Resection for ruptured duodenal varices secondary to portal hypertension.
Explore the source record for details and available documents.
Aged↗
Biomedical subjects
Bing Liu
Publications and source records attributed to Bing Liu.
[The mistakes of E. Dinc's double divisor-ratio spectra derivative method].
Double divisor-ratio spectra derivative method has been developed and applied to determining two ternary mixtures simultaneously by E. Dinc. In fact, E. Dinc's double divisor-ratio spectra derivative method is completely wrong. It can not be applied to determining ternary mixtures simultaneously. This paper proves the Mistake of E. Dinc's method in both theory and practice.
Algorithms↗
Regioselective palladium-catalyzed arylation of 3-carboalkoxy furan and thiophene.
[reaction: see text] The regioselective palladium(0)-catalyzed arylation of 3-furoate and 3-thiophenecarboxylate esters with aryl bromides is described. Conditions were developed that allow for the selective synthesis of either 2-aryl or 5-aryl products.
Catalysis↗
Extinction and permanence of a two-prey one-predator system with impulsive effect.
In this paper, we investigate a two-prey one-predator system with impulsive effect on the predator of fixed moment. By using Floquet's theorem and small-amplitude perturbation skills, we show that there exists a globally asymptotically stable two-pest eradication periodic solution when the impulsive period is less than some critical value. Further, we prove that the system is permanent if the impulsive period is larger than some critical value, and meanwhile the conditions for the extinction of one of the two prey and permanence of the remaining two species are given. Finally, numerical simulation shows that there exists a stable positive periodic solution with a maximum value no larger than a given level. Therefore, we can use the stability of the positive periodic solution and its period to control insect pests at acceptably low levels.
Animals↗
Electron microscopic immunogold localization of salivary mucins MG1 and MG2 in human submandibular and sublingual glands.
The human salivary mucins MG1 and MG2 are well characterized biochemically and functionally. However, there is disagreement regarding their cellular and glandular sources. The aim of this study was to define the localization and distribution of these two mucins in human salivary glands using a postembedding immunogold labeling method. Normal salivary glands obtained at surgery were fixed in 3% paraformaldehyde-0.1% glutaraldehyde and embedded in Lowicryl K4M or LR Gold resin. Thin sections were labeled with rabbit antibodies to MG1 or to an N-terminal synthetic peptide of MG2, followed by gold-labeled goat anti-rabbit IgG. The granules of all mucous cells of the submandibular and sublingual glands were intensely reactive with anti-MG1. No reaction was detected in serous cells. With anti-MG2, the granules of both mucous and serous cells showed reactivity. The labeling was variable in both cell types, with mucous cells exhibiting a stronger reaction in some glands and serous cells in others. In serous granules, the electron-lucent regions were more reactive than the dense cores. Intercalated duct cells near the acini displayed both MG1 and MG2 reactivity in their apical granules. In addition, the basal and lateral membranes of intercalated duct cells were labeled with anti-MG2. These results confirm those of earlier studies on MG1 localization in mucous cells and suggest that MG2 is produced by both mucous and serous cells. They also indicate differences in protein expression patterns among salivary serous cells.
Adult↗
Should household contact examination in a low endemic situation of leprosy continue?
After more than 40 yrs of effort, leprosy is finally under control in Shandong province with only 50 to 70 new cases detected each year in the past 10 yrs. Contact examination is still compulsory and household contacts will be followed for 5 to 10 yrs, as directed by the guidelines of the national leprosy control program. In order to assess the value of contact examination in terms of case finding in a low endemic situation of leprosy in Shandong, we analyzed the data regarding all newly diagnosed leprosy cases in the past 11 yrs using the data abstracted from the national leprosy recording and reporting system, and a questionnaire-based survey to see how many incident leprosy cases would be detected if we followed the policy for contact examination of leprosy in Shandong. The results showed that 252 out of 547 leprosy cases diagnosed from 1990 to 2001 reported they had contact with different categories of primary leprosy cases. Among them, 90 cases had household primary leprosy cases. The mean incubation of the 252 index cases was 23 yrs. If we followed the national policy for contact tracing for 5 or 10 yrs, then only 12 (13.3%) and 10 (11.1%) of the 90 cases whose source of infection was household contacts would have been detected, respectively. Therefore, other approaches should be sought, in order to detect the few incident leprosy cases as early as possible in such a low endemic situation of leprosy in Shandong.
China↗
Isolation of mouse marrow mesenchymal progenitors by a novel and reliable method.
Bone marrow contains a population of rare progenitor cells capable of differentiating into osteoblasts, chondrocytes, adipocytes, myoblasts, and hematopoiesis-supporting stromal cells. These cells, referred to as mesenchymal progenitor cells (MPCs), can be purified and culture-expanded from animals and humans. Using bone-marrow-conditioned medium combined with basic fibroblast growth factor, we cultured a relatively homogeneous population of MPCs from murine bone marrow, which uniformly expressed stem cell antigen-1, CD29, CD44, c-kit, and CD105, while being negative for expression of CD45, CD31, and CD34. In vitro differentiation assays showed the tripotential differentiation capacities of these cells toward adipogenic, osteogenic, and chondrogenic lineages. Most importantly, immunophenotypic analyses demonstrated that MPCs did not express major histocompatibility complex class II molecules or the T-cell costimulatory molecules CD80 and CD86, consistent with further investigation showing that MPCs failed to elicit a proliferative response from allogeneic lymphocytes. Moreover, when allogeneic or third-party MPCs were added to T cells stimulated by allogeneic lymphocytes or the potent T-cell mitogen concanavalin-A, a significant reduction in T-cell proliferation was observed. In conclusion, our data demonstrate that we successfully isolated and culture-expanded a relatively homogeneous population of MPCs from adult murine bone marrow. Additionally, these primary cells could suppress T-lymphocyte proliferation induced by cellular or nonspecific mitogenic stimuli. This immunoregulatory feature of MPCs strongly implies that they may have potential applications in allograft transplantation.
Animals↗
[Investigation of in vitro hematopoietic differentiation of embryonic stem cell line established from C57BL/6 mice].
Embryonic hematopoiesis in mammals is characterized by successive temporal and spatial changes. Previous investigations indicate that in vitro differentiation of embryonic stem cells (ES cells) derived from 129 mice can mimic embryonic hematopoiesis to some extent. To investigate the in vitro hematopoietic differentiation capacity of ES cells derived from C57BL/6 mice, the authors initially established the murine ES cell line with standard identification methods employed. Next, two-step culture system was utilized for embryoid bodies formation and the appearance of different hematopoietic precursors was confirmed by CFC assay, cellular chemical staining as well as RT-PCR. The results demonstrated that the ES cell line MES-1 fulfilled the criteria of ES cell line and its progeny after in vitro differentiation included primitive and definitive erythrocyte precursors, mixed colony-forming cells and granulocyte/macrophage colony-forming cells. RT-PCR analysis revealed the molecular consistence of transcription factors and hematopoietic markers with cellular event. In conclusion, MES-1 established from C57BL/6 mice was able to differentiate in vitro to a variety of hematopoietic precursors, thus could partly recapitulate embryonic hematopoiesis.
Animals↗
Effects of N-n-butyl haloperidol iodide on rat myocardial ischemia and reperfusion injury and L-type calcium current.
AIM: To study the effects of N-n-butyl haloperidol iodide (F2) on rat heart ischemia/reperfusion (I/R) injury and L-type calcium current (ICa) in rat ventricular myocytes. METHODS: Rat heart I/R injury was induced by occluding the left anterior descending coronary artery for 30 min and restoring perfusion for 30 min. F2 (1, 2, and 4 mg/kg) were i.v. injected before ischemia. Plasma creatine kinase (CK), creatine kinase isoenzyme MB (CK-MB), lactate dehydrogenase (LDH), alpha-hydroxybutyrate dehydrogenase (HBDH), glutamic-oxaloacetic transaminase (GOT), malondialdehyde (MDA) concentrations, and superoxide dismutase (SOD) activity were measured. The pathologic changes of I/R myocardium were assessed by the transmission electron microscopy. Single rat ventricular myocyte was obtained by enzymatic dissociation method. The currents were recorded with the whole-cell configuration of the patch-clamp technique. RESULTS: F2 reduced the release of CK, CK-MB, LDH, HBDH and GOT, preserved the activity of SOD, and decreased the MDA contents dose-dependently. For morphology, F2 mollified the pathologic changes of myocardium induced by I/R injury. F2 1 micromol/L decreased ICa from (1775+/-360) pA to (464+/-129) pA (n=8, P<0.01) and shifted the current-voltage of ICa upward, without affecting the voltage-depend-ent properties of ICa. CONCLUSION: F2 played a protective role against rat heart I/R injury in a dose-dependent manner, and inhibited ICa in rat ventricular myocytes. The cardioprotective and vasodilatory mechanisms of F2 may be related to its inhibitory effect on L-type calcium channel.
Animals↗
[Effect of bone marrow mesenchymal stem cells on hematopoietic differentiation of murine embryonic stem cells].
Mesenchymal stem cells (MSCs), precursors of diverse stromal cells, can support hematopoiesis in vitro and can promote the implantation of hematopoietic stem cells in vivo when co-transplanted with CD34(+) cells. The aim of this study was to investigate the potential effect of MSCs on the hematopoietic development of embryonic stem cells (ES cells) and the feasibility of a novel system in which ES cells will be co-cultured with MSCs. The murine bone marrow MSCs were isolated and cultured and then their phenotype and differentiation function were identified with FCM and histochemical technique. The CCE cells, murine ES cell line, were co-cultured with the isolated MSCs and the hematopoietic differentiation of CCE cells was observed with hematopoietic clonogenic assay and RT-PCR. The results showed that the morphology of MSCs became gradually homogeneous with the passage culture of cells. After passage 4, the marker of Sca-1, CD29, CD44 and CD105 were highly expressed, however, CD34 and CD45, the specific marker of hematopoietic and endothelial cells, could hardly be identified. The isolated MSCs differentiated into adipocytes and osteoblasts in specific induction culture system. After maintaining culture on mouse embryonic fibroblasts, CCE cells were plated in suspended culture system with only differentiation inductive agents and co-culture system in which MSCs were added. Compared with CCE cell suspended culture, the cells differentiated into embryoid body were obviously enhanced and there were no colony-forming cells in the co-culture system of ES cells and MSCs. In addition, transcription factor Oct-4 in co-cultured CCE cells was expressed and hematopoietic markers, Flk-1, GATA-1 and beta-H1, were negative. The ability of embryoid bodies derived from the co-culture system to produce hematopoietic colonies was markedly higher than that from the suspended culture system. It is concluded that MSCs inhibit the initial differentiation of ESC and enhance hematopoietic differentiation ability of the co-cultured ES cells.
Animals↗
[Generation of high proliferative potential hematopoietic progenitor cells from embryonic stem cell-derived BL-CFC].
The blast colony-forming cells (BL-CFC), which are detected within embryoid bodies derived from embryonic stem cells (ES cells) differentiated for 2.5-3.5 days, have dual-potential of differentiation to hematopoietic and endothelial cells. In this investigation the culture method of BL-CFC was established and colony forming assay, immunofluorescent technique as well as nested RT-PCR was employed to identify the differentiation capacity of adherent and nonadherent cells derived from individual blast colony. The results showed that the adherent cells could intake DiI-Ac-LDL and expressed the endothelium-specific surface markers including CD31, UEA-I and VE-cadherin. In addition, nonadherent cells were capable of developing primitive or/and definitive hematopoiesis potential. High proliferative potential colony-forming cells (HPP-CFC) bearing self-renewal capacity was found in 20% of BL-CFC. It is concluded that BL-CFC derived from embryonic stem cells can generate high proliferative potential hematopoietic progenitor cells. However, the whether BL-CFC can reconstitute the adult bone marrow hematopoiesis in long-term remains to be further determined.
Animals↗
[Four cases of primary neuroendocrine carcinoma in ear, nose, pharynx and larynx].
OBJECTIVE: To discuss the clinical pathologic features and therapeutic method of the primary neuroendocrine carcinoma in ear, nose, pharynx, larynx. METHOD: One case of atypical carcinoid tumor in larynx is treated by epiglottidectomy. One case of atypical carcinoid tumor in rhinopharynx is treated by radiotherapy. One case of typical carcinoid tumor in middle ear is treated by exploratory incision and radical mastoidectomy. One case of small cell neuroendocrine carcinoma in right nasal cavity is treated by resection and radiotherapy. RESULT: The patient of atypical carcinoid tumor in larynx died after 5 years and the patient of atypical carcinoid tumor in rhinopharynx died after 1 year. The patient of typical carcinoid tumor in middle ear was followed-up 3 years and the patient of small cell neuroendocrine carcinoma in right nasal cavity was followed-up 2 years, and the carcinomas didn't recrudesce. CONCLUSION: The primary neuroendocrine carcinoma in ear, nose, pharynx, larynx is classified in three states: typical carcinoid tumor, atypical carcinoid tumor and small cell neuroendocrine carcinoma. Typical carcinoid tumor is a kind of low malignant tumor and small cell neuroendocrine carcinoma is a kind of high malignant tumor and atypical carcinoid tumor is a kind of medium malignant tumor. The chief therapeutic method of the primary neuroendocrine carcinoma in ear, nose, pharynx, larynx is surgical intervention.
Aged↗
[The investigation of hematopoietic capacity of HPP-CFC derived from murine embryonic stem cells in vitro and in vivo].
The hematopoietic system of the mouse arises from extraembryonic mesoderm that migrate through primitive streak to the presumptive yolk sac at day 7.0 of gestation. However, the mechanisms regulating mesoderm commitment to hematopoietic lineages remain poorly understood. Previous studies demonstrated that the development kinetics and growth factor responsiveness of hematopoietic precursors derived from embryonic stem cells (ES cells) is similar to that found in the yolk sac, indicating that the onset of hematopoiesis within the embryoid bodies (EBs) parallels that found in the embryo. Furthermore, in vitro differentiation of ES cells to hematopoietic cells is valuable for establishment of therapeutic clone against a variety of hematological disorders. Despite the identification of multipotential hematopoietic progenitors in EBs, a subset of more primitive progenitors, identical to the high proliferative potential colony-forming cells (HPP-CFC) derived from human and murine hematopoietic tissues, have not been clearly identified regarding particular their replating potential in vitro. HPP-CFC is among the most primitive hematopoietic multipotent precursors cultured in vitro. In this study, our aim was to investigate the in vitro and in vivo hematopoietic capacity of HPP-CFC within the day 12 EBs, rather than the expansion of more committed progenitors. In this study the HPP-CFC could be detected within EBs differentiated for 5 to 14 days of murine ES cells, but the development dynamics of the HPP-CFC differed greatly among distinct serum lots. Qualitatively HPP-CFC is capable of forming secondary colonies. As to our expectation the ES cells-derived HPP-CFC demonstrated similar regeneration capacity to those from yolk sac, giving rise to secondary granulocyte, erythrocyte, macrophage and mast cells, however largely differed from the counterparts of adult bone marrow. In addition, by RT-PCR ES cells-derived HPP-CFC were found to express transcription factors associated closely with stem cell proliferation including SCL, GATA-2 and AML1 as well as various receptors of hematopoietic growth factors such as c-kit, GM-CSF receptor and interleukin 3 receptor et al. Finally, in order to understand the in vivo hematopoietic capacity of the ES cells-derived HPP-CFC, spleen colony-forming unit (CFU-S) assay was performed. Nevertheless, typical CFU-S was not observed after transplantation of the day 12 EB cells or HPP-CFC colonies into lethally irradiated adult murine. In conclusion the HPP-CFC differentiated from murine ES cells displayed robust hematopoietic activity in vitro, however their in vivo reconstitution ability was not detected. The difference between in vitro and in vivo hematopoietic activities of ES cells-derived primitive hematopoietic precursors deserves further investigation.
Animals↗
[Expansion of bone marrow LTC-ICs in vitro by mouse fetal liver-derived stromal cell lines].
As main component of fetal liver hematopoietic microenvironment, different stromal cells may play distinct roles in the regulation of hematopoietic stem cell self-renewal, proliferation and differentiation. It is a unique approach to establish stromal cell lines for analyzing the interaction of hematopoietic cells with the stroma on the clonal level to dissect the function of hematopoietic microenvironment. In this study two immortal stromal cell lines-A4, B3 were established from mouse embryonic day 12.5 fetal liver by transfection of pSV3 neo plasmid. A4 exhibited a fibroblast-like morphology, 25 hours population doubling time as well as high levels of CD29, CD44, UEA-1 and low levels of CD105 expression. In contrast B3 displayed an epithelium-like morphology, 37 hours population doubling time along with high levels of CD105 and low levels of UEA-1 expression. In addition no or low levels of CD31, CD34, CD45 and CD144 expression were found in the two cell lines. These results indicate that A4, B3 are two discriminating cell lines in terms of morphological characters, growth behaviors and surface molecular expression types. Next functional assays using Limited-Diluted Assay(LDA) and Bulk-LTC-IC were done: both stromal cell lines had similar ability to maintain the survival proportion of inoculated mouse bone marrow-derived Long-Term Culture-Initiating Cells (LTC-ICs), and they could also support LTC-ICs expansion up to 4 weeks by co-culture in vitro. More strikingly, B3 could expand the absolute number of LTC-ICs over 13-fold at week 4 than that of week 0, and the ability of B3 to expand absolute number of LTC-ICs was over 8-fold of that of A4. Proportions of LTC-ICs in proliferating cell populations in two long-term culture systems was similar at week 4, no matter with or without extra cytokines. Further study indicated that the ability of LTC-ICs to yield CFCs was held as the number 6( +/- 1.2) after 4 weeks co-culture. Extra cytokines-SCF + IL-3 + IL-6 + Epo had no influence in the maintenance and expansion of LTC-ICs, but expanded the absolute number of CFCs and proliferating cell populations, and maintained similar proportions of LTC-ICs and CFCs in the end in two culture systems at week 4. Take together, these results implicate that B3 may act as an important functional component in embryonic day 12.5 fetal liver microenvironment to effectively expand primitive hematopoietic cells, yield more committed hematopoietic progenitor cells and mature hematopoietic cells to meet the need of quick development especially in the early phase of embryonic development. Alternatively A4 can probably function as being a structural element. Moreover the function of hematopoiesis-associated cytokines employed in this investigation was not to expand LTC-ICs, but to modulate the limited-proliferation and differentiation of CFCs. The maintenance and proliferation of LTC-ICs may depend on the type of the stromal cell as well as the interaction between stromal cells and LTC-ICs. It is suggested that B3 with cytokines including SCF, IL-3, IL-6, EPO in vitro can mimic embryonic day 12.5 hematopoietic microenvironment to investigate the mechanism of interaction between hematopoietic microenvironment and hematopoietic cells in clonal level.
Animals↗
Experimental studies of the Universal Chemical Key (UCK) algorithm on the NCI database of chemical compounds.
We have developed an algorithm called the Universal Chemical Key (UCK) algorithm that constructs a unique key for a molecular structure. The molecular structures are represented as undirected labeled graphs with the atoms representing the vertices of the graph and the bonds representing the edges. The algorithm was tested on 236,917 compounds obtained from the National Cancer Institute (NCI) database of chemical compounds. In this paper we present the algorithm,some examples and the experimental results on the NCI database. On the NCI database, the UCK algorithm provided distinct unique keys for chemicals with different molecular structures.
Algorithms↗
Disruption of Smad5 gene leads to enhanced proliferation of high-proliferative potential precursors during embryonic hematopoiesis.
SMAD proteins are downstream signal transducers of the transforming growth factor beta (TGF-beta) superfamily, which serve as pleiotropic regulators in embryonic and adult hematopoiesis. SMAD5, initially considered to mediate bone morphogenetic proteins (BMPs) signals, can also transduce the inhibitory signal of TGF-beta1 on proliferation of hematopoietic progenitors derived from human bone marrow. To define its specific role in regulation of primitive multipotential progenitors during early embryonic hematopoiesis, we examined Smad5(-/-) yolk sacs at E9.0 to 9.5 and detected an elevated number of high-proliferative potential colony-forming cells (HPP-CFCs) with enhanced replating potential. To exclude the possible influence of microenvironmental deficit on embryonic hematopoiesis in vivo, we performed in vitro embryonic stem (ES) cell differentiation assay and investigated the HPP-CFCs in particular. Smad5(-/-) embryoid bodies (EBs) contained an elevated number of blast colony-forming cells (BL-CFCs), the in vitro equivalent of hemangioblast, in contrast to reduced proliferation of primitive erythroid precursors (Ery/Ps) within the mutant EBs. More importantly, profoundly increased frequency of HPP-CFCs, featured with a gene-dosage effect, was detected within day 6 Smad5(-/-) EBs compared with the wild type. In addition, Smad5(-/-) HPP-CFCs displayed enhanced self-renewal capacity and decreased sensitivity to TGF-beta1 inhibition, suggesting a critical role of Smad5 in TGF-beta1 regulation of embryonic HPP-CFCs. Consistently, reverse transcription-polymerase chain reaction analysis detected alterations of the transcription factors including GATA-2 and AML1 as well as cytokine receptors in Smad5(-/-) HPP-CFC colonies. Together, these data define an important function of SMAD5 in negative regulation of high-proliferative potential precursors during embryonic hematopoiesis.
Animals↗
Phosphine-catalyzed annulation of thioamides and 2-alkynoates: a new synthesis of thiazolines.
The annulation of thioamides with 2-alkynoates and 2,3-dienoates under the catalysis of tri-n-butylphosphine was described. The annulation reaction provided a new entry to thiazolines, particularly those with 2-aryl substituents.
Journal Article↗
Expression of swelling- and/or pH-regulated chloride channels (ClC-2, 3, 4 and 5) in human leukemic and normal immune cells.
Chloride channels on immune cells reportedly play important roles in cell volume regulation, cell proliferation and immune functions, but they are not well characterized at the molecular level. We examined the expression of swelling-and/or pH-regulated chloride channels (ClC-2, 3, 4 and 5) in human leukemic cell lines [Jurkat and Hut-78 (T cells), Raji and Daudi (B cells), K-562 and HL-60 (myeloid cells)] and T cells, B cells and neutrophils from 8 normal subjects to clarify the difference of their expression among different cell types and maturity. Semi-quantitative RT-PCR and Northern blot analysis showed that ClC-3 was most abundantly expressed in all cells regardless of the cell types and maturity, while expression of ClC-2 was weak in these cells. Expression of ClC-4 was observed mainly in leukemic B cell lines, and in B cells and neutrophils from normal subjects. ClC-5 was expressed in all cell lines, while it was observed in only T and B cells but not in neutrophils from normal subjects. Thus, these chloride channels (ClC-2, 3, 4 and 5) showed distinct distribution among human immune cells, suggesting that they have specific roles in these cells. Molecular identification of chloride channels in leukocytes of different types and maturity may provide a new approach for the treatment of leukemia.
Adult↗