The Japan-Multimodal Intervention Trial for Prevention of Dementia (J-MINT): The Study Protocol for an 18-Month, Multicenter, Randomized, Controlled Trial

Background/Objectives

The Japan-multimodal intervention trial for prevention of dementia (J-MINT) is intended to verify the effectiveness of multi-domain interventions and to clarify the mechanism of cognitive improvement and deterioration by carrying out assessment of dementia-related biomarkers, omics analysis and brain imaging analysis among older adults at high risk of dementia. Moreover, the J-MINT trial collaborates with partnering private enterprises in the implementation of relevant interventional measures. This manuscript describes the study protocol.

Design/Setting

Eighteen-month, multi-centered, randomized controlled trial.

Participants

We plan to recruit 500 older adults aged 65–85 years with mild cognitive impairment. Subjects will be centrally randomized into intervention and control groups at a 1:1 allocation ratio using the dynamic allocation method with all subjects stratified by age, sex, and cognition.

Intervention

The multi-domain intervention program includes: (1) management of vascular risk factors; (2) group-based physical exercise and self-monitoring of physical activity; (3) nutritional counseling; and (4) cognitive training. Health-related information will be provided to the control group every two months.

Measurements

The primary and secondary outcomes will be assessed at baseline, 6-, 12-, and 18-month follow-up. The primary outcome is the change from baseline to 18 months in a global composite score combining several neuropsychological domains. Secondary outcomes include: cognitive change in each neuropsychological test, incident dementia, changes in blood and dementia-related biomarkers, changes in geriatric assessment including activities of daily living, frailty status and neuroimaging, and number of medications taken.

Conclusions

This trial that enlist the support of private enterprises will lead to the creation of new services for dementia prevention as well as to verify the effectiveness of multi-domain interventions for dementia prevention.

Electronic Supplementary Material

Supplementary material is available for this article at 10.14283/jpad.2021.29 and is accessible for authorized users.

Gasless single-port laparoscopic cholecystectomy

PURPOSE

Single-port laparoscopic surgery is anticipated to become the future of minimally invasive surgery. We have devised an alternative approach for laparoscopic cholecystectomy by inserting a single port at the umbilicus and using the abdominal wall-lifting method, without establishing pneumoperitoneum.

METHODS

Retrospective analysis of 130 patients undergoing laparoscopic cholecystectomy was done to compare the conventional laparoscopic cholecystectomy (CLC) (n = 69) and the novel single-port laparoscopic cholecystectomy (SLC) using the abdominal wall-lifting method (n = 61). The surgical procedures were as follows. A 2- to 3-cm transumbilical incision was made, and a wound retractor was inserted into the abdomen without difficulty. Abdominal distension was obtained using a fan-shaped retractor without the use of carbon dioxide insufflations. A 5-mm flexible scope and modified curved graspers and dissectors were used to give the feeling of triangulation during dissection.

RESULTS

The SLC group consisted of 25 males and 36 females with a mean age of 58.1 ± 7.2 years and a mean body mass index of 23.1 ± 3.2 kg/m². The two groups were comparable for mean age, sex, disease, American Society of Anesthesiologists physical status classification, and comorbidity. Likewise, the duration of operation, postoperative hospital stays, complications, the number of use of analgesics, and conversion rate to open technique were not significantly different in the two groups.

CONCLUSION

The impaired view in single-port laparoscopic surgery can be improved by using articulating instruments that can be rotated out of the field of view. This novel gasless method is cost-effective and produces minimal postoperative discomfort with no additional scars.

Phase 1 Dose-Escalation Study of Triweekly Nab-Paclitaxel Combined With S-1 for HER2-Negative Metastatic Breast Cancer

PURPOSE

To evaluate the efficacy, toxicity, maximum tolerated dose, and recommended dose of triweekly nab-paclitaxel (nab-PTX) and S-1 combination chemotherapy for patients with metastatic breast cancer.

PATIENTS AND METHODS

This phase 1 study was conducted with a standard 3 + 3 dose escalation design. Every 3 weeks, the patients received nab-PTX at 180-260 mg/m² on day 1 and S-1 at 65-80 mg/m² daily on days 1 to 14.

RESULTS

Ten HER2-negative metastatic breast cancer patients were enrolled; their median number of prior chemotherapy regimens was 3. Dose-limiting toxicity was observed in the first patient assigned to level 4; grade 4 febrile neutropenia and grade 3 neurotoxicity such as needing a wheelchair occurred. Therefore, an additional patient was not assigned to level 4. The maximum tolerated dose was considered level 4 (260 mg/m² nab-PTX with 80 mg/m² S-1). The recommended dose determined was level 3 (220 mg/m² nab-PTX with 80 mg/m² S-1). The response rate was 60.0%. The disease control rate was 70.0%.

CONCLUSION

This combination chemotherapy therapy was feasible and safe for patients with HER2-negative metastatic breast cancer.

Phase II Study of S-1 Combined With Low-Dose Docetaxel as Neoadjuvant Chemotherapy for Operable Breast Cancer Patients (N-1 Study)

BACKGROUND

To improve the pathological complete response (pCR) rate, we devised new neoadjuvant chemotherapy. Efficacy and safety of the oral fluoropyrimidine derivative S-1 (Taiho Pharmaceutical Co, Tokyo, Japan) combined with low-dose docetaxel (S-1+DOC) were evaluated.

PATIENTS AND METHODS

Patients were treated with docetaxel (40 mg/m² intravenously on day 1) and S-1 (40 mg/m² orally twice per day on days 1-14) every 3 weeks for 4 cycles. In accord with the Response Evaluation Criteria In Solid Tumors version 1.1 criteria, the patients who showed a complete response (CR) underwent surgery, and those who achieved a partial response (PR) underwent 4 more cycles of S-1+DOC. Patients who achieved stable disease (SD) or progressive disease (PD) received EC (epirubicin and cyclophosphamide) or HT (trastuzumab and paclitaxel) according to their HER2 status. The primary end point was the pCR rate.

RESULTS

Ninety-four patients entered the study. After 4 cycles of S-1+DOC, CR was noted in 5 patients, PR in 57, SD in 18, and PD in 3. Of the patients who achieved SD and PD, 12 received EC, and 9 received HT. Among the 83 assessable patients, the pCR rate was 34.9%, and the response rate was 80.7%. The pCR rates were 19.5% in the luminal type group, 53.8% in the luminal HER2 group, 46.1% in the HER2 group, and 50.0% in the triple-negative group.

CONCLUSION

The S-1+DOC regimen in this study could be well tolerated and a new candidate neoadjuvant chemotherapy in operable breast cancer patients. It is also expected to be effective even in patients with luminal type disease. However, further randomized control trials are needed to ascertain whether pCR can contribute to favorable outcomes.

The effects of the herbal medicine Daikenchuto (TJ-100) after esophageal cancer resection, open-label, randomized controlled trial

BACKGROUND

Daikenchuto (TJ-100), a traditional Japanese herbal medicine, is widely used in Japan. Its effects on gastrointestinal motility and microcirculation and its anti-inflammatory effect are known. The purpose of this prospective randomized controlled trial was to investigate the effect of TJ-100 after esophagectomy in esophageal cancer patients.

METHODS

Forty patients for whom subtotal esophageal resection for esophageal cancer was planned at our institute from March 2011 to August 2013 were enrolled and divided into two groups at the point of determination of the operation schedule after informed consent was obtained: a TJ-100 (15 g/day)-treated group (n = 20) and a control group (n = 20). The primary efficacy end-points were maintenance of the nutrition condition and the recovery of gastrointestinal function. The secondary efficacy end-points were the serum C-reactive protein (CRP) level and adrenomedullin level during the postoperative course, the incidence of postoperative complications, and the length of hospital stay after surgery.

RESULTS

We examined 39 patients because one patient in the TJ-100 group was judged as having unresectable cancer after surgery. The mean age of the TJ-100 group patients was significantly older than that of the control group patients.The rate of body weight decrease at postoperative day 21 was significantly suppressed in the TJ-100 group (3.6% vs. the control group: 7.0%, p = 0.014), but the serum albumin level was not significantly different between the groups. The recovery of gastrointestinal function regarding flatus, defecation, and oral intake showed no significant between-group differences, but postoperative bowel symptoms tended to be rare in the TJ-100 group. There was no significant between-group difference in the length of hospital stay after surgery. The serum CRP level at postoperative day 3 was 4.9 mg/dl in the TJ-100 group and 6.9 mg/dl in the control group, showing a tendency of a suppressed serum CRP level in the TJ-100 group (p = 0.126). The rate of increase in adrenomedullin tended to be high postoperatively, but there was no significant difference between the two groups.

CONCLUSIONS

TJ-100 treatment after esophageal cancer resection has the effects of prompting the recovery of gastrointestinal motility and minimizing body weight loss, and it might suppress the excess inflammatory reaction related to surgery.

CXCR4 Expression is Associated with Poor Prognosis in Patients with Esophageal Squamous Cell Carcinoma

BACKGROUND

Chemokines and their receptors are known to play important roles in the tumorigenesis of many malignancies. The chemokine CXCL12 and its receptors CXCR4 and CXCR7 were suggested to be involved in cancer invasion and metastasis. The aim of this retrospective study was to evaluate the prognostic impact of the expressions of CXCL12, CXCR4 and CXCR7 in patients with esophageal squamous cell carcinoma (ESCC).

METHODS

We used immunohistochemistry (IHC) and reverse transcriptase-polymerase chain reaction (RT-PCR) to evaluate the expressions of CXCL12, CXCR4, and CXCR7 in ESCC patients' tumor biopsy specimens obtained during preoperative endoscopy or surgery. These results were compared with the patients' clinicopathological parameters and survival.

RESULTS

IHC was conducted for 172 patients. High expression of CXCR4 in the cytoplasm and nuclei and that of CXCR7 were associated with poor cause-specific survival (CSS) (P= .002 and .010, respectively). The specimens from 52 of the 172 patients were examined by RT-PCR and quantitative real-time PCR. The expression levels of messenger RNA (mRNA) of CXCR4 and CXCR7 were significantly increased in the tumors compared with normal esophageal mucosae (P < .0001). The expression level of mRNA of CXCR4 was associated with poor recurrence-free survival and CSS (P = .012 and .038, respectively).

CONCLUSIONS

CXCR4 expression is associated with poor prognosis in patients with ESCC.

Uric acid, indoxyl sulfate, and methylguanidine activate bulbospinal neurons in the RVLM via their specific transporters and by producing oxidative stress

Patients with chronic renal failure often have hypertension, but the cause of hypertension, other than an excess of body fluid, is not well known. We hypothesized that the bulbospinal neurons in the rostral ventrolateral medulla (RVLM) are stimulated by uremic toxins in patients with chronic renal failure. To investigate whether RVLM neurons are sensitive to uremic toxins, such as uric acid, indoxyl sulfate, or methylguanidine, we examined changes in the membrane potentials (MPs) of bulbospinal RVLM neurons of Wister rats using the whole-cell patch-clamp technique during superfusion with these toxins. A brainstem-spinal cord preparation that preserved the sympathetic nervous system was used for the experiments. During uric acid, indoxyl sulfate, or methylguanidine superfusion, almost all the RVLM neurons were depolarized. To examine the transporters for these toxins on RVLM neurons, histological examinations were performed. The uric acid-, indoxyl sulfate-, and methylguanidine-depolarized RVLM neurons showed the presence of urate transporter 1 (URAT 1), organic anion transporter (OAT)1 or OAT3, and organic cation transporter (OCT)3, respectively. Furthermore, the toxin-induced activities of the RVLM neurons were suppressed by the addition of an anti-oxidation drug (VAS2870, an NAD(P)H oxidase inhibitor), and a histological examination revealed the presence of NAD(P)H oxidase (nox)2 and nox4 in these RVLM neurons. The present results show that uric acid, indoxyl sulfate, and methylguanidine directly stimulate bulbospinal RVLM neurons via specific transporters on these neurons and by producing oxidative stress. These uremic toxins may cause hypertension by activating RVLM neurons.

Immunocytochemical results for HER2 and Ki67 in breast cancer touch-smear cell specimens are reliable

BACKGROUND

Re-evaluation of the subtype of recurrent breast cancer is necessary for deciding the treatment approach, but it is often not performed due to the difficulty of obtaining tissue specimens from a recurrent lesion, etc. However, when a recurrent lesion is close to the body surface, fine-needle aspiration cells (FNA cells) can be easily obtained, and immunocytochemical (ICC) analysis of hormone receptors expression in FNA cells is said to be highly reliable. However, there is no consensus regarding ICC analysis of human epidermal growth factor receptor type 2 (HER2) expression and the Ki67 index using FNA cells.

METHODS

Touch-smear cells (TSC) were prepared from resected specimens from 36 patients with primary invasive ductal carcinoma of the breast. The TSC were fixed in 95 % ethanol and subjected to ICC analysis for HER2 using HercepTest™ (Dako) and Ki67 using MIB-1™ (Dako). HER2 expression and the Ki67 index for the TSC were compared with the results of immunohistochemical analysis of histological section (HS). Statistical analyses used the kappa test and Pearson's correlation coefficients.

RESULTS

HER2 and Ki67 were analyzed in TSC from 36 and 28 patients, respectively. The HER2 expression scores in the TSC and HS groups showed good agreement (kappa value =0.640) and significant correlation (correlation coefficient =0.860, p < 0.001). The Ki67 indexes in the TSC and HS groups also showed significant correlation (correlation coefficient =0.861, p < 0.001).

CONCLUSIONS

The reliability of ICC analysis of HER2 expression and the Ki67 index using TSC were recognized.

Triple assessment of sentinel lymph node metastasis in early breast cancer using preoperative CTLG, intraoperative fluorescence navigation and OSNA

BACKGROUND

Sentinel lymph node biopsy (SLNB) became a standard surgical procedure for patients with early breast cancer; however, the optimal method of sentinel lymph node (SLN) identification remains controversial. The current study presents the protocol of our institution for preoperative and intraoperative SLN detection.

METHODS

Fifty female patients with early breast cancer and clinically node-negative axilla were enrolled in this study. All patients underwent preoperative CT lymphography (CTLG), intraoperative SLNB using fluorescence navigation, intraoperative one-step nucleic acid amplification (OSNA) and postoperative hematoxylin and eosin histopathological analysis. Prediction of metastasis by CTLG and detection of metastasis by OSNA were compared to results of histopathology as standard reference.

RESULTS

SLN were identified by preoperative CTLG and intraoperative SLNB with fluorescence navigation in all patients, the identification rate was 100 %. SLN metastases were detected as positive by OSNA in 9 patients (18 %), 4 were (++), 4 were (+) and 1 was (+I). SLN metastases were detected as positive by histopathology in 10 patients (20 %). The concordance rate between OSNA and permanent sections was 90 %. The negative predictive value of CTLG was 80 %.

CONCLUSION

Use of CTLG and fluorescence navigation made performing SLNB with high accuracy possible in institutions that cannot use the radioisotope method. OSNA provided accurate intraoperative method, allowing for completion of axillary node dissection during surgery and avoidance of second surgical procedure in patients with positive SLNs, thereby reducing patient distress and, finally, saving hospital costs.

[Pathological complete response in a case of advanced esophageal cancer invading aorta treated by preoperative chemotherapy with docetaxel and cisplatin plus 5-FU]

The patient was a 64-year-old man, diagnosed as cStage IVa esophageal cancer invading the aorta with lymph node metastasis. He received combination chemotherapy with docetaxel/cisplatin/5-FU(DFP therapy). After one course, CT and endoscopic examination showed remarkable reduction of the primary lesion and lymph node metastasis. We performed subtotal esophagectomy and gastric tube reconstruction by the retroposterior mediastinum route. The pathological specimen evidenced fibrosis and infiltration of inflammatory cells on almost all layers, but showed no viable malignant cells in the middle thoracic esophagus. Therefore, the pathological effect was judged as Grade 3(pCR). This case suggested that DFP combination chemotherapy may prove to be a useful treatment for advanced esophageal cancer with invasion to other organs.

Aldehyde dehydrogenase 1 expression is associated with poor prognosis in patients with esophageal squamous cell carcinoma

BACKGROUND

Aldehyde dehydrogenase 1 (ALDH1) and CD44 act as important biomarkers in several solid tumors. However, few studies have examined the relationships between ALDH1 expression and the prognosis and clinical characteristics of esophageal squamous cell carcinoma (ESCC).

METHODS

This study was a retrospective case-control study and included 152 patients with ESCC. A total of 56 patients underwent surgery (OP group), 40 patients received neoadjuvant chemotherapy involving weekly docetaxel plus 5-fluorouracil and low-dose cisplatin (DFP therapy) prior to undergoing surgery (NAC group), and 56 patients received initial systemic DFP therapy (CT group). The ALDH1 and CD44 immunohistochemical expression levels of each tumor were evaluated and compared with the prognosis and clinical characteristics of the ESCC patients.

RESULTS

In the OP and NAC groups, multivariate analysis found that ALDH1 was independently associated with postoperative recurrence and prognosis (OP group, P=0.004 and 0.016, respectively; NAC group, P=0.026 and 0.014, respectively). In addition, CD44 was found to be associated with postoperative recurrence in the OP group and prognosis in the NAC group (P=0.024 and 0.047, respectively). Among the ALDH1-negative clinical stage II/III patients, the OP and NAC groups displayed better prognoses than the CT group (P<0.001). However, among the ALDH1-positive clinical stage II/III patients, the OP and NAC groups displayed poorer prognoses than the CT group (P=0.049).

CONCLUSIONS

ALDH1 was found to be a predictor of postoperative recurrence and prognosis in ESCC, and CD44 might be a predictor of recurrence and prognosis. ALDH1 expression might affect the treatment strategy for ESCC.

The new primary chemotherapy with S-1 and docetaxel for advanced breast cancer: A first report of N-1 trial

e11560

Background: We reported the result of the efficacy and toxicity of S-1 combined with docetaxel (S-1+DOC) in ASCO 2011 (abstract No.1075). It showed good objective response rate (ORR) and some cases showed of complete response (CR) before middle of 8 cycles regimen. But this regimen was difficult to keep compliance of per oral S-1 intake. To improve pathological CR (pCR) rate, we planned a new protocol of primary chemotherapy with S-1+DOC (N-1 trial). Methods: Patients with advanced breast cancer (stage II-IV) were treated with i.v. docetaxel (40mg/m2) on day1 and oral S-1 (80mg as FT/m2/day) on day1 to 14 every 3 weeks for 4 cycles. According to the RECIST criteria, patients with CR were underwent operation, partial response were continued more 4cycles of S-1+DOC. Stable disease or progressive disease cases were changed regimen for EC or Trastuzumab and Paclitaxel (HT) according to their HER2 status. Adequate supportive therapy was provided for typical adverse events. Primary endpoint is a pCR rate. Secondary endpoints are ORR, breast conservation rate and safety. Results: Between 2009 and 2011, Forty-two patients were originally entered. After 4 cycles of S-1+DOC, CR was noted in 6 cases, and PR in 20 cases. 8 cases of SD and 1 case of PD were underwent EC, 4 cases of SD were underwent HT. Among 36 patients who had completed the whole regimen, 30.7% achieved pCR. ORR was 79.4% and breast conservation rate was 97.4%. Patients could keep an intake more than 80% dose of S-1 was 87%. Adverse events over grade3 were peripheral sensory neuropathy, nausea, nail change and neutropenia. Grade 3, 4 of neutropenia was noted in 62%. Conclusions: The new primary chemotherapy with S-1 and Docetaxel is expected to exhibit satisfactory efficacy and showed the possibility of shortened the term of primary chemotherapy. In order to establish this treatment, it is important to proper response assessment.

Prognosis of esophageal squamous cell carcinoma in patients positive for human epidermal growth factor receptor family can be improved by initial chemotherapy with docetaxel, fluorouracil, and cisplatin

BACKGROUND

The human epidermal growth factor receptor (HER) family, Ki-67 and p53 are important biomarkers for several malignancies. However, few studies have examined the role of these in prognosis and therapeutic sensitivity of esophageal squamous cell carcinoma (ESCC). The efficacy of triple-drug combination therapy with docetaxel, fluorouracil and cisplatin has recently been expected for ESCC.

METHODS

Subjects comprised 142 patients with ESCC who underwent operation (OP group, n = 54), neoadjuvant chemotherapy with docetaxel, fluorouracil, and cisplatin (DFP therapy) followed by operation (NAC group, n = 37) or initial systemic DFP therapy (CT group, n = 51) between January 2004 and December 2010. Immunohistochemical expressions of epidermal growth factor receptor (EGFR), HER2, HER3, Ki-67, and p53 were evaluated and compared with prognosis and sensitivity to DFP therapy.

RESULTS

Positive correlations existed between EGFR, HER2, and HER3 expressions. In the OP group, EGFR was independently associated with postoperative recurrence in multivariate analysis (P = .036). In the NAC group, EGFR correlated with pathological response to DFP therapy (P = .004). In the CT group, EGFR, HER2, and HER3 correlated with clinical response to DFP therapy and EGFR was independently associated with favorable prognosis in multivariate analysis (P = .022).

CONCLUSION

EGFR represents a predictor of postoperative recurrence and sensitivity to triple-drug combination therapy including a taxane. EGFR-positive patients may show improved prognosis with taxane combination chemotherapy and molecular targeted therapy for HER family members.

[A case of a patient with stage IVa esophageal cancer surviving over 4 years by combination chemotherapy with docetaxel,5 -FU and cisplatin, without operation]

A male patient in his 50s was found to have lower thoracic advanced esophageal squamous cell carcinoma by upper gastrointestinal endoscopy with the chief complaint of dysphagia in July 2006. CT revealed supraclavicular lymph node metastasis, and he was diagnosed as clinical stage IVa. He underwent two courses of combination chemotherapy with docetaxel, 5-FU and cisplatin(DFP therapy: docetaxel at 25mg/m / / 2 on day 1, 5-FU at 370 mg/m2 on days 1-5, and cisplatin at 7 mg/m2 on days 1-5 were repeated weekly for 4 weeks). The primary tumor disappeared and the lymph node was reduced as observed by upper gastrointestinal endoscopy and CT. After 2 courses of DFP therapy, PET-CT revealed that the primary tumor and lymph node had no new accumulation. Because he refused both operation and chemoradiotherapy, the patient underwent oral chemotherapy. In January 2010, PET-CT and upper gastrointestinal endoscopy revealed that the primary tumor relapsed. DFP therapy was performed and was effective once again. He has survived for over 4 years and 4 months without operation.

Sentinel lymph node biopsy using intraoperative indocyanine green fluorescence imaging navigated with preoperative CT lymphography for superficial esophageal cancer

BACKGROUND

The sentinel lymph node (SLN) concept has been gaining attention for gastrointestinal neoplasms but remains controversial for esophageal cancer. This study evaluated the feasibility of SLN identification using intraoperative indocyanine green (ICG) fluorescence imaging (IGFI) navigated by preoperative computed tomographic lymphography (CTLG) to treat superficial esophageal cancer.

METHODS

Subjects comprised 20 patients clinically diagnosed with superficial esophageal cancer. Five minutes after endoscopic submucosal injection of iopamidol around the primary lesion using a four-quadrant injection pattern with a 23-gauge endoscopic injection sclerotherapy needle, three-dimensional multidetector computed tomography was performed to identify SLNs and lymphatic routes. ICG solution was injected intraoperatively around the tumor. Fluorescence imaging was obtained by infrared ray electronic endoscopy. Thoracoscope-assisted standard radical esophagectomy with lymphadenectomy was performed to confirm fluorescent lymph nodes detected by CTLG.

RESULTS

Lymphatic vessels and SLNs were identified preoperatively using CTLG in all cases. Intraoperative detection rates were 100% using CTLG and 95% using IGFI. Lymph node metastases were found in four cases, including one false-negative case with SLNs occupied by bulky metastatic tumor that were not enhanced with both methods. The other 19 cases, including three cases of metastatic lymph nodes, were accurately identified by both procedures.

CONCLUSIONS

Preoperative CTLG visualized the correct number and site of SLNs in surrounding anatomy during routine computed tomography to evaluate distant metastases. Referring to CTLG, SLNs were identified using IGFI, resulting in successful SLN navigation and saving time and cost. This method appears clinically applicable as a less-invasive method for treating superficial esophageal cancer.

Gene expression changes in a chemoresistant model with human esophageal cancer xenografts using cDNA microarray

BACKGROUND

5-Fluorouracil (5-FU) and cisplatin combined chemotherapy (FP) is commonly used for esophageal cancer. Acquired resistance needs to be overcome to improve the chemotherapeutic effect.

MATERIALS AND METHODS

The FP-resistant xenograft model using severe combined immunodeficient (SCID) mice was established as an acquired resistance model. RNA was extracted pretreatment, at the onset of the anticancer effect, during the most effective, and regrowth period in the FP administration group and during the mid-progressive period and the far advanced period in the control group. A microarray was applied to explore gene expression changes.

RESULTS

The data set containing up-regulated genes in the regrowth period was uploaded into Ingenuity Pathway Analysis. The expression change profiles suggested that activation of not only 5-FU- and cisplatin-specific genes, but also the Phosphoinositide 3-kinase (PI3K)/AKT signal were associated with FP resistance.

CONCLUSION

A xenograft model using SCID mice with esophageal cancer cells would monitor gene changes during treatment and regrowth.

Roles of glutamate receptor delta 2 subunit (GluRdelta 2) and metabotropic glutamate receptor subtype 1 (mGluR1) in climbing fiber synapse elimination during postnatal cerebellar development

Climbing fiber (CF) synapse formation onto cerebellar Purkinje cells (PCs) is critically dependent on the synaptogenesis from parallel fibers (PFs), the other input to PCs. Previous studies revealed that deletion of the glutamate receptor delta2 subunit (GluRdelta2) gene results in persistent multiple CF innervation of PCs with impaired PF synaptogenesis, whereas mutation of the metabotropic glutamate receptor subtype 1 (mGluR1) gene causes multiple CF innervation with normal PF synaptogenesis. We demonstrate that atypical CF-mediated EPSCs (CF-EPSCs) with slow rise times and small amplitudes coexisted with typical CF-EPSCs with fast rise times and large amplitudes in PCs from GluRdelta2 mutant cerebellar slices. CF-EPSCs in mGluR1 mutant and wild-type PCs had fast rise times. Atypical slow CF responses of GluRdelta2 mutant PCs were associated with voltage-dependent Ca(2+) signals that were confined to PC distal dendrites. In the wild-type and mGluR1 mutant PCs, CF-induced Ca(2+) signals involved both proximal and distal dendrites. Morphologically, CFs of GluRdelta2 mutant mice extended to the superficial regions of the molecular layer, whereas those of wild-type and mGluR1 mutant mice did not innervate the superficial one-fifth of the molecular layer. It is therefore likely that surplus CFs of GluRdelta2 mutant mice form ectopic synapses onto distal dendrites, whereas those of wild-type and mGluR1 mutant mice innervate proximal dendrites. These findings suggest that GluRdelta2 is required for consolidating PF synapses and restricting CF synapses to the proximal dendrites, whereas the mGluR1-signaling pathway does not affect PF synaptogenesis but is involved in eliminating surplus CF synapses at the proximal dendrites.

Synthesis and evaluation of a difluoromethylene analogue of sphingomyelin as an inhibitor of sphingomyelinase

A sphingomyelin analogue 2, in which the long alkenyl chain and the phosphodiester moiety of sphingomyelin were replaced by a phenyl and an isosteric difluoromethylenephosphonic acid, was prepared to evaluate its inhibitory potency to sphingomyelinase. The analogue non-competitively inhibited the neutral sphingomyelinase in bovine brain microsomes with an IC50 of 400 microM. The compound had the ability to suppress tumor necrosis factor alpha-induced apoptosis of PC-12 neurons at a low concentration of 0.1 microM.

Cortical networks recruited for time perception: a monkey positron emission tomography (PET) study

The presence of an "internal clock" in the brain has been assumed to underlie the information processing related to time. This clock plays a critical role in time keeping and time perception, which are closely associated with integrated functions in the brain. To identify the brain areas recruited for time keeping and time perception, we performed positron emission tomography (PET) studies with rhesus monkeys to measure regional cerebral blood flow (rCBF) as an index of neural activity during time discrimination tasks of different durations ranging from 400 to 1500 ms. Changes in rCBF that covaried significantly with the durations of the target being perceived by subjects were found in the dorsolateral prefrontal cortex (DLPFC), the posterior part of the inferior parietal cortex, basal ganglia, and posterior cingulate cortex. Furthermore, a loss of neuronal function in the DLPFC caused by a local application of bicuculline resulted in the selective reduction of performance in time discrimination tasks. The results indicate that a neural network composed of the posterior inferior parietal cortex to the DLPFC plays a crucial role in the temporal monitoring process in time perception.

Screening search for organic fluorophores: syntheses and fluorescence properties of 3-azolyl-7-diethylaminocoumarin derivatives

In order to find a highly sensitive fluorophore, 3-azolyl-7-diethylaminocoumarin derivatives were synthesized. Both the absorption and fluorescence maxima of the coumarin-thiazole compounds showed red shifts with increases of the molar absorptivities and fluorescence intensities, in comparison with those of the corresponding coumarin-oxazole compounds. Among them, 3-(5-ethoxycarbonyl-1,3-thiazol-2-yl)-7-diethylamino-2H-chromen -2-one (3e) was one of the most promising candidates as a fluorophore accessible for analytical purposes in the fields of analytical and biological chemistry.

A novel subtype of prostacyclin receptor in the central nervous system

Recently, in the course of our search for the prostacyclin receptor in the brain, we found a novel subtype, designated as IP2, which was finely discriminated by use of the specific ligand (15R)-16-m-tolyl-17,18,19,20-tetranorisocarbacyclin (15R-TIC) and specifically localized in the rostral part of the brain. In the present study, the tritiated compound 15R-[15-(3)H]TIC was synthesized and utilized for more specific research on IP2. The specificity of binding to rat brain regions was confirmed by use of several prostacyclin derivatives including 15S-TIC. Mapping of 15R- and 15S-[3H]TIC binding in adjacent pairs of frozen sections of rat brain demonstrated a quite similar pattern of distribution in almost all rostral brain regions, indicating that the regions may contain only the IP2 subtype. On the other hand, 15R-[3H]TIC binding was very faint as compared with 15S-[3H]TIC binding in the caudal medullary region. High densities of 15R-[3H]TIC binding sites were shown in the dorsal part of the lateral septal nucleus, thalamic nuclei, limbic structures, and some of the cortical regions. Scatchard plot analysis showed two components of high-affinity 15R-[3H]TIC binding in the rostral regions, one with a K(D) value at approximately 1 nM and the other with approximately 30 nM. These results strengthen our previous finding that a different subtype of prostacyclin receptor is expressed in the CNS, and the map with 15R-[3H]TIC obtained here could guide further studies on the molecular and functional properties of the IP2.

A new class of synaptic response involving calcium release in dendritic spines

In the classical view, transmission of signals across synapses in the mammalian brain involves changes in the membrane potential of the postsynaptic cell. The use of high-resolution cellular imaging has revealed excitatory synapses at which postsynaptic, transient alterations in calcium ion concentration are tightly associated with electrical responses. Here, by investigating the synapse between parallel glutamatergic fibres and Purkinje cells in the mouse cerebellum, we identify a class of postsynaptic responses that consist of transient increases in dendritic Ca2+ concentration but not changes in somatic membrane potential. Our results indicate that these synaptic Ca2+ transients are mediated by activation of metabotropic glutamate-responsive mGluR1-type receptors and require inositol-1,4,5-trisphosphate-mediated Ca2+ release from intradendritic stores. The new type of synaptic response is restricted to postsynaptic microdomains, which range, depending on the frequency of stimulation, from individual spines to small spinodendritic compartments. Thus, the synaptic Ca2+-release signal may be one of the critical cues that determine the input specificity of long-term depression, a well-established form of activity-dependent plasticity at these synapses.

Evaluation of wheelchair cushions by means of pressure distribution mapping

We studied the seated buttock pressure distribution in six paraplegic patients by means of computerized pressure mapping. They were all male and their age ranged from 18 to 48 years old. Their level of paralysis varied from Th5 to L1. Five kinds of wheelchair cushions were studied: an air cushion, a contour cushion, a polyurethane foam cushion, a Cubicushion (which is made of polyurethane foams) and a silicone gel cushion. A tactile sensor consisting of 2064 matrices was used for measuring the buttock pressure distribution and the data was analyzed on a personal computer. Peak pressures measured for each cushion were as follows (in descending order): the Cubicushion, the polyurethane foam cushion, the contour cushion, the silicone gel cushion, and the air cushion. The areas of total contact measured for each cushion were as follows (in descending order): the air cushion, the silicone gel cushion, the polyurethane foam cushion, the contour cushion and the Cubicushion. Based on these findings, we conclude that the most advantageous cushion is the air cushion or the silicone gel cushion. Likewise, we conclude that the Cubicushion is not practical for pressure sore prevention.

A survey of wheelchair use by paraplegic individuals in Japan. Part 1: Characteristics of wheelchair cushions

The characteristics of wheelchair cushions used by 218 paraplegic patients who lived independent lives were surveyed to clarify the present state of wheelchair cushioning for pressure sore prevention in Japan. Out of 586 cushions surveyed, 91.0% were ready-made and the rest were custom-made. The outstanding popularity of polyurethane foam ready-made cushions (76.3%) suggested that insufficient consideration was taken in the selection of cushions. Custom-made cushions displayed unique modifications to relieve contact pressure or to stabilize sitting posture, which should be systematically provided for all patients. The variety of cushion types and the frequent dissatisfaction with cushions seen in patients with current pressure sores suggested a strong demand for the effective prescription of cushions. Furthermore, 30% of all cushions had had an excessively prolonged use, indicating insufficient follow-up. A medical system including deliberate prescription and regular follow-up of wheelchair cushions should be established for the effective prevention of pressure sores.

A survey of wheelchair use by paraplegic individuals in Japan. Part 2: Prevalence of pressure sores

A cross-sectional survey was done to clarify the incidence of pressure sores in 218 self-supported Japanese paraplegic patients and to determine effective measures for prevention. The majority of patients (85.7%) had previous pressure sores, and 46.3% had undergone multiple surgeries. Some patients (17.9%) were still suffering from persistent sores which commonly developed at the ischial tuberosities, suggesting insufficiency of self-care practice during wheelchair activities. Sensory disturbance over the seating surface, urinary incontinence, and general complications were seen in 85.8%, 49.5%, and 18.8% of total subjects, respectively. They were seen as risk factors for pressure sores, but only urinary incontinence clearly increased the current pressure sore prevalence. Nevertheless, both self-care practice and sports activities, seen in 85.3% and 36.2% of total subjects, respectively, contributed to greatly reduce the incidence. A patient education system including acquisition of basic knowledge and proper technique should be established to promote effective prevention of pressure sores in Japan.

Mapping of cortical areas involved in color vision in non-human primates

Positron emission tomography (PET) was used to measure changes in the regional cerebral blood flow (rCBF) of rhesus monkeys performing visual discrimination tasks. In comparison with both position and brightness discrimination tasks, the color discrimination task activated the posterior inferior temporal cortex and a ventromedial occipital region, which is located along the anterior one-third of the calcarine sulcus. In contrast, the position task activated the middle temporal area and intraparietal cortex as compared with the color task. These results confirm the segregation of visual pathways and delineate the visual areas involved in color vision. This approach might bridge the gap between invasive studies in animals and functional imaging studies in humans.

Analysis of stereoisomeric C27-bile acids by high performance liquid chromatography with fluorescence detection

A method for differentially measuring the 24-hydroxylated stereoisomeric intermediates (3 alpha,7 alpha,12 alpha,24-tetrahydroxy- and 3 alpha,7 alpha,24-trihydroxy-5 beta-cholestan-26-oic acids) and related C27-bile acids in beta-oxidation of bile acid biosynthesis has been developed by high performance liquid chromatography with fluorescence detection. The method involved the derivatization of the above intermediable C27-bile acids into fluorescent esters with 3-(4-bromomethylphenyl)-7-diethylaminocoumarin, a newly synthesized labeling reagent for carboxylic acids. The fluorescent derivatives were subjected to a short silica gel column to eliminate interfering products prior to analysis by high performance liquid chromatography. The separation of the 16 kinds of bile acids containing stereoisomers was carried out using a reversed-phase Inertsil C8-column by gradient elution and detected with a fluorometer (Ex. 400 nm, Em. 475 nm). The linearity of calibration curve for each bile acid was from 0.5 to 250 pmol (r = 0.999) and the detection limits were about 15 fmol at a signal-to-noise ratio of 3. The method was applied to the determination of intermediates in beta-oxidation of bile acid biosynthesis using rat liver homogenate. The results showed that two stereoisomers of 24-hydroxylated C27-bile acids were predominantly produced, indicating the formation of the isomers by the cis-hydration with water.

Local dendritic Ca2+ signaling induces cerebellar long-term depression

The coordinated activity of large numbers of adjacent parallel fiber synapses elevate calcium concentration locally in small regions of Purkinje cell dendrites. Such activity has also been reported to produce long-term depression of parallel fiber synaptic transmission. We have examined the relationship between these two events by combining patch clamp measurements of parallel fiber synaptic transmission with confocal microscopic imaging of the local calcium signals. We find that patterns of parallel fiber activity capable of evoking long-term depression invariably cause increases in Purkinje cell calcium concentration that are very spatially restricted. These results suggest that one function of the local dendritic calcium signals is to induce long-term depression of parallel fiber synapses.

Survey of above knee (A/K) prostheses currently used in the Chugoku-Shikoku district of Japan

To determine the extent to which recent advances in biomechanical technology have been implemented and to evaluate these new technologies, 84 unilateral above knee (A/K) amputees and their prostheses were surveyed in the Chugoku-Shikoku district of Japan, especially in regard to the types, sockets and components of A/K prostheses currently in use. Background factors such as age and sex of the A/K amputees and the period after amputation were also surveyed. Of the 84 amputees surveyed, 74 (88.1%) were over 40 years old and 40 (47.6%) were over 60 years old. There were 10 women (11.9%) and 74 men (88.1%). The period after amputation was under 25 years in 58 (69.0%) cases. Regarding the type of A/K prostheses, one-third of the prostheses was of the exoskeletal type and two-thirds were of the endoskeletal type. Although the endoskeletal type is becoming more popular recently, elderly A/K amputees tend to use the exoskeletal type. Thirty-one (36.9%) had plug-fit sockets which are preferable for those who follow the Japanese practice of sitting on the floor, especially for elderly amputees. Thirty-seven (44.0%) had a lock-knee, 27 (73.0%) of which were used by amputees over 60 years old. Seventy-three (86.9%) had a single-axis ankle which is generally considered to be the most stable ankle. Thus, the most common combination of prosthetic components for elderly A/K amputees was the plug-fit socket, lock-knee joint and single-axis ankle.

Receptor imaging technique with 11C-labeled receptor ligands in living brain slices: its application to time-resolved imaging and saturation analysis of benzodiazepine receptor using [11C]Ro15-1788

Recently we developed a novel imaging technique using positron emitter-labeled compounds as probes and a storage phosphor screen as a detector. This approach makes it possible to follow a variety of biochemical processes with spatial information in living brain slices. Further technical development is reported here in terms of time-resolved imaging and receptor characterization in a real equilibrium state. The method was validated by use of [11C]Ro15-1788, a benzodiazepine receptor antagonist. Fresh brain slices were incubated with [11C]Ro15-1788 in oxygenated Krebs-Ringer solution at 37 degrees C, in a specially designed chamber. By placing the chamber on a storage phosphor screen, we could obtain two-dimensional images of radioactivity in the slices. Time-resolved imaging was made at 5 min intervals, revealing that it took 60 min to reach equilibrium binding. The dissociation process was observed by adding an excess amount of unlabeled Ro15-1788 to the chamber, 25 min was required for the full dissociation. In the equilibrium state, i.e. in the presence of free radio-ligand, Scatchard plot analysis was performed on the cerebral cortex (Kd = 7.4 nM, Bmax = 146 fmol/mg tissue) and striatum (Kd = 7.5 nM, Bmax = 107 fmol/mg tissue), suggesting the presence of a single component of binding site in these two regions. The present method, for the first time, made it possible to study a ligand-receptor interaction in living brain slices with temporal and spatial resolutions. This technique should prove useful for studies of receptor function under physiological conditions.

A novel subtype of the prostacyclin receptor expressed in the central nervous system

By use of several prostacyclin analogs and an in vitro autoradiographic technique, we have found a novel subtype of the prostacyclin receptor, one having different binding properties compared with those of the known prostacyclin receptor in the rat brain. Isocarbacyclin, which is a potent agonist for the known prostacyclin receptor, had high affinity for the novel subtype (dissociation constant (Kd) of 7.8 nM). However, iloprost, which is usually used as a stable prostacyclin analog, showed low affinity binding (Kd = 159 nM) for the subtype. Other prostaglandins showed no or little affinity for the subtype. [3H]Isocarbacyclin binding was high in the thalamus, lateral septal nucleus, hippocampus, cerebral cortex, striatum, and dorsal cochlear nucleus. Although the nucleus of the solitary tract and the spinal trigeminal nucleus showed a high density of [3H]isocarbacyclin binding, [3H]iloprost also had high affinity in these regions, and the binding specificity was similar to that for the known prostacyclin receptor. Hemilesion studies of striatal neurons lesioned by kainate or of dopaminergic afferents lesioned by 6-hydroxydopamine revealed that the binding sites of the novel subtype exist on neuronal cells in the striatum, but not on the presynaptic terminal of afferents or on glial cells. Electrophysiological studies carried out in the CA1 region of the hippocampus revealed that prostacyclin analogs have a facilitatory effect on the excitatory transmission through the novel prostacyclin receptor. The widespread expression of the prostacyclin receptor in the central nervous system suggests that prostacyclin has important roles in neuronal activity.

In vitro positron emission tomography (PET): use of positron emission tracers in functional imaging in living brain slices

Positron-emitting radionuclides have short half-lives and high radiation energies compared with radioisotopes generally used in biomedical research. We examined the possibility of applying positron emitter-labeled compounds to functional imaging in brain slices kept viable in an oxygenated buffer solution. Brain slices (300 microns thick) containing the striatum were incubated with positron emitter-labeled tracers for 30-45 min. The slices were then rinsed and placed on the bottom of a Plexiglas chamber filled with oxygenated Krebs-Ringer solution. The bottom of the chamber consisted of a thin polypropylene film to allow good penetration of beta+ particles from the brain slices. The chamber was placed on a storage phosphor screen, which has a higher sensitivity and a wider dynamic range than X-ray films. After an exposure period of 15-60 min, the screen was scanned by the analyzer and radioactivity images of brain slices were obtained within 20 min. We succeeded in obtaining quantitative images of (1) [18F]fluorodeoxyglucose uptake, (2) dopamine D2 receptor binding, (3) dopa-decarboxylase activity, and (4) release of [11C]dopamine preloaded as L-[11C]DOPA in the brain slice preparation. These results demonstrate that positron emitter-labeled tracers in combination with storage phosphor screens are useful for functional imaging of living brain slices as a novel neuroscience technique.

Age-related attenuation of HSP47 heat response in fibroblasts

The collagen-binding heat shock protein of molecular weight 47,000 (HSP47), resident in the endoplasmic reticulum (ER), is assumed to play a specific role as a molecular chaperon in the processing of procollagen molecules. The present investigation of age-related alteration in the HSP47 heat response in cultured murine and human fibroblasts revealed expression in cells with a low population doubling level (PDL) derived from young mice and people more inducible by heat treatment than those from older mice and people. On the other hand, cells with a high PDL showed a very low heat response in terms of HSP47 expression regardless of the donor age. Northern blot analysis of HSP47 m-RNA indicated that the age related attenuation of HSP47 expression was regulated by transcriptional mechanisms. Furthermore, immunofluorescent analysis using a monoclonal antibody against the carboxylterminal propeptide of type I procollagen revealed far greater retention of procollagen molecules in the ER lumen of cells from old persons than in those from young persons. This was particularly prominent in heat-treated cells from old persons, indicating the possibility that the observed decrease in HSP47 heat response might cause blockage of procollagen transport to the Golgi and therefore secretion.

Brain activation study by use of positron emission tomography in unanesthetized monkeys

A system for the measurement of brain activity in conscious monkeys by positron emission tomography (PET) was established in the present study. The signal/noise ratio was maximal around 40 s for data acquisition in the PET scan with 15O-labeled water. When the monkey was stimulated by vibration and subtraction images of the data sets from regional cerebral blood flow (rCBF) changes in paired stimulation and control were superimposed on magnetic resonance images obtained from the same specimens, a somatotopic map corresponding to the sites stimulated was clearly demonstrated. Visual stimulation with a photic stimulator activated the corresponding regions of the primary visual cortex. Comparison of the activated sites and extents under the conscious state with those under anesthesia assured that the study is controllable; there was little unpredictable activation due to unlimited subject movement or to psychological effects.

Differential induction of mRNA species encoding several classes of stress proteins following focal cerebral ischemia in rats

We report here the time-dependent expression of several classes of HSP mRNAs following focal cerebral ischemia in rats. HSP70, GRP78, HSP27, HSP90 and HSP47 have been reported to possess distinct functions under normal and/or stress conditions. These different classes of HSP mRNAs were differentially induced by ischemia, as determined by Northern blot analysis. Messenger RNAs of the HSP70 family proteins were induced within 4 h after ischemia and then rapidly decreased, whereas HSP27 and HSP47 mRNAs reached a maximum level of expression at 24 h and 48 h after ischemic treatment, respectively. In situ hybridization showed that the expression of inducible HSP70 mRNA was observed predominantly in regions adjacent to the ischemic core except during the early periods of ischemia. HSP27 mRNA was expressed over a broad area of the ipsilateral cerebral neocortex except for the ischemic center 24 h after ischemia. The unique induction kinetics for each HSP mRNA species may reflect their distinct roles in the brain during various physiological stresses. We will also discuss that stress proteins may be involved in the central nervous system after ischemia in two important aspects: early protection against stress and restoration of damaged lesions in the brain at later stages after ischemia.

Alternative 5' splice site selection induced by heat shock

The mouse HSP47 gene consists of six exons separated by five introns. Three HSP47 cDNAs differing only in their 5' noncoding regions have been reported. One of these alternatively spliced mRNAs was detected only after heat shock, which caused an alternative 5' splice donor site selection. Other stress inducers, including an amino acid analog and sodium arsenite, had no effect on the alternative splicing. The alternatively spliced mRNA, which was 169 nucleotides longer in the 5' noncoding region compared to mRNA transcribed in non-heat shock conditions, was efficiently translated under heat shock conditions. This novel finding that alternative splicing is caused by artificial treatment like heat shock will provide a useful in vivo model for understanding the exon-intron recognition mechanism as well as heat shock-induced alterations in gene expression.

Stump problems in traumatic amputation

Stump problems in amputations resulting from employment related injuries were investigated in 397 cases in the Chugoku and Shikoku districts of Japan between 1987 and 1991. Ninety-seven patients (24%) had stump problems which interfered the prosthetic fitting. Stump problems of the upper extremity were seen in about 9% (17 amputees), two thirds of which were skin troubles. Stump problems of the lower extremity were seen in about 37% (80 amputees). Certain complaints were associated with specific methods of amputation; abnormal keratosis in Syme's amputation, equinus deformity in Chopart's amputation, reduced muscle power in above the knee (A/K) amputation and joint dysfunction in below the knee (B/K) amputation. Adequate prosthetic fitting was achieved by the modification of the socket and alignment in almost all amputees with stump problems. In only two cases, Chopart's amputation required subsequent Syme's amputation due to equinus deformity with abnormal keratosis. In almost every case, stump problems are avoidable by means of surgeons' deliberate evaluation of the affected limb and adequate choice of the amputation level.

Spinal cord injuries in Okayama Prefecture: an epidemiological study '88-'89

An epidemiological survey of spinal cord injury in Okayama Prefecture was carried out by reviewing the registration lists contained in the Law for the Welfare of the Physically Disabled. The authors computed the annual incidence of spinal cord injuries (SCI) in Okayama Prefecture (April 1988-March 1989) to be 49.0 (28.6 for traumatic cases) per one million inhabitants from a population of 1,920,000. In addition, distribution by age, aetiology, paralysis level and residential area were investigated.

Structure of the gene encoding the mouse 47-kDa heat-shock protein (HSP47)

HSP47, a 47-kDa heat-shock protein (HSP), is a member of a group of HSPs with the unique characteristics of collagen binding as well as transformation sensitivity. The protein belongs to the serpin (serine protease inhibitor) superfamily as determined from its amino acid sequence homology. We have isolated and characterized the mouse HSP47 including about 1 kb of the 5'-flanking region. This gene spans about 7.8 kb, consisting of six exons separated by five introns. This exon-intron structure is different from other serpin family proteins. Southern blot analysis revealed the existence of a single copy of HSP47. The promoter region contains a TATA box, four Sp1-binding sites and one AP-1-binding site. A complete heat-shock element (HSE) was found between nucleotides (nt) -61 and -79. Furthermore, the heat inducibility was reproduced by transfecting mouse BALB/3T3 cells with a plasmid carrying cat under the control of the HSE-containing fragment (nt -197 and +38) of HSP47. Computer analysis of the promoter region did not show marked homology to other vertebrate promoters.

Incidence and prognosis of dysvascular amputations in Okayama Prefecture (Japan)

This survey analysed the clinical characteristics of subjects who first underwent major amputation of lower limbs necessitated by dysvascular disease during the 5 year period from 1984 to 1988. All were residents of Okayama Prefecture, Japan, and have been issued with a Physically Disabled Person's Certificate. In total, 114 dysvascular amputees, representing 58.2% of all lower limb amputations performed in the resident population during the study period, were surveyed. The underlying diagnosis was arteriosclerotic obstruction in 64.9% of the subjects, diabetic gangrene in 22.8%, acute embolism in 7.0% and Buerger's disease in 5.3%. The yearly incidence of new dysvascular amputees per 100,000 people was estimated to be 1.2 among the general population and 5.7 among those aged over 65 years. At three years after primary amputation, the survival rate was 52.3% in arteriosclerotic obstruction, and 66.7% in diabetic gangrene. Secondary amputation was performed in 17.0% of the entire group. The concurrent incidence of hemiplegic stroke was 19.8%. Among 36 amputees due to arteriosclerotic obstruction, who survived 3 years postoperatively, 10 (27.8%) were fitted with prosthetic limbs.