[Advances in the use of neuromuscular electrical stimulation in the prevention of venous thromboembolism]

Pharmacologic prophylaxis is the most commonly used prophylaxis for venous thromboembolism (VTE), but the pharmacologic prophylaxis is limited in patients at high risk of bleeding. Mechanical prophylaxis alone or in combination is an important method of VTE prophylaxis in patients at high risk of bleeding, but the current mainstream mechanical prophylaxis, which includes graded compression stockings, intermittent inflatable compression pumps and plantar venous compression pumps, has some limitations, leading to discomfort for patients wearing them due to the large contact area, and even affecting ability to perform daily activities. Many clinical studies have found that NMES combined with pharmacological prophylaxis has better efficacy and safety than pharmacological prophylaxis alone in preventing VTE in medical and surgical patients, and the preventive effect of NMES alone is not inferior to other mechanical prophylaxis. Besides, it also has the advantages of ease of wear and patient compliance. Currently, clinicians have limited experience and knowledge of NMES. We aimed to present the rationale, progress in clinical research and future perspective of NMES in VTE prophylaxis.

Electroacupuncture Stimulation Alleviates Inflammatory Pain in Male Rats by Suppressing Oxidative Stress

In the present study, we focused on whether the analgesic effect of Electroacupuncture (EA) is related to the regulation of oxidative stress. We established a chronic inflammatory pain model in male rats by a single injection of complete Freund's adjuvant (CFA) and then treated the animals with daily EA stimulation at the site of "zusanli". The analgesic effect of EA was evaluated by measuring the paw withdrawal threshold (PWT) when rats received mechanical and thermal pain stimulation. The levels of inflammation-related molecules and oxidative stress-related markers in the spinal cord were measured by western blotting or ELISA kits. EA stimulation and antioxidants effectively increased the PWT in CFA rats. Co-treatment of CFA rats with the ROS donor t-butyl hydroperoxide (t-BOOH) further decreased the PWT and weakened the analgesic effect of EA. EA treatment inhibited inflammation and oxidative stress, as shown by decreased levels of tumor necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta), IL-6, and MDA and increased activity of SOD and catalase. Moreover, EA reduced the expression of p-p38, p-ERK, and p-p65 and simultaneously downregulated the expression of TRPV1 and TRPV4 in CFA rats. In an in vitro study, direct stimulation with t-BOOH to the C6 cells increased the production of TNF-alpha, IL-1beta, IL-6, activated p38, ERK, and p65 and up-regulated the expression of TRPV1 and TRPV4, and these effects could be prevented by the ROS scavenger PBN. Taken together, our data indicate that the inhibition of oxidative stress and the generation of ROS contribute to the analgesic effect of EA in male CFA rats.

[Recognition of abnormal changes in echocardiographic videos by an artificial intelligence assisted diagnosis model based on 3D CNN]

Objective: To investigate the diagnostic efficiency and clinical application value of an artificial intelligence-assisted diagnosis model based on a three-dimensional convolutional neural network (3D CNN) on echocardiographic videos of patients with hypertensive heart disease, chronic renal failure (CRF) and hypothyroidism with cardiac involvement. Methods: This study is a retrospective study. The patients with hypertensive heart disease, CRF and hypothyroidism with cardiac involvement, who admitted in Henan Provincial People's Hospital from April 2019 to October 2021, were enrolled. Patients were divided into hypertension group, CRF group, and hypothyroidism group. Additionally, a simple random sampling method was used to select control healthy individuals, who underwent physical examination at the same period. The echocardiographic video data of enrolled participants were analyzed. The video data in each group was divided into a training set and an independent testing set in a ratio of 5 to 1. The temporal and spatial characteristics of videos were extracted using an inflated 3D convolutional network (I3D). The artificial intelligence assisted diagnosis model was trained and tested. There was no case overlapped between the training and validation sets. A model was established according to cases or videos based on video data from 3 different views (single apical four chamber (A4C) view, single parasternal left ventricular long-axis (PLAX) view and all views). The statistical analysis of diagnostic performance was completed to calculate sensitivity, specificity and area under the ROC curve (AUC). The time required for the artificial intelligence and ultrasound physicians to process cases was compared. Results: A total of 730 subjects aged (41.9±12.7) years were enrolled, including 362 males (49.6%), and 17 703 videos were collected. There were 212 cases in the hypertensive group, 210 cases in the CRF group, 105 cases in the hypothyroidism group, and 203 cases in the normal control group. The diagnostic performance of the model predicted by cases based on single PLAX view and all views data was excellent: (1) in the hypertensive group, the sensitivity, specificity and AUC of models based on all views data were 97%, 89% and 0.93, respectively, while those of models based on a single PLAX view were 94%, 95%, and 0.94, respectively; (2) in the CRF group, the sensitivity, specificity and AUC of models based on all views data were 97%, 95% and 0.96, respectively, while those of models based on a single PLAX view were 97%, 89%, and 0.93, respectively; (3) in the hypothyroidism group, the sensitivity, specificity and AUC of models based on all views data were 64%, 100% and 0.82, respectively, while those of models based on a single PLAX view were 82%, 89%, and 0.86, respectively. The time required for the 3D CNN model to measure and analyze the echocardiographic videos of each subject was significantly shorter than that for the ultrasound physicians ((23.96±6.65)s vs. (958.25±266.17)s, P<0.001). Conclusions: The artificial intelligence assisted diagnosis model based on 3D CNN can extract the dynamic temporal and spatial characteristics of echocardiographic videos jointly, and quickly and efficiently identify hypertensive heart disease and cardiac changes caused by CRF and hypothyroidism.

[Influencing factors of iron metabolism assessment in patients with myelodysplastic syndrome: A retrospective study]

Objective: To analyze the influencing factors of iron metabolism assessment in patients with myelodysplastic syndrome. Methods: MRI and/or DECT were used to detect liver and cardiac iron content in 181 patients with MDS, among whom, 41 received regular iron chelation therapy during two examinations. The adjusted ferritin (ASF) , erythropoietin (EPO) , cardiac function, liver transaminase, hepatitis antibody, and peripheral blood T cell polarization were detected and the results of myelofibrosis, splenomegaly, and cyclosporine were collected and comparative analyzed in patients. Results: We observed a positive correlation between liver iron concentration and ASF both in the MRI group and DECT groups (r=0.512 and 0.606, respectively, P<0.001) , only a weak correlation between the heart iron concentration and ASF in the MRI group (r=0.303, P<0.001) , and no significant correlation between cardiac iron concentration and ASF in the DECT group (r=0.231, P=0.053) . Moreover, transfusion dependence in liver and cardiac [MRI group was significantly associated with the concentration of iron in: LIC: (28.370±10.706) mg/g vs (7.593±3.508) mg/g, t=24.30, P<0.001; MIC: 1.81 vs 0.95, z=2.625, P<0.05; DECT group: liver VIC: (4.269±1.258) g/L vs (1.078±0.383) g/L, t=23.14, P<0.001: cardiac VIC: 1.69 vs 0.68, z=3.142, P<0.05]. The concentration of EPO in the severe iron overload group was significantly higher than that in the mild to moderate iron overload group and normal group (P<0.001) . Compared to the low-risk MDS group, the liver iron concentration in patients with MDS with cyclic sideroblasts (MDS-RS) was significantly elevated [DECT group: 3.80 (1.97, 5.51) g/L vs 1.66 (0.67, 2.94) g/L, P=0.004; MRI group: 13.7 (8.1,29.1) mg/g vs 11.6 (7.1,21.1) mg/g, P=0.032]. Factors including age, bone marrow fibrosis, splenomegaly, T cell polarization, use of cyclosporine A, liver aminotransferase, and hepatitis antibody positive had no obvious effect on iron metabolism. Conclusion: There was a positive correlation between liver iron concentration and ASF in patients with MDS, whereas there was no significant correlation between cardiac iron concentration and ASF. Iron metabolism was affected by transfusion dependence, EPO concentration, and RS.

The deacetylation of Foxk2 by Sirt1 reduces chemosensitivity to cisplatin

In multiple types of cancer, decreased tumour cell apoptosis during chemotherapy is indicative of decreased chemosensitivity. Forkhead box K2 (FOXK2), which is essential for cell fate, regulates cancer cell apoptosis through several post‐translational modifications. However, FOXK2 acetylation has not been extensively studied. Here, we evaluated the effects of sirtiun 1 (SIRT1) on FOXK2 deacetylation. Our findings demonstrated that SIRT1 inhibition increased FOXK2‐induced chemosensitivity to cisplatin and that K223 in FOXK2 was acetylated. Furthermore, FOXK2 K223 deacetylation reduced chemosensitivity to cisplatin in vitro and in vivo. Mechanistically, FOXK2 was acetylated by the acetyltransferase cAMP response element binding protein and deacetylated by SIRT1. Furthermore, cisplatin attenuated the interaction between FOXK2 and SIRT1. Cisplatin or SIRT1 inhibition enhanced FOXK2 acetylation, thereby reducing the nuclear distribution of FOXK2. Additionally, FOXK2 K223 acetylation significantly affected the expression of cell cycle–related and apoptosis‐related genes in cisplatin‐stimulated cancer cells, and FOXK2 K223 hyperacetylation promoted mitotic catastrophe, which enhanced chemosensitivity to cisplatin. Overall, our results provided insights into the mechanisms of SIRT1‐mediated FOXK2 deacetylation, which was involved in chemosensitivity to cisplatin.

Neonatal biliary atresia combined with preduodenal portal vein: A case report

BACKGROUND

Congenital biliary atresia is a type of obstruction of the bile ducts inside and outside the liver, which can lead to cholestatic liver cirrhosis and eventually liver failure. The preduodenal portal vein (PD-PV) is a rare developmental malformation of the PV. The PV courses in front of the duodenum. However, very few cases of neonatal biliary atresia combined with PD-PV have been reported in the scientific literature.

CASE SUMMARY

A 1-mo-and-4-d-old child was admitted to the hospital in January because of yellowish skin. After surgical consultation, surgical intervention was recommended. The child underwent Hilar-jejunal anastomosis, duodenal rhomboid anastomosis, and abdominal drainage under general anesthesia. During the operation, the PV was located at the anterior edge of the duodenum.

CONCLUSION

Diagnoses: (1) Congenital biliary atresia; (2) PD-PV; and (3) Congenital cardiovascular malformations. Outcomes: Recommendation for liver transplantation. Lessons: The choice of treatment options for neonatal biliary atresia combined with PD-PV.

A positive feedback loop between Periostin and TGFβ1 induces and maintains the stemness of hepatocellular carcinoma cells via AP-2α activation

Background

Liver cancer stem cells (LCSCs) play key roles in the metastasis, recurrence, and chemotherapeutic resistance of hepatocellular carcinoma (HCC). Our previous research showed that the POSTN gene is closely related to the malignant progression and poor prognosis of HCC. This study aimed to elucidate the role of POSTN in generating LCSCs and maintaining their stemness as well as the underlying mechanisms.

Methods

Human HCC tissues and matched adjacent normal tissues were obtained from 110 patients. Immunohistochemistry, western blotting (WB), and RT-PCR were performed to detect the expression of POSTN and stemness factors. The roles of transforming growth factor (TGF)-β1 and AP-2α in the POSTN-induced stemness transformation of HCC cells were explored in vitro and in vivo using LCSCs obtained by CD133⁺ cell sorting.

Results

The high expression of POSTN was correlated with the expression of various stemness factors, particularly CD133, in our HCC patient cohort and in TCGA and ICGC datasets. Knockdown of POSTN expression decreased the abilities of HCC cell lines to form tumours in xenograft mouse models. Knockdown of POSTN expression also suppressed cell viability and clone formation, invasion, and sphere formation abilities in vitro. Knockdown of AP-2α attenuated the generation of CD133⁺ LCSCs and their malignant behaviours, indicating that AP-2α was a critical factor that mediated the POSTN-induced stemness transformation and maintenance of HCC cells. The role of AP-2α was verified by using a specific αvβ3 antagonist, cilengitide, in vitro and in vivo. Activation of POSTN could release TGFβ1 from the extracellular matrix and initiated POSTN/TGFβ1 positive feedback signalling. Furthermore, we found that the combined use of cilengitide and lenvatinib suppressed the growth of HCC cells with high POSTN expression more effectively than the use of lenvatinib alone in the patient-derived xenograft (PDX) mouse model.

Conclusions

The POSTN/TGFβ1 positive feedback pathway regulates the expression of stemness factors and the malignant progression of HCC cells by regulating the transcriptional activation of AP-2α. This pathway may serve as a new target for targeted gene therapy in HCC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13046-021-02011-8.

[The subgroup analysis of the prognostic value of the intraductal carcinoma of the prostate in patients with metastatic prostate cancer]

Objective: To determine the prognostic value of the intraductal carcinoma of the prostate IDC-P in metastatic prostate cancer (mPCa) patients of different subgroups. Methods: Data of 582 de novo mPCa patients between January 2011 and December 2017 diagnosed at Departments of Urology, West China Hospital, Sichuan University were retrospectively analyzed. The age was (70±8) years (range: 45 to 89 years). IDC-P was identified from 12-core prostate biopsy. The prognostic role of IDC-P was assessed by Kaplan-Meier curves and Cox regression. Subgroup analysis was conducted by the forest plot. The endpoints were castration-resistant prostate cancer free survival (CFS) and overall survival (OS). Results: In total, 177/582 (30.4%) patients harbored IDC-P. Patients with IDC-P had poorer CFS and OS than those without IDC-P (mCFS: 12.1 months vs. 16.9 months, P=0.000; mOS: 39.7 months vs. not reached, P=0.000). Multivariate Cox regression analysis indicated that, the existence of IDC-P was an independent prognosticator of both CFS (HR=1.40, 95% CI: 1.10 to 1.79, P=0.006) and OS (HR=1.51, 95% CI: 1.02 to 2.25, P=0.041). Subanalysis indicated that, in most subgroups, IDC-P was an adverse prognosticator of both CFS and OS. Even in subgroups with adverse clinicopathological features, e.g. Gleason score 9 to 10 (CFS: HR=1.467, P=0.007; OS: HR=1.807, P=0.013), baseline prostate specific antigen≥50 μg/L (CFS: HR=1.616, P=0.000; OS: HR=1.749, P=0.006), anemia (CFS: HR=1.653, P=0.036; OS: HR=2.100, P=0.038), alkaline phosphatase≥160 U/L (CFS: HR=1.326, P=0.038; OS: HR=1.725, P=0.010) or abnormal lactate dehydrogenase level (CFS: HR=1.614, P=0.001; OS: HR=1.900, P=0.003), IDC-P was still closely associated with shorter CFS and OS. Conclusions: The presence of IDC-P was closely related to poor survival outcomes for patients with mPCa. IDC-P was an adverse prognosticator in most subgroup patients. The description of IDC-P in the pathological report of prostate biopsy would help clinicians to evaluate the prognosis of mPCa patients more accurately and make better treatment choices.

Organoids of liver diseases: From bench to bedside

Understanding the occurrence, development, and treatment of liver diseases is the main goal of hepatopathology research. Liver diseases are not only diverse but also highly heterogeneous among individuals. At present, research on liver diseases is conducted mainly through cell culture, animal models, pathological specimens, etc. However, these methods cannot fully reveal the pathogenic mechanism and therapeutic characteristics of individualized liver diseases. Recent advances in three-dimensional cell culture technology (organoid culture techniques) include pluripotent stem cells and adult stem cells that are cultured in vitro to form self-organizing properties, making it possible to achieve individualized liver disease research. This review provides a comprehensive overview of the development of liver organoids, the existing and potential applications of liver regenerative medicine, the pathogenesis of liver disease heterogeneity, and drug screening.

Risk factors of atrial fibrillation occurring after radical surgery of esophageal carcinoma

Background

Atrial fibrillation (AF) is a common complication after radical surgery of esophageal cancer. The aim of this study was to explore AF risk factors after radical surgery of esophageal carcinoma.

Method

The data of 335 patients with esophageal cancer who were admitted in our hospital from January 2014 to August 2016 for the first time were retrospectively analyzed. We retrieved the papers in some data banks using the search terms including English and Chinese search terms, and obtained 13 factors which were mentioned in more than 6 papers. The 13 factors including age, gender, history of smoking, history of hypertension, history of peripheral vascular disease, history of cardiac stents or angina pectoris, preoperative pulmonary infection, preoperative brain natriuretic peptide (BNP) level, preoperative left ventricular diastolic dysfunction, operative method, lesion location, intraoperative blood transfusion, adhesion between lymph nodes and pericardium, underwent univariate and multivariate analyses.

Results

Of the 335 patients with esophageal cancer, 48 had AF within one week after operation. Univariate analysis indicated that the age (OR: 4.89; CI: 2.53–9.47, P: 0.000), gender (OR: 2.26; CI: 1.17–4.37, P: 0.013), history of peripheral vascular disease (OR: 2.29; CI: 1.06–4.92, P: 0.030), history of cardiac stents or angina pectoris (OR: 27.30; CI: 12.44–59.91, P: 0.000), preoperative BNP level (OR: 27.13; CI: 10.97–67.06, P: 0.000), preoperative left ventricular diastolic dysfunction (OR: 2.22; CI: 1.19–4.14, P: 0.012), operative method (OR: 2.09; CI: 1.002–4.380, P: 0.046), intraoperative blood transfusion (OR: 20.24; CI: 8.39–48.82, P: 0.000), and adhesion between lymph nodes and pericardium were risk factors (OR: 2.05; CI: 1.08–3.87, P: 0.024). Furthermore, multivariate analysis displayed that advanced age (OR: 5.044; CI: 1.748–14.554, P: 0.003), male (OR: 6.161; CI: 2.143–17.715, P: 0.001), history of cardiac stents or angina pectoris (OR: 48.813; CI: 13.674–174.246, P: 0.000), preoperative BNP > 100 (OR: 41.515; CI: 9.380–183.732, P: 0.000), open surgery (OR: 3.357; CI: 1.026–10.983, P: 0.045), intraoperative blood transfusion (OR: 58.404; CI: 10.777–316.509, P: 0.000), and adhesion between lymph nodes and pericardium (OR: 3.954; CI: 1.364–11.459, P: 0.011) were risk factors which could increase the incidence of postoperative AF.

Conclusion

We should pay attention to the above risk factors in order to reduce the incidence of postoperative AF.

[Value of MRI in prenatal diagnosis of abnormal fetal kidneys]

Objective: To investigate the value of MRI in the prenatal diagnosis of abnormal fetal kidneys. Methods: From December 2014 to March 2016, 51 women underwent MRI and were confirmed as having fetuses with abnormal fetal kidneys when follow up. Their clinical and MRI profiles were analyzed retrospectively, including MRI manifestation, the fetal kidney signal intensity of diffusion-weighted imaging (DWI) and apparent diffusion coefficient (ADC). The signal intensity of DWI and ADC of the abnormal kidney and the normal opposite kidney, and those of the normal and abnormal kidneys in different individuals were compared. The accuracies of MRI and ultrasound in evaluating abnormal fetal kidneys were also compared. Results: MRI could accurately demonstrate the morphological features of abnormal fetal kidneys. There was no statistically significant difference between DWI signal intensity and ADC value of the abnormal kidney[368 ± 125, (1.516 ± 0.420) × 10^-3 mm²/s] and the normal opposite one[410 ± 125, (1.362 ± 0.251) × 10^-3 mm²/s], P values were 0.165 and 0.184, respectively. The DWI signal intensity of normal kidneys (401 ± 124) was higher than that of renal cysts (182 ± 40, P <0.01), and the ADC value of normal kidneys[(1.306 ± 0.252) × 10^-3 mm²/s] was lower than that of renal cysts[(2.912 ± 0.235) × 10^-3 mm²/s] and multicystic dysplastic kidneys[(1.870±0.654) ×10^-3 mm²/s], P values were <0.01 and 0.045, respectively. The diagnostic accuracy of MRI and prenatal ultrasound for abnormal fetal kidneys were 94% (63/67) and 85% (57/67), respectively. However, there was no statistical difference between the two methods (P=0.070). Conclusion: MRI have an important role in the prenatal diagnosis and evaluation of abnormal fetal kidneys.

Overcoming 5-Fu resistance in human non-small cell lung cancer cells by the combination of 5-Fu and cisplatin through the inhibition of glucose metabolism

5-Fu is a pyrimidine analog which is wildly used in the treatment of cancers. The development of strategies that increase its anticancer activity has been studied over the past 20 years. Despite these advances, drug resistance remains a significant limitation to the clinical use of 5-FU. In this study, we investigate the glucose metabolic profiles of non-small cell lung cancer cells in response to 5-Fu and cisplatin. Interestingly, the glucose metabolism of A549 cells is activated by 5-Fu treatment but suppressed by cisplatin treatment. We generalize 5-Fu-resistant and cisplatin-resistant cell lines from A549 cells. The glucose metabolism in 5-Fu-resistant cells is increased but decreased in cisplatin-resistant cells. In addition, glycolysis inhibition sensitizes lung cancer cells to 5-Fu. Importantly, we report a synergistic inhibitory effect on lung cancer cells by the combination of 5-Fu with cisplatin through the suppression of glucose metabolism both in vitro and in vivo. Moreover, restoration of glucose metabolism by overexpression of glycolytic key enzymes renders A549 cells resistant to 5-Fu. In summary, our study indicates that glycolysis inhibition contributes to the synergistic antitumor effect of combinational therapy, and targeting glycolysis could be an effective strategy for overcoming 5-Fu resistance in cancer therapy.

Relationship between mir-21 expression and clinical and pathological features of esophageal squamous cell carcinoma

AIM: To investigate mir-21 expression in esophageal squamous cell carcinoma (ESCC) and to analyze its relationship with the clinical and pathological features of ESCC.

METHODS: Real-time RT-PCR and the 2-∆∆CT method were used to detect the expression of mir-21 in 96 cases of ESCC and tumor-adjacent tissue. The relationship between expression of mir-21 and clinical and pathological features of ESCC was analyzed.

RESULTS: Of 96 cases of ESCC specimens, mir-21 was highly expressed in 40 cases (41.6%). High mir-21 expression was closely related with the degree of tumor differentiation and TNM stage (both P < 0.05).

CONCLUSION: The high expression of mir-21 may play an important role in the occurrence and development of ESCC.

Significance of C-Jun expression in esophageal squamous cell carcinoma

AIM: To investigate the relationship between C-Jun protein expression and clinical biological behavior of esophageal squamous cell carcinoma (ESCC).

METHODS: Immunohistochemistry and RT-PCR were used to detect the expression of C-Jun protein and mRNA in 96 cases of ESCC tissue and matched tumor-adjacent esophageal tissue. The correlation between C-Jun protein expression and clinical biological behavior of ESCC was analyzed.

RESULTS: C-Jun expression in ESCC was significantly higher in ESCC tissue than in matched tumor-adjacent esophageal tissue (0.7703 ± 0.3330 vs 0.2546 ± 0.1328, t = -11.23, P < 0.05). C-Jun protein expression was correlated with lymph node metastasis and TNM stage in ESCC (both P < 0.05).

CONCLUSION: C-Jun protein is highly expressed in ESCC, which correlates with lymph node metastasis and TNM stage. This finding suggests that high expression C-Jun protein may be related to the occurrence and development of ESCC.

FBXW7-mediated degradation of CCDC6 is impaired by ATM during DNA damage response in lung cancer cells

CCDC6 is rearranged in approximately 20% of papillary thyroid carcinomas and some lung cancers participating in the formation of PTC1/ret proto-oncogene oncogene. CCDC6 is involved in the cellular response to DNA damage and is stabilized by ATM-mediated phosphorylation at Thr434. However, the E3 ligase that targets CCDC6 for destruction is unknown. Here, we show that FBXW7 interacts with and targets CCDC6 for ubiquitin-mediated proteasomal degradation. Moreover, FBXW7-mediated CCDC6 degradation is impaired in response to DNA damage. Mechanistically, phosphorylation of CCDC6 at Thr434 by ATM during DNA damage response prevents FBXW6-CCDC6 interaction and FBXW7-mediated CCDC6 degradation. Our results suggest that the involvement of FBXW7 in targeting CCDC6 for destruction will be useful for the establishment of new therapeutic approaches for cancer treatment.

Directed engineering of umbilical cord blood stem cells to produce C-peptide and insulin

OBJECTIVES

In this study, we investigated the potential of umbilical cord blood stem cell lineages to produce C-peptide and insulin.

MATERIALS AND METHODS

Lineage negative, CD133+ and CD34+ cells were analyzed by flow cytometry to assess expression of cell division antigens. These lineages were expanded in culture and subjected to an established protocol to differentiate mouse embryonic stem cells (ESCs) toward the pancreatic phenotype. Phase contrast and fluorescence immunocytochemistry were used to characterize differentiation markers with particular emphasis on insulin and C-peptide.

RESULTS

All 3 lineages expressed SSEA-4, a marker previously reported to be restricted to the ESC compartment. Phase contrast microscopy showed all three lineages recapitulated the treatment-dependent morphological changes of ESCs as well as the temporally restricted expression of nestin and vimentin during differentiation. After engineering, each isolate contained both C-peptide and insulin, a result also obtained following a much shorter protocol for ESCs.

CONCLUSIONS

Since C-peptide can only be derived from de novo synthesis and processing of pre-proinsulin mRNA and protein, we conclude that these results are the first demonstration that human umbilical cord blood-derived stem cells can be engineered to engage in de novo synthesis of insulin.

Differential expression of peroxisome proliferator-activated receptors alpha and gamma gene in various chicken tissues

The peroxisome proliferator-activated receptors (PPARs) are the members of superfamily of nuclear hormone receptors. A great number of studies in rodent and human have shown that PPARs were involved in the lipids metabolism. The goal of the current study was to investigate the expression pattern of PPAR genes in various tissues of chicken. The tissue samples (heart, liver, spleen, lung, kidney, stomach, intestine, brain, breast muscle and adipose) were collected from six Arber Acres broilers (8 weeks old, male and female birds are half and half). Semi-quantitative RT-PCR and Northern blot were used to characterize the expression of PPAR-alpha and PPAR-gamma genes in the above tissues. By semi-quantitative RT-PCR, the results showed the expression level of PPAR-alpha gene was higher in brain, lung, kidney, heart and intestine, medium in stomach, liver and adipose than in spleen, and it did not express in breast muscle. The expression level of PPAR-gamma gene was higher in adipose, medium in brain and kidney than in spleen, heart, lung, stomach and intestine, but it did not express in liver and breast muscle. Northern blot results showed that PPAR-alpha gene expressed in heart, liver, kidney and stomach, and the intensity of hybridization signal was the stronger in liver and kidney than in other tissues, however, PPAR-gamma gene only expressed in adipose and kidney tissues. The results of this study showed the profile of PPAR gene expression in the chicken was similar to that in rodent, human and pig. However the expression profile of chicken also have its own specific trait, i.e. compared with mammals, PPAR-alpha gene can not be detected in skeletal muscle and PPAR-gamma gene can be stronger expressed in kidney tissues. This work will provide some basic data for the PPAR genes expression and lipids metabolism of birds.

Time-resolved infrared spectroscopic study of the switching dynamics of a surface-stabilized ferroelectric liquid crystal

The orientation dynamics of a ferroelectric liquid crystal with a naphthalene ring (FLC-3) during the electric-field-induced switching between two surface-stabilized states was investigated by means of time-resolved Fourier-transform infrared spectroscopy. Time-resolved infrared spectra of the planar-aligned cell of FLC-3 were measured as a function of the polarization angle ranging from 0 degree to 180 degrees under a rectangular electric field +/-40 V with a 5-kHz repetition rate in the smectic-C* (Sm-C*) phase at 137 degrees C. From these spectra details about the mutual arrangement of different molecular segments at all the delay times in the Sm-C* phase were derived. It was found that the C=O group in the core moiety exhibits a dynamical behavior different from that in the chiral moiety during the electric-field-induced switching between the two surface-stabilized states. The most important finding in the present study is that during the electric-field-induced switching the FLC molecule not only rotates around the layer normal, but also revolves around its own long axis. Furthermore, time-resolved infrared spectroscopy revealed that each group in the core moiety passes almost simultaneously through the projection of the layer normal in the cell window during the dynamic switching.

[Effects of composition of mobile phases on retention behavior of solutes in hydrophobic interaction chromatography]

The retention behavior of aromatic alcohol homologues in hydrophobic interaction chromatography (HIC) was investigated for the first time. The differences in retention behavior between proteins and small solutes, and the eluted range and ability of different salts to small solutes and biopolymers, are elucidated with the parameter Z of the stoichiometric displacement retention model. The retention of aromatic alcohols follows the homologue rule. By the comparison of the changes of Z in different salt solutions, it is found that for small molecules the salt type only changes the hydration degree; but for proteins, it not only changes the hydration of proteins and stationary phase, but also affects the conformation of protein molecules near the contact regions between the protein and the stationary phase surface.

Polarized infrared spectroscopic study on the orientation of the molecules in the smectic-C* phase of a ferroelectric liquid crystal with a naphthalene ring: alternative theory for the analysis of polarization-angle-dependent intensity changes

A theory to explain the polarization-angle dependence of polarized infrared spectra of a ferroelectric liquid crystal in the surface-stabilized ferroelectric liquid crystal state is proposed. It describes the relationship between the intensity of the absorption bands and the polarization angle of the infrared radiation. Using this theory the polarization-angle dependence of the infrared band intensities was analyzed for a ferroelectric liquid crystal with a naphthalene ring and two phenyl rings with a stacked layer structure in the smectic-C* phase. The polarization-angle-dependent spectra were measured at 137 degrees C under external dc electric fields of +40 and -40 V to investigate the orientation of the molecules. Plots of the infrared absorbance versus polarization angle for representative bands were subjected to a curve fitting procedure by a least squares method. From the curves obtained the orientation of the transition dipole moments with respect to the molecular long axis and the orientation of the molecular long axis with respect to the rubbing direction of the cell were estimated based upon the suggested theory. The polarization-angle-dependent infrared spectra obtained were also analyzed by two-dimensional (2D) correlation spectroscopy. The 2D correlation analysis clearly detects a slight phase difference in the polarization-angle dependence which is hardly recognized in ordinary plots of the intensity changes in the infrared bands. The 2D correlation analysis allows us to separate asymmetric and symmetric stretching bands due to the chiral methyl group from those arising from other methyl groups in the alkyl chains.

GTP hydrolysis by transitional endoplasmic reticulum from rat liver inhibited by all-trans-retinol

GTP hydrolysis by an endoplasmic reticulum fraction from rat liver enriched in part-rough, part-smooth transition elements was inhibited by all-trans-retinol half maximally at a concentration of about 10 micrograms/ml. Similar results were obtained with GTPase activity partially purified by ion-exchange (DE-52) chromatography. The inhibition was non-competitive and given by both retinol and retinaldehyde but not by retinoic acid or alpha-tocopheryl acetate. The hydrolysis of other nucleoside di- and triphosphates was much less affected by retinol. The activity was inhibited by detergents but at much higher concentrations than by retinol. The results suggest that enhancement of cell-free transfer from endoplasmic reticulum to Golgi apparatus by retinol observed previously at low concentrations of cytosol may be mediated through an interaction with GTP.