Prevalence, characteristics, evaluation, and management of carotid body tumors: Systematic analysis based on available evidence.

OBJECTIVE: Although carotid body tumors (CBTs) are rare, they attract particular attention because of their propensity for malignant transformation and the high surgical risk. Because data are scarce and as it is difficult to achieve a large sample size, no study has yet comprehensively analyzed the characteristics, management, or operative complications of CBTs. Therefore, we collected and analyzed all currently available information on CBTs and used the pooled data to derive quantitative information on disease characteristics and management. METHODS: We systematically searched PubMed, Embase, the Cochrane Library, and the Web of Science up to December 1, 2022, for studies that investigated the characteristics and management of CBTs. The primary objective was to identify the prevalence of the various characteristics and the incidence of complications. The secondary objective was to compare patients who underwent preoperative embolization (PE) and those who did not (non-PE), as well as to compare patients with different Shamblin grades and those with and without succinate dehydrogenase (SDH) mutations in terms of CBT characteristics and complications. Two reviewers selected studies for inclusion and independently extracted data. All statistical analyses were performed using the standard statistical procedures of Review Manager 5.2 and Stata 12.0. RESULTS: A total of 155 studies with 9291 patients and 9862 tumors were identified. The pooled results indicated that the median age of patients with CBT was 45.72 years, and 65% were female. The proportion of patients with bilateral lesions was 13%. In addition, 16% of patients had relevant family histories, and the proportion of those with SDH gene mutations was 36%. Sixteen percent of patients experienced multiple paragangliomas, and 12% of CBTs had catecholamine function. The incidence of cranial nerve injury (CNI) was 27%, and 14% of patients suffered from permanent CNI. The incidence rates of operative mortality and stroke were both 1%, and 4% of patients developed transient ischemic attacks. Of all CBTs, 6% were malignant or associated with metastases or recurrences. The most common metastatic locations were the lymph nodes (3%) and bone (3%), followed by the lungs (2%). Compared with non-PE, PE reduced the estimated blood loss (standardized mean difference, -0.95; 95% confidence interval [CI], -1.70 to -0.20) and the operation time (standardized mean difference, -0.56; 95% CI, -1.03 to -0.09), but it increased the incidence of stroke (odds ratio, 2.44; 95% CI, 1.04-5.73). Higher Shamblin grade tumors were associated with more operative complications. Patients who were SDH gene mutation-positive were more likely to have a relevant family history and had more symptoms. CONCLUSIONS: CBT was most common in middle-aged females, and early surgical resection was feasible; there was a low incidence of serious operative complications. Routine PE is not recommended because this may increase the incidence of stroke, although PE somewhat reduced the estimated blood loss and operation time. Higher Shamblin grade tumors increased the incidence of operative complications. Patients who were SDH gene mutation-positive had the most relevant family histories and symptoms.

The characteristics of carotid body tumors in high-altitude region: Analysis from a single center.

OBJECTIVES: Though carotid body tumors are rare, increasing attentions have been given because of malignant transformation and high surgical risk. However, at present, the characteristics and etiology still remain unclear. Our study was designed to describe the clinical features of carotid body tumors in our institution and to compare the results with previous reports. METHODS: We retrospectively reviewed carotid body tumor patients diagnosed in our institution from January 2015 to May 2020. The demographics, comorbidities, lesion location, anatomic characteristics, complications, and postoperative outcomes were evaluated. Carotid body tumor measurements were determined from computed tomography, magnetic resonance imaging, and carotid arteriography examination. We described and compared the clinical features of carotid body tumors in our institution and other reports. RESULTS: We totally identified 122 carotid body tumor cases for the present analysis. The mean age was 50.26 years, with the majority being female (82%). The commonest presentation was a painless neck mass (68%). For the distribution of nationality, most patients were the Han nationality (69.7%). The mean altitude of habitat of patients was 2689.4 km; 19.7% patients suffered bilateral lesions. The main blood supply of carotid body tumors was from external carotid artery (54.1%). For patients who received operation, 11 (11.2%) patients experienced cranial nerve injury. The maximal diameter of tumors was 3.99 ± 1.98 cm in male and 3.38 ± 1.36 cm in female. The volume of tumors was 31.49 ± 29.76 cm3 in male and 15.27 ± 13.06 cm3 in female. The distance to base of skull of tumors was 3.39 ± 1.07 cm (3.99 ± 1.98 cm in male vs 3.38 ± 1.36 cm, P < 0.05). Two patients (2.04%) were identified as having malignant carotid body tumor. CONCLUSIONS: Though carotid body tumor had a low morbidity and multitudinous clinicopathologic features, it was apt to middle-aged women and the main blood supply was from external carotid artery. The painless neck mass was the commonest presentation of carotid body tumors. There were significant difference between male and female patients regarding platelet, hemoglobin, distance to base of skull, tumor volume, altitude of habitat, carotid body tumor location, and hypertension.

The noninferiority of transcatheter aortic valve implantation compared to surgical aortic valve replacement for severe aortic disease: Evidence based on 16 randomized controlled trials.

BACKGROUND: Currently, transcatheter aortic valve implantation (TAVI) as an effective and convenient intervention has been adopted extensively for patients with severe aortic disease. However, the efficacy and safety of TAVI have not yet been well evaluated and its noninferiority compared with traditional surgical aortic valve replacement (sAVR) still lack sufficient evidence. This meta-analysis was designed to comprehensively compare the noninferiority of TAVI with sAVR for patients with severe aortic disease. METHODS: A systematic search of PubMed, Embase, Cochrane Library, and Web of Science up to October 1, 2020 was conducted for relevant studies that comparing TAVI and sAVR in the treatment of severe aortic disease. The primary outcomes were early, midterm and long term mortality. The secondary outcomes included early complications and other late outcomes. Two reviewers assessed trial quality and extracted the data independently. All statistical analyzes were performed using the standard statistical procedures provided in Review Manager 5.2. RESULTS: A total of 16 studies including 14394 patients were identified. There was no difference in 30-day, 1-year, 2-year, and 5-year all-cause or cardiovascular mortality as well as stroke between TAVI and sAVR. Regarding to the 30-day outcomes, compared with sAVR, TAVI experienced a significantly lower incidence of myocardial infarction (risk ratio [RR] 0.62; 95% confidence interval [CI] 0.40-0.97; 5441 pts), cardiogenic shock (RR 0.34; 95% CI 0.19-0.59; 1936 pts), acute kidney injury (AKI) > stage 2 (RR 0.37; 95% CI 0.25-0.54; 5371 pts), and new-onset atrial fibrillation (NOAF) (RR 0.29; 95% CI 0.24-0.35; 5371 pts) respectively, but higher incidence of permanent pacemaker implantation (RR 3.16; 95% CI 1.61-6.21; 5441 pts) and major vascular complications (RR 2.22; 95% CI 1.14-4.32; 5371 pts). Regarding to the 1- and 2-year outcomes, compared with sAVR, TAVI experienced a significantly lower incidence of NOAF, but higher incidence of neurological events, transient ischemic attacks (TIA), permanent pacemaker and major vascular complications respectively. Regarding to the 5-year outcomes, compared with sAVR, TAVI experienced a significantly lower incidence of NOAF, but higher incidence of TIA and reintervention respectively. CONCLUSIONS: Our analysis shows that TAVI was equal to sAVR in early, midterm and long term mortality for patients with severe aortic disease. In addition, TAVI may be favorable in reducing the incidence of both early, midterm and long term NOAF. However, pooled results showed superiority of sAVR in reducing permanent pacemaker implantation, neurological events, TIA, major vascular complications and reintervention.

Strain Localization of Orthotropic Elasto-Plastic Cohesive-Frictional Materials: Analytical Results and Numerical Verification.

Strain localization analysis for orthotropic-associated plasticity in cohesive-frictional materials is addressed in this work. Specifically, the localization condition is derived from Maxwell's kinematics, the plastic flow rule and the boundedness of stress rates. The analysis is applicable to strong and regularized discontinuity settings. Expanding on previous works, the quadratic orthotropic Hoffman and Tsai-Wu models are investigated and compared to pressure insensitive and sensitive models such as von Mises, Hill and Drucker-Prager. Analytical localization angles are obtained in uniaxial tension and compression under plane stress and plane strain conditions. These are only dependent on the plastic potential adopted; ensuing, a geometrical interpretation in the stress space is offered. The analytical results are then validated by independent numerical simulations. The B-bar finite element is used to deal with the limiting incompressibility in the purely isochoric plastic flow. For a strip under vertical stretching in plane stress and plane strain as well as Prandtl's problem of indentation by a flat rigid die in plane strain, numerical results are presented for both isotropic and orthotropic plasticity models with or without tilting angle between the material axes and the applied loading. The influence of frictional behavior is studied. In all the investigated cases, the numerical results provide compelling support to the analytical prognosis.

Mesh-Based and Meshfree Reduced Order Phase-Field Models for Brittle Fracture: One Dimensional Problems.

Modelling brittle fracture by a phase-field fracture formulation has now been widely accepted. However, the full-order phase-field fracture model implemented using finite elements results in a nonlinear coupled system for which simulations are very computationally demanding, particularly for parametrized problems when the randomness and uncertainty of material properties are considered. To tackle this issue, we present two reduced-order phase-field models for parametrized brittle fracture problems in this work. The first one is a mesh-based Proper Orthogonal Decomposition (POD) method. Both the Discrete Empirical Interpolation Method (DEIM) and the Matrix Discrete Empirical Interpolation Method ((M)DEIM) are adopted to approximate the nonlinear vectors and matrices. The second one is a meshfree Krigingmodel. For one-dimensional problems, served as proof-of-concept demonstrations, in which Young's modulus and the fracture energy vary, the POD-based model can speed up the online computations eight-times, and for the Kriging model, the speed-up factor is 1100, albeit with a slightly lower accuracy. Another merit of the Kriging's model is its non-intrusive nature, as one does not need to modify the full-order model code.

Strain Localization of Elastic-Damaging Frictional-Cohesive Materials: Analytical Results and Numerical Verification.

Damage-induced strain softening is of vital importance for the modeling of localized failure in frictional-cohesive materials. This paper addresses strain localization of damaging solids and the resulting consistent frictional-cohesive crack models. As a supplement to the framework recently established for stress-based continuum material models in rate form (Wu and Cervera 2015, 2016), several classical strain-based damage models, expressed usually in total and secant format, are considered. Upon strain localization of such damaging solids, Maxwell's kinematics of a strong (or regularized) discontinuity has to be reproduced by the inelastic damage strains, which are defined by a bounded characteristic tensor and an unbounded scalar related to the damage variable. This kinematic constraint yields a set of nonlinear equations from which the discontinuity orientation and damage-type localized cohesive relations can be derived. It is found that for the "Simó and Ju 1987" isotropic damage model, the localization angles and the resulting cohesive model heavily depend on lateral deformations usually ignored in classical crack models for quasi-brittle solids. To remedy this inconsistency, a modified damage model is proposed. Its strain localization analysis naturally results in a consistent frictional-cohesive crack model of damage type, which can be regularized as a classical smeared crack model. The analytical results are numerically verified by the recently-proposed mixed stabilized finite element method, regarding a singly-perforated plate under uniaxial tension. Remarkably, for all of the damage models discussed in this work, the numerically-obtained localization angles agree almost exactly with the closed-form results. This agreement, on the one hand, consolidates the strain localization analysis based on Maxwell's kinematics and, on the other hand, illustrates versatility of the mixed stabilized finite element method.

Enrichment and culture of spermatogonia from cryopreserved adult bovine testis tissue.

Propagation of bovine spermatogonial stem cells (SSCs) from the cryopreserved testicular tissue is essential for the application of SSCs-related techniques. To explore the appropriate conditions for in vitro culture of bovine spermatogonia (containing putative SSCs), Sertoli cell monolayer and serum concentration were set as two main control factors. Morphological examination showed that the intactness and structure of adult bovine testicular tissue were well maintained after cryopreservation. The enriched bovine spermatogonia were large round CD9 and promyelocytic leukemia zinc finger protein (PLZF) positive cells, with high nucleocytoplasmic ratios and multiple types including single, paired-, aligned-cells or grape cluster-like colonies in vitro. In Sertoli cell co-culture system, bovine spermatogonia attached quickly and proliferated obviously faster than those in the system without Sertoli cells. Serum-free media was no good for the attachment and proliferation of bovine spermatogonia. When 2.5%, 5% and 10% fetal bovine serum (FBS) was employed in the media, spermatogonia attached easily and divided quickly to form paired-, chained-cells or grape cluster-like colonies with comparable percentages in all groups. However, the contaminated somatic cells proliferated robustly in groups containing 5% and 10% FBS. Together, bovine spermatognia isolated from cryopreserved adult testis tissue express CD9 and PLZF, can survive and proliferate conspicuously in Sertoli cell co-culture system, and low serum provides an optimal condition for the survival and proliferation of bovine spermatogonia because of avoiding the rapid growth of testis somatic cells.

RNA interference-mediated silencing of UBCH10 gene inhibits colorectal cancer cell growth in vitro and in vivo.

1. UbcH10 is the cancer-related E2 ubiquitin-conjugating enzyme, and its overexpression has been demonstrated in a variety of malignancies. The aim of the present study is to silence UbcH10 gene by RNA interference (RNAi) and to observe its inhibitory effect on the colorectal cancer cell growth in vitro and in vivo. 2. We constructed the expression vector pGPU6/GFP/Neo/UbcH10-RNAi (pUbcH10-RNAi), which contained a UbcH10 short hairpin RNA expression cassette. Then the UbcH10 gene silencing cell lines LoVo/UbcH10-RNAi and HT-29/UbcH10-RNAi were established. Reverse transcription-polymerase chain reaction and western blot analysis were used to evaluate the expression of the UbcH10 gene. Cell Counting Kit-8 was used to assess properties of tumour cell growth in vitro. Flow cytometry was used to detect the effect of pUbcH10-RNAi on the cell cycle of colorectal cancer cells. Furthermore, the anti-tumour effects of pUbcH10-RNAi were evaluated in vivo in a nude mouse xenografts model. 3. Results demonstrated that UbcH10 gene expression was significantly decreased in pUbcH10-RNAi treated cells. Colorectal cancer cells growth was markedly suppressed in the pUbcH10-RNAi group compared with control conditions and colorectal cancer cells were arrested in the G2-M phase. In vivo, the downregulation of UbcH10 gene expression by pUbcH10-RNAi also inhibited tumour growth in a nude mice xenograft model. 4. Our study suggests that RNA interference-mediated silencing of UbcH10 gene has anti-tumour activity on colorectal cancer and might have therapeutic potential for the treatment of colorectal cancer.

[Multiple organ dysfunction scoring system: comparison and evaluation of correlation and accuracy of the three scoring systems in predicting the outcome of multiple organ dysfunction syndrome on highland].

OBJECTIVE: To study the characteristics of the diagnostic parameters of acute respiratory distress syndrome/multiple organ dysfunction syndrome on plateau (H-ARDS/MODS) and compare the accuracy of the three MODS scoring criteria in predicting the outcome of syndrome. METHODS: Five hundred and forty cases fulfilling the criteria of MODS were divided into four groups according to the altitude of their inhabitation area: control group (on plain, CG, n=113, altitude: <430 m), moderate high altitude group 1 (H1G, n=314, altitude: 1,517 m), moderate high altitude group 2 (H2G, n=78, altitude: 2,261 m to 2,400 m) and high altitude group (HG, n=35, altitude: 2 808 m to 3 400 m). According to the diagnostic criteria of Lushan conference and Marshall (1995) commonly used on plain, and Lanzhou criteria drafted by the authors, three data analyzing models were set up to draw the receiver operating characteristic (ROC) curves, the Yordon Index and the optimum cutoff points of the parameters were calculated and the accuracy of the three respective diagnostic criteria was evaluated in predicting the outcome of ARDS/MODS. Multiple factors affecting the outcome of MODS were analyzed using the method of stepwise forward regress model. RESULTS: Following the increase in altitude, Lanzhou criteria was clearly superior to the other two criteria in the area of ROC, the sensitivity, the specificity, and also for the optimum cutoff points of MODS. Multi-variable regression analysis showed that the impacting factor of Lanzhou criteria was the highest (P<0.05). CONCLUSION: (1)Some parameters of the current diagnostic criteria of ARDS/MODS are not suitable in moderately high or high altitude areas. It is necessary to set up the diagnostic criteria of H-ARDS/MODS. (2)Some clinical characteristics might change in areas 1,500 m altitude or higher. The pathophysiological mechanism might be attributable to peculiar biologic reactions due to hypoxia stress reaction, and it is worth further study.

[Criteria suitable for diagnosis of acute respiratory distress syndrome/multiple organ dysfunction syndrome at moderately high altitude area].

OBJECTIVE: To compare the diagnostic parameters of acute respiratory distress syndrome/multiple organ dysfunction syndrome (ARDS/MODS) at high altitude (H-ARDS/MODS) with that on plain, and to establish a more practical diagnostic criterion of H-ARDS/MODS. METHODS: Five hundred and five cases fulfilled the criteria for the diagnosis of ARDS/MODS were divided into three groups according to the altitude of their habitation: control group including inhabitants (<430 m) on plain (CG, n=113), moderate high altitude group 1 inhabitants at the altitude of 1,517 m (H1G, n=314), moderate high altitude group 2 inhabitants at the altitude of 2,261 m to 2,400 m (H2G, n=78). The ARDS/MODS scores of the three groups were made according to the diagnostic criteria of Lushan conference, Marshall(1995) and Lanzhou criteria drafted by the authors respectively to set up three data analyzing models, followed by plotting of receiver operating characteristic curves (ROC curve) and calculation of the Yordon Index and the optimum cutoff points of the parameters,in order to study the accuracy of the three diagnostic criteria in predicting the outcome of the patients suffering from ARDS/MODS. RESULTS: In CG group, the differences were not significant in area of ROC, the maximal Yordon Index, the optimum cutoff points and the sensitivity and the specificity for three criteria; but the differences were significant for the three criteria in H1G group. Further investigation in comparing the ROC values of lung, brain, heart and kidney, the Lanzhou criteria were more advantageous in the high altitude than the other criteria. CONCLUSION: (1)The current diagnostic criteria of ARDS/MODS are not suitable for the diagnosis of these syndromes in moderately high or high altitude areas. It is necessary to revise the diagnostic criteria of H-ARDS/MODS. (2)One thousand five hundred and seventeen meters in altitude might be considered to be an important borderline, above with the diagnostic criteria of ARDS/MODS for patients inhabiting on plain could not be suitably applied to those living above this level.