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Itoh S, Lu R, Bao Y, Morrow JD, Roberts LJ, Schuster VL. Structural determinants of substrates for the prostaglandin transporter PGT. Mol Pharmacol 1996; 50:738-42. [PMID: 8863817] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
We recently identified a broadly expressed transporter, PGT, that transports primarily prostaglandins E2 and F2 alpha (PGE2 and PGF2 alpha). In the current study, we examined the structural determinants of potential PGT substrates in detail. Rat PGT was transiently expressed in HeLa cells, the timed uptake of tracer PGE2 was determined in the presence of various concentrations of unlabeled prostanoids; and the resulting inhibitory constants (Ki) were determined by curve-fitting. PGE2 and PGF2 alpha, both known to be transported, had similar affinities for PGT (Ki = 49-50 nM). The strongest interaction (Ki = 13-19 nM) was obtained with prostanoids lacking the 9- or 11-position oxygen groups. A relatively high affinity was also obtained for the bicycloendoperoxides U44069, PGH2, and U46619 (Ki = 29-39 nM). However, a radioactive representative from this group, U46619, was not transported. Structural modifications that produced a moderately reduced affinity relative to that of PGE2 (Ki = 56-286 nM) included reduction in C5 = C6, the addition of a benzene group at position C18, and isomerization at the C8 position. In complementary studies, tracer isoprostane B-iso-PGF2 alpha was found to be transported at approximately 13% the rate of tracer PGE2. Substantially weaker interaction (Ki = > 700 nM) was seen when the 1-position COO- anionic group was neutralized or when the 15(S)-OH group was changed to 15(R)-OH or to 15-keto. These results with the cloned rat PGT are very similar to those previously reported in the in vitro perfused rat lung and indicate that PGT probably represents the predominant route by which certain prostanoids, including F2 isoprostanes, are transported across plasma membranes.
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202
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Atwa MA, Smallridge RC, Burch HB, Gist ID, Lu R, Abo-Hashem EM, el-Kannishy MH, Burman KD. Immunoglobulins from Graves' disease patients stimulate phospholipase A2 and C systems in FRTL-5 and human thyroid cells. Eur J Endocrinol 1996; 135:322-7. [PMID: 8890723 DOI: 10.1530/eje.0.1350322] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
We have studied the effects of immunoglobulin G from Graves' disease patients on phospholipase A2 (PLA2) and C(PLC) systems in FRTL-5 and human thyroid cells. Immunoglobulin G (IgG) from Graves' disease patients stimulated arachidonic acid (AA) release in a time- and dose-dependent manner. In FRTL-5 thyroid cells, removal of external calcium had no significant effect on the IgG (20 micrograms/ml)-induced AA release in FRTL-5 thyroid cells. U-73122 (3 mumol/l), a PLC inhibitor, and quinacrine (100 mumol/l) but not U-26384 (5 mumol/l), PLA2 inhibitors, blocked the IgG-induced (20 micrograms/ml) AA release in FRTL-5 thyroid cells. Immunoglobulin G (100 micrograms/ml) also stimulated accumulation of inositol-1,4,5-triphosphate (IP3) in a time- and dose-dependent (20-300 micrograms/ml) manner in FRTL-5 cells. Immunoglobulin G from Graves' disease patients induced a significant increase of IP3 production (p = 0.01) compared to IgG from normal subjects. Removal of external calcium had no significant effect on the IgG-induced IP3 production. The PLC inhibitor U-73122 completely blocked IgG-induced IP3 production from FRTL-5 thyroid cells. Also, in human thyroid cells, IgG from Graves' disease patients induced a significant increase of AA release (p = 0.001) and IP3 production (p = 0.004) compared to the IgG from normal subjects. These data indicate that IgG from Graves' disease patients induced PLA2 activity that was PLC dependent, a pattern referred to as sequential activation. Our studies suggest that IgG from Graves' disease patients activates PLA2 and PLC systems in FRTL-5 and human thyroid cells. These signal transduction pathways could be involved in the pathogenesis of Graves' disease and future studies are warranted to investigate this area.
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203
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Lu R, Kanai N, Bao Y, Schuster VL. Cloning, in vitro expression, and tissue distribution of a human prostaglandin transporter cDNA(hPGT). J Clin Invest 1996; 98:1142-9. [PMID: 8787677 PMCID: PMC507536 DOI: 10.1172/jci118897] [Citation(s) in RCA: 176] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
We recently identified a cDNA in the rat that encodes a broadly expressed PG transporter (PGT). Because PGs play diverse and important roles in human health and disease, we cloned human PGT (hPGT) from an adult human kidney cDNA library. A consensus sequence (4.0 kb) derived from several clones, plus 3' polymerase chain reaction amplification, exhibited 74% nucleic acid identity and 82% amino acid identity compared to rat PGT. When transiently expressed in HeLa cells, a full-length clone catalyzed the transport of PGE1, PGE2, PGD2, PGF2alpha, and, to a lesser degree, TXB2. Northern blotting revealed mRNA transcripts of many different sizes in adult human heart, placenta, brain, lung, liver, skeletal muscle, pancreas, kidney, spleen, prostate, ovary, small intestine, and colon. hPGT mRNAs are also strongly expressed in human fetal brain, lung, liver, and kidney. The broad tissue distribution and substrate profile of hPGT suggest a role in the transport and/or metabolic clearance of PGs in diverse human tissues.
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204
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Lui Y, Fang D, Lu R. [A study on the loss of heterozygosity at the APC/MCC and DCC genetic loci in colorectal cancers]. ZHONGHUA NEI KE ZA ZHI 1996; 35:439-43. [PMID: 9592312] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
To evaluate the role of APC, MCC and DCC genes in the development and progression of colorectal cancers, loss of heterozygosity (LOH) at these genetic loci was investigated in 41 surgically resected specimens of colorectal cancer by using polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) analysis. LOH at APC or/and MCC was detected in 38.9% (14/38) of the informative cases; at the APC in 28.0% (7/25) and at MCC locus in 36.4% (8/22). LOH at DCC genetic locus was detected in 55.3% (21/38) of the informative cases. LOH rates DCC gene in the cancer specimens with lymphnode metastasis (80.0%) and in Dukes' stage III and IV (71.4%) were significantly higher than that in specimens without lymphnode metastasis (39.1%) and in Dukes' stage I and II (35.3%) (P < 0.05). Our results suggest that LOH at APC/MCC and DCC is the common genetic alterations in colorectal cancer and DCC genetic LOH assay may be useful in predicting the prognosis of patients with colorectal cancer.
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205
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Lu R, Goerzen DW, Rank GH. Use of RAPD analysis for in situ identification of Ascosphaera aggregata and Ascosphaera larvis in larval cadavers of the alfalfa leafcutting bee, Megachile rotundata. J Invertebr Pathol 1996; 68:78-83. [PMID: 8683161 DOI: 10.1006/jipa.1996.0061] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Chalkbrood of the alfalfa leafcutting bee, Megachile rotundata, is caused by the fungus Ascosphaera aggregata. We used random amplified polymorphic DNA (RAPD) analysis for the in situ identification of A. aggregata and a related species, Ascosphaera larvis, in larval cadavers of M. rotundata. A simple DNA extraction method was developed to preferentially isolate DNA from fungal spores on the cadaver surface, or from ascocysts beneath the cuticle. Similar banding patterns were obtained in A. aggregata-infected larval cadavers from different sources and geographic areas. The RAPD banding pattern of cadavers infected with A. aggregata differed from that of healthy leafcutting bee prepupae. RAPD analyses of cadavers infected with A. aggregata and A. larvis resulted in similar banding profiles as those obtained from corresponding pure fungal cultures of the two species. This suggests that the RAPD bands of infected cadavers were amplified from fungal DNA, rather than from other DNA associated with the leafcutting bee cadaver. The banding patterns of "sporulating" and "non-sporulating" chalkbrood cadavers exhibited no differences; this provides the first definitive evidence that both forms of the disease result from infection with A. aggregata.
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206
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Tao H, Wang Q, Lu R. [Prevention of epidural scar adhesion following lumb spine operation]. ZHONGHUA WAI KE ZA ZHI [CHINESE JOURNAL OF SURGERY] 1996; 34:344-7. [PMID: 9594174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Four biomaterials including pork fat (PF), glutaradehyde crosslinked pork peritonium (GCP), glutaradehyde cross-linked human amnion (GCA) and freeze-dried human amnion (FDA) dura were compared for their ability to prevent the dura from adhesion in 24 dogs. Noncontiguous laminectomies were performed on each dog. Laminectomized areas where the above mentioned 4 materials put randomly were served as experimental groups while laminectomized areas with autologous fat transplants put in place were served as standard control and empty control was set with the area left untreated. The formation of fibrosis and the adhesion of the dura were evaluated at 1, 2, 3, 4, 6, 12 weeks after operation by using a double-blind protocol. Methods of observation included gross anatomical evaluation, histological evaluation, computer-assisted image analysis, fibroblasts counting and measurement of SCEP. The results showed: 1. The epidural scar arose from the raw surface of erector spinal muscles and the bony edges created by the procedure; 2. Putting a suitable obstructor between the dura and the erector spinae muscle would make dura be exempted from adhesion; 3. The interpositional membrane should be tucked in between the bony edges in close proximity to the bony surface without leaving any room; 4. GCA seems to be efficient in preventing dural adhesion and reducing the invasion of the scar tissue in the spinal canal.
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207
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Schuster VL, Lu R, Kanai N, Bao Y, Rosenberg S, Prié D, Ronco P, Jennings ML. Cloning of the rabbit homologue of mouse 'basigin' and rat 'OX-47': kidney cell type-specific expression, and regulation in collecting duct cells. BIOCHIMICA ET BIOPHYSICA ACTA 1996; 1311:13-9. [PMID: 8603097 DOI: 10.1016/0167-4889(95)00186-7] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Monoclonal antibody '4D4' was generated against a gel-purified 43-50 kDa fraction of rabbit erythrocyte (RBC) ghosts. Immunoblots of rabbit RBCs, skeletal muscle, and kidney, and of a rabbit cortical collecting duct cell line (RC.SV3) yielded broad bands of 30-70 kDa that migrated at approximately 31 kDa after deglycosylation. In kidney sections, 4D4 labeled the basal plasma membranes of the proximal tubule, medullary thick ascending limb of Henle, cortical, medullary, and papillary collecting ducts, and papillary surface epithelium, as well as the lateral membranes of alpha and beta-type intercalated cells. Antibody 4D4 was used to clone a full-length kidney cDNA, which predicted a 31 kDa immunoglobulin-like glycoprotein with high homology to mouse 'gp42' or 'basigin', human 'M6' or 'EMMPRIN', rat 'OX-47' or 'CE-9', and avian 'neurothelin', 'HT7', or '5A11'. When heterologously expressed in HeLa cells, glycosylated immunoreactive protein was expressed at the plasma membrane. In the case of the endogenous protein in RC.SV3 cells, interferon-gamma and A23187 decreased, and fetal calf serum increased, steady-state mRNA levels. Thus, this molecule exhibits a high degree of cell type-specific expression in the kidney and undergoes regulation by cytokines and serum in kidney epithelial cells.
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MESH Headings
- Amino Acid Sequence
- Animals
- Antigens, CD
- Antigens, Neoplasm
- Antigens, Surface
- Avian Proteins
- Base Sequence
- Basigin
- Blood Proteins
- Cell Line
- Cell Membrane/chemistry
- Cloning, Molecular
- Erythrocytes/chemistry
- Gene Expression Regulation/physiology
- HeLa Cells
- Humans
- Kidney/chemistry
- Kidney Tubules, Collecting/chemistry
- Kidney Tubules, Collecting/cytology
- Kidney Tubules, Collecting/metabolism
- Membrane Glycoproteins/analysis
- Membrane Glycoproteins/genetics
- Mice
- Molecular Sequence Data
- Molecular Weight
- Muscle, Skeletal/chemistry
- Rabbits
- Rats
- Sequence Analysis, DNA
- Sequence Homology, Amino Acid
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208
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Chehab FF, Lim ME, Lu R. Correction of the sterility defect in homozygous obese female mice by treatment with the human recombinant leptin. Nat Genet 1996; 12:318-20. [PMID: 8589726 DOI: 10.1038/ng0396-318] [Citation(s) in RCA: 967] [Impact Index Per Article: 34.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The sterility of male and female homozygous ob/ob mice is a recognized feature of the ob mutation (1). Whereas ob/ob males can occasionally reproduce if maintained on a restricted diet, ob/ob females are always sterile (2). Thinning of the ob/ob females to normal weight by diet-restriction failed to correct their sterility. Early sexual development is normal in ob/ob females; however, ovulation never follows and the mice remain prepuberal indefinitely with no occurrence of oestrus cycles. Reproductive hormones are reduced in ob/ob females (3) demonstrating a functional defect from the hypothalamic-pituitary axis (4-6). The ovaries of ob/ob females are capable of producing viable eggs when transplanted into lean female recipients (7). Reconstitution of reproductive functions in the ob/ob female necessitates delivery of hypothalamic extracts to the third ventricle (8) and administration of pituitary extract (9), gonadotropic hormones (10), progesterone (11) and relaxin (12). These previous findings demonstrate that the sterility of ob/ob females is caused by an insufficiency of hormones at the hypothalamic-pituitary level rather than physical hindrance of copulatory activity, pregnancy and parturition caused by excess adipose tissue. We show here that repeated administration of only the recombinant human ob protein, leptin, into homozygous female ob/ob mice can correct their sterility, thus resulting in ovulation, pregnancy and parturition.
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209
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Shen X, Lu R, Wu M. [Metabolism and utilization of calcium derived from hydrolysed oyster shell in rats]. ZHONGHUA YU FANG YI XUE ZA ZHI [CHINESE JOURNAL OF PREVENTIVE MEDICINE] 1996; 30:91-3. [PMID: 8758856] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Experimental rats modeled on calcium deficiency were fed with calcium derived from hydrolysed oyster shell, calcium carbonate and calcium chloride respectively, equivalent to 45 mg a day, for four weeks to study their bioavailability. Calcium contents in the blood, urine, feces and bone of rats were determined with atomic absorption spectrometry and EDTA complex titration, and their bone density was measured with densitometry. Results showed proportions of calcium absorption and retention were 67.3% +/- 16.7% and 64.6% +/- 17.5%, respectively, in rats fed with calcium from hydrolysed oyster, and their femur calcium content and bone density (BMC/BW) 131.2 +/- 1.48 mg/g and 0.318 +/- 0.034 g/cm2, respectively, significantly higher than those in the rats fed with calcium carbonate. There were no significant difference in blood calcium contents, weight gains and feed intake between those three groups of rats. It suggests that calcium derived from hydrolysed oyster shell may be absorbed and utilized more easily than calcium carbonate.
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210
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Kanai N, Lu R, Bao Y, Wolkoff AW, Schuster VL. Transient expression of oatp organic anion transporter in mammalian cells: identification of candidate substrates. THE AMERICAN JOURNAL OF PHYSIOLOGY 1996; 270:F319-25. [PMID: 8779893 DOI: 10.1152/ajprenal.1996.270.2.f319] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The cDNA for the rat liver organic anion-transporting polypeptide "oatp" has been shown to encode transport of bromosulfophthalein (BSP) and bile salts in Xenopus oocytes (E. Jacquemin, B. Hagenbuch, B. Stieger, A. W. Wolkoff, and P. J. Meier. Proc. Natl. Acad. Sci. USA 91: 133-137, 1994). Because oatp mRNA is expressed strongly in the kidney, we sought to determine whether renal oatp might play a role in the known secretion of a large variety of organic anions by the kidney. We transiently expressed a full-length oatp cDNA, cloned in pSPORT, in HeLa cell monolayers using the recombinant vaccinia virus vtf7-3. We tested an array of organic anions as candidate substrates by determining their ability to compete with tracer BSP for transport. HeLa cell monolayers transfected with the oatp cDNA transported tracer BSP and taurocholate at rates substantially higher than monolayers transfected with a control plasmid. Thus good expression can be obtained with the vaccinia-HeLa system using a standard plasmid cloning vector. BSP transport varied as a function of the medium albumin, ionic conditions, and pH in a fashion similar to that in Xenopus oocytes. Several organic anions known to be secreted by the classic secretory pathway, including p-aminohippurate (PAH), phenol red, and indigo carmine (10 microM) failed to inhibit oatp-mediated BSP transport. Direct testing using tracers revealed no oatp-mediated transport of sulfate, urate, PAH, several eicosanoids, or unconjugated or conjugated bilirubin. On the other hand, BSP transport was inhibited by approximately 50% by 10 microM corticosterone sulfate, spironolactone, and several other steroids. We conclude that the functional properties of oatp expressed in the HeLa cell/vaccinia transient expression system are comparable to those following expression in Xenopus oocytes and that steroids are likely to represent high-affinity endogenous oatp substrates. The latter hypothesis is addressed in greater detail in a companion paper.
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211
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Kanai N, Lu R, Bao Y, Wolkoff AW, Vore M, Schuster VL. Estradiol 17 beta-D-glucuronide is a high-affinity substrate for oatp organic anion transporter. THE AMERICAN JOURNAL OF PHYSIOLOGY 1996; 270:F326-31. [PMID: 8779894 DOI: 10.1152/ajprenal.1996.270.2.f326] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Although substantial evidence indicates that estradiol-17 beta (E2) is conjugated to the glucuronide in the kidney and then excreted by a direct tubular secretory route and that the liver transports E2 glucuronides via carrier-mediated mechanisms, the transporters involved in these processes have not been identified. The so-called "organic anion-transporting polypeptide" (i.e., oatp) has a number of known substrates, including bromosulfophthalein (BSP) and taurocholic acid (TCA) (E. Jacquemin, B. Hagenbuch, B. Stieger, A. W. Wolkoff, and P. J. Meier. Proc. Natl. Acad. Sci. USA 91: 133-137, 1994). In a companion study, we determined that steroid hormones represent a class of hormones that interact strongly with oatp when the latter is transiently expressed in vitro. Here, we studied more extensively steroids and steroid anion conjugates as candidate oatp substrates. In HeLa cell monolayers transfected with a full-length oatp cDNA, [3H]estradiol 17 beta-D-glucuronide ([3H]E2-17G) was transported with a signal-to-noise ratio of 15:1 over that of monolayers transfected with a control plasmid. The affinity of oatp for [3H]E2-17G was significantly higher than that for TCA (K(m) of 3 microM vs. 27 microM, respectively). In contrast to E2-17G, unconjugated estradiol (E2) was not significantly transported by oatp. Several unconjugated steroids and anionic steroid conjugates were tested for their ability to compete with tracer E2-17G for oatp-mediated transport. Conjugation at the 17 or 3 position with the anion of a strong acid (sulfate) resulted in a greater degree of inhibition of tracer E2-17G transport than did conjugation at the 17 or 3 position with an uncharged group (acetate), suggesting that the strength of the negative charge at these positions is an important determinant of the affinity of a given steroid conjugate for oatp. We conclude that the preferred substrates for oatp are steroids with a strong 17- or 3-position anionic group. Since steroid sulfotransferases and glucuronosyltransferases are expressed in the proximal tubule, as is oatp, the transporter may serve as an apical exit pathway for steroids following their conjugation within the tubule cell.
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212
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Lu R, Kanai N, Bao Y, Wolkoff AW, Schuster VL. Regulation of renal oatp mRNA expression by testosterone. THE AMERICAN JOURNAL OF PHYSIOLOGY 1996; 270:F332-7. [PMID: 8779895 DOI: 10.1152/ajprenal.1996.270.2.f332] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
A recently cloned cDNA encodes the so-called "organic anion-transporting polypeptide" (i.e., oatp), which is expressed in rat liver and in the kidney S3 proximal tubule. functional characterization of the cloned transporter indicates that estradiol 17 beta-D-glucuronide is a major substrate. Because the urinary excretion of glucuronidated steroids differs between males and females, we hypothesized that renal oatp expression may be under sex hormone control. Total RNA was isolated from male or female kidneys and probed with a digoxigenin-labeled oatp antisense riboprobe. Expression of oatp mRNA expression was quantitated by densitometry from Northern blots. Male kidneys expressed at least six distinct oatp transcripts (approximately 4.0, 3.2, 2.9, 2.6, 1.7, and 1.2 kb). Of these, the 3.2-kb band was consistently the strongest. In female rats, renal oatp mRNA expression was markedly less, such that only the 3.2-kb band was consistently detectable. Administering testosterone to female rats increased, and administering estradiol (E2) to male rats decreased, the steady-state levels of renal oatp mRNA. Gonadectomized male and female rats, as well as adrenalectomized male rats, were given pharmacological hormone replacement (testosterone, E2, or dexamethasone, respectively) by subcutaneous osmotic minipump. Castration of male rats produced a dramatic drop in the steady-state level of all six renal oatp transcripts. These were returned to normal by testosterone replacement. In contrast, there was no regulation of hepatic oatp mRNA expression by testosterone. Renal oatp mRNA expression in female rats was mildly increased by oophorectomy. Administration of E2 to oophorectomized females moderately suppressed renal oatp mRNA expression. Adrenalectomy produced a small decrease in oatp expression, but dexamethasone replacement failed to return expression to normal. We conclude that renal oatp mRNA expression is under strong (stimulatory) testosterone control and perhaps weaker (inhibitory) estrogen control. We speculate that this regulation of renal oatp expression is important in modulating the renal tubular secretion of conjugated E2.
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213
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Lu R, Wang M. An evaluation of the social benefits of population education in China's ordinary middle schools. CHINESE JOURNAL OF POPULATION SCIENCE 1996; 8:103-17. [PMID: 12291449] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/19/2023]
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214
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Lu R, Hofmeister AM. Infrared fundamentals and phase transitions in CO2 up to 50 GPa. PHYSICAL REVIEW. B, CONDENSED MATTER 1995; 52:3985-3992. [PMID: 9981524 DOI: 10.1103/physrevb.52.3985] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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215
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Kanai N, Lu R, Satriano JA, Bao Y, Wolkoff AW, Schuster VL. Identification and characterization of a prostaglandin transporter. Science 1995; 268:866-9. [PMID: 7754369 DOI: 10.1126/science.7754369] [Citation(s) in RCA: 308] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Carrier-mediated prostaglandin transport has been postulated to occur in many tissues. On the basis of sequence homology, the protein of unknown function encoded by the rat matrin F/G complementary DNA was predicted to be an organic anion transporter. Expression of the matrin F/G complementary DNA in HeLa cells or Xenopus oocytes conferred the property of specific transport of prostaglandins. The tissue distribution of matrin F/G messenger RNA and the sensitivity of matrin F/G-induced prostaglandin transport to inhibitors were similar to those of endogenous prostaglandin transport. The protein encoded by the matrin F/G complementary DNA is thus preferably called PGT because it is likely to function as a prostaglandin transporter.
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216
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Shen X, Lu R, He G. [Effects of lyophilized royal jelly on experimental hyperlipidemia and thrombosis]. ZHONGHUA YU FANG YI XUE ZA ZHI [CHINESE JOURNAL OF PREVENTIVE MEDICINE] 1995; 29:27-9. [PMID: 7600886] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Rat models with experimental hyperlipidemia were fed with lyophilized royal jelly 700 mg/kg body weight daily for six weeks. Results showed lyophilized royal jelly can reduce serum cholesterol level (P < 0.01) and increase high-density lipoprotein-cholesterol level (P < 0.05). Lyophilized royal jelly can also increase the red cell deformability (RCD) and decrease plasma fibrinogen level. Thrombus was formed less in trial animals than in controls with a statistical significance. It suggested lyophilized royal jelly can be used in preventing and treatment of hyperlipidemia, and improving highly-coagulant status of blood.
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217
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Huang N, Chen YR, Luo JM, Yi J, Lu R, Xiao J, Xue ZN, Liu XH. In vitro investigation of blood compatibility of Ti with oxide layers of rutile structure. J Biomater Appl 1994; 8:404-12. [PMID: 8064591 DOI: 10.1177/088532829400800406] [Citation(s) in RCA: 100] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Structure characteristics of titanium oxide layer on titanium matrix were investigated by Rutherford Backscattering Spectroscopy (RBS), Auger Electron Spectroscopy (AES) and X-ray diffraction. It has been identified that the titanium oxide layers had rutile structure. The blood compatibility of the titanium oxide layers of different thickness was studied by blood clotting time measurement. It was shown that as the thickness of the titanium oxide layers increased, blood compatibility of these layers was obviously improved.
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218
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Lu R, Hubbard JR, Martin BR, Kalimi MY. Roles of sulfhydryl and disulfide groups in the binding of CP-55,940 to rat brain cannabinoid receptor. Mol Cell Biochem 1993; 121:119-26. [PMID: 8316228 DOI: 10.1007/bf00925970] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The roles of sulfhydryl and disulfide groups in the specific binding of synthetic cannabinoid CP-55,940 to the cannabinoid receptor in membrane preparations from the rat cerebral cortex have been examined. Various sulfhydryl blocking reagents including p-chloromercuribenzoic acid (p-CMB), N-ethylmaleimide (NEM), o-iodosobenzoic acid (o-ISB), and methyl methanethiosulfonate (MMTS) inhibited the specific binding of [3H]CP-55,940 to the cannabinoid receptor in a dose-dependent manner. About 80-95% inhibition was obtained at a 0.1 mM concentration of these reagents. Scatchard analysis of saturation experiments indicates that most of these sulfhydryl modifying reagents reduce both the binding affinity (Kd) and capacity (Bmax). On the other hand, DL-dithiothreitol (DTT), a disulfide reducing agent, also irreversibly inhibited the specific binding of [3H]CP-55,940 to the receptor and about 50% inhibition was obtained at a 5 mM concentration. Furthermore, 5 mM DTT was abelt to dissociate 50% of the bound ligand from the ligand-receptor complex. The marked inhibition of [3H]CP-55,940 binding by sulfhydryl reagents suggests that at least one free sulfhydryl group is essential to the binding of the ligand to the receptor. In addition, the inhibition of the binding by DTT implies that besides free sulfhydryl group(s), the integrity of a disulfide bridge is also important for [3H]CP-55,940 binding to the cannabinoid receptor.
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219
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Huang Y, Lu R, Halpern JB. Radiation and collisional energy transfer among the A (2)Pi(i) and X(2)Sigma(+) states of CN. APPLIED OPTICS 1993; 32:981-986. [PMID: 20802777 DOI: 10.1364/ao.32.000981] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Laser-photolysis-laser-induced-fluorescence methods are used to characterize the collisional energy transfer between CN (A (2)Pi(i)) and (X (2)Sigma(+)) states and to measure radiative lifetimes of the (A (2)Pi(i)) nu' = 2-7 vibrational levels. In addition, use of the A (2)Pi(i) ? X (2)Sigma(+) system for the laser-induced-fluorescence determination of (X (2)Sigma(+)) populations is demonstrated and discussed.
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Abstract
Failures at composite resin/porcelain interfaces under shear-like loading were examined. Porcelain surfaces were treated with hydrofluoric acid and/or one of two silane coupling agents, using two different composite resin cements. The results showed that after seven days storage, bond strengths of specimens which had undergone porcelain surface treatment were greater than the cohesive strength of the porcelain itself, resulting in brittle fracture of the porcelain. The diluted restorative composite resin performed as well as the commercial composite resin cement. Silane pretreatment of porcelain was important as the bond strength of etched/silane primed specimens was significantly higher than the etched only specimens. However, one primer appeared to be more efficient than the other in bond promotion. Some explanations for the differences in bond strengths are offered.
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Lu R, Liu M. Clinical application of single acupoint for treatment. J TRADIT CHIN MED 1991; 11:284-5. [PMID: 1795546] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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222
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Lu R. [Defecographic diagnosis of puborectalis syndrome]. ZHONGHUA YI XUE ZA ZHI 1991; 71:633-4. [PMID: 1666978] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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223
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Lu R, Palter K, Hillman N. A method for obtaining a pure population of t6/t6 mouse embryos prior to developmental arrest. THE JOURNAL OF EXPERIMENTAL ZOOLOGY 1991; 260:125-9. [PMID: 1791419 DOI: 10.1002/jez.1402600116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Developmental delay, as the result of ovariectomy, causes mouse blastocyst embryos obtained from +/t6 inter se matings to separate into two distinct populations when placed into outgrowth medium. One population remains as free floating embryos for a significantly longer period of time than the other population. Based upon their phenotypic expression following attachment and outgrowth, the former population was considered to be composed entirely of t6/t6 embryos and the latter, to be composed of +/+ and +/t6 embryos (Nadijcka et al., '81). In the present study, two-dimensional gel electrophoresis identified the embryos which were delayed in attachment as t6/t6 embryos since they synthesize only p63/6.9a, a product of the Tcp-1a locus which is unique to t-haplotypes. The early attaching embryos, assumed to be +/+ and +/t6, synthesize both p63/6.9a and b. The p63/6.9b protein is coded for by Tcp-1b on the wild-type homologous chromosome. Control +/+ blastocyst embryos synthesize only p63/6.9b. The data show that t6/t6 embryos can be identified prior to their lethal period and, thus, subjected to comparative studies to determine the cause of their lethality. Developmental delay is the first method established to enable one to unambiguously identify t6/t6 embryos prior to developmental arrest.
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Chen Z, Ma X, Zho Y, Lu R, Song J. [Preliminary study on soilless cultivation techniques of Panax quinquefolium L]. ZHONGGUO ZHONG YAO ZA ZHI = ZHONGGUO ZHONGYAO ZAZHI = CHINA JOURNAL OF CHINESE MATERIA MEDICA 1991; 16:528-30, 574. [PMID: 1804197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Our experiment has shown 1. Vermiculite with sand (volume 1:1) is a good substrate of soil for American Ginseng. The yield and contents of ginsenoside of American ginseng in this soilless substrate are a little higher than those in ordinary soil. 2. This kind of substrate can be used continuously with fewer occurrences of insect pest and plant diseases and contributes significantly to the reduction of production cost.
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Crew AD, Stoodley KD, Lu R, Old S, Ward M. Preliminary clinical trials of a computer-based cardiac arrest alarm. Intensive Care Med 1991; 17:359-64. [PMID: 1744329 DOI: 10.1007/bf01716197] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The use of a high reliability cardiac arrest alarm utilising the continuously monitored values of patient heart rate and mean arterial blood pressure is described, based on a sample of 167 patients monitored for a total of 5116 h. The analogue heart rate and mean blood pressure signals are sampled at 1 s intervals, and a smoothing algorithm is applied to each of the resulting series which rejects artefacts, and identifies slope and step changes in each. Certain combinations of events in the 2 series, occurring within a preset time window, determine whether a cardiac arrest alarm or warning signal should be activated by the system. A total of 30 acute events occurring in 14 patients during the course of the study were each identified within 10 s. No cardiac arrest event was misdiagnosed by the algorithm during the period of the study. The algorithm also generates warnings which may have predictive value, and which will be the subject of further research. A final false alarm rate of about 1/200 h of monitoring was observed in adults (1/50 h in children), with evidence that these rates could be substantially improved.
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