Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Barrier Methods”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,063 records · Page 59Linked to original sources
PubMed2006

Long-term results of guided tissue regeneration therapy with non-resorbable and bioabsorbable barriers. III. Class II furcations after 10 years.

BACKGROUND: The aim of this 10-year follow-up was to evaluate the long-term results after guided tissue regeneration (GTR) therapy of Class II furcation defects using non-resorbable and bioabsorbable barriers clinically. METHODS: In nine patients with advanced periodontitis, nine pairs of contralateral Class II furcation defects were treated. Within each patient, one defect received a non-resorbable expanded polytetrafluoroethylene barrier (ePTFE; C) and the other a bioabsorbable (polyglactin 910; T) barrier by random assignment. At baseline and 12 and 120 +/- 6 months after surgery, clinical parameters were obtained. RESULTS: Twelve and 120 months after GTR therapy, statistically significant (P <0.05) horizontal clinical attachment level (CAL-H) gain was observed in both groups (C12: 1.9 +/- 0.5 mm; C120: 1.1 +/- 1.3 mm; T12: 1.9 +/- 0.8 mm; T120: 1.7 +/- 1.4 mm). However, one patient with furcations that had been assessed as Class I 12 months after GTR therapy had lost two teeth after 10 years, and another patient had lost more than 2 mm CAL-H at one furcation from 12 to 120 +/- 6 months post-surgery 10 years after implantation of an ePTFE barrier. Horizontal bone sounding revealed similar bone gain in both groups 120 +/- 6 months post-surgery (C120: 0.8 +/- 1.0 mm; T120: 1.1 +/- 1.1 mm). CONCLUSIONS: CAL-H gain achieved after GTR therapy in Class II furcations was stable after 10 years in 15 of 18 defects (83%). The study failed to show a statistically significant difference in stability of CAL-H gain between group C and T 10 years after GTR therapy.

Absorbable Implants↗
PubMed1993

Mammography utilization in the poor and medically underserved.

There is a significant difference in the utilization of mammography for screening and diagnosis between women of lower socioeconomic groups and the rest of the female population. Information obtained by the American Cancer Society through public hearings in 1989 revealed significant problems in how the poor deal with cancer. Barriers to methods of early detection seemed to revolve around access, education, and cost. A recent study of breast health performed by the Wirthlin Group for the American Cancer Society showed similar barriers. All women, regardless of income, expressed the fear of finding breast cancer as one of the major barriers to having mammography. Although the poor and medically underserved group of women showed similar barriers to mammography, certain barriers seemed specific to ethnic group, age, and place of residence. Evaluation of these barriers to breast health will allow the development of specific programs to meet the needs of this population.

Adolescent↗
PubMed2003

Host immune responses and intestinal permeability in patients with jaundice.

BACKGROUND: Systemic endotoxaemia is implicated in the development of complications associated with obstructive jaundice. The aims of these studies were to assess the systemic immune response to intervention in patients with jaundice and to compare the effects of surgical and non-surgical biliary drainage on host immune function and gut barrier function. METHODS: In the first study, 18 jaundiced and 12 control patients were studied to assess systemic immune responses before and after intervention. In the second study, immune responses and gut barrier function were assessed following surgical and non-operative biliary decompression in 45 patients with jaundice. RESULTS: Endotoxin antibody concentrations fell significantly in patients with jaundice immediately after surgical intervention, but not after non-operative biliary drainage. This decrease was associated with a significant increase in serum P(55) soluble tumour necrosis factor (sTNF) receptor concentration (5.3 versus 10.5 ng/ml; P < 0.001), urinary excretion of P(55) TNF receptors (21.4 versus 78.8 ng/ml; P = 0.002) and intestinal permeability (lactulose : mannitol ratio 0.032 versus 0.082; P = 0.048). Intestinal permeability was significantly increased in patients with jaundice compared with controls (0.033 versus 0.015; P = 0.002). CONCLUSION: These data suggest that obstructive jaundice is associated with impaired gut barrier function and activation of host immune function that is exacerbated by intervention. Surgery causes an exaggerated pathophysiological disturbance not seen with non-operative biliary drainage procedures.

Antibodies↗
PubMed2002

Prospective preference assessment: a method to enhance the ethics and efficiency of randomized controlled trials.

The concomitant problems of underenrollment and selective enrollment limit the efficiency of many randomized controlled trials (RCTs). In addition, the traditional informed consent process is often inadequate to respect research participants' autonomy. Past efforts to overcome these problems are not universally applicable. A new method, called prospective preference assessment (PPA), is suggested as a way to simultaneously enhance participant accrual, identify groups of patients to whom a trial's results may apply, and promote participants' interests. PPA is a method by which investigators would evaluate potential trial participants' motivations for and concerns about enrolling in a planned trial prior to formal recruitment. The information provided by PPA would then be used to (1) modify the final trial design and conduct to make enrollment more attractive, and (2) identify ways in which the patients who do enroll may differ from those who do not, thereby elucidating the trial's generalizability. The methodologic and ethical advantages of this method are described, and potential barriers to the method's implementation are addressed. The added costs of prospectively assessing the views of potential research participants prior to initiating RCTs are considered in relation to the method's ability to enhance the value of the information to be obtained. It is concluded that PPA is a feasible approach to a more democratic and efficient research process and that its adoption would be consistent with current trends in health care.

Human Experimentation↗
PubMed1999

Butyrate from bacterial fermentation of germinated barley foodstuff preserves intestinal barrier function in experimental colitis in the rat model.

BACKGROUND AND AIMS: The consumption of germinated barley foodstuff (GBF) prevents inflammation and diarrhoea in a colitis model. In this study we investigated the mechanism of the preventative effect of GBF on experimental colitis in rats, in view of production of bacterial butyrate and preservation of intestinal barrier function. METHODS: Sprague-Dawley rats administered with diets supplemented with 3.5% dextran sodium sulphate were used as an experimental colitis model. Butyrate was given to rats orally or intracaecally. Intestinal barrier function was estimated by light microscopic observation of the mucosa, intestinal permeability and bacterial translocation. RESULTS: Mucosal damage was reduced by intracaecal administration of butyrate, but not by oral administration. Bacterial butyrate production and reduction of mucosal damage depended on the dose of GBF in diets. The action of endogenous bacterial butyrate, including the reduction of intestinal permeability and bacterial translocation, was inhibited by administration of an inhibitor of beta-oxidation of short-chain fatty acids. CONCLUSIONS: The feeding of GBF promotes bacterial butyrate production and improves intestinal barrier function in rats, resulting in mitigation of experimental colitis.

Animals↗
PubMedDate not supplied

Nonoxynol-9 in lubricated condoms. Results of a study in female prostitutes.

BACKGROUND AND OBJECTIVES: Debate continues on the efficacy and safety of intravaginal nonoxynol-9 for the prevention of horizontal transmission of human immunodeficiency and other sexually transmitted diseases. Little attention has been paid to the effects of nonoxynol-9 contained in the lubricant of many condoms. GOAL: To assess the tolerability of different levels of nonoxynol-9 in condom lubricants. STUDY DESIGN: Pilot, randomized, controlled trial in 70 female prostitutes. RESULTS: There was no association between dose of nonoxynol-9 and reported symptoms or signs of genital tract inflammation; an increased dose of nonoxynol-9 was associated with increased numbers of polymorphonuclear leukocytes on a vaginal wall smear. CONCLUSIONS: There is no recognized simple method of defining inflammation in the female genital tract. Future studies of the effects of low-dose nonoxynol-9 on the female genital tract require highly controlled exposures, plus colposcopy with or without vaginal biopsy to define inflammation.

Condoms↗
PubMedDate not supplied

Effects of nucleosides and a nucleotide mixture on gut mucosal barrier function on parenteral nutrition in rats.

BACKGROUND: We have previously reported that the addition of nucleosides and a nucleotide mixture (OG-VI) to total parenteral nutrition (TPN) prevents TPN-induced intestinal mucosal atrophy and results in increased intestinal cathepsin activities under TPN. The aims of the present study are to examine the effects of OG-VI on mucosal barrier functions and to clarify whether the intestinal cathepsins can be used as a new marker of mucosal barrier function. METHODS: Male Wistar rats were divided into three groups: FED (food ad libitum), TPN (a standard TPN solution), and OG (OG-VI in addition to the TPN solution). Mucosal barrier functions were analyzed by the lactulose/mannitol (L/M) test, mucosal ZO-1 messenger RNA level, and electron micrographs in the gut. Intestinal cathepsin B, H, and L activities were also measured. RESULTS: The L/M ratio for TPN was much higher than that for FED. Only lactulose excretion was significantly reduced by OG-VI. The intercellular spaces of the mucosal cells for TPN were significantly wider than those for FED, but were reduced in size by the addition of OG-VI. All cathepsin activities of the ileum were higher for TPN than for FED, whereas OG showed no increase. CONCLUSION: OG-VI contributes to the improvement of gut mucosal barrier function. Intestinal cathepsin activities can be used as a new marker of mucosal barrier function.

Animals↗
PubMed1996

Contraceptive method mix menu: providing healthy choices for women.

This article addresses expansion of the contraceptive method mix, in the specific context of underserved women in developing countries who, like all women, expect to maintain their health status while successfully regulating their fertility. It is a critical review of the health implications of the contraceptive methods most commonly included on a menu of options and includes fertility awareness methods as essential non-supply method options where barriers currently exist for supply methods.

Contraception↗
PubMed2003

Permeation of 70% isopropyl alcohol through surgical gloves: comparison of the standard methods ASTM F739 and EN 374.

Standard test methods ASTM F739 and EN 374 were compared by assessing the permeation of 70% isopropyl alcohol (2-propanol) through seven brands of surgical gloves. The two standards differ in the flow rates of the collection medium and in the chemical permeation rate at which the breakthrough time (BTT) is detected, the EN detection level being 10 times higher than the permeation rate used by ASTM. In a departure from the EN standard method, a 4 h testing time was used instead of 8 h. All of the tested gloves were from the same manufacturer and were made from either natural rubber (NR) (six brands) or chloroprene rubber (CR) (one brand). Two of the NR glove brands were double layered. For the thin NR gloves (0.22, 0.28 and 0.27 mm) the permeation rates were higher throughout the tests with a flow rate of 474 ml/min (EN) of the collection medium (nitrogen) compared with the permeation rates obtained with a flow rate of 52 ml/min (ASTM). These resulted in BTTs of 4.6, 6.5 and 7.6 min (EN) and 4.8, 6.5 and 9.1 min (ASTM), respectively. No statistical difference could be observed between the BTT values obtained with the two standard methods for any of the thin gloves. Thus, although the ASTM standard has a lower criterion for the detection of permeation, it does not necessarily produce shorter BTTs. For the better barriers the methods yielded more equivalent permeation rate curves and thus the EN BTTs were longer than the ASTM BTTs: the EN results were 21, 80, 122 and >240 min compared with the ASTM results of 12, 32, 38 and 103 min for glove thicknesses of 0.37 (NR), 0.22 + 0.22 (double layered NR), 0.31 + 0.29 (double layered NR) and 0.19 mm (CR), respectively.

2-Propanol↗
PubMed2005

Nondestructive method for the characterization of ion-implanted waveguides.

A new method, called barrier coupling, for coupling light into ion-implanted waveguides is presented in analogy to prism coupling. Light is coupled by frustrated total reflection at the barrier region of decreased refractive index by proper variation of the incident angle. Effective indices of guided modes are determined by the minima of the non-incoupled reflected light. The method is used for the determination of the effective indices of an ion-implanted waveguide in KNbO3. It is simpler than most other techniques, more accurate, and nondestructive.

Journal Article↗
PubMed2002

Stereointegrity of thalidomide: gas-chromatographic determination of the enantiomerization barrier.

Enantioselective chromatographic methods, representing the most commonly used techniques for the determination of enantiomeric ratios, can also be used for the evaluation of stereochemical integrity. In the present study, two chromatographic methods, dynamic gas chromatography (DGC) and stopped-flow gas chromatography (SFGC) were used to determine the enantiomerization barrier of thalidomide. In the presence of a chiral stationary phase (CSP), the enantiomers of thalidomide produced characteristic elution profiles exhibiting plateaus and/or peak broadening which were observed between 190 and 220 degrees C in DGC. To obtain the enantiomerization barrier of thalidomide from experimental data, the fast and efficient simulation program ChromWin was used to simulate the elution profiles and obtain kinetic activation parameters. From temperature-dependent measurements the rate constants k(1) and k(-1) and the kinetic activation parameters DeltaG#, DeltaH# and DeltaS# of the enantiomerization of thalidomide were obtained by DGC. The enantiomerization barrier DeltaG# was determined to be 154+/-2 kJ/mol with DGC and 150+/-3 kJ/mol with the sfGC technique at 200 degrees C, respectively. The concept of the retention increment R' has been applied to separate the enantiomerization barrier of thalidomide in the dissolved and complexed state of the CSP.

Chromatography, Gas↗
PubMed2001

Sites of lanthanum occlusion in the testis of the crayfish Procambarus paeninsulanus (Crustacea: Cambaridae).

The presence of stage-dependent occlusive junctions between adjacent Sertoli cells in the seminiferous epithelium of the crayfish testis was demonstrated by a lanthanum tracer study. The germinal epithelium did not appear to be compartmentalized, as evidenced by access of lanthanum to spermatogonia, spermatocytes, and spermatids. During late spermiogenesis, when encapsulated stage VI spermatids were concentrated in the center of an acinus, lanthanum was excluded apically, coincident with lumen formation. This is the first study examining occluding junctions using a barrier penetration method in the testis of a crustacean.

Animals↗
PubMedDate not supplied

EMS provider reluctance to perform mouth-to-mouth resuscitation.

OBJECTIVES: To assess the willingness of EMS providers to perform mouth-to-mouth resuscitation (MMR) both with and without a barrier device (e.g., face shield), while not on duty; and to determine the providers' perceived risk from performing MMR and the frequency with which they carry a barrier device. METHODS: A survey was mailed to 543 EMS providers presenting four scenarios describing a patient in respiratory arrest. The respondents were asked whether they would perform MMR in each scenario both with and without a barrier device. RESULTS: Of those surveyed, 342 (64%) responded. Strikingly few (< or =5%) of the respondents would perform MMR without a barrier on each of the cases, except for the case of a pediatric drowning (52%). The respondents were least likely to perform MMR on a patient with AIDS (< 1%). The respondents were much more likely to perform MMR in each case if a barrier device was available. The respondents were very concerned about the risk of contagion from MMR, yet 44% of the respondents rarely or never carried a barrier device with them. CONCLUSION: Emergency medical services providers are quite reluctant to perform MMR, and this is likely related to their perception of a high risk of contagion. The availability of barrier devices greatly decreases this reluctance, but EMS personnel carry such devices infrequently.

Adult↗