Search PubMed⌕ Search

Biomedical subjects

S Zhu

Publications and source records attributed to S Zhu.

At least 73 records · Page 4Linked to original sources
PubMed2001

Increased levels of nitrate and surfactant protein a nitration in the pulmonary edema fluid of patients with acute lung injury.

Levels of nitrite (NO2-) and nitrate (NO3-) were measured in pulmonary edema fluid and plasma from 34 patients with early acute lung injury (ALI) and 20 patients with hydrostatic pulmonary edema. Pulmonary edema fluid from patients with ALI had significantly higher levels of NO2- + NO3- compared with pulmonary edema fluid from patients with hydrostatic pulmonary edema (108 +/- 13 microM versus 66 +/- 9 microM; means +/- SEM; p < 0.05). In addition, patients with shock had higher plasma NO2- + NO3- levels than those without shock (79 +/- 11 microM versus 53 +/- 12 microM, p < 0.05). Acidemia and increased anion gap, markers of systemic hypoperfusion, were also associated with twofold higher plasma NO2- + NO3- levels (p < 0.01). Increased levels of NO2- + NO3- in edema fluid samples were associated with slower rates of alveolar fluid clearance. Nitrated pulmonary surfactant protein A (SP-A) was also detected in the edema fluid of patients with ALI after immunoprecipitation with a specific antibody against this protein. Previously, we have shown that nitration of SP-A impairs its host- defense properties. In aggregate, the results of this study indicate that reactive oxygen-nitrogen species may play a role in the pathogenesis of human ALI.

Body Fluids↗
PubMed2001

Nitric oxide and nitrotyrosine in the lungs of patients with acute respiratory distress syndrome.

Nitric oxide (NO) end-products (nitrate and nitrite) are present in bronchoalveolar lavage (BAL) fluid of patients with inflammatory lung diseases. Reactive oxygen-nitrogen intermediates damage macromolecules by oxidation or nitration of critical residues in proteins. The goal of this study was to measure NO end-products (nitrate+ nitrite), in BAL fluid before and after the onset of acute respiratory distress syndrome (ARDS) and to determine if these products are associated with expression of inducible nitric oxide synthase enzyme (iNOS) in BAL cells and nitration of BAL proteins. We performed bronchoalveolar lavage (BAL) in patients at risk for ARDS (n = 19), or with ARDS (n = 41) on Days 1, 3, 7, 14, and 21 after onset, and measured total nitrite (after reducing nitrate to nitrite) and protein-associated nitrotyrosine concentration in each BAL fluid sample. Cytospin preparations of BAL cells were analyzed by immunocytochemistry for iNOS and nitrotyrosine. Nitrate+nitrite were detected in BAL fluid from patients at risk for ARDS, and for as long as 21 d after the onset of ARDS. Nitrotyrosine was detectable in all BAL fluid samples for as long as 14 d after the onset of ARDS (range, 38.8 to 278.5 pmol/mg of protein), but not in BAL of normal volunteers. Alveolar macrophages of patients with ARDS were positive for iNOS and nitrotyrosine, and remained positive for as long as 14 d after onset of ARDS. The BAL nitrate+nitrite did not predict the onset of ARDS, but the concentration was significantly higher on Days 3 and 7 of ARDS in patients who died. Thus, NO end products accumulate in the lungs before and after onset of ARDS; iNOS is expressed at high levels in AM during ARDS; and nitration of intracellular and extracellular proteins occurs in the lungs in ARDS. The data support the concept that NO-dependent pathways are important in the lungs of patients before and after the onset of ARDS.

Adult↗
PubMed2001

A major role for VCAM-1, but not ICAM-1, in early atherosclerosis.

VCAM-1 and ICAM-1 are endothelial adhesion molecules of the Ig gene superfamily that may participate in atherogenesis by promoting monocyte accumulation in the arterial intima. Both are expressed in regions predisposed to atherosclerosis and at the periphery of established lesions, while ICAM-1 is also expressed more broadly. To evaluate functions of VCAM-1 in chronic disease, we disrupted its fourth Ig domain, producing the murine Vcam1(D4D) allele. VCAM-1(D4D) mRNA and protein were reduced to 2-8% of wild-type allele (Vcam1(+)) levels but were sufficient to partially rescue the lethal phenotype of VCAM-1-null embryos. After crossing into the LDL receptor-null background, Vcam1(+/+) and Vcam1(D4D/D4D) paired littermates were generated from heterozygous intercrosses and fed a cholesterol-enriched diet for 8 weeks. The area of early atherosclerotic lesions in the aorta, quantified by en face oil red O staining, was reduced significantly in Vcam1(D4D/D4D) mice, although cholesterol levels, lipoprotein profiles, and numbers of circulating leukocytes were comparable to wild-type. In contrast, deficiency of ICAM-1 either alone or in combination with VCAM-1 deficiency did not alter nascent lesion formation. Therefore, although expression of both VCAM-1 and ICAM-1 is upregulated in atherosclerotic lesions, our data indicate that VCAM-1 plays a dominant role in the initiation of atherosclerosis.

Animals↗
PubMed2001

Construction, expression, and characterization of recombinant hirudin in Escherichia coli.

The mutant gene of HV2-K47 was obtained by polymerase chain reaction-directed mutagenesis and expressed in Escherichia coli. Many elements that could affect its expression level were compared. The product was purified to homogeneity via three chromatographic steps--ion exchange, gel filtration, and reverse phase chromatography--on the AKTA Explorer System. The anti-thrombin activity of HV2-K47 is much higher than that of recombinant HV2. Some properties and expression conditions were investigated systematically, which would be useful for further studies of hirudin and other small proteins.

Cloning, Molecular↗
PubMed2001

Difference in the occurrence of cardiovascular events according to class of antihypertensive agent, based on a follow-up study of Japanese hypertension patients.

We conducted a nested case-control study to evaluate the relationship between antihypertensive agent class and the incidence of initial cardiovascular events. A total of 7.443 patients being treated with an antihypertensive agent in 1985-1986 were enrolled for follow-up of up to 5 years. A total of 362 patients (186 males and 176 females) developed cardiovascular events. Age (5-year interval) and sex-matched controls were then randomly selected. A Multiple logistic regression analysis was done to control for the effects of confounding factors. The results showed that the use of diuretics and beta-blockers was associated with a reduced risk of cardiovascular events (odds ratio [OR] =0.65, 95% confidence interval [CI]: 0.49-0.86, and OR=0.75, 95% CI: 0.56-1.02, respectively), against a significantly raised risk associated with the use of calcium antagonists (OR=1.34, 95% CI: 1.03-1.80). However, as far as stroke was concerned, there was no significant association of risk with the use of any agent. The control group was found to be similar to the case group with respect to the changes in the treatment program during the follow-up period. The results suggest that the calcium antagonists used in Japan during the period of 1985-1990 constituted a potential risk for the occurrence of cardiovascular events.

Adrenergic beta-Antagonists↗
PubMed2001

[Pharmacognostic identification of Herba Chrysanthemi].

OBJECTIVE: To provide evidences for the identification and utilization of Herba Chrysanthemi. METHODS: Regular mehods for morphological and histological identification, TLC and UV were used. RESELTS: The descriptions characters of Herba Chrysanthemi were recounted. The histological characters of the stem and the leaf were also described. TLC showed Herba Chrysanthemi contained chlorogenic acid. UV spectrum showed Herba Chrysanthemi had absorbed peaks at 248 nm and 327 nm. CONCLUSION: All the above-mentioned characters provided evidences for the identification of Herba Chrysanthemi.

Chromatography, Thin Layer↗
PubMed2001

[A qualititative study on p16 mutiple tumor suppressor gene, ras oncogene p21 and DNA content in parotid tumor and its' contiguous acini].

OBJECTIVE: To determine the biologic characteristics of tumor's contiguous acini and the relationship of recurrence or malignant transformation. METHODS: With the use of immunohistochemistry and flow cytometry, the features of p16, p21 and DNA expression in 68 tumors and their contiguous acini were studied. RESULTS: The expression of p16 and p21 gene were found in tumors that the possitive unit (PU) was higher than normal acini (P < 0.01). The areas of expression were mainly located in cytoplasm of gland duct cells. Strong possitives or weak possitives could be observed in the tissues of malignant tumors and their contiguous acini respectively, as well as the PU in the deep lobe of recurrent parotid tumors in which the capsule was incomplete was higher than that in the superficial lobe of primary parotid tumors with complete capsule (P < 0.05). Futhermoer the levels of DI, S% and PI were higher in perotid tumors and its contiguous acini than normal acini (P < 0.05). CONCLUSIONS: When p16 multiple tumor suppressor gene is lost and oncogene p21 is mutated, the tumor's contiguous acini maybe in the condition of "paraneoplasm" after parotid tumor removal, and it has a strong ability of preliferation, which play an important role in recurrent or malignant change of the parotid tumor.

Adolescent↗
PubMed2001

[Cytokine networks and their endogenous modulators in patients with congestive heart failure].

OBJECTIVE: To explore the pathophysiological role of cytokine network and their endogenous modulators in the development of congestive heart failure (CHF). METHODS: Plasma levels of tumor necrosis factor-alpha (TNF-alpha), interleukin-6(IL-6), soluble TNF receptor I (sTNF-RI) and transforming growth factor (TGF)-beta were measured by enzyme-linked immunoassay in 52 CHF patients with various degrees of heart failure and in 30 healthy controls. RESULTS: Patients with CHF had increased plasma concentrations of TNF alpha, IL-6 and sTNF-RI, but decreased levels of TGF-beta. They also had elevated ratios of TNF-alpha/sTNF-RI and TNF-alpha/TGF-beta, particularly those in functional class IV. The levels of TNF-alpha were positively correlated with IL-6 and sTNF-RI but negatively correlated with TGF-beta(P < 0.01). CONCLUSIONS: The imbalance in the cytokine network were most pronounced in patients with the most severe heart failure. CHF may be accompanied by a shift toward enhanced levels of inflammatory cytokines combined with inadequately raised or even decreased levels of anti-inflammatory cytokines. A poorly regulated cytokine network may be involved in the development and progression of CHF.

Antigens, CD↗
PubMed2001

[The influence of resuscitation with solutions containing different concentrations of sodium on the homeostasis of burn patients during the early postburn stage].

OBJECTIVE: To investigate the influence of resuscitation with solutions containing different concentrations of sodium on the homeostasis of burn patients during the early postburn stage. METHODS: Thirty-five cases of burn patients inflicted with 50% approximately 100% of TBSA including 20% approximately 88% of 3rd degree burn were enrolled in the study. All the patients studied were divided into A[(Na+) = 174 mmol/L] and B [(Na+) = 130 mmol/L] groups according to different concentrations of sodium in the infusion solution. The input of the fluid, plasma crystal osmotic pressure, plasma ratio of albumin to globulin, urine output and pH value and anasarcous degree were observed during 1 to 5 postburn days (PBDs). RESULTS: The infusion fluid amount per hour in A group was 20 approximately 30 ml less than that in B group within 3 PBDs. The infused sodium amount in A group was more than that in B group within 5 PBDs. The FENa in A group was in normal range within 5 PBDs, while that in B group was lower than normal. This might be related to different infusion amounts of water and sodium. CONCLUSION: The homeostasis of burn patients could be significantly affected by the water load and the sodium concentration in the resuscitation solution during early postburn stage.

Adult↗
PubMed2001

[An experimental study on the delayed resuscitation of dogs with burn shock].

OBJECTIVE: To explore the effects of delayed resuscitation on burn shock with ringer's solution. METHODS: Twelve mongrel dogs were randomly divided into control (S, n = 6) and treatment (LR, n = 6) groups. The dogs in LR group were inflicted by 35% TBSA III degree burn and were resuscitated with Lactate Ringer's solution. Urine output in amount of 1 ml.kg-1.h-1, and cardiac output at level of 70% approximately 80% of pre-burn level were referred for the modulation of the speed and amount of fluid infusion. The postburn changes of volumetric load, mean arterial pressure (MAP), LVSP +/- dp/dtmax, CI, DO2 and VO2 during the first 24 hours of resuscitation were observed. RESULTS: The infusion amount of LR solution was 8.87 +/- 1.02 ml/kg per 1% TBSA during the first 24 hours of resuscitation, which was 1.2 times more than that with Parkland formula. Furthermore, the infusion fluid amount within the first 4 hours of resuscitation was (3.63 +/- 0.99) ml.kg(-1).1% TBSA-1, which was 41% of total amount within the first 24 hours. MAP, LVSP, +/- dp/dtmax, CI, DO2 and VO2 reached or approached the levels in S group within 2 hours of resuscitation. CONCLUSION: The infusion amount of Lactate Ringer's solution needed in delayed resuscitation was larger than that in early resuscitation. And the indices of hemodynamics and myocardial mechanics were improved obviously within 2 hours of resuscitation.

Animals↗
PubMed2001

Modified cold storage of rat livers with self-made HYD solution.

OBJECTIVE: To investigate the cold preservation effect on rat livers of a modified storage method with self-made HYD solution. METHODS: The vascular bed of rat livers was expanded with an additional 20 to 40 ml self-made HYD solution/100 g liver. After resection of the liver, the extra HYD solution (expressed as % liver weight) was entrapped via portal infusion by tying off the supra- and infra-hepatic inferior vena cava. Forty rats were randomly divided into four groups including control group with conventional storage method, and 20%, 30% and 40% groups according to the amount of extra HYD solution. We compared the preservation effect of the modified storage method with that of the conventional storage method using an isolated perfused rat liver model. RESULTS: Bile production and all the indices of hepatic microcirculation including portal perfusion pressure, endothelin-1 in the effluent, trypan blue distribution time and histology were significantly superior in the modified method groups compared to those in the control group (P < 0.05). The contents of dihydroxybenzoic acid (DHBA) in the modified method groups were significantly lower than those in the control group (P < 0.05). Liver enzymes activities in the 30% group were markedly lower than those in the control group (P < 0.05). The preservation effect on rat liver in the 30% group was the best among the modified method groups. CONCLUSION: The modified cold storage method is effective and may have potential for clinical application in liver preservation.

Alanine Transaminase↗
PubMed2001

[Thin basement membrane nephropathy: a mutation in COL4A5 gene].

OBJECTIVE: To investigate the mutations in COL4A5 in 3 X-linked thin basement membrane nephropathy families. METHODS: PCR-SSCP analysis were used for 51 exons of COL4A5 gene. If bands shift were found, then automated sequencing was performed after cloning in pGEM-T easy vectors. RESULTS: In one of the three families a glycine to alanine substitution was identified in the collagenous region of the COL4A5 gene, and the mutation cosegregates with hematuria in this family. CONCLUSION: Some of thin basement membrane nephropathy may be due to mutation of COL4A5 gene.

Adolescent↗
PubMed2001

[The VIP-immunoreactive nerve fibers in dental pulp-dentin complex of human premolar].

OBJECTIVE: The expression of vasoactive intestinal peptide (VIP) in dental pulp-dentin complex of human premolar was studied to find out the relationship of distribution and function of VIP positive nerve fibers. METHODS: Fresh health premolars were collected, fixed, decalcified, embedded in paraffin and cut into slices. The slices were treated by immunohistochemical reaction of VIP and quantitative image analysis was then carried out. RESULTS: VIP positive nerve fibers in dental root were in bundle and branches of the nerve fibers were few. The nerve fibers extended in a radiative way from cervical line to the coronal pulp and branched a lot. A part of branches surrounded blood vessels, some terminated in the dental pulp matrix, the others passed odontoblast layer and ran into the predentin. In the coronal pulp the integral optical density was 12.7400 +/- 1.8070, the volume density was 0.0192 +/- 0.0127, the length density was 0.0046 +/- 0.0028; in predentin the integral optical density was 13.0700 +/- 1.9270, the line length was (19.6000 +/- 8.5970) microns. CONCLUSIONS: VIP-immunoreactive nerve fibers exist in human dental pulp-dentin complex. Some fibers surround blood vessels, some terminate in dental pulp matrix and predentin, which suggest that in addition to relating the action of blood vessels, VIP-immunoreactive nerve fibers might also relate to sense.

Adolescent↗
PubMed2001

[Study of quinolones resistance in Escherichia coli, Staphylococcus aureus and Pseudomonas areuginosa].

OBJECTIVE: To investigate the factors of quinolone-resistance mediating in Escherichia coli(E. coli), Staphylococcus aureus (S. aureus) and Pseudomonas areuginosa(P. areuginosa) and examine the characteristic changes and quinolones resistance of these bacteria after exposing them to quinolones, dye-materials, and ultraviolet respectively. METHODS: The agar plate inoculating on surface and tube broth two-fold dilution methods were adopted. RESULTS: Quinolone-resistance was mainly mediated by repeated exposure of the bacteria to low level concentration of quinolone. No quinolone-resistance was found after exposure of the bacteria to ultra-violet and dye materials such as Ethidium bromide and Acry-orange. Among the three kinds of bacteria, E. coli tended to have stable high level of quinolone- resistance(MICs > or = 256 mg/L). S. aureus acquired mediate level of quinolone-resistance(MICs < or = 32 mg/L). P. aeruginosa acquired a high but not stable level(MICs > or = 256 mg/L) of resistance. These bacteria were cultured in the concentration of 1/2 x MIC, 1 x MIC, 2 x MIC, 4 x MIC, 5 x MIC ciprofloxacin, and were compared with those cultured in the same concentration of sparfloxacin and cefotaxime. After being affected by ciprofloxacin, the E. coli underwent apparent morphologic changes, such as becoming wider(2-3 times), longer(10-30 times), thread-like, and fewer in number. These changes were consistent with the increase of quinolone concentrations. The morphologic changes in P. aeruginosa and S. aureus were not so obvious as those in E. coli. Sparfloxacin and cefotaxime mainly led to the decrease in the numbers of bacteria. When the concentration of Sparfloxacin and cefotaxime were 4 x MICs, the changes of P. aeruginosa and S. aureus were less obvious. CONCLUSION: The bacteria's quinolone-resistance is mainly induced by the quinolone itself. The quinolone-resistance is more likely occur in E. coli than in P. aeruginosa and S. aureus. After exposure of the bacteria to ciprofloxacin, E. coli might have most apparent morphologic changes and occurrence resistance.

Anti-Infective Agents↗
PubMed2001

[Changes of soft tissue profile in operated unilateral cleft lip and palate patients after maxillary protraction].

OBJECTIVE: The aim of this study is to investigate effects of maxillary protraction on soft tissue profile in operated operated unilateral cleft lip and palate (UCLP) patients. METHODS: A total of 10 growing UCLP patients (male 7, female 3), age from 8.2 to 12 years old (Average: 10.4 years old), were selected to be treated with maxillary protraction using head gear-chin cap-long hook protraction appliance. The appliance was worn 12-14 hours per day, and the protraction force was 400-500 g each side. The protraction direction was forward and slightly downward. The treatment period was 4.7 months (Average: 5.8 months). Cephalometrics were taken before and after treatment. The changes of soft-tissue profile were studied using the computer-aid X-ray cephalometric analysis. RESULTS: After protraction, the points of Prn, Sn and Ls moved forward significantly. The distance from points Ls to E plane changed significantly from 0.46 mm before treatment to 1.18 mm after treatment. The angle G-Prn-Pg' decreased significantly, and G-Sn-Pg' changed significantly from -0.30 before treatment to 6.260 after treatment. The anterior-posterior position of mandible and lower lip did not change significantly, the changes of angles Cm-Sn-Ls, A'ls/SiLi had no statistical significance. The results indicated that maxillary protraction could make maxilla and upper lip move forward, and the convexity of soft tissue profile improve significantly. CONCLUSION: Maxillary protraction is an effective way to improve the facial deformity of operated UCLP patients. UCLP patients should have early interrupted treatment.

Cephalometry↗
PubMed2001

[Comparison of the post-operative complication in head-neck malignant neoplasms between aged and pre-aged].

OBJECTIVE: To compare the post-operation complication of head-neck malignant tumor in the aged with pre-aged. METHOD: 80 aged and 92 pre-aged cases of head-neck tumor were performed operation. In the aged group, 26 cases were performed with preoperative radiotherapy and 13 cases with postoperative radiotherapy. In the pre-aged group, 40 cases were performed with preoperative radiotherapy and 6 cases with postoperative radiotherapy. RESULT: The incidence of complication in the aged is higher than that in the pre-aged group. Moreover, the post-surgery complications of tumor in head and neck in the aged preferably appear in the cardiopulmones and urology. In contrast, most of the complication in the pre-aged appears in the incision of operation. CONCLUSION: Prior to surgery, we should clear with the situation of patients, and consequently choose appropriate methods of operation. Age does not play an essential role in the decision of the methods of operation.

Age Factors↗