Analysis of chromosome aberrations and sister-chromatid exchanges in peripheral blood lymphocytes of workers with occupational exposure to the mancozeb-containing fungicide Novozir Mn80

Chromosome aberrations and sister-chromatid exchanges (SCEs) were analyzed in short-term cultures of peripheral lymphocytes of 44 workers occupationally exposed to mancozeb during the production of the pesticide Novozir Mn80 and 30 control persons. The results suggest that mancozeb exposure was associated with a significant increase in the frequencies of cells with structural chromosome aberrations (2.07% vs. 1.10% in the controls), and the number of SCEs per cell (9.19 +/- 1.81 vs. 7.82 +/- 1.04 in the controls).     

Intracytoplasmatic inclusions in cells of lettuce leaves with mosaic-like symptoms

Ultrathin sections were prepared from the tissues of lettuce leaves with mosaic-like symptoms and thickened nervature which were studied by means of electron microscopy. Intracellular inclusions surrounded by a membrane were found in the cytoplasm of parenchym cells of the investigated lettuce leaves(Lactuca saliva L. provar.capitata L. nid.jaggeri Helm., cv. Pra?an). Crystals with a distinctly apparent hexagonal lattice could be observed in the inclusions. No crystal containing inclusions were found in the tissues from the leaves without mosaic-like symptoms and in those from thickened nervature.     

Cerebrovascular Occlusive Disease—Experience with Panarteriography in 300 Consecutive Cases

Three hundred patients with cerebrovascular occlusive disease have had cerebral angiographic examination at the Veterans Administration Hospital, San Francisco, in the last five years. The present technique consists of preliminary visualization of the aortic arch and the major extracranial branches, followed by selective study of the subclavian and carotid arteries as necessary for evaluation of the intracranial circulation.Nine major complications occurred (an over-all incidence of 3 per cent). Two patients died after angiography and seven had major neurologic deficits persisting for more than 24 hours. Three of these patients had permanent damage, but four recovered completely.One-third of the patients had extracranial disease and one-third had intracranial disease. No significant lesion was found in the remainder. In the 212 patients with lesions, multiple lesions were common, the average number being three. Six patients had brain tumors and five had aneurysms.The mechanism of the stroke could be ascertained readily in most of the patients, but the extent of the disease and the resulting symptoms varied considerably. Several patients with occlusion of most of the cerebral vessels had minimal symptoms, while others had catastrophic symptoms but only minimal findings at arteriography.     

Polymorphism of the tumor necrosis factor beta gene in systemic lupus erythematosus: TNFB-MHC haplotypes

We investigated the Nco I restriction fragment length polymorphism (RFLP) of the tumor necrosis factor beta (TNFB) gene in 173 patients with systemic lupus erythematosus (SLE), 192 unrelated healthy controls, and eleven panel families, all of German origin. The phenotype frequency of the TNFB*1 allele was significantly increased in patients compared to controls (63.6% vs 47.1%, RR = 1.96, p <0.002). The results of a two-point haplotype statistical analysis between TNFB and HLA alleles show that there is linkage disequilibrium between TNFB*1 and HLA-A1, Cw7, B8, DR3, DQ2, and C4A DE. The frequency of TNFB*1 was compared in SLE patients and controls in the presence or absence of each of these alleles. TNFB*1 is increased in patients over controls only in the presence of the mentioned alleles. Therefore, the whole haplotype A1, Cw7, B8, TNFB*1, C4A DE, DR3, DQ2 is increased in patients and it cannot be determined which of the genes carried by this haplotype is responsible for the susceptibility to SLE. In addition, two-locus associations were analyzed in 192 unrelated healthy controls for TNFB and class I alleles typed by serology, and for TNFB and class II alleles typed by polymerase chain reaction/oligonucleotide probes. We found positive linkage disequilibrium between TNFB*1 and the following alleles: HLA-A24, HLA-B8, DRB1*0301, DRB1*1104, DRB1*1302, DQA1*0501, DQB1*0201, DQB1*0604, and DPB1*0101. TNFB*2 is associated with HLA-B7, DRB1*1501, and DQB1*0602.This study was supported by grants from the Federal Ministry of Research and Technology (BMFT/DFVLR, 01 VM 8608/9), the German Academic Exchange Service (DAAD, 322/501/014/0), and SFB (217).This work is part of the doctoral thesis of M. P. Bettinotti.     

Release of arachidonic acid from 1-alkyl-2-acyl-sn-glycero-3-phosphocholine, a precursor of platelet-activating factor, in rat alveolar macrophages

Platelet activating factor and the bioactive metabolites of arachidonic acid are secreted by alveolar macrophages in response to stimulation by phagocytic agents or calcium ionophore. We have previously shown a deacylation-acetylation sequence in the formation of 1-alkyl-2-acetyl-sn-glycero-3-phosphocholine (PAF) from alkylacyl-(long chain)-GPC (Albert, D.H. and Snyder, F. (1983) J. Biol. Chem. 258, 97-102). This sequence may be an important source of 20:4 during inflammatory reactions since, in alveolar macrophages, the ether lipid precursor of PAF represents 35% of the choline glycerophospholipids and has a much higher content (35%) of 20:4 in the sn-2 position than does diacyl-GPC (17%). Alveolar macrophages prelabeled with 14C-labeled fatty acids (16:0, 18:1, 18:2 and 20:4) and [1-3H]alkyllyso-GPC were used to study the release of fatty acids from ether-linked and diacyl phospholipids. Each of these fatty acids was incorporated primarily into the choline glycerophospholipids of alveolar macrophages. The release of 20:4 from macrophage phospholipids was increased by treatment of the labeled cells with the calcium ionophore A23187 (2 microM) or zymosan (1 mg/ml), whereas the release of 16:0, 18:1 and 18:2 was not increased above control levels by either stimuli. Although more of the labeled 20:4 is released from the diacyl-GPC (50% of the total released), substantial amounts (44%) of 20:4 are derived from alkylacyl-GPC after incubating the stimulated cells for 60 min. The loss of 20:4 continued from the diacyl species throughout the incubation period studied, whereas a slower net release of 20:4 lost from the alkylacyl-GPC fraction was evident after 2 h. We conclude that the deacylation-reacylation cycle is an important aspect of the metabolism of 20:4 and alkylacyl-GPC during inflammatory stimulation of alveolar macrophages and that the deacylation of this ether-linked phospholipid (which is the first step in the formation of PAF) is responsible for a significant amount of the 20:4 released.     

Dynamic organization of mitochondrial membranes: A crosslinking study with dimethylsuberimidate

Rat liver mitochondria were treated with dimethylsuberimidate, a bifunctional alkylating agent, and the effects were evaluated kinetically. Concurrently with the modification of amino groups, mitochondrial proteins were crosslinked and the organelles lost their osmotic response. When the dimethylsuberimidate reaction was performed in the presence of succinate, more primary amino groups were available when compared with a sucrose medium. Concomitantly, osmotic stabilization and crosslinking of mitochondrial proteins were accelerated. The activity of aspartate aminotransferase was also studied in crosslinked mitochondria. The enzyme activity was only slightly modified when mitochondria were amidinated in a sucrose medium and solubilized thereafter with Triton X-100 or cetyltrimethylammonium bromide. In contrast, in the presence of succinate, 60% of activity was lost after solubilization with Triton X-100, but not after solubilization with cetyltrimethylammonium bromide. This finding was correlated with the changes in intramitochondrial localization of the enzyme (A. Waksman and A. Rendon, 1974,Biochimie54, 907–924). When carbonylcyanide-p-trifluoromethoxyphenylhydrazone was added in both cases (sucrose or sucrose plus succinate), the rates of osmotic stabilization, amidination reaction, crosslinking of proteins, and aspartate aminotransferase activity were similar to those observed in a sucrose medium alone. The present results suggest that organizational changes of the mitochondrial membranes induced by succinate, including intramitochondrial protein movement, are prevented by carbonylcyanide-p-trifluoromethoxyphenylhydrazone.     

The occurrence of beet mild yellowing virus in Czechoslovakia

The occurrence of beet mild yellowing virus (BMYV) on feeding- and sugar-beet in Czechoslovakia has been proved. The virus was transmitted by aphidMyzus persicae (Sulz.) on indicator plantsSinapis alba L.,Capsella bursa-pastoris Medik, andClaytonia perfoliata Donn and from these plants back to sugar-beet cv. ‘Dobrovická A.’ A weed plantRaphanus raphanistrum L. was identified as a new natural host plant of BMYV. The virus was identified in ten of twelve biologically examined samples of beet with BMYV-like symptoms, which were collected at various places in Czechoslovakia