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1.
BMC Microbiol ; 24(1): 243, 2024 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-38965478

RESUMO

BACKGROUND: Lichens, traditionally considered as a simple partnership primarily between mycobiont and photobiont, are, in reality, complex holobionts comprised of a multitude of microorganisms. Lichen mycobiome represents fungal community residing within lichen thalli. While it is acknowledged that factors like the host lichen species and environmental conditions influence the structure of the lichen mycobiome, the existing research remains insufficient. To investigate which factor, host genus or location, has a greater impact on the lichen mycobiome, we conducted a comparative analysis of mycobiomes within Parmelia and Peltigera collected from both Turkey and South Korea, using high-throughput sequencing based on internal transcribed spacer region amplification. RESULTS: Overall, the lichen mycobiome was dominated by Capnodiales (Dothideomycetes), regardless of host or location. At the order level, the taxonomic composition was not significantly different according to lichen genus host or geographical distance. Hierarchical clustering of the top 100 abundant ASVs did not clearly indicate whether the lichen mycobiome was more influenced by host genus or location. Analyses of community similarity and partitioning variables revealed that the structure of the lichen mycobiome is more significantly influenced by location than by host genus. When analyzing the core mycobiome by host genus, the Peltigera mycobiome contained more ASV members than the Parmelia mycobiome. These two core mycobiomes also share common fungal strains, including basidiomycete yeast. Additionally, we used chi-squared tests to identify host genus-specialists and location-specialists. CONCLUSIONS: By comparing lichen mycobiomes of the same genera across different countries, our study advances our comprehension of these microbial communities. Our study elucidates that, although host species play a contributory role, geographic distance exerts a more pronounced impact on the structure of lichen mycobiome. We have made foundational contributions to understanding the lichen mycobiome occupying ecologically crucial niches. We anticipate that broader global-scale investigations into the fungal community structures will provide more detailed insights into fungal residents within lichens.


Assuntos
DNA Fúngico , Líquens , Micobioma , República da Coreia , Turquia , Líquens/microbiologia , Líquens/classificação , DNA Fúngico/genética , Ascomicetos/classificação , Ascomicetos/isolamento & purificação , Ascomicetos/genética , Sequenciamento de Nucleotídeos em Larga Escala , Filogenia , Fungos/classificação , Fungos/isolamento & purificação , Fungos/genética , Parmeliaceae/genética
2.
Mycobiology ; 51(5): 343-353, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37929008

RESUMO

Lichens play crucial roles in the ecosystems, contributing to soil formation and nutrient cycling, and being used in biomonitoring efforts to assess the sustainability of ecosystems including air quality. Previous studies on heavy metal accumulation in lichens have mostly relied on manipulated environments, such as transplanted lichens, leaving us with a dearth of research on how lichens physiologically respond to heavy metal exposure in their natural habitats. To fill this knowledge gap, we investigated lichens from two of South Korea's geographically distant regions, Gangwon Province and Jeju Island, and examined whether difference in ambient heavy metal concentrations could be detected through physiological variables, including chlorophyll damage, lipid oxidation, and protein content. The physiological variables of lichens in response to heavy metals differed according to the collection area: Arsenic exerted a significant impact on chlorophyll degradation and protein content. The degree of fatty acid oxidation in lichens was associated with increased Cu concentrations. Our research highlights the value of lichens as a bioindicator, as we found that even small variations in ambient heavy metal concentrations can be detected in natural lichens. Furthermore, our study sheds light on which physiology variables that can be used as indicators of specific heavy metals, underscoring the potential of lichens for future ecology studies.

3.
Environ Microbiome ; 18(1): 79, 2023 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-37891696

RESUMO

BACKGROUND: Lichens are symbiotic organisms composed of a fungus and a photosynthetic partner, which are key ecological bioindicators due to their sensitivity to environmental changes. The endolichenic fungi (ELF) living inside lichen thalli, are an important but understudied component of playing crucial ecological roles such as nutrient cycling and protection against environmental stressors. Therefore ELF community investigation is vital for fostering sustainable ecosystems and leveraging their ecological benefits. Deciphering the intricate relationships between ELF and their lichen hosts, alongside the influence of environmental factors on these communities, presents a significant challenge in pinpointing the underlying drivers of community structure and diversity. RESULTS: Our research demonstrated that locational factors were the main drivers of the ELF community structure, rather than host haplotype. Several climatic factors affected the diversity of the ELF community and contributed to the prevalence of different types of fungal residents within the ELF community. A decrease in isothermality was associated with a greater prevalence of pathotrophic and saprotrophic fungi within the ELF community, resulting in an overall increase in community diversity. By conducting a structural equation modeling analysis, we identified a robust link between climatic variables, fungal trophic mode abundance, and the species diversity of the ELF community. CONCLUSION: This study's discoveries emphasize the significance of examining climate-related factors when investigating ELF's structure and function. The connection between fungi and climate is intricate and complex, and can be influenced by various other factors. Investigating the potential for ELF to adapt to changing climatic conditions, as well as the potential effects of changes in ELF communities on lichen function, would be valuable research areas. We anticipate that our research results will establish a basis for numerous future ELF research projects and have a significant impact on the field.

4.
Environ Microbiome ; 18(1): 73, 2023 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-37789449

RESUMO

BACKGROUND: Lichens represent not only the mutualism of fungal and photosynthetic partners but also are composed of microbial consortium harboring diverse fungi known as endolichenic fungi. While endolichenic fungi are known to exert a remarkable influence on lichen ecology through their crucial roles in nutrient cycling, bioprospecting and biodiversity, the enigmatic community structures of these fungal inhabitants remain shrouded in mystery, awaiting further exploration and discovery. To address knowledge gap, we conducted metabarcoding on two lichens using 18S gene amplification, Dirinara applanta and Parmotrema tinctorum, and compared their microbial communities to those found in the pine bark to which the lichens were attached. Our hypothesis was that the endolichenic communities would exhibit distinct diversity patterns, community structures, network structures, and specialist composition compared to the surrounding epiphytic community. RESULTS: Our investigation has shed light on the clear demarcation between the endolichenic and epiphytic fungal communities, as they exhibit markedly different characteristics that set them apart from each other. This research demonstrated that the endolichenic communities are less diverse as compared to the epiphytic communities. Through community similarity analysis, we observed that two endolichenic communities are more similar to each other in terms of community composition than with the adjacent epiphytic communities. Moreover, we unveiled a striking contrast in the network structures between the endolichenic and epiphytic communities, as the former displayed a more modular and less nested features that is evocative of a potent host-filtration mechanism. CONCLUSIONS: Through our investigation, we have discovered that lichens harbor less intricate and interconnected fungal communities compared to the neighboring epiphytic environment. These observations provide valuable insights into the metagenomic architecture of lichens and offer a tantalizing glimpse into the unique mycobiome.

5.
ACS Nano ; 17(16): 15776-15786, 2023 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-37432767

RESUMO

Scalable production and integration techniques for van der Waals (vdW) layered materials are vital for their implementation in next-generation nanoelectronics. Among available approaches, perhaps the most well-received is atomic layer deposition (ALD) due to its self-limiting layer-by-layer growth mode. However, ALD-grown vdW materials generally require high processing temperatures and/or additional postdeposition annealing steps for crystallization. Also, the collection of ALD-producible vdW materials is rather limited by the lack of a material-specific tailored process design. Here, we report the annealing-free wafer-scale growth of monoelemental vdW tellurium (Te) thin films using a rationally designed ALD process at temperatures as low as 50 °C. They exhibit exceptional homogeneity/crystallinity, precise layer controllability, and 100% step coverage, all of which are enabled by introducing a dual-function co-reactant and adopting a so-called repeating dosing technique. Electronically, vdW-coupled and mixed-dimensional vertical p-n heterojunctions with MoS2 and n-Si, respectively, are demonstrated with well-defined current rectification as well as spatial uniformity. Additionally, we showcase an ALD-Te-based threshold switching selector with fast switching time (∼40 ns), selectivity (∼104), and low Vth (∼1.3 V). This synthetic strategy allows the low-thermal-budget production of vdW semiconducting materials in a scalable fashion, thereby providing a promising approach for monolithic integration into arbitrary 3D device architectures.

6.
Int J Mol Sci ; 24(4)2023 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-36834475

RESUMO

Quercetin 3-O-galactoside (Q3G) is a common dietary flavanol that has been shown to possess several bioactivities, including anti-melanogenesis. However, how Q3G exerts its anti-melanogenic effect has not been studied. The current study, therefore aimed to investigate the anti-melanogenesis potential of Q3G and elucidate the underlying action mechanism in α-melanocyte-stimulating hormone (α-MSH)-induced hyperpigmentation model of B16F10 murine melanoma cells. Results showed that α-MSH stimulation significantly increased tyrosinase (TYR) and melanin production, which were significantly downregulated by Q3G treatment. The treatment with Q3G suppressed the transcriptional and protein expressions of melanogenesis-related enzymes TYR, tyrosinase related protein-1 (TRP-1), and TRP-2, along with the melanogenic transcription factor microphthalmia-associated transcription factor (MITF) in B16F10 cells. It was shown that Q3G downregulated MITF expression and suppressed its transcriptional activity by inhibiting the cAMP-dependent protein kinase A (PKA)-mediated activation of CREB and GSK3ß. In addition, MAPK-regulated MITF activation signaling was also involved in the inhibition of melanin production by Q3G. The results suggest that the anti-melanogenic properties of Q3G rationalize further studies in vivo to confirm its action mechanism and consequent utilization as a cosmetic ingredient against hyperpigmentation.


Assuntos
Hiperpigmentação , Melanoma Experimental , Plumbaginaceae , Animais , Camundongos , alfa-MSH/farmacologia , Linhagem Celular Tumoral , Galactosídeos , Hiperpigmentação/metabolismo , Melaninas/metabolismo , Melanoma Experimental/metabolismo , Fator de Transcrição Associado à Microftalmia/metabolismo , Monofenol Mono-Oxigenase/metabolismo , Plumbaginaceae/metabolismo , Quercetina
7.
Int J Mol Sci ; 23(2)2022 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-35054838

RESUMO

Increased bone marrow adiposity is widely observed in patients with obesity and osteoporosis and reported to have deleterious effects on bone formation. Dracunculin (DCC) is a coumarin isolated from Artemisia spp. but, until now, has not been studied for its bioactive potential except antitrypanosomal activity. In this context, current study has reported the anti-adipogenic effect of DCC in human bone marrow-derived mesenchymal stromal cells (hBM-MSCs). DCC dose-dependently inhibited the lipid accumulation and expression of adipogenic transcription factors peroxisome proliferator-activated receptor γ (PPARγ) and CCAAT/enhancer binding protein α (C/EBPα) in hBM-MSCs induced to undergo adipogenesis. To elucidate its action mechanism, the effect of DCC on Wnt/ß-catenin and AMPK pathways was examined. Results showed that DCC treatment activated Wnt/ß-catenin signaling pathway via AMPK evidenced by increased levels of AMPK phosphorylation and Wnt10b expression after DCC treatment. In addition, DCC treated adipo-induced hBM-MSCs exhibited significantly increased nuclear levels of ß-catenin compared with diminished nuclear PPARγ levels. In conclusion, DCC was shown to be able to hinder adipogenesis by activating the ß-catenin via AMPK, providing potential utilization of DCC as a nutraceutical against bone marrow adiposity.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Adipogenia/efeitos dos fármacos , Artemisia/química , Cumarínicos/farmacologia , Células-Tronco Mesenquimais/citologia , Via de Sinalização Wnt/efeitos dos fármacos , Proteínas Estimuladoras de Ligação a CCAAT/genética , Diferenciação Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Cumarínicos/química , Relação Dose-Resposta a Droga , Perfilação da Expressão Gênica , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Células-Tronco Mesenquimais/metabolismo , Estrutura Molecular , PPAR gama/genética , Fosforilação/efeitos dos fármacos
8.
J Cerebrovasc Endovasc Neurosurg ; 21(1): 24-32, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31832384

RESUMO

OBJECTIVE: The spot sign on computed tomography angiography is little known about the relationship between the spot sign and the results of cerebral angiography We retrospectively analyzed the spot sign, digital subtraction angiography results, and other factors. MATERIAL AND METHODS: From December 2009 to May 2014, DSA was performed in 52 ICH patients with non-specific location or abnormalities on CTA findings. 26 of those patients, whose initial CTA showed the spot sign, were analyzed. Two groups, one with the spot sign in the ventricle (Group A) and others with the spot sign in another location (Group B) were statistically compared. RESULTS: The mean age of the study subjects was 46.9 years (range, 15 to 80 years) and the percentage of males was 53.8%. Thirteen of 26 patients had ICH without intraventricular hemorrhage, and 6 patients had co-existing IVH. In 17 cases, the DSA results were negative. Seven patients were diagnosed with pseudoaneurysms, and two cases showed developmental venous anomalies. Group A consisted of the 8 patients (30.8%) who showed the spot sign in a ventricle. The number of pseudoaneurysms was statistically significantly higher in Group A than in Group B (71.4% versus 28.6%; OR, 13.3; 95% CI, 1.7-103.8 P = 0.014). All three patients who underwent endovascular treatment were members of Group A (P = 0.022), whereas most (92.3%) of those in Group B underwent surgical evacuation. (P = 0.030). CONCLUSION: When CTA shows the spot sign in a ventricle, it is a clue that an existing underlying vascular lesion requires endovascular treatment.

9.
J Cerebrovasc Endovasc Neurosurg ; 21(1): 33-39, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31832385

RESUMO

BACKGROUND: Achondroplasia is one of the most common types of dwarfism and is inherited as an autosomal dominant disease. The patients with achondroplasia suffer from various complications such as craniofacial, central nervous system, spinal, respiratory and cardiac anomalies. CASE DESCRIPTION: We report a case of a 35-year-old man with achondroplasia who visited the emergency room with right hemiplegia and aphasia within 6 hours after onset. An Initial CT angiography showed the total occlusion of a left internal cerebral artery due to the thrombus. We treated the patient with endovascular thrombectomy using "Solumbra technique" with balloon guiding catheter. The procedure was successful and result was completely recanalized with Thrombolysis in Cerebral Infarction (TICI) scale 3 and the weakness also improved from grade II to grade IV. CONCLUSION: Acute ischemic stroke patients with achondroplasia could be treated with mechanical thrombectomy.

10.
World Neurosurg ; 125: e110-e116, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30677582

RESUMO

OBJECTIVE: The purpose of this study was to investigate neck movement and various conditions of the aortic arch that may hinder access to the carotid artery during neurointerventional procedures. METHODS: We reviewed 230 patients who underwent internal carotid artery angiography between February 2016 and October 2016. Use of a Davis catheter (DC) was first attempted and if not possible, movement (right, left, flexion, and extension) of the patient's head was tried before catheter exchange. We analyzed the success rate after neck motion in relation to various aortic arch factors. RESULTS: Only extension of the patient's neck was effective. Of the 209 patients with right side angiography, 23 had failed access with a DC, but neck extension was effective in 3 patients (13%). Failure to insert a DC was significantly correlated with age, male sex, acute angle, arch elongation, aortic calcification, and carotid artery angulation on the right side, whereas access was not gained in 24 out of 208 patients who underwent left side angiography, and neck extension was successful in 7 patients (29.2%). Also, significant factors determining the catheter exchange were age, male sex, acute angle, arch elongation, and aortic calcification.In the DC access failure group, neck extension was significantly more effective for younger aged patients (P = 0.011). CONCLUSIONS: Factors such as older age, acute arch angle, higher elongation type, arch calcification, and carotid artery angulation were verified as factors affecting access by a simple catheter; however, neck extension was shown to facilitate access in about 10%-30% of patents.


Assuntos
Aorta Torácica/diagnóstico por imagem , Artéria Carótida Primitiva/diagnóstico por imagem , Cateterismo/métodos , Angiografia por Tomografia Computadorizada/métodos , Idoso , Artéria Carótida Primitiva/cirurgia , Estudos de Viabilidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Pescoço , Posicionamento do Paciente/métodos , Estudos Retrospectivos , Calcificação Vascular/diagnóstico por imagem , Calcificação Vascular/cirurgia
11.
Transl Clin Pharmacol ; 27(1): 12-18, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32055576

RESUMO

In 2005, the International Council for Harmonization (ICH) established cardiotoxicity assessment guidelines to identify the risk of Torsade de Pointes (TdP). It is focused on the blockade of the human ether-à-go-go-related gene (hERG) channel known to cause QT/QTc prolongation and the QT/QTc prolongation shown on the electrocardiogram. However, these biomarkers are not the direct risks of TdP with low specificity as the action potential is influenced by multiple channels along with the hERG channel. Comprehensive in vitro Proarrhythmia Assay (CiPA) initiative emerged to address limitations of the current model. The objective of CiPA is to develop a standardized in silico model of a human ventricular cell to quantitively evaluate the cardiac response for the cardiac toxicity risk and to come up with a metric for the TdP risk assessment. In silico working group under CiPA developed a standardized and reliable in silico model and a metric that can quantitatively evaluate cellular cardiac electrophysiologic activity. The implementation mainly consists of hERG fitting, Hill fitting, and action potential simulation. In this review, we explained how the in silico model of CiPA works, and briefly summarized current overall CiPA studies. We hope this review helps clinical pharmacologists to understand the underlying estimation process of CiPA in silico modeling.

12.
Phys Rev E ; 95(4-1): 040401, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28505807

RESUMO

Although redistribution of red blood cells at bifurcated vessels is highly dependent on flow rate, it is still challenging to quantitatively express the dependence of flow rate in plasma skimming due to nonlinear cellular interactions. We suggest a plasma skimming model that can involve the effect of fractional blood flow at each bifurcation point. To validate the model, it is compared with in vivo data at single bifurcation points, as well as microvascular network systems. In the simulation results, the exponential decay of the plasma skimming parameter M along fractional flow rate shows the best performance in both cases.


Assuntos
Eritrócitos/fisiologia , Microvasos/fisiologia , Modelos Cardiovasculares , Plasma/fisiologia , Fluxo Sanguíneo Regional/fisiologia , Animais , Simulação por Computador , Hematócrito , Hemodinâmica/fisiologia
13.
J Korean Neurosurg Soc ; 60(1): 1-7, 2017 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-28061484

RESUMO

OBJECTIVE: The diagnosis of shunt malfunction can be challenging since neuroimaging results are not always correlated with clinical outcomes. The purpose of this study was to evaluate the efficacy of a simple, minimally invasive cerebrospinal fluid (CSF) lumbar tapping test that predicts shunt under-drainage in hydrocephalus patients. METHODS: We retrospectively reviewed the clinical and radiological features of 48 patients who underwent routine CSF lumbar tapping after ventriculoperitoneal shunt (VPS) operation using a programmable shunting device. We compared shunt valve opening pressure and CSF lumbar tapping pressure to check under-drainage. RESULTS: The mean pressure difference between valve opening pressure and CSF lumbar tapping pressure of all patients were 2.21±24.57 mmH2O. The frequency of CSF lumbar tapping was 2.06±1.26 times. Eighty five times lumbar tapping of 41 patients showed that their VPS function was normal which was consistent with clinical improvement and decreased ventricle size on computed tomography scan. The mean pressure difference in these patients was -3.69±19.20 mmH2O. The mean frequency of CSF lumbar tapping was 2.07±1.25 times. Fourteen cases of 10 patients revealed suspected VPS malfunction which were consistent with radiological results and clinical symptoms, defined as changes in ventricle size and no clinical improvement. The mean pressure difference was 38.07±23.58 mmH2O. The mean frequency of CSF lumbar tapping was 1.44±1.01 times. Pressure difference greater than 35 mmH2O was shown in 2.35% of the normal VPS function group (2 of 85) whereas it was shown in 64.29% of the suspected VPS malfunction group (9 of 14). The difference was statistically significant (p=0.000001). Among 10 patients with under-drainage, 5 patients underwent shunt revision. The causes of the shunt malfunction included 3 cases of proximal occlusion and 2 cases of distal obstruction and valve malfunction. CONCLUSION: Under-drainage of CSF should be suspected if CSF lumbar tapping pressure is 35 mmH2O higher than the valve opening pressure and shunt malfunction evaluation or adjustment of the valve opening pressure should be made.

14.
J Neurosurg ; 127(3): 492-502, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27834597

RESUMO

OBJECTIVE In this study the authors evaluated whether extracranial-intracranial bypass surgery can prevent stroke occurrence and decrease mortality in adult patients with symptomatic moyamoya disease (MMD). METHODS The medical records of 249 consecutive adult patients with symptomatic MMD that was confirmed by digital subtraction angiography between 2002 and 2011 at 8 institutions were retrospectively reviewed. The study outcomes of stroke recurrence as a primary event and death during the 6-year follow-up and perioperative complications within 30 days as secondary events were compared between the bypass and medical treatment groups. RESULTS The bypass group comprised 158 (63.5%) patients, and the medical treatment group comprised 91 (36.5%) patients. For 249 adult patients with MMD, bypass surgery showed an HR of 0.48 (95% CI 0.27-0.86, p = 0.014) for stroke recurrence calculated by Cox regression analysis. However, for the 153 patients with ischemic MMD, the HR of bypass surgery for stroke recurrence was 1.07 (95% CI 0.43-2.66, p = 0.887). For the 96 patients with hemorrhagic MMD, the multivariable adjusted HR of bypass surgery for stroke recurrence was 0.18 (95% CI 0.06-0.49, p = 0.001). For the treatment modality, indirect bypass and direct bypass (or combined bypass) did not show any significant difference for stroke recurrence, perioperative stroke, or mortality (log rank; p = 0.524, p = 0.828, and p = 0.616, respectively). CONCLUSIONS During the treatment of symptomatic MMD in adults, bypass surgery reduces stroke recurrence for the hemorrhagic type, but it does not do so for the ischemic type. The best choice of bypass methods in adult patients with MMD is uncertain. In adult ischemic MMD, a prospective randomized study to evaluate the effectiveness and safety of bypass surgery to prevent recurrent stroke is necessary.


Assuntos
Doença de Moyamoya/terapia , Adulto , Infarto Cerebral/etiologia , Revascularização Cerebral/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Doença de Moyamoya/complicações , Doença de Moyamoya/diagnóstico , Doença de Moyamoya/cirurgia , Estudos Retrospectivos , Acidente Vascular Cerebral/etiologia
15.
Biomech Model Mechanobiol ; 16(2): 497-507, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-27655421

RESUMO

In microvascular transport, where both blood and drug carriers are involved, plasma skimming has a key role on changing hematocrit level and drug carrier concentration in capillary beds after continuous vessel bifurcation in the microvasculature. While there have been numerous studies on modeling the plasma skimming of blood, previous works lacked in consideration of its interaction with drug carriers. In this paper, a generalized plasma skimming model is suggested to predict the redistributions of both the cells and drug carriers at each bifurcation. In order to examine its applicability, this new model was applied on a single bifurcation system to predict the redistribution of red blood cells and drug carriers. Furthermore, this model was tested at microvascular network level under different plasma skimming conditions for predicting the concentration of drug carriers. Based on these results, the applicability of this generalized plasma skimming model is fully discussed and future works along with the model's limitations are summarized.


Assuntos
Portadores de Fármacos/metabolismo , Eritrócitos/metabolismo , Microcirculação/fisiologia , Modelos Biológicos , Plasma/metabolismo , Portadores de Fármacos/análise , Humanos , Microvasos/metabolismo , Plasma/química
16.
World Neurosurg ; 94: 273-284, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27423200

RESUMO

BACKGROUND: It remains controversial which bypass methods are optimal for treating adult moyamoya angiopathy patients. This study aimed to analyze the literature about whether different bypass methods affect differently outcome results of adult moyamoya patients with symptoms or hemodynamic instability. METHODS: A systematic search of the PubMed, Embase, and Cochrane Central databases was performed for articles published between 1990 and 2015. Comparative studies about the effect of direct or combined bypass (direct bypass group) and indirect bypass (indirect bypass group) in patients with moyamoya angiopathy at 18 years of age or older were selected. For stroke incidence at the end of the follow-up period, the degree of angiographic revascularization, hemodynamic improvement, and perioperative complication rates within 30 days, pooled relative risks were calculated between the 2 groups with a 95% confidence interval. RESULTS: A total of 8 articles (including 536 patients and 732 treated hemispheres) were included in the meta-analysis. There were no significant differences between the 2 groups when we compared the overall stroke rate, the hemodynamic improvement rate, or the perioperative complication rate at the end of the follow-up period. The direct bypass group, however, had a lower risk than the indirect bypass group for obtaining a poor angiographic revascularization rate (risk ratio, 0.35; 95% confidence interval, 0.15-0.84; P = 0.02). CONCLUSIONS: The current meta-analysis suggests that the direct or combined bypass surgical method is better for angiographic revascularization in adult moyamoya patients with symptoms or hemodynamic instability. Future studies may be necessary to confirm these findings.


Assuntos
Revascularização Cerebral/métodos , Revascularização Cerebral/estatística & dados numéricos , Doença de Moyamoya/epidemiologia , Doença de Moyamoya/cirurgia , Complicações Pós-Operatórias/epidemiologia , Acidente Vascular Cerebral/epidemiologia , Adolescente , Adulto , Idoso , Causalidade , Comorbidade , Feminino , Humanos , Internacionalidade , Masculino , Pessoa de Meia-Idade , Doença de Moyamoya/diagnóstico , Complicações Pós-Operatórias/diagnóstico , Complicações Pós-Operatórias/prevenção & controle , Prevalência , Fatores de Risco , Acidente Vascular Cerebral/diagnóstico , Acidente Vascular Cerebral/prevenção & controle , Adulto Jovem
17.
Microvasc Res ; 108: 22-8, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27389627

RESUMO

Since blood viscosity is a basic parameter for understanding hemodynamics in human physiology, great amount of research has been done in order to accurately predict this highly non-Newtonian flow property. However, previous works lacked in consideration of hemodynamic changes induced by heterogeneous vessel networks. In this paper, the effect of bifurcation on hemodynamics in a microvasculature is quantitatively predicted. The flow resistance in a single bifurcation microvessel was calculated by combining a new simple mathematical model with 3-dimensional flow simulation for varying bifurcation angles under physiological flow conditions. Interestingly, the results indicate that flow resistance induced by vessel bifurcation holds a constant value of approximately 0.44 over the whole single bifurcation model below diameter of 60µm regardless of geometric parameters including bifurcation angle. Flow solutions computed from this new model showed substantial decrement in flow velocity relative to other mathematical models, which do not include vessel bifurcation effects, while pressure remained the same. Furthermore, when applying the bifurcation angle effect to the entire microvascular network, the simulation results gave better agreements with recent in vivo experimental measurements. This finding suggests a new paradigm in microvascular blood flow properties, that vessel bifurcation itself, regardless of its angle, holds considerable influence on blood viscosity, and this phenomenon will help to develop new predictive tools in microvascular research.


Assuntos
Hemodinâmica , Microcirculação , Microvasos/fisiologia , Modelos Cardiovasculares , Animais , Velocidade do Fluxo Sanguíneo , Viscosidade Sanguínea , Simulação por Computador , Humanos , Camundongos , Microvasos/anatomia & histologia , Modelos Anatômicos , Fluxo Sanguíneo Regional , Resistência Vascular
18.
J Korean Neurosurg Soc ; 58(3): 254-61, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26539270

RESUMO

OBJECTIVE: The present study aims to investigate 1) the risk factors for hydrocephalus and subdural hygroma (SDG) occurring after decompressive craniectomy (DC), and 2) the association between the type of SDG and hydrocephalus. METHODS: We retrospectively reviewed the clinical and radiological features of 92 patients who underwent DC procedures after severe head injuries. The risk factors for developing post-traumatic hydrocephalus (PTH) and SDG were analyzed. Types of SDGs were classified according to location and their relationship with hydrocephalus was investigated. RESULTS: Ultimately, 26.09% (24/92) of these patients developed PTH. In the univariate analyses, hydrocephalus was statically associated with large bone flap diameter, large craniectomy area, bilateral craniectomy, intraventricular hemorrhage, contralateral or interhemisheric SDGs, and delayed cranioplasty. However, in the multivariate analysis, only large craniectomy area (adjusted OR=4.66; p=0.0239) and contralateral SDG (adjusted OR=6.62; p=0.0105) were significant independent risk factors for developing hydrocephalus after DC. The incidence of overall SDGs after DC was 55.43% (51/92). Subgroup analysis results were separated by SDG types. Statistically significant associations between hydrocephalus were found in multivariate analysis in the contralateral (adjusted OR=5.58; p=0.0074) and interhemispheric (adjusted OR=17.63; p=0.0113) types. CONCLUSION: For patients who are subjected to DC following severe head trauma, hydrocephalus is associated with a large craniectomy area and contralateral SDG. For SDGs after DC that occur on the interhemispherical or controlateral side of the craniectomy, careful follow-up monitoring for the potential progression into hydrocephalus is needed.

19.
J Korean Neurosurg Soc ; 58(3): 276-80, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26539273

RESUMO

Tentorial dural arteriovenous fistula (DAVF) is a rare vascular disease, which has high risk of intracranial hemorrhage. We present two cases of tentorial DAVF which were successfully treated with single trial of transarterial embolization using Onyx. We briefly reviewed the types of the tentorial DAVF and strategies of treatment.

20.
J Korean Neurosurg Soc ; 56(2): 91-7, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25328644

RESUMO

OBJECTIVE: The purpose of this study was to evaluate demographic and clinical factors affecting the common femoral artery diameter and length, and anatomical relationship between the femoral head and the common femoral artery during angiography. METHODS: We retrospectively reviewed 109 femoral angiograms. We collected the clinical data of the patients and estimated the common femoral artery diameter and length. We divided the areas in the angiogram from cephalic to caudal direction (zone 0 to 5). The lowest levels of the inferior epigastric artery loop and points of the common femoral artery bifurcation were checked. RESULTS: The luminal diameter of the common femoral artery was 6.19±1.20 mm. Height, weight, body surface area, as well as common femoral artery diameter were significantly greater in men than in women (p<0.005). The length of the common femoral artery was 27.59±8.87 mm. Height, weight and body surface area showed strong positive relationships with common femoral artery diameter. All of the inferior epigastric artery loops were located above the center of the femoral head. The point of common femoral artery bifurcation was above the center of the femoral head in 4.59% of femoral angiograms. CONCLUSIONS: Males and patients with a high body surface area have a larger common femoral artery diameter. The cumulative probability of optimal targeting between the lowest margin of the inferior epigastric artery loop and the common femoral artery bifurcation is the highest in zone 3 puncture.

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