Comparative study on the natural occurrence of Fusarium mycotoxins (trichothecenes and zearalenone) in corn and wheat from high- and low-risk areas for human esophageal cancer in China

A comparative study on the natural occurrence of Fusarium toxins was done with 47 corn and 30 wheat samples collected in 1989 from Linxian and Shangqiu Counties in Henan Province, People's Republic of China, high- and low-risk areas, respectively, for esophageal cancer. Three trichothecenes (deoxynivalenol [DON], 15-acetyldeoxynivalenol [15-ADON], and nivalenol [NIV]) and zearalenone (ZEA) were detected in corn samples, and DON, NIV, and ZEA were found in wheat samples. Compared with Shangqiu corn, the incidence and mean level of DON in Linxian were 2.4 and 5.8 times higher, respectively, and those of 15-ADON were 16.3 and 2.6 times higher, respectively. The incidence and level of trichothecenes in wheat samples were significantly lower than those in corn. However, the level of DON in Linxian wheat was 3.3 times higher than in Shangqiu wheat. This is the first report indicating a significant difference in the natural occurrence of Fusarium toxins in main staple foods between high- and low-risk areas for esophageal cancer in the People's Republic of China.

Marked difference in the in vivo antitumor efficacy between two immunotoxins targeted to different epitopes of common acute lymphoblastic leukemia antigen (CD10). Mechanisms involved in the differential activities of immunotoxins

In the present study, two isotype-matching mAb, SN5d and SN5, which are directed toward two distinctively different epitopes of common acute lymphoblastic leukemia Ag (CD10) but show a very similar binding affinity to leukemia cells, were compared for their in vivo antitumor activity after conjugated to ricin A chain (RA). Our recently established nude mouse model carrying an ascitic tumor of NALM-6 human pre-B leukemia cells was used as the tumor model. A marked difference was observed in the in vivo antitumor efficacy between SN5d-RA and SN5-RA; SN5d-RA was much more effective than SN5-RA. Several experiments were carried out to gain information concerning the mechanisms involved in the different antitumor efficacy of the two immunotoxins. Although naked (unconjugated) mAb SN5d was much less effective than SN5d-RA conjugates in the in vivo tumor suppression, mAb SN5d was more effective than mAb SN5 in the in vivo tumor suppression. Additionally, marked differences were found between SN5d and SN5 in the induction of antigenic modulation and in the regulation of Ag biosynthesis and expression. Binding of SN5 to NALM-6 leukemia cells caused strong antigenic modulation (down-regulation of Ag expression) and strongly down-regulated Ag biosynthesis and cell surface expression of new Ag. In contrast, binding of SN5d to NALM-6 leukemia cells caused little modulation of overall cell surface expression of common acute lymphoblastic leukemia Ag; the decrease of old Ag by endocytosis after binding to mAb SN5d was compensated by newly exocytosed cell-surface expressed Ag. The present results appear to reveal a novel mechanism which regulates cytotoxic activities of antibodies and immunoconjugates.

Marked difference in the in vivo antitumor efficacy between two immunotoxins targeted to different epitopes of common acute lymphoblastic leukemia antigen (CD10). Mechanisms involved in the differential activities of immunotoxins

In the present study, two isotype-matching mAb, SN5d and SN5, which are directed toward two distinctively different epitopes of common acute lymphoblastic leukemia Ag (CD10) but show a very similar binding affinity to leukemia cells, were compared for their in vivo antitumor activity after conjugated to ricin A chain (RA). Our recently established nude mouse model carrying an ascitic tumor of NALM-6 human pre-B leukemia cells was used as the tumor model. A marked difference was observed in the in vivo antitumor efficacy between SN5d-RA and SN5-RA; SN5d-RA was much more effective than SN5-RA. Several experiments were carried out to gain information concerning the mechanisms involved in the different antitumor efficacy of the two immunotoxins. Although naked (unconjugated) mAb SN5d was much less effective than SN5d-RA conjugates in the in vivo tumor suppression, mAb SN5d was more effective than mAb SN5 in the in vivo tumor suppression. Additionally, marked differences were found between SN5d and SN5 in the induction of antigenic modulation and in the regulation of Ag biosynthesis and expression. Binding of SN5 to NALM-6 leukemia cells caused strong antigenic modulation (down-regulation of Ag expression) and strongly down-regulated Ag biosynthesis and cell surface expression of new Ag. In contrast, binding of SN5d to NALM-6 leukemia cells caused little modulation of overall cell surface expression of common acute lymphoblastic leukemia Ag; the decrease of old Ag by endocytosis after binding to mAb SN5d was compensated by newly exocytosed cell-surface expressed Ag. The present results appear to reveal a novel mechanism which regulates cytotoxic activities of antibodies and immunoconjugates.

[Mean transit time and partial mean transit time of spirogram in 628 normal adolescents]

The mean transit time(MTT) and partial mean transit time(MTTp) were measured and analysed by "direct method" in 628 cases of normal adolescents in Cheng-du. The results showed that both MTT and MTTp were increased with age and prolonged with the decay of lung volume. Besides, the FVC-t curve was not single exponential in nature. The specific mean transit time (SMTT) was introduced by correcting MTT with 0.5 FVC and represented the MTT when unit volume of gas passed through just at that lung volume. SMTT was highly negatively correlated with age. This reflected the development and growth of the lung recoil and airway conductance in adolescents.

Effect of tumor-derived immunosuppressive factor(s) on interleukin 2 and on expression of interleukin 2 receptor

In this paper, we have described the effects of tumor-derived immunosuppressive factor(s) (TDSF) on interleukin 2 (IL-2) production, on IL-2 responsiveness and on the expression of IL-2 receptors. The results showed that TDSF was able to markedly inhibit the production of IL-2 from PHA-stimulated lymphocytes and IL-2-dependent proliferation of activated lymphocytes, and to partially inhibit the expression of IL-2 receptor. These results suggest that inhibiting IL-2 production and responsiveness may be a major mechanism by which TDSF inhibit T lymphocyte proliferation and other immune responses. That TDSF exerted a very potent inhibiting action on IL-2 responsiveness is especially noticeable if we consider using IL-2 as an immunotherapeutic agent. This may be an important reason why treatment of tumor with IL-2 did not yield satisfactory results so far.

[Argon replacing helium in measurement of pulmonary carbon monoxide diffusing capacity, its normal value and clinical application]

Measuring DL COSB of 120 normal subjects by using a gas mixture, in which helium was replaced by argon, we determined the DL COSB mean value, standard deviation and the predicted value formula for both sexes. The lower limit value of DL COSB for normal subjects was defined and the positive diagnostic value investigated. A ratio of actual value to predicted value below 80% was defined as abnormal. With this diagnostic criterion 43 cases of silicosis and diffuse pulmonary interstitial fibrosis were investigated, the positive rate of the cases being 90.70%, with a false positive rate of below 10% for normal subjects, which indicates that this gas mixture and the criterion are applicable for clinical practice.

Detection of subclinical nasopharyngeal carcinoma by fibreoptic endoscopy and multiple biopsy

Of 6054 people who had high titres of antibodies against the viral capsid antigen of Epstein-Barr virus but no symptoms or signs of nasopharyngeal carcinoma as assessed by conventional methods, 130 were randomly recruited and examined by fibreoptic endoscopy and biopsy of several sites of the nasopharynx. 7 cases of nasopharyngeal carcinoma were detected. The tumours were largely confined to the pharyngeal recess, which suggests that it is the area of the nasopharynx most prone to the development of the tumour. Tumour was found in both recesses in 1 subject, who also had evidence of transition from severe epithelial dysplasia to carcinoma in a sample from the left roof, which suggests that the disease was multifocal in origin. This study showed that endoscopy and biopsy of several sites of the nasopharynx are more effective than the conventional approach in the detection of subclinical nasopharyngeal carcinoma among seropositive individuals at high risk of the disorder.

Synergistic potentiation of in vivo antitumor activity of anti-human T-leukemia immunotoxins by recombinant alpha-interferon and daunorubicin

In the present study, immunotoxins (ITs) containing ricin A chain (RA) and anti-human T leukemia monoclonal antibodies SN1 and SN2 were used with or without alpha-interferon (IFN) and/or daunorubicin (DNR) for in vivo tumor suppression. SN1 and SN2 are directed toward two unique human T-leukemia-associated cell surface antigens, TALLA and GP37, respectively. As the tumor model, we used nude mice bearing ascitic tumors of Ichikawa, a human T acute lymphoblastic leukemia cell line. In initial studies, we investigated the effect of the IT injection schedule on the efficacy of ITs in the in vivo suppression of the ascitic tumors. Four doses of 20 micrograms each of SN1-RA and SN2-RA completely suppress the tumor growth in 100% of the treated mice when the IT treatment is initiated either 1 or 2 days after tumor inoculation of 1.6 x 10(7) Ichikawa cells into the mice. Subsequently, we investigated the potentiating effects of IFN and DNR on the in vivo antitumor activity of ITs. To this end, we chose to initiate the treatment 4 days after the tumor inoculation when IT treatment alone is only partially effective. ITs (10 micrograms each of SN1-RA and SN2-RA) plus IFN (2 x 10(5) IU) or ITs plus IFN plus DNR (5 micrograms) completely suppress tumor growth in 100% of the treated mice while similar treatment with any one of the three agents is only partially effective. Similar treatment with ITs plus DNR or IFN plus DNR results in complete suppression of tumor growth in 80% of the treated mice. These results were reproducible in a repeated experiment. To gain information about the mechanisms involving the IFN potentiation of IT activity, we carried out several experiments. The cell surface expression of TALLA and GP37 was slightly augmented by the in vitro incubation of Ichikawa cells with IFN as measured by fluorescence-activated cell sorter analysis. The degree of the increase in either TALLA or GP37 was significantly smaller than that of HLA class I antigens in the same experiment. In in vitro experiments, IFN did not show any significant cytotoxic activity against Ichikawa cells or augment the cytotoxic activity of ITs against Ichikawa cells. On the other hand, injections of IFN into nude mice augmented activity of macrophages and NK cells; however, Ichikawa leukemia cells were rather resistant to the NK cell lysis.(ABSTRACT TRUNCATED AT 400 WORDS)

Investigation on the inhibitory effect of tumor-derived immunosuppressive factor(s) on T lymphocyte proliferation

Using five tumor cell lines, the effect of tumor-derived immunosuppressive factor(s) (TDSF) on T lymphocyte proliferation and its mechanism have been investigated. It was found that TDSF markedly inhibited PHA-stimulated T lymphocyte proliferation via a noncytotoxic mechanism. The inhibition increased in dose-dependent manner and the maximum inhibition was achieved when the factor was added at the initiation of the culture. When PBMC were preincubated with supernatants of tumor cells for 24 h, washed extensively and then cocultured with freshly prepared PBMC, similar suppressive effects were observed. The above results indicated that the activation of any suppressor cell subgroup may be one of the mechanisms of immunosuppressive action of TDSF.

Biologic characteristics of an immunosuppressive factor derived from a human lung cancer cell line

A 549, a human lung cancer cell line, spontaneously produces a tumor-derived immunosuppressive factor (TDSF) which inhibited PHA-stimulated T lymphocyte proliferation via a noncytotoxic mechanism. The inhibition increased in a dose-dependent pattern. The factor also markedly suppressed production of interleukin (IL-2) by PHA-stimulated lymphocytes and IL 2-dependent proliferation of activated lymphocytes. The fact that TDSF possessed very potent inhibitive action on IL-2 is especially noteworthy if we consider the use of IL-2 as immunotherapeutic agent. The synthesis of the factor was inhibited by mitomycin C, actinomycin D and cycloheximide, indicating that the factor is a genic product of A 549 cells. The factor is chemically a protein with a molecular weight greater than 150 KD and sensitive to extremes of pH, heating to 60 degrees C and trypsin treatment.

Establishment of ascitic tumor of human pre-B acute lymphoblastic leukemia in nonconditioned nude mice

In the present study, an ascitic tumor of NALM-6, a human pre-B acute lymphoblastic leukemia cell line, was established in nude mice which had not been subjected to any preconditioning such as X-irradiation and/or splenectomy. The ascitic tumor was also established in X-irradiated mice. Under various conditions, the tumor transplantability was 100%. NALM-6 cells were initially inoculated i.p. into 8-day-old nude mice after being admixed with X-irradiated HT-1080, a human fibrosarcoma cell line. Then, the in vivo grown (for 10 wk) tumor cells were serially transplanted i.p. into X-irradiated adult (10 to 12 wk old) nude mice. After the serial passages, we succeeded in establishing a highly transplantable NALM-6 ascitic tumor in nonpreconditioned as well as X-irradiated nude mice without the addition of HT-1080 cells. The ascitic tumor cells do not lose transplantability after in vitro culture for 20 days. Cellular radioimmunoassay and fluorescence-activated cell sorter analysis indicated that the in vivo established NALM-6 tumor cells retained the antigenic phenotype of the parental NALM-6 cells. Titration experiments revealed a reciprocal relationship between survival time of the mice and the number of tumor cells inoculated. When appropriate numbers of tumor cells (e.g., 4 x 10(6) cells) were used for the inoculation, survival times of individual mice fell within a relatively narrow range; this narrow range will facilitate the experiments where the present tumor model is used for evaluating the in vivo efficacy of antitumor agents. The present ascitic tumor models, particularly the one established in nonpreconditioned nude mice, will be useful for evaluating the in vivo efficacy of anti-human leukemia agents as well as for studying the in vivo biological behavior of the transplanted leukemia cells.

Purified human factor activates heat shock promoter in a HeLa cell-free transcription system

Heat shock protein (hsp) genes are typically silent and are activated by various stresses including heat. As a first step toward understanding this activation event, a human factor, referred to here as human heat shock transcription factor (human HTF), has been purified approximately 14,000-fold from extracts of heat-treated HeLa cells by means of sequence-specific DNA affinity chromatography. The most highly purified fraction of human HTF binds specifically to the known regulatory sequence element (HSE) of hsp genes as shown by footprinting experiments. Purified human HTF has an apparent molecular mass of 83 kDa. Human HTF is specifically required for activation of an hsp gene promoter in a reconstituted in vitro transcription system from human cells. Activation is dependent on the presence of the HSEs in the transcription template.

Effects of Tripterygium hypoglaucum (Lévl.) Hutch on male fertility

Tripterygium hypoglaucum (Lévl.) Hutch (TH) is a perennial used in Chinese traditional medicine for the treatment of rheumatoid arthritis and various skin disorders. One study showed that daily oral doses of TH significantly reduced the fertility of male rats without apparent toxicity. The effects of daily oral doses of TH on the fertility of men taking it for the treatment of rheumatoid arthritis were evaluated. Sperm concentration, motility and motility grade all were significantly reduced in the 13 men taking TH compared to 11 untreated controls. TH therapy did not affect testosterone, FSH, LH levels, and its antifertility effects appeared to be reversible.

Efficient transplantation of human non-T-leukemia cells into nude mice and induction of complete regression of the transplanted distinct tumors by ricin A-chain conjugates of monoclonal antibodies SN5 and SN6

In the present study, we established a dependable system by which human pre-B- and non-T/non-B-acute lymphoblastic leukemia (ALL) cells are efficiently transplanted into nude mice; the transplanted tumors provide a useful model for investigating the efficacy of antitumor agents in the in vivo therapy of human cancer. NALM-6 (a pre-B-ALL cell line) cells were transplanted under varying conditions as the pre-B-leukemia cells, whereas REH (a non-T/non-B-ALL cell line) cells were transplanted as the non-T/non-B-leukemia cells. Under optimal and near optimal conditions, 71 of 101 X-irradiated mice (70%) developed distinct tumors approximately 2 wk after i.d. inoculation of a mixture of NALM-6 cells and X-irradiated human fibrosarcoma cells. Under the same conditions, 9 of 11 mice (82%) developed tumors following i.d. inoculation of REH cells admixed with X-irradiated human fibrosarcoma cells. Examination of the tumor tissues demonstrated that the tumors are of leukemia origin but not of fibrosarcoma origin. To demonstrate the usefulness of the present tumors for investigating the efficacy of antitumor agents in the in vivo therapy of human cancer, immunotoxins were tested for their specific suppressive activity against growing tumors of the transplanted NALM-6 cells. To this end, monoclonal antibodies SN5 and SN6 which define a common ALL antigen, termed CALLA, and a novel leukemia-associated cell surface glycoprotein, termed gp160, respectively, were separately conjugated with the A-chain subunit of ricin, a plant toxin; CALLA and gp160 are expressed on the cell surface of various human non-T-leukemia cells including NALM-6 cells. The conjugates of SN5 and SN6 with ricin A-chain (RA) showed specific activity against the leukemia cells but not against control cells in an in vitro assay. To investigate their in vivo efficacy in suppressing tumor growth, nude mice which had been inoculated i.d. with NALM-6 cells 25 days in advance and bore distinct palpable tumors (5 to 6 mm in diameter) were divided into five groups. One group of mice was nontreated as a control. Each of the remaining four groups of mice was given an injection of one of the following agents: (a) purified control mouse IgG (IgG1); (b) purified antibodies SN5 (IgG1) and SN6 (IgG1); (c) control IgG-RA conjugate; or (d) SN5-RA and SN6-RA. Tumors in all mice of the first four groups including the untreated group grew continuously, causing the mice to die.(ABSTRACT TRUNCATED AT 400 WORDS)

Catalytic unit-independent phosphorylation and dephosphorylation of type II regulatory subunit of cyclic AMP-dependent protein kinase in rat liver plasma membranes

Rat liver plasma membranes contain a 55 kDa protein which proved to be identical with type II regulatory subunit (RII) of the cyclic AMP-dependent protein kinase (kinase A) by several criteria (gel electrophoretic behaviour, peptide map, position of the autophosphorylated site). Analysis of phosphopeptide maps revealed that the membrane-bound RII was phosphorylated by a kinase which is unrelated to the catalytic unit (C) of kinase A. Dephosphorylation of the membrane-bound RII by an endogenous phosphatase was stimulated by both cyclic AMP and fluoride. Addition of C did not stimulate dephosphorylation even in the presence of ADP; moreover, protein inhibitor of C did not modify the effects of cyclic AMP or fluoride. The effects of both cyclic AMP and fluoride were, however, inhibited by C. Results indicate that rat liver plasma membranes contain a phosphorylation-dephosphorylation system for which RII is a relatively specific substrate.

Ecdysterone selectively stimulates the expression of a 23000-Da heat-shock protein-beta-galactosidase hybrid gene in cultured Drosophila cells

To study the regulated expression of cloned heat-shock genes in homologous cells, hybrid Drosophila heat-shock-Escherichia coli beta-galactosidase genes were constructed. Segments of the ecdysterone-inducible 23,000-Da heat-shock protein (hsp23) gene and of two other hsp genes (hsp84 and 70), which are not hormone regulated, were functionally linked to the bacterial coding sequence, and the resulting hybrid genes were introduced into cultured, hormone-responsive Drosophila cells by transfection. All hybrid genes directed the synthesis of E. coli-specific beta-galactosidase in heat-treated cells. hsp23 hybrid gene expression was stimulated strongly by ecdysterone, while the activities of the other hybrid genes were not affected at all by the hormone. A hybrid gene with only 147 bp of hsp23 promoter sequence could not be activated by either heat or ecdysterone treatment. Thus, far upstream sequences contain signals required for the regulated expression of the hsp23 gene in Drosophila cells.

Binswanger's disease: progressive subcortical encephalopathy or multi-infarct dementia?

Since Binswanger's description of subcortical arteriosclerotic encephalopathy in 1894, numerous cases have been reported. Several authors doubt the validity of this malady, although the majority consider it to be a disease entity. We report seven cases with this type of pallor of myelin, only two of which are accompanied by a history of dementia. Among the seven cases, two had arteriosclerosis of penetrating arteries and arterioles in cerebral white matter. Electron microscopy showed splitting of myelin sheaths, probably the result of edema. In reviewing the blood supply of the cerebral white matter, we conclude that no pathological alterations of medullary branches of the cerebral arteries, the same vessels supplying the white matter, can give rise to such diffuse pallor of white matter and spare the arcuate fibres. This pallor can only be due to cerebral edema, most likely of hypoxic-ischemic, hypotensive, or acidotic origin. We also contend that arteriosclerosis can only cause dementia through multiple infarcts or lacunae, if it indeed leads to dementia.

Spongy degeneration of the CNS in infancy

We studied six cases of spongy degeneration of the CNS in infancy among Chinese. The main clinical features were cyclical vomiting and wailing, blindness, megalocephaly, convulsions, lethargy, and coma. Chief findings from light microscopic studies were spongiform change, moderate outfall of neurons, and marked astrocytosis, with formation of Alzheimer's cells type 2. Demyelination was only slight, if present. Electron microscopic studies revealed membrane-bound vacuoles, often containing membranous fragments or blisters and electron-dense granules.

Adult spinal muscular atrophy. A report of four cases

Four cases of spinal muscular atrophy (SMA) are reported, 3 with detailed autopsy findings. These are compared with 2 cases of typical amyotrophic lateral sclerosis (ALS) with neuropathological data. The 3 autopsy cases of SMA only showed decreased numbers of anterior horn cells in the spinal cord, with no change in the cortical pyramidal cells, including the Betz cells, and no degeneration of the pyramidal tracts, while the ALS cases showed loss both of lower and upper motor neurons and degeneration of the pyramidal tracts. In our opinion, the infantile, juvenile, adult, and late-life forms of SMA are really a single disease entity that occurs at varying ages and is separate from ALS. The term lower motor neuron disease would be preferable because the lesions are not limited to the spinal cord, but also occur in the brain stem.