Biomedical subjects

J Zhu

Publications and source records attributed to J Zhu.

At least 181 records · Page 10Linked to original sources

PubMed2001

[Two terms tympanoplasty in chronic suppurative otitis media].

OBJECTIVE: To explore the clinical manifestations and therapeutic effects of treating chronic suppurative otitis media with two terms tympanoplasty. METHOD: 36 patients were retrospectively analyzed. The criterions of success are air room in middle ear, intact eardrum and decrease of A-B gape in audiometry. RESULT: 32 cases of all patients got successful effects, 4 cases failed. The main cause of failure is to fail forming air room in middle ear. CONCLUSION: The two term's tympanoplasty can save the residual hearing in most patient. But it is difficult to get successful result if more mucous membrane in the middle ear disappeared.

Adolescent↗

PubMed2001

[Synthesis, preliminary antigastrelcosis activity and the protective effect on acute liver injury of zinc chlorin E4].

AIM: To study the synthesis of zinc chlorin e4(1), its experimental antigastrelcosis activity as well as the protection against acute liver injuries. METHODS: Chlorin e6(3) was prepared through acidic and alkaline oxidative degradation using silkworm excrement crude chlorophyll extracts as starting material. Compound 1 was synthesized via Zn(OAc)2 complex action with Chlorin e4(2) which was prepared by refluxing 3 in pyridine. Gastric ulcers were induced by abdominal injection of 0.2% indomethacin at 20 mg.kg-1 in rats. The ulcer indexes and ulcer numbers in gastric mucosa were determined. Acute liver injuries were induced by abdominal injection of 0.3% thioacetamide (TAA) or 0.3% CCl4 at 20 mg.kg-1 in mice, and activities of SGPT in mice were determined. RESULTS: Compound 1 is previously unknown. Compared with control group, abdominal administration of 1 at 100 mg.kg-1 reduced significantly the gastric ulcer index (P < 0.001) and the number of ulcer (P < 0.001) induced by indomethacin in rats. Abdominal administration of 1 at 100 mg.kg-1 x 3 exhibited marked inhibitory effects on elevated activities of SGPT induced by TAA (P < 0.02) or CCl4(P < 0.01) in mice. CONCLUSION: These results show that 1 has significant protective effect against indomethacin-induced gastric lesion in rats and TAA or CCl4 induced acute liver injuries in mice. It is suggested that 1 may be a promising new drug candidate for antigastrelcosis and liver injury protection.

Animals↗

PubMed2001

[Study on hepatic-protective effect of "yinzhihuang" granula].

OBJECTIVE: To study hepatic-protective effect of "Yinzhihuang" granula. METHODS: By D-GalN, CCl4 induced acute hepatic damage model, ALT and AST in serum, pathological degree of hepar adopted as indexes, the potency of "Yinzhihuang" granula was observed and compared with "Yinzhihuang" oral solutions. Mice administrated ig 1-naphthyl-isothiocyanate, with bilirubin in serum used as index, the effect of "Yinzhihuang" granula was observed. RESULTS: 1.8 g/kg, 3.6 g/kg "Yinzhihuang" granula groups could decrease the rising of ALT, AST in mice serum induced by D-GalN.3.6 g/kg "Yinzhihuang" granula group could also improve pathological degree of hepar.1.0 g/kg, 2.0 g/kg "Yinzhihuang" granula groups could decrease the rising of ALT, AST in rats serum induced by CCl(4).2.0 g/kg "Yinzhihuang" granula group could also improve pathological degree of hepar.1.8 g/kg, 3.6 g/kg "Yinzhihuang" granula groups could decrease the rising of bilirubin in mice serum induced by 1-naphthyl-isothiocyanate. CONCLUSIONS: "Yinzhihuang" granula had an evident hepatic-protective effect on acute hepatic damage induced by D-GalN or CCl4, and could decrease the rising of bilirubin in mice serum induced by 1-naphthyl-isothiocyanate.

1-Naphthylisothiocyanate↗

PubMed2001

[Analysis on the sex ratios at birth for deliveries in hospitals in China from 1987 to 1992].

OBJECTIVE: To estimate the sex ratios at birth (SRB) for livebirths in hospitals in China. METHODS: Data were collected by the birth defects monitoring network. The livebirths with gestation of 28 weeks or over delivered in hospitals of 30 provinces, municipalities and autonomous regions all over the country from 1987 to 1992 were analyzed and used for calculating the SRB. RESULTS: The high male bias in SRB was observed in the data from most areas, and there was an upward trend of SRB, especially in rural areas. The SRB for livebirths in the hospitals of urban areas was normal from 1987 to 1989, and rose to 108.9 in 1992. The SRB for rural areas was high and was 109.9 in 1987, and rose to 111.8 in 1992. The SRB for livebirths given by the mothers under 20 years of age and coming from lower educational background was higher than that for others. The SRB for higher parities was even higher. CONCLUSION: The SRB in China is high; this is possibly related to sex-preference. Under-reporting of female neonates and "missing females" are not the main causes of the rising SRB.

China↗

PubMed2001

[Two-photon fluorescence from recombinant green fluorescent protein].

The photoconversion process of recombinant green fluorescent protein (rGFP) was investigated by two-photon excitation. The results indicated that the rGFP had very strong two-photon excitation fluorescence. The changes of two-photon-induced fluorescence polarization suggest that there is a proton transfer process between two different proton states of rGFP chromophores. The conformation of rGFP chromophores could be changed upon illumination, which partly block the energy transfer processes from amino acid residues to chromophores in rGFP, and result in the decrease of two-photon-induced fluorescence intensity. The fluorescence from amino acid residues in rGFP was also observed by three-photon excitation, which resulted from the blocked amino acid residues in rGFP. These results suggested that it is necessary to optimize rGFP excitation and detection for quantitative fluorescence microscopy.

Energy Transfer↗

PubMed2001

[Stable high quality luminescent material CaAl4O7:Tb3+, Ce3+].

We had made CaAl4O7:Tb3+, Ce3+ samples by sintering the sample at 1,300 degrees C in reduction environment N2 + 5% H2. Emission lines corresponding to the 3D4 to 7Fj(J = 6,5,4,3) optical transitions of the Tb2+ ions were observed at 485,545,590 and 620 nm respectively. The particle size of the sample was controlled to less that 1 micron. The lattice of the sample was rather regular in atomic scale and showed very good quality. CaAl4O7:Tb3+, Ce3+ materials can reduce structure uncertainty of the host and remain typical optical properties of the Tb3+ emitting center.

English Abstract↗

PubMed2001

[Clinical analysis of 149 cases of aldosterone-producing adrenal cortical neoplasms].

OBJECTIVE: To evaluate the diagnosis and treatment of aldosterone-producing adrenal cortical neoplasms. METHODS: From 1978 to February 2001, 149 patients with aldosterone-producing adrenal cortical neoplasms were diagnosed and treated. Of these patients, 148 had adrenal adenoma and 1 had adrenal cortical carcinoma. The diagnosis was all confirmed by surgery and pathological studies. RESULTS: The diagnostic specificity of retroperitoneal pneumography, B-ultrasonography and CT scan are 39%, 67% and 95.3% respectively. It was found that there were significant differences of diagnostic specificity between retroperitoneal pneumography and B-ultrasonography, CT scan (chi2 = 23.89, P < 0.05) and there were significant differences between B-ultrasonography and CT scan (chi2 = 32.10, P < 0.05). In all the patients, serum potassium level elevated to normal range within 1 month postoperatively. In 110 cases out of 149, the blood pressure dropped to normal range within two months after surgery. CONCLUSIONS: Appropriate treatment depends on correct qualitative diagnosis and localization of the causative lesion. B-ultrasonography and CT scan play an important role in diagnosis. Surgery is the major treatment, including laparoscopic adrenalectomy. Factors affecting the therapeutic outcome are aging systemic vascular sclerosis and long duration of the disease.

Adrenal Cortex Neoplasms↗

PubMed2000

Definition of the p53 functional domains necessary for inducing apoptosis.

The p53 protein contains several functional domains necessary for inducing cell cycle arrest and apoptosis. The C-terminal basic domain within residues 364-393 and the proline-rich domain within residues 64-91 are required for apoptotic activity. In addition, activation domain 2 within residues 43-63 is necessary for apoptotic activity when the N-terminal activation domain 1 within residues 1-42 is deleted (DeltaAD1) or mutated (AD1(-)). Here we have discovered that an activation domain 2 mutation at residues 53-54 (AD2(-)) abrogates the apoptotic activity but has no significant effect on cell cycle arrest. We have also found that p53-(DeltaAD2), which lacks activation domain 2, is inert in inducing apoptosis. p53-(AD2(-)DeltaBD), which is defective in activation domain 2 and lacks the C-terminal basic domain, p53-(DeltaAD2DeltaBD), which lacks both activation domain 2 and the C-terminal basic domain, and p53-(DeltaPRDDeltaBD), which lacks both the proline-rich domain and the C-terminal basic domain, are also inert in inducing apoptosis. All four mutants are still capable of inducing cell cycle arrest, albeit to a lesser extent than wild-type p53. Interestingly, we have found that deletion of the N-terminal activation domain 1 alleviates the requirement of the C-terminal basic domain for apoptotic activity. Thus, we have generated a small but potent p53-(DeltaAD1DeltaBD) molecule. Furthermore, we have determined that at least two of the three domains (activation domain 1, activation domain 2, and the proline-rich domain), are required for inducing cell cycle arrest. Taken together, our results suggest that activation domain 2 and the proline-rich domain form an activation domain for inducing pro-apoptotic genes or inhibiting anti-apoptotic genes. The C-terminal basic domain is required for maintaining this activation domain competent for transactivation or transrepression.

Apoptosis↗

PubMed2000

Pre-mRNA splicing in the absence of an SR protein RS domain.

SR proteins are essential pre-mRNA splicing factors that act at the earliest stages of splice-site recognition and spliceosome assembly, as well as later in the splicing pathway. SR proteins consist of one or two RNA-recognition motifs and a characteristic arginine/serine-rich C-terminal RS domain. The RS domain, which is extensively phosphorylated, mediates the subcellular localization of individual SR proteins and also functions as a splicing activation module, apparently by engaging in protein-protein interactions. The RS domain of SF2/ASF is dispensable for the concentration-dependent effects of this SR protein on alternative splice-site selection. However, this RS domain is highly conserved phylogenetically, and was shown to be required for constitutive splicing in vitro and for cell viability. Here, we demonstrate that the RS domain of SF2/ASF is, in fact, dispensable for splicing of several substrates, including constitutive and enhancer-dependent pre-mRNAs. The requirement for this RS domain is substrate specific, and correlates with the strength of the splicing signals. When the 3' splice site is weak, both the SF2/ASF RS domain and U2AF(35) are required for splicing. These results show the existence of an RS domain-independent function of SR proteins in constitutive and enhancer-dependent splicing, and suggest mechanisms for their role in enhancer function besides U2AF recruitment.

Base Sequence↗

PubMed2000

Response to RAG-mediated VDJ cleavage by NBS1 and gamma-H2AX.

Genetic disorders affecting cellular responses to DNA damage are characterized by high rates of translocations involving antigen receptor loci and increased susceptibility to lymphoid malignancies. We report that the Nijmegen breakage syndrome protein (NBS1) and histone gamma-H2AX, which associate with irradiation-induced DNA double-strand breaks (DSBs), are also found at sites of VDJ (variable, diversity, joining) recombination-induced DSBs. In developing thymocytes, NBS1 and gamma-H2AX form nuclear foci that colocalize with the T cell receptor alpha locus in response to recombination activating gene (RAG) protein-mediated VDJ cleavage. Our results suggest that surveillance of T cell receptor recombination intermediates by NBS1 and gamma-H2AX may be important for preventing oncogenic translocations.

Amino Acid Sequence↗

PubMed2000

P0 protein peptide 180-199 together with pertussis toxin induces experimental autoimmune neuritis in resistant C57BL/6 mice.

The C57BL/6 mice strain is known to be reputedly resistant to induction of experimental autoimmune neuritis (EAN), an animal model of Guillain-Barré syndrome in human by bovine peripheral myelin (BPM), and P2 protein or the P2 protein peptide 57-81. The P0 peptide 180-199 is a stronger neuritogenic antigen than the P2 peptide 57-81. We found that this synthetic peptide induced both clinical and pathological characteristics of an acute monophasic EAN in C57BL/6 mice. Only male mice were more sensitive to EAN induction with the P0 peptide 180-199. Intravenously administrated pertussis toxin (PT) had an adjuvant effect that increased the incidence of P0 peptide 180-199-induced EAN as well as the inflammation and demyelination in the peripheral nerves. Spontaneous and P0 peptide 180-199 stimulated proliferation of peripheral T-cells were enhanced by PT-treatment as well. The enhancing effect was lower before onset of the disease (Day 6 post immunization) (p.i.) as compared to the early phase of the disease (Day 22 p.i.). Thus, P0 peptides together with PT are able to break tolerance to myelin in C57BL/6 mice.

Adjuvants, Immunologic↗

PubMed2000

Effects of semen plasma from different fractions of individual ejaculates on IVF in pigs.

We applied IVM/IVF techniques to investigate effects of preincubation of sperm with different fractions of semen plasma harvested from fresh ejaculates on in vitro penetration and fertilization of in vitro matured oocytes. Three fractions of semen plasma were separated from the complete ejaculate of three Landrace boars and used to coincubate sperm obtained from the first sperm-rich fraction of the same ejaculates. After 14 to 16 h coincubation at room temperature, sperm were preincubated in capacitation medium and then inseminated into fertilization medium containing porcine oocytes matured in vitro. The semen plasma used for coincubation affected penetration rate (P < 0.001); Sperm coincubated with Fraction 1 semen plasma had a higher penetration rate compared with sperm coincubated with Fraction 2 (P < 0.05), but not with Fraction 3. Boar affected male pronucleus formation rates after insemination (P < 0.05), but no difference among boars was found in monospermy rate, average number of sperm penetrating into each fertilized oocyte, or the average number of sperm attached. No boar by fraction interaction was found for any parameters studied.

Animals↗

PubMed2000

p41 as a possible marker for cell death is generated by caspase cleavage of p42/SETbeta in irradiated MOLT-4 cells.

We have reported previously that X-irradiated MOLT-4 cells during their rapid cell death exhibited dose and time dependently a new protein named p41 detected by two-dimensional polyacrylamide gel electrophoresis (2-D PAGE). An antibody, AM-1, raised against partial peptide of p41 stained two spots, p41 and p42, unexpectedly. Amino acid sequence analysis of partial peptides showed homology between p41 and a putative oncogene, set. In the present study, N-terminal amino acid sequencing of p41 and p42, and polyclonal antibodies newly prepared against different partial peptide sequences revealed that p41 was a N-terminal truncation form of p42, and p42 was identified as SETbeta. The cleavage site was at carboxyl end of SNHD 18 of p42. Radiation-induced p42 cleavage as well as apoptotic cell death was suppressed by a caspase-specific inhibitor Ac-DEVD-CHO but not by Ac-YVAD-CHO. Further in vitro cleavage experiments with recombinant p42 and either irradiated cell extracts or recombinant caspases concluded that the cleavage of p42 into p41 was catalyzed by caspase(s) mainly by caspase-7. One of newly raised antibodies, AM-4, specific to p41 or specific to cleavage site of p42, was found useful enabling simple detection of p41 by 1-D PAGE instead of laborious 2-D PAGE. p41 may serve as a marker of apoptotic cell death.

Amino Acid Sequence↗

PubMed2000

High-efficiency on-line concentration technique of capillary electrochromatography.

With the coexistence of the mobile phase, the stationary phase, and the electric field in capillary electrochromatography, the chromatographic zone-sharpening effect and field-enhanced sample-stacking technique were utilized to improve detection sensitivity. By the former means, with less organic modifier in the sample solution compared to that in the mobile phase, the concentration factors of neutral solutes benzoin and mephenytion were 134 and 219, respectively. Through the latter one, without electrolyte in the sample solution, the detection sensitivity of propatenene with positive charge was improved by 1600 times. While with the combination of these two methods, improvement of over 17,000 times for the sensitivity of propatenene was obtained. By the combined means, the analysis of basic pharmaceutical compounds at concentrations of nanograms per milliliter by UV detection was realized. In addition, parameters that might affect the efficiency of on-line concentration were studied and equations that described the on-line concentration procedure were deduced.

Journal Article↗

PubMed2000

Host response to cytomegalovirus infection as a determinant of susceptibility to coronary artery disease: sex-based differences in inflammation and type of immune response.

BACKGROUND: Positive and negative associations between cytomegalovirus (CMV) infection and coronary artery disease (CAD) have been reported. We postulated that the susceptibility to CMV-induced CAD might relate to patterns of inflammatory and immune responses to CMV infection and that sex might have an effect on these responses. METHODS AND RESULTS: In 151 men and 87 women being evaluated for CAD, blood samples were tested for humoral (Ab+) and cellular (Tc+) responses to CMV and for C-reactive protein (CRP). In men, an elevated CRP level was a significant determinant of CAD even after adjustment for CAD risk factors (OR, 3.1; 95% CI, 1.21 to 7. 97). CMV seropositivity was associated with elevated CRP levels on multivariate analysis (P:=0.006). In contrast, in women, CMV seropositivity was independently predictive of CAD (OR, 41.8; 95% CI, 4.12 to 423.74). CRP level in women with CAD was >25% higher than those without CAD, but the difference did not reach statistical significance. Importantly, compared with CMV Ab-/Tc- women, CAD prevalence was higher in Ab+/Tc- and Ab+/Tc+ (13% versus 68% and 64%, both P:<0.005) but not in Ab-/Tc+ women (25%). There were no differences in age, smoking, diabetes, hypertension, and hypercholesterolemia among women with different types of immune responses to CMV infection. CONCLUSIONS: The mechanisms by which CMV predisposes to CAD in men and women may be different. In men, CMV appears to contribute to CAD risk, insofar as it predisposes to inflammation. In women, other mechanisms, possibly related to the type of immune response generated by the host, appear to be responsible for the proatherogenic effects of CMV.

Adult↗

PubMed2000

Intracoronary delivery of adenovirus encoding adenylyl cyclase VI increases left ventricular function and cAMP-generating capacity.

BACKGROUND: We tested the hypothesis that intracoronary injection of a recombinant adenovirus encoding adenylyl cyclase type VI (AC(VI)) would increase cardiac function in pigs. METHODS AND RESULTS: Left ventricular (LV) dP/dt and cardiac output in response to isoproterenol and NKH477 stimulation were assessed in normal pigs before and 12 days after intracoronary delivery of histamine followed by intracoronary delivery of an adenovirus encoding lacZ (control) or AC(VI) (1.4x10(12) vp). Animals that had received AC(VI) gene transfer showed increases in peak LV dP/dt (average increase of 1267+/-807 mm Hg/s; P=0.0002) and cardiac output (average increase of 39+/-20 mL. kg(-1). min(-1); P<0.0001); control animals showed no changes. Increased LV dP/dt was evident 6 days after gene transfer and persisted for at least 57 days. Basal heart rate, blood pressure, and LV dP/dt were unchanged, despite changes in cardiac responsiveness to catecholamine stimulation. Twenty-three hour ECG recordings showed no change in mean heart rate or ectopic beats and no arrhythmias. LV homogenates from animals receiving AC(VI) gene transfer showed increased AC(VI) protein content (P=0.0007) and stimulated cAMP production (P=0.0006), confirming transgene expression and function; basal LV AC activity was unchanged. Increased cAMP-generating capacity persisted for at least 18 weeks (P<0.0002). CONCLUSIONS: Intracoronary injection of a recombinant adenovirus encoding AC provides enduring increases in cardiac function.

Adenoviridae↗

PubMed2000

A novel synthesis of biaryl-containing macrocycles by a domino Miyaura arylboronate formation: intramolecular Suzuki reaction.

[reaction: see text] A novel macrocyclization procedure is developed on the basis of a domino process. Thus, treatment of linear diiodide 11 under defined conditions gave the 15-membered m,m-cyclophane 12 via aryl-aryl bond formation. Two distinct cross-coupling manifolds, Miyaura's arylboronic ester synthesis and intramolecular Suzuki reaction, proceed in an ordered fashion. Concentration is an important factor for the success of this process.

Boron Compounds↗

PubMed2000

Two-dimensional molecular layers: interplay of H-bonding and van der waals interactions in the self-assembly of N,N'-dialkylsulfamides

N,N'-Dialkylsulfamide molecules assemble into solid-state structures consisting of 2D layers. The 2D layers are based on a hydrogen-bonded network of the sulfamide groups and the close-packing of alkyl groups on both sides of the 2D H-bonded network. The thickness of a 2D layer is proportional to the size of the alkyl substituents. The interplay of H-bonding and van der Waals interactions leads to stable 2D layers that pack into 3D structures.

Journal Article↗