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Owing to the potentially therapeutic enhancement of delayed particles in treating malignant diseases by radioactive ⁹C-ion beam, LET spectra at different penetration depths for a ⁹C beam with 5% momentum spread, produced in the secondary beam line (SBL) at HIMAC, were measured with a multi-wire parallel-plate proportional counter. To compare these LET spectra with those of a therapeutic ¹²C beam under similar conditions, the ¹²C beam was replaced with an ¹¹C beam, yielded in the SBL as well and having almost the same range as that of the ⁹C beam. The LET spectra of the ⁹C beam and its counterpart, i.e. the ¹¹C beam, at various depths were compared, especially around the Bragg peak regions. The results show that nearby the Bragg peak lower LET components decreased in the LET spectra of the ⁹C beam while extra components between the LET peak caused by the primary beam and the lower components due to the fragments could be observed. These additional contributions in the LET spectra could be attributed to parts of the emitted particles from the radioactive ⁹C ions with suitable conditions regarding the LET counter. Integrating these LET spectra in different manners, depth-dose and dose-averaged LET distributions were obtained for the ⁹C and ¹¹C beams, forming the basic data sets for further studies. In general, the depth-dose distributions of the ⁹C and ¹¹C beams are comparative, i.e. almost the same peak-to-plateau ratio. The ratio for the ⁹C beam, however, has room to increase due to the geometric structure limitation of the present detector. The dose-averaged LETs along the beam penetration are always lower for the ⁹C beam than for the ¹¹C beam except at the falloff region beyond the Bragg peak. Applying the present depth-dose and dose-averaged LET data sets as well as the essential radiobiological parameters obtained with ¹²C beams previously for HSG cells, an estimate concerning the HSG cell surviving effects along the penetration of the ⁹C and ¹¹C beams shows that lower survival fractions for the ⁹C beam at the distal part of the Bragg peak, corresponding to the stopping region of the incoming ⁹C ions, can be expected when the same entrance dose is given. It is still hard to appreciate the potential of ⁹C beams in cancer therapy based on the present LET spectrum measurement, but it provides a substantial basis for upcoming radiobiological experiments.

Background & Aims:Src activation is correlated with progression of colorectal cancer (CRC). CRCs accompanied by ulcerative colitis, chronic inflammation in the colon, often have elevated Src activity, and ulcerative colitis-related CRCs are more likely to become invasive, whereas Ras activation is rarely associated with this disease. The aim of this study was to investigate the effects of a proinflammatory cytokine, tumor necrosis factor @a (TNF-@a), on the invasive properties of epithelial cells constitutively expressing activated Ras or Src. Methods:A cell line derived from intestinal epithelia was transfected with a vsrc- or v-H-ras-expressing vector. The effect of TNF-@a on morphologic changes in colonies cultured in soft agar was determined. Src protein kinase activity, peroxide production, E-cadherin expression levels, and the phosphorylation status of @b-catenin and E-cadherin were determined. The invasive potential of these cells was determined by measuring cell motility and using an in vitro invasion assay. Results:TNF-@a altered the colony morphology of src-, but not ras-expressing cells. TNF-@a increased peroxide production, leading to Src protein expression as well as Src activity in src transfectants. Activation of Src by TNF-@a led to reduced E-cadherin levels and enhanced invasion of src transfectants. Pyrrolidine dithiocarbamate and herbimycin A inhibited these effects. Conclusions:These results indicate that Src kinase activation enhances the response of epithelial cells to TNF-@a leading to increased invasion through mechanisms that involve production of reactive oxygen intermediates.

We have analyzed the function of Hansenula polymorpha Pex14p in selective peroxisome degradation. Previously, we showed that Pex14p was involved in peroxisome biogenesis and functions in peroxisome matrix protein import. Evidence for the additional function of HpPex14p in selective peroxisome degradation (pexophagy) came from cells defective in HpPex14p synthesis. The suggestion that the absence of HpPex14p interfered with pexophagy was further analyzed by mutational analysis. These studies indicated that deletions at the C terminus of up to 124 amino acids of HpPex14p did not affect peroxisome degradation. Conversely, short deletions of the N terminus (31 and 64 amino acids, respectively) of the protein fully impaired pexophagy. Peroxisomes present in these cells remained intact for at least 6 h of incubation in the presence of excess glucose, conditions that led to the rapid turnover of the organelles in wild-type control cells. We conclude that the N terminus of HpPex14p contains essential information to control pexophagy in H. polymorpha and thus, that organelle development and turnover converge at Pex14p.

TxA2receptor (TP‐receptor) antagonists such as S‐1452 and Bay u 3405 have been shown to be effective in alleviating nasal blockage in patients with allergic rhinitis as well as guinea‐pig allergic rhinitis models. The present study was conducted to examine the existence and localization of the TP‐receptor in human and guinea‐pig nasal mucosa by in vitroreceptor binding autoradiography using radiolabelled (+)‐S‐145, which is a potent and specific TP‐receptor antagonist with an extremely slow dissociation rate.We ascertained the binding specificity of [3H]‐(+)‐S‐145 in human and guinea‐pig platelet membranes by comparing the ability of four TP‐receptor ligands of U‐46619, (+)‐S‐145, I‐(+)‐S‐145 and Bay u 3405 to displace the specific binding of [3H]‐(+)‐S‐145 and [3H]‐U‐46619. The rank order of potency (Ki) for the displacement was correlated highly with that determined from [3H]‐U‐46619 binding to the same preparations.Quantitative autoradiography using a radioluminographic imaging plate system, in which the radioactivity of [3H]‐(+)‐S‐145 is expressed as photostimulated luminescence (PSL) per area (mm2), revealed that specific binding of [3H]‐(+)‐S‐145 to human and guinea‐pig nasal mucosa was saturable. Scatchard analysis showed about three fold higher affinity and two fold greater maximal binding to the nasal mucosa of humans than that of guinea‐pigs: the KDand Bmaxvalues in human mucosa were 2.82±0.35 nMand 6.47±0.33 PSL mm−2and those in guinea‐pig mucosa were 8.23±1.93 nMand 3.37±0.66 PSL mm−2, respectively.Specific [3H]‐(+)‐S‐145 binding to cryostat sections of human and guinea‐pig nasal mucosa was displaced by another TP‐receptor antagonist, Bay u 3405, and a TP‐receptor agonist, U‐46619. The order of potency (Kivalue: nM) was (+)‐S‐145 (2.5) > Bay u 3405 (15.4) >> U‐46619 (359.6) in human nasal mucosa and (+)‐S‐145 (22.8) > U‐46619 (49.8) & Bay u 3405 (62.1) in guinea‐pig nasal mucosa. These rank orders showed rather good correlation with those obtained for the respective platelet membranes.Autoradiographs of human nasal mucosa demonstrated that specific [125I]‐(+)‐S‐145 binding sites mainly exist on the smooth muscle layers of venous sinusoids and arterioles in the lamina propria, with few or no binding sites in the epithelium and nasal gland.We concluded that radiolabelled (+)‐S‐145 can be used as a TP‐receptor ligand for autoradiographic study, and that the TP‐receptor is exclusively located on smooth muscle layers of venous sinusoids and arterioles in the nasal mucosa. The potent vasoconstrictive activity of TxA2may cause reduction of local blood flow followed by mucosal oedema probably through mechanisms of vascular injury such as ischaemia‐reperfusion.

A new epitaxial growth technique is proposed for local thickness modulation in simultaneously grown layers to achieve thickness-tapered waveguide structures. This technique uses a comb-shaped silicon shadow mask placed just above the substrate during metalorganic vapor phase epitaxy (MOVPE). Smoothly tapered InP and InGaAs layers were obtained with a maximum in-plane thickness reduction ratio of over 8. Tapered multiple quantum well layers exhibited clear blue-shift in quantum energy and sufficient photoluminescence in areas with uniform thickness, which were equivalent to those grown by normal MOVPE without the shadow mask.

PERgenes are essential for the biogenesis of peroxisomes in the yeast Hansenula polymorpha. Here we describe the functional complementation of a H. polymorpha per9disruption strain (Δ per9) by a heterologous gene. The Saccharomyces cerevisiaePaAbstractp, a homologue of Per9p, restored peroxisome biogenesis and peroxisomal protein import in the Δ per9mutant, allowing it to grow again on methanol as sole carbon and energy source. This result shows that heterologous complementation of peroxisome function in yeast is indeed feasible and furthermore suggests that H. polymorpha Δper9may be the candidate of choice to attempt the isolation of Per9p homologues from higher eukaryotes by functional complementation.

Three different cDNA clones, namely DM1-1, Dah1, and Dah2, encoding hepatic cytochrome P-450, were isolated from a cDNA library in lambda gt11 constructed from liver RNA of polychlorinated biphenyl-treated beagle dogs. DM1-1 was 1857 base pairs (bp) long and encoded a polypeptide of 457 residues. Dah1 was 2394 bp long and contained an entire coding region for 524 amino acid residues. In addition, Dah2 was 1623 bp long and had an open reading frame consisting of 503 amino acid residues, although it lacked the translational initiation codon. Judging from the similarity of the nucleotide and amino acid sequences, forms of cytochrome P-450 encoded by DM1-1, Dah1, and Dah2 were judged to belong to the P450IIC, P450IA1, and P450IA2 subfamilies, respectively. Northern blot analysis of RNA from various tissues, using the specific 3' noncoding regions of Dah1 and Dah2 as probes, indicated that mRNAs for P-450(Dah1) and P-450(Dah2) were not detectable in tissues from untreated dogs, except for P-450(Dah2) in livers. Polychlorinated biphenyl induced both mRNAs in liver, kidney, and lung, especially in the kidney.

Only P450 2D mRNA could be detected in Northern blot analysis of rat brain poly(A)+ RNA using probes from eight different P450s involved in drug metabolism. Four cerebral P450 cDNAs were isolated from a rat brain cDNA library using rat P450 2D2 cDNA as a probe, three of which were identified to rat P450 2D4. The expression of 2D4 mRNA was investigated by the reverse transcriptase-polymerase chain reaction and southern blot analysis using an oligonucleotide probe specific for P450 2D4. P450 2D4 mRNA was expressed at the high level in brain. Furthermore, it was detected in all other tissues examined, although to a lesser extent except in the liver and small intestine. However, total mRNAs of other P450 2D members (2D1, 2D2, 2D3, and 2D5) were mainly expressed in liver. The total level of expression of these mRNAs varied markedly among tissues. These results suggest that P450 2D4 may have a specific physiological function in the brain.Copyright 1993, 1999 Academic Press

A new eggshell color mutant was discovered in the Japanese quail. This trait was named "celadon" and was shown to be controlled by an autosomal recessive gene. Therefore, the gene symbol ce was proposed. This gene and an autosomal recessive gene we controlling a white eggshell trait were shown to be nonallelic. Also, ce was shown to be hypostatic to we. A spectrophotometric analysis revealed that the celadon eggshell pigments are protoporphyrin and biliverdin as in the wild-type eggshell, but the protoporphyrin content is much lower than that of the wild type. The biliverdin content was 44% of the wild type.

Compressively-strained InGaAsP/InP MQW lasers with a simple reversed-mesa ridge-waveguide structure attain 300 mW output and high temperature lasing operation up to 165°C.

The authors have investigated the effect of strain on 1.3 µm InGaAsP lasers under the same well thickness (6 nm) and same lasing wavelength (1.34 µm) by changing the In and As contents. The maximum photoluminescence intensity, the narrowest photoluminescence full width at half maximum (23 meV), and minimum threshold current density (450 A/cm2) were obtained for 1.4% compressive strain. Moreover, a very low CW threshold current (1.3 mA) was also achieved in a 90–70% coated 200 µm-long device.

A new structure for a 1.3 µm-wavelength beam-expander integrated ridge-waveguide laser is demonstrated that does not require a regrowth step. A narrow beam divergence of 5.4° (lateral) and 18.9° (vertical) enables a laser diode to be coupled to a cleaved singlemode fibre with an efficiency as high as 33% with a 1 dB alignment tolerance of ±2.4 µm laterally and ±1.5 µm vertically.

A record low threshold current of 0.56 mA, as a long-wavelength laser, has been obtained in a 1.3 µm InGaAsP/InP strained-MQW laser, at room temperature (25°C), by optimising an active layer and by employing a short cavity with high-reflection coatings.

Tracheobronchopathia osteochondroplastica (TO) is a relatively rare benign disease, around 300 and 130 cases have been reported in English and Japanese literature, respectively. Most of the cases have been diagnosed incidentally at autopsy. Due to the widespread use of fiberoptic bronchoscopy (FOB), the number of cases diagnosed upon examination is increasing. Here, we report a case of a 72 year-old man with a history of crown aspiration, who was diagnosed as TO upon removal of a foreign body using FOB. The diagnosis of TO and the removal of an aspirated crown by FOB are discussed.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.