Mikrokallusformationen der Spongiosa Ein bisher unterschätzter reparativer Mechanismus des Skelettsystems

Zusammenfassung Mikrokallusformationen lassen sich in nahezu allen Skelettabschnitten der Spongiosa nachweisen. Mikrokallus besteht aus Geflechtknochen, der sich an lokal überbelasteten Stellen in der Spongiosa bildet. Mit Hilfe einer speziellen Pr?parationstechnik wurden 26 skelettgesunde und 11 Wirbels?ulen von F?llen mit Osteoporose untersucht. Mikrokallusformationen finden sich bevorzugt bei Frauen ?lter als 45 Jahre in den unteren Wirbels?ulenabschnitten. Dabei hat die Mikroarchitektur der Spongiosa (TBPf) einen st?rkeren Einflu? auf die Anzahl der Mikrokalli, als individuelle Trabekelparameter (Tb.N, BV/TV und Tb.Th). Nur in 33 % der Formationen lassen sich Frakturspalten nachweisen. Mikrokallusformationen k?nnen nichtinvasive Knochenmassemessungen verf?lschen. Auch wenn Mikrokallusformationen Indikatoren für eine Instabilit?t der Spongiosa sind, tragen sie zur Knochenregeneration bei, und die Entstehung neuer Trabekel ist durch sie m?glich. Die Vorstellung, da? Osteoporose das Resultat einer verminderten Mikrokallusbildung ist, trifft nicht zu.      

Human brucellosis in a nonendemic country: a report from Germany, 2002 and 2003

Human brucellosis has become a rare disease in Germany since the eradication of bovine and ovine/caprine brucellosis in this country. Therefore, most physicians are unfamiliar with the illnesses clinical presentation, diagnostic tools, and therapeutic strategies. This retrospective study was carried out to evaluate the epidemiological, clinical, and laboratory features of human brucellosis in Germany in the years 2002 and 2003. Thirty-one bacterial isolates from 30 patients sent to the German national reference laboratory were characterized using the genus-specific bcsp31 real-time PCR, the species-specific AMOS-PCR, and standard microbiological methods for the detection and identification of Brucella spp. The medical records of all patients with bacteriologically confirmed brucellosis were evaluated. All 31 isolates proved to be Brucella (30 Brucella melitensis and 1 Brucella suis). Most of the brucellosis patients were infected in endemic countries while visiting friends and relatives during their summer holidays. One case of laboratory-acquired infection was identified. Brucellosis was transmitted mainly by the consumption of contaminated unpasteurized milk or cheese from goats and sheep. The patients presented primarily with flu-like symptoms, i.e. fever, chills, sweating, headaches, arthralgia, and myalgia. In most cases, however, symptoms and signs of focal complications, e.g. spondylitis, endocarditis, and meningoencephalitis, predominated. The rate of complications was much higher than that in endemic countries, presumably as a result of diagnostic delay due to a low index of suspicion. In summary, physicians in nonendemic countries such as Germany must be aware of brucellosis being a possible cause of fever of unknown origin in immigrants and tourists travelling from endemic countries.     

Detection of human perforin by ELISpot and ELISA: ex vivo identification of virus-specific cells

The perforin (PFN) protein is essential for the elimination of target cells by cytotoxic T lymphocytes (CTL) and natural killer (NK) cells. The study of cells releasing PFN has been hampered by a lack of sensitive methods. We therefore produced PFN-reactive monoclonal antibodies (mAb) and developed capture enzyme-linked immunosorbent (ELISA) and enzyme-linked immunospot (ELISpot) assays. Three mAbs were generated and shown to react with unique determinants of PFN. All mAbs recognized intracellular PFN in human peripheral blood mononuclear cell (PBMC) as assessed by flow cytometry and immunohistochemistry. Functional PFN capture ELISA and ELISpot assays were developed utilizing two of the mAbs for capture and the third mAb for detection. When examining PFN release by the YT lymphoma cell line, the ELISpot displayed a greater detection sensitivity than the ELISA. Assessment of PFN release by a CTL clone using ELISpot gave results consistent with a parallel (51)Cr-release cytotoxicity assay. Moreover, PFN release by PBMC could be quantified by ELISpot and ELISA after ex vivo stimulation with defined CTL epitopes from common viruses. These novel immunoassays will be valuable for further investigations of the mechanisms underlying granule-mediated apoptosis. In addition, the capture immunoassays could provide tools for studying CTL responses in infectious and tumor diseases as well as for vaccine development.     

Electrophysiological responses from Culicoides (Diptera: Ceratopogonidae) to stimulation with carbon dioxide

Because of their impact on human and veterinary health, there is considerable interest in understanding how Culicoides use olfactory cues in host location. The adequate chemical stimulus for sensilla located on the maxillary palps was determined for several species of female Culicoides. Electrophysiological studies identified and characterized the sensory neurons on Culicoides maxillary palps that responded to stimulation with low concentrations of CO2. The concentration response function in different background concentrations of CO2 was established for C. furens (Poey), C. stellifer (Coquillet) and C. mississippiensis Hoffman. Comparisons were made to previously studied CO2-sensitive neurons in mosquitoes. Understanding what sensory signals the host releases and how they are detected may lead to the development of strategies aimed at controlling these insects.     

Stratification based on language-related endophenotypes in autism: attempt to replicate reported linkage.

The identification of autism susceptibility genes has been hampered by phenotypic heterogeneity of autism, among other factors. However, the use of endophenotypes has shown preliminary success in reducing heterogeneity and identifying potential autism-related susceptibility regions. To further explore the utility of using language-related endophenotypes, we performed linkage analysis on multiplex autism families stratified according to delayed expressive speech and also assessed the extent to which parental phenotype information would aid in identifying regions of linkage. A whole genome scan using a multipoint non-parametric linkage approach was performed in 133 families, stratifying the sample by phrase speech delay and word delay (WD). None of the regions reached suggested genome-wide or replication significance thresholds. However, several loci on chromosomes 1, 2, 4, 6, 7, 8, 9, 10, 12, 15, and 19 yielded nominally higher linkage signals in the delayed groups. The results did not support reported linkage findings for loci on chromosomes 7 or 13 that were a result of stratification based on the language delay endophenotype. In addition, inclusion of information on parental history of language delay did not appreciably affect the linkage results. The nominal increase in NPL scores across several regions using language delay endophenotypes for stratification suggests that this strategy may be useful in attenuating heterogeneity. However, the inconsistencies in regions identified across studies highlight the importance of increasing sample sizes to provide adequate power to test replications in independent samples.     

Analysis of E-cadherin in diffuse-type gastric cancer using a mutation-specific monoclonal antibody

In-frame deletions from the E-cadherin mRNA, coding for a homophilic cell adhesion molecule, are characteristic for diffuse-type gastric carcinomas. Using immunohistochemical analysis the mutant form cannot be distinguished from normal E-cadherin, making results difficult to interpret. In this study, a rat monoclonal antibody, designated E-cad delta 9-1, was generated against a peptide spanning the fusion junction region between exons 8 and 10. This new epitope is present in an E-cadherin variant that lacks exon 9 from the mRNA due to different splice-site gene mutations. Using Western blotting and immunohistochemistry of E-cadherin-transfected cells, we demonstrate that E-cad delta 9-1 specifically reacts with E-cadherin lacking exon 9 but not with the wild-type protein. No immunoreactivity was observed in 31 nontumorous and embryonal tissues analyzed. In gastric carcinoma specimens known to express mutant E-cadherin mRNA lacking exon 9, E-cad delta 9-1 targets exclusively tumor cells in routine formalin-fixed and paraffin-embedded material from biopsies, primary tumors, and lymph node metastases. In a retrospective series of 172 diffuse-type gastric carcinomas expressing E-cadherin, E-cad delta 9-1 reacted with 22 tumors (13%). This new tumor marker-monoclonal antibody system could open novel avenues for selective diagnosis and specific therapy of a subgroup of diffuse-type gastric cancer patients.     

Zur Induktion einer aktiven chronischen Hepatitis durch heterologe lösliche Leberproteine

Zusammenfassung Die Untersuchungen gehen von dem früher geführten Nachweis eines im immunologischen Sinne organspezifischen und weitgehend speciesexclusiven Proteins der Leber aus. Entsprechende Proteinpräparationen aus menschlichen Lebern wurden zur Sensibilisierung von Kaninchen eingesetzt.1. Bei langdauernder Sensibilisierung (über 1 Jahr) mit kleinen Dosen gelang beim erwachsenen Kaninchen die Induktion einer Immuntoleranz, die durch Applikation von hitzeund sulfanilsäurealteriertem Protein durchbrochen werden konnte; gleichzeitig konnte eine Hypersensibilität vom verzögerten Typ induziert werden. Histologisch fand sich bei allen Tieren eine aktive chronische Hepatitis; die übrigen Organe (Herz, Lunge, Skeletmuskulatur, Schilddrüse und Niere) waren frei von pathologischen Veränderungen.2. Bei kurzzeitiger Sensibilisierung (3 Monate) mit hohen Dosen fand sich histologisch lediglich eine dichtzellige lymphocytäre Infiltration der Periportalfelder der Leber; nur bei einem Tier bestanden geringe Hinweiszeichen auf eine beginnende chronische Lebererkrankung.In der Diskussion wird auf die serologisch nachweisbare Antigenverwandtschaft der entsprechenden Proteine von humaner und Kaninchenleber hingewiesen. Für die Entwicklung einer chronisch-progredienten Organerkrankung scheint die Ausbildung einer Hypersensitivität vom verzögerten Typ im Rahmen einer langdauernden Stimulierung wesentlich zu sein.

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Induction of chronic active hepatitis by organspecific heterologic soluble proteins of the liver

Summary These investigations are concerned with species- and organspecific liver proteins, demonstrated in earlier studies. Rabbits were sensitized utilizing similar protein-preparations obtained from human liver.1. With long-term sensitizations (approximately one year) immuntolerances were induced in adult rabbits by chronic administration of small doses of protein. The state of immun tolerance could be disturbed by applying of heat- and sulfanilic acid-altered protein, which at the same time could be shown to have induced hypersensitivity of delayed type. — Histologically active chronic hepatitis was found in all animals. Other organs such as heart, lung, skeletal muscle, thyroid gland and kidney were not affected.2. In short-term sensitizations with a high dosis of liver protein only dense lymphocytic infiltrations in the periportal areas were found histologically. In one animal only early changes of a chronic hepatitis were seen.Antigenic relations between human and rabbit liver proteins, as demonstrated earlier by serological techniques, are discussed in detail. Hypersensitivity of the delayed type would seem to play an important role in the development of active chronic hepatitis. This condition can be produced with long-term stimulations.