Rasopathies - dysmorphic syndromes with short stature and risk of malignancy

OBJECTIVES

The term ´Rasopathies´ represents a group of five neurodevelopmental syndromes (Noonan, LEOPARD, Costello, Cardio-facio-cutaneous, and Neurofibromatose-Noonan syndrome) caused by germline mutation in genes encoding proteins involved in RAS/MAPK (rat sarcoma/mitogen-activated protein kinase) signaling pathway. The RAS/MAPK signaling pathway participates in regulation of cell determination, proliferation, differentiation, migration, and senescence and dysregulation of this pathway can lead to the risk of tumorigenesis. In this review, we aim to summarize the current clinical and molecular genetic knowledge on Rasopathies with special attention for the risk of cancer. We propose also clinical and therapeutic approach for patients with malignancy.

METHODS

We are reviewing the clinical and molecular basis of Rasopathies based on recent studies, clinical examination, and molecular diagnostics (mutation analysis of causal genes for Rasopathies) in Slovak pediatric patients.

RESULTS

Some clinical features, such as short stature, a specific facial dysmorphology and cardiac abnormalities are common to all of Rasopathy syndromes. However, there are unique signs by which the syndromes can differ from each other, especially multiple lentigo in LEOPARD syndrome, increased risk of malignancy in Costello syndrome, dry hyperkeratotic skin in patients with cardio-facio-cutaneous syndrome, and neurofibromas and cafe-au-lait spots in neurofibromatosis-Noonan syndrome.

CONCLUSION

Despite the overlapping clinical features, Rasopathy syndromes exhibit unique fenotypical features and the precise molecular diagnostics may lead to confirmation of each syndrome. The molecular diagnostics may allow the detection of pathogenic mutation associated with tumorigenesis.

Combined model for diabetes lifestyle support

Treatment of diabetes mellitus is a public health related problem of modern healthcare. Surveys show that current methods to estimate the required amount of insulin are quite inefficient in practice as they are based on experience. This paper offers a new approach to predict the glucose level of people with diabetes. It combines two efficient models of the literature: one for nutrient absorption and one for glucose control. The combination of them tracks the blood sugar level considering nutrition composition, applied insulin and initial glucose level. Compared to already existing mixed meal models, the current version takes into account a more detailed nutrition composition (protein, lipid, monosaccharide, fiber and starch) supported by our expert dietary systems. Although the model gives satisfactory results even with parameter sets taken from literature, parameter training by genetic algorithms yields a better tracking of the patients.

Clustering of mutations in the 5' tertile of the NF1 gene in Slovakia patients with optic pathway glioma

Optic pathway gliomas (OPG) occur in 15% of patients with neurofibromatosis type 1 (NF1; OMIM 162200). Genotype-phenotype correlations in patients with NF1 may help to determine the risk group for developing complications such as OPG in coincidence with other NF1.features. We evaluated 52 patients with NF1 (25 with OPG and 27 without OPG). All subjects underwent a clinical examination focused on neurofibromatosis type 1 and molecular diagnostics of NF1 gene using protocol based on RNA analysis confirming the diagnosis of NF1. In the group with OPG patients, there was a significantly higher incidence of freckling (P=0.017), neurofibromatosis bright objects (NBO) (P=0.0038), compared to the group without OPG. The differences between the groups with respect to Lisch nodules were on the borderline of statistical significance (P=0.088). The frequency of neurofibromas in the group with OPG was not significant (P=0.9). From all patients with the mutation localized in the first tertile of the NF1 gene majority (71%) had optic glioma compared to individuals who didn't have the OPG 29% (P=0.0049). Our results present the clustering of mutations in the 5'tertile of NF1 gene in patients with optic nerve glioma and suggest higher incidence of freckling and neurofibromatosis brain objects in these patients. Molecular analysis of NF1 gene is important part in complex management of NF1 patients and contributes to a better understanding of clinical picture of NF1 patients. .

Late onset of familial neurogenic diabetes insipidus in monozygotic twins

OBJECTIVE

Autosomal dominant familial diabetes insipidus (FNDI) is a rare disease characterized by polydipsia and polyuria due to deficiency of the antidiuretic hormone, arginine vasopressin (AVP). We report the first Slovak family with the disease. Noteworthy is the concordantly belated debut of the disease symptoms in two monozygotic twin proband girls in the age of 17 years. Because of inconclusive results of water deprivation test consistent with partial diabetes insipidus (DI), missing "bright spot" of posterior pituitary gland in T1-weighted magnetic resonance imaging and family occurrence of polyuria and polydipsia on anamnestic evaluation.

METHODS

Molecular genetic testing of the AVP gene was proceeded, because of the inconclusive results of water deprivation test consistent with partial diabetes insipidus, missing "bright spot" of posterior pituitary gland in T1-weighted magnetic resonance imaging and family occurrence of polyuria and polydipsia on anamnestic evaluation.

RESULTS

Genetic analysis revealed a heterozygous g.279G>A substitution that predicts a p.Ala19Thr substitution in the signal peptide of the AVP prohormone. The wide intrafamiliar variations (3 to 17 years) in disease onset together with the concordantly delayed debut of polyuria in two monozygotic twin girls suggest that individual differences in genetic influences family environmental factors may modify the penetrance of the mutation of the AVP gene.

CONCLUSIONS

The present paper supports the notion that molecular genetic evaluation should be performed in all patients with familial occurrence of DI regardless of the clinical results.

Applicability results of a nonlinear model-based robust blood glucose control algorithm

INTRODUCTION

Generating optimal control algorithms for an artificial pancreas is an intensively researched problem. The available models are all nonlinear and rather complex. Model predictive control or run-to-run-based methodologies have proven to be efficient solutions for individualized treatment of type 1 diabetes mellitus (T1DM). However, the controller has to ensure safety and stability under all circumstances. Robust control methods seek to provide this safety and guarantee to handle even the worst-case situations and, hence, to generalize and complement results obtained by individualized control algorithms.

METHODS

Modern robust (e.g., Hinf) control is a linear model-based methodology that we have combined with the nonlinear model-based linear parameter varying technique. The control algorithm was designed on the high-complexity modified nonlinear glucose-insulin model of Sorensen, and it was compared step-by-step with linear model-based Hinf control results published in the literature. The applicability of the developed algorithm was tested first on a control cohort of 10 healthy persons' oral glucose tolerance test results and then on a large meal absorption profile adapted from the literature. In the latter case, two preliminary virtual patients were generated based on 1-1 week real continuous glucose monitor measurements.

RESULTS

We have found that the algorithm avoids hypoglycemia (not caused by physical activity or stress) independently from the considered absorption profiles.

CONCLUSION

Use of hard constraints proved their efficiency in fitting blood glucose level within a defined interval. However, in the future, more data of different T1DM patients will be collected and tested, including dynamic absorption model and in silico tests on validated simulators.

Pilot study of the SPRINT glycemic control protocol in a Hungarian medical intensive care unit

INTRODUCTION

Stress-induced hyperglycemia increases morbidity and mortality. Tight control can reduce mortality but has proven difficult to achieve. The SPRINT (Specialized Relative Insulin and Nutrition Tables) protocol is the only protocol that reduced both mortality and hypoglycemia by modulating both insulin and nutrition, but it has not been tested in independent hospitals.

METHODS

SPRINT was used for 12 adult intensive care unit patients (949 h) at Kálmán Pándy Hospital (Gyula, Hungary) as a clinical practice assessment. Insulin recommendations (0-6 U/h) were administered via constant infusion rather than bolus delivery. Nutrition was administered per local standard protocol, weaning parenteral to enteral nutrition, but was modulated per SPRINT recommendations. Measurement was every 1 to 2 h, per protocol. Glycemic performance is assessed by percentage of blood glucose (BG) measurements in glycemic bands for the cohort and per patient. Safety from hypoglycemia is assessed by numbers of patients with BG < 2.2 (severe) and %BG < 3.0 and < 4.0 mmol/liter (moderate and light). Clinical effort is assessed by measurements per day. Results are median (interquartile range).

RESULTS

There were 742 measurements over 1088 h of control (16.4 measurements/day), which is similar to clinical SPRINT results (16.2/day). Per-patient hours of control were 65 (50-95) h. Initial per-patient BG was 10.5 (7.9-11.2) mmol/liter. All patients (100%) reached 6.1 mmol/liter. Cohort BG was 6.3 (5.5-7.5) mmol/liter, with 42.2%, 65.1% and 77.6% of BG in the 4.0-6.1, 4.0-7.0, and 4.0-8.0 mmol/liter bands. Per-patient, median percentage time in these bands was 40.2 (26.7-51.5)%, 62.5 (46.0-75.7)%, and 74.7 (61.6.8-87.8)%, respectively. No patients had BG < 2.2 mmol/liter, and the %BG < 4.0 mmol/liter was 1.9%. These results were achieved using 3.0 (3.0-5.0) U/h of insulin with 7.4 (4.4-10.2) g/h of dextrose administration (all sources) for the cohort. Per-patient median insulin administration was 3.0 (3.0-3.0) U/h and 7.1 (3.4-9.6) g/h dextrose. Higher carbohydrate nutrition formulas than were used in SPRINT are offset by slightly higher insulin administration in this study.

CONCLUSIONS

The glycemic performance shows that using the SPRINT protocol to guide insulin infusions and nutrition administration provided very good glycemic control in initial pilot testing, with no severe hypoglycemia. The overall design of the protocol was able to be generalized with good compliance and outcomes across geographically distinct clinical units, patients, and clinical practice.

Differences in the laboratory parameters of obese and healthy Hungarian children and their use in automatic classification

Obesity is a rapidly spreading endemic in almost every country of the developed world, of which Hungary is no exception. By a joint research project we aim to deepen our understanding of obesity-associated, and especially obesity-predicting changes of clinical markers (anthropometric indices, body composition, laboratory results etc.) in children, especially in teenage population. This paper presents the preliminary results of our investigations which pertain to obesity-related alterations in routine blood test parameters. For that end, we examined 340 healthy and obese children. Results show that there are differences between the routine laboratory parameters of obese and healthy subjects that are both statistically significant and medically interesting. We point out these differences in a statistically precise way, and show a method which can be efficiently used to classify children based on their laboratory parameters. This result can be used later to develop a more realistic model to predict the risk of obesity.

285 THE EFFICIENCY OF INTRACYTOPLASMIC SPERM INJECTION v. LASER-ASSISTED IN VITRO FERTILIZATION WITH FROZEN SPERM FOR RECOVERY TRANSGENIC C57BL/6 MOUSE STRAINS

The progress of molecular genetics generated thousands of new transgenic strains of mice which also requires their economic and safe maintenance in the form of genetic banks. Sperm freezing would be one of the easiest options; however, cryosensitivity of sperm in mice strains is prone to variation. In this study, we examined the efficiency of laser-assisted zona drilling in vitro fertilization (ZD-IVF) v. intracytoplasmic sperm injection (ICSI) for attempting to recover two transgenic (UBI-GFP/BL6 and B6;129P2- Hvcn1) and one mutant (C57BL/6J-Tyrc-2J) lines. The sperm was frozen with 18% raffinose and 3% skim milk (Nakagata 2000 Mamm Genome 11, 572–576). Data of the replicates was analysed by chi-square method. The motility rates after thawing of cryopreserved sperm were 10% for UBI-GFP/BL6, 30% C57BL/6J-Tyrc-2J and 50% for B6;129P2-Hvcn1 strains. Regular IVF attempts in the UBI-GFP/BL6 and the mutant strain resulted in very few embryos and no pups (data not shown). Following ZD-IVF, the 2-cell stage rates were 7/60 (12%) for UBI-GFP/BL6, 18/60 (30%) for C57BL/6J-Tyrc-2J, and 34/60 (56%) for B6;129P2- Hvcn1. After ICSI, 66–74% of the oocytes survived the procedure and their development to 2-cells stage were 12/20 (60%) (UBI-GFP/BL6), 25/39 (64%) (C57BL/6J-Tyrc-2J) and 26/37 (70%) (B6;129P2-Hvcn1). The number of 2-cell stage embryos produced by ICSI was significantly (P < 0.05) increased compared with those produced following ZD-IVF in case of UBI-GFP/BL6 and C57BL/6J-Tyrc-2J strains. The 2-cell stage embryos were transferred into recipients and the newborn rates from ZD-IVF v. ICSI embryos were 0% v. 17% (UBI-GFP/BL6), 28% v. 36% (C57BL/6J-Tyrc-2J) and 12% v. 12% (B6;129P2- Hvcn1), respectively; none of them were significantly different. In conclusion, when using cryopreserved sperm, the post-thaw motility is an important indicator for the selection of the rederivation method of cryopreserved transgenic mouse strains; while ZD-IVF, an easier method to perform, is suitable for the higher motility samples, ICSI could be strongly recommended for those showing low motility. This work was financed by EU FP6: CLONET (MRTN-CT-2006-035468), TEAMOHOLIC (MEXT-CT-2003-509582); EU FP7: RESOLVE (FP7-HEALTH-F4-2008-202047), RabPStem (PERG07-GA-2010-268422), and NKFP_07_1-ES2HEART-HU (OM-00202-2007).

Neuroendocrine and cardiovascular parameters during simulation of stress-induced rise in circulating oxytocin in the rat

Physiological functions of oxytocin released during stress are not well understood. We have (1) investigated the release of oxytocin during chronic stress using two long-term stress models and (2) simulated stress-induced oxytocin secretion by chronic treatment with oxytocin via osmotic minipumps. Plasma oxytocin levels were significantly elevated in rats subjected to acute immobilization stress for 120 min, to repeated immobilization for 7 days and to combined chronic cold stress exposure for 28 days with 7 days immobilization. To simulate elevation of oxytocin during chronic stress, rats were implanted with osmotic minipumps subcutaneously and treated with oxytocin (3.6 microg/100 g body weight/day) or vehicle for 2 weeks. Chronic subcutaneous oxytocin infusion led to an increase in plasma oxytocin, adrenocorticotropic hormone, corticosterone, adrenal weights and heart/body weight ratio. Oxytocin treatment had no effect on the incorporation of 5-bromo-2-deoxyuridine into DNA in the heart ventricle. Mean arterial pressure response to intravenous phenylephrine was reduced in oxytocin-treated animals. Decrease in adrenal tyrosin hydroxylase mRNA following oxytocin treatment was not statistically significant. Oxytocin treatment failed to modify food intake and slightly increased water consumption. These data provide evidence on increased concentrations of oxytocin during chronic stress. It is possible that the role of oxytocin released during stress is in modulating hypothalamic-pituitary-adrenocortical axis and selected sympathetic functions.

Problems of metabolic syndrome diagnostics in children

OBJECTIVE

Increasing prevalence of exogenous obesity in children appears possibly related to changes in their lipid and carbohydrate metabolism resulting from insulin resistance which, together with obesity and arterial hypertension, are among the components of metabolic syndrome. The aim of this study was to evaluate the age related incidence of obesity complications and the prevalence of metabolic syndrome in children according to the latest criteria.

METHODS

A total of 98 obese children were divided in two age groups (5 to 10 and 10 to 16 years). In all patients the BMI was calculated, standard deviation score of BMI (SDS BMI) was estimated according to the data by anthropometric surveys Slovakia and obesity was defined as SDS BMI >2 which is equal to 97th percentile for the appropriate age and gender. Blood pressure >95th percentile for the appropriate gender, age and body was classified as hypertension. Fasting glycemia, total and HDL cholesterol and triglycerides were determined in serum and oral glucose tolerance test was performed. Insulin resistance was classified according to HOMA index.

RESULTS

Among 21 children less than 10 years of age lower HOMA values and no impaired glucose tolerance appeared, but hypercholesterolemia was found in 8 cases (38.1 %). Among 77 patients aged 10 to 16 years increased frequency of cases was found with insulin resistance (37.7 %), increased triglycerides (53.3 %), decreased HDL cholesterol (54.4 %) and impaired glucose tolerance (7.8 %). In this group 32.5 % of children showed metabolic syndrome based on modified IDF criteria, while such prevalence rose to 39.0 % if borderline criteria for blood pressure were used.

CONCLUSION

The treatment of referred pathological states requires lifestyle changes and follow up at the specialized clinic.

Detection of the root canal's centerline from dental micro-CT records

This paper presents a novel image processing procedure dedicated to the automated detection of the medial axis of the root canal from dental micro CT records. The 3D model of root canal is built up from several hundreds of parallel cross sections, using image enhancement and segmentation, center point detection in the segmented slice, three dimensional inner surface reconstruction and morphological skeleton extraction in three dimensions. The central line of the root canal is interpolated as a 3D spline curve. The proposed procedure can help prepare several kinds of endodontic interventions.

The psychological impact of severe hand injury

The final outcome of severe hand injuries is not solely determined by the residual functional impairment, but is also a function of non-functional criteria, including the sequelae of the accompanying psychological trauma. This paper reviews the literature with respect to the psychological impact of severe hand injuries, including the special impact of amputations, adaptation processes, adaptation stages, prognostic criteria and aesthetic issues influencing the final individual outcome, including present recommendations for promoting a positive outcome. Motivated and psychologically stable people are reported to do well irrespective of the severity of a hand injury. In patients who find it difficult to cope mentally, successful treatment strategies have been proposed. Their implementation is in a constant state of evolution and includes not only improved surgical techniques and advanced pharmacological pain management but also early psychotherapeutic input and involvement of patients in decision making for treatment.

3D surface measurement for medical application--technical comparison of two established industrial surface scanning systems

In 3D mapping of flexible surfaces (e.g. human faces) measurement errors due to movement or positioning occur. Aggravated by equipment- or researcher-caused mistakes considerable deviations can result. Therefore first the appliances' precision handling and reliability in clinical environment must be established. Aim of this study was to investigate accuracy and precision of two contact-free 3D measurement systems (white light vs. laser). Standard specimens of known diameter for sphere deviation, touch deviation and plane deviation were tested. Both systems are appropriate for medical application acquiring solid data (<mm). The more complex white-light system shows better accuracy at 0.2 s measuring time. The laser system is superior concerning robustness, while accuracy is poorer and input time (1.5-2.5 s) longer. Due to the clinical demand the white-light system is superior in a laboratory environment, while the laser system is easier to handle under non-laboratory conditions.