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排序方式: 共有523条查询结果,搜索用时 15 毫秒
1.
aVR sign as a risk factor for life-threatening arrhythmic events in patients with Brugada syndrome 总被引:2,自引:0,他引:2
BACKGROUND: Risk stratification in Brugada syndrome (BS) is controversial, especially in asymptomatic individuals. OBJECTIVE: The aim of this study was to evaluate the significance of lead aVR in patients with BS. METHODS: Twenty-four patients with the electrocardiogram pattern of BS (24 male, mean age 32.1 +/- 13.6 years) and 24 healthy age- and gender-matched controls were studied. RESULTS: Thirteen patients were symptomatic. The R-wave amplitude or R/q ratio in lead aVR was significantly greater in patients experiencing a recurrence compared with those who did not. The aVR sign was defined as R wave >/= 0.3 mV or R/q >/= 0.75 in lead aVR. Most of the recurrences (78%) were in patients with present aVR sign; 84% of BS patients with present aVR sign had events during follow-up. In contrast, only 27% of BS patients with absent aVR sign had events during follow-up. CONCLUSION: Our study shows significant correlation between a prominent R wave in lead aVR (aVR sign) and risk for development of arrhythmic events in BS. In the presence of BS, prominent R wave in lead aVR may reflect more right ventricular conduction delay and subsequently more electrical heterogeneity, which in turn is responsible for a higher risk of arrhythmia. 相似文献
2.
Oded Gonen Afsaneh Mohebbi Radka Stoyanova Truman R. Brown 《Magnetic resonance in medicine》1997,37(2):301-306
Refocused insensitive nucleus enhancement by polarization transfer (RINEPT) from protons (1H) to a J-coupled phosphorus (31P) has been incorporated into three-dimensional (3D) chemical-shift-imaging (CSI) sequence on a clinical imager. The technique is demonstrated on a phantom and in in vivo human brain. The polarization-transfer efficiency (~1.2) is lower than the theoretical maximum of γ1H/γ31P≈ 2.4 resulting from 1H-1H homonuclear J couplings of similar magnitude competing with the 1H →31P transfer. Nevertheless, compared with direct 31P Ernst-angle excitation, signal gains of up to × 1.8 were obtained mainly as a result of T1 differences between 31P and the 1H. Spectral interpretation is simplified by editing out all non-proton-coupled 31P signals. The duration, ~50 min, and power deposition, ~1 W · kg?1, make the application suitable for human studies. 相似文献
3.
Farideh Nejat Parvin Tajik Mostafa El Khashab Syed Shuja Kazmi Ghamar Taj Khotaei Shahrzad Salahesh 《Journal of microbiology, immunology, and infection》2008,41(2):112-117
BACKGROUND AND PURPOSE: Shunt infection represents a particularly morbid condition, which can also result in mortality. In order to decrease the high morbidity and mortality rates, prevention is an essential step. The purpose of this study was to compare the prophylactic use of ceftriaxone and trimethoprim-sulfamethoxazole (SXT) for the prevention of ventriculoperitoneal (VP) shunt infection. METHODS: In this prospective, single-institution, randomized clinical trial, 107 children with hydrocephalus and an indication for shunting were randomly assigned to prophylaxis with ceftriaxone (n = 50) or SXT (55), each administered as a single dose during anesthesia and two divided doses postoperatively. Patients were followed up for at least one year. RESULTS: The mean age of patients was 15 months, and 85% were aged 6 months or younger. During the first postoperative year, meningitis occurred in 13.5% of patients receiving ceftriaxone and 14.5% of the SXT group, with no statistically significant difference between the groups. Younger age, presence of cerebrospinal fluid leakage and aqueductal stenosis as a cause of hydrocephalus showed significant correlation with meningitis occurrence on univariate analysis. However, only the latter 2 factors were associated with meningitis on multivariate analysis. The risk of shunt infection did not correlate with the gender of the patient, time of VP shunt surgery, or duration of hospitalization for shunting. CONCLUSION: Ceftriaxone and SXT showed similar efficacy in preventing shunt infection. Cerebrospinal fluid leakage before or after VP shunt placement and aqueductal stenosis were independent risk factors for meningitis after VP shunt. 相似文献
4.
Natural Convection Heat Transfer in a Porous Cavity with Sinusoidal Temperature Distribution Using Cu/Water Nanofluid: Double MRT Lattice Boltzmann Method
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Hasan Sajjadi Amin Amiri Delouei Rasul Mohebbi Mohsen Izadi & Sauro Succi 《Communications In Computational Physics》2021,29(1):292-318
In this study, natural convection flow in a porous cavity with sinusoidal
temperature distribution has been analyzed by a new double multi relaxation time
(MRT) Lattice Boltzmann method (LBM). We consider a copper/water nanofluid filling a porous cavity. For simulating the temperature and flow fields, D2Q5 and D2Q9
lattices are utilized respectively, and the effects of different Darcy numbers (Da) (0.001-0.1) and various Rayleigh numbers (Ra) ($10^3$-$10^5$) for porosity ($ε$) between 0.4 and 0.9
have been considered. Phase deviation ($θ$) changed from 0 to $π$ and the volume fraction
of nanoparticles (Ø) varied from 0 to 6%. The present results show a good agreement
with the previous works, thus confirming the reliability the new numerical method
proposed in this paper. It is indicated that the heat transfer rate increases at increasing
Darcy number, porosity, Rayleigh number, the volume fraction of nanoparticles and
phase deviation. However, the most sensitive parameter is the Rayleigh number. The
maximum Nusselt deviation is 10%, 32% and 33% for Ra=$10^3$, $10^4$ and $10^5$, respectively, with $ε = 0.4$ to $ε = 0.9$. It can be concluded that the effect of Darcy number on
the heat transfer rate increases at increasing Rayleigh number, yielding a maximum
enhancement of the average Nusselt number around 12% and 61% for Ra=$10^3$ and
Ra=$10^5$, respectively. 相似文献
5.
Lighvani S Huang X Trivedi PP Swanborg RH Hazlett LD 《European journal of immunology》2005,35(5):1567-1575
Studies have shown that after Pseudomonas aeruginosa (P. aeruginosa) corneal infection, BALB/c mice that are capable of resolving the disease, locally produce IFN-gamma. As T cells are not detected in the infected cornea of these mice, antibody depletion was used to test whether NK cells produce the cytokine. After depletion, decreased corneal IFN-gamma mRNA and increased disease severity, bacterial load, and PMN infiltrate resulted. Further work determined if substance P (SP), a pro-inflammatory neuropeptide, participated in regulation of this response. To this end, mice were treated with the SP antagonist, spantide I that blocks SP interaction with neurokinin-1, its major receptor. The treatment significantly decreased corneal IFN-gamma and IL-18 protein levels and corneal perforation resulted. In vitro experiments using isolated splenic NK cells confirmed their ability to respond to IL-18 and SP and to secrete IFN-gamma protein. We conclude: that for development of the BALB/c resistance response, NK cells are required to produce IFN-gamma; that the cells express the neurokinin-1 receptor; and that SP directly regulates IFN-gamma production through this receptor. The data suggest a unique link between the nervous system and development of innate immunity in the cornea. 相似文献
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8.
Nafise Tabasi Mahmoud Mahmoudi Maryam Rastin Hamid Reza Sadeghnia Mojtaba HosseinPour Mashhadi Shahrzad Zamani Taghizade Rabe 《Food and Agricultural Immunology》2015,26(1):138-156
Renal cell carcinoma (RCC) is the most common renal malignancy in adults and exhibits highly intrinsic and acquired resistance to standard therapeutic strategies. We sought to determine the anti-cancer activity of hydroalcoholic extract of Nigella sativa seeds (NSE) and thymoquinone (TQ). Human renal cell carcinoma (ACHN) and fibroblast L929 cell lines were treated with NSE and TQ, and cytotoxicity was measured using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium (MTT) assay. Cell death pattern was determined by annexin V and propidium iodine (PI)-staining methods. Exposure to NSE, TQ and cisplatin significantly inhibited the growth of ACHN cells and showed significant increase of early apoptotic cells. Normal cells were more resistant to NSE and TQ-induced effects. The present study demonstrates that N. sativa and TQ exert anti-proliferative and pro-apoptotic effects on ACHN cells in a concentration and time-dependent manner, which suggests their potential to be used as a new therapeutic strategy for renal cancers. 相似文献
9.
Shahrzad Zamani Taghizadeh Rabe Maryam Sahebari Zohreh Mahmoudi Hossein Hosseinzadeh Dariush Haghmorad Nafise Tabasi 《Food and Agricultural Immunology》2015,26(2):170-180
Saffron is a well-known spice produced from dried stigmas of Crocus sativus L. flowers. Apart from its wide use in food preparations, it also has a broad range of medical properties. We examined the potential anti-inflammatory effects of saffron ethanolic extract (SEE) using an animal model of arthritis. Adjuvant-induced arthritis was induced in Wistar rats by injection of Complete Freund's Adjuvant. The rats were then injected intraperitoneally every other day with 25–600 mg SEE/kg or dexamethasone (DEX, 2 mg/kg). Changes in body weight, paw oedema and arthritis indices were recorded over the subsequent 12 days of treatment. Results revealed that SEE particularly at the higher concentrations significantly reduced paw and tibiotarsal joint diameters and comparing with DEX caused no significant change in body weight. These observations suggest that SEE displays a considerable anti-inflammatory potency and could potentially be used as an anti-arthritic agent in control of inflammation in rheumatoid arthritis. 相似文献
10.
N Mohebbi R Vargas‐Poussou SCA Hegemann B Schuknecht AD Kistler RP Wüthrich CA Wagner 《Clinical genetics》2013,83(3):274-278
Mohebbi N, Vargas‐Poussou R, Hegemann SCA, Schuknecht B, Kistler AD, Wüthrich RP, Wagner CA. Homozygous and compound heterozygous mutations in the ATP6V1B1 gene in patients with renal tubular acidosis and sensorineural hearing loss. Distal renal tubular acidosis (dRTA) is characterized by the inability to excrete acid in the renal collecting ducts resulting in inappropriately alkaline urine and hyperchloremic (normal anion gap) metabolic acidosis in the context of a normal (or near‐normal) glomerular filtration rate. Inborn dRTA can be due to autosomal dominant or recessive gene defects. Clinical symptoms vary from mild acidosis, incidental detection of kidney stones or renal tract calcification to severe findings such as failure to thrive, severe metabolic acidosis, and nephrocalcinosis. The majority of patients with recessive dRTA present with sensorineural hearing loss (SNHL). Few cases with abnormal widening of the vestibular aqueduct have been described with dRTA. Mutations in three different genes have been identified, namely SLC4A1, ATP6V1B1, and ATP6V0A4. Patients with mutations in the ATP6V1B1 proton pump subunit develop dRTA and in most of the cases sensorineural hearing loss early in childhood. We present two patients from two different and non‐consanguineous families with dRTA and SNHL. Direct sequencing of the ATP6V1B1 gene revealed that one patient harbors two homozygous mutations and the other one is a compound heterozygous. To our knowledge, this is the first case in the literature describing homozygosity in the same dRTA gene on both alleles. 相似文献