METHODS: A survey on medical physics aspects of IMRT is conducted on radiotherapy departments across Malaysia to assess the usage, experience and QA in IMRT, which is done for the first time in this country. A set of questionnaires was designed and sent to the physicist in charge for their responses. The questionnaire consisted of four sections; (i) Experience and qualification of medical physicists, (ii) CT simulation techniques (iii) Treatment planning and treatment unit, (iv) IMRT process, delivery and QA procedure.
RESULTS: A total of 26 responses were collected, representing 26 departments out of 33 radiotherapy departments in operation across Malaysia (79% response rate). Results showed that the medical physics aspects of IMRT practice in Malaysia are homogenous, with some variations in certain areas of practices. Thirteen centres (52%) performed measurement-based QA using 2D array detector and analysed using gamma index criteria of 3%, 3 mm with variation confidence range. In relation to the IMRT delivery, 44% of Malaysia's physicist takes more than 8 h to plan a head and neck case compared to the UK study possibly due to the lack of professional training.
CONCLUSIONS: This survey provides a picture of medical physics aspects of IMRT in Malaysia where the results/data can be used by radiotherapy departments to benchmark their local policies and practice.
OBJECTIVE: We aimed to compare the phytochemical composition of 7 varieties growing in different conditions at various geographical locations. We also aimed to establish the quality control markers for the authentication of these varieties.
METHODS: We applied untargeted UHPLC-TOFMS metabolomics to discriminate 100 leaf samples of F. deltoidea collected from 6 locations in Malaysia. A genetic analysis on 21 leaf samples was also performed to validate the chemotaxonomy differentiation.
RESULTS: The PCA and HCA analysis revealed the existence of 3 chemotypes based on the differentiation in the flavonoid content. The PLS-DA analysis identified 15 glycosylated flavone markers together with 1 furanocoumarin. These markers were always consistent for the respective varieties, regardless of the geographical locations and growing conditions. The chemotaxonomy differentiation was in agreement with the DNA sequencing. In particular, var. bilobata accession which showed divergent morphology was also differentiated by the chemical fingerprints and genotype.
CONCLUSION: Chemotype differentiation based on the flavonoid fingerprints along with the proposed markers provide a powerful identification tool to complement morphology and genetic analyses for the quality control of raw materials and products from F. deltoidea.
FINDINGS: Our high-throughput workflow minimizes these risks via a 4-step strategy: (i) technical replication with 2 PCR replicates and 2 extraction replicates; (ii) using multi-markers (12S,16S,CytB); (iii) a "twin-tagging," 2-step PCR protocol; and (iv) use of the probabilistic taxonomic assignment method PROTAX, which can account for incomplete reference databases. Because annotation errors in the reference sequences can result in taxonomic misassignment, we supply a protocol for curating sequence datasets. For some taxonomic groups and some markers, curation resulted in >50% of sequences being deleted from public reference databases, owing to (i) limited overlap between our target amplicon and reference sequences, (ii) mislabelling of reference sequences, and (iii) redundancy. Finally, we provide a bioinformatic pipeline to process amplicons and conduct PROTAX assignment and tested it on an invertebrate-derived DNA dataset from 1,532 leeches from Sabah, Malaysia. Twin-tagging allowed us to detect and exclude sequences with non-matching tags. The smallest DNA fragment (16S) amplified most frequently for all samples but was less powerful for discriminating at species rank. Using a stringent and lax acceptance criterion we found 162 (stringent) and 190 (lax) vertebrate detections of 95 (stringent) and 109 (lax) leech samples.
CONCLUSIONS: Our metabarcoding workflow should help research groups increase the robustness of their results and therefore facilitate wider use of environmental and invertebrate-derived DNA, which is turning into a valuable source of ecological and conservation information on tetrapods.
METHODS: Xenical 120 mg capsules (Roche, Basel, Switzerland) were used as reference material. Generic products were from India, Malaysia, Argentina, Philippines, Uruguay, and Taiwan. Colour, melting temperature, crystalline form, particle size, capsule fill mass, active pharmaceutical ingredient content, amount of impurities, and dissolution were compared. Standard physical and chemical laboratory tests were those developed by Roche for Xenical.
RESULTS: All nine generic products failed the Xenical specifications in four or more tests, and two generic products failed in seven tests. A failure common to all generic products was the amount of impurities present, mostly due to different by-products, including side-chain homologues not present in Xenical. Some impurities were unidentified. Two generic products tested failed the dissolution test, one product formed a capsule-shaped agglomerate on storage and resulted in poor (=15%) dissolution. Six generic products were powder formulations.
CONCLUSIONS: All tested generic orlistat products were pharmaceutically inferior to Xenical. The high levels of impurities in generic orlistat products are a major safety and tolerability concern.