Fast protein chromatofocusing of human very-low-density lipoproteins

Using fast protein chromatofocusing, a high-efficiency column chromatography method with a self-generated pH gradient and focusing effects, soluble human very-low-density lipoprotein (VLDL) apolipoproteins were fractionated between pH 6.3 and 4.0. In the presence of 6 mol/l urea and with a flow rate of 1 ml/min, one run (up to 10 mg of protein) took 30 min. VLDL apolipoproteins were separated in seven peaks. As revealed by SDS-polyacrylamide gel electrophoresis, isoelectric focusing and double-immunodiffusion against mono-specific antisera, fractions corresponded to the following proteins: apolipoprotein C-I, albumin, apolipoproteins A-I, E, C-II plus C-III0, C-III1 and C-III2, respectively. Apolipoproteins were eluted in sharp, well-resolved peaks. The recovery of proteins was 78% of the starting material. With fast protein chromatofocusing, an efficient isolation of single apolipoproteins is possible from small amounts of VLDL apolipoprotein preparations. This technique is superior to the commonly used, time-consuming methods for apolipoprotein isolation.     

Lung injury and complement activation: Role of neutrophils and xanthine oxidase

Evidence is presented that oxygen products generated from xanthine oxidase (XO) may also be involved in the pathogenesis of neutrophil-mediate lung injury following intravascular activation of complement with cobra venom factor (CVF). CVF injection in rats resulted a rapid increase in plasma of both XO activity (but not xanthine dehydrogenase) and its reaction product, uric acid. These changes were greatly attenuated in allopurinol-treated animals. The apperance of XO activity was paralleled by a raise in plasma of histamine. Prevention of histamine release by pretreatment of rats withy cromolyn abolished both the rise in plasma histamine and the increase in XO activity. Since we have previously shown that histamine can enhance XO activity in vitro and in vivo (Am. J. Pathol. 135:203, 1989), these observations suggest that the increase in plasma XO activity following CVF injection is related to the appearance in plasma of histamine. Accordingly, pretreatment of rats with xanthine oxidase inhibitors (allopurinol, lodoxamine) or prevention of histamine release by pretreatment with cromolyn significantly attenuated development of lung injury following injection of CVF. Our data support the concept that oxygen radicals derived from both neutrophils and XO are playing a role in the CVF-induced acute lung injury.     

Vorwort

Ohne Zusammenfassung     

Adventitious embryony inNigritella (Orchidaceae)

The embryology of diploid and polyploidNigritella species is described. The development of the adventitious embryos of the polyploids in relation to the sexual embryos of the diploids has been given special consideration. Partial sexuality in the apomicticN. nigra has been proven for the first time by chromosome counts in proembryos after pollination of a tetraploid plant with pollen from a diploid species.     

Intracellular translocation of symbiotic bacteroids during late oogenesis and early embryogenesis of Bradysia tritici (syn. Sciara ocellaris) (Diptera: Sciaridae)

Abstract. The distribution of symbiotic prokaryotes (bacteroids) in ovarian follicles and young embryos of Bradysia ( Sciara ) was studied using light and electron microscopy. In mid-vitellogenic follicles (prior to oosome formation) isolated from 8-h-old midges, most symbionts were scattered in the ooplasm. Later, during oogenesis and concomitant with the formation of the oosome, symbionts aggregated at the posterior pole of the follicle. During early embryogenesis, large symbiont clusters were seen between the oolemma and oosome and lateral to the oosome. When the presumptive pole-cell nuclei moved into the oosome, the bacteroids became scattered in and around the prospective germ plasm, and many of them became incorporated into the pole cells. At the anterior pole, a nearly symbiontfree area could be recognized at first (anterior cone), but later on symbionts aggregated there (usually best seen in 1-h embryos). Thereafter, smaller symbiont clusters spread into more lateral parts of the thickened anterior cortex. Finally, the aggregates became dispersed when cleavage nuclei moved into the anterior egg cortex. The distribution of symbionts may reflect cytoplasmic streaming or other transport phenomena during development which could participate in oosome formation or in the histological differentiation of the anterior egg cortex.     

Hans Molisch

Ohne Zusammenfassung     

Eiweißspindeln und -kristalle inScutellaria

Zusammenfassung Die Eiweißnatur der in der Blattepidermis vonScutellaria altissima auftretenden Spindeln und Stäbe wurde wahrscheinlich gemacht. Bei dieser Pflanze finden sich, allerdings selten, in den Epidermiszellen auch hexagonale Eiweißkristalle. Ob diese Eiweiß-Inhaltskörper als mikroskopische Symptome einer makroskopisch latenten Virusinfektion aufzufassen sind, blieb unentschieden.     

A comparison between Andersen (ACFM) and Reuter Centrifugal Sampler (RCS-plus) for indoor sampling of airborne molds

This paper shows first results regarding thecollection efficiency and suitability of theAndersen-6-stage cascade impactor (ACFM,Graseby Andersen) and the Reuter CentrifugalSampler (RCS-plus, Biotest Diagnostics Corp.,Denville, NJ) in measuring concentrations ofindoor airborne viable mold spores. The ACFMshowed significantly higher numbers of colonyforming units than the RCS-plus. For exposureassessment the lower sampling efficiency of theRCS-plus in comparison to the ACFM is not soimportant, as no sampler is able to record theactual concentration of airbornemicroorganisms. For fungal exposure assessmentit is more important to compare indoor andoutdoor mold spore concentration and theindoors and outdoors occuring species. The ACFMdoes not overload as quickly as the RCS-plus,so there is not so much overgrowing andinhibition of colonies and it is easier tomaintain pure cultures. The advantages of theRCS plus are the simpler handling and, the optionof changing flow-rate. Even though each sampler hasits set of advantages and disadvantages, bothcan serve a useful function in airborne fungalspore sampling.