Broken reflection symmetry in 114Xe.
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Journal Article↗
Biomedical subjects
Z Zhao
Publications and source records attributed to Z Zhao.
Study of the beta-delayed alpha-particle emission of 16N.
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Journal Article↗
[Study on the induction of active immunity in human by injecting human anti-HBs antibodies].
One hundred and three health volunteers were injected with various doses of human anti-HBs (Ab1). The anti-idotypic antibodies (Ab2) and anti-antiidiotypic antibodies (Ab)3 in sera were tested at intervals of 30 days with ELISA. We found that the dynamic changes between Ab2 and Ab3 of immune sera were cyclical by way of their interaction and the Ag-specific Ab3 were the same as Ab1 in specificity. The results reconfirmed that exogenous human anti-HBs could induce active immunity by activation of idiotypic network and regulation in human body suggesting that injection of Ig into body could bring about not only passive immunity but also active immunity.
Adolescent↗
Hepatitis B virus infection in Honolulu students.
OBJECTIVES: To determine hepatitis B virus (HBV) carrier and infection rates and HBV epidemiology in Honolulu students. DESIGN: Cross-sectional survey. SETTING: Honolulu public elementary, intermediate, and high schools. PATIENTS: A volunteer sample of 4936 students from 43 Honolulu schools. MAIN OUTCOME MEASURES: HBV carrier rate (presence of hepatitis B surface antigen) and infection rate (presence of either hepatitis B surface antigen, antibody to hepatitis B surface antigen, antibody to hepatitis B core antigen, or any combinations of these) by school grade, ethnicity, and place of birth. RESULTS: Eighty-three (1.68%) students were identified as HBV carriers, and a total of 353 (7.15%) students had serologic evidence of infection. Infection rates increased from elementary school age to high school age, more so in Asian/Pacific Island-born students. The prevalence of infection was higher in Asian/Pacific Island-born students than in those born in the United States. The majority of infected Hawaiian-born students were first-generation Asian/Pacific Island Americans. CONCLUSIONS: Horizontal transmission of HBV occurs in Honolulu school-age children. HBV immunization of all infants in Hawaii, not just those born to carrier mothers, is necessary to reduce HBV transmission in Hawaii.
Adolescent↗
Dicyanogold (I) is a common human metabolite of different gold drugs.
Gold based drugs and their metabolites have been characterized using reversed phase, ion pairing chromatography with an inductively coupled plasma mass spectrometer as an element specific detector. For a patient receiving gold sodium thiomalate the principal gold species in the urine is [Au(CN)2]-, which is also seen in a low molecular weight infiltrate of the blood. The same compound is also identified in the urine and blood of a patient taking auranofin and in patients taking solganol. This represents the first identification of a specific gold metabolite in biological fluids taken from patients undergoing gold therapy and the first evidence that different gold drugs have common metabolites.
Anions↗
Design, synthesis, and biological evaluation of novel 4-substituted 1-methyl-1,2,3,6-tetrahydropyridine analogs of MPTP.
The exceptionally good MAO-B substrate properties of several 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) derivatives have prompted studies to evaluate the corresponding properties of tetrahydropyridines bearing heteroatom-linked groups at C-4. The 1-methyl-4-phenoxy-1,2,3,6-tetrahydropyridine analog proved to be an excellent MAO-B substrate. Unlike analogs bearing hydrocarbon substituents at C-4, the resulting dihydropyridinium metabolite did not undergo further oxidation to the pyridinium compound but rather underwent hydrolytic cleavage. This observation has led to studies designed to explore the possibility of developing novel, nontoxic derivatives of MPTP bearing potential pharmacologically active leaving groups at C-4. In this paper we report the results of synthetic and metabolic studies on a series of tetrahydropyridine analogs of MPTP with oxygen, sulfur, and carbamoyloxy derivatives on C-4 which serve as model compounds to evaluate the scope of this prodrug concept.
1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗
Continuous spectrophotometric assay of protein tyrosine phosphatase using phosphotyrosine.
A continuous activity assay for protein tyrosine phosphatases (PTPs), employing phosphotyrosine (P-Tyr) as a substrate, has been developed and applied to measure the activities of two purified enzymes, namely, the full length T-cell protein tyrosine phosphatase (TC PTP) and its truncated form (TC delta C11 PTP). The reaction was followed by changes in ultraviolet absorption and fluorescence resulting from the dephosphorylation of P-Tyr. Both enzymes obey Michaelis-Menten kinetics, with Km = 304 microM, Vmax = 62,000 units/mg for TC PTP and Km = 194 microM, Vmax = 73,000 units/mg for TC delta C11 PTP. The D- and L-forms of P-Tyr are equally effective as substrates. The optimum pH for both enzymes is 4.75. The known effectors of PTPs have the predicted effects on catalytic activity.
Hydrogen-Ion Concentration↗
Purification and characterization of maturation-promoting factor in fish.
Maturation-promoting factor (MPF) activity has been demonstrated for the first time in fish oocytes. We purified MPF from a 100,000g supernatant of crushed, naturally spawned carp oocytes using four chromatography columns: Q-Sepharose Fast-Flow, p13suc1-affinity Sepharose, Mono S, and Superose 12. The final preparation was purified over 1000-fold with a recovery of about 1%. On Superose 12, MPF eluted as a single peak with an apparent molecular weight of 100 kDa. SDS-PAGE analysis of the active fractions after Superose 12 revealed the presence of four proteins of 33, 34, 46, and 48 kDa. A monoclonal antibody against the PSTAIR sequence of cdc2 kinase recognized the 33- and 34-kDa proteins for which the 46- and 48-kDa proteins are endogenous substrates. The 46- and 48-kDa proteins were recognized by a monoclonal antibody against Escherichia coli-produced goldfish cyclin B, but not by an anti-cyclin A antibody. When oocytes were matured in the presence of 32P, the labeling was seen with the 34-kDa protein, but not with the 33-kDa protein. The 34-kDa protein corresponded to the MPF activity, but the 33-kDa protein did not. These findings indicate that carp MPF is a complex of cdc2 kinase and cyclin B, and further that active MPF contains the phosphorylated form of cdc2 kinase.
Animals↗
Dexmedetomidine, a potent and highly specific alpha 2 agonist, evokes cytosolic calcium surge in astrocytes but not in neurons.
Dexmedetomidine is an extremely potent alpha 2 adrenoceptor agonist which can reduce anaesthetic requirements by up to 90%. However, the precise cellular mechanism of action of this agent is not known. Primary cultures of murine neurons and astrocytes were grown to test the hypothesis that changes in free intracellular calcium may trigger cellular responses to this drug. In astrocyte cultures, experiments revealed a pronounced increase in cytosolic calcium concentration when 100 nM dexmedetomidine was administered. However, in cultured cerebellar granule cell neurons there was no calcium response observed with similar or even higher concentrations of the drug. Results suggest dexmedetomidine may exert its primary effect on the central nervous system via astrocytes.
Adrenergic alpha-Agonists↗
Diversities of transport of sodium in rodent red cells.
1. Na-K pumps of rodent red cells reveal variations among species in terms of kinetic properties such as ouabain sensitivity, Na/K coupling and temperature sensitivity and variations within an individual organism related to such physiological challenges as K deficiency, calorie deficiency and seasonal changes in temperature. 2. Passive Na entry among rodents collectively occurs through the same routes as in red cells of other mammals, but red cells of hamsters, rats and thirteen-lined ground squirrels lack or are deficient in an amiloride-sensitive, shrinkage-activated Na-H exchange. 3. In guinea-pig this pathway appears to be both activated and uncoupled by cooling from 37 to 20 degrees C. 4. Red cells of rodents in general and hamsters in particular are rich in a Na-Mg exchange pathway. In hamsters, this appears to be the only amiloride-sensitive pathway in simple media. 5. In hamster cells, Na entry through the amiloride-sensitive Mg-activated pathway exhibits the same kinetics as previously shown for Na activation of Mg extrusion.
Adenosine Triphosphate↗
Determination of gold-based antiarthritis drugs and their metabolites in urine by reversed-phase ion-pair chromatography with ICP-MS detection.
A sensitive method for the determination of gold-based drugs auranofin, myochrysine, and their metabolites has been developed. These gold-containing compounds were separated by reversed-phase ion-pair chromatography with tetrabutylammonium chloride as the ion-pairing agent. Gold-specific on-line detection utilized inductively coupled plasma mass spectrometry (ICP-MS). The separation conditions of pH, methanol content, concentration of the ion-pairing agent and ionic strength have been investigated. The detection limit for auranofin, the last peak in the chromatogram, was 0.3 ng. These methods were applied to the analysis of gold-containing species in urine from arthritis patients on auranofin, myochrysine or solganol therapy. The recovery of the total gold-containing species from urine was greater than 90%. Dicyanogold(I) anion, [Au(CN)2]-, was detected in the urine of several patients.
Auranofin↗
Determination of trace amounts of estriol and estradiol by adsorptive cathodic stripping voltammetry.
Estriol and estradiol are electroinactive in the potential range from -200 to -1000 mV versus a silver-silver chloride electrode at a mercury electrode. The conversion of these estrogens into electroactive nitro derivatives of estrogens, which are used for voltammetric determination, was studied. Such nitro derivatives give a well defined cathodic stripping wave at -600 mV in pH 10.5 borate buffer. Estriol and estradiol are determined in the ranges 1 x 10(-9)-1.5 x 10(-6) and 5 x 10(-9)-2 x 10(-6) mol dm-3, respectively, by differential-pulse adsorptive stripping voltammetry at a hanging mercury drop electrode. Some steroids, such as estrone, interfere because the three estrogens have almost the same molecular structure and have similar nitro derivatives, but progesterone does not interfere and is reduced at significantly more negative potentials than the nitrated estrogens. It can be determined simultaneously with estriol or estradiol. A method was developed for the assay of estriol in pharmaceutical preparations.
Adsorption↗
Acanthamoebae bind to glycolipids of rabbit corneal epithelium.
By use of a thin-layer chromatogram (TLC) overlay procedure, 35S-labeled acanthamoebae were shown to bind to seven glycolipids of rabbit corneal epithelium. Corneal epithelial cells were grown in culture and were subjected to Folch extraction to isolate a chloroform-rich lower phase containing neutral glycosphingolipids (NGSL) and an aqueous upper phase containing gangliosides, i.e., sialic acid-containing glycolipids. Thin-layer chromatography of the upper phase revealed the presence of 10 ganglioside components. Acanthamoebae were shown to bind to four of these components, referred to as 2, 3, 6, and 7. On TLC plates, ganglioside components 2 and 3 migrated slightly ahead of the glycolipid standard GD1a, component 7 comigrated with standard GM3, and component 6 migrated a little more slowly than GM3. Likewise, of the 10 NGSL known to be present in the lower phase, acanthamoebae bound to components 1, 5, and 6. NGSL components 1, 5, and 6 migrated on TLC plates with relative mobilities similar to those of standards asialo GM1, asialo GM2, and ceramidetrihexoside, respectively. We propose that one or more of the Acanthamoeba-reactive glycolipids of corneal epithelium identified in this study may play a role in the pathogenesis of Acanthamoeba keratitis by mediating the adherence of the parasites to the cornea.
Acanthamoeba↗
Intracoronary L-arginine during reperfusion improves endothelial function and reduces infarct size.
We tested the hypothesis that intracoronary administration of L-arginine (L-Arg), the physiological nitric oxide (NO) precursor, during reperfusion would attenuate postischemic damage by L-Arg NO-pathway mechanisms. Open-chest, anesthetized dogs underwent 60 min of left anterior descending coronary arterial (LAD) occlusion followed by 270 min of reperfusion. Dogs received intracoronary 10 mM L-Arg (n = 9 dogs), intracoronary 10 mM D-arginine (D-Arg, n = 7), or saline vehicle (Veh, n = 10) in the LAD during the first 120 min of reperfusion using an extracorporeal system. After 270 min of reperfusion, segmental systolic and diastolic function were comparably impaired in all three groups. Infarct size (triphenyltetrazolium chloride) expressed as a percentage of the area at risk (An/Ar) was significantly (P < 0.05) reduced in the L-Arg group (17.7 +/- 3.2%) compared with the Veh group (34.8 +/- 2.4%); D-Arg reversed this cardioprotection (48.8 +/- 5.2%, P < 0.05 vs. L-Arg, Veh). Cardiac myeloperoxidase activity, an index of neutrophil accumulation (U/100 mg tissue), was significantly (P < 0.05) lower in the necrotic tissue of the L-Arg group (0.88 +/- 0.26) than in the Veh group (2.46 +/- 0.38). Furthermore, responses to endothelium-dependent vasodilators acetylcholine and A23187 in isolated ischemic-reperfused LAD rings were significantly (P < 0.05) greater in the L-Arg group than in the other two groups. We conclude that intracoronary infusion of L-Arg during the early phase of reperfusion reduced neutrophil accumulation and infarct size and the infusion preserved endothelial function, possibly by increasing NO release or production by the endothelium.
Animals↗
[Detection of anti-idiotypic antibody specific for anti-HBs in HBsAg positive serum].
An ELISA for detecting anti-idiotypic antibody specific for anti-HBs(anti-anti-HBs, Ab 2) was devised and used to detect twenty-three asymptomatic HBsAg positive sera. Of these HBsAg positive samples, five were positive for anti-anti-HBs. Three anti-anti-HBs positive samples and two anti-anti-HBs negative samples were checked by immune electron microscopy (IEM). Non HBV particles were found in the anti-anti-HBs positive samples, but the particles were seen in one of the anti-anti-HBs negative samples. According to the immune networks theory, the anti-anti-HBs with the characteristic of HBsAg internal can mimic HBsAg and bind to anti-HBs(Ab 1), so that the anti-anti-HBs may interfere the routine detection of HBsAg and results in false positive. The data described above demonstrated the existence of this consideration. The authors suggested that samples with HBsAg positive, especially those from asymptomatic carriers should be detected for anti-anti-HBs in order to rule out the interference of anti-anti-HBs.
Antibodies, Anti-Idiotypic↗
[Interleukin 1, transforming growth factor beta and messenger ribonucleic acid expression during the course of glomerulonephritis and glomerulosclerosis].
The accumulation of extracellular matrix is a prominent feature of progressive glomerulonephritis and glomerulosclerosis. This study was designed to evaluate the coeffective role of interleukin 1 (IL-1), transforming growth factor beta (TGF beta), and accumulation of collagen IV, fibronectin (FN), laminin (LN) in the progress of glomerulonephritis. Rat mesangial proliferation and sclerosis was induced by injection of anti-thymocyte serum (ATS). Total RNA of glomeruli were extracted from rat kidney at 3, 7, 14, 28, 60 days after ATS administration for northern blots. The results showed that IL-1, TGF beta mRNA expression was 2 to 3 folds higher than in the controls on the 7th to 14th day after injection of ATS. At the same time, there were increased accumulations of collagen IV, FN, and LN. Increased IL-1, TGF beta mRNA expression and accumulation of collagen IV, FN, LN were closely associated with mesangial proliferation, matrix expansion and focal glomerulosclerosis. These results suggest that increased IL-1, TGF beta mRNA expression and accumulation of collagen IV, FN, LN may play an important role in the progression of glomerulonephritis.
Animals↗
[Constituents of essential oils from leaves, stems, and fruits of Perilla frutescens (L.) Britt].
The constituents of essential oils obtained from the leaves, stems, and fruits of Perilla frutescens were analysed by GC-MS. 65 compounds including perilla aldehyde, perilla alcohol, trans-caryophyllene and hexadecanoic acid, etc. were identified. Their percentages in the oils were given.
Drugs, Chinese Herbal↗
[A prospective study on the relationship between abnormal pregnant outcome and Toxoplasma gondii infection].
2821 pregnant women were divided into three groups according to the phenomena of Toxoplasma gondii infection, and the pregnancy outcomes were followed up. Results show that the total incidence rates of spontaneous abortion, premature birth, still birth and congenital defects are 0.67%, 3.47%, 0.85% and 0.96% respectively. These four rates in the group serodiagnosed as recently or actively infected are significantly higher than that diagnosed as no evidence of infections and the relative risk estimates (ORmh) are 7.38, 3.52, 8.68 and 9.44 respectively. Differences of the four rates between group diagnosed as past infection and that of no evidence of infection are not statistically significant. Analysis between the time of serodiagnosis and the incidence of abnormal pregnant outcome shows that congenital defects is statistically related with infection in the first trimester of gestation.
Abortion, Spontaneous↗