Eugen Osiac - Academia.edu (original) (raw)

Papers by Eugen Osiac

Diabetes, Metabolic Syndrome and Obesity: Targets and Therapy

The purpose of this ex vivo study is to exhibit the inflammatory changes that occur within the gi... more The purpose of this ex vivo study is to exhibit the inflammatory changes that occur within the gingival tissue by using optical coherence tomography (OCT) in periodontal patients with non-alcoholic fatty liver disease (NAFLD) and if NAFLD could influence the local periodontal inflammation. Patients and Methods: Gingival tissue samples obtained from patients were divided into three groups-P (periodontitis), NAFLD+P (NAFLD+periodontitis) and H (healthy) groups-and were scanned using an OCT light beam, in order to perform a qualitative and quantitative analysis of images. The value of average pixel density has been associated with the degree of inflammation. Results: The highest average pixel density was found in patients from the H group, while the lowest value of average pixel density was recorded in gingival tissue samples collected from patients with NAFLD+P. The image assessments from NAFLD+P group delivered lower values of average pixel density than those of P group, suggesting a possible influence of this disease on the inflammatory tissular changes produced by periodontal disease. Conclusion: After comparing the OCT analysis results obtained for the three groups of patients, we can consider that NAFLD may be an aggravating factor for the inflammation of periodontal disease.

2nd Canterbury Conference on OCT with Emphasis on Broadband Optical Sources

There are several important non carious lesions affecting the tooth structure, lesions which may ... more There are several important non carious lesions affecting the tooth structure, lesions which may be classified into four clinical forms of dental wear: abfraction, erosion, attrition and abrasion, and different types of root resorption. Search for new, non-invasive and fast methods able to detect and describe such injuries is of utmost importance. Optical coherence tomography (OCT) proved itself as an appropriate investigation method for several medical fields including ophthalmology, dermatology, cardiology etc. Our study reveals OCT preliminary investigations as a promising tool for detecting and evaluating of the mentioned lesions.

The study purpose is to highlight dental hard tissues changes of a tooth with dental wear as a co... more The study purpose is to highlight dental hard tissues changes of a tooth with dental wear as a consequence of excessive occlusal forces, using OCT. Methods: a central incisor extracted for periodontal reason was cleaned and it was embedded in a black acrylic resin block. The block was sectioned along the longitudinal axis of the tooth and prepared for OCT analysis. Results: The OCT signal showed differences between the labial and palatal dental hard tissue structures, even in areas without excessive occlusal solicitations. Conclusion: The OCT signal highlights changes of dental hard tissues structures according to excessive occlusal solicitations areas.

Although already in use in several medical domains, only recently optical coherence tomography (O... more Although already in use in several medical domains, only recently optical coherence tomography (OCT) has been applied in the study of ischemic events. In this paper, we will focus on characterizing ischemic stroke, in a rat model, by OCT. Investigations were carried on a set of 25 rats, on which ischemic stroke was inflicted by a transient occlusion of the middle cerebral artery (tMCAO). Animals were sacrificed 1, 3, 7 and 28 days after occlusion. We tested the OCT's power of detection and discrimination of stroke area compared to both normal, contralateral hemisphere and non-affected brain tissue, together with the aid of histochemical and pathological examination. Our results show a great potential of OCT to be used as a detection tool in acute and chronic phases of stroke.

Experimental and Therapeutic Medicine

Optical coherence tomography (OCT) is a modern imaging method with applicability in orthodontics.... more Optical coherence tomography (OCT) is a modern imaging method with applicability in orthodontics. In recent years, there has been an increasing trend in the use of ceramic brackets. The aim of the present study was to investigate the effects of bonding metallic and ceramic brackets on tooth enamel, using optical coherence tomography. For this purpose, 20 permanent teeth we bonded and were subsequently debonded using a side cutter or anterior bracket removal pliers. Using the OCT technique, the enamel, the amount of adhesive remaining and the bracket fragments remaining on the tooth surface were analyzed following the debonding procedure. It was demonstrated that enamel cracks were present only in the samples bonded with ceramic brackets. At the same time, it was noted that the type of pliers did not affect the incidence and extent of damage to the enamel. The type of debonding technique (using the side cutter or the anterior removal pliers) used did not markedly affect the amount of adhesive remaining on the teeth. Thus, as demonstrated herein, by analyzing the enamel structure through the use of OCT, the quality of the processes and the materials used for manufacturing brackets can be increased.

Journal of Clinical Medicine

As the average age and life expectancy increases, the incidence of both acute and chronic central... more As the average age and life expectancy increases, the incidence of both acute and chronic central nervous system (CNS) pathologies will increase. Understanding mechanisms underlying neuroinflammation as the common feature of any neurodegenerative pathology, we can exploit the pharmacology of cell specific ion channels to improve the outcome of many CNS diseases. As the main cellular player of neuroinflammation, microglia play a central role in this process. Although microglia are considered non-excitable cells, they express a variety of ion channels under both physiological and pathological conditions that seem to be involved in a plethora of cellular processes. Here, we discuss the impact of modulating microglia voltage-gated, potential transient receptor, chloride and proton channels on microglial proliferation, migration, and phagocytosis in neurodegenerative diseases.

Microscopy Research and Technique

Worldwide elderly traumatic brain injury (TBI) patients tend to become an increasing burden to th... more Worldwide elderly traumatic brain injury (TBI) patients tend to become an increasing burden to the society. Thus, a faster and less expensive way of evaluating TBI victims is needed. In the present study we investigated if optical coherence tomography (OCT) could be used as such a method. By using an animal model, we established if OCT can detect cortical changes in the acute phase of a penetrating TBI, in young (5–7 months) and old (20–22 months) rats. Due to the long‐term evolution of TBI's, we wanted to investigate to what extent OCT could detect changes within the cortex in the chronic phase. Adult (7–12 months) male rats were used. Surprisingly, OCT imaging of the normal hemisphere was able to discriminate age‐related differences in the mean gray values (MGV) of recorded pixels (p = .032). Furthermore, in the acute phase of TBI, OCT images recorded at 24 hr after the injury showed differences between the apparent damaged area of young and aged animals. Changes of MGV and skewness were only recorded 48 hr after injury. Monitoring the chronical evolution of the TBI with OCT revealed changes over time exceeding the normal range recorded for MGV, skewness and kurtosis, 14 and 21 days after TBI. Although in the present study we still used an extremely invasive approach, as technology improves, less invasive and non‐harmful ways of recording OCT may allow for an objective way to detect changes within the brain structure after brain injuries.

Revista de Chimie

To apply OCT analysis in secondary caries and marginal gap detection and evaluation for direct de... more To apply OCT analysis in secondary caries and marginal gap detection and evaluation for direct dental restorations is the aim of the paper. 15 extracted teeth with pre-existing direct dental restorations were analysed through OCT to evaluate marginal fit of restorations. The OCT system used wasmanufactured by Thorlabs (OCS1300SS), powered by a swept laser source with central 1310 nm wavelength, 100 nm spectral bandwidth and 12 mW average power. The occlusal area of the teeth was sampled pictured in 10 mm width, 10 mm distance and 3 mm depth. OCT was used also to evaluate in micrometers (mm) the maximum marginal gap between dental filling and tooth. OCT analysis of the marginal fit of direct dental restorations after A scan examination revealed that amalgam had the smallest marginal gap (width 210 mm, depth 90 mm), followed by glass ionomer (width 350 mm, depth 280 mm), and composite (width 520 mm, depth 300 mm). OCT analysis revealed that for marginal fit evaluation amalgam had best...

Annals of anatomy = Anatomischer Anzeiger : official organ of the Anatomische Gesellschaft, 2018

Optical coherence tomography (OCT) is an imaging tool used in various medical fields (ophthalmolo... more Optical coherence tomography (OCT) is an imaging tool used in various medical fields (ophthalmology, dermatology), which allows the observation of morphological particularities on the surface of tissues or internal constructive details of about 2-3mms in depth. In periodontology, it has been used as an experimental tool for periodontal pocket analysis (depth, calculus deposits) but not for the assessment of periodontal inflammation in the gingival tissues, which has been the subject of our in-vitro study. Gingival samples were collected from three types of patients: patients with periodontal disease; patients with periodontal disease and a systemic comorbidity; periodontal and systemic healthy patients. The samples were scanned with an OCT light beam, resulting two-dimensional images of the gingival tissue (full thickness epithelium and partial connective tissue). The images were assessed using dedicated software, which allowed the quantification of pixels on a given segment in the ...

Proceedings of SPIE - The International Society for Optical Engineering

The garnets with disordered structure such as calcium niobium gallium garnet (CNGG) doped with Nd... more The garnets with disordered structure such as calcium niobium gallium garnet (CNGG) doped with Nd3+ are interesting materials for diode pumping. Spectroscopic investigations on Nd3+:CNGG have revealed a multisite structure and this is reflected in laser emission characteristics. The purpose of this paper is to present several new spectral aspects, a modeling for the main nonequivalent centers, energy transfer characteristics and an attempt to connect the laser characteristics to centers structure. Samples were grown by Czochralski method with Nd3+ from 0.1 to 5 at.% and the high resolution spectral and decay measurements were performed at 10 K. Similar considerations were made in the case of Nd3+ doped in calcium lithium niobium gallium garnet (CLNGG).

Physical Review B, 2005

We report on the spectroscopic investigation of Pr 3+-doped binary, ternary, and quaternary fluor... more We report on the spectroscopic investigation of Pr 3+-doped binary, ternary, and quaternary fluoride compounds exhibiting photon cascade emission. Under vacuum-ultraviolet synchrotron excitation at wavelengths below 200 nm in the 4 f 5 d bands of the Pr 3+ ion ...

Journal of the Optical Society of America B, 2005

Optical Materials, 2007

We investigate the emission regimes of a room-temperature Er(1%):YLiF 4 laser on the transition 4... more We investigate the emission regimes of a room-temperature Er(1%):YLiF 4 laser on the transition 4 S 3/2 ! 4 I 15/2 using a model based on rate equations. The influence of the excited-state reabsorption losses and of the pump wavelength on the laser emission regime is discussed. Three pump wavelengths are investigated: 486 nm (direct pumping), 795 nm and 810 nm (both corresponding to upconversion pumping). The emission thresholds of the various regimes are determined.

This paper will review the newest results and directions for the usage of optical coherence tomog... more This paper will review the newest results and directions for the usage of optical coherence tomography as an imaging tool for brain studies, focusing mostly on a rodent model. Together with state of the art in the field, based on some of the most recent work, this paper will include a brief look on some results obtained by our group. Brain injuries and stroke data obtained by optical coherence tomography analyzing will be presented as a possibility of detection and evaluation for affected tissue, using this imaging system.

Journal of Luminescence, 2001

This paper presents an analysis of the green emission of Ho 3+ (5 S 2-5 I 8) under excitation aro... more This paper presents an analysis of the green emission of Ho 3+ (5 S 2-5 I 8) under excitation around 750 and 840 nm in the Ho 3+ , Yb 3+ :YAlO 3 system. The up-conversion process in the case of pump around 750 nm is a combination between a looping mechanism based on excited state absorption from the 5 I 7 level and an avalanche mechanism based on excited state absorption from the 5 I 6 level.

World Journal of Gastroenterology, 2011

Optical coherence tomography (OCT) is a noninvasive, high-resolution, high-potential imaging meth... more Optical coherence tomography (OCT) is a noninvasive, high-resolution, high-potential imaging method that has recently been introduced into medical investigations. A growing number of studies have used this technique in the field of gastroenterology in order to assist classical analyses. Lately, 3D-imaging and Doppler capabilities have been developed in different configurations, which make this type of investigation more attractive. This paper reviews the principles and characteristics of OCT and Doppler-OCT in connection with analyses of the detection of normal and pathological structures, and with the possibility to investigate angiogenesis in the gastrointestinal tract.

Romanian journal of morphology and embryology = Revue roumaine de morphologie et embryologie, 2014