PubMed İndeksli Yayınlar Koleksiyonu

Permanent URI for this collectionhttps://gcris.khas.edu.tr/handle/20.500.12469/4466

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Citation Count: 1
3d-Printed Actuator-Based Beam-Steering Approach for Improved Physical Layer Security in Visible Light Communication
(Optica Publishing Group, 2022) Erdem, Mehmet Can; Gurcuoglu, Oguz; Panayırcı, Erdal; Kurt, Gunes Karabulut; Ferhanoglu, Onur
In this study, we present the design, manufacture, and implementation of a 3D-printed lens scanner-based beam steering for use in visible light communication (VLC) applications. The 5 cm x 5 cm scanner is designed for low-cost 3D printing with fused deposition modeling using polylactic acid. Scanning is facilitated through electromagnetic actuation of the lens frame, carrying a conventional 25 mm lens, from two nearly orthogonal directions. The serpentine spring that connects the lens frame to the external frame is tailored to offer similar spring constants in the directions of actuation and has minimal (<1.5 mm) sag due to the mass of the lens. The manufactured actuator was integrated on a miniaturized VLC test bed (70 cm x 40 cm x 40 cm). Using the test bed, we characterized the applied voltage versus beam displacement behavior of the actuator in the lateral plane and demonstrated beam steering on amoving target with face-recognition feedback. The proposed scheme was targeted to offer an improved security measure in VLC through tracking the legitimate receiver (i.e., via face recognition) and uses the feedback to steer the focused light onto the targeted device. The joint use of focusing and steering features allows for the legitimate receiver to roam within the room while enjoying the improved secrecy due to the focused light. We calculate the secrecy capacity for the demonstrated approach, which compares favorably with a number of jamming, spatial modulation, and beam-forming counterparts. The presented actuator can be used with larger room dimensions, yet upscaling to larger illumination units will require the use of a lens having smaller focus to address a larger total steering angle. (C) 2022 Optica Publishing Group
Citation Count: 3
Abortion Services at Hospitals in Istanbul
(Taylor & Francis Ltd, 2017) O'Neil, Mary Lou
Objective: Despite the existence of a liberal law on abortion in Turkey there is growing evidence that actually securing an abortion in Istanbul may prove difficult. This study aimed to determine whether or not state hospitals and private hospitals that accept state health insurance in Istanbul are providing abortion services and for what indications. Method: Between October and December 2015 a mystery patient telephone survey of 154 hospitals 43 public and 111 private in Istanbul was conducted. Results: 14% of the state hospitals in Istanbul perform abortions without restriction as to reason provided in the current law while 60% provide the service if there is a medical necessity. A quarter of state hospitals in Istanbul do not provide abortion services at all. 48.6% of private hospitals that accept the state health insurance also provide for abortion without restriction while 10% do not provide abortion services under any circumstances. Key conclusions: State and private hospitals in Istanbul are not providing abortion services to the full extent allowed under the law. The low numbers of state hospitals offering abortions without restriction indicates a de facto privatization of the service. This same trend is also visible in many private hospitals partnering with the state that do not provide abortion care. While many women may choose a private provider the lack of provision of abortion care at state hospitals and those private hospitals working with the state leaves women little option but to purchase these services from private providers at some times subtantial costs.
Citation Count: 11
Accurate Refinement of Docked Protein Complexes Using Evolutionary Information and Deep Learning
(Imperıal College Press, 2016) Akbal-Delibas, Bahar; Farhoodi, Roshanak; Pomplun, Marc; Haspel, Nurit
One of the major challenges for protein docking methods is to accurately discriminate native-like structures from false positives. Docking methods are often inaccurate and the results have to be refined and re-ranked to obtain native-like complexes and remove outliers. In a previous work we introduced AccuRefiner a machine learning based tool for refining protein-protein complexes. Given a docked complex the refinement tool produces a small set of refined versions of the input complex with lower root-mean-square-deviation (RMSD) of atomic positions with respect to the native structure. The method employs a unique ranking tool that accurately predicts the RMSD of docked complexes with respect to the native structure. In this work we use a deep learning network with a similar set of features and five layers. We show that a properly trained deep learning network can accurately predict the RMSD of a docked complex with 1.40 angstrom error margin on average by approximating the complex relationship between a wide set of scoring function terms and the RMSD of a docked structure. The network was trained on 35000 unbound docking complexes generated by RosettaDock. We tested our method on 25 different putative docked complexes produced also by RosettaDock for five proteins that were not included in the training data. The results demonstrate that the high accuracy of the ranking tool enables AccuRefiner to consistently choose the refinement candidates with lower RMSD values compared to the coarsely docked input structures.
Citation Count: 5
The acquisition and use of relative clauses in Turkish-learning children's conversational interactions: a cross-linguistic approach
(Cambridge University Press, 2019) Uzundağ, Berna A.; Küntay, Aylin C.
Using a cross-linguistic approach, we investigated Turkish-speaking children's acquisition and use of relative clauses (RCs) by examining longitudinal child-caregiver interactions and cross-sectional peer conversations. Longitudinal data were collected from 8 children between the ages of 8 and 36 months. Peer conversational corpus came from 78 children aged between 43 and 64 months. Children produced RCs later than in English (Diessel, 2004) and Mandarin (Chen & Shirai, 2015), and demonstrated increasing semantic and structural complexity with age. Despite the morphosyntactic difficulty of object RCs, and prior experimental findings showing a subject RC advantage, preschool-aged children produced object RCs, which were highly frequent in child-directed speech, as frequently as subject RCs. Object RCs in spontaneous speech were semantically less demanding (with pronominal subjects and inanimate head nouns) than the stimuli used in prior experiments. Results suggest that multiple factors such as input frequency and morphosyntactic and semantic difficulty affect the acquisition patterns.
Citation Count: 40
Air Quality Prediction Using Cnn Plus Lstm-Based Hybrid Deep Learning Architecture
(Springer Heidelberg, 2022) Gilik, Aysenur; Ogrenci, Arif Selcuk; Ozmen, Atilla
Air pollution prediction based on variables in environmental monitoring data gains further importance with increasing concerns about climate change and the sustainability of cities. Modeling of the complex relationships between these variables by sophisticated methods in machine learning is a promising field. The objectives of this work are to develop a supervised model for the prediction of air pollution by using real sensor data and to transfer the model between cities. The combination of a convolutional neural network and a long short-term memory deep neural network model was proposed to predict the concentration of air pollutants in multiple locations of a city by using spatial-temporal relationships. Two approaches have been adopted: the univariate model contains the information of one pollutant whereas the multivariate model contains the information of all pollutants and meteorology data for prediction. The study was carried out for different pollutants which are in the publicly available data of the cities of Barcelona, Kocaeli, and Istanbul. The hyperparameters of the model (filter, frame, and batch sizes; number of convolutional/LSTM layers and hidden units; learning rate; and parameters for sample selection, pooling, and validation) were tuned to determine the architecture that achieved the lowest test error. The proposed model improved the prediction performance (measured by the root mean square error) by 11-53% for particulate matter, 20-31% for ozone, 9-47% for nitrogenoxides, and 18-46% for sulfurdioxide with respect to the 1-hidden layer long short-term memory networks utilized in the literature. The multivariate model without using meteorological data revealed the best results. Regarding transfer learning, the network weights were transferred from the source city to the target city. The model has more accurate prediction performance with the transfer of the network from Kocaeli to Istanbul as those neighbor cities have similar air pollution and meteorological characteristics.
Citation Count: 2
Altered Dynamics of S. Aureus Phosphofructokinase Via Bond Restraints at Two Distinct Allosteric Binding Sites
(Academic Press Ltd- Elsevier Science Ltd, 2022) Celebi, Metehan; Akten, Ebru Demet
The effect of perturbation at the allosteric site was investigated through several replicas of molecular dynamics (MD) simulations conducted on bacterial phosphofructokinase (SaPFK). In our previous work, an alternative binding site was estimated to be allosteric in addition to the experimentally reported one. To highlight the effect of both allosteric sites on receptor's dynamics, MD runs were carried out on apo forms with and without perturbation. Perturbation was achieved via incorporating multiple bond restraints for residue pairs located at the allosteric site. Restraints applied to the predicted site caused one dimer to stiffen, whereas an increase in mobility was detected in the same dimer when the experimentally resolved site was restrained. Fluctuations in C-alpha-C-alpha distances which is used to disclose residues with high potential of communication indicated a marked increase in signal transmission within each dimer as the receptor switched to a restrained state. Cross-correlation of positional fluctuations indicated an overall decrease in the magnitude of both positive and negative correlations when restraints were employed on the predicted allosteric site whereas an exact opposite effect was observed for the reported site. Finally, mutual correspondence between positional fluctuations noticeably increased with restraints on predicted allosteric site, whereas an opposite effect was observed for restraints applied on experimentally reported one. In view of these findings, it is clear that the perturbation of either one of two allosteric sites effected the dynamics of the receptor with a distinct and contrasting character. (c) 2022 Elsevier Ltd. All rights reserved.
Citation Count: 1
Anomalous Pancreaticobiliary Junction (apbj) With the Drainage of the Uncinate Process Into the Minor Papilla: Demonstration by Mri
(BRITISH INST RADIOLOGY, 2005) Başaranoğlu, Metin; Balcı, Numan Cem; Kloer, Hans Ulrich
We report a case of a 30-year-old patient with anomalous pancreaticobiliary junction (APBJ) that has not been described before. The patient had a clinical history of recurrent attacks of pancreatitis cholangitis and cholecystitis that were confirmed by abnormal laboratory values. Endoscopic retrograde cholangiopancreatography revealed a 20 mm long junction of choledoc and pancreatic duct and uncinate process draining into the minor papilla. On MR cholangiopancreatography strictures at the junction of hepatic duct increased gallbladder wall thickness and intraductal stone in the pancreatic duct were demonstrated as complementary findings. Other MRI findings included decreased signal intensity of the pancreas consistent with fibrosis from past pancreatitis attacks and atrophy of the left liver lobe.
Citation Count: 20
Apolipoprotein E Polymorphism in Turkish Subjects With Type 2 Diabetes Mellitus: Allele Frequency and Relation To Serum Lipid Concentrations
(EDITRICE KURTIS S R L, 2004) Duman, Belgin Süsleyici; Öztürk, Melek; Yilmazer, Selma; Hatemi, Hüsrev
The role of apolipoprotein E (apoE) genotypes in modulating plasma lipid and apolipoprotein levels was studied in 112 patients with Type 2 diabetes mellitus (T2DM) and 94 healthy individuals. ApoE genotypes were identified by PCR amplification and subsequent restriction endonuclease digestion. The apoE allele and genotype frequencies were similar in both the diabetic and control subjects. The apoE allele frequencies were found to be 74.3 for e3 10.1 for e2 15.6 for e4 in the diabetic group and 68.1 for e3 13.2 for e2 and 18.7 for e4 in the control group. Sex-specific genotypic distribution of apoE polymorphism did not differ between the study groups. To elucidate the association of apoE with lipid abnormalities with respect to gender serum lipid and apolipoprotein levels were compared among apo e2 (e2/2 and e3/2) e3 (e3/3) and e4 (e4/3 and e4/4) groups of T2DM and control subjects. Apo e2 allele was found to be associated to triglycerides for both sexes and associated to glucose and BMI only in females. Subjects with e2 allele had higher levels of BMI glucose and triglyceride in comparison to e3 and e4. Our data suggest that genetic variation at the apoE locus in Turkish subjects is a genetic factor that influences lipid levels. Further studies attempting to correlate apoE polymorphism with lipid profile in a large number of individuals would be helpful in establishing the true significance of this polymorphism in the Turkish population. (C) 2004 Editrice Kurtis.
Citation Count: 30
The Applications of Machine Learning Techniques in Medical Data Processing Based on Distributed Computing and the Internet of Things
(Elsevier Ireland Ltd, 2023) Aminizadeh, Sarina; Heidari, Arash; Toumaj, Shiva; Darbandi, Mehdi; Navimipour, Nima Jafari; Rezaei, Mahsa; Talebi, Samira
Medical data processing has grown into a prominent topic in the latest decades with the primary goal of maintaining patient data via new information technologies, including the Internet of Things (IoT) and sensor technologies, which generate patient indexes in hospital data networks. Innovations like distributed computing, Machine Learning (ML), blockchain, chatbots, wearables, and pattern recognition can adequately enable the collection and processing of medical data for decision-making in the healthcare era. Particularly, to assist experts in the disease diagnostic process, distributed computing is beneficial by digesting huge volumes of data swiftly and producing personalized smart suggestions. On the other side, the current globe is confronting an outbreak of COVID-19, so an early diagnosis technique is crucial to lowering the fatality rate. ML systems are beneficial in aiding radiologists in examining the incredible amount of medical images. Nevertheless, they demand a huge quantity of training data that must be unified for processing. Hence, developing Deep Learning (DL) confronts multiple issues, such as conventional data collection, quality assurance, knowledge exchange, privacy preservation, administrative laws, and ethical considerations. In this research, we intend to convey an inclusive analysis of the most recent studies in distributed computing platform applications based on five categorized platforms, including cloud computing, edge, fog, IoT, and hybrid platforms. So, we evaluated 27 articles regarding the usage of the proposed framework, deployed methods, and applications, noting the advantages, drawbacks, and the applied dataset and screening the security mechanism and the presence of the Transfer Learning (TL) method. As a result, it was proved that most recent research (about 43%) used the IoT platform as the environment for the proposed architecture, and most of the studies (about 46%) were done in 2021. In addition, the most popular utilized DL algorithm was the Convolutional Neural Network (CNN), with a percentage of 19.4%. Hence, despite how technology changes, delivering appropriate therapy for patients is the primary aim of healthcare-associated departments. Therefore, further studies are recommended to develop more functional architectures based on DL and distributed environments and better evaluate the present healthcare data analysis models.
Citation Count: 4
Augmentation Mentoplasty Using a Custom-Design Wire Cage
(Lippincott Williams & Wilkins, 2003) Erol ,O.; Enacar, A.
Mentoplasty is often a complimentary procedure to rhinoplasty. At least 25% of all rhinoplasty patients may need a chin implant to balance facial features better. Augmentation mentoplasty using alloplastic implants such as silicone rubber or other materials provides a simple approach to the treatment of the hypoplastic chin. Although these types of implants are readily available in developed countries there are parts of the world where they are unavailable or quite expensive. The authors have developed a chin implant made of wire that is available throughout the world and is custom designed to the mentum of the patient after a cephalometric evaluation. This technique has been used in 125 patients along with rhinoplasty over the last 20 years at our institution. In an initial series of 8 patients the prosthesis became displaced and was removed in 2 patients. Since then a new radiographic technique has been developed to demonstrate the shape of the mentum before surgery and new bone formation after surgery. By using this special radiographic technique it was possible to detect four types of mentum before surgery and to construct a custom-design wire cage according to this shape. The prosthesis is constructed by an orthodontist according to the cephalometric measurements and shape of the mentum. By using the buccal approach a pocket is prepared subperiosteally and a wire cage is inserted. In the last 20 cases the wire cage was filled with diced cartilage wrapped with Surgicel. The results were esthetically satisfactory in most patients. After the shape of the wire prosthesis was modified to conform to the shape of the underlying bone better no displacement of the prosthesis has been experienced. In 3 patients it was necessary to remove the prosthesis when new tissue formation began to fill the prosthesis. These specimens were examined histologically and the regenerating tissue was found to be connective tissue with a thin layer of bone formation. Most patients could be followed up for only 3 to 12 years. In all patients the results have been consistent and the procedure has been safe.
Citation Count: 3
The Availability of Emergency Contraception From Family Health Centers in Turkey
(Elsevier Ireland Ltd, 2022) O'Neil, Mary Lou; Aldanmaz, Bahar; Altuntas, Deniz
Reproductive health care, including contraception, is a fundamental aspect of any public health care system and it is important to reduce barriers to access to all forms of contraception, including emergency contraception. In recent years, the rhetoric of pronatalism in Turkey has come to dominate and raises questions about the availability of reproductive health care services, in particular contraception, from state run facilities. This study aimed to determine the availability of dedicated emergency contraception (EC) from government run Family Health Centers (FHCs) in Turkey. In 2019, a team of trained researchers called a random sample of 583 FHCs located in the largest cities in twelve regions across Turkey asking for dedicated EC. Dedicated EC is largely unavailable from government supported FHCs. Only 6.1% stated that they provided EC while 53.8% stated that it was not available and that they could provide no alternative. A further 28.3% declared that they could provide an alternative to dedicated EC that almost always consisted of oral contraceptives. We found statistically significant variations in response rate and availability among cities as well as the rate of referral to pharmacies. There is little access to EC from government sponsored health clinics designated to provide family planning services, which hinders access to an essential reproductive health care service that should be available to women everywhere.
Citation Count: 0
Background Tv and Infant-Family Interactions: Insights From Home Observations
(Wiley, 2024) Uzundag, Berna A.; Koskulu-Sancar, Suemeyye; Kuntay, Aylin C.
Background television has been found to negatively impact children's language development and self-regulatory skills, possibly due to decreased parent-child interactions. Most of the research on the relationship between background TV and caregiver-child interactions has been conducted in laboratory settings. In the current study, we conducted home observations and investigated whether infants engage in fewer interactions with family members in homes where background TV is more prevalent. We observed 32 infants at the ages of 8, 10, and 18 months in their home environments, coding for dyadic interactions (e.g., parent talking to and/or engaging with the child), triadic interactions (e.g., parent and infant play with a toy together), and infants' individual activities. Our findings revealed that background TV was negatively associated with the time infants spent in triadic interactions, positively associated with time spent engaging in individual activities, and not significantly related to the time spent in dyadic interactions. Apart from the relationship between background TV and individual activity time at 8 months, these associations remained significant even after accounting for families' socioeconomic status. These findings imply a correlation between background TV exposure and caregiver-infant-object interactions, warranting a longitudinal analysis with larger sample sizes.
Citation Count: 2
Biased Perceptions Against Female Scientists Affect Intentions To Get Vaccinated for Covid-19
(Sage Publications Ltd, 2022) Dogan, Isminaz; Baruh, Lemi; Cemalcilar, Zeynep; Kuru, Ozan; Yildirim, Kerem; Carkoglu, Ali
Based on role congruity theory, we investigated how gender bias may influence public attitudes toward the vaccine in Turkey. Using a between-subjects design, we tested whether an emphasis on the female versus the male scientist as the vaccine's inventor in a news story influenced attitudes about the BioNTech vaccine and vaccination intentions. Partly confirming role congruity theory, three-way interaction results from 665 participants demonstrated that among male participants with a stronger belief in traditional gender roles (compared to males with lower belief), the presence of the female inventor, either by herself or together with the male inventor, decreased the perceived efficacy and safety of the vaccine and reduced intentions to be vaccinated by the BioNTech vaccine. We did not observe such differences for women. These findings highlight how gender bias may influence individuals' information processing and decision making in a way that may have negative consequences for public health.
Citation Count: 12
Blind Dockings of Benzothiazoles To Multiple Receptor Conformations of Triosephosphate Isomerase From Trypanosoma Cruzi and Human
(Wiley-VCH Verlag GmbH, 2011) Kurkcuoglu, Zeynep; Ural, Gulgun; Akten, Ebru Demet; Doruker, Pemra
We aim to uncover the binding modes of benzothiazoles which have been reported as specific inhibitors of triosephosphate isomerase from the parasite Trypanosoma cruzi (TcTIM) by performing blind dockings on both TcTIM and human TIM (hTIM). Detailed analysis of binding sites and specific interactions are carried out based on ensemble dockings to multiple receptor conformers obtained from molecular dynamics simulations. In TcTIM dimer dockings the inhibitors preferentially bind to the tunnel-shaped cavity formed at the interface of the subunits whereas non-inhibitors mostly choose other sites. In contrast TcTIM monomer binding interface and hTIM dimer interface do not present a specific binding site for the inhibitors. These findings point to the importance of the tunnel and of the dimeric form for inhibition of TcTIM. Specific interactions of the inhibitors and their sulfonate-free derivatives with the receptor residues indicate the significance of sulfonate group for binding affinity and positioning on the TcTIM dimer interface. One of the inhibitors also binds to the active site which may explain its relatively higher inhibition effect on hTIM.
Citation Count: 18
Carboxylic Acid Derivatives Display Potential Selectivity for Human Histone Deacetylase 6: Structure-Based Virtual Screening Molecular Docking and Dynamics Simulation Studies
(Elsevier Science, 2018) Uba, Abdullahi Ibrahim; Yelekçi, Kemal
Human histone deacetylase 6 (HDAC6) has been shown to play a major role in oncogenic cell transformation via deacetylation of alpha-tubulin making it a viable target of anticancer drug design and development. The crystal structure of HDAC6 catalytic domain 2 has been recently made available providing avenues for structure-based drug design campaign. Here in our continuous effort to identify potentially selective HDAC6 inhibitors structure-based virtual screening of similar to 72 461 compounds was carried out using Autodock Vina. The top 100 compounds with calculated Delta G < -10 kcal/mol were manually inspected for binding mode orientation. Furthermore the top 20 compounds with reasonable binding modes were evaluated for selectivity by further docking against HDAC6 and HDAC7 using Autodock4. Four compounds with a carboxylic fragment displayed potential selectivity for HDAC6 over HDAC7 and were found to have good druglike and ADMET properties. Their docking complexes were then submitted to 10 ns-molecular dynamics (MD) simulation using nanoscale MD (NAMD) software to examine the stability of ligand binding modes. These predicted inhibitors remained bound to HDAC6 in the presence of water and ions and the root-mean-square deviation (RMSD) radius of gyration (Rg) and nonbond distance (protein-ligand) profiles suggested that they might be stable over time of the simulation. This study may provide scaffolds for further lead optimization towards the design of HDAC6 inhibitors with improved selectivity. (C) 2018 Elsevier Ltd. All rights reserved.
Citation Count: 1
Cervical Spine Injuries in Children
(2004) Hamzaoglu, A.; Mirzanli, C.
Cervical spine injuries in children and adolescents are rare. Common mechanisms include motor vehicle accidents, sports injuries, fall from height, and gunshot injuries. Cervical spine injuries are classified by Allen and Ferguson according to the period they occur, as infantile, early juvenile, and late juvenile. Anatomically, two main types are defined as occipitoatlantal (upper cervical) and subaxial injuries. The purpose of this paper is to review cervical spine injuries in children and adolescents with respect to epidemiology, injury mechanisms, diagnosis, clinical and radiologic aspects, and treatment in the light of the current literature.
Citation Count: 41
Comparison of Five Antimicrobial Regimens for the Treatment of Brucellar Spondylitis: a Prospective, Randomized Study
(E I F T Srl, 2003) Bayindir, Y; Sonmez, E; Aladag, A; Buyukberber, N
Brucellosis, a zoonosis with worldwide distribution, is a systemic infection and still an important public health problem in Turkey. The best antimicrobial combination and schedule for the treatment of brucellosis with spondylitis has not yet been clearly determined. In a prospective and randomized study, we compared the efficacy of five antimicrobial regimens for treatment of 102 patients with lumbar brucellar spondylitis. Patients were randomly assigned to receive antimicrobial combination therapy. Twenty patients received streptomycin 1 g/day intramuscularly for 15 days and tetracycline-HCl, 500 mg every 6 h orally for 45 days (ST), 21 patients received streptomycin 1 g/day i.m. for 15 days and doxycycline 100 mg every 12 h orally for 45 days (SD), 20 patients received doxycycline 100 mg every 12 h orally for 45 days and rifampicin 15 mg/kg per day in a single morning dose orally for 45 days (DR), 19 patients received ofloxacin, 200 mg every 12 h orally for 45 days and rifampicin 15 mg/kg per day in a single morning dose orally for 45 days (OR), and 22 patients received streptomycin 1 g/day i.m. for 15 days and doxycycline 100 mg every 12 h orally for 45 days plus rifampicin 15 mg/kg per day in a single morning dose orally for 45 days (SDR). Initial therapeutic failure occurred in 2 patients (10%) in the ST regimen group, 4 patients (19%) in the SD group, 3 patients (15%) in the DR group and 5 patients (26%) in the OR regimen. In addition, 2 patients (10%) in the DR group and 5 patients (26%) in the OR regimen relapsed during the follow-up period. There was no relapse in any patients in the ST, SD, and SDR groups. The response rates were 90% in the ST and 81% in the SD groups. In contrast, there was a maximum good response (100%) and no relapse in the SDR group. In conclusion, a combination of doxycycline, streptomycin, and rifampicin can be recommended as therapy for brucellar spondylitis and to reduce relapse rates.
Citation Count: 10
Comparison of Intraoperative Transit-Time Flow Measurement With Early Postoperative Magnetic Resonance Flow Mapping: in Off-Pump Coronary Artery Surgery
(2003) Sanisoglu,I.; Guden,M.; Balci,C.; Sagbas,E.; Duran,C.; Akpinar,B.
The purpose of this prospective study was to evaluate graft patency of off-pump coronary artery surgery intraoperatively by transit-time flow measurement and to compare this technique with postoperative magnetic resonance flow mapping. Twenty patients (13 men and 7 women; mean age, 67.9 ± 7.6 yr) underwent off-pump coronary artery surgery. Intraoperative transit-time flow measurement of grafts was performed measuring maximum, minimum, and mean flows. For each graft, the pulsatile index was calculated by dividing the difference between the maximum and the minimum flow by the mean flow. In the early postoperative period (1st week), magnetic resonance flow mapping was performed using phase contrast flow quantification. Mean intraoperative flow values and mean magnetic resonance flow mapping values were compared. At the same postoperative session, contrast-enhanced magnetic resonance angiography was performed to evaluate graft patency. In 20 patients, a total of 49 coronary graft flows were assessed with intraoperative transit-time flow measurement and postoperative magnetic resonance flow mapping. Upon comparison, there was a strong correlation between techniques, with stable and statistically significant differences between the intraoperative and postoperative flow mapping values. One saphenous vein graft was revised intraoperatively, due to graft failure. Our data suggest that the combined use of intraoperative transit-time flow measurement and postoperative magnetic resonance flow analysis has a potential role in the assessment of graft patency in off-pump coronary artery surgery, although more study is required.
Citation Count: 6
Comparison of the BBL-mycobacteria growth indicator tube method with culture in the diagnosis of tuberculosis and evaluation of the resistance patterns of isolated strains to four major drugs
(Karger, 2002) Kocazeybek, Bekir Sami
The BBL-mycobacteria growth indicator tube system (MGIT) is used for a rapid detection of the presence of mycobacteria. Our study aimed to compare MGIT with the Lowenstein-Jensen (LJ) reference method in clinical samples with suspected pulmonary and extrapulmonary tuberculosis and to evaluate the primary and secondary resistance patterns by determining the resistances of the isolated strains to four major anti mycobacteria I drugs. 648 clinical samples from different clinics with suspected pulmonary or extrapulmonary tuberculosis based on clinical radiological histopathological and immunological findings were included in the investigation. The samples were first stained with Ziehl-Neelsen (ZN) and then cultured in LJ medium according to the standard bacteriological procedure and in the MGIT as recommended by the manufacturer. Conventional biochemical tests and p-nitro-alpha-acethylamino-beta-hydroxypropiophene of the Bactec system were used to identify the isolated mycobacterial strains. The susceptibilities to streptomycin isoniazid rifampicin ethambutol were tested by the BBL-MGIT antibiotic susceptibility test and the resistances of the strains found to be resistant to any of the drugs were confirmed by the agar proportion method. Mycobacterium spp. were isolated in 61 (9.4%) out of 648 samples. Eventually 58 out of 61 strains were classified as Mycobacterium tuberculosis and the other 3 as Mycobacterium tuberculosis complex. 32 of these were ZN positive. The growth time was determined as 12.2 days by the MGIT method and 24.1 days by the LJ method (p < 0.001). 29 strains were ZN negative. Their growth time was 23 days by the MGIT method and 37 days by the LJ method (p < 0.001). Drug resistance was detected in 23 (37.7%) of 61 cases (of whom 39 were new and 22 were former patients)
Citation Count: 35
Comparison of Three Different Combination Therapies in the Treatment of Human Brucellosis
(ROYAL SOC MEDICINE PRESS LTD, 2005) Ersoy, Yasemin; Sönmez, Emine; Tevfik, Mehmet R.; But, Ayşe Dinç
The efficacy and tolerability of three different combination treatment regimens in human brucellosis were compared in 118 uncomplicated patients enrolled in a prospective study between May 1997 and December 2002. Brucellosis was diagnosed using standard clinical and microbiological findings. Patients with central nervous system involvement spondylitis endocarditis or children under 16 years of age were excluded from the study. Patients were randomly assigned to receive 400 mg of ofloxacin plus 600 mg of rifampicin (OR n = 41)200 mg of doxycycline plus 600 mg of rifampicin (DR n = 45) or 1 g intramuscularly streptomycin (administered for three weeks) plus 200 mg doxycycline (DS n = 32) daily for 6 weeks. All patients were followed up at least 6 months after cessation of therapy. There was no statistical difference between the groups on relapse rates and clinical response to the treatment (P> 0.05). Five patients in OR (12.8%) six patients in DR (14.3%) and three patients in DS groups (9.7%) suffered relapse. The side-effects were seen in eight (19.5%) 21 (46.7%) and eight (25.0%) patients of OR DR and DS groups respectively. The use of combination therapy of ofloxacin plus rifampicin for 6 weeks was found to be as effective as DR and DS. The side-effects of therapy in OR and DS groups was less severe than in the DR group.

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