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At least 55 records · Page 3Linked to original sources

Semen cahracteristics before and after ligation of the left internal spermatic veins in men with varicocele.

The semen from 20 men with varicocele was studied before and after surgical correction of the varicocele. The effect on sperm quality was only marginal and could not explain the fairly high conception rate (20%) after operation. The recommendation that varicocele in men with long-term infertility should be eliminated by ligation of the internal spermatic veins is still justified despite the absence of positive effects on sperm quality.

Acid Phosphatase↗

A Novel Moisturizer Formulated With Micronized Centella asiatica and Mandelic Acid Improves Mature, Crepey Skin.

BACKGROUND: Dermatoporosis is a condition of fragile, aging skin that manifests as altered pH, wrinkles, laxity, easy bruising, and hyperpigmentation. This study evaluated efficacy, safety, and subject perception after the use of a novel cream, GC (Galderma Laboratories, LP, Fort Worth, TX), on subjects with mature, aging skin. METHODS: A 12-week multicenter, randomized, blinded, in-use study enrolled female and male subjects aged 40 to 60 years of all races, ethnicities, and Fitzpatrick skin types. Subjects were required to have a history of fragile skin and dry, crepey skin on the knees and thighs. GC cream was applied to knee and upper thigh skin twice daily. Assessments included clinical grading, digital photography, bioinstrumentation (skin texture, pH, and heatmap hydration), standard safety assessments, and satisfaction. RESULTS: Use of GC cream for 12 weeks resulted in significant improvements in skin crepiness, photodamage, and firmness, as well as decreased skin pH and early improvements in skin roughness and smoothness from baseline. Corneometer heatmapping documented improved skin hydration over baseline. No adverse events were reported; the GC cream was well tolerated, and subjects reported high satisfaction. CONCLUSION: Twice-daily application of the novel GC skin cream significantly improved the overall skin quality of mature, aging skin, including crepiness, photodamage, firmness, texture, pH, and hydration. GC cream was well tolerated with high subject satisfaction. These data are intended to help guide healthcare providers and patients in choosing an effective moisturizer that was specifically designed for patients with fragile, mature skin.

Humans↗

Response of type B and E Botulinum toxins to purified sulfhydryl-dependent protease produced by Clostridium botulinum type F.

A sulfhydryl-dependent protease (SHP) was purified from a culture of Clostridium botulinum type F. The enzyme can activate type E progenitor toxin completely but type B progenitor toxin only partially. This may suggest that SHP by itself could completely activate the toxin of proteolytic C. botulinum types A and F in culture. The toxicity of type E progenitor toxin potentiated by the treatment with SHP persisted, whereas that of derivative toxin decreased rapidly by further incubation with SHP. This may indicate that only the progenitor toxin, the complex of the toxic and nontoxic components, activated by SHP withstands the subsequent exposure to the enzyme in cultures of proteolytic C. botulinum.

Amidohydrolases↗

[Effect of pH on properties of the cholinoreceptive membrane of snail neurons].

The influence of pH on acetylcholine (ACh)-induced responses in completely isolated neurons of Lymnaea stagnalis was studied under voltage clapm conditions. The pH drop lead to a decrease in sensitivity of cholinoreceptive membrane; at pH 5.8-6.0 ACh-responses were eliminated completely. When raising the external pH (up to 10.6) there were no changes in the ACh effect. A group responsible for sensitivity changes of the cholinoreceptive membrane appears to have pK about 6.7. It is shown that the pH drop does not influence the ionic channel functional groups. The results can be explained in the assumption that some functionally important groups in the cholinoreceptor active site are protonated at low pH.

Acetylcholine↗

[Pulmonary vascular pressures and blood gases in young patients with thoracic scoliosis (author's transl)].

Pulmonary artery and pulmonary wedge pressures were measured at rest and during exercise in 25 young patients with moderate to severe scoliosis. Simultaneous determinations of arterial blood gases and pH were performed. The results of the vascular pressure measurements were compared with those obtained in 15 healthy young subjects. In all patients the pulmonary artery and pulmonary wedge pressure were normal at rest. During mild ergometer exercise, however, an abnormal rise in pulmonary artery pressure occurred in 9 patients. Moreover, an increased diastolic pressure gradient across the pulmonary vascular bed was found in some scoliotic patients indicating an elevated pulmonary vascular resistance. It is supposed that this haemodynamic abnormality is primarily due to a restriction of the pulmonary vascular bed. Relationships between pulmonary artery pressure and arterial oxygen tension and blood pH, respectively, could be found. The possible significance of these results is discussed.

Adolescent↗

[Oospora lactis strain actively producing lipase].

Morphological, cultural and physiological properties of the fungus Oospora lactis producing lipase are described. The activity of lipase depends on the composition of a growth medium, pH, temperature, the duration of cultivation. Optimum conditions for lipase biosynthesis by the fungus have been found. The strain produces extracellular and endocellular lipases during submerged cultivation in the optimum growth medium at a high rate.

Culture Media↗

[Determination of acid-base parameters by means of programmable pocket calculators (author's transl)].

The possibility to calculate parameters of acid-base status derived by common laboratory devices without built-in computers is described. The calculation is carried out faster and more exactly than it is possible by nomograms, which is especially suitable when a great quantity of dates occurs. The number of programmable steps in some inexpensive pocket calculators is sufficient for this purpose; this type of "microcomputers" offers advantages of economy and small size so that calculations can be carried out immediately at the site where measurements are taken.

Acid-Base Equilibrium↗

[Kinetic characteristics of DNA alkylation with some chloroethylmethylarylamines and elimination of alkylated bases from DNA].

Kinetics of DNA alkylation with 2',3'-o-[N-2-chloroethyl-N-methylamino)benzylidene]uridine (UCHRCL), uridine-5'-methylphosphate (MepUCHRCL) and 4-(N-2-chloroethyl-N-methylamino)benzylamine (NH2CH2RCl) and kinetics of elimination of alkylated bases have been studied. Efficiency of DNA alkylation (p/s-ratio of rate constant of alkylation to the sum of rate constants of by-reactions of an active intermediate formed from the reagent) increases with an increase of the positive charge of the reagents as well as efficiency of tRNA alkylation. Alkylated bases are eliminated from DNA; rate of elimination depends on the structure of the reagent; it decreases in the series NH2CH2R- greater than greater than UCHR-greater than MepUCHR-. Bases alkylated by NH2CH2RCl and UCHRCl are eliminated from DNA during alkylation; therefore plots of DNA alkylation by NH2CH2RCl have a maximum. DNA alkylated by MepUCHRCl is rather stable; alkylated bases are not eliminated during alkylation. Effect of temperature and pH on elimination has been studied.

Alkylating Agents↗

[Isolation and properties of polyphosphatase of Neurospora crassa].

Polyphosphatase (polyphosphate-phosphohydrolase) has been isolated from mycelium of Neurospora crassa and purified to homogenous state. The enzyme is shown to be strictly specific to high molecular weight inorganic polyphosphates. Km for phosphate in polymeric form is 6.8-10(-4) M. The molecular weight of this enzyme is 50 000 +/- 3000. To display its activity polyphosphatase requires the presence of bivalent cations of some metals, Mg2+ ions being the best activator with Co2+, Mn2+ and Fe2+ ions-slightly less effective.

Cations, Divalent↗

[Isolation of rat liver chromatin non-histone protein].

A chromatin with the protein/DNA ratio of 3.0 was obtained from rat liver cells nuclei. The chromatin was dissolved in 2 M NaCl, pH 7, and reprecipitated by decreasing the ionic strength to 0.4 and increasing pH to 9.0. A fraction of non-histone proteins (NH-1) remained in a supernatant solution, the NH-1/DNA ratio being equal to 1.3 and the ratio of acidic to basic aminoacid residues equal to 1.31. After chromatography on Bio-Rex 70 cation-exchang resin, a fraction (NH-2) with the NH-2/DNA ratio of 1.0 +/- 0.15 and the ratio of acidic to basic aminoacid residues of 1.57 was obtained. According to the data of polyacrylamide gel electrophoresis, the NH-2 fraction contained 2.7% of histone f2 + f3 as an admixture whereas histone f1 was not revealed.

Amino Acids↗

[pH-dependence of the mechanism of pepsin action].

N-Acetyl-L-phenylalanine inhibition of the peptic hydrolysis of N-acetyl-L-phenylalanine-L-tyrosine over the pH range 2-4.5 was studied. The mixed character of inhibition which was partially competitive and partially non-competitive allowed us to infer that the separate steps of the enzymatic hydrolysis were pH dependent. The orderliness of the dissociation of the triple enzyme-product-product complex was also pH dependent. The group with pKa approximately 3 influenced the mechanisms of pepsin hydrolysis as strongly as in the case of pepsin catalyzed oxygen isotopic exchange in the acyl amino acid carboxyl group.

Binding Sites↗

Effect of variations in pH on kinetics of myosin.

The pH optimum was the same in canine tissue for cardiac and skeletal muscle myosin; when myosin was activated by monovalent cations, the pH optimum was 7.5 while activation of myosin by divalent cations gave a pH optimum of 5.5. Protons were needed for divalent cation activation of myosin. With changes in pH there were concomitant changes in the apparent affinity of enzyme for substrate (S 0.5), such that with a decrease in pH there was an elevation in K+- or NH4+ -activated myosin's apparent affinity for adenosine triphosphate (ATP), and at the same time a decrease in Vmax values of myosin. The converse was true with the divalent cations, Ca++ and Mn++; here with a decrease in pH there was a concomitant decrease in apparent affinity of myosin for ATP, and at the same time an increase in the enzymatic Vmax values. It appeared that hydrogen ions affected the apparent affinity of myosin for substrate and this in turn affected the rate-limiting step in ATPase reaction. Addition of monovalent cations to the divalent cation activating system lowered the activity of myosin, and the converse was true: divalent cations lowered the activity of myosin when activated by monovalent ones in a monovalent cation activating system.

Adenosine Triphosphatases↗

Normal blood-gas values in lambs during neonatal development and in adult sheep.

Arterial oxygen (PaO2) and carbon dioxide (PaCO2) tensions and pH were determined in 20 lambs during development from two weeks to five months of age and in 34 adult sheep. Throughout the period the lambs' mean PaCO2 (33.1 mm Hg) and pH (7.46) values were similar to those determined in the adult sheep (PaCO232.1 mm Hg; pH 7.48). The lamb's mean PaO2 increased from 63.3 mm Hg at two weeks of age to about 80 mm Hg at eight weeks and by 20 weeks was similar to the mean PaO2 (88.0 mm Hg) of adult sheep.

Animals↗