[Natural history of colorectal cancer: a Meta-analysis on global prospective cohort studies].

Objective: To acknowledge the availability and rates of annual transition of outcomes during the progression and regression stages of colorectal cancer (CRC) and related diseases, by pooling global follow-up studies on the natural history of CRC. Methods: Till March, 2017, data was collected through systematic literature review over multiple databases, including PubMed, Embase, Cochrane and Chinese Biology Medicine (CBM) disc. Information regarding the characteristics, classification system of health states, related outcomes and incidence rates on CRC or high-risk adenoma for the surveillance cohorts of the studies, were extracted and summarized. Both Meta and sensitivity analyses were performed on those outcomes if they appeared in more than 3 studies, using the random effects model. Annual transition rate with 95%CI was used to estimate each of the outcomes, Quality of the studies was assessed, using the Newcastle-Ottawa Scale. Results: A total of 29 cohort studies were included, with the mean follow-up period as 5.7 years. All studies except one, focused on adenoma-carcinoma pathway and reported the outcome parameters of adenomas by different risk, and some reported the findings on different sizes (n=6) of adenomas. These cohorts were divided into three groups (normal status, with low-risk or high-risk adenoma) according to the status of baseline endoscopic pathologic findings. Their available outcome parameters, corresponding number of involved articles, aggregated sample size and pooled annual transition rates were presented. Six parameters were obtained in the normal cohorts, including those from normal to low-risk adenoma (16 articles, 58 235, 0.030: 0.024-0.037), to high-risk adenoma (17 articles, 62 089, 0.003: 0.002-0.004), to diminutive adenoma (<5 mm, 4 articles, 1 277, 0.021: 0.013-0.029), to small adenoma (6-9 mm, 4 articles, 1 277, 0.006: 0.001-0.010), to large adenoma (≥10 mm, 7 articles, 3 531, 0.002: 0.000-0.003) and to CRC (19 articles, 104 836, 0.000 3: 0.000 2-0.000 5). Three parameters were obtained in low-risk adenoma in cohorts with polypectomy findings, including recurrence (9 articles, 4 788, 0.109: 0.062-0.157) from low-risk adenoma after polypectomy to high-risk adenoma (10 articles, 5 736, 0.009: 0.004-0.013) and to CRC (12 articles, 11 347, 0.000 6: 0.000 4-0.000 8). Three parameters were obtained on high-risk adenoma from cohorts with polypectomy findings, including recurrence (12 articles, 7 030, 0.038: 0.028-0.048) from high-risk adenoma after polypectomy to low-risk adenoma (8 articles, 2 489, 0.133: 0.081-0.185) and CRC (14 articles, 14 899, 0.002: 0.001-0.003). Except for normal to low-risk adenomas, results from the sensitivity analysis for the other parameters showed stable. Of the included studies, two presented incidence rates of CRC in different clinical stages and the another two were focusing on the parameters related to serrated pathway. Conclusions: Globally, follow-up studies reported data on natural history of colorectal cancer is of paucity. Compared to the "adenoma-carcinoma" pathway, transition parameters of the serrated lesion pathway are more limited. This Meta-analysis provided convincing evidence for optimizing the strategies regarding follow-up program on the disease, using the baseline endoscopic findings from global CRC Screening Program. These results also offered strong data-related support for Chinese population- specific interventional model on colorectal cancer.

[Non-carcinogenic health risk assessment of nickel in agricultural products and drinking water in an e-waste dismantling area of Qingyuan City, Guangdong Province].

Vegetables, rice, eggs and drinking water samples were collected from e-waste dismantling area of Qingyuan City, Guangdong Province. Nickel (Ni) was analyzed in each sample, and the non-carcinogenic health [the daily intake (DI) and hazard quotient (HQ)] of each sample was evaluated. In this e-waste dismantling area, the contents of Ni in rice and eggs were (0.46±0.24) and (0.16±0.13) µg/g, which were higher than those in the control area [the contents of Ni in rice and eggs were (0.17±0.03) and (0.02±0.02) µg/g, respectively] (both P values<0.05). The DI values of rice, vegetable, eggs, and drinking water were (3.61-5.86), (1.75-2.99), (0.11-0.24), and (0.08-0.12) µg·kg(-1)·day(-1), respectively. The HQ values were 0.180-0.290, 0.090-0.150, 0.005-0.010, 0.005-0.006, respectively. Although the HQ values of rice, vegetable, eggs, and drinking water were all lower than 1, which was an acceptable level. However, considering the possibility of combined exposure of heavy metals, the non-carcinogenic health risks of Ni in the e-waste dismantling area should still be concerned.

[Economic burden of stomach cancer in China during 1996-2015: a systematic review].

Objective: To clarify the research status of economic burden of stomach cancer in China from 1996 to 2015. Methods: Based on three electronic literature databases (China Knowledge Resource Integrated Database, Wanfang Database and PubMed), a total of 2 873, 1 244 and 84 articles published during 1996 to 2015 were found, respectively, using keywords of"cancer","neoplasms","malignant tumor","tumor","economic burden","health expenditure","cost","cost of illness", and"China". According to the inclusion and exclusion criteria, 30 literatures were included in the final analysis. Then the basic information and study subjects, indicators and main results of economic burden were abstracted and analyzed. All the expenditure data were discounted to the values in 2013 by using China's percapita consumer price index. Results: Totally, 30 articles were included, covering 14 provinces and of which 16 were published during 2011-2015. One article was based on population-level and the remaining studies were all based on individual-level. The number of individual-level articles that reported direct medical, non-medical and indirectly economic burden was 29, 1 and 2, respectively. The main indicators of direct medical expenditure were expenditure per patient (22), per clinical visit (9) and per diem (11), respectively. The median expenditure per patient was 7 387-28 743 RMB (CNY), with average annual growth rate (AAGR) of 1.7% (1996-2013). The median expenditure per clinical visit was 18 504-41 871 RMB (2003-2013), with AAGR of 5.5%. The median expenditure per diem was 313-1 445 RMB (1996-2012), with AAGR of 3.7%. Difference was found among provinces. Conclusions: The evidence for economic burden of stomach cancer was still limited over the past two decades and mainly focused on individual and regional levels. An increase and differences in provinces were observed in direct medical expenditure. Evaluation on direct non-medical and indirect medical expenditure needs to be addressed.

Successful liver transplantation for a child with life-threatening recurrent bleeding episodes due to congenital factor X deficiency: a case report.

Factor X (FX) deficiency is a rare, autosomal-recessive coagulation disorder. Diagnosis can be confirmed by a factor X assay. Although fresh frozen plasma and prothrombin complex concentrates have been used as a temporary treatment of bleeding symptoms and preparation for surgery, frequent transfusion has its risk and prothrombin complex is not available in Korea. We report the first pediatric case of successful liver transplantation for the correction of a severe congenital FX deficiency in a child with recurrent life-threatening hemorrhagic episodes.

Clinical experience of more than 200 cases of pediatric liver transplantation at a single center: improved patient survival.

The aim of this study was to present our experience with more than 200 cases of orthotopic liver transplantation (OLT) at a single center. We conducted a retrospective, single-center assessment of the demographic and clinical factors in children who underwent OLT from 1994 to 2010. Two hundred children younger than 18 years of age underwent 200 primary and 9 liver re-transplantations. The overall patient survival rates before 2003 at 1, 5, and 10 years were 86.4%, 79.5%, and 78.4%, respectively; whereas after 2003 they were 95.4% and 95.4% at 1 and 5 years, respectively (P<.05). Our center's results showed durable, improved outcomes in recent years.

A simple method for the detection of neurologic disorders associated with CAG repeat expansion using PCR-microtiter plate hybridization.

A new screening method was developed for the detection of CAG expanded alleles in patients with hereditary ataxia using polymerase chain reaction-based microtiter plate hybridization (PCR-MPH). The system can be applied to detect pathologic alleles by hybridization with the immobilized (CAG)48 repeat probe derived from the unrelated gene 'ERDA1' except for the CAG repeats. We examined 10 individuals with SCA3, 10 with Huntington disease and 30 normal controls (31 controls for SCA3) using this method. The results showed that a clear discrimination was possible in all cases. We suggest that this system be made available for mass screening of patients with hereditary ataxia disorders. This report is the first to demonstrate that a PCR-MPH system can be successfully applied to DNA size differentiation in addition to base pair mismatches. Also, our design of the probe is unique in that the probe motif stem from the unrelated gene sequence and not from the synthetic oligonucleotides.

Morphologic evaluation and integrin expression profile of renal tubular cells cultured from percutaneous renal biopsy specimen.

Kidney biopsy is an indispensible procedure for making a pathologic diagnosis of renal diseases by fixing and staining the biopsy specimen. However, it is not a routine procedure to culture the cells from a renal biopsy specimen directly, or to utilize the cultured cells for any kind of diagnostic or functional evaluation. In this study, primary culture of the renal tubular epithelial cells was tried from a piece of percutaneous kidney biopsy specimen. Successive passages of the cells were possible until fourth passage. With these cells, morphologic characteristics of the cultured cells and integrin expression profiles were investigated. On light and electron microscopy, these cells were characterized by the cobblestone-like growth, presence of microvilli and tight junction, and the preservation of polarity. Immunohistochemical studies demonstrated the epithelial nature of these cells and particularly their differentiation from renal tubular epithelial cells, of either proximal or distal nephronic segment. The integrin profile confirms the epithelial nature of the cell. We hope that our results facilitate the understanding of pathophysiology of renal tubular cells from the patient directly.

[Plant regeneration from protoplast culture in flax (Linum usitatissimum)].

Shoot protoplasts of four fiber flax (Linum usitatissimum) varieties (7309, 948, Belinka and Viking) were isolated and cultured. The optimal condition for higher protoplast yield 1.8 x 10(6)/gFW and activity 85.5% (c.v. 948) were from 10 day old seedings. Culture in V-KM Agroase-island medium led to first divisions after 3 days (c. v. 948), and after twenty days with an efficiency of 36% of divided cells and 5.2% in plating efficiency. Plant regeneration was obtained in 7309 and Belinka on agar media B5-2, MS3 containing 0.6 mg/L 6-BA and 0.1 mg/L NAA. Roots and leaves regeneration were observed in Viking and 948 respectively.

Subcellular membrane impairment and application of phospholipase A2 inhibitors in endotoxic shock.

The study aims at elucidating the mechanism involved in the cell dysfunction or impairment and the protective effects of phospholipase A2 (PLA2) inhibitors in endotoxin shock. Thirty-four rabbits were divided randomly into four groups: (1) normal control group (NC, n = 6), receiving saline intravenously; (2) endotoxin shock group (ES, n = 12), receiving 3 mg/kg of E. coli endotoxin; (3) chloroquine pretreated group (CQ, n = 8), receiving 3 mg/kg of chloroquine 3 min before endotoxin injection and (4) chlorpromazine pretreated group (CPZ, n = 8), receiving 0.3 mg/kg of chlorpromazine 30 min before endotoxin injection. Hepatic mitochondria were extracted either 8 h after commencement of the experiment or when the animals died for detecting PLA2 activity, membrane fluidity, membrane bound succinate dehydrogenate (SDH) and malondialdehyde (MDA). Mitochondria of the lung, heart and kidney were also used for detection of the membrane fluidity. It was revealed that the survival rate of 8 h was 100% (NC), 58% (ES), 87.5% (CQ) and 75% (CPZ), respectively. Mean arterial pressure (MAP) dropped soon after endotoxin injection and descended continuously afterwards in the ES group (P < 0.01). Fluorescence polarization, microviscosity and anisotrophy with a DPH probe were elevated above control levels (P < 0.01). SDH was decreased obviously following endotoxin infusion (P < 0.01). Chloroquine and chlorpromazine, serving as PLA2 inhibitors, could abate cellular dysfunction and increase survival rate. It is proposed that PLA2 plays a pivotal role in cellular injury in endotoxin shock. PLA2 inhibitor might serve as a useful adjunct in combating sepsis and shock.

Frequency of spinocerebellar ataxia types 1,2,3,6,7 and dentatorubral pallidoluysian atrophy mutations in Korean patients with spinocerebellar ataxia.

Autosomal dominant cerebellar ataxias (ADCAs) are a heterogeneous group of disorders characterized by degenerative symptoms in the cerebellum, spinal cord, and brain stem. Six different genes have been reported to be associated with ADCA, and the length of trinucleotide repeats of these genes is correlated with the age at onset and severity of symptoms. Although there are strong hereditary effects in these disorders, most of the studies carried out in heterogeneous populations and in small groups obscure the true incidence of these diseases. We examined the frequency of six types of ADCAs in 87 unrelated Korean patients with progressive ataxia and compared the results to the frequencies in other ethnic groups. Spinocerebellar ataxia (SCA) type 2 was the most frequent hereditary ataxia (12.6%) and types 3 and 6 accounted for 4.6% and 6.9% of ataxia patients, respectively. Dentatorubral pallidoluysian atrophy was also found in three patients (3.4%). No instances of SCA types 1 or 7 were detected. These findings show the striking contrast to the white population and a difference from Japanese findings. Our results demonstrate that dentatorubral pallidoluysian atrophy should be included in the differential diagnosis of Korean patients with spinocerebellar ataxia, and that there are strong hereditary effects in patients with ADCAs.

Activating mutation of GS alpha in McCune-Albright syndrome causes skin pigmentation by tyrosinase gene activation on affected melanocytes.

McCune-Albright syndrome (MAS) is a sporadic disease characterized by café-au-lait spots, polyostotic fibrous dysplasia and hyperfunctional endocrinopathies. To elucidate the mechanism of skin pigmentation, melanocytes, keratinocytes and fibroblasts were primary cultured from the café-au-lait spot of a MAS patient. Then, mutational analysis and morphologic evaluation were performed. Also, cAMP level and tyrosinase gene expression in cultured cells were determined. Only Gsalpha mutation was found in affected melanocytes and the cAMP level in affected melanocytes was higher than that of normal melanocytes. The mRNA expression of tyrosinase gene was increased in the affected melanocytes. This study suggests that skin pigmentation of MAS results from activating mutation of Gsalpha in melanocytes and the mechanism involves the c-AMP-mediated tyrosinase gene activation.

Minimum energy trajectories of the swing ankle when stepping over obstacles of different heights.

This study was performed to test the hypothesis that the motion of the lower extremities when stepping over obstacles is governed by the criterion of minimum mechanical energy. The trajectories of the swing ankle during level walking and when stepping over obstacles of 51, 102, 153, and 204 mm heights were predicted and measured for eight healthy young adults. The predictions were made with a planar, seven-link linkage model based on the criterion of minimum mechanical energy using the method of dynamic programming. When stepping over obstacles, the predicted trajectories of the swing ankle were just high enough for the swing toe to clear the obstacles. The clearances measured between the obstacle and toe were significantly larger than those predicted. When stepping over obstacles the levels of work required to generate the measured trajectories were significantly larger (p < or = 0.002) than those required to produce the predicted trajectories. The amount of work necessary to generate the measured or predicted trajectories increased linearly (significant at p < or = 0.022) with obstacle height and, except when predicting the trajectory for the lowest obstacle, was significantly greater than that required when walking on level ground (p < 0.02). Thus, conservation of energy was found to become a less dominant criterion for governing the motion of the body when crossing obstacles than when walking on level ground.

A digital model of trabecular bone.

A 3D microCT dataset of bovine bone was used to create a digital 3D model simulating trabecular bone. The model serves a dual purpose: It allows for standard quantitative histomorphometric analysis and it approximates the reality e.g. of high resolution CT in vivo datasets of trabecular bone. Thus the model can potentially be used as a reference to develop 2D and 3D structural analysis algorithms applicable in vivo while it simultaneously allows verification of the results of these algorithms by standard histomorphometry. The model can be used as a standard to evaluate the impact of image processing techniques and of restrictions of imaging systems on the quantitative analysis of structural parameters describing a trabecular network. The model can be used for a comparison of 2D and 3D structural analysis methods and for an analysis of decreasing spatial resolution. The effects of segmentation and filtration can be studied separately and grayscale analysis is possible. As examples standard 2D histomorphometry and the analysis of topological parameters like node number and trabecular network length were applied to the model. The influence of spatial resolution was investigated by decreasing the spatial resolution of the digital model. The bone surface area determined by 3D surface triangulation was only 4% smaller than the surface area determined from the traditional 2D bone histomorphometric parameter bone surface/tissue volume (BS/TV) when 2D results were averaged over all slices of the 3D volume. However, BS/TV showed large (10%) variations among slices within the volume. Both histomorphometric and topological parameters were heavily influenced by spatial resolution and image segmentation. Our initial experience with the digital model indicates a need to investigate bone microstructure based on volume data or to average the 2D results of many slices.

Predicting the kinematics and kinetics of gait based on the optimum trajectory of the swing limb.

An algorithm was developed to predict the minimum energy consumption trajectory of the swing limb. The method of dynamic programming, a multistage optimization method, was applied to generate the optimum trajectory of the swing ankle which minimized the mechanical energy required to generate the moments of the joints of the lower extremities during the single support phase of gait. Predictions and measurements of gait were compared for six healthy subjects. The predicted hip and knee flexion angles of the swing limb were not significantly different from those experimentally measured except for hip flexion at times greater than 75% of the swing period. The predicted ground reaction forces were not significantly different from the measured ground reaction forces. Furthermore, the moments about the joints were not significantly different from those computed using the measured ground reaction forces and kinematics of the limbs. The results of this study support the hypothesis that human gait is energy efficient.

Determining cardiac velocity fields and intraventricular pressure distribution from a sequence of ultrafast CT cardiac images.

A method of computing the velocity field and pressure distribution from a sequence of ultrafast CT (UFCT) cardiac images is demonstrated. UFCT multi-slice cine imaging gives a series of tomographic slices covering the volume of the heart at a rate of 17 frames per second. The complete volume data set can be modeled using equations of continuum theory and through regularization, velocity vectors of both blood and tissue can be determined at each voxel in the volume. The authors present a technique to determine the pressure distribution throughout the volume of the left ventricle using the computed velocity field. A numerical algorithm is developed by discretizing the pressure Poisson equation (PPE), which Is based on the Navier-Stokes equation. The algorithm is evaluated using a mathematical phantom of known velocity and pressure-Couette flow. It is shown that the algorithm based on the PPE can reconstruct the pressure distribution using only the velocity data. Furthermore, the PPE is shown to be robust in the presence of noise. The velocity field and pressure distribution derived from a UFCT study of a patient are also presented.

Noise reduction in three-dimensional phase-contrast MR velocity measurements.

The authors have developed a method to reduce noise in three-dimensional (3D) phase-contrast magnetic resonance (MR) velocity measurements by exploiting the property that blood is incompressible and, therefore, the velocity field describing its flow must be divergence-free. The divergence-free condition is incorporated by a projection operation in Hilbert space. The velocity field obtained with 3D phase-contrast MR imaging is projected onto the space of divergence-free velocity fields. The reduction of noise is achieved because the projection operation eliminates the noise component that is not divergence-free. Signal-to-noise ratio (S/N) gains on the order of 15%-25% were observed. The immediate effect of this noise reduction manifests itself in higher-quality phase-contrast MR angiograms. Alternatively, the S/N gain can be traded for a reduction in imaging time and/or improved spatial resolution.

A study of the stability of generalized wave gaits.

The wave gait has been observed in animal and insect walking and has been widely implemented in the control of walking machines. It has been proved that the wave gait possesses the optimum stability among all periodic gaits under the geometrical condition that R/P < or = 1, where R and P are respectively the stroke and pitch of a walking machine. Recently, based on numerical results, a generalized hexapodal wave gait was reported to be more stable than the wave gait for R/P > 1. In this paper, in order to understand more about the generalized wave gait, an analytical method is applied to study its stability in three categories of multilegged systems: quadrupeds, hexapods, and 2n-legged systems (n > or = 4). Two optimal generalized wave gaits are found for quadrupeds, and three optimal gaits are found for each of the other two categories. For all three categories, one of the optimal generalized wave gaits is the wave gait. The stability and geometrical conditions of these optimal gaits are derived and verified numerically. Furthermore, it is shown that the quadrupedal generalized wave gaits have the optimum stability among all periodic gaits with the stepping sequence 1-4-2-3.

CT angiography with spiral CT and maximum intensity projection.

The authors describe a technique for obtaining angiographic images by means of spiral computed tomography (CT), preprocessing of reconstructed three-dimensional sections to suppress bone, and maximum intensity projection. The technique has some limitations, but preliminary results in 48 patients have shown excellent anatomic correlation with conventional angiography in studies of the abdomen, the circle of Willis in the brain, and the extracranial carotid arteries. With continued development and evaluation, CT angiography may prove useful as a screening tool or replacement for conventional angiography in some patients.

Computation of 3-D velocity fields from 3-D cine CT images of a human heart.

A method of computing the three-dimensional (3-D) velocity field from 3-D cine computer tomographs (CTs) of a beating heart is proposed. Using continuum theory, the authors develop two constraints on the 3-D velocity field generated by a beating heart. With these constraints, the computation of the 3-D velocity field is formulated as an optimization problem and a solution to the optimization problem is developed using the Euler-Lagrange method. The solution is then discretized for computer implementation. The authors present the results for both simulated images and clinical cine CT images of a beating heart.