翼状胬肉显微手术切除后角膜干细胞移植

目的:观察各种类型翼状胬肉显微手术切除后角膜干细胞移植的疗效。方法:手术显微镜下根治性切除翼状胬肉后,采用角膜干细胞移植,联合眼表面重建术,共治疗各种类型的翼状胬肉46例(57眼)。结果:术后随访12~24个月,所有患者未出现球结膜明显的纤维血管增生及角膜浸润,无1例复发。结论:显微镜下切除各种翼状胬肉,同时移植角膜干细胞,能取得较好的疗效。     

细胞表面分子在骨髓间充质干细胞向成骨细胞分化过程中的表达

目的研究成人骨髓间充质干细胞(MSCs)在诱导条件下定向分化为成骨细胞过程中,细胞表面分子的表达及变化特征。方法从人骨髓中分离有核细胞,在含有15%胎牛血清、维生素C和β-甘油磷酸钠的α-MEM培养基中培养。在培养早期加入10-8mol/L地塞米松(实验组)或保持基础培养状态(对照组1),同时部分细胞仅培养于α-MEM培养基中(对照组2)。于培养第7、12、17天分别收集实验组和各对照组细胞,用流式细胞方法观察细胞表面分子CD45、CD34、CD117、CD90和人白细胞抗原-DR(HLA-DR)的表达,并定量对比分析。结果成人骨髓MSCs在体外诱导条件下分化为具有成骨细胞特征的成熟细胞。培养第7天实验组、对照组1和对照组2均少量表达CD45,第12、17天CD45表达转为阴性。各组各时间点CD34、CD117表达均为阴性。培养第12天,实验组和各对照组细胞CD90表达均较第7天升高,以对照组升高明显。实验组细胞HLA-DR表达随着成骨细胞分化成熟逐渐上升,而对照组细胞HLA-DR表达下降。结论MSCs在诱导条件下可以向成骨细胞分化。细胞表面分子的表达在细胞分化过程中呈特征性改变,是成骨细胞分化早期的一个重要标志。     

中国成年女子体表面积的测量

目前经常应用的体表面积方程,是30年代Stevenson以10名实测结果为基础,用分线法测算所得。经过近50年,中国人体发育情况及体格状况均有改善,本研究拟通过实测更多例数,求出更适于现今中国人体格发育情况的体表面积方程。测试对象为44名18～45岁女性,平均体重52.13±6.22kg、身高150.3±5.2cm、体表面积1.546±0.105m~2。受试者分布于15个省市。采用纸型法测定,并求算出体表面积的高-重方程。体表面积(m~2)=0.00586H(cm)+0.0126 W(kg)-0.0461。用本方程计算所得结果与实测结果平均误差为-0.03％,以绝对值计为1.36％。各部位所占面积百分比为:头6.33;躯干(含颈、会阴)28.27;上臂8.29;前臂5.71;手4.52;大腿(含臀)27.40;小腿12.83;足6.65。为方便查算,绘出了测算图表。     

Genetic control of humoral immunity to sperm acrosomal and cell surface antigens

We have defined the nature of genetic control of humoral immunity to sperm cell surface (TSDA) and acrosome (Ac) antigens. A sperm immunization dose that distinguishes between high-responder (BALB/c) and low-responder (B10) strains of mice was identified. B10 mice were unresponsive, whereas BALB/c and F₁ hybrid mice responded to sperm of both parental strains. The ratio of nonresponder to responder mice in the B10 × F₁ backcross and F₁ × F₁ inbred generations indicates anti-TSDA or anti-Ac antibody responsiveness is controlled through more than a single gene. The significant correlation found between the anti-TSDA and anti-Ac responses is consistent with the possibility that one or more genes controls antibody responsiveness against determinants common to both the Ac and sperm cell surface. Neither anti-TSDA nor anti-Ac antibody responses were linked to the I-A subregion of the responder H-2^d MHC haplotype. In addition to a genetic difference in the control of humoral immunity to sperm, a difference in sperm immunogenicity among strains was observed. Antigens of the Ac of B10 sperm are more immunogenic than those of BALB/c sperm, and this trait is linked to the B10 Y chromosome.     

Ecto-diadenosine polyphosphates hydrolase activity on human prostasomes

BACKGROUND: Ecto-diadenosine polyphosphates are ubiquitous compounds with several physiological roles. Ecto-diadenosine polyphosphates hydrolase control their actions by degrading and terminating their signaling. The present work deals with the identification and partial characterization of ecto-diadenosine polyphosphates hydrolase on human prostasomes. METHODS: Reverse-phase and paired-ion HPLC techniques have been used. RESULTS: Prostasomes have an ecto-diadenosine polyphosphates hydrolase that leads to the degradation of several diadenosine compounds. Kinetic parameters of the enzyme show that diadenosine tetraphosphate is the preferred substrate that is further metabolized by the prostasome-ecto-nucleotidases to adenosine. The ecto-enzyme is bound to the prostasome-membranes through a GPI-anchor and is activated by physiological concentration of Ca+2, Mg+2, and Mn+2. Its optimum pH is also in the slightly alkaline physiological range. Human spermatozoa do not possess this hydrolytic activity, but they can acquire it after fusion with prostasomes. CONCLUSIONS: The existence of an enzyme capable of degrading diadenosine compounds and can be transferred to human spermatozoa suggests new physiological implications for the role of prostasomes in fertilization.     

Rheological properties of three component creams containing sorbitan monoesters as surfactants

The objectives of the present study were (1) to evaluate the effect of formulation ingredients on the release rate of Ubiquinone from its adsorbing solid compact; and (2) to prepare and evaluate an optimized self-nanoemulsified tablet formulation. A three factor, three-level Box–Behnken design was used for the optimization procedure, with the amounts of copolyvidone (X₁), maltodextrin (X₂) and microcrystalline cellulose (X₃) as the independent variables. The response variable was cumulative percent of Ubiquinone emulsified in 45 min with constraints on weight, flowability index, tensile strength, friability and disintegration time of the dry powdered emulsion and the resultant compact. Based on the experimental design, different Ubiquinone release rates and profiles were obtained. Mathematical equations and response surface plots were used to relate the dependent and independent variables. The regression equation generated for the cumulative percent emulsified in 45 min was Y₆=64.10−12.32X₁−4.36X₂−25.53X₃+6.99X₁X₂+3.97X₁X₃+9.70X₂X₃−8.98X₁²−16.22X₂²+17.10X₃². The optimization model predicted an 85.4% release with X₁, X₂ and X₃ levels of 66.6, 560.1 and 100, respectively. A new formulation was prepared according to these levels. The observed responses were in close agreement with the predicted values of the optimized formulation.     

Influence of polymorphism on the surface energetics of salmeterol xinafoate crystallized from supercritical fluids

Purpose. To characterize the surface thermodynamic properties of two polymorphic forms (I and II) of salmeterol xinafoate (SX) prepared from supercritical fluids and a commercial micronized SX (form I) sample (MSX). Methods. Inverse gas chromatographic analysis was conducted on the SX samples at 30, 40, 50, and 60°C using the following probes at infinite dilution: nonpolar probes (NPs; alkane C5-C9 series); and polar probes (PPs; i.e., dichloromethane, chloroform, acetone, ethyl acetate, diethyl ether, and tetrahydrofuran). Surface thermodynamic parameters of adsorption and Hansen solubility parameters were calculated from the retention times of the probes. Results. The free energies of adsorption (-G_A) of the three samples obtained at various temperatures follow this order: SX-II > MSX SX-I for the NPs; and SX-II > MSX > SX-I for the PPs. For both NPs and PPs, SX-II exhibits a less negative enthalpy of adsorption (H_A) and a much less negative entropy of adsorption (S_A) than MSX and SX-I, suggesting that the high -G_A of SX-II is contributed by a considerably reduced entropy loss. The dispersive component of surface free energy (_s ^D) is the highest for MSX but the lowest for SX-II at all temperatures studied, whereas the specific component of surface free energy of adsorption (-G_A ^SP) is higher for SX-II than for SX-I. That SX-II displays the highest -G_A for the NP but the lowest _s ^D of all the SX samples may be explained by the additional -G_A change associated with an increased mobility of the probe molecules on the less stable and more disordered SX-II surface. The acid and base parameters, K_A and K_D, that were derived from H_A ^SP reveal significant differences in the relative acid and base properties among the samples. The calculated Hansen solubility parameters (_D, _P, and _H) indicate that the surface of SX-II is the most polar and most energetic of all the three samples in terms of specific interactions (mostly hydrogen bonding). Conclusions. The metastable SX-II polymorph possesses a higher surface free energy, higher surface entropy, and a more polar surface than the stable SX-I polymorph.     

Increase in the Specific Surface Area of Budesonide During Storage Postmicronization

Purpose. To evaluate an anomalous increase in the specific surface area of budesonide during storage postmicronization. Methods. Budesonide was micronized using a conventional air-jet mill. Surface areas and total pore volumes were measured using nitrogen sorption. Porosity was measured using mercury intrusion porosimetry. Particle size was measured using laser diffraction. Results. Budesonide exhibited a surface area increase of 22 ± 2% when stored at 25°C following micronization. The rate of surface area increase was lower at 20°C, suggesting a temperature-dependent stress relaxation mechanism for the micronized particles. The increase in surface area was accompanied by: (a) an increase in total pore volume; (b) a shift of the pore size distribution to smaller pore sizes; (c) a decrease in size of particles above 1 m; and (d) an increase in rugosity/surface roughness. Conclusions. Freshly micronized budesonide exhibited an unusual and significant postmicronization increase in specific surface area upon storage under ambient conditions. Postmicronization stress-relief by intraparticle crack formation, crack propagation with time, and particle fracture seems to be the primary mechanism behind this surface area increase.     

The influence of Sacoglottis gabonensis stem bark extract and its isolate bergenin, Nigerian alcoholic beverage additives, on the metabolic and haematological side effects of 2,4-dinitrophenyl hydrazine-induced tissue damage

This study was designed to study the influence of Sacoglottis gabonensis stem bark extract on the metabolic and cytotoxic side effects of 2,4-dinitrophenyl hydrazine (2,4-DNPH) on the brain and blood using male weaving rats as the experimental model. This was after the effect of the bark extract and bergenin, its isolate, on membrane lipid peroxidation and tissue natural antioxidant defences was reported. Lipid peroxidation was induced experimentally with a single intraperitoneal phenylhydrazine (2,4-DNPH) administration at the end of 3 days exposure to the bark extract or bergenin in drinking water. Three hours later, the brain, liver and red blood cells of the experimental animals were analysed for glucose level and the blood was analysed for selected key indices of oxidative stress: red blood cell (RBC) count haemoglobin (Hb), packed cell volume (PCV) and white blood cell (WBC) count (total and differential). The bark extract exhibited a protective action on brain glucose, significantly inhibiting the glucose-depleting action of both 2,4-DNPH and ethanol. It also inhibited the lowering action of DNPH and ethanol on PCV, RBC and Hb concentration of rat blood, but inhibited proliferation of white blood cells (total and differential). The data on the effect of bergenin, on the side effects of 2,4-DNPH experimental lipid peroxidation and on ethanol followed an essentially similar trend to those of the bark extract on brain glucose. Bergenin, similar to the bark extract, exerted a protective action on the brain tissue, though to a lesser extent, against the oxidants, 2,4-DNPH and ethanol. It is evident that aqueous ethanol extract of S. gabonensis stem bark has biological antioxidant properties against 2,4-DNPH and ethanol-induced tissue damage exerting its action on the haematological and metabolic side effects of the oxidants. By virtue of its essentially similar activity under the same conditions, bergenin appears to be the phytochemical constituent that is largely responsible for the observed action of the bark extract.     

Hemostatic markers with bolus versus prolonged heparin after carotid artery stenting

BACKGROUND: The evolving technique of carotid stenting (CS) requires optimal antithrombotic strategies to reduce periinterventional thromboembolic risk. In animal models of balloon injury, tissue factor (TF) was shown to be the major procoagulant of the atherosclerotic plaque mediating prolonged procoagulant activity. METHODS: We analyzed TF and TF-dependent hemostatic markers before and 2, 6 and 24 h after CS with two antithrombotic drug regimens. Group A (n=20) received prolonged unfractionated heparin (UFH) for 18-20 h starting at intervention next to aspirin and thienopyridine. In group B (n=16), single bolus UFH was administered next to combined antiplatelet therapy. Natural anticoagulants were determined at baseline. RESULTS: Patients with symptomatic and asymptomatic cerebrovascular disease did not differ in plasma TF levels. Furthermore, no statistically significant difference for TF, TFPI/Xa-complex and prothrombin fragment F1.2 was observed between bolus and prolonged heparin treatment. No significant change was found in time course for these parameters. Two patients (5.5%; one in each treatment group) suffered periinterventional minor stroke associated with increased levels of F1.2 and TFPI/Xa-complex. Both were resistant to activated protein C (APC ratio<1.9) due to heterozygous factor V Leiden mutation. CONCLUSIONS: No significant activation of the TF pathway was seen with both antithrombotic regimens suggesting that single bolus UFH combined with antiplatelet therapy is generally sufficient to control TF-dependent procoagulant activity after CS. However, patients with resistance to activated protein C may be at increased periinterventional stroke risk.