Automated identification of vessel contours in coronary arteriograms by an adaptive tracking algorithm

A tracking algorithm for identification of vessel contours in digital coronary arteriograms was developed and validated. Given an initial start-of-search point, the tracking process was fully automated by utilizing the spatial continuity of the vessel's centerline, orientation, diameter, and density. The incremental sections along a major vessel were sequentially identified, based on the assumptions of geometric similarity and continuation between adjacent incremental sections. The algorithm consisted of an extrapolation-update process which was guided by a matched filter. The filter parameters were adapted to the measured lumen width. The tracking process was robust and extremely efficient as indicated by test results on synthetic images, digital subtraction angiograms, and cineangiograms. The algorithm provided accurate measurement of lumen width and percent stenosis that was relatively invariant to the vessel's orientation, dynamic range, background variation, and degree of blurring.

Alternate pathways of DNA replication in Escherichia coli

We have described the pcbA1 mutation which enables E. coli cells to replicate DNA in the absence of a functional dnaE gene product if DNA polymerase I (the polA gene product) is present. The pcbA1 mutation phenotypically suppresses multiple dnaEts and dnaEam alleles. The pcbA1/PolI replication pathway differs from normal in sensitivity to certain DNA-damaging agents such as methylmethane sulfonate (MMS) and a lack of damage-directed mutagenesis. We report here cloning of the pcbA1 gene in a multicopy plasmid. The pcbA1 mutation is detected only in cis; therefore, cloning necessitated gene eviction. The pcbA1 gene lies closely- linked to gyrB. We have demonstrated the physical presence of DNA polymerase I in the replicating holoenzyme complex by immunoblotting using dnaEam strains. We conclude that E. coli has two alternate replisome structures: REP-A, in which DNA polymerase I is the functional synthetic subunit; and REP-E, in which the alpha-subunit, product of the dnaE gene, is functional. To investigate further the role of individual DNA polymerases in replication, we have isolated the polB gene on multicopy plasmids.

Estimation of intramyocardial pressure and coronary blood flow distribution

To characterize the intramyocardial pressure (IMP) and coronary blood flow distribution in a stenosed coronary circulation, we compared four analog circuits for modeling coronary impedance. The resistor (R)-diode (D) model simulates vascular collapse, and the capacitor (C) simulates compliance effect. Identification of the best model and magnitudes of the endocardial and epicardial IMPs (IMPendo and IMPepi) was done retrospectively using data from studies in 28 anesthetized swine. Performance evaluation was based on comparison of model predicted vs. observed coronary distal pressure (DP) waveforms and endocardial-to-epicardial (endo-epi) flow ratios as determined by radiolabeled microspheres. The R-D-C model gave the best performance at IMPendo = 1.1 times left ventricular pressure (LVP), and IMPepi = 0.1.LVP + 15 mmHg; with good fit to DP (r = 0.98, slope of regression line = 1.0) and estimates of endo-epi flow ratio (r = 0.78, slope = 1.01, P less than 0.02, SEE = 0.21, n = 139). The R-D model gave comparable results even though capacitance was omitted. Although R-C and R models predicted distal coronary pressure well, they failed to predict endo-epi flow ratios (r less than 0.50). The R-D-C and R-D models were applied in seven prospective studies. Both models generated reasonable estimates of endo-epi flow distribution (r = 0.78, n = 50). Thus the R-D-C or R-D models of the stenosed coronary circulation can be used to provide reliable estimates of transmural blood flow distribution.

Identification of disulfide-containing peptides by performic acid oxidation and mass spectrometry

In addition to reducing the analysis time, the direct examination of proteolytic digests by fast atom bombardment mass spectrometry (FABMS) greatly extends the information that is available from peptide mapping experiments. Mass spectral data are particularly useful for identifying post-translationally modified peptides. For example, the molecular weight of a disulfide-containing peptide may be used to locate the disulfide bond in the protein from which the peptide was derived. This paper describes a new procedure, which is useful for identifying disulfide-bonded peptides. Peptides are treated with performic acid to modify certain residues and thereby cause a characteristic change in the peptide molecular weight. This change in molecular weight is determined by FABMS and used to help identify peptides. Results for a series of small peptides demonstrate that Cys, Met, and Trp are the only residues that undergo a change in molecular weight under the conditions used here. Furthermore, these changes in molecular weight are diagnostic for each of the residues. Cysteinyl-containing peptides are of particular interest, because their identification is essential for locating disulfide bonds. The molecular weight of a peptide increases by 48 mu for each cysteinyl residue present. This approach is used to identify peptides that contain both cysteinyl and cystinyl residues in the peptic digest of bovine insulin. The method is extended to the analysis of a tryptic digest of cyanogen bromide-treated ribonuclease A. A computer-assisted analysis procedure is used to demonstrate the specificity with which peptide molecular weight is related to specific segments of the protein.(ABSTRACT TRUNCATED AT 250 WORDS)

Stable H2O2-resistant variants of Chinese hamster fibroblasts demonstrate increases in catalase activity

Hydrogen peroxide (H2O2)-resistant variants of the Chinese hamster ovary HA-1 line have been derived by culturing cells in progressively higher concentrations of H2O2 (greater than 200 days, in 50-800 microM H2O2). The H2O2-resistant phenotype has been stable for over 60 passages (240 days) following removal from the H2O2 stress. The resistant cells demonstrate both increased capacity to deplete exogenously added H2O2 from the growth medium and increased catalase activity. H2O2 resistance correlates well with catalase activity. An increase in chromosome number occurred in the cells adapted to 200-800 microM H2O2, but increases in aneuploidy and tetraploidy were not necessary for resistance. These results suggest that adaptation to chronic oxidative stress mediated by H2O2 in mammalian cells is accompanied by a stable heritable change in expression of catalase activity.

A simple method for clinical assay of superoxide dismutase

This assay for superoxide dismutase (SOD, EC 1.15.1.1) activity involves inhibition of nitroblue tetrazolium reduction, with xanthine-xanthine oxidase used as a superoxide generator. By using a reaction terminator, we can determine 40 samples within 55 min. One unit of activity of pure bovine liver Cu,ZnSOD and chicken liver MnSOD was expressed by 30 ng and 500 ng of protein, respectively. The mean concentrations of Cu,ZnSOD as measured by this method in blood from normal adults were 242 (SEM 4) mg/L in erythrocytes, 548 (SEM 20) micrograms/L in serum, and 173 (SEM 11) micrograms/L in plasma. The Cu,ZnSOD concentrations in serum and plasma of patients with cancer of the large intestine tended to be less and greater than these values, respectively, but not statistically significantly so.

[High-dose methotrexate with citrovorum factor rescue (HD-MTX-CFR) in the treatment of malignant solid tumors--clinical analysis of 62 patients]

From 1977 to 1982, 62 patients with various advanced malignant solid tumors were treated by HD-MTX-CFR therapy and totally 129 courses were given. Majority of the patients suffered from malignant lymphoma (10), osteogenic sarcoma (11), lung cancer (16), esophageal cancer (3), breast cancer (3) and malignant melanoma (4). All were confirmed by cytology or pathology except one primary liver cancer. There were clinically measurable lesions in 59 patients for evaluation of the treatment, and 3 osteogenic sarcoma patients without metastasis were given a postoperative adjuvant chemotherapy. 33 out of 62 had received chemotherapy and/or radiotherapy before. Dose of MTX ranged from 2 to 3 gm per course in most patients and dose of CF, from 9 to 12 mg every 6 hours for 3 days. 2 (3.4%) patients achieved complete remission (1 osteogenic sarcoma and 1 malignant lymphoma) and 8 (13.6%), partial remission (1 osteogenic sarcoma, 5 malignant lymphoma, 1 esophageal cancer and 1 breast cancer) with a total response rate of 15.9%. No response was observed in all 16 lung cancers. The main side effects of HD-MTX-CFR therapy were leukopenia, thrombocytopenia, elevation of SGPT, nausea, vomiting, mucositis, skin rash, fever and fatigue. All patients were followed more than 3 years. 4 patients are still alive (9, 9, 4 and 7 years, respectively), including 3 osteogenic sarcoma patients who received postoperative adjuvant chemotherapy and 1 mycosis fungoides.

A simple method for clinical assay of superoxide dismutase

This assay for superoxide dismutase (SOD, EC 1.15.1.1) activity involves inhibition of nitroblue tetrazolium reduction, with xanthine-xanthine oxidase used as a superoxide generator. By using a reaction terminator, we can determine 40 samples within 55 min. One unit of activity of pure bovine liver Cu,ZnSOD and chicken liver MnSOD was expressed by 30 ng and 500 ng of protein, respectively. The mean concentrations of Cu,ZnSOD as measured by this method in blood from normal adults were 242 (SEM 4) mg/L in erythrocytes, 548 (SEM 20) micrograms/L in serum, and 173 (SEM 11) micrograms/L in plasma. The Cu,ZnSOD concentrations in serum and plasma of patients with cancer of the large intestine tended to be less and greater than these values, respectively, but not statistically significantly so.

Induction of ornithine decarboxylase and histidine decarboxylase activities in rat colon mucosa after application of 12-o-tetradecanoylphorbol-13-acetate (TPA), sodium deoxycholate and indole

Ornithine decarboxylase (ODC) and histidine decarboxylase (HDC) activities of rat colon mucosa were induced after intrarectal instillation of 12-o-tetradecanoylphorbol-13-acetate (TPA) and sodium deoxycholate. After instillation of sodium deoxycholate, ODC and HDC activities increased rapidly and reached a peak at 4 h, then decreased quickly towards control levels. Both enzymes activities also increased significantly 4 h after instillation in animals treated with TPA and sodium deoxycholate plus indole. However, there were no changes in ODC and HDC activities from 0-8 h after indole administration. These data are the first to show the induction of HDC activity in colon mucosa by TPA and sodium deoxycholate and suggest that the induction of activities in these two enzymes might be one mechanism of their action as cancer promoters.

Induction of beta-glucuronidase activity during dimethylhydrazine carcinogenesis and additive effects of cholic acid and indole

The kinetic change of beta-glucuronidase (beta-G) activity was measured in mouse large intestinal mucosa during dimethylhydrazine (DMH) carcinogenesis with addition of cholic acid and/or indole. The experiment lasted 21 weeks. The enzyme activity began to increase significantly at 5th week after treatment of DMH with cholic acid and/or indole, and at 7th week with DMH alone. Then, increased activity remained the rest of the time. Mouse intestinal cancer induced by DMH injection are also shown to have an increased beta-G activity. The induction of beta-G activity in the early stage of DMH colon carcinogenesis and additive effects of cholic acid and/or indole may imply one mechanism of action of DMH as a carcinogen and cholic acid as a promoter in large intestinal cancer.

A simultaneous visualization of the antioxidant enzymes glutathione peroxidase and catalase on polyacrylamide gels

A simple and sensitive method for the simultaneous visualization of glutathione peroxidase and catalase on polyacrylamide gels is described. The procedure included: (1) running samples on a 7.5% polyacrylamide gel, (2) soaking the gel in a certain concentration of reduced glutathione (0.25-2.0 mM), (3) soaking the gel in GSH plus H2O2 or cumene hydroperoxide, (4) finally staining with a 1% ferric chloride 1% potassium ferricyanide solution. The best concentration of glutathione for simultaneous visualization of glutathione peroxidase in mouse liver homogenates and also it is specific for glutathione peroxidase since other peroxidases such as lactoperoxidase, horseradish peroxidase and glutathione S-transferase cannot be visualized. Using this method, it was found that unlike catalase, glutathione peroxidase is heat resistant (68 degrees C, 1 min), but sensitive to 10 mM sodium iodoacetate.

Superoxide dismutase activity during dimethylhydrazine colon carcinogenesis and the effects of cholic acid and indole

Copper, zinc superoxide dismutase (Cu,ZnSOD) and manganese superoxide dismutase (MnSOD) activities were measured in mouse large intestinal mucosa during dimethylhydrazine (DMH) carcinogenesis. Mice were divided into five groups. Group A was subcutaneously injected with DMH (20 mg/kg) weekly and fed with a diet containing 0.2% cholic acid (C) and 0.8% indole (I). Group B was injected with DMH and given indole feeding. Group C was treated with DMH injection and cholic acid feeding. Group D was given DMH injection alone. Group E was an age-matched control group given 0.9% NaCl injection. The experiment last 21 weeks. The Cu, ZnSOD activity of intestinal mucosa in group A animals began to increase significantly at the 7th week of the experiment. In groups B, C and D, however, this enzyme was not elevated statistically until the 16th week, and then each of these groups kept an increased Cu,ZnSOD level the rest of the experimental period. MnSOD activity was elevated statistically in group C animals at the 7th week. The enzyme activity in group A and D animals increased at the 9th week, but the enzyme activity did not increase statistically until the 11th week in group B. After the 16th week of the experiment the increased activity of MnSOD in all experimental groups returned to the level of the control group. Large intestinal cancer tissues had increased Cu,ZnSOD activity and decreased MnSOD activity.

[Promoting effect of the Chinese medicinal herb, wikstroemia chamaedaphne and tung oil extracts on carcinoma of the uterine cervix induced by HSV-2 or methylcholanthrene (MCA) in mice]

The promoting effect of the Chinese medicinal herb, Wikstroemia chamaedaphne and Tung oil extracts (WC and HHPA) on carcinoma of uterine cervix induced by HSV-2 or MCA in mice was studied. The results showed that WC and HHPA extracts were not carcinogenic themselves. After carcinogen HSV-2 and MCA treatment, WC and HHPA were added separately. The inducing rates by HSV-2 increased from 7.4% to 21.1% and 26.3%, those by MCA increased from 56.5% to 82.8% and 84.4%. There was a significant difference between the combined groups and groups with HSV-2 or MCA only. The experimental results suggest that these two kinds of extracts play a promoting effect on carcinogenesis. The relation between the carcinogenesis of uterine cervix or nasopharynx and WC or HHPA extracts is discussed.

[COMVp regimen in the treatment of small cell lung cancer--report of 106 patients]

One hundred and six consecutive small cell lung cancer patients were treated by a combination regimen COMVp (CTX 1,000-1,400 mg IV D 1,8; VCR 1-2 mg IV D 1,8; MTX 20-40 mg IV or IM D 3,5,10,12; VP-16 100 mg IV drip D 3-7; three weeks as a cycle and 2-3 cycles as a course) in our hospital during 1983 to 1984. Among the 95 patients who were evaluated, 10 (10.5%) gave CR, 57 (60%) PR, 19 (20%) no change and 9 (9.5%) progression. The overall response rate was 70.5%. In this paper, factors influencing the response and side effects are also analysed. The data show that COMVp regimen is one of the good front line combination chemotherapy regimens currently available in the management of small cell lung cancer.

[Evaluation of combined chemotherapy including high-dose cisplatin in the treatment of malignant tumors]

The results of 63 patients with advanced malignant tumors treated by combined chemotherapy including high-dose cisplatin (HD-DDP) (single dose 50-100 mg/m2) are reported. The remission rates and duration of the remission for various malignant tumors were: 40% (10 PR out of 25 patients) and 3-8 months for non-small cell lung cancer (NSCLC) treated by PMFV (DDP, MMC, 5FU and VCR) regimen; 87% (4 CR and 9 PR out of 15) and 3-14 months for breast cancer treated by PCMF (DDP, CTX, MTX and 5FU) regimen; 100% (1 CR and 3 PR out of 4) and 3-10 months for testicular cancer treated by PPV (DDP, Pingyangmycin and VCR) regimen; 57% (1CR and 3 PR out of 7) and 5-12 months for malignant melanoma treated by PBDV (DDP, BCNU, DTIC and VCR) regimen; 33% (2 PR out of 6) and 5 months for esophageal cancer treated by PPV regimen. In 6 patients with other malignant tumors, the remission rate was 50% (3 PR). The results show that the combined regimens including HD-DDP in the treatment of breast cancer and NSCLC (remission rate 87% and 40%, respectively) are better than that including low-dose DDP (17% and 7%) (P less than 0.001, P less than 0.01) and that including adriamycin (30% and 13%) (P less than 0.001, P less than 0.05). In the treatment, obvious gastrointestinal reaction, leukopenia, thrombocytopenia and mild functional damage of the liver and kidney were observed.

[Intraoperative cytodiagnosis of lung masses by fine needle aspiration]

The results of intraoperative cytodiagnosis by fine needle aspiration of 51 cases with lung masses are presented. The diagnosis of benign lesion in 17/51 cases and malignancy in 34/51 cases was established by cytology. The accuracy of this cytopathologic diagnosis was 100% in our series. In 34 cases with malignant lung tumors, the accuracy, as compared with histological diagnosis in cell type, was 84.2%. At thoracotomy, this approach is easy, safe and rapid and without any complication for undetermined pulmonary lesions. In some cases with a deep lesion, this approach has proved to be most useful to avoid a blind major pulmonary resection. We believe that intraoperative cytodiagnosis of lung masses by fine needle aspiration is a valuable supplementary diagnostic measure for pulmonary neoplasms.

Vitamin A and other deficiencies in Linxian, a high esophageal cancer incidence area in northern China

Biochemical analyses were conducted to evaluate the nutritional status of a high esophageal cancer risk population in Linxian, People's Republic of China. A study was conducted in September 1980 in which plasma levels of vitamins A, B2, and C were analyzed. In a second study in 1983, the plasma fat-soluble vitamins were analyzed with a newly developed high-performance liquid chromatography method that allowed the simultaneous determination of retinol, alpha-tocopherol, beta-carotene, alpha-carotene, and lycopene in 0.1 ml of plasma sample. The average plasma retinol levels ranged from 24 to 27 micrograms/dl among the population groups, with 20-35% of the individuals having levels under 20 micrograms/dl. Low plasma beta-carotene levels averaging 8-12 micrograms/dl were observed among the population groups. Low plasma alpha-tocopherol levels with average values around 700 micrograms/dl were also observed; about half the individuals were either low or deficient in vitamin E. After 4 months of supplementation with daily multivitamin tablets, the plasma contents of retinol and alpha-tocopherol were significantly increased. The plasma alpha-carotene and beta-carotene were also increased, possibly as a reflection of seasonal changes in the diet or a sparing effect of vitamins A and E on these carotenes. Low plasma ascorbate levels with an average of 567 micrograms/dl were observed, and about 23% of the individuals had values under 200 micrograms/dl. Riboflavin deficiency was prevalent, with about 90% of the subjects having an erythrocyte glutathione activation coefficient over 1.2. The study establishes the low nutritional status in vitamins of the population in Linxian and provides the background for further studies on the effects of nutritional deficiency on carcinogenesis.