Einsatz einer Mischkultur in Acetat-Fermentationen

Bacterial cultures were selected from the native flora of liquid manure in order to metabolize liquid manure substances. The mixed culture used in the growth experiments is characterized by low growth rates when maximum degradation of acetate occurs. The biomass concentration reached 2.2 g/l.     

Fusion and failure following anterior cervical plating with dynamic or rigid plates: 6-months results of a multi-centric, prospective, randomized, controlled study

Anterior cervical plate fixation is an approved surgical technique for cervical spine stabilization in the presence of anterior cervical instability. Rigid plate design with screws rigidly locked to the plate is widely used and is thought to provide a better fixation for the treated spinal segment than a dynamic design in which the screws may slide when the graft is settling. Recent biomechanical studies showed that dynamic anterior plates provide a better graft loading possibly leading to accelerated spinal fusion with a lower incidence of implant complications. This, however, was investigated in vitro and does not necessarily mean to be the case in vivo, as well. Thus, the two major aspects of this study were to compare the speed of bone fusion and the rate of implant complications using either rigid- or dynamic plates. The study design is prospective, randomized, controlled, and multi-centric, having been approved by respective ethic committees of all participating sites. One hundred and thirty-two patients were included in this study and randomly assigned to one of the two groups, both undergoing routine level-1- or level-2 anterior cervical discectomy with autograft fusion receiving either a dynamic plate with screws being locked in ap - position (ABC, Aesculap, Germany), or a rigid plate (CSLP, Synthes, Switzerland). Segmental mobility and implant complications were compared after 3- and 6 months, respectively. All measurements were performed by an independent radiologist. Mobility results after 6 months were available for 77 patients (43 ABC/34 CSLP). Mean segmental mobility for the ABC group was 1.7 mm at the time of discharge, 1.4 mm after 3 months, and 0.8 mm after 6 months. For the CSLP- group the measurements were 1.0, 1.8, and 1.7 mm, respectively. The differences of mean segmental mobility were statistically significant between both groups after 6 months (P = 0.02). Four patients of the CSLP-group demonstrated surgical hardware complications, whereas no implant complications were observed within the ABC-group (P = 0.0375). Dynamic plate designs provided a faster fusion of the cervical spine compared with rigid plate designs after prior spinal surgery. Moreover, the rate of implant complications was lower within the group of patients receiving a dynamic plate. These interim results refer to a follow-up period of 6 months after prior spinal surgery. Further investigations will be performed 2 years postoperatively.     

Drug conditioning induced by intrastriatal apomorphine administration

The present study examined (1) whether the neostriatum is involved in a drug-induced conditioned locomotor response and; (2) whether this structure participates in the development of behavioral sensitization. Moreover, the present study addressed the question whether the development of behavioral sensitization is necessary for the induction of conditioning. Rats received injections of either apomorphine (2 μg) or vehicle (solution of 0.1% ascorbate/saline) into the dorsal neostriatum daily for 7 days. These treatments were performed immediately prior to (apomorphine-paired group and vehicle group) or 30 min following (apomorphine-unpaired group) 10-min placement in an open field which served as the test environment. After a 3-day drug withdrawal period, the animals were given a 10-min non-drug vehicle test trial in the test environment. Three days later, a drug test with apomorphine was administered to the animals of the paired and unpaired treatment groups; the vehicle group again received an injection of vehicle. The analysis of locomotor activity in the open field (measured as the distance traversed) revealed that locomotor activity in the apomorphine-paired group was higher than in the other groups. There were no indications for behavioral sensitization to intrastriatal apomorphine, since the locomotor response in the apomorphine-paired group did not increase, but rather decreased with daily repeated injections of apomorphine. Furthermore, only the apomorphine-paired animals showed a higher locomotor response when tested after an intrastriatal injection of vehicle in the previously apomorphine-paired environment, which is indicative of a conditioned drug effect. These results suggest that the neostriatum is directly involved in the development of drug-induced conditioning of locomotor behavior but not in the establishment of behavioral sensitization.     

Influence of neonatal sympathectomy on proximal renal resistance artery function in spontaneously hypertensive rats

Renal transplantation experiments have shown that the kidney contributes to chronic sympathectomy-induced arterial pressure reduction in spontaneously hypertensive rats (SHR). The underlying mechanisms are currently unclear but may include alterations in the function of small renal arteries. Neonatal SHR were sympathectomized by intraperitoneal guanethidine injections and removal of adrenal medullary tissue. Controls were sham- or hydralazine-treated. At 12 weeks of age, distal interlobar artery segments were investigated using small-vessel wire myography. Vessels from sympathectomized animals showed increased sensitivity to noradrenaline (NE). Vasopressin- and endothelin-1-induced vasoconstriction was similar in all groups (as reflected by the pD₂, i.e. –logEC₅₀, where EC₅₀ is the molar concentration of agonist eliciting a half-maximal response). Maximum vasopressin-induced tension was similar in all groups while endothelin-1-induced maximum tension was significantly higher in sympathectomized than in sham-treated SHR. The sensitivity of NE-induced vasoconstriction to extracellular Ca²⁺ did not differ between groups while sensitivity to L-type Ca²⁺ channel activation was significantly higher in both sympathectomized and hydralazine-treated animals than in sham-treated animals. Endothelium-dependent and independent vasodilation were similar in all groups. Sequential blockade of NO-synthase and cyclooxygenase had similar effects in all groups. In conclusion, neonatal sympathectomy does not induce any changes in the function of isolated proximal renal resistance arteries from SHR that could explain the blood pressure lowering effect of a kidney graft from sympathectomized SHR.     

PCR analysis of pulsed-field gel electrophoresis-purified plastid DNA,a sensitive tool to judge the hetero-/homoplastomic status of plastid transformants

The genetic transformation of plastids of higher plants has developed into a powerful approach for both basic research and biotechnology. Due to the high copy number of the plastid genome per plastid and per cell, repeated cycles of shoot regeneration under conditions selective for the modified plastid chromosome are required to obtain transformants entirely lacking wild-type plastid genomes. The presence of promiscuous plastid DNA in nuclear and/or mitochondrial genomes that generally contaminate even gradient-purified plastid fractions reduces the applicability of the highly sensitive PCR approach to monitor the absence of residual wild-type plastid chromosomes in transformed lines. It is therefore difficult, or even impossible, to assess reliably the hetero- or homoplastomic state of plastid transformants in this manner. By analysing wild-type and transplastomic mutants of tobacco, we demonstrate that separation of plastid chromosomes isolated from gradient-purified plastid fractions by pulsed-field gel electrophoresis can overcome the problem of (co)amplification of interfering promiscuous plastid DNA. PCR analyses with primers specific for plastid, mitochondrial and nuclear genes reveal an impressive purity of such plastid DNA fractions at a detection limit of less than one wild-type plastid chromosome copy per ten transplastomic cells.     

Die durch Argas (Persicargas) persicus-Larven bedingte Paralyse der Hühner

Zusammenfassung Bei der durch Argas (Persicargas) persicus-Larven bedingten Zeckenparalyse der Hühner handelt es sich um eine generalisierte Affektion des peripheren Nervensystems, wobei es zu einer funktionellen Schädigung der schnell leitenden Nervenfasern kommt.Bei 12 Tieren mit schwersten Paralysen waren die maximalen motorischen Nervenleitungsgeschwindigkeiten, bei gleichzeitig erforderlicher Erhöhung der motorischen Schwellen- bzw. Supramaximalreize, auf 55% herabgesetzt sowie die Reizantwortpotentiale aus der distalen Muskulatur auf 15–30% abgefallen. Die distalen Überleitungszeiten verlängerten sich dabei nur geringfügig. Bei repetitiver distaler Nervenreizung kam es zu einem deutlichen Amplitudenabfall. 3 Tage nach klinischer Restitution hatten sich die neurophysiologischen Veränderungen noch nicht zurückgebildet.Bei 8 Tieren mit mittelgradigen Paresen war die Schädigung des peripheren Nervensystems nicht so stark ausgeprägt. Die maximalen motorischen Nervenleitungsgeschwindigkeiten waren nur auf 70% vermindert, während die motorischen Schwellen- und Supramaximalreize leicht erhöht waren. Die Werte für die Amplituden der Summenpotentiale waren im Vergleich mit den schwerst gelähmten Tieren bedeutend größer, die distalen Latenzzeiten blieben dagegen unverändert. Bei repetitiver Nervenreizung verminderten sich die Amplituden der Antwortpotentiale nur geringfügig. 3 Tage nach der klinischen Rekonvaleszenz waren bei allen Tieren die neurophysiologischen Veränderungen, bis auf eine noch bestehende Verminderung der Summenpotentiale, wieder völlig zurückgebildet.

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Tick paralysis in chickens caused by Argas (Persicargas) persicus-Larvae

Summary In tick paralysis caused by Argas (Persicargas) persicus-larvae a generalized affection of peripheral nervous system especially of fast conducting nerve fibres was found.In 12 animals with severe paralysis maximal motor conduction velocity slowed down to 55% of the initial value and the amplitudes of evoked compound muscle action potentials decreased to 15–30% of the initial value. Simultaneously motor threshold resp. supramaximal stimuli to the nerves were increased. Distal latencies changed only a little. By repetitive distal nerve stimulation muscle action potential amplitudes showed a decrement. Three days after clinical restitution neurophysiologically an affection of peripheral nerves to a small extent could be shown. The affection of peripheral nerves in 8 animals with moderate pareses was less pronounced. The reduction of motor conduction velocity went down only to 70% of the initial value whereas threshold and supramaximal stimuli were only slightly increased. There were in comparison with the severe paralyzed animals higher amplitudes of evoked compound muscle action potentials. Distal latencies remained unchanged. By repetitive nerve stimulation only a small decrement of muscle action potential amplitudes could be stated. Three days after clinical restitution neurophysiologically only a slight reduction of the amplitudes of the evoked muscle action potentials could be measured.

     

Das Verhalten von Blutdruck und Nierendurchblutung während des Carotissinus-Reflexes am wachen Hund

Zusammenfassung An 15 Bastardhunden wurde der Einfluß einer Na-Pentobarbital-Narkose sowei einer zusätzlichen chirurgischen Präparation auf die Ruhewerte von Blutdruck und Nierendurchblutung und deren Änderung nach doppelseitigem Carotisverschluß im Vergleich zum wachen Tier untersucht.Barbiturat-Injektion (30 mg/kg i.v.) allein erhöhte die Herzfrequenz, den systolischen und diastolischen Blutdruck, änderte jedoch nicht die mittlere Nierendurchblutung. Zusätzliche chirurgische Präparation verstärkte diese Veränderungen mit Ausnahme vom systolischen Blutdruck und der Nierendurchblutung.Bei Carotisverschuluß kam es im steady state zu einer vermehrten reflektorischen Herzfrequenzsteigerung nach Barbiturat-Injektion sowie nach Barbiturat mit chirurgischer Präparation. In Barbiturat-Narkose stieg der mittlere Blutdruck stärker an als am wachen Tier; diese Veränderung war nach chirurgischer Präparation noch deutlicher ausgeprägt. Die mittlere Nierendurchblutung wurde im steady state in keiner der 3 Gruppen signifikant verändert. Der reflektorische Herzfrequenz- und Blutdruckanstieg erfolgte im Wachzustand rascher als nach Barbiturat und Barbiturat mit chirurgischem Trauma. Unter letzteren Bedingungen fehlte auch das im Wachzustand beobachtete Unterschießen der Herzfrequenz nach Öffnen der Carotismanschetten. Der druckpassive overshoot der Nierendurchblutung am wachen Tier fehlte sowohl nach Barbiturat als auch nach zusätzlicher chirurgischer Präparation.Die Ergebnisse zeigen, daß der mit Na-Pentobarbitural narkotisierte und der narkotisierte, akut operierte Hund gegenüber dem Wachzustand betreffend der Ruhewerte und der reflektorischen Veränderungen der Herzfrequenz und des Blutdrucks im steady state des Carotissinus-Reflexes zwei quantitativ unterschiedlich reagierende Kreilaufpräparate liefert. Gemessen an der Beseitigung sowohl der raschen Herzfrequenz- und Blutdruckveränderungen als auch des phasischen Einschwingvorganges der Nierendurchblutung durch Narkose und Narkose mit Trauma unterscheiden sich solche Präparate auch qualitativ vom Wachzustand.Mit Unterstützung der Deutschen Forschungsgemeinschaft.     

Applications of a rat multiple tissue gene expression data set

With the sequencing and assembly of the rat genome comes the difficult task of assigning functions to genes. Tissue localization of gene expression gives some information about the potential role of a gene in physiology. Various examples of the utility of multiple tissue gene expression data sets are illustrated here. First, we highlight their use in finding genes that might play an important role in a particular tissue on the basis of exclusive expression in that tissue or coexpression with a gene or genes with known function. Second, we show how this data might be used to explain known phenotypic differences between strains. Third, we show how expression patterns of genes in a genomic interval might identify candidate genes in quantitative trait loci (QTL) mapping studies. Lastly, we show how multiple tissue and species data can help researchers prioritize follow up studies to microarray experiments. All of these applications of multiple tissue gene expression data sets will play a role in functionally annotating the rat genome.     

Untersuchungen über die Entwicklung und den Infektionsverlauf von Aegyptianella pullorum Carpano, 1928, im Huhn

Zusammenfassung 1. Aegyptianella pullorum nimmt im allgemeinen in Hühnern, unabhängig vom Infektionsweg, einen typischen Verlauf. Die Entwicklung des Parasiten vollzieht sich in den Erythrozyten des Wirtstieres in drei Phasen, die aber nur auf Grund typischer morphologischer Merkmale unterscheidbar sind und sich in der zeitlichen Reihenfolge nicht trennen lassen.2. Durch die Übertragung des Blutes von Kücken, die durch Zeckenbisse infiziert wurden, auf empfängliche Tiere in bestimmten Zeitabständen nach dem Saugakt infektiöser Argas (Persicargas) persicus-Zecken sowie auf Grund histologischer Untersuchungen infizierter Kücken kann eine präerythrozytäre Phase in der Entwicklung von Aegyptianella pullorum ausgeschlossen werden.3. Die in weißen Blutzellen, den Kupfferschen Sternzellen der Leber und frei im Blutplasma gefundenen Parasiten werden nicht als exoerythrozytäre Entwicklungsstadien von Aegyptianella pullorum interpretiert.

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Investigations into the development and the course of infection of aegyptianella pullorum Carpano, 1928, in chicken

Summary Generally Aegyptianella pullorum takes a typical course in chicken independent from the route of infection. In the erythrocytes of vertebrate hosts, the development of the parasite passes through three phases, which can be differentiated only by the typical morphological features.By transmission of blood from naturally infected chicken to susceptible animals, after engorgement of infected Argas (Persicargas) persicus, as well as by histological investigations of infected chicken, a preerythrocytical phase in the development of Aegyptianella pullorum can be excluded.The parasites, found in white blood cells, in the Kupffer cells of the liver and free in the blood plasma, are not interpreted as exoerythrocytic developmental stages of Aegyptianella pullorum.