Suggestions for the assessment of the allergenic potential of genetically modified organisms

The prevalence of allergic diseases has been increasing continuously and, accordingly, there is a great desire to evaluate the allergenic potential of components in our daily environment (e.g., food). Although there is almost no scientific evidence that genetically modified organisms (GMOs) exhibit increased allergenicity compared with the corresponding wild type significant concerns have been raised regarding this matter. In principle, it is possible that the allergenic potential of GMOs may be increased due to the introduction of potential foreign allergens, to potentially upregulated expression of allergenic components caused by the modification of the wild type organism or to different means of exposure. According to the current practice, the proteins to be introduced into a GMO are evaluated for their physiochemical properties, sequence homology with known allergens and occasionally regarding their allergenic activity. We discuss why these current rules and procedures cannot predict or exclude the allergenicity of a given GMO with certainty. As an alternative we suggest to improve the current evaluation by an experimental comparison of the wild-type organism with the whole GMO regarding their potential to elicit reactions in allergic individuals and to induce de novo sensitizations. We also recommend that the suggested assessment procedures be equally applied to GMOs as well as to natural cultivars in order to establish effective measures for allergy prevention.     

No evidence for involvement of the calpain-10 gene 'high-risk' haplotype combination for non-insulin-dependent diabetes mellitus in early onset obesity

In light of evidence of linkage of obesity to chromosome 2q31-q37, we hypothesized that the calpain-10 gene 'high-risk' haplotype combination for non-insulin-dependent diabetes mellitus (NIDDM) is involved in early onset obesity. We screened the NIDDM 'high-risk'-haplotype combination formed by the alleles 112 and 121 of the polymorphisms UCSNP-43, -19, and -63 in 166 families consisting of an extremely obese child or adolescent (mean BMI percentile: 99.3+/-1.38), one or more obese sibs (mean BMI percentile: 97.42+/-2.88), and both of their parents. Genotyping for three calpain-10 gene polymorphisms was performed by polymerase chain reaction (PCR) with (a) length polymorphism detection (UCSNP-19) or (b) allele-specific PCR (UCSNP-43 and -63). To allow for correct haplotype assignment all individuals were additionally genotyped for two microsatellite markers (D2S125 and D2S2338). We followed a hierarchical test procedure. As the first step, model-free linkage analysis was performed using maximum likelihood binomial statistics. The second stage consisted of a one-sided asymptotic pedigree disequilibrium test for the UCSNP-43 and on an exploratory level for the other SNP-markers and all haplotypes formed by the three SNPs. The final stage investigated the reported haplotype combination. We failed to detect an initial linkage of obesity to this region (LOD score <0.4). All subsequent exploratory analyses were negative. Our analysis of the relationship between the NIDDM 'high-risk' haplotype combination and extreme early onset obesity revealed no evidence for linkage and association.     

Dynamics of asexual transmission of a mitochondrial plasmid in Cryphonectria parasitica

In the chestnut blight fungus Cryphonectria parasitica, as in most fungi, little is known about the efficiency of the asexual transmission of optional mitochondrial plasmids, vertically through conidia, and horizontally through hyphal anastomoses. In this paper, we show that pCRY1, a circular mitochondrial plasmid, is transmitted vertically with 100%-efficiency through conidia. Moreover, the plasmid is transmitted horizontally through hyphal contact from donor strains to vegetatively compatible and most incompatible strains. An allelic difference between the donor and recipient strain, at only one of the five nuclear incompatibility genes that were tested strongly inhibited, but did not absolutely prevent, the transfer of pCRY1 through hyphal fusions. In contrast, allelic differences in any one or several of the other four heterokaryon-compatibility loci suppressed the transmission of the plasmid only partially or not at all. The plasmid was also transmitted among incompatible strains by protoplast fusion without the concomitant transfer of mitochondrial DNA (mtDNA). A comparison of plasmid-bearing with plasmid-free isogenic strains revealed that pCRY1 significantly diminishes the pathogenic potency of some strains of the fungus, but does not affect the virulence of others. Collectively, the observations indicate that the introduction of deleterious mitochondrial genetic elements into natural populations may be a means for managing fungal pathogens. Received: 22 August 1999 / 9 December 1999     

The position of pulmonary carcinoids within the spectrum of neuroendocrine tumors of the lung and other tissues

Bronchopulmonary carcinoids comprise 25% of all human carcinoids. The World Health Organization divides them into typical (TC) and atypical forms (ATC), distinguished by differences in mitotic counts lower or higher than 2/2 mm(2) and the presence or absence of necrosis. The reproducibility of this classification with respect to the borderline cases with 1-2 mitotic counts/2 mm(2) has been questioned. We have analyzed 15 TCs and 20 ATCs by comparative genomic hybridization. Loss of 11q was the most frequent aberration in ATC (55%), but was observed only twice in TC (13%). Deletions of 3p were seen only in ATC (25%). Meta-analysis of our data and data from 218 neuroendocrine tumors and 50 non-small-cell lung carcinomas obtained from the literature revealed differences between carcinoids and carcinomas. For example, loss of 5q is frequent in lung carcinomas (75%) but is rarely seen in carcinoids (1.4%). Deletions of 11q are less frequent in neuroendocrine lung carcinomas than in ATC. To obtain a more objective survey of the relationship of pulmonary carcinoids to other neuroendocrine tumors and lung carcinomas, we created a hierarchical clustering dendrogram. This statistical approach resulted in a clear separation of carcinoids and carcinomas, which both built up different clusters. In summary, this study demonstrates the benefit of chromosomal analysis supplementary to the diagnosis of bronchopulmonary carcinoids. We also identified the feasibility of hierarchical clustering to get some clues on relationship between different tumor types. This study further argues against a transition of ATC to high-grade neuroendocrine lung carcinoma.     

Pharmakologisch-aktive polymere, 21. Orientierende Untersuchungen zur körperverteilung und Ausscheidung von poly[2-(methylsulfinyl)ethylacrylat]en bei der Ratte

Poly[2-(methylsulfinyl)ethyl acrylate] ( 1 ) was synthesized as well as derivatives ¹⁴C-labelled in side groups ( 6 ) or ¹⁴C-labelled in the main chain ( 11 ). Polymer 11 with the ¹⁴C-labelled main chain was fractionated by precipitation. The η-M-relation determined by measurements of unlabelled polymers in the ultracentrifuge for comparison was used to establish the viscosimetrically determined molecular weights of the labelled fractions. After intravenous application of aqueous solutions of the polymer in rats the excretion rate up to 72 h after treatment was ascertained to ca. 50%; the concentration in the blood serum was found to be strikingly high. A tendency to reinforced storage in organs of high phagocytose activity by growing molecular weight was observed. The tumor affinity was — if at all — low.     

Antibody to Mycoplasma pneumoniae in Nasal Secretions and Sputa of Experimentally Infected Human Volunteers

After experimental infection with Mycoplasma pneumoniae, 42% of 67 volunteers developed a threefold or greater rise in antibody in nasal secretions as measured by radioimmunoprecipitation. Development of an antibody increase in sputum was detected more often, i.e., in 73% of the volunteers. Each of the antibody increases involved immunoglobulin (Ig) A. Twelve rises in IgG antibody were detected in the specimens which exhibited a rise in IgA antibody. In almost every instance the rise in IgA antibody exceeded that seen with IgG antibody. Analysis of the response to experimental challenge with M. pneumoniae of volunteers with different levels of preexisting respiratory tract IgA antibody suggested that this secretory antibody was related to host resistance to M. pneumoniae disease. Further, respiratory tract IgA antibody appeared to be more directly related to host resistance than was antibody in serum.     

Morphometric observations on the rat heart after high-dose treatment with cortisol

Summary Male Wistar rats were treated with high cortisol doses for 1 week. The dose administered daily was 15 mg per animal in group 1 (7 animals) and 30 mg in group 2 (7 animals). 7 rats served as control group. After cortisol treatment the body weights decreased due to skeletal muscle catabolism and the heart weights increased. Morphometric analysis of the left ventricular posterior papillary muscles gave evidence that the increased heart weights resulted from an increased number of mitochondria and an increased volume of the cytoplasm, whereas the myofibrillar mass was not affected. The surface area of inner mitochondrial membranes (+cristae mitochondriales) per myofibrillar unit volume increased from 15.7 ²/³ to 21.3 ²/³ in group 1 and 21.4 ²/³ in group 2. Ultrastructural changes indicating myocardial cell damage were absent. Similar quantitative results have been reported to occur in the early phase of cardiac overload. For elucidating the hemodynamic effects of glucocorticoid a second experiment was performed: 7 Wistar rats were treated with cortisol in the same way as group 1, 7 others of the same body weight served as control. The systolic arterial pressure was significantly elevated in the cortisol group. Though myocardial tissue is known to be able to accumulate large quantities of glucocorticoids our results indicate that the application of high cortisol doses for a short time does not produce myocardial cell damage and does not suppress the myocardial adaption to the glucocorticoid-induced hypertension, i.e. hypertrophy. On the contrary, it seems to be possible that the adaption process is itself facilitated or accelerated by the presence of high cortisol concentrations in the heart. This thesis is supported by the considerably higher relative heart weights in the cortisol groups and is in agreement with observations reported by other authors.Dedicated to Professor Dr. W. Doerr on the occasion of his 65th birthdayThe results have been partially reported in 1977 (cf. G. Mall and H. Reinhard, Verh. Dtsch. Ges. Path. 61, 445)This investigation was supported by the Sonderforschungsbereich 90 of the Deutsche Forschungsgemeinschaft.     

Mutations in the structural gene for cytochrome c result in deficiency of both cytochromes aa 3 and c in Neurospora crassa

The cyt-12-12 mutant of Neurospora crassa is characterized by slow growth and a deficiency of spectrophotometrically-detectable cytochromes aa ₃ and c. Using a sib-selection procedure we have isolated the cyt-12 ⁺ allele from a cosmid library of N. crassa genomic DNA. Characterization of the cyt-12 ⁺ allele reveals that it encodes the structural gene for cytochrome c. DNA sequence analysis of the cyt-12-12 allele revealed a mutation in the cytochrome c coding sequence that results in replacement of a glycine residue, which is invariant in the cytochrome c of other species, with an aspartic acid. Genetic analysis confirms that cyt-12-12 is allelic with the previously-characterized cyc-1-1 mutant, which was also shown to affect the single locus encoding cytochrome c in N. crassa. We suggest that the amount of functional cytochrome c present in mitochondria influences the level of cytochrome aa ₃ .     

神经激肽-2受体的过度表达与慢性胰腺炎的疼痛相关

目的:了解神经激肽-2受体(NK-2R)在正常胰腺和慢性胰腺炎组织中的表达, 探讨其表达与慢性胰腺炎疼痛发生的关系。方法:25个慢性胰腺炎标本取自慢性胰腺炎手术, 男性18例, 女性7例, 正常胰腺组织取自20个器官捐献者, 男性11例, 女性9例。应用实时定量逆转录聚合酶链反应技术, 检测正常胰腺和慢性胰腺炎组织NK-2R的mRNA水平, 应用Western blot技术检测NK-2R的蛋白水平, 应用免疫组织化学方法进行NK-2R的组织学定位。将NK-2R mRNA水平与疼痛的程度、发作频率和持续时间进行分析, 寻找其中的相关性。结果:与正常胰腺相比, 慢性胰腺炎组织中NK-2R mRNA和蛋白都过度表达, NK-2R mRNA水平与疼痛的程度(r=0.59, P＜0.01)、发作频率(r＝0.51, P＜0.05)和持续时间(r=0.53, P＜0.05)明显相关。免疫组化检查显示, NK-2R的表达主要位于胰腺腺泡、胰腺导管、神经纤维和炎性细胞。结论：慢性胰腺炎组织中NK-2R的mRNA和蛋白表达水平都明显上调, 扰乱了神经激肽的作用环节;NK-2R的过度表达与疼痛发生有关。