Low-density lipoprotein apheresis in children with familial hypercholesterolemia: follow-up to 21 years

Twenty-seven patients (14 girls, 13 boys) affected by familial hypercholesterolemia who had begun low-density lipoprotein (LDL) apheresis treatment before the age of 15 were studied. The median age at diagnosis was 4 years and the blood LDL cholesterol level was 704 +/- 163 mg/dL. Screening was performed for homozygous or double heterozygous mutations of the LDL cholesterol receptor gene and mutations were found in 24 of the patients. The mean age at the beginning of treatment was 8.5 years and the mean length of follow up was 12.6 years. The two main procedures used were direct adsorption of lipoproteins and dextran sulfate cellulose adsorption. Nine patients experienced anaphylactic reactions due to bradykinin and six had to have their treatment changed. The LDL cholesterol level before the session was lowered by 45 +/- 11% of the value at diagnosis. The LDL cholesterol reduction in a session was 72 +/- 10%. Tendinous xanthomas disappeared or diminished dramatically in 62% of the children. In 22 patients no cardiovascular event occurred during LDL apheresis treatment. Three had angina pectoris; two others had surgical management of aortic stenosis, but no clinical manifestations. Seven children had normal cardiovascular pictures while on treatment. Eleven had abnormalities of the aortic root or coronary arteries, which in six cases had appeared before treatment; the other five children did not undergo prior cardiac evaluation. In five children the abnormalities appeared during treatment. Based on these data, LDL-apheresis can be recommended for the treatment of homozygous familial hypercholesterolemia, even in young children, with good efficiency on biological parameters, cutaneous lesions and cardiovascular events.     

Sequential Treatment of Guillain-Barré Syndrome with Extracorporeal Elimination and Intravenous Immunoglobulin

Abstract: Plasma exchange and administration of intravenous immunoglobulin (IgG) are established treatments for Guillain-Barré syndrome (GBS). Elimination of postulated pathogenetic factors by plasma exchange or selective adsorption treatment using affinity-type adsorption columns and subsequent immunomodulation by intravenous IgG may provide a more effective treatment. Forty-five patients with acute GBS were prospectively examined using a clinical score. We treated 11 patients by plasma exchange, 13 patients by selective adsorption using a tryptophan-linked polyvinyl alcohol gel adsorbent, and 21 patients by selective adsorption followed by intravenous IgG. The patients treated sequentially by selective adsorption and intravenous IgG improved significantly better than the patients who received plasma treatment only. The results suggest that sequential treatment of GBS may be superior to plasma treatment alone. The higher cost of combined treatment may be offset by lower overall expenditure.     

Temperature-dependent adsorption/desorption behavior of lower critical solution temperature (LCST) polymers on various substrates

We have been studying adsorption and retention (resistance to desorption) behavior of temperature sensitive LCST polymers on different substrates as a function of temperature. According to our studies with Poly 64 (a copolymer of 60% (mol) NIPAAm and 40% (mol) NnBAAm, LCST = 8.5°C in water), the copolymer retention depends on the rinse temperature. When the rinse temperature is above the LCST, the polymer adheres well to most surfaces. On the contrary, at rinse temperatures below the LCST, most of the adsorbed polymer is easily rinsed off. These studies are relevant to our work on the thermally reversible adsorption of LCST polymers conjugated to peptides and proteins, such as affinity ligands, for uses in immunoassays and affinity separations. The interaction between the LCST polymer and most hydrophobic polymer surfaces is mainly due to hydrophobic interactions, and the critical surface tension (γc) and the solubility parameter (δ) of the solid polymer substrate are the most important factors which influence the LCST polymer adsorption and retention. The critical surface tension appears to correlate best with the LCST polymer adsorption levels on different substrates, while the solubility parameter correlates best with the retention of the adsorbed polymer. According to our preliminary study, n-butyl groups probably interact more strongly with the substrates than isopropyl groups because of the greater hydrophobic surface area of the former groups.     

Adsorption behavior of fibrinogen to sulfonated polyethyleneoxide-grafted polyurethane surfaces

Fibrinogen adsorptions to surface modified polyurethanes (PU, PU-PEO, and PU-PEO-SO₃) were studied from plasma in vitro. PU and PU-PEO surfaces demonstrated that initial adsorption increases with increasing plasma concentration in kinetic profiles and adsorption time in adsorption profiles as a function of plasma concentration, but after the plateau is reached, its adsorption amount decreases as plasma concentration (0.2-2.0%) and adsorption time (1-120 min) increase, respectively. In contrast, PU-PEO-SO₃ showed that initial adsorption is almost same regardless of plasma concentration and adsorption time, which is due to the high affinity of surface sulfonate group to fibrinogen. All the surfaces indicated the Vroman effect at about 0.6% plasma concentration; however, the displacement was relatively low. Adsorbed amount of fibrinogen at steady state decreased in the order: PU > PU-PEO-SO₃ > PU-PEO, regardless of adsorption time and plasma concentration. The adsorption behavior of PU-PEO-SO₃ is attributed to both effect of low binding affinity of PEO chain and high affinity of pendant sulfonate group toward fibrinogen.     

Surface studies of albumin immobilized onto PE and PVC films

The aim of this study is to evaluate the thrombogenic behaviour of the low density polyethylene and poly(vinyl chloride) modified by radiation-grafting technique. After copolymerization with acrylic acid by y-rays from a ⁶⁰Co source, BSA was immobilized onto functionalized graft copolymers. The biological interaction between these materials and blood was studies by in vitro methods. The BSA immobilization effectively suppressed the adhesion and activation of platelets when it contacted whole blood.     

Plasma gas discharge deposited fluorocarbon polymers exhibit reduced elutability of adsorbed albumin and fibrinogen

The adsorption and subsequent detergent elutability of fibrinogen and albumin were measured on various treated and untreated polymer films in order to determine whether the relative adsorption of these proteins was responsible for the enhanced thromboresistance of Dacron vascular grafts treated with tetrafluoroethylene in a radio frequency glow discharge (RFGD) apparatus. Fluorocarbon-coated surfaces varying in the relative proportions of CF, CF₂' and CF groups and in the ratio of fluorine to carbon were prepared by RFGD treatment of poly(ethylene terephthalate) (PET) films with tetrafluoroethylene or perfluoropropane. The adsorption of fibrinogen and albumin to these fluorocarbon-coated surfaces was comparable to the adsorption of the proteins to polytetrafluoroethylene (PTFE) and PET. However, the elutability of fibrinogen and albumin from the RFGD fluorocarbon surfaces with sodium dodecyl sulfate was much lower than that from PTFE or PET. Other RFGD treatments of PET, such as ethylene deposition or argon etching, did not reduce the extent of albumin elutability as dramatically as did the RFGD fluorocarbon treatments. The strong albumin binding to RFGD fluorocarbon surfaces may be exploited clinically to enhance the retention of albumin preadsorbed to blood-contacting surfaces fo render them thromboresistant.     

Effect of different composite modulation protocols on the conversion and polymerization stress profile of bulk-filled resin restorations

ObjectiveThe aim of this in vitro study was to test the effect of different composite modulation protocols (pre-heating, light-curing time and oligomer addition) for bulk filling techniques on resin polymerization stress, intra-pulpal temperature change and degree of conversion.MethodsClass I cavities (4 mm depth × 5 mm diameter) were prepared in 48 extracted third molars and divided in 6 groups. Restorations were completed with a single increment, according to the following groups: (1) Filtek Z250XT (room temperature – activated for 20 s); (2) Filtek Z250XT (at room temperature – activated for 40 s); (3) Filtek Z250XT (pre-heated at 68 °C – activated for 20 s); (4) Filtek Z250XT (pre-heated at 68 °C – activated for 40 s); (5) Filtek BulkFill (at room temperature – activated for 20 s); (6) Filtek Z250XT (modified by the addition of a thio-urethane oligomer at room temperature – activated for 40 s). Acoustic emission test was used as a real-time polymerization stress (PS) assessment. The intra-pulpal temperature change was recorded with a thermocouple and bottom/top degree of conversion (DC) measured by Raman spectroscopy. Data were analyzed with one-way ANOVA/Tukey's test (α = 5%).ResultsPre-heating the resin composite did not influence the intra-pulpal temperature (p = 0.077). The thio-urethane-containing composite exhibited significantly less PS, due to a lower number of acoustic events. Groups with pre-heated composites did not result in significantly different PS. Filtek BulkFill and the thio-urethane experimental composite presented significantly higher DC.SignificanceResin composite pre-heating was not able to reduce polymerization stress in direct restorations. However, thio-urethane addition to a resin composite could reduce the polymerization stress while improving the DC.     

茯苓皮总多糖提取纯化工艺研究

目的研究并确立茯苓皮总多糖的最佳提取和纯化工艺。方法用超声波辅助法提取总多糖,用苯酚-硫酸法测其含量并作为指标,经过单因素实验和正交试验确立最佳提取工艺;用大孔树脂纯化总多糖,以多糖保留率,脱色率和蛋白去除率为指标,经过静态和动态实验,确立最佳纯化工艺。结果以料液比1∶25,温度45℃,超声功率100w,超声时间10min为最佳提取工艺;以AB-8型大孔吸附树脂,溶液pH 5,转速180r·min^-1,上样流速24mL·min^-1,径高比1∶15为最佳纯化工艺。在此条件下静态吸附实验蛋白去除率65.29%,脱色率79.08%,多糖保留率59.50%;动态吸附实验蛋白去除率48.98%,脱色率76.84%,多糖保留率74.58%。结论茯苓皮总多糖的提取纯化工艺稳定可靠,可为其进一步开发提供参考。     

Endodontic complications in teeth with vital pulps restored with composite resins: a systematic review

Composite resin is used extensively for restoration of teeth with vital pulps. Although cell culture studies have disclosed harmful effects on pulpal cells, any untoward clinical effects, manifest as adverse pulpal responses, have yet to be determined. This study comprises a systematic review, designed to address the question of whether the risk of endodontic complications is greater with composite resin restorations than with other restorative materials, such as amalgam. The study methodology involved (i) formulation of the research question, (ii) construction and conduct of an extensive literature search with (iii) interpretation and assessment of the retrieved literature. A search of the medical database PubMed was complemented with a search of the Controlled Trials Register (CENTRAL). The initial search yielded 1043 publications, the abstracts of which were read independently by the authors. After additional searches, 10 studies were included in the review. In all the included studies, the level of evidence was assessed as low. No conclusions could therefore be drawn. The included studies reported few, if any, endodontic complications. Little or no differences emerged between teeth restored with composite resins and those restored with amalgam. To determine whether composite resin restorations of teeth with vital pulps are associated with an increased risk for development of endodontic complications such as apical periodontitis, further evidence is needed, from well‐constructed studies with a large number of participants.