Engraftment of human hematopoietic precursor cells with secondary transfer potential in SCID-hu mice

Human fetal bone fragments implanted subcutaneously in immunodeficient (SCID) mice maintain active human hematopoiesis. In this study, we show that this human hematopoietic microenvironment supports the engraftment and differentiation of HLA-mismatched, CD34+ primitive hematopoietic progenitor cells isolated from fetal and adult human bone marrow (BM). The BM CD34+ cells were depleted of CD2, CD14, CD15, CD16, glycophorin A, and CD19 lineage-committed cells (CD34+Lin-). Donor cell engraftment was manifested by the presence of B (CD19+) and myeloid (CD33+) cells of donor HLA phenotype. Successful engraftment was observed as early as 4 weeks after fetal BM donor cell injection and sustained for at least 12 weeks, with engraftment success rates of 100% (11/11 grafts) and 92% (11/12 grafts) at 8 and 12 weeks, respectively. Mixed BM chimerism of donor and endogenous cells was consistently observed in SCID-hu bones successfully engrafted with HLA-mismatched CD34+Lin- donor cells. Preconditioning of the SCID-hu bone with a single dose of sublethal (350 rad) whole body irradiation (WBI) immediately before cell injection enhanced the repopulation of the bone grafts with donor cells and, in some instances, resulted in complete repopulation. After WBI, as few as 500 fetal bone marrow CD34+Lin- cells injected in the human bone grafts resulted in donor-derived hematopoiesis. Donor progenitor cells recovered from the SCID-hu bone grafts 8 weeks postinjection had the capacity to repopulate secondary groups of HLA-disparate fetal human bones in SCID-hu mice with B and myeloid cells as well as CD34+ cells in some recipients. In addition, these cells repopulated fetal human thymus fragments in SCID mice with donor thymocytes including immature CD4+CD8+ and mature CD4+CD8- as well as CD4-CD8+ subsets. These results indicate that the fetal human bone implants of SCID-hu mice can support the maintenance of a cell population that has both multilineage potential and repopulating potential for periods of time as long as 16 weeks. The SCID-hu bone model consistently supported the engraftment of both fetal and adult CD34+Lin- cells without the administration of exogenous human cytokines to these animals. This model is currently being used to permit the isolation and characterization of candidate human hematopoietic stem cells (HSCs) and provide important information critical for human HSC therapy in humans.     

Circulation of human hematopoietic cells in severe combined immunodeficient mice after Cl2MDP-liposome-mediated macrophage depletion

Intravenous injection of dichloromethylene diphosphonate (Cl2MDP) encapsulated in liposomes results in specific elimination of macrophages in the spleen and liver of normal mice. Severe combined immunodeficient (SCID) mice were treated with Cl2MDP-liposomes followed by injection of human peripheral blood leukocytes. Control SCID mice had no detectable human cells within 72 hours as determined by fluorescence-activated cell sorting (FACS) analysis. However, Cl2MDP- liposome-treated animals maintained a large proportion (%) of human cells in peripheral blood and spleen for at least 12 days. Cl2MDP- liposome-injected SCID mice that had previously been implanted with human fetal thymus and liver showed a transient increase in human cell content in peripheral blood, and an accumulation of human cells specific to the white pulp of the spleen. These results indicate that murine mononuclear phagocytic cells may play an important role in the clearance of human cells injected intravenously or generated endogenously in SCID mice and that Cl2MDP-liposome-mediated macrophage depletion allows human hematopoietic cells to circulate and survive in SCID mice, thereby expanding the potential for studying human cellular processes in vivo.     

Effect of local anaesthetic infiltration with bupivacaine and ropivacaine on wound healing: a placebo‐controlled study

Infiltration of surgical wounds with long‐acting local anaesthetics (LA) is used to reduce postoperative incisional pain. We hypothesised that infiltration with LA interferes with wound healing in rats. Seventy‐two rats were allocated into nine groups. After intraperitoneal anaesthesia, the interscapular dorsal region was infiltrated with equivolumes of saline, 0·5% bupivacaine or ropivacaine, in a randomised double‐blind fashion. A standardised incision was performed in the infiltrated area and sutured closed. The rats were euthanised on the 3rd or 14th day after the operation and tissue from the incision site was subjected to histochemical analyses and mechanical testing (MT). Compared with the control group, bupivacaine displayed a significant increase in the macrophage number on day 3 (+63% versus +27% for ropivacaine). The transforming growth factor β‐1 expression had a significant increase in the LA (versus saline) groups, +63% in ropivacaine group and +115% in bupivacaine group on day 3 (P < 0·05). The collagen fibres as measured by dyed area were significantly higher in the bupivacaine group on day 3 (+56%, P < 0·01 versus +15% for ropivacaine). CD34 was reduced in bupivacaine group (?51%, P < 0·05 versus +3% for ropivacaine). On day 14, no statistical differences were observed in either LA group (versus saline) with respect to histopathologic or inflammatory mediators. MT on day 14 showed no differences between the LA and saline groups. The LA‐induced increases in histological markers did not extend beyond the third day, suggesting that wound infiltration with long‐acting LA does not impair the wound healing process in rats.     

THE HEPATOPULMONARY SYNDROME

Introduction

The hepatopulmonary syndrome has been acknowledged as an important vascular complication in lungs developing systemic hypoxemia in patients with cirrhosis and portal hypertension. Is formed by arterial oxygenation abnormalities induced from intrapulmonary vascular dilatations with liver disease. It is present in 4-32% of patients with cirrhosis. It increases mortality in the setting of cirrhosis and may influence the frequency and severity. Initially the hypoxemia responds to low-flow supplemental oxygen, but over time, the need for oxygen supplementation is necessary. The liver transplantation is the only effective therapeutic option for its resolution.

Aim

To update clinical manifestation, diagnosis and treatment of this entity.

Method

A literature review was performed on management of hepatopulmonary syndrome. The electronic search was held of the Medline-PubMed, in English crossing the headings "hepatopulmonary syndrome", "liver transplantation" and "surgery". The search was completed in September 2013.

Results

Hepatopulmonary syndrome is classically defined by a widened alveolar-arterial oxygen gradient (AaPO2) on room air (>15 mmHg, or >20 mmHg in patients >64 years of age) with or without hypoxemia resulting from intrapulmonary vasodilatation in the presence of hepatic dysfunction or portal hypertension. Clinical manifestation, diagnosis, classification, treatments and outcomes are varied.

Conclusion

The severity of hepatopulmonary syndrome is an important survival predictor and determine the improvement, the time and risks for liver transplantation. The liver transplantation still remains the only effective therapeutic.     

Gd-DTPA-enhanced MR imaging in pediatric patients after brain tumor resection

A prospective study was conducted in 15 pediatric patients who had undergone resection of intracranial tumors. The object of the study was to determine the safety and efficacy of magnetic resonance (MR) imaging performed after the administration of gadolinium diethylenetriamine-pentaacetic acid (Gd-DTPA) in evaluating residual or recurrent tumor. Precontrast T1-weighted, intermediate, and T2-weighted images were obtained at a field strength of 1.5 T. Gd-DTPA was then injected intravenously in a dose of 0.1 mmol per kilogram of body weight. T1-weighted images were obtained within 5 minutes after the injection, intermediate and T2-weighted images were obtained 10 minutes after the injection, and T1-weighted images were obtained approximately 20 minutes after the injection. None of the patients experienced allergic reactions or other side effects. Physical examination findings and laboratory values were unchanged after the Gd-DTPA-enhanced examination. In six patients, contrast-enhanced images depicted tumor not suspected on nonenhanced images. In four other patients, enhanced images provided better definition of the tumor core. The images of one patient with a brain stem tumor showed no evidence of enhancement. Pre- and postcontrast images of three previously treated patients showed no evidence of tumor. Gd-DTPA appears to be a safe and effective contrast agent for MR imaging and provides a more accurate method of imaging in the follow-up of brain tumors in pediatric patients.     

Central nervous system lymphoma: histologic types and CT appearance

The distribution of histologic types of lymphoma according to the proposed working formulation was determined for 55 patients with primary central nervous system (CNS) non-Hodgkin lymphoma. Fifty-five percent of these patients had diffuse large-cell histologic features. When the relationship between histologic type and computed tomographic (CT) appearance was analyzed, the following trends were noted: A greater percentage of mixed cell tumors were multiple when compared with other types; noncleaved small-cell tumors were more commonly located in the central gray matter or corpus callosum than were other types; all immunoblastic tumors were enhanced homogeneously, unlike other types; and smaller tumors appeared to be associated with an increased histologic grade. Eleven patients had CT confirmation of a CNS recurrence; in eight patients, the recurrent tumor was in a different location than the original lesion. Eleven patients had associated intraocular lymphoma, and four were immunosuppressed.     

脉压对颈动脉壁重构的影响——探讨Laplace定律对大血管重构的作用

目的血管壁的增厚和功能指数正越来越多的被用作评价心血管疾病的重要指标.然而大血管的结构、功能、压力的相互关系在活体上还没有很好的确定.我们研究组对一组正常和高血压病人进行了大血管的结构-功能-压力的相互关系的交叉研究.方法307例正常和高血压的人群被选择到此研究,其中男110例,女197例.年龄49～75岁.颈动脉内膜和中层厚度(Intima-media wall thickness,IMT)和内腔直径(Lumen diameter,LD)用Diasonic(DRF400)高分辨率超声来确定.血管壁环状压(Circumferential stress,Cs)是依据LAPLACE定律(δ=P×r/h)计算.其中压力(Pressure,P)用平均压和脉压两种方法计算.此动脉的结构和功能指数用年龄、身高和心率来校正.颈动脉压用无创压力感受器测定.结果共有70例高血压(BP＞140/90)患者.用年龄、身高和心率校正后的内中膜厚度和内腔直径在高血压组显著增加.而且IMT随着脉压的增大而增大(r=0.39,P＜0.001).内腔半径与内中膜厚度比值(R/IMT,R=LD/2)和环状压在高血压组明显增加.但是不管高血压或正常人群的R/IMT比值与脉压呈负相关关系(r=0.38,P＜0.001),而与平均压无关.结论在高血压状态下颈动脉壁重构是服从LAPLACE定律的,但颈动脉壁重构不足以抵销高血压状态下的血管壁环状压的增加.LAPLACE定律中关键性的血压指数可能是指脉压而非平均压.