Different acquisition systems for heart rate variability analysis may lead to diverse outcomes

Heart rate variability (HRV) is a relevant physiological variable for the estimation of cardiac autonomic function. Although the gold standard for HRV registration is the electrocardiogram (ECG), several applications (APPs) have been increasingly developed. The evaluation carried out by these devices must be compatible with ECG standards. The aim of this study was to compare the data obtained simultaneously with ECG and APP with chest heart rate transmitters. Fifty-six healthy individuals (28 men and 28 women) were evaluated at rest through a short simultaneous HRV measurement with both devices. Data from both acquisition systems were analyzed separately using their own analysis software and exported and analyzed using a validated software. Signal recordings were compatible between the two acquisition systems (Pearson r=0.99; P<0.0001). Although a high correlation was found for the HRV variables obtained in the time domain (Spearman r=0.99; P<0.0001), the correlation decreased in the frequency domain (Pearson r=0.85; P<0.0001) when two software programs were used. Comparison of the averages of spectral analysis parameters also showed differences when HRV data were analyzed separately in each device for low-frequency (LF) and high-frequency (HF) bands. Although the portability of these mobile devices allows for optimal HRV evaluation, the direct analysis obtained from these devices must be carefully evaluated with respect to frequency domain parameters.

Insights on the epigenetic mechanisms underlying pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH), characterized by localized increased arterial blood pressure in the lungs, is a slow developing long-term disease that can be fatal. PAH is characterized by inflammation, vascular tone imbalance, pathological pulmonary vascular remodeling, and right-sided heart failure. Current treatments for PAH are palliative and development of new therapies is necessary. Recent and relevant studies have demonstrated that epigenetic processes may exert key influences on the pathogenesis of PAH and may be promising therapeutic targets in the prevention and/or cure of this condition. The aim of the present mini-review is to summarize the occurrence of epigenetic-based mechanisms in the context of PAH physiopathology, focusing on the roles of DNA methylation, histone post-translational modifications and non-coding RNAs. We also discuss the potential of epigenetic-based therapies for PAH.

The scaffold protein Ajuba suppresses CdGAP activity in epithelia to maintain stable cell-cell contacts.

Levels of active Rac1 at epithelial junctions are partially modulated via interaction with Ajuba, an actin binding and scaffolding protein. Here we demonstrate that Ajuba interacts with the Cdc42 GTPase activating protein CdGAP, a GAP for Rac1 and Cdc42, at cell-cell contacts. CdGAP recruitment to junctions does not require Ajuba; rather Ajuba seems to control CdGAP residence at sites of cell-cell adhesion. CdGAP expression potently perturbs junctions and Ajuba binding inhibits CdGAP activity. Ajuba interacts with Rac1 and CdGAP via distinct domains and can potentially bring them in close proximity at junctions to facilitate activity regulation. Functionally, CdGAP-Ajuba interaction maintains junctional integrity in homeostasis and diseases: (i) gain-of-function CdGAP mutants found in Adams-Oliver Syndrome patients strongly destabilize cell-cell contacts and (ii) CdGAP mRNA levels are inversely correlated with E-cadherin protein expression in different cancers. We present conceptual insights on how Ajuba can integrate CdGAP binding and inactivation with the spatio-temporal regulation of Rac1 activity at junctions. Ajuba provides a novel mechanism due to its ability to bind to CdGAP and Rac1 via distinct domains and influence the activation status of both proteins. This functional interplay may contribute towards conserving the epithelial tissue architecture at steady-state and in different pathologies.

Defining functional interactions during biogenesis of epithelial junctions.

In spite of extensive recent progress, a comprehensive understanding of how actin cytoskeleton remodelling supports stable junctions remains to be established. Here we design a platform that integrates actin functions with optimized phenotypic clustering and identify new cytoskeletal proteins, their functional hierarchy and pathways that modulate E-cadherin adhesion. Depletion of EEF1A, an actin bundling protein, increases E-cadherin levels at junctions without a corresponding reinforcement of cell-cell contacts. This unexpected result reflects a more dynamic and mobile junctional actin in EEF1A-depleted cells. A partner for EEF1A in cadherin contact maintenance is the formin DIAPH2, which interacts with EEF1A. In contrast, depletion of either the endocytic regulator TRIP10 or the Rho GTPase activator VAV2 reduces E-cadherin levels at junctions. TRIP10 binds to and requires VAV2 function for its junctional localization. Overall, we present new conceptual insights on junction stabilization, which integrate known and novel pathways with impact for epithelial morphogenesis, homeostasis and diseases.

Proline levels, oxidative metabolism and photosynthetic pigments during in vitro growth and acclimatization of Pitcairnia encholirioides L.B. Sm. (Bromeliaceae) / Niveis de prolina, do metabolismo oxidativo e dos pigmentos fotossintéticos durante o crescimento in vitro e aclimatização de Pitcairnia encholirioides L.B. Sm. (Bromeliaceae)

Abstract This study aimed to evaluate the variation in the levels of proline, oxidative metabolism and photosynthetic pigments in plants of Pitcairnia encholirioides grown in vitro under different conditions and after acclimatization. The analyses were performed after 150 days of in vitro cultivation in MS media supplemented with 10 µM GA3 or 0.2 µM NAA, sucrose at 15 or 30 g L–1, in test tubes which allowed gas exchange or in a hermetically sealed system, and 180 days after acclimatization. The in vitro maintenance in hermetically sealed flasks, with GA3 and 15 g L–1 sucrose had adverse metabolic effects, which was demonstrated by the lower proline and photosynthetic pigments accumulation and by the increase in antioxidant enzymes activities. After acclimatization, differences for proline and photosynthetic pigments were no longer found and the enzymatic activities ranged unevenly. The results suggest that the in vitro cultivation in media with 0.2 µM NAA and 30 g L–1 sucrose, in test tubes capped with closures which allowed gas exchange, is more suitable for micropropagation of P. encholirioides, providing a prolonged maintenance of in vitro cultures and plantlets with superior quality for ex vitro development.

Resumo Este trabalho objetivou avaliar a contribuição da prolina, do metabolismo oxidativo e dos pigmentos fotossintéticos na propagação in vitro e aclimatização de Pitcairnia encholirioides, uma bromélia criticamente ameaçada de extinção. As análises foram realizadas após 150 dias de cultivo in vitro em meio MS suplementado com 10 µM de GA3 ou 0,2 µM de ANA, 15 ou 30 g L–1 de sacarose, em tubos de ensaio que permitiam trocas gasosas ou em sistema hermeticamente vedado, e também 180 dias após aclimatização. A manutenção in vitro em frascos hermeticamente fechados, com GA3 e 15 g L–1 de sacarose apresentou efeito metabólico adverso, demonstrado pelo menor acúmulo de prolina e pigmentos fotossintéticos e também pelo aumento das atividades de enzimas antioxidantes. Após aclimatização, as diferenças para prolina e pigmentos fotossintéticos não foram mais encontradas e as atividades enzimáticas variaram de maneira desuniforme. Os resultados sugerem que o cultivo in vitro em meio com 0,2 µM de ANA e 30 g L–1 de sacarose, em tubos fechados com tampas que permitem trocas gasosas, é mais adequado para a micropropagação de P. encholirioides, proporcionando uma manutenção prolongada das culturas in vitro e plântulas com qualidade superior para o desenvolvimento ex vitro.

Large oesophageal epiphrenic diverticulum resected by transhiatal robotic-assisted approach -- case report.

INTRODUCTION: Epiphrenic diverticula (ED) represent about 20% of oesophageal diverticula. They are considered to be pulsion diverticula, characterized by out pouchings of the oesophageal mucosa originating in the distal 10 cm of the oesophagus and are frequently associated with spastic oesophageal dysmotility. The most frequent clinical manifestations of ED are dysphagia, regurgitations and chest pain. Only symptomatic diverticula should be treated by surgery. The surgical procedure can be performed minimally invasively by robotic approach and consists of diverticulectomy,hiatus calibration and an antireflux procedure, usually adding an esophagomiotomy as well. CASE-REPORT: We present the case of 43-year-old male patient who was admitted for a four-month history of epigastric pain, pyrosis and regurgitations. Preoperative investigation shave shown an epiphrenic diverticulum 6 cm large in diameter.A robotic-assisted transhiatal diverticulectomy with a linear endostapler, hiatal calibration and a Nissen-Rossetti fundoplication were performed using a three-arm da Vinci Robotic System. Operative time was 150 min. Postoperative course was uneventful and the patient was discharged on postoperative day 9, without complications. Ten days later,he came back and was readmitted under emergency status for right chest pain, dyspnoea and fetid breath, being diagnosed with a right empyema secondary to a delayed fistula of the oesophageal suture line. A right minimal pleurotomy and pleural drainage under local anaesthesia were performed and an intravenous antibiotherapy was started with complete remission of symptomatology, the patient remaining asymptomatic after 18 months of follow-up. CONCLUSIONS: Robotic approach is a feasible and safe minimally invasive surgical option in the treatment of selected cases of ED. We consider transhiatal abdominal robotic approach possible in almost all cases of ED, regardless of size,thus avoiding thoracic approach and its possible major complications.The most common serious complication after surgery of ED is post diverticulectomy suture line fistula, but if properly and rapidly diagnosed it could be conservatively treated with very good results.

Occult thyroid carcinoma in our experience -- should we reconsider total thyroidectomy for benign thyroid pathology?

BACKGROUND: The reported incidence rate of occult thyroid carcinoma in patients operated for benign thyroid pathology has been much higher than expected in the last years,especially for multinodular goitre, which raises the question about which should the proper surgical management for these cases be. AIM: To assess the incidence rate of OTC in a single medium volume surgical center and to establish the correct indication for initial surgical management, as well as to identify the benign thyroid pathology most frequently associated with OTC. We also reviewed the relevant scientific literature on this topic. MATERIAL AND METHOD: We conducted a retrospective study in the General Surgery Clinic of "Prof. dr. Agrippa Ionescu" Clinical Emergency Hospital, Bucharest, on a series of 145 patients who underwent surgical interventions for preoperatively diagnosed benign thyroid pathology over a ten year period, between 1st January 2002 - 31st December 2012. All cases of known thyroid cancer were excluded. RESULTS: Incidence rate of occult thyroid carcinoma in our series was 6.9 % (10 out of 145 patients), 80 % of them being diagnosed with multinodular goitre and two cases (20 %) with Hashimoto's lymphocytic thyroiditis. 6.8 % of all patients with multinodular goitre were found to present occult carcinoma,but this association was without statistical significance(p 0.05). Incidence rate of occult cancer among patients with Hashimoto thyroiditis was proved to be as high as 28.6%,statistically significant (p=0.020). The mean size of postoperatively diagnosed occult microcarcinoma was 7 mm, ranging between 3 mm and 14 mm, 90% of them being smaller than 1cm. Histologically, papillary microcarcinoma was found in all cases. The mean age of the patients diagnosed with occult microcarcinoma was 47.8 years with majority of the female gender. The most frequent operation performed was total thyroidectomy (70.8%). Overall morbidity in our series was 6.9% with a 0.7 % mortality rate (1 case). CONCLUSIONS: In our opinion, primary total thyroidectomy should be performed as the procedure of choice for the most part of preoperatively diagnosed benign thyroid pathology and particularly for multinodular goitre and Hashimoto thyroiditis,in order to radically resect all possible foci of aggressive thyroid microcarcinomas.Abbreviations and Acronyms: OTC (Occult Thyroid Carcinoma), PTMC (Papillary Thyroid Microcarcinoma); TT(Total Thyroidectomy), MNG (Multinodular Goitre), GD(Graves' disease), TNG (Toxic Nodular Goitre), FNAB(fine-needle aspiration biopsy).

Ethylene synthesis inhibition effects on oxidative stress and in vitro conservation of Lippia filifolia (Verbenaceae).

This study aimed to investigate the effects of ethylene biosynthesis inhibitors on oxidative metabolisms and the in vitro conservation of Lippia filifolia, using the lipid peroxidation index (TBARS), antioxidative enzymes and pigments as biomarkers. We found that EDTA, sodium thiosulfate (STS) and especially Co had protective effects on oxidative stress in tissues cultured in vitro, resulting in a delay of the senescence and the reduction of subcultures frequency, contributing to the germplasm conservation of this species.

Angiotensin-II-induced reactive oxygen species along the SFO-PVN-RVLM pathway: implications in neurogenic hypertension

Neurogenic hypertension has been the subject of extensive research worldwide. This review is based on the premise that some forms of neurogenic hypertension are caused in part by the formation of angiotensin-II (Ang-II)-induced reactive oxygen species along the subfornical organ-paraventricular nucleus of the hypothalamus-rostral ventrolateral medulla pathway (SFO-PVN-RVLM pathway). We will discuss the recent contribution of our laboratory and others regarding the mechanisms by which neurons in the SFO (an important circumventricular organ) are activated by Ang-II, how the SFO communicates with two other important areas involved in sympathetic activity regulation (PVN and RVLM) and how Ang-II-induced reactive oxygen species participate along the SFO-PVN-RVLM pathway in the pathogenesis of neurogenic hypertension.

Characterization of reproductive disorders in ewes given an intrauterine dose of Toxoplasma gondii tachyzoites during the intrauterine insemination.

The aim of this study was to characterize the reproductive disorders in the acute and chronic phases in ewes experimentally infected with different doses of Toxoplasma gondii during artificial insemination occurred. Animals (n=41) were divided into three experimental groups: in the group 1 (G1, n=15), animals were inseminated using contaminated semen containing 6.5×104 tachyzoites; in the group 2 (G2, n=15), animals were inseminated with contaminated semen containing 4×107 tachyzoites and in the group 3 (G3, n=11), animals were inseminated using tachyzoite-free semen, serving as control group. Parasitemia and seroconversion were observed in 28 of 30 and 20 of 30, respectively, from the seventh day after infection. Embryonic reabsorption was observed in the acute phase in ewes from G1 and G2. Persistent anestrus, hydrometra, mucometra and follicular cysts were observed in the second phase of the experiment in animals from G1 and G2. Histopathological lesions similar to those of toxoplasmosis were found in the placentas. In conclusion, artificial insemination using semen containing experimentally added tachyzoites can establish toxoplasmosis in ewes and cause reproductive pathologies during the acute and chronic phases of the disease.

[Risk factors for hip fracture in elderly persons]. / Fattori di rischio per frattura di femore in persone anziane.

OBJECTIVE: The aim of this observational study, promoted by the Health Authorities of the Regione Veneto (Italy), is to assess the prevalence of the most relevant environmental and individual risk factors in subjects with a recent hip fracture. METHODS: Patients aged more than 60 years of both genders with a recent hip fracture not associated with malignancies, were administered questionnaires on dietary habits, sun exposure, and disability score. A complete family, pharmacological and pathology history was collected together with information on previous falls, details of the fracture index, and anthropometric data. In all subjects, blood was taken for the measurement of serum 25 hydroxy-vitamin D (25OHD). RESULTS: The study included 704 patients (573 women and 131 men). Mean age was 81 ± 8 years (range 60-102). Severe pre-fracture disability was a common feature (58%) associated with multiple co-morbidities (84%), more frequently cardiovascular and neurological diseases, and specific medications. In a large proportion (86%) of the patients, environmental or individual risk factors for falling were found. Vitamin D insufficiency (serum 25OHD levels < 75 nmol/l) was quite common (70%), particularly in the regional Health Districts were strategies for preventing vitamin D deficiency were not implemented (91%). Only a small proportion (17%) of the study population had been evaluated and treated for osteoporosis. CONCLUSIONS: In senile patients with a recent hip fracture, pre-existing disability, multiple co-morbidities, high risk of falling and inadequate intake of calcium and vitamin D is relatively common. Community and case-finding interventions aimed at selecting subjects at high risk of osteoporosis, preventing vitamin D and dietary calcium deficiency, and increasing awareness on the environmental risks of falling are highly warranted.

Intravenous neridronate in adults with osteogenesis imperfecta.

Osteogenesis imperfecta (OI) is a heritable disease of connective tissue, characterized by increased bone fragility. Bisphosphonates currently seems to be the most promising therapy, at least in children. We tested IV neridronate, an amino-bisphosphonate structurally similar to alendronate and pamidronate in adults with OI. Twenty-three men and 23 premenopausal women with OI were randomized to either iv neridronate (100 mg infused intravenously for 30 minutes every 3 months) or no treatment with a ratio of 2 to 1. Control patients were given the same bisphosphonate therapy at the end of the first year. Clinical evaluation included bone densitometry measurements using dual energy X-ray absorptiometry (DXA), fasting serum and urinary biochemistry every 6 months, and radiographs of the spine taken at baseline and after 12 and 24 months of follow-up. Spine and hip bone mineral density rose by 3.0 +/- 4.6% (SD) and by 4.3 +/- 3.9%, respectively, within the first 12 months of treatment, whereas small insignificant changes were observed in the control group. During the second year of follow-up, additional 3.91% and 1.49% increases were observed at the spine and hip, respectively. Markers of skeletal turnover significantly fell during neridronate treatment. Fracture incidence during neridronate treatment was significantly lower than before therapy and compared with controls. Neridronate iv infusions, administered quarterly, significantly increase bone mineral density and lowered the risk of clinical fracture in adults with OI. Bisphosphonate therapy seems to provide clinical benefits, not only to children with OI, but also to adult patients.

Relationship among VDR (BsmI and FokI), COLIA1, and CTR polymorphisms with bone mass, bone turnover markers, and sex hormones in men.

Osteoporosis is a disease characterized by low bone mineral density (BMD) and up to 80% of its variance is under genetic control. Although osteoporosis is more frequent in women, one-third of hip fractures also occur in men. Much information on genetic factors and bone density has been obtained in women, but only a few studies have been performed in osteoporotic men. We have evaluated the relationship between polymorphisms for several candidate genes such as vitamin D receptor (VDR), collagen type Ia1 (COLIA1), and calcitonin receptor (CTR) in a sample of unrelated Italian men (n = 253, mean age 58.41 +/- 15.64 SD). We found no significant differences in BMD when subjects were stratified for their VDR (BsmI and FokI) and COLIA1 genotypes. BMD both at the lumbar spine and at the femoral neck were associated with polymorphism of CTR gene. The CC genotype of CTR gene had the lowest BMD value (P <0.05 and P <0.01 at the spine and hip, respectively) and its prevalence was significantly over-represented in the subgroup of men with prior hip or vertebral fracture as compared with controls (P = 0.004% c2 = 11.10). The men with the CC genotype also showed significantly lower body mass index (BMI), serum sex hormone binding globulin (SHBG), estradiol, total alkaline phosphatase-(total AP) and bone alkaline phosphatase (bone AP) levels and significantly higher free androgen index (FAI). In conclusion, the polymorphism of CTR gene but not VDR and COLIA1 is associated with osteoporosis incidence and the levels of alkaline phosphatase and estradiol. The lower BMD in CC genotype is apparently associated in males with depressed bone formation and lower estradiol levels.

Short-term intravenous therapy with Neridronate in Paget's disease.

AIMS: To describe the effects of two consecutive intravenous infusions of aminohexane bisphosphonate (Neridronate) in patients with active Paget's disease of bone. METHODS: The study population included 83 patients, aged 41 to 85 years, randomized to 4 cumulative doses of Neridronate (25, 50, 100, 200 mg) given over 2 days, with a follow up of 180 days. The baseline serum alkaline phosphatase activity was at least 10% above the upper limit of the laboratory range. The response to treatment was assessed by changes in the serum total alkaline phosphatase (primary end point of the study), bone alkaline phosphatase and N-telopeptide urinary excretion. RESULTS: All Neridronate doses significantly suppressed the biochemical indices of disease activity. The nadir of total alkaline phosphatase levels ranged from -16 % to -57.5% of pretreatment values in the four groups, with a dose-response relationship that was apparent even between the two highest doses. The proportion of patients still maintaining a partial response (decreases in serum total alkaline phosphatase >25%) at the 6 month follow-up was also related to the dose: 98%, 67%, 57%, 21% in the patients given 200, 100, 50, 25 mg respectively. The proportion of responders in terms of bone alkaline phosphatase and N-telopeptide excretion changes was similar. Bone pain attributed to Paget's disease was significantly reduced. A typical acute phase reaction (fever and/or arthromyalgia) occurred in 16 out of 83 patients. CONCLUSIONS: We conclude that all of the Neridronate doses tested here were well tolerated and effective in decreasing, in a dose-related manner the bone turnover parameters of Paget's disease. The highest dose (200 mg) resulted in the normalization of the markers of disease activity in more than 60% of the patients.

'Super glue'.

Cell--cell adhesion is a significant mechanical component of cell and tissue structure. However, cell contacts are not just static mechanical structures: they are integrated into the cytoskeletal and signalling processes of the cell. The formation and remodelling of cell contacts are basic to both tissue morphogenesis and, after damage, wound repair. Loss of adhesion accompanies tumour metastasis. The interplay between these processes was a major theme of a recent joint meeting of the British Societies of Cell Biology and Developmental Biology on 'Cell and Tissue Morphogenesis' in Brighton, UK (3--6 April 2001).

Effects of oral alendronate in elderly patients with osteoporosis and mild primary hyperparathyroidism.

In a large proportion of the patients with primary hyperparathyroidism (PHPT), a variable degree of osteopenia is the only relevant manifestation of the disease. Low bone mineral density (BMD) in patients with PHPT is an indication for surgical intervention because successful parathyroidectomy results in a dramatic increase in BMD. However, low BMD values are almost an invariable finding in elderly women with PHPT, who are often either unwilling or considered unfit for surgery. Bisphosphonates are capable of suppressing parathyroid hormone (PTH)-mediated bone resorption and are useful for the prevention and treatment of postmenopausal osteoporosis. In this pilot-controlled study, we investigated the effects of oral treatment with alendronate on BMD and biochemical markers of calcium and bone metabolism in elderly women presenting osteoporosis and mild PHPT. Twenty-six elderly patients aged 67-81 years were randomized for treatment with either oral 10 mg alendronate on alternate-day treatment or no treatment for 2 years. In the control untreated patients a slight significant decrease was observed for total body and femoral neck BMD, without significant changes in biochemical markers of calcium and bone metabolism during the 2 years of observation. Urine deoxypyridinoline (Dpyr) excretion significantly fell within the first month of treatment with alendronate, while serum markers of bone formation alkaline phosphatase and osteocalcin fell more gradually and the decrease became significant only after 3 months of treatment; thereafter all bone turnover markers remained consistently suppressed during alendronate treatment. After 2 years in this group we observed statistically significant increases in BMD at lumbar spine, total hip, and total body (+8.6 +/- 3.0%, +4.8 +/- 3.9%, and +1.2 +/- 1.4% changes vs. baseline mean +/- SD) versus both baseline and control patients. Serum calcium, serum phosphate, and urinary calcium excretion significantly decreased during the first 3-6 months but rose back to the baseline values afterward. Increase in serum PTH level was statistically significant during the first year of treatment. These preliminary results may make alendronate a candidate as a supportive therapy in patients with mild PHPT who are unwilling or are unsuitable for surgery, and for whom osteoporosis is a reason of concern.

Activation of the small GTPase Rac is sufficient to disrupt cadherin-dependent cell-cell adhesion in normal human keratinocytes.

To achieve strong adhesion to their neighbors and sustain stress and tension, epithelial cells develop many different specialized adhesive structures. Breakdown of these structures occurs during tumor progression, with the development of a fibroblastic morphology characteristic of metastatic cells. During Ras transformation, Rac-signaling pathways participate in the disruption of cadherin-dependent adhesion. We show that sustained Rac activation per se is sufficient to disassemble cadherin-mediated contacts in keratinocytes, in a concentration- and time-dependent manner. Cadherin receptors are removed from junctions before integrin receptors, suggesting that pathways activated by Rac can specifically interfere with cadherin function. We mapped an important region for disruption of junctions to the putative second effector domain of the Rac protein. Interestingly, although this region overlaps the domain necessary to induce lamellipodia, we demonstrate that the disassembly of cadherin complexes is a new Rac activity, distinct from Rac-dependent lamellipodia formation. Because Rac activity is also necessary for migration, Rac is a good candidate to coordinately regulate cell-cell and cell-substratum adhesion during tumorigenesis.

Epithelial cell shape: cadherins and small GTPases.

Cadherins are cell-cell adhesion receptors that are essential for the establishment of the epithelial cell shape and maintenance of the differentiated epithelial phenotype. In order to show efficient adhesion, cadherin receptors require an association with actin filaments and the activity of RHO proteins. The RHO family of small GTPases is primarily involved in the reorganization of the cytoskeleton. In different cell types, each member of the family can induce specific types of organization of actin filaments: stress fibers (Rho), lamellae/ruffles (Rac), or filopodia (Cdc42). This review focuses on how the function of small GTPases may impinge on the regulation of cadherin-dependent adhesion. In particular, it discusses the impact that the above cytoskeletal structures induced by RHO proteins have on the development of epithelial morphology. Finally, the participation of small GTPase-interacting proteins is considered during the remodeling of cell shape that follows cell-cell contact formation.

Height, bone mineral density and bone markers in congenital adrenal hyperplasia.

AIM: To evaluate height, bone growth, areal bone mineral density (aBMD), volumetric bone mineral density (vBMD) and markers of bone turnover in a group of patients affected by congenital adrenal hyperplasia (CAH). PATIENTS: There were 50 patients (23 males, 27 females), aged 1-28 years, affected by CAH due to 21-hydroxylase deficiency: 27 with the salt-wasting (SW); 14 with the simple virilizing (SV), and 9 with the nonclassical (NC) forms. METHODS: Bone morphometry was evaluated with the metacarpal index (MI) and lumbar aBMD and vBMD (L2-L4) by dual energy X-ray absorptiometry. Serum osteocalcin was used as a marker of bone formation, while urinary cross-linked N-telopeptides of type-I collagen and free deoxypyridinoline levels were evaluated as indexes of bone resorption. RESULTS: The height standard deviation score (SDS) was -0.41 +/- 1.4 in SW patients, -0.01 +/- 1.9 in SV patients, and -0.01 +/- 2.3 in NC patients. There was no significant difference among groups and against zero. The MI SDS was also not different between groups and against zero. aBMD was significantly lower in the pubertal patients compared with normal values, but only when patients with the SW and SV forms were considered together (p < 0.05). vBMD was significantly reduced in all patients with the classical form. Bone markers were not different in patients and controls. CONCLUSION: Our study shows that normal height can be attained in CAH patients; however, an impairment in bone growth and mineralization may be found in adolescents and young adults affected by the classical form.

H-Ras activation promotes cytoplasmic accumulation and phosphoinositide 3-OH kinase association of beta-catenin in epidermal keratinocytes.

The mechanisms underlying downregulation of the cadherin/catenin complexes and beta-catenin signaling during tumor progression are not fully understood. We have analyzed the effect of oncogenic H-Ras on E-cadherin/catenin complex formation/stabilization and beta-catenin distribution in epidermal keratinocytes. Microinjection or stable expression of V12Ras into keratinocytes promotes the loss of E-cadherin and alpha-catenin and relocalization of beta-catenin to the cytoplasm and nucleus. Moreover, these effects are dependent on PI3K (phosphoinositide 3-OH kinase) activity. Interestingly, a strong association of p85alpha and p110alpha subunits of PI3K with beta-catenin is induced in V12Ras-expressing keratinocytes, and in vitro binding assays show a direct interaction between beta-catenin and p85alpha. Overexpression of either V12Ras or constitutively active p110alpha induces metabolic stabilization of beta-catenin and promotes its accumulation in cytoplasmic and nuclear pools. In addition, the interaction of beta-catenin with the adenomatous polyposis coli protein is blocked in V12Ras and p110alpha transformants though no changes in glycogen synthase kinase 3 beta activity could be detected. Nevertheless, in V12Ras transformants the in vivo phosphorylation of beta-catenin in Ser residues is strongly decreased. These results indicate that H-Ras activation induces the relocalization and cytoplasmic stabilization of beta-catenin by a mechanism involving its interaction with PI3K.