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S Bernasconi

Publications and source records attributed to S Bernasconi.

At least 37 records · Page 2Linked to original sources
PubMed2004

Surface electromyography of nine shoulder muscles in two iron cross conditions in gymnastics.

AIM: The rules of gymnastics impose an element of static strength such as an iron cross (IC) on the rings. For IC training, coaches use a custom made device -- the herdos -- to simulate the conditions of competition. The purpose was to compare muscle activity and coordination during IC performed both on the rings and using herdos. Secondly, we tried to determine whether herdos usage induced functional adaptations of the shoulder muscles. METHODS: Six male gymnasts performed 10 IC in each condition. Surface electromyogram of muscles pectoralis major, latissimus dorsi, teres major, infraspinatus, rhomboideus, trapezius, serratus anterior, biceps brachii, and triceps brachii in the right shoulder were analysed using root-mean-square (RMS), and muscle part's in each condition. Muscle part represents the contribution of each of the 9 shoulder muscles studied in each condition. Total muscle activity (SUM) was also used to compare the 2 conditions. RESULTS: Except for the muscle teres major, the RMS decreases (p<0.05) when using the herdos. The SUM also decreases (p<0.05) when using this device. The muscle parts indicate that the contribution of the muscle latissimus dorsi decreases (p<0.05) when using the herdos. These results suggest that the herdos modified shoulder coordination. But their usage does not seem to induce any functional adaptations of these muscles. CONCLUSIONS: The herdos do not seem to provide a valid method to reproduce the same shoulder coordination as on the rings. Therefore IC training with this special device could be called in question.

Adult↗
PubMed2003

Mitochondrial dysfunction and death in motor neurons exposed to the glutathione-depleting agent ethacrynic acid.

This study investigated the mechanisms of toxicity of glutathione (GSH) depletion in one cell type, the motor neuron. Ethacrynic acid (EA) (100 microM) was added to immortalized mouse motor neurons (NSC-34) to deplete both cytosolic and mitochondrial glutathione rapidly. This caused a drop in GSH to 25% of the initial level in 1 h and complete loss in 4 h. This effect was accompanied by enhanced generation of reactive oxygen species (ROS) with a peak after 2 h of exposure, and by signs of mitochondrial dysfunction such as a decrease in 3-(4,5-dimethyl-2-thiazoyl)-2,5-diphenyltetrazolium bromide (MTT) (30% less after 4 h). The increase in ROS and the MTT reduction were both EA concentration-dependent. Expression of heme oxygenase-1 (HO-1), a marker of oxidative stress, also increased. The mitochondrial damage was monitored by measuring the mitochondrial membrane potential (MMP) from the uptake of rhodamine 123 into mitochondria. MMP dropped (20%) after only 1 h exposure to EA, and slowly continued to decline until 3 h, with a steep drop at 5 h (50% decrease), i.e. after the complete GSH loss. Quantification of DNA fragmentation by the TUNEL technique showed that the proportion of cells with fragmented nuclei rose from 10% after 5 h EA exposure to about 65% at 18 h. These results indicate that EA-induced GSH depletion rapidly impairs the mitochondrial function of motor neurons, and this precedes cell death. This experimental model of oxidative toxicity could be useful to study mechanisms of diseases like spinal cord injury (SCI) and amyotrophic lateral sclerosis (ALS), where motor neurons are the vulnerable population and oxidative stress has a pathogenic role.

Animals↗
PubMed2003

Transition from pediatric to adult care of children with chronic endocrine diseases: a survey on the current modalities in Italy.

We report on a survey carried out in 65 pediatric and adult endocrinological centers concerning: 1) the modalities of the transfer of children with chronic endocrine diseases from pediatricians to adult endocrinologists, 2) opinions and suggestions from physicians of the Centers, and 3) specific details regarding GH deficiency. The main results are: 1) The mean age of transfer is around 18 yr of age. 2) The reasons for the transfer are personal convincement of pediatricians in 47%, administrative reasons in 37% and patient's desire in 16% of cases 3) In the majority of cases a discharge summary is sent by the pediatrician to the endocrinologist often followed by a phone call, whereas 30% of endocrinologists do not send a report back to pediatricians. 4) Less than half of the Centers are satisfied with the modalities of the transfer and the remainder complain about the lack of communication, no common guidelines, and differences in the management of patients. However, all are willing to try to improve this important time for adolescents with chronic diseases. 5) As far as GH deficiency is concerned, the main differences between pediatric and adult endocrinological centers are the different tests used to re-evaluate the diagnosis and the higher doses of GH used by pediatricians to treat young adults. In conclusion, considering the interest and desire of physicians, a structural intervention of the scientific societies to help to overcome problems is highly desirable.

Adolescent↗
PubMed2003

Interleukin-1beta (IL-1beta) and IL-6 modulate insulin-like growth factor-binding protein (IGFBP) secretion in colon cancer epithelial (Caco-2) cells.

Chronic inflammation is characterised by modifications in cytokine concentrations, whereas growth is mainly dependent on the GH-IGF axis. IGF-I bioavailability is modulated by a family of IGF-binding proteins (IGFBPs). The aim of the present study was to evaluate the interactions among interleukin-1beta (IL-1beta), IL-6 and IGFBP secretion by intestinal cells to assess whether cytokines modulate IGFBP secretion, and in turn IGF-I and IGF-II bioavailability. The human colon carcinoma derived cell line Caco-2 was used as an in vitro model for its capacity to differentiate spontaneously. Experiments were carried out on day 4 (undifferentiated state) and day 14 (differentiated state) after plating. Carcinoembryonic antigen (CEA) was used as a marker of differentiation and increased in the conditioned media (CM) from days 4 to 14 (0.2+/-0.01 ng/ml per 10(5) cells vs 3.3+/-0.2 ng/ml per 10(5) cells, P<0.05). IGFBP-2 and IGFBP-4 secretion decreased concomitantly. Cells were stimulated with IL-1beta and IL-6 at 1, 10 and 50 ng/ml, and with IL-1beta and IL-6 in combination at the same dose of 1 and 10 ng/ml. IGF-I at 50 ng/ml was used as a control. Caco-2 cells expressed and secreted mainly IGFBP-2 and IGFBP-4 into the CM. On day 4, IL-1beta (1 ng/ml) and IL-6 (10 and 50 ng/ml) reduced IGFBP-2 by 29+/-8%, and by 32+/-9 and 38+/-8% respectively (P<0.05). IGFBP-4 was also reduced by IL-1beta at 1 and 50 ng/ml (-14+/-4% and -46+/-11% vs serum free medium (SFM) respectively, P<0.05), and IL-6 at 50 ng/ml (-46+/-15%, P<0.05). Both IGFBP-2 and IGFBP-4 were reduced by IL-1beta and IL-6 in combination at 1 and 10 ng/ml (P<0.05). On day 14, IGFBP-2 band intensity was reduced at 10 ng/ml of IL-1beta (-22+/-15% vs SFM, P<0.05) and at 50 ng/ml of both cytokines (-33%+/-8% and -13%+/-13% vs baseline respectively, P<0.05). IGFBP-4 band intensity decreased with 10 and 50 ng/ml of IL-1beta (-35+/-11% and -46+/-15% vs SFM respectively) and IL-6 (-36%+/-10% and -46+/-15% vs SFM respectively). IL-1beta and IL-6 in combination at 1 and 10 ng/ml reduced both IGFBP-2 and IGFBP-4.In conclusion, IGFBP-2 and IGFBP-4 secretion in CM decreased with Caco-2 cell differentiation. IGFBP-2 and IGFBP-4 were significantly decreased by IL-1beta and IL-6 treatment in both the undifferentiated and differentiated state. Furthermore, these cytokines increased cell proliferation whereas total protein content was significantly reduced only at the higher concentrations of IL-6 and IL-1beta. These findings suggest that interleukins modulate the IGF-IGFBP system in Caco-2 cells in vitro.

Caco-2 Cells↗
PubMed2003

Growth and pubertal disorders in neurofibromatosis type 1.

The first textbook of Pediatric Endocrinology in the early 1950s reported an association of neurofibromatosis type 1 (NF1) and precocious puberty (PP) and/or short stature. Recent studies have indicated that children with NF1 grow normally until puberty; thereafter height velocity and relative height (SDS or percentiles) decreases with respect to healthy peers, reaching a mean adult height close to the 25th percentile for the general population. Moreover, the percentage of patients with true short stature (<3rd percentile) increases from childhood (5%) to late puberty (20-30% in literature, 18% in our study), and final height is significantly below the genetic target and predicted adult height calculated just before or at the beginning of puberty. Finally, among the shortest patients (<10th percentile) there is a high incidence of severe complications, such as CNS tumors, huge plexiform neurofibromas and severe scoliosis. Precocious puberty is a frequent complication of NF1, and occurs mainly in association with optic pathway tumors (OPT); however, occasionally it has been reported in the absence of optic gliomas, probably with a similar incidence as in the general population. GnRH agonist therapy must be decided individually as in some patients further growth could be normal and/or treatment would not improve final height. In the presence of early pubertal signs, an OPT must be ruled out. In addition to PP, delayed puberty has been frequently reported in NF1. In a study of 123 girls with NF1, we found that the mean age at menarche (13.0 +/- 1.9 yr) was later than in their mothers (12.7 +/- 1.4 yr) and in the general population (12.4 +/- 1.2 yr; p <0.05), with a very high incidence of delayed menarche (>2 SD): 16% vs 6.8% (mothers) vs 3.4% (controls) (p <0.01). In conclusion, growth and puberty present unusual patterns in NF1, often with true pathological findings increasing medical and psychological problems.

Body Height↗
PubMed2003

Diagnostic approach and therapy of overgrowth and tall stature in childhood.

Although referral for evaluation of tall stature is much less common than for short stature, early diagnosis in the paediatric age of clinical pictures leading to tall stature is crucial, both in order to detect conditions which can be properly treated and in order to limit excessive final heights; nowadays tall stature may be cause of psychosocial problems. This paper reviews different items related to tall stature in childhood. First of all, our review focuses on the definition of tall stature and the classification of the main clinical conditions associated with either tallness or excessive growth is discussed. Secondly, the clinical picture and the most recent breakthroughs of each of these conditions are reviewed. A diagnostic flow-chart meant to approach a patient presenting with tall stature is designed according to a few simple parameters such as chronological age, height age, bone age and growth velocity. The novel advances in the understanding of constitutional and secondary tall stature are presented and discussed, together with the hormonal treatment of constitutional tall stature and other related outstanding questions.

Child↗
PubMed2002

Induction of puberty in the hypogonadal girl--practices and attitudes of pediatric endocrinologists in Europe.

The management of children and adolescents with hypogonadism and in particular the induction of puberty in the hypogonadal girl is subject to controversy. Therefore, under the auspices and through organization of the Drugs and Therapeutics Committee of the European Society of Paediatric Endocrinology (ESPE), an interactive voting session and workshop was held at the 39th ESPE Annual Meeting in Brussels to discuss these topics. Common practice in Europe and attitudes of pediatric endocrinologists in Europe were questioned and recorded in the 1.5-hour program. We now report on some of the results of the questionnaires and discussions of that session to further the discussion on and knowledge of current concepts of induction of puberty in the hypogonadal girl in Europe. It became clear from the data accumulated here that the start of treatment, the aims of therapy and the modalities of how to treat the hypogonadal girl vary amongst pediatric endocrinologists in Europe. For example, a chronological age > or =11 years was considered appropriate for the start of estrogen therapy by 40.4% (out of 188 answers), while 47.8 and 7.5% felt that a chronological age > or =13 and > or =15 years respectively was appropriate. In respect to the form and route of estrogen administration, the audience was asked for their common estrogen replacement practice: 31.9% used oral 17beta-estradiol treatment, while 10% would prescribe 17beta-estradiol transdermal patches. Another 12.2% would recommend conjugated estrogens (e.g. Premarin) orally, 4.8% use oral estradiol valerate and 39.3% ethinylestradiol orally. Only 1.8% out of 229 physicians answering were undecided. In addition, counseling of patients and their families is quite variable and perceptions for example regarding potential pregnancies in affected women are also not uniform. In this report the authors do not want to provide their own personal views but rather reflect current practice in Europe. It is hoped that a more uniform picture will emerge once European and international guidelines on how to treat the girl with hypogonadism will be available and even more discussions amongst doctors from different countries have been led.

Adolescent↗
PubMed2002

High serum allopregnanolone levels in girls with precocious puberty.

Allopregnanolone, a circulating neuroactive steroid hormone, is involved in the modulation of behavioral functions, stress, and the neuroendocrine axis. The aim of this study was to evaluate serum allopregnanolone concentrations in girls with central precocious puberty (n = 12), girls with normal pubertal development at the same pubertal stage (n = 17), and prepubertal girls (age-matched; n = 16). Gonadotropin and steroid hormones (allopregnanolone, cortisol, dehydroepiandrosterone sulfate, and E2) were assessed in all patients. GnRH and ACTH stimulation tests were performed in all girls with central precocious puberty and in some pubertal controls. Basal allopregnanolone levels in girls with central precocious puberty were significantly higher than in normal controls (P < 0.01). Allopregnanolone levels increased significantly after GnRH and ACTH stimulation tests (P < 0.05) both in girls with central precocious puberty and in those with normal pubertal development. There was no difference found between the peak values. In conclusion, our study shows that allopregnanolone is hypersecreted in central precocious puberty, confirming a pubertal stage-related increase in its levels during normal pubertal development. The increase in serum allopregnanolone after GnRH and ACTH stimulation tests demonstrates that both adrenal cortex and gonads are sources of this neuroactive steroid.

Adrenocorticotropic Hormone↗
PubMed2002

Thyroid nodules.

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Biopsy, Needle↗
PubMed2002

Hypothyroidism.

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Humans↗
PubMed2002

Association of waist circumference and body mass index with fasting blood insulin in severely obese children: a cross-sectional study.

We tested whether body mass index (BMI) and waist circumference (WC) are associated with fasting insulin in severely obese children. A number of 391 (204 female and 187 male) obese children were consecutively enrolled in the study at a Paediatric outpatient clinic. They were aged 10+/-3 yr (mean+/-SD; range: 3-17 yr) and had a relative weight for age of 160+/-27% (mean+/-SD). BMI and WC explained respectively 9 and 13% of the variance of log-transformed (lt) insulin (p<0.0001 for both). After correction for age, however, BMI lost its association with lt-insulin (p=NS) and WC explained only 3% (p<0.001) of lt-insulin variance. Sex and pubertal status did not influence the relationship between WC, BMI and lt-insulin (p=NS, ANCOVA). We conclude that in severely obese children: 1) WC is a marginally better predictor of fasting blood insulin than BMI, 2) age has a substantial influence on the relationship between BMI, WC and insulin and, 3) the contribution of BMI and WC to insulin is of doubtful clinical relevance because it leaves a substantial portion (> or = 87%) of lt-insulin variance unexplained.

Adolescent↗
PubMed2001

CD20 levels determine the in vitro susceptibility to rituximab and complement of B-cell chronic lymphocytic leukemia: further regulation by CD55 and CD59.

Complement-dependent cytotoxicity is thought to be an important mechanism of action of the anti-CD20 monoclonal antibody rituximab. This study investigates the sensitivity of freshly isolated cells obtained from 33 patients with B-cell chronic lymphocytic leukemia (B-CLL), 5 patients with prolymphocytic leukemia (PLL), and 6 patients with mantle cell lymphoma (MCL) to be lysed by rituximab and complement in vitro. The results showed that in B-CLL and PLL, the levels of CD20, measured by standard immunofluorescence or using calibrated beads, correlated linearly with the lytic response (coefficient greater than or equal to 0.9; P <.0001). Furthermore, the correlation remained highly significant when the 6 patients with MCL were included in the analysis (coefficient 0.91; P <.0001), which suggests that CD20 levels primarily determine lysis regardless of diagnostic group. The role of the complement inhibitors CD46, CD55, and CD59 was also investigated. All B-CLL and PLL cells expressed these molecules, but at different levels. CD46 was relatively weak on all samples (mean fluorescence intensity less than 100), whereas CD55 and CD59 showed variability of expression (mean fluorescence intensity 20-1200 and 20-250, respectively). Although CD55 and CD59 levels did not permit prediction of complement susceptibility, the functional block of these inhibitors demonstrated that they play an important role in regulating complement-dependent cytotoxicity. Thus, lysis of poorly responding B-CLL samples was increased 5- to 6-fold after blocking both CD55 and CD59, whereas that of high responders was essentially complete in the presence of a single blocking antibody. These data demonstrate that CD20, CD55, and CD59 are important factors determining the in vitro response to rituximab and complement and indicate potential strategies to improve the clinical response to this biologic therapy.

Antibodies, Monoclonal↗
PubMed2001

Selective induction of phospholipase D1 in pathogen-activated human monocytes.

Phospholipase D (PLD) activation is part of the complex signalling cascade induced during phagocyte activation. Two PLD isoforms have been cloned, but their role in phagocyte functions is still poorly defined. We report that resting fresh circulating human monocytes expressed PLD1. PLD1 protein expression was rapidly down-regulated during cell culture. Lipopolysaccharide and pathogen-derived agonists (Candida albicans, arabinoside-terminated lipoarabinomannan and Gram-positive bacteria, but not mannose-capped lipoarabinomannan or double-stranded RNA) strongly induced PLD1 expression at both the mRNA and protein levels. Pro-inflammatory cytokines [interleukin (IL)-1beta and tumour necrosis factor alpha] had only a weak effect, whereas immune cytokines (IL-6 and interferon gamma), anti-inflammatory cytokines (IL-13 and IL-10) and chemoattractants (fMet-Leu-Phe and macrophage chemoattractant protein 1) were inactive. None of the agonists tested induced significant changes in the basal expression of PLD2 mRNA. Consistent with PLD1 up-regulation was the observation that PLD enzymic activity was higher in monocytes treated with active-pathogen-derived agonists than in control cells, when stimulated with PMA or with chemotactic agonists (fMet-Leu-Phe and C5a). Thus PLD2 seems to be a constitutive enzyme in circulating monocytes. Conversely, PLD1 is an inducible protein, rapidly regulated during culture conditions and selectively induced during cell activation. Therefore PLD1 might have a relevant role in immune responses against pathogens and in chronic inflammation.

Blotting, Northern↗