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PubMed1999

A cost-analysis of two approaches to infection control in a lung function laboratory.

BACKGROUND: The Thoracic Society of Australia and New Zealand (TSANZ) guidelines for infection control in respiratory laboratories are based on a 'Universal Precautions' approach to patient care. This requires that one-way breathing valves, flow sensors, and other items, be cleaned and disinfected between patient use. However, this is impractical in a busy laboratory. The recent introduction of disposable barrier filters may provide a practical solution to this problem, although most consider this approach to be an expensive option. AIM: To compare the cost of implementing the TSANZ infection control guidelines with the cost of using disposable barrier filters. METHODS: Costs were based on the standard tests and equipment currently used in the lung function laboratory at The Alfred Hospital. We have assumed that a barrier filter offers the same degree of protection against cross-infection between patients as the TSANZ infection control guidelines. Time and motion studies were performed on the dismantling, cleaning, disinfecting, reassembling and re-calibrating of equipment. Conservative estimates were made as to the frequency of replacing pneumotachographs and rubber mouthpieces based on previous equipment turnover. Labour costs for a scientist to reprocess the equipment was based on $20.86/hour. The cost of employing a casual cleaner at an hourly rate of $14.07 to assist in reprocessing equipment was also investigated. The new high efficiency HyperFilter disposable barrier filter, costing $2.95 was used in this cost-analysis. RESULTS: The cost of reprocessing equipment required for spirometry alone was $17.58 per test if a scientist reprocesses the equipment, and $15.56 per test if a casual cleaner is employed to assist the scientist in performing these duties. In contrast, using a disposable filter would cost only $2.95 per test. Using a filter was considerably less expensive than following the TSANZ guidelines for all tests and equipment used in this cost-analysis. CONCLUSIONS: The TSANZ infection control guidelines are expensive and impractical to implement. However, disposable barrier filters provide a practical and inexpensive method of infection control.

Australia↗
PubMed1992

Use of nonoxynol-9 and reduction in rate of gonococcal and chlamydial cervical infections.

The spermicide nonoxynol-9 (N-9) has been used as a contraceptive for over 30 years, but the use of a vaginal spermicide and condoms for the prevention of sexually transmitted infections has not been examined in randomised studies. We report a single-blind randomised field trial to assess the effect of N-9 film on the rate of gonococcal and chlamydial cervical infection in women at high risk of these diseases. 343 women were randomly assigned to use either condoms and N-9 (186 women) or condoms and a placebo (157). Compliance with condom use was much the same in the two groups. Overall, N-9 reduced the rate of cervical infection by 25% (rate ratio [RR] 0.75, 95% confidence interval [Cl] 0.5-1.1); in women who used N-9 for more than 75% of their coital acts the infection rate was reduced by 40% (RR 95% Cl 0.3-1.0). The rate of yeast vulvovaginitis or genital ulcers was not higher in N-9 users than in placebo users, but the rate of symptomatic irritation was increased by 70% (RR 95% Cl 1.1-2.6) among N-9 users. Condom use was more protective against cervical infection than N-9 use. The rate of infection was 50% (RR 95% Cl 0.3-0.7) lower with 75% than with 0-50% condom compliance. The use of a vaginal N-9 spermicide with condoms whenever possible seems to be a better strategy than the use of condoms only for prevention of gonococcal and chlamydial cervical infection.

Administration, Intravaginal↗
PubMed2004

Porcine ear skin as a model for the assessment of transdermal drug delivery to premature neonates.

PURPOSE: The purpose of this study was (i) to validate differentially tape-stripped, porcine skin as an in vitro model for the evaluation of transdermal drug delivery (TDD) to premature neonates, (ii) to determine whether the model could estimate neonatal skin permeability as a function of postconceptional age (PCA), and (iii) to demonstrate that iontophoretic delivery permits precise control of drug input independent of skin barrier function. METHODS: Passive permeation of caffeine, phenobarbital, and lidocaine across tape-stripped porcine skin barriers was measured. Iontophoretic delivery of lidocaine across skins with different barrier competencies was also evaluated. RESULTS: For all drugs, passive permeation correlated with skin barrier function; that is, with transepidermal water loss (TEWL): Jss = A x exp[B x TEWL]. Combining this result with a previously derived dependence of TEWL upon the PCA of premature neonates in vivo allowed a relative value of Jss to be predicted for a given PCA. Comparison of these predictions showed excellent agreement with experimental data reported for diamorphine. Iontophoretic lidocaine delivery was precisely controllable independent of barrier competency. CONCLUSIONS: Porcine skin, in vitro, differentially tape-stripped to specific barrier competencies, is a useful model to explore TDD in premature neonates. The potential for iontophoresis to provide improved dose control and adjustment, irrespective of skin barrier maturity, is established.

Administration, Cutaneous↗
PubMed1997

An investigation of dento-alveolar trauma and its treatment in an adolescent population. Part 2: Dentists' knowledge of management methods and their perceptions of barriers to providing care.

AIM: To assess dentists' knowledge of and perceived barriers to treatment of dental injuries. DESIGN: Cross-sectional postal questionnaire and personal interview. SUBJECTS AND METHODS: Questionnaires from 153 GDPs and 53 CDOs were received giving details of emergency options on 17 imaginary dental injuries and perceived barriers to treatment of trauma. Structured interviews with 21 of the GDPs and 19 CDOs seeking knowledge on diagnosis and long-term follow-up and treatment took place. Age and gender of dentist, type of practice and postgraduate courses attended were noted. MAIN OUTCOME MEASURES: Mean knowledge scores. RESULTS: Of a maximum of 14 correct responses on emergency treatment of injured teeth the mean was 7.5. Only 19% knew for how long avulsed teeth should be splinted. Of a maximum of 37 correct responses on long-term follow-up of treatment the mean was 15.4. Only 10% would correctly treat acute abscess on a traumatised tooth. 82% of dentists thought dental trauma should be treated in the primary care service, but 86% of GDPs thought fees for this type of treatment were too low. 72% of CDOs thought the treatment occupied too much clinic time and was not the responsibility of the CDS. CONCLUSIONS: Dentists in the primary care sector have insufficient knowledge to treat dental trauma.

Adolescent↗
PubMed1983

Therapeutic considerations in blood-brain barrier disturbances.

Current methods of treatment of brain damage, as e.g. edema by steroids and barbiturates, have components which benefit the blood-brain barrier. Protection of the blood-brain barrier may result from: (a) prevention of endothelial lesions, perhaps pinocytosis (b) reduction of secondary necrosis formation, (c) interference with release, or activation of mediator compounds causing endothelial lesions such as: biogenic amines, free fatty acids, prostaglandins, free radicals, or kinins, (d) stabilization of lysosomal membranes, and (e) prevention of microcirculatory disturbances. Other methods, or compounds aiming at mechanisms of barrier damage have a therapeutic potential as shown with regard to indomethacin, free radical scavengers, or phenothiazines. However, further studies appear necessary to demonstrate the benefit of these compounds under clinical circumstances. Reversible opening of the blood-brain barrier may be considered as a therapeutic approach to provide access of drugs to brain tissue which are normally excluded by the barrier.

Animals↗
PubMed2006

Barrier and operational risk analysis of hydrocarbon releases (BORA-Release). Part II: Results from a case study.

This paper presents results from a case study carried out on an offshore oil and gas production platform with the purpose to apply and test BORA-Release, a method for barrier and operational risk analysis of hydrocarbon releases. A description of the BORA-Release method is given in Part I of the paper. BORA-Release is applied to express the platform specific hydrocarbon release frequencies for three release scenarios for selected systems and activities on the platform. The case study demonstrated that the BORA-Release method is a useful tool for analysing the effect on the release frequency of safety barriers introduced to prevent hydrocarbon releases, and to study the effect on the barrier performance of platform specific conditions of technical, human, operational, and organisational risk influencing factors (RIFs). BORA-Release may also be used to analyse the effect on the release frequency of risk reducing measures.

Accidents, Occupational↗
PubMed1998

Impairment of ocular surface epithelium barrier function in patients with atopic dermatitis.

AIMS: To assess the integrity of the ocular surface epithelium in patients with atopic dermatitis from the viewpoint of its barrier function. METHODS: 49 patients with atopic dermatitis with blepharoconjunctivitis (ABC group), 27 age matched patients with seasonal or perennial allergic conjunctivitis (AC group), and 20 volunteers with normal healthy eyes (NH group) were assigned to this study. Ocular surface epithelium barrier function was evaluated by the fluorophotometric method using a slit lamp fluorophotometer. 3 microliters of 0.5% sodium fluorescein was instilled into the conjunctival sac of the right eye and fluorescein uptake (ng/ml) 30 minutes later (20 minutes after eye washing) was measured in the central cornea and the temporal bulbar conjunctiva. Fluorophoto metric measurements performed were analysed in each group and compared between the groups. RESULTS: The ABC group showed significantly higher fluorescein uptake (mean 28.2 (SEM 3.3) ng/ml) in the cornea than the AC (11.4 (2.2), p = 0.001) and NH groups (9.3 (2.1), p = 0.001). There was no significant difference between the AC and NH groups (p = 0.930). The ABC group also showed significantly higher fluorescein uptake in the bulbar conjunctiva (393.4 (54.0)) than the AC (182.9 (24.6), p = 0.011) and NH groups (169.3 (29.1), p = 0.012). There was also no significant difference in fluorescein uptake between the AC group and the NH group (p = 0.987). CONCLUSION: This study suggested that ocular surface epithelium barrier function is impaired in patients with atopic dermatitis with blepharoconjunctivitis.

Adolescent↗
PubMed2006

Comparative study of the intestinal mucus barrier in normal and inflamed colon.

AIM: To study the role of mucus in the spatial separation of intestinal bacteria from mucosa. PATIENTS AND METHODS: Mucus barrier characteristics were evaluated using histological material obtained by biopsy from purged colon, colon prepared with enema and material from untreated appendices fixed with non-aqueous Carnoy solution. Bacteria were evaluated using fluorescence in situ hybridization, with bacterial 16S RNA probes and related to the periodic acid Schiff alcian blue stain. Biopsies from controls (n = 20), patients with self-limiting colitis (SLC; n = 20), ulcerative colitis (n = 20) and 60 randomly selected appendices were investigated. RESULTS: The mucosal surface beneath the mucus layer was free of bacteria in > or =80% of the normal appendices and biopsies from controls. The thickness of the mucus layer and its spread decreased with increasing severity of the inflammation; the epithelial surface showed bacterial adherence, epithelial tissue defects and deep mucosal infiltration with bacteria and leucocytes. Bacteria and leucocytes were found within mucus in all biopsy specimens from patients with ulcerative colitis, SLC, and acute appendicitis. The concentration of bacteria within mucus was inversely correlated to the numbers of leucocytes. CONCLUSIONS: The large bowel mucus layer effectively prevents contact between the highly concentrated luminal bacteria and the epithelial cells in all parts of the normal colon. Colonic inflammation is always accompanied by breaks in the mucus barrier. Although the inflammatory response gradually reduces the number of bacteria in mucus and faeces, the inflammation itself is not capable of preventing bacterial migration, adherence to and invasion of the mucosa.

Acute Disease↗
PubMed2001

Barriers in the care of patients who have experienced a traumatic event: the perspective of general practice.

BACKGROUND: Previous research has indicated that GPs encounter barriers in the care of patients who have experienced a traumatic event. OBJECTIVES: The aims of the present study were to map barriers GPs encounter in the care of patients who experience a traumatic event and solutions for these barriers, and to estimate the influence of GP characteristics on the number of barriers experienced. METHODS: Telephone interviews were conducted among a sample of 500 Dutch GPs stratified by sex. Topics covered barriers in the care of victims of: accidents, incest in the past, ongoing physical or sexual abuse of adults, and ongoing physical or sexual abuse of children. RESULTS: The response rate was 44%. GPs are regularly confronted with patients who have experienced a traumatic event. GPs experience 10% barriers in care of patients who have difficulties getting over an accident, 13% in the care of incest victims, 16% in the care of adults who are physically or sexually abused, and 20% in the care of physically or sexually abused children. Most of the GPs recently updated their knowledge of care of victims of traumatic events, but still the majority feel in need of additional expert training. CONCLUSION: GPs experience the greatest number of barriers in the care of children who are abused. GP characteristics were not related to the number of barriers. However, seeing more victims was related to fewer barriers. To facilitate GP care of victims of traumatic events, GP training and continuing medical education should focus especially on skills education regarding the detection and initial treatment of traumatic events of ongoing physical or sexual abuse.

Accidents↗
PubMed1996

A new method for determining corneal epithelial barrier to fluorescein in humans.

PURPOSE: To derive the value of corneal epithelial barrier to fluorescein in humans from experiments in which the fluorophore in instilled in a single drop. METHOD: A commercial scanning fluorophotometer, the Fluorotron Master, was used to scan through an anterior segment. It could not resolve the tear film from the cornea, but in the early stages of measurement, the tear component predominated. After 20 minutes, the remaining fluorescein was washed out of conjunctival sac, and the amount that penetrated into the cornea was estimated. Because the resolution was not sufficient to estimate the concentrations, the total masses in the tear film and in the cornea derived from the area under the profile were used to calculate the epithelial permeability. A value for the tear film thickness had to be assumed. RESULTS: The technique led to reproducible values for epithelial permeability-a range of 2:1 in a subject. High concentrations of fluorescein were required to achieve a sufficient penetration into the cornea, and this led to error in estimating the tear film concentration of the dye. A method is presented that corrects for this effect. For 17 normal subjects, the corrected permeability was 0.15 nm/second, and the tear turnover was 0.15/minute ( +/- 0.016, standard error.) CONCLUSIONS: This technique is convenient and yields two useful physiological parameters from a single clinical procedure. The permeability values are considerably higher than those found by previous workers, and the source of the discrepancy is discussed.

Absorption↗
PubMedDate not supplied

Acceptability of an existing, female-controlled contraceptive method that could potentially protect against HIV: a comparison of diaphragm users and other method users.

OBJECTIVE: The diaphragm, an internal barrier contraceptive device, is a candidate for a female-controlled method for preventing human immunodeficiency virus (HIV) and other sexually transmitted infections (STIs). This study's objective was to examine how women who use the diaphragm differ from women using the pill and/or condoms with respect to factors hypothesized to influence the acceptability of contraceptive methods. Our goal was to increase understanding of who finds the diaphragm acceptable and why. METHODS: We conducted a cross-sectional telephone survey with selected female members of a managed care organization. For this analysis, we limited the sample to 585 women currently using the diaphragm (n = 196), pill (n = 200), condoms (n = 132), or pill and condoms (n = 57). We conducted bivariate analyses and multinomial logistic regression analyses to assess the associations between selected characteristics and diaphragm use. RESULTS: Diaphragm use was significantly associated with several variables. Of particular interest, placing less importance on hormonal method characteristics was significantly associated with diaphragm use (versus use of the pill, condoms, or both). Placing more importance on barrier method attributes was significantly associated with diaphragm use (versus pill use, alone or with condoms). In addition, lower condom use self-efficacy was significantly associated with diaphragm use (versus condom use, alone or with pill). Lack of motivation to avoid HIV/STIs was significantly associated with using the diaphragm versus condoms (only). CONCLUSION: These results have important implications for future research, interventions, counseling strategies for providers, and product development. Our findings suggest that if the diaphragm protects against HIV, it could be a desirable option for some women.

Adolescent↗
PubMedDate not supplied

Pharmaceutical container/closure integrity. VI: A report on the utility of liquid tracer methods for evaluating the microbial barrier properties of pharmaceutical packaging.

The relationship between a liquid tracer package leak test (Mg ion ingress) and microbial immersion challenge test was demonstrated by direct and indirect correlation techniques. Rubber-stoppered glass vials with micropipette leaks were evaluated by a helium leak rate method, filled with broth, sterilized, and immersed in a bath containing microorganisms (E. coli/B. diminuta) and liquid tracer (Mg ions). After exposure and incubation, each unit was evaluated for liquid tracer ingress by atomic absorption spectrophotometry and for microbial ingress by visual inspection and blood agar streaking. Two hundred and eighty sterile broth-filled test units were challenged with microorganisms and liquid tracer. One hundred and fourteen units showed neither liquid tracer nor microbial ingress. One hundred and eight units were positive for both microbial and liquid tracer ingress. No test units were positive for microbial ingress but not for liquid tracer ingress. Fifty-eight units were positive for liquid tracer ingress but failed to show microbial ingress. Logistical regression was used to demonstrate that the probability of liquid tracer ingress was greater than microbial ingress at all leak sizes. The results indicate that the liquid tracer method studied herein was a useful indicator of the microbial barrier properties of pharmaceutical packaging. Additionally, the results support the contention that liquid penetration of a leak is required for microbial ingress.

Drug Packaging↗
PubMed1995

Interaction of condom design and user techniques and condom acceptability.

In 1991, the source of public sector condom supplies in an African country changed from USAID to WHO. Following a complaint, the two types of condoms were sampled and compared. Laboratory tests indicated that the new-style condoms were of adequate quality, but a number of differences were noted between the two types. Complaints that the condoms were short and broke frequently could not be reconciled with measurements. Lubricant quantities on the WHO-supplied condoms were found to be lower than on the USAID condoms, but still within the range found on the commercial market. Also, the WHO condoms were marginally narrower and thicker. WHO asked the authors to conduct field interviews to seek reasons for the reported problems. These revealed that the relative dissatisfaction with the WHO condoms was largely confined to a group of sex workers in a follow-up programme conducted by two educators funded by a European agency. The instructions for use being given by the educators magnified the risk of incorrect application of the condom. Design changes to the WHO condoms (regarding lubricant, size and thickness) were subsequently made to minimise the chance of wrong use.

Africa↗
PubMed1996

Brain efflux index as a novel method of analyzing efflux transport at the blood-brain barrier.

A brain efflux index method has been developed to characterize an efflux transport system for substrates from the cerebrum to the circulating blood across the blood-brain barrier. The brain efflux index value is defined as the relative amount of test drug effluxed from cerebrum compared with that of a reference compound, [14C]carboxylinulin, which has limited blood-brain barrier permeability. Microinjection of 0.2, 0.5 or 1.0 microliter into the parietal cortex area 2 region was found to be an appropriate procedure for obtaining a high recovery and for restricting the test drug and reference compound to the ipsilateral cerebrum. No significant increase in influx clearance of [14C]carboxylinulin into the brain was observed for the ipsilateral cerebrum after the sham microinjection compared with the contralateral cerebrum, which demonstrated that only limited physical damage is caused. Microinjection of [3H]H2O into the cerebrum devoid of cerebral blood flow yielded no elimination from the brain. Analysis based on a pharmacokinetic model demonstrated that the elimination of a highly permeable compound [3H]H2O from the brain was governed by cerebral blood flow. The apparent elimination rate constant (Kel) of [3H]3-O-methyl-D-glucose from the brain was determined as 0.129 +/- 0.014 (min-1) and was reduced significantly by a preinjection of excess cold 3-O-methyl-D-glucose and phloridzin, whereas no significant elimination was observed for L[3H]glucose. The efflux clearance of 3-O-methyl-D-glucose was calculated from the Kel value and the compound's distribution volume, the value being close to that of the influx clearance. These results demonstrate that the brain efflux index method is a useful technique for analyzing an efflux process from the brain across the blood-brain barrier involving a carrier-mediated transport system.

Animals↗
PubMedDate not supplied

Powerlessness regarding health-service barriers: construction of an instrument.

PURPOSE: The purpose of the study was to develop a scale to calculate college students' powerlessness regarding health service barriers (PHSB). METHODS: Scale items were generated to represent two domains of interest: powerlessness and college students' powerlessness regarding health service barriers. The final 20-item instrument was subjected to multiple measures of validity with college students and panels of nurse experts in the area of nursing diagnosis. Reliability was assessed by two samples (n = 92 and n = 33) of college-age students. A final administration was conducted with 197 college students. FINDINGS: The PHSB scale was determined to be an accurate and consistent measure. CONCLUSIONS: This instrument will provide a reliable and valid measure to conduct research.

Adolescent↗
PubMed1999

Self-setting barrier membrane for guided tissue regeneration method: initial evaluation of alginate membrane made with sodium alginate and calcium chloride aqueous solutions.

Alginate membrane was proposed as a self-setting barrier membrane that can be used for guided tissue regeneration (GTR). The alginate membrane can be prepared and placed at the bone defect during the surgical procedure. The procedure consists of two simple steps. First, the bone defect is filled with sodium alginate (Na-Alg) aqueous solution. Then calcium chloride aqueous solution is dropped on the surface of the Na-Alg aqueous solution. An alginate membrane is formed on the bone defect, keeping the inside of the bone defect filled with unreacted Na-Alg aqueous solution. In this investigation, a preliminary animal study was conducted for an initial evaluation as to whether or not the alginate membrane can be used as a barrier membrane for the GTR method. Bone defects were made in the tibiae of 15-week-old rats. The alginate membrane was made on the surface of existing bone by filling the defect with Na-Alg aqueous solution and then dropping calcium chloride aqueous solution onto the surface of the Na-Alg solution. Four weeks after surgery, the bone defect was found to be reconstructed with new bone when the defect had been covered with alginate membrane whereas the bone defect was filled only with connective tissue when it had been kept open. We concluded, therefore, that this alginate membrane may be a useful barrier membrane when the GTR method is employed.

Alginates↗