131 research outputs found
A SIMPLE AND EFFICIENT MICROPROPAGATION PROTOCOL FOR DEVELOPING PLANTLETS OF EXACUM BICOLOR ROXB. – AN ENDANGERED, ORNAMENTAL, AND ANTIDIABETIC HERB
Objective: Exacum bicolor Roxb. is an endangered medicinal herb due to overexploitation by humans and its inefficient vegetative reproduction. Here, we report an efficient and simple procedure for the regeneration of E. bicolor Roxb. using leaf as an explant.
Methods: The optimal concentrations of the hormones needed for callus induction were determined by full factorial method using DOE (Design expert ver. 8.0). The hormones selected based on literature were kinetin, indole acetic acid, and 6-Benzylaminopurine (BAP). Multiple shoot regeneration was carried out in liquid and solid media with the optimal concentrations of the hormones obtained by DOE. Rooting was initiated using Murashige and Skoog media containing naphthalene acetic acid 0.5 mg/l, indole butyric acid (IBA) 1.0 mg/l, and gibberellic acid 3 0.5 mg/l along with 0.2% of activated charcoal.
Results: Analysis of full factorial design run showed that BAP in combination with kinetin was effective for the growth of callus and multiple shoot regeneration was higher in liquid media (81.25%). The rate of rooting was observed to be 88.23% and the average number of roots was 0.26. Plantlets with budding apical region and well-established leaves and roots were observed in 30 days.
Conclusion: The protocol reported here can be used for effective production of E. bicolor plants in a shorter duration compared to the conventional approach
Physical properties and solubility studies of Nifedipine-PEG 1450/HPMCAS-HF solid dispersions
Low-order high-energy nifedipine (NIF) solid dispersions (SDs) were generated by melt solvent amorphization with polyethylene glycol (PEG) 1450 and hypromellose acetate succinate (HPMCAS-HF) to increase NIF solubility while achieving acceptable physical stability. HPMCAS-HF was used as a crystallization inhibitor. Individual formulation components, their physical mixtures (PMs), and SDs were characterized by differential scanning calorimetry, powder X-ray diffraction, and Fourier transform infrared spectroscopy (FTIR). NIF solubility and percent crystallinity (PC) were determined at the initial time and after 5 days stored at 25 °C and 60% RH. FTIR indicated that hydrogen bonding was involved with the amorphization process. FTIR showed that NIF:HPMCAS-HF intermolecular interactions were weaker than NIF:PEG 1450 interactions. NIF:PEG 1450 SD solubilities were significantly higher than their PM counterparts (p \u3c 0.0001). The solubilities of NIF:PEG 1450:HPMCAS-HF SDs were significantly higher than their corresponding NIF:PEG 1450 SDs (p \u3c 0.0001-0.043). All the SD solubilities showed a statistically significant decrease (p \u3c 0.0001) after storage for 5 days. SDs PC were statistically lower than their comparable PMs (p \u3c 0.0001). The PCs of SDs with HPMCAS-HF were significantly lower than SDs not containing only PEG 1450. All SDs exhibited a significant increase in PC (p \u3c 0.0001–0.0089) on storage. Thermogravimetric analysis results showed that HPMCAS-HF bound water at higher temperatures than PEG 1450 (p \u3c 0.0001–0.0039). HPMCAS-HF slowed the crystallization process of SDs, although it did not completely inhibit NIF crystal growth
A JAFROC study of nodule detection performance in CT images of a thorax acquired during PET/CT
Purpose
Two types of CT images (modalities) are acquired in PET/CT: for attenuation correction (AC) and diagnosis. The purpose of the study was to compare nodule detection and localization performance between these two modalities.
Methods
CT images, using both modalities, of an anthropomorphic chest phantom containing zero or more simulated spherical nodules of 5, 8, 10 and 12 mm diameters and contrasts −800, −630 and 100 HU were acquired. An observer performance study using nine observers interpreting 45 normal (zero nodules) images and 47 abnormal images (1–3 nodules; average 1.26) was conducted using the free-response receiver operating characteristic (FROC) paradigm. Data were analysed using an R software package implemented jackknife alternative FROC (JAFROC) analysis. Both empirical areas under the equally weighted AFROC curve (wAFROC) and under the highest rating inferred ROC (HR-ROC) curve were used as figures of merit (FOM). To control the probability of Type I error test alpha was set at 0.05.
Results
Nodule detection as measured by either FOM was significantly better on the diagnostic quality images (2nd modality), irrespective of the method of analysis, [reader averaged inter-modality wAFROC FOM difference = −0.07 (−0.11,−0.04); reader averaged inter-modality HR-ROC FOM difference = −0.05 (−0.09, −0.01)].
Conclusion
Nodule detection was statistically worse on images acquired for AC; suggesting that images acquired for AC should not be used to evaluate pulmonary pathology.
Keywords
PET/CT; Nodule detection; JAFRO
Treatment of osteoporotic fractures in alkaptonuria by teriparatide stimulates bone formation and decreases fracture rate - A report of two cases.
Two cases of advanced alkaptonuria (AKU) with co-existing osteoporosis are described. Case 1 developed multiple non-vertebral fragility fractures, while Case 2 developed vertebral fragility fractures, both refractory to bisphosphonates. Difficulties in diagnosing osteoporosis in AKU complicated by extensive calcifying and ossifying spondylosis are discussed. Both patients continued to fracture despite nitisinone therapy for metabolic control of AKU, as well as bisphosphonate antiresorptive therapy for osteoporosis. Subsequently the patients were treated with teriparatide 20 μg subcutaneous injections daily for two years, leading to reduction in fractures soon after commencing therapy in both cases. Markers of bone remodelling P1NP and CTX were stimulated. No complications due hypercalcaemia or calcification were encountered in either case. We conclude that teriparatide is an effective adjunct in the treatment of AKU when bisphosphonates prove ineffective
Sequential ¹⁸F-fluorodeoxyglucose positron emission tomography (¹⁸F-FDG PET) scan findings in patients with extrapulmonary tuberculosis during the course of treatment—a prospective observational study
BACKGROUND: Initial studies of tuberculosis (TB) in macaques and humans using ¹⁸F-FDG positron emission tomography (PET) imaging as a research tool suggest its usefulness in localising disease sites and as a clinical biomarker. Sequential serial scans in patients with extrapulmonary TB (EPTB) could inform on the value of PET-CT for monitoring response to treatment and defining cure. PATIENTS AND METHODS: HIV-negative adults with EPTB from eight sites across six countries had three ¹⁸F-FDG PET/CT scans: (i) within 2 weeks of enrolment, (ii) at 2 months into TB treatment and (iii) at end of ATT treatment. Scanning was performed according to the EANM guidelines. ¹⁸F-FDG PET/CT scans were performed 60 ± 10 min after intravenous injection of 2.5–5.0 MBq/kg of ¹⁸F-FDG. FINDINGS: One hundred and forty-seven patients with EPTB underwent 3 sequential scans. A progressive reduction over time of both the number of active sites and the uptake level (SUVmax) at these sites was seen. At the end of WHO recommended treatment, 53/147 (36.0%) patients had negative PET/CT scans, and 94/147 (63.9%) patients remained PET/CT positive, of which 12 patients had developed MDR TB. One died of brain tuberculoma. INTERPRETATION: Current ⁸F-FDG PET/CT imaging technology cannot be used clinically as a biomarker of treatment response, cure or for decision-making on when to stop EPTB treatment. PET/CT remains a research tool for TB and further development of PET/CT is required using new Mycobacterium tuberculosis-specific radiopharmaceuticals targeting high-density surface epitopes, gene targets or metabolic pathways
Phenotypic appearances of prostate utilizing PET-MRI and PET-CT with Ga-68-PSMA, radiolabelled choline and Ga-68-DOTATATE
The objective of this study was to highlight the role of multimodality imaging and present the differential diagnosis of abnormal tracer accumulation in the prostate and periprostatic tissue. Our departments have performed molecular imaging of the prostate utilizing PET-CT and PET-MRI with a range of biomarkers including F-FDG, radiolabelled choline, Ga-DOTATATE PET-CT and Ga-PSMA images. We retrospectively reviewed the varying appearances of the prostate gland in different diseases and incidental findings in periprostatic region. The differential diagnosis of pathologies related to prostate and periprostatic tissue on multimodality imaging includes malakoplakia, rhabdomyosarcoma, lymphoma, prostate cancer, neuroendocrine tumours, uchida changes, rectoprostatic fistula, synchronous malignancies, lymphocoele and schwanoma. There exists a wide differential for abnormal tracer accumulation in the prostate gland. As a radiologist and nuclear medicine physician, it is important to be aware of range of prostatic and periprostatic pathologies
PET/CT features of extrapulmonary tuberculosis at first clinical presentation: a cross-sectional observational ¹⁸F-FDG imaging study across six countries
BACKGROUND: A large proportion of the huge global burden of Extrapulmonary tuberculosis (EPTB) are treated empirically without accurate definition of disease sites, and extent of multi-organ disease involvement. Positron emission tomography (PET) imaging using 18F-FDG in TB could be a useful imaging technique for localising disease sites and extent of disease.
METHODS: We conducted a study of HIV-negative adult patients with a new clinical diagnosis of EPTB across 8 centres located in 6 countries: India, Pakistan, Thailand, South Africa, Serbia, and Bangladesh to assess the extent of disease and common sites involved at first presentation. 18F-FDG PET/CT scans were performed within 2 weeks of presentation.
FINDINGS: A total of 358 patients with EPTB (189 females; 169 males) were recruited over 45 months. Age range 18-83 years (females: median 30 years; males: median 38 years). 350/358 (98%) patients (183 female, 167 male) had positive scan. 118/350 (33.7%) had a single extrapulmonary site and 232/350 (66.3%) had more than one site (organ) affected. Lymph nodes, skeletal, pleura and brain were common sites. 100/358 (28%) of EPTB patients had 18F-FDG PET/CT positive sites in the lung. 110 patients were 18F-FDG PET/CT positive in more body sites than were noted clinically at first presentation and 160 patients had the same number of positive body sites.
INTERPRETATION: 18F-FDG PET/CT scan has potential for further elucidating the spectrum of disease, pathogenesis of EPTB, and monitoring the effects of treatment on active lesions over time, and requires longitudinal cohort studies, twinned with biopsy and molecular studies
Validation of the Cloud_CCI (Cloud Climate Change Initiative) cloud products in the Arctic
The role of clouds in the Arctic radiation budget is not well understood. Ground-based and airborne measurements provide valuable data to test and improve our understanding. However, the ground-based measurements are intrinsically sparse, and the airborne observations are snapshots in time and space. Passive remote sensing measurements from satellite sensors offer high spatial coverage and an evolving time series, having lengths potentially of decades. However, detecting clouds by passive satellite remote sensing sensors is challenging over the Arctic because of the brightness of snow and ice in the ultraviolet and visible spectral regions and because of the small brightness temperature contrast to the surface. Consequently, the quality of the resulting cloud data products needs to be assessed quantitatively. In this study, we validate the cloud data products retrieved from the Advanced Very High Resolution Radiometer (AVHRR) post meridiem (PM) data from the polar-orbiting NOAA-19 satellite and compare them with those derived from the ground-based instruments during the sunlit months. The AVHRR cloud data products by the European Space Agency (ESA) Cloud Climate Change Initiative (Cloud_CCI) project uses the observations in the visible and IR bands to determine cloud properties. The ground-based measurements from four high-latitude sites have been selected for this investigation: Hyytiälä (61.84∘ N, 24.29∘ E), North Slope of Alaska (NSA; 71.32∘ N, 156.61∘ W), Ny-Ålesund (Ny-Å; 78.92∘ N, 11.93∘ E), and Summit (72.59∘ N, 38.42∘ W). The liquid water path (LWP) ground-based data are retrieved from microwave radiometers, while the cloud top height (CTH) has been determined from the integrated lidar–radar measurements. The quality of the satellite products, cloud mask and cloud optical depth (COD), has been assessed using data from NSA, whereas LWP and CTH have been investigated over Hyytiälä, NSA, Ny-Å, and Summit.
The Cloud_CCI COD results for liquid water clouds are in better agreement with the NSA radiometer data than those for ice clouds. For liquid water clouds, the Cloud_CCI COD is underestimated roughly by 3 optical depth (OD) units. When ice clouds are included, the underestimation increases to about 5 OD units. The Cloud_CCI LWP is overestimated over Hyytiälä by ≈7 g m−2, over NSA by ≈16 g m−2, and over Ny-Å by ≈24 g m−2. Over Summit, CCI LWP is overestimated for values ≤20 g m−2 and underestimated for values >20 g m−2. Overall the results of the CCI LWP retrievals are within the ground-based instrument uncertainties. To understand the effects of multi-layer clouds on the CTH retrievals, the statistics are compared between the single-layer clouds and all types (single-layer + multi-layer). For CTH retrievals, the Cloud_CCI product overestimates the CTH for single-layer clouds. When the multi-layer clouds are included (i.e., all types), the observed CTH overestimation becomes an underestimation of about 360–420 m. The CTH results over Summit station showed the highest biases compared to the other three sites. To understand the scale-dependent differences between the satellite and ground-based data, the Bland–Altman method is applied. This method does not identify any scale-dependent differences for all the selected cloud parameters except for the retrievals over the Summit station. In summary, the Cloud_CCI cloud data products investigated agree reasonably well with those retrieved from ground-based measurements made at the four high-latitude sites.</p
Guiding principles on the education and practice of theranostics.
The recent development and approval of new diagnostic imaging and therapy approaches in the field of theranostics have revolutionised nuclear medicine practice. To ensure the provision of these new imaging and therapy approaches in a safe and high-quality manner, training of nuclear medicine physicians and qualified specialists is paramount. This is required for trainees who are learning theranostics practice, and for ensuring minimum standards for knowledge and competency in existing practising specialists.
To address the need for a training curriculum in theranostics that would be utilised at a global level, a Consultancy Meeting was held at the IAEA in May 2023, with participation by experts in radiopharmaceutical therapy and theranostics including representatives of major international organisations relevant to theranostics practice.
Through extensive discussions and review of existing curriculum and guidelines, a harmonised training program for theranostics was developed, which aims to ensure safe and high quality theranostics practice in all countries.
The guiding principles for theranostics training outlined in this paper have immediate relevance for the safe and effective practice of theranostics
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