Synthesis and properties of [7]helicene and [7]helicene-like compounds with a cyclopenta[1,2-b:4,3-b']dithiophene or dithieno[2,3-b:3',2'-d]heterole skeleton.

A series of [7]helicene and [7]helicene-like compounds composed of a cyclopenta[1,2-b:4,3-b']dithiophene or dithieno[2,3-b:3',2'-d]heterole moiety and two naphthalene moieties were successfully synthesized from a common synthetic intermediate, 1,1'-binaphtho[2,1-b]thiophene. Their helical structures were confirmed by X-ray crystallographic analysis. The photophysical properties of them and their benzene analogues were investigated via absorption and fluorescence spectroscopy and theoretical calculations to correlate the effect of the five-membered rings in their π-conjugated skeleton. Through these investigations, the photophysical properties were found to largely depend on a combination of the central five-membered ring and the neighboring two aromatic rings. In particular, a combination of the central five-membered ring with electron-withdrawing character and the two neighboring thiophene rings was revealed to induce red-shifted emission.

Possibility of valence-fluctuatsion-mediated superconductivity in Cd-doped CeIrIn(5) probed by In NQR.

We report on a pressure-induced evolution of exotic superconductivity and spin correlations in CeIr(In(1-x)Cd(x))(5) by means of in-nuclear-quadrupole-resonance (NQR) studies. Measurements of an NQR spectrum and nuclear-spin-lattice-relaxation rate 1/T(1) have revealed that antiferromagnetism induced by Cd doping emerges locally around Cd dopants, but superconductivity is suddenly induced at T(c)=0.7 and 0.9 K at 2.34 and 2.75 GPa, respectively. The unique superconducting characteristics with a large fraction of the residual density of state at the Fermi level which increases with T(c) differ from those for anisotropic superconductivity mediated by antiferromagnetic correlations. By incorporating the pressure dependence of the NQR frequency pointing to the valence change of Ce, we suggest that unconventional superconductivity in the CeIr(In(1-x)Cd(x))(5) system may be mediated by valence fluctuations.

Spectrocolorimetric evaluation of human articular cartilage.

OBJECTIVE: The aim of this study was to investigate whether human articular cartilage can be quantitatively evaluated using a spectrocolorimeter. MATERIALS AND METHODS: Human articular cartilage specimens were analyzed using a spectrocolorimeter after macroscopic evaluation using the Outerbridge classification. The cartilage characteristics were examined, the L*, a*, b* colorimetric system, the spectral reflectance distribution and the yellow/red spectral reflectance percentage (Y/R SRP). Moreover, the results of the spectrocolorimetric evaluation were compared with the histological score described by Mankin et al. RESULTS: There were significant differences among the macroscopic four grades in the L*, a* and Y/R SRP values. The spectral reflectance distribution of grade 1 cartilage exhibited a gradual increase in the spectral reflectance ratio as the wavelength increased. The spectral reflectance curves of grades 2 to 4 cartilage had dips at a wavelength of around 580 nm. Across all the measured wavelengths, there were lower reflectance ratios with the progression of cartilage degeneration. Moreover, correlations were observed between the spectrocolorimetric values and Mankin score. A strong relationship existed between Mankin score and he Y/R SRP values. CONCLUSIONS: The present study is the first to clearly demonstrate the relationship between spectrocolorimetric evaluation and the degeneration of human articular cartilage. The spectrocolorimeter may be a new quantitative evaluation tool for articular cartilage with clinical potential.

Which cartilage is regenerated, hyaline cartilage or fibrocartilage? Non-invasive ultrasonic evaluation of tissue-engineered cartilage.

OBJECTIVE: To investigate ultrasonic evaluation methods for detecting whether the repair tissue is hyaline cartilage or fibrocartilage in new cartilage regeneration therapy. METHODS: We examined four experimental rabbit models: a spontaneous repair model (group S), a large cartilage defect model (group L), a periosteal graft model (group P) and a tissue-engineered cartilage regeneration model (group T). From the resulting ultrasonic evaluation, we used %MM (the maximum magnitude of the measurement area divided by that of the intact cartilage) as a quantitative index of cartilage regeneration. The results of the ultrasonic evaluation were compared with the histological findings and histological score. RESULTS: The %MM values were 61.1 +/- 16.5% in group S, 29.8 +/- 15.1% in group L, 36.3 +/- 18.3% in group P and 76.5 +/- 18.7% in group T. The results showed a strong similarity to the histological scoring. CONCLUSION: The ultrasonic examination showed that all the hyaline-like cartilage in groups S and T had a high %MM (more than 60%). Therefore, we could define the borderline between the two types of regenerated cartilage by the %MM.

Clinical features of the posterior horn tear in the medial meniscus.

INTRODUCTION: A lower threshold of suspicion is necessary for the appropriate diagnosis of a posterior horn tear in the medial meniscus. In these cases, radial tears or meniscus detachment from its insertion follow minor trauma and precipitate severe knee pain in middle-aged and elderly patients. The purpose of this paper is to demonstrate the key points for diagnosis through examination of the clinical features of this tear. MATERIALS AND METHODS: Arthroscopic examination of 250 knees with medial meniscus tears (and no ligamentous injuries; over 40 years old) identified 26 knees (26 tears) with a posterior horn tear. Of these 26 tears, 16 were radial, and 10 were detached. RESULTS: Eighty-five percent of patients could recall discrete events that preceded the pain. They described these events as a click or a feeling of shock. Afterwards, most patients complained of severe pain or giving way. Hydrarthrosis involving more than 5 ml was present in 81%. Most radiographs (92%) appeared nearly normal. CONCLUSION: It is important to note that this type of tear of the posterior horn in the medial meniscus is not rare. Because this area is difficult to visualize arthroscopically, it may be overlooked unless the threshold of suspicion is lowered.

Can ultrasound predict histological findings in regenerated cartilage?

OBJECTIVE: To evaluate regenerated articular cartilage quantitatively by introducing an ultrasonic probe into the knee joint under arthroscopy and analysing the A-mode echogram by means of wavelet transformation. METHODS: Three experimental rabbit models (spontaneous repair model, large cartilage defect model, treatment model) were examined using our ultrasonic evaluation system and a histological grading scale. From resulting wavelet map, the percentage of maximum magnitude was selected as the quantitative index of the ultrasonic evaluation system. RESULTS: The percentage maximum magnitude in the spontaneous repair model was 61.1%, that in the large defect model was 29.8% and that in the treatment model was 36.3%. There was modest correlation between the percentage maximum magnitude and the histological grading scale (r = -0.594) CONCLUSION: Our findings indicate that ultrasound analysis can predict the microstructure of regenerated cartilage.

The presynaptic modulation of glutamate release and the membrane dysfunction induced by in vitro ischemia in rat hippocampal CA1 neurons.

Superfusion with an oxygen and glucose deprived medium (in vitro ischemia) of rat hippocampal CA1 pyramidal neurons in tissue slices produced a rapid depolarization within 5 min and thereafter showed no functional recovery (irreversible membrane dysfunction), even if oxygen and glucose were reintroduced. We previously suggested that such a rapid depolarization is triggered by the accumulation of extracellular glutamate (Glu). As a result, we examined the effects of either the activation or inhibition of presynaptic receptors, which modulate Glu release from the nerve terminal, on the potential change produced by in vitro ischemia. The adenosine A1 receptor antagonist, 8-cyclopenthyl theophylline, A2a receptor antagonist, ZM241385, and A2b receptor antagonist, alloxazine, did not significantly alter either the latency or the maximal slope of the rapid depolarization. In addition, the GABAB receptor antagonist, 2-hydroxysaclofen, or the metabotropic Glu receptor type 4 antagonist, alpha-methylserine-O-phosphate, did not change either the latency or the maximal slope. The adenosine A(1) receptor agonist, 2-chloro-N6-cyclopentyladenosine, A2a receptor agonist, CGS2168, or A2b receptor agonist, 5'-(N-ethylcarboxamido)-adenosine, did not affect these parameters either. None of these drugs restored the membrane potential to the pre-exposure level after the reintroduction of oxygen and glucose. Simultaneous intracellular recordings from CA1 and CA3 pyramidal neurons in the same slices revealed the membrane of the CA3 neurons to be hyperpolarized when a rapid depolarization occurred in the CA1 neurons. These results suggest that presynaptic Glu release does not accelerate during the generation of the rapid depolarization induced by in vitro ischemia.

Extrusion of intracellular calcium ion after in vitro ischemia in the rat hippocampal CA1 region.

Simultaneous recordings of intracellular Ca(2+) ([Ca(2+)](i)) signal and extracellular DC potential were obtained from the CA1 region in 1-[6-amino-2-(5-carboxy-2-oxazolyl)-5-benzofuranyloxy]-2-(2-amino-5-methylphenoxy)-ethane-N,N,N',N'-tetraacetic acid penta-acetoxymethyl ester (Fura-2/AM)-loaded rat hippocampal slices. Superfusion with oxygen- and glucose-deprived medium (in vitro ischemia) for 5-6 min produced a rapid rise of the [Ca(2+)](i) level in the stratum radiatum (rising phase of the [Ca(2+)](i) signal), which occurred simultaneously with a rapid negative DC potential (rapid negative potential). When oxygen and glucose were reintroduced, the increased [Ca(2+)](i) signal diminished rapidly (falling phase of the [Ca(2+)](i) signal) during the generation of a slow negative DC potential (slow negative potential), which occurred within 1 min from the onset of the reintroduction. Thereafter, the [Ca(2+)](i) signal partially and the slow negative potential completely returned to the preexposure level approximately 6 min after the reintroduction. The changes in [Ca(2+)](i) signal during and after in vitro ischemia were very similar to the changes in the membrane potential of glial cells. The rising and falling phases of [Ca(2+)](i) signal corresponded to the rapid depolarization and a depolarizing hump, respectively, in the repolarizing phase of glial cells. A prolonged application of in vitro ischemia or a reintroduction of either glucose or oxygen suppressed the falling phase after ischemic exposure. The application of ouabain (30 microM) generated both a rapid negative potential and a rapid elevation of [Ca(2+)](i), but no slow negative potential or rapid reduction in [Ca(2+)](i) were observed. When oxygen and glucose were reintroduced to slices in the Na(+)-free or ouabain- or Ni(2+)-containing medium, the falling phase was suppressed. The falling phase was significantly accelerated in Ca(2+)- and Mg(2+)-free with EGTA-containing medium. In contrast, the falling phase was significantly slower in the Ca(2+)-free with high Mg(2+)- and EGTA-containing medium. The falling phase of the [Ca(2+)](i) signal after ischemic exposure is thus considered to be primarily dependent on the reactivation of Na(+), K(+)-ATPases, while the extrusion of cytosolic Ca(2+) via the forward-mode operation of Na(+)/Ca(2+) exchangers in glial cells is thought to be directly involved in the rapid reduction of [Ca(2+)](i) after ischemic exposure.

Localization of group IB phospholipase A(2) isoform in the gills of the red sea bream, Pagrus (Chrysophrys) major.

We previously reported that PLA(2) activity in the gills is higher than that in other tissues in red sea bream and purified PLA(2) from the gills belongs to the group IB PLA(2) as well as other red sea bream PLA(2)s. In this study, we reconfirmed that the level of PLA(2) activity is extremely high in the gills compared with other tissues, and gill PLA(2) was detected only in the gills by immunoblotting and inhibition test using anti-gill PLA(2) monoclonal antibody. The level of PLA(2) activity and protein expression in the gills are well correlated. Fish can be roughly divided into high and low groups based on the level of PLA(2) activity. Gill PLA(2) was detected in the gills of the high group, but not the low group by immunoblotting. In the gills of the high group, gill PLA(2) was detected in the mucous cells and pavement cells located on the surface of gill epithelia by immunohistochemistry. On the other hand, positive signals were observed only in the mucous cells by in situ hybridization. We also isolated inactive proPLA(2), having AR propeptide, preceding the mature enzyme from the gill extract. These results suggest that gill PLA(2) is synthesized as an inactive proPLA(2) in the mucous cells and is secreted to the surface of gill epithelia.