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At least 415 records · Page 23Linked to original sources

PubMed2001

Structural integrity of the female condom after multiple uses, washing, drying, and re-lubrication.

Establishing the safety of re-using the female condom could significantly increase women's access to barrier methods especially in poorer countries. In this study, the structural integrity of female condoms was tested (n = 295) after multiple acts of vaginal intercourse. Fifty women were recruited to the study. Each woman re-used one condom up to eight times and washed, dried, and re-lubricated between each use. Structural integrity was measured using standard quality control testing; water-leakage, air-burst, and seam tensile strength. All results were compared to the United States Food and Drug Administration (US FDA) standards for an unused female condom. The results of the structural integrity tests for all cycles were above the FDA minimum standards for seam strength and burst tests. There was no deterioration detected in condoms used 8 times when compared to new female condoms in these tests. Five holes were detected by the water leakage test across all cycles, of which three were detected by the subjects themselves and reported to the investigators, therefore, giving a breakage rate of 1.7%. The holes were not associated with increased number of uses. This study provides further evidence that suggests the structural integrity of the female condom after multiple use is still within FDA minimum standards, although random holes resulting from handling occur infrequently with the re-use procedure.

Coitus↗

PubMed1997

A note on the use of the CEC L-33-A-93 test to predict the potential biodegradation of mineral oil based lubricants in soil.

The biodegradabilities of five unformulated mineral oils (brightstock, 150 SN base oil, white oil and two gas oils) were determined in the CEC L-33-A-93 test and during 20 weeks incubation in nutrient-supplemented soil microcosms. Biodegradation in both studies was measured as the loss of extractable hydrocarbon ('primary' biodegradation). There was a statistically significant (P < 0.01) rectilinear relationship between the extents of biodegradation in both test systems. The results indicate that the CEC method could be used as a relatively simple, quick and inexpensive test for assessing the potential biodegradation of mineral oil based lubricants in soil.

Biodegradation, Environmental↗

PubMed1990

High precision, simulated cutting efficiency measurement of endodontic root canal instruments: influence of file configuration and lubrication.

A high precision method is presented for measurement of root canal instrument cutting efficiency in pure, linear movements. Operator-independent instrumentation is achieved by means of an automatic, mechanical test rig mounted as an accessory in an Instron tensile testing machine. It is now possible to do reliable cutting simulation that closely represents clinical motions. Cutting efficiency is assessed via "wear" volume measurement by means of three-dimensional surface mapping on bovine bone serving as a dentin substitute. A volume precision of 3 x 10(-3) mm3 is achieved which is equivalent to a weight resolution better than 10 micrograms. In particular, cutting efficiency data for K-type and H-type files is presented showing an enhanced performance (by roughly a factor of 3) in the latter case. Lubrication is also shown to increase the cutting efficiency (+200% for the K file and +30% for the H file). Water and 2.5% sodium hypochlorite solutions have equivalent effects.

Animals↗

PubMed2002

Efficient lipase catalysed production of a lubricant and surfactant formulation using a continuous solvent-free process.

The transesterification of sunflower oil with a high oleic acid residue content (typically 83.5%) with butanol-1 by immobilised Lipozyme was carried out in a solvent free system and in a continuous way. During the first 6 h of reactor operation, a transition phase was observed, in which the main products were butyl ester and glycerol. This latter being insoluble in the reaction mixture, it is adsorbed onto the enzyme support thus leading to a decrease in enzyme performance. Step by step, less and less glycerol is produced and finally when glycerol is no longer produced a steady state is attained. The product composition is a mixture of butyl ester (65 molar%), monoglyceride (26 molar%), diglyceride (6 molar%) and residual triglyceride (3 molar%). This mixture has interesting lubricant and surfactant properties. The reactor was maintained without any loss in activity for a period of 3 months. This result is very different to that obtained using an organic solvent (n-hexane) which leads to a total loss of enzyme activity within a few hours.

Bioreactors↗

PubMed1990

Dynamic movement of air tract fluid in lubrication of the larynx during phonation: a basic study using excised canine larynges and experimental air tract fluid by means of X-ray stroboscope system.

Experiments using excised canine larynges and experimental air tract fluid were conducted to clarify the movement of air tract fluid in association with vocal fold vibration by means of X-ray stroboscope system. It was thought that the movement of air tract fluid in lubricating of the larynx during phonation was closely correlated to vocal fold vibration, especially the wave motion of the mucous membrane of the vocal folds and the movement of air tract fluid on the glottis might be one of parameters to evaluate the flexibility of the mucous membrane of the vocal folds.

Animals↗

PubMedDate not supplied

Surgical glove lubricants: from toxicity to opportunity.

In most emergency departments, surgical gloves are coated with surface powders that act as lubricants to facilitate donning. Cornstarch powder is an absorbable powder employed as a donning agent on most powdered gloves. Talcum powder, a nonabsorbable powder, is used as a mold release agent in glove manufacture and is still commonly found on the surfaces of modern surgical gloves. These powders are foreign bodies that elicit inflammatory responses, leading to a wide number of symptoms and complications. The best method of preventing clinical complications from glove powder is to use powder-free gloves.

Gloves, Surgical↗

PubMed1997

A prospective, randomized, double-blind study comparing lignocaine gel and plain lubricating gel in relieving pain during flexible cystoscopy.

OBJECTIVE: To determine the optimum duration for the retention of 2% lignocaine gel intraurethrally as an anaesthetic for flexible cystoscopy in men. PATIENTS AND METHODS: A prospective, randomized, double-blind, placebo-controlled trial was conducted in two parts. Initially, the importance of duration was determined, i.e. whether pain relief was significantly improved when lignocaine gel was instilled for longer than is currently practised. As pain relief was improved by retaining the lignocaine gel for longer, the optimum time was determined in a second trial. Initially, 90 patients were divided into four groups receiving 20 mL of 2% lignocaine gel or plain lubricating gel for 5 or 25 min. Subsequently, 60 men were divided into two groups receiving 20 ml of 2% lignocaine gel for 15 or 25 min. The patients' discomfort was recorded using a 4-point descriptive pain scale and a 100 mm non-graphical visual analogue scale. RESULTS: In the first study, those patients receiving lignocaine gel for 25 min experienced significantly less pain than the other three groups. In the second, lignocaine gel in the urethra for 15 min provided the same level of pain relief as lignocaine for 25 min. CONCLUSION: Pain during flexible cystoscopy can be significantly reduced when 20 mL of 2% lignocaine gel is left in the urethra for 15 min; lignocaine gel would be more effective when left for longer than is currently practised.

Analgesia↗

PubMed2002

In vitro and in vivo effects of a lubricant in a contact lens solution.

PURPOSE: Physical properties and tear film function were investigated for a multipurpose contact lens solution containing the ocular lubricant hydroxypropyl methylcellulose (HPMC). METHODS: In the laboratory, wetting properties of multipurpose solutions with and without HPMC, and binding of HPMC to hydrogel lenses in vitro following an overnight soak, were measured. Tear physiology was evaluated in 35 hydrogel contact lens wearers using multipurpose solutions with and without HPMC. Pre-lens tear evaporation rate (TER), tear thinning time (TTT) and tear film structure (TFS) were recorded, and subjective responses were obtained. RESULTS: Laboratory measurements indicated improved wetting with the HPMC-containing solution, and continued release of HPMC from lenses after an overnight soak in the solution. Pre-lens TTT was longer (p < 0.001) and pre-lens TFS was improved (p = 0.034) with use of the HPMC-containing solution. Pre-lens TER and subjective comparisons did not demonstrate significant differences. CONCLUSIONS: In vitro and in vivo results are consistent with HPMC producing a thicker, longer-lasting layer of fluid on the hydrogel lens, leading to improvements in tear function in contact lens wearers.

Adult↗

PubMed2003

An evaluation of the effects of three laryngeal lubricants on phonation threshold pressure (PTP).

Clinicians frequently offer advice to performers and voice-disordered patients aimed ostensibly to manipulate the water content and/or viscosity of the mucus blanket covering the vocal folds. To evaluate the relative effects of three potential laryngeal lubricants on phonatory function (ie, water, Mannitol--an osmotic agent, and Entertainer's Secret Throat Relief (Kli Corp., Carmel, IN)--a glycerin-based product), phonation threshold pressure (PTP) was measured in 18 healthy, vocally normal female participants twice before (baseline) and then four times after 2 ml of each substance were nebulized. PTP is the minimum subglottal pressure required to initiate vocal fold oscillation, and the lowering of PTP is assumed to correspond to physiologically more efficient phonation and reduced phonatory effort. Over a 3-week period, participants were tested on three separate occasions (at 1-week intervals). On each occasion, a different nebulized treatment was administered. PTP for both comfortable and high fundamental frequency productions was measured using an oral pressure-flow system (Perci-Sars, MicroTronics Corp., Chapel Hill, NC). Analysis of the results revealed that Mannitol, an agent that encourages osmotic water flux to the luminal airway surface, lowered PTP immediately after its administration (ie, p = 0.071, for high-pitched productions only). However, the duration of its PTP lowering effect was less than 20 minutes. The other two substances did not demonstrate any significant postadministration effect on PTP.

Adult↗

PubMed2004

Clinical evaluation of an HP-guar gellable lubricant eye drop for the relief of dryness of the eye.

PURPOSE: To evaluate the efficacy of a new lubricant eye drop containing polyethylene glycol 400 and propylene glycol demulcents with hydroxypropyl-guar as a gelling agent (Test Product) to a system with carboxymethylcellulose (Control Product) for reducing dry eye signs and symptoms. METHODS: Eighty-seven dry eye volunteers were enrolled at seven sites for this six-week, concurrently controlled, double-masked clinical study. RESULTS: The Test Product significantly reduced conjunctival staining (p = 0.025) and temporal corneal staining (p = 0.024) compared to the Control. The Test Product also significantly reduced symptoms of dryness in the morning and evening, compared to the Control (p = 0.015 and p = 0.023, respectively). Subjects in the Test treatment group reported lower frequencies of foreign body sensation and felt their eyes were "refreshed longer" compared to those in the Control group (p = 0.033 and p = 0.037, respectively). CONCLUSIONS: The Test Product was more effective at reducing both the signs and symptoms of dry eye compared to the carboxymethylcellulose containing Control.

Carboxymethylcellulose Sodium↗

PubMed2000

Comparison of the constituents of two jet engine lubricating oils and their volatile pyrolytic degradation products.

Leaking oil seals in jet engines, at locations prior to the compressor stage, can be a cause of smoke in the cabins of BAe-146 aircraft. Compressed combustion air is bled off to pressurize the cabin and to provide a source of fresh air. Bleed air is diverted from a location just prior to the combustion chamber at a temperature around 500 degrees C. To prevent oil breakdown products from entering the cabin air, catalytic converters have been used to clean the air. During an oil seal failure this device becomes overloaded and smoke is observed in the cabin. Some aircraft companies have removed the catalytic converters and claim an improvement in air quality. During an oil seal failure, however, the flight crew is potentially exposed to the thermal breakdown products of the engine oils. Because very little is known regarding the thermal breakdown products of jet engine lubrication oils, two commercially available oils were investigated under laboratory conditions at 525 degrees C to measure the release of CO, CO2,NO2, and HCN as well as volatiles which were analyzed using GC-Mass spectrometry in an attempt to see if the neurotoxic agents tricresyl phosphates (TCPs) and trimethyl propane phosphate (TMPP) would be present or formed. TMPP was not found in these experiments. Some CO2 was generated along with CO which reached levels in excess of 100 ppm. HCN and NO2 were not detected. GC compositions of the two bulk oils and their breakdown products were almost identical. The presence of TCPs was confirmed in the bulk oils and in the volatiles. Localized condensation in the ventilation ducts and filters in the air conditioning packs are likely the reason why the presence of TCPs has not been demonstrated in cabin air. It was recommended that this needed to be verified in aircraft.

Air Pollutants, Occupational↗

PubMedDate not supplied

Subchronic inhalation exposures to aerosols of three petroleum lubricants.

Subchronic inhalation studies were performed with three petroleum lubricants: generic cutting oil (GCO), generic gear oil (GO), and generic commercial engine oil (CEO). Each formulation had a mineral oil base. Sprague-Dawley rats were exposed 6 hours/day, 5 days/week for 13 weeks to aerosol concentrations of 0 (untreated controls), 0 (sham-exposed controls), approximately 50, 150, or 400-520 mg/m3. At necropsy, 15 rats/sex/group were sampled for serum chemistry (18 parameters), hematology, and weights of 13 organs. Testis and epididymis of males in the control and high-dose group were used for number of spermatids and morphology of epididymal sperm. Histopathological slides were evaluated for 22 or more organs. Pulmonary function tests were done on 10 additional males/group. Pulmonary hydroxyproline was measured in these rats for GCO and GO. Residual oil in the lungs was determined for GCO. The primary organ affected by exposures to these three formulations was the lung; the main observed effects were accumulation of foamy macrophages in pulmonary alveoli and alveolar walls, very mild thickening of alveolar walls due to foamy macrophages and a mixed cell infiltrate, and subtle epithelial hyperplasia. The foamy macrophages tended to group together in aggregates, and the aggregates seemed responsible for plaques seen visibly on the surface of the lung. These histological changes were accompanied by concentration-related increases in lung weight and pulmonary hydroxyproline, whereas pulmonary function tests were generally unaffected. Effects distal to the lung were more limited. These results indicated low toxicity of these aerosols in this model.

Aerosols↗

PubMed2001

Practical prevention of vaginal and rectal transmission of HIV by adapting the oral defense: use of commercial lubricants.

HIV is transmitted to 6.4 million human beings per year and the majority of these transmissions are sexual. Condoms are highly effective and are recommended as the primary preventive. However, the fact that there are millions of sexual transmissions each year indicates that many people do not use condoms and that additional preventives are needed. The mechanisms of natural prevention of oral transmission by saliva may be adaptable to the susceptible vagina and rectum. The objective of our study was to reduce the sexual transmission of HIV by mimicking saliva's targeting of the transmitting infected leukocytes and any cell-free HIV in seminal fluid. The previously recommended anti-HIV topical microbicide, nonoxynol-9, has not prevented HIV transmission in humans, probably because it causes mucosal irritation and attracts CD4(+) cells. To identify effective preparations that are nonirritating, we studied the anti-HIV activity of commercially available, over-the-counter (OTC) lubricants and vaginal preparations that are judged safest by the U.S. Food and Drug Administration (FDA), and are nonirritating. The effect of OTC preparations on both the production of HIV by infected leukocytes and cell-free HIV suspended in seminal fluid was measured under simulated in vivo conditions. We surveyed 22 OTC vaginal preparations and excluded those with low inhibitory activity and those that were inhibitory but likely to be irritating. Three included preparations are highly active against both HIV-infected leukocytes suspended in seminal fluid and active against cell-free HIV, under in vitro conditions that simulate in vivo conditions. Since the preparations identified here as anti-HIV substances have the advantages of being widely available, inexpensive, acceptable, in the safest U.S. FDA category, and may be used by recipient women or men, they should be tested in clinical trials to help prevent sexual transmission of HIV.

Anti-HIV Agents↗

PubMed1990

Analysis of the polycyclic aromatic hydrocarbon content of petrol and diesel engine lubricating oils and determination of DNA adducts in topically treated mice by 32P-postlabelling.

Engine lubricating oils are known to accumulate carcinogenic polycyclic aromatic hydrocarbons (PAHs) during engine running. Oils from nine petrol-powered and 11 diesel-powered vehicles, in addition to samples of unused oil, were analysed for PAH content and ability to form DNA adducts when applied topically to mouse skin. The levels of 19 PAHs, determined by GC, were in total, approximately 22 times higher in used oils from petrol engines than in oils from diesel engines. Male Parkes mice were treated with 50 microliters of oil daily for 4 days before they were killed and DNA isolated from skin and lung tissue. DNA samples were analysed by nuclease P1-enhanced 32P-postlabelling. Used oils from both diesel and petrol engines showed several adduct spots on PEI-cellulose plates at total adduct levels of up to 0.57 fmol/microgram DNA [approximately 60 times greater than in experiments with samples of unused oil in which adduct levels (0.01-0.02 fmol adducts/microgram DNA) were close to the limit of detection]. Higher adduct levels were generally formed by petrol engine oils than by diesel engine oils. Lung DNA contained similar total adduct levels to those in skin although the adduct maps were less complex. Total adduct levels correlated with extent of oil use in the engine, the total PAH concentration in oils and with the concentrations of certain individual PAHs present in the oils. An adduct spot that co-eluted with that of the major benzo[a]pyrene-DNA adduct accounted for 9-26% of the total adducts in skin DNA, and approximately 8% of the adducts in lung DNA, of mice treated with petrol engine oils. A major, and as yet unidentified, adduct spot comprised up to 30% of the total adducts in skin DNA, and up to 89% of the total adducts in lung DNA, of these animals.

Administration, Topical↗

PubMed1976

A lubrication theory model of tear exchange under a soft contact lens.

Tear exchange due to squeezing of a soft contact lens onto the cornea by the lid is calculated from lubrication theory. The theory predicts that for a normal blink and the usual tear film thickness (8 to 10 microns) there will be 10 to 20% tear exchange at each blink.

Contact Lenses, Hydrophilic↗

PubMed1990

Soft lens lubricants and prelens tear film stability.

Soft contact lens wearers complaining of "dry eye" are frequently prescribed rewetting drops, although the mode of action and efficacy of this treatment have not been established. Enhancement of prelens tear film (PLTF) stability could provide a basis for symptomatic relief with solution instillation. Thirty symptomatic hydroxyethyl methacrylate (HEMA) lens wearers participated in 4 separate trials of no solution (baseline), saline, and 2 soft lens lubricants. Solutions were applied for a 6-h adaptation period, and PLTF noninvasive break-up time (NIBUT) was monitored for 1 h after a final instillation. PLTF NIBUT was significantly elevated 1 min after instillation of all solutions (p less than 0.001, logrank test) but this effect persisted for less than 5 min. The transient enhancement of PLTF stability arising from the instillation of these rewetting solutions is unlikely to provide a basis for prolonged symptomatic relief.

Adolescent↗

PubMed1978

Manufacturing exposure to coolant-lubricants. A preliminary report.

A high speed automated machining process on gray iron has been functioning over a period of 70 months with a variety of coolant-lubricant-additives used. The author followed 118 employees for variable lengths of time, with 12 having a 70-month exposure period. To date, no significant chest x-ray, pulmonary function, lung cytology, or liver function abnormalities have been discovered. Any respiratory symptomatology seems to be related to either smoking or preexisting respiratory pathology. This is the initial report of an on-going surveillance program.

Air Pollutants↗

PubMed1980

Preliminary evaluation of dika fat, a new tablet lubricant.

Dika fat, a solid vegetable oil extracted from the kernels of Irvingia gabonensis var excelsia has been evaluated as a lubricant on the basis of its effect on the flow rate of granules, disintegration time and dissolution rate of tablets. The fat shows a maximal effect on flow at a concentration of 2.5% w/w. It produces better disintegration and dissolution profiles than magnesium stearte at all concentrations tested. The indication is that there is less degradation of aspirin in tablets containing this oil than there is in tablets containing magnesium stearate. The use of Dika fat (m.p. 39--40 degrees C) eliminates the hydrogenation step often necessary for vegetable oils.

Aspirin↗