Dexmedetomidine, an α2 agonist, increases the morphine analgesic effect and decreases morphine tolerance development by suppressing oxidative stress and TNF/IL-1 signalling pathway in rats

BACKGROUND

The aim of the present study is to examine the possible effect de dexmedetomidine on the development of morphine tolerance in rats including nociception, morphine analgesia, apoptosis, oxidative stress, and tumour necrosis factor (TNF)/ interleukin-1 (IL-1) pathways.

MATERIALS AND METHODS

In this study, 36 Wistar Albino (225-245 g) rats were used. Animals were divided into 6 groups: saline (S), 20 mcg/kg dexmedetomidine (D), 5 mg/kg morphine (M), M + D, morphine tolerance (MT), and MT + D. The analgesic effect was measured with hot plate and tail-flick analgesia tests. After the analgesia tests, the dorsal root ganglia (DRG) tissues were excised. Oxidative stress parameters [total antioxidant status (TAS), total oxidant status (TOS)], TNF, IL-1 and apoptosis enzymes (Caspase-3, Caspase-9), were measured in DRG tissues.

RESULTS

Dexmedetomidine showed an antinociceptive effect when given alone (p < 0.05 to p < 0.001). In addition, dexmedetomidine increased the analgesic effect of morphine (p < 0.001), and also decreased the tolerance to morphine at a significant level (p < 0.01 to p < 0.001). Moreover, it decreased oxidative stress (p < 0.001) and TNF/IL-1 levels when given as an additional drug of single-dose morphine and morphine tolerance group (p < 0.001). Furthermore, dexmedetomidine decreased Caspase-3 and Caspase-9 levels after tolerance development (p < 0.001).

CONCLUSION

Dexmedetomidine has antinociceptive properties, and it increases the analgesic effect of morphine and also prevents tolerance development. These effects probably occur by the modulation of oxidative stress, inflammation and apoptosis.

Efficacy of pulse steroid therapy in patients critically ill with COVID-19

OBJECTIVES

The aim of this study was to determine the efficacy of pulse steroid therapy administered to patients critically ill with COVID-19 progressing into severe pneumonia.

METHODS

A total of 600 patients included in this retrospective study were divided into three groups. Group 1 (control group): 200 patients who did not receive steroid treatment, Group 2: 200 patients who received dexamethasone 1x8 milligram (mg) or methylprednisolone 1x80 mg, Group 3: (pulse steroid therapy group): 200 patients who received 1 g methylprednisolone followed by 1x80 mg methylprednisolone. Demographic and laboratory data were recorded.

RESULTS

Mortality rates in groups 1, 2 and 3 were 77 %, 53.55 %, and 58.5 %, respectively. The ratios of intubated patients in groups 1, 2 and 3 were 70 %, 45.5 % and 56 %, respectively. The numbers of patients whose D‑dimer values were above 2,250 ng/mL (cut-off value for D-dimer in this study) in groups 2, 1 and 3 were 65, 107, and 105, respectively.

CONCLUSION

Pulse steroid therapy does not shorten the duration of hospital stay, does not reduce the need for intubation and increases the risk of thrombosis by significantly increasing the level of D-dimer among patients critically and severely ill with COVID-19 (Tab. 4, Fig. 3, Ref. 20) Keywords: COVID-19, pulse steroid therapy, thrombosis, d-dimer, corticosteroid.

AB0617 OPTICAL COHERENCE TOMOGRAPHY IN THE ASSESSMENT OF SKIN FIBROSIS IN SYSTEMIC SCLEROSIS: A CROSS-SECTIONAL STUDY

Background:

Previous studies have shown that Optical Coherence Tomography (OCT) is a reliable biomarker of skin fibrosis and significantly correlates with the severity of the skin involvement in Systemic Sclerosis (SSc)1,2.

Objectives:

Aim of this cross-sectional study was to evaluate the performance of skin OCT to discriminate between SSc and healthy controls (HC) and to compare results with the current gold standard, the modified Rodnan skin score (mRss), in a different SSc study cohort.

Methods:

Dorsal forearm skin of consecutive diffuse cutaneous SSc (dcSSc) patients and matched-HC was scanned by an investigator blinded to the clinical data using Vivosight scanner (Michelson Diagnostics, Kent, UK). Minimum Optical Density (MinOD), Maximum OD (MaxOD) and OD at 300 micron-depth (OD300) were measured. Clinical involvement was assessed by a blinded operator using the mRss and results were compared with imaging data. Statistical analysis was performed using GraphPad Prism software V.7.0.

Results:

A total of 88 OCT images were obtained from 22 dcSSc patients [20 Female, mean age 49 (±11) years, 12 with < 5 years disease duration) and 22 HC (20 Female, mean age 50.7 (±6.7) years]. All OCT measures (MinOD, MaxOD and OD300) were significantly lower in SSc patients than in HC (p=0.011, p<0.0001, p<0.0001 respectively). MaxOD and OD300 were significantly different between the four groups (0-3) of patients based on the mRss at the site of analysis (p=0.035, p=0.001 respectively). Skin OCT showed a good performance in discriminating SSc skin vs HC (overall AUC 0.72, 0.8 and 0.89 for MinOD, MaxOD and OD300 respectively).

Conclusion:

These results confirm in a cohort different from those of the previous studies that skin OCT is able to reflect the severity of skin involvement in SSc. Longitudinal studies are needed to validate its potential as surrogate outcome measure of skin fibrosis in SSc patients.

References:

[1]Abignano G et al. Ann Rheum Dis 2013; 2. Pires NSM et al. Ann Rheum Dis 2018.

Disclosure of Interests:

None declared

FRI0226 OPTICAL COHERENCE TOMOGRAPHY OF THE SKIN DETECTS SCLERODERMA CHANGES IN CLINICALLY UNAFFECTED SKIN: AN OPPORTUNITY FOR EARLY DETECTION OF SYSTEMIC SCLEROSIS

Background:

The Very Early Diagnosis Of Systemic Sclerosis (VEDOSS) study has shown that 82% of patients with Raynaud’s Phenomenon, specific ANA positivity and scleroderma pattern at nail fold videocapillaroscopy will fulfil classification criteria within 5 years. This is suggesting that there is a subclinical window of opportunity to diagnose systemic sclerosis (SSc) before clinical manifestations occur. In this scenario, a non-invasive tool to diagnose SSc in clinically unaffected skin might improve the early detection of disease in at risk-patients. Optical coherence tomography (OCT) of the skin has been shown to be a sensitive and accurate biomarker of skin fibrosis in SSc.

Objectives:

Here we aimed to assess the ability of skin OCT to “detect” SSc in clinically unaffected skin from a multicentre cohort.

Methods:

Dorsal forearm skin of SSc patients and matched-healthy controls (HC) was evaluated using VivoSight scanner (Michelson Diagnostics). Mean A-scans (mean OCT signal plotted against depth-in-tissue) were derived as previously described. Minimum Optical Density (MinOD), Maximum OD (MaxOD) and OD at 300 micron-depth (OD300) were calculated. Clinical involvement was assessed by an operator blinded to OCT findings using the mRSS. Receiver-operating characteristic (ROC) curve analysis was carried out for MinOD, MaxOD, and OD300 to evaluate their ability to discriminate between SSc and HC. Statistical analysis was performed using GraphPad Prism software V.7.0.

Results:

One hundred seventy four OCT images were collected from 87 subjects [43 SSc (39 Female, mean age 49.7±9.1 years) and 44 gender/age-matched healthy controls (HC) (36 Female, mean age 50.2±8.3 years)] in two different SSc centres. All patients fulfilled classification criteria for SSc. OCT measures demonstrated discriminative ability in SSc skin detection with any clinical skin involvement (0-3 at site of analysis) with an AUC of 0.73 (MinOD, 95%CI 0.64-0.81), 0.77 (MaxOD, 95%CI 0.7-0.85) and 0.82 (OD300, 95%CI 0.76-0.89); p<0.0001 for all as previously indicated. Most importantly, all three measures showed comparable performance in detecting scleroderma also in clinically unaffected skin (mRss=0 at site of analysis), with an AUC of 0.7 (95%CI 0.6-0.81, p=0.001), 0.72 (95%CI 0.61-0.83, p=0.0003) and 0.72 (95%CI 0.61-0.83, p=0.0003) for MinOD, MaxOD and OD300 respectively.

Conclusion:

Virtual biopsy by OCT recognises clinically unaffected skin of SSc patients from the HC skin. This is consistent with gene array data showing that scleroderma specific signatures are consistent in affected and clinically unaffected skin. These results inform future studies on at risk patients with clinically unaffected skin which may define a role for OCT in detecting subclinical SSc.

Disclosure of Interests:

Giuseppina Abignano: None declared, Duygu Temiz Karadağ: None declared, Ozcan Gundogdu: None declared, Giovanni Lettieri: None declared, Maria Carmela Padula: None declared, Angela Padula: None declared, Paul Emery Grant/research support from: AbbVie, Bristol-Myers Squibb, Merck Sharp & Dohme, Pfizer, Roche (all paid to employer), Consultant of: AbbVie (consultant, clinical trials, advisor), Bristol-Myers Squibb (consultant, clinical trials, advisor), Lilly (clinical trials, advisor), Merck Sharp & Dohme (consultant, clinical trials, advisor), Novartis (consultant, clinical trials, advisor), Pfizer (consultant, clinical trials, advisor), Roche (consultant, clinical trials, advisor), Samsung (clinical trials, advisor), Sandoz (clinical trials, advisor), UCB (consultant, clinical trials, advisor), Salvatore D’Angelo: None declared, Francesco Del Galdo: None declared

Prevalence of Type VI Secretion System in Spanish Campylobacter jejuni Isolates

Infections from Campylobacter jejuni pose a serious public health problem and are now considered the leading cause of foodborne bacterial gastroenteritis throughout the world. Sequencing of C. jejuni genomes has previously allowed a number of loci to be identified, which encode virulence factors that aid survival and pathogenicity. Recently, a Type VI secretion system (T6SS) consisting of 13 conserved genes was described in C. jejuni strains and recognised to promote pathogenicity and adaptation to the environment. In this study, we determined the presence of this T6SS in 63 Spanish C. jejuni isolates from the food chain and urban effluents using whole-genome sequencing. Our findings demonstrated that nine (14%) strains harboured the 13 ORFs found in prototype strain C. jejuni 108. Further studies will be necessary to determine the prevalence and importance of T6SS-positive C. jejuni strains.

Evaluation of radon concentration in well and tap waters in Bursa, Turkey

(222)Rn measurements in water samples collected from 27 wells and 19 taps that were supplied from the investigated wells were conducted using the AlphaGUARD PQ 2000PRO radon gas analyser at sites across several geologic formations within the city of Bursa, Turkey. The measured radon concentrations ranged from 1.46 to 53.64 Bq l(-1) for well water and from 0.91 to 12.58 Bq l(-1) for tap water. Of the 27 sites sampled, only 7 had radon levels above the safe limit of 11.1 Bq l(-1) recommended by the USEPA. In general, all determined concentrations were well below the 100 Bq l(-1) revised reference level proposed by the European Union. These values of radon concentrations in water samples are compared with those reported from other countries. Doses resulting from the consumption of these waters were calculated. The minimum and the maximum annual mean effective doses due to (222)Rn intake through water consumption were 0.02 µSv a(-1) and 1.11 µSv a(-1), respectively.

A practical method for in-situ thickness determination using energy distribution of beta particles

This paper discusses a method to determine the thickness of an absorber using the energy distribution of beta particles. An empirical relationship was obtained between the absorber thickness and the energy distribution of beta particles transmitted through. The thickness of a polyethylene radioactive source cover was determined by exploiting this relationship, which has largely been left unexploited allowing us to determine the in-situ cover thickness of beta sources in a fast, cheap and non-destructive way.

Parental attitudes and varicella vaccine in Kocaeli, Turkey

OBJECTIVE

To explore what factors influence Turkish parents' decision whether to have their children immunised or not and compare them with other internationally published studies.

METHOD

Data from 300 parents were gathered via a survey completed by the parents during their policlinic visit between January 2009 and March 2010 in Kocaeli, Turkey. The survey content was based on 10 Health Belief Model, each question being based on a 5-point Likert scale together with additional 19 questions in order to discover other demographic factors.

RESULTS

One of the differences in our study when compared to other published studies is mothers' jobs as employed mothers were significantly willing to have their children vaccinated whereas studies elsewhere have generally shown that demographic background variables do not affect parents' perceptions. The parents who took part in this study were not overly concerned about the side effects in contrast to other published studies. Another major finding is the positive influence of parents being informed by a consultant paediatrician rather than their family general practitioner.

CONCLUSIONS

The acceptance of varicella vaccine depends on a complex interaction of factors but parents' perceptions may change dramatically by being well informed as well as having financial support from the government.

Micro-PIXE and SAXS studies at the bone-cartilage interface

Micro Proton Induced X-ray Emission (micro-PIXE) analysis has been employed herein in investigating and quantifying the distribution of a number of essential elements in thin human diseased articular cartilage sections affected by osteoarthritis (OA). Various cations Ca, P and Zn have been reported to play an important role both in the normal growth and remodelling of articular cartilage and subchondral bone as well as in the degenerative and inflammatory processes associated with the disease; they act as co-factors of a class of enzymes known as metalloproteinases which are believed to be active during the initiation, progress and remodelling processes associated with osteoarthritis. Other important enzymes such as alkaline phosphatase are associated with cartilage mineralization. Synchrotron radiation X-ray fluorescence (SR-XRF) for mapping of elemental distributions in bone and cartilage has also been employed by the present group and others. In the current investigations using the cSAXS beamline at the Swiss light source, Small-Angle X-ray Scattering (SAXS) was carried out on decalcified human articular cartilage to explore the structural and organizational changes of collagen networks in diseased articular cartilage.

Calculation of angular distribution of 662 keV gamma rays by Monte Carlo method in copper medium

This paper presents results on the angular distribution of Compton scattering of 662 keV gamma photons in both forward and backward hemispheres in copper medium. The number of scattered events graph has been determined for scattered gamma photons in both the forward and backward hemispheres and theoretical saturation thicknesses have been obtained using these results. Furthermore, response function of a 51 x 51 mm NaI(Tl) detector at 60 degrees angle with incoming photons scattered from a 10mm thick copper layer has been determined using Monte Carlo method.

Benchtop phase-contrast X-ray imaging

Clinical radiography has traditionally been based on contrast obtained from absorption when X-rays pass through the body. The contrast obtained from traditional radiography can be rather poor, particularly when it comes to soft tissue. A wide range of media of interest in materials science, biology and medicine exhibit very weak absorption contrast, but they nevertheless produce significant phase shifts with X-rays. The use of phase information for imaging purposes is therefore an attractive prospect. Some of the X-ray phase-contrast imaging methods require highly monochromatic plane wave radiation and sophisticated X-ray optics. However, the propagation-based phase-contrast imaging method adapted in this paper is a relatively simple method to implement, essentially requiring only a microfocal X-ray tube and electronic detection. In this paper, we present imaging results obtained from two different benchtop X-ray sources employing the free space propagation method. X-ray phase-contrast imaging provides higher contrast in many samples, including biological tissues that have negligible absorption contrast.

Calculation of total counting efficiency of a NaI(Tl) detector by hybrid Monte-Carlo method for point and disk sources

This paper presents results on the total gamma counting efficiency of a NaI(Tl) detector from point and disk sources. The directions of photons emitted from the source were determined by Monte-Carlo techniques and the photon path lengths in the detector were determined by analytic equations depending on photon directions. This is called the hybrid Monte-Carlo method where analytical expressions are incorporated into the Monte-Carlo simulations. A major advantage of this technique is the short computation time compared to other techniques on similar computational platforms. Another advantage is the flexibility for inputting detector-related parameters (such as source-detector distance, detector radius, source radius, detector linear attenuation coefficient) into the algorithm developed, thus making it an easy and flexible method to apply to other detector systems and configurations. The results of the total counting efficiency model put forward for point and disc sources were compared with the previous work reported in the literature.

Improved production by domain inversion of single-chain Fv antibody fragment against high molecular weight proteoglycan for the radioimmunotargeting of melanoma

Melanoma is among the few cancers with rising incidence. Currently there is no effective treatment for metastatic disease, but improved detection of melanoma has the potential to benefit the management of patients with early disease. Radioimmunodection by imaging with single-chain Fv (scFv) antibody fragments is one such emerging diagnostic method. However, the amount of scFv that can be produced at a scale suitable for use in patients is limiting. We have previously shown that the bacterial expression of a scFv derived from a monoclonal antibody (MAb) specific for melanoma-associated proteoglycan can be increased by light chain shuffling. In this report we show that a further increase in expression yield can be obtained by reversing the usual V(H)-V(L) orientation of scFvs to V(L)-V(H). Such seemingly minor changes have previously been reported to have unexpected effects on the in vitro and in vivo binding properties of recombinant antibodies. Our results show that reversal of the V domain orientation of the scFv improves expression by 150% without an adverse effect on melanoma binding in vitro and tumor targeting in vivo. Therefore, our results show that alteration of V domain orientation can improve the production yield of clinically useful antibody fragments. When used in combination with other antibody engineering approaches for increased antibody production changing the domain orientation is a simple strategy to achieve significant improvements in the production of scFvs for tumor radioimmunodetection for patient studies.