Exocytosis and macrophage-mediated antibody-dependent cellular cytotoxicity: a cautionary note.

The appearance of soluble radioisotope from macrophages (M phi) that previously had ingested 51Cr-labelled antibody-coated sheep erythrocytes (51Cr-EA) was assessed to determine if exocytosis contributed to the pool of radioactivity used to measure antibody-dependent cellular cytotoxicity (ADCC). M phi preloaded for 60 min with 51Cr-EA lost the majority of the ingested 51Cr over a subsequent 3 hr incubation period. The exocytotic rate was independent of the number of 51Cr-EA ingested, but was temperature dependent with no appreciable release of 51Cr observed at 4 degrees. The exocytotic process was unaffected by sodium azide (10 mM) but was markedly enhanced in the presence of iodoacetate (50 mM), cytochalasin B (20 micrograms/ml) or lidocaine (0.5 mM). The results show that M phi rapidly digest engulfed target cells and that exocytosis can contribute sufficient soluble radioactivity to the extracellular pool to lead to misinterpretation of putative ADCC activity.     

Vergleich zwischen cytologischer und cytochemischer Klassifizierung bei 47 Fällen von akuter Leukämie

Zusammenfassung Bei 47 Patienten mit akuter Leukämie wurden die Ergebnisse einer voneinander unabhängigen Klassifizierung aufgrund der panoptischen Färbung einerseits und dem Ausfall cytochemischer Reaktionen andererseits (Peroxydase, PAS-Reaktion, Naphthol-AS-Acetat-Esterase) sowie das Ansprechen auf eine adäquate Induktionstherapie in den cytologisch und cytochemisch definierten Gruppen miteinander verglichen. In 42 Fällen stimmte die cytologische und cytochemische Differenzierung miteinander überein. Hinsichtlich des Ansprechens auf Therapie ergeben sich keine signifikanten Unterschiede, gleichgültig, ob man die AL nach cytologischen oder cytochemischen Kriterien gruppiert. Eine Ausnahme bildet der bei undifferenzierten AL cytochemisch charakterisierbare PAS-Typ, bei dem ein besseres Ansprechen auf Therapie als bei den Fällen ohne diagnostisch verwendbare cytochemische Aktivität wie auch bei den granulocytär differenzierten AL gefunden wurde. Hinsichtlich des Ansprechens auf Therapie verhalten sich die Erwachsenen mit PAS-Typ ähnlich günstig wie die Kinder.Mit Unterstützung der Deutschen Forschungsgemeinschaft.     

Effects of sex steroid analogs on spontaneous autoimmune thyroiditis in obese strain chickens.

Treatment of obese strain chickens, either in ovo or after hatching, with testosterone or various testosterone-derived steroid analogs having no or only weak endocrine activities causes significant protection from spontaneous autoimmune thyroiditis occurring in these birds. This effect is not correlated with the endocrinological properties of these steroids. This observation and similar results in other models for autoimmunity may present a basis for a more selective therapy in human autoimmune diseases in that hormonal side effects no longer preclude this approach.     

Polymerisationsauslösung mit substituierten ethanen, 2. Trennung der Oligomeren aus Methylmethacrylat und 1,1,2,2-Tetraphenyl-1,2-diphenoxyethan

The telechelics 1 from methyl methacrylate and 1,1,2,2-tetraphenyl-1,2-diphenoxyethane, can be separated by adsorption chromatography. The structure of the dimers and trimers was identified by ¹H NMR-spectroscopy. The free radical oligomerization is a process in which the syndiotactic structure is favoured above the isotactic one.     

Quantitative reflection spectroscopy at the human ocular fundus

A new model of the reflection of the human ocular fundus on the basis of the adding-doubling method, an approximate solution of the radiative transport equation, is described. This model enables the calculation of the concentrations of xanthophyll in the retina, of melanin in the retinal pigment epithelium and the choroid, and of haemoglobin in the choroid from fundus reflection spectra. The concentration values found in 12 healthy subjects are in excellent agreement with published data. In individual cases of pathologic fundus alterations, possible benefits to the ophthalmologic diagnostics are demonstrated.     

DNA cross-link-dependent RAD50/MRE11/NBS1 subnuclear assembly requires the Fanconi anemia C protein

Fanconi anemia (FA) is a cancer-predisposition syndrome characterized by hypersensitivity to interstrand-cross-link (ICL) inducers. FA hypersensitivity to ICL has been correlated with alterations in homologous recombination, non-homologous end-joining, telomere maintenance, DNA-damage assessment and checkpoint regulation, processes in which the components of the RAD50/MRE11/NBS1 (RMN) complex are involved. To better characterize the mechanisms by which ICL are processed in human cells and to gain insight into their toxicity in FA, we examined (i). the RMN complex assembling in response to the ICL inducers mitomycin C (MMC) and photoactivated 8-methoxypsoralen and (ii). the proficiency of FA cells to perform RMN activation in response to ICL inducers. We show here that ICL activates the assembly of the RMN proteins into subnuclear foci, and that their formation proceeds independently of ICL incision, a step mainly dependent on XP-F/ERCC1 heterodimer activity. Interestingly, FA cells were unable to form RMN foci in response to either ICL inducer. Analysis by pulsed-field gel electrophoresis and single-cell gel electrophoresis of MMC-treated cells showed that FA cells from complementation group C (FA-C cells, defective in the FANCC gene) form double-strand breaks and unhook MMC-induced ICL similarly to FANCC wild-type cells. These observations imply that the absence of RMN assembly in FA-C cells is not simply due to the absence of DNA ends produced as intermediates of ICL processing, and indicates a direct role for FANCC in RMN focus assembly in response to ICL inducers. Moreover, we show that the formation of foci, including BRCA1 and/or RAD51 proteins, is significantly delayed in FA cells. These alterations in the assembly of DNA-repair proteins in FA provide an interpretation for the DNA-damage processing anomalies observed in FA cells and for the genetic instability and the cancer predisposition of the syndrome.     

Stabile polysauerstoff-radikale. I. Synthese von polymerisationsfähigen monomeren mit sterisch behinderter freier oder geschützter phenolischer hydroxylgruppe

New monomers with sterically hindered free or blocked phenolic hydroxyl groups were used as starting compounds for the preparation of stable oxygen polyradicals. In this paper the synthesis of these monomers is described: 2,6-Di-(tert-butyl)-4-vinylphenol was obtained by decarboxylation of 3-[3,5-di-(tert-butyl)-4-hydroxyphenyl]acrylic acid in yields of 80–;90%. 2,6-Di-(tert-butyl)-4-isopropenylphenol was prepared from 3,5-di-(tert-butyl)-4-hydroxyphenyl methyl ketone and methyl iodide by a GRIGNARD reaction followed by the dehydration of 2-[3,5-di-(tert-butyl)-4-hydroxyphenyl]-2-propanol. 2,6-Di-(tert-butyl)-4-isopropenylphenyl methyl ether was obtained with 64% yield from 3,5-di-(tert-butyl)-4-methoxybenzonitrile by two consecutive GRIGNARD reactions with methyl iodide via the unknown compounds 3,5-di-(tert-butyl)-4-methoxyphenyl methyl ketone and 2-[3,5-di-(tert-butyl)-4-methoxyphenyl]-2-propanol, followed by dehydration of the tertiary alcohol with 89% phosphoric acid.     

Recognition by peptide mapping of three different structural groups of outer membrane protein YOP-1 of Yersinia enterocolitica and Yersinia pseudotuberculosis

The structural relation of YOP-1 of european and american Yersinia enterocolitica serotypes O3, O9, O5, 27, and O8 and O20, respectively, and Y. pseudotuberculosis serotypes I, II, and III was compared by sodium dodecyl sulfate polyacrylamide gel electrophoresis and peptide mapping using Staphylococcus aureus protease V8. Apparent molecular weights of YOP-1 ranged from 206,000 (O3) to approx. 180,000 (O8). According to their respective peptide maps YOP-1 of the european and american Y. enterocolitica serotypes and Y. pseudotuberculosis serotypes could be assigned to three different groups. Evaluation of several isolates of Y. enterocolitica serotypes O3, O9, and O8 by peptide mapping indicated that YOP-1 is conserved within a serotype. However, one serotype O8 isolate differed from the consensus peptide pattern of the other serotype O8 and O20 isolates. The similarity of the peptide patterns of Yersinia serotypes which predominate in certain geographical locations, i. e., european and american Y. enterocolitica serotypes, suggest common evolution of YOP-1 of these serotypes independent of the evolution of the other serotypes.