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1.
Ann Hematol ; 100(8): 1965-1973, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34013406

RESUMO

Erythrocytosis has a diverse background. While polycythaemia vera has well defined criteria, the diagnostic approach and management of other types of erythrocytosis are more challenging. The aim of study was to retrospectively analyse the aetiology and management of non-clonal erythrocytosis patients referred to a haematology outpatient clinic in an 8-year period using a 3-step algorithm. The first step was inclusion of patients with Hb > 185 g/L and/or Hct > 0.52 in men and Hb > 165 g/L and/or Hct > 0.48 in women on two visits ≥ two months apart, thus confirming true erythrocytosis. Secondly, polycythaemia vera was excluded and secondary causes of erythrocytosis (SE) identified. Thirdly, idiopathic erythrocytosis patients (IE) were referred to next-generation sequencing for possible genetic background evaluation. Of the 116 patients, 75 (65%) are men and 41 (35%) women, with non-clonal erythrocytosis 34/116 (29%) had SE, 15/116 (13%) IE and 67/116 (58%) stayed incompletely characterized (ICE). Patients with SE were significantly older and had significantly higher Hb and Hct compared to patients with IE. Most frequently, SE was attributed to obstructive sleep apnoea and smoking. Phlebotomies were performed in 56, 53 and 40% of patients in the SE, IE, and ICE group, respectively. Approx. 70% of patients in each group received aspirin. Thrombotic events were registered in 12, 20 and 15% of SE, IE and ICE patients, respectively. Congenital erythrocytosis type 4 (ECYT4) was diagnosed in one patient. The study demonstrates real-life management of non-clonal erythrocytosis which could be optimized using a 3-step diagnostic algorithm.


Assuntos
Policitemia/diagnóstico , Policitemia/terapia , Adulto , Gerenciamento Clínico , Feminino , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Masculino , Pessoa de Meia-Idade , Flebotomia , Policitemia/congênito , Policitemia/genética , Estudos Retrospectivos
2.
J Clin Lab Anal ; 35(4): e23715, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33534944

RESUMO

BACKGROUND: Erythrocytosis is a condition with an excessive number of erythrocytes, accompanied by an elevated haemoglobin and/or haematocrit value. Congenital erythrocytosis has a diverse genetic background with several genes involved in erythropoiesis. In clinical practice, nine genes are usually examined, but in approximately 70% of patients, no causative mutation can be identified. In this study, we screened 39 genes, aiming to identify potential disease-driving variants in the family with erythrocytosis of unknown cause. PATIENTS AND METHODS: Two affected family members with elevated haemoglobin and/or haematocrit and negative for acquired causes and one healthy relative from the same family were selected for molecular-genetic analysis of 24 erythrocytosis and 15 hereditary haemochromatosis-associated genes with targeted NGS. The identified variants were further analysed for pathogenicity using various bioinformatic tools and review of the literature. RESULTS: Of the 12 identified variants, two heterozygous variants, the missense variant c.471G>C (NM_022051.2) (p.(Gln157His)) in the EGLN1 gene and the intron variant c.2572-13A>G (NM_004972.3) in the JAK2 gene, were classified as low-frequency variants in European population. None of the two variants were present in a healthy family member. Variant c.2572-13A>G has potential impact on splicing by one prediction tool. CONCLUSION: For the first time, we included 39 genes in the erythrocytosis clinical panel and identified two potential disease-driving variants in the Slovene family studied. Based on the reported functional in vitro studies combined with our bioinformatics analysis, we suggest further functional analysis of variant in the JAK2 gene and evaluation of a cumulative effect of both variants.


Assuntos
Estudos de Associação Genética , Predisposição Genética para Doença , Hemocromatose/genética , Policitemia/genética , Adulto , Idoso , Sequência de Bases , Biologia Computacional , Família , Feminino , Frequência do Gene/genética , Heterozigoto , Humanos , Padrões de Herança/genética , Masculino , Linhagem , Policitemia/congênito , Polimorfismo de Nucleotídeo Único/genética , Eslovênia
3.
Clin Infect Dis ; 71(11): 2849-2857, 2020 12 31.
Artigo em Inglês | MEDLINE | ID: mdl-31782768

RESUMO

BACKGROUND: A vaccine would be an ideal tool for reducing malaria's impact. PfSPZ Vaccine (radiation attenuated, aseptic, purified, cryopreserved Plasmodium falciparum [Pf] sporozoites [SPZ]) has been well tolerated and safe in >1526 malaria-naive and experienced 6-month to 65-year-olds in the United States, Europe, and Africa. When vaccine efficacy (VE) of 5 doses of 2.7 × 105 PfSPZ of PfSPZ Vaccine was assessed in adults against controlled human malaria infection (CHMI) in the United States and Tanzania and intense field transmission of heterogeneous Pf in Mali, Tanzanians had the lowest VE (20%). METHODS: To increase VE in Tanzania, we increased PfSPZ/dose (9 × 105 or 1.8 × 106) and decreased numbers of doses to 3 at 8-week intervals in a double blind, placebo-controlled trial. RESULTS: All 22 CHMIs in controls resulted in parasitemia by quantitative polymerase chain reaction. For the 9 × 105 PfSPZ group, VE was 100% (5/5) at 3 or 11 weeks (P < .000l, Barnard test, 2-tailed). For 1.8 × 106 PfSPZ, VE was 33% (2/6) at 7.5 weeks (P = .028). VE of dosage groups (100% vs 33%) was significantly different (P = .022). Volunteers underwent repeat CHMI at 37-40 weeks after last dose. 6/6 and 5/6 volunteers developed parasitemia, but time to first parasitemia was significantly longer than controls in the 9 × 105 PfSPZ group (10.89 vs 7.80 days) (P = .039), indicating a significant reduction in parasites in the liver. Antibody and T-cell responses were higher in the 1.8 × 106 PfSPZ group. CONCLUSIONS: In Tanzania, increasing the dose from 2.7 × 105 to 9 × 105 PfSPZ increased VE from 20% to 100%, but increasing to 1.8 × 106 PfSPZ significantly reduced VE. CLINICAL TRIALS REGISTRATION: NCT02613520.


Assuntos
Vacinas Antimaláricas , Malária Falciparum , Malária , Adulto , Animais , Europa (Continente) , Humanos , Malária/prevenção & controle , Malária Falciparum/prevenção & controle , Mali , Plasmodium falciparum , Esporozoítos , Tanzânia
4.
Hematol Rep ; 15(4): 597-607, 2023 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-37987318

RESUMO

Prophylactic treatment with emicizumab has become an important and effective bleeding prevention for people with hemophilia A (PwHA). Perioperative management of PwHA using emicizumab prophylaxis is still challenging due to a lack of experience. Medical records of perioperative management and outcomes were reviewed, and data were collected for adult PwHA receiving emicizumab and undergoing surgical procedures between August 2019 and July 2022 at the University Medical Center Ljubljana. Twelve surgical procedures were performed in eight PwHA (one with FVIII inhibitors) while on emicizumab prophylaxis. Three minor procedures included cataract surgery, cystoscopic lithotripsy, and percutaneous coronary intervention. Nine major surgeries included four osteosyntheses, necrectomy of chronic osteomyelitis with new ankle arthrodesis, two below-knee amputations, total knee replacement, and placement of ventriculostomy after a spontaneous intraventricular hemorrhage. No major bleeds, thrombotic events or deaths, or new inhibitors appeared. Our real-world experience demonstrates that minor and major surgeries can be performed safely in PwHA on emicizumab prophylaxis. Additional data are needed to optimize dosing/duration of additional hemostatic agents in diverse invasive procedures and complex clinical situations.

5.
Front Genet ; 12: 689868, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34349782

RESUMO

An erythrocytosis is present when the red blood cell mass is increased, demonstrated as elevated hemoglobin and hematocrit in the laboratory evaluation. Congenital predispositions for erythrocytosis are rare, with germline variants in several genes involved in oxygen sensing (VHL, EGLN1, and EPAS1), signaling for hematopoietic cell maturation (EPOR and EPO), and oxygen transfer (HBB, HBA1, HBA2, and BPGM) that were already associated with the eight congenital types (ECYT1-8). Screening for variants in known congenital erythrocytosis genes with classical sequencing approach gives a correct diagnosis for only up to one-third of the patients. The genetic background of erythrocytosis is more heterogeneous, and additional genes involved in erythropoiesis and iron metabolism could have a putative effect on the development of erythrocytosis. This study aimed to detect variants in patients with yet unexplained erythrocytosis using the next-generation sequencing (NGS) approach, targeting genes associated with erythrocytosis and increased iron uptake and implementing the diagnostics of congenital erythrocytosis in Slovenia. Selected 25 patients with high hemoglobin, high hematocrit, and no acquired causes were screened for variants in the 39 candidate genes. We identified one pathogenic variant in EPAS1 gene and three novel variants with yet unknown significance in genes EPAS1, JAK2, and SH2B3. Interestingly, a high proportion of patients were heterozygous carriers for two variants in HFE gene, otherwise pathogenic for the condition of iron overload. The association between the HFE variants and the development of erythrocytosis is not clearly understood. With a targeted NGS approach, we determined an actual genetic cause for the erythrocytosis in one patient and contributed to better management of the disease for the patient and his family. The effect of variants of unknown significance on the enhanced production of red blood cells needs to be further explored with functional analysis. This study is of great significance for the improvement of diagnosis of Slovenian patients with unexplained erythrocytosis and future research on the etiology of this rare hematological disorder.

6.
Eur J Cardiothorac Surg ; 59(5): 1096-1102, 2021 05 08.
Artigo em Inglês | MEDLINE | ID: mdl-33394040

RESUMO

OBJECTIVES: To evaluate the impact of the coronavirus disease 2019 (COVID-19) pandemic on acute and elective thoracic and abdominal aortic procedures. METHODS: Forty departments shared their data on acute and elective thoracic and abdominal aortic procedures between January and May 2020 and January and May 2019 in Europe, Asia and the USA. Admission rates as well as delay from onset of symptoms to referral were compared. RESULTS: No differences in the number of acute thoracic and abdominal aortic procedures were observed between 2020 and the reference period in 2019 [incidence rates ratio (IRR): 0.96, confidence interval (CI) 0.89-1.04; P = 0.39]. Also, no difference in the time interval from acute onset of symptoms to referral was recorded (<12 h 32% vs > 12 h 68% in 2020, < 12 h 34% vs > 12 h 66% in 2019 P = 0.29). Conversely, a decline of 35% in elective procedures was seen (IRR: 0.81, CI 0.76-0.87; P < 0.001) with substantial differences between countries and the most pronounced decline in Italy (-40%, P < 0.001). Interestingly, in Switzerland, an increase in the number of elective cases was observed (+35%, P = 0.02). CONCLUSIONS: There was no change in the number of acute thoracic and abdominal aortic cases and procedures during the initial wave of the COVID-19 pandemic, whereas the case load of elective operations and procedures decreased significantly. Patients with acute aortic syndromes presented despite COVID-19 and were managed according to current guidelines. Further analysis is required to prove that deferral of elective cases had no impact on premature mortality.


Assuntos
COVID-19 , Pandemias , Ásia , Procedimentos Cirúrgicos Eletivos , Europa (Continente) , Humanos , Itália , SARS-CoV-2 , Suíça
7.
BMC Mol Biol ; 11: 60, 2010 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-20712867

RESUMO

BACKGROUND: Circadian rhythms have a profound effect on human health. Their disruption can lead to serious pathologies, such as cancer and obesity. Gene expression studies in these pathologies are often studied in different mouse strains by quantitative real time polymerase chain reaction (qPCR). Selection of reference genes is a crucial step of qPCR experiments. Recent studies show that reference gene stability can vary between species and tissues, but none has taken circadian experiments into consideration. RESULTS: In the present study the expression of ten candidate reference genes (Actb, Eif2a, Gapdh, Hmbs, Hprt1, Ppib, Rn18s, Rplp0, Tbcc and Utp6c) was measured in 131 liver and 97 adrenal gland samples taken from three mouse strains (C57BL/6JOlaHsd, 129Pas plus C57BL/6J and Crem KO on 129Pas plus C57BL/6J background) every 4 h in a 24 h period. Expression stability was evaluated by geNorm and NormFinder programs. Differences in ranking of the most stable reference genes were observed both between individual mouse strains as well as between tissues within each mouse strain. We show that selection of reference gene (Actb) that is often used for analyses in individual mouse strains leads to errors if used for normalization when different mouse strains are compared. We identified alternative reference genes that are stable in these comparisons. CONCLUSIONS: Genetic background and circadian time influence the expression stability of reference genes. Differences between mouse strains and tissues should be taken into consideration to avoid false interpretations. We show that the use of a single reference gene can lead to false biological conclusions. This manuscript provides a useful reference point for researchers that search for stable reference genes in the field of circadian biology.


Assuntos
Ritmo Circadiano/genética , Expressão Gênica , Camundongos Endogâmicos/genética , Reação em Cadeia da Polimerase , Animais , Humanos , Camundongos , Dados de Sequência Molecular , Reação em Cadeia da Polimerase/métodos , Reação em Cadeia da Polimerase/normas
8.
Sci Rep ; 9(1): 13107, 2019 09 11.
Artigo em Inglês | MEDLINE | ID: mdl-31511562

RESUMO

The rapid and accurate diagnosis of Plasmodium falciparum malaria infection is an essential factor in malaria control. Currently, malaria diagnosis in the field depends heavily on using rapid diagnostic tests (RDTs) many of which detect circulating parasite-derived histidine-rich protein 2 antigen (PfHRP2) in capillary blood. P. falciparum strains lacking PfHRP2, due to pfhrp2 gene deletions, are an emerging threat to malaria control programs. The novel assay described here, named qHRP2/3-del, is well suited for high-throughput screening of P. falciparum isolates to identify these gene deletions. The qHRP2/3-del assay identified pfhrp2 and pfhrp3 deletion status correctly in 93.4% of samples with parasitemia levels higher than 5 parasites/µL when compared to nested PCR. The qHRP2/3-del assay can correctly identify pfhrp2 and pfhrp3 gene deletions in multiple strain co-infections, particularly prevalent in Sub-Saharan countries. Deployment of this qHRP2/3-del assay will provide rapid insight into the prevalence and potential spread of P. falciparum isolates that escape surveillance by RDTs.


Assuntos
Antígenos de Protozoários/genética , Antígenos de Protozoários/metabolismo , Deleção de Genes , Plasmodium falciparum/genética , Reação em Cadeia da Polimerase/métodos , Proteínas de Protozoários/genética , Proteínas de Protozoários/metabolismo , Plasmodium falciparum/fisiologia
9.
Am J Trop Med Hyg ; 100(6): 1433-1444, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30994090

RESUMO

In 2016, there were more cases and deaths caused by malaria globally than in 2015. An effective vaccine would be an ideal additional tool for reducing malaria's impact. Sanaria® PfSPZ Vaccine, composed of radiation-attenuated, aseptic, purified, cryopreserved Plasmodium falciparum (Pf) sporozoites (SPZ) has been well tolerated and safe in malaria-naïve and experienced adults in the United States and Mali and protective against controlled human malaria infection with Pf in the United States and field transmission of Pf in Mali, but had not been assessed in younger age groups. We, therefore, evaluated PfSPZ Vaccine in 93 Tanzanians aged 45 years to 6 months in a randomized, double-blind, normal saline placebo-controlled trial. There were no significant differences in adverse events between vaccinees and controls or between dosage regimens. Because all age groups received three doses of 9.0 × 105 PfSPZ of PfSPZ Vaccine, immune responses were compared at this dosage. Median antibody responses against Pf circumsporozoite protein and PfSPZ were highest in infants and lowest in adults. T-cell responses were highest in 6-10-year olds after one dose and 1-5-year olds after three doses; infants had no significant positive T-cell responses. The safety data were used to support initiation of trials in > 300 infants in Kenya and Equatorial Guinea. Because PfSPZ Vaccine-induced protection is thought to be mediated by T cells, the T-cell data suggest PfSPZ Vaccine may be more protective in children than in adults, whereas infants may not be immunologically mature enough to respond to the PfSPZ Vaccine immunization regimen assessed.


Assuntos
Anticorpos Antiprotozoários/sangue , Vacinas Antimaláricas/imunologia , Malária Falciparum/prevenção & controle , Plasmodium falciparum/imunologia , Linfócitos T/fisiologia , Adolescente , Adulto , Formação de Anticorpos , Criança , Pré-Escolar , Método Duplo-Cego , Feminino , Humanos , Lactente , Vacinas Antimaláricas/efeitos adversos , Masculino , Pessoa de Meia-Idade , Tanzânia , Vacinas Atenuadas
10.
Biochem Biophys Res Commun ; 376(1): 206-10, 2008 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-18775413

RESUMO

We show for the first time that isoforms of the cAMP response element modulator Crem, regulate the circadian expression of Cyp51 and other cholesterogenic genes in the mouse liver. In the wild type mice the expression of Cyp51, Hmgs, Fpps, and Sqs is minimal between CT12 and CT16 and peaks between CT20 and CT24. Cyp51, Fpps, and Sqs lost the circadian behavior in Crem-/- livers while Hmgcr is phase advanced from CT20 to CT12. This coincides with a phase advance of lathosterol/cholesterol ratio, as detected by GC-MS. Overexpression of CREMtau and ICER has little effect on the Hmgcr proximal promoter while they influence expression from the CYP51 promoter. Our data indicate that Crem-dependent regulation of Cyp51 in the liver results in circadian expression of this gene. We propose that cAMP signaling might generally be involved in the circadian regulation of cholesterol synthesis on the periphery.


Assuntos
Colesterol/biossíntese , Ritmo Circadiano , Modulador de Elemento de Resposta do AMP Cíclico/metabolismo , Sistema Enzimático do Citocromo P-450/biossíntese , Hidroximetilglutaril-CoA Sintase/biossíntese , Fígado/metabolismo , Animais , Ritmo Circadiano/genética , Modulador de Elemento de Resposta do AMP Cíclico/genética , Regulação da Expressão Gênica , Camundongos , Camundongos Knockout , Regiões Promotoras Genéticas , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Esterol 14-Desmetilase
11.
Acta Neurobiol Exp (Wars) ; 68(2): 204-13, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18511956

RESUMO

Neuropsychological studies in brain-injured patients with aphasia and children with specific language-learning deficits have shown the dependence of language comprehension on auditory processing abilities, i.e. the detection of temporal order. An impairment of temporal-order perception can be simulated by time reversing segments of the speech signal. In our study, we investigated how different lengths of time-reversed segments in speech influenced comprehension in ten native German speakers and ten participants who had acquired German as a second language. Results show that native speakers were still able to understand the distorted speech at segment lengths of 50 ms, whereas non-native speakers only could identify sentences with reversed intervals of 32 ms duration. These differences in performance can be interpreted by different levels of semantic and lexical proficiency. Our method of temporally-distorted speech offers a new approach to assess language skills that indirectly taps into lexical and semantic competence of non-native speakers.


Assuntos
Compreensão/fisiologia , Idioma , Percepção da Fala/fisiologia , Comportamento Verbal/fisiologia , Estimulação Acústica/métodos , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estatísticas não Paramétricas , Fatores de Tempo
12.
Acta Psychol (Amst) ; 125(1): 51-65, 2007 May.
Artigo em Inglês | MEDLINE | ID: mdl-16904621

RESUMO

Some authors have suggested separate mechanisms for the processing of temporal intervals above versus below 2-3s. Given that the evidence is mixed, the present experiment was carried out as a critical test of the separate-mechanism hypothesis. Subjects reproduced five standard durations of 1-5s presented in the auditory and visual modalities. The Corsi-block test was used to assess effects of working-memory span on different interval lengths. Greater working-memory span was associated with longer reproductions of intervals of 3-5s. A factor analysis run on mean reproduced intervals revealed one modality-unspecific factor for durations of 1-2s and two modality-specific factors for longer intervals. These results are interpreted as further indications that two different processes underlie temporal reproductions of shorter and longer intervals.


Assuntos
Memória de Curto Prazo/fisiologia , Processos Mentais/fisiologia , Percepção do Tempo/fisiologia , Estimulação Acústica/métodos , Adulto , Distribuição por Idade , Idoso , Idoso de 80 Anos ou mais , Análise de Variância , Percepção Auditiva/fisiologia , Análise Fatorial , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estimulação Luminosa/métodos , Análise e Desempenho de Tarefas , Percepção Visual/fisiologia
13.
Brain Lang ; 98(1): 1-11, 2006 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16460793

RESUMO

Standard diagnostic procedures for assessing temporal-processing abilities of adult patients with aphasia have so far not been developed. In our study, temporal-order measurements were conducted using two different experimental procedures to identify a suitable measure for clinical studies. Additionally, phoneme-discrimination abilities were tested on the word, as well as on the sentence level, as a relationship between temporal processing and phoneme-discrimination abilities is assumed. Patients with aphasia displayed significantly higher temporal-order thresholds than control subjects. The detection of an association between temporal processing and speech processing, however, depended on the stimuli and the phoneme-discrimination tasks used. Our results also suggest top-down feedback on phonemic processing.


Assuntos
Afasia/fisiopatologia , Percepção Auditiva/fisiologia , Compreensão , Discriminação Psicológica , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Compreensão/fisiologia , Discriminação Psicológica/fisiologia , Feminino , Humanos , Idioma , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Fatores de Tempo
14.
Appl Ergon ; 37(2): 187-99, 2006 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-16118009

RESUMO

To determine the relative safety of onboard display positions while driving, participants performed a lane-keeping task in a driving simulator. Concurrently, they reacted to a light by pushing the brake pedal. A secondary task was projected onto a display at one of the seven different locations in the cockpit. Behavioral data, eye movements, and subjective rating scales showed that the manipulation of display information during driving disturbed drivers' performance exponentially as a function of distance between the line of sight to the outside primary task and the onboard display position. Vertical eccentricity had a greater detrimental effect than horizontal distance. Under a certain condition with a high secondary task load, reaction time of pushing the brake to the outside stimulus nearly doubled with a diagonal eccentricity of 35 degrees as compared to lower eccentricities. Subjective workload measures complement the behavioral data of clear detrimental effects with eccentricities of at least 35 degrees .


Assuntos
Condução de Veículo , Simulação por Computador , Apresentação de Dados , Interface Usuário-Computador , Ergonomia , Humanos , Japão , Segurança
16.
Endocrinology ; 146(12): 5321-31, 2005 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16123160

RESUMO

Lanosterol 14alpha-demethylase (CYP51) responds to cholesterol feedback regulation through sterol regulatory element binding proteins (SREBPs). The proximal promoter of CYP51 contains a conserved region with clustered regulatory elements: GC box, cAMP-response elements (CRE-like), and sterol regulatory element (SRE). In lipid-rich (SREBP-poor) conditions, the CYP51 mRNA drops gradually, the promoter activity is diminished, and no DNA-protein complex is observed at the CYP51-SRE1 site. The majority of cAMP-dependent transactivation is mediated through a single CRE (CYP51-CRE2). Exposure of JEG-3 cells to forskolin, a mediator of the cAMP-dependent signaling pathway, provokes an immediate early response of CYP51, which has not been described before for any cholesterogenic gene. The CYP51 mRNA increases up to 4-fold in 2 h and drops to basal level after 4 h. The inducible cAMP early repressor (ICER) is involved in attenuation of transcription. Overexpressed CRE-binding protein (CREB)/CRE modulator (CREM) transactivates the mouse/human CYP51 promoters containing CYP51-CRE2 independently of SREBPs, and ICER decreases the CREB-induced transcription. Besides the increased CYP51 mRNA, forskolin affects the de novo sterol biosynthesis in JEG-3 cells. An increased consumption of lanosterol, a substrate of CYP51, is observed together with modulation of the postlanosterol cholesterogenesis, indicating that cAMP-dependent stimuli cross-talk with cholesterol feedback regulation. CRE-2 is essential for cAMP-dependent transactivation, whereas SRE seems to be less important. Interestingly, when CREB is not limiting, the increasing amounts of SREBP-1a fail to transactivate the CYP51 promoter above the CREB-only level, suggesting that hormones might have an important role in regulating cholesterogenesis in vivo.


Assuntos
Colesterol/biossíntese , Sistema Enzimático do Citocromo P-450/genética , Sistema Enzimático do Citocromo P-450/metabolismo , Genes Precoces , Oxirredutases/genética , Oxirredutases/metabolismo , Animais , Linhagem Celular Tumoral , Colforsina/farmacologia , AMP Cíclico/genética , AMP Cíclico/metabolismo , AMP Cíclico/fisiologia , Humanos , Lipídeos/antagonistas & inibidores , Mamíferos/genética , Camundongos , Regiões Promotoras Genéticas , RNA Mensageiro/metabolismo , Elementos de Resposta , Transdução de Sinais/efeitos dos fármacos , Esterol 14-Desmetilase , Esteróis/metabolismo , Fatores de Tempo , Ativação Transcricional
17.
Mol Cell Endocrinol ; 234(1-2): 47-56, 2005 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-15836952

RESUMO

Meiosis activating sterols (MAS) are biologically active post-lanosterol intermediates of cholesterol biosynthesis that are synthetized primarily in the gonads, including the sperm. MAS reinitiate the meiosis of oocytes in vitro while in vivo they seem to contribute to the oocyte quality and the progression of meiosis. The mRNAs for the MAS-producing enzyme lanosterol 14alpha-demethylase (CYP51) arise by alternative poly (A) signal selection. Only signals with low cleavage activity are used in the testis. Translation of mammalian CYP51s starts at one of the tandem in-frame ATGs. CYP51 protein of the bull is shorter compared to the human due to the usage of a more downstream translation start site. CYP51 proteins are post-translationally modified by glycosylations in the Golgi and on acrosomal membranes of the sperm. Green fluorescence protein-based ex vivo system has been developed to aid studying the intracellular transport of the MAS-producing CYP51. The influence of the post-translational modifications on MAS-synthesizing capacity is under investigation.


Assuntos
Colesterol/metabolismo , Sistema Enzimático do Citocromo P-450/genética , Oxirredutases/genética , Espermatogênese/fisiologia , Animais , Sequência de Bases , Células Cultivadas , Códon de Iniciação , Sistema Enzimático do Citocromo P-450/metabolismo , Humanos , Masculino , Camundongos , Dados de Sequência Molecular , Oxirredutases/metabolismo , Iniciação Traducional da Cadeia Peptídica , Poliadenilação , Processamento de Proteína Pós-Traducional , RNA Mensageiro/metabolismo , Ratos , Espermatogênese/genética , Esterol 14-Desmetilase , Esteróis/metabolismo , Transcrição Gênica
18.
Restor Neurol Neurosci ; 23(5-6): 281-96, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-16477090

RESUMO

PURPOSE: The relationship between auditory temporal-order perception and phoneme discrimination has been discussed for several years, based on findings, showing that patients with cerebral damage in the left hemisphere and aphasia, as well as children with specific language impairments, show deficits in temporal-processing and phoneme discrimination. Over the last years several temporal-order measurement procedures and training batteries have been developed. However, there exists no standard diagnostic tool for adults that could be applied to patients with aphasia. Therefore, our study aimed at identifying a feasible, reliable and efficient measurement procedure to test for auditory-temporal processing in healthy young and elderly adults, which in a further step can be applied to patients with aphasia. METHODS: The tasks varied according to adaptive procedures (staircase vs. maximum-likelihood), stimuli (tones vs. clicks) and stimulation modes (binaural- vs. alternating monaural) respectively. A phoneme-discrimination task was also employed to assess the relationship between temporal and language processing. RESULTS: The results show that auditory temporal-order thresholds are stimulus dependent, age related, and influenced by gender. Furthermore, the cited relationship between temporal-order threshold and phoneme discrimination can only be confirmed for measurements with pairs of tones. CONCLUSION: Our results indicate, that different norms have to be established for different gender and age groups. Furthermore, temporal-order measurements with tones seem to be more suitable for clinical intervention studies than measurements with clicks, as they show higher re-test reliabilities, and only for measurements with tones an association with phoneme-discrimination abilities was found.


Assuntos
Envelhecimento/fisiologia , Percepção Auditiva/fisiologia , Limiar Auditivo/fisiologia , Caracteres Sexuais , Percepção do Tempo/fisiologia , Estimulação Acústica/métodos , Idoso , Discriminação Psicológica , Feminino , Humanos , Funções Verossimilhança , Masculino , Pessoa de Meia-Idade , Psicofísica/métodos , Reprodutibilidade dos Testes , Testes de Discriminação da Fala , Estatísticas não Paramétricas
19.
Mol Endocrinol ; 16(8): 1853-63, 2002 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-12145339

RESUMO

Lanosterol 14alpha-demethylase (CYP51) is involved in the cholesterol biosynthesis pathway, producing follicular fluid meiosis-activating sterol. The promoter region of the human CYP51 gene contains a cluster of regulatory elements including GC box, cAMP response element (CRE), and sterol regulatory element (SRE). To understand the mechanism of sterol-dependent regulation of this gene, several constructs of the promoter with the reporter gene have been tested in JEG-3 cells containing overexpressed human sterol regulatory element binding protein (SREBP)-1a. The wild-type construct showed maximal SREBP-dependent activation, most of which is retained when the GC box is mutated/deleted. Activation is abolished when either CRE or SRE are removed/mutated. Furthermore, mutation of CRE abolishes SREBP-dependent activation after overexpression of SREBP-1a and CRE binding protein (CREB). This shows that CRE is essential, and that under ex vivo conditions CREB and SREBP cooperate in transactivating CYP51. Interestingly, protein kinase A shows a marked stimulation of the CYP51 promoter activity when overexpressed together with SREBP-1a but not when overexpressed with CREB, suggesting phosphorylation of SREBP-1a. Using a DNA probe containing all three regulatory elements, it is found that SREBP-1a, a CREB-like factor, and specificity protein (Sp1) all probably bind the CYP51 promoter. While SREBP-1a and the CRE-bound proteins are essential for the SREBP-dependent response, Sp1 apparently functions only to maximize sterol regulation of CYP51. To date this is the first gene in which cooperation between SREBP and a CREB/CRE modulator/activating transcription factor family transcription factor is shown to be essential and sufficient for SREBP-dependent activation.


Assuntos
Proteínas Estimuladoras de Ligação a CCAAT/genética , Proteínas Estimuladoras de Ligação a CCAAT/metabolismo , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/genética , Sistema Enzimático do Citocromo P-450/genética , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Oxirredutases/genética , Fatores de Transcrição , Sequência de Bases , Sítios de Ligação/genética , Linhagem Celular , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , DNA/genética , DNA/metabolismo , Humanos , Técnicas In Vitro , Substâncias Macromoleculares , Dados de Sequência Molecular , Mutagênese Sítio-Dirigida , Regiões Promotoras Genéticas , Deleção de Sequência , Fator de Transcrição Sp1/metabolismo , Esterol 14-Desmetilase , Proteína de Ligação a Elemento Regulador de Esterol 1 , Ativação Transcricional
20.
Acta Neurobiol Exp (Wars) ; 64(3): 341-8, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15283477

RESUMO

A lively discussion concerning the causal relation between auditory temporal processing and phoneme identification has evolved over the last decades. Subjects with language impairments not only show deficits in the identification of stop-consonant vowel syllables, but also have problems detecting the temporal order of acoustic stimuli. Recently published studies claim that an improvement in phoneme discrimination can be achieved through the training of temporal-processing abilities. Critical assessment of these studies often reveals the following weaknesses: first, the diagnostic and training methods vary between studies, which makes comparisons difficult. Second, usually only mean differences between groups or before/after treatment are presented. The success in diagnosis and training of individuals or subgroups is not documented. Third, only few diagnostic measures employed have been tested for reliability. Furthermore, the tests have not been designed according to modern psychometric methods. Fourth, several training modules are used in parallel. The effects of temporal-processing training cannot be isolated. Possible approaches for detecting the possible causal relation between the time and the language domain are discussed.


Assuntos
Idioma , Aprendizagem/fisiologia , Percepção do Tempo/fisiologia , Humanos , Psicolinguística , Psicometria , Projetos de Pesquisa
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