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Kuan EC, Wang EW, Adappa ND, Beswick DM, London NR, Su SY, Wang MB, Abuzeid WM, Alexiev B, Alt JA, Antognoni P, Alonso-Basanta M, Batra PS, Bhayani M, Bell D, Bernal-Sprekelsen M, Betz CS, Blay JY, Bleier BS, Bonilla-Velez J, Callejas C, Carrau RL, Casiano RR, Castelnuovo P, Chandra RK, Chatzinakis V, Chen SB, Chiu AG, Choby G, Chowdhury NI, Citardi MJ, Cohen MA, Dagan R, Dalfino G, Dallan I, Dassi CS, de Almeida J, Dei Tos AP, DelGaudio JM, Ebert CS, El-Sayed IH, Eloy JA, Evans JJ, Fang CH, Farrell NF, Ferrari M, Fischbein N, Folbe A, Fokkens WJ, Fox MG, Lund VJ, Gallia GL, Gardner PA, Geltzeiler M, Georgalas C, Getz AE, Govindaraj S, Gray ST, Grayson JW, Gross BA, Grube JG, Guo R, Ha PK, Halderman AA, Hanna EY, Harvey RJ, Hernandez SC, Holtzman AL, Hopkins C, Huang Z, Huang Z, Humphreys IM, Hwang PH, Iloreta AM, Ishii M, Ivan ME, Jafari A, Kennedy DW, Khan M, Kimple AJ, Kingdom TT, Knisely A, Kuo YJ, Lal D, Lamarre ED, Lan MY, Le H, Lechner M, Lee NY, Lee JK, Lee VH, Levine CG, Lin JC, Lin DT, Lobo BC, Locke T, Luong AU, Magliocca KR, Markovic SN, Matnjani G, McKean EL, Meço C, Mendenhall WM, Michel L, Na'ara S, Nicolai P, Nuss DW, Nyquist GG, Oakley GM, Omura K, Orlandi RR, Otori N, Papagiannopoulos P, Patel ZM, Pfister DG, Phan J, Psaltis AJ, Rabinowitz MR, Ramanathan M, Rimmer R, Rosen MR, Sanusi O, Sargi ZB, Schafhausen P, Schlosser RJ, Sedaghat AR, Senior BA, Shrivastava R, Sindwani R, Smith TL, Smith KA, Snyderman CH, Solares CA, Sreenath SB, Stamm A, Stölzel K, Sumer B, Surda P, Tajudeen BA, Thompson LDR, Thorp BD, Tong CCL, Tsang RK, Turner JH, Turri-Zanoni M, Udager AM, van Zele T, VanKoevering K, Welch KC, Wise SK, Witterick IJ, Won TB, Wong SN, Woodworth BA, Wormald PJ, Yao WC, Yeh CF, Zhou B, Palmer JN. International Consensus Statement on Allergy and Rhinology: Sinonasal Tumors. Int Forum Allergy Rhinol 2024; 14:149-608. [PMID: 37658764 DOI: 10.1002/alr.23262] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Accepted: 08/24/2023] [Indexed: 09/05/2023]
Abstract
BACKGROUND Sinonasal neoplasms, whether benign and malignant, pose a significant challenge to clinicians and represent a model area for multidisciplinary collaboration in order to optimize patient care. The International Consensus Statement on Allergy and Rhinology: Sinonasal Tumors (ICSNT) aims to summarize the best available evidence and presents 48 thematic and histopathology-based topics spanning the field. METHODS In accordance with prior International Consensus Statement on Allergy and Rhinology documents, ICSNT assigned each topic as an Evidence-Based Review with Recommendations, Evidence-Based Review, and Literature Review based on the level of evidence. An international group of multidisciplinary author teams were assembled for the topic reviews using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses format, and completed sections underwent a thorough and iterative consensus-building process. The final document underwent rigorous synthesis and review prior to publication. RESULTS The ICSNT document consists of four major sections: general principles, benign neoplasms and lesions, malignant neoplasms, and quality of life and surveillance. It covers 48 conceptual and/or histopathology-based topics relevant to sinonasal neoplasms and masses. Topics with a high level of evidence provided specific recommendations, while other areas summarized the current state of evidence. A final section highlights research opportunities and future directions, contributing to advancing knowledge and community intervention. CONCLUSION As an embodiment of the multidisciplinary and collaborative model of care in sinonasal neoplasms and masses, ICSNT was designed as a comprehensive, international, and multidisciplinary collaborative endeavor. Its primary objective is to summarize the existing evidence in the field of sinonasal neoplasms and masses.
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Lam TC, Tsang KC, Choi HC, Lee VH, Lam KO, Chiang CL, So TH, Chan WW, Nyaw SF, Lim F, Lau JO, Chik J, Kong FM, Lee AW. Combination atezolizumab, bevacizumab, pemetrexed and carboplatin for metastatic EGFR mutated NSCLC after TKI failure. Lung Cancer 2021; 159:18-26. [PMID: 34303276 DOI: 10.1016/j.lungcan.2021.07.004] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 06/27/2021] [Accepted: 07/01/2021] [Indexed: 12/12/2022]
Abstract
INTRODUCTION Acquired resistance to TKI is an important unmet need in the management of EGFR mutated lung cancer. Recent clinical trial IMPower150 suggested that combination approach with VEGF inhibitor, check point inhibitor immunotherapy and platinum-based chemotherapy was effective in oncogene driven lung cancer. The current trial examined the efficacy of a modified regimen in an EGFR mutated cohort. METHODS An open-labelled, single arm, phase II study was conducted in patients with EGFR mutated NSCLC who had progressed on at least one EGFR TKI. For those with T790M mutation, radiological progression on osimertinib was required for enrolment. Patients were treated with combination atezolizumab (1200 mg), bevacizumab (7.5 mg/kg), pemetrexed (500 mg/m2) and carboplatin (AUC 5) given once every 3 weeks until progression. RESULTS Forty patients were enrolled. Median age was 62 (range 45-76) years. More than one half (23/40, 57.5%) had progressed on osimertinib. PD-L1 expression was < 1% in 52.5%. Median follow-up time was 17.8 months. ORR was 62.5%. Median PFS was 9.4 months (95% CI: 7.6 - 12.1). One year OS was 72.5% (95% CI: 0.56-0.83). Treatment related grade 3 or above adverse events (AE) occurred in 37.5% (15/40). Immune-related AE occurred in 32.5% (13/40) patients. Quality of life measures of function and symptoms did not change significantly throughout the course of treatments. Post-trial rechallenge with EGFR TKI containing regimen resulted in PFS of 5.8 months (95% CI 3.9-10.0 months). CONCLUSION Combination approach of atezolizumab, bevacizumab, pemetrexed and carboplatin achieved promising efficacy in metastatic EGFR mutated NSCLC after TKI failure. The results were comparable with taxane based regimen of IMPower150 while toxicity profile was improved.
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Du R, Lee VH, Yuan H, Lam KO, Pang HH, Chen Y, Lam EY, Khong PL, Lee AW, Kwong DL, Vardhanabhuti V. Radiomics Model to Predict Early Progression of Nonmetastatic Nasopharyngeal Carcinoma after Intensity Modulation Radiation Therapy: A Multicenter Study. Radiol Artif Intell 2019; 1:e180075. [PMID: 33937796 DOI: 10.1148/ryai.2019180075] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Revised: 04/04/2019] [Accepted: 05/07/2019] [Indexed: 12/23/2022]
Abstract
Purpose To examine the prognostic value of a machine learning model trained with pretreatment MRI radiomic features in the assessment of patients with nonmetastatic nasopharyngeal carcinoma (NPC) who are at risk for 3-year disease progression after intensity-modulated radiation therapy and to explain the radiomics features in the model. Materials and Methods A total of 277 patients with nonmetastatic NPC admitted between March 2008 and December 2014 at two imaging centers were retrospectively reviewed. Patients were allocated to a discovery or validation cohort based on where they underwent MRI (discovery cohort, n = 217; validation cohort, n = 60). A total of 525 radiomics features extracted from contrast material-enhanced T1- or T2-weighted MRI studies and five clinical features were subjected to radiomic machine learning modeling to predict 3-year disease progression. Feature selection was performed by analyzing robustness to resampling, reproducibility between observers, and redundancy. Features for the final model were selected with Kaplan-Meier analysis and the log-rank test. A support vector machine was used as the classifier for the model. To interpret the pattern learned from the model, Shapley additive explanations (SHAP) was applied. Results The final model yielded an area under the receiver operating characteristic curve of 0.80 in both the discovery (95% bootstrap confidence interval: 0.80, 0.81) and independent validation (95% bootstrap confidence interval: 0.73, 0.89) cohorts. Analysis with SHAP revealed that tumor shape sphericity, first-order mean absolute deviation, T stage, and overall stage were important factors in 3-year disease progression. Conclusion These results add to the growing evidence of the role of radiomics in the assessment of NPC. By using explanatory techniques, such as SHAP, the complex interaction of features learned by the model may be understood.© RSNA, 2019Supplemental material is available for this article.
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Lee VH, Lam KO, Chang AT, Lam TC, Chiang CL, So TH, Choi CW, Lee AW. Management of Nasopharyngeal Carcinoma: Is Adjuvant Therapy Needed? J Oncol Pract 2018; 14:594-602. [PMID: 30312564 DOI: 10.1200/jop.18.00219] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Nasopharyngeal carcinoma of the undifferentiated histologic subtype is endemic and prevalent in southeast Asia. The dramatic improvement of treatment outcomes and overall prognosis during the past few decades has been attributed to advances in disease screening and diagnosis, diagnostic imaging, radiotherapy techniques, use of combination systemic therapy, and dedicated clinical and biomarker surveillance. The current practice of treating patients with advanced locoregional disease using cisplatin concurrent with conventional fractionated radiotherapy, followed by adjuvant cisplatin and fluorouracil, was established in 1998 when the landmark Intergroup-0099 Study demonstrated a survival benefit with the addition of systemic therapy. There is little doubt regarding the need for concurrent chemotherapy, but there has been uncertainty about the magnitude of the benefit attributed to the adjuvant phase. Furthermore, instead of one-size-fits-all recommendations, it will be ideal if we can tailor adjuvant therapy to high-risk patients only to avoid unnecessary toxicities. In addition, recent evidence suggests that induction chemotherapy before concurrent chemoradiation can achieve better outcomes, especially in distant control, even in the modern era of intensity-modulated radiation therapy. This article provides a comprehensive review of key literature on the current management of locoregionally advanced nasopharyngeal carcinoma and highlights future research directions to unravel these controversies.
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Abstract
Neurocardiology refers to the interplay between the nervous system and the cardiovascular system. Stress-related cardiomyopathy exemplifies the brain-heart connection and occurs in several conditions with acute brain injury that share oversympathetic activation. The brain's influences on the heart can include elevated cardiac markers, arrhythmias, repolarization abnormalities on electrocardiogram, myocardial necrosis, and autonomic dysfunction. The neurogenic stunned myocardium in aneurysmal subarachnoid hemorrhage represents one end of the spectrum, and is associated with an explosive rise in intracranial pressure that results in excess catecholamine state and possibly CBN. A brain-heart link is more known to cardiologists than neurologists. This chapter provides some insight into the pathophysiology of these pathologic neurocardiac states and their most appropriate management relevant to neurologists.
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Prabhakaran S, Soltanolkotabi M, Honarmand AR, Bernstein RA, Lee VH, Conners JJ, Dehkordi-Vakil F, Shaibani A, Hurley MC, Ansari SA. Perfusion-based selection for endovascular reperfusion therapy in anterior circulation acute ischemic stroke. AJNR Am J Neuroradiol 2014; 35:1303-8. [PMID: 24675999 DOI: 10.3174/ajnr.a3889] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Controversy exists about the role of perfusion imaging in patient selection for endovascular reperfusion therapy in acute ischemic stroke. We hypothesized that perfusion imaging versus noncontrast CT- based selection would be associated with improved functional outcomes at 3 months. MATERIALS AND METHODS We reviewed consecutive patients with anterior circulation strokes treated with endovascular reperfusion therapy within 8 hours and with baseline NIHSS score of ≥8. Baseline clinical data, selection mode (perfusion versus NCCT), angiographic data, complications, and modified Rankin Scale score at 3 months were collected. Using multivariable logistic regression, we assessed whether the mode of selection for endovascular reperfusion therapy (perfusion-based versus NCCT-based) was independently associated with good outcome. RESULTS Two-hundred fourteen patients (mean age, 67.2 years; median NIHSS score, 18; MCA occlusion 74% and ICA occlusion 26%) were included. Perfusion imaging was used in 76 (35.5%) patients (39 CT and 37 MR imaging). Perfusion imaging-selected patients were more likely to have good outcomes compared with NCCT-selected patients (55.3 versus 33.3%, P = .002); perfusion selection by CT was associated with similar outcomes as that by MR imaging (CTP, 56.; MR perfusion, 54.1%; P = .836). In multivariable analysis, CT or MR perfusion imaging selection remained strongly associated with good outcome (adjusted OR, 2.34; 95% CI, 1.22-4.47), independent of baseline severity and reperfusion. CONCLUSIONS In this multicenter study, patients with acute ischemic stroke who underwent perfusion imaging were more than 2-fold more likely to have good outcomes following endovascular reperfusion therapy. Randomized studies should compare perfusion imaging with NCCT imaging for patient selection for endovascular reperfusion therapy.
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Ng SC, Lee VH, Law MW, Liu RK, Ma VW, Tso WK, Leung TW. Patient dosimetry for 90Y selective internal radiation treatment based on 90Y PET imaging. J Appl Clin Med Phys 2013; 14:212-21. [PMID: 24036875 PMCID: PMC5714565 DOI: 10.1120/jacmp.v14i5.4371] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2013] [Revised: 03/11/2013] [Accepted: 03/20/2013] [Indexed: 11/23/2022] Open
Abstract
Until recently, the radiation dose to patients undergoing the 90Y selective internal radiation treatment (SIRT) procedure is determined by applying the partition model to 99mTc MAA pretreatment scan. There can be great uncertainty in radiation dose calculated from this approach and we presented a method to compute the 3D dose distributions resulting from 90Y SIRT based on 90Y positron emission tomography (PET) imaging. Five 90Y SIRT treatments were retrospectively analyzed. After 90Y SIRT, patients had 90Y PET/CT imaging within 6 hours of the procedure. To obtain the 3D dose distribution of the patients, their respective 90Y PET images were convolved with a Monte Carlo generated voxel dose kernel. The sensitivity of the PET/CT scanner for 90Y was determined through phantom studies. The 3D dose distributions were then presented in DICOM RT dose format. By applying the linear quadratic model to the dose data, we derived the biologically effective dose and dose equivalent to 2 Gy/fraction delivery, taking into account the spatial and temporal dose rate variations specific for SIRT. Based on this data, we intend to infer tumor control probability and risk of radiation induced liver injury from SIRT by comparison with established dose limits. For the five cases, the mean dose to target ranged from 51.7 ± 28.6 Gy to 163 ± 53.7 Gy. Due to the inhomogeneous nature of the dose distribution, the GTVs were not covered adequately, leading to very low values of tumor control probability. The mean dose to the normal liver ranged from 21.4 ± 30.7 to 36.7 ± 25.9 Gy. According to QUANTEC recommendation, a patient with primary liver cancer and a patient with metastatic liver cancer has more than 5% risk of radiotherapy-induced liver disease (RILD).
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Prabhakaran S, Wells KR, Lee VH, Flaherty CA, Lopes DK. Prevalence and risk factors for aspirin and clopidogrel resistance in cerebrovascular stenting. AJNR Am J Neuroradiol 2007; 29:281-5. [PMID: 17989373 DOI: 10.3174/ajnr.a0818] [Citation(s) in RCA: 103] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE The prevalence of antiplatelet drug resistance among patients who undergo cerebrovascular stent placement is unknown. We aimed to assess the feasibility of monitoring antiplatelet drug effects in a single-center cohort undergoing cerebrovascular stent placement. MATERIALS AND METHODS We prospectively collected medical, laboratory, and radiographic data on patients who underwent cerebrovascular stent placement. We used the rapid platelet function assay-aspirin (RPFA-ASA) to calculate aspirin reaction units (ARU) and the P2Y12 assay to calculate P2Y12 reaction units and percentage platelet inhibition. Aspirin resistance was defined as ARU > 550, whereas clopidogrel resistance was defined as percentage platelet inhibition < 40%. RESULTS Among 76 patients, stent indications were the following: wide-neck aneurysm (57, 75.0%), symptomatic intracranial stenosis (12, 15.7%), carotid stenosis (5, 6.6%), and vertebral stenosis (2, 2.6%). For aspirin, the median dosage per week was 1300 mg and median ARU was 410. Among 71 patients on aspirin, 3 patients (4.2%) were resistant; there was a significant inverse correlation between aspirin dose and ARU (r = -0.31, P = .01). Among 55 patients on clopidogrel, the median dosage per week was 525 mg with a mean platelet inhibition of 43.2%. Twenty-eight patients (51.9%) were clopidogrel-resistant. In a multivariable linear regression model, age older than 55 years (b = -16.3, P = .020) and diabetes (b = -26.8, P = .015) were inversely related to percentage platelet inhibition. CONCLUSIONS Using point-of-care tests, we found that aspirin resistance is relatively uncommon, whereas clopidogrel resistance occurred in half of patients undergoing cerebrovascular stent placement. Further studies should focus on ideal doses, timing, and duration of antiplatelet therapy for cerebrovascular stent placement.
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Wickliffe JK, Lee VH, Smith E, Tandler B, Phillips CJ. Gene expression, cell localization, and evolution of rodent submandibular gland androgen-binding protein. ACTA ACUST UNITED AC 2004; 40:257-60. [PMID: 14566605 DOI: 10.1076/ejom.40.4.257.16692] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
A small dimeric androgen-binding protein (Abp) secreted by mouse (Mus) submandibular salivary glands has been hypothesized to function in mate-selection. The alpha-subunit (Abpa) evolves rapidly under natural selection. However, cellular site(s) of synthesis, mode of function, and patterns of evolution of this biologically important protein are otherwise unknown. We used a radiolabeled riboprobe and in situ hybridization to mouse (Mus) Abpa mRNA to localize Abpa synthesis to submandibular gland acinar cells. We next used a quantitative fluorescent thermal cycler (real-time PCR) to determine relative expression levels (normalized with a constitutively expressed ribosomal gene [S15/rig; rat insulinoma gene]) in male, female, and sexually immature European striped field mice (Apodemus agrarius). We hypothesized that gender or age-related differences might occur in production of a salivary protein related to sexual selection, but found no significant differences within our sample. Finally, we also used reverse transcription-PCR of mRNAs isolated from submandibular salivary glands to determine the Abpa allele in the striped wood mouse and compare it to published information on the homologue in Mus musculus domesticus.
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Abstract
This review focuses on epithelial drug transport mechanisms in mucosal drug delivery: the final step of a four-part process. Reference is made to the mucosae lining the oral cavity and the gastrointestinal tract, the two mucosae most often succumbing to the side effects of cytotoxic chemotherapeutic drugs. This review will be devoted to carrier-mediated transport, particularly as it relates to the intestinal dipeptide transporter PepT1. This transporter protein appears to be enriched in tumor epithelial cells, to be rather robust to the cytotoxic effects of chemotherapeutic drugs, and to lend itself to the molecular engineering of drugs that target this transporter in tumor epithelial cells. In contrast to the gastrointestinal tract, much less is known about the type and capacity of drug transport processes in the buccal epithelial cells and about how these processes may be altered in disease state (including cancer) and be manipulated pharmaceutically to optimize drug absorption.
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Lee VH, Sporty JL, Fandy TE. Pharmacogenomics of drug transporters: the next drug delivery challenge. Adv Drug Deliv Rev 2001; 50 Suppl 1:S33-40. [PMID: 11576694 DOI: 10.1016/s0169-409x(01)00186-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Scientifically, the third millennium begins with a major triumph--the publishing of the human genomic map, which is destined to have a momentous impact on the quality of life in our time. Disease prevention, individualized medicine, and genotyped-based medicine will soon become a reality. Pharmacogenetics, the forerunner of pharmacogenomics, began in the 1950s with a series of observations relating drug response to various genetic factors. It took almost two more decades for scientists to discover that cytochrome p450 2D6 was responsible for the metabolism of many drugs. This landmark discovery helped focus attention on how gene expression could impact the response to drugs. The stage was set for a revolution in therapeutics some 30 years later as the Human Genome Project crossed the finishing line triumphantly. A parallel development in drug delivery that may also benefit from the fruits of the Human Genome Project is the growing acceptance/awareness of drug transporters as a gateway to epithelial drug transport. This presentation addresses an area in need of attention: the possible impact of genetic polymorphism of drug transporters in pharmacokinetics and the challenge it poses in drug delivery.
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Melton CM, Zaunbrecher GM, Yoshizaki G, Patiño R, Whisnant S, Rendon A, Lee VH. Expression of connexin 43 mRNA and protein in developing follicles of prepubertal porcine ovaries. Comp Biochem Physiol B Biochem Mol Biol 2001; 130:43-55. [PMID: 11470443 DOI: 10.1016/s1096-4959(01)00403-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
A major form of cell-cell communication is mediated by gap junctions, aggregations of intercellular channels composed of connexins (Cxs), which are responsible for exchange of low molecular weight (<1200 Da) cytosolic materials. These channels are a growing family of related proteins. This study was designed to determine the ontogeny of connexin 43 (Cx43) during early stages of follicular development in prepubertal porcine ovaries. A partial-length (412 base) cDNA clone was obtained from mature porcine ovaries and determined to have 98% identity with published porcine Cx43. Northern blot analysis demonstrated a 4.3-kb mRNA in total RNA isolated from prepubertal and adult porcine ovaries. In-situ hybridization revealed that Cx43 mRNA was detectable in granulosa cells of primary follicles but undetectable in dormant primordial follicles. The intensity of the signal increased with follicular growth and was greatest in the large antral follicles. Immunohistochemical evaluation indicated that Cx43 protein expression correlated with the presence of Cx43 mRNA. These results indicate that substantial amounts of Cx43 are first expressed in granulosa cells following activation of follicular development and that this expression increases throughout follicular growth and maturation. These findings suggest an association between the enhancement of intercellular gap-junctional communication and onset of follicular growth.
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Kompella UB, Lee VH. Delivery systems for penetration enhancement of peptide and protein drugs: design considerations. Adv Drug Deliv Rev 2001; 46:211-45. [PMID: 11259842 DOI: 10.1016/s0169-409x(00)00137-x] [Citation(s) in RCA: 86] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
This paper discusses the challenges to be met in designing delivery systems that maximize the absorption of peptide and protein drugs from the gastrointestinal and respiratory tracts. The ideal delivery system for either route of administration is one that will release its contents only at a favorable region of absorption, where the delivery system attaches by virtue of specific interaction with surface determinants unique to that region and where the delivery system travels at a rate independent of the transitory constraints inherent of the route of administration. Such a delivery system, which is as yet unavailable, will benefit not only peptide and protein drugs, but other poorly absorbed drugs.
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Donahue LM, Coates PW, Lee VH, Ippensen DC, Arze SE, Poduslo SE. The cardiac sodium channel mRNA is expressed in the developing and adult rat and human brain. Brain Res 2000; 887:335-43. [PMID: 11134623 DOI: 10.1016/s0006-8993(00)03033-x] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Expression of the rat (RH-I/SkM2) and human (hH1/SCN5A) tetrodotoxin-resistant (TTX-R), voltage-sensitive sodium channels is thought to be specific to cardiac tissue. We detected RH-I/SkM2 mRNA in newborn rat brain using both RNase protection assay analysis and in situ hybridization and in adult rat brain using RNase protection assay analysis. This expression was observed primarily in developing limbic structures of the cerebrum and diencephalon, and in the medulla of the brain stem. Using RT-PCR analysis, we detected hH1/SCN5A mRNA in both fetal and adult human brain. Interestingly, mutations in the human cardiac sodium channel are known to lead to cardiac abnormalities, which result in arrhythmias and frequently in sudden cardiac death. If these mutant channels were also expressed in limbic regions of the brain, alterations in channel function could have drastic effects on the brain's signaling ability, possibly promoting seizure activity.
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Chang X, Patiño R, Yoshizaki G, Thomas P, Lee VH. Hormonal regulation and cellular distribution of connexin 32.2 and connexin 32.7 RNAs in the ovary of Atlantic croaker. Gen Comp Endocrinol 2000; 120:146-56. [PMID: 11078626 DOI: 10.1006/gcen.2000.7549] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The in vitro effects of human chorionic gonadotropin (hCG) on ovarian connexin (Cx) 32.2 and 32.7 RNA levels and ovarian follicle maturation were assessed, and the cellular distribution of Cx transcripts in the ovary was determined. hCG caused a concentration-dependent induction of Cx32.2 RNA, which peaked coincidentally with the appearance of morphological indices of oocyte maturational competence (OMC). Cx32.2 RNA levels declined thereafter in all treatment groups, although this decline was not accompanied by the onset of germinal vesicle breakdown (GVBD) at the lowest hCG concentration used. The levels of Cx32.7 RNA initially declined and subsequently increased to preincubation values after hCG treatment, but these changes were not dependent on hCG concentration. In a separate experiment, the decline in Cx32.7 RNA occurred in the presence or absence of hCG and was prevented by low (physiological) concentrations of estradiol-17beta (E2) or by protein kinase C (PKC) inhibitor, but was enhanced in the presence of high E2 concentrations or of PKC activator. These changes in Cx32. 7 RNA abundance were not associated with any indices of oocyte maturation. In situ hybridization of tissue sections showed the presence of Cx32.2 and Cx32.7 RNA in somatic cells of the ovarian follicle but not in oocytes. Cx32.2 RNA seemed to be present in granulosa and thecal cells, but the assay resolution was insufficient to reliably determine the distribution of Cx32.7 transcript by somatic cell type. In view of earlier findings that Cx32.2-based (but not Cx32.7-based) connexons can form functional homotypic channels, these results indicate that Cx32.2 gene expression in granulosa cells is sufficient for the formation of homologous gap junctions (GJ). Northern blot of RNA extracts from ovulated eggs, which are free of follicle cells, showed the presence of relatively low levels of both Cx RNAs. Thus, it is possible that Cx32.2 is present in oocytes and that it participates in heterologous (homotypic) GJ formation between the oocyte and the granulosa cells. In conclusion, Cx32.2 RNA levels in somatic cells of the ovarian follicle correlated positively with morphological indices of OMC acquisition, but subsequently declined during GVBD. These changes in Cx32.2 RNA may function in the regulation of GJ contacts during follicular maturation.
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Abstract
Carrier-mediated drug transport is relatively unexplored in comparison with passive transcellular and paracellular drug transport. Yet, there is a host of transporter proteins that can be targeted for improving epithelial drug absorption. Generally, these are transport mechanisms for amino acids, dipeptides, monosaccharides, monocarboxylic acids, organic cations, phosphates, nucleosides, and water-soluble vitamins. Among them, the dipeptide transporter mechanism has received the most attention. Dipeptide transporters are H(+)-coupled, energy-dependent transporters that are known to play an essential role in the oral absorption of beta-lactam antibiotics, angiotensin-converting enzyme (ACE) inhibitors, renin inhibitors, and an anti-tumor drug, bestatin. Moreover, several investigators have demonstrated the utility of the dipeptide transporter as a platform for improving the oral bioavailability of drugs such as zidovudine and acyclovir through dipeptide prodrug derivatization. Thus far, at least four proton-coupled peptide transporters have been cloned. The first one cloned was PepT1 from the rabbit small intestine. The focus of this presentation will be structure-function, intracellular trafficking, and regulation of PepT1. Disease, dietary, and possible excipient influences on PepT1 function will also be discussed.
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Lee VH. Expression of rabbit zona pellucida-1 messenger ribonucleic acid during early follicular development. Biol Reprod 2000; 63:401-8. [PMID: 10906043 DOI: 10.1095/biolreprod63.2.401] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
Progress in research on initiation of folliculogenesis has progressed slowly because of a lack of markers for early folliculogenesis. The rabbit zona pellucida protein (ZP1) is synthesized in follicles during early stages of folliculogenesis. In order to establish ZP1 as a marker for initiation of folliculogenesis, in situ hybridization was used to localize ZP1 mRNA in immature follicles. ZP1 mRNA was first detected in oocytes of some but not all primordial follicles. The primordial follicles expressing ZP1 mRNA were located at the cortico-medullary junction, indicating that they were newly activated follicles. ZP1 mRNA accumulated in oocytes of intermediate, primary, and secondary follicles. In contrast, ZP1 mRNA was first detectable in granulosa cells of intermediate follicles and is present in cuboidal granulosa cells of primary and early secondary follicles, but was undetectable in granulosa cells of more mature follicles. These data demonstrate that 1) ZP1 mRNA is expressed in both oocytes and granulosa cells, 2) ZP1 mRNA is initially expressed in oocytes of activated follicles, and 3) ZP1 mRNA is transiently expressed in granulosa cells during early stages of folliculogenesis. Therefore, rabbit ZP1 is a molecular marker that can be used in future studies to measure initiation of folliculogenesis.
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Rendon A, Hewetson A, Chilton BS, Lee VH. Expression of RUSH transcription factors in developing and adult rabbit gonads. Biol Reprod 2000; 63:156-64. [PMID: 10859255 DOI: 10.1095/biolreprod63.1.156] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
The RUSH transcription factors 1alpha and 1beta bind to the Rabbit Uteroglobin promoter and are members of the SWI/SNF complex that facilitates transcription by remodeling chromatin (Helicase). To characterize gonadal expression of RUSH, a cRNA probe that recognizes both isoforms was used for in situ hybridization studies. We found RUSH mRNA to be abundant in Sertoli cells from embryonic, neonatal, prepubertal, and pubertal rabbit testes. In adults, RUSH mRNA was detected in tubules with preleptotene spermatocytes and mature spermatids lining the lumen. However, RUSH was undetectable in tubules that contained leptotene spermatocytes and that lacked mature spermatids. In females, RUSH was expressed in presumptive granulosa cells of embryonic and neonatal ovaries before follicle organization. Abundant RUSH mRNA was detected in granulosa and theca cells surrounding preantral follicles of prepubertal and adult ovaries. Expression of RUSH remained high in granulosa cells of antral follicles in mature ovaries but was negligible in late-stage atretic follicles and in corpora lutea. Western blot analysis confirmed the RUSH-1alpha isoform predominated in both testicular and ovarian tissues. The expression pattern of RUSH indicates transcriptional activity in Sertoli cells and during multiple stages of differentiating granulosa cells, especially those of primordial follicles, which heretofore were considered to be dormant.
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Chang JE, Basu SK, Lee VH. Air-interface condition promotes the formation of tight corneal epithelial cell layers for drug transport studies. Pharm Res 2000; 17:670-6. [PMID: 10955839 DOI: 10.1023/a:1007569929765] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
PURPOSE To identify the growth conditions that would favor the development of a functional primary culture of pigmented rabbit corneal epithelial cells on a permeable support comparable to the intact tissue in bioelectric properties. METHODS Rabbit corneal epithelial cells were isolated and cultured on precoated fibronectin/collagen/laminin permeable filters. Cells were grown at an air-interface with supplemented DMEM/F12 medium. Immunofluorescence and electron microscopy techniques, respectively, were used to confirm cornea-specific marker and morphological features. Permeability of the cell layers to model polar compounds was evaluated using 14C-mannitol, fluorescein isothiocyanate (FITC) and fluorescein isothiocyanate-dextran of 4,000 molecular weight (FD4). RESULTS We found that culturing the epithelial cells at an air-interface (AIC) was a critical factor in the formation of tight cell layer and that omitting fetal bovine serum and keeping the concentration of epidermal growth factor at 1 ng/ml were equally important. Phenotypically, the AIC cell layers were found to express cornea-specific 64 kD keratin. Compared with cells cultured under the liquid-covered (LCC) condition, those cultured under AIC exhibited a significantly higher peak transepithelial electrical resistance (TEER) of up to 5 kOhm x cm2, a higher potential difference (PD) of up to 26 mV, and an estimated short-circuit current (Ieq) of 5 microA/cm2 after 7-8 days of culture. These values were comparable to those in the excised cornea. Consistent with the TEER, the AIC cell layers were 4-40 times less permeable to paracellular markers than their LCC counterpart. CONCLUSIONS The AIC model merits further characterization of drug transport mechanisms as well as drug, formulation, physiological, and pathological factors influencing corneal epithelial drug transport.
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Shiue MH, Kulkarni AA, Gukasyan HJ, Swisher JB, Kim KJ, Lee VH. Pharmacological modulation of fluid secretion in the pigmented rabbit conjunctiva. Life Sci 2000; 66:PL105-11. [PMID: 10794521 DOI: 10.1016/s0024-3205(99)00638-4] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
We determined net fluid secretion rate across the pigmented rabbit conjunctiva in the presence and absence of pharmacological agents known to affect active Cl- secretion and Na+ absorption. Fluid flow across a freshly excised pigmented rabbit conjunctiva mounted between two Lucite half chambers was measured by a pair of capacitance probes in an enclosed cabinet maintained at 37 degrees C and a relative humidity of 70%. Fluid transport was also measured in the presence of compounds known to affect active Cl- secretion (cAMP, UTP, and ouabain), Na+ absorption (D-glucose), or under the Cl--free condition on both sides of the tissue. Net fluid secretion rate across the pigmented rabbit conjunctiva in the serosal-to-mucosal direction at baseline was 4.3+/-0.2 microl/hr/cm2 (mean +/- s.e.m.). Net fluid secretion rate was increased approximately two-fold by mucosally applied 1 mM 8-Br cAMP (8.4+/-0.4 microl/hr/cm2) and 10 microM UTP (9.8+/-0.6 microl/hr/cm2), but was abolished by either serosally applied 0.5 mM ouabain (0.3+/-0.1 microl/hr/cm2) or under the Cl--free conditions (0.06+/-0.04 microl/hr/cm2). Mucosal addition of 20 mM D-glucose decreased net fluid secretion rate to 1.0+/-0.5 microl/hr/cm2. In conclusion, the pigmented rabbit conjunctiva appears to secrete fluid secondary to active Cl- secretion. This net fluid secretion is subject to modulation by changes in active Cl- secretion rate and in mucosal fluid composition such as glucose concentration.
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Matsukawa Y, Yamahara H, Yamashita F, Lee VH, Crandall ED, Kim KJ. Rates of protein transport across rat alveolar epithelial cell monolayers. J Drug Target 2000; 7:335-42. [PMID: 10721795 DOI: 10.3109/10611869909085516] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The transport of model proteins, ranging from 12,300 to 150,000 Da, across tight rat alveolar epithelial cell monolayers (> 2000omegacm2) grown on polycarbonate filters, was studied. Model proteins were 14C-cytochrome c, 14C-ovalbumin, granulocyte-colony stimulating factor (G-CSF), 14C-bovine serum albumin (BSA), 125I-transferrin, and 14C-immunoglobulin G. Cytochrome c was extensively metabolized, as indicated by < 10% of the dose being translocated in intact form. This contrasts with 20-80% for the other model proteins studied. The flux of cytochrome c and G-CSF was symmetric in the apical-to-basolateral (ab) and basolateral-to-apical (ba) directions. By contrast, the flux of intact ovalbumin, BSA, transferrin and immunoglobulin G showed asymmetry, with the ab flux being higher by 2-5 times. There was no relationship between ab or ba fluxes and the molecular weights of these four model proteins. Since some of the proteins were translocated at much greater rates than are consistent with restricted diffusion or pinocytosis, receptor-mediated or adsorptive transcytosis may be involved.
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Yang JJ, Kim KJ, Lee VH. Role of P-glycoprotein in restricting propranolol transport in cultured rabbit conjunctival epithelial cell layers. Pharm Res 2000; 17:533-8. [PMID: 10888304 DOI: 10.1023/a:1007508714259] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
PURPOSE To determine the role of P-glycoprotein (P-gp) in propranolol transport in cultured rabbit conjunctival epithelial cell layers (RCEC). METHODS The localization of P-gp in the cultured RCEC as well as in the excised conjunctiva was determined by immunofluorescence technique. The role of P-gp in transepithelial transport and uptake of propranolol in conjunctival epithelial cells cultured on Transwell filters was evaluated in the presence and absence of P-gp competing substrates, an anti-P-gp monoclonal antibody (4E3 mAb), or a metabolic inhibitor, 2,4-dinitrophenol (2,4-DNP). RESULTS Immunofluorescence studies revealed positive staining in the apical membrane of cultured RCEC and in the apical surface of the superficial cell layers in the excised conjunctiva, but not the basolateral membrane of cultured RCEC. Transport of propranolol showed preference in the basolateral-to-apical direction. The net secretory flux was saturable with a Km of 71.5 +/- 24.0 nM and a Jmax of 1.45 +/- 0.17 pmol/cm2/hr. Cyclosporin A, progesterone, rhodamine 123, verapamil, 4E3 mAb and 2,4-DNP all increased apical 50 nM propranolol uptake by 43% to 66%. On the other hand, neither beta-blockers (atenolol, metoprolol, and alprenolol) nor organic cation transporter substrates (tetraethylammonium (TEA) and guanidine), affected apical 50 nM propranolol uptake. CONCLUSIONS The energy-dependent efflux pump P-gp appears to be predominantly located on the apical plasma membrane of the conjunctival epithelium. It may play an important role in restricting the conjunctival absorption of some lipophilic drugs.
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Ueda H, Horibe Y, Kim KJ, Lee VH. Functional characterization of organic cation drug transport in the pigmented rabbit conjunctiva. Invest Ophthalmol Vis Sci 2000; 41:870-6. [PMID: 10711706] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2023] Open
Abstract
PURPOSE To characterize carrier-mediated organic cation drug transport in the rabbit conjunctiva. METHODS The transport of [14C]guanidine, the model substrate, in the excised pigmented rabbit conjunctiva was evaluated in the modified Ussing chamber. Tetraethylammonium (TEA) transport also was investigated to determine substrate specificity. RESULTS The apparent permeability coefficient for guanidine and TEA in the mucosal-to-serosal (ms) direction was 5.4 and 49.6 times greater than that in the serosal-to-mucosal (sm) direction, respectively. Guanidine transport in the ms (but not sm) direction revealed temperature and concentration dependency over 0.02 to 10 mM with an apparent Michaelis-Menten constant of 3.1 mM and a maximal flux of 11.4 nmol/(cm2 x h). Net guanidine transport measured at 0.1 mM across the conjunctiva was decreased by 71% or 82%, respectively, on the addition of 1 microM valinomycin (a K+ ionophore) in both bathing fluids or in a high K+ buffer in the mucosal fluid. Interestingly, net guanidine transport was reduced, rather than enhanced, by 63% upon acidifying the mucosal bathing fluid. By contrast, net guanidine transport was not affected by the serosal presence of 0.5 mM ouabain (a Na+, K+-ATPase inhibitor), by the mucosal and serosal presence of 0.1 microM monensin (a Na+ ionophore) or 0.3 microM carbonyl cyanide p-(trifluoromethoxy)phenyl-hydrazone (FCCP, a H+ ionophore). Guanidine transport in the ms direction was polyspecific, as indicated by the 48% to 82% inhibition by structurally diverse amines. In particular, guanidine ms transport was inhibited by the antiglaucoma drugs dipivefrine (72%), brimonidine (70%), and carbachol (78%). CONCLUSIONS A carrier-mediated organic cation transport process appears to exist in the conjunctiva, mediating the absorption of organic amines, including certain amine-type ophthalmic drugs. This process may be driven by an inside-negative apical membrane potential difference.
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Yang JJ, Ueda H, Kim K, Lee VH. Meeting future challenges in topical ocular drug delivery: development of an air-interfaced primary culture of rabbit conjunctival epithelial cells on a permeable support for drug transport studies. J Control Release 2000; 65:1-11. [PMID: 10699264 DOI: 10.1016/s0168-3659(99)00226-6] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The purpose of this study was to develop and characterize a functional air-interfaced primary culture of rabbit conjunctival epithelial cells grown on a permeable support for drug transport studies. Conjunctival epithelial cells from the pigmented rabbit were isolated, seeded at 1.2 x 10(6) cells cm(-2) on permeable Transwell filters, and cultured at the air interface using a modified PC-1 medium. Conjunctival epithelial cell layers showed a transepithelial resistance of 1.1+/-0.1 kOmega cm(2), a potential difference of 17.0+/-0.5 mV, and an equivalent short-circuit current (I(eq)) of 16.1+/-0.4 microA cm(-2). The I(eq) was reduced by 35% using 0.01 mM bumetanide, 66% using 0.1 mM ouabain, 46% using 2 mM barium chloride (all three in the basolateral fluid), and 63% using 0.3 mM NPAA in the apical fluid, consistent with active Cl(-)-secretion across the conjunctival epithelial barrier. Amiloride-sensitive Na(+) channels were absent. The permeability of the cell layers to polar solutes decreased with increased solute size, and the calculated equivalent pore size was about 8.0 nm. The Papp of beta-blockers varied with lipophilicity in a sigmoidal fashion. Uridine transport showed temperature sensitivity and directionality, favoring transport in the apical-to-basolateral direction. Apical L-carnosine uptake was reduced by 46% in the absence of an inwardly directed proton gradient, and lowering the temperature to 4 degrees C abolished direction-dependent L-carnosine uptake. Furthermore, uptake was inhibited by 73% using apical 10 mM glycyl sarcosine (a dipeptide transporter substrate) and by 60% using 1 mM L-valacyclovir (a dipeptide prodrug). In conclusion, a functional air-interfaced primary culture of rabbit conjunctival epithelial cell layers was established. This air-interfaced primary culture model may be useful for studying passive and active transport processes for ion and solute translocation in the mammalian conjunctival epithelial barrier in a defined experimental setting.
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Lee VH, Chu C, Mahlin ED, Basu SK, Ann DK, Bolger MB, Haworth IS, Yeung AK, Wu SK, Hamm-Alvarez S, Okamoto CT. Biopharmaceutics of transmucosal peptide and protein drug administration: role of transport mechanisms with a focus on the involvement of PepT1. J Control Release 1999; 62:129-40. [PMID: 10518644 DOI: 10.1016/s0168-3659(99)00030-9] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Non-invasive delivery of peptide and protein drugs will soon become a reality. This is due partly to a better understanding of the endogenous transport mechanisms, including paracellular transport, endocytosis, and carrier-mediated transport of mucosal routes of peptide and protein drug administration. This paper focuses on work related to the elucidation of structure-function, intracellular trafficking, and regulation of the intestinal dipeptide transporter, PepT1.
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