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Biomedical subjects

G Wang

Publications and source records attributed to G Wang.

At least 667 records · Page 37Linked to original sources
PubMed1996

[The effect of immunoregulation of preparation of Mycobacterium vaccea by nitrogen oxide].

OBJECTIVE: Preparation of M. vaccea on synthesis of nitrite [NO2-, an oxidative end product of nitric oxide (NO) synthesis] of peritoneal macrophages by different condition of animals. METHODS: First, the BALB/c mice were immunized by preparation of M. vaccea and effect of synthesis of NO2- by murine peritoneal macrophage was detected. Second, guinea pigs intraperitonealy challenged with M. tuberculosis H37Rv were immunized by preparation of M. vaccea. RESULTS: It was demonstrated that the effect of synthesis of NO2- of the murine peritoneal macrophage of the immunized mice was significantly higher than the unimmunized mice (P < 0.01) and synthesis of NO2- of peritoneal macrophage of challenged guinea pigs immunized with M. vaccea was significantly lower than that of challenged guinea pigs unimmunized with M. vaccea (P < 0.05). CONCLUSION: The preparation of M. vaccea can not only increase the effect of releasing of NO2- of the peritoneal macrophage, but also regulate the effect of immuno-reaction of the animals so as to reduce the damage of the tissue.

Adjuvants, Immunologic↗
PubMed1996

[The ultrastructural study on radiation injuries of the jaws and soft tissues].

To search for the pathological basis of osteoradionecrosis (ORN), a ultrastructural investigation was performed on some experimental and clinical speciments. The result of this ultrastrcture study shows the nature of ORN is direct injuries of radiation rays to cells; damage of the arterioles are not the main pathologicalbasis, changes of the cytoplasm are more evident than that of nuclei. The changes of blood vessels in soft tissues are more extensive and serious than those of the bone.

Animals↗
PubMed1996

[Clinical primary pulmonary hypertension: a retrospective study of 50 cases].

UNLABELLED: A retrospective clinical study was made in 50 patients (21 male, 29 female, mean age 29 +/- 12 years) with clinical primary pulmonary hypertension (CPPH). The mean interval from symptom onset to diagnosis was 4.07 +/- 3.84 years. The most frequent symptoms were dyspnea and palpitation. Increased pulmonic second heart sound (P2) and right-sided third and/or fourth heart sounds were found in 90% and 30% of patients respectively. Electrocardiography showed right ventricular hypertrophy (86%) and underlying sinus rhythm (100%). Echocardiography showed right ventricular enlargement (78%) and tricuspid regurgitation (44%). Chest film showed prominent main pulmonary artery (90%) and right heart enlargement (82%), but it was normal in 5% of the patients. Hemodynamic study (n = 30) showed three-fold increase in mean pulmonary artery pressure (MPAP) (8.53 +/- 2.00 kPa, 1 kPa = 7.5 mmHg), mild to moderate elevation in mean right atrial pressure (MRAP) (1.60 +/- 0.80 kPa). Patients with functional class (NYHA) 3-4 had relatively higher MPAP (8.53 +/- 2.00 vs 7.73 +/- 3.20 kPa) and MRAP (1.87 +/- 2.40 vs 0.93 +/- 0.93 kPa) than those with class 1-2. Patients with class 3-4 common in female (71%) than in male (29%), P < 0.05. During a mean period of 3.8 years of follow-up in 17 patients, 10 died of right ventricular failure and 3 of sudden death; the MPAPs of the dead were 6.13-9.60 kPa (mean 7.84 kPa). CONCLUSION: CPPH patients had severe symptoms and remarkable physical or laboratory abnormalities when the disease was diagnosed. The long interval from appearance of symptoms to establishment of diagnosis emphasized the importance of being conscious of such a condition.

Adolescent↗
PubMed1996

[Evaluation of different pathologic methods for the diagnosis of sarcoidosis].

The biopsy of different tissues were reviewed in 34 patients with intrathoracic sarcoidosis for determining their value on the diagnosis of sarcoidosis. Biopsy of different tissues was performed by routine method. The transbronchial lung biopsy (TBLB) was done under bronchoscope. The diagnosis was confirmed in 90.9% (10/11) of the biopsies of periphery lymph nodes, 75.0% (3/4) of the scalene nodes' biopsies, 68.4% (13/19) of the transbronchial lung biopsies and 70.6% (12/17) of the bronchial mucosal biopsies (BMB) through fibroptic bronchoscopy. Only 4 in 7 patients were diagnosed through skin biopsies. Kveim test was positive in 5 of 6 patients. Both TBLB and BMB were undertaken in 16 patients. The coincidence ratio between them was as high as 81.3%. The total diagnostic percentage through bronchoscopy was 87.5%. Significant differences were found between the results of TBLB or SMB before and after 1990 (P < 0.05 and 0.01 separately proved by chi 2 test). After 1990, 85.7% of TBLBs and 92.3% of BMBs were diagnostic. According to the study, TBLB and BMB were the methods that were repeatable, highly diagnostic, less invasive, and mutually compensable. They were superior over the other methods in the diagnosis of sarcoidosis. The diagnostic yield could be elevated by the accumulation of experiences and the improvement of techniques. They deserved recommending in the clinical practice.

Adult↗
PubMed1996

[Anti-herpes virus action of ethanol-extract from the root and rhizome of Rheum officinale Baill].

The study has shown that the cytotoxity of ethanol-extract from the root and rhizome of Rheum of ficinale is very low. It shows no cytotoxity even at 20,000 micrograms/ml and on the contrary tends to promote cell growth. Obvious anti-viral action can be observed in cell culture. The minimum inhibition dose for herpes simplex virus (HSV) is 100 micrograms/ml. Also, the extract helps to prevent cells from viral infections and has some direct effect on viral particles.

Animals↗
PubMed1996

[Studies on the mutagenicity of artificial musk].

Artificial musk-raw material, using as a substitute for traditional Chinese medicine musk, a new drug of class I was assessed for mutagenicity. The micronucleus rates of polychromatocyte in the bone marrow of mice were 2.8, 1.3 and 1.0/1000 when the treated dosage was 1800, 700 and 350 mg/kg. The results of Ames test for the strains TA97, TA98, TA100 and TA102 were negative with and without S9 mix when the concentration of artificial musk was 625, 1,250, 2,500 and 5,000 micrograms/plate, respectively. The chromosome aberration rates were 1.0, 0.8, 1.2% when the treated dosage was 360, 180, 90 mg/kg, respectively. The above results proved that no mutagenicity was found for artificial musk.

Animals↗
PubMed1996

[A new speech training method for patients following cleft palate repair].

A new method of speech training in Chinese was established according to investigations of articulatory phonetics and speech pathology of 50 patients following cleft palate operations. All of these patients were examined thoroughly and were considered to have good velopharyngal function. However, in all of them, the articulation score was lower than 70%. 33 of these 50 patients were treated with the method for a period of 22 to 120 days (average 63 days). Results showed that their articulation improved from 38.4% to 89.5% on average, the improvement in speech was highly significant statistically (P < 0.0001). In addition, the question of correct timing for speech therapy is discussed.

Adolescent↗
PubMed1996

[Cloning and identification of the Mycobacterium bovis BCG gene for signal peptide of antigen 85-B].

OBJECTIVE: To clone and identify the Mycobacterium bovis BCG gene for signal peptide of antigen 85-B. METHODS: Using a polymerase chain reaction technique, the signal peptide sequence (position 94 to 211) of antigen 85-B was technique, which is one of the major protein secreted by Mycobacterium bovis BCG (Bacille-Calmette-Guerin). The gene of 117bp fragment was cloned into the SacI and EcoRI sites of pBluecript SK, and its sequence was determined by using T7DNA polymerase kit. RESULTS: The sequence analysis showed that the sequence of 117bp signal peptide was not misincorporated and in 3' end understream of signal peptide the 12 multi cloning sites for foreign gene could be provided by the recombinant plasmid. CONCLUSIONS: The signal sequence of BCG antigen 85-B was cloned into the pBluescript plasmid. The recombinant plasmid was called BCG-S01. According to the genetic information a secreted protein from M. bovis BCG could be utilized in making a useful vaccine vehicle to produce and secrete a vaccinal protein from M. bovis BCG living cells.

Antigens, Bacterial↗
PubMed1996

[The study on noninvasive evaluation of pulmonary artery pressure by the method of pulmonary artery flow spectrum in chronic pulmonary disease].

OBJECTIVE: Pulmonary artery flow spectrum of patients with chronic pulmonary disease were studied in order to find excellent Doppler Indexes reflected pulmonary artery pressure, and establish multiple regression equation for estimating pulmonary artery pressure more accurately. METHODS: During catheterization, 54 patients with chronic pulmonary disease were examined by echocardiography. Fourteen Doppler indexes of spectrum were compared with the pulmonary artery pressure by catheter simultaneously, and multiple regression equations were taken. RESULTS: There were significant correlation between Doppler indexes PEP/AcT, AcVm, VI/(QTxVmax), RVET/QT and pulmonary artery pressure. Two multiple regression equations were deduced: PAPs (kPa) = [9.4 x PEP/AcT-1.4 x AcVm-126.1 x VI/(QT x Vmax) + 75] divided by 7.5 and PAPm (kPa) = [7.5 x PEP/AcT-1.2 x AcVm- 87.7 x VI/(QT X Vmax) + 48] divided by 7.5. CONCLUSIONS: Above two regression equations could be used to noninvasively evaluate pulmonary artery pressure in patients with chronic pulmonary disease.

Adult↗
PubMed1995

NH2-terminal truncation of skeletal muscle troponin T does not alter the Ca2+ sensitivity of thin filament assembly.

To investigate how Ca2+ binding to troponin C regulates muscle contraction, the Ca(2+)-sensitive properties of thin filament assembly were studied as the tropomyosin binding, NH2-terminal region of troponin T was progressively shortened. Troponin complexes were prepared that contained skeletal muscle troponin C, troponin I, and either intact troponin T (TnT) (residues 1-259) or fragment TnT-(70-259), TnT-(151-259), or TnT-(159-259). In the absence of Ca2+ their respective affinities for pyrene-labeled tropomyosin were 2.3 x 10(7) M-1, 1.2 x 10(7) M-1, 1.9 x 10(5) M-1, and 1.9 x 10(5) M-1. Ca2+ had only a small effect on these affinities: 1.1 x 10(7) M-1 for whole troponin, 2 x 10(5) M-1 for troponin-(151-259), and 2.8 x 10(5) M-1 for troponin-(159-259). Forms of troponin that bound weakly to tropomyosin in the absence of actin increased the actin affinity of tropomyosin only 2-3-fold, even in the absence of Ca2+; weak binding of troponin to tropomyosin correlated with weak effects on tropomyosin-actin binding. In contrast, whole troponin had an approximately 500-fold effect on tropomyosin binding to actin, regardless of whether Ca2+ was present. The small effect of Ca2+ on the energetics of thin filament assembly is not attributable to the amino-terminal region of troponin T. The results suggest that Ca2+ causes the interaction between actin and the globular region of troponin to switch between two energetically similar states.

Actin Cytoskeleton↗
PubMed1995

Phosphatidylcholines with sn-1 saturated and sn-2 cis-monounsaturated acyl chains. Their melting behavior and structures.

Recently, we have shown by high resolution differential scanning calorimetry that the position of a cis double bond (delta-bond) in a series of 1-stearoyl-2-octadecenoyl- phosphatidylcholines can affect the phase transition temperature (Tm) or enthalpy (delta H) of the gel-to-liquid crystalline phase transition of this series of lipids in the following manner. The value of Tm (or delta H) is minimal when the delta-bond is positioned at C(11) in the sn-2 acyl chain; in addition, this value increases steadily as the delta-bond migrates toward either end of the acyl chain, resulting in a symmetrical, inverted bell-shaped profile (Wang, Z.-q., Lin, H.-n., Li, S., and Huang, C. (1995) J. Biol. Chem. 270, 2014-2023). In this communication, we have further demonstrated the inverted bell-shaped profile of Tm using 1-arachidoyl-2-eicosenoyl-phosphatidylcholines. In addition, we have extended the lipid series of 1-stearoyl-2-octadecenoyl-phosphatidylcholines to include 1-arachidoyl-2-octadecenoyl- phosphatidylcholines and 1-behenoyl-2-octadecenoyl-phosphatidylcholine, each series with a delta-bond at varying carbon position of 6, 7, 9, 11, 12, and 13. Calorimetric results obtained with these three series of lipids indicate that the inverted bell-shaped curve shifts toward higher temperatures in a nonuniform manner as the saturated sn-1 acyl chain length increases from 17 to 19 and then to 21 C-C bond lengths. Specifically, the Tm (or delta H) values are nearly identical for these cis-monoenoic lipids when their delta-bonds are positioned at C(13). Based on the height of the rotational energy barrier obtained with molecular mechanics calculations, it is evident that the rotational flexibility of the single C-C bond adjacent to the delta-bond in 1-stearoyl-2-octadecenoyl-phosphatidylcholine increases as the delta-bond migrates from C(9) to C(13). The differential scanning calorimetry results obtained with the three series of lipids can thus be attributed to an increase in the rotational flexibility of the short chain segment succeeding the C(14) atom in the sn-2 octadecenoyl chain. In this communication, we also propose that in the gel-state bilayer of sn-1 saturated/sn-2 cis-monounsaturated phosphatidylcholine the entire length of the shorter segment of the sn-2 acyl chain acts as a structural perturbing element; hence, it is mainly responsible for the large lower Tm of the monoenoic lipid relative to the saturated counterpart. Finally, two general equations relating Tm with the structural parameters of cis-monoenoic phosphatidylcholines are presented.(ABSTRACT TRUNCATED AT 400 WORDS)

Calorimetry, Differential Scanning↗
PubMed1995

Altered repair of targeted psoralen photoadducts in the context of an oligonucleotide-mediated triple helix.

Oligonucleotides can bind as third strands of DNA in a sequence-specific manner to form triple helices. Psoralen-conjugated, triplex-forming oligonucleotides (TFOs) have been used for the site-specific modification of DNA to inhibit transcription and to target mutations to selected genes. Such strategies, however, must take into account the ability of the cell to repair the triplex-directed lesion. We report experiments showing that the pattern of mutations produced by triplex-targeted psoralen adducts in an SV40 shuttle vector in monkey COS cells can be influenced by the associated third strand. Mutations induced by psoralen adducts in the context of a TFO of length 10 were the same as those generated by isolated adducts but were found to be different from those generated in the presence of a TFO of length 30 at the same target site. In complementary experiments, HeLa whole cell extracts were used to directly assess repair of the TFO-directed psoralen adducts in vitro. Excision of the damaged DNA was inhibited in the context of the 30-mer TFO, but not the 10-mer. These results suggest that an extended triple helix of length 30, which exceeds the typical size of the nucleotide excision repair patch in mammalian cells, can alter repair of an associated psoralen adduct. We present a model correlating these results and proposing that the incision steps in nucleotide excision repair in mammalian cells can be blocked by the presence of a third strand of sufficient length and binding affinity, thereby changing the pattern of mutations. These results may have implications for the use of triplex-forming oligonucleotides for genetic manipulation, and they may lead to the use of such oligonucleotides as tools to probe DNA repair pathways.

Animals↗