bluuebunny/crossref_metadata_2025_split huggingface dataset:
Influence of poly(ethylene glycol)‐α‐cyclodextrin complexes on stabilization and transdermal permeation of ascorbic acid
Authors: Davaran Soodabeh , Hanaee Jalal , Rashidi Mohammad R. , Valiolah Fatemeh , Hashemi Mahdi 
Published: May 2006

AbstractThe present study was conducted to investigate the effect of poly(ethylene glycol)‐α‐cyclodextrin (α‐CD) complexes on stabilization and cutaneous permeation of ascorbic acid from specially prepared transdermal patches. Poly(ethylene glycol) citrate (6‐armPEG) and its inclusion complex with α‐CD were prepared and used for preparation of the transdermal patches. Duro‐Tak 87–2979 was taken as an adhesive matrix in combination with ascorbic acid. A diffusion cell with an artificial membrane was used to evaluate the absorption of ascorbic acid from the patches. The influence of drug release of α‐CD and two types of its PEG complexes (as the novel permeation enhancers) was tested. The 6‐armPEG‐α‐CD complex consisting of a PEG‐citric acid ester at a concentration of 0.08–0.1% (w/v) is a suitable stabilizer for ascorbic acid during UV assay. The release studies showed that the type of enhancer is important in diffusion of the drug across membrane. Furthermore, the diffusion of ascorbic acid was considerably enhanced in the presence of 6‐armPEG‐α‐CD complex. Inclusion complexes of 6‐armPEG with α‐CD at a concentration of 0.08–0.1% (w/v) is a suitable stabilizer for UV method of assay. The present data suggest that 6‐armPEG‐α‐CD complex is also useful in enhancing the release of ascorbic acid from the acrylic type pressure sensitive adhesives. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
Butylated hydroxyanisole regulates ARE‐mediated gene expression via Nrf2 coupled with ERK and JNK signaling pathway in HepG2 cells
Authors: Yuan Xiaoling , Xu Changjiang , Pan Zui , Keum Young‐Sam , Kim Jung‐Hwan , Shen Guoxiang , Yu Siwang , Oo Khor Tin , Ma Jianjie , Kong Ah‐Ng Tony 
Published: May 2006

AbstractMany natural and synthetic cancer chemopreventive compounds are potent inducers of phase II detoxifying and antioxidant stress responsive genes. The phase II/antioxidant gene expression plays critical role in chemoprevention of carcinogenesis. The antioxidant responsive element (ARE), located on many phase II/antioxidant genes, binds with the transcription factor Nrf2, and is required for the activation of these phase II/antioxidant gene expression induced by many natural and synthetic cancer chemopreventive compounds. In this study, we investigated the potential roles of extracellular signal‐regulated kinase (ERK) and c‐jun N‐terminal kinase (JNK) in the regulation of butylated hydroxyanisole (BHA)‐induced and Nrf2‐dependent ARE transcriptional activity and ARE‐mediated endogenous heme oxygenase‐1 (HO‐1) protein expression in HepG2 cells. ARE transcriptional activity and HO‐1 protein expression were increased dose dependently after treatment with BHA in HepG2 cells. Dose‐response and time‐course experiments showed that BHA increased the accumulation of Nrf2, and concomitantly decreased the protein level of Keap1. We next examined the phosphorylation of the MAPKs, and found that BHA significantly increased the phosphorylation levels of ERK1/2 and JNK1/2. Importantly BHA‐induced ARE transcriptional activity was attenuated by the inhibition of ERK and JNK signaling using biochemical inhibitors and their dominant‐negative mutants. Using confocal microscopy technique, treatment with BHA showed the release of Nrf2 sequestered by Keap1 in the cytosol, and that Nrf2 translocated into the nucleus. Importantly, cDNA transfections of ERK and JNK signaling pathways similarly released Nrf2 from Keap1 cytosolic sequestration and translocating Nrf2 into the nucleus. Taken together, these results strongly suggested that ERK and JNK signaling pathways played important and positive roles in BHA‐induced and Nrf2‐dependent regulation of ARE‐mediated gene expression, as well as the nuclear translocation of Nrf2 in HepG2 cells. © 2006 Wiley‐Liss, Inc.
Review of existing and newly developed approaches to obtain timber embedding strength
Authors: Zhou Tinozivashe , Guan Zhongwei 
Published: May 2006

AbstractEmbedding strength is a key parameter most commonly adopted for designing laterally loaded timber joints fastened with dowel‐type fasteners. This property, however, is non‐unique for any given specimen of timber but is dependent upon several factors. Currently, there is a scarcity of literature that considers some of the major factors as a whole. In this review, an attempt is made to bring some of these factors together and then examine them in the context of historical test results. This is followed by new test results derived from idealized tests for application in designing double‐sided punched metal plate fastened joints. It is shown that changes in combinations of factors can potentially lead to appreciable differences in the values of embedding strength obtained from tests. By accounting for the quantitative effect of some key factors, it is possible to explain differences between theoretically obtained embedding strength values and idealized test results. In addition, the proposed indirect method of obtaining effective embedding strengths for punched metal plate timber joints is validated through correlation of idealized test results with theoretical calculations.
LINKAGE AND SELECTION: NEW EQUILIBRIUM PROPERTIES OF THE TWO-LOCUS SYMMETRIC VIABILITY MODEL
Authors: Karlin Samuel , Feldman Marcus W. 
Published: May 2006

In the two-locus symmetric viability model with recombination, conditions for the existence and stability of a new class of polymorphic equilibria are given. These „unsymmetric” equilibria, which exist for relatively loose linkage, can be explicitly obtained, in contrast to the previously known symmetric equilibria which are generally given by the solutions of a cubic equation.
For sufficiently tight linkage, there is always at least one stable symmetric equilibrium. Seven is the precise maximum for the number of interior equilibria. The qualitative consequences of these results are briefly examined. In particular it is pointed out that since for some linkage values no stable polymorphic equilibria exist, there is no „overdominance theorem” comparable to the single-locus case.
SELECTIVE DESTRUCTION OF ADRENAL CORTEX BY PULSE DOSES OF DERIVATIVES OF 12-METHYLBENZ(a)ANTHRACENE
Authors: Huggins Charles , Morii Sotokichi , Pataki John 
Published: May 2006

Pulse doses of emulsions of ten polynuclear aromatic hydrocarbons were found to destroy the adrenal cortex selectively.
The corticolytic hydrocarbons are derivatives of 12-methylbenz(a)anthracene which possess at position 7 an alkyl, methoxymethyl, formyl, or hydroxyalkyl group. It would appear that the active corticolytic agent is 7-hydroxyalkyl-12-methylbenz(a)anthracene, of chemical source or generated in metabolism.
STABLE FREE-RADICAL FORMS OF PLASMA PROTEINS OR SIMPLER RELATED STRUCTURES WHICH INDUCE BRAIN EXCITATORY EFFECTS
Authors: Polis B. David , Wyeth John , Goldstein Leonide , Graedon Joe 
Published: May 2006

Stable free radicals have been prepared from purified plasma proteins, pituitary peptides, and simpler related structures like 5-OH tryptophan and melatonin by oxidation with the free-radical nitrosyl disulfonate in alkaline solution under controlled conditions. The presence of tyrosine or trytophan amino acid residues in the protein was found essential for free-radical formation. These red-colored, stable free radicals showed electron spin resonance spectra in aqueous solutions at room temperature and maintained this characteristic for weeks when stored at 5°C. Illumination, by visible light, of the free-radical proteins and peptides separated from excess nitrosyl disulfonate by salt fractionation or chromatography enhanced the free-radical concentration in the light. The increased signal decayed in the dark.
Intravenous administration of the free-radical proteins or peptides into rabbits equipped with chronic cranial electrodes and sedated with a small dose of pentobarbital caused a sudden EEG arousal accompanied by behavioral changes indicative of brain excitation. Illumination of the free-radical compounds prior to administration enhanced the effects. Untreated control proteins or peptides had no effects. The observations are interpreted to suggest the involvement of free-radical structures in the transfer of energy in nervous tissue.
HYBRIDIZATION OF RNA FROM ROUS SARCOMA VIRUS WITH CELLULAR AND VIRAL DNA'S
Authors: Yoshikawa-Fukada M. , Ebert J. D. 
Published: May 2006

The RNA of Rous sarcoma virus (RSV) hybridizes with DNA's isolated from all eukaryotes tested (animal and plant) with the possible exception of yeast. Bacterial DNA's show no homology to RSV-RNA. DNA's from the oncogenic viruses, adenovirus type 12 and SV40 show significant homology with RSV-RNA, but those from nononcogenic adenoviruses types 2 and 4 are not homologous.
RSV-RNA hybridized to all of the DNA's examined has the same, or a closely similar, base composition. Moreover, the melting temperatures of all of the hybrids analyzed are very similar, further suggesting that a common base sequence in DNA functions in hybridization with RSV-RNA.
Selection and Characterization of an
E. coli
Mutant Defective in Membrane Lipid Biosynthesis
Authors: Cronan John E. , Ray Tapas K. , Vagelos P. Roy 
Published: May 2006

A procedure is described for the selection of temperature-sensitive phospholipid mutants based upon radiation suicide of the wild-type organisms by tritiated L-glycerol-3-phosphate incorporated in the phospholipids.
One of these mutants possesses an acyltransferase activity much more thermolabile than that of its parent. This mutant ceases growth and phospholipid biosynthesis immediately upon shift to a nonpermissive temperature although DNA, RNA, and protein continue to be synthesized. The phenotype of this mutant appears due to a single mutation by reversion analysis and by enzymatic analysis of temperature-resistant revertants.
The Nutritive Value of Single Foods
Authors: Williams Roger J. , Heffley James D. , Bode Charles W. 
Published: May 2006

This is an extension of an earlier study in which we found that while commercial “enriched” bread alone would not support the life of weanling rats in a 90-day test, enrichment could be updated at low cost, with the result that rats consuming the improved bread alone lived during the test period and grew seven times as fast. Prominent nutritionists criticized this study on the basis that bread is not eaten alone and that other single foods are likewise deficient. It was stated: “the experiments you performed would have given the same or similar results if you had begun with milk, eggs, meat, or any other food”.
Skepticism regarding this statement led to experimental trials in which milk, meat, eggs, and several other foods, including breakfast cereals, were fed singly to groups of animals. Eggs proved to be a remarkably complete food, and milk exhibited about the same excellence until the iron deficiency became evident after about two months. “Enriched” breakfast foods and macaroni were highly deficient and could be improved greatly by supplementation.
As an outgrowth of this study, we are developing a method of biological testing which is incomparably better for evaluating foods than consulting food composition tables. On the basis of the tabulated data alone one might conclude that “enriched” puffed rice, for example, is only slightly inferior nutritionally to eggs. Our experiments have shown this assumption to be grossly in error.
Host-Gene Control of C-Type Tumor Virus-Expression and Tumorigenesis: Relevance of Studies in Inbred Mice to Cancer in Man and Other Species
Authors: Meier Hans , Huebner Robert J. 
Published: May 2006

C-type RNA viruses are tumorigenic in mice and other species. They are widespread and transmitted in an intimate relationship with host-cell genetic material. Tumorigenesis is no doubt a complex biological phenomenon, and involves both genetic and environmental factors. Among the genetic factors, single-locus determination is probably exceptional; yet, a number of genes are known in inbred mice and other species, including man, that can exert a major influence. Clearly, studies with inbred mice apply outside the murine model and justify generalizations on the etiology of cancer.
The types of cancer observed in man are similar to those of inbred strains of mice, and their stochastic and often familial occurrences suggest that genetic factors play important roles in both man and mouse. A number of heritable disorders predipsose to tumorigenesis. Investigations of the relationship between various polymorphic phenotypes and human tumors should be intensified. For instance, a study of high-risk human-tumor groups could aid considerably not only in the recognition of etiological agents but also of underlying host-gene controlled mechanisms. Indeed epidemiological studies have already led to the identification of mutant genes that influence the incidence of human cancer. Such studies may be guided by findings in inbred strains of mice. There is good evidence in inbred mice that mutations in host chromosomes determine whether or not genes coding for RNA oncogene viral “functions” become expressed as cancer. Although an etiological role of C-type RNA virus has not yet been demonstrated in human cancer, studies of the interaction of viral and host-cell genomes in mice and other species, and the visualization of C-type virus in human tumors have provided good reasons for suspecting the presence in man of oncogenic genes (oncogenes) homologous to those of the C-type viral genomes, which are well studied in mice, hamsters, cats, rats, and chickens.
A DNA-Binding Protein in the Serum of Certain Mammalian Species
Authors: Thoburn R. , Hurvitz A. I. , Kunkel H. G. 
Published: May 2006

Various mammalian species contain an anionic serum protein that reacts specifically with native DNA. It is considerably less reactive with single-strand DNA and does not react with monodeoxyribonucleotides, homopolyribonucleotides, or duplexes of homopolyribonucleotides. Synthetic dA·dT was an effective inhibitor of the reaction with native DNA, while
Micrococcus luteus
DNA and dG·dC were not inhibitory.

This protein was encountered in the course of studies on DNA antibodies. Although it reacted with red cells coated with DNA and gave agar precipitation bands, it was clearly distinct from DNA antibodies. It was found in the serum of all animals of a given species, migrated as an α-β globulin, and did not crossreact with gammaglobulins. It reacted with DNA in solution to give precipitation curves that were strongly influenced by changes in ionic strength. The protein was isolated from canine serum by precipitation with DNA and purified to homogeneity, as judged by immunochemical and electrophoretic criteria.
A similar protein was found in mink, equine, and other sera, but not in human sera. Previous studies on DNA antibodies in certain experimental animals may have given false positive results due to this protein.
Ion-Diffusion Potentials and Electrical Rectification Across Lipid Membranes Activated by Excitation-Induced Material
Authors: Kalkwarf D. R. , Frasco D. L. , Brattain W. H. 
Published: May 2006

Membranes synthesized from sphingomyelin-tocopherol mixtures and treated with the protein, “excitation-inducing material,” to increase their electrical conductance were tested for applicability of the Nernst equation and changes in electrical rectifying behavior with temperature. Above pH 7, and in the temperature range 303-323°K, ion-diffusion potentials created by salts of monovalent cations showed that areas of the membrane activated by excitation-inducing material were only permeable to cations. Results also indicated that a parallel current with an activation energy of 1.00 eV per molecule passed through unactivated areas of the membrane. Below pH 7, the ratio of measured diffusion potentials to predicted values decreased steadily.
Electrical rectification was exhibited by membranes activated by excitation-inducing material with positive current consistently passing preferentially from the side rich in excitation-inducing material to the opposite side. For a given membrane, the current-voltage curves did not change from 312 to 323°K; but below 312°K, the membrane suddenly increased its conductance and became ohmic. This phenomenon was independent of salt concentration and pH, and resembled a phase transition.
Pressure Effect on the Membrane Action of a Nerve-Blocking Spin Label
Authors: Hsia J. C. , Boggs J. M. 
Published: May 2006

A reversible nerve-blocking spin label, 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) was used to study the nature of anesthetic-binding sites in nerve membranes as a function of pressure. The nerve-blocking effect of TEMPO is enhanced under pressure. At atmospheric pressure, TEMPO blocks nerve conduction by solubilizing in the apolar region of the nerve membrane. However, the nerve-conduction-block by TEMPO at 150 atm of helium was related to the binding of TEMPO to a pressure-induced high-affinity polar site in the nerve membrane. The new TEMPO-binding site could not be detected in lipid model membranes and, thus, the involvement of membrane protein in the new site was inferred. Pressure may induce a nerve membrane conformation change in the presence of TEMPO.
The observation that under different pressure, a single anesthetic, i.e., TEMPO, was capable of blocking nerve conduction by binding to two different sites within the nerve membrane, supports the view that there are multiple anesthetic receptor sites, which differ in chemical composition and location within the nerve membrane. These sites, when occupied by different classes of anesthetics, produce the general phenomenon of nerve-conduction block. The enhancement of nerve-conduction block by pressure may be due to the increased concentration of TEMPO in the new site in the nerve membrane under pressure.
The “Trophic” Value of Foods
Authors: Williams Roger J. , Heffley James D. , Yew Man-Li , Bode Charles W. 
Published: May 2006

Foods must furnish (
i
) calories, which can readily be measured, and (
ii
) raw materials necessary for the building and maintenance of metabolic machinery which makes possible fuel utilization. We have called this “beyond-calorie” quality of food its “trophic” value.

This concept has more unity than appears on the surface, and is capable of approximate measurement by biological testing as our experiments show.
The trophic value of a food cannot be ascertained from food composition tables because only a smattering of the necessary information is commonly furnished. A food cannot support life if it is missing, or deficient with respect to, any one of the necessary nutrients. A tabulation which includes only a few nutrients—e.g., calcium, thiamin, riboflavin, niacin, phosphorus, and iron—can be woefully misleading, especially if these individual nutrients have been added by way of fortification.
The measurement we have applied to a number of foods is potentially valuable for comparing similar food products: two grains, two breads, two milk products, or for comparison of the same food grown, processed, or preserved in different ways. By using essentially this method we have found that barnyard eggs are somewhat superior to battery eggs, but that whether they are fertile or infertile makes no difference.
We are of the opinion that extensive biological testing of many commercial food products is highly desirable to help promote human health and better internal environments for our cells and tissues.
Contact Inhibition of Movement in the Cultures of Transformed Cells
Authors: Guelstein V. I. , Ivanova O. Yu. , Margolis L. B. , Vasiliev Ju. M. , Gelfand I. M. 
Published: May 2006

Results of cell-cell collisions were studied with the aid of time-lapse microcinematography in primary cultures of normal mouse-embryo fibroblast-like cells and in cultures of transformed mouse cells of two types: (
a
) primary fibroblast-like cells transformed by Moloney mouse sarcoma virus; (
b
) neoplastic fibroblasts of the CIM strain.

Collisions of normal fibroblast-like cells and CIM cells in mixed cultures were also analyzed. Classification of the results of collisions was based on observation of the movements of the active cell edge during the first hour after the moment when this edge had contacted another cell. Three types of collision results were detected: halt of the active edge, overlapping, and underlapping.
The relative number of overlappings was not higher and that of halts not lower in the cultures of transformed cells as compared with those of normal cells. Analysis of the collisions of normal fibroblasts with transformed cells gave similar results. Thus, the altered morphology of the cultures of these transformed cells cannot be explained by loss of contact inhibition of movement leading to increased ability of cells to move over the surfaces of other cells after collision.
Localization of Adenovirus 2 Messenger RNAs to Segments of the Viral Genome Defined by Endonuclease R·R1
Authors: Tal Jacov , Craig Elizabeth A. , Zimmer Stephen , Raskas Heschel J. 
Published: May 2006

Adenovirus 2 mRNAs synthesized in productive infection were assigned to specific regions of the genome by hybridization to unique fragments of viral DNA. Radioactive viral RNA synthesized early or late in infection was first fractionated by polyacrylamide gel electrophoresis. Eluted RNAs were then tested for complementary hybrid formation with each of the six fragments of adenovirus 2 DNA generated by cleavage with endonuclease R·R1.
Early RNA species migrating as 13S, 19S, and 20S RNAs were identified as transcription products of fragments A, B, and D, respectively. In addition to the 13S RNA transcribed from A fragment DNA, 13S RNA also hybridized to the D and E fragment DNAs; 11S RNA annealed to both A and B fragments. The RNA that hybridized to fragment C DNA was heterogeneous in size.
Viral RNA synthesized late in infection included 27S, 24S, 19S, and 11S size classes, all of which annealed to A fragment DNA. Additional RNA migrating as 24S hybridized to E and C fragment DNA, and 23S RNA annealed to F fragment DNA.
The results of the hybridizations of size fractionated RNAs with viral DNA fragments enabled formation of a partial map of viral mRNAs with respect to the adenovirus 2 genome. Some of the viral RNAs may represent transcripts which overlap R1 cleavage sites, because in at least three instances hybridization revealed viral RNAs which have the same electrophoretic mobility and anneal to fragments that are contiguous on the genome.
The Stoichiometry of the Conversion of Cholesterol and Hydroxycholesterols to Pregnenolone (3β-Hydroxypregn-5-en-20-one) Catalysed by Adrenal Cytochrome
P
-450
Authors: Shikita Mikio , Hall Peter F. 
Published: May 2006

The stoichiometry of the side-chain cleavage of cholesterol (cholest-5-en-3β-ol), 20α-hydroxycholesterol (cholest-5-ene-3β,20α-diol), and 20α,22-dihydroxycholesterol (cholest-5-ene-3β,20α,22-triol) has been examined with respect to TPNH, oxygen and H
+
. Side-chain cleavage of cholesterol can be described by the following equation:

Cholesterol + 3TPNH + 3H
+
+ 3O
2
→ Pregnenolone (3β-hydroxypregn-5-ene-20-one) + isocapraldehyde + 3 TPN
+
4H
2
O

Stoichiometry of 20 α-hydroxycholesterol is 2TPNH and 2O
2
per mole of cleavage and with 20α, 22-dihydroxycholesterol the values are 1:1:1. In addition 1 mole of H
+
is consumed per mole of TPNH oxidized in each of these reactions. These observations are in keeping with a mechanism previously proposed in the literature, namely:

Cholesterol → 20α-OH-Cholesterol → 20α, 22-di-OH-Cholesterol → pregnenolone
Discordant observations are reviewed and it is concluded that insufficient data are available to sustain objections to this pathway.