Thermoreversible gel formulation containing sodium lauryl sulfate as a potential contraceptive device

The contraceptive properties of a gel formulation containing sodium lauryl sulfate were investigated in both in vitro and in vivo models. Results showed that sodium lauryl sulfate inhibited, in a concentration-dependent manner, the activity of sheep testicular hyaluronidase. Sodium lauryl sulfate also completely inhibited human sperm motility as evaluated by the 30-sec Sander-Cramer test. The acid-buffering capacity of gel formulations containing sodium lauryl sulfate increased with the molarity of the citrate buffers used for their preparations. Furthermore, experiments in which semen was mixed with undiluted gel formulations in different proportions confirmed their physiologically relevant buffering capacity. Intravaginal application of the gel formulation containing sodium lauryl sulfate to rabbits before their artificial insemination with freshly ejaculated semen completely prevented egg fertilization. The gel formulation containing sodium lauryl sulfate was fully compatible with nonlubricated latex condoms. Taken together, these results suggest that the gel formulation containing sodium lauryl sulfate could represent a potential candidate for use as a topical vaginal spermicidal formulation to provide fertility control in women.     

A precaution when preparing very large plasmids by alkaline lysis procedure

The extractabilities of plasmids of different sizes by the sodium lauryl sulfate (SDS)-alkali procedure were compared using either sodium acetate or potassium acetate buffer as the neutralizing agent. There was a selective loss of large plasmids (above 100 kb) when the potassium salt was used. When N-lauryl sarcosine instead of SDS was used as the detergent, no loss of large plasmids occurred in the presence of potassium salt. A comparison of the kinetics of precipitate formation with sodium acetate and potassium acetate indicated that the rate and the amount of lauryl sulfate precipitated were lower with the sodium salt. It is suggested that faster precipitation of lauryl sulfate with potassium acetate leads to trapping of large denatured plasmids that cannot renature as fast as the small ones.     

The interaction between vitamin B-12 and micelles in aqueous solution.

The apparent pK for benzimidazole displacement of a number of cobalamins is markedly affected by the presence of sodium lauryl sulfate micelles. However, micelles of cetyltrimethylammonium bromide or Triton X have little or no effect on the pK. By measuring the apparent pK as a function of sodium lauryl sulfate concentration, the association constants between the micelles and both base on and base off methylcobalamin were calculated. This calculation indicates that the base off form is strongly associated with the micelle while the base on form is not.     

Structure and Composition of a Small Particle Prepared from a Simian Adenovirus.

Mayor, Heather D. (Baylor University College of Medicine, Houston, Tex.), Richard M. Jamison, Liane E. Jordan, and Joseph L. Melnick. Structure and composition of a small particle prepared from a simian adenovirus. J. Bacteriol. 90:235-242. 1965.-When tissue-culture fluids infected with simian adenovirus SV15 are examined in an electron microscope, either as fresh harvests or after treatment with Genetron, typical mature adenovirus particles are found. These are 65 to 70 mmu in diameter, with an icosahedral capsid built from 252 capsomeres. Also present is a population of small polyhedral particles approximately 20 mmu in diameter. These small particles can be separated from the mature virions by ultrafiltration or density gradient centrifugation. The small particles have a density of 1.43 in cesium chloride. They contain protein and double-stranded deoxyribonucleic acid. They appear to possess cubic symmetry of the icosahedral type, with a coat composed of 12 subunits each at the vertex of an icosahedron.     

Evaluation of Procedures for Isolation of Nontuberculous Mycobacteria from Soil and Water

Six methods of decontamination each for the isolation of mycobacteria from soil and water were compared. On the basis of the results obtained, three of the six methods for soil and two of the six methods for water were further evaluated. For both soil and water samples, the method using 3% sodium lauryl sulfate in combination with 1% NaOH yielded more positives than the other methods.     

The interaction between vitamin B-12 and micelles in aqueous solution

The apparent pK for benzimidazole displacement of a number of cobalamins is markedly affected by the presence of sodium lauryl sulfate micelles. However, micelles of cetyltrimethylammonium bromide or Triton X have little or no effect on the pK. By measuring the apparent pK as a function of sodium lauryl sulfate concentration, the association constants between the micelles and both base on and base off methylcobalamin were calculated. This calculation indicates that the base off form is strongly associated with the micelle while the base on form is not.     

Symmetry types, systems and their multiplicity in the structure of adenovirus capsid. I. Symmetry networks and general symmetry motifs

Each of the more than 1500 polypeptide molecules of 7 different types building up the adenovirus capsid--probably even those of their amino-acids--are in symmetrical location. Every kind of polypeptide forms a separately also symmetrical network in the capsid distributed according to their functions in the inner and outer side and the inside of the facets and edges, but always in compliance with the icosahedral symmetry. Therefore, each different polypeptide also means a general symmetry motif in the capsid in its own symmetry network. Hexons can be considered as general symmetry motifs in some special association that is because of their environmental position four kinds of hexon types can be found, which are on every facet, next to one another, like three identical groups of four (GOF) according to the three-fold rotational symmetry. Two polypeptides of a peripentonal hexon of each GOF orient toward the penton and the third toward the other penton located further on the same edge. There are two versions of the arrangement of the GOFs: the hexons surround either a polypeptide IX or a polypeptide IlIa. The two versions of GOFs on 20 facets symmetrically recurring 60 times as general hexon symmetry motifs form the capsid in combination with the network of other polypeptides. Ideally, the surface of the hexon trimer shows three-fold rotational and three-fold reflexional symmetries. In the arrangement of hexons in the facets the translational, rotational, horizontal and vertical reflexional symmetry and the combination of these, as well as the glide reflexion and the antisymmetry can be found. Each hexon has six nearest neighbours and every hexon takes part in the construction of three hexon rows. Every facet and every vertex made up of five facets has an antisymmetrical pair located on the opposite side of the capsid. Every triangular facet participates in forming three vertices and every facet has three nearest neighbouring facets. In the facets, the polypeptide subunits of polypeptide IX centered GOF hexons have identical counter-clockwise orientation but the orientation of the neighbouring facets is always opposite compared to each other. On the five-fold symmetry axis, any facet can be "turned on" to the adjacent facet or "rotated" to all the others and will take the symmetry and orientation of the facet it got turned on or rotated to. Thus, every facet together with the polypeptides attached to it shows a twenty-fold symmetry and multiplicity. An other type of symmetry and multiplicity in the capsid is that perpendicular to the 6 five-fold rotation axes run a geodetic (equatorial) ribbon like motif (superfieces) altogether six made up of 10 x 10 triangular facets and bent ten-times with an angle of 36 degrees. A triangular facet participates in forming three ribbon-like motifs, which intersect with each other on the given facet, but the same three motifs intersect repeatedly only on the antisymmetrically located facet.     

Aliesterase activity in normal and postheparin human blood sera.

An enzyme with characteristics typical of aliesterase has been found in human blood serum using a gas solid chromatographic assay technique. This conflicts with the findings of several authors that aliesterase is absent in the human blood. Another aliesterase is released into the blood stream after intravenous administration of heparin. Partial purification of the aliesterase in normal (preheparin) and postheparin sera was effected by column chromatography using CM- and DEAE-Sephadex. The preheparin aliesterase and postheparin aliesterase have different pH optima of 7.0 and 8.5 respectively. The preheparin aliesterase activity was very sensitive to sodium fluoride and insensitive to a negatively charged detergent, sodium lauryl sulfate, unlike the postheparin esterase which was highly sensitive to sodium lauryl sulfate and comparatively less sensitive to sodium fluoride.     

Patterns of polypeptide synthesis in various maize organs under anaerobiosis

The pattern of protein synthesis was compared in several organs of maize (Zea mays L.) under aerobic and anaerobic conditions. Protein synthesis was measured by [³⁵S]methionine incorporation and analysis by two-dimensional native-SDS (sodium lauryl sulfate) polyacrylamide gel electrophoresis and fluorography. The aerobic protein-synthesis profiles were very different for root, endosperm, scutellum and anther wall. However, except for some characteristic qualitative and quantitative differences, the patterns of protein synthesis during anaerobiosis were remarkably similar for these diverse organs and also for mesocotyl and coleoptile. The proteins synthesized were the anaerobic polypeptides (ANPs) which have been previously described in anaerobic roots of seedlings. Leaves exhibited no detectable protein synthesis under anaerobic conditions, and died after a short anaerobic treatment. Evidence is presented that the ANPs are not a generalized response to stress. This indicates that the ANPs are synthesized as a specific response to anaerobic conditions such as flooding.Abbreviations ADH alcohol dehydrogenase - ANP anaerobic polypeptide - SDS sodium lauryl sulfate     

Effect of defined lipopolysaccharide core defects on resistance of Salmonella typhimurium to freezing and thawing and other stresses

A family of mutants of Salmonella typhimurium with altered lipopolysaccharide (LPS) core chain lengths were assessed for sensitivity to freeze-thaw and other stresses. Deep rough strains with decreased chain length in the LPS core were more susceptible to novobiocin, polymyxin B, bacitracin, and sodium lauryl sulfate during growth, to ethylenediaminetetraacetic acid and sodium lauryl sulfate in resting suspension, and to slow and rapid freeze-thaw in water and saline, and these strains exhibited more outer membrane damage than the wild type or less rough strains. Variations in the LPS chain length did not dramatically affect the sensitivity of the strains to tetracycline, neomycin, or NaCl in growth conditions or the degree of freeze-thaw-induced cytoplasmic membrane damage. The deeper rough isogenic strains incorporated larger quantities of less-stable LPS and less protein into the outer membrane than did the wild type or less rough mutants, indicating that the mutations affected outer membrane synthesis or organization or both. Nikaido's model of the role of LPS and protein in determining the resistance of gram-negative bacteria to low-molecular-weight hydrophobic antibiotics is discussed in relation to the stress of freeze-thaw.     

Effect of defined lipopolysaccharide core defects on resistance of Salmonella typhimurium to freezing and thawing and other stresses.

A family of mutants of Salmonella typhimurium with altered lipopolysaccharide (LPS) core chain lengths were assessed for sensitivity to freeze-thaw and other stresses. Deep rough strains with decreased chain length in the LPS core were more susceptible to novobiocin, polymyxin B, bacitracin, and sodium lauryl sulfate during growth, to ethylenediaminetetraacetic acid and sodium lauryl sulfate in resting suspension, and to slow and rapid freeze-thaw in water and saline, and these strains exhibited more outer membrane damage than the wild type or less rough strains. Variations in the LPS chain length did not dramatically affect the sensitivity of the strains to tetracycline, neomycin, or NaCl in growth conditions or the degree of freeze-thaw-induced cytoplasmic membrane damage. The deeper rough isogenic strains incorporated larger quantities of less-stable LPS and less protein into the outer membrane than did the wild type or less rough mutants, indicating that the mutations affected outer membrane synthesis or organization or both. Nikaido's model of the role of LPS and protein in determining the resistance of gram-negative bacteria to low-molecular-weight hydrophobic antibiotics is discussed in relation to the stress of freeze-thaw.     

Prevention of formation of acid drainage from high-sulfur coal refuse by inhibition of iron- and sulfur-oxidizing microorganisms. II. Inhibition in "run of mine" refuse under simulated field conditions

The combination of sodium lauryl sulfate and benzoic acid effectively inhibits iron- and sulfur-oxidizing bacteria in coal refuse and prevents the conversion of iron pyrite to sulfate, ferric iron, and sulfuric acid, thereby significantly reducing the formation of acidic drainage from coal refuse. The inhibitors were effective in a concentration of 1.1 mg/kg refuse, and data indicate that the SLS was in excess of the concentration required. The treatment was compatible with the use of lime for neutralization of acid present prior to inhibition of its formation.     

Chitosan–Sodium Lauryl Sulfate Nanoparticles as a Carrier System for the In Vivo Delivery of Oral Insulin

The present work explores the possibility of formulating an oral insulin delivery system using nanoparticulate complexes made from the interaction between biodegradable, natural polymer called chitosan and anionic surfactant called sodium lauryl sulfate (SLS). The interaction between chitosan and SLS was confirmed by Fourier transform infrared spectroscopy. The nanoparticles were prepared by simple gelation method under aqueous-based conditions. The nanoparticles were stable in simulated gastric fluids and could protect the encapsulated insulin from the GIT enzymes. Additionally, the in vivo results clearly indicated that the insulin-loaded nanoparticles could effectively reduce the blood glucose level in a diabetic rat model. However, additional formulation modifications are required to improve insulin oral bioavailability.KEY WORDS: chitosan, insulin, nanoparticles, oral delivery system, sodium lauryl sulfate     

Inhibition of small intestinal mucosal and smooth muscle cell function by ricinoleic acid and other surfactants.

Sodium ricinoleate, dioctyl sodium sulfosuccinate, sodium dodecyl (lauryl) sulfate, polysorbate 80, sodium deoxycholate and chenodeoxycholate were found to produce depression of $\text{in vitro}$ mucosal and smooth muscle cell function. These actions were assessed by measuring net water and electrolyte transport from everted hamster gut sacs and contractile activity of the electrically stimulated guinea-pig ileum. All compounds were effective depressants of both systems at concentrations which were likely to be below their respective critical micellar concentration. Ricinoleic acid may produce its cathartic effect due to its amphipathic nature, possibly by hydrophobic interaction with membrane lipoproteins. Ricinoleic acid and the other surfactants may be acting through a common mechanism.     

Electrophoretic purification of biologically active structural proteins of the simian adenovirus SA7 in the presence of sodium dodecyl sulfate

The modification of disc electrophoresis technique in polyacrylamide gel with sodium dodecylsulphate (SDS) has been elaborated for synchronous isolation of some structural proteins in biologically active form and in preparative quantities from adenoviruses. Virions of SA7 adenovirus were mildly dissociated in SDS solution at 20 degrees C and structural proteins were stained by fluorescamin. After separation the zones of proteins corresponding to the native capsomeres of hexon and protein IV as well as the zones of inner proteins V and VII have been identified as fluorescent at UV-irradiation, excised and extracted by SDS solution. After the removal of SDS by protein precipitation in acetone the preparations of hexon and IV reveal the quaternary structure of native capsomers and full spectrum of antigenic and immunogenic activities of native proteins. Preparations of inner proteins V and VII possess activity in condensing adenoviral DNA. The technique is usable for preparative purification of inner polypeptide VI SA7, as well as capsomers and inner proteins of other adenoviruses.     

Solubilization of the Cytoplasmic Membrane of Escherichia coli by the Ionic Detergent Sodium-Lauryl Sarcosinate

The sensitivity of the outer and cytoplasmic membranes of Escherichia coli to detergent was examined by isopycnic sucrose density gradient centrifugation. Sodium lauryl sarcosinate (Sarkosyl) was found to disrupt the cytoplasmic membrane selectively under conditions in which Triton X-100 and dodecyl sodium sulfate solubilized all membrane protein. These results were verified by gel electrophoresis; membrane proteins solubilized by Sarkosyl were identical to those of the cytoplasmic membrane. The presence of Mg(2+) during treatment with Sarkosyl was found to afford partial protection of the cytoplasmic membrane from dissolution.     

Antioxidant protection from solar-simulated radiation-induced suppression of contact hypersensitivity to the recall antigen nickel sulfate in human skin.

Solar radiation induces suppression of the local effector mechanisms involved in immune responses to recall antigens. By using a low-dose solar-simulated radiation protocol, we investigated whether oral supplementation of the antioxidants RRR-alpha-tocopherol combined with L-ascorbic acid prevented radiation-induced suppression of the contact hypersensitivity response to nickel sulfate. In a prospective, randomized study, nickel-sensitive individuals were given RRR-alpha-tocopherol 2 g/d oral supplements combined with L-ascorbic acid 3 g/d for 50 d (group 1). Individuals in the control group were given a placebo (group 2). The reaction to a standardized patch test with serial dilutions of nickel sulfate and the irritant skin reaction to sodium lauryl sulfate were assessed by visual grading and by reflectance spectrophotometry in radiation-exposed and nonexposed skin 50 days after supplementation. Results showed that the contact hypersensitivity response to the recall antigen nickel sulfate was significantly suppressed in the radiation-exposed skin of those who took the placebo. Supplementation with RRR-alpha-tocopherol combined with L-ascorbic acid significantly protected against the radiation-induced suppression of the contact hypersensitivity response to nickel sulfate. The irritant reaction to sodium lauryl sulfate was not suppressed by radiation, and antioxidant supplementation did not modulate this response. In conclusion, a combination therapy of systemic high-dose RRR-alpha-tocopherol combined with L-ascorbic acid prevented solar-simulated radiation-induced suppression of the local immune response to the recall antigen nickel sulfate in human skin. This immunoprotective effect of combined RRR-alpha-tocopherol and L-ascorbic acid could be exploited for the prevention of solar radiation-induced skin cancer in an antioxidant intervention study.     

Characterization of a temperature-sensitive mutant of human adenovirus type 7.

The properties of a naturally occurring temperature-sensitive (ts) mutant of human adenovirus type 7 (Ad7) were studied. Mutant Ad7 (19), or E46-, was the nonhybrid adenovirus component derived from the defective simian virus 40 (SV40)-Ad7 hybrid (PARA). Growth of the mutant was restricted at 40.5 degrees C, and the ratios of virus yields in KB cells at 40.5 and 33 degrees C were 10(-2) to 10(-3). Viral DNA synthesis and the synthesis of adenovirus-specific antigens (tumor, capsid, hexon, and penton antigens) appeared normal at the restrictive temperature. The assembly of virus particles was aberrant, as determined by thin-section of infected cells. The infectivity of mutant virions was heat labile at 50 degrees C, suggesting a ts defect in a structural component of the viron. Analysis by polyacrylamide gel electrophoresis of [35S]methionine-labeled polypeptides synthesized in mutant-infected cells suggested that at least the major virion polypeptides were synthesized at the restrictive temperature. A lack of inhibition of host protein synthesis late in mutant infections, as compared with wild-type (WT) infections at both the permissive and nonpermissive temperatures, made quantitation of infected-cell polypeptides difficult. Analysis of the assembly of capsomeres from cytoplasmic extracts of infected cells on sucrose gradients and by non-dissociating polyacrylamide gel electrophoresis suggested that hexon capsomeres were made at 40.5 degrees C. The hexon capsomeres made by the mutant at either 33 or 40.5 degrees C displayed a decreased migration in the non-dissociating gels compared with the WT hexon capsomeres. The molecular weights of the mutant and WT hexon polypeptides were identical. These results suggest that the ts lesion of this group B human Ad7 mutant may be reflected in altered hexons. The mutant Ad7 interfered with the replication of adenovirus types 2 and 21 at the elevated temperature.     

Purification and characterization of esterases D1 and D2 from human erythrocytes. Evidence that they are monomers

Esterase D1 and esterase D2, two common esterase D (EC 3.1.1.1) isozymes, were isolated and purified from human erythrocytes. Their substrate specificity, pH profile and Km values were essentially identical. Their molecular mass was the same at 34 kDa on sodium dodecyl sulfate/polyacrylamide electrophoresis and at 27 kDa on Sephadex G-100 gel filtration. Antisera to each of the esterase D1 and esterase D2 isozymes were successfully raised in chickens; each antiserum reacted identically with both isozymes. These findings indicate that the isozymes are close to each other in structure. The fact that the molecular mass of the esterase D1 and esterase D2 isozymes computed on sodium dodecyl sulfate/polyacrylamide electrophoresis was close to that obtained on Sephadex G-100 gel filtration in non-dissociating buffer indicates that the isozymes are not dimers bound by disulfide bonds or a noncovalent force. These facts together indicate that the esterase D isozymes are monomers, contrary to the prevailing view that they are dimers.