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Biomedical subjects

Z M Li

Publications and source records attributed to Z M Li.

At least 55 records · Page 3Linked to original sources

Plasma gamma-aminobutyric acid in experimental fulminant hepatic failure of rats and its diagnostic value in hepatic encephalopathy.

The plasma concentration of gamma-aminobutyric acid (GABA) was measured by radioreceptor assay in galactosamine (GalN)-induced Wistar rat model of fulminant hepatic failure (FHF). The results of sequential observations in 10 FHF rats showed that the plasma GABA concentration doubled 24 hours after GalN injection, while there was no obvious clinical evidence of hepatic encephalopathy (HE). In overt HE 48 hours after the administration of GalN, the plasma concentration of GABA reached the peak value of 9,744 +/- 1,661 pmol/ml, which was 12 times as high as that before GalN injection. The consciousness, plasma concentration of GABA and SGPT activity became normal 120 hours after GalN injection. It is suggested that determination of plasma concentration of GABA is of value in the diagnosis of HE.

Alanine Transaminase↗

[Diagnosis of myocarditis with endomyocardial biopsy].

Endomyocardial biopsy (EMB) was performed in 24 cases suspected of having myocarditis and 42 cases with cardiac symptoms and signs of unknown etiology. There was an obvious correlation between the clinical manifestations and the pathological findings in cases suspected of having myocarditis (r = 0.5296, P less than 0.005). The ratio of correspondence was 78.8%. It is shown that EMB is more sensitive than 201TI myocardial imaging in diagnosing myocarditis and serial EMB can follow its clinical process closely. Moreover, EMB can discriminate myocarditis from myocardiopathy.

Biopsy↗

[Basic research on endomyocardial biopsy].

To determine the risk of biopsy in different parts of heart and the artifacts of histomorphology, right heart endomyocardial biopsy in eight dogs were done. The result showed no tamponade occurred even 53 pieces of heart muscles were got from right ventricular free wall. In contrast, biopsies on right atrial free wall had higher risk in causing tamponade. It was confirmed by autopsy and histomorphology that endomyocardial biopsy could cause heart muscle damage. The artifacts caused by biopsy of normal beating heart muscle include: contraction bands (21.8%), widen of intracellular space (100%), interstitial edema (78%) and interstitial bleeding (53%). The results of the patients of right ventricular endomyocardial biopsy may provide practical value in the application of endomyocardial biopsy.

Animals↗

Comparison of type 2 and type 6 fimbriae of Bordetella pertussis by using agglutinating monoclonal antibodies.

Two types of fimbriae have been identified on the pathogenic gram-negative organism Bordetella pertussis. Monoclonal antibodies to these fimbriae were produced to better understand the role of fimbriae as serotype-specific agglutinogens and to investigate the antigenic relationship between these fimbriae. Three monoclonal antibodies were identified that specifically agglutinated B. pertussis cells containing the U.S. Reference Factor 2 agglutinogen, and six monoclonal antibodies were produced that agglutinated only those strains containing the U.S. Reference Factor 6 agglutinogen. Indirect immunofluorescence studies and immunogold electron microscopy demonstrated that these monoclonal antibodies bind to an outer membrane component on serotype-specific strains of B. pertussis. All of the monoclonal antibodies reacted with native or partially assembled type-specific fimbriae but not with monomeric fimbrial subunits as indicated by Western blot (immunoblot) analysis. The fimbrial agglutinogens recognized by the monoclonal antibodies were also uniquely reactive with either U.S. Reference Factor 2 or 6 antiserum (Eldering agglutinogen 2 or 6 polyclonal antiserum) in an indirect ELISA. No cross-reactivity of the monoclonal antibodies with the unrelated fimbriae was observed in any of the comparative immunological studies. Some of the monoclonal antibodies agglutinated certain strains of B. bronchiseptica, suggesting that this closely related species can contain antigenically similar fimbriae. These monoclonal antibodies should prove useful for further structural and functional analysis of Bordetella fimbriae and for studies on the role that these antigens play in prevention of infection and disease.

Agglutination Tests↗

Identification of a 69-kilodalton nonfimbrial protein as an agglutinogen of Bordetella pertussis.

Cells of Bordetella pertussis BP353, a nonfimbriated Eldering serotype 1.3 strain, were used as an immunogen to produce three monoclonal antibodies, BPE3, BPD8, and BPE8, that agglutinated the immunizing cells, as well as certain other nonfimbriated and fimbriated serotype 3-containing B. pertussis strains. The antibodies did not agglutinate serotype 1 or nontypable B. pertussis cells. These monoclonal antibodies specifically detected a 69-kilodalton (kDa) band on Western blots (immunoblots) containing whole B. pertussis cell lysates of Eldering agglutinogen serotypes 1.3, 1.3.6, 1.2.3.4, and 1.2.3.4.6. This 69-kDa antigen was released from the bacteria by cell incubation for 60 min at 60 degrees C, and it was purified by affinity chromatography with a BPE3-agarose affinity matrix. Purified material was used to produce a polyclonal antiserum that agglutinated all nonfimbriated and fimbriated B. pertussis cells containing serotype 3 agglutinogen. Immunogold electron microscopy and indirect immunofluorescence studies demonstrated that it is an outer membrane constituent but nonfimbrial in appearance. BPE3 did not detect purified fimbriae on Western blots, and antibodies to these fimbriae did not bind to the 69-kDa component. Although B. bronchiseptica and B. parapertussis cells were not agglutinated by the monoclonal antibodies, antigenically similar proteins were detected in extracts of the bacteria. These results identify the 69-kDa protein as a nonfimbrial agglutinogen present on all virulent strains of B. pertussis. The monoclonal antibodies described here should be useful for further studies on the structure and function of this protein.

Agglutinins↗

Agglutinating monoclonal antibodies that specifically recognize lipooligosaccharide A of Bordetella pertussis.

Monoclonal antibodies that specifically agglutinate strains of Bordetella pertussis having serotype 1 agglutinogen were uniquely reactive with the electrophoretically slow-migrating A form of lipooligosaccharide. These monoclonal antibodies should be useful for the structural analysis of B. pertussis lipooligosaccharide and for the establishment of a better-defined serogroup for Bordetella species.

Agglutinins↗

Thalassemia in the Silk Road region of China.

This paper summarizes data obtained during a screening program involving 11,563 persons from the Silk Road region in China. The mean incidence of thalassemia is 1.62% with an increase from east to west. The incidence in the Hui population (3.01%) is higher than in Kazaks (2.92%), and in Uygur (2.22%). The Han population also has a higher incidence (0.98%) than seen for other regions in Northern China. The thalassemias observed are classified into seven groups; beta-thalassemia accounts for 89.48% of the total, and alpha-thalassemia for 10.52%.

China↗

Structural and functional properties of a 69-kilodalton outer membrane protein of Bordetella pertussis.

A-69-kDa outer membrane protein present on virulent Bordetella pertussis cells is recognized by the agglutinating monoclonal antibodies BPE3, BPD8, and BPE8. The amino acid composition of this protein, purified from heat extracts of B. pertussis BP353 cells, is different from that of the two major fimbrial antigens of B. pertussis, which is consistent with its being a nonfimbrial protein based on other criteria. Western blot analysis using the monoclonal antibody BPE3 demonstrated that a slightly larger but antigenically cross-reactive protein is also expressed by Bordetella bronchiseptica and Bordetella parapertussis. In addition, a large molecular weight species of about 180-kDa is found in outer membrane extracts of B. bronchiseptica which may represent a precursor form of the protein or indicate that the protein can exist as an oligomer. The monoclonal antibody BPD8 directed against the 69-kDa protein almost completely inhibited the enzymatic activity of adenylate cyclase purified from B. pertussis and also inhibited the intoxication of mammalian cells by this enzyme. Since little enzymatic activity was found associated with the purified 69-kDa protein, these data suggest a role for the 69-kDa protein in regulating the adenylate cyclase toxin of B. pertussis. An additional monoclonal antibody directed against the 69-kDa protein, BPE8, decreases lymphocytosis and delays death in mice receiving a respiratory challenge of virulent B. pertussis cells. These studies suggest that further investigation into the role of this protein as a protective antigen and vaccine candidate is warranted.

Adenylyl Cyclase Inhibitors↗

In vitro in vivo studies on removal of middle molecules by macroporous resins.

Various types of macroporous resin beads were screened for the adsorption of middle molecules in vitro. In order to obtain high adsorption capacity, the pore size of the resin should be large enough to allow diffusion of the middle molecules. The adsorption capacity of X-5 resin for Vitamin B12, inulin and cytochrome C was 35.3 mg/g, 1.2 mg/g and 42.9 mg/g respectively in vitro tests. Hemoperfusion with acute renal failure rat model showed good clearance (0.35 +/- 0.25) with X-5 resin for middle molecules.

Acute Kidney Injury↗

Effect of activated charcoal on endotoxin adsorption. Part I. An in vitro study.

An in vitro study by using cross-linked agarose coated activated charcoal (CAAC-II) as adsorbent was conducted. Endotoxin was quantitatively measured by chromogenic method of limulus lysate test. Results of the study demonstrated that endotoxin was fairly efficiently removed by CAAC-II. It may therefore be possible for effective adsorption of endotoxin in vivo studies and warrant further experimental study for CAAC-II hemoperfusion in clinical endotoxemia.

Adsorption↗

Effect of hemoperfusion of cross-linked agarose coated activated charcoal (CAAC-II) on T-lymphocyte function in rats and guinea pigs.

Blood of rats and guinea pigs on cross-linked agarose coated activated charcoal (CAAC-II) hemoperfusion was analyzed over a follow-up period of 48 hours for the capacity of T-lymphocyte to transform under the stimulation of mitogen (PHA) in vivo and in vitro respectively. In the rate hemoperfusion, the in vivo T-lymphocyte transformation and lymphocyte count of peripheral blood were involved. In guinea pigs, the lymphocyte cultures were labelled with 3H-TdR and the radioactive incorporation was measured on the liquid scintillation counter. Our results revealed that the T-lymphocyte transformation function remained unchanged after 60-minute CAAC-II hemoperfusion although there was a transient and incomplete suppression of the T-lymphocyte transformation function both in vivo and in vitro immediately after the anesthesia and operation with blood vessel cannulation. The peripheral blood lymphocyte count also remained stable during the 60-minute CAAC-II hemoperfusion on rats and guinea pigs. We concluded that the charcoal hemoperfusion can be used as an important method of treatment for drug intoxication, uremia and hepatic coma with no harm to the body's immune function.

Animals↗