Biomedical subjects

S Yamamoto

Publications and source records attributed to S Yamamoto.

At least 73 records · Page 4Linked to original sources

PubMed2005

[Primary pulmonary meningioma; report of a case].

Primary pulmonary meningiomas are quite rare, and their occurrence has been reported only sporadically. A 49-year-old, asymptomatic female was hospitalized for the evaluation of a coin lesion in the left lung radiography. She has no history of previous neoplasm or symptom referable to the central nervous system. Chest computed tomography (CT) demonstrated a 9 x 14 mm, round, noncalcified, well-demarcated lesion in the left upper lobe of the lung (S(1+2)). For diagnostic purposes, enucleation of the tumor was performed. The resected specimen revealed histologically classical typical meningioma. Because postoperative magnetic resonance imaging (MRI) of the brain did not show any intracranial mass, this case was and diagnosed as a primary pulmonary meningioma. The patient was discharged with no complication, and alive without recurrence of disease 14 months after surgery.

Female↗

PubMed2005

[Pericardial abscess by aspergillus mimicking a cardiac tumor].

We report a rare case of 34-year-old man who was diagnosed as cardiac tumor after therapy for acute lymphatic leukemia. Echocardiography and computed tomography (CT) showed that the tumor was located from the right atrium to the right ventricle and about 6.0 cm in diameter. Resection of the tumor was performed under cardiopulmonary bypass. The histological findings revealed pericardial abscess by Aspergillus.

Abscess↗

PubMed2005

[Microwave coagulation therapy with potassium titanyl phosphate (KTP) laser therapy for airway stenosis from a recurrent tracheocarinal tumor].

About 2 years after right lower lobectomy for anadenocarcinoma in the right lung, an 80-year-old man had a reccurent tumor in tracheocarinal lymph nodes. Although concurrent chemoradiotherapy was performed, there was no change (NC) and the tumor grew back slowly. He was admitted to our hospital with exertional dyspnea and stridor 2 years later. The bronchoscopic microwave coagulation therapy was performed in the right main bronchus. After potassium titanyl phosphate (KTP) laser therapy had been performed in the tracheocarinal lumen, an expandable metallic stent was performed. The postopertive course was uneventful.

Adenocarcinoma↗

PubMed2005

[Treatment strategy for patients, with locally advanced non-small cell lung cancer].

A total of 89 patients with locally advanced lung cancer (pT3-4N0-1) underwent pulmonary resection from April 1994 to April 2003 at our institutions. The overall 5-year survival rate of the 89 patients was 35.5%. No significant difference in the 5-year survival rate was found according to the following variables: histologic type, type of operation, number of resected organs, performance of adjuvant therapy and pulmonary function. In patients with pN1 disease, when patients with nodal metastasis were divided into patients with hilar (# 10) or lobar (# 11 approximately 13) metastasis, the survival rate of lobar metastasis group was superior to those of hilar metastasis group, but not significantly. In patients with pN1 disease, 5 patients were survived for more than 1,000 days. The histology was squamous cell carcinoma in 4 cases. According to the characteristics of pN1 involvement, all cases was involved only a single station.

Adult↗

PubMed2005

Level of 5-fluorodeoxyuridine 5'-monophosphate in cancerous tissue in patients with gastric cancer under preoperative administration of TS-1. A preliminary study.

Metabolizing enzymes such as thymidylate synthase (TS) and dihydropyrimidine dehydrogenase (DPD) have long been known to be useful for predicting response and outcome in patients receiving 5-fluorouracil (5-FU). However, few studies have examined the cancerous tissue levels of 5-fluorodeoxyuridine 5'-monophosphate (FdUMP), a metabolite of 5-FU that has an important role in inhibiting DNA synthesis. In this study, for the first time to our knowledge, we measured concentrations of FdUMP in tumor specimens and surrounding non-cancerous tissue obtained at operation in 10 patients with gastric cancer who received TS-1 before surgery (80 mg/m2, 3 days). The FdUMP level in the cancerous tissue was significantly higher than that in the non-cancerous tissue (153.0 +/- 85.7 pmol/g tissue vs. 53.0 +/- 47.0 pmol/g tissue)(p = 0.0046). Furthermore, the TS level in tumor was significantly higher than that in non-cancerous tissue (6.362 +/- 5.106 pmol/g tissue vs. 2.092 +/- 2.050 pmol/g tissue) (p = 0.0310). The mean ratios of TS-bound FdUMP to TS and FdUMP concentrations in the cancerous tissues were 45.9% and 2.00%, respectively. Our results demonstrate that in cancerous tissue, TS-1 may produce high FdUMP concentration and suppress about half FdUMP concentration by forming ternary complexes.

Adult↗

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

Tyrosine phosphorylation sites on FRS2alpha responsible for Shp2 recruitment are critical for induction of lens and retina.

Early development of the lens and retina depends upon reciprocal inductive interactions between the embryonic surface ectoderm and the underlying neuroepithelium of the optic vesicle. FGF signaling has been implicated in this signal exchange. The docking protein FRS2alpha is a major mediator of FGF signaling by providing a link between FGF receptors (FGFRs) and a variety of intracellular signaling pathways. After FGF stimulation, tyrosine-phosphorylated FRS2alpha recruits four molecules of the adaptor protein Grb2 and two molecules of the protein tyrosine phosphatase Shp2, resulting in activation of the Ras/extracellular signal-regulated kinase (ERK) and phosphatidylinositol-3 kinase/Akt signaling pathways. In this report, we explore the role of signaling pathways downstream of FRS2alpha in eye development by analyzing the phenotypes of mice that carry point mutations in either the Grb2-(Frs2alpha(4F)) or the Shp2-binding sites (Frs2alpha(2F)) of FRS2alpha. Although Frs2alpha(4F/4F) mice exhibited normal early eye development, all Frs2alpha(2F/2F) embryos were defective in eye development and showed anophthalmia or microphthalmia. Consistent with the critical role of FRS2alpha in FGF signaling, the level of activated extracellular signal-regulated kinase in Frs2alpha(2F/2F) embryos was significantly lower than that observed in wild-type embryos. Furthermore, expression of Pax6 and Six3, molecular markers for lens induction, were decreased in the Frs2alpha(2F/2F) presumptive lens ectoderm. Similarly, the expression of Chx10 and Bmp4, genes required for retinal precursor proliferation and for lens development, respectively, was also decreased in the optic vesicles of Frs2alpha(2F/2F) mice. These experiments demonstrate that intracellular signals that depend on specific tyrosine residues in FRS2alpha lie upstream of gene products critical for induction of lens and retina.

Adaptor Proteins, Signal Transducing↗

PubMed2004

Evidence for an oscillatory signature in atmospheric neutrino oscillations.

Muon neutrino disappearance probability as a function of neutrino flight length L over neutrino energy E was studied. A dip in the L/E distribution was observed in the data, as predicted from the sinusoidal flavor transition probability of neutrino oscillation. The observed L/E distribution constrained nu(micro)<-->nu(tau) neutrino oscillation parameters; 1.9x10(-3) 0.90 at 90% confidence level.

Journal Article↗

PubMed2004

A comparison of the complication rates between laparoscopic colectomy and laparoscopic low anterior resection.

BACKGROUND: This study compared the short-term outcomes, including the complication rate and minimum surgical invasiveness, between patients with colon and rectal carcinomas, who underwent laparoscopic surgery. METHODS: A review evaluated 151 patients who underwent laparoscopic colectomy (Lap-colectomy; n = 120) and laparoscopic low anterior resection (Lap-LAR; n = 31) between July 2001 and December 2003. The short-term outcomes were compared between the two groups. RESULTS: The mean operative time and blood loss were significantly greater in the Lap-LAR group. However, the complication rates and postoperative course between the two approaches were similar, and no anastomotic leakage was observed. There was no significant difference in the serum C-reactive protein level and white blood cell count between the two groups in the early postoperative period. CONCLUSIONS: Lap-LAR for rectal carcinoma can be performed safely without increased morbidity or mortality, and its short-term benefits are comparable with those conferred by Lap-colectomy.

Adult↗

PubMed2004

Limits on the neutrino magnetic moment using 1496 days of Super-Kamiokande-I solar neutrino data.

A search for a nonzero neutrino magnetic moment has been conducted using 1496 live days of solar neutrino data from Super-Kamiokande-I. Specifically, we searched for distortions to the energy spectrum of recoil electrons arising from magnetic scattering due to a nonzero neutrino magnetic moment. In the absence of a clear signal, we found micro(nu)</=(3.6x10(-10))micro(B) at 90% C.L. by fitting to the Super-Kamiokande day-night spectra. The fitting took into account the effect of neutrino oscillation on the shapes of energy spectra. With additional information from other solar neutrino and KamLAND experiments constraining the oscillation region, a limit of micro(nu)</=(1.1x10(-10))micro(B) at 90% C.L. was obtained.

Journal Article↗

PubMed2004

Monophyletic origin of naked barley inferred from molecular analyses of a marker closely linked to the naked caryopsis gene (nud).

To elucidate the origin of naked barley, molecular variation of the marker sKT7 tightly linked to the nud locus was examined. A total of 259 (53 wild, 106 hulled domesticated, and 100 naked domesticated) barley accessions were studied. Restriction analysis of the sKT7 PCR-amplified product revealed the alleles I, II, III, and IV. All four alleles were found in wild barley, but allele IV was found only in a single accession from southwestern Iran. Hulled domesticated accessions showed alleles I, II, or III, but all naked domesticated accessions had allele IV. The distribution of allele IV in wild barley and its pervasive presence in naked domesticated lines support the conclusion that naked barley has a monophyletic origin, probably in southwestern Iran. The available results suggest two scenarios for the origin of naked barley: either directly from a wild barley with allele IV or from a hulled domesticated line with allele IV that later became extinct. Naked domesticated accessions from different regions of the world have extremely homogeneous DNA sequences at the sKT7 locus, supporting the monophyletic origin of naked barley. For allele IV, four haplotypes (IVb to IVe) were found in 30 naked accessions: IVb was predominant (66.7%) and widely distributed, while the other three haplotypes, differing by only one nucleotide at different positions relative to IVb, showed a localized distribution. The geographical distribution of the haplotypes of sKT7 allele IV suggests migration routes of naked domesticated barley in central and eastern Asia.

Alleles↗

PubMed2004

Smell identification test as an indicator for cognitive impairment in Alzheimer's disease.

OBJECTIVES: The aim of the present study was to assess olfactory dysfunction in patients with Alzheimer's disease (AD) and to compare utility of the olfactory tests as possible clinical markers. METHODS: Two olfactory identification tests (The Cross-Cultural Smell Identification Test [CC-SIT] and the Picture-based Smell Identification Test [P-SIT]) and the Mini Mental State Examination (MMSE) were administered to patients with AD and age-matched controls. Apolipoprotein E (Apo E) genotypes of patients with AD were identified. RESULTS: Patients with AD had significantly lower olfactory identification scores than age-matched non-demented elderly subjects in both olfactory assessments. In the AD group, the coefficient of correlation between the MMSE scores and the P-SIT scores was higher than that between the MMSE scores and the CC-SIT scores. Receiver operating curve (ROC) analyses for both tests indicated that the P-SIT discriminated AD patients from controls more reliably than did the CC-SIT. Within AD patients, those who were carrying one or two ApoE epsilon4 alleles had a higher coefficient of correlation between the MMSE scores and the P-SIT scores than patients without the ApoE epsilon4 allele. CONCLUSIONS: The results suggest that a short and simple non-lexical olfactory identification test can be useful as a clinical marker of AD appropriate for Japanese elderly population.

Aged↗

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

Decreased proteinuria following liver transplantation in a patient with type C liver cirrhosis complicated with nephrotic syndrome: a case report.

Type C liver cirrhosis is often associated with a nephrotic syndrome secondary to membranoproliferative glomerulonephritis. Liver transplantation in such patients may sometimes worsen viremia, causing renal dysfunction upon the introduction of immunosuppressive drugs. We present a case of a patient whose proteinuria decreased after liver transplantation. The patient was a 49-year-old male who had been followed due to chronic hepatitis type C from 1984. From 1999 he was diagnosed as having nephrotic syndrome. We performed a living related liver transplant on August 21, 2001. An intraoperative renal biopsy revealed the histology to show membranoproliferative glomerulonephritis. The volume of proteinuria was 2 to 11 g/day before surgery. After surgery it varied from 6 to 10 g/day, gradually decreasing to 1 to 2 g/day. One of the causes of reduced proteinuria may be alleviation of membranoproliferative glomerulonephritis by immunosuppression. But from the view that the recovery of the renal function followed the recovery of liver function, the major effect may have been alleviated hepatorenal syndrome.

Biopsy↗

PubMed2004

Changes in serum LECT 2 levels during the early period of liver regeneration after adult living related donor liver transplantation.

We investigated changes in serum leukocyte cell-derived chemotaxin2 (LECT2) levels between donors and recipients in the early period during liver regeneration following adult living related donor liver transplantation (LRDLT). Five recipients (three women, two men; 37.0 +/- 15.8 years old), all of whom had end-stage liver failure, underwent LRDLT from healthy five donors (two women, three men; 41.6 +/- 14.3 years old) between June 2000 and February 2001. FK506 and methylprednisolone were used as immunosuppressants for recipients. Serum LECT2 levels decreased immediately after both the hepatectomy in all donors and the implantation of liver graft in all recipients. Donors showed a nadir at 3 to 12 hours, increasing at 24 to 48 hours. The nadir in recipients occurred several hours after the donors. The serum LECT2 levels of donors were significantly higher than those of recipients on day 5 (9.5 +/- 5.9 ng/mL vs 3.1 +/- 2.2 ng/mL, P = .04) and on day 7 (9.3 +/- 3.8 ng/mL vs 3.5 +/- 1.1 ng/mL, P = .04). Serum GPT and GOT levels were inversely proportionate to the serum LECT2 levels. The present studies suggest that LECT2 participates in liver regeneration and injury following hepatectomy.

Adult↗

PubMed2004

Serum LECT2 level as a prognostic indicator in acute liver failure.

In the present study, we investigated the relationship between serum leukocyte cell-derived chemotaxin2 (LECT2) levels and liver function in patients with acute liver failure, and its use as a prognostic indicator. We studied six acute liver failure patients (two women, four men; 49.8 +/- 20.7 years old) admitted to our hospital in 2002. These patients had diagnoses of fulminant hepatitis due to acute liver failure (1) from congestive heart failure; (2) from portal venous gas, and (3) from postoperative disseminated intravascular coagulation (DIC). We measured serum LECT2, GOT, and GPT levels, the last two being inversely proportionate to the serum LECT2 levels. When the serum GPT levels peaked, the serum LECT2 levels were the lowest. When the liver function recovered, serum LECT2 levels increased. Three of four patients died due to liver failure, one to congestive heart failure. Maximum serum LECT2 levels among the expired group were significantly lower than those among the alive group (0.96 +/- 0.8 ng/mL vs 12.9 +/- 4.3 ng/mL). Serum LECT2 levels may be a prognostic indicator of recovery from liver failure. The present study suggests that in clinical medicine LECT2 participates in regeneration after injury of hepatocytes.

Adult↗

PubMed2004

Rapid progressive hepatitis C after liver transplantation: a case report.

A 56-year-old man on hemodialysis for 3 years because of chronic renal failure underwent living related donor liver transplantation (LRDLT) and splenectomy using the right hepatic lobe for liver cirrhosis type C (genotype 1b) with hepatocellular carcinoma. At 69 postoperative days (POD), he displayed a high fever and his blood transaminase and total bilirubin were increased. Based on finding in his liver biopsy, we diagnosed rapid recurrence of progressive hepatitis C after LRDLT, so we administered IFNbeta. Thereafter his liver function returned to normal and his HCV-mRNA decreased to 1200 kcopy/mL. We inferred that hemodialysis and splenectomy decreased his immunity, allowing rapidly progressive hepatitis C recurrence after LRDLT.

Adult↗

PubMed2004

Living related donor liver transplantation for primary sclerosing cholangitis with hepatocellular carcinoma and Crohn's disease: a case report.

INTRODUCTION: Primary sclerosing cholangitis (PSC) is a premalignant condition associated with a risk of developing cholangiocarcinoma in 10% to 20% of patients. However, the prevalence of hepatocellular carcinoma (HCC) in patients with PSC is estimated to be only 2%. In addition, PSC often occurs in association with inflammatory bowel disease. Ulcerative colitis occurs in 60% of PSC patients and Crohn's disease occurs in about 10%. We diagnosed a patient as having PSC with HCC and concomitant Crohn's disease prior to living related donor liver transplantation (LRDLT). PATIENTS AND METHODS: A 63-year-old woman was diagnosed as having PSC with solitary HCC. Preoperative liver condition was Child-Pugh grade C. Colonoscopic findings showed an active longitudinal ulcer in the terminal ileum and clinically diagnosed Crohn's disease. The medical treatment was 5'-aminosalicylates. She received a left lobe graft from her daughter. The immunosuppressants were tacrolimus and azathioprine, which was changed to predonisolone because of leukopenia and moderate acute cellular rejection, after which the postoperative course was uneventful. Colonoscopic findings revealed disappearance of the longitudinal ulcer in the terminal ileum at 15 months after LRDLT. There was no evidence of PSC or HCC recurrence. CONCLUSIONS: Generally, PSC with HCC is rare with a poor prognosis; however, LRDLT may be a treatments option although the patient with PSC had a combined HCC. Moreover, aminosalicylates together with the immunosuppressants may be effective for the clinical management of concomitant Crohn's disease.

Cholangitis, Sclerosing↗