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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] [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.
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327
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Sun A, Hsieh RP, Chu CT, Wu YC. Strong association of HLA-DRw9 in Chinese patients with recurrent oral ulcers. J Am Acad Dermatol 1991; 24:195-8. [PMID: 2007663 DOI: 10.1016/0190-9622(91)70026-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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.
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328
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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] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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329
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Chan HS, Sun A, Hoheisel GB. Endobronchial tuberculosis--is corticosteroid treatment useful? A report of 8 cases and review of the literature. Postgrad Med J 1990; 66:822-6. [PMID: 2099420 PMCID: PMC2429702 DOI: 10.1136/pgmj.66.780.822] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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.
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330
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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.
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331
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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. THE AMERICAN JOURNAL OF PHYSIOLOGY 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] [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-.
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332
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Sun A, Hebert SC. Rapid hypertonic cell volume regulation in the perfused inner medullary collecting duct. Kidney Int 1989; 36:831-42. [PMID: 2559237 DOI: 10.1038/ki.1989.269] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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.
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333
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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.
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334
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Sun A, Wu YC. Anti-mucosal antibodies in recurrent aphthous ulcers. TAIWAN YI XUE HUI ZA ZHI. JOURNAL OF THE FORMOSAN MEDICAL ASSOCIATION 1989; 88:122-7. [PMID: 2671255] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [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.
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335
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Hebert SC, Sun A. Hypotonic cell volume regulation in mouse medullary thick ascending limb: effects of ADH. THE AMERICAN JOURNAL OF PHYSIOLOGY 1988; 255:F962-9. [PMID: 3142272 DOI: 10.1152/ajprenal.1988.255.5.f962] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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.
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336
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Sun A, Wu YC, Kwan HW. Lymphocyte function in patients with recurrent aphthous ulcers. ZHONGHUA MINGUO WEI SHENG WU JI MIAN YI XUE ZA ZHI = CHINESE JOURNAL OF MICROBIOLOGY AND IMMUNOLOGY 1987; 20:204-9. [PMID: 3428014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [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.
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337
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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. JOURNAL OF THE FORMOSAN MEDICAL ASSOCIATION 1987; 86:718-22. [PMID: 3500270] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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338
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Brubaker PL, Sun A, Vranic M. Lack of effect of beta-endorphin on basal or glucagon-stimulated hepatic glucose production in vitro. Metabolism 1987; 36:432-7. [PMID: 2952864 DOI: 10.1016/0026-0495(87)90039-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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.
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339
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340
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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] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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341
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Sun A, Wu YC, Liang LC, Kwan HW. Serum immunoglobulins, complements and circulating immune complexes in oral lichen planus. ZHONGHUA MINGUO WEI SHENG WU JI MIAN YI XUE ZA ZHI = CHINESE JOURNAL OF MICROBIOLOGY AND IMMUNOLOGY 1986; 19:46-51. [PMID: 3816355] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [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.
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342
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Samorajski T, Strong JR, Sun A. Dihydroergotoxine (Hydergine) and Alcohol-induced Variations in Young and Old Mice. ACTA ACUST UNITED AC 1977. [DOI: 10.1093/geronj/32.2.145] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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343
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Eden M, Green JE, Sun A. Feasibility of computer screening of blood films for the detection of malaria parasites. Bull World Health Organ 1973; 48:211-8. [PMID: 4578363 PMCID: PMC2481007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
This paper considers the feasibility of automatic screening procedures for detecting malaria parasites in blood smears prepared in the field. A simple programme for pattern recognition by computer has been developed for thin blood films that identifies parasites as densely stained particles within an erythrocyte. The parasites are detected correctly, but platelets falling accidentally within the outline of an erythrocyte and perhaps reticulocytes may be wrongly classified as parasites. The results indicate that automated detection of parasites is technically feasible but that the technique needs to be refined to reduce the incidence of false positives. A substantial increase in processing speed is required if the automatic procedure is to be economically feasible in screening programmes. The complexity of the equipment and the need for well prepared blood smears point to a possible use of the technique in laboratory checks but not under usual field conditions.
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Sunder JH, Danowski TS, Kenny FM, Khurana RC, Sun A, Nolan S, Stephan T. Pedigrees with diabetes insipidus, diabetes mellitus, and optic atrophy. J Med Genet 1972; 9:408-12. [PMID: 4646547 PMCID: PMC1469075 DOI: 10.1136/jmg.9.4.408] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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