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1.
Bio Protoc ; 14(12): e5016, 2024 Jun 20.
Article in English | MEDLINE | ID: mdl-38948263

ABSTRACT

Human babesiosis is a tick-borne disease caused by Babesia pathogens. The disease, which presents with malaria-like symptoms, can be life-threatening, especially in individuals with weakened immune systems and the elderly. The worldwide prevalence of human babesiosis has been gradually rising, prompting alarm among public health experts. In other pathogens, genetic techniques have proven to be valuable tools for conducting functional studies to understand the importance of specific genes in development and pathogenesis as well as to validate novel cellular targets for drug discovery. Genetic manipulation methods have been established for several non-human Babesia and Theileria species and, more recently, have begun to be developed for human Babesia parasites. We have previously reported the development of a method for genetic manipulation of the human pathogen Babesia duncani. This method is based on positive selection using the hDHFR gene as a selectable marker, whose expression is regulated by the ef-1aB promoter, along with homology regions that facilitate integration into the gene of interest through homologous recombination. Herein, we provide a detailed description of the steps needed to implement this strategy in B. duncani to study gene function. It is anticipated that the implementation of this method will significantly improve our understanding of babesiosis and facilitate the development of novel and more effective therapeutic strategies for the treatment of human babesiosis. Key features This protocol provides an effective means of transfection of B. duncani, enabling genetic manipulation and editing to gain further insights into its biology and pathogenesis. The protocol outlined here for the electroporation of B. duncani represents an advancement over previous methods used for B. bovis [1]. Improvements include higher volume of culture used during the electroporation step and an enhancement in the number of electroporation pulses. These modifications likely enhance the efficiency of gene editing in B. duncani, allowing for quicker and more effective selection of transgenic parasites.

2.
J Infect Dev Ctries ; 18(5): 834-838, 2024 May 30.
Article in English | MEDLINE | ID: mdl-38865398

ABSTRACT

INTRODUCTION: Q fever, a zoonotic disease caused by Coxiella burnetii (C. burnetii), presents diagnostic challenges due to its clinical and radiological nonspecificity, which often mimics community-acquired pneumonia, coupled with the limitations of traditional diagnostic methods. Metagenomic next-generation sequencing (mNGS) has become an indispensable tool in clinical diagnostics for its high-throughput pathogen identification capabilities. Herein, we detail a case of acute Q fever pneumonia diagnosed with mNGS. CASE PRESENTATION: The patient exhibited symptoms of fever, cough, expectoration, and diarrhea for three days, with the pathogen undetected in initial laboratory assessments. Bronchoscopy and bronchoalveolar lavage (BAL) were conducted, leading to the identification of C. burnetii in the lavage fluid via mNGS. Consequently, the patient was promptly initiated on a treatment regimen of 100 mg doxycycline, administered orally every 12 hours. RESULTS: Post-treatment, the patient's temperature normalized, and a full recovery was observed. The follow-up chest CT scan revealed complete resolution of the right lower lobe consolidation. CONCLUSIONS: The clinical presentation of Q fever pneumonia lacks specificity, making diagnosis based solely on symptoms and imaging challenging. mNGS offers a superior alternative for identifying elusive or rarely cultured pathogens.


Subject(s)
Coxiella burnetii , High-Throughput Nucleotide Sequencing , Metagenomics , Q Fever , Humans , Q Fever/diagnosis , Q Fever/drug therapy , Q Fever/microbiology , Coxiella burnetii/genetics , Coxiella burnetii/isolation & purification , Metagenomics/methods , Male , Pneumonia, Bacterial/diagnosis , Pneumonia, Bacterial/microbiology , Pneumonia, Bacterial/drug therapy , Anti-Bacterial Agents/therapeutic use , Doxycycline/therapeutic use , Bronchoalveolar Lavage Fluid/microbiology , Middle Aged , Tomography, X-Ray Computed
3.
Transl Vis Sci Technol ; 13(1): 17, 2024 01 02.
Article in English | MEDLINE | ID: mdl-38236189

ABSTRACT

Purpose: We aimed to analyze the trends and patterns in outpatient health service treatment of dry eye disease (DED) using real-world data from Yinzhou District in China. Methods: The Yinzhou Health Information System is a comprehensive database including electronic medical records from 277 medical institutions representing over 1.64 million residents. We extracted outpatient records from January 1, 2017, to December 31, 2021, that included the first diagnosis of DED according to the International Classification of Diseases, 10th Revision (H04.101, H04.103, H11.104, H16.202, or H18.803). We analyzed the trends and patterns of DED outpatient visits using the Mann-Kendall trend test and Cochran-Armitage trend test. Results: We identified a total of 369,755 outpatient visits from 145,712 patients with DED of all ages (60.37% female; 54.10% 50 years or older). Primary medical institutions had the largest number of DED outpatient visits (42%), followed by tertiary medical institutions (35%). Over the 5-year period, the number of DED outpatient visits increased from 59,260 to 90,807 (53.23%). We observed significant consecutive annual proportion increases in females (from 61.09% to 62.01%; P = 0.001), patients 50 years or older (from 55.10% to 60.08%; P < 0.001), and outpatient visits in primary medical institutions (from 33.19% to 48.75%; P < 0.001). Conclusions: Our study found an increase in outpatient health service use for DED in Yinzhou from 2017 to 2021, with higher proportions and increases among females, patients 50 years or older, and primary medical institutions. Translational Relevance: The rapid growth in the prevalence of DED indicates high eye healthcare needs in patients.


Subject(s)
Dry Eye Syndromes , Outpatients , Humans , Female , Male , Dry Eye Syndromes/diagnosis , Dry Eye Syndromes/epidemiology , Dry Eye Syndromes/therapy , Electronic Health Records , Patient Acceptance of Health Care
4.
Parasit Vectors ; 16(1): 268, 2023 Aug 07.
Article in English | MEDLINE | ID: mdl-37550766

ABSTRACT

BACKGROUND: Babesia gibsoni, the causative agent of canine babesiosis, belongs to the phylum Apicomplexa. The development of in vitro culture technology has driven research progress in various kinds of omics studies, including transcriptomic analysis of Plasmodium spp. between in vitro and in vivo environments, which has prompted the observation of diagnostic antigens and vaccine development. Nevertheless, no information on Babesia spp. could be obtained in this respect, which greatly hinders the further understanding of parasite growth and development in the blood stage. METHODS: In this study, considerable changes in the morphology and infectivity of continuous in vitro cultured B. gibsoni (Wuhan isolate) were observed compared to in vivo parasites. Based on these changes, B. gibsoni (Wuhan isolate) was collected from both in vivo and in vitro cultures, followed by total RNA extraction and Illumina transcriptome sequencing. The acquired differentially expressed genes (DEGs) were validated using qRT-PCR, and then functionally annotated through several databases. The gene with the greatest upregulation after in vitro culture was cloned from the genome of B. gibsoni (Wuhan isolate) and characterized by western blotting and indirect immunofluorescence assay for detecting the native form and cellular localization. RESULTS: Through laboratory cultivation, multiple forms of parasites were observed, and the infectivity of in vitro cultured parasites in dogs was found to be lower. Based on these changes, Illumina transcriptome sequencing was conducted, showing that 377 unigenes were upregulated and 334 unigenes were downregulated. Notably, an AP2 transcription factor family, essential for all developmental stages of parasites, was screened, and the transcriptional changes in these family members were tested. Thus, the novel AP2 transcription factor gene (BgAP2-M) with the highest upregulated expression after in vitro adaptation was selected. This gene comprises an open reading frame (ORF) of 1989 base pairs encoding a full-length protein of 662 amino acids. BgAP2-M contains one AP2 domain and one ACDC conserved domain, which may be involved in the nuclear biology of parasites. The prepared polyclonal antibodies against the BgAP2-M peptides further detected a native size of ~ 73 kDa and were localized to the nuclei of B. gibsoni. CONCLUSION: This study presents a thorough transcriptome analysis of B. gibsoni in vivo and in vitro for the first time, contributing to a detailed understanding of the effects of environmental changes on the growth and development of parasites in the blood stage. Moreover, it also provides a deeper investigation for the different members of the ApiAP2 transcription factor family as various life stage regulators in Babesia spp.


Subject(s)
Babesia , Babesiosis , Dog Diseases , Animals , Dogs , Amino Acid Sequence , Dog Diseases/parasitology , Babesiosis/parasitology , Antibodies, Protozoan , Transcription Factors/metabolism
5.
Microbiol Spectr ; 11(3): e0025823, 2023 06 15.
Article in English | MEDLINE | ID: mdl-37158742

ABSTRACT

The establishment of in vitro culture methods has greatly facilitated the research of Babesia. However, the current Babesia gibsoni in vitro culture medium requires high concentrations of canine serum, which intensively limits the culture and is unable to satisfy the demands of long-term studies. In this study, AlbuMAX I (2 mg/mL) and 2.5% dog serum (vol/vol) were added to VP-SFM medium to develop a low-concentration serum culture medium named VP-SFMAD (2.5%), and the effectiveness of this medium was assessed by the growth of B. gibsoni. The results showed that VP-SFMAD (2.5%) could support the continuous growth of the parasite, and the parasitemia has no difference with the cultivation in RPMI 1640 with 20% dog serum. In contrast, either a low concentration of dog serum or absence of AlbuMAX I will significantly lower the parasite growth or fail to maintain B. gibsoni growth in the long term. The strategy of reducing the hematocrit was also evaluated, and VP-SFMAD (2.5%) improved the parasitemia to over 50% within 5 days. The high parasitemia is helpful for larger numbers of parasite collection, which is valuable for studying the biology, pathogenesis, and virulence of Babesia and other intraerythrocytic parasites. In addition, VP-SFMAD (2.5%) medium was successfully used for monoclonal parasite screening, which obtained monoclonal strains with parasitized erythrocytes about 3%, which is similar to RPMI-1640D (20%) medium that obtains monoclonal strains on the 18th day. Those results showed that VP-SFMAD can be applied to B. gibsoni continuous long-term, expansion culture, and subclone culture. IMPORTANCE The VP-SFM as a base medium supplemented with AlbuMAX I and a low concentration of canine serum (2.5%) allowed the continuous in vitro culture of Babesia gibsoni at both small and large volumes, which was to meet different experimental needs, such as long-term culture and obtaining high parasitemia and subclone culture. The establishment of in vitro culture systems allows researchers to better understand the metabolism and growth patterns of Babesia. Importantly, several technical problems impeding such studies have been overcome.


Subject(s)
Babesia , Babesiosis , Dog Diseases , Animals , Dogs , Parasitemia/veterinary , Erythrocytes/metabolism
6.
Digit Health ; 8: 20552076221110543, 2022.
Article in English | MEDLINE | ID: mdl-35910815

ABSTRACT

Background: To develop a highly discriminative machine learning model for the prediction of intensive care unit admission (>24h) using the easily available preoperative information from electronic health records. An accurate prediction model for ICU admission after surgery is of great importance for surgical risk assessment and appropriate utilization of ICU resources. Method: Data were collected retrospectively from a large hospital, comprising 135,442 adult patients who underwent surgery except for cardiac surgery between 1 January 2014, and 31 July 2018 in China. Multiple existing predictive machine learning algorithms were explored to construct the prediction model, including logistic regression, random forest, adaptive boosting, and gradient boosting machine. Four secondary analyses were conducted to improve the interpretability of the results. Results: A total of 2702 (2.0%) patients were admitted to the intensive care unit postoperatively. The gradient boosting machine model attained the highest area under the receiver operating characteristic curve of 0.90. The machine learning models predicted intensive care unit admission better than the American Society of Anesthesiologists Physical Status (area under the receiver operating characteristic curve: 0.68). The gradient boosting machine recognized several features as highly significant predictors for postoperatively intensive care unit admission. By applying subgroup analysis and secondary analysis, we found that patients with operations on the digestive, respiratory, and vascular systems had higher probabilities for intensive care unit admission. Conclusion: Compared with conventional American Society of Anesthesiologists Physical Status and logistic regression model, the gradient boosting machine could improve the performance in the prediction of intensive care unit admission. Machine learning models could be used to improve the discrimination and identify the need for intensive care unit admission after surgery in elective noncardiac surgical patients, which could help manage the surgical risk.

7.
Front Cell Infect Microbiol ; 12: 844498, 2022.
Article in English | MEDLINE | ID: mdl-35463640

ABSTRACT

Genetic modification provides an invaluable molecular tool to dissect the biology and pathogenesis of pathogens. However, no report is available about the genetic modification of Babesia duncani, a pathogen responsible for human babesiosis that is widespread in North America, suggesting the necessity to develop a genetic manipulation method to improve the strategies for studying and understanding the biology of protozoan pathogens. The establishment of a genetic modification method requires promoters, selectable markers, and reporter genes. Here, the double-copy gene elongation factor-1α (ef-1α) and its promoters were amplified by conventional PCR and confirmed by sequencing. We established a transient transfection system by using the ef-1αB promoter and the reporter gene mCherry and achieved stable transfection through homologous recombination to integrate the selection marker hDHFR-eGFP into the parasite genome. The potential of this genetic modification method was tested by knocking out the thioredoxin peroxidase-1 (TPX-1) gene, and under the drug pressure of 5 nM WR99210, 96.3% of the parasites were observed to express green fluorescence protein (eGFP) by flow cytometry at day 7 post-transfection. Additionally, the clone line of the TPX-1 knockout parasite was successfully obtained by the limiting dilution method. This study provided a transfection method for B. duncani, which may facilitate gene function research and vaccine development of B. duncani.


Subject(s)
Babesia , Babesiosis , Babesiosis/parasitology , Genes, Reporter , Green Fluorescent Proteins/genetics , Homologous Recombination , Humans , Transfection
8.
Respirology ; 27(8): 645-652, 2022 08.
Article in English | MEDLINE | ID: mdl-35297140

ABSTRACT

BACKGROUND AND OBJECTIVE: The pulmonary embolism severity index (PESI) and simplified PESI (sPESI) are recommended to recognize patients with acute pulmonary thromboembolism (PTE) with low prognosis risk, which is of great significance for treatment. This study aims to verify the influence of hypocalcaemia on the prognosis of patients with PTE and to establish a new prognosis assessment model. METHODS: This is an observational, multicentre study enrolling patients with PTE from February 2010 to June 2020 across 12 Chinese hospitals. Variables in PESI, serum calcium levels and patient survival status as of 5 July 2020 were collected. The area under the curve of the receiver operating characteristic curve, sensitivity, specificity and Youden index were used to evaluate model performance. RESULTS: In the cohort of 4196 patients with PTE, independent associations existed between hypocalcaemia and mid- and long-term mortalities (p <0.05). By including hypocalcaemia, the new 30-day death risk prediction rule, Peking Union Medical College Hospital rule (PUMCH rule), showed significantly higher specificity (0.622 [0.582, 0.661]; p <0.001) than the PESI (0.514 [0.473, 0.554]) and sPESI (0.484 [0.444, 0.525]) and similar sensitivity (0.963 [0.810, 0.999]; p = 0.161) with PESI (0.889 [0.708, 0.976]) and sPESI (0.963 [0.810, 0.999]) in the internal validation cohort. Well-performing predictive validity was also verified on a constructed external validation cohort. CONCLUSION: Hypocalcaemia is independently associated with mid- and long-term PTE mortalities. The PUMCH rule showed significantly higher specificity than the PESI and sPESI and similar sensitivity, which may be used as a prognostic assessment tool for patients with acute PTE.


Subject(s)
Hypocalcemia , Pulmonary Embolism , Acute Disease , Calcium , Humans , Hypocalcemia/complications , Hypocalcemia/diagnosis , Predictive Value of Tests , Prognosis , Pulmonary Embolism/complications , Risk Assessment , Severity of Illness Index
9.
Int Immunopharmacol ; 104: 108468, 2022 Mar.
Article in English | MEDLINE | ID: mdl-35066343

ABSTRACT

BACKGROUND: Previous studies have substantiated that M2-activated tumor-associated macrophages (M2-TAMs) are involved in multiple malignancies. Presently, we probe the impact and related mechanisms of 13-methyl-palmatrubine (13MP), the Corydalis yanhusuo extract, on M2-TAM-mediated non-small cell lung cancer (NSCLC) development. METHODS: IL-4 and IL-13 were adopted to induce M2-TAMs. The polarization state of TAMs was evaluated by quantitative reverse transcription PCR (qRT-PCR), Western blot (WB) and cellular immunofluorescence. NSCLC cells (A549 and NCL-H1975) were co-cultured with the conditioned medium (CM) of M2-TAMs. Followed by 13MP treatment, cell viability, proliferation, invasion, epithelial-mesenchymal transition (EMT), and in-vivo growth of NSCLC cells were determined. Additionally, human umbilical vein endothelial cells (HUVECs) were co-cultured with the CM of M2-TAMs. The tube formation assay was made to test the tube formation capacity of HUVECs, and the expression of MMP3, MMP9, and VEGF was assessed by WB in the co-culture model. Mechanistically, WB was performed to validate the expression of the PI3K/AKT and JAK/STAT3 pathways in NSCLC cells (A549 and NCL-H1975) as well as in endothelial cell lines co-cultured with M2-TAMs. RESULTS: 13MP inhibited the proliferation, invasion, EMT, growth and enhanced apoptosis of NSCLC cells. 13MP dose-dependently boosted the polarization of TAM from M2 to M1 state. M2-TAMs enhanced the malignant behaviors of NSCLC cells, whereas 13MP hindered M2-TAM-mediated NSCLC cell proliferation and invasion. Meanwhile, 13MP weakened the M2-TAM-mediated angiogenesis. Moreover, 13MP inactivated the PI3K/AKT and JAK/STAT3 signaling in A549 cells, NCL-H1975 cells and HUVECs. CONCLUSION: 13MP suppresses TAM-mediated NSCLC progression via transforming the polarization of TAM from M2 to M1.


Subject(s)
Antineoplastic Agents/therapeutic use , Berberine Alkaloids/therapeutic use , Carcinoma, Non-Small-Cell Lung/drug therapy , Lung Neoplasms/drug therapy , Animals , Antineoplastic Agents/pharmacology , Berberine Alkaloids/pharmacology , Carcinoma, Non-Small-Cell Lung/genetics , Carcinoma, Non-Small-Cell Lung/immunology , Carcinoma, Non-Small-Cell Lung/metabolism , Cell Line , Cell Movement/drug effects , Cell Proliferation/drug effects , Coculture Techniques , Cytokines/genetics , Epithelial-Mesenchymal Transition/drug effects , Humans , Lung Neoplasms/genetics , Lung Neoplasms/immunology , Lung Neoplasms/metabolism , Mice, Inbred BALB C , Mice, Nude , Tumor-Associated Macrophages/drug effects , Tumor-Associated Macrophages/immunology
10.
Zhong Nan Da Xue Xue Bao Yi Xue Ban ; 46(8): 920-924, 2021 Aug 28.
Article in English, Chinese | MEDLINE | ID: mdl-34565740

ABSTRACT

Pasteurella multocida empyema is rare and easy to be misdiagnosed. An 81-year-old male patient showed symptoms with cough, sputum, and fever for 3 days. Community-acquired pneumonia was diagnosed firstly. After anti-infection treatment, the patient was still in fever. Chest radiography showed pleural effusion, closed thoracic drainage was performed and the reddish-brown fluid was drained out. The second-generation sequencing was performed on pleural fluid and Pasteurella multocida was detected. Pasteurella multocida has strict requirements for growth conditions and it difficult to cultivate. The application of second-generation sequencing is helpful to diagnose the pathogen rapidly.


Subject(s)
Empyema , Pasteurella Infections , Pasteurella multocida , Pleural Effusion , Aged, 80 and over , Humans , Male , Pasteurella Infections/diagnosis , Pasteurella multocida/genetics , Sputum
11.
Pathol Res Pract ; 216(11): 153157, 2020 Nov.
Article in English | MEDLINE | ID: mdl-32858372

ABSTRACT

OBJECTIVE: This study aimed at probing into the effect of lncRNA NCK1-AS1 on proliferation, migration and invasion of non-small cell lung cancer (NSCLC) cells and its regulatory function on miR-512-5p/p21 molecular axis. METHODS: Quantitative real-time polymerase chain reaction (qRT-PCR) was used to assess the expressions of NCK1-AS1 and miR-512-5p in NSCLC tissues and cell lines. The alterations of cell proliferation, migration, invasion and cell cycle were examined by cell counting kit-8 (CCK-8) assay, BrdU experiment, Transwell experiment and flow cytometry, respectively. The dual-luciferase reporter assay and RNA immunoprecipitation experiment were performed to validate the binding relationships between miR-512-5p and NCK1-AS1, and miR-512-5p the 3'UTR of p21 mRNA. Western blot was used to determine the effects of NCK1-AS1 and miR-512-5p on p21 protein expression. RESULTS: NCK1-AS1 expression was up-regulated in NSCLC tissues and cells, and its high expression was correlated with shorter overall survival time and faster progression of patients. Overexpression of NCK1-AS1 promoted NSCLC cell proliferation, migration and invasion, and accelerated the cell cycle, whereas NCK1-AS1 siRNA inhibited these malignant biological behaviors, and arrested cell cycle. NCK1-AS1 could bind to miR-512-5p, p21 was verified as a target gene of miR-512-5p, and NCK1-AS1 could up-regulate the expression of p21 in NSCLC cells via repressing miR-512-5p expression. CONCLUSION: NCK1-AS1 promotes NSCLC progression by regulating miR-512-5p/p21 molecular axis.


Subject(s)
Adaptor Proteins, Signal Transducing/genetics , Carcinoma, Non-Small-Cell Lung/pathology , Lung Neoplasms/pathology , MicroRNAs/genetics , Oncogene Proteins/genetics , RNA, Antisense/genetics , RNA, Long Noncoding/genetics , Adult , Aged , Carcinoma, Non-Small-Cell Lung/genetics , Cell Movement/genetics , Cell Proliferation/genetics , Disease Progression , Female , Gene Expression Regulation, Neoplastic/genetics , Humans , Lung Neoplasms/genetics , Male , Middle Aged
12.
Comput Math Methods Med ; 2020: 1012796, 2020.
Article in English | MEDLINE | ID: mdl-32508973

ABSTRACT

OBJECTIVE: In order to find the quantitative relationship between timing of surgical intervention and risk of death in necrotizing pancreatitis. METHODS: The generalized additive model was applied to quantitate the relationship between surgical time (from the onset of acute pancreatitis to first surgical intervention) and risk of death adjusted for demographic characteristics, infection, organ failure, and important lab indicators extracted from the Electronic Medical Record of West China Hospital of Sichuan University. RESULTS: We analyzed 1,176 inpatients who had pancreatic drainage, pancreatic debridement, or pancreatectomy experience of 15,813 acute pancreatitis retrospectively. It showed that when surgical time was either modelled alone or adjusted for infection or organ failure, an L-shaped relationship between surgical time and risk of death was presented. When surgical time was within 32.60 days, the risk of death was greater than 50%. CONCLUSION: There is an L-shaped relationship between timing of surgical intervention and risk of death in necrotizing pancreatitis.


Subject(s)
Models, Anatomic , Pancreatitis, Acute Necrotizing/mortality , Pancreatitis, Acute Necrotizing/surgery , Adult , China/epidemiology , Computational Biology , Debridement , Drainage , Female , Humans , Infections/complications , Male , Middle Aged , Organ Dysfunction Scores , Pancreatectomy , Pancreatitis, Acute Necrotizing/complications , Retrospective Studies , Risk Factors , Time Factors
13.
Oncol Lett ; 18(6): 6759-6765, 2019 Dec.
Article in English | MEDLINE | ID: mdl-31807185

ABSTRACT

Previous studies have reported that microRNA-133a (miR-133a) is involved in the pathogenesis of human cancers. This study investigated the effect of miR-133a on cell proliferation in non-small cell lung cancer (NSCLC). The expression of miR-133a and YES proto-oncogene 1 (YES1) was detected using reverse transcription-quantitative polymerase chain reaction (RT-qPCR) assay. The CCK-8 assay was used to measure cell proliferation. The relationship between miR-133a and YES1 was confirmed by dual luciferase assay. Downregulation of miR-133a was identified in NSCLC and correlated with poor prognosis in NSCLC patients. Moreover, the overexpression of miR-133a inhibited proliferation of NSCLC cells. YES1 was also confirmed as a direct target of miR-133a. Downregulation of YES1 was found to inhibit cell proliferation in NSCLC. By contrast, the upregulation of YES1 abolished the inhibitory effect of miR-133a on cell proliferation in NSCLC. miR-133a inhibited cell proliferation in NSCLC by targeting YES1, indicating that miR-133a can be used as an indicator of prognosis in NSCLC patients.

14.
AAPS J ; 15(4): 1025-34, 2013 Oct.
Article in English | MEDLINE | ID: mdl-23861022

ABSTRACT

The hydration layer plays a key role in the controlled drug release of gel-forming matrix tablets. For poorly water-soluble drugs, matrix erosion is considered as the rate limiting step for drug release. However, few investigations have reported on the quantification of the relative importance of swelling and erosion in the release of poorly soluble drugs, and three-dimensional (3D) structures of the hydration layer are poorly understood. Here, we employed synchrotron radiation X-ray computed microtomography with 9-µm resolution to investigate the hydration dynamics and to quantify the relative importance of swelling and erosion on felodipine release by a statistical model. The 3D structures of the hydration layer were revealed by the reconstructed 3D rendering of tablets. Twenty-three structural parameters related to the volume, the surface area (SA), and the specific surface area (SSA) for the hydration layer and the tablet core were calculated. Three dominating parameters, including SA and SSA of the hydration layer (SA hydration layer and SSA hydration layer ) and SA of the glassy core (SA glassy core ), were identified to establish the statistical model. The significance order of independent variables was SA hydration layer > SSA hydration layer > SA glassy core , which quantitatively indicated that the release of felodipine was dominated by a combination of erosion and swelling. The 3D reconstruction and structural parameter calculation methods in our study, which are not available from conventional methods, are efficient tools to quantify the relative importance of swelling and erosion in the controlled release of poorly soluble drugs from a structural point of view.


Subject(s)
Chemistry, Pharmaceutical/methods , Felodipine/chemistry , Synchrotrons , Water/chemistry , X-Ray Microtomography/methods , Delayed-Action Preparations/analysis , Delayed-Action Preparations/chemistry , Felodipine/analysis , Solubility , Tablets
15.
Yao Xue Xue Bao ; 47(4): 529-34, 2012 Apr.
Article in Chinese | MEDLINE | ID: mdl-22799039

ABSTRACT

To optimize the preparation method of the complex of dihydroartemisinin (DHA) included by hydroxypropyl-beta-cyclodextrin (HP-beta-CD), the molar ratio of DHA and HP-beta-CD, inclusion temperature and inclusion time were optimized by the orthogonal design method with the inclusion drug yield and drug loading as the evaluation indexes. The IR spectrum, DSC and PXRD analyses were employed to characterize the complex and the molecular simulation was processed to investigate the tendency of complex formation. The optimized molar ratio of DHA and HP-beta-CD was 1 : 5, and the optimized preparation was performed under 50 degrees C for 1 h. The IR spectrum, DSC and PXRD analyses indicated the formation of the complex. The low binding free energy and the high solvent accessible surface obtained by molecular simulation showed that DHA could be included by HP-beta-CD and its solubility could be improved significantly. In conclusion, the optimized conditions for the preparation of DHA-HP-beta-CD complex provide a theoretical and experimental basis for further scale-up research.


Subject(s)
Artemisinins/chemistry , Drug Compounding/methods , beta-Cyclodextrins/chemistry , 2-Hydroxypropyl-beta-cyclodextrin , Artemisinins/administration & dosage , Calorimetry, Differential Scanning , Chromatography, High Pressure Liquid , Solubility , Spectroscopy, Fourier Transform Infrared , Surface Properties , Temperature , Time Factors , X-Ray Diffraction , beta-Cyclodextrins/administration & dosage
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