Aldosterone and dexamethasone stimulate calcineurin activity through a transcription-independent mechanism involving steroid receptor-associated heat shock proteins

1. PD 81,723 has been shown to enhance binding of adenosine to A1 receptors by stabilizing G protein-receptor coupling ('allosteric enhancement'). Evidence has been provided that in the perfused hearts and isolated atria PD 81,723 causes a sensitization to adenosine via this mechanism. 2. We have studied the effect of PD 81,723 in guinea-pig isolated atrial myocytes by use of whole-cell measurement of the muscarinic K+ current (I[K(ACh)]) activated by different Gi-coupled receptors (A1, M2, sphingolipid). PD 81,273 caused inhibition of I[K(ACh)] (IC50 approximately 5 microM) activated by either of the three receptors. Receptor-independent I[K(ACh)] in cells loaded with GTP-gamma-S and background I[K(ACh)], which contributes to the resting conductance of atrial myocytes, were equally sensitive to PD 81,723. At no combination of concentrations of adenosine and PD 81,723 could an enhancing effect be detected. 3. The compound was active from the outside only. Loading of the cells with PD 81,723 (50 microM) via the patch pipette did not affect either I[K(ACh)] or its sensitivity to adenosine. We suggest that PD 81,723 acts as an inhibitor of inward rectifying K+ channels; this is supported by the finding that ventricular I(K1), which shares a large degree of homology with the proteins (GIRK1/GIRK4) forming I[K(ACh)] but is not G protein-gated, was also blocked by this compound. 4. It is concluded that the functional effects of PD 81,723 described in the literature are not mediated by the A1 adenosine receptor-Gi-I[K(ACh)] pathway.     

Chondroma of the mandibular condyle: an example of a rare tumour

Chondromas are benign tumours of cartilage which are rare in the head and neck. We present a case report of a chondroma in the neck of condyle and demonstrate the value of multiplanar spiral CT and the limitations of 3D reconstruction.     

Instrumentation and techniques in equine fracture fixation

In recent years fracture fixation in the horse has changed significantly. New devices, mainly adapted from the human field, have been successfully introduced into large animal surgery. Examples of such implants include the DCS/DHS implant system, the self-tapping screw, the cannulated screw, and the pinless external fixator. However, new devices have also been developed exclusively for equine fracture management, including the interlocking intramedullary nail and the external skeletal fixation device. With these devices the surgeon has more options for repairing fractures in horses. Nevertheless, many problems are still unsolved. Indications exist that during the next few years new, exciting fracture fixation systems will be developed, providing further advancements in the quest for the ideal implant for horses. However, the development stages of these devices are such that mentioning the possibilities here is premature.     

The interaction of dexamethasone with ondansetron on drug-induced emesis in the ferret

The characteristics of the five Korean isolates of Japanese encephalitis (JE) virus were compared with those of the already reported JE virus strains from Japan and China using the hemagglutination test and polymerase chain reaction direct sequencing of the JE virus genomes (capsid/premembrane, envelope region). The hemagglutination patterns of all the isolates were distinctly different from the Nakayama-NIH strain. The optimal pH of hemagglutination of all the Korean isolates was 6.6-7.0 and the reaction range was broader than that of the Nakayama-NIH strain. The 198 nucleotide sequences in the capsid/premembrane gene region of the five Korean strains indicated that they were classified into the third genotype group, the JE strains from the countries in the temperate zone including the Nakayama-NIH, JaOArS982, and Beijing-1 strains. Four of the five Korean isolates formed a unique phylogenetic tree within the third genotype group, although the last one was genetically highly related to the Nakayama-NIH strain. The 251 nucleotide sequences in the envelope region of the five isolates were more divergent than the capsid/premembrane region. Four of the five isolates showed a large nucleotide divergency as compared with the JaOArS982 strain (< or = 12.4%), but the last one was similar to the JaOArS982 strain (98% of nucleotide homology). These results suggest the evolutionary divergence of the JE viruses isolated in Korea from the Japanese and Chinese strains and that there may exist at least two antigenically different JE virus strains in Korea.     

Peritraumatic dissociation and posttraumatic stress in male Vietnam theater veterans

OBJECTIVE: The aim of this study was to determine the reliability and validity of a proposed measure of peritraumatic dissociation and, as part of that effort, to determine the relationship between dissociative experiences during disturbing combat trauma and the subsequent development of posttraumatic stress disorder (PTSD). METHOD: A total of 251 male Vietnam theater veterans from the Clinical Examination Component of the National Vietnam Veterans Readjustment Study were examined to determine the relationship of war zone stress exposure, retrospective reports of dissociation during the most disturbing combat trauma events, and general dissociative tendencies with PTSD case determination. RESULTS: The total score on the Peritraumatic Dissociation Experiences Questionnaire--Rater Version was strongly associated with level of posttraumatic stress symptoms, level of stress exposure, and general dissociative tendencies and weakly associated with general psychopathology scales from the MMPI-2. Logistic regression analyses supported the incremental value of dissociation during trauma, over and above the contributions of level of war zone stress exposure and general dissociative tendencies, in accounting for PTSD case determination. CONCLUSIONS: These results provide support for the reliability and validity of the Peritraumatic Dissociation Experiences Questionnaire--Rater Version and for a trauma-dissociation linkage hypothesis: the greater the dissociation during traumatic stress exposure, the greater the likelihood of meeting criteria for current PTSD.