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1.
Leg Med (Tokyo) ; 70: 102482, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38959586

RESUMO

A case of death due to combined use of multiple drugs is reported, and the pharmacokinetic interactions are discussed. A woman in her thirties was found dead in her home. A medico-legal autopsy found no findings suggestive of injury or natural disease. Toxicological analysis using liquid chromatography tandem mass spectrometry (LC-MS/MS) identified a toxic level of fluvoxamine (0.947 µg/mL), and concentrations greater than the therapeutic levels of levomepromazine (0.238 µg/mL) and trihexyphenidyl (0.225 µg/mL) were present, while bromazepam, haloperidol, sulpiride, and 7-aminoflunitrazepam were within or below their therapeutic ranges. Fluvoxamine is mainly metabolized by cytochrome P450 2D6 (CYP2D6), and levomepromazine is a potent CYP2D6 inhibitor. A high concentration of levomepromazine may increase the blood fluvoxamine level. Since the combined use of levomepromazine and fluvoxamine induces seizures, it may have been involved in causing the subject's death. In addition, combined use of trihexyphenidyl may potentiate anticholinergic effects of fluvoxamine overdose, including convulsions and coma. It was concluded that the cause of the subject's death was the interaction of multiple drugs.

2.
Forensic Toxicol ; 2024 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-38436881

RESUMO

PURPOSE: We have investigated the absorption dynamics of petroleum fuel components from the analytical results of autopsy samples. METHODS: Post-mortem samples of the severely burned case, including femoral blood, intratracheal contents (mucus) and intratracheal gas-phase samples were collected, and analysed by gas chromatography-mass spectrometer with head-space solid-phase microextraction. RESULTS: The composition of flammable substances in the tracheal gas phase differed slightly from that in mucus. CONCLUSION: High-boiling point components are retained in the trachea, whereas relatively lower-boiling point components are detected predominantly in the tracheal gas phase and blood.

3.
Leg Med (Tokyo) ; 64: 102294, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37369168

RESUMO

A man in his forties was found dead in his friend's home, with moderate putrefaction. Quantitative toxicological analysis showed that concentrations of caffeine, chlorpheniramine, dihydrocodeine, and methylephedrine were 183.3 µg/mL, 0.533 µg/mL, 2.469 µg/mL and 8.336 µg/mL, respectively. Ephedrine, amitriptyline, nortriptyline, etizolam, fluvoxamine and 7-aminoflunitrazepam were detected in an aortic blood sample. Caffeine, chlorpheniramine, dihydrocodeine and methylephedrine are the main components of BRONTM, an over-the-counter antitussive sold in Japan. Those concentrations in blood were within fatal ranges. Caffeine is classified as a methylxanthine and is mainly metabolized by cytochrome P450 (CYP)1A2. Fluvoxamine is a potent CYP1A2 inhibitor. Blood fluvoxamine concentration was within the therapeutic range, but would have increased blood caffeine level by the inhibition of caffeine metabolism. The conclusion was that his death was caused by BRONTM overdose. Inhibition of caffeine metabolism may increase blood caffeine concentrations. This suggests that more attention should be paid to potential interactions between multiple drugs.


Assuntos
Cafeína , Overdose de Drogas , Masculino , Humanos , Cafeína/metabolismo , Fluvoxamina , Clorfeniramina/farmacologia , Autopsia , Ingestão de Alimentos
4.
Front Pharmacol ; 14: 1196565, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37292155

RESUMO

A case of fatal poisoning involving multiple psychotropic drugs is presented. Quantitative toxicological analysis showed femoral blood concentrations of pentobarbital, phenobarbital, duloxetine, acetaminophen and tramadol were 10.39, 22.57, 0.22, 0.61 and 0.22 µg/ml, respectively. We concluded that the death was due to the additive effects of two barbiturates. As both pentobarbital and phenobarbital act on gamma-aminobutyric acid (GABA) receptors, central nervous system activity was suppressed, causing respiratory depression. Additive pharmacological effects should be considered in cases of massive ingestion of multiple drugs.

6.
Nat Commun ; 13(1): 611, 2022 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-35105870

RESUMO

Organs consist of the parenchyma and stroma, the latter of which coordinates the generation of organotypic structures. Despite recent advances in organoid technology, induction of organ-specific stroma and recapitulation of complex organ configurations from pluripotent stem cells (PSCs) have remained challenging. By elucidating the in vivo molecular features of the renal stromal lineage at a single-cell resolution level, we herein establish an in vitro induction protocol for stromal progenitors (SPs) from mouse PSCs. When the induced SPs are assembled with two differentially induced parenchymal progenitors (nephron progenitors and ureteric buds), the completely PSC-derived organoids reproduce the complex kidney structure, with multiple types of stromal cells distributed along differentiating nephrons and branching ureteric buds. Thus, integration of PSC-derived lineage-specific stroma into parenchymal organoids will pave the way toward recapitulation of the organotypic architecture and functions.


Assuntos
Rim/citologia , Rim/fisiologia , Células-Tronco Pluripotentes/citologia , Células-Tronco Pluripotentes/fisiologia , Animais , Diferenciação Celular , Feminino , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos ICR , Néfrons , Organogênese/genética , Organogênese/fisiologia , Organoides/citologia , Transcriptoma
7.
J Infect Chemother ; 27(3): 497-502, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33303359

RESUMO

INTRODUCTION: There is some evidence that Bordetella pertussis (B. pertussis) can co-infect with viral respiratory infections in young infants. METHODS: B. pertussis infection was studied by culture, polymerase chain reaction (PCR), and loop-mediated isothermal amplification (LAMP) from nasopharyngeal swabs (NPSs) in 49 infants < 12 months of age, who were admitted for lower respiratory tract infections during the winter season. Seven other possible viral pathogens were documented by antigen detection or PCR in NPSs. The clinical feature of infants with mixed infection of B. pertussis and respiratory viruses were examined. RESULTS: Overall, B. pertussis infection was found in 10 (20.4%) cases, nine were less than 6 months of age and seven were unvaccinated. Viral etiology was found in 41 (84%) cases and pertussis-viral co-infection was present in eight patients, five of whom had mixed infection with respiratory syncytial virus. Only the presence of staccato coughing, cyanosis, and lymphocytosis were significantly different in B. pertussis-positive cases compared with B. pertussis-negative cases. Of the 10 pertussis cases, only the culture-positive cases showed the typical symptoms and laboratory findings of pertussis in addition to virus-associated respiratory symptoms with severe hospital course, whereas cases identified as DNA-positive lacked the characteristics of pertussis and their clinical severities were the same as B. pertussis-negative cases. CONCLUSION: In the absence of typical paroxysmal cough and lymphocytosis, we should carefully consider diagnosis of pertussis in young children hospitalized for presumed viral respiratory illness according to local epidemiological surveillance.


Assuntos
Infecções Respiratórias , Coqueluche , Bordetella pertussis/genética , Criança , Pré-Escolar , Humanos , Lactente , Técnicas de Diagnóstico Molecular , Técnicas de Amplificação de Ácido Nucleico , Infecções Respiratórias/diagnóstico , Infecções Respiratórias/epidemiologia , Estações do Ano , Coqueluche/diagnóstico , Coqueluche/epidemiologia
8.
Pediatr Int ; 59(12): 1266-1269, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28833971

RESUMO

BACKGROUND: Adhesive strapping for umbilical hernia has been re-evaluated as a promising treatment. We evaluated the influence of adhesive strapping on the outcome of umbilical hernia. METHODS: We retrospectively evaluated patients with umbilical hernia referred to the present institution from April 2011 to December 2015. Patients who were treated with adhesive strapping were compared with an observation alone group. The adhesive strapping group was also subdivided into two groups: the cure group and the treatment failure group. RESULTS: A total of 212 patients with umbilical hernia were referred to the present institution. Eighty-nine patients were treated with adhesive strapping, while 27 had observation only. The cure rate in the adhesive strapping group was significantly higher than that in the observation group. The duration of treatment of the adhesive strapping group was significantly shorter than that of the observation group. In the adhesive strapping group, the patients in the cure group were treated significantly earlier than those in the treatment failure group (P < 0.001). Furthermore, even in cases of umbilical hernia non-closure, surgical repair was easier after adhesive strapping. CONCLUSION: Adhesive strapping represents a promising treatment for umbilical hernia. To achieve the best results, adhesive strapping should be initiated as early as possible.


Assuntos
Adesivos , Bandagens , Hérnia Umbilical/terapia , Feminino , Seguimentos , Humanos , Recém-Nascido , Masculino , Estudos Retrospectivos , Resultado do Tratamento , Conduta Expectante
9.
Nephrology (Carlton) ; 21(9): 765-73, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26560070

RESUMO

AIM: Mutations of LMX1B cause nail-patella syndrome, a rare autosomal dominant disorder. Recently, LMX1B R246Q heterozygous mutations were recognised in nephropathy without extrarenal manifestation. The aim of this study was to clarify characteristics of nephropathy caused by R246Q mutation. METHODS: Whole exome sequencing was performed on a large family with nonsyndromic autosomal dominant nephropathy without extrarenal manifestation. Clinical and histological findings of patients with LMX1B mutation were investigated. RESULTS: LMX1B R246Q heterozygous mutation was identified in five patients over three generations. Proteinuria or haematoproteinuria was recognized by urinary screening from all patients in childhood. Proteinuria gradually increased to nephrotic levels and renal function decreased in adolescence. Two patients progressed to end-stage renal disease in adulthood. Renal histology demonstrated minimal change in childhood and focal segmental glomerulosclerosis in adulthood. Using electron microscopy, focal collagen deposition could be detected in glomeruli even when a "moth-eaten appearance" was not apparent in the glomerular basement membrane. In addition, podocin expression in glomerular podocytes was significantly decreased, even in the early stages of disease progression. CONCLUSION: Comprehensive genetic analyses and collagen or tannic acid staining may be useful for diagnosis of LMX1B-associated nephropathy. While renal prognosis of R246Q may be worse than that of typical NPS nephropathy, signs of podocytopathy can be detected during the infantile period; thus, childhood urinary screening may facilitate early detection.


Assuntos
Glomerulosclerose Segmentar e Focal/genética , Falência Renal Crônica/genética , Rim/patologia , Proteínas com Homeodomínio LIM/genética , Mutação , Nefrose Lipoide/genética , Nefrose/genética , Proteinúria/genética , Fatores de Transcrição/genética , Adolescente , Adulto , Biópsia , Criança , Pré-Escolar , Colágeno/metabolismo , Análise Mutacional de DNA , Progressão da Doença , Feminino , Imunofluorescência , Marcadores Genéticos , Predisposição Genética para Doença , Glomerulosclerose Segmentar e Focal/metabolismo , Glomerulosclerose Segmentar e Focal/patologia , Heterozigoto , Humanos , Lactente , Rim/metabolismo , Rim/fisiopatologia , Falência Renal Crônica/patologia , Falência Renal Crônica/fisiopatologia , Masculino , Nefrose/patologia , Nefrose/fisiopatologia , Nefrose Lipoide/metabolismo , Nefrose Lipoide/patologia , Linhagem , Fenótipo , Proteinúria/patologia , Proteinúria/fisiopatologia , Fatores de Tempo , Adulto Jovem
10.
Eur J Pediatr ; 175(1): 137-41, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26283294

RESUMO

Germline mutations in the succinate dehydrogenase complex subunit B (SDHB) gene (SDHB) cause susceptibility to paragangliomas and pheochromocytomas; however, it is exceedingly rare in childhood and especially in sporadic cases. We report the first Japanese pediatric case of paraganglioma with a de novo mutation in the SDHB gene. A 6-year-old girl with convulsions and hypertension was found to have a paravertebral abdominal tumor. Urinary and blood examinations revealed markedly elevated levels of norepinephrine. Following treatment for hypertension, the tumor was removed completely and histological findings were consistent with paraganglioma. Immunohistochemistry studies demonstrated the absence of SDHB protein expression, indicating an underlying SDH mutation with high probability. Germline mutation analysis of the SDHB gene revealed a heterozygous splice site mutation in intron 4 (C.423 + 1G > A). Subsequently, a second somatic genetic change was confirmed by multiplex ligation-dependent probe amplification (MLPA) analysis, showing that deletion of the wild-type allele resulted in loss of function of SDHB. No germline mutations in SDHB were detected in her parents. CONCLUSION: Genetic testing should be considered for pediatric patients with paragangliomas, even in the absence of familial history, as closer lifelong screening to detect the development of malignancy will be required for patients with SDHB mutations. WHAT IS KNOWN: Most sporadic cases of paraganglioma with SDHB mutations occur between adolescence and adulthood. Screening methods for carriers of SDHB mutations assessing recurrence and detecting developing metastases are yet to be standardized. WHAT IS NEW: The current case of an extra-adrenal paraganglioma with a de novo SDHB mutation had an onset at 6 years. We suggest much closer periodical observation for these high-risk children.


Assuntos
Paraganglioma/genética , Succinato Desidrogenase/genética , Criança , Feminino , Mutação em Linhagem Germinativa , Humanos
11.
Nephrol Dial Transplant ; 30(5): 862-4, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25758434

RESUMO

We report the first case of familial C3 glomerulonephritis (C3GN) associated with mutations in the gene for complement factor B (CFB). A 12-year-old girl was diagnosed with biopsy-proven C3GN. Her mother had a history of treatment for membranoproliferative glomerulonephritis, and her brother had hypocomplementemia without urinary abnormalities. DNA analysis revealed heterozygosity for CFB p.S367R in the patient, mother and brother. Evaluation of the structure-function relationship supports that this mutation has gain-of-function effects in CFB. The present case suggests that CFB has an important role in the etiology of C3GN and provides a new insight into anticomplement therapy approaches.


Assuntos
Fator B do Complemento/genética , Glomerulonefrite Membranoproliferativa/genética , Mutação , Adolescente , Biópsia , Criança , Análise Mutacional de DNA , Saúde da Família , Feminino , Glomerulonefrite/genética , Hematúria/diagnóstico , Heterozigoto , Humanos , Rim/patologia , Masculino , Pessoa de Meia-Idade , Proteinúria/diagnóstico
12.
Pediatr Nephrol ; 29(5): 927-30, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24408226

RESUMO

BACKGROUND: There is ongoing discussion regarding the mechanisms underlying edema formation in nephrotic syndrome (NS). Many studies published in the last decade reported that primary renal sodium retention was a major factor in edema formation. However, many of the factors influencing edema formation in NS remain unclear, including the role of arginine vasopressin (AVP). CASE-DIAGNOSIS/TREATMENT: We report a 12-year-old boy with steroid-dependent NS complicated by idiopathic central diabetes insipidus (CDI). He did not develop edema during his first relapse of NS after developing CDI, despite having hypoalbuminemia. He had polydipsia, polyuria, low urine osmolality, and a low serum arginine AVP level. His fractional excretion of sodium was only slightly low. Endocrinological testing and magnetic resonance imaging revealed idiopathic CDI. After starting desmopressin therapy, he developed edema when his NS relapsed. CONCLUSIONS: This is the first known reported case of NS in a patient with CDI. The findings suggest that appropriate AVP secretion in response to an increase in serum osmolality caused by renal sodium retention is necessary for excess extracellular fluid accumulation in NS. Further investigation is needed to more fully understand the role of AVP in edema formation in NS.


Assuntos
Diabetes Insípido Neurogênico/complicações , Síndrome Nefrótica/complicações , Anti-Inflamatórios/uso terapêutico , Arginina Vasopressina/sangue , Criança , Desamino Arginina Vasopressina/uso terapêutico , Diabetes Insípido Neurogênico/diagnóstico , Diabetes Insípido Neurogênico/tratamento farmacológico , Edema/etiologia , Humanos , Masculino , Síndrome Nefrótica/diagnóstico , Síndrome Nefrótica/tratamento farmacológico , Prednisolona/uso terapêutico , Privação de Água
13.
Clin Exp Optom ; 96(1): 100-5, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22963010

RESUMO

BACKGROUND: The aim was to determine the low luminance visual acuity in eyes with central serous chorioretinopathy. METHODS: Seven eyes of seven patients with central serous chorioretinopathy and six eyes of six age-matched normal volunteers were examined. Low luminance visual acuity charts were created by an Apple Power Mac G5 computer and displayed on a cathode ray tube monitor (SONY GDM-F500). The background luminance was set at six different levels from 78.20 cd/m(2) to 0.37 cd/m(2). The visual acuities of the eyes with central serous chorioretinopathy at each of the six luminance levels were compared to those from their fellow eyes and to normal eyes. RESULTS: The mean visual acuities varied from 0.13, 0.23, 0.29, 0.42, 0.62 to 0.70 logMAR units as luminance varied from high to low. At the lowest luminance (0.37 cd/m(2)), five of the seven eyes could not read any character. The mean visual acuities of the fellow eyes at the same luminance levels were 0.03, 0.06, 0.11, 0.20, 0.27 and 0.45 logMAR units and those of the normal volunteers were 0, 0.03, 0.08, 0.14, 0.23 and 0.38 logMAR units, respectively. The visual acuities of the eyes with central serous chorioretinopathy were significantly poorer than those of the normal eyes at all luminance levels except 0.37 cd/m(2) (p < 0.05 for all). CONCLUSIONS: Although the eyes from all three groups had 0 logMAR units visual acuity under standard testing condition, the visual acuity of the eyes with central serous chorioretinopathy were significantly worse at low luminance levels. The low luminance visual acuity may provide information on the visual disturbances reported by central serous chorioretinopathy patients with 0 logMAR units visual acuity.


Assuntos
Coriorretinopatia Serosa Central/fisiopatologia , Adaptação à Escuridão/fisiologia , Acuidade Visual/fisiologia , Adulto , Coriorretinopatia Serosa Central/diagnóstico , Feminino , Seguimentos , Humanos , Iluminação , Masculino , Pessoa de Meia-Idade , Estimulação Luminosa/métodos , Retina/patologia , Retina/fisiopatologia , Estudos Retrospectivos , Tomografia de Coerência Óptica , Adulto Jovem
14.
Clin Ophthalmol ; 6: 1681-7, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23097612

RESUMO

BACKGROUND: The purpose of this study was to determine baseline clinical factors to correlate the outcome of half-dose verteporfin photodynamic therapy (PDT) in eyes with chronic central serous chorioretinopathy (CSC). METHODS: In this prospective, non-comparative, interventional case series, 14 eyes of 14 patients with chronic CSC who received half-dose verteporfin PDT were examined. The best-corrected visual acuity (BCVA), macular sensitivity in the central 4, 8, and 12 degrees, and fixation stability were evaluated at baseline and at months 1, 3, 6, and 12 after half-dose verteporfin PDT. Macular sensitivity and fixation stability were determined by MP-1 microperimetry. RESULTS: Mean retinal sensitivity in the central 4 and 8 degrees was significantly better at 1, 3, 6, and 12 months after half-dose verteporfin PDT than at baseline. BCVA was significantly better after half-dose verteporfin PDT but only after 3 months. Fixation was relatively unstable in three eyes at baseline, but became stable at 12 months. BCVA at 12 months was significantly correlated with pre-PDT fixation stability (r = 0.7120, P = 0.0038). CONCLUSION: Half-dose verteporfin PDT results in a significant increase in mean central retinal sensitivity for at least 12 months. Our findings indicate that microperimetry is a useful method for evaluating the functional benefits of half-dose verteporfin PDT in eyes with chronic CSC.

16.
J Physiol Sci ; 62(3): 241-50, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22431072

RESUMO

Rapid lowering of the solution temperature (rapid cooling, RC) from 24 to 3°C within 3 s releases considerable amounts of Ca(2+) from the sarcoplasmic reticulum (SR) in mammalian cardiac muscles. In this study, we investigated the intracellular mechanism of RC-induced Ca(2+) release, especially the role of Ca(2+), in ferret ventricular muscle. Saponin-treated skinned trabeculae were placed in a glass capillary, and the amount of Ca(2+) released from the SR by RC and caffeine (50 mM) was measured with fluo-3. It was estimated that in the presence of ATP about 45% of the Ca(2+) content in the SR was released by RC. The amount of SR Ca(2+) released by RC was unchanged by the replacement of ATP by AMP-PCP (a non-hydrolysable ATP analogue and agonist for the ryanodine receptor but not for the Ca(2+) pump of SR), suggesting that the suppression of the Ca(2+) pump of SR at low temperature might not be a major mechanism in RC-induced Ca(2+) release. The free Ca(2+) concentration of the solution used for triggering RC-induced Ca(2+) release was estimated to be only about 20 nM with fluo-3 or aequorin. When this solution was applied to the preparation at 3°C, only a small amount of Ca(2+) was released from SR presumably by the Ca(2+)-induced Ca(2+) release (CICR) mechanism. Thus, in mammalian cardiac muscles, RC releases a part of the (<50%) stored Ca(2+) contained in the SR, and the mechanism of RC-induced Ca(2+) release may differ from that of CICR, which is thought to play a role in frog skeletal muscle fibres that express ryanodine receptors of different types.


Assuntos
Cálcio/metabolismo , Temperatura Baixa , Músculos Papilares/metabolismo , Retículo Sarcoplasmático/metabolismo , Trifosfato de Adenosina/análogos & derivados , Trifosfato de Adenosina/farmacologia , Equorina , Compostos de Anilina , Animais , Cafeína/farmacologia , Cálcio/farmacologia , Furões , Masculino , Retículo Sarcoplasmático/efeitos dos fármacos , Xantenos
17.
Biochem Biophys Res Commun ; 358(2): 608-14, 2007 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-17502110

RESUMO

The biological function of hnRNP family proteins is widely diverse and involved in pre-mRNA processing, transcriptional regulation, recombination, and telomere maintenance. In the course of our study on the elucidation of biological functions of minisatellite DNA, we isolated several nuclear proteins that bind to the mouse minisatellite Pc-1, which consists of a tandem array of d(GGCAG) repeats, from NIH3T3 cells. One of the minisatellite binding proteins, MNBP-A, which binds to a single-stranded G-rich strand of the Pc-1 repeat, was proven identical to the hnRNP A3. Recombinant hnRNP A3 was demonstrated to bind to the single-stranded telomeric d(TTAGGG) repeat with much higher affinity than the d(GGCAG) repeat. Binding of hnRNP A3 to the single-stranded telomeric repeat protected the repeat from nuclease attack, and inhibited both telomerase reaction and DNA synthesis in vitro. These results suggest a possible biological role of hnRNP A3 in the stable maintenance of telomere repeats.


Assuntos
Ribonucleoproteínas Nucleares Heterogêneas Grupo A-B/química , Ribonucleoproteínas Nucleares Heterogêneas Grupo A-B/genética , Proteínas de Ligação a Telômeros/química , Proteínas de Ligação a Telômeros/genética , Sequência de Aminoácidos , Sítios de Ligação , Humanos , Dados de Sequência Molecular , Ligação Proteica
18.
Mutat Res ; 598(1-2): 120-31, 2006 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-16513142

RESUMO

Mammalian genomes contain several types of repetitive sequences. Some of these sequences are implicated in various specific cellular events, including meiotic recombination, chromosomal breaks and transcriptional regulation, and also in several human disorders. In this review, we document the formation of DNA secondary structures by the G-rich repetitive sequences that have been found in several minisatellites, telomeres and in various triplet repeats, and report their effects on in vitro DNA synthesis. d(GGCAG) repeats in the mouse minisatellite Pc-1 were demonstrated to form an intra-molecular folded-back quadruplex structure (also called a G4' structure) by NMR and CD spectrum analyses. d(TTAGGG) telomere repeats and d(CGG) triplet repeats were also shown to form G4' and other unspecified higher order structures, respectively. In vitro DNA synthesis was substantially arrested within the repeats, and this could be responsible for the preferential mutability of the G-rich repetitive sequences. Electrophoretic mobility shift assays using NIH3T3 cell extracts revealed heterogeneous nuclear ribonucleoprotein (hnRNP) A1 and A3, which were tightly and specifically bound to d(GGCAG) and d(TTAGGG) repeats with K(d) values in the order of nM. HnRNP A1 unfolded the G4' structure formed in the d(GGCAG)(n) and d(TTAGGG)(n) repeat regions, and also resolved the higher order structure formed by d(CGG) triplet repeats. Furthermore, DNA synthesis arrest at the secondary structures of d(GGCAG) repeats, telomeres and d(CGG) triplet repeats was efficiently repressed by the addition of hnRNP A1. High expression of hnRNPs may contribute to the maintenance of G-rich repetitive sequences, including telomere repeats, and may also participate in ensuring the stability of the genome in cells with enhanced proliferation. Transcriptional regulation of genes, such as c-myc and insulin, by G4 sequences found in the promoter regions could be an intriguing field of research and help further elucidate the biological functions of the hnRNP family of proteins in human diseases.


Assuntos
DNA/química , Guanina , Células 3T3 , Animais , Sequência de Bases , Dicroísmo Circular , Camundongos , Peso Molecular , Conformação de Ácido Nucleico , Polimorfismo Genético , Sequências de Repetição em Tandem , Repetições de Trinucleotídeos
19.
Nippon Ganka Gakkai Zasshi ; 109(11): 761-5, 2005 Nov.
Artigo em Japonês | MEDLINE | ID: mdl-16363671

RESUMO

PURPOSE: An optimal strategy for treating psychogenic visual disturbances in adults has not been established. We report a patient with psychogenic visual disturbances who recovered his visual acuity and showed an improvement in his reading performance after undergoing training based on a reading performance assessment. CASE: A 37-year-old man who had been diagnosed as having myopic macular degeneration was referred to our clinic. Three months after his initial diagnosis, no changes in his fundi were observed, but his visual acuity had significantly decreased and his peripheral field of vision had become severely restricted. In view of his tunnel vision, the discrepancy among the visual acuity results obtained by different test methods, the results of a reading assessment, objective eye examination data, and his behavioral patterns, we diagnosed a psychogenic visual disturbance in the patient and referred him to an ophthalmologist and a psychiatrist for follow-up care. In our low vision clinic, we assessed his visual function, including reading performance, and developed a training program including reading, writing, and computer skills. We also provided information to help the patient find a job. The training program included instructions on how to manipulate reading aids and how to select reading materials to maximize his vision; these instructions were effective. Nine months after his rapid decrease in visual acuity, the results of his visual function tests showed an improvement. The patient also became motivated to find a job. CONCLUSION: Reading assessments are a useful tool for diagnosing psychogenic visual disturbances in adults and for coping with functional vision impairment.


Assuntos
Transtornos Psicofisiológicos/complicações , Leitura , Transtornos da Visão/diagnóstico , Transtornos da Visão/terapia , Adulto , Humanos , Degeneração Macular/complicações , Masculino , Auxiliares Sensoriais , Transtornos da Visão/etiologia
20.
Genes Cells ; 10(10): 953-62, 2005 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16164596

RESUMO

Fragile X syndrome is caused by expansion of a d(CGG) triplet repeat in the 5'-untranslated region of the first exon of the FMR1 gene resulting in silencing of the gene. The d(CGG) repeat has been reported to form hairpin and quadruplex structures in vitro, and formation of these higher structures could be responsible for its unstable expansion in the syndrome, although molecular mechanisms underlying the repeat expansion still remain elusive. We have previously proved that UP1, a proteolytic product of hnRNP A1, unfolds the intramolecular quadruplex structures of d(GGCAG)5 and d(TTAGGG)4 and abrogates the arrest of DNA synthesis at d(GGG)n sites. Here, we demonstrate that the d(CGG) repeat forms a peculiar DNA structure, which deviates from the canonical B-form structure. In addition, UP1 was demonstrated by CD spectrum analysis to unfold this characteristic higher structure of the d(CGG) repeat and to abrogate the arrest of DNA synthesis at the site. This ability of UP1 suggests that unfolding of unusual DNA structures of a triplet repeat is required for DNA synthesis processes.


Assuntos
Conformação de Ácido Nucleico , Ribonucleoproteínas/metabolismo , Hormônios do Timo/metabolismo , Repetições de Trinucleotídeos/efeitos dos fármacos , Dicroísmo Circular , DNA/biossíntese , Proteínas de Ligação a DNA/química , Proteínas de Ligação a DNA/metabolismo , Relação Dose-Resposta a Droga , Ensaio de Desvio de Mobilidade Eletroforética , Ribonucleoproteína Nuclear Heterogênea A1 , Ribonucleoproteínas Nucleares Heterogêneas Grupo A-B , Humanos , Cinética , Cloreto de Potássio/metabolismo , Proteínas Recombinantes/metabolismo , Ribonucleoproteínas/farmacologia , Hormônios do Timo/farmacologia , Repetições de Trinucleotídeos/genética
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