Host-derived pentapeptide affecting adhesion, proliferation, and local pH in biofilm communities composed of Streptococcus and Actinomyces species

Salivary proline-rich proteins (PRPs) attach commensal Actinomyces and Streptococcus species to teeth. Here, gel filtration, mass spectrometry and Edman degradation were applied to show the release of a pentapeptide, RGRPQ, from PRP-1 upon proteolysis by Streptococcus gordonii. Moreover, synthetic RGRPQ and derivatives were used to investigate associated innate properties and responsible motifs. The RGRPQ peptide increased 2.5-fold the growth rate of S. gordonii via a Q-dependent sequence motif and selectively stimulated oral colonization of this organism in a rat model in vivo. In contrast, the growth of Streptococcus mutans, implicated in caries, was not affected. While the entire RGRPQ sequence was required to block sucrose-induced pH-decrease by S. gordonii and S. mutans, the N-terminal Arg residue mediated the pH increase (i.e., ammonia production) by S. gordonii alone (which exhibits Arg catabolism to ammonia). Strains of commensal viridans streptococci exhibited PRP degradation and Arg catabolism, whereas cariogenic species did not. The RGRPQ peptide mediated via a differential Q-dependent sequence motif, adhesion inhibition, and desorption of PRP-1-binding strains of A. naeslundii genospecies 2 (5 of 10 strains) but not of S. gordonii (n=5). The inhibitable A. naeslundii strains alone displayed the same binding profile as S. gordonii to hybrid peptides terminating in RGRPQ or GQSPQ, derived from the middle or C-terminal segments of PRP-1. The present findings indicate the presence of a host-bacterium interaction in which a host peptide released by bacterial proteolysis affects key properties in biofilm formation.     

Subjective and objective measures of function and return to work: an observational study with a clinical psychiatric cohort

Purpose

To evaluate the association between two measurement tools (Social and Occupational Functioning Assessment Scale, SOFAS and Sheehan Disability Scale, SDS), returning to work (RTW) and their inter-correlation.

Methods

132 psychiatric patients referred to assessment of work ability participated. The association between SOFAS and SDS Work to RTW were assessed by logistic regression. Inter-correlations between SOFAS and SDS were assessed with the Spearman’s rho correlation coefficient.

Results

SOFAS and SDS Work scores were associated with a 1-year RTW and SOFAS and SDS were inter-correlated.

Conclusions

When assigning the ability to work, both subjective and objective measures of function predict RTW.

     

The effects of whey protein on myostatin and cell cycle-related gene expression responses to a single heavy resistance exercise bout in trained older men

Myostatin decreases muscle mass and this is accomplished, in part, by inhibiting muscle satellite cell proliferation and differentiation by regulating the expression of cell cycle-related proteins (e.g. p21 and cdk2) and myogenic regulatory factors (e.g. myogenin and MyoD). The purpose of this investigation was to determine whether protein ingestion before and after a resistance exercise (RE) bout affects myostatin and cell cycle-related gene expression. Strength-trained middle-aged to older men were divided into a protein group (61.4 ± 4.3 years, n = 9) or a placebo group (62.1 ± 4.2 years, n = 9). Muscle biopsies from the vastus lateralis muscle were taken at rest and 1 and 48 h after a 5 × 10 repetition leg press RE bout. Protein (15 g whey) or non-caloric placebo was taken immediately before and after the RE bout. mRNA expression levels of myostatin and related genes (AcvrIIb, FLRG, p21, p27, cdk2, myogenin and MyoD) were determined by Taqman probe-based real-time RT-PCR and normalized to GAPDH mRNA. Myostatin mRNA decreased after a RE bout, but only in the placebo group (P ≤ 0.05). Conversely, myostatin-binding protein FLRG and cell-cycle kinase cdk2 mRNA increased only in the protein group (P ≤ 0.05). p21 mRNA was increased at 1 h post-RE in placebo (P ≤ 0.05) and tended to be increased in the protein group (P = 0.08). Myostatin, its binding protein and cell cycle-related gene expressions are affected by single RE bout and these responses are further modified by whey protein intake. Therefore, controlling nutrition intake is important when studying gene expression responses to exercise.     

Early detection of COPD combined with individualized counselling for smoking cessation: A two-year prospective study

Objective

Though the prevalence of COPD is related to the definition, even with this proviso COPD remains under-diagnosed. Screening can detect many new COPD cases, but its effects on smoking cessation remain unknown.

Design

To evaluate symptoms in “healthy” cigarette smokers, to screen new COPD cases using international and national guidelines, and to assess the success of a smoking cessation.

Subjects

Healthy asymptomatic smokers with a >20 pack-years smoking history were recruited. The first visit included a standardized personal interview, Fagerstom nicotine dependence test (FNDT) and individualized smoking counselling by Motivational Interviewing. At the follow-up visit two years later, the same analyses were repeated and smoking status assessed. To avoid bias in the counselling attributable to spirometry, the test was evaluated at the two-year follow-up assessment.

Results

Almost all, 93.2%, of 584 participants attended the second visit. Spirometry revealed COPD by GOLD criteria in 11.0% and by national guidelines in 15.3%, mid-expiratory flow (MEF50) had significantly declined in 19.5%, chronic cough or sputum production was detected in 62% of the subjects. After two years, 23.3% had succeeded in giving up smoking. There were four predictors of successful quitting, i.e. positive attitude to the intervention, pharmacotherapy, older age, and higher BMI, whereas other factors such as cough, obstruction, gender, pack-years, or nicotine dependence showed no association with ability to achieve successful cessation.

Conclusion

Significant numbers of “healthy” smokers experience symptoms, according to detailed questionnaires, and have COPD. Motivation is the most significant factor in determining the chance of stopping smoking.Key Words: COPD, GOLD, Motivational Interviewing, screening, smoking counselling, spirometryScreening can detect many new COPD cases, but its effects on smoking cessation and disease progression are unknown.

• Significant numbers of “asymptomatic” smokers (n = 544) with a >20-year smoking history actually experienced symptoms, >10% had COPD.
• One individualized counselling using the technique of Motivational Interviewing combined with pharmaceutical therapies achieved 23% success in smoking cessation.
• The rate of success displayed a clear association with motivation and with pharmacotherapy but not with the extent of airway obstruction.

It is well known that the prevalence of chronic obstructive pulmonary disease (COPD) is related to which definition/classification is in use [1], but nonetheless COPD is under-diagnosed. There is wide debate not only about the best COPD definition, but especially on the role of screening of COPD [2–4]. Globally the prevalence and mortality of COPD is predicted to increase [5], and thus there is an urgent need to identify efficient ways for smoking cessation.COPD is internationally classified by GOLD criteria (Global Initiative for Chronic Obstructive Lung Disease) available from http://www.goldcopd.com, (see also Rabe et al. [6]). The fixed FEV1/FVC limit in the GOLD criteria can cause COPD over-diagnosis in older individuals [7,8], though there are also results indicating that GOLD criteria can also identify at-risk patients in this population [6,9]. It is virtually impossible to adapt international post-bronchodilator reference values, since earlier databases do not contain post-bronchodilator investigations [10]. In addition, GOLD Stage 0, i.e. those subjects with chronic cough and sputum production but a normal FEV1/FVC ratio, have been omitted from the newest GOLD guidelines [11–13]. On the other hand, recent results suggest that symptoms such as chronic cough and sputum production may precede COPD development and/or be associated with increased mortality [14–17]. The evaluation of mid-expiratory flow (MEF 50) may reflect early COPD but it is subject to extensive variability, it is effort dependent, and its association with other spirometric values or symptoms characteristic for COPD is unknown. Despite the problems in MEF assessment [18], it has been found to have significance at least in the differentiation between asthma and COPD [19].COPD screening is not recommended in the US Preventive Services Task Force (USPSTF) Guidelines [2], largely because of concerns about the cost/benefits/harms in screening for COPD (time and effort required by both patients and the healthcare system, false positive screening tests, and adverse effects of subsequent unnecessary therapy). However, this has to be balanced against the huge costs of treating individuals with severe COPD and hospitalizations [20]. The recommendation by USPSTF is in agreement with those of the American College of Physicians [21], but ATS/ERS or GOLD recommendations do not strictly forbid COPD screening ([3], http://www.GOLD.com). Some studies do indicate that success in smoking cessation is higher in those subjects with airway obstruction but these studies have investigated the lung function values before the smoking cessation counselling [22–24]. It has been claimed that those studies are biased because the type of counselling provided may have been dependent on the lung function values themselves [25].This study was undertaken to focus on the diagnosis of early COPD in a group of smokers who considered themselves as symptom-free and healthy with no diagnosed diseases or medications, and to assess what factors influenced their success in quitting smoking in a two-year prospective follow-up. Spirometry with bronchodilatation was only conducted as part of the second visit, in order to avoid any bias attributable to knowledge of the extent of obstruction on the success of smoking cessation.     

Effects of age and life-time physical training on fibre composition of slow and fast skeletal muscle in rats

The effects of age and endurance training on muscle fibre characteristics were studied in a slow (m. soleus, MS) and in a fast (m. rectus femoris, MRF) skeletal muscle. Wistar rats at ages of 1, 2, 4, 10, and 24 months were used as experimental animals. The trained rats were put to run on a motor-driven treadmill 5 d/wk beginning from the age of 1 month. The body weights of the animals increased continuously throughout their lives. The muscle weights increased up to the age of 10 months, after which they tended to decrease. The trained adult rats had lower body weights as well as lower muscle weights than the untrained adult rats. The amount of the intramuscular lipid decreased with age, especially during the first months of life. The activity of isocitrate dehydrogenase (ICDH) decreased during the growth period in both muscles and remained more or less constant thereafter, whereas the activity of phosphofructokinase decreased with age only in MS. In MS, the trained animals tended to have higher ICDH activities than the untrained animals. The cross-sectional area of the different fibre types in both muscles increased up to the age of 10 months. The major fibre types, type I in MS and type IIB in MRF, were smaller for trained than untrained rats. The percentage number of the slower fibre types of both muscles — type I in MS and types I and IIA in MRF —increased with advancing age. The muscles of the trained animals contained higher percentages of the slower fibre types than those of the untrained rats. The present paper indirectly supports the opinion that not only the metabolic but also the contractile properties of different muscle cell types can be changed by age and long-term endurance-type physical training.     

Saliva flow rate, amylase activity, and protein and electrolyte concentrations in saliva after acute alcohol consumption

OBJECTIVE: The aim of our study was to evaluate the effects of acute alcohol consumption on saliva secretion rate and selected salivary parameters in healthy nonalcoholic volunteers. STUDY DESIGN: Twenty-four volunteers (37.7 +/- 9.6 years, mean +/- SD) consumed 0.6 g or 0.7 g alcohol/kg of body weight (for women and men, respectively) in a soft drink. Saliva samples were collected, first (S0) before any alcohol was consumed, 45 minutes after consumption (S1) and, finally, 60 minutes after S1 (S2). Flow rates of both resting whole saliva and paraffin-stimulated (SWS) whole saliva were assessed. SWS was assessed for amylase, total protein, inorganic phosphate (PO4(3-)), sodium (Na+), potassium (K+), and calcium (Ca2+) content. RESULTS: SWS, but not resting whole saliva (in milliliters/minute), decreased significantly after consumption of alcohol. Amylase activity (P =.010) and the concentrations of Na+ (P =.000) and Ca2+ (P =.002) decreased significantly between S0 and S1. When SWS was analyzed for output, the total protein concentration (S0 to S1, P =.000; S0 to S2, P =.033) and amylase activity (S0 to S1, P =.000) decreased significantly. Further, the output of all the studied electrolytes decreased significantly as blood alcohol concentration increased. CONCLUSIONS: We conclude that acute alcohol consumption causes a decrease in SWS flow rate. The decrease in flow rate also results in impaired output of total protein and amylase, as well as in a decrease in the output of electrolytes.     

Effects of bovine immune and non-immune whey preparations on the composition and pH response of human dental plaque

Colostral products from non-immunized cows (CP) and cows immunized with mutans streptococci (IP) were used as mouth rinses in a short-term human study. The acidogenic potential of the products was tested and found to be negligible in vivo before application to subsequent rinsing tests. At first, all the participants received a professional tooth cleaning, after which they rinsed with one of the solutions (IP; CP; water) three times per day for 3 d. After each rinsing period, the resting pH and decrease in plaque pH after sucrose challenge were determined, the amount of plaque was estimated, and all available plaque was collected. No significant differences were recorded in the composition or in the amounts of accumulated plaque. The resting pH values of plaques with low "innate" pH were increased after the IP rinsing period. Surprisingly, the lowest pH values after the sucrose challenge were recorded in IP plaques. The number of cultivable facultative flora or total streptococci were not affected by different rinsings, but the relative number of mutans streptococci significantly decreased after the IP rinsing period when compared to the CP period. Thus, the short term rinsing indicates favourable effects of bovine immune whey on human dental plaque.     

Traumatic injuries of children and adolescents--are they associated with psychiatric contacts?

Our aim was to investigate whether a large number of hospital visits by children and adolescents because of injuries are associated with psychiatric treatments and subsequent suicides. We examined the case records of 250 randomly chosen patients, 156 (62%) boys and 94 (38%) girls, out of 2306 outpatients who were 0-16 years old and had been treated because of traumatic injuries in Oulu University Hospital in 1984 and were alive in 1997. Boys with seven or more accidents had had psychiatric treatments more commonly than did boys with fewer accidents (39% vs. 8%). In addition, the case records of the patients who had died before the end of 1997 out of the 2306 patients were examined. Twenty-one (0.9%) patients (20 males and one female) had died, and seven (0.3%) of them had committed suicide. The traumatically injured male patients had a twofold suicide rate compared to the national average. The researchers also re-coded the causes of death from the death certificates. There seems to be a tendency to interpret adolescent suicides as accidental, as one of the seven registered suicides (14%), but six of the seven re-coded suicides (86%) had occurred before the age of 20.