Vanadium levels in urine and cystine levels in fingernails and hair of exposed and normal persons

Vanadium was determined by radiochemical neutron activation analysis (RNAA) with proven accuracy in urine of workers occupationally exposed to vanadium-rich dust in a vanadium pentoxide production plant, and values in the range of 3.02–762 ng/mL (median 33.0 ng/mL) were found. In a control group consisting of administrative workers of the plant, urinary vanadium levels were found in the range of 1.05–53.4 ng/mL (median 2.53 ng/mL), whereas in an another control group of occupationally nonexposed persons, these values amounted to 0.066–0.489 ng/mL (median 0.212 ng/mL). Accuracy of the results was tested by analysis of reference material IAEA A-13 Animal Blood and NIST SRM-1515 Apple Leaves, and very good agreement was found with literature and the NIST certified values, respectively. Unlike urine, no significant differences were found for cystine levels in fingernails and hair of exposed and control persons.     

Results and recommendations

In the first phase of a collaborative study by the International Programme on Chemical Safety (PRCS), four coded chemicals, i.e. azidoglycerol (AG, 3-azido-1,2-propanediol), methyl nitrosurea (MNU), sodium azide (NaN₃) and maleic hydrazide (MH), and ethyl methanesulfonate (EMS) as a positive control were tested in four plant bioassays, namely the Arabidopsis embryo and chlorophyll mutation assay, the Tradescantia stamen hair assay (Trad-SH assay), the Tradescantia micronucleus assay (Trade-MCN), and the Vicia faba root tip assay. Seventeen laboratories from diverse regions of the world participated with four to six laboratories each using one plant assay. For the Arabidopsis assay, laboratories were in agreement with MNU and AG giving positive responses and NaN₃ giving a negative response. With the exception of one laboratory which reported MH as weakly mutagenic, no mutagenic response was reported for MH by the other laboratories. For the Vicia faba assay, all laboratories reported a positive response for MNU, AG, and MH, whereas two of the six laboratories reported a negative response for NaN₃. For the Trad-SH assay, MH was reported as giving a positive response and a positive response was also observed for MNU with the exception of one laboratory. NaN₃, which exhibited a relatively high degree of toxicity, elicited a positive response in three of the five laboratories. AG was found positive in only one of the two laboratories which tested this chemical. For the Trad-MCN assay, MNU and MH were reported as positive by all laboratories, while four out of five laboratories reported NaN₃ to be positive. Only one of three laboratories reported AG to be positive. The major sources of variability were identified and considered to be in the same range as found in similar studies on other test systems. Recommendations were made for minor changes in methodology and for initiating the second phase of this study.     

Latency of cathepsin B secreted by human colon carcinoma cells is not linked to secretion of cystacin C and is relieved by neutrophil elastase

The lysosomal cystein proteinase cathepsin B is shown to be secreted by ten human colon carcinoma cell lines and to accumulate in culture media as a latent enzyme. The cell lines also secrete a physiological inhibitor of cathepsin B, cystatin C. A significant correlation was found between secretion of the latent enzyme and the inhibitor (r = 0.755, P < 0.01). The aim of the present study was to modulate the respective secretion of the two antagonists to test whether or not latency of cathepsin B was due to the concomitant secretion of the inhibitor. SW480 colon carcinoma cells were treated with the acidotropic agent ammonium chloride, phorbol 12-myristate 13-acetate, and the inflammatory cytokines TGF-β, TNF-α, and IL-1β. Ammonium chloride significantly increased latent cathepsin B levels without affecting the constitutive secretion of cystatin C. Phorbol 12-myristate 13-acetate induced a 4- to 5-fold increase in secreted latent cathepsin B, but did not alter significantly the accumulation of cystatin C in media. The cytokines, TGF-β, TNF-α, and IL-1β, had no major effect on the expression of these two antagonists. Latent cathepsin B released from human carcinoma cells could be efficiently activated by neutrophil elastate at neutral pH. It is concluded that latent cathepsin B is a true proenzyme rather than an enzyme-inhibitor comples. In addition, our data from neutrophil elastate activation experiments indicate that a proteolytic system for activation of the tumor cell-secreted latent enzyme may exist in vivo.     

关于吸附精制百日咳菌苗、白喉、破伤风类毒素混合制剂配方的实验报告

本文对吸附精制百白破混合制剂的不同配方进行了实验,结果表明,新一代吸附精制百白破混合制剂最佳配方为：精制百日咳菌苗１８μｇＰＮ／ｍｌ、精制白喉类毒素为３０Ｌｆ／ｍｌ、精制破伤风类毒素为１０Ｌｆ／ｍｌ。由该配方组成的吸附精制百白破混合制剂,其中百日咳菌苗的毒性试验ＢＷＤＵ／ｍｌ、ＬＰＵ／ｍｌ、ＨＳＵ／ｍｌ三种指标均符合制检规程要求。其效力单位（ＩＵ／ｍｌ）超过规程要求一倍以上,精制白喉和破伤风类毒素的安全试验均符合规程要求,白类效力试验≥８０－１００％,破类效力试验≥０．５－４．５ＩＵ／ｍｌ。上述结果说明本文提出的配方作为新一代精制百白破混合制剂的配方是适宜和实用的。     

Partial Resistance to Heterodera avenae in Wheat Lines with the 6M v Chromosome from Aegilops ventricosa

Lines of wheat with the 6M^v chromosome from Aegilops ventricosa display partial resistance to both pathotypes Hal2 and Ha41 of Heterodera avenae. With either pathotype, the effect of this alien chromosome on cyst production, size, and fecundity was expressed in resistance tests. Partial resistance of five 6M^v(6D) substitution lines varied according to the intrinsic cyst-forming capacity of the nematode pathotypes and the recipient germplasms. Such partial resistance can be utilized in wheat breeding lines for integrated management of the cereal cyst nematode.     

Molecular integrity of monoclonal antibodies produced by hybridoma cells in batch culture and in continuous-flow culture with integrated product recovery

The molecular integrity of monoclonal antibodies (MCAB) produced by murine hybridoma cell line TB/C3 was studied in batch and continuous-flow cultures. In batch culture, one band of MCAB was detected initially by Western blotting of sodium dodecyl sulfate (SDS)-polyacrylamide gels run under unreduced conditions, but heterogenous MCAB bands appeared as the culture aged. The latter were due to the degradation of MCAB by proteases active at the neutral pH of the culture. The deleterious effect of proteases was minimized in the continuous-flow cultures which were integrated for product recovery. The MCAB of high quality was purified over 26 days from a culture grown at a dilution rate of 0.025 h(-1) (experiment 1). However, at a lower dilution rate of 0.015 h(-1) (experiment 2), the integrity of MCAB was compromised after the initial 13 days of culture. This was shown to be due to the variation in the carbohydrate content of MCAB produced, as judged by the increased sialylation of heavy chains and the varied reactivity of MCAB with lectins (Maackia amurensis agglutinin, Galanthus nivalis agglutinin, and Datura stramonium agglutinin) as the age of the culture increased. The concentration of the purified MCAB samples by enzyme-linked immunosorbent assay (ELISA) (used normally) was usually higher than that estimated by absorbance at 280 nm. Best correlation between the two methods (ELISA-280 nm ratio of 1.02-1.25) was obtained with experiment 1 samples. This ratio increased in experiment 2 and batch culture samples as the heterogeneity of MCAB produced increased, being 1.03-2.94 and 2.53-4.62, respectively. Therefore, ELISA overestimated MCAB concentration when the molecular integrity of the latter was compromised. The ELISA-A(280) nm ratio might hence provide a useful indicator for assessing the quality of MCAB produced. Comparison of SDS-polyacrylamide gels stained with Coomassie Brilliant Blue R and silver showed that the former correlated better with the MCAB activity stain, whereas the silver stained both the protein- and carbohydrate-rich components. Comparison of the patterns produced with these two stains might therefore offer another parameter to monitor the overall integrity of MCAB produced. Finally, the data presented have important implications on the validity of using long-term and intensive cultures for generating MCAB because such cultures would be subjected to the additive effects reported for batch and continuous modes of growth. (c) 1993 John Wiley & Sons, Inc.     

Japanese macaque microsatellite PCR primers for paternity testing

Capture and blood sampling in wild primate populations are difficult. For this reason, we need to use DNA extracted from the hair or feces of target animals. The polymerase chain reaction (PCR) method, which amplifies small volumes of DNA, provides an ideal means for studying DNA variations in wild populations. Three sets of PCR primers which amplify highly polymorphic (GT/AC)_n dinucleotide repetitive regions were synthesized from DNA sequences of Japanese macaques (Macaca fuscata). One of the primer pairs detected at least seven alleles in one captive Japanese macaque group. Also, the fathers of four offspring whose mothers had died in a captive group of Japanese macaques were identified. In such cases, the father cannot be determined by the previous DNA fingerprinting method based on the polymorphism of minisatellite DNA. These primers were further tested with some species of the Cercopithecidae, e.g. grivet monkeys (Cercopithecus aethiops tantalus) and hamadryas baboons (Papio hamadryas). The results obtained suggest that these primers can detect stably inherited polymorphic regions in each species.     

Clinical pharmacology of the new COMT inhibitor CGP 28 014

CGP 28 014 is a specific inhibitor of catechol-O-methyltransferase (COMT) in vivo. In humans, the inhibition was assessed by measuring urinary excretion of isoquinolines and with the levodopa test. Following administration of CGP 28 014, urinary excretion of isoquinolines was significantly increased. In rats, CGP 28 014 reduced plasma and striatal concentrations of 3-O-methyldopa (30MD) in a dose-dependent manner. Acute and subchronic administration of CGP 28 014 alone or in combination with the peripherally acting decarboxylase inhibitor benserazide decreased plasma 30MD as an index of COMT inhibition by about 50%. There seems to be a close relationship between the time-course of plasma concentrations of CGP 28 014 and the extent of COMT inhibition assessed by the 30MD/DOPA ratio in plasma.     

Multikink quantile regression for longitudinal data with application to progesterone data analysis

Motivated by investigating the relationship between progesterone and the days in a menstrual cycle in a longitudinal study, we propose a multikink quantile regression model for longitudinal data analysis. It relaxes the linearity condition and assumes different regression forms in different regions of the domain of the threshold covariate. In this paper, we first propose a multikink quantile regression for longitudinal data. Two estimation procedures are proposed to estimate the regression coefficients and the kink points locations: one is a computationally efficient profile estimator under the working independence framework while the other one considers the within-subject correlations by using the unbiased generalized estimation equation approach. The selection consistency of the number of kink points and the asymptotic normality of two proposed estimators are established. Second, we construct a rank score test based on partial subgradients for the existence of the kink effect in longitudinal studies. Both the null distribution and the local alternative distribution of the test statistic have been derived. Simulation studies show that the proposed methods have excellent finite sample performance. In the application to the longitudinal progesterone data, we identify two kink points in the progesterone curves over different quantiles and observe that the progesterone level remains stable before the day of ovulation, then increases quickly in 5 to 6 days after ovulation and then changes to stable again or drops slightly.