Final Analysis of 3 Versus 6 Months of Adjuvant Oxaliplatin and Fluoropyrimidine-Based Therapy in Patients With Stage III Colon Cancer: The Randomized Phase III ACHIEVE Trial.

PURPOSE: The phase III ACHIEVE trial conducted in Japan was one of six prospective studies included in the International Duration Evaluation of Adjuvant Therapy collaboration, which explored whether 3 months of adjuvant fluorouracil, leucovorin, and oxaliplatin (FOLFOX) or capecitabine and oxaliplatin (CAPOX) therapy would be noninferior to 6 months of treatment in patients with curatively resected stage III colon cancer. We report the final analyses of survival and long-term safety. PATIENTS AND METHODS: Eligible patients were randomly assigned (1:1) to either 3 or 6 months of adjuvant chemotherapy (modified [m]FOLFOX6 or CAPOX, as selected by the treating physician). Random assignment was stratified according to number of involved lymph nodes, center, regimen, primary site, and age. The primary end point was disease-free survival, assessed in the modified intention-to-treat population. Overall survival (OS) was a secondary end point. RESULTS: The modified intention-to-treat population comprised 1,291 patients: 641 in the 6-month treatment group and 650 in the 3-month treatment group. Median follow-up for this analysis was 74.7 months. Five-year OS rates were comparable: 87.0% in the 3-month treatment group and 86.4% in the 6-month treatment group (hazard ratio, 0.91; 95% CI, 0.69 to 1.20; P = .51). Subgroup analysis of OS did not reveal a significant interaction between baseline characteristics and treatment duration. Peripheral sensory neuropathy lasting longer than 5 years was more common in the 6- compared with 3-month treatment group (16% v 8%, respectively), and in those receiving mFOLFOX6 compared with CAPOX (14% v 11%, respectively). CONCLUSION: In Asian patients, shortening adjuvant therapy duration from 6 to 3 months did not compromise efficacy and reduced the rate of long-lasting peripheral sensory neuropathy. In this setting, 3 months of CAPOX therapy is an appropriate adjuvant treatment option.

Effect of Pd Precursor Salts on the Chemical State, Particle Size, and Performance of Activated Carbon-Supported Pd Catalysts for the Selective Hydrogenation of Palm Biodiesel.

To improve the oxidative stability of biodiesel fuel (BDF), the polyunsaturated fatty acid methyl esters (poly-FAME) presented in commercial palm oil-derived biodiesel fuel (palm-BDF) were selectively hydrogenated to monounsaturated fatty acid methyl esters (mono-FAME) under a mild condition (80 °C, 0.5 MPa) using activated carbon (AC)-supported Pd catalysts with a Pd loading of 1 wt.%. The partially hydrotreated palm-BDF (denoted as H-FAME) which has low poly-FAME components is a new type of BDF with enhanced quality for use in high blends. In this study, we reported that the chemical states and particle sizes of Pd in the prepared Pd/AC catalysts were significantly influenced by the Pd precursors, Pd(NO3)2 and Pd(NH3)4Cl2, and thus varied their hydrogenation activity and product selectivity. The 1%Pd/AC (nit) catalyst, prepared using Pd(NO3)2, presented high performance for selective hydrogenation of poly-FAME into mono-FAME with high oxidation stability, owning to its large Pd particles (8.4 nm). Conversely, the 1%Pd/AC (amc) catalyst, prepared using Pd(NH3)4Cl2, contained small Pd particles (2.7 nm) with a little Cl residues, which could be completely removed by washing with an aqueous solution of 0.1 M NH4OH. The small Pd particles gave increased selectivity toward unwanted-FAME components, particularly the saturated fatty acid methyl esters during the hydrogenation of poly-FAME. This selectivity is unprofitable for improving the biodiesel quality.

Vaccine Based on Dendritic Cells Electroporated with an Exogenous Ovalbumin Protein and Pulsed with Invariant Natural Killer T Cell Ligands Effectively Induces Antigen-Specific Antitumor Immunity.

(1) Background: Cancer vaccines are administered to induce cytotoxic CD8+ T cells (CTLs) specific for tumor antigens. Invariant natural killer T (iNKT) cells, the specific T cells activated by α-galactosylceramide (α-GalCer), play important roles in this process as they are involved in both innate and adaptive immunity. We developed a new cancer vaccine strategy in which dendritic cells (DCs) were loaded with an exogenous ovalbumin (OVA) protein by electroporation (EP) and pulsed with α-GalCer. (2) Methods: We generated bone marrow-derived DCs from C57BL/6 mice, loaded full-length ovalbumin proteins to the DCs by EP, and pulsed them with α-GalCer (OVA-EP-galDCs). The OVA-EP-galDCs were intravenously administered to C57BL/6 mice as a vaccine. We then investigated subsequent immune responses, such as the induction of iNKT cells, NK cells, intrinsic DCs, and OVA-specific CD8+ T cells, including tissue-resident memory T (TRM) cells. (3) Results: The OVA-EP-galDC vaccine efficiently rejected subcutaneous tumors in a manner primarily dependent on CD8+ T cells. In addition to the OVA-specific CD8+ T cells both in early and late phases, we observed the induction of antigen-specific TRM cells in the skin. (4) Conclusions: The OVA-EP-galDC vaccine efficiently induced antigen-specific antitumor immunity, which was sustained over time, as shown by the TRM cells.

A case of laparoscopic anterior resection for rectal cancer with duplication of the inferior vena cava using preoperative 3D computed tomography angiography.

We report the case of a patient with duplication of the inferior vena cava (DIVC) who underwent anterior laparoscopic resection for rectal cancer. A 66-year-old woman presented with abnormal lung shadows on a chest x-ray during a routine health checkup. She was diagnosed with rectal cancer and lung metastasis using colonoscopy and thoracoabdominal computed tomography (CT). In addition, a 3D CT angiography revealed double inferior vena cava, one on either side of the aorta. The preoperative diagnosis was rectal cancer cT3N0M1a(Lung) cStage IVA with DIVC, and a two-stage surgery was planned. The first stage was high anterior laparoscopic resection. This was safely performed because the pre-hypogastric nerve fascia was preserved and the left inferior vena cava was not visualized during the surgery. During the second stage of the surgery, video-assisted thoracoscopic left lower lobectomy was performed and no recurrence was observed for >6 months after the second surgery.

Does anastomotic leakage after rectal cancer resection worsen long-term oncologic outcome?

PURPOSE: The influence of anastomotic leakage on long-term survival in patients with rectal cancer is debatable. The aim of this study was to evaluate relationships between anastomotic leakage and long-term survival. METHODS: In this multicenter retrospective cohort study, 395 consecutive stage I to III rectal cancer patients underwent anterior resection between 2007 and 2012. Five-year overall survival, 5-year disease-free survival, and 5-year local recurrence-free survival were compared between patients with leakage (Leakage (+)) and patients without leakage (Leakage (-)). RESULTS: Of 395 patients, 50 (12.7%) had anastomotic leakage. Of these 50, 34 (68.0%) required urgent surgery and 16 (32.0%) could be managed by watchful waiting or with percutaneous drainage. The median follow-up period was 62.6 months. Five-year overall survival did not differ between the two groups (Leakage (+) 93.8% vs. Leakage (-) 89.0%, P = 0.121). Five-year disease-free survival also did not differ between the two groups (81.6% vs. 80.3%, P = 0.731), and neither did 5-year local recurrence-free survival (91.9% vs. 86.1%, P = 0.206). In a multivariable Cox regression model, BMI > 25, preoperative CA19-9 > 37, pathological T stage, pathological N stage, and circumferential resection margin (CRM) positive were independent predictors of disease-free survival. Moreover, pathological T stage, pathological N stage, and CRM positive were the only independent predictors of overall survival and local recurrence-free survival. Anastomotic leakage was not a risk factor for overall survival, disease-free survival, or local recurrence-free survival. CONCLUSION: Anastomotic leakage is not associated with a significant decrease in long-term survival in rectal cancer patients.

Three-dimensional laparoscopic vision improves forceps motion more in the depth direction than in the horizontal direction: An analysis of data from prospective randomized controlled trials.

INTRODUCTION: Three-dimensional (3D) laparoscopic vision can improve depth perception. However, it is a question whether 3D vision can improve motion in the depth direction. The aim of this study was to compare the impact of 3D vision on forceps motion in the depth and horizontal directions. METHODS: All data were obtained from our previous two studies, where, in total, 40 novices and 20 moderately experienced surgeons participated. A simple phantom task was performed in a training box. The participants were randomly assigned to two groups. Specifically, one group performed the task five times initially under a two-dimensional (2D) system, and the other group started under a 3D system. Both groups then performed the same task five times under the alternative system. Performances were recorded by an optical position tracker. We separately evaluated forceps motion in the x-, y-, and z-axis directions. RESULTS: Compared with the findings for 2D vision, the forceps path lengths were significantly decreased among novices and moderately experienced surgeons in almost all tasks under 3D vision. In a comparison of the path length ratio (3D/2D) in each direction, larger reduction was observed for the depth direction among novices, whereas no significant directional difference was noted among moderately experienced surgeons. CONCLUSIONS: For novices, 3D laparoscopic vision improves depth perception and may give shorter forceps movement in the depth direction even for simple tasks.

Laparoscopic hepatectomy for liver metastasis of lung large-cell neuroendocrine carcinoma: A case report.

INTRODUCTION: Lung large-cell neuroendocrine carcinoma (LCNEC) is an aggressive and a rare type of lung cancer, and the prognosis of LCNEC with distant metastasis is extremely poor, with a five-year survival rate of 0%. Here, we report a case of laparoscopic hepatectomy for liver metastasis of lung LCNEC. PRESENTATION OF CASE: A 63-year-old man received a routine physical examination, and abnormal chest radiographic findings were observed; chest computed tomography (CT) in our hospital revealed that the patient had left pneumothorax and a lesion measuring 18 mm in the inferior lingular segment of the lung. The patient underwent thoracoscopic lobectomy, and the final pathological diagnosis was lung LCNEC. Four years after surgery, abdominal CT revealed a mass measuring 27 mm in the liver. The patient underwent laparoscopic partial hepatectomy, and postoperative pathological examination showed liver metastasis of LCNEC. There was no sign of recurrence 6 months after hepatectomy. DISCUSSION: LCNEC with distant metastasis has a poor response to systemic chemotherapy, and the median survival time of patients with distant metastasis is estimated to be approximately 6 months, with a five-year survival rate of 0%. Although the common site of metastasis from LCNEC is the liver, there are no previous reports of hepatectomy for liver metastasis of LCNEC. CONCLUSION: We report a case of laparoscopic hepatectomy for liver metastasis of lung LCNEC. It is suggested that surgical resection for solitary distant metastasis of LCNEC may improve prognosis.

Laparoscopic anatomical segment 3 segmentectomy for hepatocellular carcinoma accompanied by hypoplasia of the right hepatic lobe.

We report a case of laparoscopic anatomical segment 3 segmentectomy for hepatocellular carcinoma (HCC) accompanied by hypoplasia of the right hepatic lobe. An 80-year-old man was admitted with a suspicion of HCC diagnosed by computed tomography during follow-up for thyroid cancer. Dynamic computed tomography showed 40-mm HCC in segment 3 and hypoplasia of the right hepatic lobe with the Chilaiditi sign. We performed laparoscopic anatomical segment 3 segmentectomy. There were no postoperative complications, and the patient was discharged 6 days postoperatively. This procedure can be performed safely and is technically feasible, but special attention should be paid to anatomical alterations to avoid fatal surgical complications.

Application of iNKT Cell-targeted Active Immunotherapy in Cancer Treatment.

In tumor immunity, invariant natural killer T (iNKT) cells play a pivotal role as a link between the innate and adaptive immune systems. With a precisely regulated activation mechanism, iNKT cells have the ability to respond quickly to antigenic stimulation and rapidly produce cytokines and chemokines, and subsequently an effective antitumor immune response. The development of iNKT cell-targeted active immunotherapy enables, not only an antitumor immune response through innate and acquired immunity, but also the conversion of an immunosuppressive into an immunogenic microenvironment. This review is focused on the activation mechanism and the role of iNKT cells after therapeutic active immunization. The therapeutic strategy targeting iNKT cells is expected to be applied to clinical practice in combination with surgery and chemotherapy.

The learning effect of using stereoscopic vision in the early phase of laparoscopic surgical training for novices.

BACKGROUND: Recently to improve depth perception, the performance of three-dimensional (3D) laparoscopic surgeries has increased. However, the effects of laparoscopic training using 3D are still unclear. This study aimed to clarify the effects of using a 3D monitor among novices in the early phase of training. METHODS: Participants were 40 novices who had never performed laparoscopic surgery (20 medical students and 20 junior residents). Three laparoscopic phantom tasks (task 1: touching markers on a flat disk with a rod; task 2: straight rod transfer through a single loop; and task 3: curved rod transfer through two loops) in the training box were performed ten times, respectively. Performances were recorded by an optical position tracker. The participants were randomly divided into two groups: one group performed each task five times initially under a 2D system (2D start group), and the other group performed each task five times under a 3D system (3D start group). Both groups then performed the same task five times. After the trial, we evaluated the performance scores (operative time, path length of forceps, and technical errors) and the learning curves for both groups. RESULTS: Scores for all tasks performed under the 3D system were significantly better than scores for tasks using the 2D system. Scores for each task in the 2D start group improved after switching to the 3D system. However, scores for each task in the 3D start group were worse after switching to the 2D system, especially scores related to technical errors. CONCLUSIONS: The stereoscopic vision improved laparoscopic surgical techniques of novices from the early phase of training. However, the performance of novices trained only by 3D worsened by changing to the 2D environment.

Surplus adsorption of bromide ion into π-conjugated carbon nanospaces assisted by proton coadsorption.

Nanoporous carbons can preferentially adsorb bromide ions from an aqueous solution of alkali metal bromides, even on π-conjugated surfaces. Our results show a new adsorption mechanism whereby coadsorption of protons enhances the adsorption of the anions onto the carbons.

Frequency of Myeloid-derived Suppressor Cells in the Peripheral Blood Reflects the Status of Tumor Recurrence.

BACKGROUND: Malignant tumors inhibit antitumor immune responses, which are driven by T-regulatory cells or myeloid-derived suppressor cells (MDSCs). Since MDSCs are involved in invasion, migration, and metastasis of tumor cells, we hypothesized that MDSCs are also involved in tumor recurrence after surgical resection. MATERIALS AND METHODS: C57BL/6 mice were subcutaneously inoculated with B16F10 melanoma cells in the right flank. In some experiments, established tumors were surgically resected. Peripheral blood was drawn over time, and immune cells and cytokines were evaluated using flow cytometry. RESULTS: MDSCs and relevant pro-inflammatory cytokines increased in the peripheral blood of tumor-bearing mice. Moreover, the frequency of MDSCs rapidly increased in mice with tumor recurrence. CONCLUSION: The frequency of MDSCs in the peripheral blood of tumor-bearing mice reflects the status of tumor progression as well as tumor recurrence. Continuous monitoring of MDSCs in the peripheral blood might be a useful indicator of tumor recurrence.

Comparison of two- and three-dimensional display for performance of laparoscopic total gastrectomy for gastric cancer.

PURPOSE: Introduction of three-dimensional (3D) display might remove technical obstacles of laparoscopic surgery and improve laparoscopic skills. We analyzed the effect of 3D technology on operative performance during laparoscopic total gastrectomy (LTG) for gastric cancer and assessed its advantages over two-dimensional (2D) laparoscopy. METHODS: This study included 30 consecutive surgeries of LTG with esophagojejunostomy by the overlap method performed (3D group, n = 15, 2D group, n = 15). The surgical outcomes were compared between the 3D and 2D groups. Further, we compared the performance time, the frequency of bleeding requiring hemostasis, and the frequency of remaking the surgical view by the assistant's forceps in each laparoscopic scene between the 3D and 2D groups. RESULTS: All surgeries were completed without any complications. The total time of pure laparoscopic scenes was shorter in the 3D than 2D group (154.2 vs. 182.7 min, P = 0.026), and total blood loss was almost the same (10 vs. 20 g, P = 0.195). The operative time during lymphadenectomy in scenes 6 and 7 were significantly shorter in the 3D than the 2D group (scene 6, 13.5 vs. 17.5 min, P = 0.003, and scene 7, 12.4 vs. 18.4, P = 0.025) and esophagojejunostomy (30.3 vs. 39.4 min, P = 0.008). The frequency of tissue exposure by the assistant was significantly less in the 3D group than the 2D group in scenes 6 and 7 (scene 6, n = 3.0 vs. 4.0, P = 0.006, and scene 7, n = 3.0 vs. 4.0, P = 0.017). CONCLUSIONS: 3D display is useful due to improvement of surgical skill during difficult situations such as lymphadenectomy around the celiac artery, which requires handling in the tangential view, and reconstruction using the suturing technique in a narrow space.

Quantitative comparison of operative skill using 2- and 3-dimensional monitors during laparoscopic phantom tasks.

BACKGROUND: The recent development of stereoscopic images using 3-dimensional monitors is expected to improve techniques for laparoscopic operation. Several studies have reported technical advantages in using 3-dimensional monitors with regard to operative accuracy and working speed, but there are few reports that analyze forceps motions by 3-dimensional optical tracking systems during standardized laparoscopic phantom tasks. We attempted to develop a 3-dimensional motion analysis system for assessing laparoscopic tasks and to clarify the efficacy of using stereoscopic images from a 3-dimensional monitor to track forceps movement during laparoscopy. METHODS: Twenty surgeons performed 3 tasks (Task 1: a simple operation by the dominant hand, Task 2: a simple operation using both hands, Task 3: a complicated operation using both hands) under 2-dimensional and 3-dimensional systems. We tracked and recorded the motion of forceps tips with an optical marker captured by a 3-dimensional position tracker. We analyzed factors such as forceps path lengths, operation times, and technical errors for each task and compared the results of 2-dimensional and 3-dimensional monitors. RESULTS: Mean operation times and technical errors were improved significantly for all tasks performed under the 3-dimensional system compared with the 2-dimensional system; in addition, mean path lengths for the forceps tips were shorter for all tasks performed under the 3-dimensional system. CONCLUSION: We found that stereoscopic images using a 3-dimensional monitor improved operative techniques with regard to increased accuracy and shorter path lengths for forceps movement, which resulted in a shorter operation time for basic phantom laparoscopic tasks.

Host CD40 Is Essential for DCG Treatment Against Metastatic Lung Cancer.

BACKGROUND/AIM: For the application of invariant natural killer T (iNKT) cells in cancer therapy, the CD40-CD40L interaction is indispensable in administering alpha-galactosylceramide (αGalCer). We hypothesized that CD40 plays an important role in dendritic cells (DC) pulsed with αGalCer (DCGs) in the treatment of lung metastases. MATERIALS AND METHODS: Wild-type (WT) and CD40(-/-) mice were treated with DCGs isolated from WT or CD40(-/-) mice in a B16F10 lung metastases model and NK and NKT cell activity in lungs and the spleen were examined. RESULTS: DCG treatment improved WT mice survival but CD40(-/-) hosts received no survival benefit. Conversely, attenuation of a therapeutic effect in mice treated with CD40(-/-) DCGs was not observed. The functional activities of NK and NKT cells in DCG-treated CD40(-/-) mice were partially suppressed. CONCLUSION: Host CD40 is essential for DCG treatment to have a therapeutic effect on B16F10 lung metastases.

Experimental Information on the Adsorbed Phase of Water Formed in the Inner Pore of Single-Walled Carbon Nanotube Itself.

Thus far, nobody has successfully obtained the accurate information on the properties of the adsorbed phases of gases or vapors formed inside a cylindrical micropore of single-walled carbon nanotube (SWCNT) itself based on the experimental procedure. In this work, we succeeded in analyzing experimentally the properties of adsorbed nitrogen and water confined in the inner pore of SWCNT itself by opening the pore composed of close-ended SWCNT without any changes in the surface state and also by applying the unique method for characterization; both the amounts, as well as properties, of surface functional groups and the bundle structure are the same even after the treatments for introducing an open-ended structure to a close-ended one. As a result, the average pore sizes, as well as characteristic adsorption behavior, on the two types of sample were available from the analysis of respective difference adsorption isotherms of nitrogen measured at 77 K between the adsorbed amounts on the open-ended SWCNT and that on the close-ended one. The evaluated pore sizes well coincide with the results estimated by Raman data. These results strongly support that we could analyze the adsorbed phases formed only in the inner pore of SWCNTs by applying the present method. Furthermore, we could analyze the adsorbed phase of water formed inside the cylindrical micropore of SWCNTs, showing the difference in the densities of adsorbed water depending on the pore sizes from the value of bulk water; the densities of the adsorbed water were evaluated to be 0.62 and 0.71 g mL(-1) for SWCNTs having average pore sizes of 1.3 and 1.7 nm, respectively, which were in harmony with those obtained by the theoretical calculations reported by other researchers. The proposed analysis method makes it possible to recognize the focused states of the adsorbed water formed inside the cylindrical micropore of SWCNT more precisely and correctly. The method proposed will shed light on the discussion related to the detailed nature of various adsorbed gases into SWCNT, to the detailed role of adsorbed species formed inside pore in various phenomena, and to the designing the useful materials based on the gained knowledge.

Early-phase Treatment by Low-dose 5-Fluorouracil or Primary Tumor Resection Inhibits MDSC-mediated Lung Metastasis Formation.

BACKGROUND/AIM: The outcome of patients with malignant tumors is poor if they suffer from lung metastases. Myeloid-derived suppressor cells (MDSCs), a major player for tumor-induced immunosuppression, can be suppressed by certain chemotherapeutic agents, such as low-dose 5-fluorouracil (5-FU) or surgical treatment. Based on these findings, we hypothesized that early-phase treatment by low-dose 5-FU or surgical resection of primary tumors would prevent lung metastasis formation by inhibiting MDSCs. MATERIALS AND METHODS: B16F10 melanoma-bearing C57BL/5 mice with lung metastases were treated with low-dose 5-FU or surgical resection of primary tumors. RESULTS: Low-dose 5-FU chemotherapy inhibited systemic and lung-accumulating MDSCs in tumor-bearing mice. The therapy inhibited lung metastasis formation and prolonged the survival of the animals. Consistently, early-phase resection of primary tumors improved survival, which was concomitant with a reduction of lung-accumulating MDSCs and lung metastases. CONCLUSION: Early-phase treatment may provide therapeutic values to prevent MDSC-mediated lung metastasis formation in tumor-bearing hosts.

Laparoscopic partial resection for hemangioma in the third portion of the duodenum.

Benign duodenal tumors are rare and less common than malignant tumors. Furthermore, vascular lesions of the duodenum, including hemangiomas, are rare causes of gastrointestinal bleeding. This report describes a case with bleeding hemangiomas in the third portion of the duodenum and jejunum and their successful treatment using a laparoscopic approach. There is no report of totally laparoscopic resection for tumor in the third portion of duodenum. After performing a laparoscopic Kocher maneuver, the location of the duodenal hemangioma was confirmed by endoscopic and laparoscopic observation. The lesion was excised using ultrasonic coagulating shears and the defect in the duodenal wall was sutured laparoscopically. The hemangioma of the jejunum was treated extracorporeally through a 3.0 cm umbilical incision. The operating time was 241 min and blood loss was negligible. The postoperative course was uneventful. For benign duodenal tumors in the third portion, if endoscopic resection is not adapted, this less invasive technique may be a standard treatment.

Structure of hydrated cobalt ions confined in the nanospace of single-walled carbon nanotubes.

The structure of hydrated Co ions confined in the nanospace of single-walled carbon nanotubes (SWNTs) has been studied using the X-ray absorption fine structure (XAFS) technique. Water adsorption isotherms on Co-impregnated SWNTs indicate a high affinity of Co ions to water molecules. The results of XAFS analysis provided the information on the proportion of dissolved species in nanospaces against the total amount of cobalt ions adsorbed on the open-pored SWNT. The structural information of the first shell around a Co ion was expressed in terms of the hydration number, Co-O distance and Debye-Waller factor. The actual coordination number and the interatomic distance of Co-O for the dissolved species were remarkably reduced compared to the bulk aqueous solution indicating the dehydration of water molecules from Co ions and a compact hydrated structure in the micropore of SWNTs.

Highly compressed nanosolution restricted in cylindrical carbon nanospaces.

We shed light on the specific hydration structure around a zinc ion of nanosolution restricted in a cylindrical micropore of single-wall carbon nanotube (SWNT) by comparison with the structure restricted in a cylindrical mesopore of multi-wall carbon nanotube (MWNT) and that of bulk aqueous solution. The average micropore width of open-pore SWNT was 0.87 nm which is equivalent to the size of a hydrated zinc ion having 6-hydrated water molecules. We could impregnate the zinc ions into the micropore of SWNT with negligible amounts of ion-exchanged species on surface functional groups by the appropriate oxidation followed by heat treatment under an inert condition. The results of X-ray absorption fine structure (XAFS) spectra confirmed that the proportion of dissolved species in nanospaces against the total adsorbed amounts of zinc ions on the open-pore SWNT and MWNT were 44 and 61%, respectively, indicating the formation of a dehydrated structure in narrower nanospaces. The structure parameters obtained by the analysis of XAFS spectra also indicate that the dehydrated and highly compressed hydration structure can be stably formed inside the cylindrical micropore of SWNT where the structure is different from that inside the slit-shaped micropore whose pore width is less than 1 nm. Such a unique structure needs not only a narrow micropore geometry which is equivalent to the size of a hydrated ion but also the cylindrical nature of the pore.