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A Iwasaki

Publications and source records attributed to A Iwasaki.

At least 37 records · Page 2Linked to original sources
PubMed2005

Penetration to the aortic wall by a metallic airway stent. A successfully treated case with left pneumonectomy and aortic repair.

Metallic airway stents were used widely at the beginning of airway stent use, but an accumulation of cases has revealed complications due to their use. A patient who received a Gianturco Z stent for bronchial tuberculosis suffered massive haemoptysis due to stent migration into the aortic wall. Left pneumonectomy with aortic repair was successfully performed. We suggest that metallic stents should not be used for benign airway palliation, as they may later cause life-threatening complications.

Adult↗
PubMed2004

Randomized placebo-controlled trial assessing the effect of bifidobacteria-fermented milk on active ulcerative colitis.

BACKGROUND: Probiotics are efficacious for treating and maintaining remission of ulcerative colitis. AIM: To conduct a randomized placebo-controlled trial of bifidobacteria-fermented milk supplementation as a dietary adjunct in treating active ulcerative colitis. METHODS: Twenty patients with mild to moderate, active, ulcerative colitis randomly received 100 mL/day of bifidobacteria-fermented milk or placebo for 12 weeks with conventional treatment. RESULTS: Clinical and endoscopic activity indices and histological scores were similar in the two groups before treatment. Although improvements were significant in both groups, the clinical activity index was significantly lower in the bifidobacteria-fermented milk than in the placebo group after treatment. The post-treatment endoscopic activity index and histological score were significantly reduced in the bifidobacteria-fermented milk, but not the placebo group. Increases in faecal butyrate, propionate and short-chain fatty acid concentrations were significant in the bifidobacteria-fermented milk, but not the placebo group. No adverse effects were observed in either group. CONCLUSION: Supplementation with this bifidobacteria-fermented milk product is safe and more effective than conventional treatment alone, suggesting possible beneficial effects in managing active ulcerative colitis. This is a pilot study and further larger studies are required to confirm the result these preliminary results.

Adult↗
PubMed2004

Video-assisted thoracoscopic surgery (VATS) segmentectomy for small peripheral lung cancer tumors: intermediate results.

BACKGROUND: We investigated the feasibility and suitability of video-assisted thoracoscopic surgery (VATS) segmentectomy for curing selected non-small cell lung cancer (NSCLC) with this less invasive technique. METHODS: We performed VATS segmentectomy for small (< 20 mm) peripherally located tumors and pathologically confirmed lobar lymph node-negative disease by frozen-section examination during surgery. Of the 34 patients who underwent this limited resection, 22 were treated with complete hilar and mediastinal lymph node dissection (intentional group), whereas 12 patients who were deemed to be high risk in their toleration for lobectomy underwent VATS segmentectomy with incomplete hilar and mediastinal lymph node dissection (compromised group). The surgical and clinical parameters were evaluated and compared with those of segmentectomy under standard thoracotomy to evaluate the technical feasibility of VATS segmentectomy. RESULTS: We found that VATS segmentectomy could be performed safely with a nil mortality rate and acceptably low morbidity. The mean period of observation was relatively short at 656.7 +/- 572.1 and 783.4 +/- 535.8 days in the intentional and compromised groups, respectively. At the time of writing, all intentional patients remain alive and free of recurrence. There were two cases of non-cancer-related death in the compromised group. Clinical data indicated that VATS segmentectomy caused the same number or fewer surgical insults compared with segmentectomy under standard thoracotomy. CONCLUSIONS: The present results are intermediate only; the rate of long-term survival and the advantages of the less invasive procedure still need further investigation. Nevertheless, we believe that VATS segmentectomy with complete lymph node dissection is a reasonable treatment option for selected patients with small peripheral NSCLC.

Aged↗
PubMed2004

Biosorbable poly-L-lactide rib-connecting pins may reduce acute pain after thoracotomy.

OBJECTIVE: Conventional thoracotomy is currently used as a standard procedure, and is often required to treat numerous diseases. Additionally, rib resections are occasionally required to maintain an adequate field of view for surgery. The benefits of using rib pins for chest closure following such procedures have not yet been established. This study sought to evaluate the usefulness of rib pins in reducing acute postoperative pain. METHODS: Thirty-three consecutive patients with lung cancer underwent lobectomies using the posterolateral approach. The patients were rib-resected and reconstructed with two techniques: 21 patients with absorbable rib pins (ARP group) and 12 patients by ligation with absorbable sutures (LAS group). Intensity of pain was assessed during the 3 days immediately following surgery. The two groups were assessed using the visual analogue scale (VAS) as a pain scale, amounts consumed of patient-controlled analgesics (PCA), and additional chest x-rays. RESULTS: On the first day following surgery, the mean VAS intensity of the ARP group for patient motion was 2.71 +/- 2.14, compared to 5.33 +/- 2.99 in the LAS group. After three days, the mean score for the ARP group was 1.98 +/- 1.89, compared to 4.60 +/- 1.97 in the LAS group. Scores in the ARP group were significantly lower than in the LAS group one day and three days following thoracotomy. The LAS group (55.0 +/- 15.9 times) made more frequent requests than the ARP group (16.1 +/- 10.3 times). The PCA requirement was also significantly lower in the ARP group. Excessive derangement of the rib (grade 2) was found in one case (4.7 %) in the ARP group compared to five cases (41.6 %) in the LAS group. Rib shifts were seen in numerous cases in the LAS group compared to the ARP group as measured by chest x-rays. CONCLUSIONS: Use of absorbable rib pins reduced postoperative pain and may improve long-term prospects for the post-thoracotomy course.

Acute Disease↗
PubMed2004

Mediastinal solitary fibrous tumor: report of a case with direct invasion to the trachea.

The solitary fibrous tumors in the pleura are a rare entity that is usually adhesive and sometimes invasive. Because of its benign feature, complete surgical resection is generally considered. We describe a very rare case of mediastinal solitary fibrous tumor arised or invaded into the tracheal wall, which was surgically resected with combined cylindrical resection of the trachea.

Adult↗
PubMed2004

Results of surgical treatment for non-small cell lung cancer of 20 mm or less in diameter.

BACKGROUND: Surgical efficacy is still unsatisfactory for small lung cancer; accordingly, minimal resection has recently been the focus of increased study. The objective of the current study was to evaluate the factors associated with small lung cancer, and to determine whether such factors are reliable predictors of long-term survival. METHODS: We retrospectively investigated 130 patients with histologically confirmed non-small cell carcinoma, whose treatments were primarily surgical, with no chemotherapy or radiotherapy prior to surgery. All tumors were located peripherally and were less than 20 mm in diameter. Follow-up was performed for five-year and eight-year survivors and multivariate analysis with Cox's proportional hazards regression model was performed. RESULTS: Of all 130 patients, the 5-year survival rate among patients with tumors less than 15 mm was 82.5 %, vs. 57.4 % of patients with tumors with a diameter of 16 - 20 mm. The 5-year survival rate of patients who were node negative was 73.9 % while it was 28.5 % for node-positive patients. Status of nodal invasion was also significantly associated with survival in small-size tumors ( p < 0.0001). Furthermore, the 5-year survival rate among patients with pleural involvement was 55 % vs. 83.8 % for patients without pleural involvement. Using multivariate Cox analysis, lymph node involvement ( p = 0.0004), size ( p = 0.0475), and pleural invasion ( p = 0.0482) were found to be independent prognostic factors in cases of tumors 20 mm or less in diameter. CONCLUSIONS: The results of this study at least demonstrate that the optimal therapy for patients with nodal involvement or patients with tumors of 16 - 20 mm must be carefully determined even in cases of small lung cancer.

Aged↗
PubMed2003

Video-assisted thoracic needle aspiration cytology for malignancy of the peripheral lung.

BACKGROUND: The technique of video-assisted thoracic fine-needle aspiration cytology (VAT-FNA) to the lung has been described in very few publications, and its diagnostic role has not been evaluated so far. Thus current studies focus on whether the diagnostic role could be applied usefully to VAT-FNA of peripheral lung lesions. METHODS: Between January 1995 and January 2000, a total of one hundred and twenty-eight cases of VAT-FNA on lung tumors were reviewed retrospectively. The superficial lung was visualized a part of directly or indirectly by scope and a 22-gauge needle inserted for FNA. Material was expressed onto glass slides, and smears were stained by our modified quick-stain method. The cytological diagnoses based on VAT-FNA were reviewed and compared with the final histopathological diagnoses. RESULTS: The cytological diagnosis was true positive in 100 cases (93.5% sensitivity), whereas the true negative result in 20 cases was 95.2% specificity. The false-positive rate was 4.8%, and false-negative results were 6.5%. The accordance in all malignant cases between cytology and histology was 73.8%. VAT-FNA caused no difficulties in any of the cases. CONCLUSION: The application of VAT-FNA to the peripheral lung lesion is not only useful, cost-beneficial, safe and minimally invasive but also accurate. Especially, this method may play an important role in cases of suspected malignancy in peripheral cases.

Adult↗
PubMed2003

Evaluation of lung volume reduction surgery (LVRS) based on long-term survival rate analysis.

OBJECTIVE: Lung volume reduction surgery (LVRS) is an effective therapy for some patients with end-stage emphysema. In most cases, functional improvement is maximized during the first 6 months after surgery and decreases steadily afterwards. This study was aimed at gaining further understanding of the optimal candidates for LVRS and survival rates. METHODS: 62 patients with LVRS were selected according to the inclusion criteria. Changes in lung function were evaluated by FEV1, VC, RV, TLC, DLCO, PaO2, and PaCO2, and survival rates were analyzed at 12, 24, 36, and 48 months. Patients with LVRS were divided into two groups--those surviving after 48 months and those not surviving after 48 months--and analyzed according to group. RESULTS: The overall survival rate at 2 years and 4 years was 81.0 % and 67 %, respectively, with LVRS. VC, FEV1, TLC, DLCO, PaO2, and PaCO2 were potential factors leading to mortality according to univariate analysis. Multivariate analysis demonstrated that DLCO was the only independent factor that could predict the post-LVRS prognosis; the other factors failed as independent factors. Preoperatively, the FEV1 percentage predicted gave a good index for post-LVRS survival. CONCLUSIONS: Patients with higher preoperative FEV1 values had higher survival rates. These favorable long-term survival rates might justify LVRS for treating selected patients with severe emphysema. Additionally, DLCO turned out to be the only predictive factor for high mortality risk 4 years after LVRS. DLCO may thus be a very important marker in surgical planning.

Aged↗
PubMed2002

Third-harmonic generation and self-channeling in air using high-power femtosecond laser pulses.

It is shown, both theoretically and experimentally, that during laser pulse filamentation in air an intense ultrashort third-harmonic pulse is generated forming a two-colored filament. The third-harmonic pulse maintains both its peak intensity and energy over distances much longer than the characteristic coherence length. We argue that this is due to a nonlinear phase-locking mechanism between the two pulses in the filament and is independent of the initial material wave-vector mismatch. A rich spatiotemporal propagation dynamics of the third-harmonic pulse is predicted. Potential applications of this phenomenon to other parametric processes are discussed.

Journal Article↗
PubMed2002

Circadian rhythm of melatonin and prostaglandin in modulation of stress-induced gastric mucosal lesions in rats.

BACKGROUND: We previously demonstrated the circadian variation of water-immersion restraint stress (WRS)-induced gastric mucosal lesions in rats. AIM: To investigate the roles of melatonin and prostaglandin in the gastric mucosa in circadian modulation of WRS. METHODS: Fasted rats were subjected to 4-h WRS during both the diurnal and nocturnal phases of a light/dark cycle. Mucosal lesions, serum melatonin concentrations, mucosal generation of prostaglandin E2 (PGE2) and mucosal gene expressions of cyclooxygenase (COX)-1 and -2 were evaluated. RESULTS: Lesion area after 4-h stress during the dark phase was significantly smaller than that in light-phase controls. Serum melatonin concentration in control rats during the light phase was significantly increased 4 h after WRS, but PGE2 generation was decreased by 48% as compared to that in intact mucosa before stress. In the dark phase, melatonin concentration after 4-h WRS was significantly depressed as compared with the control level at the corresponding time. PGE2 concentrations after 4-h WRS in the dark phase were not decreased compared with the control level at the corresponding time, although PGE2 level was significantly lower than that in light-phase controls. Expression of COX-1 and COX-2 mRNA was detected after exposure to stress in both the light and dark phases. CONCLUSION: These results suggest that circadian rhythm has an important role in the formation of stress-induced gastric mucosal lesions in rats. The circadian rhythm of melatonin responses and PGE2 generation may contribute to nocturnal/diurnal rhythmicity of gastric mucosal defences between day and night.

Animals↗
PubMed2002

Comparison of 201 Tl- with 67 Ga single photon emission tomography in the diagnosis of head and neck cancer recurrence.

The purpose of this study was to evaluate the usefulness of 201Tl single photon emission tomography (SPET) in comparison with 67Ga SPET for distinguishing recurrent tumours in patients previously treated for head and neck cancer. A total of 37 patients with suspicion of recurrent cancer were investigated. SPET images with 201Tl were acquired 10min (early) and 3h (delayed) and SPET images with 67Ga were acquired 72h, after injection. The visual and semiquantitative (T/N ratio) analysis were performed. On visual analysis, results from early 201Tl SPET were the same as those from delayed 201Tl SPET. The sensitivity, specificity and accuracy of the diagnosis of local recurrence using 201Tl SPET were all 100%. The three values using 201Tl SPET for neck lymph node metastases were 73%, 100% and 91%. The corresponding values using 67Ga SPET for local recurrence were 57%, 100% and 89%, respectively, and those using 67Ga SPET for neck lymph node metastases 55%, 100% and 84%, respectively. In the semiquantitative analysis, there was a statistically higher T/N ratio obtained using 201Tl when compared with 67Ga. 201Tl early SPET, especially, has the potential to replace 67Ga SPET in the follow-up of patients with head and neck cancer.

Adult↗
PubMed2001

Neutralization of interleukin-1beta in the acute phase of myocardial infarction promotes the progression of left ventricular remodeling.

OBJECTIVES: We sought to examine the role of the pro-inflammatory cytokine, interleukin-1-beta (IL-1beta), in the process of left ventricular (LV) remodeling in the early phase after myocardial infarction (MI). BACKGROUND: Studies have shown that pro-inflammatory cytokines are closely related to the progression of LV remodeling after MI. METHODS: Mice underwent coronary artery ligation, and the time course of LV remodeling was followed up to 20 weeks. The gene expression level of IL-1beta was examined. In a second set of experiments, the mice underwent coronary artery ligation followed by treatment with anti-IL-1beta antibody (100 microg, intravenously), versus control immunoglobulin G (100 microg, intravenously) immediately after the operation. RESULTS: Rapid hypertrophy of noninfarcted myocardium was observed by four weeks, and interstitial fibrosis progressed steadily up to 20 weeks. Anti-IL-1beta treatment increased the occurrence of ventricular rupture and suppressed collagen accumulation in the infarct-related area. At four and eight weeks after the operation, total heart weight and LV end-diastolic dimension were significantly greater in the anti-IL-1beta-treated mice than in the other groups. In the infarct-related area, collagen accumulation was suppressed, whereas in the noninfarcted area, pro-collagen gene expression levels, particularly type III, were decreased in the anti-IL-1beta-treated mice. CONCLUSIONS: Anti-IL-1beta treatment suppressed pro-collagen gene expression and delayed wound healing mechanisms-properties that are likely to lead to progression of LV remodeling. In the acute phase of MI, IL-1beta appears to play a protective role.

Acute Disease↗
PubMed2001

Unique functions of CD11b+, CD8 alpha+, and double-negative Peyer's patch dendritic cells.

We have recently demonstrated the presence of three populations of dendritic cells (DC) in the murine Peyer's patch. CD11b(+)/CD8alpha(-) (myeloid) DCs are localized in the subepithelial dome, CD11b(-)/CD8alpha(+) (lymphoid) DCs in the interfollicular regions, and CD11b(-)/CD8alpha(-) (double-negative; DN) DCs at both sites. We now describe the presence of a novel population of intraepithelial DN DCs within the follicle-associated epithelium and demonstrate a predominance of DN DCs only in mucosal lymphoid tissues. Furthermore, we demonstrate that all DC subpopulations maintain their surface phenotype upon maturation in vitro, and secrete a distinct pattern of cytokines upon exposure to T cell and microbial stimuli. Only myeloid DCs from the PP produce high levels of IL-10 upon stimulation with soluble CD40 ligand(-) trimer, or Staphylococcus aureus and IFN-gamma. In contrast, lymphoid and DN, but not myeloid DCs, produce IL-12p70 following microbial stimulation, whereas no DC subset produces IL-12p70 in response to CD40 ligand trimer. Finally, we show that myeloid DCs from the PP are particularly capable of priming naive T cells to secrete high levels of IL-4 and IL-10, when compared with those from nonmucosal sites, while lymphoid and DN DCs from all tissues prime for IFN-gamma production. These findings thus suggest that DC subsets within mucosal tissues have unique immune inductive capacities.

Animals↗
PubMed2001

Melatonin's gastroprotective and antistress roles involve both central and peripheral effects.

Systemic administration of melatonin (5 to 20 mg/kg) has been reported to inhibit the induction of acute gastric mucosal lesions by stress or ischemia-reperfusion in rats. We recently demonstrated that intracisternal (i.c.) melatonin at low doses (1 to 100 ng) dose-dependently decreased acid and pepsin outputs in rats. The aim of the present study was to further investigate the peripheral and central roles of melatonin in gastric mucosal defense. Using a radioimmunoassay, we measured melatonin concentrations in the plasma and cerebrospinal fluid (CSF) of the cisterna magna in rats subjected to water immersion restraint stress and given intraperitoneal (i.p.) or i.c. injection of melatonin. Water immersion restraint stress was followed by a significant duration-related increase in peripheral plasma melatonin levels; the stress similarly produced a time-dependent increase in the extent of gastric mucosal lesions. Administration of melatonin (1 or 10 mg/kg, i.p., or 100 ng/10 microl, i.c.) significantly reduced the extent of stress-induced gastric damage, by 46%, 67%, and 54%, respectively. The effective i.c. dose of melatonin was at least 10,000-fold smaller than the effective i.p. dose. Melatonin levels in plasma and CSF after the i.p. injection of melatonin at 10 mg/kg were dramatically higher than those after the i.c. injection of vehicle or 100 ng of melatonin. Our results suggest that the peripheral gastroprotective action of melatonin should be investigated with due regard to these central effects.

Animals↗
PubMed2001

Roles of nocturnal melatonin and the pineal gland in modulation of water-immersion restraint stress-induced gastric mucosal lesions in rats.

The roles of melatonin and the pineal gland in the circadian variation of water-immersion restraint stress-induced gastric mucosal lesions in rats were investigated. Fasted rats were subjected to water-immersion restraint stress during both the diurnal and nocturnal phases of a light:dark cycle. Pinealectomized and sham-operated rats were also subjected to water-immersion restraint stress at night. The lesion area after 4 hr of stress during the dark phase was significantly lower than in light-phase controls. Pinealectomy increased the lesion area in the dark phase, compared to the sham operation, but this effect was counteracted by intracisternal melatonin preadministration at a dose of 100 ng/rat. Melatonin concentrations in control rats during the light phase were significantly increased 4 hr after water-immersion restraint stress. In contrast, melatonin concentrations 4 hr after water-immersion restraint stress in the dark phase were significantly depressed compared with the control levels at the corresponding time. Melatonin levels after stress exposure were markedly decreased in pinealectomized rats as compared with sham-operated rats. These results suggest that circadian rhythm has an important role in the formation of stress-induced gastric mucosal lesions in rats and that melatonin responses to water-immersion restraint stress differ between day and night. The pineal gland modulates the stress response and melatonin contributes to gastric protection via a mechanism involving the central nervous system.

Animals↗
PubMed2001

Glutathione S-transferase mu1 null genotype is associated with K-ras gene mutation in lung adenocarcinoma among smokers.

Glutathione S-transferase mu1 (GSTM1) plays a role in the detoxification of benzo[a]pyrene (BP) diol epoxide in tobacco smoke. Individuals who genetically lack the GSTM1 gene are likely to have an increased risk of smoking-related lung cancers, however, the target oncogenes for mutation are unknown. To investigate the relation between GSTM1 genotype and K-ras gene mutation we examined 193 adenocarcinomas and 119 squamous cell carcinomas of lung. The GSTM1 genotype was determined by PCR and K-ras gene mutations at codons 12 and 13 were detected by dot-blot hybridization analysis using sequence-specific oligonucleotide probes. K-ras gene mutations were found in 29 of 312 (9.3%) tumors. All of them arose in patients who were habitual smokers. Mutations of the K-ras gene were detected in 6 of 100 (6%) and 15 of 93 (16.1%) adenocarcinoma cases with the GSTM1(+) and GSTM1(-) genotypes, respectively, and the difference was statistically significant. These findings suggest that the cause of K-ras gene mutation in smokers with lung adenocarcinoma may be in part an accumulation of BP diol epoxide which is not well detoxified in individuals with the GSTM1 null genotype.

Adenocarcinoma↗
PubMed2001

[A case of heparin-induced thrombocytopenia after transurethral resection of prostate during anticoagulant therapy].

A 66-year-old man had been receiving anticoagulant therapy for myocardial infarction with warfarin potassium (abbreviated as warfarin) 2 mg/day. Though he had been treated with tamsulosin hydrochloride 0.2 mg/day as diagnosis of benign prostatic hyperplasia, he experienced severe dysuria and wanted to undergo transurethral resection of the prostate. We decided to continue anticoagulant therapy because cardiologist judged that intermission of anticoagulant therapy could cause myocardial infarction. Warfarin 2 mg/day p.o. was replaced with heparin sodium (abbreviated as heparin) 5000 u x 2/day s.c. 6 days prior to surgery, and anticoagulant therapy was stopped on the day of surgery, but resumed on the following day. Purpura appeared around the extremities 18 days after the surgery. Although coagulation testing was normal, platelet counts had markedly been reduced (2,000/mm3). Platelet counts recovered to a level of 228,000/mm3 13 days after cessation of heparin. No other adverse effects were observed. Heparin-induced thrombocytopenia (abbreviated as HIT) was diagnosed clinically. We consider monitoring of platelets to be necessary because an increasing number of patients are on anticoagulant therapy in Japan, and accordingly, the use of heparin is likely to be increased.

Aged↗