Extensive degradation of Aroclors and environmentally transformed polychlorinated biphenyls by Alcaligenes eutrophus H850.

We have isolated and characterized a strain of Alcaligenes eurtrophus, designated H850, that rapidly degrades a broad and unusual spectrum of polychlorinated biphenyls (PCBs) including many tetra- and pentachlorobiphenyls and several hexachlorobiphenyls. This strain, which was isolated from PCB-containing dredge spoils by enrichment on biphenyl, grows well on biphenyl and 2-chlorobiphenyl but poorly on 3- and 4-chlorobiphenyl. Capillary gas-chromatographic analysis showed that biphenyl-grown resting cells of H850 degraded the components of 38 of the 41 largest peaks of Aroclor 1242 and 15 of the 44 largest peaks of Aroclor 1254, resulting in an overall reduction of PCBs by 81% for Aroclor 1242 (10 ppm) and 35% for Aroclor 1254 (10 ppm) in 2 days. Furthermore, H850 metabolized the predominantly ortho-substituted PCB congeners that resulted from the environmental transformation of the more highly chlorinated congeners of Aroclor 1242 by the upper Hudson River anaerobic meta-, para-dechlorination agent system C (J. F. Brown, R. E. Wagner, Jr., D. L. Bedard, M. J. Brennan, J. C. Carnahan, R. J. May, and J. J. Tofflemire, Northeast Environ. Sci. 3:167-179, 1984). The congener selectivity patterns indicate that a two-step process consisting of anaerobic dechlorination followed by oxidation by H850 can effectively degrade all of the congeners in Aroclor 1242 and possibly all those in Aroclor 1254.     

Rapid repression of quiescence-specific gene expression by epidermal growth factor, insulin, and pp60v-src.

We isolated a cDNA for p20K, a secreted protein preferentially synthesized in nonproliferating cells. p20K mRNA and protein levels declined rapidly following treatment with various mitogens. DNA sequence analysis of the p20K cDNA predicted a novel protein distantly related to alpha 2 mu-globulin and plasma retinol-binding protein.     

Effects of endogenous calcium transport inhibitor from heart muscle on the active calcium uptake and passive calcium release properties of sarcoplasmic reticulum

In the present study, the effects of the cytosolic Ca2+ transport inhibitor on ATP-dependent Ca2+ uptake by, and unidirectional passive Ca2+ release from, sarcoplasmic reticulum enriched membrane vesicles were examined in parallel experiments to determine whether inhibitor-mediated enhancement in Ca2+ efflux contributes to inhibition of net Ca2+ uptake. When assays were performed at pH 6.8 in the presence of oxalate, low concentrations (less than 100 micrograms/mL) of the inhibitor caused substantial inhibition of Ca2+ uptake by SR (28-50%). At this pH, low concentrations of the inhibitor did not cause enhancement of passive Ca2+ release from actively Ca2+-loaded sarcoplasmic reticulum. Under these conditions, high concentrations (greater than 100 micrograms/mL) of the inhibitor caused stimulation of passive Ca2+ release but to a much lesser extent when compared with the extent of inhibition of active Ca2+ uptake (i.e., twofold greater inhibition of Ca2+ uptake than stimulation of Ca2+ release). When Ca2+ uptake and release assays were carried out at pH 7.4, the Ca2+ release promoting action of the inhibitor became more pronounced, such that the magnitude of enhancement in Ca2+ release at varying concentrations of the inhibitor (20-200 micrograms/mL) was not markedly different from the magnitude of inhibition of Ca2+ uptake. In the absence of oxalate in the assay medium, inhibition of Ca2+ uptake was observed at alkaline but not acidic pH.(ABSTRACT TRUNCATED AT 250 WORDS)     

Rapid assay for screening and characterizing microorganisms for the ability to degrade polychlorinated biphenyls

We designed a rapid assay that assesses the polychlorinated biphenyl (PCB)-degradative competence and congener specificity of aerobic microorganisms, identifies strains capable of degrading highly chlorinated biphenyls, and distinguishes among those that degrade PCBs by alternative pathways. Prior attempts to assay PCB-degradative competence by measuring disappearance of Aroclors (commercial PCB mixtures) have frequently produced false-positive findings because of volatilization, adsorption, or absorption losses. Furthermore, these assays have generally left the chemical nature of the competence obscure because of incomplete gas chromatographic resolution and uncertain identification of Aroclor peaks. We avoided these problems by using defined mixtures of PCB congeners and by adopting incubation and extraction methods that prevent physical loss of PCBs. Our assay mixtures include PCB congeners ranging from dichloro- to hexachlorobiphenyls and representing various structural classes, e.g., congeners chlorinated on a single ring (2,3-dichlorobiphenyl), blocked at 2,3 sites (2,5,2'5'-tetrachlorobiphenyl), blocked at 3,4 sites (4,4'-dichlorobiphenyl), and lacking adjacent unchlorinated sites (2,4,5,2',4',5'-hexachlorobiphenyl). The PCB-degrative ability of microorganisms is assessed by packed-column gas chromatographic analysis of these defined congener mixtures following 24-h incubation with resting cells. When tested with 25 environmental isolates, this assay revealed a broad range of PCB-degradative competence, highlighted differences in congener specificity and in the extent of degradation of individual congeners, predicted degradative competence on commercial PCBs, and (iv) identified strains with superior PCB-degradative ability.     

Le lymphosarcome folliculaire: La maladie de Brill-Symmers

From a survey of the literature on follicular lymphoma it appears that the lesion of Brill-Symmers disease may be considered to be a form of neoplasm. The authors have reviewed a series of 18 cases seen at the Hôtel-Dieu of Québec between 1950 and 1960 and have adopted Rappaport''s classification published in 1956, but leaving out the “Hodgkin” Type 5 which they propose to examine more fully in another paper.There appears to be a degree of positive correlation between the histologic type and the course of the disease, the well differentiated cell Type 1 being associated with a protracted course. This neoplasm should not be mistaken for benign follicular hyperplasia.     

Comparative effects of trichothecene mycotoxins on bovine platelet function: Acetyl T-2 toxin,a more potent inhibitor than T-2 toxin

The effects of the trichothecene mycotoxins (acetyl T-2 toxin, T-2 toxin, HT-2 toxin, palmityl T-2 toxin, diacetoxyscirpenol (DAS), deoxynivalenol (DON), and T-2 tetraol) on bovine platelet function were examined in homologous plasma stimulated with platelet activating factor (PAF). The mycotoxins inhibited platelet function with the following order of potency: acetyl T-2 toxin > palmityl T-2 toxin = DAS > HT-2 toxin = T-2 toxin. While T-2 tetraol was completely ineffective as an inhibitor, DON exhibited minimal inhibitory activity at concentrations above 10×10^?4M. The stability of the platelet aggregates formed was significantly reduced in all mycotoxin treated platelets compared to that of the untreated PAF controls. It is suggested that the increased sensitivity of PAF stimulated bovine platelets to the more lipophilic mycotoxins may be related to their more efficient partitioning into the platelet membrane compared to the more hydrophilic compounds.     

Aerobic degradation of polychlorinated biphenyls by Alcaligenes sp. JB1: metabolites and enzymes

In contrast to the degradation of penta-and hexachlorobiphenyls in chemostat cultures, the metabolism of PCBs by Alcaligenes sp. JB1 was shown to be restricted to PCBs with up to four chlorine substituents in resting-cell assays. Among these, the PCB congeners containing ortho chlorine substituents on both phenyl rings were found to be least degraded. Monochloro-benzoates and dichlorobenzoates were detected as metabolites. Resting cell assays with chlorobenzoates showed that JB1 could metabolize all three monochlorobenzoates and dichlorobenzoates containing only meta and para chlorine substituents, but not dichlorobenzoates possessing an ortho chlorine substituent. In enzyme activity assays, meta cleaving 2,3-dihydroxybiphenyl 1,2-dioxygenase and catechol 2,3-dioxygenase activities were constitutive, whereas benzoate dioxygenase and ortho cleaving catechol 1,2-dioxygenase activities were induced by their substrates. No activity was found for pyrocatechase II, the enzyme that is specific for chlorocatechols. The data suggest that complete mineralization of PCBs with three or more chlorine substituents by Alcaligenes sp. JB1 is unlikely.Abbreviations PCB polychlorinated biphenyls - CBA chlorobenzoate - D di - Tr tri - Te tetra - Pe penta- - H hexa     

Metastasis of cancer of the thyroid gland as a cause of goitre.

In three cases of cancer (arising in the pancreas, the breast and the lung) that had metastasized to the thyroid an unusual primary thyroid lesion was the presenting problem. While reputedly rare, metastases in the thyroid gland are not infrequently encountered at necropsy. These cases illustrate the varied causes of goitre, the value of needle aspiration and cytologic study in thyroid disease and the need for histologic vigilance. Worthwhile palliation by simple means can be obtained in such cases.     

Initiation and translation in vitro of mRNA for MOPC 315 immunoglobulin heavy chain and characterization of translation product.

An initiation study of mineral oil-induced plasmacytoma (MOPC) 315 heavy chain immunoglobulin (H315) in vitro has been conducted using formyl-[35S]methionyl-tRNAfMet and a highly purified 18 S message from MOPC 315 solid tumor in a crude rabbit reticulocyte lysate system. The product was specifically precipitated by antibodies directed against MOPC 315 immunoglobulin and H315. The in vitro H315 products terminally labeled with formyl-[35S]methionine or internally labeled with [3H]leucine were electrophoretically identical with in vivo H315 on sodium dodecyl sulfate-polyacrylamide gels. All of the [35S]-methionine was incorporated at the NH2 terminus, not internally, since there is a near complete recovery of [35S]methionine following one cycle of Edman degradation. The NH2-terminal cyanogen bromide peptide, CN2, of in vivo and in vitro H315 co-migrated exactly on gel electrophoresis under conditions which completely resolved two proteins differing in size by only 14 amino acids. These data strongly suggest that there is no NH2-terminal precursor of H315 in this system. Cyanogen bromide peptide profiles of in vivo and in vitro H315 were chromatographically indistinguishable. Three peptides, CN1, CN2, and CN4, which represent approximately 85% of the total amino acids of H315 were isolated and further characterized by electrophoresis and paper chromatography. All were very similar to the corresponding peptides of authentic H315. We conclude that the fidelity of H315 translation is preserved in vitro.     

吐鲁番市胃食管反流病发生相关危险因素分析（附280例报道）

目的：探讨280例胃食管反流病（GERD）的分布特点及危险因素。方法：对临床诊断和胃镜确诊的280例GERD患者进行临床和风险因子相关性分析。结果：不论汉族还是维族,男性患者比例均明显高于女性;汉族患者高发年龄段早于维族患者（z=-2．939,P=0．003,）;汉族和维族患者占反流性食管炎和Barrett食管比例分别为42．4％、81_3％及56．5％、18．8％,其中汉族患者Barrett食管比例较高（X2=14．358,P=0．000）;肥胖、习惯性便秘、重体力活动者、饮食习惯不良在维族患者中的比例较高（P〈0．001）。结论：GERD与性别、年龄密切相关,男性多于女性,汉族患者发病年龄高峰旱于维族患者;汉族患者Barrett食管发生比例高于维族患者;肥胖、习惯性便秘、重体力活动、饮食习惯不良可能是GERD尤其是维族人群GERD的危险因素。