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.

Lack of immunity to hepatitis B virus among the expatriates residing in southern Taiwan

Taiwan is an endemic area for hepatitis B virus (HBV) infection. There are more than 3-million carriers on this island. Chronic HBV infections may result in liver cirrhosis and hepatocellular carcinoma, which are common in Taiwan. However little information is available concerning the immunity and the susceptibility to HBV among the expatriate-population (non-permanent residents from foreign countries) in Taiwan. Thus controversies exist on the indications for HBV vaccination among the foreign visitors and expatriates. This study evaluated the serological status of those who attended the Kaohsiung Adventist Clinic between May 1986 and August 1989. Hepatitis B surface antigen (HBsAg) and antibody (anti-HBs) were determined by ELISA. A total of 152 expatriates (85M, 67F, aged 5 to 64 years, duration of residence in Taiwan: 2 weeks to 11 years) without previous HBV vaccination, were tested. HBsAg and anti-HBs were not detected in 125 (82%). Anti-HBs was found in 22 (15%). There was no correlation between the duration of residence and anti-HBs positivity. However, there was an increased prevalence of anti-HBs with increasing age after 30. For those expatriates who were anti-HBs positive, 64% had a history of sexual contact with a partner from an endemic area of HBV. HBsAg was detected in 5 (3%). Three were symptomatic with abnormal liver function tests. Four had a history of sexual exposure. Their children were not antigenemic. It is concluded that most (greater than 82%) of the expatriates residing in southern Taiwan have no immunity to HBV and sexual contact is a major route (70%) of transmission.(ABSTRACT TRUNCATED AT 250 WORDS)

Transfectomas expressing both secreted and membrane-bound forms of chimeric IgE with anti-viral specificity

Because of the lack of a cell line expressing on surface and secreting human IgE of known Ag specificity, the construction of a transfectoma line possessing such properties would be useful for studying the roles of surface IgE and the effects of anti-IgE antibodies on IgE-producing B cells. Toward this goal, the human genomic DNA segment encompassing the two exons encoding the membrane anchor peptide of epsilon-chain and their flanking regions was sequenced. Hybrid epsilon and kappa genomic DNA comprising the C regions of human epsilon- and kappa-chains and the H and L chain V regions of the murine mAb BAT123, which reacts with the gp120 envelope protein of HIV-1, were constructed. Mammalian expression vectors containing these fusion genes were used to transfect murine myeloma Sp2/0 cells, and transfectants stably expressing on surface and secreting into culture medium chimeric IgE were obtained. The chimeric IgE showed identical Ag-binding properties as the murine mAb BAT123. Acting in concert with the specific peptide Ag polyvalently coupled to a protein carrier, the chimeric antibody could induce histamine release from human blood basophils. These results demonstrate the potential utility of the transfectoma cells and the chimeric IgE in studying the roles of membrane-bound IgE and effects of anti-IgE antibodies on IgE-producing B cells.

Monitoring of cyclosporine concentrations by using dry blood-spot samples

We modified the Incstar Cyclo Trac SP kit to enable its use with dry blood-spots on filter paper. The recovery ranged from 92 to 106%. Dilution studies have shown excellent linearity and parallelism throughout the range of the assay. Precision is demonstrated by within-assay CV's of 6.6 and 4.3% at 96 and 342 micrograms/L respectively and between-assay CV's of 9.1 and 7.0% at 138 and 506 micrograms/L respectively. A comparison study (n = 209) with whole blood assay gave a correlation coefficient of 0.97, a slope of 1.04, and an intercept of 13.2. Whole blood and dry blood-spot cyclosporine assays on heart, kidney, liver, and lung transplants were also compared.

Transfectomas expressing both secreted and membrane-bound forms of chimeric IgE with anti-viral specificity

Because of the lack of a cell line expressing on surface and secreting human IgE of known Ag specificity, the construction of a transfectoma line possessing such properties would be useful for studying the roles of surface IgE and the effects of anti-IgE antibodies on IgE-producing B cells. Toward this goal, the human genomic DNA segment encompassing the two exons encoding the membrane anchor peptide of epsilon-chain and their flanking regions was sequenced. Hybrid epsilon and kappa genomic DNA comprising the C regions of human epsilon- and kappa-chains and the H and L chain V regions of the murine mAb BAT123, which reacts with the gp120 envelope protein of HIV-1, were constructed. Mammalian expression vectors containing these fusion genes were used to transfect murine myeloma Sp2/0 cells, and transfectants stably expressing on surface and secreting into culture medium chimeric IgE were obtained. The chimeric IgE showed identical Ag-binding properties as the murine mAb BAT123. Acting in concert with the specific peptide Ag polyvalently coupled to a protein carrier, the chimeric antibody could induce histamine release from human blood basophils. These results demonstrate the potential utility of the transfectoma cells and the chimeric IgE in studying the roles of membrane-bound IgE and effects of anti-IgE antibodies on IgE-producing B cells.

Fission-neutron-induced expression of a tumour-associated antigen in human cell hybrids (HeLa x skin fibroblasts): evidence for increased expression at low dose rate

The induction of a tumour-associated antigen in a human cell hybrid line (HeLa x skin fibroblast) following exposure to fission neutrons of average energy 0.85 MeV (Janus reactor, Argonne National Laboratory) at two dose rates, 0.086 and 10.3 cGy/min, has been examined. The dose-response data obtained indicate the lower dose rate to be 2.9-fold more effective than the higher in inducing expression of the tumour-associated antigen, while there was no significant dose-rate effect in terms of cell killing. These results are qualitatively in agreement with previous observations using neutrons from the Janus reactor for the neoplastic transformation of C3H10T1/2 cells and Syrian hamster embryo cells.

Suppression of radiation-induced neoplastic transformation of human cell hybrids by long term incubation at low extracellular pH

We have previously reported that, when 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid buffer was used in the growth medium to control pH fluctuations during the 21-day expression period of our human cell hybrid (HeLa x skin fibroblast) transformation assay, the yield of radiation-induced neoplastically transformed foci after 7 Gy of gamma-irradiation was suppressed. We now demonstrate that the observed suppression is not related to the presence of the 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid buffer per se but rather is a function of the growth medium pH. Detailed studies reveal that incubation of the irradiated cells during the entire 21-day expression period at pH 6.7-6.8 versus pH 7.0-7.2 significantly suppressed the transformation frequency after 7 Gy, from 4.4 x 10(-4) to 4.6 x 10(-5) (accumulated data). The endpoint fraction of flasks containing foci was also significantly reduced at the lower pH. Suppression was evident whether the growth medium pH was lowered from pH 7.0-7.2 to pH 6.7-6.8 by medium exchange on day 0, 1, or 9 or even up to 15 days post-irradiation. Growth curves revealed that the population doubling time of the cells is extended and the unirradiated and irradiated plating efficiencies are lowered by long term low pH exposure. We discuss possible mechanisms for the observed suppression, in terms of the influence of low extracellular pH on cell turnover, repair of radiation damage, cell toxicity, and activity of cellular proteases.

[Determination of traces of gallium in air by oscillographic polarography]

Gallium and its compounds in air collected by millipore filter membrane are leached by 10% HNO3 at room temperature. After being adjusted with ammonia solution to pH8-9, the leachate is filtered and the filtrate is evaporated to dryness on a water bath. The residue is dissolved with 2 ml of 10% HNO3 and then into the solution are added 0.5 ml of 5% hydroxylamine hydrochloride solution, 0.20 ml of 5% sulfosalicyclic acid solution, 0.5 ml of NaF solution (1mg F/ml) and 1 drop of methyl red solution. Let it stand for 5 min after the color of the solution turns orange by addition of 1:1 NH4OH solution. Add 0.20ml of 0.20% cupferron solution, 0.20ml of 0.5% diphenyl-guanidine solution (prepared in 95% ethanol) and 0.5ml of acetic acid-ammonium acetate buffer (pH 7.0). Then add water to make the final volume of the test solution to be 10ml and measure the height of the second derivative polarographic wave at -1.08V (vs.SCE). The sensitivity of the method is 0.005-0.10 microgram/ml, the coefficient of variation 6.8%, recovery 97.8%. Within 0.005-0.10 microgram/ml, the wave height is linear with the concentration of gallium.

Sensitivity of a human hybrid cell line (HeLa X skin fibroblast) to radiation-induced neoplastic transformation in G2, M, and mid-G1 phases of the cell cycle

The dependence of gamma-radiation-induced neoplastic transformation frequency on position in the cell cycle was measured for a human hybrid cell line (HeLa X skin fibroblast). The end point used was the induction of a tumor-associated antigen which in these cells correlates with tumorigenicity. Induction was measured in cells at G2, M, and mid-G1 phases and compared with the frequency induced in asynchronous cells. For studies of cells in G2 phase, the cells of an asynchronous population were collected for 3 h post-irradiation using the mitotic shake-off technique. For studies of cells in M and mid-G1 phases, cells were collected by mitotic harvest and then treated at the appropriate time. The data show that cells in G2 and M phase are very radiosensitive in terms of both cell killing and induction of neoplastic transformation compared to cells in mid-G1 or asynchronous populations. At a dose of 1 Gy, the transformation frequency was 10- to 20-fold higher for cells in M and G2 phase than for cells in mid-G1 or for asynchronous cells. However, the data indicate that the transformation frequencies were similar in the different phases of the cell cycle when correlated with surviving fraction. The results indicate that transformation frequency is more sensitive to changes in dose than is cell survival.

A chimeric mouse-human antibody that retains specificity for HIV gp120 and mediates the lysis of HIV-infected cells

Murine mAb BAT123, which was made against the envelope glycoprotein gp120 of HTLV-IIIB strain of HIV type 1 (HIV-1), is capable of neutralizing HTLV-IIIB in vitro. It also inhibits the fusion between uninfected CD4+ cells and HIV-1-infected cells to form syncytia. As a step to explore the potential utility of the anti-HIV antibody in vivo, we have constructed a mouse-human chimeric antibody by rDNA techniques. The chimeric antibody, which bears the variable domains of mouse antibody BAT123 and constant domains Cr1 and C kappa of human Ig retains the Ag specificity of BAT123 as determined by its reactivity with HIV-1-infected H9 cells, gp120 in Western blot analysis, and the oligopeptide recognized by BAT123. The antiviral activities of the chimeric antibody in neutralizing HIV-1 infection as well as inhibiting the syncytia formation are also found identical to those of the parent murine antibody. Moreover, in the presence of human blood mononuclear cells, the chimeric antibody but not BAT123 (mouse IgG1) induces antibody-dependent cellular cytotoxicity. The findings point to the potential usefulness of the chimeric antibody in treating patients infected with HIV-1.

A chimeric mouse-human antibody that retains specificity for HIV gp120 and mediates the lysis of HIV-infected cells

Murine mAb BAT123, which was made against the envelope glycoprotein gp120 of HTLV-IIIB strain of HIV type 1 (HIV-1), is capable of neutralizing HTLV-IIIB in vitro. It also inhibits the fusion between uninfected CD4+ cells and HIV-1-infected cells to form syncytia. As a step to explore the potential utility of the anti-HIV antibody in vivo, we have constructed a mouse-human chimeric antibody by rDNA techniques. The chimeric antibody, which bears the variable domains of mouse antibody BAT123 and constant domains Cr1 and C kappa of human Ig retains the Ag specificity of BAT123 as determined by its reactivity with HIV-1-infected H9 cells, gp120 in Western blot analysis, and the oligopeptide recognized by BAT123. The antiviral activities of the chimeric antibody in neutralizing HIV-1 infection as well as inhibiting the syncytia formation are also found identical to those of the parent murine antibody. Moreover, in the presence of human blood mononuclear cells, the chimeric antibody but not BAT123 (mouse IgG1) induces antibody-dependent cellular cytotoxicity. The findings point to the potential usefulness of the chimeric antibody in treating patients infected with HIV-1.

Studies of the UVC-sensitivity of non-tumorigenic and tumorigenic human cell hybrids (HeLa x skin fibroblasts)

The UVC-sensitivities of a non-tumorigenic and a tumorigenic human cell hybrid (HeLa x skin fibroblasts) are compared and contrasted. The tumorigenic cells differ from the non-tumorigenic cells in that they have lost one copy each of chromosomes 11 and 14. For exponentially growing cultures, the tumorigenic cells are considerably more resistant than the non-tumorigenic cells. For confluent cultures, the differential in photosensitivity is much less. Flow cytometric studies of cell cycle distributions of both exponentially growing and confluent cultures of these cells indicate that the differences in photosensitivity cannot be explained by differences in cell cycle distribution. Studies of the kinetics of potentially lethal damage repair (PLDR) in confluent cultures of both cell lines indicate little or no recovery over the first 6 h followed by an increase in survival over the next 12-24 h. These data are consistent with previously published observations in human skin fibroblasts where the kinetics of PLDR reflected the kinetics of thymine dimer loss. The data are not consistent with 6-4 photoproducts being a potentially lethal lesion since such damage is rapidly repaired in human cells.

UVC-induced expression of a tumor-associated antigen in human cell hybrids (HeLa X skin fibroblasts): repair of potentially lethal and potentially transforming damage

The UVC-induced expression of a cell surface protein which correlates with the induction of tumorigenicity has been observed in human cell hybrids (HeLa X skin fibroblasts). A dose - response curve for the induction of this marker of neoplastic transformation has been obtained. Studies of the repair of potentially lethal and potentially transforming damage indicate a slow repair process which results in enhanced survival and decreased neoplastic transformation over the period 6-24 h post-treatment. The kinetics of this repair process are consistent with previously published work on the kinetics of removal of thymine dimers from UVC-irradiated human skin fibroblasts. During the first few hours post-irradiation (0-6 h) there are fluctuations in transformation frequency while survival remains essentially constant. It is during this period that 6-4 photoproducts are removed from UV-irradiated DNA. It is possible that repair of these lesions may lead to an increase in transformation frequency and have no impact in terms of survival.

Measurement of boar sperm motility by the trans-membrane migration method

The conventional microscopic methods for evaluating sperm motility of domestic animals are mostly inadequate due to their subjectivity and lack of precision. Recently, a trans-membrane migration method, originally developed for the examination of human sperm motility, has substantially overcome these problems. This study investigated the applicability of the method to boar sperm motility measurement. The apparatus used was simple and consisted only of syringe plungers, poriferous membranes, and modified multi-well culture plates. It measured the proportion of sperm in the semen that moved across the membrane after incubation at 37 degrees C for 3 hr. The sperm motility as measured by this method correlated well with that measured by direct microscopic examinations. The measurement was more reliable using an 8-microns instead of a 5-microns pore-size membrane. The method was found to work equally well for the sperm motility measurement of the semen with a sperm concentration between 1.5 x 10(8)/ml and 6.0 x 10(8)/ml. The results indicate that this method is a simple, objective, quantitative, and reproducible design for the measurement of boar sperm motility.