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Biomedical subjects

G Zhang

Publications and source records attributed to G Zhang.

At least 667 records · Page 37Linked to original sources
PubMed1990

[A study on the relationship between human papilloma virus (HPV) and cervical cancer].

Samples of cervical tissues of patients from Shandong province were detected by using Southern blot hybridization technique of nucleic acid with the probe of (alpha-32P)-dCTP HPV16 DNA fragment cleaving with BamHI. The total positive rate of HPV16 DNA related sequences in 116 cases with cervical cancer was 50.9%, and much higher than that in 36 cases with non-cervical disease (5.6%). There is a strong correlation between the HPV and cervical cancer (OR = 17.60, P less than 0.001). It was showed that there was no association between the positive rate of HPV 16 DNA related sequences and age, clinical period and local appearance in cases with cervical cancer. This was the first paper described that HPV 33 DNA sequences were found in four cervical carcinoma samples, and HPV 31 DNA sequence in one cervical carcinoma sample under low stringent conditions of hybridization in Shandong province.

Adult↗
PubMed1990

[Pharmacological action of various processed Mylabris phalerata Pallas].

We have compared the acute toxicity, sub-acute toxicity and in vitro and in vivo anti-tumor action of the rude drug, stir-fried with rice, and alkali-processed drugs of Mylabris phalerata before and after removing the head, feet and wings. The results indicate that the toxicity of the processed drugs is lower than that of the rude ones; the toxicity becomes higher without head, feet, and wings; and the alkali-processing method is better than stir-frying with rice recorded in the pharmacopeia.

Animals↗
PubMed1990

[The measurement of radial bone mineral content in children].

The bone mineral contents of radius of 255 boys and 243 girls (7 to 16 year old of the Han nationality, living in Chengdu) were measured with Bone Mineral Analyzer (Type:SPA-I). The standard values of g/cm was made. There was a positive correlation between the value in boys or girls and chronological age, height or weight. The coefficients were respectively 0.83, 0.77, 0.64 in boys and 0.82, 0.82, 0.82 in girls (P less than 0.005). At the age of 13 (in boys or in girls) the value of the g/cm was the highest.

Adolescent↗
PubMed1989

Effect of the hinge protein on the heme iron site of cytochrome c1.

X-ray absorption spectroscopic (XAS) studies on cytochrome C1 from beef heart mitochondria were conducted to identify the effect of the hinge protein [Kim, C.H., & King, T.E. (1983) J. Biol. Chem. 258, 13543-13551] on the structure of the heme site in cytochrome c1. A comparison of XAS data of highly purified "one-band" and "two-band" cytochrome c1 [Kim, C.H., & King, T.E. (1987) Biochemistry 26, 1955-1961] demonstrates that the hinge protein exerts a rather pronounced effect on the heme environment of the cytochrome c1: a conformational change occurs within a radius of approximately 5 A from the heme iron in cytochrome c1 when the hinge protein is bound to cytochrome c1. This result may be correlated with the previous observations that the structure and reactivity of cytochrome c1 are affected by the hinge protein [Kim, C.H., & King, T.E. (1987) Biochemistry 26, 1955-1961; Kim, C.H., Balny, C., & King, T.E. (1987) J. Biol. Chem. 262, 8103-8108].

Animals↗
PubMed1989

Production and characterization of antibodies cross-reactive with major aflatoxins.

Antibodies cross-reactive with 4 major aflatoxins were demonstrated three weeks after immunization of rabbits with an immunogen which was prepared by conjugating aflatoxin B3 to bovine serum albumin. Aflatoxin B3 was first converted to its hemisuccinate before conjugation to the protein. Tritiated aflatoxin B1 (AFB1) was used as the marker ligand both for antibody titer determination as well as for analysis of antibody specificity. Competitive RIA revealed that the antibodies have good cross-reactivity with aflatoxins B1, B2, G1, and G2 when tritiated AFB1 was used as the marker ligand. The concentrations causing 50% inhibition of binding of 3H-AFB1 to the antibodies by unlabeled aflatoxins B1, B2, G1, G2 and B3 were found to be 0.25, 3.34, 0.32, 4.0 and 0.53 ng/assay, respectively. The antibodies could be used for simultaneous analysis of aflatoxins B1 and G1, two of the most important toxic metabolites produced by Aspergillus flavus and A. parasiticus.

Aflatoxin B1↗
PubMed1989

The role of ilioinguinal lymphadenectomy and significance of histological differentiation in treatment of carcinoma of the penis.

We reviewed retrospectively the medical records of 58 patients treated for squamous cell carcinoma of the penis who were followed for more than 3 years or until they died. Tissue sections from all patients were reviewed. Of 15 patients with stage I disease 11 underwent partial penectomy, and 4 underwent partial penectomy and immediate ilioinguinal lymphadenectomy; none died of cancer. Nine patients with stage II and 9 with stage III disease underwent partial or total penectomy and immediate ilioinguinal lymphadenectomy, and 5-year survival was 100 and 75%, respectively. Of 20 patients with clinical stage II disease who did not undergo immediate ilioinguinal lymphadenectomy 18 had metastasis to the groin. Of these 18 patients 12 underwent delayed ilioinguinal lymphadenectomy but only 1 survived more than 5 years. We evaluated the possible significance of the degree of histological differentiation of the primary tumor to the course of the disease. Of the 23 cases of carcinoma in situ or well differentiated disease only 1 became metastatic, while of the 35 cases of moderately to poorly differentiated disease 31 metastasized to the groin. Vascular invasion of cancer cells in the primary tumor was another indicator for poor prognosis.

Aged↗
PubMed1989

Sarcomas of the retroperitoneum and genitourinary tract.

A total of 62 patients with retroperitoneal or genitourinary sarcoma was treated at our institutions during the last 46 years. Of the patients 51 were followed for at least 5 years or until they died (median followup 11 years); 5 patients were lost to followup. The most common site was the retroperitoneum. Liposarcoma, leiomyosarcoma and malignant fibrous histiocytoma were the most common tumors (74 per cent). Tumors were completely resected in 42 patients (68 per cent) and incompletely resected in 11, while a biopsy only was performed in 9. Some patients also received adjuvant radiation therapy and/or chemotherapy. There were no long-term survivors among patients with unresectable tumors. Over-all 3 and 5-year survival rates were 68 and 39 per cent, respectively. The histological type of the tumor appeared to have prognostic significance. The highest 5-year survivals were for liposarcoma (70 per cent), malignant fibrous histiocytoma (33 per cent) and leiomyosarcoma (13 per cent). The mean survival for patients after adjuvant radiation therapy or chemotherapy was similar to that after a radical operation alone. The primary cause of treatment failure was local recurrence (45 per cent of the patients), which was detected within 3 years of complete resection in most cases (82 per cent). Complete extirpation that provided adequate margins free of tumor was the most effective initial treatment and provided the best chance for cure.

Combined Modality Therapy↗
PubMed1989

Kinetics of Aluminum Uptake by Excised Roots of Aluminum-Tolerant and Aluminum-Sensitive Cultivars of Triticum aestivum L.

Uptake of aluminum (Al) by excised roots of two Al-tolerant cultivars and two Al-sensitive cultivars of Triticum aestivum L. (wheat) was biphasic, with a rapid phase of uptake in the first 30 minutes followed by a linear phase of uptake up to 180 minutes. At the end of the uptake period, higher concentrations of Al were found in roots of the Al-sensitive cultivars (Neepawa and Scout-66) than in the Al-tolerant cultivars (Atlas-66 and PT-741), but differences were small. Experiments testing the effectiveness of several desorption agents demonstrated that citric acid was most effective in desorption of loosely bound Al (the putative apoplasmic compartment) followed by others in the order tartaric acid > EDTA > CaSO(4) = ScCl(3). In all cultivars, 30 minutes of desorption with citric acid depleted the rapidly exchanging, putative apoplasmic compartment, although some tightly bound Al remained in that compartment. The relationship between Al remaining after desorption and time in the uptake medium was nearly linear and no distinction was observed between Al-tolerant and Al-sensitive cultivars. However, uptake of Al by the Al-tolerant cultivars was increased by treatment with the protonophore 2,4-dinitrophenol (DNP), while uptake of Al by Al-sensitive cultivars was relatively unaffected. Such results suggest the possible involvement of an active exclusion mechanism in Al-tolerant cultivars of T. aestivum.

Journal Article↗
PubMed1989

Application of ion-pair high performance liquid chromatography for analysis of hyoscyamine and scopolamine in solanaceous crude drugs.

A new ion-pair high-performance liquid chromatographic method for the analysis of hyoscyamine and scopolamine in various kinds of crude drugs derived from solanaceous plants was evaluated using sodium dodecyl sulfate as a counter ion. A reversed-phase chromatographic system consisting of a chemically bonded ODS silica gel column with phosphate buffer (pH 2.5)-acetonitrile (65:35) containing 17.5 mM sodium dodecyl sulfate as the mobile phase was used. Hyoscyamine and scopolamine in crude drugs derived from Scopolia, Atropa, Hyoscyamus and Datura species were separated from other compounds in the crude drugs and determined within 20 min after direct injection of the solution extracted with the mobile phase. The results for various kinds of samples are presented.

Atropine↗
PubMed1989

Adenosine A1 receptor activation mediates suppression of (-) bicuculline methiodide-induced seizures in rat prepiriform cortex.

The protective effects of a series of stable adenosine analogs against generalized seizures initiated by focal injection of bicuculline methiodide into the rat prepiriform cortex (PPC) were studied by microinjection of these compounds into this brain area. The adenosine agonists, 5'-N-(ethyl)carboxamido-adenosine (NECA), cyclohexyladenosine, cyclopentyadenosine, 2-chloroadenosine and R- and S-phenylisopropyladenosine (R- and S-PIA), protected animals against seizures in a dose-dependent, and extremely potent manner. NECA, the most potent compound evaluated, completely prevented seizures at doses greater than or equal to 6.8 pmol. In contrast, heroic doses of the A2 selective ligand, 2-phenylaminoadenosine, afforded no protection against seizures. The rank order of potency of these compounds in suppressing seizures is as follows: NECA greater than cyclohexyladenosine greater than cyclopentyladenosine greater than or equal to R-PIA greater than 2-chloroadenosine greater than S-PIA much greater than 2-phenylaminoadenosine. These data suggest that the antiseizure activity of these compounds in the PPC results from activation of A1 adenosine receptors. Quantitative autoradiographic analysis of the distribution of tritiated adenosine agonists 30 min after microinjection in the PPC reveals that [3H]NECA diffuses to a significantly greater extent than R-[3H]PIA, which may contribute to the relatively greater potency of the former compound in suppressing bicuculline methiodide-induced seizures. These results suggest that adenosine A1 receptors may participate in the normal inhibitory regulation of the PPC, a forebrain area which may play a significant role in the pathobiology of epilepsy.

2-Chloroadenosine↗
PubMed1989

Colony formation of CFU-MK and other hemopoietic progenitors in patients with acute non-lymphoblastic leukemia at diagnosis and following complete remission.

Blood and marrow mononuclear cells were cultured in methylcellulose and plasma clot. In patients with acute non-lymphoblastic leukemia (ANLL) at diagnosis, marrow multipotential progenitors (CFU-Mix), megakaryocyte progenitors (CFU-MK) and granulocyte-monocyte progenitors (CFU-GM) were reduced or undetectable (all p less than 0.01). Two to 4 weeks after completion of induction therapy, marrow CFU-Mix returned to normal level (p greater than 0.05), CFU-MK and CFU-GM reached levels significantly higher than normal controls (both p less than 0.01), and circulating CFU-Mix, CFU-MK and CFU-GM were about 3, 6 and 6 times normal controls respectively (all p less than 0.01). During maintenance therapy CFU-Mix remained in low normal range (p greater than 0.05) and CFU-MK and CFU-GM were significantly reduced (both p less than 0.01). In patients at relapse CFU-Mix was undetectable (p less than 0.01) and CFU-MK and CFU-GM were undetectable or reduced (both p less than 0.01). The percentages of CFU-MK and CFU-GM in cell cycle S-phase as analysed by ara-c suicide technique were 51.4 +/- 5.8 and 52.3 +/- 2.3 two weeks after the completion of induction therapy, and 61.1 +/- 7.9 and 53.8 +/- 8.7 during maintenance therapy, all significantly higher than normal controls (all p less than 0.01). Our results suggest that chemotherapy may not result in severe damage to CFU-Mix, and that cell culture technique may be helpful in assessing prognosis.

Adolescent↗