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Objective: To investigate the efficacy and safety of acute stent implantation during endovascular treatment for patients with emergent large vessel occlusion due to intracranial atherosclerotic stenosis. Methods: A retrospective analysis was carried out on 46 patients with emergent large vessel occlusion due to intracranial atherosclerotic stenosis who received endovascular treatment at the Strategic Support Force Medical Center from January 2015 to August 2022. Twenty-seven patients underwent balloon angioplasty alone and 19 patients underwent acute stent implantation. The baseline characteristics, modified thrombolysis in cerebral infarction (mTICI) score of the responsible vessels, modified Rankin scale (mRS) score 90 days after operation, incidence of symptomatic intracranial hemorrhage and mortality of the two groups were evaluated. Results: The proportion of effective recanalization of the offending vessels (mTICI≥2b) in the acute stenting group was slightly higher than that in the balloon angioplasty group (16/19 vs. 81.5%), but the difference was not statistically significant (P>0.05). Besides, there was no significant difference in the median of mRS between the acute stenting group [3.0(0, 4.0)] and the balloon angioplasty group [4.0(1.0, 5.0)] 90 days after operation (P>0.05). In terms of safety, the incidence of symptomatic intracranial hemorrhage and mortality were comparable between the two groups (P>0.05). Conclusions: The effect of acute stent implantation during endovascular treatment for patients with emergent large vessel occlusion due to intracranial atherosclerotic stenosis is not inferior to that of balloon angioplasty, and it does not increase the risk of intracranial bleeding complications.
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Arteriosclerosis Intracraneal , Hemorragias Intracraneales , Humanos , Constricción Patológica , Estudios Retrospectivos , Hemorragias Intracraneales/etiología , Infarto Cerebral , Arteriosclerosis Intracraneal/complicacionesRESUMEN
AIM: To explore the value of radiomics for predicting the expression of programmed death ligand 1 (PD-L1) in non-small-cell lung cancer (NSCLC) based on multiparameter spectral computed tomography (CT) images. MATERIALS AND METHODS: A total of 220 patients with NSCLC were enrolled retrospectively and divided into the training (n=176) and testing (n=44) cohorts. The radiomics features were extracted from the conventional CT images, mono-energy 40 keV images, iodine density (ID) maps, Z-effective maps, and electron density maps. The logistic regression (LR) and support vector machine (SVM) algorithms were employed to build models based on radiomics signatures. The prediction abilities were qualified by the area under the curve (AUC) obtained from the receiver operating characteristic (ROC) curve. Internal validation was performed on the independent testing dataset. RESULTS: The combined model for PD-L1 ≥1%, which consisted of the radiomics score (rad-score; p<0.0001), white blood cell (WBC; p=0.027) counts, and air bronchogram (p=0.003), reached the highest performance with the AUCs of 0.873 and 0.917 in the training and testing dataset, respectively, which was better than the radiomics model with the AUCs of 0.842 and 0.886. The combined model for PD-L1 ≥50%, which consisted of rad-score (p<0.0001) and WBC counts (p=0.027), achieved the highest performance in the training and testing dataset with AUCs of 0.932 and 0.903, respectively, which was better than the radiomics model with AUCs of 0.920 and 0.892, respectively. CONCLUSION: The radiomics model based on the multiparameter images of spectral CT can predict the expression level of PD-L1 in NSCLC. The combined model can obtain higher prediction efficiency and serves as a promising method for immunotherapy selection.
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Carcinoma de Pulmón de Células no Pequeñas , Neoplasias Pulmonares , Humanos , Antígeno B7-H1 , Carcinoma de Pulmón de Células no Pequeñas/diagnóstico por imagen , Radiómica , Estudios Retrospectivos , Neoplasias Pulmonares/diagnóstico por imagen , Tomografía Computarizada por Rayos XRESUMEN
Objective: To explore the risk factors of malnutrition in infants with congenital heart disease within one year after surgery. Methods: This retrospective cohort study selected 502 infants with congenital heart disease who underwent surgical treatment in Guangzhou Women and Children's Medical Center from February 2018 to January 2019. Their basic information and clinical data were analyzed, and their nutrition status after the surgery was followed up by questionnaire survey. Weight-for-age Z score (WAZ)≤-2 one year after operation was defined as malnutrition group, and WAZ>-2 was non-malnutrition group. The perioperative indicators and complementary food advancement were compared between the two groups by chi-square test, t-test, and Kruskal-Wallis test. The risk factors of malnutrition were analyzed by Logistic regression. Results: A total of 502 infants were selected, including 301 males and 201 females, with the age of 4.1 (2.0, 6.8) months. There were 90 cases in malnutrition group and 412 cases in non-malnutrition group. The body length and weight at birth in the malnutrition group were lower than those in the non-malnutrition group ((47.8±3.8) vs. (49.3±2.5) cm, (2.7±0.6) vs.(3.0±0.5) kg, both P<0.001). The proportion of paternal high school education or above and the proportion of family per capita income of 5 000 yuan or above in the malnutrition group were lower than those in the non-malnutrition group ((18.9% (17/90) vs. 30.8% (127/412), 18.9% (17/90) vs. 33.7% (139/412), both P<0.05). Compared to the non-malnutrition group, the proportion of complex congenital heart disease in the malnutrition group was higher (62.2% (56/90) vs. 47.3% (195/412), P<0.05). The postoperative mechanical ventilation time, postoperative intensive care unit (ICU) stay time, postoperative hospital stay, total length of ICU stay and total hospital stay in the malnutrition group were significantly longer than those in non-malnutrition group (all P<0.05). The proportion of egg and fish supplementation over 2 times/week within one year after the surgery was also lower in the malnutrition group (both P<0.05). Logistic regression analysis showed that mother's weight at delivery (OR=0.95,95%CI 0.91-0.99), the pre-operative WAZ≤-2 (OR=6.04, 95%CI 3.13-11.65), the complexity of the cardiac disease (OR=2.23, 95%CI 1.22-4.06), the hospital stay after the surgery over 14 days (OR=2.61, 95%CI 1.30-5.26), the types of complementary food<4 (OR=2.57, 95%CI 1.39-4.76), and the frequency of meat and fish<2 times/week (OR=2.11, 95%CI 1.13-3.93) were the risk factors associated with malnutrition within one year after the surgery. Conclusion: Mother's weight at delivery pre-operative nutritional status, complexity of cardiac disease, postoperative hospital stay, types of daily supplements and frequency of fish are risk factors associated with malnutrition within one year after surgery in children with congenital heart disease.
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Procedimientos Quirúrgicos Cardíacos , Cardiopatías Congénitas , Trastornos de la Nutrición del Lactante , Desnutrición , Masculino , Humanos , Femenino , Estudios Retrospectivos , Desnutrición/complicaciones , Cardiopatías Congénitas/cirugía , Factores de Riesgo , Tiempo de Internación , Trastornos de la Nutrición del Lactante/complicacionesRESUMEN
Objective: To analyze the follow-up and clinical effect of multidisciplinary treatment on the children with spinal muscular atrophy (SMA). Methods: The clinical data including nutritional status, respiratory function, bone health and motor function of 45 children with SMA who received multidisciplinary management 1-year follow-up in the Children's Hospital, Zhejiang University School of Medicine from July 2019 to October 2021 were retrospectively collected. Comparisons before and after management were performed using paired-samples t-test or Wilcoxon rank-sum test, etc. Results: The age of 45 patients (25 boys and 20 girls) was 50.4 (33.6, 84.0) months at the enrollment, with 6 cases of type 1, 22 cases of type 2, and 17 cases of type 3 respectively. After the multidisciplinary management, the cases of SMA patients with malnutrition decreased from 22 to 12 (P=0.030), the level of vitamin D were significantly increased ((45±17) vs. (48±14) nmol/L, t=-4.13, P<0.001). There was no significant difference in the forced vital capacity %pred, the forced expiratory volume at 1 second %pred, and the peak expiratory flow %pred ((76±19)% and (76±21)%, (81±18)% and (79±18)%, (81±21)% and (78±17)%; t=-0.24, 1.36, 1.21; all P>0.05). The Cobbs angle of scoliosis also improved significantly (8.0°(0°, 13.0°) vs. 10.0°(0°, 18.5°), Z=-3.01, P=0.003). The Hammersmith functional motor scale expanded scores of children with SMA type 2 and type 3 both showed significant elevation (11.0 (8.0, 18.0) vs. 11.0 (5.0, 18.5) scores, 44.0 (36.5, 53.0) vs. 44.0 (34.0, 51.5) scores, Z=2.44, 3.11, P=0.015, 0.002). Conclusion: Multidisciplinary management is beneficial for delaying the progression of the multi-system impairments of SMA patients, such as malnutrition, restrictive ventilation dysfunction and scoliosis.
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Desnutrición , Atrofia Muscular Espinal , Escoliosis , Niño , Masculino , Femenino , Humanos , Preescolar , Estudios Retrospectivos , Estudios de SeguimientoRESUMEN
Objective: To set up a prediction scoring system for the hypoxemia in infants with Pierre Robin sequence after weaning and evaluate its clinical value. Methods: Data of consecutive patients from November 2016 to June 2019, who underwent mandibular distraction osteogenesis in Guangzhou Women and Children's Medical Center, were retrospectively analyzed (n=148). All the cases were divided into two groups according to the appearance of hypoxemia after weaning. They were randomly divided into the derivation cohorc (2/3,n=100) and the validation cohort (1/3,n=48). Single factor and multiple logistic regression analysis were used to select the independent risk factors related to hypoxemia and establish a prediction model. A prediction scoring system was developed in accordance with assigning of the value of each variable ß in the model. Internal verification of scoring system by validation population. Data of consecutive patients from July 2019 to November 2019, who underwent mandibular distraction osteogenesis, were prospectively analyzed (n=26). The diagnostic accuracy were conducted to evaluate the clinical value of the scoring system. Results: The logistic regression demonstrated that age at operation, pulmonary infection and the length of distraction less than 5 mm at weaning were the independent risk factors for hypoxemia. The P value of logistic regression model in Hosmer and Lemeshow goodness of fit test was 0.848, and a prediction scoring system was established accordingly. The area under the ROC curve of the scoring system was 0.890, and the optimum critical value was 53. The sensitivity, specificity, accuracy of the model were 78.6%(11/14),86.1%(74/86), 85.0%(85/100) respectively. The predictive effectiveness of the scoring system in the retrospective validation population was similar to that in the modeling population. 26 patients were included in the prospective analysis. The area under ROC curve of the scoring system was 0.870. The sensitivity, specificity and accuracy were 80.0%(5/6),95.0%(20/21), 96.1%(25/26) respectively. Conclusion: The prediction scoring system established in the study are efficacious for the hypoxemia in infants with Pierre Robin sequence after weaning.
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Osteogénesis por Distracción , Síndrome de Pierre Robin , Humanos , Hipoxia , Lactante , Estudios Prospectivos , Estudios Retrospectivos , Resultado del Tratamiento , DesteteRESUMEN
OBJECTIVE: To investigate the influences of long non-coding ribonucleic acid (lncRNA) small nucleolar RNA host gene 20 (SNHG20) on proliferation and apoptosis of glioma cells, and further explore the mechanism of SNHG20 in the incidence and development of glioma. PATIENTS AND METHODS: A total of 80 cases of glioma specimens and 80 cases of para-carcinoma specimens were collected, and the expression level of SNHG20 was detected via reverse transcription-polymerase chain reaction (RT-PCR). The human glioma U118 and U251 cell lines with the stable knockout of SNHG20 were constructed using the small-interfering RNA (siRNA). The influence of SNHG20 on proliferation of human glioma cells was detected via cell counting kit-8 (CCK-8), and the protein expression levels of apoptosis-related genes, B-cell lymphoma-2 (Bcl-2) and Bcl-2 associated X protein (Bax), were also detected. The apoptosis level of glioma cells was detected in blank control group and SNHG20 siRNA group using the terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) technique. At the same time, the expression levels of proteins related to the phosphatase and tensin homolog deleted on chromosome ten/phosphatidylinositol 3-hydroxy kinase/protein kinase B (PTEN/PI3K/AKT) signaling pathway were detected via Western blotting. RESULTS: The expression level of SNHG20 messenger RNA (mRNA) in glioma tissues was significantly higher than that in para-carcinoma tissues (p<0.05). After the inhibition of siRNA on SNHG20, the proliferation of U118 and U251 cells was significantly inhibited, and the expression of Bax was significantly up-regulated, while that of Bcl-2 was down-regulated. The TUNEL results showed that the number of apoptotic cells in SNHG20 siRNA group was about 12 times that in control group (p<0.05). After SNHG20 knockout, the protein expressions in the PTEN/PI3K/AKT signaling pathway were inhibited (p<0.05). CONCLUSIONS: Inhibiting the SNHG20 expression in glioma cells can increase the apoptosis of glioma cells, and the mechanism may be related to the SNHG20-mediated PTEN/PI3K/AKT signaling pathway.
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Neoplasias Encefálicas/genética , Carcinoma/genética , Regulación Neoplásica de la Expresión Génica , Glioma/genética , ARN Largo no Codificante/metabolismo , Apoptosis/genética , Encéfalo/patología , Encéfalo/cirugía , Neoplasias Encefálicas/patología , Neoplasias Encefálicas/cirugía , Carcinoma/patología , Carcinoma/cirugía , Línea Celular Tumoral , Femenino , Técnicas de Inactivación de Genes , Glioma/patología , Humanos , Masculino , Persona de Mediana Edad , Fosfohidrolasa PTEN/metabolismo , Fosfatidilinositol 3-Quinasa/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , ARN Largo no Codificante/genética , ARN Mensajero/metabolismo , ARN Interferente Pequeño/metabolismo , Transducción de Señal/genéticaRESUMEN
Objective: To survey the conduction and evaluate the effectiveness of extracorporeal membrane oxygenation (ECMO) therapy in pediatric intensive care unit (PICU) in China mainland. Methods: In a questionnaire-based survey, we retrospectively reviewed the application of ECMO in children's hospital and general hospital in China mainland to summarize and analyze the categories of diseases and prognosis of children treated with ECMO therapy. Results: By December 31, 2017, a total of 23 hospitals using ECMO, including 22 tertiary referral hospitals and 1 secondary hospital, among which 16 were children's hospitals and 7 were general hospitals. Thirty-seven ECMO equipment was available. A total of 518 patients treated with ECMO, within whom 323 (62.4%) successfully weaned from ECMO and 262 (50.6%) survived to discharge. Among 375 pediatric patients, 233 (62.1%) were successfully weaned from ECMO and 186 (49.6%) survived to discharge. Among 143 newborn patients, 90 (62.9%) successfully weaned from ECMO, 76 (53.1%) survived to discharge. ECMO was applied in veno-arterial (VA) mode to 501 (96.7%) patients, veno-venous (VV) mode to 14 (2.7%) patients, and VV-VA conversion mode to 3 (0.6%) patients. Sixty-nine patients required extracorporeal cardiopulmonary resuscitation (ECPR), including 20 newborn patients (29.0%) and 38 pediatric patients (71.0%), who were all with cardiovascular disease. Neonatal respiratory distress syndrome (26/61), persistent pulmonary hypertension of the newborn (PPHN) (12/61), and meconium aspiration syndrome (MAS) (11/61) are the most common pulmonary diseases in newborn patients; among whom, infants with PPHN had highest survival rate (10/12), followed by MAS (9/11). Among newborn patients with cardiovascular diseases, those who admitted were after surgery for congenital cardiac disease were the most common (54/82), while those with septic shock had the highest survival rate (2/3). In pediatric pulmonary diseases, acute respiratory distress syndrome was the most common (42/93), while plastic bronchitis was with the highest survival rate (4/4), followed by viral pneumonia (13/16). Among pediatric cardiovascular diseases, congenital cardiac defect was the most common (124/282), while fulminant myocarditis had the highest survival rate (54/77). Conclusion: The application of ECMO as a rescue therapy for children with severe cardiopulmonary failure has dramatically developed in China mainland.
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Oxigenación por Membrana Extracorpórea , Enfermedades del Recién Nacido , Enfermedades Cardiovasculares/terapia , Niño , China , Humanos , Lactante , Recién Nacido , Enfermedades del Recién Nacido/terapia , Unidades de Cuidado Intensivo Pediátrico , Síndrome de Aspiración de Meconio/terapia , Estudios Retrospectivos , Resultado del TratamientoRESUMEN
Objective: To evalute the clinical outcomes of intracytoplasmic sperm injection(ICSI) for infertility male with severe asthenospermia induced by multiple morphological anomalies of the flagella (MMAF). Methods: The clinical data of 15 patient with MMAF were retrospectively analyzed, who underwent ICSI treatment using hyponotic swelling test the "live" sperm in the Department of Reproductive Medicine of Yantai Yuhuangding Hospital from January 2011 to December 2016. Another 30 obstructive azoospermia (OA)patients are matched strictly who also accepted ICSI in the same treatment time. The two groups were compared in the couples'age, the body mass index(BMI), the duration of infertility, the retrieved oocytes, the number of ICSI oocytes, and the rates of fertilization, cleavage, transferrable embryos, good embryos, embryos implanted, clinical pregncncy, early abortion, singleton and twins. Results: After 27 cycles of ICSI, all of the MMAF patients achieved clinical pregnancy, including 11 cases of live birth, 2 cases of spontaneous abortion, and 2 cases of pregnancy maintenance. There were no significant difference between MMAF and OA groups in the couples'age and BMI, or the numbers of retrieved oocytes and ICSI oocytes(P>0.05), but the differences in the infertility duration had statistical meaning(P<0.001). No statistical differences were observed among groups in ICSI fertility rate(92.0% vs 91.6%), clesvage rate(95.4% vs 96.5%), high-quality embryonic rate(56.5% vs 57.5%), good blastocyst rate(23/61 vs 35/94), embryo implantation rate(20/48 vs 35/75), early abortion rate(4/19 vs 8/36), clinical pregncncy rate(15/27 vs 28/50), singleton rate (10/13 vs 20/25)and twinning rate(3/13 vs 5/25)(P>0.05). Conclusions: MMAF may not affect ICSI treatment outcomes, but genetic defects can be transmitted through ICSI. The affected couples should be informed of the necessity of prenatal genetic diagnosis before embryo implantation and the inevitable vertical transmission of genetic problems to the offspring.
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Índice de Embarazo , Inyecciones de Esperma Intracitoplasmáticas , Transferencia de Embrión , Femenino , Flagelos , Humanos , Infertilidad Masculina , Masculino , Embarazo , Estudios RetrospectivosRESUMEN
The absorption of ultraintense, femtosecond laser pulses by a solid unleashes relativistic electrons, thereby creating a regime of relativistic optics. This has enabled exciting applications of relativistic particle beams and coherent X-ray radiation, and fundamental leaps in high energy density science and laboratory astrophysics. Obviously, central to these possibilities lies the basic problem of understanding and if possible, manipulating laser absorption. Surprisingly, the absorption of intense light largely remains an open question, despite the extensive variations in target and laser pulse structures. Moreover, there are only few experimental measurements of laser absorption carried out under very limited parameter ranges. Here we present an extensive investigation of absorption of intense 30 femtosecond laser pulses by solid metal targets. The study, performed under varying laser intensity and contrast ratio over four orders of magnitude, reveals a significant and non-intuitive dependence on these parameters. For contrast ratio of 10(-9) and intensity of 2 × 10(19)W cm(-2), three observations are revealed: preferential acceleration of electrons along the laser axis, a ponderomotive scaling of electron temperature, and red shifting of emitted second-harmonic. These point towards the role of J × B absorption mechanism at relativistic intensity. The experimental results are supported by particle-in-cell simulations.
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The influence of L-lys and L-his on the solubility, surface hydrophobicity, sulphydryl content and conformational characteristics of porcine myosin solubilised in high (0.6 M), physiological (0.15 M) and low (1 mM) ionic strength solutions were explored. The solubility of myosin was increased in the presence of L-his and/or L-lys in all ionic strength solutions used. The presence of L-his and L-lys caused increases in the surface hydrophobicity and reactive sulphydryl content (p<0.05). Circular dichroism revealed a significant decrease of α-helical content with an increase of random coils, ß-turns and ß-sheets in the presence of L-his and/or L-lys. These results demonstrate that the introduction of L-lys and L-his causes the unfolding of myosin, resulting in loss of α-helical structure, which is followed by increases in random coils, ß-turns and ß-sheets, which exposes buried hydrophobic and sulphydryl groups to the myosin surface, ultimately increasing the solubility of porcine myosin.
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Lisina/química , Miosinas/química , Animales , Estructura Secundaria de Proteína , Solubilidad , PorcinosRESUMEN
We used flow cytometry and a DNA-binding dye efflux assay to isolate a side population (SP) of cells with stem cell characteristics from the human pancreatic carcinoma cell line, PANC-1. Non-obese diabetic/severe combined immunodeficiency mouse xenograft experiments showed that SP cells were enriched in tumor initiating capability compared with non-SP cells. Cultured SP cells were able to differentiate into daughter cells and non-SP cells, through asymmetric division. Our study demonstrated that SP cells had high drug-resistance, both in vivo and in vitro. SP cells also showed significantly higher levels of mRNA expression for CD133, ABCG2 and Notch1, when compared to non-SP cells. Furthermore, xenografted tumors derived from injected SP cells and treated with gemcitabine had more CD133+ cells than untreated ones. We therefore suggest that these SP cells from the PANC-1 cell line were enriched with cancer stem cells.
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Células Madre Neoplásicas/patología , Neoplasias Pancreáticas/patología , Antígeno AC133 , Transportador de Casetes de Unión a ATP, Subfamilia G, Miembro 2 , Transportadoras de Casetes de Unión a ATP/análisis , Animales , Antígenos CD/análisis , Línea Celular Tumoral , Glicoproteínas/análisis , Humanos , Ratones , Ratones Endogámicos NOD , Ratones SCID , Proteínas de Neoplasias/análisis , Neoplasias Pancreáticas/química , Péptidos/análisis , Receptor Notch1/análisisRESUMEN
Various studies on ancient DNA have attempted to reconstruct population movement in Asia, with much interest focused on determining the arrival of European lineages in ancient East Asia. Here, we discuss our analysis of the mitochondrial DNA of human remains excavated from the Yu Hong tomb in Taiyuan, China, dated 1400 years ago. The burial style of this tomb is characteristic of Central Asia at that time. Our analysis shows that Yu Hong belonged to the haplogroup U5, one of the oldest western Eurasian-specific haplogroups, while his wife can be classified as haplogroup G, the type prevalent in East Asia. Our findings show that this man with European lineage arrived in Taiyuan approximately 1400 years ago, and most probably married a local woman. Haplogroup U5 was the first west Eurasian-specific lineage to be found in the central part of ancient China, and Taiyuan may be the easternmost location of the discovered remains of European lineage in ancient China.
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ADN Mitocondrial/genética , Emigración e Inmigración/historia , Fémur/química , Fósiles , Diente/química , Secuencia de Bases , China , Cartilla de ADN , Femenino , Fémur/anatomía & histología , Haplotipos/genética , Historia Medieval , Humanos , Masculino , Datos de Secuencia Molecular , Análisis de Secuencia de ADN , Diente/anatomía & histología , Población Blanca/genéticaRESUMEN
The effects of dissolved oxygen tension and mechanical forces on fungal morphology were both studied in the submerged fermentation of Aspergillus awamori. Pellet size, the hairy length of pellets, and the free filamentous mycelial fraction in the total biomass were found to be a function of the mechanical force intensity and to be independent of the dissolved oxygen tension provided that the dissolved oxygen tension was neither too low (5%) nor too high (330%). When the dissolved oxygen concentration was close to the saturation concentration corresponding to pure oxygen gas, A. awamori formed denser pellets and the free filamentous mycelial fraction was almost zero for a power input of about 1 W/kg. In the case of very low dissolved oxygen tension, the pellets were rather weak and fluffy so that they showed a very different appearance. The amount of biomass per pellet surface area appeared to be affected only by the dissolved oxygen tension and was proportional to the average dissolved oxygen tension to the power of 0.33. From this it was concluded that molecular diffusion was the dominant mechanism for oxygen transfer in the pellets and that convection and turbulent flow in the pellets were negligible in submerged fermentations. The biomass per wet pellet volume increased with the dissolved oxygen tension and decreased with the size of the pellets. This means that the smaller pellets formed under a higher dissolved oxygen tension had a higher intrinsic strength. Correspondingly, the porosity of the pellets was a function of the dissolved oxygen tension and the size of pellets. Within the studied range, the void fraction in the pellets was high and always much more than 50%.
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Aspergillus/citología , Aspergillus/metabolismo , Reactores Biológicos , Oxígeno/metabolismo , Fenómenos Biomecánicos , Metabolismo Energético , Fermentación , Modelos Biológicos , Reología , Propiedades de Superficie , Resistencia a la TracciónRESUMEN
Generalizing results from fungal fermentations is difficult due to their high sensitivity toward slight variation in starting conditions, poor reproducibility, and difference in strains. In this study a mathematical model is presented in which oxygen transfer, agitation intensity, dissolved oxygen tension, pellet size, formation of mycelia, the fraction of mycelia in the total biomass, carbohydrate source consumption, and biomass growth are taken into account. Two parameters were estimated from simulation, whereas all others are based on measurements or were taken from literature. Experimental data are obtained from the fermentations in both 2 L and 100 L fermentors at various conditions. Comparison of the simulation with experiments shows that the model can fairly well describe the time course of fungal growth (such as biomass and carbohydrate source concentrations) and fungal morphology (such as pellet size and the fraction of pellets in the total biomass). The model predicts that a stronger agitation intensity leads to a smaller pellet size and a lower fraction of pellets in the total biomass. At the same agitation intensity, pellet size is hardly affected by the dissolved oxygen tension, whereas the fraction of mycelia decreases slightly with an increase of the dissolved oxygen tension in the bulk. All of these are in line with observations at the corresponding conditions.
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Hongos/crecimiento & desarrollo , Aspergillus/citología , Aspergillus/crecimiento & desarrollo , Aspergillus/metabolismo , Biomasa , Medios de Cultivo , Fermentación , Hongos/citología , Cinética , Matemática , Modelos Biológicos , Consumo de OxígenoRESUMEN
Both parallel fermentations with Aspergillus awamori (CBS 115.52) and a literature study on several fungi have been carried out to determine a relation between fungal morphology and agitation intensity. The studied parameters include hyphal length, pellet size, surface structure or so-called hairy length of pellets, and dry mass per-wet-pellet volume at different specific energy dissipation rates. The literature data from different strains, different fermenters, and different cultivation conditions can be summarized to say that the main mean hyphal length is proportional to the specific energy dissipation rate according to a power function with an exponent of -0.25 +/- 0.08. Fermentations with identical inocula showed that pellet size was also a function of the specific energy dissipation rate and proportional to the specific energy dissipation rate to an exponent of -0.16 +/- 0.03. Based on the experimental observations, we propose the following mechanism of pellet damage during submerged cultivation in stirred fermenters. Interaction between mechanical forces and pellets results in the hyphal chip-off from the pellet outer zone instead of the breakup of pellets. By this mechanism, the extension of the hyphae or hair from pellets is restricted so that the size of pellets is related to the specific energy dissipation rate. Hyphae chipped off from pellets contribute free filamentous mycelia and reseed their growth. So the fraction of filamentous mycelial mass in the total biomass is related to the specific energy dissipation rate as well.To describe the surface morphology of pellets, the hyphal length in the outer zone of pellets or the so-called hairy length was measured in this study. A theoretical relation of the hairy length with the specific energy dissipation rate was derived. This relation matched the measured data well. It was found that the porosity of pellets showed an inverse relationship with the specific energy dissipation rate and that the dry biomass per-wet-pellet volume increased with the specific energy dissipation rates. This means that the tensile strength of pellets increased with the increase of specific energy dissipation rate. The assumption of a constant tensile strength, which is often used in literature, is then not valid for the derivation of the relation between pellet size and specific energy dissipation rate. The fraction of free filamentous mycelia in the total biomass appeared to be a function of the specific energy dissipation in stirred bioreactors. (c) 1997 John Wiley & Sons, Inc. Biotechnol Bioeng 55: 715-726, 1997.
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OBJECTIVE: To detect congenital cytomegalovirus (CMV) infection of chorionic villi in early pregnancy. METHODS: Extraction of DNA of chorionic villi and amplification of the gene of major immediate-early (MIE) antigen of CMV using a polymerase chain reaction (PCR). RESULTS: Sixty-eight specimens of chorionic villi and 16 specimens were positive for CMV infection by PCR. The incidence of congenital CMV infection in the first trimester of pregnancy was 23.5%. CONCLUSIONS: The risk of transmission of CMV from mother to fetus in early pregnancy is very high and potential CMV carriers may transmit CMV to their fetus in early pregnancy.
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Vellosidades Coriónicas/microbiología , Infecciones por Citomegalovirus/congénito , Infecciones por Citomegalovirus/diagnóstico , Citomegalovirus/aislamiento & purificación , Complicaciones Infecciosas del Embarazo/diagnóstico , Muestra de la Vellosidad Coriónica , Infecciones por Citomegalovirus/epidemiología , Femenino , Humanos , Incidencia , Recién Nacido , Reacción en Cadena de la Polimerasa , Embarazo , Complicaciones Infecciosas del Embarazo/epidemiología , Primer Trimestre del Embarazo , Factores de RiesgoRESUMEN
The sinoatrial nodes (SAN) were observed, dissected, and measured on 95 adults and 30 child hearts under a dissection microscope. The majority of the SANs in adults are characterized by their pale color, firm consistency, and the location in relation to the penetration of the SAN artery, and they can be located in the superior part of the terminal sulcus. The SANs in children, however, are not easily discerned. The variation of the apex of the right auricular crest and the notch in the superior part of the terminal sulcus have been described, and the present authors suggested that the trigone of the SAN could be used as an important landmark to identify the SAN. The surface features on the SAN, its relationship to the surrounding myocardium and its surgical significance during operation are further discussed.
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Nodo Sinoatrial/anatomía & histología , Adulto , Factores de Edad , Arterias , Niño , Color , Tejido Conectivo/anatomía & histología , Atrios Cardíacos/anatomía & histología , Humanos , Miocardio , Venas Pulmonares/anatomía & histología , Ramos Subendocárdicos/anatomía & histología , Nodo Sinoatrial/cirugía , Vena Cava Superior/anatomía & histologíaRESUMEN
PIP: Chromosome breakage can lead to teratology and neoplasia, although mutagenicity is not identical with carcinogenicity. The human chorionic villus micronucleus (CVMN) test was first developed in 1987 to study the mutagenicity of smoking, drinking, and contraceptives on offspring. 507 couples were studied, and human chorionic villi were taken from abortion material of women aged 18-43 with gestation of 10 weeks. None of these women drank; however, among their husbands there were 172 smokers (2-40 cigarettes/day for 2-20 years), 15 who drank (.5-3 liters of liquor/month for 2-20 years), 107 smoked and drank (1-40 cigarettes/day for 2-10 years and .5-3 liters of liquor/month for 2-15 years), and 115 nondrinking and nonsmoking controls. Micronuclei (MN) were scored according to Countryman's standard, and 2000 interphase was observed in each subject of CVMN frequency. 1,014,000 interphase cells were scored. There was no correlation between CVMN frequency and maternal age. The difference of the correlation coefficient between CVMN frequency and pregnancy was not statistically significant. 105 women had aborted before, 9 had had spontaneous abortion, and 113 had neither. There were no statistical differences between these women and no correlation with CVMN frequency. The gestation ranged from 32 days to 79 days; again, no correlation was found. The mean frequency of CVMN was significantly higher in those with smoking husbands than in nonsmokers and nondrinkers. The CVMN frequency of women with drinking husbands was also high but without statistical significance. The group with husbands who both smoked and drank had the highest CVMN frequency, but this did not differ significantly from controls. The mutagens and carcinogens of cigarettes linger in the smoke. In addition to effect on the function and MN frequency in the sperm of smokers, the ova and embryo of passive smokers may be affected as damage in the DNA and spindle apparatus of chorionic villi increases the frequency of MN.^ieng
Asunto(s)
Vellosidades Coriónicas/ultraestructura , Pruebas de Micronúcleos , Aborto Espontáneo , Adolescente , Adulto , Factores de Edad , Consumo de Bebidas Alcohólicas , Vellosidades Coriónicas/efectos de los fármacos , Anticoncepción , Femenino , Edad Gestacional , Humanos , Masculino , Paridad , Embarazo , Fumar , Contaminación por Humo de TabacoRESUMEN
Rapid determination of DNA damage by micronucleus test is well accepted. Animal bone marrow cells or human peripheral lymphocytes used in most studies could not directly reflect the influence of the mutagenic effect on the offsprings by environmental factors. Human chorionic villi micronucleus test to detect directly the mutagenic effect of environmental factors has not been reported in the literature. Direct determination of human chorionic villi micronuclei (CVMN) was established in our laboratory, to study the mutagenic effect of mother's age, gravidity, gestation age, abortion history, contraception (condom, diaphragm, rhythm, oral contraceptives, spermicide or IUD), smoking and drinking on the offsprings. Cross investigation and micronucleus test were used in 507 couples undergoing artificial abortion. Micronuclei were scored according to Countryman's standard 2,000 interphases were observed in each subject for CVMN frequency (%). Arcsine transformation (arcsine [Sqr (P)]) was used in transforming CVMN frequency and the analysis of variance were used for statistics. No correlation between CVMN frequency and mother's age, gravidity, gestation age, abortion history, and contraception was found. Neither smoking nor drinking habit was found among the women of this study. The CVMN frequency of husband smoking was 0.7645 +/- 0.0561%, of husband non-smoking-drinking was 0.5522 +/- 0.0616%, of husband drinking was 0.5667 +/- 0.2004%, of husband smoking and drinking was 0.7944 +/- 0.0754%. There was a statistical difference in CVMN frequency between husband smoking and non-smoking (F = 2.78 DF = 408 P less than 0.05). No significant difference was found between husband drinking and non-drinking.