On the occurrence of Bursatella leachii de Blainville, 1817 in Izmir Bay, Turkey

One of the well- established alien species in the eastern Mediterranean basin is Bursatella leachii, also known as a lessepsian immigrant. The present paper provides a contribution to Bursatella leachii’sdistribution in the Bay of Izmir, Turkish Aegean Sea

A novel application of queueing theory on the Caulerpenyne secreted by invasive Caulerpa taxifolia (Vahl) C.Agardh (Ulvophyceae, Caulerpales): a preliminary study

Aquarium originated marine green alga Caulerpa taxifolia was introduced into the Mediterranean Sea accidentally in 1984. This invasion has been negatively affecting the sub-littoral ecosystem of the Mediterranean. One of the important reasons for its success in the Mediterranean is its secondary toxic metabolite called caulerpenyne (CPN). Furthermore, CPN has anti-proliferative and apoptotic activities, therefore, CPN can be considered as a potential native source in cancer therapy. For that reason, modeling this metabolite might be of importance. Increase and decrease of the CPN level before reaching the critical level can be expressed by means of a queueing system in which the number of ‘customers' increases and decreases. In fact, production of CPN shows fluctuations for many environmental reasons, which allow us to apply queueing theory. In the present study, the expected time to reach the maximum caulerpenyne level was analyzed and evaluated using queueing theory

Seasonal rubisco enzyme activities and caulerpenyne levels in invasive Caulerpa racemosa var. cylindracea and native Caulerpa prolifera

Caulerpa racemosa var.cylindracea (C.racemosa) is an invasive marine seaweed in the Mediterranean Sea. Since no valid eradication method has been existed in the scientific literature on this species, it has currently been continuing its invasion along the coastlines of 13 Mediterranean countries. One of the important factors responsible for its invasion is thought as its toxic secondary metabolite, caulerpenyne (CYN). The present paper investigates seasonal changes in the secondary metabolite CYN, and rubisco enzyme (EC 4.1.1.39) activities of the invasive C. racemosa and native C. prolifera. Inasmuch as no correlation between CYN level and rubisco enzymic activity was observed in these species, it is considered that the regulation of CYN synthesis caulerpenyne and rubisco enzymic activity might be controlled independently. In conclusion, the further analysis on the rubisco enzymic activity determinations with MEP and mevalonate pathway which are considered responsible for CYN bio-synthesis should be studied in great detail in invasive and native Caulerpa species in the Mediterranean Sea to get the overall picture

The Effects of UV Exposure on the Antioxidant Enzyme Systems of Anemones

Superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) which are housekeeping enzymes protect cells from harmful side effects of reactive oxygen species (ROS). Anemonia sulcata var. smaragdina andAnemonia rustica are widely distributed along the Turkish coastlines of Aegean Sea. Recent studies showed that the environmental stresses such as elevated temperature, ultraviolet light, pathogen infection and decreased salinity might cause well known bleaching effects in Anemonia species. The effect of UV-light on antioxidant enzyme activities such as SOD, CAT, GSH-Px, protein levels and secondary pigments were determined in A. sulcata var. smaragdina and A. rustica. SOD, CAT, GSH-Px activities, protein levels and secondary pigments of these morphotypes were observed in both tentacles and columns separately. According to studies on bleaching, the elevated UV radiation may cause this bleaching event as a stress factor. However, in the present study no bleaching event was observed in anemone samples even they are exposed to 5 hours UV-exposure. Moreover, UV exposure did not change antioxidant systems remarkably. However, many investigations are still needed for obtaining the complete picture of the effects of UV-light on cellular pathways of cnidarian–algal symbiosis

Iterative Methods for the Biomechanical Evaluation of Corneal Response. A Case Study in the Measurement Phase

The number of corneal surgeries steadily grew in recent years and boosted the development of corneal biomechanical models. These models can contribute to simulating surgery by reducing associated risks and the need for secondary interventions due to ectasias or other problems related to correcting other diseases. Biomechanical models are based on the geometry obtained with corneal topography, which is affected by intraocular pressure and material properties. Knowledge of stress distribution in the measurement phase is a key factor for improving the accuracy of in silico mechanical models. In this work, the results obtained by two different methods: prestress method and displacements method were compared to evaluate the stress and strain distribution in a general geometric model based on the Navarro eye geometry and two real corneal geometries. The results show that both methods are equivalent for the achievement of the stress distribution in the measurement phase. Stress distribution over the corneal geometry in the measurement phase is a key factor for accurate biomechanical simulations, and these simulations could help to develop patient-specific models and reduce the number of secondary interventions in clinical practice.This publication was carried out in the framework of the Thematic Network for Co‐Operative Research in Health (RETICS) reference number RD12/0034/0007 and RD16/0008/0012, financed by the Carlos III Health Institute—General Subdirection of Networks and Cooperative Investigation Centers (R&D&I National Plan 2008–2011) and the European Regional Development Fund (FEDER). The author David P. Piñero was supported by the Ministry of Economy, Industry, and Competitiveness of Spain within the program Ramón y Cajal, RYC‐2016‐20471

Molecular identification of the tropical seagrass Halophila stipulacea from Turkey

Halophila stipulacea (Forsskål) Ascherson, a tropical seagrass, is thought to be a Lessepsian immigrant that entered the Mediterranean Sea from the Red Sea after the opening of the Suez Canal (1869). Up to date, no genetic studies of H. stipulacea from Turkey are available. In order to verify the molecular identity of Turkish isolates of H. stipulacea, a part of the rDNA ITS region was sequenced. Comparisons of the genetic polymorphism of this region between isolates from the Turkish coasts of the Aegean Sea and individuals from putative native (Red Sea) and introduced (Mediterranean) populations deposited previously in GenBank were performed. No intra-individual variability was found in the region considered among the isolates from Turkey

Alpha-amylase inhibition kinetics by caulerpenyne

Many algae have important secretions which are generally used for defensive purposes. These secretions take attentions of a lot of researchers who are wondering if these metabolites can be used for medical researches or not. Among these metabolites, caulerpenyne (CYN) which is the main metabolite of Caulerpa species, have had an important place in Caulerpa researches since the results related to its determined properties such as cytotoxic, antiviral, antiproliferative and apoptotic effects have been proven by many scientific reports. In the present study, the inhibitory effect of CYN isolated from C. prolifera on alpha-amylase was investigated. The inhibition experiments were done with CYN by spectrophotometric determination method. In order to evaluate the type of inhibition Lineweaver–Burk plot was produced. The results obtained from enzyme kinetic studies exhibited an un-competitive type of inhibition, which is characterized by the difference of Vmax and KM from those of the free enzyme, of alpha-amylase in the presence of CYN. The present study showed that Caulerpa species can be a potential target for producing diabetic drugs in the light of the results obtained for CYN

Relationship between Corneal Morphogeometrical Properties and Biomechanical Parameters Derived from Dynamic Bidirectional Air Applanation Measurement Procedure in Keratoconus

The morphogeometric analysis of the corneal structure has become a clinically relevant diagnostic procedure in keratoconus (KC) as well as the in vivo evaluation of the corneal biomechanical properties. However, the relationship between these two types of metrics is still not well understood. The current study investigated the relationship of corneal morphogeometry and volume with two biomechanical parameters: corneal hysteresis (CH) and corneal resistance factor (CRF), both provided by an Ocular Response Analyzer (Reichert). It included 109 eyes from 109 patients (aged between 18 and 69 years) with a diagnosis of keratoconus (KC) who underwent a complete eye examination including a comprehensive corneal topographic analysis with the Sirius system (CSO). With the topographic information obtained, a morphogeometric and volumetric analysis was performed, defining different variables of clinical use. CH and CRF were found to be correlated with these variables, but this correlation was highly influenced by corneal thickness. This suggests that the mechanical properties of KC cornea contribute only in a partial and limited manner to these biomechanical parameters, being mostly influenced by morphogeometry under normal intraocular pressure levels. This would explain the limitation of CH and CRF as diagnostic tools for the detection of incipient cases of KC.This publication was carried out in the framework of the Thematic Network for Co-Operative Research in Health (RETICS) reference number RD12/0034/0007 and RD16/0008/0012, financed by the Carlos III Health Institute—General Subdirection of Networks and Cooperative Investigation Centers (R&D&I National Plan 2008–2011) and the European Regional Development Fund (FEDER). The author David P. Piñero has been supported by the Ministry of Economy, Industry, and Competitiveness of Spain within the program Ramón y Cajal, RYC-2016-20471

Morphogeometric analysis for characterization of keratoconus considering the spatial localization and projection of apex and minimum corneal thickness point

This work evaluates changes in new morphogeometric indices developed considering the position of anterior and posterior corneal apex and minimum corneal thickness (MCT) point in keratoconus. This prospective comparative study included 440 eyes of 440 patients (age, 7–99 years): control (124 eyes) and keratoconus (KC) groups (316 eyes). Tomographic information (Sirius®, Costruzione Strumenti Oftalmici, Italy) was treated with SolidWorks v2013, creating the following morphogeometric parameters: geometric axis–apex line angle (GA–AP), geometric axis–MCT line angle (GA–MCT, apex line–MCT line angle (AP–MCT), and distances between apex and MCT points on the anterior (anterior AP–MCTd) and posterior corneal surface (posterior AP–MCTd). Statistically significant higher values of GA–AP, GA–MCT, AP–MCT and anterior AP–MCTd were found in the keratoconus group (p ≤ 0.001). Moderate significant correlations of corneal aberrations (r ≥ 0.587, p < 0.001) and corneal thickness parameters (r ≤ −0.414, p < 0.001) with GA–AP and AP–MCT were found. Anterior asphericity was found to be significantly correlated with anterior and posterior AP–MCTd (r ≥ 0.430, p < 0.001). Likewise, GA–AP and AP–MCT showed a good diagnostic ability for the detection of keratoconus, with optimal cutoff values of 9.61° (sensitivity 85.5%, specificity 80.3%) and 18.08° (sensitivity 80.5%, specificity 78.7%), respectively. These new morphogeometric indices allow a clinical characterization of the 3-D structural alteration occurring in keratoconus, with less coincidence in the spatial projection of the apex and MCT points of both corneal surfaces. Future studies should confirm the potential impact on the precision of these indices of the variability of posterior corneal surface measurements obtained with Scheimpflug imaging technology.This publication has been carried out in the framework of the Thematic Network for Co-Operative Research in Health (RETICS), reference number RD16/0008/0012, financed by the Carlos III Health Institute–General Subdirection of Networks and Cooperative Investigation Centers (R&D&I National Plan 2013–2016) and the European Regional Development Fund (FEDER). The author David P. Piñero has been supported by the Ministry of Economy, Industry and Competitiveness of Spain within the program Ramón y Cajal, RYC-2016-20471

Comparison of corneal morphologic parameters and high order aberrations in keratoconus and normal eyes

The aim of this study is evaluating the influence of corneal geometry in the optical system’s aberrations, and its usefulness as diagnostic criterion for keratoconus.159 normal eyes (normal group, mean age 37.8 ± 11.6 years) and 292 eyes with the diagnosis of keratoconus (keratoconus group, mean age 42.2 ± 17.6 years) were included in this study. All eyes received a comprehensive ophthalmologic examination. A virtual 3D model of each eye was made using CAD software and different anatomical parameters related with surface and volume were measured. Statistically significant differences were found for all anatomical parameters (all p < 0.001). AUROC analysis showed that all parameters reached values above 0.7, with the exception of the total corneal surface area (TCSAA-S). In conclusion, the methodology explained in this research, that bases in anatomical parameters obtained from a virtual corneal model, allow to analyze the diagnostic value of corneal geometry correlation with optical aberrations in keratoconus pathology.This publication has been carried out in the framework of the Thematic Network for Co-Operative Research in Health (RETICS), reference number RD16/0008/0012, financed by the Carlos III Health Institute–General Subdirection of Networks and Cooperative Investigation Centers (R&D&I National Plan 2013–2016) and the European Regional Development Fund (FEDER)