Synergistic interactions of essential oil components with antibiotics against multidrug-resistant Corynebacterium striatum.

AIM: In this study, it was aimed to examine the antibacterial activity of the essential oil components (EOCs), carvacrol (CAR), cinnamaldehyde (CIN), thymol (TH), alpha pinene (α-PN), eucalyptol (EU), limonene (LIM), and the antibiotics, linezolid (LZD), vancomycin (VAN), gentamicin (GEN), ciprofloxacin (CIP), clindamycin (CLN), and penicillin (PEN) against 50 multidrug resistant Corynebacterium striatum strains, and the synergistic interactions of CAR and CIN with the antibiotics against 10 randomly selected Coryne. striatum strains to explore synergistic interactions to determine if their combined use could enhance antibiotic activity and potentially reduce resistance. METHODS AND RESULTS: The activity of the EOCs and the antibiotics against Coryne. striatum strains isolated from clinical specimens, was examined by broth microdilution method. The synergistic interactions of the EOCs with the antibiotics against 10 randomly selected Coryne. striatum strains were determined by checkerboard method. EOCs, CIN, and CAR and antibiotics, LZD, VAN, GEN, CIP, and CLN were detected to have antibacterial activity against Coryne. striatum strains alone and either synergistic interactions were observed in combinations of the antibiotics with EOCs. CONCLUSIONS: All Coryne. striatum strains were determined to be susceptible to VAN and LZD and resistant to GEN, PEN, CIP, and CLN. Synergistic interactions were observed in all combinations of antibiotics tested with CAR and CIN.

The relation of recurrent laryngeal nerve to inferior thyroid artery and extralaryngeal nerve branching may increase the risk of vocal cord paralysis in thyroidectomy.

PURPOSE: The anatomical variations of the recurrent laryngeal nerve (RLN) are common during thyroidectomy. We aimed to evaluate the risk of RLN paralysis in case of its anatomical variations, retrospectively. METHODS: The patients with primary thyroidectomy between January 2016 and December 2019 were enrolled. The effect of age, gender, surgical intervention, neuromonitorisation type, central neck dissection, postoperative diagnosis, neck side, extralaryngeal branching, non-RLN, relation of RLN to inferior thyroid artery (ITA), grade of Zuckerkandl tubercle on vocal cord paralysis (VCP) were investigated. RESULTS: This study enrolled 1070 neck sides. The extralaryngeal branching rate was 35.5%. 45.9% of RLNs were anterior and 44.5% were posterior to the ITA, and 9.6% were crossing between the branches of the ITA. The rate of total VCP was 4.8% (transient:4.5%, permanent: 0.3%). The rates of total and transient VCP were significantly higher in extralaryngeal branching nerves compared to nonbranching nerves (6.8% vs. 3.6%, p = 0.018; 6.8% vs. 3.2%, p = 0.006, respectively). Total VCP rates were 7.2%, 2.5%, and 2.9% in case of the RLN crossing anterior, posterior and between the branches of ITA, respectively (p = 0.003). The difference was also significant regarding the transient VCP rates (p = 0.004). Anterior crossing pattern increased the total and transient VCP rates 2.8 and 2.9 times, respectively. CONCLUSION: RLN crossing ITA anteriorly and RLN branching are frequent anatomical variations increasing the risk of VCP in thyroidectomy that cannot be predicted preoperatively. This study is the first one reporting that the relationship between RLN and ITA increased the risk of VCP.

A unique complication of thyroidectomy for Hashimoto's thyroiditis: central retinal artery thrombosis.

BACKGROUND: Central retinal artery occlusion (CRAO) is a rare ophthalmological emergency and also a unique complication after thyroid surgery. METHODS: We present the first case of CRAO following thyroid surgery in a patient with Hashimoto's thyroiditis, along with a variety of interventions to overcome this complication. RESULTS: A 42-year-old female patient suffering from sudden vision loss following total thyroidectomy was diagnosed with CRAO. Hyperbaric oxygen therapy was started within the postoperative first 6 hours. CONCLUSION: Although it is extremely rare, it should be noted that patients may experience retinal artery occlusion following the thyroid surgery. Immediate evaluation of patients with visual impairment in the early postoperative period, and planning of emergent hyperbaric oxygen therapy for the management are critical.

[Investigation of Cytotoxic and Antileishmanial Activity of Hybrid Silver Nanoparticle Complexes: Potential Drug Candidates against Leishmania Species]. / Hibrit Gümüs Nanoparçacik Komplekslerinin Sitotoksik ve Antilaysmanyal Aktivitesinin Arastirilmasi: Leishmania Türlerine Karsi Potansiyel Ilaç Adaylari.

In recent years, isolation of resistant Leishmania species to drugs in use has made it necessary to search alternative molecules that may be drug candidates. In this study, it was aimed to investigate the cytotoxic and in vitro antileishmanial activity of hybrid silver nanoparticle (AgNP) complexes. In this study, three types of nanoparticles (NPs), oxidized amylose-silver (OA-Ag) NPs, oxidized amylose-curcumin (OA-Cur) NPs and oxidized amylose-curcumin-silver (OA-CurAgNP) nanoparticles were synthesized. The cytotoxic activity of the synthesized nanoparticles was determined against L929 mouse fibroblasts and the in vitro antileishmanial activity was determined against Leishmania tropica, Leishmania infantum and Leishmania donovani isolates by the broth microdilution method. It was observed that the hybrid OA-CurAgNP complex obtained by combining curcumin and silver nanoparticles showed cytotoxic effects against L929 mouse fibroblasts at concentrations of 1074 µg/mL and above. IC50 values expressing the antileishmanial activity of the hybrid OA-CurAgNP complex against L.tropica, L.infantum and L.donovani isolates, were found to vary between 95-121 µg/mL, 202-330 µg/mL and 210-254 µg/mL, respectively. Resistance development has emerged as a major challenge in the treatment of leishmaniasis in recent times. Metallic nanoparticles are considered excellent candidates for medical applications due to their chemical and physical properties, as well as their prolonged circulation in the body. The current drugs used for leishmaniasis treatment are highly toxic, while nanoparticles offer advantages such as low toxicity and easy cellular uptake due to their nanoscale dimensions. The identification of strong efficacy in these particles may contribute scientific evidence for their potential use in leishmaniasis treatment. Therefore, the therapeutical value of OA-CurAgNP complex alone in combination with existing drugs should be examined.

Label-Free Identification of Exosomes using Raman Spectroscopy and Machine Learning.

Exosomes, nano-sized extracellular vesicles (EVs) secreted from cells, carry various cargo molecules reflecting their cells of origin. As EV content, structure, and size are highly heterogeneous, their classification via cargo molecules by determining their origin is challenging. Here, a method is presented combining surface-enhanced Raman spectroscopy (SERS) with machine learning algorithms to employ the classification of EVs derived from five different cell lines to reveal their cellular origins. Using an artificial neural network algorithm, it is shown that the label-free Raman spectroscopy method's prediction ratio correlates with the ratio of HT-1080 exosomes in the mixture. This machine learning-assisted SERS method enables a new direction through label-free investigation of EV preparations by differentiating cancer cell-derived exosomes from those of healthy. This approach will potentially open up new avenues of research for early detection and monitoring of various diseases, including cancer.

[Investigation of the Efficacy of Cinnamaldehyde, Cannabidiol and Eravacycline in a Malaria Model]. / Sitma Modelinde Cinnamaldehyde, Cannabidiol ve Eravacycline'in Etkinliginin Arastirilmasi.

In this study, it was aimed to investigate the antimalarial activity of cinnamaldehyde (CIN) and cannabidiol (CBD) which have shown various biological activities such as potent antimicrobial activity and eravacycline (ERA), a new generation tetracycline derivative, in an in vivo malaria model. The cytotoxic activities of the active substances were determined by the MTT method against L929 mouse fibroblasts and their antimalarial activity were determined by the four-day test in an in vivo mouse model. In this study, five groups were formed: the CIN group, the CBD group, the ERA group, the chloroquine group (CQ) and the untreated group (TAG). 2.5 x 107 parasites/mL of P.berghei-infected erythrocyte suspension was administered IP to all mice. The determined doses of active substances were given to the mice by oral gavage in accordance with the four-day test and the parasitemia status in the mice was controlled for 21 days with smear preparations made from the blood taken from the tail end of the mice. The IC50 values, which express the cytotoxic activity values of the active substances were determined as 27.55 µg/mL, 16.40 µM and 48.82 µg/mL for CIN, CBD and ERA, respectively. The mean parasitemia rate in untreated mice was 33% on day nine and all mice died on day 11. On the ninth day, when compared with the TAG group, no parasites were observed in the CIN group, while the average parasitemia was 0.08% in the CBD group and 17.8% in the ERA group. Compared to the mice in the TAG group, the life expectancy of the other groups was prolonged by eight days in the CIN group, 12 days in the CBD group and eight days in the ERA group. It has been determined that all three active subtances tested in this study suppressed the development of Plasmodium parasites in an in vivo mouse model and prolonged the life span of the mice. It is thought that the strong antimalarial activity of CIN and CBD shown in the study and the possible positive effect of ERA on the clinical course can be improved by combining them with the existing and potential antimalarial molecules.

[Comparison of Conventional Methods with Molecular Methods in the Diagnosis of Trichomonas vaginalis and Investigation of Metronidazole Resistance]. / Trichomonas vaginalis'in Tanisinda Konvansiyonel Yöntemlerin Moleküler Yöntemlerle Karsilastirilmasi ve Metronidazol Direncinin Arastirilmasi.

Trichomoniasis is a sexually transmitted parasitic infection caused by Trichomonas vaginalis. In the diagnosis of trichomoniasis, direct microscopy (DM) is preferred, which is a cheap and fast method, although it has low sensitivity. Culture methods, which are accepted as the gold standard, can only be applied in certain centers due to the need for experienced personnel and the ability to get results within 2-7 days, despite their high sensitivity. In this study, it was aimed to compare conventional microscopic and culture methods used in the routine diagnosis of T.vaginalis with polymerase chain reaction (PCR) method and to investigate ntr4 and/or ntr6 gene polymorphism in the nitroreductase gene region, which are thought to be associated with metronidazole resistance in T.vaginalis strains isolated from clinical specimens. Vaginal swab specimens were collected from the posterior fornix of the vagina with two sterile ecuvion sticks during the gynecological examinations of 200 patients who applied to the Balikesir University Health Practice and Research Hospital, Obstetrics and Gynecology Polyclinic between March 2019 and August 2021. The first swab sample was used for direct microscopic examination, Giemsa staining and conventional PCR analysis, while the second swab specimen was taken into trypticase-yeast-extract-maltose (TYM) medium for T.vaginalis culture and followed for eight days at 37 °C. All specimens were screened for the presence of T.vaginalis using primers specific to the ß-tubulin (btub1) gene region and clinical isolates grown in TYM medium were examined for metronidazole resistance using primers specific for the nitroreductase gene region by using conventional PCR. Drug resistance test was also performed for the isolates in which polymorphism associated with metronidazole resistance was detected. Eight (4%) of 200 patient specimens were found positive by both culture/staining and PCR methods. The mean age of the patients included in the study was 39.9, while the mean age of the patients with positive T.vaginalis was 41.8. The most common clinical findings in the patients were foul-smelling vaginal discharge (36%), groin pain (21%), vaginal itching (19%), and burning sensation during urination (18%). In three out of eight T.vaginalis strains isolated from clinical samples, the presence of polymorphism in the ntr6 gene, which is thought to be associated with metronidazole resistance, was demonstrated by PCR. It was observed that three isolates with ntr6 gene polymorphism were phenotypically resistant to metronidazole (MLK= 390 µM). In this study, the fact that three of eight clinical isolates that were resistant to metronidazole by the broth microdilution method and as well as showing ntr6 gene polymorphism supported the thesis that there might be a close relationship between metronidazole resistance and ntr6 gene polymorphism. As a result, the use of culture and molecular methods in the diagnosis of T.vaginalis, in addition to the microscopy method, may contribute to a more accurate laboratory diagnosis of the agent, to detect metronidazole resistance molecularly and phenotypically, to determine metronidazole resistance rates in our country and to update treatment protocols within the framework of these data.

Analysis of ADAS Radars with Electronic Warfare Perspective.

The increasing demand in the development of autonomous driving systems makes the employment of automotive radars unavoidable. Such a motivation for the demonstration of fully-autonomous vehicles brings the challenge of secure driving under high traffic jam conditions. In this paper, we present the investigation of Advanced Driver Assistance Systems (ADAS) radars from the perspective of electronic warfare (EW). Close to real life, four ADAS jamming scenarios have been defined. Considering these scenarios, the necessary jamming power to jam ADAS radars is calculated. The required jamming Effective Radiated Power (ERP) is -2 dBm to 40 dBm depending on the jamming scenario. These ERP values are very low and easily realizable. Moreover, the effect of the jamming has been investigated on the radar detection at radar Range Doppler Map (RDM) and 2-Dimensional Constant False Alarm Rate (2D-CFAR). Furthermore, the possible jamming system requirements have been investigated. It is noted that the required jamming system will not require high-end technology. It is concluded that for the security of automotive driving, the ADAS radar manufacturer should consider the intentional jamming and related Electronic Counter Countermeasures (ECCM) features in the design of ADAS radars.

[Antibacterial Activity and Synergistic Interaction of Various Essential Oil Components and Antibiotics]. / Çesitli Uçucu Yag Bilesenleri ile Antibiyotiklerin Antibakteriyel Etkinligi ve Sinerjik Etkilesimi.

Inappropriate and uncontrolled use of antibiotics in humans and animals leads to the emergence of multi-resistant bacteria. Before the discovery of antibiotics, plant extracts and essential oils were used for therapeutic purposes. Today, due to increasing antibiotic resistance, many studies are frequently carried out on the antimicrobial activities of natural active substances that can be a source for new drug candidates. The aim of this study was to investigate the antibacterial activity of components such as α-pinene (α-PN), p-cymene (p-CYM), carvacrol (CAR), thymol (TY) and eugenol (EG) found in the essential oils of many plants and their synergistic interaction with antibiotics. In this study, the antibacterial activity of these essential oil components and antibiotics in clinical use such as gentamicin (GEN), tetracycline (TET), tigecycline (TGC) and linezolid (LZD), against Staphylococcus aureus [methicillin resistant S.aureus (MRSA), and methicillin sensitive S.aureus (MSSA)], Escherichia coli and Pseudomonas aeruginosa strains were determined by disc diffusion and microdilution method. In addition, the interaction between the essential oil components and antibiotics was also determined by the checkerboard method. While CAR, TY and EG components showed strong antibacterial activity, the antibacterial activity of αPN and p-CYM was found to be weak. Combinations of α-pinene, carvacrol, thymol and eugenol with gentamicin and tetracycline mostly showed synergistic interactions against all bacteria. In αPN, CAR, TY and EG with GEN and TET, synergistic/partial synergistic interaction was observed against S.aureus strains, while indifferent interaction was detected in E.coli and P.aeruginosa strains. The combination of αPN and p-CYM with TGC showed synergistic interaction against E.coli and P.aeruginosa strains, and additive and indifferent interaction against S.aureus strains. On the other hand, synergistic interaction was observed against all bacterial strains in combinations of TGC and CAR, TY and EG components. Antagonistic interaction was not detected in any of the tested component-antibiotic combinations against the bacteria used in our study. A synergistic interaction between natural bioactive components and commonly used antibiotics may contribute to the effectiveness of antibiotics and components at lower doses, minimizing their potential toxic side effects and reducing treatment costs. However, more research is needed in terms of their pharmacokinetic and toxic properties to evaluate the therapeutic application potential of phytochemicals.

Multi-Wavelength Photo-Magnetic Imaging System for Photothermal Therapy Guidance.

BACKGROUND AND OBJECTIVES: In photothermal therapy, cancerous tissue is treated by the heat generated from absorbed light energy. For effective photothermal therapy, the parameters affecting the induced temperature should be determined before the treatment by modeling the increase in temperature via numerical simulations. However, accurate simulations can only be achieved when utilizing the accurate optical, thermal, and physiological properties of the treated tissue. Here, we propose a multi-wavelength photo-magnetic imaging (PMI) technique that provides quantitative and spatially resolved tissue optical absorption maps at any wavelength within the near-infrared (NIR) window to assist accurate photothermal therapy planning. STUDY DESIGN/MATERIALS AND METHODS: The study was conducted using our recently developed multi-wavelength PMI system, which operates at four laser wavelengths (760, 808, 860, and 980 nm). An agar tissue-simulating phantom containing water, lipid, and ink was illuminated using these wavelengths, and the slight internal laser-induced temperature rise was measured using magnetic resonance thermometry (MRT). The phantom optical absorption was recovered at the used wavelengths using our dedicated PMI image reconstruction algorithm. These absorption maps were then used to resolve the concentration of the tissue chromophores, and thus deduce its optical absorption spectrum in the NIR region based on the Beer-Lambert law. RESULTS: The optical absorption of the phantom was successfully recovered at the used four wavelengths with an average error of ~1.9%. The recovered absorption coefficient was then used to simulate temperature variations inside the phantom. A comparison between the modeled temperature maps and the MRT measured ones showed that these maps are in a good agreement with an average pseudo R2 statistic of 0.992. These absorption values were used to successfully recover the concentration of the used chromophores. Finally, these concentrations are used to accurately calculate the total absorption spectrum of the phantom in the NIR spectral window with an average error as low as ~2.3%. CONCLUSIONS: Multi-wavelength PMI demonstrated a great ability to assess the distribution of tissue chromophores, thus providing its total absorption at any wavelength within the NIR spectral range. Therefore, applications of photothermal therapy applied at NIR wavelengths can benefit from the absorption spectrum recovered by PMI to determine important parameters such as laser power as well as the laser exposure time needed to attain a specific increase in temperature prior to treatment. Lasers Surg. Med. 00:00-00, 2020. © 2020 Wiley Periodicals LLC.

Analysis of microcantilevers excited by pulsed-laser-induced photoacoustic waves.

This study presents a simulation-based analysis on the excitation of microcantilever in air using pulsed-laser-induced photoacoustic waves. A model was designed and coded to investigate the effects of consecutive photoacoustic waves, arising from a spherical light absorber illuminated by short laser pulses. The consecutiveness of the waves were adjusted with respect to the pulse repetition frequency of the laser to examine their cumulative effects on the oscillation of microcantilever. Using this approach, oscillation characteristics of two rectangular cantilevers with different resonant frequencies (16.9 kHz and 505.7 kHz) were investigated in the presence of the random oscillations. The results show that the effective responses of the microcantilevers to the consecutive photoacoustic waves provide steady-state oscillations, when the pulse repetition frequency matches to the fundamental resonant frequency or its lower harmonics. Another major finding is that being driven by the same photoacoustic pressure value, the high frequency cantilever tend to oscillate at higher amplitudes. Some of the issues emerging from these findings may find application area in atomic force microscopy actuation and photoacoustic signal detection.

Quantifying the effects of antiangiogenic and chemotherapy drug combinations on drug delivery and treatment efficacy.

Tumor-induced angiogenesis leads to the development of leaky tumor vessels devoid of structural and morphological integrity. Due to angiogenesis, elevated interstitial fluid pressure (IFP) and low blood perfusion emerge as common properties of the tumor microenvironment that act as barriers for drug delivery. In order to overcome these barriers, normalization of vasculature is considered to be a viable option. However, insight is needed into the phenomenon of normalization and in which conditions it can realize its promise. In order to explore the effect of microenvironmental conditions and drug scheduling on normalization benefit, we build a mathematical model that incorporates tumor growth, angiogenesis and IFP. We administer various theoretical combinations of antiangiogenic agents and cytotoxic nanoparticles through heterogeneous vasculature that displays a similar morphology to tumor vasculature. We observe differences in drug extravasation that depend on the scheduling of combined therapy; for concurrent therapy, total drug extravasation is increased but in adjuvant therapy, drugs can penetrate into deeper regions of tumor.

[Frequency of restless legs syndrome and relationship between depression, anxiety and sleep quality among medical school students]. / Tip fakültesi ögrencileri arasinda huzursuz bacak sendromu sikligi, depresyon, anksiyete ve uyku kalitesi arasindaki iliski.

INTRODUCTION: We aimed to investigate the relationship between frequency of restless legs syndrome (RLS), depression, anxiety and sleep quality among medical school students. MATERIALS AND METHODS: We applied a questionnaire to medical school students. This questionnaire includes some questions about demographic features of participants, questions related with RLS diagnosis, the pittsburgh sleep quality index (PSQI), beck-depression-scale (BDS), beck-anxiety scale (BAS) to all subjects. Participants diagnosed with RLS asked to response some additional questions related with RLS severity rating scale. All results compared between RLS diagnosed and healthy subjects. RESULT: A total of 402 medical school students, of whom 55.2% (n= 22) were female, were participated into this study. The ratio of subjects diagnosed as RLS was 16.9% (n= 68). The ratio of RLS diagnosed participants in female students was 18.0% (n= 40) and in male students was 15.6% (n= 28). Of 169 participants who got a poor sleep quality, 36 subjects (21.3%) was diagnosed as RLS. On the other hand, of 233 participants who got a good sleep quality, 32 subjects (13.7%) was diagnosed as RLS (p= 0.004). Score for the RLS severity ranging scale for participants who were diagnosed as RLS was positively correlated with both BDS and BAS scores (p= 0.002, r= 0.372 ve p< 0.001, r= 0.506, respectively). CONCLUSIONS: In this study, the rate of RLS in medical school students were higher than the rate presented in the literature. Additionaly, participants who were diagnosed as RLS in our study had worse sleep quality than healthy subjects. Moreover, RLS may be associated with some psychological mood disorders.

Ex vivo validation of photo-magnetic imaging.

We recently introduced a new high-resolution diffuse optical imaging technique termed photo-magnetic imaging (PMI), which utilizes magnetic resonance thermometry (MRT) to monitor the 3D temperature distribution induced in a medium illuminated with a near-infrared light. The spatiotemporal temperature distribution due to light absorption can be accurately estimated using a combined photon propagation and heat diffusion model. High-resolution optical absorption images are then obtained by iteratively minimizing the error between the measured and modeled temperature distributions. We have previously demonstrated the feasibility of PMI with experimental studies using tissue simulating agarose phantoms. In this Letter, we present the preliminary ex vivo PMI results obtained with a chicken breast sample. Similarly to the results obtained on phantoms, the reconstructed images reveal that PMI can quantitatively resolve an inclusion with a 3 mm diameter embedded deep in a biological tissue sample with only 10% error. These encouraging results demonstrate the high performance of PMI in ex vivo biological tissue and its potential for in vivo imaging.

Four cases of pulmonary thromboembolism diagnosed by endobronchial ultrasound.

Endobronchial ultrasound (EBUS) is a technique for the detection of mediastinal abnormalities. A total of 548 EBUS procedures were performed for various indications, and in four cases (0.7%), filling defects in central pulmonary arteries were demonstrated fortuitously during the procedure. Subsequently, all patients underwent contrast-enhanced CT of the thorax to confirm the diagnosis of pulmonary thromboembolism (PTE). In three of the four cases, there was a concomitant lung cancer. PTE can be incidentally detected during EBUS; therefore, pulmonary arteries should be examined carefully during EBUS in all patients, particularly in patients with suspected or proven malignancy. © 2016 Wiley Periodicals, Inc. J Clin Ultrasound 45:441-444, 2017.

Lumbar Opening Pressure and Radiologic Scoring in Idiopathic Intracranial Hypertension: Is There Any Correlation?

BACKGROUND: To investigate correlation between lumbar opening pressure (LOP) and radiological scores based on cranial MRI and contrast-enhanced MR venography in patients with idiopathic intracranial hypertension (IIH). MATERIAL/METHODS: Patients with IIH who underwent brain MRI and contrast-enhanced MR venography before measurement of LOP between 2010-2014 were evaluated retrospectively. Three experienced radiologists (blinded to LOP values) evaluated a total of 51 patients. They reached a consensus on the presence or absence of 6 radiological findings identified in the literature as characteristic for IIH: empty sella, perioptic dilation, optical tortuosity, flattening of the posterior globe, swelling of the optic disc, and bilateral transverse sinus stenosis. The radiological score was obtained by giving 1 point for the presence of each finding, with the highest possible score of 6 points. The correlation between the calculated radiological scores and LOP was evaluated. RESULTS: There was no significant correlation between LOP and radiological scores (r=0.095; p=0.525, Spearman's rank coefficient). Similarly, no significant correlation was detected between LOP and each of the radiological findings (partial empty sella [p=0.137], perioptic dilation [p=0.265], optical tortuosity [p=0.948], flattening of the posterior globe [p=0.491], swelling of the optic disc [p=0.881], and bilateral dural sinus stenosis [p=0.837], Mann-Whitney U test). CONCLUSIONS: There was no significant correlation between LOP and reliable radiological features of IIH.

Arterial stiffness in obstructive sleep apnoea: Is there a difference between daytime and night-time?

BACKGROUND AND OBJECTIVE: Obstructive sleep apnoea syndrome (OSAS) is a common chronic systemic disease in the general population, with known associated cardiovascular outcomes. We aimed to investigate arterial stiffness in OSAS patients and compare daytime and night-time values with control subjects. METHODS: A total of 104 patients undergoing investigation for OSAS with polysomnography also underwent pulse wave velocity (PWV) and augmentation index (AIx) measurements with Mobil-O-Graph for 24 h. Eighty-two patients were found to have OSAS and 22 did not have OSAS and acted as controls. RESULTS: PWV values of the 82 OSAS patients during the 24-h period, both daytime and night-time, were significantly higher than that of the control subjects. Moreover, night-time levels of AIx were significantly higher in OSAS patients than control subjects (P = 0.025). PWV during night-time was higher than daytime measurements in OSAS patients (P = 0.012). Apnoea hypopnoea index (AHI) was significantly correlated with PWV and AIx over 24 h (P = 0.0001, r = 0.412; P = 0.002, r = 0.333, respectively). Positive correlations were also found between oxygen desaturation index (ODI) with PWV and AIx during the night (P = 0.0001, r = 0.480; P = 0.002, r = 0.325, respectively). However, daytime AIx was not significantly correlated with ODI (P = 0.052, r = 0.205). CONCLUSION: OSAS patients, without known cardiovascular disease, have increased PWV, indicating an increased arterial stiffness, compared with control subjects and correlations between AHI and arterial stiffness indices suggest increased arterial stiffness with increased disease severity. Therefore, arterial stiffness should be considered as a possible cause for cardiovascular complications in OSAS patients.

Differentiation of tumor vasculature heterogeneity levels in small animals based on total hemoglobin concentration using magnetic resonance-guided diffuse optical tomography in vivo.

Insight into the vasculature of the tumor in small animals has the potential to impact many areas of cancer research. The heterogeneity of the vasculature of a tumor is directly related to tumor stage and disease progression. In this small scale animal study, we investigated the feasibility of differentiating tumors with different levels of vasculature heterogeneity in vivo using a previously developed hybrid magnetic resonance imaging (MRI) and diffuse optical tomography (DOT) system for small animal imaging. Cross-sectional total hemoglobin concentration maps of 10 Fisher rats bearing R3230 breast tumors are reconstructed using multi-wavelength DOT measurements both with and without magnetic resonance (MR) structural a priori information. Simultaneously acquired MR structural images are used to guide and constrain the DOT reconstruction, while dynamic contrast-enhanced MR functional images are used as the gold standard to classify the vasculature of the tumor into two types: high versus low heterogeneity. These preliminary results show that the stand-alone DOT is unable to differentiate tumors with low and high vascular heterogeneity without structural a priori information provided by a high resolution imaging modality. The mean total hemoglobin concentrations comparing the vasculature of the tumors with low and high heterogeneity are significant (p-value 0.02) only when MR structural a priori information is utilized.

Comprehensive analytical model for CW laser induced heat in turbid media.

In this work, we present a new analytical approach to model continuous wave laser induced temperature in highly homogeneous turbid media. First, the diffusion equation is used to model light transport and a comprehensive solution is derived analytically by obtaining a special Greens' function. Next, the time-dependent bio-heat equation is used to describe the induced heat increase and propagation within the medium. The bio-heat equation is solved analytically utilizing the separation of variables technique. Our theoretical model is successfully validated using numerical simulations and experimental studies with agarose phantoms and ex-vivo chicken breast samples. The encouraging results show that our method can be implemented as a simulation tool to determine important laser parameters that govern the magnitude of temperature rise within homogenous biological tissue or organs.

Effects of nondipping pattern on systemic inflammation in obstructive sleep apnea.

BACKGROUND: Obstructive sleep apnea syndrome (OSAS) is a highly prevalent chronic systemic disease in the general population with high morbidity and mortality. Nondipping pattern-failure to drop blood pressure levels in nighttime-is also seen in OSAS patients. We aim to investigate dipping and nondipping patterns of OSAS patients and to compare inflammatory markers. MATERIALS AND METHODS: Patients with the confirmed diagnosis of OSAS with polysomnography underwent ambulatory blood pressure monitoring. During monitoring, patients with decreased nighttime mean systolic blood pressures 10 % or more were defined as dippers, and the patients without this amount of decrease were defined as nondippers. Peripheral venous blood samples were collected for the analysis of IL-2, IL-6, IL-8, IL-10, IL-12, and TNF-α. Results were compared with convenient statistical tests. RESULTS: According to monitoring results, 34 of 62 OSAS patients were dipper and 28 of 62 patients were nondipper. Demographic characteristics, OSAS severity, and Apnea Hypopnea Index were similar in both groups. When inflammatory markers were compared between two groups, IL-2 levels were found to be significantly different (p = 0.014). CONCLUSION: In conclusion, nondipping pattern appears to be associated with increased serum IL-2 levels indicating the increased inflammatory response independently from OSAS severity, and this pattern should be evaluated carefully for possible cardiovascular complications.