) patients died and 20 (62.5%) survivors had a modified Rankin Scale (mRS) score of 3 to 5. At 24 to 36 hours, asymptomatic intracerebral hemorrhage (ICH) was reported in eight (17.4%) patients and symptomatic ICH (sICH) in two (4.3%) patients. Causes of death were severe ischaemic stroke (n = 8), a new ischaemic stroke (n = 2), acute respiratory failure (n = 1), acute renal failure (n = 1), acute myocardial infarction (n = 1), and endocarditis (n = 1). In survivors with a 1-month mRS score of 3 to 5, baseline glucose level was higher, whereas endovascular procedure time in cases of bridging therapy was longer. Baseline National Institutes of Health Stroke Scale glucose and creatinine levels were higher in patients who died. CONCLUSIONS: Intravenous thrombolysis for patients with stroke and Covid-19 was not a rare event in the most affected areas by pandemic, and rates of 1-month unfavorable outcomes were high compared to previous data from the pre-Covid-19 literature. However, risk of sICH was not increased.


Assuntos
COVID-19/complicações , COVID-19/terapia , AVC Isquêmico/complicações , AVC Isquêmico/terapia , Terapia Trombolítica/métodos , Idoso , Idoso de 80 Anos ou mais , Glicemia/análise , COVID-19/mortalidade , Causas de Morte , Creatinina/sangue , Feminino , Fibrinolíticos/administração & dosagem , Fibrinolíticos/uso terapêutico , Humanos , Injeções Intravenosas , AVC Isquêmico/mortalidade , Itália/epidemiologia , Masculino , Pandemias , Análise de Sobrevida , Trombectomia , Resultado do Tratamento
3.
Eur J Neurol ; 27(10): 2036-2040, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32460442

RESUMO

BACKGROUND AND PURPOSE: Multiple studies have suggested an immunomodulatory role of cholesterol. We investigated whether cholesterol levels are associated with the risk of infectious complications (ICs) in acute ischemic stroke patients. METHODS: A single-center prospective cohort was analyzed. Total (TOTc), low-density lipoprotein cholesterol and high-density lipoprotein cholesterol levels were measured within 24 h from admission. The outcome of interest was the occurrence of any IC (pneumonia, urinary tract infection, sepsis, other infection) during hospitalization. Predictors of ICs were investigated with multivariable logistic regression. RESULTS: A total of 603 patients were included (median age 78 years, 49.3% males), of whom 134 (22.2%) developed an IC. Subjects with ICs had lower TOTc compared with patients without ICs (median 157 vs. 173 mg/dL; P < 0.001). When TOTc was stratified in quartiles, we observed a linear decrease in the prevalence of ICs with higher TOTc levels (Q1, <144 mg/dL, 32.7%; Q2, 145-168 mg/dL, 24.7%; Q3, 169-197 mg/dL, 17.8%; Q4, >197 mg/dL, 13.3% P < 0.001). The inverse relationship between TOTc and ICs remained significant after adjustment for confounders in logistic regression [odds ratio (OR) for 10 mg/dL increase, 0.92; 95% confidence intervals (CI), 0.87-0.97; P = 0.001]. This association was also confirmed for low-density lipoprotein cholesterol (OR, 0.93; 95% CI, 0.88-0.99; P = 0.013) and high-density lipoprotein cholesterol (OR, 0.85; 95% CI, 0.73-0.98; P = 0.026) and was not mediated by statin treatment. CONCLUSION: Higher cholesterol levels are independently associated with lower risk of ICs in ischemic stroke patients. Further studies are needed to confirm our findings and characterize the biological mechanisms underlying this association.


Assuntos
Isquemia Encefálica , AVC Isquêmico , Idoso , Isquemia Encefálica/complicações , Isquemia Encefálica/epidemiologia , Colesterol , Feminino , Humanos , Masculino , Estudos Prospectivos , Fatores de Risco
4.
Plant Biol (Stuttg) ; 20(6): 956-967, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30022587

RESUMO

Members of CYCLOIDEA (CYC)/TEOSINTE BRANCHED1 (TB1) transcription factor family are essential to control flower symmetry and inflorescence architecture. In the Helianthus annuus genome, ten CYC/TB1 genes have been identified. Studies performed on mutants recognised HaCYC2c as one of the key players controlling zygomorphism in sunflower. We identified CYC2c genes in the diploid Helianthus decapetalus (HdCYC2c) and in the interspecific hybrid Helianthus × multiflorus (H × mCYC2cA and H × mCYC2cB), a triploid (2n = 3× = 51), originated from unreduced eggs of H. decapetalus fertilised by reduced H. annuus male gametes. Phylogenetic analysis showed that HdCYC2c and H × mCYC2c were placed within a CYC2 subclade together with HaCYC2c but distinct from it. The present data showed that in H. × multiflorus the allele derived from H. annuus is deleted or highly modified. The H. × multiflorus taxon exists as radiate and ligulate inflorescence types. We analysed CYC2c expression in H. decapetalus and in the cultivar 'Soleil d'Or' of H. × multiflorus, a ligulate inflorescence type with actinomorphic corolla of disk flowers transformed into a zygomorphic ray-like corolla. In H. decapetalus, the HdCYC2c gene showed differential expression between developing flower types, being up-regulated in the corolla of ray flowers in comparison to the disk flower corolla. In H. × multiflorus, an insertion of 865 bp, which is part of a CACTA transposable element, was found in the 5'-untranslated region (5'-UTR) of H × mCYC2cB. This insertion could promote, even with epigenetic mechanisms, ectopic expression of the gene throughout the inflorescence, resulting in the observed loss of actinomorphy and originating a ligulate head.


Assuntos
Elementos de DNA Transponíveis/genética , Flores/genética , Genes de Plantas/genética , Helianthus/genética , Fatores de Transcrição/genética , DNA de Plantas/genética , Flores/crescimento & desenvolvimento , Regulação da Expressão Gênica de Plantas/genética , Helianthus/crescimento & desenvolvimento , Filogenia , Reação em Cadeia da Polimerase em Tempo Real , Fatores de Transcrição/fisiologia
5.
Int J Colorectal Dis ; 30(7): 891-8, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25989926

RESUMO

PURPOSE: The purpose of this study was to explore the potential role of deranged fecal microRNA (miRNA) pattern as a reliable warning signal of colorectal cancer (CRC), a subset of fecal CRC-related miRNAs was evaluated in CRC patients, before and after surgery, and in healthy controls. METHODS: Twenty CRC patients and 20 age/sex-matched healthy volunteers with negative colonoscopy entered the study. Cancer biopsy, colonic mucosa from the resected specimens, and fecal samples from patients and controls were screened for 13 miRNAs involved in CRC onset and progressions by reverse transcription quantitative PCR (RT-qPCR). Postoperative evaluation of fecal miRNAs was carried out after a median follow-up of 18 months (range 12-30). RESULTS: Two out 13 miRNAs (RNU6B, miR-16-3p) were used as internal controls leaving 11 available for analysis. Cancer tissue contained significantly higher expression of all miRNAs, compared to normal mucosa (p < 0.05). Expression of preoperative levels of five fecal miRNAs, (miR-19-b-3p, miR-20a-5p, miR-21-3p, miR92a-3p, miR141) was significantly higher in CRC patients compared to controls and significantly decreased after curative surgery. Three out of these five miRNAs (miR20a-5p, miR21-3p, and miR141) returned to values comparable to normal controls. CONCLUSIONS: A set of three specific fecal miRNAs is overexpressed before surgery, and return within the normal range after cancer removal could be considered as an appealing opportunity for a new reliable tool for CRC secondary prevention. However, their role needs to be explored in large prospective trials and compared with the existing screening tools.


Assuntos
Neoplasias Colorretais/genética , Neoplasias Colorretais/cirurgia , Cirurgia Colorretal , Fezes/química , MicroRNAs/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Demografia , Feminino , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Humanos , Mucosa Intestinal/metabolismo , Mucosa Intestinal/patologia , Masculino , MicroRNAs/metabolismo , Pessoa de Meia-Idade , Estabilidade de RNA/genética , Curva ROC , Reprodutibilidade dos Testes
6.
Eur J Neurol ; 22(3): 514-9, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25443877

RESUMO

BACKGROUND AND PURPOSE: There is an increasing interest in new risk factors for ischaemic stroke. Acute and chronic infections could contribute to different aetiological mechanisms of atherosclerosis that lead to cerebrovascular disease. The aim of this study was to investigate the hypothesis that previous infections and Chlamydia pneumoniae in particular increase the risk of ischaemic stroke in the population. METHODS: This was a prospective case-control study involving 11 Italian stroke units. Controls were age- and sex-matched with cases, represented by patients admitted to hospital for acute ischaemic stroke. For each participant classical vascular risk factors and previous inflammatory and infectious events up to 1 month before were registered. Blood samples were collected to analyse inflammatory markers and titres of antibodies against C. pneumoniae. RESULTS: A total of 1002 participants were included (mean age 69 years) with 749 ischaemic stroke patients. Infections occurred within 1 month previously in 12% of the entire sample with a higher prevalence in the case group (14.4% vs. 3.9%). At multivariate analysis of the seropositivity of IgA antibodies against C. pneumoniae increased the risk of stroke significantly (relative risk 2.121; 95% confidence interval 1.255-3.584) and an early previous infection (up to 7 days before the event) contributed to a rise in probability of acute cerebral ischaemia (relative risk 3.692; 95% confidence interval 1.134-6.875). CONCLUSIONS: Early previous infections and persistent chronic infection of C. pneumoniae could contribute to increase the risk of ischaemic stroke significantly, in the elderly especially.


Assuntos
Anticorpos Antibacterianos/sangue , Isquemia Encefálica/epidemiologia , Infecções por Chlamydophila/epidemiologia , Chlamydophila pneumoniae/patogenicidade , Infecções/epidemiologia , Acidente Vascular Cerebral/epidemiologia , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Doença Crônica , Feminino , Humanos , Imunoglobulina A/imunologia , Itália/epidemiologia , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Fatores de Risco
7.
Int Angiol ; 34(3): 243-9, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24945916

RESUMO

AIM: Endovenous laser treatment (EVLT) is an accepted form of axial vein ablation for symptomatic venous reflux but its role in the treatment of anterior accessory saphenous vein (AASV) has not been well characterized. The aim of this paper is to show the short-term result of EVLT with a ball-tipped fiber and a 1540 nm diode laser of the AASV with preservation of a competent great saphenous vein (GSV). METHODS: Nine incompetent AASV veins in 8 patients (6 female) were treated. The gravity of chronic venous disease was determined according to the CEAP classification and the severity of symptoms was scored according to the revised Venous Clinical Severity Score. Patient satisfaction was assessed by a 0 to 3 scale. RESULTS: The average linear endovenous energy density was 60.5 J/cm vein (SD: 7.5). Patients returned to daily activities after a mean of 3.8 days (SD: 1.4). 5 patients (63%) have had pain but of mild intensity. No patients developed paresthesia or phlebitis reactions in the treated area. Post-operative ecchymoses are frequent (89%). During the follow-up period (mean 13 months, range: 7-17 months) all the veins were occluded. The VCSS improved drastically from a mean of 3.2 (SD: 1.3) preinterventional to 0 (SD: 0.38) at 17 months. All patients were satisfied or very satisfied with the method. No severe complications occurred. CONCLUSION: EVLT of an incompetent AASV with a 1540 nm diode laser is a safe and efficient therapy option, with a high success rate and with no evidence of GSV neo-reflux or recurrent varicosities during the follow-up period.


Assuntos
Equimose/etiologia , Terapia a Laser/efeitos adversos , Lasers Semicondutores/uso terapêutico , Complicações Pós-Operatórias , Veia Safena/cirurgia , Varizes/cirurgia , Adulto , Idoso , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Satisfação do Paciente , Resultado do Tratamento
8.
Int Angiol ; 34(1): 1-8, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24927020

RESUMO

Endovenous laser treatment (EVLT) is an efficient method to treat incompetent saphenous veins with high occlusion rates. Major side effects reported with 810 nm and 980 nm diode laser are postoperative pain and bruising. Recently laser systems with higher wavelengths (WSLWs), associated with new energy delivery devices, seem to reduce some side effects previously reported. Aim of this study is to verify if there are real clinical advantages in the use of WSLWs, reviewing the comparison studies present in the literature. After a search on MEDLINE database, a review of all papers concerning WSLWs, was made. Five studies of comparison between different wavelength, 810 vs.. 980 nm, 940 vs.. 1320 nm, 810 vs.. 1320 nm, 980 vs.. 1500 nm and 980 vs.. 1470 nm were found. These studies report similar results: the WSLWs produce fewer side effects. New optical fibers have also been developed; WSLWs with the use of these new fibers dramatically changed the postoperative period, with a reduction of pain and bruising. There is no scientific evidence that WSLWs have any effect on long-term outcome, although short-term differences have been found for some side effects. Other parameters are also important: in particular, LEED and cold tumescent anesthesia are critical points. Laser fiber design probably has a significant effect on treatment success in the performance of EVLT and also how the energy is delivered (pulsing or continuous mode) and the pull-back rate of the laser fiber are possible factors affecting complication ratios and pain scores, regardless of the type of wavelength used.


Assuntos
Procedimentos Endovasculares/instrumentação , Terapia a Laser/instrumentação , Lasers , Veia Safena/cirurgia , Insuficiência Venosa/cirurgia , Procedimentos Endovasculares/efeitos adversos , Desenho de Equipamento , Humanos , Terapia a Laser/efeitos adversos , Lasers/efeitos adversos , Dor Pós-Operatória/etiologia , Fatores de Risco , Veia Safena/fisiopatologia , Resultado do Tratamento , Insuficiência Venosa/diagnóstico , Insuficiência Venosa/fisiopatologia
9.
Biosens Bioelectron ; 53: 283-7, 2014 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-24144559

RESUMO

This paper reports the characterization of an electrochemical biosensor for the continuous monitoring of Naproxen based on cytochrome P450. The electrochemical biosensor is based on the drop-casting of multi-walled carbon-nanotubes (MWCNTs) and microsomal cytochrome P4501A2 (msCYP1A2) on a graphite screen-printed electrode (SPE). The proposed biosensor was employed to monitor Naproxen (NAP), a well-known anti-inflammatory compound, through cyclic voltammetry. The dynamic linear range for the amperometric detection of NAP had an upper limit of 300 µM with a corresponding limit of detection (LOD) of 16 ± 1 µM (S/N=3), which is included in NAP physiological range (9-300 µM). The MWCNT/msCYP1A2-SPE sensor was also calibrated for NAP detection in mouse serum that was previously extracted from mice, showing a slightly higher LOD (33 ± 18 µM). The stability of the msCYP1A2-based biosensor was assessed by longtime continuous cyclic voltammetric measurements. The ability of the sensor to monitor drug delivery was investigated by using a commercial micro-osmotic pump. Results show that the MWCNT/msCYP1A2-SPE sensor is capable of precisely monitoring the real-time delivery of NAP for 16 h. This work proves that the proposed electrochemical sensor might represent an innovative point-of-care solution for the personalization of drug therapies, as well as for pharmacokinetic studies in both animals and humans.


Assuntos
Técnicas Biossensoriais/métodos , Sistema Enzimático do Citocromo P-450/química , Naproxeno/isolamento & purificação , Animais , Eletrodos , Humanos , Limite de Detecção , Camundongos , Nanotubos de Carbono/química , Naproxeno/sangue , Oxirredução
10.
Neurol Sci ; 34(7): 1227-33, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23392898

RESUMO

The purpose of this study is to identify which factors are able to limit or hamper the access to systemic thrombolysis (evTPA) in Lombardia to define corrective interventions. We analyzed 1,015 patients with ischemic stroke admitted to emergency departments (ED) participating to the Lombardia Stroke Unit Registry and eligible for evTPA; 303 (29.9%) patients were treated with evTPA (evTPA+ group) and 712 (70.1%) were not (evTPA- group). We collected case-mix and stroke care process variables.The evTPA+ group was characterized by a shorter ED arrival time, a greater neurological impairment, a more chance to be admitted to ED linked to comprehensive stroke center (CSC) and a shorter waiting time to access to diagnostic procedures. The chance to be treated with evTPA was greater if neurological evaluation anticipated neuroimaging (p = 0.0003). The multivariate analysis confirmed that the admission to ED linked to CSC (OR: 2.50, 95% CI: 1.39-4.48, p < 0.0001) and neurological evaluation performed before neuroimaging (OR: 2.34, 95% CI: 1.35-4.04, p = 0.002) increased the probability to receive rtPA. The evTPA treatment is strictly dependent on pre-hospital and ED care process phases and strongly influenced by the degree of stroke severity. Door-to-needle time is shorter in patients with a greater stroke severity and a shorter ED arrival time. A 24-h/week availability of the neurologist in ED can increase the percentage of thrombolysis optimizing the selection of patients and the timing of the diagnostic procedures.


Assuntos
Isquemia Encefálica/tratamento farmacológico , Serviço Hospitalar de Emergência/tendências , Fibrinolíticos/administração & dosagem , Acidente Vascular Cerebral/tratamento farmacológico , Terapia Trombolítica/tendências , Adulto , Idoso , Idoso de 80 Anos ou mais , Isquemia Encefálica/diagnóstico , Isquemia Encefálica/epidemiologia , Grupos Diagnósticos Relacionados , Feminino , Humanos , Itália/epidemiologia , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Sistema de Registros , Risco Ajustado , Acidente Vascular Cerebral/diagnóstico , Acidente Vascular Cerebral/epidemiologia , Terapia Trombolítica/métodos , Adulto Jovem
11.
Nanotechnology ; 23(11): 115701, 2012 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-22369762

RESUMO

The effect of image charges on current transport mechanisms investigated at the nanoscale in Al(1-x)In(x)N/GaN heterostructures was studied. Current-voltage (I-V) measurements were performed locally using a conductive AFM-tip as a nanoprobe and the conduction mechanism was modeled to explain the observed behavior. This model suggests that current transport is controlled by thermionic emission (TE) of the two-dimensional electron gas (2DEG) across the potential barrier at the heterointerface, where the image charges generated by the 2DEG induce a barrier lowering at the Al(1-x)In(x)N/GaN interface, enhancing electron transport. This barrier lowering depends on the 2DEG characteristics, such as 2DEG density n(2D), first subband energy E0 and the average distance x0 of the 2DEG from the interface. By fitting the experimental I-V curves with the present model the 2DEG density was evaluated. The obtained results were in very good agreement with the Hall measurements.

12.
Colorectal Dis ; 13(12): e388-95, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21831172

RESUMO

AIM: The treatment of desmoid tumours (DTs) is controversial. Anti-oestrogen therapy has frequently been used, but clear information of its efficacy is lacking. In this systematic review we have undertaken a comprehensive analysis to assess the effectiveness of anti-oestrogen therapy in terms of ability to induce partial or complete regression of DTs. METHOD: A systematic review of articles published in English between January 1983 and December 2009 was carried out according to the RECIST criteria. A literature search was performed on electronic databases including: United States National Library of Medicine (MEDLINE-PubMed), Excerpta Medica (EMBASE), Cochrane Library and Google search engine. Two-hundred articles dealing with DTs were identified but only fourty-one were were selected as appropriate for the study. The chi-square test was used for statistical analysis. RESULTS: Data on 168 DTs treated with anti-oestrogen agents, alone or in combination with nonsteroidal anti-inflammatory drugs, were identified with an overall response rate of 51%. There was no difference in response according to the type of DTs or between different anti-oestrogen therapies. Combination with anti-inflammatory drugs did not improve the outcome. Toremifene was sometimes effective in cases resistant to tamoxifen. Response did not seem to be related to oestrogen receptor status. CONCLUSIONS: Despite potential inaccuracies in the methodology, the results of the review indicate that anti-oestrogen therapy produces some effect in about one half of patients with DTs. Its indication compared with other treatments is discussed.


Assuntos
Antagonistas de Estrogênios/uso terapêutico , Fibromatose Agressiva/tratamento farmacológico , Tamoxifeno/uso terapêutico , Anti-Inflamatórios não Esteroides/uso terapêutico , Quimioterapia Combinada , Humanos , Toremifeno/uso terapêutico
13.
Theor Appl Genet ; 123(5): 779-91, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21647740

RESUMO

Improved knowledge of genome composition, especially of its repetitive component, generates important informations in both theoretical and applied research. In this study, we provide the first insight into the local organization of the sunflower genome by sequencing and annotating 349,380 bp from 3 BAC clones, each including one single-copy gene. These analyses resulted in the identification of 11 putative gene sequences, 18 full-length LTR retrotransposons, 6 incomplete LTR retrotransposons, 2 non-autonomous LTR-retroelements (LINEs), 2 putative DNA transposons fragments and one putative helitron. Among LTR-retrotransposons, non-autonomous elements (the so-called LARDs), which do not carry any protein-encoding sequence, were discovered for the first time in the sunflower. The insertion time of intact retroelements was measured, based on sister LTRs divergence. All isolated elements were inserted relatively recently, especially those belonging to the Gypsy superfamily. Retrotransposon families related to those identified in the BAC clones are present also in other species of Helianthus, both annual and perennial, and even in other Asteraceae. In one of the three BAC clones, we found five copies of a lipid transfer protein (LTP) encoding gene within less than 100,000 bp, four of which are potentially functional. Two of these are interrupted by LTR retrotransposons, in the intron and in the coding sequence, respectively. The divergence between sister LTRs of the retrotransposons inserted within the genes indicates that LTP gene duplication started earlier than 1.749 MYRS ago. On the whole, the results reported in this study confirm that the sunflower is an excellent system to study transposons dynamics and evolution.


Assuntos
Evolução Molecular , Genoma de Planta , Helianthus/genética , Clonagem Molecular , Elementos de DNA Transponíveis , DNA de Plantas/química , Duplicação Gênica , Retroelementos , Análise de Sequência de DNA
14.
Theor Appl Genet ; 122(6): 1039-49, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21184050

RESUMO

With the aim to study variability in genes involved in ecological adaptations, we have analysed sequence polymorphisms of eight unique genes putatively involved in drought response by isolation and analysis of allelic sequences in eight inbred lines of sunflower of different origin and phenotypic characters and showing different drought response in terms of leaf relative water content (RWC). First, gene sequences were amplified by PCR on genomic DNA from a highly inbred line and their products were directly sequenced. In the absence of single nucleotide polymorphisms, the gene was considered as unique. Then, the same PCR reaction was performed on genomic DNAs of eight inbred lines to isolate allelic variants to be compared. The eight selected genes encode a dehydrin, a heat shock protein, a non-specific lipid transfer protein, a z-carotene desaturase, a drought-responsive-element-binding protein, a NAC-domain transcription regulator, an auxin-binding protein, and an ABA responsive-C5 protein. Nucleotide diversity per synonymous and non-synonymous sites was calculated for each gene sequence. The π (a)/π (s) ratio range was usually very low, indicating strong purifying selection, though with locus-to-locus differences. As far as non-coding regions, the intron showed a larger variability than the other regions only in the case of the dehydrin gene. In the other genes tested, in which one or more introns occur, variability in the introns was similar or even lower than in the other regions. On the contrary, 3'-UTRs were usually more variable than the coding regions. Linkage disequilibrium in the selected genes decayed on average within 1,000 bp, with large variation among genes. A pairwise comparison between genetic distances calculated on the eight genes and the difference in RWC showed a significant correlation in the first phases of drought stress. The results are discussed in relation to the function of analysed genes, i.e. involved in gene regulation and signal transduction, or encoding enzymes and defence proteins.


Assuntos
Adaptação Fisiológica/genética , Sequência de Bases , Secas , Variação Genética , Helianthus/genética , Regulação da Expressão Gênica de Plantas , Helianthus/fisiologia , Dados de Sequência Molecular , Proteínas de Plantas/genética , Reação em Cadeia da Polimerase , Análise de Sequência de DNA
15.
Clin Genet ; 78(5): 432-40, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20584031

RESUMO

Infantile neuroaxonal dystrophy, INAD, is a severe progressive psychomotor disorder with infantile onset and characterized by the presence of axonal spheroids throughout the central and peripheral nervous systems. A subset of INAD patients shows also brain iron accumulation which represents instead the distinctive feature of the idiopathic neurodegeneration with brain iron accumulation, NBIA. These diseases share the same causative gene, PLA2G6, encoding iPLA2-VIA, a calcium-independent phospholipase. Mutations that lead to a complete absence of protein are associated with a severe INAD profile, while compound heterozygous mutations with possibly a residual protein activity are instead associated with the less severe NBIA phenotype. Here we describe two INAD patients both with an unusually rapid disease progression and a peculiar neuroradiological presentation in one of them. Compound heterozygosity for a large intragenic deletion and a nonsense mutation was found in one of them while the other is carrying two novel splice-site mutations. Breakpoint-sequence analysis suggests a non-allelic-homologous-recombination (NAHR) event, probably underlying the rearrangement. These findings, while supporting the genotype-phenotype correlation already observed in INAD patients, provide the first sequence characterization of a genomic rearrangement in PLA2G6 gene, thus orienting the search for missing mutant alleles in PLA2G6 related diseases.


Assuntos
Fosfolipases A2 do Grupo VI/genética , Distrofias Neuroaxonais/genética , Sequência de Bases , Pré-Escolar , Fosfolipases A2 do Grupo VI/fisiologia , Humanos , Lactente , Ferro/metabolismo , Splicing de RNA , Deleção de Sequência
16.
Curr Pharm Des ; 16(7): 847-53, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20388096

RESUMO

Chemoprevention by dietary constituents has recently emerged as a novel approach to control gastric cancer incidence. Over the past years, functional foods and food supplements, especially probiotics, have received much attention as potential dietary cancer prevention agents. The precise mechanisms by which these lactic cultures exert their antitumorigenic activities are not fully elucidated, but there is some evidence of their influence on cell proliferation and growth. Ornithine decarboxylase (ODC) and spermidine/spermine N1-acetyltransferase (SSAT) are the key enzymes involved in polyamine biosynthesis and catabolism, respectively. These polycationic compounds are significantly associated with cancer risk and represent a specific markers for neoplastic proliferation. The aim of this study was to investigate the effects of increasing concentrations of Lactobacillus rhamnosus strain GG (ATCC 53103) (L. GG) homogenate on polyamine biosynthesis and polyamine degradation as well as on resulting polyamine levels in HGC-27 human gastric cancer cells. The influence of this probiotic on cell proliferation was also evaluated. Administration of probiotic homogenate significantly reduced both ODC mRNA and activity as well as polyamine content and neoplastic proliferation. Besides, an increase in both SSAT mRNA and activity occurred after LGG administration in HGC-27. These data suggest that a nutritional component such as the probiotic L. GG could be proposed in an alternative approach to prevention of gastric cancer. This strategy could overcome the limitations due to a prolonged use of drugs and/or the occurrence of their adverse effects, and it could reasonably also start at a young age.


Assuntos
Proliferação de Células/efeitos dos fármacos , Lacticaseibacillus rhamnosus/fisiologia , Poliaminas/metabolismo , Probióticos/farmacologia , Neoplasias Gástricas/metabolismo , Neoplasias Gástricas/prevenção & controle , Acetiltransferases/genética , Acetiltransferases/metabolismo , Linhagem Celular Tumoral , Humanos , Ornitina Descarboxilase/genética , Ornitina Descarboxilase/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Neoplasias Gástricas/microbiologia
17.
Minerva Chir ; 65(6): 619-25, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21224796

RESUMO

AIM: In this paper we retrospectively analyzed prospectively-collected data on our myelofibrosis with myeloid metaplasia (MMM) patients who underwent splenectomy. The aim was to ascertain the hematological response and any resolution of symptoms existing prior to splenectomy; redefining timing and role of splenectomy in the treatment of MMM. METHODS: This prospective study considered 31 patients with MMM who underwent splenectomy for transfusion-dependent anemia, thrombocytopenia, abdominal swelling and pain. Postoperative work-up consisting in laboratory tests and clinical evaluation performing a quality of life (QoL) test based on EORTC QLQ-C30 questionnaire. Follow-up data were collected for one year after surgery. Statistical analysis used Student's t-test, the Mann-Whitney rank sum, Fisher's exact test, the Friedman test and the Wilcoxon test. RESULTS: Mortality was 3.2%. Respiratory symptomatic complications occurred in 35.4%. In all patients the need for blood transfusions was significantly reduced (P=0.005). An improvement in the painful symptoms was reported and a significant improve of postoperative quality of life was observed at one year after surgery. CONCLUSION: In our experience splenectomy is associated with limited perioperative mortality and morbidity. Acute complications are almost exclusively limited to respiratory tract. The removal of spleen seems can be recommended to increase the QoL and to palliate hematological disorders in patients no more responder to chemotherapy.


Assuntos
Mielofibrose Primária/complicações , Mielofibrose Primária/cirurgia , Esplenectomia , Humanos , Pessoa de Meia-Idade , Estudos Prospectivos , Estudos Retrospectivos
18.
Genome ; 52(11): 904-11, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19935914

RESUMO

In this paper we report on the isolation and characterization, for the first time, of a complete 6511 bp retrotransposon of sunflower. Considering its protein domain order and sequence similarity to other copia elements of dicotyledons, this retrotransposon was assigned to the copia retrotransposon superfamily and named HACRE1 (Helianthus annuus copia-like retroelement 1). HACRE1 carries 5' and 3' long terminal repeats (LTRs) flanking an internal region of 4661 bp. The LTRs are identical in their sequence except for two deletions of 7 and 5 nucleotides in the 5' LTR. Based on the sequence identity of the LTRs, HACRE1 was estimated to have inserted within the last approximately 84 000 years. The isolated sequence contains a complete open reading frame with only one complete reading frame. The absence of nonsense mutations agrees with the very high sequence identity between LTRs, confirming that HACRE1 insertion is recent. The haploid genome of sunflower (inbred line HCM) contains about 160 copies of HACRE1. This retrotransposon is expressed in leaflets from 7-day-old plantlets under different light conditions, probably in relation to the occurrence of many putative light-related regulatory cis-elements in the LTRs. However, sequenced cDNAs show less variability than HACRE1 genomic sequences, indicating that only a subset of this family is expressed under these conditions.


Assuntos
DNA de Plantas/genética , Genoma de Planta/genética , Helianthus/genética , Retroelementos/genética , Sequências Repetidas Terminais/genética , Sequência de Bases , Dados de Sequência Molecular , Fases de Leitura Aberta/genética , Alinhamento de Sequência , Análise de Sequência de DNA
19.
Theor Appl Genet ; 119(6): 1027-38, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19618160

RESUMO

The inter-retrotransposon amplified polymorphism (IRAP) protocol was applied for the first time within the genus Helianthus to assess intraspecific variability based on retrotransposon sequences among 36 wild accessions and 26 cultivars of Helianthus annuus L., and interspecific variability among 39 species of Helianthus. Two groups of LTRs, one belonging to a Copia-like retroelement and the other to a putative retrotransposon of unknown nature (SURE) have been isolated, sequenced and primers were designed to obtain IRAP fingerprints. The number of polymorphic bands in H. annuus wild accessions is as high as in Helianthus species. If we assume that a polymorphic band can be related to a retrotransposon insertion, this result suggests that retrotransposon activity continued after Helianthus speciation. Calculation of similarity indices from binary matrices (Shannon's and Jaccard's indices) show that variability is reduced among domesticated H. annuus. On the contrary, similarity indices among Helianthus species were as large as those observed among wild H. annuus accessions, probably related to their scattered geographic distribution. Principal component analysis of IRAP fingerprints allows the distinction between perennial and annual Helianthus species especially when the SURE element is concerned.


Assuntos
Variação Genética , Helianthus/classificação , Helianthus/genética , Retroelementos , Sequências de Repetição em Tandem , Sequência de Bases , Impressões Digitais de DNA , Primers do DNA/genética , DNA de Plantas/genética , Evolução Molecular , Genes de Plantas , Dados de Sequência Molecular , Polimorfismo Genético , Análise de Sequência de DNA , Especificidade da Espécie
20.
Genome ; 51(12): 1047-53, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19088818

RESUMO

The amplification and chromosomal localization of tandem repeated DNA sequences from Helianthus annuus (clone HAG004N15) and the physical organization of ribosomal DNA were studied in annual and perennial species of Helianthus. HAG004N15-related sequences, which did not show amplification in other Asteraceae except for Viguiera multiflora, were redundant in all the Helianthus species tested, but their frequency was significantly higher in perennials than in annuals. These sequences were located at the ends and intercalary regions of all chromosome pairs of annual species. A similar pattern was found in the perennials, but a metacentric pair in their complement was not labelled. Ribosomal cistrons were carried on two chromosome pairs in perennials and on three pairs in annuals except for H. annuus, where rDNA loci were on four pairs. No difference was observed between cultivated H. annuus and its wild accessions in the hybridization pattern of the HAG004N15 and ribosomal probes. These findings support the hypothesis that the separation between annual and perennial Helianthus species occurred through interspecific hybridization involving at least one different parent. However, GISH in H. annuus using genomic DNA from the perennial Helianthus giganteus as blocking DNA failed to reveal different genomic assets in annual and perennial species.


Assuntos
Evolução Molecular , Helianthus/genética , Sequências de Repetição em Tandem/genética , Análise Citogenética , DNA de Plantas/genética , Helianthus/classificação , Helianthus/citologia , Filogenia , Estações do Ano
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