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PubMed1995

Sodium hydroxide-induced irritant dermatitis as assessed by computerized elaboration of 20 MHz B-scan images and by TEWL measurement: a method for investigating skin barrier function.

Sodium hydroxide-induced irritation was studied in 34 volunteers, by means of 24-h patch testing at different concentrations, and by a 10-min testing procedure employing 0.1 mol/l NaOH. As a supplement to subjective evaluation of skin changes, assessments of test areas by TEWL measurement and sonography were performed at 24, 48 and 72 h. After 24-h patch testing, instrumental evaluations showed an increase in the extension of the hypo-echogenic dermal area and in TEWL, whereas a 10-min NaOH application induced a decrease of the dermal and epidermal reflectivity and an increase in TEWL. Twenty-four hour patch testing with 4% NaOH allowed a classification of subjects into two categories: subjects who reacted normally and hyper-reactors. Hyper-reactors showed an enhanced inflammatory response and a more pronounced barrier function damage, as assessed clinically and instrumentally by decreased dermal reflectivity, and by higher postexposure TEWL. Subjects with a more marked inflammatory response to 4% NaOH also showed greater TEWL increases during the short-term testing procedure employing 0.1 mol/l NaOH. Moreover, these subjects were characterized by higher baseline TEWL values, indicating that cutaneous reactivity to NaOH is at least partly correlated to impaired stratum corneum function, which is inadequate to effectively prevent compounds from penetrating the skin.

Adolescent↗
PubMed1995

[Quantitative assessment of blood-aqueous humor barrier permeability using densitometry methods combined with high performance thin layer chromatography].

The paper presents an original method of examining blood-aqueous humor permeability. The examinations were performed on grey rabbits that had been intravenously injected 10% fluorescein solution. Subsequently, at definite time intervals from the moment of the administration, fluid of the anterior chamber was taken in which the amount of aqueous fluorescein permeating to aqueous humor was measured. The measurements were performed using the method of high potency thin layer chromatography (HPTLC) in DS type chambers. Examination results were presented as densitometry, and the area of individual points was counted using a computer programme. This method yielded a diagram quantitatively presenting fluorescein permeation from the blood to the aqueous humor.

Animals↗
PubMedDate not supplied

Gender differences in HIV-related self-reported knowledge, attitudes, and behaviors among college students.

A survey of 265 college students was conducted to determine HIV-related knowledge, attitudes, behavior, and perceived self-efficacy with regard to engaging in HIV-protective behaviors. A self-administered 52-item survey was completed by 265 college students (60% response rate). Resident advisors in college dormitories distributed the survey, returned anonymously. Data were analyzed using SPSS to identify differential responses by gender. Although HIV knowledge was high, perceived self-efficacy differed significantly by gender, with men describing themselves as less able to insist upon condom use (P < .00001). Men were also significantly more likely to report using drugs or alcohol in situations likely to lead to a sexual encounter (P < .001) and to having lower self-efficacy in relation to HIV protection than women in such situations (P < .02). Men were also significantly more likely to believe that monogamy obviates the need to use condoms (P < .01). A substantial number of men (13) and women (14.6) say they do not use condoms because they are protected from unwanted pregnancy by pill. Gender-specific HIV education and skills-building programs may improve the success of AIDS prevention efforts by confronting and addressing gender differences. The reliance on hormonal methods of birth control alone may be a barrier to condom use for both male and female adolescents and young adults. Medical Subject Headings (MeSH): AIDS; HIV; knowledge, attitudes, and practice; gender; condoms; birth control; family planning; teenage pregnancy.

Adult↗
PubMed2003

Mean escape time over a fluctuating barrier.

An approximate method for studying activation over a fluctuating barrier of potential is proposed. It involves considering separately the slow and fast components of barrier fluctuations, and it applies for any value of their correlation time tau. It gives exact results for the limiting values tau-->0 and tau--> infinity, and the agreement with numerics in between is also excellent, both for dichotomic and Gaussian barrier perturbations.

Journal Article↗
PubMed2002

The nursing shortage as a community transformational opportunity.

The nursing shortage is continuing toward its projected peak in 2010. As a profession we seem unable to devise effective strategies to enhance growth and overcome this looming crisis. By focusing on predictable barriers using methods of reductionism, nurses may have forgotten the biggest barrier: the challenge of creating a holistic professional group presence and inclusive nursing stance. Without first addressing and solving internal paradoxical identity struggles, nursing will continue to try to overcome the multiple internal and external barriers that resulted in the current shortage. This article discusses the group dynamics that have fostered the cyclic loop of nursing shortage situations and explores the reflection and inquiry needed to formulate a cohesive national nursing group posture.

Age Factors↗
PubMed2006

Report of an ISRTP workshop: progress and barriers to incorporating alternative toxicological methods in the U.S.

The workshop objectives were to explore progress in implementing new, revised and alternative toxicological test methods across regulatory evaluation frameworks and decision-making programs in the United States, to identify barriers and to develop recommendations to further promote adoption of approaches that reduce, refine, or replace the use of animal methods. The workshop included sessions on: (1) current research, development, and validation of alternative methods within the U.S. federal government; (2) emerging alternative methodologies with potential applications to a broad spectrum of toxicity evaluation strategies; (3) tiered evaluation ("intelligent testing") strategies; and (4) identification of, and recommendations to address, critical barriers that affect adoption and use of new, revised alternative toxicological test methods by U.S. regulatory agencies. Through facilitated discussion, a list of barriers and recommendations were developed and grouped into categories of economic/financial, scientific/technical, and regulatory/policy. Overall, participants from all sectors collectively supported catalyzing actions to promote more meaningful and rapid progress for research to develop alternative methods focused for use in regulatory programs, accelerated lab investigations to validate such alternative methods and adoption of regulatory frameworks which embrace and incorporate these validated alternatives.

Animal Testing Alternatives↗
PubMed2002

Development and validation of a survey to assess barriers to drug use in patients with chronic heart failure.

Scot H. Simpson, Pharm.D., M.Sc., Jeffrey A. Johnson, Ph.D., Karen B. Farris, Ph.D., and Ross T. Tsuyuki, Pharm.D., M.Sc. Objective. To report the development of and initial experience with a survey designed to assess patient-perceived barriers to drug use in ambulatory patients with heart failure. Methods. The Barriers to Medication Use (BMU) survey, developed from previous qualitative work by our group, was administered to 128 consecutive patients attending an outpatient heart failure clinic. The first 42 patients to return the survey were mailed a second survey to evaluate response stability over time. The survey contained 31 questions in five barrier domains (knowledge, previous drug therapy experiences, social support, communication, and relationship with health care professionals). Patients also completed the Minnesota Living with Heart Failure (MLHF) questionnaire and a self-reported drug use scale. Frequency of drug refills was used to estimate adherence. Reliability and construct validity of the BMU survey were assessed using correlation coefficients. Results. Response rates were 89% and 93% for the first and retest surveys, respectively The BMU survey showed modest internal consistency in the overall survey and in two of the five barrier domains. Responses to the first and retest surveys showed good stability over time in the overall survey and in four of the five barrier domains. Patients with good adherence reported few barriers; however, the association was not strong (Pearson correlation coefficient r = -0.14, p=0.14). Patients who reported few barriers also reported better MLHF scores (r = 0.42, p < 0.001), with the strongest association in the social support domain (r = 0.53; p < 0.001). All respondents reported having a good relationship with health care professionals. The most common barriers to drug use were poor support networks and previous adverse reactions. Conclusion. The BMU survey demonstrated reasonable reliability and validity characteristics in this first clinical experience. Despite high adherence, patients still reported barriers that may hinder optimal drug use.

Aged↗
PubMed1999

Cutaneous barrier repair and pathophysiology following barrier disruption in IL-1 and TNF type I receptor deficient mice.

Disruption of the permeability barrier elicits a homeostatic repair response which rapidly restores barrier function while repeated barrier perturbation results in cutaneous pathology. In response to barrier disruption there is a marked increase in epidermal TNF-alpha and IL-1 production. To determine the potential role of TNF and IL-1 in mediating the cutaneous changes that occur following barrier disruption we compared the kinetics of barrier recovery and the degree of epidermal hyperplasia and cutaneous inflammation in TNF type I (p55) receptor and IL-1 receptor type I (p80) deficient mice. No abnormalities in epidermal morphology were observed with light or electron microscopy in receptor deficient mice. Under baseline conditions epidermal barrier function was unchanged in receptor deficient mice. Following barrier disruption the kinetics of barrier recovery were similar in control vs TNF receptor deficient mice regardless if the barrier was disrupted by acetone treatment, SDS treatment, or tape stripping. In contrast, barrier recovery was slightly but significantly accelerated regardless of the method of barrier disruption in IL-1 receptor deficient mice. The degree of epidermal hyperplasia and cutaneous inflammation following repeated barrier disruption was similar in control, TNF receptor, and IL-1 receptor deficient mice. The present study demonstrates that barrier recovery is not delayed and the degree of epidermal hyperplasia and inflammation are not altered in either TNF receptor or IL-1 receptor deficient mice, indicating that neither TNF nor IL-1 alone are essential for either barrier repair or the cutaneous pathology induced by barrier perturbation. Whereas the increase in IL-1 following barrier disruption may delay components of the repair response, whether either TNF-alpha or IL-1 regulate aspects of the homeostatic response remains unresolved.

Animals↗
PubMed1999

A whole-glove method for the evaluation of surgical gloves as barriers to viruses.

BACKGROUND: Today, because of the wide variety of infectious agents encountered in the health care environment, clinicians must be particularly concerned about the potential for small-sized virus penetration through glove defects. OBJECTIVE: To describe a method for testing gloves that evaluates the entire glove and allows for detection of low levels of virus penetration. Ten sets of 10 different gloves from 4 manufacturers were evaluated using this method. METHODS: Barrier properties were evaluated using the bacteriophage, phiX174. Gloves were filled with surfactant solution placed in flasks containing 10(6) viruses per mL. Flasks were agitated at 37 degrees C +/- 2 degrees C and assayed for 180 minutes. RESULTS: Virus penetration was detected in 8% of the 100 gloves tested using the quantitative assay. The qualitative assay determined that 14% of the gloves tested allowed penetration.

Evaluation Studies as Topic↗
PubMed1998

AIDS and reproductive health.

Over 24 million adults worldwide have been infected with HIV. Primarily a sexually transmitted disease, AIDS is inexorably linked to reproductive health and care. Because HIV tends to infect those who are in their reproductive years, the impact of this disease on population growth and life expectancy is projected to be immense in some parts of the world, especially in sub-Saharan Africa. Not least is the challenge to individual families and infant care programs to care for AIDS babies. Estimates of the rate of vertical transmission of HIV range from < 10 to 46%. Transmission through sexual contact accounts for 75-85% of HIV infection worldwide, and today, nearly 20 years into the epidemic, the main tool to stall the spread is advocating change in sexual conduct. Numerous studies leave no doubt that the attributable risk of co-infection with other STDs--both ulcerative and non-ulcerative--in heterosexual transmission is substantial. The only known contraceptive method proven to reduce both infectiousness and susceptibility to HIV is barrier contraception. Spermicidal agents currently available have not been shown to reduce HIV concentrations in genital secretions, or to reduce transmission of the virus. The challenges that lie ahead are tremendous: we must continue to focus on development of affordable preventive measures; urge policy-makers to back further research in prevention to complement condom use; and advocate for continued support of basic research to learn more about fundamental mechanisms of HIV transmission.

AIDS-Related Opportunistic Infections↗
PubMed1995

Identifying concepts in medical knowledge.

The barrier word method of identifying nominal phrases in text, using a very long barrier word list, was evaluated in two different sets of text. In a sample of 10 paragraphs from the Medical Knowledge Self-Assessment Program of the American College of Physicians, the yield of nominal phrases as a percent of total chunks isolated was 66%. Some 500,000 chunks were isolated from Principles and Practice of Oncology (PPO). 38% of these chunk-occurrences were of chunks which matched to 10,000 concept names in Meta-1.4, the most recent version of the UMLS Metathesaurus. 50 paragraphs from PPO were chosen at random. Co-occurrences of concepts in those paragraphs were reviewed. 42 of the paragraphs had unique or infrequently occurring co-occurrences which described closely the major thrust of the paragraph.

Medical Oncology↗
PubMed1992

Barrier contraceptives and sexually transmitted diseases in women: a comparison of female-dependent methods and condoms.

INTRODUCTION: Most efforts at sexually transmitted disease (STD) protection center on condom use, but little is known about how condoms compare with other barrier methods, particularly those controlled by women. METHODS: To evaluate the effect of different barrier contraceptives on the prevalence of STDs and other vaginal infections, we retrospectively studied 5681 visits by women to an urban STD clinic. RESULTS: As compared with women using no contraceptive or with tubal ligations, women using the contraceptive sponge or diaphragm had at least 65% lower rates of infection with Neisseria gonorrhoeae and Trichomonas vaginalis, while condom users had 34% and 30% lower rates, respectively. For Chlamydia trachomatis, the reduction was 13% among sponge users, 72% among diaphragm users, and 3% among condom users, although these differences were not significant. When compared with women using condoms, women using female-dependent methods (sponge or diaphragm) had significantly lower rates of both gonorrhea and trichomoniasis. Vaginal candidiasis was more common among women using diaphragms but not other barrier methods, while rates of bacterial vaginosis were similar among all groups. CONCLUSIONS: Women using the contraceptive sponge or diaphragm experience protection from STDs to a greater extent than those relying on condoms. Female-dependent barrier contraceptives should receive more attention in STD risk-reduction programs.

Adult↗
PubMed1985

A follow-up study of the efficacy and safety of injectable microencapsulated megestrol acetate and a discussion on its contraceptive mechanism.

A monthly injectable microencapsulated contraceptive was developed by the researchers of the School of Pharmacy of Sichuan Medical College, and a comparative clinical study was undertaken by the Sichuan Cooperative Research Group. It has been found that the microencapsulated compound consisting of 15 mg megestrol acetate and 5 mg estradiol valerate is associated with the lowest incidences of menstrual disturbances and other side effects. This is a follow-up report on the 434 women who used this 'optional' dosage of compound by before-and-after comparisons and by comparisons with two other groups of women: 41 women who were given the compound with the same dosage combination but with microencapsular coat dissolved, and 20-30 women who were using a non-steroidal contraceptive method such as IUDs, barrier or rhythm methods. The microencapsulated compound was highly effective in preventing accidental pregnancies. All except two of the 119 women who discontinued the medication experienced normal menstruation within 3 months. The study did not show changes in blood pressure, liver function, glucose tolerance level and plasma concentration of cholesterol in women using the compound. Cervical smears and breast examination also showed no evidence of epithelial abnormality or breast tumors. This new delivery system of microencapsulated injections affects the cervical mucus function, and inhibits ovulation as well as implantation of fertilized ovum.

Adult↗
PubMed2004

Development and validation of an immunosuppressant therapy adherence barrier instrument.

BACKGROUND: To decrease allograft rejection as a result of non-adherence to immunosuppressant therapy (IST), a valid and reliable instrument that measures solid organ transplant patients' adherence barriers is needed. METHODS: An immunosuppressant therapy barrier scale (ITBS) was developed to assess transplant patients' perceived barriers to IST adherence and was completed by 222 transplant patients who lived in Georgia, USA. A renal transplant population subset was used to test the ITBS reliability and validity. Scale reliability was estimated using Cronbach's alpha coefficient of internal consistency; scale dimensionality was assessed using principal components analysis. The criterion-related validity of the scale was assessed by relating subscale scores to adherence measures and graft rejection. Nomological validity was assessed by relating barrier subscales to specific patient factors. RESULTS: Two subscales that represented 'controllable' and 'uncontrollable' barriers were found. Cronbach's alpha coefficients demonstrated acceptable reliabilities of 0.93, 0.86 and 0.91 for the 'uncontrollable' and 'controllable' subscales, and for the entire ITBS, respectively. The ITBS subscales correlated negatively with a self-reported measure of IST adherence, IST serum concentrations and IST pharmacy refill adherence rate (P<0.01). The 'uncontrollable barrier' subscale was positively correlated to kidney graft rejection (P<0.01), thus demonstrating the ITBS's validity. Males and older patients reported more adherence barriers (P<0.05). CONCLUSIONS: The ITBS is a reliable and valid instrument that can be used to measure patients' perceived barriers to IST adherence.

Adult↗
PubMed2002

Dual protection against unintended pregnancy and sexually transmitted infections: what is the best contraceptive approach?

In the midst of the global epidemics of both unintended pregnancy and sexually transmitted infection, contraceptive options that provide dual protection are ideal. However, those contraceptives with the best record of preventing pregnancy under typical use conditions (sterilization, hormonal methods, intrauterine devices) provide little if any protection against sexually transmitted infection. Alternatively, barrier contraceptive methods (specifically, condoms), which can reduce risks of many sexually transmitted infections, are associated with relatively higher pregnancy rates for most users than other contraceptives. This situation has produced a dilemma for those wishing to promote dual protection: whether to advocate use of two methods (one primarily to prevent pregnancy and the other primarily to prevent infections) or whether to emphasize use of condoms for both purposes. Data comparing these two approaches are limited and often contradictory. We discuss the underlying concepts of exposure to both pregnancy and infection, provide a broad overview of the effectiveness of contraceptive methods against these two conditions, present approaches to optimize dual protection, and propose several new directions for necessary research. In the absence of evidence-based recommendations, we believe clinicians should assist clients in assessing their likelihood of exposure to infection, either by prevalence of sexually transmitted infection in the community or by the specific risk factors of the client. If exposure is likely, particularly to the more serious infections such as human immunodeficiency virus, the one-method approach should be given greater weight. However, in settings where unintended pregnancy is the greater concern, emphasizing the two-methods approach as a first option may be appropriate.

Condoms↗