Proteomics-based identification of novel proteins in temporal tendons of patients with masticatory muscle tendon--aponeurosis hyperplasia.

Masticatory muscle tendon-aponeurosis hyperplasia (MMTAH) is a new disease associated with limited mouth opening that is often misdiagnosed as a temporomandibular disorder; subsequently, patients are mistakenly treated with irreversible operations. Due to the poor presentation and characterization of symptoms, the underlying pathological conditions remain unclear. We have previously conducted a proteomic analysis of tendons derived from one MMTAH subject and one facial deformity subject using two-dimensional fluorescence difference gel electrophoresis and liquid chromatography coupled with tandem mass spectrometry. However, the results were obtained for only one subject. The aim of the present study was to confirm the expression of specific molecules in tendon tissues from multiple subjects with MMTAH by applying two-dimensional polyacrylamide gel electrophoresis with matrix-assisted laser desorption ionization time-of-flight mass spectrometry. Of the 19 proteins identified in tendons from both MMTAH and facial deformity patients, fibrinogen fragment D and beta-crystallin A4 were up-regulated, whereas myosin light chain 4 was down-regulated in MMTAH. We also found fibrinogen to be expressed robustly in tendon tissues of MMTAH patients. Our data provide the possibility that the distinctive expression of these novel proteins is associated with the pathology of MMTAH.

Factors involved in the susceptibility of spontaneously hypertensive rats to low K+-induced arrhythmias.

Disorders of intracellular Ca2+ homeostasis and intercellular coupling are thought to be crucial in the initiation and maintenance of malignant arrhythmias. The aim of this study was to investigate possible arrhythmogenic factors in spontaneously hypertensive rats (SHR) as well as their susceptibility to low K+-related arrhythmias. The experiments were performed on isolated hearts of 13 weeks-old SHR and age-matched Wistar Kyoto rats (WKY). Equilibration of the heart by Langendorff perfusion with oxygenated, 37 degrees C warm, standard Krebs solution at a constant pressure was followed by perfusion with low K+ solution for 60 min, unless sustained ventricular fibrillation occurred earlier. Electrocardiogram and epicardial monophasic action potentials (MAPs) were continuously monitored for incidence of arrhythmias and action potential changes. Myocardial tissue was taken for ultrastructural analysis and immunodetection of the main gap junction protein, connexin-43. The results showed that hypertrophic hearts of SHR exhibited prolongation of MAPs and a decrease in phosphorylation of connexin-43. Moreover, they were more prone to low K+-induced early after-depolarisations and ventricular premature beats as well as to connexin-43 and ultrastructural alterations than WKY rats. Consequently, the incidence of ventricular tachycardia (70% vs. 50%) and both transient (50% vs. 25%) and sustained (60% vs. 25%) ventricular fibrillation was higher in SHR than WKY rats. The results suggest that both prolongation of MAP and connexin-43 alterations are important arrhythmogenic factors facilitating arrhythmias in the setting of Ca2+ disorders due to hypokalaemia.

Characteristics of learning and memory impairment induced by delta9-tetrahydrocannabinol in rats.

We investigated the characteristics of delta9-tetrahydrocannabinol (THC)-induced impairment of learning and memory using an 8-arm radial maze task, a water maze, a visual discrimination task with 2 figures and a passive avoidance test in rats. THC (6 mg/kg, i.p.) impaired spatial memory in the standard task of the 8-arm radial maze. THC (4-6 mg/kg, i.p.) selectively impaired working memory in a reference and working memory task of the 8-arm radial maze. Even at a dose of 10 mg/kg, THC did not impair spatial memory in the water maze. In addition, THC at a dose of 6 mg/kg, which had inhibitory effects in the 8-arm radial maze, did not affect performance in the visual discrimination task. These results indicate that at low doses (2-6 mg/kg), THC may not produce visual function abnormalities. THC impaired retrieval (6 mg/kg, i.p.) as well as acquisition (10 mg/kg, i.p.) in the passive avoidance test. The consolidation process was also impaired by i.c.v. injection (100 microg), but not i.p. injection (6-10 mg/kg) of THC. These results suggest that THC-induced impairment of spatial memory is based on the selective impairment of working memory through its effects on acquisition and retrieval processes.

[A quantitative analysis of the cells infected with Epstein-Barr virus in the peripheral blood mononuclear cells derived from the patients with infectious mononucleosis].

The quantitative analysis of the cells infected with Epstein-Barr virus was performed on the peripheral blood mononuclear cells from the patients with infectious mononucleosis, by using in situ hybridization with Epstein-Barr virus encoded small nuclear RNA1 (EBER1). An alkaline-phosphatase conjugated oligonucleotide probe complementary to EBER1 was used as an antisense probe, while oligonucleotide DNA probe compatible with the sequence of EBER1 was used as a sense probe, control probe. The EBER1 positive cells on the slide-glass were enumerated microscopically. In situ hybridization revealed that 50,000 peripheral blood mononuclear cells from the patients in the acute phase of infectious mononucleosis contained 35 +/- 36 cells infected with Epstein-Barr virus (n = 11). The cells infected with Epstein-Barr virus apparently decreased in the convalescence of all the patients with infectious mononucleosis and the mean of the cells infected with Epstein-Barr virus was 3 +/- 4 in the convalescence (n = 6) (p < 0.02). On the other hand, no positive cells were detected in healthy individuals with past-infection of Epstein-Barr virus (n = 10) or without any previous Epstein-Barr virus infection (n = 11). The striking increase of the cells with Epstein-Barr virus genome was clearly demonstrated in the peripheral blood mononuclear cells from the patients with infectious mononucleosis.