Spectral characteristics of early receptor potential in congenital red-green color blindness

The spectral response curve (amplitude versus wavelength) of the R₂ of the early receptor potential (ERP) was studied in normal, protan, and deutan subjects. The R₂ amplitude peaked at 520nm in most normal subjects. The R₂ at long wavelengths was smaller than normal in protans and larger than normal in deutans when the maximum amplitudes were normalized to 100% at the peak. The ratio of the R₂ amplitude at 460 nm to that at 600 nm clearly differed between protans and deutans. The ERP and the rapid off-response, which is mainly due to the cessation of the late receptor potential, were recorded in the same subjects. The ratio of the sensitivity of the rapid off-response at 500 nm to that at 600 nm was correlated with the ratio of the R₂ amplitude at 460 nm to that at 600nm (correlation coefficient, 0.823, p < 0.001). This study, in conjunction with our previous study, indicates that the abnormality is in the outer segments of the cones in protans and deutans.     

Quantitative analysis of the suppressive effect on the light rise of the hypertonic solution

We previously reported the hyperosmolarity response (a decrease of the ocular standing potential by hyperosmolarity) as a new clinical test of the retinal pigment epithelium (RPE) activity. In the present study a hypertonic solution (Fructmanit, 1.4 × 10³ m0sm/1) was intravenously injected for 20 min in proportion to a subject's total blood volume (TBV). At the injection speed of 5, 10, and 15% of the subjects' TBV per hour the mean amplitude of the hyperosmolarity response in normal subjects was 19.7, 30.1 and 36.4% respectively. The amplitude of the hyperosmolarity response depends on the logarithm of the dose of the hypertonic solution within the range of the dose tested.We previously found that hyperosmolarity suppresses the light rise. The present study investigated this suppressive effect in a quantitative manner. The light rise (a full-field illumination of 1.2 × 10³ cdl/m²) was dose-dependently suppressed by Fructmanit. The mean of the light rise to dark trough ratio in normal subjects was 1.81 with no osmotic stress, and 1.64, 1.41 and 1.29 respectively at the injection speeds of 5, 10, and 15%. The suppression of the light rise by hyperosmolarity is compatible with the view that the hyperosmolarity response and the light rise share the basal membrane of the RPE as the main site of their generation.     

Polymer conformation and NMR chemical shifts, 9. Poly(α-methylene-γ-butyrolactone)

The conformational energies of poly(α-methylene-γ-butyrolactone) are calculated and compared with those of poly(methyl methacrylate). In spite of the structural resemblance of these two polymers, the patterns of the energy contour maps are clearly distinguishable from each other; the energy barriers between rotational isomeric states are appreciably higher in the former than in the latter polymer. The calculation indicates large non-bonded interactions between the protons in one lactone ring and those in the adjacent lactone rings. The broad NMR spectrum of poly(α-methylene-γ-butyrolactone) apparently reflects its rigid conformational structure. ¹H and ¹³C NMR chemical shifts are calculated by theoretical shielding calculations based on conformational analysis. Much lower magnetic field resonances of the O? CH₂ and α-CH₂ carbons in poly(α-methylene-γ-butyrolactone) as compared with those of the O? CH₃ and α-CH₃ carbons in poly(methyl methacrylate) are well reproduced by the calculation. The shift to lower magnetic field is mainly attributed to paramagnetic shielding derived from the interaction between O? CH₂ carbon and α-CH₂ carbon. Tacticity- and conformation-dependent ¹H and ¹³C NMR chemical shifts of poly(α-methylene-γ-butyrolactone) are well interpreted on the basis of the conformational analysis.     

Polymer conformation and NMR chemical shifts, 6. Alternating copolymer of α-methylene-γ-butyrolactone with styrene

In view of the structural resemblance of α-methylene-γ-butyrolactone to methyl methacrylate, conformation and NMR chemical shifts of poly(α-methylene-γ-butyrolactone-alt-styrene). are calculated and compared with those of poly(methyl methacrylate-alt-styrene). The conformational energy surfaces for the dyad sequence models of the both copolymers are analogous to each other, as is expected from the similarity in the constituting monomeric units. Agreement of calculation with observation is satisfactory with respect to the cotacticity-dependent splittings in the ¹³C NMR spectra and is improved by the fixation of a substituent in poly(α-methylene-γ-butyrolactone-alt-styrene). Calculation of ¹H chemical shifts gives an alignment of NMR signals which is in accordance with the observation.     

Mediolateral intercalation in planarians revealed by grafting experiments.

We investigated how planarians organize their left-right axis by using ectopic grafting. Planarians have three body axes: anteroposterior (A-P), dorsoventral (D-V), and left-right (L-R). When a small piece is implanted into an ectopic region along the A-P and D-V axes, intercalary structures are always formed to compensate for positional gaps. There are two hypotheses regarding L-R axis formation in this organism: first, that the left and right sides of the animal may be recognized as different parts, and L-R intercalation can induce midline structures (asymmetry hypothesis); second, that both sides may have symmetrical positional values, and mediolateral (M-L) intercalation creates positional values along the L-R axis (symmetry hypothesis). We performed ectopic grafting experiments in the head region of the planarian, Dugesia japonica, to examine these hypotheses. A left lateral fragment containing a left auricle was implanted into the medial region of the host. Ectopic structures were always formed only on the left side of the graft, where lateral tissues abutted onto the medial tissues. However, no morphologic change was induced on the right side of the graft, where left-sided tissues faced onto right-sided tissues. Molecular marker analyses indicated that ectopic structures formed on the left side of the graft were induced by M-L intercalation, supporting the "symmetry hypothesis." When the midline tissues were implanted into a lateral region, they induced a complete ectopic head, demonstrating that M-L intercalation may be sufficient to establish the L-R axis in planarians.     

Vaccination of dendritic cells loaded with interleukin-12-secreting cancer cells augments in vivo antitumor immunity: characteristics of syngeneic and allogeneic antigen-presenting cell cancer hybrid cells.

Cancer immunotherapy by fusion of antigen-presenting cells and tumor cells has been shown to induce potent antitumor immunity. In this study, we characterized syngeneic and allogeneic, murine macrophage/dendritic cell (DC)-cancer fusion cells for the antitumor effects. The results showed the superiority of allogeneic cells as fusion partners in both types of antigen-presenting cells in an in vivo immunotherapy model. A potent induction of tumor-specific CTLs was observed in these immunized conditions. In addition, the immunization with DC-cancer fusion cells was better than that with macrophage-cancer fusion cells. Both syngeneic and allogeneic DC-cancer fusion cells induced higher levels of IFN-gamma production than macrophage-cancer fusion cells. Interestingly, allogeneic DC-cancer fusion cells were superior in that they efficiently induced Th1-type cytokines but not the Th2-type cytokines interleukin (IL)-10 and IL-4, whereas syngeneic DC-cancer fusion cells were powerful inducers of both Th1 and Th2 cytokines. These results suggest that allogeneic DCs are suitable as fusion cells in cancer immunotherapy. To further enhance the antitumor immunity in the clinical setting, we prepared DCs fused with IL-12 gene-transferred cancer cells and thus generated IL-12-secreting DC-cancer fusion cells. Immunization with these gene-modified DC-cancer fusion cells was able to elicit a markedly enhanced antitumor effect in the in vivo therapeutic model. This novel IL-12-producing fusion cell vaccine might be one promising intervention for future cancer immunotherapy.     

Contribution of early lumen loss after balloon angioplasty for in-stent restenosis to lumen loss at follow-up.

The treatment of in-stent restenosis using balloon angioplasty alone often produces excellent early results, but is associated with high rate of recurrence. Previous studies have demonstrated significant tissue reintrusion shortly after the treatment of in-stent restenosis with balloon angioplasty. The study was designed to elucidate the contribution of early lumen loss 6 hr after balloon angioplasty to lumen loss at follow-up. We prospectively performed quantitative coronary angiography and intravascular ultrasound in 12 patients with in-stent restenosis before intervention, after the final procedure, 6 hr later (5.6 +/- 1.4 hr), and at follow-up (7.7 +/- 2.3 months). Compared with immediately after balloon angioplasty, by 6 hr postintervention, the minimum lumen diameter (MLD) and lumen cross-sectional area had decreased significantly (2.48 +/- 0.44 to 2.01 +/- 0.57 mm, P = 0.01, and 7.0 +/- 1.2 to 5.5 +/- 1.4 mm2, P = 0.004, respectively). Furthermore, the MLD decreased further between 6 hr postintervention and long-term follow-up (2.01 +/- 0.57 to 1.55 +/- 0.64 mm; P = 0.001). Patients who showed recurrence of restenosis at follow-up had greater early lumen loss than patients without recurrence of restenosis (0.71 +/- 0.31 vs. 0.23 +/- 0.13 mm; P = 0.006). Diffuse lesions had greater early lumen loss compared to focal lesions (0.75 +/- 0.35 vs. 0.28 +/- 0.13 mm; P = 0.008). Early lumen loss is common after the treatment of in-stent restenosis by balloon angioplasty. Within the first 6 hr postintervention, 32% +/- 29% of acute lumen gain is lost, and early lumen loss contributed to 42% +/- 18% of total lumen loss at follow-up.     

Endoscopic submucosal resection of rectal carcinoid tumors with a ligation device

BACKGROUND: Local endoscopic mucosal resection of rectal carcinoid tumors is often associated with margin involvement that requires further intervention. The efficacy of resection of these tumors with endoscopic submucosal resection with a ligation device (ESMR-L) was evaluated. METHODS: Fourteen rectal carcinoid tumors were treated by ESMR-L between 1999 and 2002. ESMR-L was performed with a conventional colonoscope with an attached band-ligator device. For comparison, 14 rectal carcinoid tumors, treated by either endoscopic mucosal resection or polypectomy between 1990 and 1997, were evaluated as historical controls. All tumors were estimated to be 1 cm or less in diameter. OBSERVATIONS: There were no differences between the 2 groups in terms of age, gender, or tumor size. For 6 (43%) patients in the control group, there was tumor involvement at the margin of the resection specimen, whereas all tumors removed by ESMR-L had histopathologically proven negative margins (p < 0.05). The mean vertical resection margin also was significantly deeper in the ESMR-L group (p < 0.05). There was no complication of any procedure. CONCLUSIONS: ESMR-L is technically simple, minimally invasive, and safe for treatment of small rectal carcinoid tumors contained within the submucosa. ESMR-L provides a deeper resection margin compared with that obtained with conventional endoscopic mucosal resection or polypectomy.     

Longest neurite‐specific activation of Rap1B in hippocampal neurons contributes to polarity formation through RalA and Nore1A in addition to PI3‐kinase

In a developing nervous system, axon‐dendrite formation is instructed by extrinsic cues, and the mechanism whereby a developing neuron interprets these cues using intracellular signaling is particularly important. Studies using dissociated hippocampal neurons have identified many signaling pathways underlying neuronal polarization. Among the components of these pathways, Rap1B is essential for axon specification in hippocampal cultures. However, spatiotemporal regulation of Rap1B activity in polarizing neurons and how it affects neuronal polarization remain unclear. Herein, we investigated spatiotemporal activity‐change of Rap1B and its target molecules in hippocampal neurons. FRET imaging showed that specific activation of Rap1B was observed at the tip of a future axon. To dissect downstream signaling, we used three effector mutants of Rap1B. Expression of Rap1B‐G12V/E37G and G12V/Y40C mutants resulted in supernumerary axons. The targets of Rap1B‐G12V/E37G were RalA and Nore1A, whereas Rap1B‐G12V/Y40C activated PI3‐kinase. RalA was activated in the tip of stage 3 axons, and RalA‐S28N expression reduced the fraction of neurons with supernumerary axons induced by Rap1B‐G12V/E37G. Furthermore, Nore1A depletion reduced the number of cells without axons. These results indicate that specific activation of Rap1B contributes to neuronal polarization via interaction with RalA and Nore1A in addition to PI3‐kinase.