An alternative method for measuring total respiratory resistance during quiet breathing: a feasibility and validation study

OBJECTIVE

Determining the respiratory system's mechanical properties with minimal patient effort has been an important field of investigation addressing patients unable to perform pulmonary function testing and in light of the preventive measures due to the recent pandemic. The current study aimed to present an alternative method for total respiratory resistance measurement during tidal breathing, compare it with airway resistance (Raw), measured by body plethysmography, and validate the procedure in three groups of subjects with normal, constrictive and obstructive respiratory patterns in spirometry.

PATIENTS AND METHODS

We developed an alternative method of assessing total respiratory resistance during quiet breathing. After manufacturing the appropriate hardware apparatus, we applied a steady extrinsic resistance (ΔR) for 100-200 m/s during tidal breathing. Α theoretical mathematical model allowed measurement of total respiratory resistance (Rtot) during inspiration (Rin) and expiration (Rex). To validate the method, 15 individuals were enrolled and assigned to the normal, obstructive and restrictive groups based on their spirometry patterns. All groups participated in two sets of measurements, the plethysmographic and novel method. Finally, respiratory resistance measurements were compared between groups and methods.

RESULTS

The method was successfully developed, and Rtot measurements were recorded in five normal subjects and in five obstructive and restrictive subjects. Mean Rin and mean Rex were 4.99 cm H2O/L/sec and 4.42 cm H2O/L/sec in the healthy, 4.87 cm H2O/L/sec, and 6.63 cm H2O/L/sec in the obstructive and 5.97 cm H2O/L/sec and 4.12 cm H2O/L/sec in the restrictive group, respectively. Rex was notably higher than Rin in the obstructive group and was positively correlated with Raw (p<0.005, r=0.47).

CONCLUSIONS

This method provides the theoretical background for a plausible alternative tool for accessing a mechanical parameter of the respiratory system, which is easy to perform and requires only passive patient cooperation while enabling rough differentiation between obstructive and restrictive disorders. The model's feasibility potential in a real-life setting was studied in a small sample, and additional implementation and validation of the method in a larger population are guaranteed.

Resilience of the hellenic navy SEALs assessed by heart rate variability during cognitve tasks

Background

The interaction between high physical performance under extreme conditions and simultaneous control of the cognitive executive functioning has been a subject of research in literature for the past few decades. Stroop test and Heart-rate variability (HRV), have been verified clinical tools for the assessment of cerebral and autonomic/ cardiovascular stress responses respectively.

Purpose

The investigation of HRV adaptive response to stress and cognitive stress resilience under extremely strenuous conditions.

Methods

34 consecutive subjects were enrolled. Of them, 18 were candidates under intense preparation for their enlistment in the Hellenic Navy SEALs (HNS) and 16 were healthy controls (HC). All subjects underwent stroop tasks, along with mental state and personality examination. HRV variables in time and frequency domains recordings were acquired, during each aforementioned cognitive testing procedure.

Results

HNS's performance on both cognitive and emotion stroop tasks were equivalent to controls. During the size comparison of the number stroop and emotion stroop, HC had statistically significantly higher power content at different HRV frequency bands compared to HNS participants (p=0.036 and p=0.06 respectively). Finally, in a between group comparison of the psychometric tools, HNS had significantly higher somatization (p&lt;0.01), anxiety (p=0.037) and neuroticism (p=0.047) than HC. Correlation was conducted for each group separately, between the psychometric tools and the measurements of HRV for both number and emotion stroop. Moderate negative correlations were found between SDNN (Standard deviation of normal-to-normal RR-intervals) during the size comparison of number stroop and three out of nine categories of psychometric questionnaire; somatization (r(23)=−0.452, p&lt;0.05), anxiety (r(23)=−0.457, p&lt;0.05) and hostility (r(23)=−0.445, p&lt;0.05)

Conclusion

The above findings suggest that HNS display flexibility in their autonomic regulation during cognitive and emotional tasks. This characteristic is closely related to problem solving or adaptability skills. Additionally, HRV can be a promising clinical index regarding the assessment of psychophysiological resilience especially in the neurovisceral integration (NVI) model.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Region of Attica

Endocannabinoids and heart rate variability alterations after exposure to prolonged intensive physical exercise of the Hellenic Navy SEALs

Background

Recent research indicates that endocanabinoids (eCB) and heart rate variability (HRV) are associated with stress-induced experiences. However, these underlying mechanisms have not been elucidated.

Purpose

The aim of the present study is to investigate if exposure to acute and chronic stress promotes measurable changes concurrently to the peripheral eCB ligands and the HRV.

Methods

13 candidates under intense preparation for their enlistment in the Hellenic Navy SEALs (H.N.S.) participated in the study. All subjects underwent mental state examination, while HRV variables in time and frequency domains recordings were acquired. Furthermore, at baseline and 30 days after prolonged and intensive physical exercise hair were collected in order to measure eCB ligands, such as anandamide (AEA), 2-arachidonoylglycerol (2-AG), and the N-acyl ethanolamine (NAE) molecules: palmitoylethanolamide (PEA) and oleoylethanolamide (OEA).

Results

Comparing basal hair concentrations of eCB ligands before and after intensive physical exercise, we found that AEA, PEA and OEA were notably increased (p&lt;0.01, p&lt;0.05 and p&lt;0.01 respectively) whereas no differences were observed regarding the ligand 2-AG. Regarding time domain features of HRV, a strong positive correlation was found between mean HR, AEA and PEA [r(13)=0.934, p&lt;0.05, (r(13)=0.902, p&lt;0.05]. Regarding frequency domain, a strong negative correlation was found between low frequency (LF) HRV and PEA (r(13)=−0.853, p&lt;0.01). No statistically significant associations were noted between high frequency HRV and EC ligands.

Conclusions

These findings suggest that endocannabinoid-HRV interrelations might share a short-term, and long-term adaptability of the changes in self-regulation associated with stress. Further studies are required to determine the validity of peripheral eCB signaling and HRV as a biomarker for different aspects of stress response.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Region of Attica

B-cell Activating Factor Polymorphisms in Rheumatoid Arthritis-Associated Atherosclerosis

Rheumatoid Arthritis (RA) is a common chronic inflammatory disorder affecting 0,5-1% of the population, characterised by intense cellular activation and inflammation in the affected joints ultimately leading to bone and cartilage destruction. Cardiovascular disease is the leading cause of death among patients suffering from RA, with chronic inflammation and genetic background emerging as major predisposing factors. Although the pathogenetic events leading to an increased rate of atherosclerosis in the affected group are not precisely described, several genetic variations have been suggested as possible mediators of this process. The aim of the current research proposal is to investigate the role of B-cell activating factor (BAFF) variants in the pathogenesis of RA-related atherosclerosis. Stored DNA samples from the Biobank in the Department of Physiology of the Medical School of the University of Athens from RA individuals and healthy controls will be analysed for polymorphisms of B-cell activating factor (BAFF) by polymeric chain reaction (PCR) based assays. Detection of plaque formation and calculation of the mean intima media thickness (mIMT) of the vessel wall will be performed in RA patients by using carotid and femoral artery ultrasonography. Complete personal and family history, biochemical and serological markers will be obtained from the RA group and associated with the genetic and IMT data. The results will be compared across the different subgroups in order to determine whether any particular genetic variants can act as prognostic markers for RA-related cardiovascular disease giving eventually new insights to atherosclerotic processes in the context of chronic inflammatory diseases. Such a result would invariably lead to a possible new treatment approach and/or prevention method to benefit this group of patients.

P–676 Mild stimulation followed by embryo accumulation via vitrification appears to be beneficial for managing poor ovarian response: A retrospective cohort study including 610 patients

Study question

Could embryo accumulation employing mild stimulation cycles prove beneficial for managing patients presenting with poor ovarian response (POR)?

Summary answer

Embryo accumulation may be an efficient POR management strategy, enabling a higher number and quality cohort of embryos, ultimately improving success results.

What is known already

It is widely accepted that POR constitutes a challenging condition. The limited oocyte yield associated with POR detrimentally impacts in vitro fertilization (IVF) success rates. Moreover, the documented heterogeneity among POR patients compromises our efforts to successfully address POR, despite the advances noted regarding stimulation protocols employed today. Considering the aforementioned, embryo accumulation following consecutive stimulation cycles has emerged as an alternative management strategy towards increasing the number of available embryos prior to embryo transfer (ET), mimicking normoresponding conditions. However, only few studies have been so far conducted and the need for further data is underlined.

Study design, size, duration

A single-center retrospective study was conducted in the Centre of Human Reproduction, Genesis-Athens Clinic from January 2015-December 2019. Only patients presenting with POR according to Bologna criteria were included. In total, 610 POR patients were considered eligible and were divided in three groups namely, mild stimulation-fresh ET (150 IUs of gonadotropins) (MILDF), mild stimulation employing embryo accumulation (MILDA), and natural cycle employing embryo accumulation (NATA). Respective comparisons on embryology and pregnancy data are provided.

Participants/materials, setting, methods

Resulting embryos from the MILDF, MILDA, and NATA groups were cultured up to the cleavage stage and categorized into three groups according to quality, namely top (grade 1), good (grade 2–3) and poor (grade 4–5) (Veeck, 1999). Top and good quality embryos were considered eligible for ET/vitrification. The banking scenario entailed accumulation of at least three embryos, including at least one top quality embryo. Embryo transfers included up to two cleavage stage embryos.

Main results and the role of chance

Comparing MILDF and MILDA groups, a higher number of available oocytes and embryos was observed in MILDA (2.36±1.15 vs 6.58±1.11; 1.72±1.02 vs 3.51±0.61, P-value&lt;0.001). However, a mean number of 3.90±1.56 oocyte retrievals were required to conclude MILDA compared to MILDF which was concluded following a single oocyte retrieval (P-value&lt;0.001). Cancellation-rate was significantly lower in the MILDA compared to MILDF group (0% vs 18.93%, P-value &lt;0.001). A higher proportion of top quality embryos were transferred in the MILDA group (66.58% vs 43.67%, P-value&lt;0.001). The MILDA group presented with higher positive-HCG (27.89% vs 23.30%, P-value=0.302), clinical-pregnancy (22.11% vs 17.96%, P-value=0.316) and live-birth rates (16.84% vs 14.08%, P-value=0.487). However, these differences were not significant. Comparing MILDA and NATA groups, the MILDA presented with a lower number of required oocyte retrievals and a higher number of oocytes per oocyte retrieval compared with NATA (3.90±1.56 vs 7.15±1.80; 1.95±0.74 vs 0.89±0.20, P-value&lt;0.001). Moreover, the MILDA presented with a higher mean number of resulting embryos (5.20±0.78 vs 4.82±0.88, P-value&lt;0.001). No difference was observed regarding the proportion of the resulting top quality embryos. The MILDA group presented with slightly higher clinical-pregnancy (22.11% vs 20.09%, P-value=0.628) and live-birth (16.84% vs 14.02%, P-value=0.490) rates, however these differences were not significant.

Limitations, reasons for caution

The retrospective nature of the study constitutes a major limitation. Considering that numerous confounders are inevitable when retrospective data is analyzed, authors employed strict eligibility criteria in an effort to reduce bias. Statistical analysis revealed a well-controlled population, considering that general patients’ characteristics did not differ between the three groups.

Wider implications of the findings: Embryo accumulation may constitute an efficient management strategy for POR, as more embryos of better quality are available for ET compared to fresh-IVF-ET. Mild stimulation should be preferred for embryo accumulation instead of natural cycles, as less oocyte retrievals are required. Future studies should be conducted to verify these conclusions.

Trial registration number

Not applicable

P–674 Development of a predictive model indicating the population of poor responders benefiting from luteal phase oocyte retrieval

Study question

Can successful implementation of luteal phase oocyte retrieval (LuPOR) following conventional follicular phase oocyte retrieval (FoPOR) be predicted for poor ovarian response (POR) patients?

Summary answer

Antral follicle count (AFC), number of small follicles recorded in FoPOR, and estradiol (E2) levels on FoPOR and LuPOR trigger days, predict successful LuPOR application.

What is known already

A second follicular wave in the same menstrual cycle was first observed in domestic animals such as horses and cattle and thenceforth in women. The second follicular wave has been introduced as an encouraging means towards optimizing the context of in vitro fertilization (IVF) success rates for infertile women and especially for POR patients. Double ovarian stimulation coupled with two oocyte retrievals in the same menstrual cycle has been proposed, and encouraging results have been reported. However, the high heterogeneity characterizing POR patients dictates that studies should focus on factors indicating efficient LuPOR application.

Study design, size, duration

This retrospective observational study included 1688 women diagnosed with POR, undergoing natural IVF cycles between 2012–2020 including two oocyte retrievals in the same menstrual cycle. Patients’ age, body mass index (BMI), number of previous POR incidences, basal hormonal levels, AFC, E2 evaluated on both trigger days and number of small follicles (8–13 mm) were evaluated on their predictive power regarding retrieval of at least one MII oocyte following LuPOR, being regarded as successful LuPOR implementation.

Participants/materials, setting, methods

A diagnosis of POR according to Bologna criteria served as the inclusion criterion for this single center study. All other infertility etiologies were excluded. Patient dataset was stratified according to age in quantiles. A random 20% of each quantile was employed to validate the model. The remaining 80% was employed to develop this model. The predictive value was determined employing the Area Under the Curve (AUC) of the Receiver Operating Characteristics, employing Youden’s index.

Main results and the role of chance

Patients’ age, BMI, number of previous failed IVF attempts, basal levels of follicle stimulating hormone (FSH), luteinizing hormone (LH), prolactin and progesterone failed to be predictive of a successful LuPOR as the AUC was below 0.6. AFC with a threshold value of 4.47, was found to be predictive of an effective LuPOR with an AUC of 0.86, sensitivity 0.8, specificity 0.75, and accuracy 0.79. E2 levels evaluated on the FoPOR trigger day, with a threshold value of 232.66 pg/ml, were similarly predictive of an effective LuPOR presenting with an AUC 0.86, specificity 0.75, sensitivity 0.86 and accuracy 0.82. Similarly, E2 evaluated on the LuPOR trigger day, with a threshold value of 200.89 pg/ml, presented with an AUC 0.89, specificity 0.85, sensitivity 0.95 and accuracy 0.92. The number of small follicles during FoPOR also appeared to be predictive of the presence of at least one MII oocyte during LuPOR, with a threshold value of 2.94. The AUC was 0.82, specificity 0.75, sensitivity 0.76 and accuracy 0.75. When combining the above characteristics into a single predictive model the AUC was 0.88, specificity 0.73, sensitivity 0.94 and accuracy 0.89. The positive and negative predictive value of the model were 93.5% and 46.8%, respectively.

Limitations, reasons for caution

Employment of natural cycles may present as a limitation when examining the value of this study, as the cut-off values reported herein may be altered when stimulation is employed. Since internal validation may be confounded by the fact that this was a single center study, external validation is required.

Wider implications of the findings: The clinical end-point of this study reporting back to the practitioner, is the development of a predictive model identifying the optimal POR population for whom LuPOR practice is valuable. The high positive predictive value of this model may assist clinicians in identifying poor responders who will benefit from this approach.

Trial registration number

Not applicable

The Role of Novel Autoantibodies in the Diagnostic Approach and Prognosis of Patients with Raynaud's Phenomenon

Raynaud's phenomenon (RP) is a condition characterised by distinct colour changes of the digits upon exposure to sympathomimetic conditions, such as cold temperature. It can be either primary or secondary, depending on whether it presents alone or as part of an underlying disorder. One of the most common causes of secondary RP are systemic autoimmune rheumatic diseases (SARDs), in which RP may precede the onset of other autoimmune features by many years. Thus, timely and accurate recognition of secondary RP is of great importance as it alters patient management and prognosis. An important step in the diagnostic approach of RP is the detection of antinuclear antibodies (ANAs) by indirect immunofluorescence. However, identification of specific autoantibodies is not yet common practice, though many of them have shown important clinical associations. Moreover, the role of some autoantibodies has not yet been elucidated, given their relatively recent discovery and low reported prevalence rates in autoimmune population. The goal of this study is to reveal clinical associations of these novel autoantibodies in SARDs through the application of an extended serology workup in patients presenting with RP.

Discarding IVF embryos: reporting on global practices

PURPOSE

To provide a global scale report on a representative sample of the clinical embryology community depicting the practice of discarding supernumerary IVF embryos.

METHODS

A web-based questionnaire titled "Anonymous questionnaire on embryo disposal practices" was designed in order to ensure anonymous participation of practicing clinical embryologists around the world.

RESULTS

During a data collection period of 8 months, 703 filled-in questionnaires from 65 countries were acquired. According to the data acquired, the majority of practitioners, dispose of embryos by placing them directly in a trash can strictly dedicated for embryo disposal for both fresh and frozen cycles (39% and 36.7% respectively). Moreover, 66.4% of practitioners discard the embryos separately-case by case-at different time points during the day. Over half of embryologists (54%) wait until day 6 to discard the surplus embryos, while 65.5% do not implement a specially allocated incubator space as a designated waiting area prior to disposal. The majority of 63.1% reported that this is a witnessed procedure. The vast majority of embryologists (93%) do not employ different protocols for different groups of patients. Nonetheless, 17.8% reported the request to perform a ceremony for these embryos. Assessing the embryologists' perspective, 59.5% of participants stated that the embryology practice would benefit from a universally accepted and practiced protocol.

CONCLUSION(S)

This study uniquely provides insight into global embryo disposal practices and trends. Results highlight the divergence between reported practices, while indicating the significance on standardization of practice, with embryologists acknowledging the need for a universally accepted protocol implementation.

Efficacy of a Mediterranean diet supplemented with fatty fish in ameliorating inflammation in paediatric asthma: a randomised controlled trial

BACKGROUND

Childhood asthma is the most common respiratory disorder worldwide, being associated with increased morbidity and a decreased quality of life. Omega-3 fatty acids have anti-inflammatory and immunomodulating properties; however, their efficacy in asthma is controversial. The present study aimed to examine the efficacy of a Mediterranean diet supplemented with a high omega-3 'fatty' fish intake in Greek asthmatic children.

METHODS

A single-centred, 6-month, parallel randomised controlled trial compared the consumption of a Mediterranean diet supplemented with two meals of 150 g of cooked fatty fish weekly (intervention) with the usual diet (control) with respect to pulmonary function in children (aged 5-12 years) with mild asthma. Pulmonary function was assessed using spirometry and bronchial inflammation by fractional exhaled nitric oxide analysis.

RESULTS

Sixty-four children (52% male, 48% female) successfully completed the trial. Fatty fish intake increased in the intervention group from 17 g day^-1 at baseline to 46 g day^-1 at 6 months (P < 0.001). In the unadjusted analysis, the effect of the intervention was of borderline significance (P = 0.06, β = -11.93; 95% confidence interval = -24.32 to 0.46). However, after adjusting for age, sex, body mass index and regular physical activity, a significant effect was observed (P = 0.04, β = -14.15 ppb; 95% confidence interval = -27.39 to -0.91). No difference was observed for spirometry, asthma control and quality of life scores.

CONCLUSIONS

A Mediterranean diet supplemented with two fatty fish meals per week might be a potential strategy for reducing airway inflammation in childhood asthma. Future robust clinical trials are warranted to replicate and corroborate these findings.

IL-6 is associated to IGF-1Ec upregulation and Ec peptide secretion, from prostate tumors

Background

Ec peptide (PEc), resulting from the proteolytic cleavage of the IGF-1Ec isoform, is involved in prostate cancer progression and metastasis, whereas in muscle tissue, it is associated with the mobilization of satellite cells prior to repair. Our aim is to determine the physiological conditions associated to the IGF-1Ec upregulation and PEc secretion in prostate tumors, as well as, the effect of tumor PEc on tumor repair.

Methods

IGF-1 (mature and isoforms) expression was examined by qRT-PCR, both in prostate cancer cells co-incubated with cells of the immune response (IR) and in tumors. PEc secretion was determined by Multiple Reaction Monitoring.

The effect of PEc, on mesenchymal stem cell (MSC) mobilization and repair, was examined using migration and invasion assays, FISH and immunohistochemistry (IHC). The JAK/STAT signaling pathway leading to the IGF1-Ec expression was examined by western blot analysis. Determination of the expression and localization of IL-6 and IGF-1Ec in prostate tumors was examined by qRT-PCR and by IHC.

Results

We documented that IL-6 secreted by IR cells activates the JAK2 and STAT3 pathway through IL-6 receptor in cancer cells, leading to the IGF-1Ec upregulation and PEc secretion, as well as to the IL-6 expression and secretion. The resulting PEc, apart from its oncogenic role, also mobilizes MSCs towards the tumor, thus promoting tumor repair.

Conclusions

IL-6 leads to the PEc secretion from prostate cancer cells. Apart from its oncogenic role, PEc is also involved in the mobilization of MSCs resulting in tumor repair.

Electronic supplementary material

The online version of this article (10.1186/s10020-018-0003-z) contains supplementary material, which is available to authorized users.

Melancholy as a risk factor for cancer: a historical overview

In antiquity, physicians related depression or melancholic humour to cancer's pathogenesis. Galen (130-201 AD), sustained that melancholy could give rise to a tumour and his theory was repeated by the Byzantine and Arab physicians. In the 19th century, malignancy and depression became synonymous and people attributed their cancer to sadness. In 1893, the London surgeon Hebert Snow (1847-1930), performed an epidemiological study in order to clarify that link. The results revealed a probable connection. His work was followed by several large scale prospective studies some of which identified depression as a risk factor for cancer where others found no association. However, a possible explanation could be given by our current knowledge in immunology: inflammation and nonspecific immune activation play a role in the pathophysiology of depression and cancer growth.

Popular palliative cancer treatments in 18th--mid 19th century

In the 18th century cancer was an incurable disease and the only therapeutic approach was surgery which was accompanied with several life threatening complications. In the absence of effective cancer treatment, palliative approach was proposed by physicians. Compression, ligation, "cura famis" and treatment by cold were four popular treatments in the 18th century provoking an outbreak of therapeutic illusions in cancer patients and physicians, before being lost in oblivion.

Cadherin-11 mRNA transcripts are frequently found in rheumatoid arthritis peripheral blood and correlate with established polyarthritis

Rheumatoid arthritis (RA) synovial fibroblasts hyperexpress the mesenchymal cadherin-11, which is involved also in tumor invasion/metastasis, whereas anti-cadherin-11 therapeutics prevent and reduce experimental arthritis. To test the hypothesis that cadherin-11 is aberrantly expressed in RA peripheral blood, 100 patients (15 studied serially) and 70 healthy controls were analyzed by real-time reverse transcription-PCR. Cadherin-11 mRNA transcripts were detected in 69.2% of moderately/severely active RA, versus 31.8% of remaining patients (p=0.001), versus 17.1% of controls (p<0.0001). Notably, cadherin-11 positivity correlated significantly and independently only with established (>1year) polyarthritis (>4 swollen tender joints), by multivariate logistic regression analysis including various possible clinical/laboratory factors. Rare cells of undefined nature, detected by flow cytometry following CD45(-) enrichment, strongly expressed surface cadherin-11 (estimated 10-50cells/ml of blood) in 5/6 patients with polyarticular established disease versus 1/6 patients with early RA. Studies on the potential pathogenic role of circulating cells expressing cadherin-11 in RA are warranted.

Peripheral targets in obesity treatment: a comprehensive update

Obesity is a major epidemic of our time and is associated with diseases such as metabolic syndrome, type 2 diabetes mellitus and atherosclerotic cardiovascular disease. Although weight loss drugs, when accompanied by diet and exercise, could be a very helpful medical tool in treating obese or overweight patients, their usefulness has been questioned due to the complexity of this type of medication, which regards a plethora of issues such as efficacy and safety of the drug and also risks and benefits among different patients. In general, obesity drugs that target peripheral pathophysiological mechanisms can be divided into two main categories. The first category includes anti-obesity agents able to reduce or limit energy absorption, such as pancreatic lipase and microsomal triglyceride transfer protein inhibitors. The second category consists of a heterogeneous group of compounds aiming to decrease fat mass by increasing energy expenditure or by redistributing adipose tissue. Angiogenesis inhibitors, beta-3 receptor agonists, sirtuin-I activators, diazoxide and other molecules belong to this group. The glucagon-like peptide-1 receptor agonists consist the third category of peripheral anti-obesity agents discussed therein. This review aims to provide a general overview of the molecules and substances that are already or could potentially be used as peripheral anti-obesity drugs, the molecular mechanisms by which they act, as well as their current stage of development, production and/or availability.

[Psychological burden of patients diagnosed with obstructive sleep apnea]

Obstructive sleep apnea syndrome (OSAS) is characterized by repeated episodes of upper airway obstruction during sleep, which leads to the presence of excessive daytime drowsiness. Regarding the psychological comorbidity in patients diagnosed with OSAS, previous studies focused mainly on depressive and secondarily on anxiety symptoms. Due to the lack of research data regarding the prevalence of anxiety and depressive symptoms as well as of alexithymic characteristics in patients with OSAS in Greece, the aim of the study was to record the above symptomatology in a sample of Greek OSAS patients and to investigate its relation to the respiratory parameter (Apnea-Hypopnea Index, AHI) of polysomnography. The study was conducted in a certified sleep laboratory. Thirty five randomly selected patients who attended the laboratory with symptoms of daytime drowsiness, fatigue, disrupted sleep and snoring, were examined for anxiety, depression and alexithymia using the Spielberger Trait Anxiety Inventory (STAI), the Beck Depression Inventory (BDI) and the Toronto Alexithymia Scale (TAS-20), respectively, 24 hours prior to being submitted to polysomnography. All 35 patients met the inclusion criteria of the study (age≤75 years, no other chronic diseases and no history of major psychiatric disorders). Six patients did not meet the diagnostic criteria for OSAS and were thus used as the control group of the study. A high prevalence of anxiety (41.4%) and depressive (55.2%) symptoms and of alexithymic characteristics (41.4%) was observed in OSAS patients. Although the control group showed a higher prevalence of anxiety (66.7%) and depressive (83.3%) symptoms, there were no differences between the two groups (STAI: t=-0.927, p=0.360, BDI: t=-1.537, p=0.134, TAS-20: t=0.196, p=0.846). With regard to severity, no differences were observed between control, mild, moderate and severe OSAS subgroups (STAI: F=0.583, p=0.660, BDI: F=0.829, p=0.488, TAS-20: F=0.987, p=0.412). Females scored higher on the BDI and on the STAI compared to males (STAI: t=-2.38, p=0.039, BDI: t=-3.59, p=0.01). Finally, no correlation was observed between psychometric scores and AHI (Pearson correlation p>0.05). The study confirms the high prevalence of anxiety and depressive symptoms which has been found in previous studies. Furthermore, we found a high prevalence of alexithymic characteristics, a factor that has not been investigated previously and which is positively correlated with anxiety symptoms. The coexistence of alexithymic characteristics may further complicate the clinical manifestations of OSAS due to the fact that patients with alexithymia typically have difficulty in indentifying and describing their underlying psychological symptomatology and, moreover, tend to exhibit more, and often atypical, physical symptoms. In conclusion, the study supports the presence of a high degree of psychological burden in patients diagnosed with OSAS, regardless of the severity of their symptoms, as determined by the AHI. This comorbidity should be taken into consideration during the clinical assessment of OSAS and for the treatment planning.

Epigenetic regulation on gene expression induced by physical exercise

It is well established that physical exercise modulates the function of many physiological systems, such as the musculoskeletal, the cardiovascular and the nervous system, by inducing various adaptations to the increased mechanical load and/or metabolic stress of exercise. Many of these changes occur through epigenetic alterations to DNA, such as histone modifications, DNA methylations, expression of microRNAs and changes of the chromatin structure. All these epigenetic alterations may have clinical relevance, thus playing an important role in the prevention and confrontation of neurophysiological disorders, metabolic syndrome, cardiovascular diseases and cancer. Herein we review the known epigenetic modifications induced by physical exercise in various physiological systems and pathologies, and discuss their potential clinical implications.

Wnt signaling in cardiovascular physiology

Wnt signaling pathways play a key role in cardiac development, angiogenesis, and cardiac hypertrophy; emerging evidence suggests that they are also involved in the pathophysiology of atherosclerosis. Specifically, an important role for Wnts has been described in the regulation of endothelial inflammation, vascular calcification, and mesenchymal stem cell differentiation. Wnt signaling also induces monocyte adhesion to endothelial cells and is crucial for the regulation of vascular smooth-muscle cell (VSMC) behavior. We discuss how the Wnt pathways are implicated in vascular biology and outline the role of Wnt signaling in atherosclerosis. Dissecting Wnt pathways involved in atherogenesis and cardiovascular disease may provide crucial insights into novel mechanisms with therapeutic potential for atherosclerosis.

The quarrel between iatromechanists and animists about the cause of cancer: lymph's role in oncogenesis

In the 17th century, iatromechanists based to the solidist theory for the lymphatic system and lymph established a new speculation for the essential role of lymph in oncogenesis, while animists gave their own views in relation to the cause of cancer. Gradually, with the rise of pathological anatomy, new more rational theories have emerged.

KISS1/KISS1R expression in eutopic and ectopic endometrium of women suffering from endometriosis

BACKGROUND

The KISS1/KISS1R system has been implicated in the physiology of reproduction and many studies have documented the stimulatory effect of kisspeptin on Gonadotropin-releasing Hormone (GnRH) and gonadotropin secretion. In addition, the KISS1/KISS1R system has been implicated in several pathophysiological processes, including cancer.

MATERIALS AND METHODS

We examined the pattern of KISS1 and KISS1R expression in eutopic and ectopic endometrium tissues which were obtained from 24 women suffering from endometriosis and 16 control women who underwent laparoscopic excision for other benign gynecological diseases.

RESULTS

Significant KISS1R expression was detected in 10 out of the 24 samples of eutopic endometrial biopsies of women suffering from endometriosis, while their matched biopsies of ectopic endometrial lesions did not reveal any KISS1R expression. KISS1R expression was not detected in the endometrial biopsies of control women. In addition, KISS1 expression was not detected in practically any the endometrial tissues of either control women or women with endometriosis.

CONCLUSION

The expression of KISS1R in 10/24 samples of human endometrial biopsies of women suffering from endometriosis and the loss of its expression in the samples of matched ectopic endometrial tissues, suggests that the KISS1/KISS1R system may play a role in the pathophysiology of endometriosis only for a particular group of patients. Since KISS1 is not expressed by the endometrium and endometriotic tissue, it is conceivable that the activation of KISS1R in this particular group is mediated by KISS1 expression by non-endometrial tissues (endocrine action).

Dexamethasone plus octreotide regimen increases anticancer effects of docetaxel on TRAMP-C1 prostate cancer model

AIM

The aim of this study was to evaluate whether the neoadjuvant use of the dexamethasone (DEX) plus octreotide (OCT) regimen can improve the direct anticancer effects of docetaxel (DOC) in the TRAMP-C1 prostate cancer model.

MATERIALS AND METHODS

TRAMP-C1 cells were first characterized for the expression of SSTR1-5 and then were inoculated onto the femur of C57Bl mice. Investigation protocols employed TRAMP-C1 cell proliferation and invasion assays, analysis of radiographic images of the bone lesions and overall survival of the diseased animals.

RESULTS

The triple combination treatment scheme showed significant anticancer effects, in both proliferation and invasion assays, compared to any single agent treatment scheme. DOC treatment following the neoadjuvant administration of DEX plus OCT regimen improved significantly the anticancer effects both on the grading of the bone lesions and on the overall survival of the diseased animals.

CONCLUSION

Our data suggest that the neoadjuvant administration of DEX plus OCT regimen can improve the anticancer effects of DOC on the TRAMP-C1 model.

The role of kisspeptin/GPR54 in the reproductive system

The Kiss-1 gene encodes a secreted protein that is proteolytically cleaved to produce a number of structurally related peptides, with high interspecies conservation, globally termed kisspeptins. The original niche for the role of kisspeptin in human physiology is derived from cancer biology, with the loss of Kiss-1 expression being associated with poor prognosis in several malignancies. However, kisspeptin has recently emerged as a fundamental player in the field of reproductive biology. Genetic analysis of large consanguineous pedigrees by two independent groups led to the association of inactivating mutations of GPR54, the receptor which mediates kisspeptin action, with idiopathic hypogonadotropic hypogonadism. In the present paper the most salient aspects of the multifaceted role of kisspeptin in the reproductive system are reviewed, including the association of kisspeptin with the gonadal steroid feedback loop and the triggering of puberty onset.

The impact of endocrine disruptors on endocrine targets

Endocrine disruption represents one of the most controversial environmental issues of our époque. So far, many substances, both natural and artificial, have been recognized to interfere with endocrine signaling pathways. In intact laboratory animals, this interaction has been documented to generate adverse health outcomes by impairing normal functions. With regard to humans, evidence is limited and inconsistent to clearly establish a causal inference, however, accumulating data incriminate endocrine disrupting chemicals to reproductive disorders and disturbed thyroid homeostasis. Recently, as a result of animal models and preliminary human studies, a new area of interest has arisen concerning the implication of endocrine disruptors in the etiology of obesity and diabetes, the two major, life-threatening, epidemics of modern world. This article reviews the evidence linking endocrine disrupting chemicals to a broad spectrum of clinical perturbations from reproduction and thyroid to metabolic regulation.

Changes in the mechanical properties of human quadriceps muscle after eccentric exercise

Muscular adaptation which occurs following eccentric exercise-induced muscle damage has been associated with changes in the mechanical properties of muscle manifested as a shift in the length-tension relationship towards longer muscle lengths. However, it is not clear whether this shift is a long term adaptation to eccentric exercise. The purpose of this study was to investigate functional adaptations to skeletal muscle damage in humans, tracking such responses several days into muscle recovery. Ten healthy young men performed an eccentric exercise protocol involving the quadriceps muscle and functional measurements were performed before and on days 1, 2, 5, 8, 12 and 16 post-exercise. Blood samples were also withdrawn before and at 6 h, and 2 days, 5 days and 16 days post-exercise. The exercise protocol resulted in muscle damage, indicated by changes in clinical markers including increased serum creatine kinase activity and muscle soreness compared to pre-exercise levels (p<0.05-0.001). An acute, but not sustained shift in the quadriceps isokinetic and isometric angle-torque curves towards longer muscle lengths was observed post-exercise (p<0.05). It was speculated that the functional adaptations following eccentric exercise might be affected by the short resting and functional length of the quadriceps muscle, relative to its optimum. More studies are needed to confirm the hypothesis that a sustained shift in the muscle's length-tension relationship, as an adaptation after lengthening contraction-induced damage, is muscle specific.

Expression of IGF-1 isoforms after exercise-induced muscle damage in humans: characterization of the MGF E peptide actions in vitro

Different insulin-like growth factor-1 (IGF-1) isoforms, namely IGF-1Ea, IGF-1Eb and IGF-1Ec (MGF), have been proposed to have various functions in muscle repair and growth. To gain insight into the potentially differential actions of IGF-1 isoforms in the regulation of muscle regeneration, we assessed the time course of their expressions at both mRNA and protein levels after exercise-induced muscle damage in humans. In addition, we characterized mature IGF-1 and synthetic MGF E peptide signalling in C2C12 myoblast-like cells in vitro. Ten healthy male volunteers were subjected to exercise-induced muscle damage and biopsy samples were taken from the exercised muscles before and 6 h, 2, 5 and 16 days post exercise. Muscle damage was documented by specific functional and biochemical responses post exercise. PCR-based analyses of muscle biopsy samples revealed a rapid and transient up-regulation of MGF mRNA expression which was followed by a prolonged increase of IGF-1Ea and IGF-1Eb mRNA expression (p<0.05). Patterns similar to those for mRNA expression were detected for MGF and IGF-1Ea expression at the protein level. The action of synthetic MGF E peptide differed from that of mature IGF-1 since its proliferative effect on C2C12 myoblast-like cells was not blocked by an anti-IGF-1 receptor neutralizing antibody and it did not phosphorylate Akt. Therefore, we conclude that the differential expression profile of IGF-1 isoforms in vivo and the possible IGF-1R - independent MGF E peptide signalling in skeletal muscle-like cells in vitro support the notion that tissue-specific mRNA expression of MGF isoform produces mature IGF-1 and MGF E peptides which possibly act as distinct mitogens in skeletal muscle regeneration.

In vivo models for heart failure research

The medical treatment of heart failure (HF) is associated with 50% survival at 5 years, thus being one of the major causes of mortality in Western countries. An understanding of the pathophysiology of HF is essential for the development of novel efficient therapies. Consequently, the use of animal models is indispensable. In addition, the development of new in vivo models of HF is critical for the evaluation of treatments such as gene therapy, mechanical devices and new surgical approaches. However, every animal model has advantages and limitations and none of them is suitable to study all aspects of HF. Besides the technical determinants of a model, species, strain and gender affect the pathophysiology of a given heart pathogenesis and, therefore, have to be considered in each animal model. The most common in vivo models used in cardiology research and in particular in HF remodeling are presented.

Mechanisms of the action of zoledronic acid on human MG-63 osteosarcoma cells

The aim of our study was to analyze the action of zoledronic acid on MG-63 human osteosarcoma cells. The proliferation of MG-63 cells was inhibited by either continuous or pulsatile exposures of zoledronic acid in a dose-dependent manner (10-250 microM). Zoledronic acid did not produce evidence of MG-63 cell death when administered at 100 mM for 48 hours, but only after exposure of 96 hours. Zoledronic acid (100 microM) increased the distribution of MG-63 cells in G0/G1 phase, however, it did not increase the adriamycin-induced apoptosis. In addition, zoledronic acid action was partially neutralized by exogenous administration of geranylgeranyl pyrophosphate (GGPP), but not by farnesyl pyrophosphate (FPP). Furthermore, zoledronic acid resulted in the attenuation of the prenylated form of Ras. Zoledronic acid and EDTA increased fluorescence of Fluo-3 loaded MG-63 cells in a similar pattern. This increase was owing to the release of Ca2+ from intracellular stores since zoledronic acid failed to reveal such a change to intracellular Ca2+ when cells were previously treated with 1 mM caffeine. Moreover, zoledronic acid significantly decreased the expression of estrogen receptor alpha (ERalpha) whereas it did not change significantly the expression of estrogen receptor beta (ERbeta) in MG-63 cells. These data suggest that zoledronic acid can control the proliferation and the differentiation of osteosarcoma-like cells.

The role of urokinase-type plasminogen activator (uPA) and transforming growth factor beta 1 (TGFbeta1) in muscle regeneration

Skeletal muscle regeneration is a highly synchronized process involving the activation of various cellular and molecular events, coordinating inflammation and regeneration processes which are crucial for the beneficial outcome of tissue remodeling. Fibrosis, a failure of tissue remodeling, is initiated with muscle regeneration; however, it is the result of an excessive inflammatory response, representing an imbalance between enhanced production and deposition and impaired degradation of extracellular matrix (ECM) components of the muscle. Therefore, factors influencing the relative degree of muscle fiber regeneration as compared to the amount of scar formation have a critical role in functional muscle remodeling. Herein we have focused on the role of urokinase-type plasminogen activator (uPA) and transforming growth factor beta 1 (TGF/1) in ECM degradation and reconstitution in muscles.

Molecular diagnosis of the viral component in cardiomyopathies: pathophysiological, clinical and therapeutic implications

BACKGROUND

Myocarditis is defined as the inflammation of myocardium associated with cardiac dysfunction. Despite this clear-cut definition, diagnosis and etiologic treatment continue to create considerable debate. Viral infections are frequent causes of myocarditis and there is evidence that persistent viral infection is associated with poor prognosis in different subtypes of cardiomyopathy.

OBJECTIVE

To review methods for diagnosis of viral myocarditis and present the use of polymerase chain reaction (PCR)-based protocols for evaluating viral infection in myocarditis/cardiomyopathies.

METHODS

A review of published literature.

RESULTS/CONCLUSION

There is increasing evidence that PCR-based protocols can provide reliable molecular evidence for the presence of viral infection in myocardium. Thus application of molecular techniques will allow collection and analysis of more information on the epidemiology of viral cardiomyopathies, patient risk stratification and appropriate medical treatment.

cGMP-independent anti-tumour actions of the inhibitor of soluble guanylyl cyclase, ODQ, in prostate cancer cell lines

BACKGROUND AND PURPOSE

Soluble guanylyl cyclase (sGC) is a receptor for nitric oxide that generates cGMP. This second messenger molecule has established roles in cellular physiology; however, less is known about its effects in tumour cells.

EXPERIMENTAL APPROACH

The effects of 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ) and 4H-8-bromo-1,2,4-oxadiazolo(3,4-d)benz(b)(1,4)oxazin-1-one (NS2028), both selective sGC inhibitors on proliferation, death and migration were determined in prostate cancer cell lines.

KEY RESULTS

Western blot analysis confirmed the presence of alpha1 and beta1 subunits of sGC in LNCaP and PC-3 cells. Sodium nitroprusside (SNP) increased cGMP accumulation in LNCaP and PC-3, but not DU-145 cells. SNP-stimulated cGMP production in LNCaP cells was dose-dependently reduced by ODQ, with more than 90% inhibition being observed at 0.1 microM. ODQ activated caspase-3 in all three cell lines, but not in normal prostate epithelial cells, at concentrations over 10 muM. High concentrations of ODQ also promoted DNA fragmentation and nucleosome accumulation in the cytosol of LNCaP cells. Interestingly, the chemically related inhibitor, NS2028 was without effect on caspase-3. In addition, ODQ inhibited LNCaP, Du145 and PC-3 cell growth. Finally, although fibroblast growth factor-2 did not enhance cGMP levels in LNCaP cells, its ability to stimulate LNCaP motility was abolished by ODQ.

CONCLUSIONS AND IMPLICATIONS

These observations taken together suggest that the action of ODQ in LNCaP cells did not reflect sGC inhibition. We conclude that ODQ promotes cell death and inhibits growth and migration of prostate cancer cells and that these actions are independent of its effects on GMP levels.

Characterization of a rabbit antihuman mechano growth factor (MGF) polyclonal antibody against the last 24 amino acids of the E domain

The human insulin-like growth factor-1 (IGF-1) gene gives rise to multiple, heterogeneous mRNA transcripts by alternative splicing, thus producing different IGF-1 isoforms. The mechano growth factor (MGF) is an IGF-1 isoform that was found to be markedly up-regulated in exercised or damaged muscle. The specific E domain of the MGF splice variant may act as an independent growth factor. The aim of the present study was to characterize a rabbit antihuman MGF polyclonal antibody. New-Zealand rabbits were immunized by injections of a purified synthetic peptide corresponding to the last 24 amino acids of the human C-terminal of the MGF E domain. Western blotting and immunohistochemical techniques were used to characterize the specificity of the polyclonal anti-MGF antiserum. The anti-MGF antiserum was found to recognize the MGF E-peptide and not the common part of the IGF-1 isoforms, i.e. the mature IGF-1 peptide. Furthermore, it specifically bound to the MGF protein in human skeletal and in rat cardiac muscle, apparently due to the considerable homology between the human and rat MGF E-peptide sequences. Immunostaining analysis showed that this polyclonal anti-MGF antibody was able to detect MGF in human muscle and in rat cardiomyocytes and vessels' smooth muscle cells. We conclude that this rabbit polyclonal anti-human/rat MGF antibody could become a valuable tool in the study of IGF-1 isoforms in human and rat tissues.

Type I insulin-like growth factor receptor signaling in skeletal muscle regeneration and hypertrophy

Skeletal muscle is able not only to increase its mass as an adaptation to mechanical loading generated by and imposed upon muscle but also to regenerate after damage, via its intrinsic regulation of gene transcription. Both cellular processes, muscle regeneration and hypertrophy, are mediated by the activation, proliferation and differentiation of muscle satellite cells and appear to be modulated by the mitotic and myogenic activity of locally produced insulin-like growth factor 1 (IGF-1), which functions in an autocrine/paracrine mode. Differentiation of satellite cells into myoblasts involves the regulation of skeletal muscle-specific proteins belonging to the family of myogenic regulatory factors (MRFs). The endocrine, autocrine and paracrine functions of IGF-1 are mediated through binding to the type I IGF receptor (IGF-1.R), which is a ligand-activated receptor tyrosine kinase. The binding of IGF-1 to IGF-1.R induces its autophosphorylation, which recruits specific cytoplasmic molecules containing the Insulin Receptor Substrate Proteins (IRS). The recruitment of IRS proteins by IGF-1/IGF-1.R binding is a critical level at which the proliferative and differentiative actions of IGF-1 diverge. Specific signaling pathways downstream of IGF-1, potentially involved in the mitogenic and myogenic responses and mediating skeletal muscle protein synthesis and hypertrophy following exercise-induced muscle overloading and damage, are discussed. A potential alternative activation of different signaling pathway(s) via a different receptor remains to be demonstrated.

Microarray analysis of survival pathways in human PC-3 prostate cancer cells

BACKGROUND

Insulin-like growth factor 1 (IGF-1), transforming growth factor beta 1 (TGFbeta1), and interleukin 6 (IL-6), act as survival factors inhibiting chemotherapy-induced apoptosis in PC-3 human prostate cancer cells, in vitro.

MATERIALS AND METHODS

To study the intracellular pathways activated by these survival factors we performed a comparative genomic analysis using oligonucleotide microarray chips. A validation by real time-PCR was also performed for the genes of interest.

RESULTS

The expression data derived were analysed using various normalization algorithms. The differentially expressed genes were clustered and their ontological annotations were statistically tested to provide evidence for possible deregulated biological processes on the action of the aforementioned survival factors. Emphasis was given on the regulation and the role of the genes AKR1C1, SDPR and GADD45B in the survival pathways of prostate cancer cells, whose expression was also validated by real time-PCR.

CONCLUSION

The overall analyses reveal an overrepresentation of differentially expressed genes related to cellular processes such as cell cycle regulation, lipid metabolism and steroid biosynthesis.

Regulation of the mGluR5, EAAT1 and GS expression by glucocorticoids in MG-63 osteoblast-like osteosarcoma cells

INTRODUCTION

Growth factors, cytokines, sex steroid hormones and glucocorticoids have differential and complex effects on skeletal metabolism. Recently, the presence of the glutamatergic (Glu) system in bone cells has provided new evidence for its possible role in bone physiology. Consequently, we have investigated the regulation of certain components of the Glu system by glucocorticoids in MG-63 osteoblast-like osteosarcoma cells, in vitro.

MATERIALS AND METHODS

We characterized the effects of dexamethasone on the expression of the mGluR5, EAAT1 and GS, at mRNA and protein level, using relative quantitative RTPCR and Western blot analysis, respectively.

RESULTS

We confirmed the induction of GS expression by dexamethasone published previously. In addition, we documented for the first time the expression of the mGluR5 and EAAT1 in MG-63 cells, as well as the ability of dexamethasone to upregulate the expression of the mGluR5 and EAAT1 in the MG-63 cells.

CONCLUSIONS

Components of the glutamatergic system may play a role in bone pathophysiology.

Combinational effect of topotecan and octreotide on murine leukemia cells in vivo and in vitro

PURPOSE

The activity of topotecan (TPT) against a number of hematological malignancies is now notably increased. TPT is a drug which inhibits the DNA enzyme topoisomerase I (topo I), thereby leading to the induction of tumor cell apoptosis. On the other hand, octreotide (OCT) is a synthetic analogue of somatostatin, which can induce apoptosis and antiproliferative effects on various human tumor cell lines, human xenografts and animal tumors, as well as on lymphoproliferative neoplasms. Hereby, we studied the effects of TPT and OCT, and their combination in the treatment of the rodent P388 lymphocytic leukemia, in vitro and in vivo.

MATERIALS AND METHODS

Cell cultures of P388 lymphocytic leukemia cells, as well as BDF1 male and female mice implanted with the P388 leukemia cells, were used for the in vitro and in vivo evaluation of the antineoplastic activity of OCT and TPT.

RESULTS

A significant increase of antileukemic activity of the combined treatment with both TPT and OCT was demonstrated. These results suggest that OCT enhances the effectiveness of TPT in the treatment of leukemia.

CONCLUSION

Our results indicate that the combination of OCT with TPT in the treatment of hematological neoplasias is effective, and represents an interesting addition to the future therapeutic options, because os its mechanism of action and its toxicity profile.

Bone microenvironment-related growth factors, zoledronic acid and dexamethasone differentially modulate PTHrP expression in PC-3 prostate cancer cells

Bone metastasis microenvironment-related growth factors such as insulin-like growth factor 1 (IGF-1), transforming growth factor beta 1 (TGF-beta1), basic fibroblast growth factor (bFGF) and interleukin 6 (IL-6) show survival factor activity, thereby inhibiting chemotherapy-induced apoptosis of PC-3 prostate cancer cells in vitro. Recently, zoledronic acid has been shown to induce apoptosis in PC-3 prostate cancer cells while overexpression of parathyroid hormone-related protein (PTHrP) inhibits serum deprivation-induced apoptosis in PC-3 cells. Consequently, we have investigated whether IGF-1, TGF-beta1, bFGF, IL-6, zoledronic acid and/or dexamethasone affect the expression of the PTHrP and type I PTH/PTHrP receptor (PTH.1R) in PC-3 prostate cancer cells using relative quantitative PCR and real-time PCR (expression at mRNA level) and immunocytochemical and immunofluorescence analysis (expression at protein level). Our data show that IGF-1, TGF-beta1, bFGF and IL-6 increase PTHrP mRNA expression and its perinuclear localization, while zoledronic acid (50 muM, 100 muM for 24 h and 48 h) and dexamethasone suppress PTHrP expression in PC-3 cells. We did not detect any appreciable change of the PTH.1R expression due to IGF-1, TGF- beta1, bFGF, IL-6, zoledronic acid or dexamethasone in PC-3 cells. Therefore, it is conceivable that bone metastasis microenvironment-related survival factor/anti-apoptotic activity and zoledronic acid anticancer action/pro-apoptotic activity on PC-3 cells is mediated, at least in part, by differential modulation of PTHrP expression.

Prostate cancer cell survival pathways activated by bone metastasis microenvironment

The development of resistance to anti-cancer therapies in bones is a major hurdle preventing long-lasting clinical responses to anti-cancer therapies in hormone refractory prostate cancer. Herein, we present the major signal transduction pathways, which are activated in prostate cancer cells residing at bone metastasis microenvironment. These intracellular signal transduction pathways can inhibit anti-cancer therapy-induced apoptosis of metastatic prostate cancer cells, thereby optimizing their survival, locally. Employment of this knowledge in a clinical setting provides the conceptual framework for the development of bone-targeted therapies for advanced prostate cancer. Indeed, bone metastasis microenvironment-targeted therapies illustrate a novel paradigm in cancer treatment: anti-tumor treatment strategies may not only aim at directly inducing cancer cell apoptosis, but can also target the tumor metastasis microenvironment, and neutralize the protection it confers on metastatic cancer cells.

Carotid body paraganglioma and SDHD mutation in a Greek family

BACKGROUND

Carotid body (CB) is a highly specialized paraganglion originating from the neural crest ectoderm. CB paraganglion can be caused either by a genetic predisposition (hereditary paraganglia) or by chronic hypoxic stimulation. Germline mutations in any of the following genes: SDHD, SDHC, SDHB, PGL2 or other unknown genes, can cause paragangliomas (PGLs).

MATERIALS AND METHODS

We studied a Greek family in which the two daughters had carotid body paraganglioma, whereas both parents did not. RNA extraction, reverse transcriptase polymerase chain reaction and direct DNA sequencing were performed, in order to identify SDHD mutations in all four exons.

RESULTS

Our results revealed the existence of the missense mutation Y114C, in exon-4 of the SDHD gene, in the unaffected father and both affected sisters.

CONCLUSION

DNA testing was performed, for the first time in Greece, on patients with carotid body tumor. This marks a new geographical location, in the literature, for this mutation.

Octreotide neutralizes dexamethasone antitumor actions on P388 murine lymphocytic leukemia in vivo

PURPOSE

A wide variety of human malignancies, including lymphoproliferative neoplasms, express somatistatin (SS) receptors (SS-R). SS induces apoptosis and exerts pronounced antiproliferative effects on various human tumors cell lines, human xenografts, and animal tumors including P388 lymphocytic leukemia. In patients with thymoma the combination of octreotide (OCT) with corticosteroids improves the overall response rate. It has been reported that SS can increase glucocorticoid activity. Hereby, we studied the in vitro and in vivo activity of the SS analogue OCT and of the glucocorticoid dexamethasone (DEX) alone or in combination against the murine P388 lymphocytic leukemia.

MATERIALS AND METHODS

Cultures of P388 lymphocytic leukemia and BDF(1) male mice implanted with P388 cells where used for the in vitro an in vivo evaluation of the antileukemic activity of SS and DEX.

RESULTS

OCT induced a moderate and DEX a satisfactory cytostatic effect in vitro. OCT produced borderline antileukemic effect when administered on days 1-5 while DEX was effective in all schemes and routes of administration. However, none of the combination schemes exerted any anti-leukemic activity both in vitro and in vivo.

CONCLUSION

Since both SS and glucocorticoids exert direct (via receptors) and indirect antitumor actions (regulation of growth factor activity) on several cell lines, in vitro and in vivo, it becomes obvious that further in vitro studies shall provide the molecular evidence for the signal transduction pathways which are involved in the interactions of such important anticancer drugs. Based on the results of the present study, the simultaneous use of these drugs in clinical practice should be carefully considered.

Three-dimensional type I collagen cell culture systems for the study of bone pathophysiology

Three-dimensional (3-D) type I collagen cell culture systems composed of reconstituted collagen fibres are able to support short- and long-term growth of various cell types, including cancer cell lines, endothelial cells, endometrial cells, hepatocytes, osteoblasts and fibroblasts and to sustain or even enhance cell differentiation, in vitro. In addition, 3-D culture systems have been successfully used in the investigation of complex biological processes, such as angiogenesis, wound healing, tumour invasion and metastasis. The latter suggested that 3-D culture systems have the potential to simulate cell-cell interactions, which take place in tissues under physiological and pathophysiological conditions. This review focuses on the investigational use of 3-D collagen cell culture systems in bone physiology and the pathophysiology of skeletal metastasis.

Epoetin beta (NeoRecormon) corrects anaemia in patients with hormone-refractory prostate cancer and bone metastases

BACKGROUND

Severe anaemia is common in patients with metastatic, hormone-refractory prostate cancer (HRPC).

PATIENTS AND METHODS

We evaluated the efficacy of epoetin beta in correcting anaemia and maintaining haemoglobin (Hb) levels in this group of patients. Patients with HRPC, bone metastases and anaemia (Hb < 12 g/dl) were included. Epoetin beta, 30,000 IU per week in three divided doses, was administered subcutaneously, with iron supplementation when needed. If Hb increased by < 1 g/dl during the first 4 weeks of therapy the epoetin dose was increased (increments of 5,000 IU per dose) at fortnightly intervals to a maximum of 60,000 IU per week. Patients with haematopoietic response (Hb increase > or = 2 g/dl from baseline or Hb level > or = 12 g/dl without blood transfusions) went on to receive epoetin beta 10,000 IU once weekly for up to 24 weeks.

RESULTS

All 29 evaluable patients demonstrated a haematopoietic response to epoetin beta treatment. None of the patients required blood transfusions. All patients showed improvements in quality of life (assessed using the EORTC QLQ-C30 questionnaire). Hb levels were maintained for the remainder of the trial. Epoetin beta was very well tolerated.

CONCLUSION

Epoetin beta therapy resulted in a rapid and sustained improvement in Hb levels in patients with HRPC metastatic to bone.