A multi-analyte assay of opioids in API and drug products using HPLC and HRMS.

Surveillance testing is an essential component to ensuring safe, effective, and high-quality drug products are available in the commercially marketed US supply chain. Surveillance allows the agency to assess product quality and monitor for potential adulteration of drug products being used by consumers. Opioid drug products can be adulterated to enhance the effect of the intended active ingredient. Numerous accounts have been reported where fentanyl has been used as an adulterant in illicit street drugs such as heroin, cocaine, or methamphetamine. To efficiently surveil the legitimate opioid supply chain, an analytical method with the ability to simultaneously detect, identify and quantify opioid molecules is desired. In this study, a multi-opioid protocol (MOP) using liquid chromatography-high resolution mass spectrometry (HPLC-HRMS) technology was developed and validated for the detection and quantification of 27 opioid drugs. The MOP analytical procedure was applied to the analysis of drug substance and finished dosage forms. MOP was used to identify and quantify active pharmaceutical ingredients (API) listed on the label claim, and in the case of suspected economically motivated adulteration could identify and quantify undeclared opioid APIs. The analytical method analysis time was 16 minutes and the LOD and LOQ in full MS mode were (average) 0.3 and 0.8 ng/mL, respectively. The validation criteria parameters were satisfactory based on international guidelines (ICH). The MOP was successfully applied to the analysis of over 160 drug substances and finished products. For all samples tested in the study, their identities were confirmed, and assays met specifications. Overall, there was no evidence of illegal substitution or adulteration in any of the ingredients and products tested from the legitimate commercial marketed US supply chain.

Quality of New Domestic Hand Sanitizer Drug Product Manufacturers During COVID-19.

The FDA initiated a cross-sectional, statistically based sampling and testing study to characterize the quality of marketed alcohol-based hand sanitizer (ABHS) by evaluating the alcohol content and impurities present in ABHS products manufactured by establishments that registered with the FDA during March-April 2020. A stratified sampling design divided the population of manufacturers into independent groups based on each establishment's level of experience with FDA oversight and its geographic location. ABHS products were collected and analyzed by spatially offset Raman spectroscopy and gas chromatography with mass spectrometry (GC-MS). The GC-MS results for 310 products, from 196 newly registered domestic manufacturers, showed that 71.6% (± 5.7%) of these manufacturers had violative products. In 104 (33.5%) cases, the alcohol content did not meet label claim assay specifications but still fell within CDC efficacy ranges. Ethanol ABHS products failed more often overall (assay and impurities) (84.3%) and for impurities (84.3%), than isopropanol ABHS products (11.2% and 6.2%, respectively). Differences in test results across active ingredients were statistically significant. Ethanol ABHS products often (63.5% of cases) failed due to the presence of acetal or acetaldehyde, particularly in products with pH ≤ 6. Other impurities were also detected in several ABHS products, suggesting the use of low-grade alcohol in the manufacture of these products. Evidence was insufficient to conclude that having experience manufacturing FDA-regulated products, or lack thereof, influenced product-level violative results. This study highlights the importance of sourcing and testing active pharmaceutical ingredients to produce quality drug products.

The mutation spectrum of SLC25A13 gene in citrin deficiency: identification of novel mutations in Vietnamese pediatric cohort with neonatal intrahepatic cholestasis.

BACKGROUND: Citrin deficiency (CD), a disorder caused by mutations in the SLC25A13 gene, may result in neonatal intrahepatic cholestasis. This study was purposely to explore the mutation spectrum of SLC25A13 gene in Vietnamese CD patients. METHODS: The 292 unrelated CD patients were first screened for four high-frequency mutations by PCR/PCR-RFLP. Then, Sanger sequencing was performed directly for heterozygous or undetected patients. Novel mutations identified would need to be confirmed by their parents. RESULTS: 12 pathogenic SLC25A13 mutations were identified in all probands, including three deletions c.851_854del (p.R284Rfs*3), c.70-63_133del (p.Y24_72Ifs*10), and c.[1956C>A;1962del] (p.[N652K;F654Lfs*45]), two splice-site mutations (IVS6+5G>A and IVS11+1G>A), one nonsense mutations c.1399C>T (p.R467*), one duplication mutation c.1638_1660dup (p.A554fs*570), one insertion IVSl6ins3kb (p.A584fs*585), and four missense mutation c.2T>C (p.M1T), c.1231G>A (p.V411M), c.1763G>A (p.R588Q), and c.135G>C (p.L45F). Among them, c.851_854del (mut I) was the most identified mutant allele (91.78%) with a total of 247 homozygous and 42 heterozygous genotypes of carriers. Interestingly, two novel mutations were identified: c.70-63_133del (p.Y24_72Ifs*10) and c.[1956C>A;1962del] (p.[N652K;F654Lfs*45]). CONCLUSION: The SLC25A13 mutation spectrum related to intrahepatic cholestasis infants in Vietnam revealed a quite similar pattern to Asian countries' reports. This finding supports the use of targeted SLC25A13 mutation for CD screening in Vietnam and contributed to the SLC25A13 mutation spectra worldwide. It also helps emphasize the role of DNA analysis in treatment, genetic counseling, and prenatal diagnosis.

Apply MIKE 11 model to study impacts of climate change on water resources and develop adaptation plan in the Mekong Delta, Vietnam: a case of Can Tho city.

Can Tho city in the Mekong Delta is in the top ten areas affected by climate change. Therefore, assessing climate change impacts, social and economic activities require proposed solutions to respond to climate change. This study aims to (i) apply the MIKE 11 model (Hydrodynamic module and Advection-Dispersion module) to simulate the impacts of climate change scenarios on water resources in Can Tho city; (ii) calculate water balance in Can Tho city; and (iii) suggest climate change adaptation plan for sustainable social-economic activities of the city. The results show that when the rainfall changes due to climate change, the flow rate tends to decrease at high tide and increase at low tide. When the sea level rises due to climate change, the flow rate tends to increase at high tide and decrease at low tide. For 2030, the flow will decrease up to 15.6% and 14.3% at the low tide period for RCP 2.6 and RCP 8.5 compared to the present, respectively. The flow will increase up to 63.5% and 58.9% at the high tide period for RCP 2.6 and RCP 8.5 compared to the present, respectively. The water demand evaluation shows that the water resource reserve in Can Tho city meets water demands in current and future scenarios under climate change. While rainwater and groundwater can provide enough water in the rainy season, the city has to use surface water during the dry season due to a lack of rainwater. Of these, agriculture contributes the most water demands (85%). Eight adaptation measures to climate change for Can Tho city are developed from 2021 to 2050.

Mutation spectrum of ATP7B gene in pediatric patients with Wilson disease in Vietnam.

Background: Wilson disease (WD) is caused by mutations in the copper-transporting P-type adenosine triphosphatase encoded by the ATP7B gene. In this study, we screened and identified the ATP7B mutations among unrelated Vietnamese pediatric patients. Methods: One-hundred-thirteen pediatric patients with clinically diagnosed WD were recruited. DNA samples were extracted from peripheral blood. Mutations in the ATP7B gene were identified by Sanger sequencing. Results: Approximately 98% of the clinically diagnosed WD patients carried ATP7B mutations. A total of 35 different ATP7B variants were detected, including five novel mutations (L658P, L792P, T977K, IVS4 + 1G > A and IVS20 + 4A > G). Remarkably, this study revealed that S105* was the most prevalent variant (32.27%), followed by L1371P (9.09%), I1148T (7.27%), R778L (6.36%), T850I (5.45%), V176Sfs*28 and IVS14-2A > G (4.55%). Most ATP7B mutations were located in the exon 2 (37.73%), exon 16 (10.00%), exon 8 (9.55%), exon 20 (9.09%), exon 10 and exon 18 (5.45%), exon 14 (5.00%), exon 13 and intron 14 (4.55%). We developed a streamlined procedure to quickly characterize mutations in the ATP7B gene in the Vietnamese children, starting with sequencing exon 2 and subsequently to exons 8,10,13-16,18, and 20 to allow quick diagnosis of clinically suspected patients. Conclusion: The mutational spectrum and hotspots of ATP7B gene in the Vietnamese population were fairly different from other East Asian populations. A streamlined procedure was developed to screen exon 2 in ATP7B gene among suspected WD patients to reduce genetically diagnostic cost, to facilitate early detection and intervention in countries with limited resources.

Clinical and genetic features of congenital bile acid synthesis defect with a novel mutation in AKR1D1 gene sequencing: Case reports.

RATIONALE: Congenital bile acid synthesis defect (BASD) is a rare disease caused by mutations in the aldo-keto reductase 1D1 gene, which encodes the primary Δ4-3-oxosteroid 5ß-reductase enzyme. Early disease diagnosis is critical for early treatment with bile acid replacement therapy, with an excellent chance for recovery. In contrast, protracted diagnosis and treatment may lead to poor outcomes, including decompensated hepatic cirrhosis, liver transplant, and even death. PATIENT CONCERNS: Three clinical congenital bile acid synthesis defect cases in the Vietnamese population are herein reported. These pediatric patients presented with symptoms of prolonged postpartum jaundice and abnormal loose stool (mucus, lipids, and white). The clinical examinations showed hepatosplenomegaly. Urinalysis showed a very low fraction of primary bile acids and atypical 3-oxo-Δ4- bile acids in all three patients. DIAGNOSES: The patients were diagnosed with primary Δ4-3-oxosteroid 5ß-reductase deficiency. Next-generation gene sequencing revealed two homozygous mutations in the aldo-keto reductase family 1 member D1 gene. The first is a documented variant, c.797G>A (p.Arg266Gln), and the second is a novel mutation at c.155T>C (p.Ile52Thr). INTERVENTIONS: Immediately after diagnosis, patients were treated with oral chenodeoxycholate 5 mg/kg/d. OUTCOMES: The patients' symptoms, signs, and primary bile acids levels improved significantly. LESSONS: Clinicians should consider genetic disorders related to cholestasis for effective and life-saving treatment. A prompt genetic analysis by next-generation gene sequencing enables patients to access bile acid replacement therapy earlier, significantly improving short- and long-term outcomes.

Cockayne syndrome without UV-sensitivity in Vietnamese siblings with novel ERCC8 variants.

Cockayne syndrome (CS) is a rare progeroid disorder characterized by growth failure, microcephaly, photosensitivity, and premature aging, mainly arising from biallelic ERCC8 (CS-A) or ERCC6 (CS-B) variants. In this study we describe siblings suffering from classical Cockayne syndrome but without photosensitivity, which delayed a clinical diagnosis for 16 years. By whole-exome sequencing we identified the two novel compound heterozygous ERCC8 variants c.370_371del (p.L124Efs*15) and c.484G>C (p.G162R). The causality of the ERCC8 variants, of which one results in a frameshift and the other affects the WD3 domain, was tested and confirmed by a rescue experiment investigating DNA repair in H2O2 treated patient fibroblasts. Structural modeling of the p.G162R variant indicates effects on protein-protein interaction. This case shows the importance to test for ERCC6 and ERCC8 variants even if patients do not present with a complete CS phenotype.

Loss of the ClpXP Protease Leads to Decreased Resistance to Cell-Envelope Targeting Antimicrobials in Bacillus anthracis Sterne.

The ClpX ATPase is critical for resistance to cell envelope targeting antibiotics in Bacillus anthracis, however, it is unclear whether this is due to its function as an independent chaperone or as part of the ClpXP protease. In this study, we demonstrate that antibiotic resistance is due to formation of the ClpXP protease through construction of a ClpX complementation plasmid that is unable to interact with ClpP. Additionally, we genetically disrupted both clpP genes, clpP1 and clpP2, found in B. anthracis Sterne and find that the loss of either increases susceptibility to cell envelope targeting antimicrobials, although neither has as strong of a phenotype as loss of clpX and neither clpP gene is essential for virulence in a G. mellonella model of infection. Lastly, we looked at changes to cell envelope morphology that could contribute to increased antibiotic sensitivity. We find no difference in cell charge or cell lysis, although we do see increased hydrophobicity in the ΔclpX strain, decreased cellular density and slightly thinner cells walls. We also see significant cell division defects in ΔclpX, although only when cells are grown in the mammalian cell culture medium, RPMI. We conclude that the intrinsic resistance of B. anthracis to cell wall active antimicrobials is dependent on formation of the ClpXP protease and that this could be due, at least in part, to the role of ClpX in regulating cell envelope morphology.

Identification of a wide spectrum of ciliary gene mutations in nonsyndromic biliary atresia patients implicates ciliary dysfunction as a novel disease mechanism.

BACKGROUND: Biliary atresia (BA) is the most common obstructive cholangiopathy in neonates, often progressing to end-stage cirrhosis. BA pathogenesis is believed to be multifactorial, but the genetic contribution, especially for nonsyndromic BA (common form: > 85%) remains poorly defined. METHODS: We conducted whole exome sequencing on 89 nonsyndromic BA trios to identify rare variants contributing to BA etiology. Functional evaluation using patients' liver biopsies, human cell and zebrafish models were performed. Clinical impact on respiratory system was assessed with clinical evaluation, nasal nitric oxide (nNO), high speed video analysis and transmission electron microscopy. FINDINGS: We detected rare, deleterious de novo or biallelic variants in liver-expressed ciliary genes in 31.5% (28/89) of the BA patients. Burden test revealed 2.6-fold (odds ratio (OR) [95% confidence intervals (CI)]= 2.58 [1.15-6.07], adjusted p = 0.034) over-representation of rare, deleterious mutations in liver-expressed ciliary gene set in patients compared to controls. Functional analyses further demonstrated absence of cilia in the BA livers with KIF3B and TTC17 mutations, and knockdown of PCNT, KIF3B and TTC17 in human control fibroblasts and cholangiocytes resulted in reduced number of cilia. Additionally, CRISPR/Cas9-engineered zebrafish knockouts of KIF3B, PCNT and TTC17 displayed reduced biliary flow. Abnormally low level of nNO was detected in 80% (8/10) of BA patients carrying deleterious ciliary mutations, implicating the intrinsic ciliary defects. INTERPRETATION: Our findings support strong genetic susceptibility for nonsyndromic BA. Ciliary gene mutations leading to cholangiocyte cilia malformation and dysfunction could be a key biological mechanism in BA pathogenesis. FUNDING: The study is supported by General Research Fund, HMRF Commissioned Paediatric Research at HKCH and Li Ka Shing Faculty of Medicine Enhanced New Staff Start-up Fund.

Developing a Sufficient Protocol for the Enhancement of α-Glucosidase Inhibitory Activity by Urena lobata L. Aeroponic Hairy Roots Using Exogenous Factors, a Precursor, and an Elicitor.

Aeroponics is considered as a potential method for the culture of herbal plants due to the high growth rate, quantity and quality enhancement of secondary metabolites, and substantial environmental progress associated with this method. The aim of this study was to develop a sufficient protocol for successful Urena lobata hairy root induction by Agrobacterium rhizogenes ATCC 15834, using a precursor and elicitor to enhance α-glucosidase inhibitory activity (GIA) of aeroponic hairy roots (AHRs) in greenhouse conditions. In this study, we found that the optimized procedure (10 min, Woody plant medium (WPM), 1/25 salt strength) had an outstanding effect with a reduction in the rooting time (RT), promotion of the rooting rate (RR), and increase in the fresh weight (FW) and dry weight (DW) compared with the original procedure (30 min, Murashige and Skoog (MS) medium, 1/25 salt strength) after 30 days of culture. The highest DW, GIA, flavonoid (FLA) and phenolic (PHEL) contents were observed for individual addition of 10 mM phenylalanine (PA) or 50 mM chitosan (CS) in the late exponential phase (eighth week) with 15 days of elicitation compared to the control AHRs. However, individual treatment was less effective than the combination of the two. Positive correlations among the GIA, FLA and PHEL indicate that AHRs accumulated phenolic compounds, leading to an increase in the GIA by a synergistic effect. In conclusion, the culture of Urena lobata AHRs with PA and CS is an efficient procedure to produce GIA material in greenhouse conditions.

Distal duplication of chromosome 16q22.1q23.1 in a Vietnamese patient with midface hypoplasia and intellectual disability.

The clinical presentation of distal duplications of the long arm of chromosome (chr) 16 is currently not well described. Only one case of microduplication of chr16q22.1 and another involving the chr16q22.1q23.1 region have been reported so far. Here, using array comparative genomic hybridization, we identified a second case of chr16q22.1q23.1 duplication in a Vietnamese boy, who shares significant clinical phenotype with the previously described case. Aside from developmental delay, intellectual disability and midface hypoplasia, our patient also displays a forked tongue, visual impairment and external ptosis. Our report further expands the clinical spectrum associated with duplication of this region.

Three novel mutations in the ATP7B gene of unrelated Vietnamese patients with Wilson disease.

BACKGROUND: Wilson disease (OMIM # 277900) is a autosomal recessive disorder characterized by accumulation of copper in liver and brain. The accumulation of copper resulting in oxidative stress and eventually cell death. The disease has an onset in a childhood and result in a significant neurological impairment or require lifelong treatment. Another serious consequence of the disease is the development of liver damage and acute liver failure leading to liver transplant. The disorder is caused by mutations in the ATP7B gene, encoding a P-type copper transporting ATPase. CASE PRESENTATION: We performed genetic analysis of three unrelated patients from three different Vietnamese families. These patients had clinical features such as numbness of hands and feet, vomiting, insomnia, palsy, liver failure and Kayser-Fleischer (K-F) rings and were diagnosed with Wilson disease in the Human Genetics Department, Vietnam National Children's Hospital. The entire coding region and adjacent splice sites of ATP7B gene were amplified and sequenced by Sanger method. Sequencing data were analyzed and compared with the ATP7B gene sequence published in Ensembl (ENSG00000123191) by using BioEdit software to detect mutations. CONCLUSIONS: In this study, five mutations in the ATP7B gene were found. Among of these, three mutations were novel: c.750_751insG (p.His251Alafs*19) in exon 2, c.2604delC (p.Pro868Profs*5) in exon 11, and c.3077 T > A (p.Phe1026Tyr) in exon 14. Our results of the mutations associated with Wilson disease might facilitate the development of effective treatment plans.

Direct Medical Costs of Dengue Fever in Vietnam: A Retrospective Study in a Tertiary Hospital.

BACKGROUND: In Vietnam, dengue fever is a major health concern, yet comprehensive information on its economic costs is lacking. The present study investigated treatment costs associated with dengue fever from the perspective of health care provision. METHODS: This retrospective study was conducted between January 2013 and December 2015 in Cu Chi General Hospital. The following dengue-related treatment costs were calculated: hospitalisation, diagnosis, specialised services, drug usage and medical supplies. Average cost per case and treatment cost across different age was calculated. RESULTS: In the study period, 1672 patients with dengue fever were hospitalised. The average age was 24.98 (SD = 14.10) years, and 47.5% were males (795 patients). Across age groups, the average cost per episode was USD 48.10 (SD = 3.22). The highest costs (USD 56.61, SD = 48.84) were incurred in the adult age group (> 15 years), and the lowest costs (USD 30.10, SD = 17.27) were incurred in the paediatric age group (< 15 years). CONCLUSION: The direct medical costs of dengue-related hospitalisation place a severe economic burden on patients and their families. The probable economic value of dengue management in Vietnam is significant.

Chemical constituents from Sonneratia ovata Backer and their in vitro cytotoxicity and acetylcholinesterase inhibitory activities.

Sonneratia ovata Backer, Sonneratiaceae, is a widespread plant in mangrove forests in Vietnam, Cambodia, Thailand, Indonesia. Sonneratia ovata's chemical composition remains mostly unknown. Therefore, we now report on the structural elucidation of three new phenolics, sonnerphenolic A (1), sonnerphenolic B (2), and sonnerphenolic C (23), a new cerebroside, sonnercerebroside (3) together with nineteen known compounds, including nine lignans (5-13), two steroids (14, 15), two triterpenoids (16, 17), three gallic acid derivatives (18-20), two phenolic derivatives (4, 22) and a 1-O-benzyl-ß-d-glucopyranose (21) isolated from the leaves of Sonneratia ovata. Their chemical structures were established by spectroscopic data, as well as high resolution mass spectra and comparison with literature data. The in vitro acetylcholinesterase (AChE) inhibition and cytotoxic activities against HeLa (human epithelial carcinoma), NCI-H460 (human lung cancer), MCF-7 (human breast cancer) cancer cell lines and PHF (primary human fibroblast) cell were evaluated on some extracts and purified compounds at a concentration of 100 µg/mL. Compounds (5, 6, 23) exhibited cytotoxicity against the MCF-7 cell line with the IC50 values of 146.9±9.0, 114.5±7.2, and 112.8±9.4 µM, respectively, while they showed nontoxic with the normal cell (PHF) with IC50s >277 µM. Among 15 tested compounds, (S)-rhodolatouchol (22) showed inhibition against AChE with an IC50 value of 96.1±14.5 µM.

A novel homozygous mutation IVS6+5G>T in CYP11B1 gene in a Vietnamese patient with 11ß-hydroxylase deficiency.

Congenital adrenal hyperplasia (CAH) is an autosomal recessive disease which is characterized by a deficiency of one of the enzymes involved in the synthesis of cortisol from cholesterol by the adrenal cortex. CAH cases arising from impaired 11ß-hydroxylase are the second most common form. Mutations in the CYP11B1 gene are the cause of 11ß-hydroxylase deficiency. This study was performed on a patient with congenital adrenal hyperplasia and with premature development such as enlarged penis, muscle development, high blood pressure, and bone age equivalent of 5 years old at 2 years of chronological age. Biochemical tests for steroids confirmed the diagnosis of CAH. We used PCR and sequencing to screen for mutations in CYP11B1 gene. Results showed that the patient has a novel homozygous mutation of guanine (G) to thymine (T) in intron 6 (IVS6+5G>T). The analysis of this mutation by MaxEntScan boundary software indicated that this mutant could affect the gene splicing during transcription.

Developing an in vitro understanding of patient experience with hydrofluoroalkane-metered dose inhalers.

As a result of the Montreal Protocol on Substances that Deplete the Ozone Layer, manufacturers of metered dose inhalers began reformulating their products to use hydrofluoroalkanes (HFAs) as propellants in place of chlorofluorocarbons (CFCs). Although the new products are considered safe and efficacious by the US Food and Drug Administration (FDA), a large number of complaints have been registered via the FDA's Adverse Events Reporting System (FAERS)-more than 7000 as of May 2013. To develop a better understanding of the measurable parameters that may, in part, determine in vitro performance and thus patient compliance, we compared several CFC- and HFA-based products with respect to their aerodynamic performance in response to changes in actuator cleaning interval and interactuation delay interval. Comparison metrics examined in this study were: total drug delivered ex-actuator, fine particle dose (<5 µm), mass median aerodynamic diameter, plume width, plume temperature, plume impaction force, and actuator orifice diameter. Overall, no single metric or test condition distinguishes HFA products from CFC products, but, for individual products tested, there were a combination of metrics that differentiated one from another.

Targeted next-generation sequencing on Hirschsprung disease: a pilot study exploits DNA pooling.

To adopt an efficient approach of identifying rare variants possibly related to Hirschsprung disease (HSCR), a pilot study was set up to evaluate the performance of a newly designed protocol for next generation targeted resquencing. In total, 20 Chinese HSCR patients and 20 Chinese sex-matched individuals with no HSCR were included, for which coding sequences (CDS) of 62 genes known to be in signaling pathways relevant to enteric nervous system development were selected for capture and sequencing. Blood DNAs from eight pools of five cases or controls were enriched by PCR-based RainDance technology (RDT) and then sequenced on a 454 FLX platform. As technical validation, five patients from case Pool-3 were also independently enriched by RDT, indexed with barcode and sequenced with sufficient coverage. Assessment for CDS single nucleotide variants showed DNA pooling performed well (specificity/sensitivity at 98.4%/83.7%) at the common variant level; but relatively worse (specificity/sensitivity at 65.5%/61.3%) at the rare variant level. Further Sanger sequencing only validated five out of 12 rare damaging variants likely involved in HSCR. Hence more improvement at variant detection and sequencing technology is needed to realize the potential of DNA pooling for large-scale resequencing projects.

Evaluation of an abbreviated impactor for fine particle fraction (FPF) determination of metered dose inhalers (MDI).

Abbreviated impactors have been developed recently to allow more rapid evaluation of inhalation products as alternates to the eight-stage Andersen Cascade Impactor (ACI) which has been widely used in the pharmaceutical industry for assessing aerodynamic particle size distribution. In this paper, a two-stage abbreviated impactor, Westech Fine Particle Dose Impactor (WFPD), was used to characterize the aerodynamic particle size of metered dose inhaler (MDI) products, and the results were compared with those obtained using the standard eight-stage ACI. Seven commercial MDI products, with different propellants (chlorofluorocarbon/hydrofluoroalkane) and formulation types (suspension/solution, dry/normal/wet), were tested in this study by both WFPD and ACI. Substantially equivalent measures of fine particle fraction were obtained for most of the tested MDI products, but larger coarse particle fraction and extra-fine particle fraction values were measured from WFPD relative to those measured using the ACI. Use of the WFPD also produced more wall loss than the ACI. Therefore, it is recommended that the system suitability be evaluated on a product-by-product basis to establish substantial equivalency before implementing an abbreviated impactor measurement methodology for routine use in inhaler product characterization.

Screening of the RET gene of Vietnamese Hirschsprung patients identifies 2 novel missense mutations.

BACKGROUND/PURPOSE: Hirschsprung disease (HSCR; megacolon, congenital aganglionosis) is a congenital disorder characterized by the absence of ganglion cells along variable segments of the gut. Both rare (RV) and common variants of the RET gene are associated with HSCR. The aim of this study is to assess, for the first time, the variation in the RET gene of Vietnamese HSCR patients. METHODS: We used Sanger sequencing to screen the coding sequence of the RET gene of 97 Vietnamese HSCR patients of Southern Chinese ancestry. The healthy population consisted of 250 Southern Chinese individuals with no diagnosis of HSCR. RESULTS: We detected 8 heterozygous RVs distributed among 13 patients (13.40%) and that were not present in healthy individuals. Among those variants, there were 2 novel and deleterious (R133C [c.397 C>T]; R144C [c.430 C>T]) missense amino acid substitutions, 2 novel silent variants (P667P [c.2001 A>T]; Y809Y [c.2427 C>T]), and 4 previously described missense substitutions (R114H [c.341 G>A]; V292M [c.874 G>A]; G533S [c.1597 G>A]; R982C [c.2944 C>T]). As expected, the common RET coding sequence variants rs1800858 (A45A [c.135 G>A]) and rs1800861 (L769L [c.2307 T>G]) were highly associated with the disease. CONCLUSIONS: The identification of novel deleterious variants together with the fact RET RVs are virtually unique to HSCR patients indicates that the RET gene is a target for mutations among Hirschsprung patients of any population.

FoxP3+, and not CD25+, T cells increase post-transplant in islet allotransplant recipients following anti-CD25+ rATG immunotherapy.

Anti-CD25 antibodies are used as an induction therapy in islet allotransplantation for type 1 diabetes. Although previous reports suggested that anti-CD25 treatment may lead to depletion of CD4+CD25+ regulatory T cells (Tregs) and questioned its use in tolerance-promoting protocols for transplantation, the effect of anti-CD25 antibodies on the frequency and function of Tregs remains unclear. We examined the effect of anti-CD25 antibody, daclizumab, in vivo on Tregs in islet allograft recipients enrolled in a single-center study and monitored post-transplant. Our data shows that the reduction in CD25+ Treg cells observed post-transplant is due to masking of CD25 receptor by daclizumab and not due to depletion. In addition, using Treg marker, FoxP3, we show that anti-CD25+ ATG treatment leads to an increase in FoxP3+ Tregs post-transplant. These data suggest that anti-CD25-based therapy has beneficial effects on Tregs and combined with ATG may be a promising therapy for autoimmunity and transplantation.