Validation of an automated dispensing system for subsequent dose dispensing of different radionuclides.

BACKGROUND: Automated dispensing systems (ADSs) for radiopharmaceuticals have been developed to reduce the radiation exposure of personnel, to improve the accuracy of the dispensed dose and to limit the microbiological contamination. However, before implementing such systems, validation according to various applicable guidelines is necessary to ensure safety and quality. Here we present the selection, validation and implementation of the PT459R2 from manufacturer Lynax s.r.o. as a guidance protocol for validation according to GMP and GRPP guidelines. Validation included linearity accuracy and precision of the internal scintillation detector for different isotopes and microbiological validation for aseptic procedures. RESULTS: The ADS can dispense accurate doses in the following linear range: 1000-10,000 MBq for lutetium-177, 20-74 MBq for zirconium-89, 100-1000 MBq for gallium-68 and 100-2000 MBq for fluorine-18. The maximum bias is 2.35% and the maximum coefficient of variation is 3.03% which meets the acceptance criteria of < 5%. Furthermore, the ADS does not affects the GMP class A environment in a laminar airflow cabinet and can dispense aseptically. In addition, radiation exposure is acceptable and data integrity is preserved. CONCLUSION: The PT459R2 ADS met all the requirements from our performance qualification and is therefore suitable for daily routine use in our center. Our approach can be used as a guidance for PQ of an ADS in a Radiopharmacy according to GMP and GRPP guidelines.

Perspectives on COVID-19 prevention and treatment using herbal medicine in Vietnam: A cross-sectional study.

Introduction: The significance of herbal medicine (HM) during the COVID-19 pandemic has been confirmed. Nevertheless, limited studies have included the people perspectives on COVID-19 prevention/treatment using herbal medicine in Vietnam. Thus, this study tackled the aforementioned issue. Methods: Online-based cross-sectional study was conducted in Vietnamese adults between February-April 2021. Descriptive analysis, regression and Chi-squared tests were implemented for the statistical purposes. Results: total of 787 respondents attended the study, 368 (46.8%) confirmed that they use herbal medicine/nutritional supplements for COVID-19 prevention/treatment. Over 50% of the respondents possessed positive perspective on vitamin C ingestion. Using herbal medicine for external use as a disinfectant was mostly preferred. Respondents who had a 'very good' health self-perception or who lived in rural areas, were more likely to have a positive opinion in the COVID-19 prevention/treatment using herbal medicine. The main barrier for herbal medicine utilization was the deficiency of personal experience or expert advice. Conclusion: The Vietnamese people commonly utilize herbal medicine for the COVID-19 prevention/treatment. These data might help policy-makers in managing the public knowledge and practice on herbal medicine use in Vietnam.

HMGA1 accelerates the malignant progression of gastric cancer through stimulating EMT.

OBJECTIVE: To clarify the role of HMGA1 in influencing proliferation and migration abilities, and EMT (epithelial-mesenchymal transition) in gastric cancer (GC) cells. MATERIALS AND METHODS: Differential expressions of HMGA1 in GC tissues and normal gastric tissues were analyzed in the GEPIA dataset. Its influence on overall survival of GC patients was evaluated as well. Moreover, HMGA1 levels in GC cells and gastric mucosal cells were detected. Regulatory effects of HMGA1 on the proliferation and migration abilities in SGC7901 and MGC803 cells were assessed through a series of functional experiments. At last, influences of HMGA1 on the expression levels of EMT-related genes, E-cadherin, Snail, and Slug were determined in GC cells. RESULTS: Analysis of data in TCGA GEPIA dataset revealed that HMGA1 was upregulated in GC tissues, and GC patients with a high expression level of HMGA1 suffered poorer prognosis. In addition, HMGA1 was identically upregulated in GC cells, and the overexpression of HMGA1 improved the proliferation and migration abilities of SGC7901 and MGC803 cells, downregulated E-cadherin, and upregulated Snail and Slug in GC cells, while silence of HMAG1 yielded the opposite results CONCLUSIONS: HMGA1 is upregulated in GC tissues and predicts poor prognosis, and it aggravates the progression of GC via stimulating EMT.

Epidemiological features and risk factors of Salmonella gastroenteritis in children resident in Ho Chi Minh City, Vietnam.

Non-typhoidal Salmonella are an important but poorly characterized cause of paediatric diarrhoea in developing countries. We conducted a hospital-based case-control study in children aged <5 years in Ho Chi Minh City to define the epidemiology and examine risk factors associated with Salmonella diarrhoeal infections. From 1419 diarrhoea cases and 571 controls enrolled between 2009 and 2010, 77 (5∙4%) diarrhoea cases were stool culture-positive for non-typhoidal Salmonella. Salmonella patients were more likely to be younger than controls (median age 10 and 12 months, respectively) [odds ratio (OR) 0∙97; 95% confidence interval (CI) 0∙94-0∙99], to report a recent diarrhoeal contact (8∙1% cases, 1∙8% controls; OR 5∙98, 95% CI 1∙8-20∙4) and to live in a household with >2 children (cases 20∙8%, controls 10∙2%; OR 2∙32, 95% CI 1∙2-4∙7). Our findings indicate that Salmonella are an important cause of paediatric gastroenteritis in this setting and we suggest that transmission may occur through direct human contact in the home.

Phytoplankton distribution and productivity in a highly turbid, tropical coastal system (Bach Dang Estuary, Vietnam).

Phytoplankton diversity, primary and bacterial production, nutrients and metallic contaminants were measured during the wet season (July) and dry season (March) in the Bach Dang Estuary, a sub-estuary of the Red River system, Northern Vietnam. Using canonical correspondence analysis we show that phytoplankton community structure is potentially influenced by both organometallic species (Hg and Sn) and inorganic metal (Hg) concentrations. During March, dissolved methylmercury and inorganic mercury were important factors for determining phytoplankton community composition at most of the stations. In contrast, during July, low salinity phytoplankton community composition was associated with particulate methylmercury concentrations, whereas phytoplankton community composition in the higher salinity stations was more related to dissolved inorganic mercury and dissolved mono and tributyltin concentrations. These results highlight the importance of taking into account factors other than light and nutrients, such as eco-toxic heavy metals, in understanding phytoplankton diversity and activity in estuarine ecosystems.

A transplantable sorting signal that is sufficient to mediate rapid recycling of G protein-coupled receptors.

The beta(2)-adrenergic receptor and delta opioid receptor represent distinct G protein-coupled receptors that undergo agonist-induced endocytosis via clathrin-coated pits but differ significantly in their postendocytic sorting between recycling and degradative membrane pathways, respectively. Previous results indicate that a distal portion of the carboxyl-terminal cytoplasmic domain of the beta(2)-adrenergic receptor, which engages in PDZ domain-mediated protein interaction, is required for efficient recycling of receptors after agonist-induced endocytosis. Here we demonstrate that a four-residue sequence (DSLL) comprising the core of this protein interaction domain functions as a transplantable endocytic sorting signal that is sufficient to re-route endocytosed delta opioid receptor into a rapid recycling pathway, to inhibit proteolytic down-regulation of receptors, and to mediate receptor-autonomous sorting of mutant receptors from the wild type allele when co-expressed in the same cells. These observations define a transplantable signal mediating rapid recycling of a heterologous G protein-coupled receptor, and they suggest that rapid recycling of certain membrane proteins does not occur by bulk membrane flow but is instead mediated by a specific endocytic sorting mechanism.

A kinase-regulated PDZ-domain interaction controls endocytic sorting of the beta2-adrenergic receptor.

A fundamental question in cell biology is how membrane proteins are sorted in the endocytic pathway. The sorting of internalized beta2-adrenergic receptors between recycling endosomes and lysosomes is responsible for opposite effects on signal transduction and is regulated by physiological stimuli. Here we describe a mechanism that controls this sorting operation, which is mediated by a family of conserved protein-interaction modules called PDZ domains. The phosphoprotein EBP50 (for ezrinradixin-moesin(ERM)-binding phosphoprotein-50) binds to the cytoplasmic tail of the beta2-adrenergic receptor through a PDZ domain and to the cortical actin cytoskeleton through an ERM-binding domain. Disrupting the interaction of EBP50 with either domain or depolymerization of the actin cytoskeleton itself causes missorting of endocytosed beta2-adrenergic receptors but does not affect the recycling of transferrin receptors. A serine residue at position 411 in the tail of the beta2-adrenergic receptor is a substrate for phosphorylation by GRK-5 (for G-protein-coupled-receptor kinase-5) and is required for interaction with EBP50 and for proper recycling of the receptor. Our results identify a new role for PDZ-domain-mediated protein interactions and for the actin cytoskeleton in endocytic sorting, and suggest a mechanism by which GRK-mediated phosphorylation could regulate membrane trafficking of G-protein-coupled receptors after endocytosis.

DNA content by in situ fluorescence imaging and S-phase detection, with chromatin structure preserved.

OBJECTIVE: To test the feasibility of in situ DNA quantitation of adherent cells' nuclei by fluorescence imaging, preserving chromatin structure and to follow-up S phase, in relation to DNA content, in order to assess the precision of DNA measurements. STUDY DESIGN: Double labeling experiments involved total DNA staining with Hoechst 33342 and BrdU immunostaining (after either Br photolysis and DNA strand break labeling by terminal transferase or acid denaturation) to detect replicating DNA. An epifluorescence microscope was used, images captured with a CCD camera and quantitative total DNA measurements done in 12 bits with IPLab software. BrdU results were related to DNA content on an individual cell basis. Cell cycle analyses were run with Imastat software (developed in the laboratory) on Hoechst-stained cells and on double labeled cells. RESULTS: In cells progressing through the cycle, as assessed by BrdU, a corresponding increase in DNA content was measured. Early S differed from G1 (P < .05). Imastat analyses gave a CV for GI peak of 6-7%. CONCLUSION: Quantitative fluorescence imaging allows a sensitive determination of DNA content for adherent-cell nuclei in situ. Topologic analyses of nuclear components will be possible in relation to DNA content.

NRG-3 in human breast cancers: activation of multiple erbB family proteins.

Ligands of the EGF/Heregulin family control the growth of epithelial cells by binding to receptors of the erbB family. By searching a large database of cDNA sequences at Human Genome Sciences Inc. we have identified a new encoded protein sequence containing all the conserved elements of the EGF/Heregulin family. The same sequence has recently been independently identified as NRG-3. The EGF-like domain of NRG-3 was generated as a recombinant protein in E. coli and used to test the specificity of receptor binding. In human breast cancer cells and in 32D cells transfected by erbB family members, NRG-3 activated multiple erbB family members. These include EGF receptor (erbB1) and erbB4 when expressed individually and erbB2 and erbB3 when expressed together. Recombinant NRG-3 altered the growth of human breast cancer cells growing in vitro. NRG-3 was expressed in cell lines derived from breast cancer. These results indicate that NRG-3 is a potential regulator of normal and malignant breast epithelial cells in vivo.

Regulated endocytosis of G-protein-coupled receptors by a biochemically and functionally distinct subpopulation of clathrin-coated pits.

beta-2 Adrenergic receptors (B2ARs) are endocytosed by clathrin-coated pits. This process serves specialized functions in signal transduction and receptor regulation, raising the question of whether B2ARs are associated with biochemically specialized membrane vesicles during their endocytic trafficking. Here we show that B2ARs are endocytosed by a distinct subpopulation of clathrin-coated pits, which represent a limited subset of coated pits present in the plasma membrane, even in cells overexpressing both B2ARs and beta-arrestin. Coated pits mediating agonist-induced endocytosis of B2ARs differ from other coated pits mediating constitutive endocytosis of transferrin receptors in their temperature dependence for fission from the plasma membrane and in the association of their membrane coats with beta-arrestin. Endocytosis of these coated pits generates endocytic vesicles selectively enriched in B2ARs, which fuse within approximately 10 min after their formation with a common population of endosomes containing both B2ARs and transferrin receptors. These observations demonstrate, for the first time, the existence of a functionally and biochemically distinct subpopulation of clathrin-coated pits that mediate the agonist-regulated endocytosis of G-protein-coupled receptors, and they suggest a new model for the formation of compositionally specialized membrane vesicles at the earliest stage of the endocytic pathway.

A waterborne outbreak of hepatitis E virus transmission in southwestern Vietnam.

A hepatitis outbreak affecting primarily adults occurred in southwestern Vietnam, along the Hau river bordering Cambodia, in June and July 1994. One month after the outbreak, sera and epidemiologic information were collected from 150 subjects: 50 patient cases, 50 matched, healthy community controls, and 50 geographic controls living 50 km upriver. The prevalence of immunoglobulin G (IgG) to hepatitis E virus (HEV) was significantly (P < 0.001) higher (76%) among cases than among the matched (38%) and geographic (38%) control populations. Immunoglobulin M to HEV was detected by enzyme-linked immunosorbent assay and Western blot in 16% of sera collected from patients one month after the outbreak. Hepatitis E virus RNA was detected with the polymerase chain reaction in 6% of sera from patients; RNA was not detected in either control group. These results indicate that HEV was the etiologic agent responsible for the outbreak. Children were under-represented among clinical cases. River water served as the principal source for drinking and bathing among most (96%) of the case and control study populations. Boiling of drinking water was negatively associated (P < 0.05) with IgG anti-HEV seropositivity. Unusually heavy rainfall likely contributed to conditions that favored the outbreak. This is the first recognized outbreak of epidemic HEV transmission in Indo-China.