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Potassium and sodium ions in the glycerinated skeletal muscle. Distribution changes induced by adenosine triphosphate and nondissociable anesthetic substances.

Investigation of the ionic behavior of glycerinated muscle fibers showed that the residual structures of this biologic cellular material, lacking functional membranes, are able to discriminate between alkaline ions. The characteristics of the ionic selectivity of the glycerinated fibers change with their functional state and with the presence in the medium of certain nonionic substances. Among the more important features of ionic distribution between the membrane-free fibers and the medium are the following: (1) There is evident adsorption of potassium on the fibers, in the absence of ATP. (2) This adsorption increases in contraction and decreases in relaxation. (3) At high ionic concentrations, in contrast to what occurs at low potassium concentrations, the glycerinated muscle prefers sodium to potassium, but even under these conditions both ions are accumulated in the fibers to far greater levels than in the medium. This strongly suggests a Donnan ionic equilibrium developing parallel to the adsorption process. (4) Nonionic substances of the general anesthetic group markedly alter the ionic selectivity of the glycerinated fibers, probably by their action on the water's physical state. A mechanism is proposed for the observed ionic adsorption specific of the muscle-a mechanism in which actin-myosin coupling plays the cardinal adsorption role. In the general interpretation of the data a synthetic concept is advanced according to which an entire set of processes and factors concurs with the distribution of ions between the muscle and the medium.

Adenosine Triphosphate↗

Intravenous nitro-glycerine versus general anaesthesia for placental extraction--a sequential comparison.

BACKGROUND: Postpartum haemorrhage due to retained placenta is one of the commonest life-threatening conditions during the third stage of labour. Uterine relaxation is usually required to facilitate placental removal. 'Full-stomach' obstetric patients (which includes those who delivered within 48 h), parturients with a history of antepartum or recurrent postpartum hemorrhage, grand multiparity, twin pregnancy, and those with cardiac abnormalities may benefit from an alternative to volatile-based general anaesthesia for uterine relaxation to avoid complications associated with the technique (e.g. aspiration pneumonitis and cardiovascular compromise). CASE REPORT: A 34-year-old gravida 4, para 3 parturient with rheumatic valvular heart disease presented with retained placenta and postpartum haemorrhage on two consecutive deliveries and had the placenta removed manually by the same surgeon under two different anaesthetic techniques. On the first occasion, general anaesthesia was administered whereas only i.v. fentanyl and nitro-glycerine were used on the second occasion. The postoperative course was uneventful on both occasions. CONCLUSIONS: The use of nitro-glycerine was found to be efficacious for manual removal of placenta with minimal haemodynamic perturbations, avoiding the use (and associated risks) of general anaesthesia for uterine relaxation. The ability of nitro-glycerine to reduce spontaneous uterine activity, induce uterine relaxation, coupled with its short duration of action and high efficacy, may render it a safe alternative to general anaesthesia for facilitating intrauterine manoeuvres. Nitro-glycerine may be useful especially in patients with associated co-morbid chronic cardiac conditions, e.g. rheumatic heart disease, which is characterised by impaired haemodynamics and cardiac reserves.

Anesthesia, General↗

Ototopical ciprofloxacin in a glycerin vehicle for the treatment of acute external otitis.

We conducted a prospective, randomized, controlled, double-blind study of 33 patients to compare the efficacy and tolerability of a new glycerin formulation of ototopical 0.3% ciprofloxacin with that of a conventional aqueous formulation of ciprofloxacin for the treatment of acute external otitis. Outcomes measures were resolution of discharge, swelling, pain, and redness and the incidence of adverse side effects. Patients were examined on three occasions: on the day of enrollment (visit 1), 48 to 72 hours later (visit 2), and 7 days after enrollment (visit 3). At visit 2, the patients in the glycerin group showed a significantly greater resolution of discharge. We observed the same pattern with respect to swelling, pain, and redness, which resolved more quickly in the glycerin group, although not significantly so. All patients were cured by visit 3, and the two treatments were equally well tolerated. On the basis of our findings, we conclude that the glycerin formulation of ototopical 0.3% ciprofloxacin appears to be at least as effective as the aqueous form in the treatment of acute external otitis--and in the case of otorrhea, more so.

Acute Disease↗

[Chronic gastritic changes induced in rats after pyloromyotomy and per os administration of acetic acid-glycerin].

We have experimentally studied whether or not repeated episodes of acute gastric mucosal lesions can induce chronic gastritic changes. Rats received pyloromyotomy and repeated per os administration of acetic acid-glycerin. Gastric mucosal lesions thus induced were studied histopathologically in cardiac glandular areas using morphometric analysis. It was found that pyloromyotomy induced fibrosis between the bottom of the gland and muscularis mucosa. On the other hand, the per os administration of acetic acid-glycerin induced hyperplastic change of mucous neck cells. They were increased in number and in size. Distribution of mucous neck cells were distended vertically to the mucosal surface and towards the bottom of the gland. Greater the amount of acetic acid-glycerin administration, stronger the changes of mucous neck cells, i.e., the distended zone of mucous neck cells spread more and more from the cardiac area. Parietal and chief cells were decreased in number in the course of the mucous neck cell hyperplasia. Branching of glands was occasionally seen in rats receiving greater amount of acetic acid-glycerin. It was concluded that there are basic structural similarity between the gastric mucosal changes induced by repeated episodes of acute gastric mucosal lesions and the change seen in human chronic gastritis. Thus acute gastric mucosal lesions can be one of the cause of chronic gastritis.

Acetates↗

[Na+ and K+ binding by glycerinated muscle fibers with reciprocal cation concentrations in the medium].

The binding of Na+ and K+ by glycerinated muscle fibres was observed at reserve concentrations of NaCl in the medium. Under external concentrations of Na+ of K+ up to 0.4-0.5 mM, a constant fraction (0.15-0.25 mmoles/kg dry weight of the fibres) bound by glycerinated fibres was revealed. With the increase of NaCl or KCl concentration in the medium up to 10 mM the concentration of bound cations increased too. The parameters of Na+ and K+ sorption by glycerinated models were calculated. The values of Na+ and K+ binding limits were 4.4 and 1.8 mmole/kg dry weight of the fibres and those of affinity, 3.2 and 4.1 kcal/mol, respectively. The binding of one cation took place in conditions when its concentration was 10,000-20,000 fold less than that of the other cation. This points to the fact that Na+ and K+ binding is highly specific and is carried out by different centres. It is suggested that myosin ATPase is a substratum binding Na+ and K+ in glycerinated muscle fibres at reverse ratio concentrations of these cations in the medium.

Animals↗

Gas chromatographic, liquid chromatographic, and titrimetric procedures for determination of glycerin in allergenic extracts and diagnostic antigens: comparative study.

Three methods for the determination of glycerin are examined as applied to several allergenic extracts and diagnostic antigens. The liquid chromatographic procedure uses a sulfonic acid functional PSDVB resin (Aminex HPX-87H), a mobile phase of 0.013N H2SO4; and refractive index detection. The titrimetric procedure involves oxidation of glycerin with sodium metaperiodate followed by potentiometric titration of the resulting formic acid with sodium hydroxide. Samples are quantitated by comparing the equivalence point obtained from the sample to those obtained from a series of standards. The gas chromatographic procedure includes a column of 5% Carbowax 20 M on 80-100 mesh Chromosorb WHP; p-cresol was used as an internal standard. The 3 procedures are shown to be valid for the majority of product types examined. A positive interference was encountered in the titrimetric analysis of a tuberculin purified protein derivative that contained simple sugars. Recoveries of added glycerin ranged from 95.0 to 100.2% by the liquid chromatographic method, from 98.7 to 101.4% by the gas chromatographic method, and from 99.8 to 101.6% by the metaperiodate oxidation method when interference from simple sugars was not present. Coefficients of variation determined from 8 replicates of samples that contained glycerin were 2.2% or less for the liquid chromatographic method, 2.3% or less for the GC method, and 3.6% or less for the metaperiodate oxidation method.

Allergens↗

[Correlation of glycerin-level and body weight (author's transl)].

In 202 non selected males and females the concentration of free glycerin in the fasting serum was evaluated. There was a significant parabolic correlation of the glycerin-levels in the serum with the deviation of the actual body weight from the ideal weight. There is a theory that glycerin regulates the appetite through a negative feed-back mechanism. Our findings do not contradict this hypothesis, as it cannot be excluded that feedback mechanism is disturbed in long lasting obesity. The serum level of free glycerin is not correlated with the concentration of triglycerides or total cholesterol.

Adult↗

[Production and characteristics of glycerin mutants of S. typhimurium].

S. typhimurium glycerine mutants-gly 90 and gly 87 were obtained under the action of ethylmethanesulfonate. The mutants obtained were characterized by the site of block in the course of glycerine utilization:gly 90 mutant bore the mutation in the glp K-gene, this leading to the defect by glycerokinase-the enzyme of the first stage of glycerine metabolism; gly 87 mutant had derangements in the other stage of glycerine utilization. Both mutants lost their capacity to induce keratoconjunctivitis in guinea pigs, but differed by the LD50 value in intraperitoneal infection of albino mice (y gly 87--5 cells, y gly 90--1x10(7) cells).

Animals↗

Osmolality changes in perilymph after systemic administration of glycerin.

Blood osmolality was altered in guinea pigs by intravenous administration of glycerin (glycerol). After glycerin administration, serum osmolality increased rapidly, reaching a plateau within 15 minutes. Perilymph osmolality lagged significantly behind the increase of serum osmolality and equalled serum osmolality only after one hour. While perilymph osmolality responded to changes of serum osmolality, there was some time lag noted in the response of perilymph, suggesting the existence of a blood-labyrinth barrier. It was observed that this barrier is permeably to glycerin and water, suggesting the possibility of transient reduction of hydrostatic pressure in the labyrinth by the injection of an osmotic agent into the systemic circulation.

Animals↗

Ca(2+)-induced tension development in the stalks of glycerinated Vorticella convallaria.

We have developed a method of measuring the isometric tension in glycerinated stalks of Vorticella convallaria. Using this method, we measured tension vs. pCa relations in glycerinated V. convallaria stalks. The maximum isometric tension was 4 x 10(-8) N on average. The Hill's parameter, n, which is the number of calcium ions bound simultaneously and cooperatively to a contractile element (a force generating element), is approximately 3.2 when the Ca2+ concentration is increased and 2.5 when it is decreased. In order to estimate the efficiency of the energy conversion of Ca2+ binding to mechanical work, we measured the Ca(2+)-induced Carnot cycle in the Vorticella stalk. The energy efficiency was tentatively estimated to be about 7%. With this method, we have also succeeded in measuring the isometric tension of isolated spasmoneme, the rubber-like contractile fibrous organelle in the stalk. The maximum tension of spasmoneme was approximately one tenth that of the glycerinated stalk. We speculate that the isolated spasmoneme was only partially functional due to damage sustained when it was pulled out of the stalk.

Animals↗

Evidence for regulation of lamellipodial and tail contraction of glycerinated chicken embryonic fibroblasts by myosin light chain kinase.

Permeabilized cell models of muscle and nonmuscle cells have proven useful for examining the regulation of actin, myosin, and other cytoskeletal proteins during cell contraction. Upon addition of Ca2+ and ATP, glycerinated chick embryonic skin fibroblasts retract their tails and lamellipodia. Ca2+-independent contractions are obtained by preincubation of cell models in Ca2+ ATP gamma S, followed by EGTA and ATP addition, or by addition of trypsin-treated myosin light chain kinase that no longer requires Ca2+ for reactivation. By pretreating cells before glycerination with colchicine, it is possible to study lamellipodial contraction independent of tail contraction. Similar responses to ATP gamma S pretreatment and unregulated myosin light chain kinase are observed in cells that only contain lamellipodia. SDS-PAGE electrophoresis of glycerinated fibroblasts incubated in ATP gamma 35S and Ca2+ shows that only two major proteins are thiophosphorylated, and that one of them, a band that comigrates with the 20K MW light chain of myosin, is thiophosphorylated in a Ca2+-dependent manner. Since the rate of tail contraction is several-fold faster after Ca2+ and ATP gamma S pretreatment or incubation in excess myosin light chain kinase, myosin light chain phosphorylation may be a rate-limiting step during contraction.

Animals↗

A femtogram resolution mass sensor platform based on SOI electrostatically driven resonant cantilever. Part II: sensor calibration and glycerine evaporation rate measurement.

This paper presents mass measurements of glycerine beads performed by means of laterally resonant micro-cantilevers. The transducer architecture is based on a resonant cantilever electrostatically coupled by two parallel placed electrodes. Previous to glycerine measurements, a calibration of the mass sensor has been performed by measuring a standard mass based on latex spheres. From these measurements, a value of the mass responsivity is deduced. In addition, a study of the transducer phase noise has been carried out in order to determine the minimum detectable mass. Mass measurements experiments have been performed by detecting the change on the resonance frequency of the on-plane cantilever resonant mode, produced by locally deposited mass. Additionally, the mass losses detected on the calibrated transducer after glycerine drop deposition allowed determining its evaporation rate.

Journal Article↗

Toxicologic evaluation of humectants added to cigarette tobacco: 13-week smoke inhalation study of glycerin and propylene glycol in Fischer 344 rats.

Glycerin (CAS no. 56-81-5) and propylene glycol (CAS no. 57-55-6) are commonly used as humectant ingredients in manufactured cigarettes to control and maintain the moisture content of the cut tobacco filler. The potential of these added humectants to affect the toxicity of cigarette smoke was investigated in a subchronic nose-only smoke inhalation study in rats. Filtered test cigarettes were prepared from an American-style tobacco blend containing either glycerin added at 5.1% w/w tobacco, propylene glycol at 2.2% w/w tobacco, or combinations of these humectants totaling 2.3%, 3.9%, and 7.2% w/w tobacco. Other groups of animals were exposed similarly to the smoke of reference cigarettes without added humectants, or to filtered air (sham control). Smoke exposures were conducted for 1 h/day, 5 days/wk for 13 wk, at target smoke particulate concentrations of 350 mg/m(3). All smoke-exposed groups had equivalent increases in blood carboxyhemoglobin, serum nicotine, and serum cotinine relative to the air controls. Smoke-associated reductions in body weights and occasional increases in heart and lung weights were generally similar among the various exposure conditions at necropsy. Increases in serum alkaline phosphatase and decreases in serum glucose and cholesterol were observed among smoke-exposed females relative to air controls. However, no significant differences in these parameters were evident between the humectant-containing and reference cigarette smoke exposure groups. Assessments of respiration conducted after 3, 6, 9, and 12 wk of smoke exposure indicated an initial smoke-related but not humectant-related decrease in respiratory rate, tidal volume, and minute volume during the first 20 min of each smoke exposure. Respiratory-tract histopathology was consistent across sexes and smoke groups, comprising (1) diffuse and focal alveolar pigmented macrophages and chronic interstitial inflammation in the lung, (2) laryngeal epithelial hyperplasia, squamous metaplasia, and scab formation, and (3) epithelial hyperplasia in the anterior nose. Smoke-related histopathology resolved substantially during a 6-wk postexposure recovery period. Addition of the tested humectants to cigarettes, singly or in combination, had no meaningful effect on the site, occurrence, or severity of respiratory-tract changes or on the measured indices of pulmonary function. It was concluded that the addition of glycerin and propylene glycol to cigarettes does not significantly affect the biological activity of inhaled cigarette smoke in this rat model.

Administration, Inhalation↗

FITC-labeled I-protein specifically binds to A-bands and/or Z-lines of glycerinated myofibrils of chicken breast muscle.

Ion-exchange column-purified I-protein was labeled by fluorescein isothiocyanate (FITC) at an equimolar ratio. When FITC-labeled I-protein was reacted with glycerinated myofibrils of chicken breast muscle in a phosphate-buffered saline, fluorescence was observed at the A-band and/or the Z-line of the sarcomere. However, FITC-labeled I-protein did not stain freshly prepared myofibrils. When FITC-I-protein was reacted with a nitrocellulose paper sheet on which muscle proteins were blotted after SDS-polyacrylamide gel electrophoresis, some peptide bands, including connectin and nebulin, were fluorescent. These facts can explain why anti-I-protein antibodies stain the A-I junctional region of fresh myofibrils and A-bands and/or Z-lines of glycerinated myofibrils. It is very likely that I-protein is transferred from the A-I junctions of myofibrils and translocates to A-bands and Z-lines, where some components that can bind to I-protein are localized, as myofibrils are degraded during the glycerination.

Animals↗

Oxygen exchange reaction during ATP hydrolysis by glycerinated muscle fibers, myofibrils, and synthetic actomyosin filaments.

The oxygen exchange during ATP hydrolysis by glycerinated muscle fibers, myofibrils, and synthetic actomyosin filaments was studied from the distribution of the [18O]Pi species produced by the hydrolysis of [gamma-18O]ATP. The products were mixtures of two species, one with a low extent of oxygen exchange and the other with a high extent. The low and high extents of oxygen exchange in these two Pi species were the same as those of the acto-S-1 ATPase reaction through the routes with and without the dissociation of actomyosin, respectively (Yasui, M., Ohe, M., Kajita, A., Arata, T., & Inoue, A. [1988] J. Biochem. 104, 550-559). During isometric contraction of glycerinated muscle fibers at 20 degrees C, the fraction of ATP hydrolysis with low extent of oxygen exchange was 0.83 and 0.70, respectively, in 0 and 120 mM KCl. In myofibrils, the fraction of ATP hydrolysis with a low extent of oxygen exchange was 0.72-0.88 in 0-120 mM KCl at 20 degrees C. Therefore, in glycerinated muscle fibers and myofibrils ATP seems to be mainly hydrolyzed through a route without the dissociation of actomyosin, especially at low ionic strength and at room temperature when the tension development is high. ATP hydrolysis through this route may be coupled with muscle contraction.

Adenosine Diphosphate↗

Predictability of the glycerin test in the diagnosis of Ménière's disease.

The response of patients with suspected Ménière's disease to the glycerin test was reviewed in a prospective evaluation covering a 10 year period. Three hundred and eighty three patients with 495 suspect ears were tested and were classified as to hearing improvement 3 h post-orally administered glycerin. Two hundred twenty-five patients (265 ears) were diagnosed as Ménière's disease. Sixty-six percent of these ears showed significant hearing improvement by pure tone threshold and/or speech discrimination measurements with the glycerin test. The test protocol developed and revised at the University of Washington provides a differential diagnostic means of identifying endolymphatic hydrops which is a specific and practical test. It is easily available as a routine office procedure.

Adult↗

Holographic microscopy of glycerination of Amoeba proteus.

The process of glycerination of Amoeba proteus was observed under the holographic microscope with coherent noise elimination. It was found that during glycerination redistribution of cell material occurs, and is accompanied by reversible deformation of the cell cortex. The rôle of the cortex in shape maintenance in glycerinated models was demonstrated.

Amoeba↗

Tension responses to quick length changes of glycerinated skeletal muscle fibres from the frog and tortoise.

1. Twitch fibres isolated from the sartorius muscle of the frog were glycerinated (cf. Heinl, 1972) and thin fibre bundles dissected from the m. ileofibularis of the tortoise were briefly glycerinated as described by Julian (1971).2. The glycerinated fibres (length 0.3-0.5 cm) were fixed to an apparatus which performed length changes within 5 msec and recorded the time course of tension changes in the fibres.3. The fibres were suspended in a relaxing medium, containing ATP and 4 mM-EGTA. Contraction was induced by raising the calcium concentration to 4 mM-CaEGTA.4. The tension time course of activated fibres following quick length changes (0.1-1% L(0)) was studied. The tension records produced by quick releases and stretches could be resolved into four phases similar to the kind shown in Fig. 1 a.5. The phase of quick tension recovery was found to take place more rapidly in frog than in tortoise fibres: it was completed in approximately 30 msec (after stretch) and in approximately 20 msec (after release) in frog fibres (3 degrees C). The corresponding values obtained for tortoise fibres were approximately 300 and approximately 400 msec (3 degrees C).6. In tortoise fibres the size of the elastic and quick recovery phase increased with rising isometric tension (induced by raising the calcium concentration (pCa 8 to 5)), and decreased with increasing sarcomere length (2.5-4.2 mum). In fibres, in which the rigor state was induced by withdrawal of ATP, no quick tension recovery was recorded.7. It is suggested that the rotational movement of the crossbridge head on the actin filament, postulated by Huxley & Simmons (1971 b) is taking place more slowly in the tortoise than in the frog muscle. Furthermore, it is suggested that this rotational movement does not occur in the rigor state, as no quick tension recovery was recorded there.

Adenosine Triphosphate↗