Coxiella burnetii (Q fever) as a cause of community-acquired pneumonia during the warm season in Germany.

Q fever is a notifiable disease in Germany. The majority of the reported cases are related to outbreaks. The objective of our study was to evaluate the general role of Q fever in community-acquired pneumonia (CAP). We investigated respiratory samples and sera from 255 patients with CAP, who were enrolled into a CAPNETZ cohort in summer 2005. Altogether, our data showed a significant prevalence of Q fever as CAP (3·5%). If a patient's condition leads to a diagnostic test for Chlamydophila sp., Mycoplasma sp. or Legionella sp., then a Q fever diagnostic test should also be included. In particular, ELISA as a first diagnostic step is easy to perform. PCR should be performed at an early stage of the disease if no antibodies are detectable. Because of our highly promising findings we suggest performing PCR in respiratory samples.

Electron spectroscopic imaging analyses of the distribution of phosphorus in Balbiani ring granules and in the surrounding nucleoplasm.

The in situ distribution of phosphorus was studied in unstained ultrathin sections of salivary glands of Chironomus tentans and Ch. thummi larvae using elemental mapping by means of an energy-filtering transmission electron microscope. This distribution was related to the structures observed using contrast enhancement with inelastically scattered electrons at 250 eV. This procedure demonstrated that a phosphorus-containing fibril about 2 nm thick is the common substructure of the following nuclear ribonucleoprotein structural constituents: the Balbiani ring granules, their precursor fibrils seen at the sites of transcription, especially at the Balbiani rings, and the fibres traversing the pore of the nuclear envelope. These phosphorus-containing thin fibrils are sensitive to RNase. Thicker substructural features of the Balbiani ring granules, occurring as a curved ribbon on a dense particle, appear to be formed by the dense packing of the fine fibrils. The Balbiani ring granules located near the nuclear envelope are often linked to it by fine filaments.

Coaching: the art of creating exceptional results.

Functioning as a Coach is a key role for a manager and, in fact, distinguishes the manager as a leader. Coaching focuses on two distinct areas: 1) coaching to orient employees to new situations, and 2) coaching for performance with employees who are showing marginal performance, who are meeting expectations, or who are showing high performance. This article describes coaching for orientation and for performance, identifies coaching skills, and provides a coaching self-assessment.

Retention of glycogen in cryosubstituted mouse liver.

A periodic acid-Schiff (PAS)-type reaction in which osmium-ammine was used as the reagent was carried out on ultrathin sections of mouse liver in order to study the extent to which glycogen is preserved. Comparisons were made between tissues that were, on the one hand, conventionally fixed and dehydrated and, on the other, those that were high-pressure frozen and cryosubstituted in acetone. A control was carried out for both groups using a routine uranyl acetate-lead citrate staining procedure. In the latter case, glycogen could be identified as electron-clear patches in the cytoplasm whereas after a PAS-type reaction, glycogen became darkly contrasted. In the case of conventionally fixed samples, glycogen appeared to display a certain amount of clumping separated by gaps whereas in cryosubstituted specimens it was denser and often showed elongated interconnecting structures. These results suggest that cryofixation and cryosubstitution provide better preservation of glycogen in mouse liver tissue compared with chemically fixed specimens. In addition, the fine structure of glycogen appears more homogeneous, showing less aggregation in cryo-treated liver samples.

Immunoelectron microscope localization of snRNP, hnRNP, and ribosomal proteins in mouse spermatogenesis.

We have studied the ultrastructural distribution of heterogeneous nuclear ribonucleoproteins (hnRNPs), small nuclear ribonucleoproteins (snRNPs), and ribosomal proteins during mouse spermatogenesis and spermiogenesis by means of specific antibodies and immunocytochemistry. All the above components were detectable from primary spermatocytes until the spermatid elongation phase, when the RNA synthetic activity is known to cease. Ribosomal protein (P1/P2 and L7) labeling disappeared as early as during the acrosome phase, and nucleoli were no longer labeled even during the cap phase. The nucleoplasmic structures labeled with the different anti-nucleoplasmic RNP immunoprobes corresponded, until the acrosome phase, to those previously observed as targets of the same antibodies in the nucleoplasm of somatic cell nuclei. Clusters of interchromatin granules of spermatocyte and early spermatid nuclei exhibit some labeling for hnRNP when compared with nuclei of Sertoli cells or previously analyzed liver or tissue culture cells, where these structural constituents usually remain weakly labeled or unlabeled. In spermatids in step 10, another type of nuclear granule, resembling perichromatin granules, but occurring in aggregates, can be observed. These structural constituents were labeled with antibodies recognizing nucleoplasmic snRNP antigens and therefore suggesting a non-nucleolar origin of these granules. Finally, we have observed nucleoplasmic areas of fibrogranular material, occurring only in primary spermatocytes. These components were labeled with anti-ribosomal protein antibodies but did not contain either hnRNPs or snRNPs.

Cryofixation and cryosubstitution: a useful alternative in the analyses of cellular fine structure.

A study of the fine structure of cultured mouse P815 cells as well as of mouse liver tissue after having undergone cryofixation and cryosubstitution is reported here. The P815 cells were cryofixed by a projection onto a liquid nitrogen (LN2), or liquid helium (LHe), cooled copper mirror: the liver tissue was processed (cryofixed) by high pressure freezing using a Balzers HPM 010 apparatus. No conventional chemical fixatives were used in the substitution medium which consisted of pure acetone. Embedding was carried out either in Lowicryl K11M, Lowicryl HM23, Epon or in LR White resins. The results of this study enabled us to conclude that a) one can obtain good preservation of cellular ultrastructure using different cryofixation methods and cryosubstitution without the use of chemical fixatives: b) different methods of embedding can be applied after various cryofixation techniques giving rise to slight differences in the well preserved fine structure; and c) high pressure freezing is to be recommended, in cryosubstitution studies, over that of slam freezing especially when cryofixing larger pieces of tissue which can result in a good morphology of up to 400 microns in depth.

Some applications of cryosubstitution in ultrastructural studies of the cell nucleus.

Cryofixation followed by cryosubstitution, without the use of any chemical fixatives, was carried out on cultured mouse P815 cells. The principal aim of our work, which was to show that these techniques provide excellent morphological preservation of cellular and in particular nuclear components, was demonstrated. All nuclear structural components, nucleolar or nucleoplasmic, were clearly revealed using this technology. The cells were cryofixed by impact freezing onto a copper mirror cooled with liquid nitrogen or helium, cryosubstituted in acetone and embedded in either Lowicryl K11M or 1R White acrylic resin. Ultrathin sections were contrasted using either the usual uranyl acetate-lead citrate double staining, a differential staining for nuclear nucleoprotein structures, or the silver staining revealing nucleolar organizer regions. In view of the absence of conventional fixatives, the specimens prepared in this way would offer to be material of choice for ultrastructural identification of intra-nuclear antigens, especially those sensitive to conventional fixatives such as, for example, aldehydes. Advantages and differences of these techniques with regard to more conventional electron microscopic procedures are discussed.