An artificial biofilm induced secondary caries model for in vitro studies.

BACKGROUND: The aim of this study was to establish a new in vitro model for biofilm induced secondary caries studies using an oral biofilm reactor. METHODS: An approximately 2 × 3 × 2 mm(3) sized dentino-enamel Class I cavity was prepared in the middle of a square-shaped specimen from the mid-labial portion of bovine incisors. The cavities were partially filled with either Clearfil AP-X with SE-Bond or Clearfil AP-X without any bond. Artificial biofilms were then formed on the resin composite filled surfaces using three species of oral bacteria in an oral biofilm reactor for 20 hours followed by 7- or 30-day incubation periods. RESULTS: The lesions were clearly visible on fluorescence microscopy and by scanning electron microscopy in the enamel at the interface of resin restorations in all samples. The data from image analysis showed that the lesion size was largest in the No-bond samples with statistically significant differences (p < 0.05). Demineralization along the cavity wall extended deeper in No-bond compared to SE-Bond samples and penetration was significantly deeper in No-bond 30-day samples. CONCLUSIONS: A primary artificial secondary caries model was established using biofilms for in vitro studies and the significance of using a bonding system could also be verified.

Evaluation of post-surgical cognitive function and protein fingerprints in the cerebro-spinal fluid utilizing surface-enhanced laser Desorption/Ionization time-of-flight mass-spectrometry (SELDI-TOF MS) after coronary artery bypass grafting: review of proteomic analytic tools and introducing a new syndrome.

Cognitive dysfunction following surgery is a common complication, which increases the incidence of other co-morbid conditions, hospital and health-care costs. The reported rate of the occurrence of post-operative cognitive decline varies with different studies, depending on population profile, type of surgery, definition of cognitive disorder and detection methods, design of study, etc. It remains unclear whether these psychiatric signs and symptoms are direct results of the effects of surgery or general anesthesia. Nonetheless they are more frequent after cardiac surgery and are likely to be multi-factorial, but the patho-mechanisms are not yet fully characterized. This communication provides a synopsis of proteomics tools and delineates novel SELDI-TOF results to evaluate biomarkers in this regard. Presented for the first time is a classification of the clinically relevant forms of post-operative cognitive decline with the advent of a novel subclass.

Effects of root dentin surface coating with all-in-one adhesive materials on biofilm adherence.

OBJECTIVES: Sealing of exposed root dentinal surfaces with adhesive materials is expected to be a promising approach for preventing root dentin caries. The aim of this study was to evaluate the effects of surface coating with all-in-one adhesives on inhibiting Streptococcus mutans biofilm attachment. MATERIALS AND METHODS: Bovine root dentin was cut and ground with #600-grit SiC paper. Each of the three all-in-one adhesives, Hybrid Bond (HB), Reactmer Bond (RB) or Shake One (SO) was single-coated on the dentin surfaces according to the manufacturers' instructions. The dentin surface without coating served as the control. The surface roughness of the coated and non-coated dentin surfaces was recorded by means of laser microscope measurements. S. mutans artificial biofilms were then grown on the surface of each specimen in a microcosm for 20h. The amounts of bacteria and water insoluble glucan in the retained biofilm on the surface of the specimens were measured. All numerical data were statistically analyzed using one-way ANOVA & Tukey's HSD (p<0.05). RESULTS: All of the coated groups showed significantly lower susceptibility to biofilm attachment compared with the non-coated root dentin (p<0.05). Among the coated groups, SO showed the lowest susceptibility for biofilm formation. CONCLUSIONS: Three all-in-one adhesive materials could be effective for root surface coating. A fluoride-releasing adhesive, SO demonstrated the strongest potentiality in resisting biofilm formation.

Anti-hyperalgesic effect of octreotide in patients with irritable bowel syndrome.

BACKGROUND: Octreotide has been found to be beneficial in the treatment of chronic pain, although the mechanisms underlying its therapeutic effect are incompletely understood. AIMS: To assess the effect of octreotide on perceptual responses to rectal distension in irritable bowel syndrome patients and healthy controls at baseline and following the experimental induction of rectal hyperalgesia. METHODS: In study 1, rectal perception thresholds for discomfort were determined in seven irritable bowel syndrome patients and eight healthy controls on three separate days using a computer-controlled barostat. Subjects received saline, low-dose and high-dose octreotide in a random double-blind fashion. In study 2, perceptual responses to rectal distension were obtained in nine irritable bowel syndrome patients and seven controls before and after repetitive high-pressure mechanical sigmoid stimulation. RESULTS: Octreotide increased the discomfort thresholds in irritable bowel syndrome patients, but not in controls, without changing rectal compliance. Repetitive sigmoid stimulation resulted in decreased rectal discomfort thresholds in the patient group only. In irritable bowel syndrome patients, octreotide prevented the sensitizing effect of repetitive sigmoid stimulation on rectal discomfort thresholds. CONCLUSIONS: Octreotide effectively increased discomfort thresholds in irritable bowel syndrome patients, but not in controls, at baseline and during experimentally induced rectal hyperalgesia. These findings suggest that octreotide exerts primarily an anti-hyperalgesic rather than analgesic effect on visceral perception.

Impact of recombinant human bone morphogenetic protein-2 on residual ridge resorption after tooth extraction: an experimental study in the rat.

Residual ridge resorption begins following tooth extraction and continuously reduces alveolar bone volume, potentially creating a significant problem in dental implant treatment. In this study, the role of recombinant human bone morphogenetic protein-2 (rhBMP-2) in residual ridge resorption after tooth extraction was investigated. A polylactic acid/polyglycolic acid copolymer-coated gelatin sponge carrier was implanted with or without rhBMP-2 (1 microg) in the mesial root sockets after removal of maxillary first molars in male Wistar rats. Fine structural and histomorphologic analyses were conducted 3 to 84 days after implantation. Direct bone formation was first observed after 5 days on the rhBMP-2 side, which was transformed into cortical alveolar ridge with a smooth periosteal layer by 84 days, whereas the control side displayed slower healing. Bone histomorphometry revealed greater total bone area and increased bone height after 14, 28, 56, and 84 days on the rhBMP-2 side compared to the control side, and differences were significant after 14, 28, and 56 days. Larger numbers of proliferating cells and densely populated differentiating mesenchymal cells were observed on the rhBMP-2 side than on the control side in the early stage, and chondrogenesis was not observed. The findings indicate that rhBMP-2 may stimulate proliferation and differentiation of mesenchymal cells in the rat maxillary root socket to preserve cortical bone volume in the socket without any evidence of chondrogenesis.

Inhibitory effects of MoAbs against a surface protein antigen in real-time adherence in vitro and recolonization in vivo of Streptococcus mutans.

A surface protein antigen (PAc) of Streptococcus mutans, particularly the A-region of the molecule, has been reported to interact with salivary components on the tooth surface. It might be a candidate antigen inducing the production of antibodies against the adherence of S. mutans to the tooth surface. We investigated the effects of monoclonal antibodies (MoAbs) obtained by immunization of synthetic PAc peptides that completely correspond to the amino acid sequence of part of the A-region. These MoAbs recognize several core B-cell epitopes in the sequence. Two (KH5 and SH2) of these antibodies reacted with both S. mutans and Streptococcus sobrinus, but not with Streptococcus sanguis, Streptococcus salivarius, Porphyromonas gingivalis or Lactobacillus casei. They clearly inhibited the real-time adherence of S. mutans to salivary components in a biosensor. KH5, which showed a real-time inhibition (71%), also significantly prevented the recolonization of S. mutans on the tooth surface in rats. These results suggested that the core B-cell epitope (-Y---L--Y----) recognized by KH5 was the essential sequence in the antigenic epitopes of PAc protein recognized specifically by the inhibitory antibody. Therefore, the amino acid residues were found to be important in the initial attachment of S. mutans to the tooth surface. These results provide for the mechanism of PAc molecule in the initial attachment of S. mutans on the tooth surface and more effective designs for the removal of S. mutans and S. sobrinus from the oral cavity.

Perceptual responses in patients with inflammatory and functional bowel disease.

BACKGROUND AND AIMS: Enhanced visceral sensitivity following a transient inflammatory process in the gut has been postulated as an aetiological mechanism of irritable bowel syndrome (IBS). In this study we compared perceptual responses to rectosigmoid distension in patients with mild chronic inflammation of the rectum (ulcerative colitis (UC)) and patients without mucosal inflammation (IBS) to determine if chronic low grade mucosal inflammation may be a plausible explanation for rectosigmoid hypersensitivity reported in both IBS and UC patients. METHODS: UC disease activity was quantified using activity index scores. Perception thresholds for discomfort during rectosigmoid distension were compared between 11 UC patients with quiescent or mild disease activity, 18 IBS patients, and 13 healthy controls. RESULTS: Although UC activity index scores negatively correlated with perceptual thresholds for discomfort (r=-0.76, p=0.016), UC patients had higher discomfort thresholds compared with IBS patients and controls before (p=0.02) and after (p<0.001) a noxious sigmoid conditioning stimulus. CONCLUSIONS: Rectal perception was attenuated in UC but enhanced in IBS. In chronic mild inflammation, activation of antinociceptive mechanisms may prevent the development of visceral hyperalgesia. Low grade mucosal inflammation alone is unlikely to be responsible for symptoms in functional gastrointestinal disorders.

Audio and visual stimulation reduces patient discomfort during screening flexible sigmoidoscopy.

OBJECTIVE: Despite current recommendations calling for regular screening flexible sigmoidoscopies over the age of 50, only a small percentage of the population have regular examinations. Improving patient tolerance of flexible sigmoidoscopies could therefore increase patient compliance with these recommended guidelines. The aim of this study was to determine whether audio and visual stimulation reduces discomfort during flexible sigmoidoscopy and whether the effects of the stimulation are secondary to distraction. METHODS: A total of 37 patients undergoing routine screening flexible sigmoidoscopy were randomized to receive no intervention, audio stimulation alone, or audio and visual stimulation. Patient discomfort ratings and affect states were measured prior to and immediately following flexible sigmoidoscopy using a visual analogue scale and the Stress Symptom Ratings (SSR) ratings. RESULTS: Patients receiving audio and visual intervention had lower abdominal discomfort ratings (7.1 +/- 1.4) than patients receiving audio stimulation (9.5 +/- 1.3) or no intervention (10.8 +/- 1.6) (p < 0.05). Patients receiving audio and visual intervention also had higher arousal (7.3 +/- 0.4) and attention (9.2 +/- 0.2) ratings than patients receiving no intervention (6.1 +/- 0.4 and 6.2 +/- 0.7, respectively) (p < 0.05). Anxiety and anger ratings, on the other hand, were significantly lower in patients receiving audio and visual intervention (2.5 +/- 0.4, 1.4 +/- 0.3, respectively) than patients receiving no intervention (4.4 +/- 0.6, 3.6 +/- 0.7). CONCLUSION: Audio and visual stimulation reduces abdominal discomfort associated with flexible sigmoidoscopy. This effect appears to be due to distraction.

Off-site dental evaluation program for prospective bone marrow transplant recipients.

The authors evaluated the usefulness of an off-site dental evaluation program for bone marrow recipients. This evaluation packet enabled patients scheduled for bone marrow transplants to be evaluated by, and receive any treatment from, their own dentist rather than a dentist at the transplant center. The program generally was effective in achieving its goals and was well-accepted by patients and dentists alike.

Working life tables, Bangladesh 1981.

PIP: Data from the 1981 Bangladesh Population Census were used to construct life tables for working men and women. Bangladesh has a dependency burden of 109 dependents to 100 economically active population. Labor force participation rates in 1981 were 74.1/100 population aged 10 years and over for males and 4.3/100 population aged 10 years and over for females. The age-specific economic activity rates provided the essential link in translating life table data to working life table data. It was calculated that a newborn Bangladesh male had a working life expectancy of 37.8 years and an overall life expectancy of 50.0 years; working life expectancy peaks at 44.2 years at 10 years of age. A newborn female has a working life expectancy of 1.8 years and an overall life expectancy of 49.0 years; a maximum working life expectancy of 2.4 years is obtained at 10 years of age. In the period 1962-81, male working life expectancy registered a slight decline at all ages, while female working life expectancy increased by about 6 months for ages up to 30 years. Mortality accounts for a loss of about 10% of gross years of active life in the 10-69-year goups and 20% in the 10-79-year age group. The male working life expectancy values for Bangladesh in 1981 correspond well with those found in India in 1971, Pakistan in 1978, and Sri Lanka in 1971. However, there is wide divergency in terms of female working life expectancy values: such rates were significantly higher in Sri Lanka and India than in Bangladesh up to the age of 30 years, after which point there was little divergence.^ieng

Residence background and fertility in Chittagong, Bangladesh.

PIP: Field investigation was conducted during 1976 to gather data on the fertility of currently married women in Chittagong city, Bangladesh, in relation to their husband's former residence. Both husband and wife were interviewed. Detailed information on fertility and socioeconomic variables were collected from 510 currently married women (under 50) who were living with their husbands at the time of the interview. The data on former residence were classified into 2 main groups: nonmigrants and migrants. In considering the migration status, the residence background of the husband was taken into account. The migrants were those who had stayed most of their lives outside Chittagong city before migrating there. The nonmigrants were those who were born in Chittagong city. Of the 510 currently married women interviewed, only 40 (7.8%) were urban migrants and as such it was considered more useful to merge them with the rural migrants who were 360 (70.6%). The mean number of children ever born for the nonmigrant women was 5.96, which was much higher than the corresponding value of 3.81 for the migrant women. The difference in mean number of children ever born between the nonmigrant and migrant women was statistically highly significant. The mean number of desired children for the nonmigrant women was 4.78; it was 3.99 for the migrant women. The difference in the mean number of desired children between the nonmigrant and migrant women also was statistically highly significant. The mean number of children ever born was consistently higher for nonmigrant women in all the age groups in comparison to migrant women in corresponding age groups. When fertility was standardized for the educational attainment of women, the original difference of mean number of children ever born between the nonmigrant and migrant groups was reduced to 0.59 child. The nonmigrant women were evenly distributed among the 3 socioeconomic groups, their percentages in poor, medium, and high socioeconomic status groups being 36%, 32%, and 32%, respectively. About 2/3 of the migrant women belonged to the high socioeconomic group; the remaining 1/3 were evenly distributed in the poor and medium socioeconomic groups. Thus, there was a clear indication that the migrants belong to a high aspirant group in terms of social achievement.^ieng

Adolescent pregnancy: the perspective of the sisterhood of black single mothers.

The Sisterhood of Black Single Mothers Inc. (The Sisterhood) is an organization which exemplifies the considerable potential of community members united for a common good. The Sisterhood began eleven years ago under the leadership of Ms. Daphne Busby. The objective of the Sisterhood is "salvation of a generation subject to insensitivity and misunderstanding--through helping families, especially those headed by women and adolescent women--to establish a new and positive mind set." The Sisterhood regards individuals and social phenomenon as parts of a complex and dynamic whole and uses a positive approach to assessment of situations. Therefore, adolescents who come to the Sisterhood already parents, as well as those who may become parents in their formative years, are provided programming appropriate to their overall needs. They are given opportunities for help in such areas as: securing medical care, public assistance, counseling, housing and financial assistance. Outreach to other significant persons in the life of these adolescents includes intervention with the service providers with whom they come in contact (doctors, teachers, social workers etc.). In addition to addressing the practical needs of adolescents who come to the Sisterhood, positive examples of healthy ways of relating to others and presentation of a system of values consonant with self and family development are provided. Examples are: the Youth Awareness Project (YAP) which deals with concerns of young people as a specific group. The program's focus is bringing young people together who are growing in positive ways and encouraging continuation of that growth.(ABSTRACT TRUNCATED AT 250 WORDS)

The impact of female education on fertility desires in Bangladesh.

PIP: The objective of this study is to determine whether in Bangladesh a wife's educational level significantly affects her desire for more children, or whether Bangladesh has not yet reached the threshold of socioeconomic development where education has any effect on the number of additional children desired. The analysis was carried out in a rural-urban context and also at different stages in the woman's life cycle, as defined by parity at time of interview. 2-3 live births were considered early stage, and 4 or more were defined as later stage. The analysis was carried out on 2791 women selected from the Bangladesh Fertility Survey of 1975-76 who at the time of interview met the criteria of being married, fecund, parity of 2 or more, and having a husband present in the household. The method used to perform the analysis was the Maximum Likelihood estimation method for the truncated dependent variable developed by J. Tobin. The method is a hybrid of probit analysis and classical regression and was chosen because the dependent variable, number of additional children desired, had a clustering of values at the lower limit of O. Separate regressions were run by life cycle stage (parity) and rural-urban background. The effect of variables such as the education of the husband, age, age at first marriage, work status of wife, number of living male children, and infant mortality were held constant in order to find the impact of education on desired fertility. The study found that the number of additional children desired by rural wives was greater than that desired by urban wives at all stages of the life cycle. The mean number of additional children desired by a rural wife at the early stage of the life cycle was .57 and in the later stage .15. For urban women the corresponding values were .29 and .12. The study found that the educational level of both the wife and the husband and the age of the wife at first marriage were not significant. The age of the woman was not significant in urban areas but was negatively significant.in rural areas. The percent of dead children was positively significant in both urban and rural areas for early stage women but for later stage women only in rural areas. In rural areas also the number of living male children was positively significant. The author concludes that Bangladesh is not at the developmental level where education has a significant effect on desire for additional children and that desired fertility is more influenced by antecedent factors such as income, infant mortality, and preference for male children. He recommends that measures be taken to improve socioeconomic levels and provide employment opportunities for women. He also suggests that additional analysis be done to identify the factors important in determining fertility decisions in urban areas and that separate policies be adopted for rural and urban areas.^ieng

Reproducibility of Doppler aortic blood flow measurements: studies on intraobserver, interobserver and day-to-day variability in normal subjects.

Doppler aortic flow velocity measurements have been used to assess quantitatively left ventricular performance at rest and after pharmacologic and other hemodynamic interventions. To permit more meaningful interpretation of Doppler data, 10 normal subjects were studied to establish the intraobserver, interobserver and day-to-day variability in Doppler aortic flow velocity measurements. In each subject, pulsed Doppler recordings of ascending aortic flow velocity were obtained from the suprasternal notch on 2 different days (mean interval 6 days), with the same technician performing and same physician reading both Doppler studies to evaluate day-to-day variability of measurements. Interobserver variability was assessed by having 2 observers read each Doppler study. Both observers read the Doppler records from both days again at a second session to determine intraobserver variability. Intraobserver variability ranged from 1.9 +/- 1.8 to 3.2 +/- 2.9% for ejection time, peak flow velocity and flow velocity integral, but was higher for acceleration time (7.9 +/- 6.6%). Interobserver variability ranged from 3.5 +/- 2.2 to 5.4 + 3.4% for peak flow velocity, ejection time and flow velocity integral, but was notably higher for acceleration time (17 +/- 9%). Day-to-day variability was higher for acceleration time (7.0 +/- 5.2%) than for ejection time, peak flow velocity and flow velocity integral (range from 3.6 +/- 3.1 to 5.2 +/- 4.0%).(ABSTRACT TRUNCATED AT 250 WORDS)