Gamma Sterilization of a Semi-Solid Poly(ortho ester) Designed for Controlled Drug Delivery—Validation and Radiation Effects

Radiation sterilization is becoming increasingly popular for the sterilization of many pharmaceutical products. Although this technique is not limited to the sterilization of polymers, it is probably the most suitable method for such materials. This method however suffers several drawbacks. The sterilization of a product must lead to a safety level of 10^–6, i.e. one chance in a million to find a contaminated sample. In many cases, this assurance of sterility can be achieved by using a uniform treatment dose of 2.5 Mrad, recommended by the pharmacopeia. We investigated the possibility of using doses of radiation inferior to 2.5 Mrad to sterilize a semi-solid poly(ortho ester) (POE) developed for use as carrier in controlled drug delivery. After determination of the initial bioburden, the polymer was intentionally contaminated with the bioindicator Bacillus pumilus E 601. Following exposure to gamma irradiation, the D₁₀ value of the radio resistant bioindicator was determined. Using the initial contamination value, the reduction factor D₁₀ and the safety level, it is possible to calculate an optimal sterilizing dose for POE. All polymers are affected by ionizing radiation and the amount of radiation which produces a significant change in properties may vary from one polymer to the other. A molecular weight and dynamic viscosity decrease resulting from backbone cleavage was observed for this POE at a dose lower than 2.0 Mrad. Evaluation of the structure using ¹H-NMR, ¹³C-NMR and IR analysis shows that for doses higher than 2.0 Mrad, another degradation process takes place. Formation of two isomeric esters of the triol used for the synthesis was identified by these methods. Cleavage of the monomer cycle is believed to be the main cause of the degradation observed. A radiation dose of not less than 7 times the D₁₀ value but less than 2.0 Mrad was used for this semi-solid biodegradable poly-(ortho ester) in order to ensure its sterility and avoid an excessive formation of degradation products.     

重质石油中含氮化合物的形态及分布分析Ⅰ

建立了萃取－柱色谱的预分离方法。对南京管输油中的含氮化合物进行了富集，并用ＧＣ／ＭＳ和红外光谱定性鉴定了所得的含氮化合物各组分。     

Evaluation of cytokeratin markers to differentiate between benign and malignant prostatic tissue

Cytokeratins are intermediate filaments found within basal and secretory epithelial cells. Antisera raised against cytokeratins are available but frequently differ in specificity. Many are incompletely characterized for their reactivity against epithelial components. Cytokeratin (Cyto) P is a polyclonal antisera specific for 56 and 64 kd cytokeratins. Cyto M is a pool of monoclonals reacting against 40, 46, 50, 52, 58, and 65-67 kd cytokeratins. Initially, utilizing immunohistologic techniques, we evaluated these two antisera for their ability to distinguish between prostatic tissues of benign (benign prostatic hypertrophy [BPH]) or malignant (carcinoma of the prostate [CAP]) origin in the 34 cases evaluated. Specimens were analyzed for both Cyto P and Cyto M reactivity, as well as for the degree of reactivity. Lastly, in an effort to determine the morphologic relationship of atypical hyperplasia (AH) with either BPH or CAP, nine additional prostate specimens were analyzed. Cyto P was reactive in 8 of 8 (100%) BPH specimens and in 2 of 26 (8%) CAP specimens. Mean Cyto P degree of reactivity in the positive specimens was greater in BPH than in CAP (2.6 vs. 1.0). Cyto M reactivity was present in 8 of 8 (100%) BPH specimens and in 23 of 25 (92%) CAP specimens. Mean Cyto M degree of reactivity in the positive specimens was greater in CAP than in BPH (3.6 vs. 2.8). Cyto P was reactive in 3 of 9 (33%) AH specimens, with a mean degree of reactivity of 2.7. Cyto M was reactive in 9 of 9 (100%) AH specimens, with a mean degree of reactivity of 3.9. Cyto P reacted with only the basal cells, whereas Cyto M reacted with basal as well as secretory cells. These differences appeared to be the result of the differential reactivity of basal cells, which are present in BPH but absent in CAP. In summary, Cyto P and Cyto M are potentially useful markers in differentiating BPH from CAP, and it appears that AH is immunohistopathologically related to both.     

Infertility: Composition of commercial gonadotrophin preparations extracted from human post-menopausal urine: characterization of non-gonadotrophin proteins

Gonadotrophin preparations extracted from post-menopausal urineare of low purity and the major protein components are not gonadotrophins.A study was undertaken to identify some of these non-gonadotrophinproteins present in the extracted human urinary gonadotrophinpreparations that are commercially available, i.e. Humegon (Organon),HMG Massone (Massone), Metrodin (Serono), Metrodin HP (Serono),Pergonal (Serono) and Progonadyl (Elea). As revealed by sodiumdodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE)with Coomassie blue staining and Western blotting analysis,these products had electrophoretic protein profiles which differedin the amounts and species of proteins present. With the exceptionof Metrodin HP, all the other preparations tested containedtumour necrosis factor binding protein-I, transferrin, and immunoglobulin-relatedproteins. Some of the products contained in addition: urokinase,Tamm-Horsfall glyco-protein and epidermal growth factor. Recently,a highly purified human urinary follicle stimulating hormone(FSH) preparation (Metrodin HP) became available. In this preparationhuman FSH represents >95% of the total proteins ( 10 000IU of FSH/mg of protein). Metrodin HP was demonstrated to bethe purest preparation tested, with none of the above-mentionedcontaminants detected.     

Monolayers of Human Alveolar Epithelial Cells in Primary Culture for Pulmonary Absorption and Transport Studies

Purpose. To develop a cell culture model of human alveolar epithelial cells in primary culture for the in vitro study of pulmonary absorption and transport. Methods. Type II pneumocytes isolated from normal human distal lung tissue by enzyme treatment and subsequent purification were plated on fibronectin/collagen coated polyester filter inserts, and cultured using a low-serum growth medium. Characterization of the cell culture was achieved by bioelectric measurements, cell-specific lectin binding, immunohistochemical detection of cell junctions, and by assessment of transepithelial transport of dextrans of varying molecular weights. Results. In culture, the isolated cells spread into confluent monolayers, exhibiting peak transepithelial resistance of 2,180 ± 62 X cm² and potential difference of 13.5 ± 1.0 mV (n = 30–48), and developing tight junctions as well as desmosomes. As assessed by lectin-binding, the cell monolayers consisted of mainly type I cells with some interspersed type II cells, thus well mimicking the situation in vivo. The permeability of hydrophilic macromolecular FITC-dextrans across the cell monolayer was found to be inversely related to their molecular size, with P_app values ranging from 1.7 to 0.2 X 10^–8 cm/sec. Conclusions. A primary cell culture model of human alveolar epithelial cells has been established, which appears to be a valuable in vitro model for pulmonary drug delivery and transport studies.     

听诊器研发历程对于中医新型诊断方法的启示

通过阐述听诊器的研发历程,思考其对于中医新型诊断方法的启示。中医新型诊断方法的具体内涵包括诊断工具的改进,临床表征的系统收集与分类以及临床表征病理意义的诠释3部分。     

Effects of nickel-oxide nanoparticle pre-exposure dispersion status on bioactivity in the mouse lung

Nanotechnology is emerging as one of the world's most promising new technologies. From a toxicology perspective, nanoparticles possess two features that promote their bioactivity. The first involves physical–chemical characteristics of the nanoparticle, which include the surface area of the nanoparticle. The second feature is the ability of the nanoparticle to traverse cell membranes. These two important nanoparticle characteristics are greatly influenced by placing nanoparticles in liquid medium prior to animal exposure. Nanoparticles tend to agglomerate and clump in suspension, making it difficult to reproducibly deliver them for in vivo or in vitro experiments, possibly affecting experimental variability. Thus, we hypothesize that nanoparticle dispersion status will correlate with the in vivo bioactivity/toxicity of the particle. To test our hypothesis, nano-sized nickel oxide was suspended in four different dispersion media (phosphate-buffered saline (PBS), dispersion medium (DM), a combination of dipalmitoyl-phosphatidyl choline (DPPC) and albumin in concentrations that mimic diluted alveolar lining fluid), Survanta®, or pluronic (Pluronic F-68). Well-dispersed and poorly dispersed suspensions were generated in each media by varying sonication time on ice utilizing a Branson Sonifer 450 (25W continuous output, 20?min or 5?min, respectively). Mice (male, C57BL/6J, 7-weeks-old) were given 0–80?µg/mouse of nano-sized nickel oxide in the different states of dispersion via pharyngeal aspiration. At 1 and 7 d post-exposure, mice underwent whole lung lavage to assess pulmonary inflammation and injury as a function of dispersion status, dose and time. The results show that pre-exposure dispersion status correlates with pulmonary inflammation and injury. These results indicate that a greater degree of pre-exposure dispersion increases pulmonary inflammation and cytotoxicity, as well as decreases in the integrity of the blood–gas barrier in the lung.     

Secondary metabolites of seven Hypericum species growing in Turkey

Context The genus Hypericum (Hypericaceae) has attracted remarkable scientific interest as its members have yielded many bioactive compounds.

Objective The current study presents investigations on the accumulation of hypericin, pseudohypericin, hyperforin, adhyperforin, chlorogenic acid, neochlorogenic acid, caffeic acid, 2,4-dihydroxybenzoic acid, 13,118-biapigenin, hyperoside, isoquercitrin, quercitrin, quercetin, avicularin, rutin, (+)-catechin and (?)-epicatechin in seven Hypericum (Hypericaceae) species growing wild in Turkey, namely, H. aviculariifolium Jaup. and Spach subsp. aviculariifolium (Freyn and Bornm.) Robson var. albiflorum (endemic), H. bithynicum Boiss., H. calycinum L., H. cardiophyllum Boiss., H. elongatum L. subsp. microcalycinum (Boiss. and Heldr.) Robson, H. hirsutum L. and H. xylosteifolium (Spach) N. Robson.

Materials and methods The plant materials were collected at flowering period and dissected in different tissues. Air-dried plant material including stems, leaves and flowers was mechanically powdered with a laboratory mill and samples (0.1?g) were extracted in 10?mL of 100% methanol by ultrasonication at 40?°C for 30?min for HPLC-PDA analyses.

Results Accumulation levels of the investigated compounds varied greatly depending on species and plant part.

Discussion For the first time, the detailed chemical profiles of corresponding Turkish Hypericum species were reported and the results were discussed from a phytochemical point of view.

Conclusions The present data have importance in evaluation of plant resources of Hypericum genus in selecting the new potential sources of bioactive compounds.     

壳聚糖修饰的丹皮酚PEG-PLGA纳米粒的制备及其体外释药性能考察

目的:制备壳聚糖修饰的丹皮酚聚乙二醇-(聚乳酸-羟基乙酸共聚物)(PEG-PLGA)纳米粒,对其体外性质进行表征,考察纳米粒的体外释药性能,为丹皮酚的新型纳米制剂研究提供参考。方法:以PEG-PLGA为载体材料,壳聚糖为表面修饰剂,采用纳米沉淀法制备了壳聚糖修饰的丹皮酚PEG-PLGA纳米粒,利用正交试验优化处方工艺,并对其体外性质进行表征。以p H 7.4磷酸盐缓冲液为释放介质,考察壳聚糖修饰的丹皮酚PEG-PLGA纳米粒的体外释药行为。结果:载药纳米粒经壳聚糖修饰后,Zeta电位由负电荷转为正电荷且更加稳定,粒径略有增加。制备出的纳米粒外观呈球形,平均粒径和Zeta电位分别为(96.6±3.2)nm,(30.61±0.34)m V,载药量及包封率分别为10.87%和79.37%。体外释药试验表明载药纳米粒24 h的累计释放率62.4%。结论:按优选的处方成功制备了壳聚糖修饰的丹皮酚PEG-PLGA纳米粒,该制剂的体外性质良好且具有一定的缓释特性。