Expression of VIP receptors in mouse peritoneal macrophages: Functional and molecular characterization

Receptors for VIP in mouse peritoneal macrophages (MPM) were examined using [¹²⁵I]labeled VIP as ligand. The receptor binding was rapid, reversible, saturable, specific, and dependent on time, pH, temperature and cell concentration. At 15°C, the stoichiometric data suggested the presence of two classes of VIP receptors with K_d values of 1.05 ± 0.2 and 66.4 ±11.0 nM and binding capacities of 19.2 ± 2.8 and 706.6 ± 172.0 fmol VIP/10⁶ cells. The interaction showed a high degree of specificity, as suggested by competition experiments with various peptides structurally related to VIP as follows: VIP > helodermin > rGRF > PHI secretin. Glucagon, pancreastatin, somatostatin, insulin, and octapeptide of cholecystokinin (CCK 26–33) were ineffective at concentrations as high as 1 μM. VIP was a potent and efficient stimulator of cyclic AMP production in MPM. The stimulation was observed at a concentration as low as 0.01 nM VIP. Half-maximal stimulation (ED₅₀) was observed at 1.0 ± 0.2 nM VIP, and maximal stimulation (three-fold above basal levels) was obtained between 0.1 – 1 μM. The cyclic AMP system of mouse peritoneal macrophages showed a high specificity for VIP. The order of potency observed in inducing cyclic AMP production was VIP > helodermin > rGRF > PHI secretin. Glucagon, insulin, pancreastatin, somatostatin and octapeptide of cholecystokinin did not modify cyclic AMP levels at concentrations as high as 1 μM. To characterize the molecular mass of VIP receptors, [¹²⁵I]VIP was covalently bound to membranes from MPM using the cross-linker dithiobis(succinimidyl propionate) (DTSP); sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the solubilized membranes proteins revealed the presence of a major specific componentwith an M_r value of 55 300 ± 1100 as estimated in denaturing conditions. Other proteins with M_r values of 34 500 ± 700, 23 900 ± 500 and 18 500 ± 500 also were labeled. Taken together, these results demonstrate the presence of specific and functional VIP receptors in MPM and further support the concept of VIP as a neuroimmunoregulatory peptide.     

Ultrasonic characterization of myocardial photocoagulation lesion size in vivo during Nd:YAG laser irradiation

Endocardial coagulation lesions were created using transcatheter continuous-wave Nd:YAG laser irradiation. Ultrasound monitoring of thermal lesion dimensions was performed using 7.5-MHz and 10-MHz transducers directly from the epicardial surface in short-axis configuration (group A) or through the chest wall (group B). A total of 33 lesions were created in 10 dogs at energy levels ranging from 300 J to 1000 J. Mean histological lesion width (HW) compared with ultrasonically determined mean width (UW) showed that the differences (mean ± standard deviation) in group A (UW ? HW) was = 1.14 ± 0.8 mm, which was not statistically significantly different from zero. In group B, (UW ? HW) = 2.04 mm ± 0.7 mm (p < .05), which was statistically significantly different from zero. Mean histological depth (HD) differentially related to ultrasound mean depth (UD) for group A and B combined showed (UD ? HD) = ? 0.19 mm ± 0.46 mm, not statistically significantly different from zero. The frequency distribution for width in group A showed ∣UW ? HW∣ > 3 mm in 32% of cases. In group B ∣UW ? HW∣ > 3 mm in 15%, whereas ultrasound width was larger than histology in 75% of the cases. For depth, ∣UD ? HD∣ > 3 mm in 15% of cases. With further refinement of the technique, ultrasonic tissue characterization may become a useful adjunct to monitoring lesion dimensions during transcatheter laser photocoagulation. © 1994 John Wiley & Sons, Inc.     

Preparation and Physicochemical Characterization of Aqueous Dispersions of Coenzyme Q10 Nanoparticles

The present study describes a novel pharmaceutical formulation of coenzyme Q₁₀, viz. submicron-sized dispersions of the substance prepared by emulsification of molten coenzyme Q₁₀ in an aqueous phase. Photon correlation spectroscopy reveals mean diameters of 60 to 300 nm depending on process parameters. Coenzyme Q₁₀ nanoparticles remain stable on storage for more than 30 months. Lipophilic drugs can be incorporated into the nanoparticles demonstrating their potential use as a drug carrier system. Transmission electron micrographs of freeze-fractured replica show spherical particles with an amorphous core. Cryo-electron microscopy reveals the coexistence of small unilamellar vesicles in phospholipid stabilized dispersions. Thermoanalysis and X-ray studies indicate that the dispersed and emulsified coenzyme Q₁₀ does not recrystallize even at 4°C over 30 months. These agree with ¹H NMR data which demonstrate that coenzyme Q₁₀ molecules have a high mobility when formulated as nanoparticles and that colloidally dispersed coenzyme Q₁₀ remains in the state of a supercooled melt. Despite the high melting point of the bulk material, coenzyme Q₁₀ dispersions represent no suspensions but O/W emulsions according to the IUPAC definition (1).     

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。