Diagnostic Dose Research Articles

Baseline susceptibility of Asian corn borer (Ostrinia furnacalis (Guenée)) populations in Vietnam to Cry1Ab insecticidal protein

Abstract Susceptibility of Asian corn borer (ACB), Ostrinia furnacalis (Guenee) to Bacillus thuringiensis (Bt) Cry1Ab protein was studied between 2015 and 2016 with 11 ACB populations, collected from various geographical regions in Vietnam. A concentration range of Cry1Ab from 0.20 to 26.10 ng/cm2 of diet was evaluated against F1 ACB neonates using diet surface-overlay bioassays. Mortality data was recorded daily until seven days after infestation. Growth inhibition was recorded at the end of seven days. The median lethal concentration (LC50) varied ≈3-fold among the different populations, ranging from 0.58 to 1.83 ng/cm2 of diet with an overall mean of 0.86 ng/cm2 of diet. Even the lowest concentration of 0.20 ng/cm2 caused 73.53% growth inhibition. >90% growth inhibition was achieved at 0.82 ng/cm2 or higher concentrations. The results reflect natural variation in Bt susceptibility among ACB populations rather than variation caused by prior exposure to selection pressures. LC99 value (17.26 ng/cm2) was generated by pooling mortality data across different populations. The upper fiducial limit of LC99 (24.38 ng/cm2) could be a potential diagnostic dose for future resistance monitoring programs. The findings from this study suggest that ACB populations in Vietnam are highly susceptible to Cry1Ab protein. This is the first report of Cry1Ab susceptibility of different ACB populations in Vietnam and will serve as a baseline for future resistance monitoring work.

Evaluation of toxicity of clothianidin (neonicotinoid) and chlorfenapyr (pyrrole) insecticides and cross-resistance to other public health insecticides in Anopheles arabiensis from Ethiopia

BackgroundInsecticide-based interventions play an integral role in malaria vector control. However, the continued spread of insecticide resistance threatens to undermine progress made thus far and may ultimately lead to operational failure of current control measures. Clothianidin and chlorfenapyr both have unique modes of action and have expanded the number of insecticide classes available to vector control programmes. Prior to field use, it is imperative to establish their toxicity against local mosquito populations and evaluate potential cross-resistance with other chemicals used contemporarily or historically. The aim of this study was to determine the diagnostic doses of clothianidin and chlorfenapyr and their efficacies against Anopheles arabiensis, the predominant Ethiopian malaria vector species.MethodsA range of doses of clothianidin and chlorfenapyr were tested, using modified WHO susceptibility tests and CDC bottle bioassays, respectively, against an Ethiopian susceptible laboratory strain and a wild population of An. arabiensis collected from Oromia Region, Ethiopia. Cross-resistance to other public health insecticides: carbamates (bendiocarb and propoxur), organophosphate (malathion) and pyrethroids (deltamethrin and permethrin), was assessed in the same mosquito populations using CDC bottle bioassays.ResultsComplete mosquito mortality was observed with the laboratory strain using the recommended diagnostic doses for clothianidin (2%/filter paper) and chlorfenapyr (100 µg/bottle). The field population was resistant to malathion (83% mortality), capable of surviving 2×, 5× and 10× the diagnostic dose of both deltamethrin and permethrin, but susceptible to bendiocarb and propoxur. The field population of An. arabiensis was significantly more susceptible to clothianidin, reaching 100% mortality by day 2 compared to the laboratory strain (100% mortality by day 3). In contrast, the wild population was less susceptible to chlorfenapyr, with the highest mortality of 99% at 72 h using 200 µg/bottle compared to the laboratory colony, which reached complete mortality at 50 µg/bottle by 24 h.ConclusionsThe putative diagnostic doses of clothianidin and chlorfenapyr are appropriate for monitoring resistance in An. arabiensis from Ethiopia. The unique modes of action and an absence of cross-resistance render clothianidin and chlorfenapyr potential candidates for inclusion in the National Malaria Control Programme vector control efforts, particularly in areas with high pre-existing or emergent resistance to other insecticide classes.

Dual-energy CT angiography-derived virtual non-contrast images for follow-up of patients with surgically clipped aneurysms: a retrospective study.

To evaluate the diagnostic performance, image quality, artifacts, and radiation doses of virtual non-contrast (VNC) images, relative to true non-contrast (TNC) images, in patients with surgically clipped aneurysms. Seventy-six patients who underwent unenhanced computed tomography (CT) and dual-energy (DE)-CT angiography after surgical clipping of 85 intracranial aneurysms were included in the study. Diagnostic performances of VNC and TNC images were compared with respect to sensitivity, specificity, and positive and negative predictive values. The results of quantitative and qualitative analyses were compared between VNC and TNC images. Radiation doses were also compared between VNC and TNC images. Diagnostic performance of VNC images was lower than that of TNC images; however, addition of contrast-enhanced images improved diagnostic performance. Image noise and mean attenuation of VNC images were significantly higher than those of TNC images in the centrum semiovale, cerebellum, and pons. The quality of VNC images was excellent or sufficient (85.5% for observer 1, 85.5% for observer 2), and complete acceptance of VNC images was achieved in 64.5% for observer 1 and in 71.0% for observer 2; however, the addition of contrast-enhanced images increased the level of acceptance (92.0% for observer 1, 90.9% for observer 2). Clip artifacts were significantly lower in VNC images than in TNC images. CT dose index, dose-length product, and effective dose were significantly lower without TNC images. VNC images showed lower diagnostic performance and image quality, and higher image noise than TNC images; however, VNC images could reduce clip artifacts and radiation doses.

Virtual Guidance of Percutaneous Transthoracic Needle Biopsy with C-Arm Cone-Beam CT: Diagnostic Accuracy, Risk Factors and Effective Radiation Dose.

C-arm cone-beam computed tomography-guided transthoracic lung core needle biopsy (CBCT-CNB) is a safe and accurate procedure for the evaluation of patients with pulmonary nodules. The purpose of our study was to evaluate the diagnostic performance, complication rates and effective radiation dose of CBCT-CNB with virtual guidance. We retrospectively collected data regarding 375 CBCT-CNBs performed with virtual guidance (XperGuide-Philips Healthcare, Best, The Netherlands) from January 2010 to June 2015 on 355 patients (mean age, 68.1years ± 11.8; age range, 31-88years). Patients were divided into groups and compared based on the diagnostic failure and lesion size (15mm cutoff). Diagnostic performance, complication rate and effective radiation dose were investigated. Variables influencing diagnostic performance and complications were assessed using Student's T test and Pearson's χ2 test. The sensitivity, specificity, positive and negative predictive value and accuracy for patients subjected to CNBs were 96.8%, 100%, 100%, 100% and 97.2%, respectively. Considering risk factors for pneumothorax, no significant differences were found regarding patient and lesion characteristics. Perilesional hemorrhage occurred more frequently in older patients (p = 0.046) and in smaller lesions (p = 0.001). Hemoptysis was significantly more frequent in patients with perilesional hemorrhage (p = 0.01). Mean effective radiation dose in CBCT-CNB was 7.12 ± 8.78mSv. CBCT-CNB combined with virtual guidance is a reliable and accurate technique that allows exact localization of pulmonary lesions, effective preprocedural planning and real-time fluoroscopy altogether.

Reduced scan range abdominopelvic CT in patients with suspected acute appendicitis - impact on diagnostic accuracy and effective radiation dose

BackgroundTo evaluate a reduced range CT protocol in patients with suspected acute appendicitis as compared to standard abdominal CT regarding diagnostic performance, effective radiation dose and organ doses.MethodsIn this study, we retrospectively included 90 patients (43 female, mean age 56.7 ± 17 years) with suspected acute appendicitis who underwent CT of abdomen and pelvis. From those CTs, we reconstructed images with a reduced scan range from L1 to the the pubic symphysis. Full range and reduced range datasets were assessed by two radiologists for i) coverage of the Appendix, ii) presence/absence of appendicitis and iii) presence of differential diagnoses. Furthermore, effective radiation doses as well as organ doses were calculated using a commercially available dose management platform (Radimetrics, Bayer HealthCare).ResultsThe Appendix was covered by the reduced range CT in all cases. In 66 patients CT confirmed the presence of appendicitis. In 14 patients, other relevant differential diagnoses were identified by CT, whereas in 10 patients no relevant findings were detected. Both readers identified all patients with appendicitis on both full and reduced range CT.For reduced range CT, total effective dose was 39% lower than for full range CT (reduced range: 4.5 [1.9–11.2] vs. full range: 7.4 [3.3–18.8] mSv; p ≤ 0.001). Notably, a remarkable reduction of organ dose in the female breasts by 97% (0.1 [0.1–0.6] vs. 3.8 [0.5–18.8] mSv; p ≤ 0.001) and in the testicles in males by 81% (3.4 [0.7–32.7] vs. 17.6 [5.4–52.9] mSv; p ≤ 0.001) was observed for reduced range CT compared to full range CT.ConclusionsIn patients with suspected acute appendicitis, reduced range abdominopelvic CT results in a comparable diagnostic performance with a remarkable reduction of total effective radiation dose and organ doses (especially breast dose in female and testicle dose in male patients) as compared to full range CT.

Laboratory and semi-field evaluations on lethal and residual effects of temephos and pyriproxyfen insecticides to control malaria mosquito larvae, Anopheles stephensi Liston

BackgroundThe application of insecticides against vector mosquito larvae is a crucial step to control human malaria. Insecticide resistance is a major impediment to vector control strategies. The main aim of this study was to conduct laboratory and semi-field evaluations on lethal and residual effects of temephos and pyriproxyfen insecticides against malaria mosquito larvae, Anopheles stephensi.MethodsBoth susceptibility test and residual bioassay were performed to assess the lethal concentrations of each insecticide on 50% (LC50) of the IV instars larval populations and their activity periods according to standard protocols of WHO. Nine and eleven different concentrations with two sets of control in each case were applied for temephos and pyriproxyfen, respectively. Data were analyzed using probit analysis and SPSS software.ResultsThe LC50 and LC90 for temephos and pyriproxyfen under laboratory conditions were 0.4 and 0.63, and 1.69 × 10-4 and 4.036 × 10-4 ppm, respectively. Although the field strain of An. stephensi larvae was completely susceptible to pyriproxyfen, there was noticeable resistance (8% mortality at the diagnostic dose) to temephos in Nikshahr County, Southeast Iran. This is the first report of resistance to temephos for this malaria main vector in Iran. Depending on the applied variable doses, the residual effects of temephos and pyriproxyfen under semi-field conditions lasted maximally for 3 and 10 weeks, respectively.ConclusionThe high lethal and residual effects of pyriproxyfen on mosquito larvae confer an unprecedented opportunity in vector control operations leading to elimination of malaria in Iran.

Investigation of Computed Tomography Exposure Dose for Whole-body 18F-FDG PET/CT Examination in Chugoku-Shikoku Regions

We investigated the way of thinking about the CT dose setting, the exposure dose (CTDIvol, DLP) and the image quality (standard deviation of liver: SDliver) of whole-body PET/CT examinations in the Chugoku and Shikoku regions for the optimized CT dose setting. It was researched in the target 29 facilities which is equipped with 18F-FDG, PET/CT scanner in that regions. We examined how to determine the dose of complete physical PET/CT setting, the CT radiation dose (CTDIvol and DLP) and the image quality of CT fusion image that is the standard deviation of liver CT value in each facility. The optimized CT dose was lower than the diagnostic CT in many facilities. The 75th percentile CTDIvol was 6.01 mGy. The 75th percentile DLP was 560.9 mGy ×cm. The SDliver was 14.6±5.3 HU. The CT condition was low setting in comparison with diagnostic CT in many facilities. The exposure dose was lower than the diagnostic CT dose. The image quality of the normal region of liver was very close to the diagnostic CT. Even though it was low dose, images were less noise components.

Resistance status of main malaria vector, Anopheles stephensi Liston (Diptera: Culicidae) to insecticides in a malaria Endemic Area, Southern Iran

Objective: To evaluate the susceptibility of Anopheles stephensi (An. stephensi) Liston, the main malaria vector in southern Iran, to WHO recommended insecticides. Methods: Larvae of An. stephensi were collected from three different larval habitats in both urban and rural area of Bandar Abbas city and one rural area in Rudan county southern Iran. WHO standard method was used for evaluation of adult and larval mosquito susceptibility. Bendiocarb, permethrin, lambda-cyhalothrin, deltamethrin as insecticide and temephos and chlorpyriphos as larvicide were used at the diagnostic dosages recommended by WHO. Results: Findings of this study showed all larval populations of An. stephensi were completely susceptible to temephos and candidate for resistance to chlorpyriphos. Adult mosquitoes in rural areas of Bandar Abbas city were resistant to pyrethroid and carbamate insecticides. Conclusion: Comparison of the results of this survey with previous studies indicates that the resistance to pyrethroids and carbamates in this malaria endemic region is increasing. Wide use of pesticides in agriculture is certainly effective in increasing resistance. The inter-sectoral coordination and collaboration in health and agriculture seem to be necessary to manage insecticide resistance in malaria vectors.

Durability Results of Non-Myeloablative (NMA) Allogeneic Stem Cell Transplantation (alloSCT) for Relapsed Follicular Lymphoma: 17- Year Experience

Abstract Purpose: We have previously reported the outcomes of NMA alloSCT in 47 patients with relapsed/chemosensitive follicular lymphoma (FL) who received a matched sibling donor (MSD) after FCR conditioning (Khouri, Blood 2008;111:5530). In subsequent trials, eligibility was expanded to include transplants from matched unrelated donors (MUDs) using a 90yttrium ibritumomab tiuxetan (90YIT)-based regimen (Khouri, Blood 2012 ;119:6373) or, more recently, BFR (bendamustine, fludarabine, rituximab; Khouri, Blood 20014;124:2306) conditioning. Herein we report on long-term outcomes in 98 FL patients treated on these 3 consecutive trials between 1999-2017. Methods: The BFR regimen (N=20) consisted of bendamustine 130 mg/m2 IV daily on days -5 to - 3 prior to transplantation, thus substituting for the cyclophosphamide in the FCR regimen (N=47) . The dose and schedule of fludarabine (30 mg/m2 IV daily x3) and rituximab (375 mg/m2 IV on day -13 and 1000 mg/m2 on days -6, +1, and +8) were similar in both regimens. 90YIT-regimens (N=31) : A diagnostic dose of 111In-ibritumomab was administered on day-14, followed by a fixed dose of 0.4 mCi/kg 90YIT on day -7; FC or BF chemo was then administered at the same dose and schedule (days -5 to -3) as described above. Tacrolimus and methotrexate was used for GVHD prophylaxis. In addition, thymoglobulin of 1 mg/kg was given on days -2, -1 in patients receiving a MUD transplant. Results: Median age was 53 years (range, 29-71) and 24 patients (24%) were >60 years. Twenty-eight patients (29%) had a HCT-CI of ≥ 3. The median prior number of treatments was 3 (range, 2-9); 51 patients (52%) had rituximab-chemo induction at diagnosis. Seventy-one patients (72%) relapsed within 2 years of their induction treatment and median duration of last remission prior to alloSCT was < 1 year in 61% of patients. At transplant, 82 patients (84%) had chemosensitive disease (46% CR, 38% PR); 16% had refractory disease; 22% were PET+; and 20% had elevated serum LDH. Seventy patients (71%) had a transplant from a MSD and 28 (29%) from MUDs; 15 (15%) transplants had female-to-male donors, and 42 (43%) were ABO-mismatched. In addition, CMV was reactive in 80% of patients/ and or donors. Most patients (94%) had alloSCT from peripheral blood. Median number of CD34-positive cells infused was 4.9 x 106/kg. A significant difference in ANC recovery between the 3 conditioning regimens was observed. Neutrophil counts recovered to > 0.5 x 109/L a median of 0 days (range 0-16) for the BFR groups vs. 10 days (range, 0-17) and 11 days (range, 5-17) for the FCR and 90YIT-regimen groups, respectively (p<0.0001). This difference was consistent for each transplant type. With a median follow-up time for all patients of 98 months (range, 3-208 months), the overall survival (OS) and progression-free-survival (PFS) rates at 98 months were 82% (95%CI, 73-89) and 74% (95% CI, 64-82), respectively (Figure 1) . The cumulative incidence (CI) of grade II-IV and III-IV acute GVHD was 22% and 9%, respectively. The CI of chronic GVHD was 38%. Treatment-related mortality at 1 year was 9%. Patient demographic, disease characteristics, and transplant characteristics and their correlation with outcomes were evaluated. Disease status of > 1st relapse, >2 prior chemotherapies, duration of last remission prior to alloSCT < 1 year, ≥ 3 comorbidities, elevated LDH, acute II-IV GVHD, chronic extensive GVHD were associated with inferior OS. By multivariable analysis (MVA), duration of last remission prior to alloSCT (<1year) [HR 6.48 (1.28, 32.69); p=0.024]) and acute II-IV GVHD [HR 8.61 (2.99, 24.83); p<0.001] were associated with inferior OS. No significant prognostic factors on MVA for PFS, or risk for acute or chronic GVHD were noted for this cohort of patients. Conclusions: Nonmyeloablative allogeneic transplant can induce complete responses lasting over a decade in most patients with relapsed FL. Our initial findings published in 2008 were thus confirmed in a larger number of patients including those who received MUD transplants. BFR conditioning has been associated with significantly lesser myelosuppression and a faster neutrophil recovery than other regimens used, validating our initial observation in earlier reports. Disclosures Jabbour: Novartis: Research Funding; Pfizer: Consultancy, Research Funding; Bristol-Myers Squibb: Consultancy, Research Funding; Abbvie: Research Funding; Takeda: Consultancy, Research Funding. Oran:AROG pharmaceuticals: Research Funding; ASTEX: Research Funding; Celgene: Consultancy, Research Funding. Champlin:Otsuka: Research Funding; Sanofi: Research Funding.

Systematic review and meta-analysis: Dose-response curve of SSRIs and SNRIs in anxiety disorders.

We aimed to examine the efficacy of selective serotonin reuptake inhibitors (SSRIs) and serotonin norepinephrine reuptake inhibitors (SNRIs) for anxiety disorders examining overall symptom improvement, likelihood of treatment response, time course of treatment response, individual pharmacological agent, diagnostic indication dose, and tolerability. We searched PubMed and Cochrane Central Register of Controlled Trials. We included randomized placebo-controlled clinical trials of SSRIs/SNRIs in adult patients with anxiety disorders that provided data at three or more time points. Extracted data included trial duration, weekly/biweekly anxiety scores for 12weeks. Meta-analysis included 57 trials (N=16,056). A linear mixed model analysis based on weekly outcome data suggested that for SNRI a logarithmic model offered the best fit compared to placebo (indicating the greatest incremental improvement from baseline occurred early in treatment); whereas for SSRI a linear model provided the best fit (indicating a similar improvement over the duration of the acute treatment phase). There were no significant differences in efficacy between pharmacological agents within each class or when comparing SSRIs to SNRIs. The greatest treatment benefits were observed for social anxiety disorder for both medication classes. Higher doses of SSRIs, but not SNRIs, were associated with significantly greater symptom improvement and likelihood of treatment response. For both medical classes, higher doses were associated with an increased likelihood of dropout due to side effects. SSRIs and SNRIs are effective in treating anxiety disorders. Higher doses of SSRIs within the therapeutic range are associated with greater treatment benefit, whereas higher doses of SNRIs are not.

Monitoring Insecticide Resistance Profiles ofAedes aegypti(Diptera: Culicidae) in the Sunda Islands of Indonesia Based on Diagnostic Doses of Larvicides

This study was conducted to monitor the susceptibility status of Aedes aegypti (Linnaeus) larvae in the Sunda Islands of Indonesia against various organophosphates and organochlorines. Larval bioassay was performed in accordance with the World Health Organization standard protocol. Field-collected and reference strains of Ae. aegypti larvae were tested against diagnostic doses of eight larvicides belonging to organophosphates and organochlorines, namely bromophos (0.050 mg/liter), chlopyrifos (0.002 mg/liter), fenitrothion (0.020 mg/liter), fenthion (0.025 mg/liter), malathion (0.125 mg/liter), temephos (0.012 mg/liter), DDT (0.012 mg/liter), and dieldrin (0.025 mg/liter). Mortality rates of larvae were recorded at 24-h posttreatment. This study showed that Ae. aegypti larvae from Padang, Samarinda, Manggarai Barat, and South Central Timor were susceptible to both fenitrothion and dieldrin (mortality rates ≥ 98%). About 6 out of 10 field strains of Ae. aegypti larvae were resistant (<80% mortality rates) against fenthion, whereas Ae. aegypti larvae from Kuningan, Samarinda, Sumba, and South Central Timor exhibited some degrees of resistance (mortality rates 80-98%). All field-collected Ae. aegypti larvae were resistant against diagnostic doses of chlorpyrifos, malathion, temephos, and DDT with mortality rates ranging from 0 to 74.67%. Continued insecticide susceptibility studies are essential to identify the efficacy of insecticides for an improved dengue vector control and to delay the development of insecticide resistance.

Biodistribution and Dosimetry of Indigenously Produced131I-Rituximab in B-Cell Lymphoma: Pilot Study Estimating Patient-Specific Dose Comparing 2 Different Dosimetric Methods

Cost containment through indigenous production of radioimmunotherapy agents for non-Hodgkin lymphoma (NHL) would be a pivotal step toward wider clinical availability, especially in developing countries. We examined the biodistribution and dosimetry of indigenously developed and radiolabeled 131I-rituximab, using the monoclonal antibody of chimeric origin, in patients with B-cell lymphoma for potential use in radioimmunotherapy. Methods: This prospective study included 13 patients with B-cell NHL who underwent low-dose diagnostic scanning for dosimetric and biodistribution studies. Soon after rituximab infusion, a diagnostic dose of radioiodinated rituximab was administered. Serial planar whole-body γ-camera images were taken soon afterward and on days 1, 2, 4, and 6. A source of 131I with known activity was used as a reference standard for dosimetry calculations. Results: The patient-specific administered dose that would give a whole-body absorbed radiation dose of 75 cGy, calculated by the MIRD schema, ranged from 3,095.42 to 6,330.33 MBq (83.66-171.09 mCi), with a mean of 3,986.01 ± 863.95 MBq (107.73 ± 23.35 mCi) and a median of 3,697.41 MBq (99.93 mCi). The mean residence time was 69.54 h. Within the first 48 h at least 50% of the injected activity was cleared, and by 144 h at least 80% was cleared. The patient-specific administered dose that would give a whole-body absorbed radiation dose of 75 cGy, calculated by mean residence time and activity-hours, ranged from 2,654.75 to 6,210.45 MBq (71.75-167.85 mCi), with a mean of 3,576.42 ± 927.59 MBq (96.66 ± 25.07 mCi) and a median of 3,421.02 MBq (92.46 mCi). With respect to organ-specific dosimetry, the mean absorbed doses to organs (apart from blood pool [3.77 Gy] and spleen [4.02 Gy]) were 0.97 Gy to the lungs, 0.69 Gy to the liver, and 0.7 Gy to the kidneys. Conclusion: The indigenous product had kinetics similar to commercial radiopharmaceuticals, with the advantage of a lower human antimouse antibody response because of the pharmaceutical's being a chimeric antibody rather than a murine antibody. Hence, clinical administration was safe. In none of the organs did dose-limiting radiation exposure occur at the proposed therapeutic dose.

Insecticides resistance and detoxification enzymes activity changes in brown planthopper, Nilaparvata lugens in Guizhou Province

The brown planthopper (BPH), Nilaparvata lugens (Homoptera: Delphacidae), is a kind of seriously pest of rice crops throughout Asia and effective control is essential for economical crop production. Insecticides Abamectin, Imidacloprid, Chlorantraniliprole, Phoxim and Chlorpyrifos have been broadly used to control the brown planthopper for recent years. To investigate the resistance development of the BPH in Guizhou Province, we collected BPH from 5 sites (Panxian, Jinping, Sandu, Daozhen and Huaxi) in Guizhou Province June–August 2014. Their responses to two diagnostic doses of 5 insecticides (LD50 and detoxification enzyme activity) were examined. The results showed that LD50 value for Chlorantraniliprole in Jinping and Huaxi BPH population were 199.810 and 282.082 μg/g higher than imidacloprid, phoxim and chlorpyrifos. LD50 value for Imidacloprid in Jinping population was 3.957 μg/g lower than other BPH populations for 4 insecticides. The GSTs activity is significantly higher with Abamectin, Chlorpyrifos and Phoxim treatments. AchE activity is higher with Chlorantraniliprole and Imidacloprid, but lowest among three enzymes with Phoxim and Chlorpyrifos. The data demonstrate the development and spread of multiple resistance in N. lugens in Guizhou Province and support reports of reduced field efficacy of imidacloprid.

Raman Micro-Spectroscopy of Dental Pulp Stem Cells: An Approach to Monitor the Effects of Cone Beam Computed Tomography Low-Dose Ionizing Radiation

The objective of this study was to determine the molecular and biochemical changes in dental pulp stem cells (DPSCs) due to consecutive low-dose ionizing radiation exposures using label-free Raman micro-spectroscopy (RMS). Ionizing radiation produces biological damage leading to health effects of varying severity. The effects and subsequent health implications caused by exposure to low-dose radiation, such as diagnostic exposure, remain ambiguous. We identified Raman biomarkers characteristic to low-dose cone beam computed tomography (CBCT) irradiation of the DPSCs. The biomarkers were monitored inside the cells using the relative intensity distribution of the 785 and 1734 cm−1 bands. The control cells presented a higher relative intensity of the nucleic acid specific Raman bands, whereas the irradiated cells revealed an increased intensity of the lipid-induced bands. The results obtained in this study demonstrate the capability of RMS for the detection of cell response to diagnostic radiation dose levels. This may indicate the potential of the technique for future applications such as monitoring the radiation responses in pediatric patients suffering repeated radiological exposures.

Evaluation of Toxicity and Neural Uptake In Vitro and In Vivo of Superparamagnetic Iron Oxide Nanoparticles.

Superparamagnetic iron oxide nanoparticles (SPIO-NPs) have great potential to be used in different pharmaceutical applications, due to their unique and versatile physical and chemical properties. The aim of this study was to quantify in vitro cytotoxicity of dextran 70,000-coated SPIO-NPs labelled/unlabelled with rhodamine 123, in C6 glioma cells and primary hippocampal neural cells. In addition, we analyzed the in vitro and in vivo cellular uptake of labelled SPIO-NPs. The nanoparticles, with average size of 10–50 nm and polydispersity index of 0.37, were synthesized using Massart’s co-precipitation method. The concentration-dependent cytotoxicity was quantified by using tetrazolium dye 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT). Intracellular localization of SPIO-NPs was detected by confocal laser microscopy. In vivo confocal neuroimaging (ICON) was performed on male Wistar rats after intravitreal injection followed by ex vivo retina whole mount analysis. When used for in vitro testing concentrations in the range of diagnostic and therapeutic dosages, SPIO-NPs proved to be non-cytotoxic on C6 glioma cells for up to 24 h incubation time. The hippocampal cell culture also did not show impaired viability at low doses after 24 h incubation. Our results indicate that our dextran-coated SPIO-NPs have the potential for in vivo drug delivery applications.

Resistensi Malathion dan Aktivitas Enzim Esterase pada Populasi Nyamuk Aedes aegypti di Kabupaten Pekalongan

Pekalongan regency, Central Java (Indonesia) is one of area which experienced with Dengue Hemorrhagic Fever (DHF) incidence since many years ago. The extensive use of insecticides for dengue vector control has been carried out for long period in Pekalongan Regency. This fact stimulate the need to study the resistence status and esterase enzyme avtivity of Aedes aegypti to Malathion. The research was conducted in April-November 2014. Insecticide susceptibility assays were performed on F1 generation of wild-caught adult female Ae. aegypti mosquitoes from Simbangkulon Village Buaran Sub district, Kedungwuni Barat Village Kedungwuni Sub dsitrict and Karangsari Village Karanganyar Sub district, with the diagnostic doses of malathion (0,8%). Esterase enzyme activity of these mosquitoes was tested biochemically to find out the mechanisms of resistance to Malathion. Mosquitoes mortality as a result of Malathion effect showed variation in range from 3.33 to 13.75% in all study sites. That result indicated that Ae.aegypti mosquitoes are resistant to Malathion in all study sites . Based on biochemical assays, there was an increase if esterase enztyme activity of Ae aegypti in all study sites.. Therefore, alpha esterase enzyme activity could be associated with the mechanisms which responsible to malathion resistance in Ae. aegypti in Pekalongan. The results of this study provided the information about the malathion resistance status of Ae. aegypti in Pekalongan, and biochemical mechanisms which essential for monitoring the insecticide resistance in this area.&#x0D;

Efficacy and Radiation Exposure of Ultra-Low-Dose Chest CT at 100 kVp with Tin Filtration in CT-Guided Percutaneous Core Needle Biopsy for Small Pulmonary Lesions Using a Third-Generation Dual-Source CT Scanner

PurposeTo prospectively investigate efficacy and radiation dose of ultra-low-dose CT–guided percutaneous core needle biopsy (PCNB) at 100 kVp with tin filtration (100Sn kVp) for small pulmonary lesions. Materials and MethodsStudy enrolled and randomly assigned 210 patients to standard-dose CT (n = 70) or ultra-low-dose CT (n = 140; 1:2 randomization scheme) protocol. Standard-dose CT settings were reference 110 kVp and 50 mAs, and ultra-low-dose CT settings were fixed at 100Sn kVp and 70 mAs. All PCNBs in patients with small pulmonary lesions (< 3 cm) were performed on a third-generation dual-source CT scanner. Diagnostic performance, complication rate, image quality, and radiation dose were compared. ResultsSensitivity, specificity, and accuracy for diagnosis of malignancy were 95.7%, 100%, and 96.9% with standard-dose CT and 93.8%, 100%, and 95.4% with ultra-low-dose CT (P > .05). Complication rate showed no significant differences between protocols (P > .05). Mean volume CT dose index) and total dose-length product were significantly lower in ultra-low-dose CT compared with standard-dose CT (0.24 mGy vs 3.3 mGy ± 1.1 and 9.84 mGy-cm ± 0.70 vs 110.5 mGy-cm ± 45.1; P < .001). Effective dose for ultra-low-dose CT was significantly lower than that for standard-dose CT (0.14 mSv ± 0.02 vs 1.78 mSv ± 0.76; −92.1%; P < .001). Image quality of ultra-low-dose CT met the requirements of PCNB. ConclusionsUltra-low-dose CT-guided PCNB at 100Sn kVp spectral shaping significantly reduced radiation dose on a third-generation dual-source CT, while maintaining high diagnostic accuracy and safety for small pulmonary lesions.

A Review on the Insecticide Resistance of Three Species of Cockroaches (Blattodea: Blattidae) in Iran.

In Iran, there are four pest domestic species of cockroaches: Periplaneta americana (Linnaeus, Blattodea: Blattidae), Blatta orientalis (Linnaeus, Blattodea: Blattidae), Blattella germanica (Linnaeus, Blattodea: Blattidae), and Supella longipalpa (Fabricius, Blattodea: Blattellidae). The aim of this study was to compile and review studies conducted on insecticide resistance of domestic cockroaches in Iran to assess the current knowledge and gaps. Twenty insecticides were used in susceptibility testing of cockroaches. The bioassay methods varied, and included surface contact (exposure tests), topical applications and feeding studies on baits. Resistance ratio (RR) stated in the reviewed studies showed that B. germanica was resistant (RR > 10) to DDT, permethrin, and cypermethrin, while P. americana and S. longipalpa were categorized as low levels of resistance (RR = 1-2). S. longipalpa is newly reported from houses in some areas of Iran, including Tehran, and there are very few studies on its' biology, ecology and insecticidal resistance. Most studies used adult cockroaches, while the susceptibility status of nymphs was evaluated only in few studies. Use of different test methods and lack of a World Health Organization (WHO) updated procedure, including revised/updated insecticide diagnostic dosages and test kits. The lack of susceptible strains of cockroaches was a major challenge in the assessment of data. A comprehensive national program for monitoring susceptibility of household pests to insecticides in Iran is of great concern and is highly recommended.

Ultra-low dose multiphasic coronary computed tomography angiography for pediatric patients with congenital heart diseases: A prospective cross-sectional study

Background The use of coronary computed tomography angiography (CCTA) in children with coronary artery anomalies (CAA) is increasing. However, it remains technically demanding and the need to adapt acquisition parameters to a patient's cardiac characteristics has not yet been addressed. Objectives The aim of the study was to prospectively assess the feasibility, in terms of diagnostic performance and dose reduction, of personalized multiphasic CCTA for pediatric patients. Methods Fifty pediatric patients (mean age 6.1 ± 4.9 years) with CAA underwent a CCTA on last generation single-source CT equipment. Fifteen different acquisition patterns were used to trigger the acquisition at the best theoretical moment within the cardiac cycle. The appropriate pattern was automatically selected based on the patient's heart rate (HR) and HR variability, derived from the patient's electrocardiogram. Two independent radiologists qualitatively evaluated images. Results All acquisitions fully answered the clinical question for a mean effective dose of 0.97 ± 0.34 mSv. Image quality qualified as “good” or “excellent” in 94% of cases (47/50). No examination was considered as “not assessable” but 6% (3/50) were scored as “adequate” for diagnosis ( Fig. 1 ). For these three patients, motion artifacts were the main cause of average image quality. No significant visual differences were reported between the different coronary segments (mean score of 3.6 on a 4-point scale; 200 segments analyzed in total). No correlation between image quality and cardiac parameters were reported (r = −0.19 and r = 0.00 respectively for HR and HR variability). Conclusions Personalized multiphasic CCTA acquisitions could be performed with diagnostic quality for a dose equivalent of less than four months of natural background irradiation. Clinical trial registration ClinicalTrials.gov ( NCT03194763 ). Funding Montpellier University Hospital Clinical Research Program (UF 9785).

P155] Exposure levels from CT scanning for treatment planning in radiotherapy

Purpose CT-scanning for treatment planning in radiotherapy is often hampered by the fact that scan parameter optimization may be limited due to treatment planning system constraints. The current work reviews the exposure levels for a selected group of treatment locations, i.e. head, head&neck, thorax, breast, abdomen and prostate. Methods Equal scan protocols, based on filtered back projection, are set on the two scanners (Siemens Definition AS+). Scan parameters from the CT scanners are automatically transferred, using the DICOM SR protocol, after each scanning sequence to a dose monitoring system (Sectra DoseTrack). These data include, but are not limited to CTDI, DLP, weight and age. For adult patients with weights between 60 and 80 kg the median CTDI (mGy) and DLP (mGycm) values as well as standard deviation (1 SD) have been calculated for the treatment locations. 20 or more patients are included for each location. Results The exposure levels for the selected sites are more or less equal between the two scanners. CTDI and DLP values (CTDI/DLP) for CT 1 are: Head 41 ± 4/1125 ± 145, Head&neck 11 ± 1/452 ± 61, Thorax 9 ± 3/390 ± 161, Breast ca 9 ± 2/355 ± 61, Abdomen 17 ± 3/815 ± 239, Prostate ca respectively. Corresponding values for CT 2 are: Head 42 ± 6/1168 ± 222, Head&neck 11 ± 1/458 ± 89, Thorax 9 ± 2/412 ± 136, Breast ca 9 ± 1/357 ± 60, Abdomen 17 ± 3/801 ± 177, Prostate ca 17 ± 2/813 ± 110 for each scan site. CTDI values are well below current national dose reference levels (DRL) in diagnostic radiology were these are given. DLP values are however slightly outside the diagnostic DRL values were these exist. Increased scan length requirements due to treatment planning flexibility, dose calculation accuracy and DVH evaluation of complete organs add to higher DLP values. Conclusions Exposure levels have been evaluated for the head, head&neck, thorax, breast, abdomen and prostate regions. These exposure levels turn out to be lower for CTDI than current national diagnostic radiology dose reference levels indicating well adapted scan protocols. Scan length requirements for treatment planning do however add to DLP making them slightly higher than current DRL levels.