Biomedical subjects

J Cao

Publications and source records attributed to J Cao.

At least 127 records · Page 7Linked to original sources

PubMed2000

Age-related retinal pigment epithelium and Bruch's membrane degeneration in senescence-accelerated mouse.

PURPOSE: To investigate age-related changes in the retinal pigment epithelium (RPE), Bruch's membrane, and choriocapillaris in the senescence-accelerated mouse (SAM). METHODS: The external and eyecup features and light and electron microscopic findings were examined in three male and two female mice of a senescence-prone mouse strain (SAM P(8)) monthly for 12 months. These results were compared with those in age-matched mice of similar background but senescence resistant (SAM R(1)). Choroidal vascular casts were prepared at 12 months in seven mice each of the SAM P(8) and SAM R(1) strains. Quantitative analysis of area of choriocapillaris was performed by automated image analysis, and the results were analyzed by paired Student's t-test. RESULTS: We found in the SAM P(8) strain that hair loss, coarseness of hair texture, and ulceration of skin appeared and increased as the age advanced (at approximately 5-9 months). Eyecup examination showed no differences. Light and electron microscopy revealed progressively more prominent abnormalities in the RPE and Bruch's membrane mice older than 10 months. Two of the five SAM P(8) mice older than 11 months showed what appeared to be intra-Bruch's membrane choroidal neovascularization. The RPE and Bruch's membrane appeared normal in the SAM R(1) strain. In the SAM P(8), vascular casts of the choriocapillaris showed a mild but significant decrease in vascular area when compared with the SAM R(1) strain at 12 months (P = 0.011). CONCLUSIONS: Senescence accelerated mice develop progressive age-related changes in the RPE-Bruch's-choriocapillaris complex that have features that may be relevant in the study of age-related macular changes in humans.

Aging↗

PubMed2000

[Bcl-2 anti-sense oligonucleotide sensitizes Fas-mediated apoptosis of gastric cancer cells].

OBJECTIVE: To study the effect of bcl-2 anti-sense oligonucleotide on the sensitivity of gastric cancer cells to Fas-mediated apoptosis. METHODS: Gastric cancer cell line MKN45 was transfected with bcl-2 anti-sense oligonucleotide, and expression of bcl-2 was examined by Western blotting. Agonistic Fas antibody was used to induce apoptosis detected by TUNEL staining and flow cytometry. RESULTS: Bcl-2 expression in MKN45 cells transfected with bcl-2 anti-sense oligonucleotide was markedly inhibited. When cultured with antibody apoptosis index of the anti-sense oligonucleotide-treated MKN45 cells was 55.6% +/- 4.7% (n = 5), which was significantly higher than that of the control (8.4% +/- 2.1%, n = 5). CONCLUSION: Expression of bcl-2 in gastric cancer cells may antagonize Fas-mediated apoptosis.

Apoptosis↗

PubMed2000

The expression of E-cadherin-catenin complex in adenoid cystic carcinoma of salivary glands.

OBJECTIVE: The aim of this study was to investigate the expression of the E-cadherin-catenin (E-cad-cat) complex in human salivary adenoid cystic carcinoma (ACC) and determine the effects of E-cad-cat expression on tumor differentiation, metastasis, and invasion, as well as its clinical significance. METHODS: The expression of adhesion molecules, which included E-cadherin, alpha-catenin, and beta-catenin, on 10 cases of normal salivary glands, and 50 cases of human salivary ACC were investigated by immunohistochemistry. RESULTS: Strong and stable expression of E-cad-cat complex showed in normal salivary glands tissues. However, weaker expression and even complete absence, of the positive signals were shown on all ACC cases. Coexpression of E-cad-cat were detected in 29 (58%) of the 50 ACC specimens. Positive staining of E-cad-cat complex were detected in 7 (39%) of the 18 ACC primary sites that had aggressive phenotype of nerve and vasculature. CONCLUSION: Strong positive signals of E-cad-cat complex are shown in normal salivary glands, and the down-regulated expression were observed in ACC cases. The expression of E-cad-cat complex is associated with a more aggressive phenotype on nerve and vasculature. No association with various histopathologic subtypes was found. However, absent or low E-cad expression was observed more frequently in solid carcinomas than in cribriform or tubular carcinomas. Down-regulation of E-cad-cat complex may be associated with canceration of normal salivary glands. The expression levels of E-cad-cat were positively correlated to the differentiation of ACC tumor cells.

Antibodies, Monoclonal↗

PubMed2000

Human papillomavirus infection and p53 alteration in oral squamous cell carcinoma.

OBJECTIVE: The aim of this study was to examine human papillomavirus 16/18 infection incidence and p53 alteration in oral squamous cell carcinoma and to determine whether a correlation existed between HPV infection incidence and p53 alteration in this disease. METHODS: A series of 60 oral tissues (40 oral squamous cell carcinomas, 20 normal oral mucosas) was studied by polymerase chain reaction (PCR) to detect HPV 16 and 18 infection, and was studied by single strand conformation polymorphism (SSCP) and immunohistochemistry (IHC) to detect p53 mutation and accumulation, respectively. RESULTS: HPV sequences were detected in 29 of 40 (72.5%) tumor specimens. A higher incidence (P = 0.037) of HPV 16/18 infection was observed in oral squamous cell carcinomas than in normal oral mucosas. Altered p53, either in genetic sequence or protein overexpression, was observed in 18 of 40 (45%) oral squamous cell carcinomas. Eleven of the 29 HPV-positive tumors contained observed alterations in either p53 protein expression or DNA sequence. No significant correlation (P = 0.145) was observed between HPV infection and p53 alteration. CONCLUSIONS: These data suggest that HPV16/18 infection and/or p53 alterations are associated with oral squamous cell carcinoma. No inverse correlation exists between oncogenic HPV infection and p53 alteration.

Adult↗

PubMed2000

[The relationship between dental fluorosis and dietary pattern among Tibetan children in natural protective areas of Mount Qomolangma].

OBJECTIVE: To study the relationship between dietary pattern and dental fluorosis among Tibetan children in natural protective areas of Mount Qomolangma. METHODS: Environmental fluorine levels, dietary pattern and occurrence of dental fluorosis among children in Xieger town, Dingri County and Zhangmu town, Nielamu County, were studied. RESULTS: The total fluorine intake in children was 8.039 mg in Xieger town and the prevalence rate of dental fluorosis was 75.93%. The total fluorine intake and morbidity of dental fluorosis are 2.797 mg and 25.86% respectively in Zhangmu town. CONCLUSION: It suggested that fluorosis of children is related to total fluoride intake.

Adolescent↗

PubMed2000

[Human Fab antibodies derived from phage display library neutralize hepatitis A virus in vitro].

OBJECTIVE: Development of recombinant human monoclonal antibody to hepatitis A virus as a emergent measure for prevention of hepatitis A virus infection. METHODS: Human neutralizing monoclonal antibody Fab fragments to HAV have been developed by using phage display technique. The heavy and light chains of human IgG Fab genes were amplified from a HAV patient in convalescent stage. The combinatorial phage antibody library was established by inserting both heavy and light chains of Fab genes into phage mid-vector pComb3 and followed by help phage infection after 4 rounds of panning with purified HAV as coated antigen. RESULTS: The human Fab fragments to HAV were selected and expressed in bacteria. CONCLUSIONS: The specific binding of Fab antibodies to HAV were demonstrated by their reaction with HAV antigen in ELISA. These results provide the basis for further development of a neutralizing recombinant human whole IgG molecule and hold promise for future use in the prophylaxis of HAV infection.

Antibodies, Monoclonal↗

PubMed2000

[Effect of different fertilizer combinations on water supply-demand status of winter wheat].

The soil water status during various growing stages of winter wheat and the effect of different fertilizer combinations on its yield and water use efficiency (WUE) were studied in a semihumid and slanting drought area by using the design of D-optimum saturation. According to water balance law, soil water supply was obviously different with different fertilizer combinations, reaching a peak when N and P fertilizers were combined applied with organic fertilizer, accounting for 27% of total water consumption. N fertilizer added alone took up 100% of total water consumption from rainfall. Water deficiency was most severe when N fertilizer was applied alone, but was the smallest when P fertilizer was applied with organic fertilizer. The combination of N, P and organic fertilizer could significantly improve winter wheat yield and its WUE.

Economics↗

PubMed2000

[Environmental fluorine level in Tibet].

The concentration of fluorine in water, soil, fuel, food, vegetable and tea in Tibetan habitats with different environmental characteristic were measured by ion-specific electrode potentiometer. The results showed that the fluorine concentration in water, soil, fuel, food vegetable, butter tea and Zanba both of them were made from brick teas was 0.06 mg.L-1, 0.45 mg.kg-1, 0.10 mg.kg-1, 0.06-0.33 mg.kg-1, 3.09 mg.L-1 and 3.61 mg.kg-1, respectively. The water-soluble fluorine content in brick tea which came from Sichuan and Yunnan Provinces reached up to 533.89-617.32 mg.kg-1. It is suggested that drinking brick tea may induce fluorosis in Tibetan habitats.

Environment↗

PubMed2000

[Uptake of particulate lead via gills of goldfish].

This paper studied the uptake of Pb absorbed on suspended gibbsite via gills of goldfish (Carassius auratus). Under conditions of the concentration of the particulate Pb varied while that of free Pb maintained at a constant level, the levels of both Pb and Al in the gills increased with increasing exposed Pb concentration. The increasing rate (slope 0.171) of Pb level in the blood with the Pb level in the gills was lower than that (slope 0.343) of soluble Pb exposure experiment. Partial Pb adhered on the gills did not transfer into blood. The ratio of Pb/Al in the gills was 1-2 orders of magnitude higher than that in the water, and on the microtome section of filament, the gibbsite particles adhered on gill mucus were observed, indicating the bioavailability of the particulate Pb uptake by the gills of goldfish. The major mechanism was: when the absorbed Pb on suspended particles was flowed into gill filaments, it was desorbed on the surface of gills, and then, passively diffused or transferred by carriers via gill cells into flood, and after the particles stayed on the surface of gill filaments for a short time, in company with sloughed mucus, they were released from the gills along with waterflow.

Absorption↗

PubMed2000

[Interaction of Cu and Pb in accumulation process by fish].

With synthetic water, the accumulation of co-existed Ca and Pb by Paracheirodon innesvi and of Pb by Cu-tamed P. innesvi was studied. The result showed that under both conditions, there existed a significant synergistic effect on the accumulation of Cu and Pb by the fish.

Animals↗

PubMed2000

[The variation of nasal obstruction in patients with OSAS].

OBJECTIVE: To study the variation of nasal resistance and its possible relationship to obstructive sleep apnea. METHODS: The detection of nasal resistance and polysomnography were performed in 30 normal subjects, 30 snoring patients and 60 patients with OSAS. RESULTS: The study reveal that nasal resistance of the patients with OSAS (1.06 +/- 4.25) Pa.s/ml, (2.29 +/- 9.74) Pa.s/ml or snoring (0.71 +/- 0.31) Pa.s/ml was higher than that of normal group (0.40 +/- 0.13) Pa.s/ml (P < 0.01). There was a positive correlation between nasal resistance and snoring index (r = 0.258, P < 0.01), but there was no correlation among AHI, waken intervals, and nasal resistance. CONCLUSION: Nasal resistance increased in the patients with snoring or OSAS, it may be a factor related with OSAS.

Adult↗

PubMed2000

[Changes and cardiac protective effects of adrenomedullin during myocardial ischemia-reperfusion period].

OBJECTIVE: To investigate if adrenomedullin (Adm) is concerned with cardiac ischemia-reperfusion (I/R) process and to study its effects on I/R injury. METHODS: Plasma Adm dynamic levels were tested in 17 patients with acute myocardial infarction (AMI), who had got successful blood reperfusion through intravenous thrombolytic therapy. The indices of I/R injury were measured in I/R models of isolated perfused rat heart when Adm (10(-7) mol/L) was given in reperfusion period. RESULTS: Plasma Adm concentrations before thrombolytic therapy in AMI patients were significantly higher than those of control group (3.8 pmol/L +/- 0.8 pmol/L vs 1.9 pmol/L +/- 0.8 pmol/L P < 0.01), and rose further after successful thrombolytic therapy, which resulted in efficient myocardial reperfusion. The peak level of plasma Adm, which appeared 4 hours after thrombolytic therapy, was 42.9% higher than that before therapy. The levels began to decrease and dropped to the levels before therapy at 12 and 24 hours after thrombolysis, respectively. In isolated perfused rat heart models, when Adm (10(-7) mol/L) was added in perfusion fluid for 15 minutes reperfusion after 45 minutes ischemic period, +/-LVdp/dt max of the heart increased 76.9% and 67.9%, and the average volume of coronary efflux increased 48.8%, respectively, compared with that of control group of ischemia-reperfusion. The amount of total protein, myoglobin and activities of LDH in effluent samples of Adm group were 34.3%, 63.6% and 29.2% lower than those of control group, respectively. CONCLUSION: Plasma Adm concentrations in AMI patients increase significantly during myocardiac reperfusion period after thrombolytic therapy. To some extent, Adm may have myocardial protective effects during ischemia-reperfusion period.

Adrenomedullin↗

PubMed2000

[Coronary venous variation in patients with portal hypertension].

OBJECTIVES: To observe the changes in the anatomic variation and the hepatofugal flow of coronary vein and to evaluate the clinical significance of these changes in patients with portal hypertension. METHODS: The anatomic variations and the retrograde flow of the coronary vein, and the portal antegrade flow and the portal pressure were observed by direct and indirect portography, direct measurement of portal pressure and Doppler sonography in 200 cirrhotic patients with portal hypertension. RESULTS: Single branch and two branches of the coronary vein were noted in 79.46% and 20.54% of the patients with portal hypertension respectively by direct portography. The sites of coronary vein arising from the portal vein, splenic vein or portosplenic junction were found in 62.33%, 27.35% or 8.07% respectively. The confluence of coronary vein and portal vein was found in most patients with variceal bleeding and recurrent bleeding after devascularization. The confluence of the coronary vein and splenic vein was observed in most patients with refractory ascites without variceal bleeding. Arterial portography demonstrated retrograde opacification of the coronary vein in 26.19% (grade II portal venous pattern), 56.64% (grade III portal venous pattern), 100% (portal thrombosis and action bleeding) 47.79% (controuing periods of bleeding), and 19.05% (refractory ascites). CONCLUSIONS: The anatomic variation of the coronary vein may be related to variceal bleeding in cirrhotic patients with portal hypertension and the retrograde opacification of the coronary vein is a significant sign of variceal bleeding.

Coronary Vessel Anomalies↗

PubMed2000

[Comparison of TIPS, a modified Sugiura procedure and TIPS plus a modified Sugiura procedure for portal hypertension].

OBJECTIVE: Transjugular intrahepatic portosystemic shunts (TIPS), a modified Sugiura procedure and TIPS plus a modified Sugiura procedure were compared to evaluate their clinical results in treatment of portal hypertension. METHODS: Ninety patients with portal hypertension respectively underwen TIPS (group I, n = 30), a modified Sugiura procedure (group II, n = 30) and TIPS plus a modified Sugiura procedure (group III, n = 30). The rates of rebleeding and encephalopathy, and the mortality of patients with portal hypertension were observed. RESULTS: The early postoperative complications were observed in 23.33% of the patients in group I, in 30.0% of those in group II, and in 20.0% of those in group III. The early postoperative rates of rebleeding were 6.67% in group I, 10% in group II, and 0% in group III. Hepatic encephalopathy was seen in 16.67% of the patients in group I, 0% in group II and 13.33% in group III. The early mortality was 3.33% in group I. During follow-up for 1 - 36 months, the rates of rebleeding were 34.48% in group I, 33.33% in group II, and 3.33% in group III. The rates of encephalopathy and mortality were respectively 17.20% and 20.69% in group I, 3.33% and 13.33% in group II, 3.33% and 3.33% in group III. The shunt patency in group III was higher than that in group I. CONCLUSION: Combination of TIPS and a modified Sugiura procedure can be effective to prevent and treat variceal bleeding.

Adult↗

PubMed2000

[Secondary glaucoma after penetrating keratoplasty].

OBJECTIVE: To investigate the etiology and management of secondary glaucoma after penetrating keratoplasty (PKP). METHODS: Eighty cases (80 eyes) with secondary glaucoma occurring in 1,450 cases (1,500 eyes) of PKP, its causes, time of onset and the relationship with the primary disease were analyzed. According to different causes, they were treated with different therapies. RESULTS: The intraocular pressure (IOP) of 63 cases (63 eyes) became normal after drug treatment for 2 - 3 weeks. In 17 cases (17 eyes) who had received antiglaucomatous operations, 13 cases' (13 eyes) IOPs were normal and 4 cases' (4 eyes) still high. CONCLUSIONS: Accurate perioperative management can decrease the incidence of secondary glaucoma after PKP. The majority of secondary glaucoma can be controlled by different therapies according to different causes.

Adolescent↗

PubMed2000

[Studies on gene mutation and micronucleus formation induced by ethylnitrosourea (ENU) in transgenic mice in vivo].

OBJECTIVE: To determine the feasibility of using pUC 118NX plasmid-based transgenic mice in the study of induced mutation in vivo with known mutagen, ethylnitrosourea (ENU). METHODS: pUC 118NX plasmid was recovered from the spleen genomic DNA of ENU-treated and untreated xylE, C57BL/6J transgenic mice with enzyme digestion and circularizing. The recovered pUC 118NX plasmid was electroporated into DH10B host cells, which were incubated in LB solid medium containing proper ampicillin overnight and then sprayed with catechol solution. Mutant could be detected by difference in yellow and white color of the stains and its xylE target gene could be sequenced for further identifying its mutation type. In addition, peripheral blood and bone marrow cells were isolated from xylE, C57BL/6J transgenic mice and micronucleus frequency (MNF) induced by ENU was observed. RESULTS: The spontaneous mutant frequency for xylE gene in the spleen of xylE, C57BL/6J transgenic mice was less than 4.79 x 10(-5), significantly different from that treated with ENU (50 mg/kg), 19.83 x 10(-5). Types of gene mutation induced by ENU in the spleen of xylE, C57BL/6J transgenic mice included transversion (50%), one or two-base insertion (37.5%) and transition (12.5%). MNF in peripheral blood normochromatic erythrocyte (NCE) and in bone marrow polychromatic erythrocyte (PCE) of ENU-treated (50 mg/kg x 5) mice were 7.6 per thousand and 8.8 per thousand, respectively, both significantly different from the controls treated with solvent (P < 0.01). It indicated that chromosome aberration could be induced by ENU. CONCLUSION: The pUC118NX plasmid-based xylE, C57BL/6J transgenic mice, which could be used in detecting gene mutation and chromosome aberration in vivo simultaneously, provided a novel detection system for overall assessment of genetic toxicity of chemicals.

Animals↗

PubMed2000

[Studies on micronuclei induced by colchicine and cyclophosphamide using multicolor fluorescence in situ hybridization].

OBJECTIVE: To study chromosomal composition of micronuclei (MN) induced by colchicine (COL) and cyclophosphamide (CP) in mouse bone marrow erythrocytes. METHODS: Multicolor fluorescence in situ hybridization (FISH) with centromeric and telomeric DNA probes was applied to analyze chromosomal composition of micronuclei induced by COL and CP in mouse bone marrow erythrocytes. RESULTS: About 83.5% of COL-induced MN revealed both centromeric and telomeric signals. Of the CP-induced MN, 74.5% showed telomeric signals only. CONCLUSION: Majority of COL-induced MN contain whole chromosome and that of CP-induced MN mainly contain acentric fragments. Multicolor FISH with centromeric and telomeric DNA probes was a precise technique for analyzing chromosomal composition of MN.

Animals↗

PubMed2000

[A cross-sectional study on injuries in the residents of Shijiazhuang city].

OBJECTIVE: To comprehend current status of injury in the residents of Shijiazhuang city and to lay a foundation for prevention from injury. METHODS: A retrospective study on injury in the 21,544 residents of two and six rural villages was conducted by multi-stage stratified sampling. RESULTS: Standardized incidence rate of injury was 4.21% in Shijiazhuang city, higher in the rural than in the urban areas and higher in men than in women. The top three causes of injuries were traffic accidents, falls and poisoning. Traffic accidents and poisoning ranked the first place in the urban areas and in the rural areas, respectively. Falls occurred mostly in those aged less than 14 years and more than 60 years. Gas poisoning and traffic accidents occurred more often in those aged 15 - 34 years and traffic accidents ranked the first in the age group of 35 - 59 years old. Standardized mortality rate of injury was 48.78 per 100,000, higher in the rural than in the urban areas. Standardized mortality rate of suicide was the highest with 23.21 per 100,000 in the countryside and that of traffic accidents ranked the next. In average, 22 years of potential life lost, 17 work years of potential life lost and nine valued years of potential life lost for each death were caused by injury. Disability rate caused by injury was 1.1 percent. Direct economic loss for each case with injury cost 679.98 RMB yuan. Incidence rate for traffic accidents ranked the highest and the most severe in all injuries. CONCLUSION: Injury has become an important public health problem harmful to the people's health.

Accidental Falls↗