4201
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Drossman DA, Li Z, Leserman J, Patrick DL. Ulcerative colitis and Crohn's disease health status scales for research and clinical practice. J Clin Gastroenterol 1992; 15:104-12. [PMID: 1401820 DOI: 10.1097/00004836-199209000-00005] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
We report the development of ulcerative colitis (UC) and Crohn's disease (CD) Health Status Scales that improve on existing inflammatory bowel disease (IBD) activity measures by their added association with health status. We surveyed 991 members of the Crohn's and Colitis Foundation of America (CCFA) and analyzed the half with greater disease activity (114 UC, 330 CD, ostomies excluded). Our analysis strategy involved (a) identification of items that discriminated active from inactive disease, (b) factor analysis to reduce the items to clusters sharing common symptom relationships, and (c) regression analysis to select those variables best associated with a composite measure of health status (health care use, daily function, psychologic distress). The factor analyses yielded two indexes for UC and CD: "Diarrhea," and "Other GI symptoms" (Cronbach's alpha 0.59-0.84). The regression analyses for both diseases showed that poorer well-being, the Diarrhea index, and dependence on medication for pain were associated with poorer health status. For UC, lower educational attainment and lower steroid dose, and for CD, the Other GI symptoms index and eye disease, also correlated with poorer health status. By design, the UC and CD Scales are better predictors of health status than the survey version of the CD Activity Index (CDAI), explaining 17 and 21% more of the variance of the health status measure. The final UC and CD Health Status Scales can be used in research and clinical care. They contain symptom items used to assess disease activity and also correlate with health status. Prospective assessment is needed to confirm their accuracy in assessing prognosis and treatment response.
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4202
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Li Z, Hosick HL, Fan K. Microprocedure for in situ nick translation of chromosomes. CANCER GENETICS AND CYTOGENETICS 1992; 62:150-3. [PMID: 1394101 DOI: 10.1016/0165-4608(92)90254-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
We have modified the procedure of in situ nick translation to shorten the autoradiographic exposure time from 1 month to 3 days and reduce the volume of nick translation solution by a factor of at least 10. The modified procedure can be carried out on individually chosen chromosome spreads. The procedure was used on chromosome spreads of three related lines of mouse mammary epithelium (+SA, -SA, CL-S1) with different degrees of tumorigenicity. We found that the autoradiographic silver grains that are observed following in situ nick translation were often placed at the apparent junction site of chromosome translocations or at the breakpoint of chromosomal pieces. We found also that silver grains were located above double minute chromosomes, which suggests that there are active genes in double minutes.
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4203
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Tribollet E, Li Z, Inenaga K, Yamashita H, Raggenbass M, Dubois-Dauphin M, Dreifuss JJ. Functional neuronal binding sites for oxytocin in the ventromedial hypothalamus of the guinea pig after gonadectomy. Brain Res 1992; 588:346-50. [PMID: 1327411 DOI: 10.1016/0006-8993(92)91598-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Castration in rats of either sex has been shown to markedly decrease hypothalamic oxytocin binding in the ventromedial hypothalamus and this can be reversed by injecting gonadal steroids. We wondered whether castration exerts similar effects on homologous oxytocin binding sites present in the guinea pig hypothalamus. Adult male guinea pigs were castrated and killed 2-90 days later. Binding sites for oxytocin in the ventromedial nucleus and neuronal responses to this peptide were little affected by gonadectomy, in contrast to what is observed in the rat under similar experimental conditions. The steroid dependency of hypothalamic oxytocin receptors appears therefore to be species dependent.
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4204
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Kelly KO, Reuven NB, Li Z, Deutscher MP. RNase PH is essential for tRNA processing and viability in RNase-deficient Escherichia coli cells. J Biol Chem 1992; 267:16015-8. [PMID: 1644789] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
RNase PH is a Pi-dependent exoribonuclease that can act at the 3' terminus of tRNA precursors in vitro. To obtain information about the function of this enzyme in vivo, the Escherichia coli rph gene encoding RNase PH was interrupted with either a kanamycin resistance or a chloramphenicol resistance cassette and transferred to the chromosome of a variety of RNase-resistant strains. Inactivation of the chromosomal copy of rph eliminated RNase PH activity from extracts and also slowed the growth of many of the strains, particularly ones that already were deficient in RNase T or polynucleotide phosphorylase. Introduction of the rph mutation into a strain already lacking RNases I, II, D, BN, and T resulted in inviability. The rph mutation also had dramatic effects on tRNA metabolism. Using an in vivo suppressor assay we found that elimination of RNase PH greatly decreased the level of su3+ activity in cells deficient in certain of the other RNases. Moreover, in an in vitro tRNA processing system the defect caused by elimination of RNase PH was shown to be the accumulation of a precursor that contained 4-6 additional 3' nucleotides following the -CCA sequence. These data indicate that RNase PH can be an essential enzyme for the processing of tRNA precursors.
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4205
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Huang Z, Li Z. [Identification of skeleton of 40 species of snake]. ZHONGGUO ZHONG YAO ZA ZHI = ZHONGGUO ZHONGYAO ZAZHI = CHINA JOURNAL OF CHINESE MATERIA MEDICA 1992; 17:457-9, 509. [PMID: 1482529] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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4206
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Wasty F, Alavi MZ, Li Z, Cianflone K, Sniderman AD, Moore S. In vitro interactions between low density lipoprotein from hyperapobetalipoproteinemic plasma and arterial wall proteoglycans. Can J Cardiol 1992; 8:605-10. [PMID: 1504914] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
OBJECTIVE To examine the interactions of low density lipoprotein-B (LDL-B) with proteoglycans (PG) in vitro. DESIGN The PG were isolated from human aortas, removed at autopsy by a combination of extraction with 4M guanidine-Tris buffer containing protease inhibitors and fractionation on a DEAE-Sephacel ion-exchange chromatography column. LDL and LDL-B from healthy or hyperapobetalipoproteinemic sera, respectively, were isolated by standard density flotation techniques followed by radioiodination. Radiolabelled lipoproteins (LP) were incubated with proteoglycans at 4 or 37 degrees C in a low ionic strength buffer with or without addition of polyethylene glycol (PEG) which was used to enhance precipitation of the resulting LP-PG complexes. MAIN RESULTS Data revealed that a specific ratio of LP to PG is a prerequisite for optimal interactions between these macromolecules. Further, it was observed that LDL-B forms fewer precipitable complexes than normal LDL at 4 degrees C. However, at physiological temperature or with the addition of PEG, precipitation of the two LDLs was equal. CONCLUSION LDL and LDL-B showed equal reactivity with PG in terms of precipitable complexes.
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4207
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Alavi MZ, Wasty F, Li Z, Galis ZS, Ismail N, Moore S. Enhanced incorporation of [14C]glucosamine into glycosaminoglycans of aortic neointima of balloon-injured and cholesterol-fed rabbits in vitro. Atherosclerosis 1992; 95:59-67. [PMID: 1642693 DOI: 10.1016/0021-9150(92)90176-h] [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: 12/28/2022]
Abstract
Glycosaminoglycans (GAG), which form the elementary constituent of extracellular matrix proteoglycans (PG), are implicated in the pathogenesis of atherosclerosis, mainly due to their lipoprotein binding capability and their abundance in a developing lesion during atherogenesis. However, the reasons for the increment of GAG content are poorly understood. In the present study, the influence of two well known atherogenic factors on arterial GAG synthesis were examined by estimating the incorporation of [14C]glucosamine into aortic GAG in an in vitro incubation system. Radioactivity associated with GAG was taken to represent their synthesis. GAG synthesis by neointimal tissue of rabbit aortas, 12 weeks following balloon catheter deendothelialization was measured and compared in rabbits fed a normal or 0.25% cholesterol supplemented diet for the preceding 6 weeks. In normolipaemic rabbits synthesis was found to be 12,438 +/- 173, 17,884 +/- 1390 and 15,960 +/- 1355 dpm/mg dry defatted tissue from uninjured (control), deendothelialized (DEA) and reendothelialized (REA) areas of rabbit aortas, respectively. This incorporation of radioactivity was significantly greater in hypercholesterolaemic rabbits corresponding to 13,426 +/- 239, 32,670 +/- 3077 and 27,496 +/- 3287 in the control, DEA and REA, respectively. The results demonstrated a synergistic effect of cholesterol feeding and arterial endothelial denudation in stimulating GAG synthesis. Although GAG synthesis was found to be stimulated by either cholesterol feeding or arterial injury, the stimulation by cholesterol feeding alone was only marginal. Further, results show a much higher retention of newly synthesized GAG by the tissue from REA. This study provided a possible explanation for increased GAG content in a developing proliferative lesion.
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4208
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Li Z, Burkert V. Electroproduction of the Roper resonance as a hybrid state. PHYSICAL REVIEW. D, PARTICLES AND FIELDS 1992; 46:70-74. [PMID: 10014741 DOI: 10.1103/physrevd.46.70] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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4209
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Li L, Li Z, Huo HS, Wang HZ, Wang LY. Sensory nerve endings in the puborectalis and anal region of the fetus and newborn. Dis Colon Rectum 1992; 35:552-9. [PMID: 1587173 DOI: 10.1007/bf02050535] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The study was carried out in seven fetuses (ovulation ages were 16, 18, 20, 22, 26, 28, and 31 weeks, respectively) and in five full-term newborn babies. The modified Bielschowsky method and Barker's block silver impregnation were used. It was found that the muscle spindle was arranged in the puborectalis and the external sphincter muscles from the 20th week onward; the tendon organ was located in association with the musculo-tendinous junction of the puborectalis from the 20th week onward; the Pacinian corpuscle lay in the plane of cleavage between the internal anal sphincter and the external anal sphincter from the 22nd week onward, and in the presacral space from the 28th week onward, and the later lagged behind the former in development; the globular endings lay in the presacral space from the 28th week onward; and the free nerve ending was distributed in the epithelium of the anal mucosa and the epidermis around the anus from the 31st week onward. These sensory nerve endings tend to mature gradually with increasing age. It was concluded that these endings may be responsible for the reflex of the external anal sphincter and the anal sensation.
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4210
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Wu ZY, Bai XM, Li Z. [Comparison of drug release rate between Chinese subcutaneous implants and Norplant in vitro]. SHENG ZHI YU BI YUN = REPRODUCTION AND CONTRACEPTION 1992; 12:7-10. [PMID: 12317566] [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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4211
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Li Z, Gambino R, Fless GM, Copeland RA, Halfpenny AJ, Scanu AM. Expression and purification of kringle 4-type 2 of human apolipoprotein (a) in Escherichia coli. Protein Expr Purif 1992; 3:212-22. [PMID: 1327342 DOI: 10.1016/1046-5928(92)90017-q] [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: 12/26/2022]
Abstract
The most frequently occurring kringle 4 domain of human apolipoprotein (a), Kringle 4-subtype 2 (K4(2)), was expressed as a fusion protein with the maltose binding protein in Escherichia coli using the "tac" promoter. Although the fusion protein was expressed without a signal sequence, 25% was secreted into the periplasmic space; the remainder was found associated with the soluble cytosolic fraction. The fusion protein was readily isolated from whole cell lysate by amylose agarose affinity chromatography. Although a factor Xa cleavage site was engineered into the fusion protein, it was found that release of the K4(2) protein was most conveniently achieved by proteolysis with subtilisin A. The cleavage product produced in this way was shown to be intact K4(2) with only the first three amino acid residues of the leading flanking peptide missing, as judged by N-terminal sequence analysis. K4(2) was isolated from the hydrolysate by FPLC on a Mono-Q column with a yield of 170 +/- 30 micrograms/g wet cells. The resulting protein was monomeric in phosphate-buffered saline as judged by size-exclusion chromatography and appeared to be folded as shown by spectroscopic and immunological assays. The recombinant K4(2) did not bind to either lysine- or proline-Sepharose, suggesting that the ligand binding activities of lipoprotein (a) may reside in the other kringle domains of apolipoprotein (a).
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4212
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Galis ZS, Ghitescu LD, Li Z, Alavi MZ, Moore S. Distribution of endogenous apoprotein B-containing lipoproteins in normal and injured aortas of normocholesterolemic rabbits. J Transl Med 1992; 66:624-38. [PMID: 1573856] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The distribution of endogenous apolipoprotein B (apo B) was studied in both normal and balloon catheter-injured aortas of standard fed rabbits. Using light and electron microscopy, the distribution within entire aortic walls and individual tissue compartments was investigated by immunocytochemistry using an antibody raised against rabbit apo B. The concentration of apo B across the vessel wall dropped sharply from the luminal front towards the media of the normal aortas. The strong superficial reaction was mainly due to a heavy, yet specific, labelling of endothelial cells. Significant concentrations of apo B were also detected within the innermost regions of the extracellular space. The characteristics associated with the labelling of the intimal layer suggested an intense uptake and transcellular transport of apo B by endothelial cells. In contradistinction, normal smooth muscle cells did not appear to be labelled. In the previously injured aortas, the same features of strong superficial apo B labelling were present in the areas covered by regenerated endothelial cells, but not in those persistently deendothelialized. The smooth muscle cells of these regions appeared to show a low uptake of apo B. The increased concentrations of apo B in deeper interstitial areas of injured aortas, indicated the contribution of the extracellular matrix to apo B accumulation. This was especially prominent in the advanced lesions, selectively developed within neointima covered by regenerated endothelium. A rather uniform labelling pattern accompanying small lipid particle deposits, suggested a direct extracellular accumulation of circulating lipoproteins. Intensely labelled foam cells and irregularly distributed apo B within areas of cellular necrosis were detected as well. Injury-mediated responses of the cellular and extracellular aortic components can trigger the development of lipoprotein accumulations characteristic of atherosclerosis within aortas of normocholesterolemic animals.
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4213
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Song DY, Zhuang H, Li Z. [Hepatitis E in Hetian city. Analysis of 562 cases]. ZHONGHUA NEI KE ZA ZHI 1992; 31:275-7, 316. [PMID: 1478123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Between August and September 1987, 562 patients were hospitalized with acute non-A, non-B hepatitis. The male to female ratio was 1.4:1, and 75% of the patients was of 15-40 years of age. Jaundice developed in 87%. The overall case-fatality rate was 1.4%, but it was highest among pregnant women (5.2%) and newborn infants (24.2%). In general, the disease was self-limited with no evidence of chronic infection. Liver biopsies obtained during the acute illness showed portal inflammation and cytoplasmic cholestasis. Of 31 specimens of stool examined with a prototype ELISA for HEV antigen, 8 were found to be 'positive' and confirmed with immune electron microscopy (IEM). IEM examination of 'patients' stool revealed 27-32 nm viruslike particles. Inoculation of rhesus monkeys with patients stool containing virus-like particles produced acute hepatitis and the acute phase serum reacted with these particles in IEM, while preinoculation serum specimens were non-reactive.
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4214
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Li Z, Williamson JF. Volume-based geometric modeling for radiation transport calculations. Med Phys 1992; 19:667-77. [PMID: 1508105 DOI: 10.1118/1.596810] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Accurate theoretical characterization of radiation fields is a valuable tool in the design of complex systems, such as linac heads and intracavitary applicators, and for generation of basic dose calculation data that is inaccessible to experimental measurement. Both Monte Carlo and deterministic solutions to such problems require a system for accurately modeling complex 3-D geometries that supports ray tracing, point and segment classification, and 2-D graphical representation. Previous combinatorial approaches to solid modeling, which involve describing complex structures as set-theoretic combinations of simple objects, are limited in their ease of use and place unrealistic constraints on the geometric relations between objects such as excluding common boundaries. A new approach to volume-based solid modeling has been developed which is based upon topologically consistent definitions of boundary, interior, and exterior of a region. From these definitions, FORTRAN union, intersection, and difference routines have been developed that allow involuted and deeply nested structures to be described as set-theoretic combinations of ellipsoids, elliptic cylinders, prisms, cones, and planes that accommodate shared boundaries. Line segments between adjacent intersections on a trajectory are assigned to the appropriate region by a novel sorting algorithm that generalizes upon Siddon's approach. Two 2-D graphic display tools are developed to help the debugging of a given geometric model. In this paper, the mathematical basis of our system is described, it is contrasted to other approaches, and examples are discussed.
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4215
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Li Z, Huang L, Su G. Structure of 4'-methoxychalcone. Acta Crystallogr C 1992. [DOI: 10.1107/s010827019101140x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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4216
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Li Z, Smith CD, Smolley JR, Bridge JH, Frank JS, Philipson KD. Expression of the cardiac Na(+)-Ca2+ exchanger in insect cells using a baculovirus vector. J Biol Chem 1992; 267:7828-33. [PMID: 1560015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
We constructed a recombinant baculovirus containing cardiac Na(+)-Ca2+ exchanger cDNA under control of the polyhedrin promoter. When either Sf9 or Sf21 insect cells are infected with the recombinant baculovirus, both Na(+)-Ca2+ exchanger protein and Na(+)-Ca2+ exchange activity are expressed at high level. The exchanger protein can be detected either by immunoblot or by sodium dodecyl sulfate-polyacrylamide gel electrophoresis of whole cell lysate. At maximal expression, the exchanger protein comprises about 3-5% of total cell protein. The Na(+)-Ca2+ exchanger can be purified by alkaline extraction of infected cells followed by elution from a Bio-Rad Prep Cell. The expressed exchanger, in contrast to the native sarcolemmal exchanger, is not glycosylated. Sf9 cells expressing the exchanger are intensely stained by anti-exchanger antibodies as observed by immunofluorescence. The expressed exchanger is predominantly in the cell plasma membrane since it is susceptible to extracellular trypsin. In 45Ca2+ flux experiments, the expressed Na(+)-Ca2+ exchange activity is about 4-fold higher than that in cultured neonatal rat heart cells. The expressed exchanger was also analyzed electrophysiologically using whole cell patch clamp techniques. The characteristics of inward exchange currents in infected Sf21 cells are very similar to those of ventricular myocytes, although of a larger magnitude.
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4217
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4218
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Li Z, Abboud FM, Chapleau MW. Aggregating human platelets in carotid sinus of rabbits decrease sensitivity of baroreceptors. Circ Res 1992; 70:644-50. [PMID: 1551191 DOI: 10.1161/01.res.70.4.644] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Aggregating platelets release factors that act in a local paracrine manner to alter vascular tone. The purpose of the present study was to explore the possibility that factors released from aggregating platelets may alter the sensitivity of arterial baroreceptors. Baroreceptor activity was recorded from the vascularly isolated carotid sinus of rabbits anesthetized with sodium pentobarbital. The carotid sinus was filled with oxygenated Krebs-Henseleit buffer and distended with slow ramp increases in nonpulsatile pressure. Sensitivity of baroreceptors to increased pressure was determined before and during intraluminal exposure of the sinus to washed human platelets suspended in Krebs' buffer. Platelets activated with thrombin (0.4 units/ml) decreased baroreceptor activity and the slope of the pressure-activity curve significantly (n = 6). The platelet-induced decrease in baroreceptor sensitivity was related to the duration of exposure to platelets with no change in baroreceptor activity after 4 minutes and a progressive decrease in activity over the next 12 minutes. The slope of the pressure-nerve activity relation averaged 1.26 +/- 0.08 %/mm Hg during control and decreased to 0.97 +/- 0.22, 0.80 +/- 0.19, and 0.53 +/- 0.15 %/mm Hg after 12-16 minutes of exposure to 10(7), 10(8), and 3-6 x 10(8) activated platelets/ml, respectively (p less than 0.05). Baroreceptor sensitivity was restored after removal of platelets from the carotid sinus. Thrombin alone had no effect on baroreceptor sensitivity. Activated platelets did not alter the carotid pressure-diameter relation, suggesting a direct inhibitory effect on baroreceptors. The slope of the pressure-activity curve and maximum baroreceptor activity were not decreased by the stable thromboxane analogue U46619, serotonin, or ADP.(ABSTRACT TRUNCATED AT 250 WORDS)
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4219
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Deber CM, Li Z, Joensson C, Glibowicka M, Xu GY. Transmembrane region of wild-type and mutant M13 coat proteins. Conformational role of beta-branched residues. J Biol Chem 1992; 267:5296-300. [PMID: 1544912] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Although transmembrane (TM) segments of integral membrane proteins are putatively alpha-helical in conformation, beta-sheet promoters (Val, Ile, Thr) often account for approximately 40% of TM residue composition. We are examining the conformational role(s) of these residues, using as a model system the major coat protein of the filamentous bacteriophage M13. This 50-residue protein, which is located at the Escherichia coli host membrane during phage reproduction, contains a prototypic 19-residue hydrophobic midregion (residues 21-39: YIGYAWAMVVVIVGATIGI). Using "Eckstein" site-directed mutagenesis, we have generated several viable M13 coat protein mutants with beta-branched amino acid substitutions within their TM region. Mutant coat proteins, including Ile32----Val (I32V) and Ala27----Thr (A27T), were obtained in milligram quantities by growing M13 mutant phages in liter preparations, confirming that these coat proteins are capable of assuming their normal biological function(s) in phage reproduction. Circular dichroism spectroscopy performed in the membrane-mimetic medium of deoxycholate micelles indicated comparable alpha-helical contents of mutants I32V and A27T to wild-type protein. 13C nuclear magnetic resonance experiments with mutant A27T demonstrated that the combination of additional beta-branched content and introduction of an -OH substituent induced chemical shift and temperature-dependent changes and influenced the local protein environment at sites up to 12 residues remote from the mutation site. In contrast, mutant I32V (of which a salient feature is a mid-TM pentavaline segment) behaved very similarly to wild-type coat. These findings are interpreted in terms of the range of TM secondary structure and stability which can be accommodated by viable M13 coat protein mutants.
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4220
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Ye L, Zhang A, Li Z, Qin S. [A mid-infrared spectra study of a series of benzocrown ether and macrocyclic polyether diester]. HUA XI YI KE DA XUE XUE BAO = JOURNAL OF WEST CHINA UNIVERSITY OF MEDICAL SCIENCES = HUAXI YIKE DAXUE XUEBAO 1992; 23:102-5. [PMID: 1398617] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
With a Nicolet 20 SX B Fourier Transform infrared spectrometer, the mid-infrared spectra in region of 4000-400 cm-1 were observed for a series of benzocrown ether and macrocyclic polyether diester. A difference in the wavelength of absorption of the ether bond was found between benzocrown ether and macrocyclic polyether diester. The wavelength of absorption of the ether bond of the compounds I-IV moved down about 25 cm-1, as compared with that of the compounds V-IX.
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4221
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Deber C, Li Z, Joensson C, Glibowicka M, Xu G. Transmembrane region of wild-type and mutant M13 coat proteins. Conformational role of beta-branched residues. J Biol Chem 1992. [DOI: 10.1016/s0021-9258(18)42765-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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4222
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Tilly JL, Kowalski KI, Li Z, Levorse JM, Johnson AL. Plasminogen activator activity and thymidine incorporation in avian granulosa cells during follicular development and the periovulatory period. Biol Reprod 1992; 46:195-200. [PMID: 1536895 DOI: 10.1095/biolreprod46.2.195] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The hormonal and second messenger regulation of plasminogen activator (PA) activities in avian granulosa and theca cells has been documented. However, the physiological role(s) of PAs in the avian ovary remains poorly understood. The present studies were designed to evaluate PA activity in hen granulosa cells collected from the most mature (F1) preovulatory follicle at three discrete time points relative to a spontaneous ovulation and from follicles collected at various stages of follicular development. Levels of PA activity in the granulosa layer of the F1 follicle declined by greater than 90% as follicles were collected closer to their anticipated time of ovulation (e.g., from 17-16 h to 0.75-0.15 h; p less than 0.05). Timing of tissue collection was confirmed by evaluation of serum progesterone levels, which peaked as expected at the 6-5-h time point. During follicular development, PA activity was several times greater in rapidly growing follicles (6-12 mm, 1-3 wk prior to ovulation) than in slowly growing (1-5 mm) or preovulatory (F3 and F1) follicles (p less than 0.05). Granulosa cells of these rapidly growing follicles also incorporated significantly higher levels of 3H-thymidine than did granulosa cells of mature follicles (p less than 0.05), suggesting a higher level of DNA synthesis. Similarly, granulosa cells of the mitotically active germinal disc region of the F1 granulosa layer were found to possess at least 3-fold higher (p less than 0.05) levels of PA activity and a 2-fold greater level of 3H-thymidine incorporation than the more mature granulosa cells isolated from the remaining F1 granulosa layer.(ABSTRACT TRUNCATED AT 250 WORDS)
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4223
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Li Z, Wang X, Bian Z, Li S, Zheng H, Zhao B, Chen J. Proteus penneri isolated from the pus of a patient with epidural abscess. KANSENSHOGAKU ZASSHI. THE JOURNAL OF THE JAPANESE ASSOCIATION FOR INFECTIOUS DISEASES 1992; 66:144-8. [PMID: 1402074 DOI: 10.11150/kansenshogakuzasshi1970.66.144] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
P. mirabilis and P. vulgaris are the two wellknown species in the genus Proteus. P. myxofaciens and P. penneri are recent additions to the genus. We isolated P. penneri from the pus of a patient with suppurative otitis media and an epidural abscess. The characteristics of the organism, including morphology, staining, physiology and biochemistry, were studied. Clinical microbiological laboratories should suspect P. penneri in the case of as Proteus strain that is negative for indole, salicin and esculin, but otherwise resembles P. vulgaris. Proteus penneri, formerly known as Proteus vulgaris indole-negative or as Proteus vulgaris biogroup 1, was named by Hickman et al in 1932. Little information about human infection by this organism is available. In 1982, Hickman and co-workers studied 20 strain of P. penneri which were isolated from clinical specimens (urine, stool, etc.) in the USA. However, its clinical significance, until recently, was unknown. We isolated a strain of P. penneri from the pus of a patient with suppurative otitis media and an epidural abscess on June 10 and 15, 1989. This paper concerns the problems encountered in identifying this organism and its clinical significance.
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4224
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Li Z. [Model of atrophic gastritis in rats by various method]. ZHONGHUA YI XUE ZA ZHI 1992; 72:81-3, 127. [PMID: 1327437] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Model of atrophic gastritis was made in rats by synthetical method which comprised twice of active immunization and continual oral administration of bile and hot water for 70 days. There was a highly significant difference (P less than 0.01) between the normal group and testing group in the number of rats with changes in body-weight, PH value of gastric mucous membrane, gastric membrane blood flow (GMBF) and its potential difference (PD), and pathology (thinned mucous membrane, decreased gland, infiltration of inflammatory cells and intestinal metaplasia). By observations for additional 45 days, the above-mentioned values still showed significant or highly significant differences (P less than 0.05 or P less than 0.01) between the testing group and the normal group. The animal model of atrophic gastritis made by this method can be used for the valuation of drug efficacy.
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4225
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Wang BC, Li Z, Yang DL. [Detection of hepatitis B virus DNA in leucocytes of primary hepatocarcinoma using polymerase chain reaction]. ZHONGHUA NEI KE ZA ZHI 1992; 31:90-2, 126. [PMID: 1327673] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The detection of HBV DNA in sera and leucocytes of 30 primary hepatocarcinoma patients whom were negative for HBsAg by reverse passive hemagglutination using polymerase chain reaction (PCR) were reported. The detectable rates of HBV DNA in leucocytes and sera were 86.7% and 70% respectively and the serological indexes, 43.4%. These indicated that HBV DNA may existent in blood of the patients with negative serological indexes. It was common that HBV DNA presented in peripheral leucocytes of primary hepatocarcinoma, indicated that extrahepatic sites of the HBV genome, and perhaps replication of HBV virus, existed. It was of great importance for the role of HBV DNA in lemology and epidemiology, etiology of hepatocarcinoma, diagnosis and treatment of infection as well as standard of cure.
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