251
|
Ding S, Hou J, Sun A. [Both myeloma cells and bone marrow stromal cells are involved in the overproduction of interleukin 6 in multiple myeloma]. Zhonghua Xue Ye Xue Za Zhi 1998; 19:306-8. [PMID: 11243111] [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: 02/19/2023]
Abstract
OBJECTIVE To investigate the mechanism of interleukin 6 (IL-6) overexpression in multiple myeloma(MM). METHODS Human myeloma cells(KM3) and bone marrow stromal cells(BMSCs) were fixed by paraformaldehyde. KM3 cells and BMSCs (fixed and non-fixed) were co-cultured in 10%FCS-RPMI1640. IL-6 activity in the supernatant was determined by B9 cell proliferation test. RESULTS Both non-fixed myeloma cells and BMSCs could automatically secret IL-6, while the fixed cells did not. Co-cultures of fixed one with non-fixed the other of either kind of the cells could significantly increase the IL-6 activity in the supernatants. The promoting effect on IL-6 production was greater in BMSCs from MM patients than that in BMSCs from normal controls. CONCLUSION There exists dual mechanism of IL-6 overproduction in MM, i.e. both autocrine and paracrine of IL-6 are involved in the pathogenesis of MM.
Collapse
Affiliation(s)
- S Ding
- Changzheng Hospital, 2nd Military Medical University, Shanghai 200003
| | | | | |
Collapse
|
252
|
Sun A, Chang JG, Chu CT, Liu BY, Yuan JH, Chiang CP. Preliminary evidence for an association of Epstein-Barr virus with pre-ulcerative oral lesions in patients with recurrent aphthous ulcers or Behçet's disease. J Oral Pathol Med 1998; 27:168-75. [PMID: 9563572 DOI: 10.1111/j.1600-0714.1998.tb01935.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In this study we used the polymerase chain reaction (PCR), slot blot and Southern blot hybridization, direct sequencing and in situ hybridization (ISH) to show the possible presence of EBV-DNA in pre-ulcerative oral aphthous lesions of patients with recurrent aphthous ulcers (RAU) or Behçet's disease (BD). For this purpose, formalin-fixed biopsy specimens were obtained from 13 pre-ulcerative oral aphthous lesions of nine RAU and four BD patients. Five specimens of normal oral mucosa (NOM) from five normal control subjects and 10 specimens of oral erosive or ulcerative lesions from 10 patients with erosive lichen planus (ELP) were also included. EBV-DNA was detected by PCR in 5 of the 13 (38.5%) pre-ulcerative oral aphthous lesions, two from RAU patients and three from BD patients. However, no EBV-DNA was demonstrated in five NOM specimens from normal control subjects and in 10 specimens of oral lesions from ELP patients. EBV-DNA was also demonstrated in patients' peripheral blood lymphocytes and/or plasma, suggesting that the lymphocytes may be the reservoir of latent EBV infection and there is EBV shedding in the plasma. EBV-DNA was detected by ISH in only one PCR-positive case; the reaction product was found to deposit on the nuclei of some of the epithelial cells and lymphocytes. By immunohistochemistry, expression of Epstein-Barr nuclear antigen and EBV/C3d receptors was also noted in some of the epithelial cells and lymphocytes in this ISH-positive case. Therefore, we suggest that the epithelial cells of pre-ulcerative oral aphthous lesions may be infected by EBV through EBV-infected lymphocytes; also, the cytotoxic T lymphocyte-induced lysis of the EBV-infected epithelial cells, but not the virus-induced cytolysis, may be the main mechanism causing oral ulcer formation. Our data provide preliminary evidence for an association of EBV with pre-ulcerative oral aphthous lesions in RAU and BD patients.
Collapse
MESH Headings
- Adolescent
- Adult
- Antigens, Viral/analysis
- Behcet Syndrome/virology
- Cell Nucleus/immunology
- Cell Nucleus/virology
- Child
- DNA, Viral/analysis
- DNA, Viral/genetics
- Epithelial Cells/virology
- Female
- Herpesviridae Infections
- Herpesvirus 4, Human/genetics
- Herpesvirus 4, Human/immunology
- Herpesvirus 4, Human/isolation & purification
- Humans
- Lichen Planus, Oral/virology
- Lymphocytes/virology
- Male
- Middle Aged
- Mouth Mucosa/virology
- Oral Ulcer/virology
- Receptors, Complement 3d/analysis
- Recurrence
- Stomatitis, Aphthous/virology
- T-Lymphocytes, Cytotoxic/immunology
- T-Lymphocytes, Cytotoxic/virology
- Tumor Virus Infections
- Virus Latency
- Virus Shedding
Collapse
Affiliation(s)
- A Sun
- School of Dentistry, National Taiwan University, Taipei, ROC
| | | | | | | | | | | |
Collapse
|
253
|
Kirkbride P, Pater J, Zee B, Palmer M, Sun A, Wong R, Cross P, Dundas G, Ganguly P, Lim J, Chowdhury A, Gulavita S, Kumar E, Dar R, Blood P. A phase III study of the efficacy of dexamethasone (DEX) in the prophylaxis of radiation induced emesis (RIE). Int J Radiat Oncol Biol Phys 1998. [DOI: 10.1016/s0360-3016(98)80229-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
|
254
|
Sun A, Tang Y, Wang G. [Synovial sarcoma in the head and neck with 3 case reports]. Lin Chuang Er Bi Yan Hou Ke Za Zhi 1997; 11:502-4. [PMID: 10323019] [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: 04/13/2023]
Abstract
Synovial sarcoma in the head and neck with 3 cases are reported. Some clinical features and experiences of surgical excision are analysed according to our materials and review of the literature. We believe that the key to prevent synovial sarcoma from recurrence and matastasis is to avoid local excision, and pay more attention to this disease before operation. It is not sensitive to radiation therapy.
Collapse
Affiliation(s)
- A Sun
- Department of ENT, General Hospital of Shenyang Military Area, Shenyang
| | | | | |
Collapse
|
255
|
Fu Y, Wang S, Sun A, Lu Z, Li S. The relationship between insulin resistance and abnormality of cellular calcium metabolism in patients with essential hypertension. Chin Med J (Engl) 1997; 110:891-2. [PMID: 9772426] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023] Open
Affiliation(s)
- Y Fu
- Department of Biochemistry, Hebei Academy of Medical Sciences, Shijiazhuang, China
| | | | | | | | | |
Collapse
|
256
|
Sun A, Wang Z, Li J. [Disturbance of iron metabolism and sudden hearing loss: a prospective and retrospective survey]. Lin Chuang Er Bi Yan Hou Ke Za Zhi 1997; 11:243-5. [PMID: 9812800] [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: 02/09/2023]
Abstract
Two hundred and eighteen patients with disorders of disturbance of iron metabolism, 215 with hematonosis and 4850 in a normal control group were studied in a prospective with sudden hearing loss and were meanwhile investigated in a retrospective review in order to evaluate the relationship between the disorders of disturbance of iron metabolism and sudden hearing loss. The findings revealed a significantly higher incidence of sudden hearing loss in the cases of disturbance of iron metabolism, than in the patients with hematonosis as well as in the normal control group. Iron deficiency and iron deficiency anemia were found in 60.84% of 429 patients with sudden hearing loss. We concluded that the risk of disturbance of iron metabolism in the cochlea will significantly increase when systemic disturbance of iron metabolism is present although the one does not necessarily indicate the other. It seems that acute disturbance of iron metabolism in cochlea causes sudden hearing loss directly or provides a pathologic basis for the disorder.
Collapse
Affiliation(s)
- A Sun
- Department of Otolaryngology, Changhai Hospital, Second Military Medical University, Shanghai
| | | | | |
Collapse
|
257
|
Wirshing WC, Ames D, Bisheff S, Pierre JM, Mendoza A, Sun A. Hepatic encephalopathy associated with combined clozapine and divalproex sodium treatment. J Clin Psychopharmacol 1997; 17:120-1. [PMID: 10950478 DOI: 10.1097/00004714-199704000-00013] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
|
258
|
Abstract
Human fibrinogen (340 kDa) is a dimer, with each identical half-molecule composed of three different polypeptides (Aalpha, 66 kDa; Bbeta, 55 kDa; and gamma, 48 kDa). To understand the mechanisms of chain assembly, a coupled in vitro transcription translation system capable of assembling fibrinogen chains was developed. Fibrinogen chain assembly was assayed in an expression system coupled to rabbit reticulocyte lysate in the presence or absence of dog pancreas microsomal membranes. Fibrinogen chain assembly required microsomal membranes and oxidized glutathione. Co-expression of two of the chains, Bbeta and gamma or Aalpha and gamma, yielded free chains and two-chain complexes. Unlike combinations of Aalpha with gamma and Bbeta with gamma, co-expression of Aalpha and Bbeta did not form a single two-chain complex but produced a mixture of two-chain complexes. Co-expression of all three chains yielded free chains, two-chain complexes, and higher molecular weight complexes that corresponded to a half-molecule and to fully formed fibrinogen. Upon treatment of this mixture with thrombin and factor XIIIa, a gamma.gamma dimer, similar to that obtained from cross-linked human fibrin, was produced, indicating that properly folded fibrinogen was formed in vitro. Molecular chaperones may participate in fibrinogen assembly, since antibodies to resident proteins of the endoplasmic reticulum (BiP, Hsp90, protein disulfide isomerase, and calnexin) co-precipitated the chaperones together with nascent fibrinogen chains and complexes.
Collapse
Affiliation(s)
- S Roy
- Lindsley F. Kimball Research Institute, New York Blood Center, New York, New York 10021, USA
| | | | | |
Collapse
|
259
|
Sun A, Chen X, Kuang J. [Effects of levonorgestrel subdermal implants on estradiol and progesterone receptors of endometrium and ovarian tissues in rats]. Zhonghua Fu Chan Ke Za Zhi 1996; 31:530-2. [PMID: 9275423] [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: 02/05/2023]
Abstract
OBJECTIVE To study the influence of subdermal implantation of levonorgestrel (LNG) on the levels of estradiol receptor (ER) and progesterone receptor (PR) in ovaries and endometrium of rats. METHODS 45 female mature rats were divided into 3 groups: control group, silicon tube group and LNG implants group. Using single-point determination at saturating concentration method, ER and PR levels of both ovaries and endometrium were measured at 15, 30 and 45 days after subdermal implantation of LNG or silicon tube, and compared with that of the control group. RESULTS ER and PR levels in LNG group were significantly lower than those in the other 2 groups (P < 0.01). The concentration of ER and PR decreased gradually as implantation prolonged. CONCLUSION subdermal implantation of LNG resulted in the reduction of ER and PR levels in ovaries and endometrium of rats, which may be related to the mechanism of contraception and breakthrough bleeding after implantation.
Collapse
Affiliation(s)
- A Sun
- General Military Hospital of Guanzhou Command Area
| | | | | |
Collapse
|
260
|
Stuart RO, Sun A, Bush KT, Nigam SK. Dependence of epithelial intercellular junction biogenesis on thapsigargin-sensitive intracellular calcium stores. J Biol Chem 1996; 271:13636-41. [PMID: 8662885 DOI: 10.1074/jbc.271.23.13636] [Citation(s) in RCA: 90] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Perturbation of potentially regulatable endoplasmic reticulum (ER) calcium stores with the Ca-ATPase inhibitor, thapsigargin (TG), perturbs the formation of desmosomes and tight junctions during polarized epithelial cell biogenesis, despite the development of cell contact. In a Madin-Darby canine kidney cell model for intercellular junction assembly, TG treatment inhibited the development of transepithelial electrical resistance (TER), a measure of tight junction assembly, in a dose-dependent manner. The TG-induced inhibition of tight junction assembly was paralleled by a defect in the sorting of the tight junction protein, ZO-1. An even more dramatic delay in sorting of the desmosomal protein, desmoplakin, was observed in the presence of TG. In addition, while both ZO-1 and desmoplakin-I in control cells were shown to become associated with the Triton X-100 insoluble cytoskeleton during intercellular junction assembly, prior treatment with 100 nM TG diminished this biochemical stabilization into the detergent-insoluble fraction, particularly in the case of ZO-1. Although spectrofluorimetric measurements in fura-2 loaded Madin-Darby canine kidney cells confirmed the occurrence of TG-mediated release of calcium from internal stores, total cytosolic calcium during junction assembly remained similar to untreated cells. Therefore, the presence of cytosolic calcium alone is not sufficient for normal intercellular junction biogenesis if intracellular stores are perturbed by TG. The results indicate the presence of calcium-sensitive intracellular mechanisms involved in the sorting and cytoskeletal stabilization of both tight junction and desmosomes and suggest a role for calcium-dependent signaling pathways at an early (possibly common) step in polarized epithelial biogenesis.
Collapse
Affiliation(s)
- R O Stuart
- Renal Division, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts 02115, USA
| | | | | | | |
Collapse
|
261
|
Ye Z, Sun A, Li L, Cao X, Ye W. [Reversal of adriamycin or vincristine resistance by tetrandrine in human cancer cells in vitro]. Zhongguo Zhong Yao Za Zhi 1996; 21:369-71, 384. [PMID: 9388928] [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: 02/05/2023]
Abstract
In an in vitro culture system of human cancer cells MCF-7 and its adriamycin-resistant line MCF-7/Ad or KB and its vincristine-resistant line KBv200, tetrandrine was found to exhibit significantly selective anticancer activity against the drug-resistant cancer cell MCF-7/Ad. In addition, essentially complete reversal effects of tetrandrine on drug resistance were observed in MCF/Ad or KBv200.
Collapse
Affiliation(s)
- Z Ye
- Institute of Chinese Materia Medica, China Academy of Traditional Chinese Medicine, Beijing
| | | | | | | | | |
Collapse
|
262
|
Feng F, Sun A. [Laparoscopic surgery in benign ovarian cysts]. Zhonghua Fu Chan Ke Za Zhi 1996; 31:375-7. [PMID: 9206173] [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: 02/04/2023]
|
263
|
Sun A, Chang JG, Kao CL, Liu BY, Wang JT, Chu CT, Yuan JH, Chiang CP. Human cytomegalovirus as a potential etiologic agent in recurrent aphthous ulcers and Behçet's disease. J Oral Pathol Med 1996; 25:212-8. [PMID: 8835817 DOI: 10.1111/j.1600-0714.1996.tb01374.x] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
In a preliminary study on anti-human cytomegalovirus (HCMV) antibody (Ab) by ELISA, the serum anti-HCMV/IgG Ab concentrations in 22 patients with recurrent aphthous ulcers (RAU) in the remission stage were found to be significantly higher than in 22 control subjects (121 +/- 42 vs 100 +/- 27, P < 0.05) and in 39 patients with RAU in the active stage (121 +/- 42 vs 88 +/- 45, P < 0.01). Therefore, the potential of HCMV as an etiologic agent in RAU was proposed and studies using the polymerase chain reaction (PCR) and in situ hybridization (ISH) have been performed to investigate the possible presence of HCMV DNA in pre-ulcerative oral aphthous lesions in patients with RAU or Behçet's disease (BD) of the mucocutaneous type. For this purpose, formalin-fixed biopsy specimens were obtained from 13 pre-ulcerative oral aphthous lesions, 2 samples of normal oral mucosa and 1 ileal mucosal lesion from 9 RAU patients and 4 BD patients. Five specimens of normal oral mucosa from 5 normal control subjects and 12 specimens of oral erosive or ulcerative lesions from 12 patients with erosive lichen planus (ELP) were also included. By PCR, HCMV DNA was detected in 5 of the 13 (38.5%) pre-ulcerative oral aphthous lesions, 3 from RAU patients and 2 from BD patients. The ileal mucosa specimen was also HCMV DNA-positive, whereas HCMV DNA was not demonstrated in any of the 7 specimens of normal oral mucosa from RAU patients and normal control subjects; 12 specimens of oral lesions from ELP patients were similarly negative. ISH did not detect HCMV DNA in any of the biopsy specimens from RAU patients and control subjects. Our findings suggest that HCMV may be an etiologic agent in some cases of RAU and BD.
Collapse
Affiliation(s)
- A Sun
- School of Dentistry, National Taiwan University, Taipei, Taiwan, ROC
| | | | | | | | | | | | | | | |
Collapse
|
264
|
Kavanagh MC, Sun A, Hu Q, Hill RP. Comparing techniques of measuring tumor hypoxia in different murine tumors: Eppendorf pO2 Histograph, [3H]misonidazole binding and paired survival assay. Radiat Res 1996; 145:491-500. [PMID: 8600510] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Using five transplantable murine tumors (SCC-VII, B16F1, KHT-C, KHT-LP1, RIF-1), measurements of tumor hypoxia have been made with two techniques which have the potential to be used for assessing oxygenation in human tumors (the Eppendorf pO2 Histograph and binding of [3H]misonidazole) and have been compared with an established radiobiological technique, the paired survival assay. There were significant differences in the pO2 measurements made in individual tumors both within and between the five different tumor types. Significant differences between the tumor types were also found for the [3H]misonidazole binding. A correlation was observed between the mean values of the hypoxic proportion as measured by the paired survival assay and the mean binding of [3H]misonidazole as measured by both tumor activity in dpm/100 mg tissue (r = 0.94, P = 0.02) and the tumor-to-muscle activity ratio (r = 0.87, P = 0.06). No biologically significant correlation was seen between the mean values of the hypoxic proportion from anesthetized mice as measured by the paired survival assay (range 20-58%) and the pooled Eppendorf pO2 Histograph measurements made on groups of tumors. These results with the Eppendorf pO2 Histograph are similar to those reported by others. When both Eppendorf pO2 Histograph measurements and paired survival measurements were made on the same individual KHT-C tumors, it was again found that there was no correlation between the two measurements of hypoxia.
Collapse
Affiliation(s)
- M C Kavanagh
- Department of Research, Ontario Cancer Institute/Princess Margaret Hospital, Canada
| | | | | | | |
Collapse
|
265
|
|
266
|
Fyles A, Milosevic M, Sun A, Kavanagh MC, Levin W, Manchul L, Hill R. 483 Hypoxia in cervix cancer–preliminary results with the eppendorf electrode. Eur J Cancer 1995. [DOI: 10.1016/0959-8049(95)95737-q] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
267
|
Sun A, Li C, Wang M. [Laparoscopic treatment of endometriosis with Nd: YAG laser and microwave]. Zhonghua Fu Chan Ke Za Zhi 1995; 30:138-41. [PMID: 7796644] [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: 01/27/2023]
Abstract
A series of 200 cases of endometriosis were treated laparoscopically by Nd: YAG laser and microwave at Peking Union Medical College Hospital. All the operations were performed under local and topical anesthesia follow-up for 10-48 months revealed good results. Of 76 cases with infertility, 46 (60.5%) conceived after treatment. Of 114 cases with ovarian endometriomas, the cysts were no longer found in 81 cases (71.1%), decreased in size in 24 cases (21.0%). Of 180 cases with pain symptoms, 105 patients (58.3%) were achieved complete relief, Partial relief in 61 cases (33.9%). It has been found that laparoscopic surgery is effective to improve fertile rate for the patients with all the stages of endometriosis. The results showed that the microwave and Nd: YAG laser can be achieved with safety and success. The microwave is safer than Nd: YAG laser and is easier to operate and less expensive.
Collapse
Affiliation(s)
- A Sun
- Peking Union Medical College Hospital, Beijing
| | | | | |
Collapse
|
268
|
Liu R, Liu D, Sun A, Liu G. Simultaneous determination of copper and zinc in the hair of children by pH gradient construction in a flow-injection system. Analyst 1995; 120:569-72. [PMID: 7710129 DOI: 10.1039/an9952000569] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
A flow-injection method is described for the simultaneous determination of copper and zinc with a single detector using the pH gradient technique. Zincon is used as the colour reagent for the spectrophotometric determination. The linear range for the determination of zinc is 0.4-12 micrograms ml-1 and for copper is 0.1-3.0 micrograms ml-1. About 20-30 samples can be determined in one hour. The proposed method has been applied to the determination of zinc and copper in childrens' hair.
Collapse
Affiliation(s)
- R Liu
- Department of Chemistry, Liaocheng Teachers College, Shandong, Peoples' Republic of China
| | | | | | | |
Collapse
|
269
|
Luk JK, Wong EF, Sun A, Wong NL. Cyclic guanosine monophosphate responses to atrial natriuretic factor, brain natriuretic peptide, but not C-type natriuretic peptide, and the characterization of their receptors in rat medullary thick ascending limb. Metabolism 1994; 43:1531-5. [PMID: 7990707 DOI: 10.1016/0026-0495(94)90012-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The effects of atrial natriuretic factor (ANF), brain natriuretic peptide (BNP), and C-type natriuretic peptide (CNP) on renal medullary thick ascending limb (mTAL) have not been fully understood. The aim of this study is to examine the second-messenger responses of rat mTAL to ANF, BNP, and CNP. Characterizations of the ANF, BNP, and CNP receptors in mTAL were also performed by radioligand studies. Results showed that ANF and BNP were both capable of eliciting cyclic guanosine monophosphate (cGMP) responses in mTAL. Conversely, no cGMP response was observed upon stimulation by CNP in mTAL. The presence of ANF receptors was demonstrated by radioligand studies. One receptor site was found, and the Kd and maximum binding capacity were 4.0 +/- 0.45 nmol/L and 277.8 +/- 47.7 fmol/mg protein, respectively. BNP receptors were also found in mTAL, and ANF and BNP were sharing the same receptor. On the contrary, no CNP receptor could be shown by radioligand studies. These results suggest that guanylyl cyclase-coupled receptors (atrial natriuretic peptide receptor-A [ANPR-A]) specific for ANF and BNP are present in rat mTAL, while those for CNP (ANPR-B) are absent. ANF and BNP but not CNP act on mTAL to control water excretion.
Collapse
Affiliation(s)
- J K Luk
- Department of Medicine, University of British Columbia, University Hospital, Vancouver, Canada
| | | | | | | |
Collapse
|
270
|
Abstract
Using the Madin Darby canine kidney (MDCK) cell "calcium switch," we have previously demonstrated that, as MDCK cells establish contact and ultimately form tight junctions, there are marked global and localized changes in intracellular calcium at the sites of cell-cell contact (Nigam et al., 1992, Proc. Natl. Acad. Sci. USA, 89:6162-6166). We have now examined whether intracellular Ca++ is critical to the biogenesis of tight junctions by chelating this ion and monitoring the formation of junctions by electrical, immunocytochemical, and biochemical criteria. Intracellular Ca++ was chelated with the cell-permeant chelators, dimethyl-BAPTA-AM and BAPTA-AM. By digital imaging of fura-2 loaded cells, it was demonstrated that both agents efficiently chelated Ca++ during the "switch" in a dose-dependent manner which paralleled their respective in vitro affinities for Ca++. Chelation of Ca++ during the switch markedly attenuated the development of transepithelial electrical resistance (TER), a measure of tight junction assembly. Immunofluorescent staining of the tight junctional protein, zonula occludens-1 (ZO-1), revealed that chelation of intracellular Ca++ retarded the movement of ZO-1 from intracellular sites to the plasma membrane during the switch. During the development of tight junctions, a fraction of ZO-1 redistributed from the Triton X-100 soluble to the Triton X-100 insoluble pool; chelation of Ca++ during the induction of cell-cell contact prevented this stabilization into the Triton X-100 insoluble fraction. Taken together, these data indicate an important role for intracellular Ca++ in tight junction biogenesis and suggest a specific role for calcium in the early sorting and possible cytoskeletal association of tight junction components.
Collapse
Affiliation(s)
- R O Stuart
- Department of Medicine, Harvard Medical School, Boston, Massachusetts 02115
| | | | | | | | | | | |
Collapse
|
271
|
Licavoli L, Smith A, Sun A, Lipacomb J, White M. Developing appropriate TB in-service programs for nurses. Am J Infect Control 1994. [DOI: 10.1016/0196-6553(94)90221-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
272
|
Abstract
The purpose of this study was to evaluate the effect of levamisole on the immune system of patients with recurrent aphthous ulcers (RAU) or oral lichen planus (OLP) in an open trial. Lymphocyte subsets, serum immunoglobulins, and circulating immune complexes (CIC) in patients with RAU or OLP and in normal control subjects were determined by an indirect immunofluorescence (IIF) technique with monoclonal anti-lymphocyte antibodies, by single radial immunodiffusion, and by precipitation with 3% polyethylene glycol, respectively. In addition, the anti-nuclear antibodies (ANA) and anti-basal cell antibodies (anti-BCA) in sera were detected by an IIF technique. We found a significant improvement in clinical symptoms and normalization of the decreased CD4/CD8 ratio in RAU patients after levamisole treatment. Moreover, the decreased CD4/CD8 ratio, which persisted until the remission stage in the untreated RAU patients, reverted to normal in the active late stage in the levamisole-treated patients. This reversion of aberrant cellular immunity in an earlier stage of the ulcer cycle may explain why RAU patients experience symptom improvement after levamisole treatment. Although RAU patients treated with levamisole for 1 to 3 or 4 months still had higher than normal levels of CIC and serum immunoglobulins, the levels of their IgA and IgM returned to normal values after 4 months of levamisole treatment. The serum ANA detected in 6 patients with RAU and 3 patients with erosive OLP disappeared after 1-22 months of levamisole treatment. The disappearance of serum anti-BCA was also observed in 50% of the anti-BCA-positive patients with erosive OLP after 3-13 months of levamisole treatment.(ABSTRACT TRUNCATED AT 250 WORDS)
Collapse
Affiliation(s)
- A Sun
- School of Dentistry, National Taiwan University, Taipei, ROC
| | | | | | | | | | | |
Collapse
|
273
|
Ma X, Vacek I, Sun A. Generation of alginate-poly-l-lysine-alginate (APA) biomicrocapsules: the relationship between the membrane strength and the reaction conditions. Artif Cells Blood Substit Immobil Biotechnol 1994; 22:43-69. [PMID: 8055097 DOI: 10.3109/10731199409117399] [Citation(s) in RCA: 81] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Alginate-poly-l-lysine-alginate (APA) microcapsules have proven effective in protecting enclosed live cells from immune rejection following transplantation into experimental animals, thereby eliminating the need for immunosuppressive therapy. However, in order for the capsules to remain intact for extended periods in vivo, the thickness of the membrane material must be optimized. In this study, the membrane thickness was examined as an indicator of membrane strength and measured under different reaction conditions. The thickness was found to increase 1) from 4.6 microns to 6.6 microns with an increase in the concentration of sodium alginate from 1.25 (w/v) to 2.0% (w.v); 2) from 4.2 microns to 6.2 microns with an increase in the concentration of the calcium solution from 20 mM to 100mM; 3) from 3.9 microns to 10.3 microns with an increase in the concentration of poly-l-lysine (PLL) from 0.02% (w/v) to 0.08% (w/v); and 4) from 2.3 microns to 7.4 microns with an increase in the reaction time with the PLL from two to seven minutes. On the other hand, membrane thickness decreased 1) from 9.8 microns to 8.6 microns with an increase of the pH in the PLL solution from 5.8 to 9.2; 2) from 13.2m to 5.8 microns with an increase in the molecular weight of PLL from 14,000 to 57,000; 3) from 8.4 microns to 6.0 microns with an increase in the treatment time with 0.9 (w/v) NaCl solution from zero to fifteen minutes and; 4) from 7.5 microns to 6.1 microns with an increase in the treatment time of the second sodium alginate coating from zero to ten minutes. Membrane thickness was inversely proportional to capsule volume expansion during membrane synthesis. By replacing calcium chloride by calcium lactate and eliminating the use of CHES in the construction of capsule membranes, we improved the strength and biocompatibility of our capsules, as evidenced by marked improvements in the survival rates of diabetic mice treated with islet transplants enclosed in the new capsules. These results indicate that it is possible to obtain optimal membrane thickness for a given purpose by creating specific reaction conditions under which membranes are synthesized.
Collapse
Affiliation(s)
- X Ma
- Department of Physiology, University of Toronto, Ontario, Canada
| | | | | |
Collapse
|
274
|
Brown EM, Gamba G, Riccardi D, Lombardi M, Butters R, Kifor O, Sun A, Hediger MA, Lytton J, Hebert SC. Cloning and characterization of an extracellular Ca(2+)-sensing receptor from bovine parathyroid. Nature 1993; 366:575-80. [PMID: 8255296 DOI: 10.1038/366575a0] [Citation(s) in RCA: 1732] [Impact Index Per Article: 55.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Maintenance of a stable internal environment within complex organisms requires specialized cells that sense changes in the extracellular concentration of specific ions (such as Ca2+). Although the molecular nature of such ion sensors is unknown, parathyroid cells possess a cell surface Ca(2+)-sensing mechanism that also recognizes trivalent and polyvalent cations (such as neomycin) and couples by changes in phosphoinositide turnover and cytosolic Ca2+ to regulation of parathyroid hormone secretion. The latter restores normocalcaemia by acting on kidney and bone. We now report the cloning of complementary DNA encoding an extracellular Ca(2+)-sensing receptor from bovine parathyroid with pharmacological and functional properties nearly identical to those of the native receptor. The novel approximately 120K receptor shares limited similarity with the metabotropic glutamate receptors and features a large extracellular domain, containing clusters of acidic amino-acid residues possibly involved in calcium binding, coupled to a seven-membrane-spanning domain like those in the G-protein-coupled receptor superfamily.
Collapse
Affiliation(s)
- E M Brown
- Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts
| | | | | | | | | | | | | | | | | | | |
Collapse
|
275
|
Abstract
A monoclonal antibody, HSA-10 initially produced against acrosome-reacted human sperm was also shown to cross-react with human placenta/trophoblast. Transmission electron microscopy, as well as indirect immunofluorescent assay, demonstrated that HSA-10 was found to react with antigen on the inner acrosome of human sperm. The cognate antigen, designated as STX-10, was found to exist as an aggregate in the native form when analyzed by Sephacryl S-300 gel filtration chromatography. When purified by HSA-10-immunoaffinity chromatography from human placenta extract, STX-10 was found to be predominantly a group of glycoproteins with a subunit molecular mass in the range of 75 +/- 5 kDa, whereas an additional group of three proteins with subunit molecular mass less than 20 kDa were copurified from human sperm extract. A sandwich enzyme immunoassay was designed to quantitatively determine the immunoactivity of STX-10 in solution, using HSA-10 monoclonal antibody for coating and for signal detection via enzyme conjugation. Based on this assay, it was found that STX-10 could be detected only in human sperm and placenta extract, but not in any other human somatic tissues, such as serum, brain, heart, muscle, kidney and liver. The immunoactivity of STX-10 was found to be sensitive to proteolytic digestion, low pH, in the presence of reducing agent, but resistant to treatment with sodium periodate. This observation suggests that HSA-10 specific epitope is a peptide in nature and not a carbohydrate moiety. Results of antifertility studies revealed that HSA-10 significantly inhibited human sperm penetration to zona-free hamster ova. Thus, the results of this study are consistent with those of WHO Workshop evaluations that seem to suggest that STX-10 is a highly gamete-specific antigen localized on the inner acrosome of human sperm and in human trophoblast/placenta. Therefore, it may play an important role during human fertilization and embryo development.
Collapse
Affiliation(s)
- C Y Lee
- Department of Obstetrics and Gynaecology, University of British Columbia, Vancouver, Canada
| | | | | | | | | | | | | | | | | |
Collapse
|
276
|
McManus M, Fischbarg J, Sun A, Hebert S, Strange K. Laser light-scattering system for studying cell volume regulation and membrane transport processes. Am J Physiol 1993; 265:C562-70. [PMID: 8368283 DOI: 10.1152/ajpcell.1993.265.2.c562] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
A simple and relatively inexpensive device utilizing laser light scattering for the study of volume regulatory behavior and membrane transport phenomena in cells cultured on or affixed to a rigid substrate is described in detail. Validation of the method is provided by study of cell types with known volume regulatory responses. The method we describe has numerous advantages over currently available techniques used to monitor cell volume changes. These advantages include 1) the ability to rapidly detect and quantify small cell volume changes on-line, 2) the ability to maintain natural cell morphology, cell surface contacts, and cell-to-cell interactions, 3) the ability to easily control solution temperature and gas and solute composition, and 4) the ability to perform multiple perturbations in a single experiment. The light-scattering system we describe can be modified to allow for simultaneous measurement of light-scattering signals and fluorescence emission from intracellular ion-sensitive probes and membrane potential dyes. In addition, our method may be useful for the study of apical and basolateral membrane transport processes in epithelial monolayer cell cultures.
Collapse
Affiliation(s)
- M McManus
- Department of Medicine, Children's Hospital, Boston, Massachusetts
| | | | | | | | | |
Collapse
|
277
|
Abstract
The frequencies of HLA-DR and DQ antigens in 24 Chinese patients with Behçet's disease (BD) were calculated and compared with those in 130 healthy control Chinese and those in 80 Chinese patients with recurrent oral ulcers (ROU). Although an increased trend of DRw6 and DRw8 antigens in patients with BD was noted, there was no significant difference in frequencies of HLA-DR and DQ antigens between patients with BD and healthy control subjects or patients with ROU after correction of P values (Pc > 0.05). Further analysis of our data of the phenotype frequencies of DRw6 and DRw8 antigens according to the subtypes of BD also showed the increased frequencies of DRw6 and DRw8 antigens in patients with mucocutaneous type of BD as compared with those in healthy control subjects. However, only the phenotype frequency of DRw8 antigen in patients with mucocutaneous type of BD was significantly higher than that in patients with ROU (P < 0.005, Pc < 0.05, relative risk = 17.7, and etiologic fraction = 0.30). This significant increase of the phenotype frequency suggests that the gene coding for HLA-DRw8 antigen in patients with ROU was only partially (30%) responsible for susceptibility to the mucocutaneous type of BD.
Collapse
Affiliation(s)
- A Sun
- School of Dentistry, College of Medicine, National Taiwan University, Taipei, ROC
| | | | | | | |
Collapse
|
278
|
Wang Y, Han M, Li C, Sun A, Guo X, Zhang Y. The value of hysteroscopy in the diagnosis of infertility and habitual abortion. Chin Med Sci J 1992; 7:226-9. [PMID: 1307498] [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: 12/26/2022]
Abstract
Ninety cases of infertility and habitual abortion were analyzed by hysteroscopy between April 1983 and July 1990 in PUMC hospital. Abnormal changes of the uterine cavity were seen in 74.4%. The result of hysterosalpingography corresponded with that of hysteroscopy in 62.5%, and the result of B-ultrasound corresponded to that of hysteroscopy in 52.5%. The diagnosis of adhesion and polyps of the uterine cavity was made accurately by hysteroscopy, and both could be operated under hysteroscopy. After operative removal of the adhesion, an IUD should be put into the uterine cavity for 3 months. In 60 cases operations were performed during or after hysteroscopy. Of the 45 patients followed, 19 achieved pregnancy. Five patients achieved pregnancy after operative removal of the adhesion. It is concluded that hysteroscopy is more important than B-ultrasound and hysterosalpingography in the examination and treatment of infertility.
Collapse
Affiliation(s)
- Y Wang
- PUMC Hospital, CAMS, Beijing
| | | | | | | | | | | |
Collapse
|
279
|
Abstract
BACKGROUND An autoimmune hypothesis for oral lichen planus (OLP) has been proposed, but no anti-basal cell antibodies (anti-BCA) have been found in the sera of patients with OLP. OBJECTIVE Our purpose was to test whether the negative results of anti-BCA assays in sera have been due to the insensitivity of the substrates. Rat esophagus, monkey esophagus, as well as human oral mucosa and skin were used to detect anti-BCA in sera of OLP patients. METHODS By indirect immunofluorescence technique, the rat esophagus was found to be the most sensitive substrate. Therefore it was used as the only substrate to test the presence of anti-epithelial cell antibodies (anti-ECA) in a large group of patients with OLP and other oral mucosal diseases or normal control subjects. RESULTS The results showed that anti-ECA were detected in 54% (34 of 63) of patients with OLP, 71% (15 of 21) of patients with aphthous ulcers, 29% (6 of 21) of patients with oral carcinoma, 20% (2 of 10) of patients with traumatic ulcer, and 7% (1 of 15) of patients with periodontitis but none of the healthy control subjects (n = 41). The presence of anti-BCA in OLP patients' sera was persistent and lasted for a few months or years. There was a decrease in the serum anti-BCA titers in six of eight anti-BCA-positive OLP patients after topical application of triamcinolone. CONCLUSION These anti-BCA that persist longer in OLP patients' sera may be autoantibodies that are raised against altered basal cell-specific antigens.
Collapse
Affiliation(s)
- S C Lin
- Department of Dentistry, Provincial Tao-Yuan Hospital, Taiwan, ROC
| | | | | | | |
Collapse
|
280
|
Abstract
Fluorescence and electrophysiological methods were used to determine the effects of intracellular pH (pHi) on cellular NH4+/K+ transport pathways in the renal medullary thick ascending limb of Henle (MTAL) from CD1 mice. Studies were performed in suspensions of MTAL tubules (S-MTAL) and in isolated, perfused MTAL segments (IP-MTAL). Steady-state pHi measured using 2,7-biscarboxyethyl-5(6)-carboxyfluorescein (BCECF) averaged 7.42 +/- 0.02 (mean +/- SE) in S-MTAL and 7.26 +/- 0.04 in IP-MTAL. The intrinsic cellular buffering power of MTAL cells was 29.7 +/- 2.4 mM/pHi unit at pHi values between 7.0 and 7.6, but below a pHi of 7.0 the intrinsic buffering power increased linearly to approximately 50 mM/pHi unit at pHi 6.5. In IP-MTAL, NH4+ entered cells across apical membranes via both Ba(2+)-sensitive pathway and furosemide-sensitive Na+:K+(NH4+):2Cl- cotransport mechanisms. The K0.5 and maximal rate for combined apical entry were 0.5 mM and 83.3 mM/min, respectively. The apical Ba(2+)-sensitive cell conductance in IP-MTAL (Gc), which reflects the apical K+ conductance, was sensitive to pHi over a pHi range of 6.0-7.4 with an apparent K0.5 at pHi approximately 6.7. The rate of cellular NH4+ influx in IP-MTAL due to the apical Ba(2+)-sensitive NH4+ transport pathway was sensitive to reduction in cytosolic pH whether pHi was changed by acidifying the basolateral medium or by inhibition of the apical Na+:H+ exchanger with amiloride at a constant pHo of 7.4. The pHi sensitivities of Gc and apical, Ba(2+)-sensitive NH4+ influx in IP-MTAL were virtually identical. The pHi sensitivity of the Ba(2+)-sensitive NH4+ influx in S-MTAL when exposed to (apical+basolateral) NH4Cl was greater than that observed in IP-MTAL where NH4Cl was added only to apical membranes, suggesting an additional effect of intracellular NH4+/NH3 on NH4+ influx. NH4+ entry via apical Na+:K+ (NH4+):2Cl- cotransport in IP-MTAL was somewhat more sensitive to reductions in pHi than the Ba(2+)-sensitive NH4+ influx pathway; NH4+ entry decreased by 52.9 +/- 13.4% on reducing pHi from 7.31 +/- 0.17 to 6.82 +/- 0.14. These results suggest that pHi may provide a negative feedback signal for regulating the rate of apical NH4+ entry, and hence transcellular NH4+ transport, in the MTAL. A model incorporating these results is proposed which illustrates the role of both pHi and basolateral/intracellular NH4+/NH3 in regulating the rate of transcellular N H4+ transport in the MTAL.
Collapse
Affiliation(s)
- D Kikeri
- Harvard Center for the Study of Kidney Disease, Harvard Medical School
| | | | | | | |
Collapse
|
281
|
Wang G, Zheng Y, Sun A, Wu S, Wang Z. Polarization pinhole interferometer. Opt Lett 1991; 16:1352-1354. [PMID: 19776968 DOI: 10.1364/ol.16.001352] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
A polarization pinhole interferometer is based on the principles of pinhole diffraction, a common light path, and the polarization technique in its design. It has many advantages, such as adjustable contrast of the fringes, nondestructive testing, and less sensitivity to environmental factors. The instrument can be used extensively in optical element testing and glue-layer testing. The accuracy of the fringe pattern analysis is controlled by the number of sampled points in the fringes. The analysis results of the closed fringe pattern are given.
Collapse
|
282
|
Abstract
Natural killer (NK) cell activity was studied serially in the peripheral blood obtained from 35 patients with recurrent aphthous ulcers (RAU) and from 46 age/sex-matched normal healthy controls. The NK cell activity was assayed by a 4-hr 51Cr release assay using K562 cells as targets. The results showed that the patients in remission (2 weeks of convalesence) had normal NK cell activity compared to that of normal controls. Four stages of evolution (early, exacerbation, postexacerbation, and convalescence) in these patients were further evaluated. Increased NK cell activity in the exacerbation of major aphthous ulcer was noted. In contrast, depressed NK cell activity in postexacerbation and in 1 week of convalescence was found at different effector/target (E/T) ratios. The depressed NK cell activity was interpreted as temporary and a secondary phenomenon in the immunopathogenesis of this disease. Partial restoration of depressed NK cell activity by adding recombinant interleukin-2 (rIL-2) suggests that other factors are also involved in the process or that IL-2 deficiency exists in RAU patients. However, no deficiency of plasma IL-2 and interferon-gamma (IFN-gamma) was noted. The percentage of large granular lymphocytes (LGL, NK/K) was correlated with NK cell activity, with both parameters being depressed in the postexacerbation of RAU patients. NK cell activity of RAU patients was still depressed after the depletion of plastic adherent cells. Suprisingly, in contrast to the remission stage, unresponsiveness to rIL-2 of normal NK cell activity in the exacerbation stage was found. The discrepancy was not associated with different subpopulations of NK heterogeneous cells. Immunopathogenesis of RAU on the NK-IFN-IL-2-IL-2R system needs further clarification.
Collapse
Affiliation(s)
- A Sun
- School of Dentistry, College of Medicine, National Taiwan University, Taipei, Republic of China
| | | | | | | |
Collapse
|
283
|
Sun A. [Treatment of gynecological diseases by laparoscopic operation]. Zhonghua Yi Xue Za Zhi 1991; 71:257-9, 20. [PMID: 1650641] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
A series of 101 cases of gynecological diseases were treated laparoscopically by Nd: YAG laser (n = 68), electrocautery (n = 23) and microwave (n = 10) from September 1989 to November 1990 at PUMC Hospital in Beijing. This series included 64 patients with endometriosis, 17 with ectopic pregnancy, 13 with paraovarian cysts and other ovarian cysts; 4 with hydrosalpinx; 2 with subserosal myomata and 1 with polycystic ovary disease. All the operations were performed under local and topical anesthesia with procaine and dicaine respectively. Follow-up for 2-16 months revealed that, all the cases of endometriosis and other ovarian cysts produced good results. The patients of ectopic pregnancy were treated successfully by mere laparoscopy without laparotomy. No operative complications occurred. The technique, indications and characteristics of the operations are discussed.
Collapse
|
284
|
Abstract
Fetal pancreatic islets were isolated from 21-day pregnant Wistar rats and enclosed in semipermeable alginate-polylysine-alginate capsules. Encapsulated islets that had been previously cultured for eight days in vitro were shown to secrete insulin in response to glucose challenge: low-glucose, high-glucose, and high-glucose + 3-isobutyl-1-methyl-xanthine (IBMX). Transplants of 800-1000 encapsulated cultured fetal islets into the peritoneal cavities of BALB/c mice with streptozotocin-induced diabetes restored normoglycemia for up to 171 days without immunosuppression. When the capsules were removed from 2 of the recipients they both quickly regressed to a diabetic state. Control groups of diabetic mice received unencapsulated, uncultured islets or empty capsules. The mortality rate among these animals was high and none experienced relief from hyperglycemia for longer than 6 days. These results demonstrate that cultured microencapsulated fetal rat islets of Langerhans can release insulin in response to an in vitro glucose challenge, and that transplants of these islets into diabetic mice can restore normoglycemia without the need for immunosuppressive therapy.
Collapse
Affiliation(s)
- M Krestow
- Department of Physiology, University of Toronto, Ontario, Canada
| | | | | | | |
Collapse
|
285
|
Sun A, Grossman EB, Lombardi M, Hebert SC. Vasopressin alters the mechanism of apical Cl- entry from Na+:Cl- to Na+:K+:2Cl- cotransport in mouse medullary thick ascending limb. J Membr Biol 1991; 120:83-94. [PMID: 2020021 DOI: 10.1007/bf01868594] [Citation(s) in RCA: 80] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Experiments were performed using in vitro perfused medullary thick ascending limbs of Henle (MTAL) and in suspensions of MTAL tubules isolated from mouse kidney to evaluate the effects of arginine vasopressin (AVP) on the K+ dependence of the apical, furosemide-sensitive Na+:Cl- cotransporter and on transport-related oxygen consumption (QO2). In isolated perfused MTAL segments, the rate of cell swelling induced by removing K+ from, and adding one mM ouabain to, the basolateral solution [ouabain(zero-K+)] provided an index to apical cotransporter activity and was used to evaluate the ionic requirements of the apical cotransporter in the presence and absence of AVP. In the absence of AVP cotransporter activity required Na+ and Cl-, but not K+, while the presence of AVP the apical cotransporter required all three ions. 86Rb+ uptake into MTAL tubules in suspension was significant only after exposure of tubules to AVP. Moreover, 22Na+ uptake was unaffected by extracellular K+ in the absence of AVP while after AVP exposure 22Na+ uptake was strictly K(+)-dependent. The AVP-induced coupling of K+ to the Na+:Cl- cotransporter resulted in a doubling in the rate of NaCl absorption without a parallel increase in the rate of cellular 22Na+ uptake or transport-related oxygen consumption. These results indicate that arginine vasopressin alters the mode of a loop diuretic-sensitive transporter from Na+: Cl- cotransport to Na+: K+: 2Cl- cotransport in the mouse MTAL with the latter providing a distinct metabolic advantage for sodium transport. A model for AVP action on NaCl absorption by the MTAL is presented and the physiological significance of the coupling of K+ to the apical Na+: Cl- cotransporter in the MTAL and of the enhanced metabolic efficiency are discussed.
Collapse
Affiliation(s)
- A Sun
- Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts 02115
| | | | | | | |
Collapse
|
286
|
Abstract
The frequency of HLA-DR and -DQ antigen occurrence was investigated in 80 Chinese patients with recurrent oral ulcers and 107 matched healthy control subjects of the same ethnic group. No significant differences in the presence of HLA-DQ antigens were found. However, the HLA-DRw9 antigen occurs more frequently in patients with recurrent oral ulcers (p less than 0.0001, corrected p less than 0.005) and may be considered as a genetic marker of the disease in the Chinese population.
Collapse
Affiliation(s)
- A Sun
- School of Dentistry, National Taiwan University, Taipei, ROC
| | | | | | | |
Collapse
|
287
|
Sun A. [Relation between sudden loss of hearing and disturbances of iron metabolism]. Zhonghua Yi Xue Za Zhi 1990; 70:652-4. [PMID: 1963363] [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: 12/29/2022]
|
288
|
Abstract
Eight patients with endobronchial tuberculosis diagnosed on bronchoscopy were treated with antituberculosis drugs and a course of prednisone. The progress of the endobronchial lesions was assessed on repeated examinations. The course of the disease was variable and the endobronchial narrowing improved in two patients only. Hypersensitivity reactions associated with initiation of antituberculosis treatment may constitute a special group where corticosteroid is indicated. In other situations, the usefulness of corticosteroid for treatment of endobronchial tuberculosis is not well documented.
Collapse
Affiliation(s)
- H S Chan
- Department of Medicine, Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, N.T
| | | | | |
Collapse
|
289
|
Abstract
A study of HLA-DR and DQ typing in 44 patients with oral lichen planus (OLP) (28 women and 16 men) and in 107 normal controls of both sexes was performed by using Terasaki's oriental tray. Twenty-eight patients had erosive forms of lichen planus (OLPe). Serologic typing revealed a highly significant increase of HLA-DR 9 and Te 22 antigens in the patient group. Considering our findings and those in other autoimmune diseases, it is hypothesized that OLP is a localized autoimmune disease and the HLA-DR9 in Chinese takes the place of HLA-DR3 in Caucasians in carrying the genes which predispose to the development of autoimmune disease.
Collapse
Affiliation(s)
- S C Lin
- Department of Dentistry Provincial Tao-Yuan Hospital, Taipei, Republic of China
| | | |
Collapse
|
290
|
Kikeri D, Azar S, Sun A, Zeidel ML, Hebert SC. Na(+)-H+ antiporter and Na(+)-(HCO3-)n symporter regulate intracellular pH in mouse medullary thick limbs of Henle. Am J Physiol 1990; 258:F445-56. [PMID: 2156445 DOI: 10.1152/ajprenal.1990.258.3.f445] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
To determine mechanisms of intracellular pH (pHi) regulation in mouse medullary thick limbs (MTAL), pHi was measured in MTAL suspensions and in the isolated perfused MTAL by use of 2',7'-bis(carboxyethyl)-5(6)carboxyfluorescein (BCECF). A method to obtain MTAL suspensions from the mouse outer medulla is reported. Characterization of suspensions with microscopy, anti-Tamm-Horsfall antibody labeling, measurement of O2 consumption, and adenosine 3',5'-cyclic monophosphate responses to antidiuretic hormone indicated that these suspensions were highly purified for viable MTAL tubules. The resting pHi was 7.41 +/- 0.02 (means +/- SE) in N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid-buffered media and 7.23 +/- 0.02 in CO2- HCO3(-)-buffered media, both at extracellular pH 7.4. MTAL tubules exhibited rapid pHi recovery from intracellular acidification. Recovery of pHi was dependent on luminal Na+ (apparent Km = 13.2 +/- 3.2 mM) and was inhibited by amiloride (apparent Ki = 10.6 microM), consistent with the activity of an apical Na(+)-H+ antiporter. Antiporter activity was enhanced by acidification and was diminished at the resting pHi. Recovery from intracellular alkalinization (rapid withdrawal of CO2- HCO3-) was sensitive to the stilbene anion transport inhibitor 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid, Cl(-)-insensitive, and Na(+)-sensitive, consistent with the activity of a Na(+)-(HCO3-)n symporter. Both transporters were significantly involved in steady-state pHi regulation in the presence of CO2- HCO3-. In contrast, the Na(+)-H+ antiporter played the dominant role in steady-state pHi regulation in the absence of CO2- HCO3-.
Collapse
Affiliation(s)
- D Kikeri
- Harvard Center for the Study of Kidney Diseases, Harvard Medical School, Boston, Massachusetts
| | | | | | | | | |
Collapse
|
291
|
Abstract
Differential interference contrast microscopic images were used to assess the cell volume regulatory increase (VRI) response of rat IMCD segments isolated from the mid-inner medullary region of pathogen-free Sprague-Dawley rats and perfused in vitro at 37 degrees C. In the absence of ADH. IMCD cells behaved in an osmometric fashion over the range of extracellular osmolalities 290 to 386 mOsm/kg H2O and had an osmotic space equal to 54.2% of total geometric volume. After initial shrinkage in hypertonic perfusing and bathing solutions (340 mOsm/kg H2O using sucrose), cell volume increased rapidly to the isotonic value only in tubules preincubated in ADH (100 microU/ml). The rates of VIR were: (-ADH) 0.0142 +/- 0.0046 nl.min-1.cm-1 or 0.30 +/- 0.10%/min and (+ADH) 0.7225 +/- 0.1278 nl.min-1.cm-1 or 15.42 +/- 2.31%/min (N = 4; P less than 0.01). An overshoot in cell volume was observed on return to isotonic media only in the ADH exposed tubules showing a hypertonic VRI response, indicating that IMCD cells accumulated solute during hypertonic VRI. In the absence of ADH, one mM dibutyryl cyclic AMP mimicked the effect of hormone on hypertonic VRI. This ADH-dependent VRI process required Na+ and (CO2 + HCO3-) in external media and was reduced or abolished by 0.1 mM amiloride, 0.1 mM 4,4'-diisothiocyanatostilbene-2,2-'-disulfonic acid (DIDS) in peritubular solutions. These data suggest that ADH-dependent, rapid hypertonic cell volume regulation in rat inner medullary collecting duct depends on NA+ uptake, which may be mediated by parallel Na+-H+ and an HCO3(-)-dependent. DIDS-sensitive pathway (such as, Cl+-HCO3- exchanger) in basolateral cell membrane. In addition, a luminal amiloride-sensitive pathway (most likely the cation-selective channel) may contribute to cell volume regulation in the rat IMCD.
Collapse
Affiliation(s)
- A Sun
- Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts
| | | |
Collapse
|
292
|
Abstract
Classically, there is a direct correlation between the lipophilic nature of a molecule and its rate of permeation across a biological membrane, so cell membranes should be more permeable to small, neutral molecules than they are to charged molecular species of similar size. Consequently, the distribution of NH+4 in biological systems is generally believed to be due to the rapid diffusion and equilibration of lipophilic NH3 across cell membranes and the accumulation of NH+4 to be governed by pH differences between compartments. Here we report that renal tubule cells from the medullary thick ascending limb of Henle have an apical membrane which is not only virtually impermeable to NH3, but is also highly permeable to NH+4. These remarkable properties have been incorporated into a model which explains how this renal epithelium can mediate vectorial movement of NH+4 between compartments of equal pH.
Collapse
Affiliation(s)
- D Kikeri
- Department of Medicine Brigham and Women's Hospital, Boston, Massachusetts
| | | | | | | |
Collapse
|
293
|
Sun A, Wu YC. Anti-mucosal antibodies in recurrent aphthous ulcers. Taiwan Yi Xue Hui Za Zhi 1989; 88:122-7. [PMID: 2671255] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Using indirect immunofluorescent antibody technique, anti-mucosal antibodies were evaluated in single or sequentially multiple sera from 21 patients with recurrent aphthous ulcers (RAU), 41 age/sex-matched healthy subjects, and 40 patients with miscellaneous oral mucosal diseases. Although anti-mucosal antibodies were found widely distributed in patients having oral mucosal diseases, there were significantly higher rates of positive anti-mucosal antibodies (15/21, 71%) and circulating intercellular substance (ICS) antibodies (14/21, 67%) in RAU patients as compared with either the healthy subjects or patients with miscellaneous oral mucosal diseases. Circulating ICS antibodies of IgG class were found to be significantly predominant in the active phase of 67% (14/21) RAU patients. The percentage decreased in the order of 25% (4/16) in the remission phase of one week, and to 10% (1/10) in the remission phase of two weeks. The presence of pemphigus-like antibodies might be elicited by the epidermal occult antigens released from damaged tissue and/or due to the transient immunoregulatory dysfunction caused by certain infectious agents.
Collapse
|
294
|
Abstract
Differential interference contrast microscopy was used in combination with standard electrophysiological techniques in the in vitro perfused mouse medullary thick ascending limb of Henle's loop (MAL) to evaluate the cell volume responses of this nephron segment during and following exposure to hypotonic media and to assess the role of antidiuretic hormone (ADH) and net salt absorption on the associated volume regulatory processes. Reductions in extracellular osmolality by 50 mosmol resulted in rapid increases in cell volume of approximately 20% with or without exposure to ADH. Cell volume recovery (volume-regulatory decrease, VRD) was much slower in the presence, than in the absence, of ADH. This hormone-mediated impairment of the VRD response could be overcome by the abolishment of net salt absorption with luminal 10(-4) M furosemide. An inverse linear relationship was observed between the rates of net salt absorption and VRD, indicating a finite ability of this nephron segment to enhance solute exit mechanisms whether induced by increases in transcellular traffic or by hypotonic cell swelling. Finally, returning to the isotonic media resulted in cell shrinkage under all conditions [+/- ADH and +(ADH and furosemide)] consistent with cell solute loss mediating VRD. However, recovery of cell volume back to the initial isotonic control value [post-VRD volume regulatory increase (VRI)] was only observed in ADH-treated tubules and was independent of net salt absorption. The post-VRD VRI response could be abolished by isohydric CO2-HCO3- removal or by addition of 10(-4) M amiloride to the peritubular medium. The latter results suggest that parallel Na+-H+ and Cl- -HCO3- exchangers located in basolateral membranes mediate the post-VRD VRI response.
Collapse
Affiliation(s)
- S C Hebert
- Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts
| | | |
Collapse
|
295
|
Sun A, Wu YC, Kwan HW. Lymphocyte function in patients with recurrent aphthous ulcers. Zhonghua Min Guo Wei Sheng Wu Ji Mian Yi Xue Za Zhi 1987; 20:204-9. [PMID: 3428014] [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: 01/05/2023]
Abstract
Lymphocyte proliferation (LP) responses to mitogens: phytohemagglutinin (PHA), concanavalin A (ConA) and pokeweed mitogens (PWM) were studied in 17 patients with recurrent aphthous ulcers (RAU) of minor type (MiAU) and 20 age/sex-matched healthy subjects. RAU patients elicited normal T-cell and B-cell responses to mitogens in comparison with healthy subjects. Proliferative responses were neither enhanced during active episodes of oral ulceration nor suppressed during periods of remission. It seems unlikely that non-specific lymphocyte dysfunction plays a major role in the pathogenesis of RAU.
Collapse
Affiliation(s)
- A Sun
- School of Dentistry, College of Medicine, National Taiwan University, Taipei, ROC
| | | | | |
Collapse
|
296
|
Sun A, Wu YC, Hsieh RP, Kwan HW, Lu YC. Changes of T-lymphocyte subsets in recurrent aphthous ulcers. Taiwan Yi Xue Hui Za Zhi 1987; 86:718-22. [PMID: 3500270] [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: 01/06/2023]
|
297
|
Abstract
beta-Endorphin appears to have effects on hepatic glucose production in vivo. In order to determine whether beta-endorphin modulates glucose production directly, the effects of beta-endorphin on isolated rat hepatocytes were investigated. This permitted isolation of the effects of beta-endorphin from hormonal and/or neuronal influences. A significant dose-related stimulatory effect of glucagon (10(-10) to 10(-6) mol/L) on both hepatic glucose production and glycogen phosphorylase a activity was demonstrated. No effect of either physiologic (10(-11) to 10(-9) mol/L) or supraphysiologic (10(-6) mol/L) concentrations of beta-endorphin on these parameters, under basal or glucagon-stimulated conditions, could be detected. These results suggest that reported in vivo effects of beta-endorphin to inhibit hepatic glucose production were either indirect or centrally mediated.
Collapse
|
298
|
|
299
|
Sun A, Kwan HW. Serum IgD and IgE concentrations in recurrent aphthous ulcers and oral lichen planus. Zhonghua Ya Yi Xue Hui Za Zhi 1986; 5:7-11. [PMID: 3471303] [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: 01/05/2023]
|
300
|
Sun A, Wu YC, Liang LC, Kwan HW. Serum immunoglobulins, complements and circulating immune complexes in oral lichen planus. Zhonghua Min Guo Wei Sheng Wu Ji Mian Yi Xue Za Zhi 1986; 19:46-51. [PMID: 3816355] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Serum IgG, IgM, IgA, C3, C4 concentrations and circulating immune complexes (CIC) were measured in a series of 46 patients with oral lichen planus (LP). This investigation revealed a significant increase in the level of serum IgG in patients with oral LP as compared with 36 healthy subjects. In erosive LP, serum IgM was also elevated as compared with healthy subjects and patients with the non-erosive type. The results of this study did not support the suggestion that a humoral immunodeficiency underlies oral LP. Elevated serum level of IgM may be considered to represent secondary oral infection during mucosal erosion. The study also demonstrated a significant reduction in serum C4 in both variants of oral LP, but the C3 level was normal. A 3% polyethylene glycol precipitation (PEG-ppt) method was used, no significant amount of CIC could be detected in the patients. It is tempting to speculate that oral LP reflects an immunologic disorder in which serum IgG and C4 is disturbed. However, further investigation is needed to clarify the pathogenesis of oral LP.
Collapse
|