4051
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Liu Z, D'Amore PA, Mikati M, Gatt A, Holmes GL. Neuroprotective effect of chronic infusion of basic fibroblast growth factor on seizure-associated hippocampal damage. Brain Res 1993; 626:335-8. [PMID: 8281447 DOI: 10.1016/0006-8993(93)90598-h] [Citation(s) in RCA: 53] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Basic fibroblast growth factor (bFGF) has been shown to have neuroprotective effects in animal models of ischemia. To determine whether bFGF is protective against seizure-induced brain damage, we administered bFGF through osmotic pumps prior to, and after treatment with kainic acid (KA). Recombinant bFGF, CS23, a modified human bFGF, was infused into the lateral ventricles in rats for 2 days before and 5 days after the injection of KA. Control rats received equal volumes of phosphated saline over the same period of time. Infusion of 5 micrograms/ml of bFGF (0.5 microliter/h) did not modify the latency and duration of seizures induced by intraperitoneal injections of KA. However, bFGF prevented cell loss in the hippocampus in 80% of the rats. In control rats, cell loss in the hippocampus was found in all rats. These results indicate that bFGF has a substantial neuroprotective effect.
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4052
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Ostrow RS, Liu Z, Schneider JF, McGlennen RC, Forslund K, Faras AJ. The products of the E5, E6, or E7 open reading frames of RhPV 1 can individually transform NIH 3T3 cells or in cotransfections with activated ras can transform primary rodent epithelial cells. Virology 1993; 196:861-7. [PMID: 8396814 DOI: 10.1006/viro.1993.1547] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Rhesus papillomavirus (RhPV) type 1 was recently shown to cooperate with the activated ras oncogene to transform primary rodent epithelial cells at a level comparable to HPV 16. In similar cotransfection studies, subgenomic portions of RhPV 1 driven by either their natural or a strong heterologous promoter were used in primary baby rat kidney cells to demonstrate that transforming properties of RhPV 1 could be localized individually to the E5, E6, and E7 open reading frames. Fully transformed cells were observed when either E5 or E7 were downstream of a strong heterologous promoter. Similarly, either E6 or E6 and E7 downstream of the native promoter fully transformed these cells as determined by immortalization, anchorage independent growth and tumorigenicity studies.
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4053
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Kruse E, Liu Z, Kloppstech K. Expression of heat shock proteins during development of barley. PLANT MOLECULAR BIOLOGY 1993; 23:111-122. [PMID: 8219044 DOI: 10.1007/bf00021424] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Barley heat shock proteins have been cloned, characterized by hybrid release translation and sequenced. Clones coding for proteins of 17, 18, 30, 32 and 70 kDa have been obtained. Out of these the 32 and 30 kDa proteins have been characterized as precursors to plastidic proteins of 26 kDa by posttranslational transport and by cDNA sequencing. The coding regions of these two transcribed genes are highly homologous. Accumulation of the plastid HSP as well as of HSP 70 as well as their corresponding mRNAs has been studied in 2- to 6-day old seedlings and in the 7-day old barley leaf. The mRNA for all investigated proteins were only found after a heat shock; the mRNA levels increase towards the tip of the leaf and with development. Furthermore, under the conditions used the mRNAs for all investigated heat shock proteins accumulate in parallel. Unexpectedly, both proteins, HSP 70 and HSP 26, are found by western blotting in the 2-day old control plants in the absence of any inducing heat shock. At later stages of development and in the leaf gradient only immunoreactivity with HSP 70 was observed. In contrast to the levels of their mRNAs the highest levels of HSP 30-26 and 70 have been observed in the basal segments indicating that translational control plays a role during HSP expression. Under severe heat shock a protein of 30 kDa is induced whose identity is not known but which reacts with the antibody to HSP 30-26 and might represent the accumulating precursors of the plastidic proteins.
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4054
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Liu Z, Furnier GR. Comparison of allozyme, RFLP, and RAPD markers for revealing genetic variation within and between trembling aspen and bigtooth aspen. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 1993; 87:97-105. [PMID: 24190200 DOI: 10.1007/bf00223752] [Citation(s) in RCA: 53] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/1993] [Accepted: 03/01/1993] [Indexed: 06/02/2023]
Abstract
We examined genetic variation in allozyme loci, nuclear DNA restriction fragment length polymorphisms (RFLPs), and random amplified polymorphic DNAs (RAPDs) in 130 trembling aspen (Populus tremuloides) and 105 bigtooth aspen (P. grandidentata) trees. In trembling aspen 10 out of 13 allozyme loci assayed (77%) were polymorphic (P), with 2.8 alleles per locus (A) and an expected heterozygosity (He) of 0.25. In contrast, bigtooth aspen had a much lower allozyme genetic variability (P=29%; A=1.4; He=0.08). The two species could be distinguished by mutually exclusive alleles at Idh-1, and bigtooth aspen has what appears to be a duplicate 6PG locus not present in trembling aspen. We used 138 random aspen genomic probes to reveal RFLPs in HindIII digests of aspen DNA. The majority of the probes were from sequences of low copy number. RFLP results were consistent with those of the allozyme analyses, with trembling aspen displaying higher genetic variation than bigtooth aspen (P=71%, A=2.7, and He=0.25 for trembling aspen; P=65%, A=1.8, and He=0.13 for bigtooth aspen). The two species could be distinguished by RFLPs revealed by 21 probes (15% of total probes assayed). RAPD patterns in both species were studied using four arbitrary decamer primers that revealed a total of 61 different amplified DNA fragments in trembling aspen and 56 in bigtooth aspen. Assuming a Hardy-Weinberg equilibrium, estimates of P=100%, A=2, and He=0.30 in trembling aspen and P=88%, A=1.9, and He=0.31 in bigtooth aspen were obtained from the RAPD data. Five amplified DNA fragments were species diagnostic. All individuals within both species, except for 2 that likely belong to the same clone, could be distinguished by comparing their RAPD patterns. These results indicate that (1) RFLPs and allozymes reveal comparable patterns of genetic variation in the two species, (2) trembling aspen is more genetically variable than bigtooth aspen at both the allozyme and DNA levels, (3) one can generate more polymorphic and species-specific loci with DNA markers than with allozymes in aspen, and (4) RAPDs provide a very powerful tool for "fingerprinting" aspen individuals.
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4055
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Holmes GL, Thurber SJ, Liu Z, Stafstrom CE, Gatt A, Mikati MA. Effects of quisqualic acid and glutamate on subsequent learning, emotionality, and seizure susceptibility in the immature and mature animal. Brain Res 1993; 623:325-8. [PMID: 8106123 DOI: 10.1016/0006-8993(93)91447-z] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
To compare the long-term behavioral effects of chronic administration of excitatory amino acids in the mature and immature brain quisqualic acid (QA) and glutamate (GLU) were administered intraventricularly by osmotic pumps over 7 days in 20- and 60-day-old rats. Both age groups received identical dosages of QA or GLU. At age 90 days, all animals were assessed for abnormalities of learning and memory using the Morris water maze, emotionality using the handling test, and seizure threshold using flurothyl inhalation. No significant differences were found in either the water maze or handling test. However, 60-day-old rats receiving QA or GLU had more spontaneous seizures than the 20-day-old rats. In both age groups histological damage following QA and GLU was limited to the ipsilateral hippocampus, was maximum at the site of the catheter tube, and was similar in the two age groups studied. The adverse effects of long-term effects of chronic exposure to excitatory amino acids are similar in the immature and mature brain.
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4056
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Yu VL, Liu Z, Stout JE, Goetz A. Legionella disinfection of water distribution systems: principles, problems, and practice. Infect Control Hosp Epidemiol 1993; 14:567-70. [PMID: 8228147 DOI: 10.1086/646638] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
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4057
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Barrett EJ, Liu Z. Hepatic glucose metabolism and insulin resistance in NIDDM and obesity. BAILLIERE'S CLINICAL ENDOCRINOLOGY AND METABOLISM 1993; 7:875-901. [PMID: 8304916 DOI: 10.1016/s0950-351x(05)80238-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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4058
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Liu Z, Carmichael GG. Polyoma virus early-late switch: regulation of late RNA accumulation by DNA replication. Proc Natl Acad Sci U S A 1993; 90:8494-8. [PMID: 8397407 PMCID: PMC47383 DOI: 10.1073/pnas.90.18.8494] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Early in infection of permissive mouse cells, messages from the early region of the polyoma virus genome accumulate preferentially over those from the late region. After initiation of DNA replication, the balance between early and late gene expression is reversed in favor of the late products. In previous work from our laboratory, we showed that viral early proteins do not activate the polyoma late promoter in the absence of DNA replication. Here we show that activation of the late genes in replication-incompetent viral genomes can occur if actively replicating genomes are present in the same cell. A low level of DNA replication, however, is insufficient to induce the early-late switch. Furthermore, replication-competent genomes that fail to accumulate late RNA molecules are defective in the transactivation of replication-incompetent genomes. We suggest that titration of an unknown diffusible factor(s) after DNA replication relieves the block to late RNA accumulation seen in the early phase, with most of this titration being attributable to late-strand RNA molecules themselves.
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4059
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Klip A, Ramlal T, Bilan PJ, Marette A, Liu Z, Mitsumoto Y. What signals are involved in the stimulation of glucose transport by insulin in muscle cells? Cell Signal 1993; 5:519-29. [PMID: 8312129 DOI: 10.1016/0898-6568(93)90047-p] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
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4060
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Liu Z, Furnier GR. Inheritance and Linkage of Allozymes and Restriction Fragment Length Polymorphisms in Trembling Aspen. J Hered 1993. [DOI: 10.1093/oxfordjournals.jhered.a111365] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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4061
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Liu Z, Sun F, Li J, Wang Y, Hu K. Effect of acupuncture on weight loss evaluated by adrenal function. J TRADIT CHIN MED 1993; 13:169-73. [PMID: 8246584] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
In order to understand the relationship between patients' adrenal function and simple obesity and effect of acupuncture on it, the obesity indices, lipid indices, fasting blood-glucose, noradrenaline, dopamine, adrenalin and cortisol were observed. The results indicated that patients with simple obesity had hypofunction of the sympathetic-adrenal system and the hypothalamus-pituitary-adrenal system. Acupuncture treatment not only affected weight loss but also enhanced functioning of the two systems, suggesting that the effect of acupuncture on weight loss may be produced by enhancing the functions of both the sympathetic-adrenal system and the hypothalamus-pituitary-adrenal system.
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4062
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Liu Z. [Renal structure and function in experimental diabetic rats following unilateral nephrectomy]. ZHONGHUA YI XUE ZA ZHI 1993; 73:520-3, 573. [PMID: 8313192] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Renal structure and function in 50 streptozotocin-induced diabetic rats having unilateral nephrectomy and the effect of captopril treatment were observed for 3 months. The glomerular filtration rate, renal plasma flow, KW/BW, mean glomerular volume, wide glomerular basement membrane, glomerular mesangial cell proliferation as well as the ratio of 6-keto-PGF1 alpha/TXB2 of kidney tissue in the diabetic rats were significantly increased than those in the non-diabetic rats. These indexes were not significantly different between groups with and without captopril treatment. The results mentioned above illustrated that the obvious renal injury in diabetic rats receiving unilateral nephrectomy could be found as early as in the 3rd month of the experiment. These changes might be related to the metabolic abnormality of glucose and prostaglandins in the kidney and no effect of low dose captopril were noted on the renal injury.
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4063
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Chen Z, Zhang S, Li L, Liu Z, Chen D, Fan A. [Prevention of reserpine induced experimental gastric ulcer in rat with amoxicillin a report of preliminary controlled study]. HUA XI YI KE DA XUE XUE BAO = JOURNAL OF WEST CHINA UNIVERSITY OF MEDICAL SCIENCES = HUAXI YIKE DAXUE XUEBAO 1993; 24:317-9. [PMID: 8288209] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
In recent years, amoxicillin (A) has been proved very effective in clearing helicobacter pylor (HP) and promoting ulcer healing. Is the cure due solely to the clearance of HP? Forty three Wistar rats were randomized into four groups to investigate the efficacy of A in preventing the experimental ulcer induced by reserpine and compare it with that of ranitidine (R) and antacid weishuping (W). A normal saline (NS) group was used as control. The total numbers of ulcer induced per rat for the NS, W, R and A groups were 7.8 +/- 5.1, 2.2 +/- 3.2, 1.0 +/- 1.2 and 2.1 +/- 1.9, respectively. The ulcer indices were 20.8 +/- 13.2, 4.5 +/- 7.7, 2.0 +/- 3.7 and 4.5 +/- 3.9, respectively. No HP was identified. The results indicated that A, R and W were all effective in preventing reserping induced ulcer with no significant difference (P > 0.05); they were significantly more effective than NS (P < 0.05). Since A is not an antacid and no HP existed in the experimental rats, there must be a mechanism of A involved in the prevention of experimental ulcer.
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4064
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Liu Z, Gardner LB, Barrett EJ. An endogenous glycogen-associated compound modulates glucose-6-phosphatase activity in rat liver microsomes. Biochem Biophys Res Commun 1993; 195:173-8. [PMID: 8395823 DOI: 10.1006/bbrc.1993.2026] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Liver glycogen is closely associated with the endoplasmic reticulum, which contains the glucose-6-phosphatase enzyme system that catalyses the final step of hepatic glucose production. To examine whether this structural association has functional consequences, microsomes were isolated from 48 h fasted (n = 6) and ad lib fed rats (n = 3). Microsomes from fed rats had a higher glycogen content and lower enzyme activity than fasted rats. Overall, glucose-6-phosphatase activity was inversely proportional to microsomal glycogen content. Partially purified rabbit or rat liver glycogen, at physiological relevant concentrations (10-100 mM glucose equivalents), added directly to either intact or Triton-disrupted microsomes from fasted rats significantly decreased glucose-6-phosphatase activity. Inhibitory activity was present in native liver glycogen prepared by sedimentation and could be dissociated from glycogen by ion-exchange and ultrafiltration. These findings suggest that a low molecular weight (< 5000 D) compound closely associated with glycogen can modulate glucose-6-phosphatase and may have a physiologic role in the regulation of hepatic glucose production.
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4065
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Hundal HS, Marette A, Ramlal T, Liu Z, Klip A. Expression of beta subunit isoforms of the Na+,K(+)-ATPase is muscle type-specific. FEBS Lett 1993; 328:253-8. [PMID: 8394248 DOI: 10.1016/0014-5793(93)80938-q] [Citation(s) in RCA: 59] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Hindlimb skeletal muscles of the rat express two isoforms of the alpha (alpha 1 and alpha 2) and two isoforms of the beta (beta 1 and beta 2) subunits of the Na+,K(+)-ATPase. Because several muscles constitute the hindlimb, we investigated if specific isoforms are expressed in particular muscles. Northern blot analysis using isoform-specific cDNA probes demonstrated that soleus muscle expressed only the beta 1 transcript, whereas EDL or white gastrocnemius muscles expressed only the beta 2 transcript, and red gastrocnemius muscle expressed both mRNAs. All muscles tested expressed both alpha 1 and alpha 2 transcripts, albeit to various degrees: alpha 1 transcripts were present to about the same extent in all muscles but alpha 2 mRNA was 4-fold more abundant in soleus than in EDL for the same amount of total RNA. Beta subunit protein levels were investigated in purified plasma membrane fractions of pooled red (soleus + red gastrocnemius + red quadriceps) or white (white gastrocnemius + white quadriceps) muscles using isoform-specific antibodies. Red muscles expressed mostly the beta 1 protein while white muscles expressed mostly the beta 2 subunit. Both muscle groups had similar levels of alpha 1 or alpha 2 subunits, and crude membranes isolated from red muscles had 30% higher Na+,K(+)-ATPase activity than white muscle membranes. We conclude that oxidative muscles (slow and fast twitch) express beta 1 subunits, whereas glycolytic, fast twitch muscles express beta 2 subunits, and that both beta isoforms support the Na+,K(+)-ATPase activity of the alpha subunits.
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4066
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Liu Z, Williams KP, Chang YH, Smith JA. Immunodominance: a single amino acid substitution within an antigenic site alters intramolecular selection of T cell determinants. THE JOURNAL OF IMMUNOLOGY 1993. [DOI: 10.4049/jimmunol.151.4.1852] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Abstract
The mechanism of immunodominance was studied by mutating a single amino acid residue within an immunodominant determinant of Staphylococcus aureus nuclease (Nase). Residues 81 to 100, which can be further reduced to 86 to 100, were determined to be the immunodominant determinant of Nase in H-2k mice. By introducing selected single amino acid substitutions into the peptide encompassing residues 86 to 100 (p86-100), residue 90 was shown to be one of the critical amino acids for T cell recognition, inasmuch as most of the T cells recognizing p86-100 do not respond to a p86-100 analog with a substitution of leucine for alanine at the residue 90. A mutant of Nase with a replacement of alanine by leucine at residue 90 (A90L) was constructed, and for A90L region 112 to 130, which is a subdominant determinant in Nase, becomes immunodominant. Although unable to respond to Nase, T cells primed in vivo with the peptides covering various cryptic determinants proliferate when challenged with A90L in vitro. Our results suggest that at the protein level there is competition among potential T cell determinants of protein Ag for binding to MHC molecules, and that this competition plays a role in determining which determinant may become immunodominant.
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4067
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Liu Z, Williams KP, Chang YH, Smith JA. Immunodominance: a single amino acid substitution within an antigenic site alters intramolecular selection of T cell determinants. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 1993; 151:1852-8. [PMID: 7688387] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The mechanism of immunodominance was studied by mutating a single amino acid residue within an immunodominant determinant of Staphylococcus aureus nuclease (Nase). Residues 81 to 100, which can be further reduced to 86 to 100, were determined to be the immunodominant determinant of Nase in H-2k mice. By introducing selected single amino acid substitutions into the peptide encompassing residues 86 to 100 (p86-100), residue 90 was shown to be one of the critical amino acids for T cell recognition, inasmuch as most of the T cells recognizing p86-100 do not respond to a p86-100 analog with a substitution of leucine for alanine at the residue 90. A mutant of Nase with a replacement of alanine by leucine at residue 90 (A90L) was constructed, and for A90L region 112 to 130, which is a subdominant determinant in Nase, becomes immunodominant. Although unable to respond to Nase, T cells primed in vivo with the peptides covering various cryptic determinants proliferate when challenged with A90L in vitro. Our results suggest that at the protein level there is competition among potential T cell determinants of protein Ag for binding to MHC molecules, and that this competition plays a role in determining which determinant may become immunodominant.
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4068
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Giorgi JV, Liu Z, Hultin LE, Cumberland WG, Hennessey K, Detels R. Elevated levels of CD38+ CD8+ T cells in HIV infection add to the prognostic value of low CD4+ T cell levels: results of 6 years of follow-up. The Los Angeles Center, Multicenter AIDS Cohort Study. JOURNAL OF ACQUIRED IMMUNE DEFICIENCY SYNDROMES 1993; 6:904-912. [PMID: 7686224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
A cohort of 98 HIV-infected initially AIDS-free homosexual men from the Multicenter AIDS Cohort Study (MACS) was followed for 6 years to investigate whether CD8+ cell subsets have prognostic value for progression to AIDS. In the present study, four subsets of CD8+ T cells that previously have been shown to be selectively elevated in HIV-infected asymptomatic persons, specifically the CD8+ T cell subsets that were CD38+, HLA-DR+, CD57+ and L-selectin negative (Leu8-), were measured. Forty-nine of the 98 developed AIDS. Prognostic value of these CD8+ cell subsets was evaluated using the proportional hazards model. Levels of both CD38+ CD8+ and Leu8- CD8+ cells individually had prognostic value for progression to AIDS. In contrast, CD57+ CD8+ and HLA-DR+ CD8+ cell subsets levels did not have prognostic value. After adjustment for level of CD4+ T cells, however, only the elevation in the CD38+ CD8+ cell subset had additional prognostic value. These results suggest that the level of CD38+ CD8+ cells could be used together with the CD4+ T cell level to more accurately predict progression to AIDS among HIV-infected men. These results provide further support for the observation that dramatic and progressive activation of CD8+ T cells in HIV infection occurs. The power of elevated levels of the CD38+ CD8+ subset to predict poor prognosis in this cohort suggests these CD8+ T cells reflect an immune stimulation that is ultimately unable to control disease progression.
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4069
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Giudice G, Emery D, Zelickson B, Anhalt G, Liu Z, Diaz L. Bullous pemphigoid and herpes gestationis autoantibodies recognize a common non-collagenous site on the BP180 ectodomain. J Dermatol Sci 1993. [DOI: 10.1016/0923-1811(93)90940-q] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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4070
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Saunders BM, Liu Z, Zhan Y, Cheers C. Interleukin-6 production during chronic experimental infection. Immunol Cell Biol 1993; 71 ( Pt 4):275-80. [PMID: 8225396 DOI: 10.1038/icb.1993.32] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The appearance of interleukin-6 (IL-6) in serum of mice was monitored during the course of chronic infection with either Brucella abortus vaccine strain 19 or a virulent Mycobacterium avium Complex (MAC) isolate. Serum IL-6 during brucella infection was higher than during infection with MAC, despite similar numbers of bacteria. Furthermore, IL-6 titres decreased after the peak of infection, falling to baseline levels before these chronic infections were eradicated. The ability of peritoneal cells or spleen cell suspensions to produce IL-6 under either specific or non-specific stimulus was greatly enhanced by infection. While production of IL-6 by these cultures was apparently mostly independent of T cells, T cells from infected mice could produce an IL-6 response. Thus CD4+ T lymphocytes prepared from mice which had recovered from B. abortus infection, cultured with antigen and antigen presenting cells, resulted in IL-6 production, which was not observed in similarly cultured CD8+ T cells, indicating a role for T cells.
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4071
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Begemann-Blaich M, Müller WF, Aichelin J, Adloff JC, Bouissou P, Hubele J, Imme G, Iori I, Kreutz P, Kunde GJ, Leray S, Lindenstruth V, Liu Z, Lynen U, Meijer RJ, Milkau U, Moroni A, Ngô C, Ogilvie CA, Pochodzalla J, Raciti G, Rudolf G, Sann H, Schüttauf A, Seidel W, Stuttge L, Trautmann W, Tucholski A. Quantum molecular dynamics simulation of multifragment production in heavy ion collisions at E/A=600 MeV. PHYSICAL REVIEW. C, NUCLEAR PHYSICS 1993; 48:610-617. [PMID: 9968872 DOI: 10.1103/physrevc.48.610] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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4072
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Marette A, Atgié C, Liu Z, Bukowiecki LJ, Klip A. Differential regulation of GLUT1 and GLUT4 glucose transporters in skeletal muscle of a new model of type II diabetes. The obese SHR/N-cp rat. Diabetes 1993; 42:1195-201. [PMID: 8325452 DOI: 10.2337/diab.42.8.1195] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The obese diabetic SHR/N-cp rat is a newly developed strain that inherits obesity as an autosomal recessive trait. These rats display early-onset hyperinsulinemia and hyperglycemia, which are hallmarks of type II diabetes. This study was undertaken to determine the expression and the subcellular distribution of the GLUT1 and GLUT4 glucose transporters in skeletal muscle of obese diabetic SHR rats. D-glucose-protectable cytochalasin-B binding to subcellular membrane fractions of hindlimb muscles was used to determine glucose transporter number. GLUT1 and GLUT4 glucose transporter isotypes were detected using antibodies to the COOH-terminal region of the GLUT1 and GLUT4 proteins. Glucose transporter number was significantly lower (-40%) in crude unfractionated membranes of obese diabetic SHR than of lean SHR muscles. When crude membranes were fractionated to separate plasma membranes and the intracellular membranes containing glucose transporters, the number of cytochalasin-B binding sites was found to be markedly lower (-50%) in intracellular membranes and slightly but not significantly reduced (-20%) in plasma membranes of muscle from obese diabetic SHR compared with lean SHR rats. Western blot analysis revealed that a lower GLUT4 protein abundance (-40%) accounts for the reduced glucose transporter number in intracellular membranes of obese diabetic SHR compared with lean SHR muscles. GLUT4 protein content was also reduced by 50% in plasma membranes from obese SHR muscles relative to lean rat muscles.(ABSTRACT TRUNCATED AT 250 WORDS)
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4073
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Lirette A, Towner RA, Liu Z, Janzen EG, Chambers JR, Fairfull RW, Milligan LP, Crober DC. In vivo nuclear magnetic resonance spectroscopy of chicken embryos from two broiler strains of varying fat content. Poult Sci 1993; 72:1411-20. [PMID: 8378216 DOI: 10.3382/ps.0721411] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
In vivo nuclear magnetic resonance (NMR) imaging and spectroscopy techniques were used to monitor changes in P- and H-containing molecules in embryos of two broiler strains (30 and 31) differing genetically in fat content and ranging in age from 0 to 20 days of incubation. Chemical analysis showed that Strain 30 has more carcass fat than Strain 31 at market age (7 wk). Proton (1H) and 31P spectra were obtained on four eggs per strain at Days 0, 2, 4, 6, 8, 11, 12, 14, 16, 17, 19, and 20 of incubation. Fat:water, phosphomonoester (PME):phosphodiester (PDE), and adenosine triphosphate (ATP):PDE ratios were calculated. Chicks were hatched, grown to market weight (2,000 g for females and 2,300 g for males at 7 wk), and the whole intact carcasses were analyzed for crude fat. Hydrogen-1 NMR spectroscopy studies of incubated eggs indicated no significant difference (P > .05) in the fat:water ratio between the two strains. The difference in the PME:PDE ratios between the two strains as obtained by 31P-NMR spectroscopy over all days of incubation analyzed was not significant (P > .05); however, there was a significant difference in this ratio between the two strains at Days 4, 6, and 11. Up to Day 16, Strain 30 had a slightly, but not significantly (P > .05), higher ATP:PDE ratio as shown on 31P-NMR spectra, whereas after Day 17 the ATP:PDE ratio was significantly higher (P < .01) for Strain 31. Strain 31 birds had a significantly lower (P < .05) crude fat content. There was a significant difference (P < .05) in 7-wk carcass fat content between sexes, males having significantly (P < .01) less fat than females, which was correlated with a significantly higher (P < .01) ATP:PDE ratio in male embryos. It might be possible to use ATP:PDE ratios obtained during embryonic development by 31P-NMR to select strains of birds for low fat content at market weight and to distinguish between sexes during late embryonic development.
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4074
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Liu Z, Thompson KS, Towle HC. Carbohydrate regulation of the rat L-type pyruvate kinase gene requires two nuclear factors: LF-A1 and a member of the c-myc family. J Biol Chem 1993; 268:12787-95. [PMID: 8509413] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Transcription of the L-type pyruvate kinase (L-PK) gene is induced in response to increased carbohydrate metabolism in the liver. We have demonstrated previously that a segment of the 5'-flanking region of the L-PK gene between -183 and -96 is necessary and sufficient for the glucose response in primary hepatocytes. To explore the protein factors that are involved in carbohydrate regulation, we have performed mutational analyses and in vitro binding studies of this segment. Sequences critical for the glucose response were mapped from -171 to -124. This segment contains the consensus binding sites for two nuclear transcription factors: LF-A1 and MLTF. Both factors are capable of binding to the corresponding L-PK sites in vitro. Mutational and functional analyses indicated that LF-A1 is indeed involved in glucose induction of the L-PK gene. The PK MLTF-like site consists of two imperfect CACGTG motifs, the core binding site for a family of transcription factors related to c-myc. Unexpectedly, mutations in either motif that resulted in defective glucose stimulation retained in vitro binding to MLTF. Furthermore, an authentic MLTF binding site from the adenovirus major late promoter was not functionally interchangeable with the natural sequence. These data indicate that binding of MLTF, in presence of LF-A1, is not capable of supporting the glucose response. Conversion of either imperfect motif to CACGTG within the context of the mutations disrupting the opposite site restored the response to elevated glucose. Thus, the factor that recognizes the PK MLTF-like site and participates in mediating the carbohydrate response of the L-PK gene appears to be a member of the c-myc family distinct from MLTF.
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4075
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Zhu J, Wang D, Lu Z, Liu Z, Yang D. Hemodynamic effects of terazosin in congestive heart failure. CHINESE MEDICAL SCIENCES JOURNAL = CHUNG-KUO I HSUEH K'O HSUEH TSA CHIH 1993; 8:98-100. [PMID: 7904837] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
To determine the hemodynamic effects of a new alpha-1 blocker, terazosin, in congestive heart failure, 10 patients with this condition underwent hemodynamic testing at rest. Thirty minutes after the oral administration of 4 mg terazosin, mean right atrial pressure, mean pulmonary artery pressure and pulmonary capillary wedge pressure were found to be decreased, while the cardiac index was increased significantly. Improvement in hemodynamics persisted for more than 15 h, without an increase in heart rate. It is suggested that terazosin may have effective applications in the treatment of congestive heart failure.
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4076
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Liu Z, Sun YK, Xi YP, Maffei A, Reed E, Harris P, Suciu-Foca N. Contribution of direct and indirect recognition pathways to T cell alloreactivity. J Exp Med 1993; 177:1643-50. [PMID: 7684431 PMCID: PMC2191044 DOI: 10.1084/jem.177.6.1643] [Citation(s) in RCA: 196] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
T cells from an HLA-DR11/DR12 responder were stimulated in mixed lymphocyte culture with cells carrying the DR1 antigen. After priming, T cells proliferated in response to both DR1-positive-stimulating cells and a peptide derived from a polymorphic region of the HLA-DR beta 1*0101 chain presented by responder's antigen-presenting cells (APC). The dominant epitope recognized by the primed T cells corresponded to residue 21-42 and was presented by the responder's HLA-DR12 antigen. The DR1 peptide-reactive T cells express T cell receptor V beta 3. The results demonstrate that allopeptides derived from the processing and presentation of donor major histocompatibility complex molecules by host-derived APC trigger alloreactivity. The frequency of T cells engaged in the indirect pathway of allorecognition is about 100-fold lower than that of T cells participating in the direct recognition of native HLA-DR antigen. However, indirect allorecognition may play an important role in chronic allograft rejection, a phenomenon that is mediated by the activation of T helper cells and of alloantibody-producing B cells.
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4077
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Abstract
The cellular source of interleukin-6 (IL-6) during infection of mice with Listeria monocytogenes was investigated both in vitro and in vivo. Peritoneal cells taken at intervals from infected mice and cultured in vitro without added stimulus produced high titers of IL-6 peaking 2 days postinfection in a time course similar to that observed in vivo. Adherent cells with the morphology of macrophages were a major source of this IL-6. Spleen cells similarly harvested at intervals and cultured with heat-killed Listeria or heat-killed Brucella organisms as specific and nonspecific stimuli, respectively, showed two distinct IL-6 responses: (i) an early-phase response up to 5 days after infection when IL-6 production was elicited by either a specific or nonspecific stimulus, and when depletion of T cells had no effect, and (ii) a later response 7 to 10 days after infection when very high levels of IL-6 were produced in response to a specific stimulus. This response was lost when T cells were depleted in vitro or in vivo or in spleen cell cultures from mice with severe combined immunodeficiency. However, studies in vivo failed to show an important role for T cells governing serum IL-6. We conclude that most of IL-6 detected in vivo is produced by nonlymphocytes. Whether IL-6 produced by T lymphocytes in local foci of infection has any role in resolution of that infection is unknown.
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4078
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Liu Z, Thompson K, Towle H. Carbohydrate regulation of the rat L-type pyruvate kinase gene requires two nuclear factors: LF-A1 and a member of the c-myc family. J Biol Chem 1993. [DOI: 10.1016/s0021-9258(18)31457-1] [Citation(s) in RCA: 59] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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4079
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Li Y, Yi Y, Feng G, Zheng J, Lin J, Liu Z. [Pathologic, electron microscopic and experimental examination of band keratopathy]. YAN KE XUE BAO = EYE SCIENCE 1993; 9:93-7. [PMID: 8276098] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
One hundred and thirteen cases previously diagnosed as band keratopathy were reexamined by light microscopy and histochemistry, 10 cases of which were studied by TEM and 2 cases were studied by SEM. We find that the calcium deposition initially occur as fine calcific particles within the cytoplasm of epithelic cells and in the basal membrane and bowman's layer, which aggregated to form calcific spherules and large calcific masses extracellularly. When 3 normal corneal tissues were frozen and cultured, the calcium deposition occur in the superficial layer of bowman's membrane and in the stromal lamellae, Authors suggest that the degeneration and calcific abnormal metabolism of the cell caused by various factors is the main pathogenesis that leads to the calcific deposit. The evaporation and constructive destruction of the corneal surface in the interpiperbral area inhibits the formation of the lacrimal membrane and results in deposition of calcium salts in the superficial tissue of exposed cornea in a band configuration. The combination of glycosaminoglycan with calcium salts is the dynamics of aggregation of the fine calcific particles to form the calcific spherules and calcific masses.
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4080
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Liu Z, Ostrovsky I, Farnsworth PB, Lee ML. Instrumentation for comprehensive two-dimensional capillary supercritical fluid-gas chromatography. Chromatographia 1993. [DOI: 10.1007/bf02267918] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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4081
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Moav B, Liu Z, Caldovic LD, Gross ML, Faras AJ, Hackett PB. Regulation of expression of transgenes in developing fish. Transgenic Res 1993; 2:153-61. [PMID: 8353534 DOI: 10.1007/bf01972609] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The transcriptional regulatory elements of the beta-actin gene of carp (Cyprinus carpio) have been examined in zebrafish and goldfish harbouring transgenes. The high sequence conservation of the putative regulatory elements in the beta-actin genes of animals suggested that their function would be conserved, so that transgenic constructs with the same transcriptional control elements would promote similar levels of transgene expression in different species of transgenic animals. To test this assumption, we analysed the temporal expression of a reporter gene under the control of transcriptional control sequences from the carp beta-actin gene in zebrafish (Brachydanio rerio) and goldfish (Carrasius auratus). Our results indicated that, contrary to expectations, combinations of different transcriptional control elements affected the level, duration, and onset of gene expression differently in developing zebrafish and goldfish. The major differences in expression of beta-actin/CAT (chloramphenicol acetyltransferase) constructs in zebrafish and goldfish were: (1) overall expression was almost 100-fold higher in goldfish than in zebrafish embryos, (2) the first intron had an enhancing effect on gene expression in zebrafish but not in goldfish, and (3) the serum-responsive/CArG-containing regulatory element in the proximal promoter was not always required for maximal CAT activity in goldfish, but was required in zebrafish. These results suggest that in the zebrafish, but not in the goldfish, there may be interactions between motifs in the proximal promoter and the first intron which appear to be required for maximal enhancement of transcription.
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4082
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Liu Z, Sun YK, Xi YP, Hong B, Harris PE, Reed EF, Suciu-Foca N. Limited usage of T cell receptor V beta genes by allopeptide-specific T cells. THE JOURNAL OF IMMUNOLOGY 1993. [DOI: 10.4049/jimmunol.150.8.3180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Abstract
T cell reactivity to alloantigens results from direct and indirect recognition of allogeneic MHC molecules and/or peptides. Although direct recognition is not self-MHC restricted, indirect recognition, the result of alloantigen processing and presentation by host APC, is restricted by the self (responder) MHC molecule to which the allopeptide has bound. We have studied the MHC restriction and TCR usage in T cell alloreactivity to a synthetic peptide corresponding to amino acid residues 21-42 of the DR beta 1*0101 molecule. T cell lines were developed by in vitro immunization of T cells from three responders carrying the DR beta 1*1101 allele with this peptide. In all three responders, reactivity to peptide 21-42 was restricted by the DR11 molecule. A limited usage of V beta genes was found in these T cell lines, all of which shared the expression of V beta 13.2. Because indirect recognition of allopeptide may play an important role in chronic, antibody-mediated allograft rejection, study of the TCR gene usage may contribute to the development of specific immunosuppression therapy.
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4083
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Liu Z, Sun YK, Xi YP, Hong B, Harris PE, Reed EF, Suciu-Foca N. Limited usage of T cell receptor V beta genes by allopeptide-specific T cells. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 1993; 150:3180-6. [PMID: 8468463] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
T cell reactivity to alloantigens results from direct and indirect recognition of allogeneic MHC molecules and/or peptides. Although direct recognition is not self-MHC restricted, indirect recognition, the result of alloantigen processing and presentation by host APC, is restricted by the self (responder) MHC molecule to which the allopeptide has bound. We have studied the MHC restriction and TCR usage in T cell alloreactivity to a synthetic peptide corresponding to amino acid residues 21-42 of the DR beta 1*0101 molecule. T cell lines were developed by in vitro immunization of T cells from three responders carrying the DR beta 1*1101 allele with this peptide. In all three responders, reactivity to peptide 21-42 was restricted by the DR11 molecule. A limited usage of V beta genes was found in these T cell lines, all of which shared the expression of V beta 13.2. Because indirect recognition of allopeptide may play an important role in chronic, antibody-mediated allograft rejection, study of the TCR gene usage may contribute to the development of specific immunosuppression therapy.
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4084
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Liu Z, Frantz JD, Gilbert W, Tye BK. Identification and characterization of a nuclease activity specific for G4 tetrastranded DNA. Proc Natl Acad Sci U S A 1993; 90:3157-61. [PMID: 8475054 PMCID: PMC46258 DOI: 10.1073/pnas.90.8.3157] [Citation(s) in RCA: 69] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
We have identified a nuclease activity that is specific for G4 tetrastranded DNA. This activity, found in a partially purified fraction for a yeast telomere-binding protein, binds to DNA molecules with G4 tetrastranded structure, regardless of their nucleotide sequences, and cleaves the DNA in a neighboring single-stranded region 5' to the G4 structure. Competition with various G4-DNA molecules inhibits the cleavage reaction, suggesting that this nuclease activity is specific for G4 tetrastranded DNA. The existence of this enzymatic activity that reacts with G4 DNAs but not with single-stranded or Watson-Crick duplex DNAs suggests that tetrastranded DNA may have a distinct biological function in vivo.
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4085
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Lazaro AM, Fernandez-Viña MA, Liu Z, Stastny P. Enzyme-linked DNA oligotyping. A practical method for clinical HLA-DNA typing. Hum Immunol 1993; 36:243-8. [PMID: 8340233 DOI: 10.1016/0198-8859(93)90131-j] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The use of PCR and oligonucleotide hybridization has increased the accuracy and resolution of typing for HLA class II alleles, but current procedures, performed in batches, take too long and are not suited for testing single samples. We have developed a typing method using enzyme-linked oligonucleotides and PCR products immobilized in 96-well trays. Trays preloaded with typing probes, covalently linked with alkaline phosphatase, have been kept for weeks at 4 degrees C without loss of enzyme-probe activity. Bound alkaline phosphatase was detected using a color reaction with enzymatic amplification which produces readings in 30 minutes. Coupled with a quick DNA preparation method, results can be obtained in about 4 hours. This method can be easily performed in small laboratories. It is accurate, reproducible, and sensitive, and will make oligotyping for HLA alleles more convenient for testing clinical samples.
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4086
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Liu Z, Brien JF, Marks GS, McLaughlin BE, Nakatsu K. Lack of evidence for the involvement of cytochrome P-450 or other hemoproteins in metabolic activation of glyceryl trinitrate in rabbit aorta. J Pharmacol Exp Ther 1993; 264:1432-9. [PMID: 8450477] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
The present study was conducted to test the hypothesis that glyceryl trinitrate (GTN) metabolic activation in blood vessels is mediated by cytochrome P-450 or some other hemoprotein. The effects of cytochrome P-450 inhibitor [2-dimethylaminoethyl-2,2-diphenyl-n-pentanoate (SKF-525A) and metyrapone] on the response of rabbit aortic rings to GTN was determined by recording cumulative GTN dose-response curves in the presence of either or both inhibitors. The cytochrome P-450 inhibitors did not interfere with the ability of GTN to relax rabbit aortic rings. Treatment of rabbit aortic strips (RAS) with carbon monoxide (CO) was undertaken to elucidate a potential role of ferrous hemoproteins in mediating GTN-induced relaxation. CO did not significantly inhibit GTN-induced vasodilation of RAS. Biotransformation of GTN to glyceryl dinitrates by RAS exposed to CO for 5 min or nitric oxide (NO) for 10 min was determined by incubation of the tissues with 0.5 microM [3H]- or [14C]-GTN in the presence of CO or NO for 10 sec, 30 sec or 2 min. Neither CO nor NO exposure inhibited glyceryl-1,2- or -1,3-dinitrate formation by RAS after the 10-sec or 2-min incubation with RAS. For the 30-sec incubation, NO exposure did inhibit glyceryl dinitrate formation by RAS. This was deemed to be less important than the 10-sec data, the time just before the onset of relaxation. Therefore, emphasis is placed on lack of inhibition by NO at this earlier time point.(ABSTRACT TRUNCATED AT 250 WORDS)
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4087
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Zhang H, Liu Z, Xu J, Qian X, Chen S, Lu L. Experimental evidence against a model incorporating fission before K equilibration. PHYSICAL REVIEW. C, NUCLEAR PHYSICS 1993; 47:1309-1310. [PMID: 9968568 DOI: 10.1103/physrevc.47.1309] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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4088
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Hoffman K, Gil J, Barba J, Liu Z, Pertsemlidis D, Kaneko M, Unger P. Morphometric analysis of benign and malignant adrenal pheochromocytomas. Arch Pathol Lab Med 1993; 117:244-7. [PMID: 8442669] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
At present, there are no reliable histologic features that can predict malignancy in adrenal pheochromocytomas other than the documentation of metastases. With the use of computerized interactive morphometry, our aim was to assess nuclei from tissue sections of confirmed cases of benign and malignant pheochromocytomas to determine whether consistent quantitative differences existed between the two. Eight benign cases with at least a 5-year follow-up and nine malignant cases with documented metastases were evaluated. Size distribution plots of the maximum nuclear cord length and of the nuclear area showed a narrow peak for the malignant cases, whereas benign cases showed a right-shifted curve with a wider peak. We concluded that nuclear morphometric analysis of benign and malignant pheochromocytomas yields two distinctive patterns and may be of utility in the assessment of future cases.
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4089
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Liu Z. [Chart for estimating neonatal weight]. ZHONGGUO YI XUE KE XUE YUAN XUE BAO. ACTA ACADEMIAE MEDICINAE SINICAE 1993; 15:67-70. [PMID: 8324842] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Estimation of neonatal weight can be used to aid management during gestation as well as to help choose the delivery method. In this study, the uterine height and abdominal circumference of 403 normal women were measured within a week before delivery. The babies were weighed immediately after birth and the data calculated by a computer and analyzed by stepwise regression analysis. A multiple linear regression equation was formed, as follows: Y gram (neonatal weight) = 101.24X1 (uterine height) +16.58X2 (abdominal circumference) -1907.64. This equation was used to construct a chart for estimating neonatal weight. Error analysis between the predicted and actual weights of 115 babies was conducted, and the results showed that the error was within +/- 300 g in 82.6%. The chart is considered a simple, convenient and accurate method for estimating fetal weight in the clinic.
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4090
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Suciu-Foca N, Xi YP, Sun YK, Liu Z. T-cell alloreactivity to major histocompatibility complex peptides in context of self major histocompatibility complex. Transplant Proc 1993; 25:73-4. [PMID: 8438461] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
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4091
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Abstract
The eigensolution of nonaxisymmetric entry flow of a Newtonian viscous fluid with very small Reynolds number in a semiinfinite rigid circular pipe is obtained. Leading eigenvalues are computed for steady flow and two periodic cases. The result shows that the entry length for nonaxisymmetric flows should be longer than the entry length for axisymmetric flows.
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4092
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Unger PD, Watson CW, Liu Z, Gil J. Morphometric analysis of neoplastic renal aspirates and benign renal tissue. ANALYTICAL AND QUANTITATIVE CYTOLOGY AND HISTOLOGY 1993; 15:61-6. [PMID: 8471107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
This study was designed to develop a practical morphometric procedure for the diagnosis of carcinoma in renal aspirates. We studied aspirates from renal cell carcinomas (grades 1-2) and normal kidneys. Video images of nuclei were traced on a high-resolution, touch-sensitive screen connected to an image analysis system. From each tracing the computer calculated nuclear perimeter length, nuclear profile area, maximal chord length, and the means and standard deviation for all measurements. Size distribution of nuclear profile areas and perimeter length in discrete bins ranged, respectively, from 30 to 80 at 10 microns2 intervals for areas and from 1 to 12 microns at 1-micron intervals for the maximum chords. The size distribution plots for the maximal chord of individual nuclei demonstrated an early narrow peak at low values for normal renal aspirates (peak located in the class ranging from 7 to 8 microns), while a broader, flatter peak with a shift to the right and a malignant tail was seen in renal cell carcinoma aspirates (peak located at 9-10 microns). These data were used for multivariate analysis to form two categories to establish a data base against which unknown cases could be tested. Multivariate analysis using a total of 14 variables yielded a value of 169.1 for the euclidean distances between the center of clusters of the neoplastic and normal renal aspirates and confirmed the classification with posterior probabilities of 1.0. From these data, automated classificatory analysis of 10 unknown cases was performed by means of the k-nearest neighbor procedure, with correct classification established in each case.
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4093
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Bashan N, Burdett E, Gumà A, Sargeant R, Tumiati L, Liu Z, Klip A. Mechanisms of adaptation of glucose transporters to changes in the oxidative chain of muscle and fat cells. THE AMERICAN JOURNAL OF PHYSIOLOGY 1993; 264:C430-40. [PMID: 8447373 DOI: 10.1152/ajpcell.1993.264.2.c430] [Citation(s) in RCA: 80] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Cells in which glucose uptake is rate limiting respond to hypoxic insults with an increase in glucose transport activity. To understand the underlying cellular mechanisms involved in this adaptive response, the effects of an uncoupler of oxidative phosphorylation, 2,4-dinitrophenol (DNP), and of an inhibitor of the electron transport chain, rotenone, were compared with the effect of hypoxia in L6 muscle cells and 3T3-L1 adipocytes. All three conditions (DNP, rotenone, and 3% oxygen) elevated hexose uptake by approximately twofold in 4 h relative to control cells. All three insults decreased cellular ATP levels rapidly. A subsequent recovery was observed within 1-2 h in the presence of DNP or 3% oxygen, probably as a result of anaerobic production of ATP through increased glucose uptake and glycolysis. DNP and rotenone elevated the content of GLUT-1 protein in isolated plasma membranes and decreased it in intracellular light microsomes, suggestive of translocation of this transporter isoform. No change in GLUT-4 protein distribution was detected. In contrast, 3% oxygen caused a marked specific increase in GLUT-1 protein in both plasma membranes and microsomes. Consistently, cycloheximide had no effect on the hexose transport responses to DNP or rotenone, but prevented the response to hypoxia. However, GLUT-1 mRNA and the total cell content of GLUT-1 protein were elevated by all three treatments. It is proposed that within the time frame studied, reductions in the energy charge may activate the glucose transport system in L6 myotubes and 3T3-L1 adipocytes by GLUT-1 protein biosynthesis and translocation. When both responses exist, the biosynthetic pathway is dispensable, and posttranslational mechanisms, including transporter translocation suffice to sustain the adaptive elevation in glucose transport activity for several hours.
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4094
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Liu Z, Szabo LJ, Bushnell WR. Molecular cloning and analysis of abundant and stage-specific mRNAs from Puccinia graminis. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 1993; 6:84-91. [PMID: 8439672 DOI: 10.1094/mpmi-6-084] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
To characterize highly expressed mRNAs from germinated urediniospores of Puccinia graminis f. sp. tritici, we isolated 68 cDNA clones of abundant mRNA species belonging to at least six homology groups. The two most abundant homology groups, HG1 and HG2, contained 54 of the 68 cDNA clones and accounted for 2.4 and 0.6% of the poly(A)+ RNA in germinated urediniospores, respectively. By sampling different developmental stages of the uredinial cycle, we showed that the uam transcript, corresponding to HG2, accumulated in all stages of hyphal and urediniospore development, whereas the accumulation of usp transcript, corresponding to HG1, was specific to the sporulation stage. Southern blot analysis indicated that usp is a small gene family consisting of three to four members. Sequence analysis of 10 cDNA clones indicated that two different members of the usp gene family were expressed in germinated urediniospores. This gene family encodes small hydrophobic polypeptides of 113 amino acids with an unusual amino acid composition, in that alanine, glycine, leucine, and proline represent 48% of the protein. These polypeptides are predicted to be localized extracellular because they contain a putative signal sequence and may be functionally related to hydrophobins, a family of small hydrophobic proteins abundantly expressed during sporulation in Schizophyllum commune and Aspergillus nidulans. The uam and usp genes deserve further investigation, including isolation of genomic clones. The regulatory regions of the uam gene, which is highly expressed in hyphae, may be useful in the construction of a transformation vector for rust fungi.
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4095
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Liu Z, Hackett PB. Reverse cloning procedure for generation of subclones for DNA sequencing. Methods Enzymol 1993; 218:47-58. [PMID: 8389968 DOI: 10.1016/0076-6879(93)18007-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
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4096
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Liu Z, Li J. Characteristics and priorities of China's population control from an international perspective. CHINESE JOURNAL OF POPULATION SCIENCE 1993; 5:107-18. [PMID: 12287282] [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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4097
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Xu X, Liu Z. Discussion of H substance in urine. J Forensic Sci 1993; 38:8-9. [PMID: 8426161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
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4098
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Walden J, Grunze H, Mayer A, Düsing R, Schirrmacher K, Liu Z, Bingmann D. Calcium-antagonistic effects of carbamazepine in epilepsies and affective psychoses. Neuropsychobiology 1993; 27:171-5. [PMID: 8232834 DOI: 10.1159/000118975] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Carbamazepine (CBZ) is known to have beneficial effects in the treatment of epilepsies and in the prophylaxis of affective disorders. Since increased transmembrane calcium fluxes and intracellular calcium concentrations play a key role in the generation of epilepsies and possibly also in the development of these psychiatric disorders the effects of CBZ on epileptic discharges (elicited by caffeine, penicillin and low Mg2+) in CA3 neurons of hippocampal slices were compared with those of the organic calcium antagonist verapamil and found to be almost the same.
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4099
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Sun D, Liu Z, Nan J, Dai Y, Pi M. Wave-front matching measurement in coherent CO(2) laser-radar. APPLIED OPTICS 1992; 31:7647-7649. [PMID: 20802645 DOI: 10.1364/ao.31.007647] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Wave-front matching of the local oscillator beam and the signal beam is of vital importance in optical heterodyne efficiency. A method for aligning the local oscillator beam and the signal beam is described. Mixing efficiency is improved. One can directly observe the matching procedure on an oscilloscope.
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4100
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Liu Z, Perlin AS. Regioselectivity in the sulfation of some chemically-modified heparins, and observations on their cation-binding characteristics. Carbohydr Res 1992; 236:121-33. [PMID: 1291046 DOI: 10.1016/0008-6215(92)85011-n] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Two modified forms of heparin, polymers A and B, have been prepared, one containing residues of nonsulfated alpha-L-idopyranosyluronic acid (3) and the other residues of alpha-L-galactopyranosyluronic acid (7), in place of the normal alpha-L-idopyranosyluronic acid 2-sulfate (1). In addition, both A and B contained 2-acetamido-2-deoxy-alpha-D-glucopyranosyl 6-sulfate residues (6) in place of the corresponding N-sulfated residues (2) of the original heparin. These polymers were subjected to sulfation under various conditions. Examination of the products by NMR spectroscopy showed that polymer A was sulfated initially at position-3 of residue 3, and that slower substitution occurred at position-3 of 6. By contrast, polymer B exhibited low regioselectivity, as sulfation occurred with about equal facility at positions-2 and -3 of 7, and -3 of 6. The sulfation products had no significant anti Xa activity. Based on the paramagnetic effects of Cu2+ and chemical shift displacements induced by Ca2+, NMR spectroscopy was used to compare cation-binding properties of A and B with those of heparin. In contrast to heparin, which forms a complex with Cu2+ detectable at a level of < 10(-3) mol per dimeric unit of the polymer, neither A nor B exhibited an interaction with the cation. However, polymer A was found to bind Ca2+, in this respect being distinct from the related modification, 1-->6, which contains a 2-sulfate group in 1, as well as from polymer B.
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