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PubMed1997

Preinduction cervical ripening: prostaglandin E2 gel vs hygroscopic mechanical dilator.

OBJECTIVES: To evaluate the efficacy and safety of hygroscopic mechanical dilators (Dilapan) for ripening the pregnant cervix prior to induction of labour at or near term and to compare it with an intracervical PGE2 gel (Prepidil). METHODS: One hundred and eighty-five women (69 nulliparae, 116 multiparae) at term with singleton pregnancies in cephalic presentation, who were scheduled for induction of labour in the labour ward at the National University Hospital, but had an unfavourable cervical score were randomized into 2 groups by random number table. In group 1 (Prepidil), 0.5 mg of PGE2 in 2.5 ml of triacetin gel was inserted into the endocervical canal. In women in group 2 (Dilapan) upto a maximum of 4 hygroscopic dilators were placed in the endocervical canal. If labour did not ensue at the end of 12 hours of ripening, the cervical score was assessed, amniotomy was performed and oxytocin commenced. Neonatal and obstetric outcome was compared, statistical analysis performed using Chi-square, and t-tests. RESULTS: Significantly more women in the group who received Dilapan for cervical ripening required amniotomy and oxytocin for induction of labour > 12 hours after priming compared with the group who received Prepidil (p < 0.001). Operative delivery for no progress and fetal distress respectively was similar in the 2 groups. The number of cases of hyperstimulation were higher in the Prepidil group but did not result in an increased incidence of operative deliveries for fetal distress. There was one neonatal death and one case of neonatal sepsis in the Dilapan group. Uterine rupture occurred in 1 woman who received Prepidil. CONCLUSION: Dilapan, a mechanical method of cervical ripening is as effective as the more widely accepted mode of ripening with an endocervical PGE2 gel in achieving vaginal delivery. Dilapan would be useful for cervical priming prior to induction of labour in places where prostaglandins are not available because of cost and the need for a cold chain.

Adult↗
PubMed1989

Labour induction with low dose PGE2 vaginal gel: result of an Australian multicentre randomized trial.

An open-label, parallel, randomized study was conducted in 6 Australian hospitals involving 320 women near term who required induction of labour. Labour induction with 1 or 2mg of PGE2 in a vaginal triacetin gel repeated if necessary at 6 hours was compared to induction by amniotomy and intravenous oxytocin. Analysis of the 2 groups confirmed matching with regards demographic and clinical data. A significantly longer and more variable mean induction to onset of established labour interval was recorded in the PGE2 group (6.7 +/- 4.8 versus 2.0 +/- 1.1 hours. (p less than 0.001). The mean period of established labour was also longer (8.1 versus 6.0 hours, p less than 0.001) in the PGE2 group. However, 48% of PGE2 treated patients versus 29% oxytocin treated patients (p less than 0.01) were recorded as not experiencing strong contractions. Twelve hours after induction 65% of the PGE2 group and 93% of the oxytocin group were in established labour; 24% of the PGE2 treated group required subsequent augmentation with oxytocin. Spontaneous delivery occurred in 69% of PGE2 treated women and 62% of those treated with oxytocin (N.S.). Analgesic requirements were not statistically different between the groups. Fewer fetal heart rate abnormalities were recorded in the PGE2 treated group (p less than 0.02). No serious and only minimal adverse events were recorded in either treatment group.

Administration, Intravaginal↗
PubMed1966

Handling of glycerides of acetic acid by rat small intestine in vitro.

1. When mono-, di- and triacetins are incubated with sacs of rat everted intestine, they enter the epithelial cells and are hydrolysed to free glycerol and acetic acid.2. The rate-limiting step in the process is the entry of glyceride into the epithelial cell.3. The three acetins enter the epithelial cell at the same rate, and the mechanism of this remains unknown.4. The acetate released appears in higher concentrations on the serosal side, and the relation of this to the mechanism for transfer of volatile fatty acids is discussed.5. It is not necessary to postulate a special mechanism for entry of volatile fatty acids into the cell.

Acetates↗
PubMed1970

Intracellular hydrolysis of short chain glycerides by rat small intestine in vitro and transfer of glycerol.

1. When triacetin, tripropionin and tributyrin are incubated with sacs of rat everted intestine, they enter the epithelial cells and are completely hydrolysed to free fatty acids and glycerol.2. The distribution between the mucosal and serosal fluids of the glycerol released is very different from that of the fatty acid. Although both hydrolytic products are accumulated in the serosal fluid, a much higher fraction of the fatty acid appears in this compartment.3. When glycerol is initially present in the mucosal fluid there is no evidence of its movement against a concentration gradient.4. The results confirm the existence of a transport mechanism for fatty acids released intracellularly but do not require the hypothesis of a special mechanism for glycerol transfer.

Animals↗
PubMed1982

Comparative antimicrobial activity, in vitro and in vivo, of soft N-chloramine systems and chlorhexidine.

Antimicrobial activity of the following four new N-chloramine compounds was evaluated: two chlorinated simple amino acids, a chlorinated half-ester of succinic acid, and a chlorinated half-ester of glutaric acid. For comparison, the known bactericidal agents 3-chloro-4,4-dimethyl-2-oxazolidinone and chlorhexidine were evaluated by the same procedure. The contact germicidal efficiency screen was used to examine the in vitro bactericidal activity of all six compounds in the absence and presence of 5% horse serum or 5% Triton X-100. The four new compounds were found to have greater germicidal activity than the other compounds tested and to exhibit low toxicity and skin irritation values. The in vivo bactericidal activity was evaluated in two studies. In the occlusion test, three of the four new compounds plus chlorhexidine diacetate were tested. The N-chloramines were significantly superior to chlorhexidine in preventing the expansion of the normal flora under occlusion. In the scrub test, a gloved-hand wash method was used to compare the antimicrobial effect of a 1% solution of the chlorinated half-ester of succinic acid in triacetin with that of a commercial germicidal hand wash containing 4% chlorhexidine gluconate. The two preparations exhibited essentially the same hand-degerming activity.

Animals↗
PubMed1987

Some Properties of Extracellular Acetylxylan Esterase Produced by the Yeast Rhodotorula mucilaginosa.

The red yeast Rhodotorula mucilaginosa produced an esterase that accumulated in the culture supernatant on induction with triacetin. The enzyme was specific for substrates bearing an O-acetyl group, but was relatively nonspecific for the rest of the molecule, which could consist of a phenol, a monosaccharide, a polysaccharide, or an aliphatic alcohol. The esterase was more active against acetylxylan and glucose beta-d-pentaacetate than were a number of esterases from plant and animal sources, when activities on 4-nitrophenyl acetate were compared. The enzyme exhibited Michaelis-Menten kinetics and was active over a broad pH range (5.5 to 9.2), with an optimum between pH 8 and 10. In addition, the enzyme retained its activity for 2 h at 55 degrees C. The yeast that produced the enzyme did not produce xylanase and, hence, is of interest for the production of acetylxylan esterase that is free of xylanolytic activity.

Journal Article↗
PubMed1973

Characterization of esterases produced by a ruminal bacterium identified as Butyrivibrio fibrisolvens.

An obligately anaerobic ruminal bacterial isolate was selected from 18 tributyrin-degrading isolates and identified as Butyrivibrio fibrisolvens strain 53. The culture in late exponential phase contained enzymes which could be released by sonic disruption. These enzymes degraded substrates at a rate in the order 1-naphthyl acetate (NA) > 1-naphthyl butyrate > 1-naphthyl propionate but did not degrade 1-naphthyl palmitate or 1-naphthyl phosphate. The enzymes on NA were neither stimulated nor inhibited by CoCl(2), MgCl(2), and MnCl (each varied from 10(-6) to 10(-4) M). CaCl at 10(-3) M stimulated esterase activity by 16%. Aliphatic substrates were hydrolyzed at a rate in the order triacetin > tributyrin > tripropionin, and ethyl acetate > ethyl formate. Similarly, aromatic fluorescein diesters were degraded at a rate in the order acetyl > propionyl > caproyl > butyryl > capryl > lauryl. Polyacrylamide gel electrophoretic zymograms indicated that the enzyme composite contained cathodally migrating bands. By column chromatography, these enzymes were separated into six NA-degrading fractions. Fraction V contained an esterase which had an optimal temperature of 39 C, a K(m) of 7.6 x 10(-4) on NA, and a molecular weight of about 66,000. This enzyme was inhibited by paraoxon (41%, 10(-4) M), eserine (17%, 10(-2) M), NaF (17%, 10(-2) M), and diisopropyl fluorophosphate (62%, 10(-4) M) but not by 1-naphthyl N-methyl carbamate at 8.4 x 10(-4) M.

Anaerobiosis↗
PubMed1997

Characterization of the aes gene of Escherichia coli encoding an enzyme with esterase activity.

malQ mutants of Escherichia coli lacking amylomaltase cannot grow on maltose. They express the maltose system constitutively and are sensitive to maltose when grown on another carbon source. In an attempt to isolate a multicopy suppressor that would result in growth on maltose, we transformed a malQ mutant with a gene bank of E. coli DNA which had been digested with Sau3a and cloned in pBR322. We screened the transformants on MacConkey maltose plates. A colony was isolated that appeared to be resistant to maltose and was pink on these plates, but it was still unable to grow on minimal medium with maltose as the carbon source. The plasmid was isolated, and the gene causing this phenotype was characterized. The deduced amino acid sequence of the encoded protein shows homology to that of lipases and esterases. We termed the gene aes, for acetyl esterase. Extracts of cells harboring plasmid-encoded aes under its own promoter exhibit a fivefold higher capacity to hydrolyze p-nitrophenyl acetate than do extracts of cells of plasmid-free strains. Similarly, strains harboring plasmid-encoded aes are able to grow on triacetyl glycerol (triacetin) whereas the plasmid-free strains are not. The expression of plasmid-encoded aes resulted in strong repression of the maltose transport genes in malT+ strains (10-fold reduction), but not in a malT(Con) strain which is independent of the inducer. Also, overproduction of MalT counteracted the Aes-dependent repression, indicating a direct interaction between MalT and Aes.

Acetylesterase↗
PubMed1965

EGG YOLK FACTOR OF STAPHYLOCOCCUS AUREUS. II. CHARACTERIZATION OF THE LIPASE ACTIVITY.

Shah, D. B. (University of Wisconsin, Madison), and J. B. Wilson. Egg yolk factor of Staphylococcus aureus. II. Characterization of the lipase activity. J. Bacteriol. 89:949-953. 1965.-The staphylococcal egg yolk factor was characterized as a lipase. The enzyme had an optimal pH of 7.8, but the optimal pH of stability was 7. Substrate specificity data showed that the relative rate of hydrolysis was lowest with triacetin as substrate, was maximal with tributyrin, and decreased as the chain length of the acyl moieties increased. The enzyme showed an absolute requirement for a fatty acid acceptor like calcium, when the acyl moiety of triglyceride was water-insoluble. Magnesium, strontium, and barium functioned equally well as fatty acid acceptors. The enzyme was able to hydrolyze coconut oil, peanut oil, olive oil, and egg yolk oil.

Calcium↗
PubMed1997

Interaction between poly-3-hydroxybutyrate-co-3-hydroxyvalerate and a denitrifying Pseudomonas strain.

In a laboratory-scale system, dentrification activity of a heterotrophic microbial starter culture changed when different lots of poly-3-hydroxybutyrate-co-3-hydroxyvalerate (P(HB-co-HV)) were used as the solid carbon source in the heterotrophic denitrification reactor. In this study, possible influences of physical and chemical properties of commercially produced P(HB-co-HV) (Biopol) on biofilm formation and metabolic activity of a denitrifying starter culture were investigated. These parameters indicate the polymers' suitability for the application as the matrix substance in the bioreactor. No differences in microstructure were detected between the different lots of polymers. Growth inhibitory effects by chemical additives were found in the case of triacetine, which was included as a plasticizer in seven of eight tested lots. The amount of hydroxyvaleric acid in the polymer was not assumed to affect denitrification activity. Relevant differences could be detected regarding primary adhesion of the starter culture Pseudomonas sp. strain 2nIII. It showed good adsorption properties to hydrophobic substances with a dependence on precultivation conditions. Pseudomonas sp. strain 2nIII degraded poly-3-hydroxybutyrate acid homopolymer and P(HB-co-HV) copolymers but was unable to break up poly-3-hydroxyvaleric acid. A possible reason for these findings is the substrate specifity of the polyhydroxyalkanoate depolymerase.

Adsorption↗
PubMed2004

Design of a mechanical-tunable filter spectrometer for noninvasive glucose measurement.

The development of an accurate and reliable noninvasive near-infrared (NIR) glucose sensor hinges on the success in addressing the sensitivity and the specificity problems associated with the weak glucose signals and the overlapping NIR spectra. Spectroscopic hardware parameters most relevant to noninvasive blood glucose measurement are discussed, which include the optical throughput, integration time, spectral range, and the spectral resolution. We propose a unique spectroscopic system using a continuously rotating interference filter, which produces a signal-to-noise ratio of the order of 10(5) and is estimated to be the minimum required for successful in vivo glucose sensing. Using a classical least-squares algorithm and a spectral range between 2180 and 2312 nm, we extracted clinically relevant glucose concentrations in multicomponent solutions containing bovine serum albumin, triacetin, lactate, and urea.

Algorithms↗
PubMed2004

Molar absorptivities of glucose and other biological molecules in aqueous solutions over the first overtone and combination regions of the near-infrared spectrum.

Molar absorptivities are measured for water, glucose, alanine, ascorbate, lactate, triacetin, and urea in the near-infrared spectral region at 37 degrees C. Values are based on the Beer-Lambert law and cover the first overtone (1550-1850 nm; 6450-5400 cm(-1)) and combination (2000-2500 nm; 4000-5000 cm(-1)) spectral windows through aqueous media. Accurate calculations demand accounting for the impact of water displacement upon dissolution of solute. In this regard, water displacement coefficients are measured and reported for each solute. First overtone absorptivities range from 2 to 7 x 10(-5) mM(-1)mm(-1) for all solutes except urea, for which absorptivity values are below 0.5 x 10(-5) mM(-1) mm(-1) across this spectral range. Molar absorptivities over the combination spectral region range from 0.8 to 3.2 x 10(-4) mM(-1) mm(-1), which is a factor of four to five greater than the first overtone absorptivities. Accuracy of the measured values is assessed by comparing calculated or modeled spectra with spectra measured from standard solutions. This comparison reveals accurately modeled spectra in terms of magnitude and position of solute absorption bands. Both actual and modeled spectra from glucose solutions reveal positive and negative absorbance values depending on the measurement wavelength. It is shown that the net absorbance of light is controlled by the magnitude of the absorptivity of glucose compared to the product of the absorptivity of water and the water displacement coefficient for glucose.

Glucose↗
PubMed2005

The novel formulation design of self-emulsifying drug delivery systems (SEDDS) type O/W microemulsion II: stable gastrointestinal absorption of a poorly water soluble new compound, ER-1258 in bile-fistula rats.

The stabilization effect of the novel self-emulsifying drug delivery systems (SEDDS) type O/W microemulsion on the gastrointestinal absorption of a poorly water soluble new compound, ER-1258 was examined by bile-fistula model rats. In the components of this formulation, medium chain fatty acid triglyceride (MCT), diglyceryl monooleate (DGMO-C), polyoxyethylene hydrogenated castor oil 40 (HCO-40) and ethanol were used as an oil, a lipophilic surfactant, a hydrophilic surfactant and a solubilizer at the mixture ratio of 25/5/45/25 w/w%, respectively. The ratios of AUC in the non-treated rats to that in the bile-fistula rats were 5.1, 12.1 and 3.0 for the suspension, the oily solution and the SEDDS type O/W microemulsion, respectively. The risk from which the difference between individuals of the compound absorption amounts resulting from the flow of the bile secretion serves as the maximum was high in order of oily solution>suspension>SEDDS type O/W microemulsion. Therefore, it was verified that the SEDDS type O/W microemulsion was able to reduce this risk, compared with the other formulations. When short chain fatty acid triglyceride (Triacetin) was used as an oil, the similar effect was demonstrated in the formulation composed of sorbitan sesquioleate (SO-15) as a lipophilic surfactant and polyoxyethylene hydrogenated castor oil 60 (HCO-60) or polyoxyethylene 20 sorbitan monooleate (TO-10M) as a hydrophilic surfactant.

Animals↗
PubMed1983

Nutritive value of acetate in growing pigs.

Twelve crossbred barrows from four litters (average initial body weight of 21 kg) were used to examine the nutritive value of acetate in growing pigs. The treatments were the addition of acetate in the form of triacetin to the basal diet at 0, 5 and 10% of the metabolizable energy (ME) intake. Metabolism tests were conducted during wk 1 and 4 on acetate. The responses of weight gain and N retention to increasing levels of acetate were linear (P less than .001). Efficiency of acetate utilization for body weight gain was .90 g/g acetate, and the mean N-sparing effect of acetate was 32.9 mg N/g acetate. In the liver, heart and femoral muscle examined from d 36 to 47 on acetate, there was a linear increase in RNA content (P less than .05) and in protein content (P less than .01), as the level of acetate intake was increased. Digestible energy and N-corrected ME (MEn) of acetate found in the first week on acetate were not different from its heat of combustion. Those found in the fourth week on acetate, however, were larger (P less than .05) than the heat of combustion. It was considered that a nutritional adaptation to acetate utilization, or a synergistic action of acetate with other energy sources, occurred. The energetic efficiency of acetate utilization for growth was estimated to be 56 to 59%.

Acetates↗
PubMed2006

Laparoscopic application of PGE2 to re-establish oviducal patency and fertility in infertile mares: a preliminary study.

REASONS FOR PERFORMING STUDY: Mares are occasionally encountered that consistently fail to conceive when inseminated, naturally or artificially, with fertile stallion semen in the absence of any identifiable pathology of either the structure or function of their reproductive tract. HYPOTHESIS: Temporary blockage of the oviducts by accumulations of naturally occurring oviducal masses may be preventing oviducal transport of the embryo to the uterus. METHODS: Mares, with known reproductive histories, that had exhibited inexplicable failure of conception were treated by laparoscopically guided administration of PGE2-laced triacetin gel directly onto the surface of their oviducts. RESULTS: Fifteen mares age 10-21 years that had exhibited inexplicable failure of conception during 1-4 years were treated, of which 14 (93%) conceived within the same or subsequent breeding season. CONCLUSIONS: The high success rate of this treatment supports the tentative diagnosis of oviducal obstruction in these mares and indicates that blockage of the mare's oviducts may occur in the form of a moveable accumulation of debris rather than from permanent fibrous adhesions resulting from salpingitis. POTENTIAL RELEVANCE: This laparoscopic application of PGE2 to the oviducts constitutes a sound and practical method of restoring fertility in mares suffering oviducal obstruction and further studies involving the procedure are warranted.

Animals↗
PubMedDate not supplied

Microencapsulation of drugs by the coacervation technique using ethylcellulose and acrylate-methacrylate copolymer as wall materials.

In this study, ethylcellulose and acrylate-methacrylate copolymer (Eudragit RL 100, Eudragit RS 100) membranes were prepared by using appropriate types and amounts of plasticizers. Thirty percent and 20% of triacetin based on polymer weight were found to be appropriate plasticizers for ethylcellulose membranes and acrylate-methacrylate copolymer membranes, respectively. The ratios of 3:2 and 2:3 Eudragit RL 100: Eudragit RS 100 also gave transparent and flexible membranes. Cephalexin was chosen as a model drug. The coacervation technique was investigated for the preparation of cephalexin microcapsules. Ethylcellulose and acrylate-methacrylate copolymer corresponding to the above ratios were selected as wall materials of the microcapsules. The effects of core-to-wall ratios on the surface characteristics and dissolution of the microcapsules were also studied. The coacervation technique with ethylcellulose as wall material gave the higher yield (90%) of microcapsules. The release of cephalexin from ethylcellulose walled microcapsules was slow whilst the release from those of acrylate-methacrylate copolymer was faster. The increase of deposition of wall materials due to the decrease of the core-to-wall ratio resulted in a decrease of dissolution rate.

Cellulose↗
PubMed1976

Bovine pancreatic lipase. III. Lipolysis of oils and fats and fatty acid specificity.

Purified bovine pancreatic lipase hydrolyzed butteroil, vegetable oils, and synthetic glycerides. The enzyme hydrolyzed triglycerides more rapidly than di- and monoglycerides and tripropionin faster than any other synthetic glyceride. Triacetin was the least hydrolyzed glyceride. Gas-liquid chromatographic analysis of the free fatty acids liberated by the lipase from milk fat indicated that the enzyme selectively liberated butyric acid in higher proportion than the relative amount originally in the fat. The enzyme released saturated as well as unsaturated fatty acids from commericial vegetable oils. With regard to the lipolytic behavior, in general, the bovine pancreatic lipase closely resembled milk lipase.

Animals↗