1
|
Teng YN, Kao MC, Huang SY, Wu TS, Lee TE, Kuo CY, Hung CC. Novel application of rhein and its prodrug diacerein for reversing cancer-related multidrug resistance through the dual inhibition of P-glycoprotein efflux and STAT3-mediated P-glycoprotein expression. Biomed Pharmacother 2022; 150:112995. [PMID: 35658243 DOI: 10.1016/j.biopha.2022.112995] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2022] [Revised: 04/12/2022] [Accepted: 04/17/2022] [Indexed: 11/29/2022] Open
Abstract
Multidrug resistance (MDR) is a multifactorial issue in cancer treatment. Drug efflux transporters, particularly P-glycoprotein (P-gp), are major contributors to such resistance. In the present study, we evaluated the P-gp-inhibiting and MDR-reversing effects of two compounds, namely rhein, an anthraquinone, and diacerein, the acetylated prodrug of rhein. ABCB1/Flp-In-293 was used as a model for investigating the related molecular mechanisms, and the multi-drug-resistant cancer cell line KB/VIN was used as a platform for evaluating the reversal of MDR0. The results indicated that at a concentration of 2.5 μM, both diacerein and rhein significantly inhibited P-gp efflux function. They also downregulated P-gp expression by interacting with the signal transducer and activator of transcription 3. Further investigation of the inhibitory mechanism of these compounds revealed that both stimulated P-gp ATPase activity dose dependently and engaged in the noncompetitive inhibition of rhodamine 123 efflux. Furthermore, rhein was revealed to be a potent reverser of MDR in cancer, and the combination of 30 μM rhein and 1000 nM vincristine exerted a strong synergistic effect, achieving a high combination index (CI) of 0.092. Diacerein demonstrated potential applications as a selective cytotoxic agent against multi-drug-resistant cancer cells at a concentration of > 18.92 μM and as a mild MDR reverser at doses of < 10 μM. In conclusion, diacerein and rhein are potential candidates for P-gp inhibition and MDR reversal in cancer cells.
Collapse
Affiliation(s)
- Yu-Ning Teng
- School of Medicine, College of Medicine, I-Shou University, 8 Yida Road, Kaohsiung 82445, Taiwan.
| | - Ming-Chang Kao
- Department of Anesthesiology, New Taipei Municipal TuCheng Hospital (Built and Operated by Chang Gung Medical Foundation), New Taipei City, Taiwan.
| | - Shih-Ya Huang
- Department of Pharmacy, College of Pharmacy, China Medical University, 100, Section 1, Jingmao Rd., Beitun Dist., Taichung City 406040, Taiwan.
| | - Tian-Shung Wu
- School of Pharmacy, College of Medicine, National Cheng Kung University, Tainan 701, Taiwan; Department of Pharmacy, College of Pharmacy and Health Care, Tajen University, Pingtung 907, Taiwan.
| | - Tsui-Er Lee
- Office of Physical Education, Asia University, 500, Lioufeng Rd., Wufeng, Taichung 41354, Taiwan.
| | - Chan-Yen Kuo
- Department of Research, Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, New Taipei City, Taiwan; Department of Nursing, Cardinal Tien College of Healthcare and Management, New Taipei City, Taiwan.
| | - Chin-Chuan Hung
- Department of Pharmacy, College of Pharmacy, China Medical University, 100, Section 1, Jingmao Rd., Beitun Dist., Taichung City 406040, Taiwan; Department of Pharmacy, China Medical University Hospital, 2 Yude Road, Taichung 40447, Taiwan; Department of Healthcare Administration, Asia University, 500, Lioufeng Rd., Wufeng, Taichung 41354, Taiwan.
| |
Collapse
|
2
|
Teng YN, Huang BH, Huang SY, Wu IT, Wu TS, Lee TE, Hung CC. Cinnamophilin overcomes cancer multi-drug resistance via allosterically modulating human P-glycoprotein on both drug binding sites and ATPase binding sites. Biomed Pharmacother 2021; 144:112379. [PMID: 34794239 DOI: 10.1016/j.biopha.2021.112379] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Revised: 10/20/2021] [Accepted: 10/25/2021] [Indexed: 11/17/2022] Open
Abstract
Cancer multi-drug resistance (MDR) caused by P-glycoprotein (P-gp) efflux is a critical unresolved clinical concern. The present study analyzed the effect of cinnamophilin on P-gp inhibition and MDR reversion. The effect of cinnamophilin on P-gp was investigated through drug efflux assay, ATPase assay, MDR1 shift assay, and molecular docking. The cancer MDR-reversing ability and mechanisms were analyzed through cytotoxicity and combination index (CI), cell cycle, and apoptosis experiments. P-gp efflux function was significantly inhibited by cinnamophilin without influencing the drug's expression or conformation. Cinnamophilin uncompetitively inhibited the efflux of doxorubicin and rhodamine 123 and exhibited a distinct binding behavior compared with verapamil, the P-gp standard inhibitor. The half maximal inhibitory concentration of cinnamophilin for doxorubicin and rhodamine 123 efflux was 12.47 and 11.59 μM, respectively. In regard to P-gp energy consumption, verapamil-stimulated ATPase activity was further enhanced by cinnamophilin at concentrations of 0.1, 1, 10, and 20 μM. In terms of MDR reversion, cinnamophilin demonstrated synergistic cytotoxic effects when combined with docetaxel, vincristine, or paclitaxel. The CI was < 0.7 in all experimental combination treatments. The present study showed that cinnamophilin possesses P-gp-modulating effects and cancer MDR resensitizing ability.
Collapse
Affiliation(s)
- Yu-Ning Teng
- School of Medicine, College of Medicine, I-Shou University, 8 Yida Road, Kaohsiung 82445, Taiwan, ROC.
| | - Bo-Hau Huang
- Department of Pharmacy, China Medical University Hsinchu Hospital, No. 199, Section1, Xinglong Rd., Zhubei City, Hsinchu Country 302056, Taiwan, ROC.
| | - Shih-Ya Huang
- Department of Pharmacy, College of Pharmacy, China Medical University, 100, Section 1, Jingmao Rd., Beitun Dist., Taichung City 406040, Taiwan, ROC.
| | - I-Ting Wu
- Department of Pharmacy, College of Pharmacy, China Medical University, 100, Section 1, Jingmao Rd., Beitun Dist., Taichung City 406040, Taiwan, ROC.
| | - Tian-Shung Wu
- School of Pharmacy, College of Medicine, National Cheng Kung University, Tainan 701, Taiwan, ROC; Department of Pharmacy, College of Pharmacy and Health Care, Tajen University, Pingtung 907, Taiwan, ROC.
| | - Tsui-Er Lee
- Office of Physical Education, Asia University, 500, Lioufeng Rd., Wufeng, Taichung 41354, Taiwan, ROC.
| | - Chin-Chuan Hung
- Department of Pharmacy, College of Pharmacy, China Medical University, 100, Section 1, Jingmao Rd., Beitun Dist., Taichung City 406040, Taiwan, ROC; Department of Pharmacy, China Medical University Hospital, 2 Yude Road, Taichung 40447, Taiwan, ROC; Department of Healthcare Administration, Asia University, 500, Lioufeng Rd., Wufeng, Taichung 41354, Taiwan, ROC.
| |
Collapse
|
3
|
Chang YT, Wang CCN, Wang JY, Lee TE, Cheng YY, Morris-Natschke SL, Lee KH, Hung CC. Tenulin and isotenulin inhibit P-glycoprotein function and overcome multidrug resistance in cancer cells. Phytomedicine 2019; 53:252-262. [PMID: 30668405 PMCID: PMC6421864 DOI: 10.1016/j.phymed.2018.09.008] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Revised: 06/24/2018] [Accepted: 09/03/2018] [Indexed: 06/09/2023]
Abstract
BACKGROUND Multidrug resistance (MDR) in cancer is one of the main obstacles in treatment with chemotherapy. Drug efflux through P-glycoprotein is the major mechanism involved in MDR. A potential strategy to provide the best possible clinical outcomes is to develop P-glycoprotein (P-gp) inhibitors from natural products. PURPOSE The present study investigated the effects of the natural sesquiterpene lactone tenulin and its derivative isotenulin on human P-gp; the mechanisms of kinetic interactions were also explored. METHODS The human P-gp (ABCB1/Flp-In™-293) stable expression cells were established by using the Flp-In™ system. The effects of tenulin and isotenulin on cell viability were evaluated by SRB assays in established cell lines, sensitive cancer cell line (HeLaS3), and resistant cancer cell line (KB-vin). The transporter inhibition ability was evaluated by calcein-AM uptake assays. The P-gp inhibition kinetics of tenulin and isotenulin were evaluated by rhodamine123 and doxorubicin efflux assays. The ATPase activity was evaluated with the Pgp-Glo™ Assay System. RESULTS Tenulin and isotenulin significantly inhibited the P-gp efflux function by stimulating P-gp ATPase activity. Tenulin and isotenulin interacted with the effluxes of rhodamine 123 and doxorubicin through a competitive and noncompetitive mechanism, respectively. The combinations of tenulin and isotenulin with chemotherapeutic drugs significantly resensitized MDR cancer cells. CONCLUSION These results suggested that tenulin and isotenulin are potential candidates to be developed for synergistic treatment of MDR cancers.
Collapse
MESH Headings
- ATP Binding Cassette Transporter, Subfamily B/antagonists & inhibitors
- ATP Binding Cassette Transporter, Subfamily B/genetics
- ATP Binding Cassette Transporter, Subfamily B/metabolism
- ATP Binding Cassette Transporter, Subfamily B, Member 1/antagonists & inhibitors
- ATP Binding Cassette Transporter, Subfamily B, Member 1/genetics
- ATP Binding Cassette Transporter, Subfamily B, Member 1/metabolism
- Antineoplastic Agents, Phytogenic/pharmacology
- Cell Line, Tumor
- Doxorubicin/pharmacology
- Drug Resistance, Multiple/drug effects
- Drug Resistance, Neoplasm/drug effects
- Drug Screening Assays, Antitumor
- HeLa Cells
- Humans
- Lactones/pharmacology
- Rhodamine 123/pharmacology
- Sesquiterpenes/pharmacology
Collapse
Affiliation(s)
- Ying-Tzu Chang
- Department of Pharmacy, College of Pharmacy, China Medical University, 91 Hsueh-Shih Road, Taichung 40402, Taiwan, ROC
| | - Charles C N Wang
- Department of Bioinformatics and Medical Engineering, Asia University. 500, Lioufeng Rd., Wufeng, Taichung 41354, Taiwan, ROC
| | - Jiun-Yi Wang
- Department of Healthcare Administration, Asia University, 500, Lioufeng Rd., Wufeng, Taichung 41354, Taiwan, ROC
| | - Tsui-Er Lee
- Office of Physical Education, Asia University, 500, Lioufeng Rd., Wufeng, Taichung 41354, Taiwan, ROC
| | - Yung-Yi Cheng
- Natural Products Research Laboratories, UNC Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC 27599, United States.; Department of Medical Research, China Medical University Hospital, China Medical University, Taichung 404, Taiwan, ROC
| | - Susan L Morris-Natschke
- Natural Products Research Laboratories, UNC Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC 27599, United States
| | - Kuo-Hsiung Lee
- Natural Products Research Laboratories, UNC Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC 27599, United States.; Chinese Medicine Research and Development Center, China Medical University and Hospital, 2 Yude Road, Taichung 40447, Taiwan, ROC
| | - Chin-Chuan Hung
- Department of Pharmacy, College of Pharmacy, China Medical University, 91 Hsueh-Shih Road, Taichung 40402, Taiwan, ROC; Department of Pharmacy, China Medical University Hospital, 2 Yude Road, Taichung 40447, Taiwan, ROC.
| |
Collapse
|
4
|
Wang RY, Chen HJ, Huang CL, Wang JY, Lee TE, Lee HY, Hung CC. Impacts of GRIN3A, GRM6 and TPH2 genetic polymorphisms on quality of life in methadone maintenance therapy population. PLoS One 2018; 13:e0201408. [PMID: 30059533 PMCID: PMC6066242 DOI: 10.1371/journal.pone.0201408] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Accepted: 07/14/2018] [Indexed: 11/18/2022] Open
Abstract
Opioid addiction is a major public health issue worldwide. Methadone maintenance treatment (MMT) is used to detoxify users of illicit opiates, but drug relapse is common and associated with poor quality of life (QoL). This study investigated the associations between the GRIN3A, GRM6, and TPH2 genetic variants and QoL in the MMT population. A total of 319 participants were included in the study, and genotyping of GRIN3A, GRM6, and TPH2 genes was performed using the Sequenom iPLEX. Associations between genotypes and the domains of QoL were examined through posthoc analysis with LSMEANS syntax using SAS 9.1.3. The single nucleotide polymorphisms rs9325202 and rs1487275 in the TPH2 gene were significantly associated with the QoL domain of physical functioning. The least absolute shrinkage and selection operator regression model revealed that the risk allele rs1487275-G was significantly correlated with the domain of physical functioning when clinical characteristics were considered as covariates. The results of the present study illuminate the importance of the genetic basis of QoL in the MMT population, and suggest that genotypes should be considered as a potential QoL indicator.
Collapse
Affiliation(s)
- Ruey-Yun Wang
- Department of Public Health, China Medical University, Taichung, Taiwan, R.O.C
- Brain Disease Research Center, China Medical University Hospital, Taichung, Taiwan, R.O.C
| | - Hsiu-Ju Chen
- Department of Pharmacy, College of Pharmacy, China Medical University, Taiwan, R.O.C
| | - Chieh-Liang Huang
- Brain Disease Research Center, China Medical University Hospital, Taichung, Taiwan, R.O.C
- Center for Drug Abuse and Addiction, China Medical University Hospital, Taichung, Taiwan, R.O.C
- College of Medicine, China Medical University, Taichung, Taiwan, R.O.C
| | - Jiun-Yi Wang
- Department of Healthcare Administration, Asia University, Wufeng, Taichung, Taiwan, R.O.C
| | - Tsui-Er Lee
- Office of Physical Education, Asia University, Taichung, Taiwan, R.O.C
| | - Hsiang-Yen Lee
- Department of Internal Medicine, Taipei Medical University Hospital, Xinyi District, Taipei City, Taiwan, R.O.C
| | - Chin-Chuan Hung
- Department of Pharmacy, College of Pharmacy, China Medical University, Taiwan, R.O.C
- Department of Pharmacy, China Medical University Hospital, Taichung, Taiwan, R.O.C
- * E-mail:
| |
Collapse
|
5
|
Teng YN, Chang CS, Lee TE, Hung CC. Cordycepin re-sensitizes multidrug resistance cancer cells to chemotherapeutic agents through modulating P-glycoprotein expression and ATPase function. J Funct Foods 2016. [DOI: 10.1016/j.jff.2016.08.039] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
|
6
|
Thompson CJ, Lee TE, McCarthy MA. Species distributions and area relationships. J Theor Biol 2014; 363:129-33. [PMID: 25150460 DOI: 10.1016/j.jtbi.2014.08.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2013] [Revised: 08/04/2014] [Accepted: 08/05/2014] [Indexed: 11/25/2022]
Abstract
The well-known species-area relationship is one of many scaling laws, or allometries, in ecology and biology that have received much attention over the years. We present a new derivation of this relationship based on Yule׳s theory of evolution of species. Using definitions of mutation rates, our analysis yields species-area exponents that are in close agreement with previously observed values.
Collapse
Affiliation(s)
- C J Thompson
- Department of Mathematics and Statistics, University of Melbourne, VIC 3010, Australia
| | - T E Lee
- School of Botany, University of Melbourne, VIC 3010, Australia; Biomathematics Unit, Department of Zoology, Faculty of Life Sciences, Tel-Aviv University, P.O. Box 39040, Tel-Aviv 69978, Israel.
| | - M A McCarthy
- School of Botany, University of Melbourne, VIC 3010, Australia
| |
Collapse
|
7
|
Chen SJ, Lee TE, Wang EM, Cho TJ, Wang CH. Monitoring the hygene of chicken hatcheries in Taiwan during 1999-2001. J Microbiol Immunol Infect 2002; 35:236-42. [PMID: 12542249] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Abstract
Microorganism contamination in hatcheries and eggs has a serious impact on the viability and quality of chicks as well as on the overall growth performance of chickens. Microbiological agents are present in the fluff when chicks hatch. Detecting microorganisms in fluff is a convenient method for evaluating the hygienic status in a hatchery. Fluff samples from 31 hatcheries collected over 3 years were tested for the total bacterial count, the presence of Salmonella spp., and fungus to evaluate the hygienic status of hatcheries in Taiwan from 1999 through 2001. The total bacterial score from the fluff samples was calculated and expressed as a bacterial score in a log scale. Most hatcheries had a bacterial count ranged from scale 1 to 3. Among the hatcheries, 13% to 29% were contaminated with Salmonella spp.; and 33% to 73% were contaminated with fungi in different quarters. The third quarter of each year was the most contaminated period (p<0.01). According to the data obtained from the fluff tests, hatcheries keep their hygienic status and supply good quality chicks by cleaning and disinfecting.
Collapse
Affiliation(s)
- Su-Jen Chen
- Department of Veterinary Medicine, National Taiwan University, Taipei, Taiwan, ROC
| | | | | | | | | |
Collapse
|
8
|
Abstract
Russia has undergone sweeping political and social reforms within the past 5 years. The economic and social reforms heralded by the "new openness" of perestroika have led to a restructuring of medicine as well. Changes include the emergence of "for profit" organizations and acute care facilities, the introduction of private health insurance, modifications in the medical education system, and realignment of health priorities with a new trend toward primary care.
Collapse
Affiliation(s)
- D A Townes
- Department of Emergency Medicine, Office of International Health, University of Illinois College of Medicine, Chicago, USA
| | | | | | | |
Collapse
|
9
|
Abstract
Mammalian voltage-gated K+ channels are oligomeric proteins, some of which may be composed in vivo of subunits derived from several similar genes. We have studied N-type inactivation in the rapidly inactivating Kv1.4 channel and, in specific, heteromultimers of this gene product with Kv1.5 noninactivating subunits. Heteromultimeric channels were analyzed for the stoichiometry of Kv1.4:Kv1.5 subunits by observing shifts in the midpoints of steady-state availability from that of homomultimeric channels. This analysis was employed to examine inactivation of heteromultimeric channels expressed in Xenopus oocytes using two model systems: by expression of a Kv1. 4-Kv1.5 tandem fusion construct and by coexpression of native Kv1.4 and Kv1.5 channels across a wide relative concentration range of microinjected mRNA. Additionally, inactivation was examined in coexpression experiments of N-terminal deletion mutants of Kv1.4. We found that (i) a single inactivating subunit conferred inactivation in all hetero-multimers studied; (ii) the rate of inactivation could not be distinguished in channels containing two inactivating subunits from those containing one inactivating subunit; and (iii) large deletions in the linker region between the N-terminal inactivation region and the first membrane-spanning domain had no effect on the rate of inactivation. These data confirm the importance of the proximal N-terminal region in the inactivation of mammalian Kv1.4 channels, and suggest that the inactivation particle remains in close proximity to the permeation pathway even when the channel is in the open state.
Collapse
Affiliation(s)
- T E Lee
- Department of Neurology, The University of Chicago, Chicago, IL 60637, USA
| | | | | |
Collapse
|
10
|
Abstract
K+ channel function is regulated through the assembly of channel subunit isoforms into either homo- or heterotetrameric structures each characterized by distinct pharmacologic and kinetic properties. In studying the molecular basis of subunit association in mammalian Shaker-like K+ channels, we constructed deletion mutants of the inactivating K+ channel hKv1.4 alone and in tandem with hKv1.5 and examined the functional properties electrophysiologically in Xenopus oocytes. Deletion of 255 amino acids in the amino-terminal domain of hKv1.4 prevented the formation of hybrid channels within the subfamily but had no effect on homomultimerization or voltage-dependent gating. The amino-terminal deletion mutant of Kv2.1, a noninactivating K+ channel from a distantly related subfamily also forms functional homomultimeric channels. Although members of different K+ channel subfamilies do not coassemble, coexpression of the amino-terminal deletion mutants of hKv1.4 and Kv2.1 resulted in the formation of functional hybrid channels. These results demonstrate that the amino-terminal region of mammalian K+ channels subserves two functions. It provides a recognition site necessary for hetero- but not homomultimeric channel assembly within a subfamily and prevents coassembly between subfamilies.
Collapse
Affiliation(s)
- T E Lee
- University of Chicago, Department of Neurology, Illinois 60637
| | | | | | | |
Collapse
|
11
|
Abstract
One of the main uses of topical fibrin glue is hemostasis. Fibrin glue from pooled human plasma has been used in Europe for many years. It was used for fixation of skin grafts as early as 1944. Because of the risk of hepatitis and now of acquired immunodeficiency syndrome, this compound has not been approved by the U.S. Food and Drug Administration for use in the United States. It is now possible to make fibrin glue from a single unit of blood. Many blood banks have this capability, and burn centers in the United States are beginning to report its use in skin grafting procedures performed on patients with burns. In an effort to document a hemostatic effect, a prospective double-blind study was designed. Donor sites of patients with burns undergoing skin grafting were studied to provide a uniform wound; anatomic location varied, particularly with respect to gravity. Half of each donor site was sprayed with thrombin and fibrin glue, and the other half was sprayed with thrombin and placebo. A large absorbent pad was placed over the gauze dressing, and all dressings were collected and weighed by the investigators at 6 and 18 hours after the operation. Ten patients have been studied to date. In five patients slightly more bleeding occurred in the site treated with fibrin. One patient had no difference, and four had slightly less bleeding on the donor site treated with fibrin. No significant difference could be found in this initial study group.(ABSTRACT TRUNCATED AT 250 WORDS)
Collapse
Affiliation(s)
- B M Achauer
- Department of Surgery, University of California, Irvine, Orange 92668
| | | | | |
Collapse
|
12
|
Abstract
Electron micrographs of deoxyhemoglobin S fiber cross sections provide an end-on view of the fiber whose appearance is sensitive to small changes in orientation. We have developed a procedure to exploit this sensitivity in order to determine the hand of these particles. In a sickle hemoglobin fiber the hemoglobin molecules form long pitch helical strands which twist about the particle axis with a pitch of about 3000 A. Tilting a 400-A-thick cross section by a few degrees aligns one of the long pitch helices so that it is nearly parallel to the direction of view. When a strand of hemoglobin molecules in a fiber is aligned in this manner it appears as a strongly contrasted bright spot. It is this spot, rather than the fiber axis, which appears to be the apparent center of rotation of the cross section. The direction of the displacement of the spot from the particle axis depends upon the particle hand and tilt direction. We have used this property to determine that sickle hemoglobin fibers are right-handed particles. This method may be applicable to other particles with long pitch helices as well.
Collapse
Affiliation(s)
- M R Lewis
- Department of Molecular Genetics and Cell Biology, University of Chicago, Illinois 60637
| | | | | |
Collapse
|
13
|
Abstract
In a case-control, cross-cultural study of the psychiatric morbidity of systemic lupus erythematosus in an Oriental population, 30 patients suffering from SLE and 29 controls with rheumatoid arthritis were interviewed. The SLE patients in Singapore exhibited greater psychiatric morbidity than their Western counterparts. Significant correlation was observed between psychiatric morbidity and the clinical disease activity. The patient's perception of the severity of arthritis, myalgia and dermatological lesions was an important aetiological factor. Culturally determined, disease-related psychological stresses also contributed to the psychopathology.
Collapse
Affiliation(s)
- L C Lim
- Department of Psychological Medicine, National University of Singapore
| | | | | |
Collapse
|
14
|
Abstract
A pattern of differential binding between an NZB/NZW mouse-derived monoclonal anti-ssDNA antibody, V'D2, and restriction fragments of plasmid pBR322 DNA was shown by electrophoresis of the fragments through a denaturing agarose gel followed by their transfer onto nitrocellulose membrane and subsequent reaction of the immobilized DNA with the antibody and 125I-protein A. The antibody showed preferential binding to a 328 base pair Alu I + Hinf I fragment (denoted FD) (AT content, 60%), compared with the other fragments (AT contents, 40-56%). In dot blot assays the antibody bound only to poly(dT) and poly(dA,dT), failing to bind to other synthetic deoxyribopolynucleotides even at the highest concentration tested (300 ng). In competition experiments, the ability of unlabeled DNA to inhibit binding of V'D2 to FD increased with AT content of the DNA. It is concluded that V'D2 has preference for AT-rich DNA. In addition, poly(dA,dT) inhibited binding to a greater extent than either poly(dA) or poly(dT), indicating that base sequence may be important in defining the antigenic determinant. The method, appropriately modified, may be applicable to a wide range of natural nucleic acids and monoclonal antibodies, allowing detection and isolation of specific DNA fragments for detailed studies of antigenic determinants.
Collapse
|
15
|
Lee TE. Warning: Home reliners cause bone resorption. Chronicle 1971; 34:212-3. [PMID: 5283149] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
|