The interaction of the nuclear estrogen receptor from hen oviduct with nucleic acids were studied by competition assay using DNa-cellulose centrifugation. We demonstrated that the estradiol-receptor complex binds similarly well to poly(A) RNA and denatured DNA. The estrogen receptor was found to interact more strongly with poly(G), poly(U) than with poly(A), poly(C). The receptor complex binds similarly to poly(A) and poly(dA), and to poly(U) and poly(dU). However, the receptor complex shows stronger binding to poly(G) than to poly(dG) and to poly(C) than to poly(dC). Studies with heteropolyribonucleotides indicated that poly(U1G1) is more effective in competing for the estrogen receptor, and poly(AC) and poly(AUG) are moderately effective, whereas poly(ACU) is least effective. GMP and dGMP showed some competition for the nuclear receptor at 300-fold higher nucleotide concentrations than that of the synthetic poly(G). Observations that the nuclear estrogen receptor binds to poly(A) RNA and interacts selectively with polyribonucleotides suggest that the estrogen receptor-RNA interaction may play a role for the function of estrogens in gene regulation.

Animals↗

PubMed1983

Direct preparation of solid particulates of aminopyrine-barbital complex (pyrabital) from droplets by a spray-drying technique.

Aqueous slurries of aminopyrine and barbital (molecular ratio 2:1) containing various excipients such as colloidal silica, synthetic aluminum silicate, montmorillonite clay, corn starch, microcrystalline cellulose, hydroxypropylcellulose, methylcellulose, gelatin, and chitosan were spray-dried by a centrifugal wheel atomizer with various rotation speeds (10,000-40,000 rpm) at various temperatures (85-145 +/- 5 degrees). The spray-dried products were a mixture of aminopyrine-barbital complex (molecular ratio 1:1), aminopyrine, and the excipient used. The flowability and the packing property of the products were improved by compounding colloidal silica into the formulation used for spray-drying. The products with montmorillonite clay, chitosan, and a corn starch-colloidal silica mixture were compressed directly into tablets. It was found that aminopyrine in the products was oxidized during spray-drying. The oxidation products were assumed to be a trace mixture of 5-oxo-2-methyl-4-dimethylamino-1-phenyl-3-pyrazoline carboxyaldehyde and miscellaneous oxidation products. Montmorillonite clay compounded in the formulation considerably prevented the oxidation of aminopyrine during spray-drying. The present study proposes an improved method for the preparation of solid particulates of aminopyrine-barbital complex for tableting, which combines the synthesis, drying, and agglomeration processes into a single process.

Aerosols↗

PubMed1983

Study of chromosomal replication of red muntjac (Muntiacus muntjac).

The technique of cell fusion, the method of sister chromatid differentiation (SCD), and the silver staining method modified by us that can show nucleolus organizing region (NOR) and sister chromatid differentiation at the same time have been used in the study of red muntjac chromosomes. Differential staining of sister chromatid has been observed in metaphase chromosomes and in premature condensed chromosomes (PCC) at various stages of the interphase. Our silver staining method shows that the NOR in the dark staining chromatid is Ag-positive, while that in the light staining chromatid is Ag-negative. The chromatid differentiation staining and the NOR sister staining suggest that the structure of metaphase chromosomes is similar to that of the premature condensed chromosomes of the interphase cell. The chromosomal replication of red muntjac conforms with the semiconservative replication mechanism and the replication of rDNA is also semiconservative.

Animals↗

PubMed1982

Preparations of solid particulates of theophylline--ethylenediamine complex by a spray-drying technique.

Aqueous solutions of ethylenediamine and theophylline were spray dried to obtain solid particulates of theophylline--ethylenediamine complex to improve solubility of theophylline. Packing and flow properties of the spray-dried products were much improved when compared with those of original theophylline particles, due to their spherical shapes which were confirmed by a scanning electron microscope. The solubility of theophylline in the resultant products was found to be three to five times higher than that of original theophylline. The solubilities of the products decreased with increasing drying temperature and rotation speed of the atomizer, which was interpreted in terms of the contents of ethylenediamine in the products. The products were confirmed to be a mixture of aminophylline, alpha-aminophylline, and theophylline by X-ray analysis and NMR spectroscopy. The logarithm of the relative intensity of the X-ray diffraction peak of alpha-aminophylline to that of theophylline decreased linearly with drying temperature and rotation speed of the atomizer. Thermal decomposition of the spray-dried products involved liberations of crystal water at 100 degrees and ethylenediamine between 110 and 127 degrees. Liberation of ethylenediamine occurred via three steps for aminophylline, but with different steps for the spray-dried products.

Aerosols↗

PubMed1981

Interactions of a fragment of bleomycin with deoxyribodinucleotides: nuclear magnetic resonance studies.

Proton NMR spectroscopy was used to establish certain geometrical parameters of the complexes formed between N-(3-aminopropyl)-2'-(2-acetamidoethyl)-2,4'-bithiazole-4-carboxamide hydrochloride (BLMF), a fragment of bleomycin, and various deoxyribodinucleotides. All proton resonances in these compounds have been assigned; chemical shifts were recorded as functions of their concentration. In the complex formed between BLMF and pdG-dC, chemical shifts of the bithiazole protons (measured with respect to values extrapolated to infinite dilution) were displaced upfield by 0.4 ppm. Other proton resonances of BLMF were shifted upfield but to a lesser extent. After corrections are made for self-stacking, maximum values for induced chemical shifts of the bithiazole protons are reached at a dinucleotide/BLMF ratio of 2. Coupling sums for dinucleotides (12.5-13.7 Hz) were unchanged following complexation, suggesting that there is no marked change in sugar conformation when BLMF is bound. On the basis of these results and of molecular model building studies, we propose a three-dimensional structure for a BLMF:pdG-dc complex in which the thiazole rings are intercalated in the duplex and stack preferentially on the purines. Projected on the same plane, the horizontal axis connecting the center of both bithiazole rings in this configuration superimposes on the axis connecting the centers of the purine bases. In this complex, both thiazole protons extend into the minor groove and the positively charged terminal amine binds to the negatively charged phosphate group of DNA.

Binding Sites↗

PubMed1981

The binding of androgen receptor to DNA and RNA.

The androgen receptor from mouse kidney cytosol has been studied for its nucleic acid binding properties by DNA-cellulose centrifugation assay. The receptor appears to bind to RNA (mRNA, tRNA, rRNA) as well as to DNA. Salt and heat activation of the androgen receptor enhances both DNA and RNA binding. The receptor binds slightly better to denatured DNA than to native DNA. The androgen receptor binds about 2-fold tighter to poly(dG-dC) than to poly (dA-dT). The interaction of the receptor with DNA is not greatly affected by the BrdUrd substitution. The observation that androgen receptor shows a significant affinity to RNA may imply that androgen receptor-RNA interaction could play a role in gene regulation.

Animals↗

PubMed1981

Electrophoretic properties of sulfamethoxazole microcapsules and gelatin-acacia coacervates.

The electrophoretic properties of sulfamethoxazole microcapsules and the coacervates prepared by gelatin-acacia coacervation were investigated. The effects of the parameters in the microcapsule preparation, such as the coacervation pH, amount of formaldehyde used for hardening, and drying method of the coacervates, on the zeta-potential of the resultant microcapsules were clarified. The Büchner effect was observed in coacervates in an electric field, which indicated that the coacervate wall was flexible. The zeta-potential versus pH curves of the coacervates appeared on the upper side of the plain sulfamethoxazole, while those of the microcapsules dried conventionally shifted to the lower side due to the denaturation of the gelatin in the microcapsule wall, which occurred during drying. Spray drying increased the denaturation of gelatin, which imparted a negative charge to the spray-dried microcapsules. Formalization of the coacervates refined the electrophoretic behavior of the microcapsules, depending on the amount of formaldehyde used. The zeta-potential of the plain sulfamethoxazole also was measured in the simulated coacervation solution to analyze the mechanism of coacervation electrophoretically.

Acacia↗

PubMed1981

Polymorphism of spray-dried microencapsulated sulfamethoxazole with cellulose acetate phthalate and colloidal silica, montmorillonite, or talc.

Sulfamethoxazole was microencapsulated with cellulose acetate phthalate and talc, colloidal silica, or montmorillonite clay by a spray-drying technique. The surface topography of the products varied with the type of excipient used and the pH of the suspending medium. The products without the excipient were coated with flake-like crusts, while the products containing the excipient tended to become well-rounded spheres. In addition, the crystalline form of sulfamethoxazole converted from Form I to an amorphism and Form II during the spray-drying process. This polymorphic transformation was attributed to the interaction of cellulose acetate phthalate with sulfamethoxazole. Increasing the concentration of cellulose acetate phthalate in the formulation increased the attainment of amorphism. Form II was also obtained by freeze and vacuum drying. Talc was the only excipient that contributed to polymorphism, which occurred in the alkaline suspension medium. Montmorillonite products prepared from the acidic medium exhibited an exothermic differential scanning calorimetry thermogram, which might be interpreted in terms of adsorption of the fused sulfamethoxazole with the internal surface of montmorillonite,

Bentonite↗

PubMed1981

Umbilical core-out operation for a completely patent vitelline duct.

An umbilical core-out operation for a completely patent vitelline duct in a premature baby with successful preoperative manual reduction of the prolapsed ileal loops is described. In certain cases with this rare anomaly this procedure can be applied. The procedure is easy, timesaving, bloodless and necessitates no laparotomy incision.

Humans↗

PubMed1980

Micromeritic properties of sulfamethoxazole microcapsules prepared by gelatin-acacia coacervation.

Micronized sulfamethoxazole particles were microencapsulated using the gelatin-acacia complex conacervation method. The effects of the coacervation pH and the amount of formaldehyde used on the micromeritic parameters of the microcapsules were investigated. The particle-size and the wall thickness distributions were log-normal forms. As the pH was increased, the particle size decreased (8.5-28.5 micrometers). The porosity of various pH-adjusted microcapsules was between 0.158 and 0.277. The particle size of formalized microcapsules was larger than that of the unformalized microcapsules because formalization prevents shrinking of microcapsules during the dehydration and drying process. A smooth surface appeared on the unformalized microcapsule, but a net-like wrinkled structure was observed upon scanning the formalized one. Moreover, folding and invaginating structures were found on the spray-dried microcapsules. The optimum coacervation pH value was 3.5, at which the highest core content was obtained (77.5% w/w). Approximately 6.73 microgram of formaldehyde remained in 1 g of the microcapsules formalized with 50 ml of formaldehyde. The crystalline sulfamethoxazole in the microcapsules prepared by spray drying the coacervate slurries was changed into the amorphous form, while the microcapsules dried in the conventional manner showed the same sulfamethoxazole form as the starting substance.

Acacia↗

PubMed1980

Preparation of enteric-coated microcapsules for tableting by spray-drying technique and in vitro simulation of drug release from the tablet in GI tract.

Improved methods were developed for the preparation of enteric-coated microcapsules for tableting by a spray-drying technique, and the drug release behavior from the tableted microcapsules was investigated using a disintegration apparatus and a new in vitro method of simulating the GI tract. As a model system, ammonium solutions of sulfamethoxazole and cellulose acetate phthalate were spray dried using a centrifugal wheel atomizer at 140 degrees. Additives such as colloidal silica, montmorillonite clay, and talc were included in the formulations for spray drying. The influence of the additives on the particle diameter, density, packing properties, and compressibility of the product and on the release characteristics of the resultant tablet in vitro were investigated. The additives in the formulations greatly improved the flow properties of the spray-dried products, which could be tableted easily. Products from the nonadditive formulations could not be tableted due to their poor flowability. The hardness and disintegration rate of the tablet increased with increasing concentration of additives in the formulations. X-ray analysis and IR spectroscopy confirmed that the crystals of sulfamethoxazole in the spray-dried microcapsules with cellulose acetate phthalate were converted from Form I to Form II. In vitro release characteristics of the tablets were studied using a disintegrator (JP) in buffer solutions (pH 1.2 and 7.5) and distilled water. Enteric action of the spray-dried products was proved by comparison with the original nontreated powders. The additives in the tablet increased the release rate at the initial stage in all dissolution media used. A new in vitro release simulator was devised consisting of a flow-type dissolution container in which the pH of the medium was changed continuously from 1.2 to 7.0 to simulate the pH change of tablets exposed to the GI tract.

Chemical Phenomena↗

PubMed1980

[Prevalence of hepatitis virus infections in restaurant workers in Taipei (author's transl)].

Hepatitis B surface antigen (HBsAg) and anti-hepatitis A virus antibody (antiHAV) in sera or saliva of restaurant workers in Chung Shan District, Taipei, were tested by radioimmunoassay from October 1978 to March 1979. Among the 2006 serum samples 387 (19.3%) were HBsAg positive. While significant difference between male and female restaurant workers was observed, no age difference was noted. The workers originated from Taiwan demonstrated the highest frequency of hepatitis B antigenemia (20.9%). The next high group was the workers originated from southern mainland (16.5%). The lowest frequency was observed in those from northern mainland (9.4%). HBsAg was found in saliva of 40 out of 82 serum carriers (48.8%) Of the 946 workers 896 (94.7%) carried the anti-HAV antibody. There was no sex difference and the positive rates were 91.2%, 92.6%, 96.1%, 98.4% in 14--19, 20--24, 25--29 and > 30 years old population, respectively, i.e. a trend of increase in the rates with age was observed.

Adolescent↗

PubMed1979

The effects of wall thickness and amount of hardening agent on the release characteristics of sulfamethoxazole microcapsules prepared by gelatin-acacia complex coacervation.

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Acacia↗

PubMed1979

[Nursing responsibilities for monitoring and maintaining C.V.P. line].

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Catheterization↗