[The oculocardiac reflexes in extraocular muscle operations of generally anesthetized children].
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Anesthetics, General↗
Biomedical subjects
D Xu
Publications and source records attributed to D Xu.
[Dynamic study of anti-NS5 and ALT in post-transfusion hepatitis C].
In order to study the character and dynamic changes of HCV NS5 antigen in post-transfusion hepatitis C, EIA was established with fusion protein, and different groups of population were investigated. The results showed the positive rate of whole blood donor, normal people, chronic hepatitis C patients and post transfusion hepatitis C patients is 0.0%, 1.66%, 50.7% and 70.5%, respectively. Serial blood samples of 25 cases of acute or chronic post-transfusion hepatitis C were detected, and the results indicated that the antibody of NS5 appeared relatively late, and the serum conversion time was 182.9 +/- 168.5 days. The anti-NS5 positive rate in 1, 3, 6, 12 and 24 months after HCV infection was 28%, 40%, 52%, 68% and 76%, respectively. The positive rate of anti-NS5 in sera with HCV RNA was 61.9%. Analysis on the appearance of antibody to the different antibody region of the gene, ALT and HCV RNA showed the dynamic changes of anti-NS5 were corresponding to the serum ALT in some cases, indicating antibody of NS5 appear later and may reflect the disease activity to some extent. The dynamic changes of anti-NS5 are of four kinds: transient positive, intermittent positive, persistent positive and persistent negative in during the two years period.
Alanine Transaminase↗
[Fluorescence studies on the mixed solid complexes of europium-terbium-1, 10-phenanthroline-phthalate systems].
The 1, 10-phenanthroline-phthalate complexes of europium and terbium have been synthesized. Two series of mixed complexes, mechanical ground complexes (series 1) and chemical synthesized with mixed EuCl3 and TbCl3 solutions (series 2), have been also prepared. Fluorescence studies on all of the samples were performed. The results of their fluorescence spectra excited by 365nm UV-light showed that there are interactions between europium ions and terbium ions in these two kinds of mixed complexes. Their fluorescence intensities strongly changed especially for chemical synthesized mixed complexes, in which the fluorescence intensities of europium ions were greatly sensitized by terbium ions and those of terbium ions were strongly quenched by europium ions. But the peak positions of their emission bands did not shift obviously. The structure of these complexes have been characterized by FT-IR spectra. The results suggested that no free COOH groups exist and all of the nitrogen atoms of 1, 10-phenanthroline molecules coordinate to rare earth ions in all of these complexes.
English Abstract↗
The plasma concentrations of lidocaine after slow versus rapid administration of an initial dose of epidural anesthesia.
We measured venous blood concentrations of lidocaine in 15 patients undergoing lower abdominal or extremity surgery after epidural injection of lidocaine. Patients were divided into either an infusion group (Group I, n = 6) or a bolus injection group (Group II, n = 9). We administered 15 ml of 2% lidocaine into the epidural space at 1 mL/min in Group I and at 1 mL/3 in Group II. Venous blood was drawn at 3, 6, 9, 12, 15, 18, 21, 30, 60, and 90 min after injection for measurement of plasma lidocaine concentrations. The peak plasma concentration (Cmax) of lidocaine in Group I was significantly less than that in Group II (P < 0.0005). We conclude that slow epidural infusion can produce a lower Cmax of lidocaine compared with that of a bolus administration and thereby decrease the potential for systemic toxicity of the local anesthetic.
Anesthesia, Epidural↗
[A follow-up study on correlated factors for intrauterine infection of hepatitis B virus].
One hundred and twenty-two pregnant women with positive serum hepatitis B surface antigen (HBsAg) and their infants were followed-up to study the risk factors related to intrauterine infection of hepatitis B virus (HBV). Infants were immunized with three doses of hepatitis B vaccine within 24 hours after birth, one month and six months of age, respectively, and hepatitis B immunoglobulin (HBIG) was injected simultaneously with the first dose. Markers of HBV infection in pregnant women and infants were detected by enzyme linked immunosorbent assay (ELISA). Results showed that 13 infants were detected positive for HBsAg in their sera, eight of them were positive at their birth and the other five converted positive during follow-up. Simple and multiple logistic regression analyses showed that positivity of hepatitis Be antigen (HBeAg) in mothers and their threatened abortion related to intrauterine infection, with relative risks of 31.27 and 10.87, respectively.
Female↗
Impaired signaling in alloantigen-specific CD8+ T cells tolerized in vivo: employing a model of Ld-specific TCR transgenic mice transplanted with allogenic hearts under the cover of a short-term rapamycin treatment.
Peripheral tolerance of T cells is necessary because thymic deletion is not complete, and tissue-specific Ags exist outside the thymus. We have reported that persistent Ag is required to maintain peripheral tolerance in vivo. We suspect that the TCR signaling pathway in in vivo tolerized cells is compromised due to continuous exposure to the Ags. In this study, the TCR signaling events in these cells were investigated using TCR transgenic mice (2C mice) whose T cells are predominantly Ld alloantigen-specific CD8 cells. The 2C mice were thymectomized and then rendered tolerant to Ld Ag by allogenic heart transplantation plus short-term treatment with rapamycin. We found that 1) the in vivo tolerized CD8 cells have compromised intracellular Ca2+ flux upon mitogen stimulation; and 2) their cellular tyrosine proteins fail to be phosphorylated properly upon TCR cross-linking. These results indicate that the signaling pathway in the in vivo tolerized CD8 cells is indeed defective. We also found that 1) the tolerized CD8 cells have no characteristic surface markers; and 2) the allograft is probably the place where the rejection response is initiated according to the appearance of an early activation marker of T cells on graft-infiltrating cells.
Animals↗
Serologic association between human papillomavirus type 16 infection and esophageal cancer in Shaanxi Province, China.
BACKGROUND: The existence of large geographic variations in the prevalence of esophageal cancer in some countries, such as China, indicates that environmental risk factors may be important in the development of this disease. Some studies have implicated genital-mucosal strains of human papillomaviruses (HPVs) in the etiology of this cancer. PURPOSE: We conducted a case-control study in Shaanxi Province, China, an area with a population at high risk for esophageal cancer, to assess the association of this disease with infection by HPV type 16 (HPV16), the most common cancer-associated genital-mucosal HPV type. METHODS: Ninety individuals with esophageal cancer and 121 cancer-free control subjects were identified among the patients in two hospitals in Xi'an, Shaanxi Province. The control subjects were matched to the case patients on the basis of age and sex. Blood specimens were drawn from all study subjects, and serum was isolated by routine methods. The presence of HPV16 antibodies in serum samples was determined by use of an enzyme-linked immunosorbent assay (ELISA) that used baculovirus-derived HPV16 virus-like particles as the antigen. A similar ELISA that used bovine papillomavirus type 1 (BPV1) virus-like particles as the antigen controlled for the specificity of HPV16 seroreactivity. Data from the HPV16 and the BPV1 assays were normalized with respect to results obtained in each assay with a control serum of known HPV16 seroreactivity. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to examine the association between HPV16 seroreactivity and esophageal cancer. Reported P values are two-sided. RESULTS: The mean seroreactivity to HPV16 virus-like particles was significantly higher for the cancer patients than for the control subjects (mean value +/- standard deviation = 0.85 +/- 0.22 versus 0.74 +/- 0.18; P<.0001). When the cancer patients and control subjects were compared by sex and age groups, the differences in mean seroreactivity remained statistically significant. The difference in mean seroreactivity to BPV1 virus-like particles between cancer patients and control subjects was not statistically significant (0.81 +/- 0.28 versus 0.88 +/- 0.32; P = .12); this result was not altered when sex and age groups were compared. By use of a cutoff point for HPV16 seropositivity that was established in studies of cervical neoplasia, 24% of the cancer patients were seropositive compared with 7% of the control subjects, yielding a sex- and age-adjusted OR of 4.5 (95% CI = 1.8-11.9). In general, the OR for esophageal cancer increased with increasing HPV16 seroreactivity. CONCLUSIONS AND IMPLICATIONS: HPV16 infection may be a risk factor for esophageal cancer. Further studies of the association between HPV16 infection and the incidence of esophageal cancer are needed.
Antibodies, Viral↗
Genesis, a winged helix transcriptional repressor with expression restricted to embryonic stem cells.
A novel member of the winged helix (formerly HNF-3/Forkhead) transcriptional regulatory family, termed Genesis, was isolated and characterized. Putative translation of the complete cDNA revealed the winged helix DNA binding domain to be centrally located within the protein, with regions on either side that contain known transcriptional regulatory motifs. Extensive Northern analysis of Genesis found that the message was exclusively expressed in embryonic stem cells or their malignant equivalent, embryonal carcinoma cells. The Genesis transcript was down-regulated when these cells were stimulated to differentiate. DNA sequences that Genesis protein would interact with were characterized and were found to contain a consensus similar to that found in an embryonic stem cell enhancer sequence. Co-transfection experiments revealed that Genesis is a transcriptional repressor. Genesis mapped to mouse chromosome 4 in a region syntenic with human chromosome 1p31, a site of nonrandom abnormalities in germ cell neoplasia, neuroblastoma, and acute lymphoblastic leukemia. Genesis is a candidate for regulating the phenotype of normal or malignant embryonic stem cells.
Amino Acid Sequence↗
Sequence, organization, and transcription of the Dlx-1 and Dlx-2 locus.
There are at least five murine Dlx genes that are related to the Drosophila Distal-less homeobox gene. The Dlx genes are primarily expressed in the developing forebrain, derivatives of the cranial neural crest and restricted epidermal craniofacial and limb domains. Dlx-2 is required for differentiation of subsets of cranial neural crest and forebrain cells. Previous genomic studies have shown that Dlx-1 and Dlx-2 are linked on mouse chromosome 2, near the HoxD cluster. Here we report a detailed analysis of the nucleotide sequence (approximately 14 kb), organization, and transcription of the murine Dlx-1 and Dlx-2 locus. In addition, we show that Dlx-1 makes multiple sense transcripts and at least one antisense transcript, whereas Dlx-2 makes one major transcript. The sequence of the human Dlx-2 gene is reported and is compared to that of the murine gene. Finally, sequence analysis of the deduced protein sequences reveals several candidate functional domains.
Amino Acid Sequence↗
An RNA-dependent ATPase associated with U2/U6 snRNAs in pre-mRNA splicing.
The hydrolysis of ATP by a group of RNA-dependent ATPases (DEAD/H proteins) is required for spliceosome assembly, but not for the subsequent transesterification reactions. Little is known about the function of these ATPases in relation to the RNA conformational changes that occur in formation of active structures, in which U2/U6 small nuclear RNA (snRNA) interactions are essential for splicing to take place. Using a synthetic lethal genetic screen, we have isolated four yeast splicing factors involved in U2/U6 snRNA interactions (D.X. et al., manuscript in preparation). The RNA-dependent ATPase activity associated with one such factor, the Slt22 protein, is stimulated preferentially by annealed U2/U6 snRNAs. Both mutant slt22-1 and U2 snRNA cause a reduction in stimulation. The slt22-1 mutation blocks splicing at or before the first step, resulting in the accumulation of an unusual complex which lacks U5 snRNA. Our results indicate that the U2/U6 snRNA interactions facilitated by Slt22 are also involved in the interaction of U5 snRNA with the spliceosome.
Adenosine Triphosphatases↗
The immunosuppressive effect of rapamycin on mouse small bowel transplantation.
The efficacy of rapamycin (RAPA) was tested on small bowel transplantation in the mouse and compared with cyclosporine (CsA). Four groups were involved, each one included three combinations (n > or = 6) for evaluation of host-versus-graft (HVG, C57BL/6 X BALB/c F1 (CB6F1)-to-BALB/c), graft-versus-host (GVH, BALB/c-to-CB6F1), and combined HVG and GVH responses (C57BL/6-to-BALB/c). Grafts were transplanted to recipients heterotopically. Groups were as follows: group 1: naive controls; groups 2 and 3: recipient mice treated with RAPA 2 mg/kg/day and 4 mg/kg/day orally for 14 days, respectively; group 4: recipient mouse treated with CsA 4 mg/kg/day orally for 14 days. In the HVG model, the mean survival time (MST) of recipients was significantly longer in group 2 (32.9 +/- 17.7 days, P=0.006), group 3 (32.7 +/- 10.4 days, P=0.0001), and group 4 (37.9 +/- 11.8 days, P=0.0001), compared with naive controls in group 1 (8.5 +/- 1.6 days). In the GHV model, the MST of recipients in group 2 (41.8 +/- 19.9 days, P=0.002), group 3 (48.2 +/- 21.4 days, P=0.001) and group 4 (56.5 +/- 30.6 days, P=0.003) were significantly prolonged compared with control group 1 (8.5 +/- 1.6 days). In combined HVG and GVH responses, MST of recipient in group 2 (20.9 +/- 4.9 days, P=0.0001), group 3 (27.0 +/- 4.3 days, P=0.008), and group 4 (35.2 +/- 23.9 days, P=0.0001) were also significantly longer than that in controls (6.9 +/- 1.4 days), but in all three combinations, there were no statistically significant differences between groups 2 and 3, groups 2 and 4, or groups 3 and 4 (P>0.05). RAPA is a potent immunosuppressant able to significantly prolong small bowel allograft survival in mice using a short-term treatment. There is no statistically significant difference in recipient survival between low and high doses of RAPA treatment and the CsA standard dose used in this study.
Animals↗
Acetaldehyde and malondialdehyde react together to generate distinct protein adducts in the liver during long-term ethanol administration.
Acetaldehyde and the lipid peroxidation-derived aldehyde malondialdehyde (MDA), are reactive compounds that are generated during ethanol metabolism in the liver, and both aldehydes have been shown to be capable of binding to proteins and forming stable adducts. Because similar concentrations of MDA and acetaldehyde can coexist in the liver during ethanol oxidation, protein adduct formation in the presence of both of these aldehydes was studied under both in vitro and in vivo conditions. When proteins were incubated in the presence of both MDA and acetaldehyde, MDA caused a marked and concentration-dependent increase in the stable binding of acetaldehyde to proteins. Maximum stimulation of binding occurred at approximately a fourfold molar excess of MDA relative to acetaldehyde when concentrations of 1.0 mmol/L and 0.1 mmol/L were tested. The formation of highly fluorescent product or products was associated with the MDA stimulation of acetaldehyde binding, indicating that new and distinct products were being generated. These hybrid adducts of MDA and acetaldehyde have been designated as MAA adducts. An affinity-purified polyclonal antibody was produced that specifically recognized MAA epitopes on proteins and did not cross-react with carrier proteins or proteins modified with either acetaldehyde or MDA alone. A quantitative competitive enzyme-linked immunosorbent assay (ELISA) was developed and detected the presence of MAA-modified proteins in liver cytosol from ethanol-fed rats but not in pair-fed controls. Quantification of the data from the competitive ELISA indicated the presence of approximately 75 pmoles protein-bound MAA per milligram liver cytosol proteins of the ethanol-fed animals. These results indicate that acetaldehyde and MDA can react together in a synergistic manner and generate hybrid adducts (MAA-adducts) and further suggest that MAA adducts may represent a major species of adducts formed in the liver during ethanol metabolism in vivo.
Acetaldehyde↗
Immunosuppressive effects of the cyclosporin derivative SDZ IMM 125 on kidney allograft in the dog and small bowel and pancreas allografts in the rat.
The efficacy of SDZ IMM 125 in preventing allograft rejection was evaluated in kidney transplantation in the dog and orthotopic small bowel and heterotopic pancreas transplantation in the rat. Seven groups (n = 6) were involved in dog kidney transplantation. Untreated recipients rejected kidney allografts with a mean survival time (MST) of 8.0 +/- 1.8 days. There was a graded dose response in SDZ IMM 125-treated groups: 10 mg/kg/day, MST 11.3 +/- 3.5 days, P = 0.065; 15 mg/kg/day, MST 44.8 +/- 10.8 days, P = 0.0001; and 20 mg/kg/day, MST 47.3 +/- 5.6 days, P = 0.0001, same as in cyclosporin A (CsA)-treated groups: 10 mg/kg/day, MST 25.8 +/- 13.7 days, P = 0.001; 15 mg/kg/day, MST 38.3 +/- 18.1 days, P = 0.002; and 20 mg/kg/day, MST 38.7 +/- 17.7 days, P = 0.002. Low dose of SDZ IMM 125 (10 mg/kg/day) was less effective in prolonging the graft survival than low dose of CsA. High dose (20 mg/kg/day) treatment of both SDZ IMM 125 and CsA led to abnormal recipient liver enzymes alanine aminotransferase and aspartate aminotransferase postoperatively. A histopathological study demonstrated fatty degeneration of hepatic cells in both 20 mg/kg/day SDZ IMM 125- and CsA-treated groups. We also tested the effect of SDZ IMM 125 in orthotopic small bowel transplantation with three combinations, namely host-versus-graft (HVG), graft-versus-host (GVH), and combined HVG and GVH immune responses and pancreas transplantation in the rat with different doses. The results indicate that SDZ IMM 125 is a potent immunosuppressant to prolong the kidney allograft survival in the dog, to alleviate HVG and GVH responses in small bowel transplantation, and to delay pancreas allograft rejection in the rat. Low dose of SDZ IMM 125 is less effective than a similar dose of CsA to prevent kidney allograft rejection in the dog.
Animals↗
Hematopoietic transcriptional regulation by the myeloid zinc finger gene, MZF-1.
Transcriptional regulators control much of hematopoiesis. One such transcriptional regulator is the myeloid zinc finger gene MZF-1. MZF-1 has been localized to the telomere of chromosome 19q, where a large number of related zinc finger genes reside. It has been found to be essential in granulopoiesis. It is a bi-functional transcriptional regulator, repressing transcription in non-hematopoietic cells, and activating transcription in cells of hematopoietic origins. Its consensus DNA binding site has been isolated, and sites in several promoters of myeloid-specific genes, such as CD34, lactoferrin, and myeloperoxidase, have been defined. In co-transfection experiments MZF-1 has been found to regulate transcription from the CD34 promoter.
Base Sequence↗
A perfume odour-sensing system using an array of piezoelectric crystal sensors with plasticized PVC coatings.
Using PVC polymer as membrane matrix and di-n-octylphenyl phosphate (DOPP) as plasticizer, a piezoelectric crystal sensor (PCS) array with 12 adsorptive materials selected from 68 compounds by cluster analysis has been constructed as a perfume odour-sensing system. The frequency shift data obtained from the sensor array responding to four commercial perfume odours are first autoscaled and then treated by principal component analysis. The experimental results show that the plasticized PVC membrane PCS array provides improved performance of pattern recognition compared with the single adsorptive coating PCS array. The frequency shift response characteristics of these sensors have been investigated experimentally. The proposed sensor array has also been applied to the classification of commercial spirituous liquor, wine and soft drink samples, as well as aliphatic alcohol homologues and isomers.
Journal Article↗
Presence of cell-free human immunodeficiency virus in cervicovaginal secretions is independent of viral load in the blood of human immunodeficiency virus-infected women.
OBJECTIVE: The purpose of this study was to establish virologic or molecular criteria for evaluating the rate of transmission of human immunodeficiency virus type 1 and for defining the role of virus burden in the development of gynecologic diseases in human immunodeficiency virus-infected women. STUDY DESIGN: Paired samples of blood and cervicovaginal secretions from 63 human immunodeficiency virus-seropositive women were evaluated for cell-free and cell-associated virus load by several methods, including quantitative cultures and reverse transcription polymerase chain reaction. RESULTS: All women showed evidence of virus infection in both blood and cervicovaginal secretions by a combination of in vitro culture and molecular detection methods. The CD4+ cell counts in these women ranged from < 200/microliter to > 500/microliter. Blood plasma of 26% women (12/46) did not show detectable levels of human immunodeficiency virus ribonucleic acid by reverse transcription polymerase chain reaction (< 10(2)/100 microliters). These same women had significant amounts of human immunodeficiency virus in the cell-free cervicovaginal secretions (10(2) to 10(5) copies per 100 microliters). In contrast, 17% (8/46) women with significant quantity of human immunodeficiency virus ribonucleic acid in the blood plasma had negative results for human immunodeficiency virus in the cervicovaginal secretions. Further, treatment of women with the antiviral drug zidovudine did not change the human immunodeficiency virus-1 detection rate in plasma ribonucleic acid but showed significant reduction in the ability to detect human immunodeficiency virus ribonucleic acid in cell-free cervicovaginal secretions (p = 0.036). CONCLUSIONS: We conclude that the replication kinetics of human immunodeficiency virus in the blood and cervicovaginal cells are unrelated, independent events. Further, there is no correlation between the virus load or the CD4+ cell counts in the blood and the presence or absence of quantifiable human immunodeficiency virus in cervicovaginal secretions.
Antiviral Agents↗
Molecular dynamics study of early picosecond events in the bacteriorhodopsin photocycle: dielectric response, vibrational cooling and the J, K intermediates.
Molecular dynamics simulations have been carried out to study the J625 and K590 intermediates of bacteriorhodopsin's (bRs) photocycle starting from a refined structure of bR568. The coupling between the electronic states of retinal and the protein matrix is characterized by the energy difference delta E(t) between the excited state and the ground state to which the protein contributes through the Coulomb interaction. Our simulations indicate that the J625 intermediate is related to a polarization of the protein matrix due to the brief (200 fs) change of retinal's charge distribution in going to the excited state and back to the ground state, and that the rise time of the K590 intermediate is determined by vibrational cooling of retinal.
Bacteriorhodopsins↗
Transgenic rice plants harboring an introduced potato proteinase inhibitor II gene are insect resistant.
We introduced the potato proteinase inhibitor II (PINII) gene (pin2) into several Japonica rice varieties, and regenerated a large number of transgenic rice plants. Wound-inducible expression of the pin2 gene driven by its own promoter, together with the first intron of the rice actin 1 gene (act1), resulted in high-level accumulation of the PINII protein in the transgenic plants. The introduced pin2 gene was stably inherited in the second, third, and fourth generations, as shown by molecular analyses. Based on data from the molecular analyses, several homozygous transgenic lines were obtained. Bioassay for insect resistance with the fifth-generation transgenic rice plants showed that transgenic rice plants had increased resistance to a major rice insect pest, pink stem borer (Sesamia inferens). Thus, introduction of an insecticidal proteinase inhibitor gene into cereal plants can be used as a general strategy for control of insect pests.
Animals↗