RESUMEN
In order to clarify the transmission mechanism of the impact of mechanization on the occupational health of miners and to provide empirical evidence for the development of new quality productivity in the coal industry that balances health and efficiency. In August 2022, we selected a typical coal mine, constructed a comprehensive evaluation index of miners' occupational health through a questionnaire survey based on the fully connected neural network model. A Bayesian model was used to verify the influence of mechanization level on miners' occupational health. We found that: the predicted probability of occupational diseases could be used as a comprehensive indicator of the level of occupational health, providing a basis for early intervention and prevention of occupational diseases. Mechanization could directly promote the improvement of miners' occupational health level, and also indirectly affect occupational health level by influencing hazards level and work intensity. The indirect effect of mechanization on work intensity was positive, and the indirect effect of mechanization on hazards level was positive. Presented the "inverted U-shaped" process in the mechanization breakthrough semi-mechanized level would realize the economies of scale of health protection, its impact on the prevention and control of occupational hazards would turn from negative to positive.
Asunto(s)
Minas de Carbón , Redes Neurales de la Computación , Enfermedades Profesionales , Salud Laboral , Humanos , Encuestas y Cuestionarios , Enfermedades Profesionales/prevención & control , Teorema de Bayes , Mineros/estadística & datos numéricosRESUMEN
Objective: To analyze the clinical characteristics of pulmonary embolism patients from different altitudes in plateau areas. Methods: A retrospective cross-sectional study was used to analyze the patients with acute pulmonary embolism diagnosed definitely by pulmonary angiography or pulmonary artery CT angiography admitted to Tibet Autonomous Region People's Hospital from August 2014 to December 2018. The subjects were divided into 3 groups according to the altitude of long-term residence before onset, i.e. low-altitude group (group 1, 2 700 m ≤ altitude ≤3 700 m, n=44), medium-altitude group (group 2, 3 700 mAsunto(s)
Altitud
, Arteria Pulmonar/diagnóstico por imagen
, Embolia Pulmonar/diagnóstico por imagen
, Dolor en el Pecho/epidemiología
, China/epidemiología
, Angiografía por Tomografía Computarizada
, Estudios Transversales
, Disnea/epidemiología
, Humanos
, Hipoxia
, Incidencia
, Embolia Pulmonar/epidemiología
, Estudios Retrospectivos
RESUMEN
BACKGROUND: Obstructive sleep apnea (OSA) is associated with cancer incidence and mortality. The underlying mechanism is unclear. This study aims to evaluate the influence of intermittent hypoxia (IH), a novel hallmark of OSA, on tumor and to access the anti-tumor effect of endostatin on a mouse model with OSA. METHODS: The C57BL/6 J mice were randomly classified into four groups: control (normoxia) (CTL), control plus endostatin (CTL + ED), IH, and IH plus endostatin (IH + ED). Mice in IH and IH + ED groups were subjected to IH 8 h per day in 5 weeks. Lewis lung cancer cells were injected into the flank of each mouse after 1 week of IH exposure. Endostatin was also intraperitoneally injected after tumor volume reached about 200 mm3. The maximum standard uptake values (SUVmax) were detected by micro-positron emission tomography-computed tomography (micro-PET-CT) imaging prior and post-endostatin administration. Microvessel density (MVD) and vascular endothelial growth factor (VEGF) were determined for evaluating the anti-tumor effect of endostatin among the normoxia and IH conditions. RESULTS: Mice had higher SUVmax in the IH group than the CTL group (p < 0.01). When compared with mice in the CTL group, those in the IH group had significantly greater MVD values (p < 0.001). The SUVmax can be attenuated by endostatin both in the CTL (p < 0.01) and IH conditions (p < 0.001). When compared with CTL group, mice in the IH group had increased MVD values (p < 0.001) and VEGF expression both at mRNA (p < 0.05) and protein levels (p < 0.001 in western blotting results). Treatment with endostatin attenuated serum and tissue VEGF levels, lowering the MVD values. As compared to normoxia condition, the endostatin-therapeutic effects were more significant under the IH condition (p < 0.05 in western blotting results). CONCLUSIONS: Micro-PET-CT imaging is a promising non-invasive technique to evaluate the tumor metabolic characteristics under IH condition in vivo. The anti-tumor effect of endostatin under IH condition is superior to that of the normoxia condition.
Asunto(s)
Antineoplásicos/farmacología , Carcinoma Pulmonar de Lewis/tratamiento farmacológico , Modelos Animales de Enfermedad , Endostatinas/farmacología , Hipoxia/fisiopatología , Apnea Obstructiva del Sueño/complicaciones , Animales , Carcinoma Pulmonar de Lewis/etiología , Masculino , Ratones , Ratones Endogámicos C57BL , Células Tumorales CultivadasRESUMEN
This case-control study aimed to investigate the association between PHLDB1 rs498872 polymorphism and the risk of glioma in a Chinese Han population. A total of 210 patients and 235 controls were enrolled in this study. The CT genotype and TT genotype were significantly associated with the risk of glioma (OR=1.48, 95%CI 1.00-2.19, P=0.05 and OR=2.40, 95%CI 1.06-4.10, P=0.03), respectively. In addition, T allele of PHLDB1 rs498872 polymorphism was significantly associated with an increased risk of glioma (OR=1.58, 95%CI 1.08-2.29, P=0.02). We also found that PHLDB1 rs498872 polymorphism was not associated with histology and tumor grade of glioma. In conclusion, this study found that PHLDB1 rs498872 polymorphism was significantly associated with glioma risk in Chinese Han population.
Asunto(s)
Neoplasias Encefálicas/genética , Predisposición Genética a la Enfermedad , Glioma/genética , Péptidos y Proteínas de Señalización Intracelular/genética , Proteínas del Tejido Nervioso/genética , Polimorfismo de Nucleótido Simple , Adulto , Alelos , Pueblo Asiatico , Neoplasias Encefálicas/diagnóstico , Neoplasias Encefálicas/etnología , Neoplasias Encefálicas/patología , Estudios de Casos y Controles , Femenino , Expresión Génica , Frecuencia de los Genes , Glioma/diagnóstico , Glioma/etnología , Glioma/patología , Haplotipos , Humanos , Masculino , Persona de Mediana Edad , Clasificación del Tumor , Oportunidad Relativa , Factores de RiesgoRESUMEN
OBJECTIVE: To investigate the effects of different drugs on systolic blood pressure (SBP) and left ventricular hypertrophy (LVH) in spontaneously hypertensive rats under cold stress. METHODS: A total of 40 male spontaneously hypertensive rats aged 10 weeks (160~200 g) were given adaptive feeding for 7 days at a temperature of 20±1°C and then randomly divided into control group, cold stress group, metoprolol group, amlodipine group, and benazepril group, with 8 rats in each group. SBP, body weight, and heart rate were measured once a week. After the rats were sacrificed by exsanguination, left ventricular weight (LVW) was measured, and left ventricular weight index (LVWI; mg/g) was calculated. Radioimmunoassay was used to measure the concentrations of endothelin-1 (ET-1) and angiotensin-II (Ang-II) in plasma and myocardium, and the chemical method was used to measure the concentrations of nitric oxide (NO) in plasma and myocardium. RT-PCR was used to measure the mRNA expression of endothelin-A receptor. RESULTS: Compared with the cold stress group, all medication groups showed significant reductions in SBP since week 5 (P<0.05). The cold stress group showed a significant increase in LVWI compared with the control group (3.38±0.27 mg/g vs 2.89±0.19 mg/g, P<0.05). The amlodipine group showed a significant reduction in LVWI compared with the cold stress group (2.98±0.28 mg/g vs 3.38±0.27 mg/g, P<0.05). The cold stress group showed a significant reduction in plasma NO concentration compared with the control group (104.9±19.5 µmol/L vs 129.3±17.8 µmol/L, P<0.05) ; compared with the cold stress group, all the medication groups showed significant increases in blood NO concentration (P<0.05). The cold stress group showed a significant increase in myocardial ET-1 concentration compared with the control group (6.3±1.5 pg/100 mg vs 4.5±1.9 pg/100 mg, P<0.05) ; compared with the cold stress group, the amlodipine group showed a significant reduction in myocardial ET-1 concentration (4.4±1.0 pg/100 mg vs 6.3±1.5 pg/100 mg, P<0.05). The cold stress group had significantly higher mRNA expression of endothelin-A receptor than the control group (0.86±0.23 vs 0.45±0.16, P<0.01) ; compared with the cold stress group, the amlodipine group showed a significant reduction in the mRNA expression of endothelin-A receptor (0.41±0.14 vs 0.86±0.23, P<0.01). CONCLUSION: Amlodipine can reduce the increase in SBP and inhibit LVH in spontaneously hypertensive rats under cold stress.
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Hipertrofia Ventricular Izquierda , Estrés Fisiológico , Angiotensina II , Animales , Benzazepinas , Presión Sanguínea , Frío , Endotelina-1 , Hipertensión , Masculino , Miocardio , Ratas , Ratas Endogámicas SHRRESUMEN
High-sensitivity cardiac troponin T is a useful tool for diagnosing myocardial ischemia. However, its role in the prognosis of patients with acute myocardial infarction has not been studied. Here, the prognostic value of high-sensitivity cardiac troponin T for patients with acute myocardial infarction was investigated. The concentrations of high-sensitivity cardiac troponin T, other clinical chemistry makers, and living habits were investigated at the time of admission in patients with acute coronary syndrome, whereas the high-sensitivity cardiac troponin T concentrations at 6 h after admission and during recovery were analyzed in other patient groups. The concentration of high-sensitivity cardiac troponin T was significantly higher in patients with acute myocardial infarction than in those with other cardiac diseases and in controls (P < 0.01). Based on the standard diagnostic criterion, 134 patients were diagnosed with acute myocardial infarction. Monitoring the change in concentration of high-sensitivity cardiac troponin T in patients with acute coronary syndrome can reduce the risk of recurrence and death.
Asunto(s)
Síndrome Coronario Agudo/sangre , Infarto del Miocardio/sangre , Pronóstico , Troponina T/sangre , Síndrome Coronario Agudo/diagnóstico , Síndrome Coronario Agudo/patología , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana Edad , Infarto del Miocardio/diagnóstico , Infarto del Miocardio/patología , Recurrencia , Factores de RiesgoRESUMEN
OBJECTIVES: We sought: 1) to investigate the relationship between vascular wall shear stress and flow-mediated dilation (FMD) in humans, and 2) to investigate whether this relationship could explain why FMD is greater in small arteries. BACKGROUND: Arterial wall shear stress (WSS) is considered to be the primary stimulus for the endothelial-dependent FMD response. However, the relationship between WSS and FMD has not been investigated in humans. Furthermore, FMD is greater in small arteries, though the reasons for this phenomenon are unclear. METHODS: Using phase-contrast magnetic resonance angiography (PMRCA), we measured hyperemic WSS and FMD in 18 healthy volunteers. Peak systolic WSS was calculated assuming a blunted parabolic velocity profile. Diameter by PCMRA and by ultrasound was compared in nine subjects. RESULTS: Flow-mediated dilation was linearly proportional to hyperemic peak systolic WSS (r = 0.79, p = 0.0001). Flow-mediated dilation was inversely related to baseline diameter (r = 0.62, p = 0.006), but the hyperemic peak WSS stimulus was also inversely related to baseline diameter (r = 0.47, p = 0.049). Phase-contrast magnetic resonance angiography and ultrasound diameters were compared in nine subjects and correlated well (r = 0.84, p < 0.0001), but diameter by PCMRA was greater (4.1 +/- 0.7 mm vs. 3.7 +/- 0.5 mm, p = 0.009). CONCLUSION: Arterial FMD is linearly proportional to peak hyperemic WSS in normal subjects. Thus, the endothelial response is linearly proportional to the stimulus. Furthermore, the greater FMD response in small arteries is accounted for, at least partially, by a greater hyperemic WSS stimulus in small arteries. By allowing the calculation of vascular WSS, which is the stimulus for FMD, and by imaging a fixed arterial cross-section, thus reducing operator dependence, PCMRA enhances the assessment of vascular endothelial function.
Asunto(s)
Velocidad del Flujo Sanguíneo/fisiología , Endotelio Vascular/fisiopatología , Angiografía por Resonancia Magnética , Músculo Liso Vascular/fisiopatología , Vasodilatación/fisiología , Adulto , Femenino , Humanos , Hiperemia/fisiopatología , Masculino , Persona de Mediana Edad , Valores de Referencia , Sístole/fisiologíaRESUMEN
A comparison between the prospective and retrospective respiratory navigator gating in MR coronary angiography was performed with eight normal subjects. A three-dimensional (3D) ECG-gated fast gradient echo pulse sequence was used for image data acquisition. The results show that the MR coronary angiography obtained using retrospective gating retains a considerable amount of motion artifacts. In this study, the images acquired using prospective navigator gating demonstrated significantly reduced motion artifacts (p = 0.009), improved vessel visibility (p = 0.021) with reduced imaging time (p = 0.013) compared to the images obtained using retrospective navigator gating.
Asunto(s)
Angiografía Coronaria , Angiografía por Resonancia Magnética/métodos , Movimiento (Física) , Músculos Respiratorios/diagnóstico por imagen , Músculos Respiratorios/fisiología , Adulto , Arterias/ultraestructura , Artefactos , Vasos Coronarios/ultraestructura , Humanos , Masculino , Estudios Prospectivos , Intensificación de Imagen Radiográfica , Valores de Referencia , Estudios RetrospectivosRESUMEN
Important advances in rapid magnetic resonance (MR) imaging technology and its application to cardiovascular imaging have been made during the past decade. High-field-strength clinical magnets, high-performance gradient hardware, and ultrafast pulse sequence technology are rapidly making the vision of a comprehensive "one-stop shop" cardiac MR imaging examination a reality. This examination is poised to have a significant effect on the management of coronary artery disease by means of assessment of wall motion with tagging and pharmacologic stress testing, evaluation of the coronary microvasculature with perfusion imaging, and direct visualization of the coronary arteries with MR coronary angiography. This article reviews current state-of-the-art pulse sequence technology and its application to the evaluation of ischemic heart disease by means of MR tagging with dobutamine stress testing, MR perfusion imaging, and MR coronary angiography. Cutting edge areas of research in coil design and exciting new areas of metabolic and oxygen level-dependent imaging are also explored.
Asunto(s)
Imagen por Resonancia Magnética/métodos , Isquemia Miocárdica/diagnóstico , Isquemia Miocárdica/fisiopatología , Cardiotónicos , Medios de Contraste , Dobutamina , Humanos , Angiografía por Resonancia Magnética , Imagen por Resonancia Magnética/instrumentaciónRESUMEN
AIM: To study the role of cholecystokinin octapeptide (CCK-8),beta endorphin (beta EP), and gastrin in an anorexic infantile rat model and no subsequent regulation of nose peptides by the Yunpi complex prescription ErBao Granule. METHODS: We fed infantile rats with special prepared forage. A liquid extract of ErBao Granule was administered to the rats daily for 3 weeks, CCK-8, beta-EP, and gastrin concentrations in hypothalamus, gastric antrum, and plasma of the rats were measured by radioimmunoassay, and were compared with controls. RESULTS: Treatment of rats with ErBao Granule inhibited CCK-8 secretion and increased beta-EP and gastrin secretion. CCK-8 concentration in hypothalamus and plasma of model control group increased significantly and correlated negatively with food intake of models, respectively. beta-EP concentration in gastric antrum and plasma of model control group decreased significantly and showed a positive correlation with food intake of models, respectively. Hypothalamus concentration of beta-EP was similar in models and controls. Gastrin concentration in gastric antrum of models was lower than in the blank control group, and correlated positively to food intake of models. Finally, CCK-8 concentrations in plasma of rats showed a positive correlation with plasma beta-EP (r=-0.68, P<0.05). CONCLUSION: The increased plasma and hypothalamus concentration of CCK-8, decreased gastric antrum and plasma level of beta-EP, and decreased gastric antrum concentration of gastrin are associated significantly with the anorexia of infantile anorexic rat models produced by special for-age. ErBao Granule can reverse these changes, which may be the major mechanisms of ErBao Granule simulating feeding.
Asunto(s)
Anorexia/metabolismo , Gastrinas/metabolismo , Hipotálamo/metabolismo , Antro Pilórico/metabolismo , Sincalida/metabolismo , betaendorfina/metabolismo , Animales , Dieta , Femenino , Masculino , Modelos Animales , Ratas , Ratas Sprague-DawleyRESUMEN
It was previously found that a phosphorothioated antisense oligodeoxynucleotide (ETASODN) significantly inhibits production of endothelin-1 (ET-1). The purpose of the present study was to determine whether intracerebroventricular injection of ETASODN targeted to prepro-ET-1 is capable of exerting the same preventing effect on the aorta narrowing of experimentally modeled hypertensive rats. Radioimmunoassay showed that ET-1 level in the brain stem of hypertensive rats was significantly elevated. In addition to down-regulating the ET-1 level, astisense could also reduce mean arterial pressure (MAP), heart rate and LVSP in model rats. The antisense also down-regulated the ET-1 level in hypothalamus and brain stem, reducing MAP in normal control rats. After treatment with the antisense, the value of delta MAP was markedly lowered in experimental hypertensive rats as compared to the control ones. Thus it appears that (1) ET-1 might play an important role in central cardiovascular regulation in rats and (2) antisense ETASODN might be used in treatment of hypertension via inhibiting ET-1 production.
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Endotelina-1/farmacología , Hemodinámica/efectos de los fármacos , Hipertensión/fisiopatología , Oligodesoxirribonucleótidos Antisentido/farmacología , Animales , Encéfalo/metabolismo , Endotelina-1/genética , Endotelina-1/metabolismo , Masculino , Ratas , Ratas WistarRESUMEN
The "forward" method of an optimal gradient coil design provides a coil that has the minimal cost function value. It is shown in this study that the solution obtained by minimizing the cost function is directly dependent on the specified cost function and generally results in a deviation from the most desirable coil design. In this paper, a gradient coil design approach for obtaining the best achievable coil performance for pre-determined imaging applications is presented. Through this approach, all intermediate coil performance values calculated during an optimization process, using a simulated annealing algorithm, are stored and presented in a three-dimensional data set. Using this three-dimensional data set, a coil designer is able to make a balance between different coil performance parameters and to select a coil that is the most desirable for the pre-determined imaging applications.
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Imagen por Resonancia Magnética/instrumentación , Algoritmos , Artefactos , Control de Costos , Diseño de Equipo/economía , Humanos , Aumento de la Imagen/instrumentación , Procesamiento de Imagen Asistido por Computador/economía , Procesamiento de Imagen Asistido por Computador/instrumentación , Imagen por Resonancia Magnética/economíaRESUMEN
When a linear magnetic field gradient is used, spatially higher-order magnetic fields are produced to satisfy the Maxwell equations. It has been observed that the higher-order magnetic field produced by the readout gradient causes axial echo planar images acquired with a horizontal solenoid magnet to shift along the phase-encoding direction and lose image intensities. Both the shift and intensity reduction become increasingly severe as the slice offset from the isocenter increases. These phenomena are quantitatively analyzed, and good correlation between experiments and theory has been established. The analysis also predicts a previously unreported Nyquist ghost on images with very large slice offsets. This ghost has been verified with computer simulations. Based on the analysis, several methods have been developed to eliminate the image shift, the intensity reduction, and the ghost. Selected methods have been implemented on a commercial scanner and proved effective in removing these image artifacts.
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Artefactos , Imagen Eco-Planar/métodos , Magnetismo , Encéfalo/anatomía & histología , Simulación por Computador , Humanos , Matemática , Modelos Estructurales , Fantasmas de Imagen , Valor Predictivo de las PruebasRESUMEN
Small vessels in three-dimensional MR angiograms have low visibility in maximum-intensity projection images because of their low contrast. In a previous study, we had two nonlinear filters that appeared to give significant improvement in small vessel detail. In this paper, we report on a generalization of this filter that allows a more general modeling of the vessels and a more complete suppression of background. One implementation of the general filter gave a vessel mean contrast-to-noise ratio that is 2.52 and 3.51 times higher than the vessel mean contrast-to-noise ratio obtained using our previously reported maximum-minimum (max-min) filter and cross-section filter, respectively.
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Vasos Sanguíneos/anatomía & histología , Aumento de la Imagen/métodos , Angiografía por Resonancia Magnética/métodos , Círculo Arterial Cerebral/anatomía & histología , Humanos , Angiografía por Resonancia Magnética/instrumentación , Modelos Cardiovasculares , Valores de Referencia , Sensibilidad y EspecificidadRESUMEN
Elliptical z-gradient coils with different ellipticities are optimized using a simulated annealing algorithm. This study demonstrates that when the coil ellipticity was changed from 1.0 to 1.67, the gradient strength was increased by 21% and the coil inductance was reduced by about 34%. At the same time, the gradient inhomogeneity was increased by a factor between 15 to 47%. In these examples we also observed that when the coil ellipticity was increased from 1.0 to 1.11, the gradient inhomogeneity was reduced by a factor between 16 to 19%. This study provides a quantitative assessment of the advantages and disadvantages in coil performance obtained by using elliptical z-gradient coils.
Asunto(s)
Algoritmos , Imagen por Resonancia Magnética/instrumentación , Diseño de Equipo/métodos , Estudios de Evaluación como AsuntoRESUMEN
In this paper, the theoretical dependence of the signal of flowing fluids is considered in terms of the imaging parameters and the physical condition of the flowing fluid. For the vessel sizes, flow ranges, and imaging conditions studied, it is demonstrated that the fluid signal can be predicted from the solution of Bloch equations. For vessels on the order of the imaging resolution or smaller, the effects of the image resolution must be included
Asunto(s)
Vasos Sanguíneos/anatomía & histología , Aumento de la Imagen , Angiografía por Resonancia Magnética , Algoritmos , Circulación Sanguínea , Velocidad del Flujo Sanguíneo , Volumen Sanguíneo , Medios de Contraste , Predicción , Hemorreología , Humanos , Procesamiento de Imagen Asistido por Computador , Modelos Cardiovasculares , Fantasmas de ImagenRESUMEN
RATIONALE AND OBJECTIVES: The authors compare the effectiveness of various magnetic resonance (MR) angiography acquisition strategies in enhancing the visibility of small intracranial vessels. METHODS: Blood vessel contrast-to-noise ratio (CNR) in time-of-flight MR angiography was studied as a function of vessel size and several selectable imaging parameters. Contrast-to-noise measurements were made on 257 vessel segments ranging in size from 0.3 mm to 4.2 mm in patients who recently had undergone intraarterial cerebral angiography. Imaging parameters studied included magnetization transfer, spatially variable radio frequency (RF) pulse profile (ramped RF), and imaging slab thickness. RESULTS: The combination of thin slabs (16 slices/slab), ramped RF, and magnetization transfer resulted in the highest CNR for all but the smallest vessel sizes. The smallest vessels (< 0.5 mm) had the highest CNR, using the thick slab (64 slices/slab) with ramped RF and magnetization transfer. Magnetization transfer always improved vessel CNR, but the improvement diminished as the slab thickness was reduced. The CNR increased with a decrease in slab thickness for all but the smallest vessel sizes. CONCLUSIONS: Overall, the results provide a quantitative demonstration that inflow enhancement of blood is reduced for small vessels. Thus, whereas magnetization transfer is important at all vessel sizes, it becomes the primary factor in improving the visibility of the smallest vessels.
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Angiografía Cerebral/métodos , Aumento de la Imagen/métodos , Angiografía por Resonancia Magnética/métodos , Ondas de Radio , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana EdadRESUMEN
CNR studies were performed for human intracranial vessels in 3D MRA data sets. The CNR dependency of different imaging parameters, such as flip angle, field of view, echo time, repetition time, and echo readout symmetry, was studied for vessels in the region of the circle of Willis. A theoretical model was developed for MR vascular imaging based on the Bloch equations and Fourier imaging theory. This model predicts the MR image intensity of vessels from basic subject parameters, such as the relaxation times of blood and stationary tissue, vessel dimension, and flow velocity, and the parameters of the imaging technique, such as flip angle, voxel volume, repetition time, and echo time. For most experiments, the model was found to fit the experimental results well. The validity of this model allows the optimization of imaging parameters to maximize vessel CNR in MR angiography.