Publications by authors named "Kin Tang"

The transplantation of CD34 hematopoietic stem-progenitor cells (HSPCs) derived from cord blood serves as the standard treatment for selected hematological, oncological, metabolic, and immunodeficiency disorders, of which the dose is pivotal to the clinical outcome. Based on numerous maternal and neonatal parameters, we evaluated the predictive power of mathematical pipelines to the proportion of CD34 cells in the final cryopreserved cord blood product adopting both parametric and non-parametric algorithms. Twenty-four predictor variables associated with the cord blood processing of 802 processed cord blood units randomly sampled in 2020-2022 were retrieved and analyzed.

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This study aimed to identify radiomic features of primary tumor and develop a model for indicating extrahepatic metastasis of hepatocellular carcinoma (HCC). Contrast-enhanced computed tomographic (CT) images of 177 HCC cases, including 26 metastatic (MET) and 151 non-metastatic (non-MET), were retrospectively collected and analyzed. For each case, 851 radiomic features, which quantify shape, intensity, texture, and heterogeneity within the segmented volume of the largest HCC tumor in arterial phase, were extracted using Pyradiomics.

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The American Association of Pharmaceutical Scientists (AAPS) Chemistry, Manufacturing, and Controls (CMC) Community hosted two virtual panel discussions focusing on several novel regulatory review pathways for innovative oncology products: Real-Time Oncology Review (RTOR), Project Orbis, and the Product Quality Assessment Aid (PQAAid). The panel sessions were held on August 27, 2021, for the discussion of RTOR, and January 21, 2022, for the discussion of Project Orbis and the PQAAid. Both panel sessions included representatives from the US Food and Drug Administration (FDA) and subject matter experts from the pharmaceutical and biotechnology industries, with the aim of facilitating knowledge sharing on CMC-specific advantages, challenges, eligibility criteria for participation, and operational modifications instituted through the utilization of these acceleration initiatives.

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Axon regeneration is an energy-demanding process that requires active mitochondrial transport. In contrast to the central nervous system (CNS), axonal mitochondrial transport in regenerating axons of the peripheral nervous system (PNS) increases within hours and sustains for weeks after injury. Yet, little is known about targeting mitochondria in nervous system repair.

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Objective: To evaluate the effects of cryopreservation in post-thaw umbilical cord blood units for the survivability of Gram-positive bacteria strains.

Background: Microbial screening is required for all cord blood units (CBUs). Four gram-positive contaminants were documented to survive cryopreservation poorly and isolation of other contaminants were reported.

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The American Association of Pharmaceutical Scientists (AAPS) Chemistry, Manufacturing, and Control (CMC) Community hosted a virtual panel discussion on December 9, 2020, to provide a forum to discuss N-nitrosamine control strategies in the pharmaceutical and biotechnology industries. The panel included staff from the US Food and Drug Administration (FDA) and industry subject matter experts. Meeting topics included acceptable intake levels for nitrosamine impurities, definitions of "acceptable level of risk," water as a contributor in nitrosamine risk assessments, nitrosamine impurity control strategies based upon fate/purge data, early vs.

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With the expected rise in patients undergoing refractive lenticule extraction worldwide, the number of discarded corneal stromal lenticules will increase. Therefore, establishing a lenticule bank to collect, catalog, process, cryopreserve, and distribute the lenticules (for future therapeutic needs) could be advantageous. In this study, we validated the safety of lenticule banking that involved the collection of human lenticules from our eye clinic, transportation of the lenticules to a Singapore Ministry of Health-licensed lenticule bank, processing, and cryopreservation of the lenticules, which, after 3 months or, a longer term, 12 months, were retrieved and transported to our laboratory for implantation in rabbit corneas.

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Antimicrobial peptides (AMPs) have emerged as a promising alternative to small molecule antibiotics. Although AMPs have previously been isolated in many organisms, efforts on the systematic identification of AMPs in fish have been lagging. Here, we collected peptides from the plasma of medaka (Oryzias latipes) fish.

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The aim of this study is to investigate the dissolution properties of poorly soluble drugs from their pure form and their amorphous formulation under physiological relevant conditions for oral administration based on surface dissolution ultraviolet (UV) imaging. Dissolution of two poorly soluble drugs (cefuroxime axetil and itraconazole) and their amorphous formulations (Zinnat and Sporanox) was studied with the Sirius Surface Dissolution Imager (SDI). Media simulating the fasted state conditions (compendial and biorelevant) with sequential media/flow rate change were used.

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The Wharton's Jelly (WJ) is an established source of mesenchymal stem cells (MSC). We compared 3 methods of extracting WJ-MSC from cryopreserved tissue and determined that enzymatic digestion of the WJ yielded the most viable MSC, compared to the explant and mechanical digestion methods. The enzymatically-released WJ-MSC conformed to the International Society for Cellular Therapy (ISCT) criteria: displayed plastic-adherence, co-expressed CD73, CD90, CD105 and were negative for hematopoietic lineage cell markers.

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Viruses must evade the host innate defenses for replication and dengue is no exception. During secondary infection with a heterologous dengue virus (DENV) serotype, DENV is opsonized with sub- or nonneutralizing antibodies that enhance infection of monocytes, macrophages, and dendritic cells via the Fc-gamma receptor (FcγR), a process termed antibody-dependent enhancement of DENV infection. However, this enhancement of DENV infection is curious as cross-linking of activating FcγRs signals an early antiviral response by inducing the type-I IFN-stimulated genes (ISGs).

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A characteristic clinical feature of dengue virus infection is thrombocytopenia, though its underlying mechanism is not definitively determined. By adoptive transfer of human CD34(+) fetal liver cells into immunodeficient mice, we have constructed humanized mice with significant levels of human platelets, monocytes/macrophages, and hepatocytes. Infection of these mice with both lab-adapted and clinical strains of dengue virus induces characteristic human hematological changes, including transient leukopenia and thrombocytopenia.

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Human biorelevant media have been shown to be a useful tool in pharmaceutical development and to provide input for in silico prediction of pharmacokinetic profiles after oral dosing. Dogs, in particular Beagles, are often used as animal models for preclinical studies. Key differences in the composition of human and canine gastric and intestinal fluids are described in the literature and underscore the need to develop a discrete set of biorelevant media, adapted to the conditions of the proximal canine gastrointestinal (GI) tract, to improve forecast and interpretation of preclinical results using in vitro dissolution studies.

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The present work deals with improving the solubility of vemurafenib, a practically insoluble drug, by converting it into an amorphous-solid dispersion using a solvent-controlled precipitation process. The dispersion containing vemurafenib and hypromellose acetate succinate (HPMCAS), an enteric polymer, is termed microprecipitated bulk powder (MBP), in which the drug is uniformly dispersed within the polymeric substrate. HPMCAS was found to be the most suitable polymer for vemurafenib MBP, among a series of enteric polymers based on superior physical stability and drug-release characteristics of the MBP.

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Diagnosis of dengue: an update.

Expert Rev Anti Infect Ther

August 2012

Early diagnosis of dengue, the most common mosquito-borne disease globally, remains challenging. Dengue presents initially as undifferentiated fever, with symptoms becoming more pathognomonic in the later stages of illness. This limits the timeliness in the delivery of appropriate supportive interventions.

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A novel method was developed to manufacture amorphous formulations of poorly soluble compounds that cannot be processed with existing methods such as spray drying and melt extrusion. The manufacturing process and the characterization of the resulting amorphous dispersion are presented via examples of two research compounds. The novel process is utilized N,N-dimethylacetamide (DMA) to dissolve the drug and the selected ionic polymer.

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This summary workshop report highlights presentations and over-arching themes from an October 2011 workshop. Discussions focused on best practices in the application of biopharmaceutics in oral drug product development and evolving bioequivalence approaches. Best practices leverage biopharmaceutic data and other drug, formulation, and patient/disease data to identify drug development challenges in yielding a successfully performing product.

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Outbreaks of dengue disease are constant threats to tropical and subtropical populations but range widely in severity, from mild to haemorrhagic fevers, for reasons that are still elusive. We investigated the interferon (IFN) response in infected human cell lines A549 and HepG2, using two strains (NGC and TSV01) of dengue serotype 2 (DEN2) and found that the two viruses exhibited a marked difference in inducing type I IFN response. While TSV01 infection led to activation of type I antiviral genes such as EIF2AK2 (PKR), OAS, ADAR and MX, these responses were absent in NGC-infected cells.

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Biorelevant dissolution test methods for lipid formulations of RZ-50, an experimental Roche compound, were developed and compared with standard compendial methods in terms of their in vivo predictability. Release of RZ-50, a poorly soluble weakly acidic drug, from lipid suspensions filled in soft gelatin capsules was studied in compendial and biorelevant media using the USP Apparatus 2 (paddle method) and the USP Apparatus 3 (Bio-Dis method). Pharmacokinetic data were obtained in dogs after oral administration of a single 2.

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The laboratory diagnosis of dengue has largely relied on serological assays, although many different RT-PCR protocols have been reported. Owing to its limited use, the value of RT-PCR in the clinical laboratory has not been fully evaluated. During the outbreak of severe acute respiratory syndrome (SARS) in Singapore in 2003, RT-PCR to detect dengue viral RNA was used as a rapid diagnostic tool to differentiate dengue from SARS among patients who presented to a hospital designated to manage and quarantine SARS cases.

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Background: The SARS coronavirus is the etiologic agent for the epidemic of the Severe Acute Respiratory Syndrome. The recent emergence of this new pathogen, the careful tracing of its transmission patterns, and the ability to propagate in culture allows the exploration of the mutational dynamics of the SARS-CoV in human populations.

Methods: We sequenced complete SARS-CoV genomes taken from primary human tissues (SIN3408, SIN3725V, SIN3765V), cultured isolates (SIN848, SIN846, SIN842, SIN845, SIN847, SIN849, SIN850, SIN852, SIN3408L), and five consecutive Vero cell passages (SIN2774_P1, SIN2774_P2, SIN2774_P3, SIN2774_P4, SIN2774_P5) arising from SIN2774 isolate.

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Interleukin-18 (IL-18) is a single-chain cytokine that is produced by various cells. With interleukin-12 (IL-12), it synergistically stimulates activated T cells and natural killer (NK) cells to produce interferon-gamma (IFN-gamma). Nasopharyngeal carcinoma (NPC) is the most common form of nasal and nasopharyngeal malignancy, and in NPC tumor tissues there is an intense leukocyte infiltration comprising predominantly T cells and macrophages.

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