PubMed Health⌕ Search

Biomedical subjects

D Wang

Publications and source records attributed to D Wang.

At least 721 records · Page 40Linked to original sources
PubMed1997

[New digital carotid compressor].

Since 1979, many cases of paraganliomas in the neck have been successfully treated in Tianjin Cancer Hospital. All patients who would be subjected to this operation should undergo preoperative compressing exercises of the carotid artery to promote better circulation of collateral cerebral crossflow. Therefore, a reliable and compact instrument is necessary for the compressing exercises of the carotid artery and the long-term ambulatory monitoring of the compressing effect. This paper introduces our developed instrument, Adjustable and Digital Carotid compressor, which is based on the principle of volume-oscillometric method. During the gradual change in cuff pressure, the amplitude of consecutive arterial volume pulsation associated with pulse pressure shows change characteristically due to the nonlinearity of arterial pressure-volume (P-V) relation. Arterial pressure can be determined by detecting this change in the amplitude, while the arterial volume change can be noninvasively obtained as a function of this transmural pressure, provided that the state of blood flow are determined during this pressure measurement. Considering the simplicity and practicability of this instrument, we have designed a new portable one which consists of pulse pressure transducer, signal amplifier, peak voltage locking circuit and liquid crystal displayer. The validity and accuracy of this instrument and a few examples of its clinical application are presented.

Blood Pressure↗
PubMed1997

Chinese dietary composition and intakes of elements and radionuclides by ingestion.

As update and complement of Chinese Total Diet Study in 1990, a renewing study was conducted during 1992-1993 according to regulated procedure. Contents of 32 elements, including 19 newly determined, in 12 categories of food from 12 provinces were analyzed by NAA or AAS technique and the daily intakes of Chinese adult man were estimated and hygienically evaluated. Meanwhile, a typical survey on dietary composition and intake for difference among 4 age groups and between Spring and Autumn was surveyed too. The results provide important basis for decision for further improvement of Chinese diet from hygienic view point and compilation of physiological characteristics of Chinese Reference Man. At the end of this article, the estimated nationwide average intakes for adult man are compared with those for current ICRP Reference Man.

Adolescent↗
PubMed1997

[The effect of indirect trauma on the goat temporomandibular joint: a histopathologic study].

The aim of this experiment was to study the effect of indirect trauma on the goat temporomandibular joint (TMJ). Trauma to the TMJ was achieved through an impact to the right mandibular angles of 20 goats, their left TMJs were used as a controls. The animals were killed after 2 h, 1 month, 3 months and 6 months. Light microscopic observations revealed that the condyles exhibited an eburnated, eroded surface with osteophytes, the disks were thinned or perforated, and the temporal surfaces were thickened and the lining were separated. These changes were histologically similar to those of the advanced osteoarthritis. This study suggests that the indirect trauma on TMJ lead to osteoarthritis.

Animals↗
PubMed1997

[The culture of TMJ condylar cartilage cells and study on their biological behaviors in vitro].

To investigate the behavoir of TMJ condylar cartilage cells in vitro, the mandibular condylar cartilage cells were harvested from a 5-month-old human fetus by dissection and sequential digestion with 0.25% trypsin and 0.2% collagenase (type II). The isolated cells were cultured in DMEM medium and identified by histochemical and immunohistochemical methods. Cell proliferation, morphology and ultrastructure were observed by phase-contrast microscope, cytologic staining and electronic microscope. In primarily cultured cells, polygonal chondroblast-like cells dominated and they were confirmed by the positive result of immunohistochemical examination for type II collagen and Toludin blue staining. In conclusion, the TMJ cells in this culture system kept their phenotype in vivo.

Cartilage, Articular↗
PubMed1997

[Soft tissue profile changes following surgical correction for Chinese adults with maxillary protrusion].

The soft tissue profile response to anterior maxillary osteotomy for anterior maxillary excess patients was evaluated. Soft tissue change to hard tissue change ratios as well as linear regression equation were calculated from a patient pool representing fifteen anterior maxillary osteotomies. The soft tissue profile response to anterior maxillary osteotomy appeared to be predictable. The results led to the following abbreviated conclusion: posterior movement of subspinale was accompanied by posterior movement of 37% (r = 0.73) at subnasale, 63% (r = 0.87) at superior labial sulcus. Posterior movement of incision superius was accompanied by posterior movement of 75% (r = 0.86) at labrale superius.

Adult↗
PubMed1997

[Experimental study of artificial bone composite with high biological induction in repairing bone defect].

On the basis of the animal model of segmental ultra defects in rabbits, two different composite artificial bones (HA-bBMP-Co and HA-Co) were first used to repair the segmental bone defect respectively in 12 rabbits. The results of X-ray, gross, stereomicroscopic and histological examination were found that HA-bBMP-Co was much faster and much better than HA-Co, involving induction of new bone formation in quality and quantity. It is suggested that there is a widespread prospect in use of HA-bBMP-Co as a bone substitute material.

Animals↗
PubMed1997

[Orthodontic treatment for the surgical correction of mandibular skeletal retrognathism].

The purpose of this paper is to discuss the combining orthodontic treatment that is based on seventeen consecutive patients of severe mandibular skeletal retrognathism who have been treated by orthognathic surgery. Not only the presurgical preparation, but also the presurgical and postsurgical orthodontic treatment and the use of interocclusal splints were introduced. The goals of orthodontic treatment for patients with orthognathic surgery are (1) decompensating the teeth, expanding the upper dental arch, (2) aligning the teeth, (3) leveling the curve of Spee, (4) making the shape and width of upper and lower dental arch harmonious, (5) getting the occlusal equilibrium and fine occlusal contact. The author's experience indicates that: in order to get satisfactory results of esthetics and function, the combination of surgical and orthodontic treatment, the presurgical and postsurgical orthodontic treatment is absolutely necessary and important.

Adolescent↗
PubMed1997

[Ultramicrostructure study of artificial bone composite with high biological induction in repairing bone defect].

The scanning electric microscopy (SEM). X-ray energy graph and Ca, P contents analysis were adopted in studying the mechanism and superiority of two different composite artificial bones (HA-bBMP-Co and HA-Co) to repair segmental bone defect in rabbits. The results indicated that HA-bBMP-Co had a double effects of bone induction and bone conduction. No difference of P content in two weeks after reconstructive surgery was found, but in other periods, there was an obvious difference in Ca and P content between HA-bBMP-Co group and HA-Co group (P < 0.05).

Animals↗
PubMed1997

[Reinnervation of pectoralis major myoflap by the hypoglossal nerve: an experimental study in rabbits].

In order to investigate the morphological, electrophysiological and histochemical characteristics of the pectoralis major myoflaps with original nerve innervation and with hypoglossal nerve reinnervation, after denervation, the model of myoflap transposition to reconstruct the tongue was adopted on 27 New Zealand white rabbits. After the myoflaps were transferred, original nerve innervation (ON), hypoglossal-genioglossus muscle branch nerve implantation (NI) and hypoglossal-genioglossus muscle neuromuscular pedicle implantation (NMP) were performed. The flaps were examined at the intervals of 4, 8, 12 weeks and 16 weeks after operation. The results showed that the denervated myoflaps were reinnervated in NI and NMP, myoflaps contracted when the hypoglossal nerves were stimulated. The histochemical properties of muscle fibers changed. Some type II fibers in the myoflaps transformed into type I fibers, but the pattern of distribution of the muscle fibers displayed mosaic and was similar to that of genioglossus muscle. In terms of speed and scope of reinnervation, the NMP was superior to the NI.

Animals↗
PubMed1997

Application of fuzzy graph theory to evaluation of human cardiac function.

To explore the possibility of application of the fuzzy graph theory to the evaluation of human cardiac function, the cardiac function of two groups of personnel working under special environment were evaluated using the method of fuzzy graph theory. The first group consists of 31 subjects aged 19-21 years. They were classified according to their cardiac function evaluated by the method of maximum support tree. While the second group consists of 24 subjects aged 30-40 years and were classified with fuzzy graph theory on the basis of 6 maximum principal components extracted from 16 physiological indices. Medical explanation of the results is convincing.

Adult↗
PubMed1997

[The antitumour activity of Sinopodophyllum emodi].

This paper has shown the cytocidal effects of alcohol extracts of roots and rhizomes of Sinopodophyllum emodi (Wall.) Ying on human erythroleukemia K562 cells, leukemia L1210 cells, leukemia L7712 cells in vitro, using microculture method for 24 hours. The survival rates on K562 cells in the final concentrations of 10.0, 5.0, 2.5, 1.0 micrograms/ml of the extracts of Sinopodophyllum emodi (WA11.) Ying were 44.17%, 47.63%, 64.43%, 79.57% respectively. The survival rates on L1210 and L7712 cells were 42.84%, 50.73%, 63.21%, 75.10%, and 39.76%, 46.36%, 61.42%, 75.24% respectively. LD50 of the extracts singly i.p. in mice was 76.3-60.6 mg/kg. In vivo, the growth of transplanted mouse tumours (EAC, U14 and Hc) was inhibited by the extracts of Sinopodophyllum emodi (Wall.) Ying with inhibitory rates 42.2%, 38.8%, 41.5% (14.0 mg/kg); 37.8%, 33.3%, 35.6% (7.0 mg/kg).

Animals↗
PubMed1997

[Vertical transmission of hepatitis C virus].

To study the transmission of hepatitis C virus (HCV) from infected mother to their infants, out of 1047 mothers studied, 8 were anti-HCV antibody and 6 were HCV RNA positive as well as 2 mothers who were anti-HCV antibody and HCV RNA positive. 12 mothers and their 12 babies were followed up for 12 months. Only one of 12 infants showed persistently positive for anti-HCV antibody and HCV RNA at 1, 6 and 12 months of age. His HCV type was identical to his mother. These results suggest that vertical transmission is present but not an important route for HCV infection.

Adult↗
PubMed1997

[Determination of 5-fluorouracil in human serum by high performance liquid chromatography].

A reversed-phase HPLC method is described for determination of 5-fluorouracil in human serum. After being extracted with ethyl acetate 5-fluorouracil was analyzed by reversed-phase HPLC column (Zorbax ODS) and UV-detector (273nm) with tegaful as internal standard. The mobile phase was a mixture of methyl alcohol and water (20:80, V:V) at a flow rate of 1mL/min. The linear range was 0.04-50mg/L (r=0.9990) and the detectable limit was 10ng/mL. The average recovery was 96.85% and the coefficients of variation were 4.38% and 5.37% for within-day and day-to-day tests respectively.

Chromatography, High Pressure Liquid↗
PubMed1997

[Analysis of season variation of methyleugenol and safrole in Asarum heterotropoides by gas chromatography].

We established a method for quantitative analysis of methyleugenol and safrole in Asarum heterotropoides by GC to study their season variation. The results showed that the content of methyleugenol in the essential oil of the subterranean part of different seasons was 21%-39%, and that for safrole was 17%-33%. In the upterranean part, methyleugenol was 1.4%-9.6%, and safrole was 0.36%-2.1%. It is clear that methyleugenol and safrole are provided mainly by the subterranean part. The quantity of methyleugenol is the richest in the period of sprouting and after-fruiting, and for the safrole content the richest periods are that of sprouting, blooming and after-fruiting. In the case of upterranean part, the richest time is blooming period both for methyleugenol and safrole, and after blooming they decrease gradually.

Asarum↗
PubMed1997

[Separation of drugs cephalexin, ampicillin, and their biosynthetic precursors L-Phe-L-Cys-D-Val and D-Phe-L-Cys-D-Val by capillary zone electrophoresis].

The separation of drugs cephalexin, ampicillin and their biosynthetic precursors L-Phe-L-Cys-D-Val and D-Phe-L-Cys-D-Val was investigated by using capillary zone electrophoresis in acidic Tris-H3PO4 buffer at pH 2.3. With 50 mmol/L Tris-H3PO4 (pH 2.3) buffer, L-Phe-L-Cys-D-Val and D-Phe-L-Cys-D-Val were only partially separated whereas near baseline separation was achieved between cephalexin and ampicillin. The experiments showed that the addition of beta-type cyclodextrins (beta-CD) to the running buffer can influence the separation selectivity. When beta-CD was used as buffer additives at 12 mmol/L, the separation between L-Phe-L-Cys-D-Val and D-Phe-L-Cys-D-Val was much improved, however, the separation between cephalexin and ampicillin was impaired. When using 50 mmol/L Tris-H3PO4 containing 12 mmol/L DM-beta-CD (pH 2.3) buffer system, all compounds investigated were completely separated. This separation method is simple, fast and easy to operate. It involves only the conventional reagents with a much lower run cost than using HPLC. It is expected to be used in the synthetic process monitoring.

Ampicillin↗
PubMed1997

[Determination of prostaglandinum E1 by fluorescence extinction method].

In this paper, we have studied the fluorescence extinction effect of methyl alcohol by prostaglandinum E1 (PG E1) and found the linear relation between the fluorescence extinction intensity and prostaglandinum E1 concentration. Its linear equation is deltaF = 0.222c + 9.33 x 10(-2)(deltaF: fluorescence extinction value; c: PG E1 concentration microg/mL), correlation coeficient r = 0.99930. The results derived from fluorescence extinction method correspond to the results from violet spectrophotometric method.

Alprostadil↗
PubMed1997

[FT-IR characterization of extracted organic phase containing D2EHPA-lanthanide complexes and effects of adding DMHPA].

FT-IR spectroscopy was used to characterize the extracted organic phase of di (2-ethylhexyl) phosphoric acid-n-heptane containing lanthanide ions Ln3+ (Ln: Y, Pr, Nd, Eu ). It was found that the coordination interaction of heavy lanthanide ions with D2EHPA is stronger than that of light lanthanide ions, and saponification percentage of D2EHPA affects both the absorption frequency and the intensity of P=O bond in the extracted organic phase. Furthermore, the addition of di (1-methylheptyl) phosphoric acid to the D2EHPA extraction system leads to the variation of both peak position and intensity of P=O bond.

English Abstract↗