New peritoneal dialysis solutions

Summary: Current peritoneal dialysis solutions are not biocompatible, particularly in respect to low pH, high osmolality and use of lactate. In addition, glucose is not an ideal osmotic agent. Recent advances in the formulation of peritoneal dialysis fluids aim to provide a more physiological environment to preserve membrane integrity. the effects of pH and lactate have been overcome by the use of bicarbonate based solutions whilst icodextrin (glucose polymers) often prolonged ultrafiltration in spite of being isomotic to uraemic plasma. Future formulations will see a combination of osmotic agents (including amino acids) and bicarbonate to achieve a more biocompatible solution whilst still meeting the ultrafiltration needs of the patients. Additives (glycosaminoglycans, procysteine) may protect the peritoneum from free radical injury.     

异种角膜片层间植入的组织相容性及形态学研究

采用层间囊袋分离法在２８只兔眼角膜上行角膜层间植入术，植片由人尸体角膜制成，最后进行观察并取得结果的２３只，术后观察３个月，角膜保持透明，形态学的主要特点是植片内角膜细胞缺如，内皮细胞形态结构未见明显影响，提示人眼角膜植片与兔眼角膜具有较好的组织相容性，为非人类角膜材料的应用提供了初步的经验与依据。     

Biocompatibility pattern of a bicarbonate/lactate-buffered peritoneal dialysis fluid in APD: a prospective, randomized study.

BACKGROUND: In chronic ambulatory peritoneal dialysis, bicarbonate-buffered fluids, with their neutral pH and less advanced glycosylation end-products (AGE) and glucose degradation products (GDP), have better biocompatibility than conventional peritoneal dialysis (PD) solutions. That difference may be more beneficial in automated peritoneal dialysis (APD), due to its more frequent exchanges and longer contact times with fresh dialysate. We performed a prospective, randomized study in APD patients to compare the biocompatibility of conventional and bicarbonate/lactate-buffered PD fluids. METHODS: We randomized 14 APD patients to have APD with either conventional or bicarbonate/lactate-based fluids. After 6 months, both groups changed to the other solution. The overall observation period was 12 months. After 1 and 5 months and again after 7 and 11 months, phagocytotic and respiratory burst capacities of effluent peritoneal macrophages were determined. Plasma interleukin (IL)-6 and C-reactive protein (CRP) as well as effluent IL-6, CRP, transforming growth factor (TGF)-beta 1, AGE and CA125 concentrations were measured. Inflow pain was quantified using a patient questionnaire. RESULTS: Respiratory burst capacity remained unchanged and phagocytotic activity increased significantly during APD (P<0.001) with the bicarbonate/lactate fluid. Effluent IL-6 release was significantly lower than with the lactate fluid (P<0.05). While in the effluent TGF-beta 1 was unaffected, AGE concentration was lower after bicarbonate/lactate treatment (P<0.05). Effluent CA125 concentration, an indicator of mesothelial cell integrity, was higher (P<0.05) in neutral effluents. Finally, patients' inflow pain diminished (P = 0.05) when using the neutral fluid. CONCLUSIONS: The use of a neutral PD fluid in APD improved patients' inflow pain as well as biocompatibility parameters reflecting enhanced phagocytotic activity of peritoneal macrophages, reduced constitutive inflammatory stimulation (IL-6), reduced AGE accumulation in the peritoneal cavity and better preservation of the mesothelial cell integrity. From the biocompatibility point of view, a neutral fluid with low GDP content can be recommended as the primary choice for APD.     

Endotoxin transfer through dialysis membranes: small- versus large-pore membranes.

In this in-vivo study, dialysate and serum endotoxin was evaluated before and after haemodialysis with small-pore (PS400) and large-pore (PS600) polysulphone dialysers, and before and after haemodiafiltration with the PS600 filter. The source of the endotoxin was the presence in dialysate of Pseudomonads at a concentration of 10(3)-10(4) CFU/ml. Endotoxin was measured by a modified chromogenic limulus amoebocyte lysate (LAL) assay. In spite of dialysate endotoxin concentrations greater than 100 pg/ml, no changes in pre- versus posttreatment LAL reactivity were observed in PS400 dialysis and PS600 haemodiafiltration. In contrast, PS600 haemodialysis was related to an increase in serum LAL reactivity from 1.3 +/- 1.5 to 3.8 +/- 2.0 pg/ml (n = 15, P less than 0.01), and five patients (33.3%) showed a post-dialysis value in excess of 5 pg/ml. Our data are consistent with the absence of in-vivo endotoxin transfer during haemodialysis with small-pore dialyser membranes, and during haemodiafiltration with membranes with larger pores. An increase in LAL reactivity during haemodialysis with membranes with larger pores is, however, present, presumably due to the occurrence of backdiffusion/filtration with that specific strategy.     

Cell-associated adhesion molecules as early markers of bioincompatibility

BACKGROUND.: Transient nature of adhesive interactions occurring during cellmargination is mainly dependent on expression of selectins whichare shed by activated cells. This shedding in the circulationmay play an important role as anti-inflammatory mediator. Haemodialysisis also associated with P-selectin (CD62P)/sialyl-Lewisx (CD15s)interactions which mediate platelet-leukocyte coaggregation.We further investigated the mechanisms underlying leukocytemargination during haemodialysis. METHODS.: CD15s, CD11b and CD61 expression on circulating leukocytes frompatients dialysed on synthetic membranes (modified polyacrylonitrile(SPAN), polysulphone (PS), and polyacrylonitrile (AN69) wasassessed by cytofluorometry in a prospective crossover trial.We measured plasma levels C3a/C3a desArg, soluble CD62P, andCD62E molecules obtained from patients and healthy individuals. RESULTS.: Expression of CD11b and CD15s was upregulated on neutrophilsfrom patients dialysed with SPAN and PS membranes during thedialysis session. A significant negative correlation was foundbetween the expression of CD11b or CD15s molecules and neutrophilcounts as well as between CD15s expression and monocyte countsduring haemodialysis. As assessed by CD61 expression on leukocytes,we observed that platelets bound significantly onto both neutrophilsand monocytes during dialysis with both membranes. A significantpositive correlation was found between the expression of CD11bmolecules and the percentage of CD61 ⁺ monocytes counts duringSPAN and PS dialysis. We found a significant increase of solubleCD62P in plasma samples obtained from haemodialysed patientsbefore the dialysis session as compared to the levels detectedin plasma from healthy individuals. CONCLUSIONS.: This study documents a major role of CD15s, CD11b, CD61, CD62Pmolecules in the transient leukocytes activation and marginationduring haemodialysis on synthetic membranes despite their lowcomplement-activating properties.     

牙龈成纤维细胞与牙周韧带细胞在二种玻璃离子水门汀上附着及增？…

目的 比较人类牙龈成纤维细胞（ＨＧＦ）与牙周韧带细胞（ＰＤＬＣ）在两种玻璃离子水门汀（ＧＩＣ）上的附着及增殖情况。方法 利用体外细胞培养技术及＾３Ｈ－ＴｄＲ掺入法检测ＨＧＦ及ＰＤＬＣ在两种ＧＩＣ上的附着及ＤＮＡ合成。结果 ＨＧＦ与ＰＤＬＣ在培养板上的附着及ＤＮＡ合成差异无显著性（Ｐ〉０．０５）,但ＨＧＦ在ＧＩＣ上的附着及ＤＮＡ合成明显强于ＰＤＬＣ（Ｐ〈０．０５）。结论 Ｋｅｔａｃ Ｆｉｌ和Ｆｕｊｉ     

羟基磷灰石根管充填诱导根尖形成的临床研究

目的：探讨羟基磷灰石（hydroxyapatite,HA）诱导根尖形成的性能。方法：选择90例根尖未发育完成合并牙髓病或根尖病的年轻恒牙，分3组分别充填HA糊剂，氢氧化铝糊剂（Ca(OH)2)氧化锌丁香油糊剂（ZOE）诱导根尖形成于治疗后1年、2年随访评价临床疗效。结果：HA糊剂、Ca(OH)2糊剂、ZOE糊剂3组疗效无显著性差异。结论：HA糊剂充填根管具有诱导根尖形成的能力。     

壳聚糖脑组织相容性的实验观察

目的:探讨壳聚糖在脑组织中的生物相容性,为临床提供新型、可用于颅内植入化疗的药物缓释载体.方法:32只SD大鼠随机分为实验组和对照组,分别植入壳聚糖颗粒和明胶海绵.观察术后的行为改变和3,7,14,30 d时的局部组织反应(HE染色).结果:所有动物无明显行为改变.术后3,7,14.30 d的组织学观察表明,实验组与对照组有类似的异物反应(P<0.05),且随时间推移,壳聚糖有不同程度降解.结论:壳聚糖可在脑组织内降解,且脑组织生物相容性良好.可作为颅内植入缓释化疗基质之一.     

新型骨替代材料硅磷酸钙的生物相容性实验研究

目的:评价新型骨替代材料硅磷酸钙的生物相容性,从而为其在骨缺损修复领域中的临床应用提供依据。方法:分别选用含10%、5%硅酸钙的硅磷酸钙,分别进行急性毒性试验、肌肉植入试验。结果:含10%与5%硅酸钙的硅磷酸钙无急性全身毒性,对肌肉组织无刺激,植入肌肉后呈降解趋势。结论:新型骨替代材料硅磷酸钙具有良好的生物相容性。     

纳米羟基磷灰石/壳聚糖支架材料复合大鼠成骨细胞培养的实验研究

目的 将纳米羟磷灰石/壳聚糖(nHA/CS)支架材料与大鼠的成骨细胞在体外复合培养,研究其生物相容性,以期在骨组织工程支架材料的选择方面提供依据.方法 原代培养大鼠成骨细胞,倒置显微镜作细胞形态学观察,碱性磷酸酶(ALP)染色和茜素红钙染色对细胞进行鉴定.将第三代细胞与nHA/CS材料体外复合培养,采用MTT比色法和...