PubMed Health⌕ Search

Biomedical subjects

B Cao

Publications and source records attributed to B Cao.

At least 37 records · Page 2Linked to original sources
PubMed2000

[Advances in diagnosis and treatment of ectopic pregnancy during the past ten years].

OBJECTIVE: To investigate the changes of diagnosis and treatment of ectopic pregnancy (EP) during the past ten years. METHODS: Medical records of 1,970 cases with EP seen in our hospital from Jan. 1987 to Dec. 1996 were collected and analyzed retrospectively. RESULTS: (1) The incidence of EP increases from 1.0 per 42.4 labours during 1987-1988 to 1.0 per 6.6 labours in 1995-1996. (2) Diagnosis was confirmed more by television laparoscopy, transvaginal ultrasonography and sensitive human chorionic gonadotropin-beta subunit assay rather than loparotomy and with a shorter period, (6.5 +/- 0.7) days in 1987-1988 versus (3.7 +/- 0.2) days in 1995-1996. (3) The choice of treatment was more conservative or through laparoscopic surgery than abdominal salpingectomy. (4) The success rate of conservative surgery expectant management reached 100.0% and medical treatment with a variety of choices around 80.0%-85.%. CONCLUSIONS: Although the incidence of EP increased, with the improvement of diagnostic approaches, patients were detected at an earlier stage and possible to be treated more conservatively.

Female↗
PubMed2000

[Conformity of cancerous diagnosis of serum-fluorimetry under the influence of carotenoid fluorescence].

We observed that carotenoid had sensitization for fluorescence of porphyrin as cancerous diagnostic technology was applied in clinic by serum-fluorimetry. The Forster theory was used in order to analyse sensitized fluorescence between carotenoid and porphyrin in this paper. Transfer characteristic between energy donor and energy acceptor was calculated and discussed its influence on cancerous diagnosis.

Biomarkers, Tumor↗
PubMed1999

Secondary structure peptide mimetics: design, synthesis, and evaluation of beta-strand mimetic thrombin inhibitors.

Constrained dipeptide mimetic templates were designed to mimic the secondary structure of peptides in a beta-strand conformation. Two templates corresponding to the D-Phe-Pro portion of the thrombin inhibitor D-Phe-Pro-ArgCH2Cl were synthesized and converted into nine alpha-ketoamide and alpha-ketoheterocycle inhibitors of thrombin. Additionally, a template corresponding to L-Phe-Pro was synthesized and converted to a thrombin inhibitor. The in vitro inhibition of thrombin by these compounds was determined, and those corresponding to the D-Phe-Pro were found to be more potent inhibitors than the L-Phe-Pro mimetic. The alpha-ketoamides were found to be more potent than the alpha-ketoheterocycles but had much slower on rates. By comparison of a series of alpha-ketoamide analogues, it is apparent that the there is a preference for binding of bulky hydrophobic substituents in the P' portion of the thrombin active site. Three of the inhibitors (MOL098, MOL144, and MOL174) were screened against a series of coagulation and anticoagulation enzymes and found to be selective for inhibition of the coagulation enzymes. Two of the inhibitors were tested in in vitro models of intestinal absorption and found to have low absorption potential. The compounds were then tested in vivo in both rats and primates, and one of them (MOL144) was approximately 25% absorbed in both species. This study has delineated the synthesis of constrained dipeptide beta-strand mimetics and validated the potential for compounds of this type as potent thrombin inhibitors and possible drug leads.

Administration, Oral↗
PubMed1999

Loss of heterozygosity, by mitotic gene conversion and crossing over, causes strain-specific adenine mutants in constitutive diploid Candida albicans.

Molecular evidence is provided in this paper to elucidate a long-standing intriguing phenomenon in fungal genetics: that many natural isolates of the constitutive diploid organism Candida albicans yield strain-specific, recessive mutants at a reproducible frequency that is as high as a few percent of the surviving cells after exposure to UV irradiation or other mutagens. Southern hybridization analysis and DNA sequence data indicated that C. albicans CA12, a clinical isolate, is heterozygous for the ADE2 gene, carrying one functional and one null allele. Sequence analysis of the null allele revealed the presence of a 1.3 kb deletion, which locates between two AATC repeats and spans the promoter and coding regions of the gene. The adenine auxotrophic mutants, which were readily isolated after UV irradiation of C. albicans CA12, were proved to be the segregants of mitotic recombination as they remained as diploid, not hemizygous or haploid, cells and were homozygous for ade2. Analysis of reciprocal products of the mitotic recombination detected that the process of loss of heterozygosity was mediated by mitotic crossing over (reciprocal exchange of genetic information) as well as gene conversion (non-reciprocal exchange of genetic information).

Adenine↗
PubMed1999

[The potential role of cytokine expression and its relation to angiogenesis in idiopathic pulmonary fibrosis].

OBJECTIVE: The expression of insulin-like growth factor (IGF)-I and platelet-derived growth factor (PDGF) in open lung biopsies from patients with idiopathic pulmonary fibrosis (IPF) was studied to investigate their precise role in the development of fibrosis in IPF. METHODS: The distribution and expression of IGF-I and PDGF were examined in lung sections of IPF patients with antibodies and cDNA probes of IGF-I and PDGF by immunohistochemistry and in situ hybridization. RESULTS: IGF-I was predominantly localized in vascular smooth muscle cells and vascular endothelial cells of newly formed vessels in IPF. Smooth muscle cells of pulmonary arteries which underwent hypertrophy and hyperplasia strongly expressed IGF-I (+ + +). Type II cells, alveolar macrophages, and interstitial cells were also stained with anti-IGF-I, but with lesser intensity (+). PDGF-AA and BB were localized in hyperplastic bronchio-alveolar epithelial cells and interstitial fibroblasts (+ + +). Alveolar macrophages, vascular endothelial cells and smooth muscle cells were also stained positive (+ +). CONCLUSION: IGF-I and PDGF promote angiogenesis and vascular smooth muscle cell hypertrophy and hyperplasia, which contribute to the progression of fibrosis in IPF. IGF-I and PDGF are also involved in reepithelization and fibroproliferation in IPF through interaction with mesenchymal cells.

Adult↗
PubMed1999

[The potential role of cytokines expression in idiopathic pulmonary fibrosis].

OBJECTIVE: To investigate the protein and gene expression in bronchoalveolar lavage cells and open lung biopsies from patients with IPF. METHODS: The immunohistochemical methods were used to analyze the expression of PDGF, TGF-beta in bronchoalveolar lavage cells of patients with IPF. For open lung biopsies, both immunohistochemistry and in situ hybridization were used. RESULTS: In specimens of bronchoalveolar lavage fluid, PDGF-AA, PDGF-BB, TGF-beta were localized to alveolar macrophages in patients with IPF. Though there were no differences between IPF and sarcoidosis in terms of the staining intensity (2.5 - 3.0) or number of positive cells 81% - 90%, the number of such cells were less in the control (0 - 1.7, 25% - 32% respectively). Evaluation of open lung biopsies from patients with IPF showed that PDGF, TGF-beta proteins were localized to hyperplastic bronchio-alveolar epithelial cells (2.4 - 3.7, in control 0), alveolar macrophages (2.9 - 3.7, in control 0.8 - 1.3), fibroblasts (3.0 - 3.6, in control 2.7 - 2.8), vascular smooth muscle cells, vascular endothelial cells, and fibroblast-like cells surrounding pulmonary vessels (2.7 - 4.0, in control 2.1 - 2.9). In situ hybridization results were consistent with that of immunohistochemistry except that PDGF and TGF-beta mRNA transcripts were not detected in bronchio-alveolar epithelial cells. In control lungs, however, both ISH and IHC revealed that PDGF and TGF-beta were only present in the pleura and in fibroblast-like cells surrounding pulmonary vessels. CONCLUSIONS: PDGF and TGF-beta, which interplay with pulmonary mesenchymal cells, are involved in fibroplasia and deposition of extracellular matrix as well as angiogenesis and epithelial cell repopularization.

Becaplermin↗
PubMed1999

[The effect of age on the regional blood flow of neck of femur in normal Chinese].

This study aimed to assess the effect of age on the regional blood flow of neck of femur in normal Chinese. 133Xe washout method was adopted. The result showed that the femur regional blood flow of normal Chinese decreased slowly with the increase of their age. The relation between age and femur blood flow might be expressed as F = -0.042Y + 9.01(F refers to blood flow, Y refers to age). The average femur regional blood flow of normal Chinese was 7.37 +/- 0.62 ml.(100 g.min)-1 for 21-40 years old. The authors suggest this result can be considered to stand for regional femur blood flow of young healthy adults.

Adolescent↗
PubMed1998

Highly efficient and versatile synthesis of libraries of constrained beta-strand mimetics.

The general approach of using a bicyclic template to produce inhibitors of the protease superfamily of enzymes has been investigated. The Diels Alder cycloaddition reaction on solid support has been found to be highly efficient for the synthesis of libraries of compounds that mimic the beta-strand secondary structure of proteins. Several potent and selective inhibitors of proteases have been discovered.

Bridged Bicyclo Compounds, Heterocyclic↗
PubMed1997

[Alteration in regional blood flow in minipigs' femur under inadequate decompression studied by isotopes washout method].

We studied the alteration in regional blood flow in minipigs' femur under inadequate decompression after hyperbaric air exposure. The animals were placed in the hyperbaric chamber and exposed to the pressure of 0.5 MPa for 1.5 h, which was reduced to atmosphere at an ascent rate of 0.03-0.04 MPa/min. Regional blood flow in the femur was measured by the isotopes washout method of inhaling 133Xe. The radioactivity was monitored by a multifunctional blood flowmeter interfaced to a minicomputer. Before exposure, the values of average blood flow (F) of femur on the left and right were 15.4 +/- 1.8 and 16.9 +/- 2.0 ml/100 g.min respectively. The values of blood flow (f1) of hematopoietic marrow were 19.1 +/- 2.0 and 21.3 +/- 2.0 ml/100 g.min (n = 7). After inadequate decompression, F values were reduced to 10.3 +/- 1.8 and 11.1 +/- 1.6 ml/100 g.min and f1 values reduced to 13.9 +/- 1.4 and 13.8 +/- 1.0 ml/100 g.min (n = 7), which were obviously lower than those before exposure (P < 0.05). This experiment showed that significant reduction in blood flow in the femur region occurred under inadequate decompression after the exposure of minipigs hyperbaric environment, suggesting that ischemia is a causative factor of osteonecrosis.

Animals↗
PubMed1996

UV irradiation-induced apoptosis leads to activation of a 36-kDa myelin basic protein kinase in HL-60 cells.

UV irradiation induces apoptosis (or programmed cell death) in HL-60 promyelocytic leukemia cells within 3 h. UV-induced apoptosis is accompanied by activation of a 36-kDa myelin basic protein kinase (p36 MBP kinase). This kinase is also activated by okadaic acid and retinoic acid-induced apoptosis. Irrespective of the inducing agent, p36 MBP kinase activation is restricted to the subpopulation of cells actually undergoing apoptosis. Activation of p36 MBP kinase occurs in enucleated cytoplasts, indicating no requirement for a nucleus or fragmented DNA in signaling. We also demonstrate the activation of p36 kinase in tumor necrosis factor-alpha- and serum starvation-induced cell death using the human prostatic tumor cell line LNCap and NIH 3T3 fibroblasts, respectively. We postulate that p36 MBP kinase is a common component in diverse signaling pathways leading to apoptosis.

3T3 Cells↗
PubMed1996

Distal 8p deletion (8)(p23.1): an easily missed chromosomal abnormality that may be associated with congenital heart defect and mental retardation.

We describe the clinical manifestations and molecular cytogenetic analyses of three patients with a similar distal deletion of chromosome 8. Each child had mild developmental delay and subtle minor anomalies. Two had cardiac anomalies but no other major congenital anomalies were present. High resolution G and R banding showed in all three patients del(8)(p23.1), but the breakpoint in case 1 was distal to 8p23.1, in case 2 was in the middle of 8p23.1, and in case 3 proximal to 8p23.1. Fluorescence in situ hybridization (FISH) studies with a chromosome 8 paint probe confirmed that no other rearrangement had occurred. FISH with a chromosome 8-specific telomere probe indicated that two patients had terminal deletions. Chromosome analysis of the parents of case 1 and mother of case 2 were normal; the remaining parents were not available for study. Thirteen individual patients including the three in this study, and three relatives in one family with del(8)(p23.1), have been reported in the past 5 years. Major congenital anomalies, especially congenital heart defects, are most often associated with a breakpoint proximal to 8p23.1. Three patients were found within a 3-year period in this study and five cases were found within 4 years by another group, indicating that distal 8p deletion might be a relatively common chromosomal abnormality. This small deletion is easily overlooked (i.e., cases 1 and 2 were reported as normal at amniocentesis) and can be associated with few or no major congenital anomalies.

Adult↗
PubMed1996

Expression of steroidogenic factor-1 (SF-1) mRNA and protein in the human placenta.

Steroidogenic factor-1 (SF-1), also known as adrenal-4-binding protein (Ad4BP), is a recently-described transcription factor, which has been shown to be important for the differentiation of steroidogenic tissues. In addition, SF-1 has been implicated in regulating the glycoprotein hormone alpha-subunit gene in a pituitary gonadotroph cell line. Considering that the human placenta produces both steroids and human chorionic gonadotrophin (HCG), we studied the expression of SF-1 in this tissue. Human first trimester and term placentas were collected at the time of therapeutic abortion and birth respectively. Messenger RNA was extracted, reverse transcribed, and used for polymerase chain reaction (PCR) amplification with primers specific for the human SF-1 cDNA sequence. A band of the expected size was obtained from both first and third trimester samples, indicating that SF-1 expression in the human placenta starts early in pregnancy and is maintained until birth. In addition to normal placental samples, JEG3 and JAR choriocarcinoma cells were also analysed and found to express SF-1 mRNA. The identity of the amplified products was confirmed by diagnostic restriction digest and Southern hybridization. SF-1 protein was localized mainly to the nuclei of the cyto- and syncytiotrophoblast and to some mesenchymal villous nuclei by immunocytochemistry using a specific antibody. We conclude that SF-1 is expressed in human first trimester and term placenta, where it could be implicated in the regulation of HCG production, in steroidogenesis, or both.

Base Sequence↗
PubMed1996

Nuclear magnetic resonance chemical shift: comparison of estimated secondary structures in peptides by nuclear magnetic resonance and circular dichroism.

Traditionally, CD has been used extensively for peptides in secondary structure analysis. In recent years, NMR chemical shifts and nuclear Overhauser enhancements have been widely used in conjunction with CD to assess the secondary structures of peptides and proteins; however, there are many instances where the estimation of secondary structure contents differs significantly between the two methods. In order to elucidate the perceived differences between the two methods, secondary structure estimations by CD and 1H NMR chemical shifts were compared for over 50 peptides. The linear peptides investigated were largely unstructured, approximately 15-50 residues in size, and lacked stable tertiary conformation. These peptides were studied in different solvent systems including water, alcohol-water, micelles and urea. A strong correlation exists for secondary structure assessment by CD and NMR chemical shifts; however, an interesting trend of higher estimation of helical contents by NMR was observed for peptide fragments from globular proteins studied in water. This may be a result of associative properties of these peptides in water. Additionally, a new method of quantitating secondary structure contents based on 1H NMR chemical shifts is reported.

Alcohols↗
PubMed1996

The transcription activator steroidogenic factor-1 is preferentially expressed in the human pituitary gonadotroph.

Steroidogenic factor-1 (SF-1), also known as adrenal-4-binding protein, is a transcription factor that is important for the differentiation of steroidogenic tissues. We investigated whether SF-1 is expressed in specific hormone-producing cell types in the human pituitary and its adenomas. Pituitary adenomas (n = 35) were collected at the time of surgery, and normal adenohypophyses were obtained from autopsies; 3 corticotroph adenomas were excluded because pit-1 messenger ribonucleic acid (mRNA) expression indicated contamination by nontumorous elements. Expression of SF-1 mRNA was determined by reverse transcription-PCR. SF-1 protein was localized with immunocytochemistry. By reverse transcription-PCR, SF-1 mRNA was found in the nontumorous pituitary and in pituitary adenomas expressing gonadotropins. All 8 gonadotroph adenomas had a strong signal for SF-1. SF-1 mRNA was also detected in 2 of 3 corticotroph adenomas, 2 of 13 somatotroph/mammosomatotroph adenomas, 1 of 6 lactotroph adenomas, and 2 silent subtype 3 adenomas; however, in most of the positive tumors there was also positivity for FSH beta and/or LH beta mRNA, suggesting that contaminating nontumorous gonadotrophs may be the source of SF-1 mRNA signal. SF-1 protein was localized by immunocytochemistry in the nuclei of scattered cells of the nontumorous adenohypophysis that were shown to be gonadotrophs with double immunostaining and in gonadotroph adenomas; nuclear staining was not found in other adenoma types, except in areas shown to contain trapped nontumorous tissue. We conclude that SF-1 expression correlates with the expression of gonadotropins. These findings implicate SF-1 as a cell-specific transcription factor that may regulate gonadotroph differentiation in the pituitary.

Adenoma↗
PubMed1996

Exploration for drug therapy in endometrial carcinoma.

OBJECTIVE: To explore the therapeutic effect of three drugs, i.e., hydroxyprogesterone caproate (HPC), Tamoxifen (TMX) and Aminoglutethimide (AG), in the treatment of endometrial carcinoma. METHODS: The patients were collected by double-blind method and classified into 6 groups (3 groups used single drug and 3 groups used combined drugs) at random. The patient was given assigned drug therapy for 10 days according to her group after being admitted to the hospital. Operations were performed 7-10 days after drug therapy. Plasma FSH, LH, E2 and P were measured by standard radioimmunoassay of WHO. ER and PR in cancer tissues were examined by enzyme linked histochemistry. Cancer tissues obtained before and after drug therapy were examined pathologically. RESULTS: The values of FSH, LH and E2 decreased and that of P increased after single drug therapy in the group treated with HPC; and the values of FSH, LH, E2 and P all decreased in the groups treated with TMX and AG respectively (P < 0.05). The values of FSH, LH and E2 decreased to different extent in the groups treated with combined drugs. The changes of FSH and E2 are remarkable (P < 0.05). The value of P increased a little with no statistical difference (P > 0.05). PR and ER usually increased after treatment with TMX, but decreased with HPC or AG, or combined drugs. The pathological changes indicate that the tumors responded to all of the three drugs. The response to TMX was most significant, following which was HPC. CONCLUSIONS: HPC and TMX are two drugs proved to be useful in endometrial carcinoma. AG also can be used to treat endometrial carcinoma. It adds a new drug to the drug therapy for endometrial carcinoma.

17 alpha-Hydroxyprogesterone Caproate↗
PubMed1995

[Antidepressant active constituents in the roots of Morinda officinalis How].

Five compounds having antidepressant activities have been isolated from the roots of Morinda officinalis, a Chinese traditional Yang-tonic drug. These compounds were identified as succinic acid (1), nystose (2), 1F-fructofuranosylnystose (3), inulin-type hexasaccharide (4) and heptasaccharide (5) by chemical and spectroscopic methods. All of the compounds are isolated from the species of genus Morinda for the first time.

Animals↗