Minimally Invasive Parathyroidectomy in Patients with Previous Endocrine Surgery

Minimally invasive parathyroidectomy with a lateral approach was found to be an acceptable option in select patients with sporadic primary hyperparathyroidism and previous endocrine neck surgery

A multidisciplinary approach for an effective and rational energy transition in Crete Island, Greece.

This article proposes a mixture of actions for the development of an effective and rational energy transition plan for all sectors and for all types of onshore final energy use in Crete. Energy transition is initiated with an appropriate capacity building campaign. The plan is based on the introduction of energy saving measures and the exploitation of all the locally available energy resources (wind, solar, geothermal potential, biomass), integrated in a cluster of centralized and decentralized power plants and smart grids to produce electricity and heat and for the transition to e-mobility. The core of the energy transition in Crete will be a set of 14 wind parks and Pumped Hydro Storage systems (PHS) for electricity generation and 12 Combined Heat and Power plants, properly designed and dispersed in the insular territory. Economic analysis is executed for the proposed essential power plants on the island. Biomass, solar and geothermal potential can cover the heating demand in Crete several times. Heat can be produced with a specific cost of 0.05 EUR/kWhth from cogeneration plants fired with solid biomass and biogas. The wind parks-PHS systems exhibit payback periods of approximately 10 years with a final electricity selling price at 0.12 EUR/kWhel. The article shows that 100% energy transition in Crete constitutes a feasible target

Investigation of the role of pharmacokinetics and the development of novel anti-obesity agents

Oxyntomodulin is a gut hormone that promotes satiety by exhibiting an anorectic effect through the action at the GLP-1 receptor while at the same time it has been suggested that it is able to increase energy expenditure through the glucagon receptor, albeit with a less potency than native peptides. This dual mode of action makes it an ideal candidate for an anti-obesity medication. However, oxyntomodulin possesses an inadequate pharmacokinetic profile with a very short half-life and duration of action. These observations promoted the idea that oxyntomodulin could be used as the starting point for developing an anti-obesity drug agent through modifications of its primary amino acid structure. The exact knowledge of the pharmacokinetic properties of peptides (half-life, metabolic clearance rate, volume of distribution) is crucial in drug development as it allows investigating the effect of amino acid changes in the presence of the peptide in the plasma and correlates this with the exerted biological effect. The first aim of this thesis was to develop a reliable in vivo animal model that could be used to measure the pharmacokinetic properties of anti-obesity drug candidates based on oxyntomodulin. Results have shown that the proposed model is robust enough to be used for this scope. The second aim was to develop an analogue, based on oxyntomodulin, with a higher anorectic effect and a prolonged duration of action with the aim of developing an anti-obesity medication that could be used as a therapeutic agent in humans given once-weekly. Point substitutions in the primary amino acid structure of oxyntomodulin (positions 16, 23, 24, 29 and 30) were done in order to enhance the anorectic effect of oxyntomodulin and 26 analogues were developed and tested in order to investigate the effect of these substitutions. The pharmacokinetic properties of these analogues were measured with the help of the in vivo animal model. Other substitutions in the C terminal of the analogues were made in order to allow the formation of a subcutaneous depot when given in a zinc-containing slow-release formulation with the aim to prolong the presence of the peptide in the circulation. Data presented in this thesis have identified OXM analogue X26 presents a 8.3– and 45-fold higher potency at the GLP-1R and GCGR respectively when compared to native OXM. When administered in a zinc containing formula, X26 is present in the circulation 7 days post-injection. Furthermore, it has demonstrated a significantly longer half-life than OXM (21.3 vs. 12 min). Its ability to inhibit food intake and reduce body weight has been shown in rodent species; mice and rats. Analogue X26 is a novel and valuable pharmaceutical approach for the treatment of obesity.Open Acces

Analysis of PrP genotypes in relation to reproductive and production traits in Chios sheep

The study describes the changes with time in gene and genotype frequencies of a closed Chios herd. Genomic DNA was isolated and purified from peripheral blood leucocytes using standard procedures. The identification of the allelic variants present in the DNA samples, was performed in a simple multiplex PCR reaction and melting curve analysis of the PrP gene. Only ARR/ARR female genotypes were kept for breeding, and only males of the same genotype were used following year 2 of the study. As a result of planned individual matings and selection, the susceptible ARQ/ARQ genotype was eliminated from the flock in 4 years. The gene frequency of the R allele from a low 0.056 at year 1 reached a high 0.911 at year 6 of the study. Data from first lactation ewes of known genotypes were used to examine possible associations between PrP genotypes and ewe reproductive (litter size at birth and at weaning) and production traits (litter weight at birth and at weaning and 60-day milk yield after weaning). No effects of the sire genotype (ARR/ARR and ARR/ARQ) were found for any of the traits studied. The ewe genotype was associated with performance for reproductive traits but not with total weight of lamb output at birth or at weaning. ARR/ARR ewes had a higher litter size at birth (2.09) compared to ARQ/ARQ ewes (1.79) and higher litter size at weaning (1.84) compared to ARR/ARQ ewes (1.59). 60-day milk yield after weaning was not influenced by genotype (114.8, 105.8 and 114.8 kg for ARR/ARR, ARR/ARQ and ARQ/ARQ genotypes, respectively). Birth weight and 98-day weight were not influenced by the lamb genotype. ARQ/ARQ lambs were slightly heavier (P < 0.05) than ARR/ARR lambs at weaning as a result of faster pre-weaning growth. Post weaning growth was similar for the homozygous genotypes

Air Pollution Monitoring via Wireless Sensor Networks: The Investigation and Correction of the Aging Behavior of Electrochemical Gaseous Pollutant Sensors

The continuously growing human activity in large and densely populated cities pollutes air and consequently puts public health in danger. This is why air quality monitoring is necessary in all urban environments. However, the creation of dense air monitoring networks is extremely costly because it requires the usage of a great number of air monitoring stations that are quite expensive. Instead, the usage of wireless sensor networks (WSNs) that incorporate low-cost electrochemical gas sensors provides an excellent alternative. Actually, sensors of this kind that are recommended for low-cost air quality monitoring applications may provide relatively precise measurements. However, the reliability of such sensors during their operational life is questionable. The research work presented in this article not only experimentally examined the correlation that exists between the validity of the measurements obtained from low-cost gas sensors and their aging, but also proposes novel corrective formulae for gas sensors of two different types (i.e., NO2, O3), which are aimed at alleviating the impact of aging on the accuracy of measurements. The following steps were conducted in order to both study and lessen the aging of electrochemical sensors: (i) a sensor network was developed to measure air quality at a place near official instruments that perform corresponding measurements; (ii) the collected data were compared to the corresponding recordings of the official instruments; (iii) calibration and compensation were performed using the electrochemical sensor vendor instructions; (iv) the divergence between the datasets was studied for various periods of time and the impact of aging was studied; (v) the compensation process was re-evaluated and new compensation coefficients were produced for all periods; (vi) the new compensation coefficients were used to shape formulae that automatically calculate the new coefficients with respect to the sensors’ aging; and (vii) the performance of the overall procedure was evaluated through the comparison of the final outcomes with real data

Minimally invasive parathyroidectomy in patients with previous neck surgery

OBJECTIVE: Previous neck surgery (PNS) in patients with primary hyperparathyroidism (PHP) is considered as a contraindication for minimally invasive parathyroidectomy (MIP). The purpose of our study was to determine the effectiveness of MIP in such patients. DESIGN: From January 2003 to June 2011, 380 patients with PHP were treated in our department; 42 had had previous neck surgery. Twenty-seven (27/42) were selected to have MW; the remaining 15 patients had traditional neck explorations. Selection criteria for MIP were unilateral single or two gland disease localized preoperatively with at least two imaging techniques and patient’s informed consent. Imaging studies included high resolution neck ultrasound and sestamibi scan in the majority, and CT scan, selective venous sampling and MRI in seven patients. The type of operation done included unilateral approach under local anesthesia (UALA) (22 cases) with one conversion to general anesthesia and minimally invasive parathyroidectomy under general anesthesia (MIPG) (5 cases). RESULTS: Twenty-six of the 27 patients became normocalcemic after the operation. The patient with persistent hypercalcemia underwent successful parathyroidectomy 8 months later via mesothoracoscopy, since the parathyroid gland was localized correctly but was beyond access via neck. A single adenoma was found in 21 cases and hyperplasia in six. There were no conversions to traditional exploration and no postoperative complications. Mean duration of the procedure and length of stay were similar to MIP in patients without PNS. Mean follow-up of 40 months (4-89 months) did not reveal any recurrence. CONCLUSION: These results illustrate that MIP is a valuable option in selected patients with PHP and PNS associated with no morbidity (0%), high biochemical cure rate (96.3% in this series) and rapid recovery, while it also substantially lowers the cost of the procedure. Preoperative localization with two or more agreeing imaging techniques eliminates the need for intraoperative sestamibi or qPTH test