Ultrastructural study of the alveolar lining and the bronchial mucus layer by block staining with oolong tea extract: the role of various surfactant materials

To investigate the roles of various surfactant materials in the lung, we examined rat lung fixed with a mixture of 0.2% oolong tea extract (which contains various polyphenols) and 2.5% glutaraldehyde by electron microscopy. We also measured the surface tension of various isolated surfactant fractions, with a Wilhelm balance. A fraction containing lamellar bodies and a fraction containing lattice-like structures were obtained by discontinuous sucrose gradient centrifugation. From the 15 000 g supernatant, a fraction containing electron-dense amorphous materials was obtained as the 105 g precipitate. The fraction containing lamellar bodies and the fraction containing electron-dense amorphous materials displayed surfactant activity, but the fraction containing lattice-like structures did not. The lamellar bodies were found to be gradually secreted from type II epithelial cells while self-decomposition occurred. The alveolar lining layer had the form of a thin film consisting of electron-dense amorphous materials. These electron-dense amorphous materials may be precursors of the phospholipid film, which exhibits surfactant activity, on the alveolar surface. Lattice-like structures and lamellar bodies were found to be located in the interalveolar pores. The interalveolar pores were filled with surfactant, and this indicated that they do not play a role in the collateral ventilation of the alveoli. It may be that the lattice-like structures serve to connect lung epithelial cells in the interalveolar pores, as well as serving as the basis for the formation of the alveolar ducts. The bronchial mucus layer, which consisted of fibrillar mucous materials, was not divided into an epiphase and a hypophase. A surfactant, in the form of an osmiophilic surface film and some trilaminar materials, was found to cover the mucus layer. Thus, it is possible that the lamellar bodies could be transformed into various surfactant materials, which then serve bronchial or alveolar mechanical and physiological functions.     

The influence of light intensities irradiated directly and indirectly through resin composite to self-etch adhesives on dentin bonding

This study was designed to evaluate effects of light-irradiated intensities directly and indirectly through resin composites to one- and two-step self-etch adhesives on dentin bonding. One-step (Clearfil S(3) Bond; TS, Bond Force; BF) or two-step (Clearfil SE Bond; SE) self-etch adhesives was applied to dentin surface. The adhesive agent was light-cured with light-intensity of 350 or 600 mW/cm(2), and then resin composite with different colors (translucent or opaque shade) was filled and light-cured with the same light-intensity as the bonding procedure. After 24 h water storage, bond strengths to dentin were determined using μTBS test. For the 600 and 350 mW/cm(2) groups, translucent shade resin obtained higher μTBS than opaque shade resin. Using SE and BF, the 350 mW/cm(2) group in translucent shade resin was higher μTBS than the 600 mW/cm(2) group in opaque shade resin, while TS showed no different μTBS between them.     

Accuracy of conventional plus transoral carotid ultrasonography in distinguishing pseudo-occlusion from total occlusion of the internal carotid artery

BACKGROUND: To investigate the accuracy of conventional carotid ultrasonography (CCU) combined with transoral carotid ultrasonography (TOCU) for distinguishing pseudo-occlusion from total occlusion of the internal carotid artery (ICA). METHODS: This study included 95 patients who were suspected of having an occlusion of the ICA on magnetic resonance angiography (MRA) and underwent both CCU and conventional digital subtraction angiography (DSA) in order to confirm the diagnosis. TOCU was also performed to observe the cervical portion of the ICA distal to the stenosis. We compared the ultrasonographic findings with the DSA findings. RESULTS: Twelve of the 95 patients were defined as having an ICA pseudo-occlusion on DSA. On B-mode images with CCU color Doppler, slight residual flow signals in the ICA lumen were shown in 20 patients. Among them, 2 patients had a pulsed Doppler waveform of the distal ICA occlusion pattern. Among the remaining 18 patients, 4 had a pulsed Doppler waveform of the to and fro flow pattern, and 14 had a weak antegrade flow pattern in the ICA lumen. The conventional ultrasonographic method showed 100% sensitivity with 93% specificity for diagnosing an ICA pseudo-occlusion. The addition of TOCU findings increased the specificity to 98%. In 2 patients, who were overdiagnosed as having an ICA pseudo-occlusion even using TOCU, DSA revealed an occlusion of the ICA distal to the ophthalmic artery with a severe stenosis of the proximal ICA. CONCLUSIONS: Using conventional and transoral carotid ultrasonography, an ICA pseudo-occlusion can be diagnosed with higher accuracy.     

Expression and identification of a new splice variant of neuroglycan C, a transmembrane chondroitin sulfate proteoglycan, in the human brain

Neuroglycan C (NGC) is a transmembrane chondroitin sulfate proteoglycan with an EGF module. We studied the expression of NGC in the human brain, mainly in the hippocampus, and confirmed some observations by conducting experiments using rat brain. In humans, NGC mRNA was expressed exclusively in the brain, especially in the immature brain. The telencephalon, including the hippocampus and neocortex, showed strong mRNA expression. NGC was immunolocalized to neuropils in the hippocampus and neocortex of the adult rat. RT-PCR experiments showed that four splice variants (NGC-I, -II, -III, and -IV) were expressed in the adult human hippocampus. By Western blotting, the expression as proteins of all splice variants except NGC-II was confirmed in the adult rat hippocampus. NGC-IV, which was first found in the present study, had the shortest cytoplasmic domain among the four variants. NGC-IV mRNA was expressed by neurons, but not by astrocytes, in culture prepared from the fetal rat hippocampus, suggesting that NGC-IV plays a role specific to neurons. In addition, the human NGC gene, which is registered as CSPG5, comprised six exons and was approximately 19 kb in size. In exon 2, a single nucleotide polymorphism resulting in Val188Gly in the NGC ectodomain was observed.     

Histone deacetylase inhibitors enhance the chemosensitivity of tumor cells with cross-resistance to a wide range of DNA-damaging drugs

Although DNA-damaging agents are among the most effective anticancer drugs in clinical use, their overall effectiveness is limited by the development of cross-resistance to these drugs. Given that histone deacetylase (HDAC) inhibitors increase the acetylation of core histones, resulting in an open chromatin configuration that is more accessible to DNA-targeting agents, we examined whether HDAC inhibitors might enhance the cytotoxicity of DNA-damaging drugs in six human ovarian tumor cell lines that exhibit different cisplatin sensitivities. Low concentrations of HDAC inhibitors, which alone exhibited little cytotoxicity, markedly enhanced the induction of apoptotic cell death not only by cisplatin but also by a wide variety of DNA-targeting anticancer drugs in these tumor cell lines, irrespective of their sensitivities to the respective drugs. In contrast, HDAC inhibitors did not increase the cytotoxicity of metabolic antagonists or microtubule-targeting agents. HDAC inhibitors potentiated both the phosphorylation of histone H2AX on serine-139 (a marker of DNA double-strand breaks) as well as the accumulation of reactive oxygen species induced by DNA-damaging agents in tumor cells. The enhanced generation of reactive oxygen species appeared to be responsible for the enhanced apoptotic cell death induced by the combination of these drugs. These results indicate that the combination of an HDAC inhibitor with a wide variety of DNA-damaging agents is a promising chemotherapeutic strategy for the eradication of tumor cells, regardless of whether the cells are sensitive or resistant to the DNA-damaging anticancer drugs. ( Cancer Sci 2008; 99: 376–384)     

Standard values of inter-inner canthal, inter-outer canthal, and inter-pupillary distances in normal Japanese infants and children]

PURPOSE AND MATERIALS: We studied inter-inner canthal distance(DIC), inter-outer canthal distance (DOC), and inter-pupillary distance (PD) in 1,006 normal Japanese infants and children to establish the normal ratio of DIC/PD and DOC/DIC for the diagnosis of congenital anomalies such as Waardenburg syndrome. RESULTS: DIC, DOC, and PD increased significantly from one month after birth to 12 years of age. DIC and DOC were stable but PD increased from 13 years of age to 15 years of age in junior high school. The DIC/PD and DOC/DIC averages were 0.61 and 2.73, respectively, one month after birth and 0.63 and 2.69 at three months after birth. On the other hand, DIC/PD and DOC/DIC were stable at 0.55-0.59 and 2.45 from 8 to 15 years of age. CONCLUSION: Since there have been no reports on standard values of DIC, DOC and PD in infants, we established the standard values in this study. These values are expected to be very useful in the diagnosis of neural crest cell migration anomalies, such as Waardenburg syndrome.     

Gliomas with dural invasion: computed tomography and angiography

This report is a review of the findings of computed tomography and angiography of eight supratentorial gliomas with dural invasion. Computed tomography revealed localized increases in the thickness of ring enhancements at the sites of dural invasion in four cases, which was attributed to increased blood supplies by the meningeal vessels. Angiographically, feeders from the meningeal vessels entered the tumors mostly through relatively broad areas of tumor-dura attachment. A sunburst type of neovascularity from a meningeal artery was seen in only one case. In most such cases the differential diagnosis from meningioma was possible by the computed tomographic and angiographic findings. Selective external carotid angiography was the most important examination for diagnosing dural invasion by gliomas.     

Characteristics of action potentials and contractions evoked by electrical-field stimulation of pregnant human myometrium

Evoked electrical and mechanical activities of pregnant human myometrium were recorded by the single sucrose-gap method. Each muscle strip has an individual rhythm of membrane excitability and the evoked activity was affected by spontaneous membrane fluctuation. However, high-frequency stimulation caused changes in the rhythm of fluctuation and the pattern of action potential converted from plateau to spike type. Twitch contractions evoked by spike potentials were summated and became fused tetanus in accordance with shortening of the pulse interval. This method is suitable for clarifying the excitation-contraction relationship in human myometrium.