Validation of Alzheimer’s disease CSF and plasma biological markers: The multicentre reliability study of the pilot European Alzheimer’s Disease Neuroimaging Initiative (E-ADNI)

Background

Alzheimer’s Disease Neuroimaging Initiatives (“ADNI”) aim to validate neuroimaging and biochemical markers of Alzheimer’s disease (AD). Data of the pilot European-ADNI (E-ADNI) biological marker programme of cerebrospinal fluid (CSF) and plasma candidate biomarkers are reported.

Methods

Six academic EADC centres recruited 49 subjects (healthy controls, subjects with mild cognitive impairment (MCI) and AD). We measured CSF β-amyloid 42 (CSF Aβ42), total tau-protein (t-tau), phosphorylated tau-proteins (P-tau181, P-tau231), plasma β-amyloid 40 and 42 (Aβ40/Aβ42). Immediate fresh shipment was compared to freezing and later shipment on dry ice.

Results

CSF T-tau (fresh samples) was increased in AD versus controls (p = 0.049), CSF Aβ42 (frozen samples) was decreased in MCI and AD (p = 0.02), as well as plasma Aβ40 (fresh and frozen samples) in AD (p = 0.049 and p = 0.016). Pooled values of neurochemical parameters and ratios thereof were different between centres (p < 0.005). Analysis of frozen samples yielded higher diagnostic accuracy than immediate fresh shipment with 100% (fresh: 100%) correctly classified in control subjects, 100% (78%) in MCI, 91% (91%) in AD.

Conclusion

The use of frozen rather than fresh samples renders higher diagnostic accuracy within a multicentre context. We confirmed the feasibility of a multicentre AD biomarker programme for future clinical trials.     

Hypertensive patients' willingness to participate in placebo-controlled trials: implications for recruitment efficiency

Background

Underenrollment and selective enrollment plague many clinical trials. Little is known about why hypertensive patients agree or refuse to participate in placebo-controlled trials (PCT) of antihypertensive drugs, whether the prospect of receiving placebo influences willingness to participate (WTP), or whether patients who participate differ from those who do not.

Methods

We described a hypothetical PCT of a new antihypertensive drug to 126 patients who would be eligible for ongoing phase III trials. We solicited patient motivations and concerns regarding trial participation by using open-ended questions, assessed the patients' stated WTP, and used logistic regression to determine patient characteristics associated with WTP. We reassessed WTP in 62 patients after revealing, in random order, that 10%, 30%, and 50% of patients would receive placebo.

Results

The most commonly cited motivations for participating included personal health benefits (40%), helping other patients (37%), and contributing to scientific knowledge (15%). The most common concerns were having to stop current medications (56%), inconvenience/annoyance (38%), fear of known side effects (35%), and the possibility of receiving placebo (24%). Overall, 47% of patients (95% confidence interval, 38% to 56%) were willing to participate. Younger patients (57% versus 37%; P = .01), nonsmokers (50% versus 24%; P = .04), and patients who had participated in research previously (77% versus 20%; P = .009) were all significantly more willing to participate. Fewer patients were willing to participate as the percentage who would receive placebo increased (P = .02), but randomly assigning fully half of patients to placebo still yielded maximal recruitment efficiency.

Conclusions

Hypertensive patients participate in trials for altruistic and personal health reasons. Differences between patients who do or do not participate may influence trial outcomes. The proportion of patients receiving placebo influences some patients' enrollment decisions but is not a key determinant of recruitment efficiency.     

Peroral endoscopic myotomy (POEM) for oesophageal achalasia: Preliminary results in humans

Background

Peroral endoscopic myotomy has been developed to provide a less invasive treatment for oesophageal achalasia compared to surgical cardiomyotomy.

Aims

To report our initial experience on feasibility, safety and clinical efficacy of peroral endoscopic myotomy.

Methods

Eleven patients (eight women, mean age 32, range 24–58) underwent an attempt at peroral endoscopic myotomy under general anaesthesia. After submucosal injection, a mucosal entry into the oesophageal submucosa, and a tunnel extending to the oesophagogastric junction and beyond into the stomach were created (total mean length: 15 ± 1.7 cm). Myotomy of the circular oesophageal and gastric muscle bundles was then achieved under direct vision (total mean length: 10.2 ± 2.8 cm). Haemostatic clips were used to close the mucosal entry. The Eckardt Score and manometry were used to evaluate the results.

Results

Peroral endoscopic myotomy could be completed in 10 out of 11 patients (91%). Mean procedure time was 100.7 min (range 75–140 min). No major complication occurred. Clinical success was achieved in all patients at 1-month follow-up (Eckardt Score 7.1 vs. 1.1, p = 0). Lower oesophageal sphincter pressure decreased from 45.1 to 16.9 mmHg (p = 0).

Conclusions

This initial experience with peroral endoscopic myotomy shows its safety and efficacy in the treatment of achalasia. Further studies are warranted to assess the long-term efficacy and to compare peroral endoscopic myotomy with other treatment modalities.     

Latent pulmonary inflammation in patients with systemic sclerosis

Background

Induced sputum is a non-invasive method for studying pulmonary inflammation.

Objectives

To assess pulmonary inflammation by analysis of induced sputum specimens in patients with systemic sclerosis and lung involvement, and to determine whether there is a correlation with the pulmonary function alterations in these patients.

Methods

Twenty-five patients with systemic sclerosis were included (20 women). Patients were divided into 3 groups according to the type of lung involvement: group 1, diffuse interstitial lung disease (n = 10); group 2, those with pulmonary arterial hypertension (n = 7), and group 3, patients with systemic sclerosis without lung involvement (n = 8). All patients underwent a complete lung function study. Induced sputum samples were obtained and differential cell count was performed by optic microscopy.

Results

The mean percentage of sputum neutrophils was 85%, 71%, and 75% for groups 1, 2, and 3, respectively. A significant negative correlation between sputum total cell count and DLCO was seen in group 1 and group 3 (r = – 0.733, P = .016; and r = – 0.893, P = .007, respectively). This negative correlation was not observed in group 2.

Conclusions

Pulmonary inflammation was present in all patients with systemic sclerosis included in the study, regardless of the presence of documented signs of pulmonary involvement. This finding suggests that induced sputum could be helpful for detecting early abnormalities indicative of subclinical pulmonary involvement in patients with systemic sclerosis.     

Attitudes towards new HIV biomedical prevention technologies among a cohort of HIV‐negative gay men in Sydney,Australia

Objectives

The aim of the study was to explore the awareness of rectal microbicides, the use of pre‐exposure prophylaxis (PREP) and the willingness to participate in biomedical HIV prevention trials in a cohort of HIV‐negative gay men.

Methods

In a community‐based cohort study, HIV‐negative homosexually active men in Sydney, Australia were questioned about awareness of rectal microbicides, use of PREP, and willingness to participate in trials of such products. Predictors of awareness and willingness to participate were analysed by logistic regression. Use of PREP was examined prospectively.

Results

Overall, 14% had heard of rectal microbicides. Older (P=0.05) and university‐educated men (P=0.001) were more likely to have knowledge of rectal microbicides. Almost one‐quarter (24%) of men reported that they were likely/very likely to participate in rectal microbicide trials. Among those men with definite opinions on participation, awareness of rectal microbicides was significantly associated with unwillingness to participate [odds ratio (OR) 0.78, 95% confidence interval (CI) 0.65–0.93, P=0.007]. Willingness to participate in trials using antiretroviral drugs (ARVs) to prevent HIV infection was reported by 43% of men, and was higher among those who reported unprotected anal intercourse (UAI) with HIV‐positive partners (OR 1.88, 95% CI 0.99–3.56). There was no evidence of current PREP use.

Conclusions

This study demonstrates that Australian gay men have had little experience with PREP use and rectal microbicides. About half would be willing to consider participation in trials using ARVs to prevent HIV infection. Extensive community education and consultation would be required before PREP or rectal microbicides could be trialled in populations of gay Australian men.

     

Timing of polyethylene glycol administration is a key factor in the tolerability and efficacy of colon preparation in colorectal cancer screening

Introduction

The quality and tolerability of antegrade gut lavage bowel preparation are key elements in the success of population-based colorectal cancer screening.

Objectives

To evaluate cleansing quality and tolerability according to the timing of polyethylene glycol administration in persons undergoing colorectal cancer screening.

Method

Participants in colorectal cancer screening were randomized to two groups: a) control group (colonoscopy scheduled at 9-12 h); preparation with polyethylene glycol on the previous afternoon; b) study group (colonoscopy scheduled at 12-15 h): preparation with polyethylene glycol on the morning of the colonoscopy, with the option of a split dose. The quality of cleansing was evaluated with the Boston scale and tolerability through a questionnaire.

Results

A total of 282 participants were included: preparation was carried out the day before the procedure in 134 and on the same day in 148, of which 26 received a split dose. Cleansing was adequate in 95% (n = 268) of the participants. The quality of cleansing was higher in the study group (P = .045). The interval between the end of administration and the beginning of the procedure was inversely correlated with the Boston scale score (P = .036; r = −0.125). Tolerability was unrelated to the time of administration (P > .2). Acceptance of the timing of administration was lower in the study group than in the control group (26% vs 10%, respectively; P = .001).

Conclusions

Preparation as close as possible to the colonoscopy improves the quality of cleansing with no detrimental effects on tolerability, although this option is less comfortable.     

Variability of respiratory symptoms in severe COPD

Introduction

While it is known that asthma symptoms have a very variable pattern, the general belief is that the respiratory symptoms in COPD patients usually present little or no variability. Nevertheless, COPD patients report having “bad days”. The objective of this present study was to evaluate the variability of the respiratory symptoms and their impact on the daily activities of a cohort of Spanish COPD patients.

Method

We present the results of the Spanish patients who participated in a cross-sectional epidemiological study carried out in 17 European countries. Pulmonologists and Family Care physicians recruited patients with stable severe COPD (FEV1 < 50%). The perception of the patients on the variation in their symptoms was recorded by telephone interviews.

Results

A total of 472 patients provided data that was valid for analysis. Mean age was 68.6; 93% were men; mean FEV1(%) was 41%. 84.1% of the patients experimented at least one respiratory symptom in the previous week and 60.9% affirmed that their symptoms varied over the course of the day or week. The moment of the day when the symptoms were perceived to be more intense was during the morning.

Conclusions

An important proportion of severe COPD patients perceive variability in their respiratory symptoms, with a greater intensity in the morning. The observation can have implications in treating patients with severe COPD as variability can be an initial sign of decompensation of the disease.     

Results of percutaneous radiofrequency ablation of hepatocellular carcinoma in patients with cirrhosis aged 75 years and over

Purpose

The objective of this study was to assess the results and tolerance of radiofrequency ablation in patients with cirrhosis and hepatocellular carcinoma (HCC) older than 75 years.

Patients and methods

Over a period of 9 years from January 2001, 235 patients with cirrhosis and 3 or less HCC ≤ 5 cm of diameter were treated by radiofrequency ablation. Among them, 52 patients older than 75 years were selected for this study.

Results

The mean age was 79.4 ± 3. 5 years. There were 36 males, cirrhosis was classified Child-Pugh class A (n = 52) related to alcohol (n = 13), HCV infection (n = 33), or other causes (n = 6). The mean tumour diameter was 32.5 ± 10,6 mm, and 14 patients had a multifocal HCC. A complete ablation was obtained in 50/52 patients (96%). No severe complication occurred. The estimated overall survival rates were 62%, 52% and 36% at 3 years, 4 years and 5 years, respectively; it was similar to those observed in patients younger than 75 years.

Conclusion

In patients with cirrhosis older than 75 years, radiofrequency ablation of 3 or less HCC ≤ 5 cm is well tolerated and survivals rates are similar to those of younger patients.     

Effect of fructose on postprandial triglycerides: A systematic review and meta-analysis of controlled feeding trials

Background

In the absence of consistent clinical evidence, concerns have been raised that fructose raises postprandial triglycerides.

Purpose

A systematic review and meta-analysis was conducted to assess the effect of fructose on postprandial triglycerides.

Data sources

Relevant studies were identified from MEDLINE, EMBASE, and Cochrane databases (through September 3, 2013).

Data selection

Relevant clinical trials of ≥7-days were included in the analysis.

Data extraction

Two independent reviewers extracted relevant data with disagreements reconciled by consensus. The Heyland Methodological Quality Score (MQS) assessed study quality. Data were pooled by the generic inverse variance method using random effects models and expressed as standardized mean differences (SMD) with 95% confidence intervals (CI). Heterogeneity was assessed (Cochran Q statistic) and quantified (I² statistic).

Data synthesis

Eligibility criteria were met by 14 isocaloric trials (n = 290), in which fructose was exchanged isocalorically for other carbohydrate in the diet, and two hypercaloric trials (n = 33), in which fructose supplemented the background diet with excess energy from high-dose fructose compared with the background diet alone (without the excess energy). There was no significant effect in the isocaloric trials (SMD: 0.14 [95% CI: −0.02, 0.30]) with evidence of considerable heterogeneity explained by a single trial. Hypercaloric trials, however, showed a significant postprandial triglyceride raising-effect of fructose (SMD: 0.65 [95% CI: 0.30, 1.01]).

Limitations

Most of the available trials were small, short, and of poor quality. Interpretation of the isocaloric trials is complicated by the large influence of a single trial.

Conclusions

Pooled analyses show that fructose in isocaloric exchange for other carbohydrate does not increase postprandial triglycerides, although an effect cannot be excluded under all conditions. Fructose providing excess energy does increase postprandial triglycerides. Larger, longer, and higher-quality trials are needed.

Protocol registration

ClinicalTrials.gov identifier, NCT01363791.     

Antisynthetase syndrome: a retrospective study of 14 patients

Purpose

Antisynthetase syndrome is a rare entity characterized by myositis (dermatomyositis or polymyositis), interstitial lung disease, arthritis, Raynaud's phenomena and mechanic's hands skin manifestation, and the presence of autoantibodies against aminoacyl-transfer RNA synthetase.

Patients and methods

Fourteen patients with antisynthetase syndrome followed-up between 1997 and 2009 were included. We studied retrospectively their clinical, radiological, and pathological findings.

Results

The sex ratio women/men was 2.5. Mean age at disease onset was 46 years. Arthritis (43%) and interstitial lung disease (38%) were the most frequent features at disease onset. Seven patients had myositis. Ten patients had anti-Jo1 autoantibodies, three had anti-PL7 and one anti-PL12. Corticosteroid therapy was given in all cases, immunosuppressive drugs in 12 cases, due to initial severity (n = 8), disease relapse (n = 3) or corticosteroid dependence (n = 1). After a mean follow-up of 64 months, nine patients improved, four stabilized and one patient died after lung transplantation, required for pulmonary hypertension.

Conclusion

The diffusion of immunologic assay will help us in the future to identify the specificity of this syndrome in order to improve care.     

Physical activity and cardiovascular risk factors in Spanish children aged 11-13 years

Introduction and objectives

The prevalence of childhood obesity has increased in recent decades. The aim was to determine whether a 3-month intervention on daily physical activity at school could affect body weight and cardiovascular risk factors associated with childhood obesity.

Methods

A total of 137 children (12[1] years old) volunteered to participate in an observational cross-sectional study. Children were allowed to join one of the following groups: a) sedentary group (2 h/week of physical education at school); b) active group (2 h/week of physical education at school plus 3 h/week extra physical activity), and c) sports group (2 h/week of physical education at school plus 5 h/week extra physical activity). Anthropometric characteristics, blood pressure, physical condition (estimated by the Course-Navette test), and biochemical parameters related with cardiovascular risk factors were determined.

Results

Body weight, body mass index, waist circumference, sum of skinfold thickness, body fat percentage, and fat mass index of children were decreased with high physical activity level, whereas body water content significantly increased with activity. Parameters related with cardiovascular risk —triglycerides, insulin, systolic blood pressure, and homeostatic model assessment index— presented lower values in the sports group. Maximal oxygen uptake and maximum heart rate (Course Navette test) progressively increased with activity. Children participating in a total of 7 h/week of physical activity presented significantly lower odds ratio of having high levels of the following cardiovascular risk factors: waist circumference, fat mass index, and homeostatic model assessment index.

Conclusions

Physical activity is important for metabolic health in children. Children with higher levels of physical activity presented better anthropometric and biochemical profiles.Full English text available from:www.revespcardiol.org     

Defining the severity of liver dysfunction in patients with hepatocellular carcinoma by the model for end-stage liver disease-derived systems

Background

The model for end-stage liver disease (MELD) and serum sodium (Na) are important markers for liver functional reserve in patients with hepatocellular carcinoma. We aimed to determine the best model to define the severity of liver dysfunction in terms of outcome prediction among the 4 currently used systems (MELD, MELDNa, MELD-Na and ReFit MELDNa).

Methods

A total of 2308 prospectively enrolled patients with hepatocellular carcinoma were analysed. The prognostic ability was compared by the Akaike information criterion.

Results

MELDNa had the best prognostic accuracy overall, and for patients receiving curative and non-curative treatments, followed by MELD-Na, MELD and ReFit MELDNa. When patients were categorized into <8, 8–12, 12–16, 16–20 and >20, the adjusted risk ratios for MELDNa were 1.065 (p = 0.46), 0.996 (p = 0.973), 1.38 (p = 0.048) and 1.563 (p = 0.003) for the scores of 8–12, 12–16, 16–20 and >20, respectively, compared to the group with scores <8. The adjusted risk ratio for MELDNa was 1.014 (95% confidence interval, 1.001–1.027; p = 0.034) per unit score increment in the Cox model.

Conclusions

The MELDNa is the best marker to define the severity of liver dysfunction in hepatocellular carcinoma patients independent of treatment strategy. The ReFit MELDNa does not enhance the predictive accuracy of the MELD.     

Short-term practice effects and variability in cognitive testing in a healthy elderly population

Background

Cognitive decline in the elderly is a subject of intense focus. However, there is a lack of consensus regarding definition of significant decline in connection with repeated testing and the interpretation of cognitive tests results must take into account the practice effect and variability in test performance.The aim of this study was to collect cognitive test results with repeated testing in an elderly healthy population.

Methods

161 healthy controls ≥ 60 years were included. Cognitive testing was performed upon entry into the study, at 1 week and 3 months. Practice effect was evaluated on 7 neuropsychological measures and reference values of clinically important changes were calculated according to z-scores above 1.96.

Results

Test scores improved significantly (p < 0.05) in 2 of 7 measures between baseline and 2nd test and in 6 of 7 measures between baseline and 3rd test session. No significant correlation was found between magnitude of practice effect and age or educational status.

Conclusion

Practice effect and variability in cognitive testing in the elderly are important to consider when evaluating changes in cognitive performance over a short period of time.     

Association of serum uric acid with body mass index among long-lived Chinese

Objectives

To examine the individual association between BMI and level of serum uric acid (SUA) among the very elderly Chinese population.

Methods

A survey was conducted on 870 long-lived subjects (aged ≥ 90 years). Subjects were divided into four groups according to quartile of BMI (< 16.6, 16.6–18.9, 18.9–21.1, ≥ 21.1 kg/m²) and to classification criteria of underweight, normal weight, overweight and obesity in BMI (< 18.5, 18.5–23.0, 23.0–27.5, ≥ 27.5 kg/m², respectively). Subjects were also divided into hyperuricemia and normal SUA groups.

Results

The sample included 661 unrelated Chinese. The mean age was 93.52 ± 3.29 years (range 90–108 years). The mean level of BMI was 19.16 ± 3.47 kg/m² and mean SUA was 318.72 ± 87.01. Compared to individuals without hyperuricemia, high level of SUA was associated with a higher level of BMI in both genders (p < 0.001). According to the both BMI classification criteria, the group with higher BMI had higher level of SUA (p < 0.001). Pearson correlation showed that SUA was significantly correlated with BMI (with coefficients r = 0.235, 0.140, in men and women, respectively). Unadjusted and adjusted multiple logistic regressions showed that odds ratios for hyperuricemia were associated with BMI according to quartile of BMI.

Conclusions

We found that among long-lived Chinese subjects, higher levels of SUA may be associated with higher BMI.     

Somatostatin receptor sst2 gene transfer in human prolactinomas in vitro: impact on sensitivity to dopamine, somatostatin and dopastatin, in the control of prolactin secretion

Objective

As prolactinomas fail to respond to dopamine agonist (DA) in 10–20% of cases, we hypothesized that somatostatin subtype 2 receptor (sst2) overexpression in DA-resistant prolactinomas may enhance suppression of prolactine (PRL) using chimeric agonist (dopastatin) that simultaneously binds sst2 and the dopamine subtype 2 receptor (D2DR).

Design and methods

PRL suppression by octreotide, sst5 agonist, sst2-D2DR agonist (BIM-23A760 dopastatin) and cabergoline was assessed in primary cultures of seven DA-resistant prolactinomas overexpressing sst2.

Results

sst2 was effectively overexpressed via adenoviral expression in prolactinomas (38.1 ± 7.4 vs. 0.1 ± 0.1 copy/copy β-Gus) and induced octreotide sst2-mediated PRL suppression that remained lower than that induced by DA. BIM-23A760 inhibited PRL similarly to cabergoline both in the control and sst2-expressing cells. Antagonist experiments confirmed predominant dopaminergic effect in dopastatin activity.

Conclusion

sst2 was successfully overexpressed in prolactinomas. However BIM-23A760 was unable to enhance PRL suppression underlining a predominant dopaminergic contribution in its action.     

Smoking in non-student Mexican adolescents with asthma: relation with family structure, educational level, parental approval of smoking, parents who smoke, and smoking friends

Introduction

The association between some factors of the familial and social environment with smoking in non-student adolescents with asthma has not been explored. The aim of the study was to determine the association between family structure, educational level, parental approval of smoking, parents who smoke, and smoking friends with smoking in non-student adolescents with asthma.

Subjects and methods

In a cross-sectional study, data were obtained by means of a structured questionnaire applied to 4,778 non-student adolescents aged 13–18 years. Diagnosis of asthma was performed using a questionnaire based on the International Study of Asthma and Allergy in Childhood questionnaire. The smoking habit was determined by application of a self-administered questionnaire. Odds ratios (OR) were determined for smoking using logistic regression.

Results

From the total sample, asthma prevalence was 6.6% and of active smoking, 34.2%. Age at initiation of asthma symptoms was 5.15 ± 3.52 years, and that of active smoking was 13.65 ± 2.07 years. Percentage of non-intact family (40.1 vs. 32.7%) was greater in the group of adolescents with asthma. Logistic regression models show that parental approval of smoking (adjusted OR = 5.57; 95% confidence interval = 2.48–12.51) and smoking friends (adjusted OR = 2.92; 95% confidence interval = 1.04–8.19) are associated with smoking in non-student adolescents with asthma.

Conclusion

In this study, parental approval of smoking and having friends who smoke appear to be associated with smoking among non-student adolescents with asthma.     

Internal consistency and validity of the Spanish version of the "Quebec Sleep Questionnaire" quality-of-life questionnaire for obstructive sleep apnea

Introduction

There is no specific health-related quality of life (HRQL) questionnaire that has been validated in Spanish for its use in patients with sleep apnea-hypopnea syndrome (SAHS). The objective of the present study was to validate the Spanish version of the Quebec Sleep Questionnaire (QSQ).

Patients and methods

A multi-center study including a group of patients with SAHS (AHI ≥ 5) referred to the Sleep Unit. All patients completed the following questionnaires: SF-36, FOSQ, QSQ and Epworth scale. Internal consistency, construct validity, concurrent validity, predictive validity, repeatability and responsiveness to change of the QSQ (32 items in five domains: daytime sleepiness, diurnal symptoms, nocturnal symptoms, emotions, and social interactions) were assessed.

Results

A hundred twenty one patients were included in the study (mean age: 57 ± 13; mean Epworth: 9 ± 4; mean Body Mass Index (BMI): 28 ± 3 kg · m⁻² and mean AHI: 36 ± 20 hour⁻¹). The factorial analysis showed a construct of five factors with similar distribution to the original questionnaire domains. Internal consistency (Cranach's alpha between 0.78 and 0.93 for the different domains), concurrent validity (compared to SF-36, Epworth scale and FOSQ), predictive validity of SAHS severity and test-retest reliability were appropriate. The test showed good responsiveness to change in diurnal (P = .003) and nocturnal symptoms domains (P = .02).

Conclusions

The Spanish version of the QSQ is a valid HRQL measure with appropriate psychometric properties for use in patients with SAHS and is responsive to change in symptoms domains.     

C-peptide induces human renal mesangial cell proliferation in vitro, activating Src-kinase, PI-3 kinase and ERK1/2

Background

Elevated levels of C-peptide have been found in patients with insulin resistance and early type 2 diabetes. These patients are at greater risk to develop micro- and macrovascular complications. Since diabetic nephropathy involves glomerular hyperproliferation, the present study evaluates the role of C-peptide on human renal mesangial cell proliferation.

Methods and results

C-peptide induces proliferation of human renal mesangial cells in a concentration-dependent manner with a maximal 2.6 ± 0.4-fold induction at 10 nmol/L (P < 0.05 compared with unstimulated cells; n = 6), as revealed by [3H]-thymidine incorporation experiments. The proliferative effect of C-peptide is prevented by Src-kinase inhibitor-PP2, PI-3 kinase inhibitor-LY294002, and the ERK1/2 inhibitor-U126. Moreover, C-peptide induces phosphorylation of Src, as well as activation of PI-3 kinase and ERK1/2. Furthermore, C-peptide induces cyclin D1 expression as well as phosphorylation of retinoblastoma protein (Rb).

Conclusions

These results demonstrate an active role of C-peptide on the proliferation of human renal mesangial cells in vitro involving PI-3 kinase and MAP kinase signaling pathways, suggesting a possible role of C-peptide in glomerular hyperproliferation in patients with diabetic nephropathy.     

The cortisol awakening response is related with PERIOD1 clock gene expression in older women

Background and objective

The cortisol awakening response (CAR) is a useful endocrine marker for the hypothalamic–pituitary–adrenal axis activity. Recent studies suggest that the cortisol level influences the expression of the hPER1 clock gene which is involved in the generation of biological rhythms. This study aimed to analyze the relationship between CAR and hPER1 gene expression with respect to human aging.

Subjects and methods

Salivary cortisol levels were determined in 20 older women (mean age ± SD, 67.9 ± 5.12 yrs) and 30 young women (24.4 ± 2.13 yrs) at awakening (T0) and at 15 min, 30 min, 45 min, and 60 min after awakening (T15, T30, T45, T60) by enzyme linked immunosorbent assay. CAR was calculated as difference of the cortisol levels at T0 and T30. The expression of the hPER1 gene at 0800 h was determined from oral mucosa cells by relative quantification using h36B4 as house-keeping gene. Additional variables, which may affect the CAR, were assessed by questionnaire. Relationships between CAR and other variables were analyzed by correlation and regression analyses.

Results

Older women showed significantly lower mean cortisol levels than young women at all five time points (P < 0.05 to P < 0.01). The cortisol levels at T30, T45, and T60 correlated positively and significantly with hPER1 gene expression in older women (each, P < 0.01), but not in young women. In both older and young women, the CAR correlated positively with the hPER1 gene expression. This relationship was very strong in older women (r = − 0.90, P < 0.001) and non-significant in young women (r = 0.33, P = 0.390). Regression analysis showed that hPER1 gene expression was the only significant predictor of CAR (r² = 0.798, SEM = 0.07, P < 0.001) in older women.

Conclusions

The present study documents the influence of cortisol secretion on hPER1 gene expression in older women. The morning cortisol increase as indicated by CAR correlated positively and significantly with hPER1 gene expression in older women suggesting that hPER1 expression increases in response to the morning cortisol increase in older women. The higher hPER1 response to cortisol increase in older women could be due to the finding that the hPER1 response to cortisol increase seems to be sensitive only at low cortisol levels, but not at higher cortisol levels. This would explain why the older women with low cortisol levels showed an increase of hPER1 expression with increasing cortisol level, whereas young women with higher cortisol levels did not.     

Low level laser therapy (830nm) improves bone repair in osteoporotic rats: similar outcomes at two different dosages

Background and objective

The goal of this study was to investigate the effects of low level laser therapy (LLLT) in osteoporotic rats by means of subjective histopathological analysis, deposition of collagen at the site of fracture, biomechanical properties and immunohistochemistry for COX-2, Cbfa-1 and VEGF.

Material and methods

A total of 30 female Wistar rats (12 weeks-old, ± 250 g) were submitted to ovariectomy (OVX). Eight weeks after the OVX, a tibial bone defect was created in all animals and they were randomly divided into 3 groups (n = 10): control bone defect group (CG): bone defects without any treatment; laser 60 J/cm² group (L60): animals irradiated with LLLT, at 60 J/cm² and laser 120 J/cm² group (L120): animals irradiated with LLLT, at 120 J/cm².

Results

In the laser treated groups, at both fluences, a higher amount of newly formed bone was evidenced as well as granulation tissue compared to control. Picrosirius analysis demonstrated that irradiated animals presented a higher deposition of collagen fibers and a better organization of these fibers when compared to other groups, mainly at 120 J/cm². COX-2, Cbfa-1 or VEGF immunoreactivity was detected in a similar manner either 60 J/cm² or 120 J/cm² fluences. However, no differences were shown in the biomechanical analysis.

Conclusion

Taken together, our results support the notion that LLLT improves bone repair in the tibia of osteoporotic rats as a result of stimulation of the newly formed bone, fibrovascularization and angiogenesis.