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1.
Zhonghua Yi Xue Za Zhi ; 100(27): 2144-2149, 2020 Jul 21.
Artigo em Chinês | MEDLINE | ID: mdl-32689757

RESUMO

Objective: To investigate the clinical outcomes and effects of distal oblique osteotomy and the Youngswick osteotomy in the treatment of grade Ⅲ and Ⅳ hallux rigidus. Methods: Totally 29 patients (33 feet) suffered from grade Ⅲ and Ⅳ hallux rigidus who received the distal first metatarsal osteotomy in Ningbo NO.6 Hospital from May 2013 to December 2018 were analyzed retrospectively. Among them, there were 10 males and 19 females. The average age was (56±6) years. Seventeen cases (18 feet) underwent distal oblique osteotomy of the first metatarsal, 12 cases (15 feet) underwent the Youngswick osteotomy. The overall clinical evaluations were investigated before the operation and at the final follow-up, included the visual analogue scale (VAS) of the pain, American Orthopedic Foot & Ankle Society (AOFAS) scores, the motionrange of the first metatarsophalangeal joint and the first metatarsophalangeal joint space. The data before and after operation were compared by paired t test and non-parametric rank sum test. Results: The operation time were (1.1±0.2) hours and (1.3±0.1) hours, and the intraoperative bleeding was 35 (25, 36) ml and 35 (30, 40) ml in the distal oblique osteotomy and Youngswick osteotomy respectively. All patients were followed up for 12 to 46 months. No nonunion or delayed union occurred in all patients. All patients did not need to be operated again, and no complications such as transferring metatarsalgia, infection and osteonecrosis occurred. In the two groups, the pain VAS score decreased significantly (Z=-3.8, -3.5, both P<0.01), the first metatarsophalangeal joint dorsal extension activity increased (Z=-3.7, -3.4, both P<0.01), the AOFAS score increased (t=28.0, 15.4, both P<0.05) and the first metatarsophalangeal joint space also improved significantly (t=17.7, 14.6, P<0.05) after the operation. There was no significant difference in VAS score, the first metatarsophalangeal joint activity and Horton index between the two groups(Z=-1.3, -0.3, -0.4, all P>0.05), and there was no statistical difference inAOFAS score (t=0.1, P>0.05). But compared with it in the first distal oblique metatarsal osteotomy, the joint space with the Youngswick osteotomy after the operation was larger ((2.4±0.3) mm vs (2.1±0.4) mm, t=2.2, P=0.04). Conclusions: The oblique metatarsal osteotomy and Youngswick osteotomy can effectively relieve the pain of the hallux rigidus, increase the dorsal extension activity and joint space of the first metatarsophalangeal joint, sink the first metatarsal head, and improve the living conditions of the patients. The results of the distal metatarsal osteotomy and the Youngswick osteotomy in the treatment of stage Ⅲ and Ⅳ patients with rigid are similar, which can delay the progress of the disease.


Assuntos
Hallux Rigidus/diagnóstico por imagem , Hallux Valgus , Ossos do Metatarso , Articulação Metatarsofalângica , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Osteotomia , Radiografia , Estudos Retrospectivos , Resultado do Tratamento
2.
J Biol Regul Homeost Agents ; 33(2): 511-516, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30915828

RESUMO

To explore the possible cytological mechanism underlying the role of Astragaloside IV in promoting the repair of bone defects, osteoblasts were cultured in vitro and identified using inverted phase contrast microscopy, alkaline phosphatase (ALP) staining and alizarin red staining.


Assuntos
Osteoblastos/efeitos dos fármacos , Saponinas/farmacologia , Triterpenos/farmacologia , Fosfatase Alcalina , Antraquinonas , Osso e Ossos/patologia , Diferenciação Celular , Células Cultivadas , Humanos , Microscopia de Contraste de Fase
3.
Br J Cancer ; 112(1): 177-84, 2015 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-25314066

RESUMO

BACKGROUND: As more patients are treated by haematopoietic stem cell transplantation (HSCT), development of secondary malignancy (SM) becomes an increasingly common issue in long-term survivors. METHODS: We conducted a nationwide population-based study of the Taiwanese population to analyse patients who received HSCT between January 1997 and December 2010. Standardised incidence ratios (SIRs) were used to compare the risk of SM in HSCT patients and the general population. Multivariate analysis was performed to identify independent predictors of SM. RESULTS: Patients receiving HSCT had a significantly greater risk of developing SM (SIR 2.00; 95% confidence interval (CI) 1.45-2.69; P<0.001). Specifically, the incidence increased for cancers of the oral cavity (SIR 14.18) and oesophagus (SIR 14.75) after allogeneic HSCT. Multivariate analysis revealed an increased SIR for cancer in patients who received the immunosuppressant azathioprine. The risk of SM also increased with greater cumulative doses of azathioprine. CONCLUSIONS: This study demonstrates an increased incidence of SM in Taiwanese patients who received allogeneic HSCT, especially for cancers of the oral cavity and oesophagus. This finding is different from results in populations of Western countries. Physicians should be cautious about azathioprine use for graft-vs-host disease after HSCT.


Assuntos
Azatioprina/administração & dosagem , Doença Enxerto-Hospedeiro/tratamento farmacológico , Transplante de Células-Tronco Hematopoéticas/estatística & dados numéricos , Segunda Neoplasia Primária/epidemiologia , Adulto , Estudos de Coortes , Feminino , Doença Enxerto-Hospedeiro/etiologia , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Risco , Sobreviventes , Taiwan/epidemiologia , Condicionamento Pré-Transplante/efeitos adversos , Adulto Jovem
4.
Biochem Biophys Res Commun ; 458(4): 790-5, 2015 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-25686491

RESUMO

Cachexia or muscle wasting is a common condition that occurs in many chronic diseases. The wasting conditions are characterized by increased levels of TNF-α which was also known as cachectin in the past. But how TNF-α exerts its cachetic effects remains controversial. To clarify this issue, we investigated the impact of TNF-α on C2C12 cell myogenic differentiation. Our results demonstrate that myotube formation was completely inhibited by TNF-α when added to differentiating C2C12 myoblasts. The inhibitory effect of TNF-α on differentiation was accompanied by activation of NF-κB and down regulation of myogenin and Akt. Importantly, TNF-α's effect on differentiation was abolished when IGF-1 was added to the culture. IGF-1 treatment also inhibited NF-κB reporter activity and restored Akt levels. Our data suggest that TNF-α inhibits myogenic differentiation through NF-κB activation and impairment of IGF-1 signaling pathway. The reversal of TNF-α induced inhibition of myogenesis by IGF-1 may have significant therapeutic potential.


Assuntos
Fator de Crescimento Insulin-Like I/imunologia , Fibras Musculares Esqueléticas/citologia , Mioblastos/citologia , NF-kappa B/imunologia , Fator de Necrose Tumoral alfa/imunologia , Animais , Diferenciação Celular , Linhagem Celular , Camundongos , Desenvolvimento Muscular , Fibras Musculares Esqueléticas/imunologia , Mioblastos/imunologia , Transdução de Sinais
5.
Biochem Biophys Res Commun ; 445(2): 375-80, 2014 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-24525132

RESUMO

Proteosome inhibitors such as bortezomib (BTZ) have been used to treat muscle wasting in animal models. However, direct effect of BTZ on skeletal muscle cells has not been reported. In the present study, our data showed that C2C12 cells exhibited a dose-dependent decrease in cell viability in response to increasing concentrations of BTZ. Consistent with the results of cell viability, Annexin V/PI analysis showed a significant increase in apoptosis after exposing the cells to BTZ for 24h. The detection of cleaved caspase-3 further confirmed apoptosis. The apoptosis induced by BTZ was associated with reduced expression of p-ERK. Cell cycle analysis revealed that C2C12 cells underwent G2/M cell cycle arrest when incubated with BTZ for 24h. Furthermore, BTZ inhibited formation of multinucleated myotubes. The inhibition of myotube formation was accompanied by decreased expression of Myogenin. Our data suggest that BTZ induces cell death and inhibits differentiation of C2C12 cells at clinically relevant doses.


Assuntos
Apoptose/efeitos dos fármacos , Ácidos Borônicos/farmacologia , Pontos de Checagem da Fase G2 do Ciclo Celular/efeitos dos fármacos , Pontos de Checagem da Fase M do Ciclo Celular/efeitos dos fármacos , Fibras Musculares Esqueléticas/efeitos dos fármacos , Inibidores de Proteassoma/farmacologia , Pirazinas/farmacologia , Animais , Bortezomib , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Regulação para Baixo/efeitos dos fármacos , MAP Quinases Reguladas por Sinal Extracelular/genética , Camundongos , Fibras Musculares Esqueléticas/citologia , Fibras Musculares Esqueléticas/metabolismo
6.
Phys Rev Lett ; 108(26): 267002, 2012 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-23005008

RESUMO

We utilize steady-state and transient optical spectroscopies to examine the responses of nonthermal quasiparticles with respect to orbital modifications in normal-state iron-chalcogenide superconductors. The dynamics shows the emergence of gaplike quasiparticles (associated with a ~36 meV energy gap) with a coincident transfer of the optical spectral weight in the visible range, at temperatures above the structural distortion. Our observations suggest that opening of the high-temperature gap and the lattice symmetry breaking are possibly driven by short-range orbital and/or charge orders, implicating a close correlation between electronic nematicity and precursor order in iron-based superconductors.

7.
Scand J Rheumatol ; 41(6): 458-65, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22827323

RESUMO

OBJECTIVES: This study aimed to evaluate increased coronary artery dimensions in patients with paediatric-onset systemic lupus erythematosus (SLE) in comparison with healthy controls, and to identify risk factors associated with increased coronary artery dimensions in the SLE patients. METHODS: As part of a longitudinal cohort study of coronary artery disease (CAD) in paediatric-onset SLE, 83 children with SLE and 36 healthy controls were enrolled for a cross-sectional analysis. Their coronary artery diameters were measured by echocardiography while their body mass index (BMI), blood pressure, and other cardiovascular factors were recorded. The age at diagnosis, serum uric acid (UA) and creatinine levels, and other lupus-related factors were further evaluated in SLE patients. Data were analysed using linear regression. RESULTS: Mean body surface area (BSA)-adjusted dimensions of the left coronary artery (LCA) and right coronary artery (RCA) were significantly larger in SLE patients than in controls (both p < 0.001). The age at diagnosis, BMI, and serum UA and creatinine levels were associated with LCA and RCA diameters. There were no correlations between the coronary artery diameters and blood pressure, SLE duration, SLE Disease Activity Index (SLEDAI), C-reactive protein (CRP), C3, C4, anti-double-stranded-DNA (anti-dsDNA), or lipid profile. In multivariate analysis, serum UA level, age at diagnosis, and BMI were consistently associated with coronary artery dimensions (p < 0.001, p = 0.008, and p = 0.006 for LCA; p = 0.020, 0.013, and 0.008 for RCA). CONCLUSIONS: Increased coronary artery diameters were found in children with SLE and were associated with higher serum UA levels. The pathogenic mechanisms warrant further investigation.


Assuntos
Doença da Artéria Coronariana/diagnóstico por imagem , Vasos Coronários/diagnóstico por imagem , Lúpus Eritematoso Sistêmico/diagnóstico por imagem , Adolescente , Índice de Massa Corporal , Criança , Doença da Artéria Coronariana/complicações , Doença da Artéria Coronariana/fisiopatologia , Vasos Coronários/fisiopatologia , Creatinina/sangue , Feminino , Humanos , Estudos Longitudinais , Lúpus Eritematoso Sistêmico/complicações , Lúpus Eritematoso Sistêmico/fisiopatologia , Masculino , Fatores de Risco , Índice de Gravidade de Doença , Ultrassonografia , Ácido Úrico/sangue , Adulto Jovem
8.
Eur Rev Med Pharmacol Sci ; 25(18): 5610-5618, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34604953

RESUMO

OBJECTIVE: This study aims to explore the biological roles of long non-coding RNA (lncRNA) ZNF281 and KLF15 in regulating cervical carcinoma progression. PATIENTS AND METHODS: Differential expressions of ZNF281 in 58 collected cervical carcinoma and normal tissues were detected by quantitative real-time polymerase chain reaction (qRT-PCR). The relationship between ZNF281 and clinicopathologic characteristics in cervical carcinoma patients was analyzed. By generating ZNF281 knockdown model in HeLa and SiHa cells through the transfection of shZNF281, migratory ability changes were examined via transwell and wound healing assay. The role of ZNF281 in in vivo tumorgenicity of cervical carcinoma was examined by implanting xenografted cancers in nude mice. The downstream target of ZNF281 and their interaction were assessed by bioinformatics tool and Dual-Luciferase reporter assay, respectively. Finally, co-regulations of ZNF281 and KLF15 on cervical carcinoma progression were elucidated. RESULTS: ZNF281 was upregulated in cervical carcinoma tissues and cell lines. It was correlated to TNM staging, and incidences of lymphatic metastasis and distant metastasis in cervical carcinoma patients, while it was unrelated to age and tumor size. The knockdown of ZNF281 effectively attenuated migratory ability in HeLa and SiHa cells. Besides, knockdown of ZNF281 also reduced tumorigenicity of cervical carcinoma in nude mice. KLF15 was the downstream gene binding ZNF281, and they were negatively correlated to each other in cervical carcinoma tissues. Notably, KLF15 was responsible for ZNF281-induced regulation on cervical carcinoma migration. CONCLUSIONS: LncRNA ZNF281 is upregulated in cervical carcinoma samples, and it is correlated to lymphatic metastasis, distant metastasis, and poor prognosis in cervical carcinoma patients. By targeting KLF15, ZNF281 triggers migratory potential in cervical carcinoma. We believed that ZNF281 is a promising biomarker for cervical carcinoma.


Assuntos
Regulação Neoplásica da Expressão Gênica/genética , Fatores de Transcrição Kruppel-Like/metabolismo , Fatores de Transcrição Kruppel-Like/fisiologia , RNA Longo não Codificante/metabolismo , RNA Longo não Codificante/fisiologia , Proteínas Repressoras/metabolismo , Proteínas Repressoras/fisiologia , Neoplasias do Colo do Útero/genética , Animais , Carcinogênese/genética , Linhagem Celular Tumoral , Movimento Celular/genética , Progressão da Doença , Feminino , Células HeLa , Humanos , Metástase Linfática/genética , Camundongos Nus , Ligação Proteica/genética , Neoplasias do Colo do Útero/patologia
9.
J R Soc Interface ; 17(164): 20190563, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32183638

RESUMO

Organisms have evolved sensory mechanisms to extract pertinent information from their environment, enabling them to assess their situation and act accordingly. For social organisms travelling in groups, like the fish in a school or the birds in a flock, sharing information can further improve their situational awareness and reaction times. Data on the benefits and costs of social coordination, however, have largely allowed our understanding of why collective behaviours have evolved to outpace our mechanistic knowledge of how they arise. Recent studies have begun to correct this imbalance through fine-scale analyses of group movement data. One approach that has received renewed attention is the use of information theoretic (IT) tools like mutual information, transfer entropy and causation entropy, which can help identify causal interactions in the type of complex, dynamical patterns often on display when organisms act collectively. Yet, there is a communications gap between studies focused on the ecological constraints and solutions of collective action with those demonstrating the promise of IT tools in this arena. We attempt to bridge this divide through a series of ecologically motivated examples designed to illustrate the benefits and challenges of using IT tools to extract deeper insights into the interaction patterns governing group-level dynamics. We summarize some of the approaches taken thus far to circumvent existing challenges in this area and we conclude with an optimistic, yet cautionary perspective.


Assuntos
Comunicação , Teoria da Informação , Animais , Aves , Entropia , Peixes
10.
Science ; 294(5550): 2345-8, 2001 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-11743199

RESUMO

Oxygen isotope records of five stalagmites from Hulu Cave near Nanjing bear a remarkable resemblance to oxygen isotope records from Greenland ice cores, suggesting that East Asian Monsoon intensity changed in concert with Greenland temperature between 11,000 and 75,000 years before the present (yr. B.P.). Between 11,000 and 30,000 yr. B.P., the timing of changes in the monsoon, as established with 230Th dates, generally agrees with the timing of temperature changes from the Greenland Ice Sheet Project Two (GISP2) core, which supports GISP2's chronology in this interval. Our record links North Atlantic climate with the meridional transport of heat and moisture from the warmest part of the ocean where the summer East Asian Monsoon originates.

11.
J Mol Biol ; 212(1): 67-78, 1990 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-2157022

RESUMO

Many studies have been carried out to map the putative binding sites of eukaryotic topoisomerase I on double-stranded DNA. As assayed by the SDS-induced cleavage reaction, results from these studies showed little sequence specificity surrounding the enzyme binding sites. In order to investigate the possible involvement of local helix variations in the recognition of double-stranded DNA by topoisomerase I, we have applied the Calladine-Dickerson rules to analyze the structural variations surrounding over 100 HeLa topoisomerase I cleavage sites on human DNA. Our data suggest that (5'-NRRYRNN-3'/3'-NYYRYNN-5') and (5'-YRRRYYN-3'/3'-RYYYRRN-5'), in which R is a purine, Y is a pyrimidine and N is any nucleotide, form the consensus recognition sequences for the enzyme. The specific structural features of these two consensus sequences recognized by HeLa topoisomerase I appear to be the local helical twist angle variations. The same consensus sequences are present in the vicinities of other eukaryotic topoisomerase I binding sites. These results have led to a model in which the eukaryotic topoisomerase I enzymes recognize sequence-dependent structural variations of DNA double helices in a specific but flexible mode.


Assuntos
DNA Topoisomerases Tipo I/metabolismo , DNA/metabolismo , Animais , Sequência de Bases , DNA Viral , Células HeLa , Humanos , Dados de Sequência Molecular , Conformação de Ácido Nucleico , Sequências Repetitivas de Ácido Nucleico , Vírus 40 dos Símios/genética , Dodecilsulfato de Sódio , Especificidade por Substrato , Tetrahymena/genética
12.
Nat Commun ; 6: 8061, 2015 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-26329911

RESUMO

Proxy records of temperature from the Atlantic clearly show that the Younger Dryas was an abrupt climate change event during the last deglaciation, but records of hydroclimate are underutilized in defining the event. Here we combine a new hydroclimate record from Palawan, Philippines, in the tropical Pacific, with previously published records to highlight a difference between hydroclimate and temperature responses to the Younger Dryas. Although the onset and termination are synchronous across the records, tropical hydroclimate changes are more gradual (>100 years) than the abrupt (10-100 years) temperature changes in the northern Atlantic Ocean. The abrupt recovery of Greenland temperatures likely reflects changes in regional sea ice extent. Proxy data and transient climate model simulations support the hypothesis that freshwater forced a reduction in the Atlantic meridional overturning circulation, thereby causing the Younger Dryas. However, changes in ocean overturning may not produce the same effects globally as in Greenland.

13.
Endocrinology ; 103(6): 2040-52, 1978 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-218799

RESUMO

The 17 beta-hydroxy-C19-steroid dehydrogenase activity of adult male guinea pig kidney was separated into one isolated and two contiguous enzymatically pure fractions by submitting the cytosol to (NH4)2SO4 (40-80% saturation) precipitation, Sephadex G-75 filtration, and DEAE-Sephadex A-50 and CM-Sephadex C-50 chromatography. Further DEAE-Sephadex A-50 and CM-Sephadex C-50 chromatography separated eight isozymes, which were divided into four groups in accordance with their behavior on chromatography and mobility on gel electrophoresis. The molecular weights of the purified enzymes were identical by Sephadex filtration (33,000) and SDS gel electrophoresis (34,000). Two of the enzymes were separated by SDS gel electrophoresis into two subcomponents of 23,000 and 11,000 daltons. The amino acid composition, Km values, and coenzyme and substrate specificities of the enzymes (except one) were very similar. The pI values varied from 5.1-6.4 HgCl2 and PCMB inhibited enzyme activity, but prior addition of cysteine prevented the inhibition. The presence of phosphate or pyrophosphate greatly enhanced the trace of DPN+ -linked activity. The heterogeneity was due to at least two factors. Rapid (within 3 h) preparation of the cytosol in 7 mM 2-mercaptoethanol yielded one intense and one minor enzyme band on gel electrophoresis. Omission of the mercaptoethanol resulted in the appearance of three enzyme bands, which were reversible on the addition of 2-mercaptoethanol. Storage of the cytosol at 4 or -20 C in the absence or presence of 7 mM 2-mercaptoethanol and of the kidney before extraction also resulted in the exhibition of enzyme bands which were not reversible on addition of 2-mercaptoethanol. The purified enzymes exhibited only a single form on storage at -20 C with 2-mercaptoethanol, but multiple forms appeared when the mercaptoethanol was removed by dialysis. The multiple forms were reverted to a single form on addition of mercaptoethanol.


Assuntos
17-Hidroxiesteroide Desidrogenases/metabolismo , Rim/enzimologia , 17-Hidroxiesteroide Desidrogenases/isolamento & purificação , Aminoácidos/análise , Animais , Cobaias , Cinética , Masculino , Mercaptoetanol , Especificidade por Substrato
14.
Ann N Y Acad Sci ; 939: 416-24, 2001 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-11462797

RESUMO

A single, delayed dose of nicotinamide (NAm) was shown to be protective against focal cerebral ischemia in rats, but the protection was limited to three to seven days following stroke. The investigation reported here was conducted to examine if the use of multiple doses of NAm, administered after the onset of focal cerebral ischemia, would extend the duration of neuroprotection compared with a single dose treatment regimen. Male Wistar rats were subjected to transient focal cerebral ischemia by occluding the right middle cerebral artery (MCAo) for two hours. Following MCAo, motor and sensory behavioral tests were performed daily and the cerebral infarct volumes were measured at two weeks after sacrifice. Each animal was placed into one of four groups that received either normal saline alone (Group S), one (Group A), two (Group B), or three (Group C) doses of NAm (500 mg/kg). Each animal, therefore, received three treatments over two weeks, with the first dose administered intravenously two hours after the onset of MCAo. Single and multiple doses of NAm reduced the infarction (p < 0.01) and improved (p < 0.05) the neurologic sensory and motor behavior when compared with the saline-treated animals up to two weeks after stroke. Moreover, animals that received multiple doses of NAm recuperated full motor function not different from normal, preoperative motor behavior. Delayed treatment with NAm given as multiple doses, therefore, further enhances the extent and duration of neuroprotection by significantly reducing cerebral infarct volumes, improving neurologic behavioral scores, and confers a complete motor recovery up to two weeks from the onset of focal cerebral ischemia in Wistar rats.


Assuntos
Infarto Cerebral/tratamento farmacológico , Ataque Isquêmico Transitório/tratamento farmacológico , Atividade Motora/efeitos dos fármacos , Niacinamida/administração & dosagem , Desempenho Psicomotor/efeitos dos fármacos , Animais , Infarto Cerebral/fisiopatologia , Ataque Isquêmico Transitório/fisiopatologia , Masculino , Atividade Motora/fisiologia , Fármacos Neuroprotetores/administração & dosagem , Ratos , Ratos Wistar
15.
Neurosurgery ; 35(4): 665-9; discussion 669-70, 1994 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-7808609

RESUMO

For the study of pathogenesis and treatment of recurrent trigeminal neuralgia, we performed 31 repeat operations from among 400 patients with trigeminal neuralgia in the past 10 years. Initially, of these 400 patients, 376 underwent microvascular decompression only, and 24 underwent partial sensory rhizotomy with or without microvascular decompression. Fifty-three patients (14%) had recurrences after microvascular decompression, of which 31 patients underwent repeat operations. Among the repeat operations, there was negative exploration in 16 patients (52%), arterial loop compression in 7 (22%), venous compression in 4 (13%), and Teflon compression or adhesion in 4 (13%). Twenty-one patients had early recurrences within 1 year, and 10 patients had late recurrences. Negative exploration and arterial compression were more likely in early recurrence (P = 0.01). Continuing demyelination might occur in patients with negative exploration, even when adequate decompression had been initially performed. Seventy percent of the patients had no recurring pain by way of partial sensory rhizotomy for negative explorations, redecompression of arterial loops, division of offending veins, or lysis and reposition of Teflon. About half of the patients had positive findings that were amenable without rhizotomy in the repeat operations. A repeat operation for failed microvascular decompression is a good choice if the condition of the patient is tolerant.


Assuntos
Cerebelo/irrigação sanguínea , Microcirurgia , Síndromes de Compressão Nervosa/cirurgia , Complicações Pós-Operatórias/cirurgia , Neuralgia do Trigêmeo/cirurgia , Artérias/cirurgia , Seguimentos , Humanos , Exame Neurológico , Politetrafluoretileno , Próteses e Implantes , Recidiva , Reoperação , Raízes Nervosas Espinhais/cirurgia , Veias/cirurgia
16.
Mutat Res ; 337(1): 19-23, 1995 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-7541109

RESUMO

Damage to mitochondrial DNA (mtDNA) has recently been associated with a variety of human diseases including cancer, diabetes mellitus, and aging. The mechanisms by which the mitochondria respond to DNA damage are of prime importance in understanding how damage can persist and cause disease. Here we demonstrate the repair of mitochondrial DNA damage induced by the naturally occurring, radiomimetic drug bleomycin. WI-38 cells were first permeabilized using 20 micrograms/ml lysophosphatidylcholine in order to increase the intracellular concentration of bleomycin. Dose response studies with the permeabilized cells showed that a concentration of 5 micrograms/ml bleomycin given for 30 min caused sufficient DNA damage for repair studies. Following treatment with this concentration of bleomycin, repair of mtDNA damage was found to be about 80% by 2 h. However, after 4 h no additional repair was observed. The results indicate that there is an efficient DNA repair system in human mitochondria for some types of damage caused by bleomycin. However, there is a component of damage caused by this agent that either is not repaired or is removed at a much slower rate.


Assuntos
Bleomicina/toxicidade , Dano ao DNA , Reparo do DNA , DNA Mitocondrial/efeitos dos fármacos , Mutagênicos/toxicidade , Permeabilidade da Membrana Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Humanos , Pulmão/citologia , Lisofosfatidilcolinas/farmacologia
17.
Spine (Phila Pa 1976) ; 20(2): 244-7, 1995 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-7716632

RESUMO

STUDY DESIGN: This report analyzed the likely locations of lesions that cause a combination of Horner's and Brown-Séquard syndromes. One must know the anatomic structure of spinal cord and the sympathetic nerve chain. OBJECTIVES: A hypertensive patient had Brown-Séquard and Horner's syndromes after neck trauma. The magnetic resonance imaging and surgical findings showed the correlation between the clinical symptoms and the likely lesion. METHODS: The patient underwent right hemilaminectomy from C2 to C6 with total removal of hematoma. CONCLUSION: The spinal epidural hematoma rarely is a surgical emergency. The patient presented with Brown-Séquard and Horner's syndromes. Magnetic resonance imaging made a rapid and correct diagnosis. The patient received an emergent right hemilaminectomy from C2 to C6 with removal of hematoma and subsequently made a complete recovery.


Assuntos
Síndrome de Brown-Séquard/complicações , Hematoma Epidural Craniano/complicações , Síndrome de Horner/complicações , Síndrome de Brown-Séquard/etiologia , Vértebras Cervicais/irrigação sanguínea , Síndrome de Horner/diagnóstico , Síndrome de Horner/etiologia , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Compressão da Medula Espinal/etiologia , Compressão da Medula Espinal/patologia
18.
Artigo em Inglês | MEDLINE | ID: mdl-11381696

RESUMO

Image quality degradation caused by harmonic leakage was studied for finite amplitude distortion-based harmonic imaging. Various sources of harmonic leakage, including transmit waveform, signal bandwidth, and system nonlinearity, were investigated using both simulations and hydrophone measurements. Effects of harmonic leakage in the presence of sound velocity inhomogeneities were also considered. Results indicated that sidelobe levels of the harmonic beam pattern were directly affected by harmonic leakage when the harmonic signal was obtained by filtering out the fundamental signal. Because sidelobe levels also increase with the bandwidth of the transmitted signal, a trade-off exists between axial resolution and contrast resolution. It is concluded that accurate control of the frequency content of the waveform prior to propagation is necessary to optimize imaging performance of tissue harmonic imaging. The filtering technique was also compared with the pulse inversion technique. It was shown that the pulse inversion technique effectively suppresses harmonic leakage at the cost of imaging frame rate and potential motion artifacts.


Assuntos
Ultrassonografia/métodos , Simulação por Computador , Modelos Teóricos
19.
Artigo em Inglês | MEDLINE | ID: mdl-11800127

RESUMO

The van Cittert-Zernike theorem has been widely used to describe spatial covariance of the pressure field backscattered from a speckle object. Spatial covariance contains important information in the context of correlation-based correction of sound velocity inhomogeneities. Previous work was primarily based on spatial covariance analysis for linear imaging. In this paper, we extend the analysis to tissue harmonic imaging. Specifically, we investigate effects of the signal-to-noise ratio (SNR) and sound velocity inhomogeneities on spatial covariance. Results from tissue harmonic imaging are also compared with those from linear imaging. Both simulations and experiments are performed. At high SNRs, although both linear imaging and tissue harmonic imaging have spatial covariance functions close to theory, the spatial covariance of tissue harmonic imaging is consistently lower than that of linear imaging regardless of the presence of sound velocity inhomogeneities. At low SNRs, on the other hand, spatial covariance of tissue harmonic imaging is significantly affected. Because the tissue harmonic signal is much weaker than the linear counterpart, the low SNR reduces the accuracy of correlation-based estimation. It is concluded that the linear signal is more suitable for correlation-based correction of sound velocity inhomogeneities, despite the fact that tissue harmonic imaging generally has improved image quality over linear imaging.


Assuntos
Ultrassonografia/métodos
20.
Artigo em Inglês | MEDLINE | ID: mdl-18238530

RESUMO

Conventional Doppler techniques can only detect the axial component of blood flow. To obtain the transverse flow component, an approach based on the dependence of Doppler bandwidth on Doppler angle has been widely investigated. To compute the bandwidth, a full Doppler spectrum is often required. Therefore, this approach has not been applied to real-time, two-dimensional Doppler imaging because of the long data acquisition time. To overcome this problem, a correlation-based method is proposed. Specifically, variance of the Doppler spectrum is used to approximate the square of the Doppler bandwidth. Because variance is computed efficiently and routinely in correlation-based color Doppler imaging systems, implementation of this method is straightforward. In addition, the two-dimensional velocity vector can be calculated and mapped to different colors using the color mapping function of current systems. Simulations were performed, and experimental data were also collected using a string phantom with the Doppler angle varying from 23 degrees to 82 degrees . Results indicate that the correlation-based method may produce significant errors if only a limited number of flow samples are available. With averaging, however, the Doppler angles estimated by the correlation-based method can achieve good agreement with the true angles by using only four flow samples with proper variance averaging.

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