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PubMed2003

Enhanced microbial biomass assay using mutant luciferase resistant to benzalkonium chloride.

In a biomass assay based on adenosine 5(')-triphosphate (ATP) bioluminescence, extracellular ATP is removed; then intracellular ATP is extracted from the microorganism by an ATP extractant and subsequently reacted with luciferase. To provide a highly sensitive assay, the concentration of benzalkonium chloride (BAC) in the ATP extractant was optimized by using a mutant luciferase resistant to BAC. The use of 0.2% BAC, which was acceptable for the luciferase, simultaneously achieved the maximum extraction of intracellular ATP from microorganisms and the inactivation of the ATP-eliminating enzymes for removal of extracellular ATP. The detection limit (blank+3 SD) for ATP was 1.8x10(-14)M (1.8x10(-18)mol/assay) in the presence of the ATP extractant with coefficients of variation of 0.7 to 6.3%. The reagent system coupled with the ATP-eliminating enzymes allowed for the detection of 93 colony-forming units (CFU)/ml of Escherichia coli ATCC 25922, 170CFU/ml of Pseudomonas aeruginosa ATCC 27853, 170CFU/ml of Proteus mirabilis ATCC 29906, 68CFU/ml of Staphylococcus aureus ATCC 25923, and 7.7CFU/ml of Bacillus subtilis ATCC 6051. The yeast cell of Saccharomyces cerevisiae IFO 10217 could be detected at 1CFU/ml. With 54 kinds of microorganisms, the average ATP extraction efficiency compared to the trichloroacetic acid extraction method was 81.0% in 24 strains among gram-negative bacteria, 99.4% in 13 strains among gram-positive bacteria, and 97.0% in 17 strains among yeast. The ATP contents of the gram-negative bacteria, gram-positive bacteria, and yeasts ranged from 0.40 to 2.70x10(-18)mol/CFU (mean=1.5x10(-18)mol/CFU), from 0.41 to 16.7x10(-18)mol/CFU (mean=5.5x10(-18)mol/CFU), and from 0.714 to 54.6x10(-16)mol/CFU (mean=8.00x10(-16)mol/CFU), respectively.

Adenosine Triphosphate↗
PubMed1980

Symptomatic methemoglobinemia with a commonly used topical anesthetic, cetacaine.

Severe cyanosis resulting from acquired methemoglobinemia after application of a topical anesthetic, Cetacaine spray, occurred in a 37-year-old patient following bronchoscopy for postoperative atelectasis. Response to methylene blue therapy was dramatic and complete. Attention is drawn to a dangerous adverse effect of this commonly used topical anesthetic agent.

4-Aminobenzoic Acid↗
PubMed1999

Serendipity and the development of heparin and carbon surfaces.

In the early 1960s, bileaflet valves fabricated with polymer housings routinely thrombosed within a few hours after implantation in the canine heart. In a serendipitous series of events, the authors found a way to bond heparin to these bileaflet valves using a coating of graphite-carbon and benzalkonium chloride. Over the ensuing 30 years, improved heparin coatings have been developed by other investigators for bonding to various biomedical devices; currently, about 25% of oxygenators used in this country utilize heparin coatings to minimize surface activation of clotting factors. Also, and somewhat serendipitously, a pyrolytic carbon material developed in the 1960s as a coating for nuclear fuel rods was submitted to the authors' laboratory for possible coating with benzalkonium and heparin. This carbon coating, developed at Gulf General Atomic, Inc, would not bond heparin, but it proved to be the best rigid material available for prosthetic valve construction; more than one million pyrolytic carbon valves have been clinically implanted over the last 29 years.

Animals↗
PubMed2003

A real-time analysis of QacR-regulated multidrug resistance in Staphylococcus aureus.

Here we describe the construction and characterization of a biosensing reporter where luxCDABE genes from Photorhabdus luminescens, engineered for expression in Gram-positive organisms, are under the transcriptional control of QacR repressor from Staphylococcus aureus. In non-pathogenic S. aureus model system we analyzed the activity of the regulatory region acting as multidrug-resistance mediator in wild type strains. The use of full-length bacterial luciferase and the measurement of real-time light emission from intact, living cells make the present system suitable to follow the short term activity of different inducers. Among the tested molecules, tetracyclines showed a peculiar behavior by giving very high induction in a fashion seemingly more related to a general stress condition of the culture than to the direct binding and displacement of QacR from its operator. Temperature shocks confirmed that active transcription from qacA promoter is started in response to unspecific conditions where cell growth is strongly inhibited.

Anti-Infective Agents, Local↗
PubMed2003

Interaction between N-dodecyl-N,N-dimethyl-N-benzylammonium halides and phosphatidylcholine bilayers-the effect of counterions.

The interaction of N-dodecyl-N,N-dimethyl-N-benzylammonium halides (DBeAX) with two types of phospholipid vesicles (MLV and SUV) was investigated using DSC and 1H NMR. It was suggested that the benzyl group like the micellisation process (J. Colloid Interface Sci. 218 (1999) 529) changes its position when interacting with phosphatidylcholine bilayers and incorporates into the bilayer. In order to enhance counterion-water interactions, the surfactants were added either to the water phase or directly to the lipid phase (a mixed film was formed). It follows from the obtained results that for both types of liposomes and both manners in which the surfactant was added, the interaction of DBeAX with liposomes and consequent changes in the phospholipid bilayer organisation depend on the kind of counterion. Results are discussed in terms of counterion ability to modify water structure.

Benzalkonium Compounds↗
PubMed1997

A phase I comparative study of contraceptive vaginal films containing benzalkonium chloride and nonoxynol-9. Postcoital testing and colposcopy.

Benzalkonium chloride (BZK) has been shown in in vitro and in vivo studies to immobilize sperm, to be active against STD-causing organisms, and to penetrate and thicken cervical mucus. A US clinical study of a sponge containing 60 mg BZK showed life table pregnancy rates at 6 and 12 months of 11.7 and 18.9 per 100 women, respectively. BZK is not currently marketed in the US as a contraceptive. The present study aimed to assess 1) the ability of a new contraceptive vaginal film containing either of two doses of BZK to prevent the penetration of sperm into midcycle cervical mucus; 2) the effect of the film on the vaginal epithelium; and 3) the acceptability of the film. All results were compared with VCF, a currently marketed film containing nonoxynol-9 (N-9). Ten women underwent two baseline cycles of postcoital testing in which no film was used, followed by three test cycles in which Allendale-BZK film, a new film containing either 19 or 25 mg BZK, or VCF, containing 70 mg N-9, was used. The sequence of testing cycles was randomized. In each cycle, condoms were used prior to midcycle, then a midcycle cervical mucus specimen was examined to ensure midcycle characteristics and the absence of sperm. Each woman then had intercourse using either no film (baseline cycles) or a test film (test cycles) and returned 2-3 h afterwards. Cervical mucus was again assessed for adequacy and the presence of sperm. Each woman also underwent colposcopy, using a protocol developed by the World Health Organization. The average number of progressively motile sperm seen per high power field was as follows: first baseline cycle, 22.2; second baseline cycle, 22.1; test cycle with film containing 19 mg BZK, 0.2; test cycle with film containing 25 mg BZK, 0.0; and test cycle with VCF containing 70 mg N-9, 0.0. There was no significant difference between baseline cycles or among test cycles in the average number of progressively motile sperm seen (p = 0.78 and p > or = 0.75, respectively). The average number of progressively motile sperm seen in each test cycle did, however, differ significantly from the average number seen in either baseline cycle (p < 0.01). Colposcopy showed superficial de-epithelialization without underlying inflammation in 15-20% of baseline cycles, regardless of whether colposcopy was done before or after coitus; in 50% of cycles in which either dose of BZK was used; and in 69% of cycles in which VCF was used. In all cases women were asymptomatic. Erythema and petechiae were also seen on colposcopy although at a lower frequency than de-epithelialization. There was no difference in the acceptability of the films. A vaginal contraceptive containing either 19 or 25 mg BZK in a new film base appears to be comparable with VCF in preventing sperm from entering midcycle cervical mucus and may be somewhat less disruptive to the vaginal epithelium.

Administration, Intravaginal↗
PubMed2000

Influence of salmeterol and benzalkonium chloride on G-protein-mediated exocytotic responses of rat peritoneal mast cells.

The long-acting beta(2)-adrenoceptor agonist salmeterol and the invert soap benzalkonium chloride share physicochemically important structures, namely a polar head group and a long aliphatic chain. Low concentrations of benzalkonium chloride have been shown to inhibit exocytotic responses in rat peritoneal mast cells by selectively interacting with heterotrimeric G-proteins of the G(i)-type. The present study investigates whether salmeterol inhibits, independently of beta-adrenoceptors, exocytotic responses of rat peritoneal mast cells induced by the direct agonists at G-proteins mastoparan or guanosine 5'-O-(3-thiotriphosphate) (++GTP gamma S++). Exocytosis was studied by secretion assays ([3H]5-hydroxytryptamine ([3H]5-HT)-release) using intact, streptolysin O-permeabilised or metabolically inhibited (antimycin, deoxyglucose) rat peritoneal mast cells. Both amphiphilics, salmeterol, and benzalkonium chloride, dose-dependently exerted biphasic effects on mastoparan-induced [3H]5-HT release in intact mast cells. In contrast to benzalkonium chloride, the dose-response curves for secretostatic and celltoxic effects of salmeterol markedly overlapped. Similar to benzalkonium chloride, salmeterol in non-cytotoxic concentrations (1-25 microg/ml) dose-dependently inhibited exocytosis induced by mastoparan (intact cells) or ++GTP gamma S (permeabilised cells). These findings indicate a direct, adrenoceptor-independent affection of G proteins by salmeterol in mast cells.

Adrenergic beta-Agonists↗
PubMed2000

Minimal stimulation IVF using clomiphene citrate and oral contraceptive pill pretreatment for LH suppression.

OBJECTIVE: To determine if oral contraceptive pill (OC) pre-treatment prior to minimal stimulation IVF using clomiphene citrate (CC) would make the procedure easier to perform by preventing the LH surge and result in pregnancy rates (PRs) comparable to stimulated IVF. DESIGN: Prospective cohort study. SETTING: Private tertiary infertility center. PATIENT(S): Thirty-two women with tubal or pelvic adhesive disease as the cause of their infertility, ovulatory cycles, under the age of 40, and no male factor. INTERVENTION(S): Two-month ovarian-hypothalamic-pituitary axis suppression with OC followed by CC 100 mg on day 3 of the cycle for 8 days, hCG administration midcycle, follicle aspiration, IVF, and embryo transfer. MAIN OUTCOME MEASURE(S): Oocytes retrieved, serum LH and estradiol levels, maturity of oocytes, fertilization rates, embryo number and quality, and PRs. RESULT(S): Thirty-six patients completed 71 stimulation cycles and 64 follicle aspirations. No LH surges occurred with a mean mature oocytes retrieved of 3.2, 90% fertilization rate, and mean 2.5 embryos transferred. Twenty-one of the 64 cycles resulted in a clinical pregnancy (32.8% PR per retrieval) with 2 other biochemical pregnancies and 3 twin gestations. This was not significantly different from the matched cohort stimulated IVF. CONCLUSION(S): Minimal stimulation IVF is a simple, low-cost, and low-risk alternative to stimulated IVF with comparable PRs.

Adult↗
PubMed1985

Controlled comparison of topical anesthetic agents in flexible upper gastrointestinal endoscopy.

Topical anesthetics are generally part of the premedication associated with upper gastrointestinal endoscopy. Selection is not usually based on objective criteria. We performed a randomized study comparing six anesthetic agents: three sprays (Cetacaine, Hurricaine, and 10% Xylocaine spray) and three gargles (2% lidocaine, and two combinations of 2% lidocaine diluted 1:1 with mouthwash). Normal subjects, experienced in undergoing gastroscopy, underwent repeated upper gastrointestinal endoscopic examinations with a 34 F Pentax fiberscope. Topical anesthetic was the only premedication used. The parameters evaluated by the subjects were taste, effectiveness of anesthesia, and ease of scope passage. At the end of the trial each subject ranked the agents in order of preference. Although subjects differed in their preference for the different anesthetic agents (sometimes significantly), there was no single parameter such as taste, degree of anesthesia, or ease of passage of the endoscope that could be correlated with overall preference. All agents gave acceptable levels of local anesthesia, although there was a distinct subjective preference for spray forms. We recommend that if a local anesthetic is used, it should be one of the spray formulations. This recommendation is based on safety, the relative ease of application, and the lack of profound differences between agents.

Adult↗
PubMedDate not supplied

Topical pharyngeal anesthesia for easing endoscopy: a double-blind, randomized, placebo-controlled study.

The aim of this work was to compare the efficacy of the Cetacaine topical anesthetic spray preparation to placebo. Cetacaine and placebo, from coded but otherwise identically packaged and scented sprays, were administered to 150 consecutive patients. After endoscopy, patients and physicians completed questionnaires evaluating the difficulty of the endoscopy. No statistically significant differences were found between the full formula and placebo-treated patient responses to the amount of cough or gag, or the degree of difficulty of intubation of the endoscope. Analysis of physician responses showed that in the subgroup of patients being endoscoped for the first time, the gastroscope was introduced more easily (p less than 0.05) when the premedication had been full formula rather than placebo.

4-Aminobenzoic Acid↗
PubMedDate not supplied

Evaluation of alternative proximal gastric vagotomy techniques after a 9-month interval in a rat model.

Proximal gastric vagotomy (PGV) is an accepted operation for patients with ulcers that are refractory to medical management. Results comparable to those of standard, operative PGV have previously been demonstrated using endoscopic chemoneurolytic injection or laparoscopic laser seromyotomy in a porcine model. In this study, we evaluated several PGV techniques in regard to long-term effects on acid secretion, ulcer prophylaxis, and permanent vagal denervation in a rat model. Trans-mucosal injection of chemoneurolytic agents (cobaltous chloride, benzalkonium chloride, and phenol) and seromyotomy by CO2 laser were performed. After 9 months, all rats received sub-serosal gastric injections of horseradish peroxidase (HRP) during laparotomy. Twenty-four hours later, an ulcerogenic dose of pentagastrin was administered sub-cutaneously. Three days after administration of HRP (to allow time for retrograde axonal transport and labeling of cells of the dorsal vagal nucleus with HRP), necropsy was performed. The pre-pyloric gastric mucosa was inspected for ulcerogenic changes, and a Congo red solution was applied to the gastric mucosa to map the acid-secreting areas. All PGV methods significantly diminished pentagastrin-induced ulceration when compared to sham controls. Benzalkonium chloride chemoneurolytic and laser methods were most effective for decreasing the size of acid-secreting areas. A reduced number of HRP-stained cells in the dorsal vagal nucleus indicated permanent denervation of vagal-gastric connections by operative and laser techniques.

Animals↗
PubMed2002

Development and validation of a capillary zone electrophoresis method for the determination of benzalkonium chlorides in ophthalmic solutions.

A systematic investigation of optimal conditions for determining the benzalkonium chlorides in ophthalmic products by capillary zone electrophoresis (CZE) was presents. The most effective separation conditions was 40 mM phosphate buffer with 40% acetonitrile at pH 4.0, and the sample hydrodynamic injection of up to 10 s at 2 p.s.i. (1 p.s.i.=6892.86 Pa) (approximately 35.15 nl), and an applied voltage of 15 kV. The reproducibility of the migration time and quantitative analysis can be improved by using internal standard, triethylbenzylammonium chloride, giving the relative standard deviation less than 0.2% for the relative migration times, and 5.0-7.8% for the relative peak areas. A good linearity of CZE analysis was obtained in the range of 1.0-20 microg/ml with r2 values of above 0.99. The established HPLC with UV-Vis detection was applied to evaluate the CZE method, and compatible results were obtained by using CZE with much shorter analysis time and a small quantity of solvents consumed.

Benzalkonium Compounds↗
PubMed1986

Surgical treatment of total colonic aganglionosis: efficacy of aganglionic patch enteroplasty in the rat.

This study evaluates ileo endorectal pull-through (IEP) with and without an aganglionic colon patch in an experimental rat model for the surgical treatment of total colonic aganglionosis (TCA). Animals were randomly assigned to Group 1 (no patch, No. = 6), Group 2 (right colon patch, No. = 8), Group 3 (transverse colon patch, No. = 7), Group 4 (left colon patch; No. = 6), sham operation (SH, No. = 6), and unoperated controls (UC, No. = 10). Change in percent body weight at 4 weeks after operation was -30.9 +/- 3.68% in Group 1, +5.1 +/- 1.67% in Group 2, -3.4 +/- 3.96% in Group 3, -1.8 +/- 4.17% in Group 4, and +12.7 +/- 1.54% in SH (Group 1 v other groups: P less than .001). Restoration of initial body weight occurred in 100% in Group 2 and SH (8/8 and 6/6, respectively), 50% in Group 4 (3/6), 42.9% in Group 3 (3/7), and 0% in Group 1 (0/6). Transit time (stomach to anus) was significantly shorter in Group 1. All rats in patched groups had a prolonged transit time compared with Group 1. Manometric studies in IEP rats showed favorable anal canal pressures, which were slightly lower than SH and UC. Water and Na+ absorption were significantly greater in patched groups. Rats with a right colon patch (Group 2) showed slightly greater absorption at 4 weeks. These data suggest that an aganglionic colon patch may be an important adjunct in the surgical treatment of TCA.

Animals↗
PubMed1987

Chemically induced bowel denervation improves survival in short bowel syndrome.

This study evaluates the effect of chemically induced bowel denervation on survival, weight gain or loss, transit time, and d-xylose absorption in rats following 80% small bowel resection. Forty-three male Sprague-Dawley rats (150 g) underwent 80% midsmall bowel resection and anastomosis. Twenty rats were short bowel controls (group I). In 23 rats (group II), a 2.0 cm segment of jejunum proximal to the anastomosis was denervated by application of 0.1% benzalkonium chloride (BK) for 30 minutes. Ten additional rats underwent sham laparotomy without bowel resection. Five remained untreated (group III) and in 5 (BK) denervation was added (group IV). Bowel denervation was confirmed by histologic study in all (BK) rats. Weight and daily food and water intake were measured for 30 days and the groups compared. Weight in group I was 43.8 +/- 52.9 g, group II 95.0 +/- 50.1, (P less than .005), group III 177 g, and group IV 175 g. Food intake was greater in group I than II (P less than .05) and was similar to groups III and IV. Water intake calculated as animal weight (g)/mL H2O ingested was lowest in group I (P less than .05). Mortality was 30% in group I (6/20) and only 8.6% in group II (2/23). No deaths were observed in unresected controls (III and IV). Twenty-four additional rats were evaluated for d-xylose absorption and transit time by bringing out a loop enterostomy 10.0 cm from the Ligament of Treitz. Twelve rats were ostomy controls (group V).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗