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Yoshie Iwasaki

Publications and source records attributed to Yoshie Iwasaki.

13 recordsLinked to original sources
PubMed2006

Intradiploic epidermoid cyst with focal internal enhancement.

We report a case of intradiploic epidermoid cyst with focal internal enhancement. The patient was a 55-year-old woman presenting with right temporal head protrusion and head heaviness. Skull radiography and computed tomography demonstrated an expansile mass in the right diploic space. On magnetic resonance imaging, the mass showed makedly high signal T2-weighted images (T2WI) and intermediate to low signal on T1WI. On contrast-enhanced T1WI, there was nodular internal enhancement, which corresponded to neovascularity on pathology, as well as rim-like enhancement. It should be noted that internal enhancement, an indicator of malignant transformation, may be seen even in a benign epidermoid cyst.

Epidermal Cyst↗
PubMed2006

Pulmonary spread of laryngeal papillomatosis: radiological findings.

Laryngeal papillomatosis is a rare benign disease seen in children and young adults. The spread of laryngeal papillomas throughout the respiratory tract occurs rarely; and involvement of the distal bronchi, bronchioles, and lung parenchyma is very rare. We report a case of pulmonary spread of laryngeal papillomatosis in a 34-year-old man, focusing on the radiological evidence. Chest radiographs showed pulmonary nodules, but computed tomography scans more clearly demonstrated multiple small nodules showing cavitations and distributed centrilobularly. Pulmonary nodules and cavitations progressed gradually through the 6-year follow-up. The combination of clinical and characteristic radiological features suggests a diagnosis of pulmonary spread of laryngeal papillomatosis.

Adult↗
PubMed2005

Small left atrium: an adjunctive sign of hemodynamically compromised massive pulmonary embolism.

Pulmonary embolism (PE) is a common disease with a high mortality rate due to right ventricular dysfunction and underfilling of the left ventricle. We present a case of a 33-year-old man with hemodynamically compromised massive PE. His left atrium was collapsed with marked dilatation of the right atrium and ventricle on multi-detector-row CT scans. The patient was treated with an intracatheter injection of a mutant tissue-type plasminogen activator and subsequently showed clinical and radiological improvements. The small left atrial size in combination with a right ventricular pressure overload was considered to be an adjunctive sign of hemodynamically compromised massive PE.

Adult↗
PubMed2005

Should mediastinoscopy actually be incorporated into the FDG PET strategy for patients with non-small cell lung carcinoma?

BACKGROUND: Incorporating mediastinoscopy (MS) into the PET-based strategy for non-small cell lung carcinoma (NSCLC) patients might be cost-effective because MS can allow unnecessary thoracotomies to be avoided. The objective of our study was to assess the cost-effectiveness of incorporating MS into a PET strategy for NSCLC patients. METHODS: To determine life expectancy (LE), quality adjusted life years (QALY), and the incremental cost-effectiveness ratio (ICER), a decision-tree sensitivity analysis was designed for histopathologically confirmed NSCLC patients with M0 disease, based on the three competing strategies of chest CT only vs. PET + CT vs. PET + CT + MS. A simulation of 1000 NSCLC patients was created using baselines of other relevant variables in regard to sensitivity, specificity, mortality, LE, utilities and cost from published data. One-way sensitivity analyses were performed to determine the influences of mediastinal metastasis prevalence on LE, QALY and ICER. RESULTS: The LE and QALY per patient in the CT only strategy, PET + CT strategy and PET + CT + MS strategy were 4.79 and 4.35, 5.33 and 4.93 and 5.68 and 5.33 years, respectively, with a 20% prevalence of mediastinal metastasis. The ICERs were 906.6 yen x 10(3) (7555 US dollars)/QALY/patient at a 20% mediastinal metastasis prevalence, and 2194 yen x 10(3) (18,282 US dollars)/QALY/patient at a 50% prevalence, but exceeded 5280 yen x 10(3) (44,000 US dollars)/QALY/ patient at 80%. CONCLUSIONS: Our study quantitatively showed the CT + PET + MS strategy in place of the PET + CT strategy in managing NSCLC patients to be cost-effective. MS should be incorporated into the PET + CT strategy for NSCLC patients except in those highly suspected of having mediastinal disease on chest CT or PET.

Carcinoma, Non-Small-Cell Lung↗
PubMed2004

Dietary sodium gluconate protects rats from large bowel cancer by stimulating butyrate production.

Butyrate has an antitumorigenic effect on colorectal cancer cell lines. Dietary sodium gluconate (GNA) promotes butyrate production in the large intestine. Accordingly, we examined the effect of dietary GNA on tumorigenesis in the large intestine in rats. Male Fisher-344 rats (n = 32) were divided into 4 groups: 2 diets (with or without 50 g GNA/kg basal diet) x 2 treatments (with or without carcinogen administration). Colonic tumors were induced by 3 intraperitoneal injections of azoxymethane (15 mg/kg body wt, 1 time/wk) and dietary deoxycholic acid (2 g/kg basal diet). The experiment was conducted for 33 wk except for a few rats. Ingestion of GNA increased cecal butyrate concentration at the end of experiment (P < 0.01). No tumor development occurred in the untreated groups. Ingestion of GNA decreased the incidence of tumors in rats administered the carcinogen (37.5 vs. 100%, P < 0.05). Ingestion of GNA also decreased the mean number of tumors per rat (0.5 +/- 0.8 vs. 2.8 +/- 1.5, P < 0.01). beta-Catenin accumulation and TdT-mediated dUTP nick end labeling (TUNEL) positive cells in tumors were histochemically examined. The results of this study suggested that the antitumorigenic effect of GNA may involve the stimulation of apoptosis through enhanced butyrate production in the large intestine.

Adenocarcinoma↗
PubMed2003

Microscopic structure of the large intestinal mucosa in piglets during an antibiotic-associated diarrhea.

Antibiotic-associated diarrhea (AAD) is caused by the treatments of broad-spectrum antimicrobials that seriously affect the activity and composition of the large intestinal microflora. The pathogenic bacteria or low concentration of short-chain fatty acids (SCFAs) has been repeatedly discussed in relation to AAD. Recently, we reported the detection of a large amount of succinate and lactate in the diarrheal feces in AAD-induced piglets. In this study, we investigated histologically the large intestinal mucosa in AAD-induced piglets, in which succinate and lactate were accumulated. AAD was induced in the piglets by an oral dose of polymyxin B sulfate (PL) or by an intra-muscular injection of enrofloxacin (ERFX). When the piglets were defecating diarrheal feces with a high concentration of succinate and/or lactate, the large intestine was removed and separated into four segments (cecum, gyri centripetales, gyri centrifugales, and rectum). Healthy piglets were used as the control. In the AAD-induced piglets, the lamina propria was edematous in the gyri centripetales. Piglets treated with ERFX were also edematous in gyri centrifugales. These edematous lamina propria contained larger amounts of inflammatory cells than observed in control tissues. ERFX-treated piglets had a more shallow crypt than PL-treated and control piglets. The mucosal tissue of the large intestine was more seriously damaged in the ERFX- than in the PL-treated piglets, which might have been caused by the high succinate and low SCFAs concentration in the digesta.

Animals↗
PubMed2003

Stimulation of butyrate production in the large intestine of weaning piglets by dietary fructooligosaccharides and its influence on the histological variables of the large intestinal mucosa.

Fructooligosaccharides (FOS) reach the large intestine and are fermented into short-chain fatty acids (SCFA), lactate, and carbon dioxide. As the major energy source for the epithelial cells of the large intestine, n-butyrate stimulates the proliferation of cells as well as mineral and water absorption from the lumen. We examined the effect of dietary FOS supplementation on luminal SCFA production and its influence on the morphometrical variables of mucosa of the large intestine in commercially available pigs. Six weaning piglets were used. After 7 d of adaptation, three pigs were given a test diet containing FOS (10%) ad libitum for 10 d. The other three remained on the basal diet and were used as controls. At the end of the experiment, their large intestines were removed, and the cecum, gyri centripetales, gyri centrifugales, and rectum were separated. The contents of each portion were collected and measured for SCFA concentration, pH, and moisture. A micrometer was used to measure the crypt depth. The numbers of epithelial and mitotic cells in the crypt columns were also counted. The concentration of SCFA was significantly higher in piglets fed FOS than in the controls. The concentration of n-butyrate was markedly stimulated by FOS. The number of epithelial. mitotic, and mucin-containing cells was higher in piglets fed FOS than in the controls. Accordingly, the crypt depth was larger in the FOS-fed piglets. The luminal n-butyrate concentration showed a significantly positive correlation with the crypt depth and the number of epithelial, mitotic, and mucin-containing cells.

Animals↗
PubMed2002

Coil compaction after embolization of the superior mesenteric artery pseudoaneurysm.

A 58-year-old man with an abscess of the psoas muscle was returned to our hospital with hematemesis. Two years earlier, he had undergone coil embolization for a superior mesenteric artery (SMA) pseudoaneurysm secondary to pancreatitis. Based on the physical examination, serum amylase level, and abdominal radiographs, a diagnosis of acute exacerbation of pancreatitis and coil compaction of the SMA pseudoaneurysm was made. The patient underwent re-embolization for the coil compaction using interlocking detachable coils. His condition improved gradually, and he was discharged 3 weeks later. To our knowledge, this is the first report of coil compaction of SMA pseudoaneurysm.

Acute Disease↗
PubMed2002

An improved technique for the histological evaluation of the mucus-secreting status in rat cecum.

Mucin secreted into the alimentary tract often forms a mucus layer on the mucosa and is believed to protect the underlying epithelium against various factors in the lumen. We developed an improved histological technique for the evaluation of the mucus layer in the rat cecum. We used this technique to compare the effect of three nonstarch poly- and oligosaccharides on the status of mucus layer. Rats were divided into four groups (fiber-free [FF], cellulose [CEL], fructooligosaccharide [FOS], or guar gum [GG]). The frozen cecum with its contents was cut into cross-sections (5 mm thick) and fixed overnight in half-strength Bouin's solution. The sections were then transferred to 80% ethanol for 24 h. After being stained with alcian green, the mucus layers were clearly visualized in thin sections of the rat cecum, except for those that received FOS where the mucus layer had disappeared; the strong signal of mucus was seen in the cecal digesta of FOS-fed rats. Our histological method successfully provided information about the status of mucus layer that is important for an assessment of the epithelial state in the intestine.

Acetic Acid↗
PubMedDate not supplied

Carcinoid tumor of the ampulla of Vater. Magnetic resonance imaging findings.

Carcinoid tumors arising from the ampulla of Vater are rare, and their magnetic resonance (MR) imaging findings have not been reported in the literature to date. We report a case of carcinoid tumor of the ampulla of Vater and discuss the characteristic MR imaging findings. The tumor was isointense relative to the muscle on both the T1- and T2-weighted images with heterogeneous enhancement after gadolinium administration. Both the common bile and the pancreatic ducts were dilated on the MR cholangiopancreatography.

Aged↗
PubMedDate not supplied

Primary peritoneal clear cell carcinoma.

The computed tomography (CT) and magnetic resonance imaging findings of primary peritoneal clear cell carcinoma in a 53-year-old woman are reported. A CT scan showed a complex cystic mass with solid components that involved the right upper quadrant and displaced the liver and the right kidney. Magnetic resonance imaging revealed a multicystic mass with hemorrhage and heterogeneous solid protrusions. The diagnosis of primary peritoneal clear cell carcinoma was made by histopathologic study of the surgical specimen.

Adenocarcinoma, Clear Cell↗
PubMedDate not supplied

Soft copy using image processing in place of hard copy for detection of subtle pulmonary lesions: is it actually cost-effective?

PURPOSE: To comparatively assess the interpretation performance of hard-copy versus soft-copy presentations for detecting subtle pulmonary lesions and to estimate soft-copy cost-effectiveness. METHODS: Computed radiography was used to obtain images with a 1,600x 1,200 matrix having 8 bits of gray-scale definition. The two separate image formats (hard and soft copy), which consisted of 60 chest radiograph combinations, were shown to five board-certified radiologists. The costs of hard copies, chemicals, waste disposal, and labor were calculated. RESULTS: The mean accuracies and Az values were 0.63 (hard) vs. 0.64 (soft) and 0.657 (hard) vs. 0.729 (soft), respectively. Reading one set of hard copies took on average 8.0 sec less than reading soft copies (30.3 vs. 38.3 sec). Estimated savings resulting from replacement of hard copy with soft were US$128,004 per year or US$6.20 per patient at our hospital. CONCLUSION: Conversion from hard copy to soft copy, using image processing, is feasible and cost-effective.

Adult↗