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Biomedical subjects

G S Wang

Publications and source records attributed to G S Wang.

18 recordsLinked to original sources

[Association of chromosomal telomere DNA with nuclear matrix in HeLa cells].

Nuclear matrix from HeLa cells was gently extracted with a high salt solution and treated with DNase I. DNA that remained associated with the nuclear matrix (N. M. DNA) and DNA fragments released into the supernatant (SN.DNA) were isolated respectively and dot hybridized to human telomere sequence (AGGGTT/TCCCAA)40 probe. As the time of DNase I treatment was extended, the amount of N. M. DNA decreased while the concentration of telomere sequence in N.M. DNA proportionally increased. These preliminary results suggest that the telomere sequence is tightly bound to nuclear matrix in HeLa cells.

Base Sequence

Sputum occult blood screening for lung cancer. Stage II screening of 14,431 subjects.

Sputum occult blood screening (SOBS) for lung cancer was performed in outpatients with suspected lung cancer. A total of 1011 patients were seen. Among them, 604 patients were found to be negative for SOBS, and 407 were found to be positive. The false-negative rate was 3.97% (24 of 604), and the opposite positive rate was 19.65% (80 of 407). A total of 14,431 normal subjects over 40 years of age were screened by SOBS. In the series, 1942 specimens were found to be positive. Among the 1942 patients, 31 were found to have definite cancer cells.

Adult

Antigenic domains on the U1 small nuclear ribonucleoprotein-associated 70K polypeptide: a comparison of regions selectively recognized by human and mouse autoantibodies and by monoclonal antibodies.

Antigenic regions on the U1 small nuclear ribonucleoprotein (snRNP)-associated 70K polypeptide recognized by human and mouse autoantibodies or by monoclonal antibodies were identified and compared. Using a set of 70K fusion proteins as antigen in enzyme-linked immunosorbent assay and immunoblotting revealed that serum autoantibodies of human and of MRL/Mp mouse origin recognized a common region of the 70K polypeptide. Monoclonal anti-70K antibodies derived from a patient with mixed connective tissue disease, from an autoimmune MRL/Mp mouse, and from a BALB/c mouse immunized with purified U1 snRNP were all shown to bind to a part of the 70K polypeptide rich in charged residues and different from the region recognized by most human and MRL/Mp mouse serum autoantibodies.

Animals

Radiotracer study on residues and residue distribution of zineb in plant-soil system.

In view of the widespread use of zineb on food plants and the toxicity of one of its metabolites, ETU, a study on the residues and residue distribution of zineb and ETU in plant-soil systems was carried out. The half-life values for total zineb residues on egg-plant leaves and in soil were observed to be over three and two weeks, respectively. Egg-plant skin contained higher amount of zineb residues than the fruit pulp. Washing with water greatly reduced zineb residue levels, especially those in the fruit skin. Compared with zineb, ETU is much easier to be uptaken by plants and to leach into deeper layer of soil due to its high water solubility. Therefore, attention should be paid to the contents of ETU in zineb formulations as impurity and formation of ETU in the environment.

Carbon Radioisotopes

Enzyme-linked immunosorbent assay using isolated (U) small nuclear ribonucleoprotein polypeptides as antigens to investigate the clinical significance of autoantibodies to these polypeptides.

In order to investigate the clinical significance of autoantibodies to individual U small nuclear ribonucleoprotein (snRNP) polypeptides, an enzyme-linked immunosorbent assay (ELISA) using isolated 68K, A, B/B', and D polypeptides from purified U1 snRNP was developed. The ELISA levels of IgG antibodies were positively correlated with results of immunoblotting and hemagglutination. In patients positive for antibodies to ribonucleoprotein, IgG anti-68K reactivity was associated with active mixed connective tissue disease, and in particular with myositis and esophageal hypomotility. IgG B/B' and D polypeptide reactivities were associated with systemic lupus erythematosus and renal disorder. Raynaud's phenomenon was infrequent in patients with high IgG B/B' and D polypeptide reactivities. Pleuritis/pericarditis was associated with the IgG B/B' polypeptide reactivities. In longitudinal studies, ELISA levels of IgG antibodies against these polypeptides changed in parallel with disease activity.

Animals

Medical uses of mylabris in ancient China and recent studies.

Mylabris is the dried body of the Chinese blister beetle. The species used in medicine are Mylabris phalerata and M. cichorii. The use of mylabris as a traditional medicine in China can be traced back more than 2000 years, and it is still used as a folk medicine today. In recent studies, it has been found that mylabris possesses antitumor properties, increases the number of leucocytes, and has irritant effects on the urinary organs. The active constituent of mylabris is cantharidin. The synthesis of cantharidin is rather difficult. In order to find a less toxic analogue of cantharidin, its hydrolytic compound, disodium cantharidate, and its demethylated form, norcantharidin, were prepared. By biochemical and biological methods, it was found that these compounds may affect cancer cells in several ways. In clinical studies, antihepatoma effectiveness sequentially increased from cantharidin to disodium cantharidate to norcantharidin. Disodium cantharidate showed less urinary irritation than cantharidin while norcantharidin showed little to no such irritation. It appears that the two methyl groups of cantharidin are not the main functional groups for antitumor activity and for the stimulation of bone marrow but are associated with urinary irritation. Hydrocantharidimide, methylcantharidimide and dehydronorcantharidin have also been studied. All these compounds, except the last one, have been produced as antitumor agents in China. Since demethylated cantharidin may be prepared by total synthesis, it may be more suitable for medical investigation than cantharidin itself.

Animals

[Studies on the chemical constituents of the roots of Aralia continentalis Kitag].

Seven compounds were isolated from the roots of Aralia continentalis. Four of these compounds were identified as ent-kaur-16-en-19-oic acid, beta-sitosterol glucoside (daucosterol), beta-sitosterol and 16 alpha-hydroxy-(-)-kauran-19-oic acid. It is the first time that 16 alpha-hydroxy-(-)-karan-19-oic acid and beta-sitosterol glucoside were isolated from this plant.

Diterpenes

A study of the immunofunction in patients of coronary heart disease with the fundamental deficiency and outward excess syndrome.

The fundamental deficiency and outward excess syndrome of coronary heart disease can be classified into Qi Yang deficiency with blood stasis (QYD) and Yin deficiency with blood stasis (YD). The patients showed disturbances in immunofunction manifested as marked increase of serum IgG, CIC, IC-IgG and IC-C3 levels and the percentage of B cells in the peripheral blood, while the percentages of OKT3+, OKT4+ and OKT8+ cells markedly decreased, especially the percentage of OKT8+ cells, resulting in an increase of the ratio of T4/8 and imbalance between TS and TH. The authors deem that the fundamental deficiency of coronary heart disease is related to the low cellular immunity, especially the imbalance between TS and TH cells, while outward excess of coronary heart disease is related to hyperactivity of humoral immunity.

Angina Pectoris

Bacterial adhesion onto particulate substrates.

The adhesion of anaerobic saccharolytic bacteria onto cellulose powder and raw starch granules through scanning electron microscope were observed. The adhering bacteria had a tendency to penetrate the granule surface; colonization was observed to occur on both the surface and inside the starch granule. The inner material of the starch granules was first digested, resulting in a shell type of structure at this stage. This implied that the surface of starch granules might have a different structure from its inner material. Bacterial adhesion and substrate digestion were found to be affected by operating temperature.

Bacterial Adhesion

The treatment of chronic hematogenous osteomyelitis.

Eighty-five patients with a total of 103 foci of chronic hematogenous osteomyelitis were treated in the period from 1965-1982. Only patients who had been followed for two or more years of treatment were included in the series for evaluation. All foci were treated surgically with thorough debridement. According to the management of the wounds, patients were divided into three groups: wound healing by secondary intention in cases where skin closure was impossible; primary closure of wound with or without pedicle muscle transfer in cases of a small debrided cavity or in cases where a nearby skeletal muscle is available; and closed irrigation and suction drainage of the wound cavity. After a long-term follow-up period, satisfactory results to varying degrees were obtained in each group. Closed intermittent irrigation and suction drainage with high concentrations of antibiotic solutions gave the best results. In instances of failure, the causes may be due to inadequate removal of infected sclerotic bone and sequestra, obstruction of drainage tubes, resistance to antibiotics, or inadequate systemic antibiotic treatment. The use of myocutaneous flap transference to close the postoperative wound of chronic osteomyelitis was introduced, and preliminary results are encouraging.

Adolescent