Serologic association between human papillomavirus type 16 infection and esophageal cancer in Shaanxi Province, China

BACKGROUND

The existence of large geographic variations in the prevalence of esophageal cancer in some countries, such as China, indicates that environmental risk factors may be important in the development of this disease. Some studies have implicated genital-mucosal strains of human papillomaviruses (HPVs) in the etiology of this cancer.

PURPOSE

We conducted a case-control study in Shaanxi Province, China, an area with a population at high risk for esophageal cancer, to assess the association of this disease with infection by HPV type 16 (HPV16), the most common cancer-associated genital-mucosal HPV type.

METHODS

Ninety individuals with esophageal cancer and 121 cancer-free control subjects were identified among the patients in two hospitals in Xi'an, Shaanxi Province. The control subjects were matched to the case patients on the basis of age and sex. Blood specimens were drawn from all study subjects, and serum was isolated by routine methods. The presence of HPV16 antibodies in serum samples was determined by use of an enzyme-linked immunosorbent assay (ELISA) that used baculovirus-derived HPV16 virus-like particles as the antigen. A similar ELISA that used bovine papillomavirus type 1 (BPV1) virus-like particles as the antigen controlled for the specificity of HPV16 seroreactivity. Data from the HPV16 and the BPV1 assays were normalized with respect to results obtained in each assay with a control serum of known HPV16 seroreactivity. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to examine the association between HPV16 seroreactivity and esophageal cancer. Reported P values are two-sided.

RESULTS

The mean seroreactivity to HPV16 virus-like particles was significantly higher for the cancer patients than for the control subjects (mean value +/- standard deviation = 0.85 +/- 0.22 versus 0.74 +/- 0.18; P<.0001). When the cancer patients and control subjects were compared by sex and age groups, the differences in mean seroreactivity remained statistically significant. The difference in mean seroreactivity to BPV1 virus-like particles between cancer patients and control subjects was not statistically significant (0.81 +/- 0.28 versus 0.88 +/- 0.32; P = .12); this result was not altered when sex and age groups were compared. By use of a cutoff point for HPV16 seropositivity that was established in studies of cervical neoplasia, 24% of the cancer patients were seropositive compared with 7% of the control subjects, yielding a sex- and age-adjusted OR of 4.5 (95% CI = 1.8-11.9). In general, the OR for esophageal cancer increased with increasing HPV16 seroreactivity.

CONCLUSIONS AND IMPLICATIONS

HPV16 infection may be a risk factor for esophageal cancer. Further studies of the association between HPV16 infection and the incidence of esophageal cancer are needed.

[Overexpression of P53 and its risk factors in esophageal cancer in urban areas of Xian]

OBJECTIVE

To investigate the risk factors of esophageal cancer (EC) in urban areas of Xi'an, and to correlate these risk factors with overexpression of P53 in EC.

METHODS

A hospital-based case-control study was performed. All cases (89) and controls (97) were permanent residents in urban areas of Xi'an. Tumor tissues and normal tissues adjacent to tumors of 65 cases, and 24 available normal esophageal tissues of controls were detected by P53 overexpression via immunohistochemical method.

RESULTS

Smoking and family history of EC were significantly associated with EC in Xi'an inhabitants. OR was 3.26 and 10.48, respectively. The laboratory findings indicated that P53 positive stain in Ec was 52.3% (34/65) and 6.1% (4/65) in normal tissues adjacent to tumor, but no positive stain was found in normal esophageal tissues of controls. Moreover, the results showed that P53 overexpression was closely related to smoking and family history of EC. OR was 3.89 and 17.28, respectively.

CONCLUSION

These findings suggest that smoking and family history of EC are important risk factors for EC, and the alteration of P53 gene may be related to smoking and inherited factor.

[Protective effects of radix Salviae miltiorrhizae on azathioprine hepatotoxicity in rats]

The changes of liver function and malondialdehyde (MDA) and glutathione (GSH) were studied in rats intoxicated with azathioprine (Aza) 15mg/(kg.d) and in rats treated with Aza mixed Salviae 8g/(kg.d). The results showed that in the Aza group, the levels of ALT, AKP, MDA increased and GSH decreased significantly in week 1 and week 2. But in the Salviae group the levels of ALT, AKP, MDA decreased and GSH increased significantly, approaching the normal levels, It follows that Salviae has protective effects on Aza hepatotoxicity in rats.

[Effect of total flavonoids of radix Astragali on free radical production by myocardial ischemia-reperfusion in rats]

Observation was made on the effect of TFA on FR produced by ischemia-reperfusion in two groups of Langendorff hearts of rats. The result showed that oxygen free radicals were reduced by TFA in myocardial ischemia-reperfusion in rats.

Reversion of UVC-induced tumorigenic human hybrid cells to the non-tumorigenic phenotype

Non-tumorigenic HeLa x skin fibroblast human hybrid cells were UVC-irradiated (10 J/m2) and induced to neoplastic transformation with accompanying morphological change and expression of the HeLa tumour-associated antigen, intestinal alkaline phosphatase (IAP). A single-cell-derived cell line was cloned out of a neoplastically transformed focus and designated as UV-12. In low density culture, this cell line demonstrated the ability to undergo reversion to a morphology similar to that of the non-tumorigenic parent with accompanying, much reduced levels of IAP expression. The frequency of this reversion to low IAP expression increased with passage of low density cultures reaching 10(-2) at 26 passages. A revertant colony was selected and expanded into a cell line which was designated UV-12-RM-1. This cell line had a 67-fold reduction in IAP expression compared to UV-12 and demonstrated a much reduced tumorigenic phenotype. A cell line reconstituted from a tumour derived from this cell line demonstrated a high IAP expression level (3-fold less than UV-12) and was highly tumorigenic. Six single-cell-derived lines were cloned from UV-12-RM-1 and all had low IAP expression. Of these, one demonstrated an aggressive tumorigenicity, four showed the reduced tumorigenic phenotype characteristic of UV-12-RM-1, and one (UV-12-RM-105) was non-tumorigenic. However, with passage in culture, this latter cell line reverted to a weakly tumorigenic phenotype and a much elevated IAP level. It is hypothesised that the phenotypic shifts demonstrated by these UV-induced tumorigenic cells are under epigenetic control, and that they are most likely a consequence of an underlying genetic instability in the survivors of UVC-irradiation.

Effect of low-concentration CO2 on stereoacuity and energy expenditure

BACKGROUND

Low-concentration CO2 commonly exists in our living environment in such locations as airplanes and cars. Its effect on visual performance and energy metabolism (through O2 uptake) has not been well studied, although several studies have shown that high-level CO2 (6-10%) significantly impaired visual performance.

HYPOTHESIS

We felt that breathing CO2 might also interfere with the energy expenditure pathway, partly due to the reduced O2 fraction. Thus, we studied the effect of low-concentration CO2 (2.5%) on human visual stereoacuity and energy expenditure.

METHODS

Computer-controlled Random Dot Stereograms and psychometric function were used for stereoacuity tests. A whole-room indirect calorimeter allowed for the accurate measurement of energy expenditure, and also served as a good testing environment.

RESULTS

Of 10 subjects tested, 8 had a slight increase in resting energy expenditure after exposure to 2.5% CO2. The increase ranged from 0.4-6.1% (p = 0.087, paired t-test). In stereoacuity tests, the psychometric function curves of all three subjects tested shifted to the right when breathing 2.5% CO2 and returned to baseline 2 h after breathing fresh air. Stereoacuity value, which is the reciprocal of stereoscopic threshold, was significantly lower (p < 0.01, 2-tailed z score test) after CO2 exposure for all subjects tested.

CONCLUSION

We conclude that CO2 levels as low as 2.5% can cause temporary reduction in human stereoacuity, and also cause a persistent but small increase in energy expenditure.

Factors affecting removal and prognosis of thymic tumors

One hundred and ten cases of thymic tumors were intervened surgically, including 92 thymoma, 8 thymic carcinoid, and 10 thymic carcinoma. In this series, 50.9% of the cases were complicated with various syndromes, 44.5% with myasthenia gravis (MG). Resection rate was correlated with the size and invasion of the tumor. There was significant difference in resection rate among thymoma, thymic carcinoid and thymic carcinoma. The degree of invasion undoubtedly influenced on resection. The 3-, 5- and 10- year survival rate of the thymoma were 82.7%, 68.1% and 40.0%, respectively. The prognosis depended on the pathological classification and the severity of the neighbouring invasion, but MG had no significant effect on prognosis. Recurrence and metastasis of the tumor were the main cause of late death.

[Production and characterization of specific monoclonal antibody against Porphyromonas endodontalis]

Porphyromonas endodontalis was known to be important microorganisms in the etiology of pulp and apical infection. In this paper, we generated hybridomas secreting monoclonal antibody against Porphyromonas endodontalis ATCC 35406. The specificity of the monoclonal antibody was examined by ELISA against a battery organisms (109 Strains). The results indicated that the monoclonal antibody did not react with any non-Porphy romanas endodontalis (104 Strains). So our monoclonal antibody is specific for Porphyromanas endodontalis and can be used in clinical samples for detection of pulp and apical infections.

[Mutagenicity of tyramine extracted from salted dried fish in high-risk area of gastric cancer in Zhuanghe county]

Content of tyramine was determined in salted and dried small fish collected from high-risk area of gastric cancer in Zhuanghe County, Liaoning Province with high pressure liquid chromatography, and its mutagenicity after nitrosification was assayed. Results showed content of tyramine in the fish correlated significantly with its mutagenicity (r = 0.993, and P < 0.01). And, tyramine extracted from the fish was verified by thin layer chromatography.

Induction of cisplatinum sensitivity without alteration in radiation sensitivity by fractionated radiation treatment of a human laryngeal squamous cell carcinoma cell line

PURPOSE

To determine if fractionated radiation treatment can alter cisplatinum sensitivity of a human laryngeal squamous carcinoma cell line.

METHODS AND MATERIALS

Human squamous carcinoma cells, both previously untreated, as well as survivors of fractionated radiation therapy, were tested in vitro for their sensitivity to gamma radiation and cisplatinum. Fractionated gamma radiation was delivered in 14 or 10 daily fractions of 2 Gy. The cell line, cSCC-20, was derived from an untreated primary human laryngeal carcinoma.

RESULTS

The human laryngeal squamous cell carcinoma cell line, cSCC-20, was demonstrated to have heterogeneous subpopulations with respect to cisplatinum sensitivity. No variation in radiation sensitivity was seen among subpopulations of varying cisplatinum sensitivity. The cells were relatively radioresistant (Do = 2.5 Gy). Fractionated radiation treatments of the parent cell line (14 fractions, 14 days, 2 Gy/fraction) or a cisplatinum sensitive subline (10 fractions, 12 days, 2 Gy/fraction) induced cisplatinum sensitivity (factor of 1.3 to 1.4) in the surviving cells.

CONCLUSION

Fractionated radiation treatment of human squamous carcinoma cells in vitro induced sensitivity to cisplatinum without concomitant alteration in radiation sensitivity.

Late mitosis/early G1 phase and mid-G1 phase are not hypersensitive cell cycle phases for neoplastic transformation of HeLa x skin fibroblast human hybrid cells induced by fission-spectrum neutrons

A two- to threefold increase in the rate of neoplastic transformation in cells irradiated at a dose rate of 0.22 cGy/min with fission-spectrum neutrons compared to that at 10.7 cGy/min has been confirmed with the use of alkaline phosphatase chromogenic substrate Western Blue staining to detect foci of neoplastically transformed cells through their expression of a tumor-associated antigen, the end point of the HeLa x skin fibroblast human hybrid cell transformation assay. To investigate whether the inverse dose-rate effect is due to the existence of a period in the cell cycle in which cells are significantly more sensitive to neoplastic transformation than in the rest of the cell cycle, as has been postulated previously (Rossi and Kellerer, Int. J. Radiat. Biol. 50, 353-361, 1986; Brenner and Hall, Int. J. Radiat. Biol. 58, 745-758, 1990; Elkind, Int. J. Radiat. Biol. 59, 1467-1475, 1991), we compared the sensitivity of late mitotic/early G1-phase and mid-G1-phase cells with that of asynchronous cells. The rationale for examining these particular cell cycle phases was based on the fact that mitosis has been hypothesized to be a candidate for the extremely sensitive period, and on a preliminary report that mid-G1-phase C3H 10T1/2 cells may exhibit enhanced sensitivity for neutron-induced transformation. A nominal dose of 45 cGy of fission-spectrum neutrons was delivered at approximately 10 cGy/min. The data indicate that neither late mitotic/early G1-phase nor mid-G1-phase cells are significantly more sensitive than asynchronous cells. Further, the dependence on the phase of the cell cycle for neoplastic transformation of CGL1 cells induced by fission-spectrum neutrons is different from that previously demonstrated for gamma radiation, where late-mitotic cells were approximately five times more sensitive than mid-G1-phase and asynchronous cells (Redpath and Sun, Radiat. Res. 121, 206-211, 1990).

A clinical analysis of 38 patients with primary tracheo bronchial tumors

During a 17-year period, 38 patients with primary tracheobronchial tumors received surgical treatment in PUMC Hospital. Among the 38, 12 had low-malignancy tracheal tumors, 11 had benign tracheal tumors, 14 had low malignancy bronchial tumors and 1 had a benign bronchial tumor. Fifteen operations were performed on 12 patients with low-malignancy tracheal tumors, including local resection of the tumor and tracheal wall in 4 and curettage of the tumor plus electrical cauterization in 10. Postoperative radiotherapy was used as an adjuvant treatment in 8 patients with adenocystic carcinoma. Eight patients have survived for more than 5 years and 3 patients have survived for longer than 10 years postoperatively. All 11 patients with benign tumors received curettage of the tumor and were followed up for an average of 6.5 years. Among them, 9 are still alive. Of the 14 patients with low malignancy bronchial tumors, 5 underwent curettage of the tumor plus electrical cauterization through incision of the main bronchus or intermedial bronchus, and 7 underwent lobectomy or pneumonectomy. The authors conclude that the correct diagnosis rate can be increased by enhancing recognition of this disease and applying tracheal tomography and bronchoscopy.

[Study on size distribution of 8 polycylic aromatic hydrocarbons in airborne suspended particulates indoor and outdoor]

During Jan. 20-27, 1992, the size distribution of 8 polycyclic aromatic hydrocarbons (PAHs) in airborne suspended particulates in Tokyo, Japan was studied. The results showed that PAHs, 79.0%-94.5% in indoor air and 65.4%-90.4% in outdoor air, were associated with aerodynamic diameter less than 2.5 microns particles. The contents of these PAHs in indoor air were: pyrene (Py) 1.98, benzo (a) anthracene (BaA) 0.92, benzo (k) fluoranthene (BkF) 0.91, benzo (a) pyrene (BaP) 2.13, dibenzo (a,h) anthracene (dBahA) 0.30, benzo (b) chrysene (BbC) 0.15, benzo (g,h,i) perylene (BghiP) 2.56, dibenzo (a,e) pyrene (dBaeP) 0.23 ng/m3 and in outdoor air 3.93, 2.01, 1.41, 2.91, 0.40, 0.19, 3.65 and 0.30 ng/m3 respectively. The indoor/outdoor ratios for these PAHs ranged from 0.46 to 0.79. These PAHs contents were significantly correlative with one another and so were between the PAHs contents and the concentrations of airborne particulates both indoor and outdoor (the correlation coefficients ranged from 0.774 to 0.999). The PAHs contents (excluding Py) and the concentrations of airborne particulates between outdoor and indoor samples also correlated well with each other (correlation coefficients ranged from 0.821 to 0.944).

[The clinical characters and treatment of lung cancer in youth]

From January 1970 to December 1990, 67 patients with lung cancer aged younger than 40 years, were treated in the PUMC Hospital. There were 43.3% with SCLC and 37.3% with adenocarcinoma. Twenty-eight patients underwent resection of the lung. Thirty-five cases received chemotherapy or radiotherapy only. The clinical and pathological characteristics of lung cancer in youth, and the influence of surgical and non=surgical treatments to the patients with lung cancer are discussed. The authors consider that the bronchoscopic and sputum smear examinations are very helpful for diagnosing lung cancer in the early stage. Postoperative adjuvant chemo- and radio-therapy is suggested because of the high incidence of SCLC and adenocarcinoma in the young patients with lung cancer.

A mannose-specific lectin from Vicia villosa seeds

A lectin specific to mannose has been purified from Vicia villosa seed by (NH4)2SO4 fractionation, GalNAc-Sepharose and Man-Sepharose affinity chromatography. It was defined as VVLM, which showed a single band on an acidic-PAGE stained with Coomassie brilliant blue. The molecular weight of VVLM was 50 kDa as determined by gel filtration on Biogel P-100 column. The VVLM molecule consists of 2 distinct subunits with apparent molecular weight of 30 kDa and 22 kDa determined by SDS-PAGE. VVLM has at least four isolectins with similar haemagglutinating activity. Its extinction coefficient is calculated as A1(1cm) = 16.4 at 280 nm. Sugars could not be detected by phenol-sulfuric acid method. The circular dichroism analysis at far UV indicated that VVLM was a beta-sheet-rich protein, and gave no alpha-helix, 69% beta-sheet, 14% beta-turn by Provencher and Glockner method. The lectin was inhibited by alpha-methyl-D-mannose at 12.5 mM and glucose or GlcNAc at 50 mM. The carbohydrate binding specificity of VVLM was investigated by using affinity chromatography on a VVLM-Sepharose column. Among various Asn-linked oligosaccharides, core structure Man alpha 1-->3(Man alpha 1-->6)Man beta 1-->4GlcNAc beta 1-->4GlcNAcOT were found to have high affinity for VVLM-Sepharose. The antisera of VVLM did not produce precipitin line with VVLG in agar double diffusion plate indicating no serological relationship between VVLM and VVLG. However VVLM showed similar immunodeterminants of some other lectins of mannose specificity such as Con A, PSL, LCA and VFL.

[A study of DNA damage induced by asbestos fibers in vitro]

The results of our in vitro study showed that Rhodesia chrysotile, X. K. chrysotile, UICC chrysotile, crocidolite and amosite could cause damage to calf thymus DNA by inducing the production of 8-hydroxy-2'-deoxyguanosine (8-OH-dG). After adding H2O2 and/or FeSO4, the production of 8-OH-dG, induced by asbestos fibers was significantly increased. The fiber of UICC crocidolite has the most untoward effect, that of UICC amosite comes next, and the three chrysotile fibers are the weakest ones. The effect of asbestos fibers on the production of 8-OH-dG has some relationship with hydroxy free radical and the type of asbestos. It is suggested that asbestos fibers could induce DNA point mutation through A.T and G.C transversion by the production of 8-OH-dG, which is related with the carcinogenesis of asbestos.

The yeast NOP4 gene product is an essential nucleolar protein required for pre-rRNA processing and accumulation of 60S ribosomal subunits

The Saccharomyces cerevisiae NOP4 gene was isolated by screening a lambda gt11 yeast genomic DNA library with a monoclonal antibody against a yeast nucleolar protein. NOP4 encodes a 78 kDa protein that contains two prototypical RNA recognition motifs (RRMs) flanking an imperfect RRM lacking characteristic RNP1 and RNP2 motifs. In addition, there is a fourth incomplete RRM. NOP4 is a single copy essential gene present on chromosome XVI, between RAD1 and PEP4. To examine the function of Nop4p, we constructed a conditional null allele of NOP4 by placing this gene under the control of the glucose-repressible GAL1 promoter. When cells are shifted from galactose-containing medium to glucose-containing medium, NOP4 transcription is terminated, Nop4 protein is depleted and cell growth is impaired. Nop4 protein depletion results in diminished accumulation of 60S ribosomal subunits, assignable to a defect in ribosome biogenesis arising from a lack of production of mature 25S rRNA from 27S precursor rRNA.

Hemorrhagic fever with renal syndrome: relationship between pathogenesis and cellular immunity

After phenotype analysis of peripheral blood mononuclear cells (PBMC), soluble interleukin-2 receptor (sIL-2R) levels in plasma or sera from patients with hemorrhagic fever with renal syndrome (HFRS) were measured. The results showed the ratio of activated antigen (CD25, TLiSA1, CD71, and Ia)-positive lymphocytes of PBMC in the acute phase of HFRS was higher than that in convalescent phase. Moreover, there was much higher expression of heteromorphologic lymphocytes than of small lymphocytes. Decreases in T lymphocytes and CD4:CD8 ratios were seen with increases in B lymphocyte ratios and interferon-gamma (IFN-gamma) expression on PBMC surfaces in the acute phase of HFRS. IFN-gamma-positive lymphocytes included CD4, CD8, and CD56 subsets. sIL-2R levels were much higher in sera and plasma in the acute phase, especially the oliguric phase. These findings suggest that patients with HFRS are in a state of high-level cellular immune response, which may be involved in the development of inflammation and pathologic lesions.

The effect of postirradiation holding at 22 degrees C on the repair of sublethal, potentially lethal and potentially neoplastic transforming damage in gamma-irradiated HeLa x skin fibroblast human hybrid cells

The effect of postirradiation holding at 22 degrees C on cell growth, progression of cells through the cell cycle, and the repair of sublethal, potentially lethal and potentially neoplastic transforming damage in gamma-irradiated HeLa x skin fibroblast human hybrid cells has been examined. Cell growth and cell cycle progression were essentially stopped at this reduced temperature. Cell survival was dramatically reduced by holding confluent cultures for 6 h at 22 degrees C, as opposed to 37 degrees C, after 7.5 Gy gamma radiation delivered at a rate of 2 Gy/min. Return of the cells to 37 degrees C for 6 h after holding at 22 degrees C did not result in increased survival. A similar effect was obtained when the cells were held at 22 degrees C between split-dose irradiation of log-phase cultures where no increase in survival was observed over a split-dose interval of 4 h. In this case a partial increase in survival was observed upon returning the cells to 37 degrees C for 3 h after holding at 22 degrees C for the first 3 h of the split-dose interval. Neoplastic transformation frequency was not enhanced by holding confluent cultures for 6 h at 22 degrees C after 7.5 Gy gamma radiation. This is consistent with previous observations that misrepair of potentially neoplastic transforming damage already occurs at 37 degrees C. The overall results are interpreted in terms of the reduced temperature favoring misrepair, rather than inhibition of repair, of sublethal, potentially lethal and potentially transforming radiation damage.

Total gastrectomy via thoracotomy for cancer of the cardia or fundus of the stomach (report of 90 cases)

From 1978 through 1990, 90 total gastrectomies with esophagojejunostomy via thoracotomy were performed for the treatment of cancer of the cardia or fundus of the stomach in our hospital. Eighty-five patients were in TNM-stage III and five in stage IV. The 30-day postresectional mortality was 1.1%, and the 5-year survival rate was 13.8%. 14CO2 breathing test and clinical evaluation of 34 postoperative patients (not included in the 90 patients) showed that total gastrectomy may decrease the incidence of positive residual cancer along the incision lines, and may help to avoid small stomach syndrome. There was no statistical difference in postoperative fat absorption between patients treated by ordinary proximal subtotal gastrectomy and those receiving total gastrectomy via thoracotomy.

Effects of cholesterol on the miscibility of synthetic glucosamine diesters in lipid bilayers and the entrapment of superoxide dismutase into the positively charged liposomes

Methyl-D-glucosamine-3,6-dilauroyl, dimyristoyl, dipalmitoyl or distearoyl esters were synthesized as positively charged lipids. They were incorporated into phosphatidylcholine liposomal membranes and the entrapment of superoxide dismutase (SOD) into the liposomes was attempted. The efficiency of the SOD-entrapment into the positively charged multilamellar vesicles (MLVs), comprising egg yolk phosphatidylcholine and synthetic glucosamine diesters, was enhanced by the addition of cholesterol to the membranes. A differential scanning calorimetric study showed that the miscibility (solubility) of glucosamine diesters in phosphatidylcholine-bilayers increased on the addition of cholesterol to the membranes. Cholesterol assisted in the mixing of phosphatidylcholines with positively charged glucosamine diesters and increased the positive charges on the liposomal membranes. This was confirmed by incremental increases in the zeta-potential of liposomal membranes with an increase in the cholesterol content. Entrapment of SOD thus became more efficient due to the enhanced electrostatic attraction between the positively charged membranes and the negatively charged SOD, and/or the electrostatic repulsive interactions between positively charged membranes; the latter interactions induced a thickening of the water layer in MLVs.

Misdiagnosis of lung cancer in patients under age 40--a clinical analysis of 47 cases

Diagnosis of lung cancer in 47 patients aged younger than 40 years was delayed as a result of misdiagnosis, accounting for 70.1% of all cases of lung cancer in those aged less than 40 years treated in PUMC Hospital in the same period. Pulmonary tuberculosis and tuberculous pleurisy were diagnosed in 26 cases (55.3%). Pulmonary inflammation was suspected in 24 cases (51.1%). The delay in diagnosis was one to three months in 28 cases and longer than 3 months in 19 cases. Twenty-eight (59.6%) of the 47 patients underwent surgery, including exploratory thoracotomy (21.4%) and pneumonectomy (40.9%). The five-year survival rates in the resectable group and in the non-surgical group were 31.6% and 5.3%, respectively. We recommend that accessory examinations should be performed wherever possible in younger patients with suggestive pulmonary nodules in order to collect sufficient evidence to confirm or rule out the diagnosis of lung cancer and thereby reduce the rate of misdiagnosis in such younger people.

Conformation and activity of Phaseolus coccineus var. rubronanus lectin

The conformation of native and denatured Phaseolus coccineus var. rubronanus lectin was studied by circular dichroism (CD) and correlated to the hemagglutinating activity. The far-UV CD spectrum at 25 degrees C showed a broad, negative band around 223 nm and a positive one at 196 nm. CD data analysis of the lectin indicated a beta-sheet-rich protein. At high temperatures, the spectrum was blue-shifted with increasing magnitude; these changes correlated well with the loss of the activity. The conformation of lectin between pH 2 and 10 remained essentially unchanged. At pH 13 the CD spectrum resembled that of unordered form with a negative band near 200 nm and the activity was completely lost. The denatured lectin in 6 M guanidine hydrochloride would be renatured upon diluting the denaturant to 0.75 M; the changes in CD spectrum again correlated well with the loss of the activity. The effect of sodium dodecyl sulfate on the lectin was drastic; it sharply increased the alpha-helix at the expense of the beta-sheet and reduced the activity; the changes reached a plateau above 20 mM surfactant.

Effects of copper coordinate complexes on the scavenging of reactive oxygen species

Effects of a 20-membered macrocyclic bicopper complex and dioxotetramine copper complexes with linear or cyclic structure on the scavenging of ROS have been studied by ESR. The results indicated that all three copper coordinate complexes have SOD mimetic activity. The dioxotetramine copper complex with linear or cyclic structure did not have the scavenging effect on .OH produced by H2O2-Fe++ and 1O2 produced by the H2O2-NaOCl system, but the 20-membered macrocyclic bicopper complex was found to be capable of depressing the intensity of the ESR spectrum of the adduct formed from TMP and 1O2 as well as making the spectrum of DMPO-OH adduct splittings. This fact may suggest that there are interactions between the ROS and 20-membered macrocyclic ring in the SOD mimic.

Election spin resonance studies of free radical formation and oxygen consumption of lens epithelium during ultraviolet exposure

A long life election spin resonance (ESR) signal at g = 2.0006 was observed in the normal lens epithelium and cortical fibers. During ultraviolet (UV) exposure, a new ESR signal at g = 2.0060 was found in the lens epithelium. But this specific signal was not detected in the lens cortical fibers. This suggested that lens epithelial cells were more susceptible to the free radical formation which was induced by UV light. By means of ESR spin probe oximetry, the oxygen uptake of lens epithelial cells was measured. The more the oxygen uptake, the higher the K value was. The K value of the oxygen consumption of epithelial cell linearly correlated with time of consumption (20-60 min) and increased as a function of UV exposure time (1-5 min). The oxygen consumption rate of lens epithelial cell was approximately 1.38 x 10(6) and increased to 7.1 x 10(6) O2 molecules per cell per sec. The oxygen consumption rate increased more than 5 times. These results indicates that UV light can accelerate the respiratory function of lens epithelial cells. The necessity of excess oxygen of lens epithelial cells may play a role in the cataract formation induced by UV light.

The effects of hybridoma growth factor in conditioned media upon the growth, cloning, and antibody production of heterohybridoma cell lines

Interleukin 6 (IL-6)/hybridoma growth factor (HGF) has been shown to be the requirement for growth of murine hybridomas in vivo or in vitro. In this paper, two kinds of conditioned media (CM) from the culture supernatants of a human fibroblast cell line CRL1506 and a cloned Epstein-Barr virus (EBV) transformed human lymphoblastoid cell line (LCL) N23 were found to have IL-6 activity by strongly promoting the growth, antibody secretion (increase of one- to three-fold), and cloning efficiencies of heterohybridomas secreting human monoclonal anti-hemorrhagic fever with renal syndrome virus antibodies and LCL. Since these CM contained no detectable IL-2, and IL-4 had no effects on the growth of the cell lines, IL-6 was considered to be the main active component of the CM responsible for promoting hybridoma growth. This effect was further confirmed by IL-6-dependent cell line 7TD1 bioassay (IL-6 activity in the CM ranging from 1,000 to 10,000 units/ml). Moreover, we successfully established four EBV-transformed lymphoblastoid cell lines at single-cell level by adding an equal volume of CRL1506-CM to 10% FCS-RPMI1640 in limiting dilution. Finally, it is worth noting that the sensitivity of the heterohybridomas to the two kinds of CM was not the same and was not consistent with that of their parental myeloma cell lines. Thus, it suggests that the CM might contain more than one factor, and the choice of proper conditioned media should be very useful for human monoclonal antibody production.

Conformation and activity of mannose- and N-acetylgalactosamine-specific lectins from Vicia villosa seeds

The conformation of two Vicia villosa lectins specific for mannose and N-acetylgalactosamine, respectively, was studied by circular dichroism. Both showed a broad negative CD band around 220 nm and a positive one above 190 nm. CD data analysis indicated that they were rich in beta-sheet. However, they differed in conformational stability against extreme pH, at elevated temperature, and in guanidine hydrochloride and sodium dodecyl sulfate solutions. The unusual feature was that the conformation of N-acetylgalactosamine-specific lectin was virtually unaltered in 6 M guanidine hydrochloride and 7.5 mM surfactant.

The effect of multi-glycosides of Tripterygium wilfordii Hook f. (GTW) on the survival time of cardiac allografts in rats

Heterotopic heart transplantation was carried out in rats and the influence of multi-glycosides of Tripterygium wilfordii Hook f. (GTW) and a subtherapeutic dose of cyclosporine A (CsA) on the mean survival time (MST) of the cardiac allografts was investigated. The results showed that the MSTs of cardiac allografts in both the GTW and CsA-treated groups were significantly prolonged (P < 0.01 vs control). The rate of allograft rejection in the drug-treated groups was much lower than that in the control group.

[Morphology and delta-endotoxin proteins of Bacillus thuringiensis from soils and their toxicities to insects]

94 strains of Bacillus thuringiensis were isolated from soils in southwest and northwest of China. The morphology of cells, spores and parasporal crystals of these strains was investigated under transmission and scanning electro-microscope. Proteins of delta-endotoxins from all strains were analysed by rapid SDS-PAGE. 9 species of insects in Lepidoptera, Coleoptera and Diptera were tested for assay of delta-endotoxins. Some kinds of parasporal crystals were quite different in form and in composition of protein from those reported before. Most of strains were nontoxic to all of 9 species used in bio-assay. Some strains were very effective in species of Coleoptera or Noctuidae.

Lack of differential G2 chromosomal radiosensitivity between non-tumorigenic and tumorigenic human hybrid cells (HeLa x skin fibroblasts)

Previous studies have shown, that for log phase cultures, tumorigenic segregants of HeLa x skin fibroblast human hybrid cells are slightly more radiosensitive in terms of cell killing than their nontumorigenic parents (Redpath et al. 1985, Colman et al. 1988). Other studies have shown that these same tumorigenic segregants exhibit a markedly enhanced G2 chromosomal radiosensitivity (Sanford et al. 1986) thus offering a possible explanation for the cell killing data. The present study set out to examine the G2-phase radiosensitivity of these cells in terms of cell killing with the expectation that an enhanced sensitivity in the tumorigenic cells would be seen. No enhanced sensitivity was observed. The G2 chromosomal radiosensitivity was then examined and no differential was seen between the non-tumorigenic and tumorigenic cells. This lack of confirmation of previously reported studies may be due to some technical differences in the experimental protocols.

A simplified and rapid staining method for the HeLa x skin fibroblast human hybrid cell neoplastic transformation assay

A simplified and rapid screening method for detecting radiation-induced neoplastically transformed foci in the HeLa x skin fibroblast human hybrid cell assay system has been developed. The method is based on the recent identification of the tumor-associated antigen in this system as intestinal alkaline phosphatase (IAP), and on the recent commercial development of a stable alkaline phosphatase chromogenic substrate solution, Western blue (WB). Cleavage of the substrate results in the production of a blue insoluble precipitate. It is shown that WB can be used on both viable and paraformaldehyde-fixed cells. Fixation does not noticeably reduce the IAP enzymatic activity. A direct comparison with the current method of immunoperoxidase (IMPO) staining indicates that the WB method is not only easier, but appears to be more sensitive in picking up weakly positive foci with a resulting higher (factor of 2.5) induced transformation frequency for 7 Gy of 137Cs gamma radiation. Whereas the IMPO staining procedure is time-consuming and requires access to large amounts of expensive IAP-specific BD6 monoclonal antibody and peroxidase-labeled secondary antibody, the WB staining procedure is rapid and utilizes an inexpensive and readily available reagent. It should now allow this assay system to enter general use.

Another discontinuous epitope on glycoprotein gp120 that is important in human immunodeficiency virus type 1 neutralization is identified by a monoclonal antibody

To define the domains in the envelope glycoprotein important for antibody neutralization of the human immunodeficiency virus type 1 (HIV-1), monoclonal antibodies (mAbs) were generated by immunizing mice with purified glycoprotein gp120 of the IIIB isolate. One mAb, G3-4, reacted with the gp120 of homologous (IIIB) and heterologous (RF) isolates. In addition, mAb G3-4 efficiently neutralized both IIIB and RF viruses in vitro, as well as four of nine primary HIV-1 isolates. In competition immunoassays, mAb G3-4 and soluble CD4 were found to inhibit one another in binding to gp120. However, no competition was seen between mAb G3-4 and mAbs directed to the third variable region or the fourth conserved region of gp120. In particular, mAb G3-4 did not compete with our human mAb 15e, which identifies a discontinuous epitope on gp120 involved in group-specific neutralization of HIV-1 and in gp120-CD4 binding. Epitope-mapping studies on mAb G3-4 with synthetic or unglycosylated recombinant peptides were negative, suggesting that its epitope may be discontinuous. Indeed, this hypothesis was confirmed by showing the loss of mAb G3-4 serologic reactivity when gp120 was first denatured. We conclude that the site recognized by mAb G3-4 represents another discontinuous epitope on gp120 important for neutralization of HIV-1.

Effect of fission-neutron dose rate on the induction of a tumor-associated antigen in human cell hybrids (HeLa X skin fibroblasts)

The HeLa X skin fibroblast human cell hybrid system has been used to study the effect of fission-neutron dose rate on the induction of neoplastic transformation. Previously published data using neutrons from the JANUS reactor at Argonne National Laboratory are compared with some preliminary data obtained on the TRIGA reactor at the Armed Forces Radiobiology Research Institute. Comparable results were obtained on both reactors, both in terms of absolute values of transformation frequency and in terms of magnitude of the inverse dose-rate effect (a factor of 2.5 to 3).

Treatment of small cell lung cancer

During a 28-year period, 110 patients with small cell lung cancer were treated at our hospital. Fifty-nine patients received surgery, and 58 patients (including 7 cases after exploratory thoracotomy) received chemotherapy and/or radiotherapy. The 5-year survival rate of the surgically treated group was 17%, while none in the non-surgical group survived for more than 5 years.

[Orthogonal test for the best conditions of treating licorice seeds with sulphuric acid]

Adopting the method of orthogonal test and using the orthogonal table of L25(5(6)), this paper has made a test of the influential factors in treating the licorice seeds with sulphuric acid. The result shows that the best treating conditions are as follows: H2SO4 concentration over 80%. H2SO4 amount 10-20 ml/kg. Treating temperature 10-25 degrees C. Treating time 2 hours.