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Biomedical subjects

J Z Zhu

Publications and source records attributed to J Z Zhu.

At least 19 recordsLinked to original sources
PubMed2006

Nanocrystalline silicon-based oligonucleotide chips.

A novel oligonucleotide array sensor has been developed with nanocrystalline Si (ncSi) substrates. The ncSi was prepared by electrochemical etching technique. Our study indicated that both the binding capacity and the hybridization efficiency are dependent upon the particle size of ncSi. In contrary, the chips developed with Si substrates exhibit the lower binding capacity and hybridization efficiency. The improved performances of the sensor chips are attributed to the large specific surface area of ncSi compared to the existing conventional techniques. The sensor chips with the ncSi substrate of 13 nm-sized particle can be regenerated and reused for at least 12 times. The oligonucleotide array sensor also shows high stability, which can bear relatively the stringent conditions (e.g. 80 degrees C, 75% of relative humidity and 3.6 klx of irradiation).

Nanoparticles↗
PubMed2001

Primary study of vascular endothelial growth factor immunohistochemical staining in the diagnosis of early acute myocardial ischemia.

The expression of vascular endothelial growth factor (VEGF) in the model of rat early acute myocardial ischemia was studied by Strept-Avidin-Biotin-Peroxidase Complex (SABC) immunohistochemical staining. After ligating the anterior descending branch of the left coronary artery, an initial rapid (30min) positive expression of VEGF in myocardial ischemic areas was observed, the intensity of positive expression of VEGF increased with the continuation of myocardial ischemia. After 5h infarction, the strongly positive myocytes of SABC-VEGF staining were predominantly limited to perimyocardial infarction areas. No positive expression of VEGF was found in the control group. These findings suggested that SABC-VEGF method could give a sensitive, specific, simple and objective morphologic evidence to the diagnosis of sudden cardiac death caused by acute early myocardial ischemia.

Animals↗
PubMed2001

[Study on the specificity of complement C5 for the postmortem diagnosis of myocardial infarction].

In order to explore the specificity of complement C5 in the postmortem diagnosis of myocardial infarction, changes of C5 staining in normal, infarcted and other non-infarcted myocardia with direct or indirect myocardial injuries (myocarditis, mechanical asphyxia, electrocution, hemorrhagic shock, cardiac contusion and organophosphate poisoning) were studied with immunohistochemistry and image analysis. The results showed that positive C5 staining could be observed in groups of myocardial infarction and myocarditis, but not in groups of mechanical asphyxia, electrocution, hemorrhagic shock, cardiac contusion, and organophosphate poisoning. It is indicated that positive reaction of C5 could only be affected by myocarditis, which means that it was more specific for the diagnosis of myocardial infarction.

Adolescent↗
PubMed2001

[Histochemical observation of changes of neurons and axons in injured brainstem].

Brainstem of rats were stabbed with a needle and pathological changes of neurons and axons in brainstem were observed at different time after injury with Nissl's body staining, silver staining and modified trichrome staining. It was found that, by silver staining, the axons showed irregular swelling and disconnection at 1-3 h, marked swelling of the severe end at 6 h, retraction ball at 15 h and remarkable retraction ball at 24 h. By modified trichrome staining, the space between myelin sheaths and axons was widened at 3-6 h, and tortuous myelin sheaths adhered incompletely on axons, or even peeled off at 15 h to 24 h. Perinuclear lysis of Nissl's bodies at 24 h after injury could be seen by Nissl body staining. The results indicated that, the pathological changes in injured brainstem could be observed with histochemical staining, which might be used for timing brainstem injuries.

Animals↗
PubMed1999

[Observation of repair of wounded rat skin by affinity histochemical method of SJA].

Time expression of SJA tissue receptors surrounding wounded skin of 40 rats was studied by affinity histochemical method. The results were compared to that by EGFR immunohistochemical method and c-myc situ hydridization method. It was observed that SJA receptors began to decrease after the skin was injured and reached the lowest quantities in 15 minutes. After that, they began to increase and reached the highest quantities in 2 hours. It needs to be further studied whether there is the correlation between SJA receptors and EGFR has the function of repairing wounded skin.

Animals↗
PubMed1999

[Immunohistochemical study on myocardial acute ischemia reperfusion injury in rats with anti-FOS protein antibody].

To investigate law of FOS protein induced by myocardial ischemia reperfusion (MI/R) in acute period, a model in 20 anaethetized SD rats was established. Rats with normal and ischemia were used as control groups. Specimens were studied immunohistochemically with c-fos antibody. After ischemia 20 minutes, followed by 30 minutes reperfusion, the area of MI/R showed nuclei of myocytes positive staining in cryosection slides. In C2 group, the area showed nuclei of myocytes (37.76% +/- 9.66%) positive staining weakly. In C3 group, nuclei of cardiac myocytes(40.34% +/- 3.32%) was significantly positive. In C4 group it began to attenuate(35.36% +/- 4.81%). The myocardium in normal and ischemic control groups showed negative staining. No changes were seen with HE staining. Our data indicated that immunohistochemical method may reveal acute MI/R injury of ischemia 20 min and reperfusion 30 min with anti-FOS protein staining and there is problely a peak between 60-120 min after reperfusion. It is possible that the method be used to diagnose sudden cardiac death in forensic medicine.

Animals↗
PubMed1999

[Brainstem changes in death from head injury].

The cortex and brainstem changes in death from head injury were observed. There were hemorrhage, edema and neuron necrosis in brain injury group, and also in disputed group of brainstem injury.

Adolescent↗
PubMed1999

[Evaluation of anti-muscle actin monoclonal antibody HHF35 in the diagnosis of early myocardial infarction].

In order to explore the specificity of anti-muscle actin monoclonal antibody HHF35 in the postmortem diagnosis of early myocardial infarction, the changes of HHF35 staining in the infarcted myocardia and other non-infarcted myocardia with direct or indirect myocardial injury were studied with immunohistochemical S-P method. The results showed that the loss of HHF35 staining of different degrees was found in the infarcted myocardia, but also in the other non-infarcted myocardia with direct or indirect myocardial injury, such as cardiac contusion, myocarditis, hemorrhagic shock, electrocution, mechanical asphyxia. So it should be cautious in diagnosing early myocardial infarction with HHF35 immunohistochemistry.

Actins↗
PubMed1999

[Gas chromatographic and gas chromatography-mass spectrometric analyses of aromatic hydrocarbons in oils and rock extracts simultaneously by using bench-top gas chromatograph-mass spectrometer].

This article reports a successful example that an injected sample is simultaneously introduced into two fused silica capillary columns and detected separately by a flame ionization detector (FID) and an HP 5973 mass selective detector (MSD) both installed on an HP 6890 Gas Chromatograph. This GC and GC/MS analyses of aromatic hydrocarbons in oils and rock extracts were carried out by using this method and good results were achieved. This method is of great value in organic geochemistry research because it is efficient and economical.

English Abstract↗
PubMed1997

Acrobeads test as a predictor of fertilization in vitro.

PROBLEM: To determine whether the results of the Acrobeads test, which measures the expression of the complement regulator molecule CD46 on the inner acrosomal membrane following the acrosome reaction, accurately identifies semen specimens that will exhibit reduced or failed fertilization following conventional IVF insemination. METHOD: The Acrobeads test was performed on semen specimens from 97 consecutive patients preparing to undergo an IVF cycle utilizing a standardized insemination protocol. Motile sperm populations were examined at 6 h and 24 h post-isolation for sperm-bead agglutination. Results of the Acrobeads test were compared to that of TRITC-PSA staining in matched specimens to directly measure the spontaneous loss of acrosome content. The percentages of TRITC-PSA-negative sperm were determined in freshly isolated motile populations and in duplicate aliquots incubated 18 to 20 h under sperm capacitating conditions. The relationship between the results of both analyses estimating spontaneous acrosome reactions and the rate of fertilization of metaphase II oocytes was examined. RESULTS: The Acrobeads score did not correlate significantly with the rate of fertilization by insemination at 6 h or at 24 h. The negative predictive value of this test was 21.4%. There was no correlation between the Acrobeads score and the percentage of sperm undergoing a spontaneous acrosome reaction as detected by TRITC-PSA labeling. In contrast, the increment increase in the percentage of spontaneous acrosome reactions as quantified by TRITC-PSA staining was correlated with the fertilization rate. CONCLUSIONS: Contrary to previous reports, our prospective, double-blinded study failed to demonstrate that the Acrobeads test can accurately predict fertilization outcome in IVF. Therefore, the routine use of this test to screen patients prior to an IVF cycle in order to select appropriate treatment (i.e., ICSI) cannot be recommended.

Acrosome↗
PubMed1996

Immunohistochemical study of fibronectin for postmortem diagnosis of early myocardial infarction.

The postmortem diagnosis of early myocardial infarction has been a puzzling problem in forensic practice. In the present study, an immunohistochemical study of fibronectin (FN) was performed for the first time on 34 autopsy hearts to determine early myocardial infarction with streptavidin/biotin/peroxidase technique. Five cases of definite myocardial infarction showed positive FN staining of cardiomyocytes; of 18 cases where early myocardial infarction was suspected, positive FN staining of cardiomyocytes was found in 15 cases, but no such staining was seen in 11 non-cardiac death controls. The results led to the conclusion that positive FN staining in cardiomyocytes is a reliable marker of acute myocardial infarction and could be used as a new, sensitive method for the postmortem diagnosis of early myocardial infarction. It is worth noting that all cases in this study were autopsied between 8 h and 4 days after death and 5 cases had been fixed in 10% formalin for over 10 years. FN immunohistochemistry still gave satisfactory results in those cases. It seemed that FN was not affected by postmortem autolysis and formalin-fixation and could be used in routine forensic practice, especially for retrospective analysis of cases.

Adult↗
PubMed1995

Diagnostic value of ions as markers for differentiating antemortem from postmortem wounds.

In the present study, the diagnostic value of ions as markers for differentiating antemortem from postmortem wounds was investigated. To accomplish this, skin and muscle samples were taken from antemortem and postmortem wounded cadavers and the contents of ions (Fe, Zn, Mg, Cu, K and Na) were determined with atomic absorption spectrophotometry. Our results show that the concentrations of Fe in antemortem wounded skin and muscle were significantly higher as compared with the control skin and muscle and the K/Na ratio in antemortem wounded muscle was reduced significantly compared to control muscle. However, the concentrations of Zn, Mg, Cu in antemortem wounded skin and muscle, and the K/Na ratio in antemortem wounded skin, were not significantly different from their controls. The concentrations of all these ions in postmortem wounded skin and muscles were not significantly different from their controls. It is indicated that the concentrations of Fc in skin and muscle and K/Na ratio in muscle are useful markers for differentiating antemortem from postmortem wounds. However, their routine use in forensic practice needs further investigation, since there are some overlaps of the ionic concentrations between normal and wounded skin and muscle.

Adolescent↗
PubMed1992

[Effects erythropoietin on experimental anemia in rats with chronic renal failure].

Erythropoietin (EPO) is a glycoprotein hormone secreted by human kidney cells. Human EPO was induced from human embryo kidney cells, isolated and purified from medium by biochemical method in our laboratory. The hypoproliferative anemia in chronic renal failure (CRF) has been assumed to be the result of decreased EPO production by the damaged kidney and of the shortening of the survival of erythrocytes. In this study, CRF anemia was formed 9 weeks after the removal of five-sixths of the renal mass of rats. These anemic rats were divided into 6 groups: treated with different dosages of EPO or physiological saline. The results indicate that EPO has apparent effects on anemia in rats with CRF. It may stimulate erythropoiesis and improve the anemia state of rats with CRF. Hematological parameters (RBC, Hb, PLT, Ht and Rt) may be reverted to normal levels (P less than 0.001). The level of BUN and Cr were significantly decreased. The optimum dose of EPO was 1000 U/kg. All these results show that injection of EPO has therapeutic effect on anemia in rats with CRF. EPO showed no effect on normal rats.

Anemia↗
PubMed1991

Preliminary report on a new method of human age estimation from single adult teeth.

A total of 317 upper and lower third molars were randomly divided into working and control samples and used to estimate chronological age employing a method which combined multiple regression analysis of data from Gustafson's and Maples's scoring system, direct morphological measurements obtained with a Kontron image analysis system and logarithmic data transformation. The standard errors of estimate were 2.4-6.8 years in the working sample and 1.9-7.5 years when the derived formulae were tested on the control sample, respectively. Compared to previous studies, this method provides a smaller standard error of estimate from a single molar tooth. The method is presently being tested on other tooth categories, like premolars, canines and other types of molars.

Adolescent↗
PubMed1991

[Dynamic investigation of antithrombin III in the plasma of patients with acute myocardial infarction].

Antithrombin III level in the plasma of patients with AMI was determined dynamically by using the methods of chromogenic substrate and rocket electrophoresis. Meanwhile, plasma specimens of 40 normal subjects were examined with the same method. The results showed that the AT III level in AMI patients was much lower than that in normal controls at the first and third day after infarction. The level was also significantly lower than that at the 7th, 14th and 21st day after the onset of the disease. It revealed that there was a hypercoagulative state in patients within the first three days of infarction. The AT III level in patients who died within ten days was much lower than that in the survivor group, P less than 0.01. The authors concluded that a patient may be in a severe condition when their plasma AT III levels decrease apparently and persistently.

Adult↗
PubMed1990

The significance of detecting serum fluorine level in the diagnosis of drowning.

In view of the high content of fluorine in the water of a vast area of Guangdong Province, we detected the serum fluorine level in rabbits that died of drowning and compared them with those obtained from rabbits immersed in water after death from hanging. The fluorine content in water is about 15-fold higher than in the normal serum content. In drowned rabbits, the serum fluorine values are significantly higher than normal while in control cases the serum fluorine values are slightly lower than normal. The fluorine content in human serum is similar with that of rabbits. It suggests that detection of serum fluorine content might be a valuable method for the diagnosis of drowning in those areas where there are high water fluorine content.

Animals↗
PubMed1989

[Significance of serum beta 2-microglobulin in the differential diagnosis of benign and malignant M-globulinemia].

Serum beta 2-microglobulin (S beta 2-M) and marrow plasma cell count were surveyed in 30 cases of M-globulinemia. The average value of S beta 2-M and number of patients with increased value were much higher in 20 malignant than 10 benign patients including cases of undetermined causes of M-globulinemia (P less than 0.005) with the same results as traditional examination of plasma cell. This method is useful in the differential diagnosis of benign and malignant cases. However, for those patients with undetermined causes of M-globulinemia and different lengths of disease course, the values may vary to a greater extent. In 11 cases multiple myeloma the value of S beta 2-M was high before treatment and decreased after chemotherapy. When the disease was exacerbated (as in 2 cases before dying), the value remained high persistently. Therefore, serum beta 2-M level can be used to predict the therapeutic effect as well as the prognosis.

Adult↗