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Biomedical subjects

B Wang

Publications and source records attributed to B Wang.

At least 883 records · Page 49Linked to original sources
PubMed1990

[States of dentine surface and interface between dentine and coupling agent].

In order to research the states of dentine surface and dentine surface primed with coupling agent, we used microscope, transmission electron microscope (TEM) and solid fluorescence method. Observed under microscope, patterning of dentinal tubules and their poles was very explicit; through the view of interface between coupling agent adsorbed and human dentine powder by TEM, it was revealed that the coupling agent was adsorbed onto the dentine surface as if it "grew out" of the dentine surface; through examination of interface between the coupling agent adsorbed and dentine surface by fluorescence spectrum, which differed from that of the coupling agent or dentine surface, i.e., this fluorescence spectrum of interface changed obviously (red shift). This phenomenon indicated that there was a chemical reaction occurring between tooth surface and adsorbed coupling agent. Therefore we can conclude that the three examinations are necessary to provide the argument for establishment of chemical bonding mechanism between dentine and coupling agent.

Adhesives↗
PubMed1990

False-positive coding for acute myocardial infarction on hospital discharge records: chart audit results from a tertiary centre.

Hospital medical records staff enter diagnostic codes on charts using the International Classification of Diseases (Clinically Modified), Ninth Revision (ICD-9-CM). In a downtown Toronto tertiary hospital, 209 consecutive charts coded for acute myocardial infarction as the primary diagnosis in 1987-88 were reviewed. Criteria for documentation of acute myocardial infarction included symptomatic, electrocardiographic and enzymatic elements. Forty-three (21%) false-positives, ie, charts coded acute myocardial infarction where criteria were not fulfilled, were found (95% confidence interval 15 to 26%). Physician diagnosis of acute myocardial infarction appeared on the face sheet of 30 of the false-positive cases. Common reasons for false-positive face sheet entries and chart coding were acute myocardial infarction within the previous eight weeks with transfer or readmission for coronary angiography and other procedures; and presumed acute myocardial infarction on admission subsequently unproven or disproved. The false-positive proportion was similar to a Canadian study drawing on charts from hospitals of various sizes in 1977, lower than in recent reports from various American tertiary teaching hospitals (P less than 0.0001), and higher than in five Boston area community hospitals (P = 0.0005) where procedure-related transfers or readmissions of previous acute myocardial infarction patients were less likely. This audit lends credence to arguments that changes are needed in ICD-9-CM codes for acute myocardial infarction and in the assignation of reasons for hospitalization.

Canada↗
PubMed1990

Observations on the treatment of coronary heart disease by kuo guan qu yu ling.

Based on the therory of promoting flow of qi and dispersing blood stasis, the KUO GUAN QU YU LING coronary--dilating and stagnation--dispersing) powder in capsules were prepared for the treatment of 60 cases of coronary heart disease. After a 30 day course of treatment, cardiac ischemia was improved in 64.7% and the symptom of angina pectoris was relieved in 61.7% of the patients. This drug also acted to reduce blood lipids and to improve left cardiac function. Pharmacological study indicated that this preparation improved the tolerance of cardiac muscle against anoxia and prevented ventricular fibrillation and cardiac damage from ischemia.

Adult↗
PubMed1990

[406 cases of angina pectoris in coronary heart disease treated with saponin of Tribulus terrestris].

Coronary heart disease (CHD) was treated with saponin of Tribulus terrestris. According to 406 cases of clinical observation and a cross test (67 cases treated with Yufen Ningxin Pian as control), the results showed that the total efficacious rate of remission angina pectoris was 82.3%. It was higher than the control group with a total effective rate of 67.2% (P less than 0.05). The total effective rate of ECG improvement (52.7%) was even higher than that of the control group (35.8%). It is shown that saponin of Tribulus terrestris has the action of dilating coronary artery and improving coronary circulation, and thus has better effects on improving ECG of myocardial ischemia. If taken for a long time, it has no adverse reaction on blood system and hepatic and renal functions. Neither does it have side effects. It is one of the ideal medicines to treat angina pectoris.

Adult↗
PubMed1990

[Further observation on the ultrastructural characteristics of Trichomonas vaginalis].

In longitudinal sections, T. vaginalis visualized by TEM was round or ovoid with an ovoid nucleus situated close to the anterior one-third of the body. There was an independent and well-developed Golgi complex dorsal to the nucleus and parabasal filaments. The anterior end of the cell had a blepharoplast complex which consisted of three parts, i.e., periflagellar canal, C-shaped structure of the pelta in the wall of periflagellar canal and five blepharoplasts. Four anterior flagella and one posterior flagellum were extended respectively from each of the blepharoplasts, simultaneously with one costa and two parabasal filaments. The axostyle was divided into three parts, i.e., capitulum, trunk and caudal. The spoon-shaped axostylar capitulum originated from the peltar-axostylar junction was composed of many microtubules and extended around the side of the nucleus posteriorly and turned itself at the end of the nucleus forming an axostylar trunk which projected externally in the form of a spicule.

Animals↗
PubMed1990

[Treatment of ischemic cerebral stroke with isovolemic hemodilution].

The results of using isovolemic hemodilution in the treatment of 71 cases with acute cerebral infarction showed that the overall effective rate increased by 58.3% and the total number of cases with no effect and with worsening decreased by 89.4% while in 43 comparable cases treated by the conventional methods the overall response was much less satisfactory. Some indices of blood rheology and microcirculation during hemodilution improved obviously. The indications for and the precautions needed in using the hemodilution were discussed.

Aged↗
PubMed1989

Reconstitution of Escherichia coli DNA photolyase with various folate derivatives.

DNA photolyase from Escherichia coli contains both flavin and pterin. However, the isolated enzyme is depleted with respect to the pterin chromophore (0.5 mol of pterin/mol of flavin). The extinction coefficient of the pterin chromophore at 360 nm is underestimated by a method used in earlier studies which assumes stoichiometric amounts of pterin and flavin. The extinction coefficient of the pterin chromophore, determined on the basis of its (p-aminobenzoyl)polyglutamate content (epsilon 360 = 25.7 x 10(3) M-1 cm-1), is in good agreement with that expected for a 5,10-methenyltetrahydrofolate derivative. Also consistent with this structure, the pterin chromophore could be reversibly hydrolyzed to yield a 10-formyltetrahydrofolate derivative or reduced to yield a 5-methyltetrahydrofolate derivative. The isolated enzyme could be reconstituted with various folate derivatives to yield enzyme that contained equimolar amounts of pterin and flavin. Similar results were obtained in reconstitution studies with the natural pterin chromophore, with 5,10-methenyltetrahydrofolate, and with 10-formyltetrahydrofolate. The results show that the polyglutamate moiety, previously identified in the natural chromophore, is not critical for binding. Reconstitution with the natural pterin chromophore did not affect catalytic activity. The latter is consistent with our previous studies which show that, although the pterin chromophore acts as a sensitizer in native enzyme, it is not essential for dimer repair which can occur at the same rate under saturating light with flavin (1,5-dihydro-FAD) as the only chromophore.

Deoxyribodipyrimidine Photo-Lyase↗
PubMed1989

[The structure of glyuranolide, a new triterpene of Glycyrrhiza uralensis Fisch].

Using a medium pressure liquid chromatographic system, a new triterpene lactone named glyuranolide [3 beta, 22 alpha-dihydroxy-11-oxo-delta 12-oleanene-27 alpha-methoxy carbonyl-29-oic acid (29, 22 alpha-) lactone.] was isolated from the crude sapogenins of Glycyrrhiza uralensis Fisch. Its structure was elucidated by IR, UV, FAB-MS, and various NMR spectra (including NOE, BBD, INEPT, SR, COSY, NOESY etc.).

Chemical Phenomena↗
PubMed1989

[Epidermal Langerhans cells in cholesteatoma].

This article introduces an indirect immunologic fluorescent technique employing the monoclonal antibody OKT-6 to label and demonstrate Langerhans cells (LCs). These epidermal LCs were identified in normal tympanic membranes, canal skin and cholesteatoma. It was suggested that the only apparent difference among them was an increased number and distribution of LCs located at various levels within the epithelium in the cholesteatoma matrix. The LCs in the cholesteatoma matrix displayed morphologic features similar to those in contact hypersensitivity state.

Adolescent↗
PubMed1989

[Projection of afferent impulses from the brachial plexus and sciatic nerve to the corpus striatum in pigeons].

The corpus striatum were systematically explored by recording averaged potentials elicited by stimulation of the brachial plexus and sciatic nerve in 53 pigeons. It was found that the projection areas of brachial afferents were located within the neostriatum, the hyperstriatum and the ectostriatum. The sciatic projection areas overlap with the brachial projection areas in the neostriatum and a part of the hyperstriatum. Moreover, the brachial and sciatic projection are as in the striatum receive the inputs from both sides of the body. We suggest that the somatic projection areas of fore- and hindlimb are distributed diffusely in the striatum of the pigeon. That the projection area of forelimb is relatively larger is probably related with functional differentiation of the forelimb. Furthermore, the convergence of afferent impulses originating in the different regions of the body within the same brain area may be important for the integration of limb activities in pigeon.

Afferent Pathways↗
PubMed1988

Overlapping transcriptional units on the same strand within the murine beta-glucuronidase gene complex.

We have identified and partially characterized a complex transcriptional unit within the murine beta-glucuronidase gene complex on chromosome 5. On the same strand and within the first intron of the beta-glucuronidase structural gene, Gus-s, we observe an RNA polymerase II promoter motif. That sequences within this carefully defined region can promote RNA polymerase II transcription is supported by results of in vitro transcriptional runoff assays and by expression of a linked reporter gene in both cultured cells and transgenic mice. Results of RNA blot hybridization and S1 nuclease protection studies reveal a 2.2-kilobase processed liver transcript which is initiated just downstream of the promoter motif and sharing little, if any, sequence with the 2.7-kilobase beta-glucuronidase mRNA. Both RNA species are found in liver where beta-glucuronidase is known to be expressed in all cell types. To our knowledge, this is the first description of eukaryotic mRNAs from overlapping transcription units which share the same strand yet exhibit little, if any, sequence similarity. A possible regulatory relationship between these overlapping structural genes is discussed.

Animals↗
PubMed1988

Rapid identification of bacterial genes that are lethal when cloned on multicopy plasmids.

A procedure to identify genes that are lethal when cloned on multicopy plasmids was developed. It depends on the ability of mini-Mu plasmid elements to be used for both in vivo cloning and generalized transduction of enterobacterial genes. The feasibility of this procedure was demonstrated by using the tetA gene of Tn10, which is lethal when in multiple copies in the presence of 25 micrograms of tetracycline per ml.

Cloning, Molecular↗