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Biomedical subjects

K Togashi

Publications and source records attributed to K Togashi.

At least 19 recordsLinked to original sources
PubMed2007

Diffusion tensor fiber tractography of the optic radiation: analysis with 6-, 12-, 40-, and 81-directional motion-probing gradients, a preliminary study.

BACKGROUND AND PURPOSE: Knowing the exact location of the optic radiation preoperatively is important for surgery of the temporal lobe. We hypothesized that a greater number of motion-probing gradients (MPGs) would provide better results of diffusion tensor (DT) fiber tractography of the optic radiation. To test this hypothesis, this study evaluated differences in DT fiber tractography of the optic radiation under different MPG settings. METHODS: DT images were obtained in 12 healthy volunteers (7 men, 5 women) with a mean age of 32 years (range, 22-45 years) by using a 3T MR imaging scanner with single-shot echo-planar imaging with parallel acquisition (reduction factor = 2). MPG was applied in 6, 12, 40, and 81 independent directions. The first region of interest (ROI) was placed in the occipital lobe, and the second ROI was placed in the lateral geniculate body. Fibers penetrating both ROIs were considered as the optic radiation. Anteroposterior distance between the tip of the Meyer loop and the lateral geniculate body on an axial section was defined as a loop index. Numbers of fibers and loop indices in both cerebral hemispheres were evaluated statistically. RESULTS: The optic radiation was well visualized in full length by DT fiber tractography in 20 of 24 hemispheres (83%). No significant differences were noted in number of fibers and loop indices among different MPG settings. CONCLUSION: DT fiber tractography can frequently depict almost the entire optic radiation. MPG number does not exert any significant effect on visualization of the optic radiation, and 6-directional MPG is thus sufficient for this purpose.

Adult↗
PubMed2006

The use of acetic acid in magnification chromocolonoscopy for pit pattern analysis of small polyps.

BACKGROUND AND STUDY AIMS: The role of acetic acid spray during magnification chromocolonoscopy has not previously been evaluated. We aimed to compare the accuracy of predicting polyp histology at magnification colonoscopy, using acetic acid and indigo carmine, either alone or in combination. PATIENTS AND METHODS: A total of 46 consecutive patients with polyps detected during colonoscopy which measured 10 mm or less were alternately divided into two groups. In group A patients, 1.5 % acetic acid was applied to the mucosa first, followed by indigo carmine spray; in group B patients, the order was reversed. The pit pattern was assessed after application, in real time. All the lesions were resected and examined histologically. RESULTS: Altogether, 37 adenomas and 36 hyperplastic polyps were evaluated. In group A, the diagnostic accuracy after spraying with acetic acid was 95 %, which increased to 98 % after application of indigo carmine. In group B, the accuracy after indigo carmine application was 83 %. After subsequent spraying with acetic acid, images were enhanced in 70 % of patients, with an increase in accuracy to 97 %. The mean time required to obtain an initial clear image with the first dye was 14 seconds for both groups. CONCLUSIONS: This is the first description of the use of acetic acid for pit pattern analysis of colonic polyps. Its ease of use, low cost, and safety, together with its excellent accuracy in the assessment of polyp pit patterns suggest that this method could easily be applied to routine magnification colonoscopy.

Acetic Acid↗
PubMed2006

Selection for milk production and persistency using eigenvectors of the random regression coefficient matrix.

The purpose of this study was to investigate the relationships of the eigenvectors of the additive genetic random regression coefficient matrix (K) to selection responses and to determine how many eigenvectors are necessary in the breeding goal to explain the variation. The construction of various eigenvector indexes was based on the K matrix estimated from test-day records of Japanese Holstein cattle. The first (leading) eigenvector index produced constant responses for each day of lactation, indicating that the first eigenvector is responsible for scaling the lactation curve without altering its shape. Daily genetic responses to the second eigenvector index increased linearly as DIM increased. Genetic responses to the third eigenvector index were negative in mid-lactation but were positive in early and late lactation (concave curve). Genetic responses to the fourth and fifth eigenvector indexes hovered around zero across the lactation. The results suggest that both second and third eigenvectors account for the change in the shape of the lactation curve and there is little utility of the fourth and fifth eigenvectors in improving lactation milk or persistency. When the goal is to increase lactation milk yield alone, the index based on the first eigenvector produced a similar response to the index based on all 5 eigenvectors. When the goal is to improve both lactation milk yield and persistency, the index based on the first 3 eigenvectors achieved more than 99.9% of the genetic response to an index based on all 5 eigenvectors. The advantage of an eigenvector index over conventional selection based on total lactation milk yield increases with increasing economic weight assigned to persistency.

Animals↗
PubMed2006

Frequent involvement of ras-signalling pathways in both polypoid-type and flat-type early-stage colorectal cancers.

The development of colorectal neoplasms proceeds mainly via the adenoma-carcinoma sequence. BRAF and RASSF1A are members of Ras-signaling pathways, but the roles of their aberrations in colorectal carcinogenesis remain unclear. The authors studied mutations of the BRAF and K-ras genes, RASSF1A promoter methylation, and p53 overexpression in 43 polypoid-type and 30 flat-type early-stage colorectal cancers. No tumor simultaneously showed any combination of K-ras mutations, BRAF mutations, and RASSF1A promoter methylation. Three of the 73 tumors (4.1%) had BRAF mutations. All BRAF mutation-positive tumors were flat-type cancers, not associated with coexisting adenoma or p53 overexpression. RASSF1A promoter methylation was detected in 12 out of 73 tumors (16.4%), and the proportion of positive cases was similar in polypoid-type and flat-type cancers. BRAF mutations, K-ras mutations, and RASSF1A promoter methylation independently participate in early-stage colorectal carcinogenesis. BRAF mutations are involved only in flat-type cancers, whereas RASSF1A promoter methylation is involved in both polypoid-type and flat-type cancers. Thus, BRAF mutations most likely participate in de novo colorectal carcinogenesis, K-ras mutations in the adenoma-carcinoma sequence of colorectal carcinogenesis, and RASSF1A promoter methylation in both cascades.

Adenocarcinoma↗
PubMed2005

Elastic moduli of thyroid tissues under compression.

The aim of this study was to evaluate the elastic moduli of thyroid tissues under uniaxial compression and to establish the biomechanical fundamentals for accurate interpretation of thyroid elastograms. A total of 67 thyroid samples (24 samples of normal thyroid tissue, 2 samples of thyroid tissue with chronic thyroiditis, 12 samples of adenomatous goiter lesions and 7 samples of follicular adenoma, 19 samples of papillary adenocarcinoma (PAC) and 3 samples of follicular adenocarcinoma (FAC)) obtained from 36 patients who had received thyroid surgery were subjected to biomechanical testing within three hours after surgical resection at precompression strains of 5%, 10% and 20% and applied strains of 1%, 2%, 5% and 10% of sample height. As a result, the mean values of elastic moduli for benign thyroid lesions at all examined precompression levels were significantly higher than those for normal thyroid tissue measured at the same load (p<0.01). At low precompression (5%) and compression (1-2%) levels, benign thyroid nodule samples were 1.7 times harder than normal thyroid tissue. At high precompression (20%) and compression (10%) levels, this difference increased to 2.4 times. Stiffness of PAC samples was significantly higher than those for normal thyroid tissue and benign thyroid tumors measured at the same load (p<0.01). At low precompression (5%) and compression (1-2%) levels, PAC samples were 5.0 times harder than normal thyroid tissue. At high precompression (20%) and compression (10%) levels, this difference increased to 17.7 times. In contrast, samples of FAC were much softer than PAC (p<0.05) and were comparable in stiffness to normal thyroid tissues. The significant differences in the stiffness between normal thyroid tissue and thyroid tumors may provide useful information for accurate interpretation of thyroid elastograms.

Adult↗
PubMed2005

Maximization of lactation milk production without decreasing persistency.

This study treats each daily estimated breeding value (EBV) of the lactation as a separate trait to modify the lactation curve on a daily basis. Six selection strategies for improving lactation milk without decreasing persistency were compared: 1) index I(R1), subject to the restriction of equal genetic gains at days in milk (DIM) 60 and 280, 2) I(R2), subject to the restriction of zero gain at DIM 60, 3) desired gains index I(d), designed to increase lactation milk without altering the lactation curve, 4) index I(u), comprising lactation EBV and persistency without standardization, 5) index I(w), consisting of lactation EBV (EBV(L)) and persistency with standardization, and 6) conventional selection on EBV(L) and used as a basis for comparison. Of the 6 selection strategies compared, I(R2) yielded the greatest persistency, but achieved the smallest response in EBV(L), suggesting that it is impractical to increase persistency by inhibiting change in the peak yield. Index I(u) showed the same response in lactation milk as conventional selection on EBV(L), but resulted in the same decreased persistency. Although both I(R1) and I(d) achieved constant persistency, the former produced a greater lactation response (669 kg EBV) than the latter (560 kg EBV). Thus, I(R1) is a viable strategy for improving EBV(L) while holding persistency constant. None of the 6 selection strategies excelled in both lactation milk and persistency. Index I(w) appears to be a reasonable choice for improving both traits, although responses would depend on the relative economic importance of the 2 traits. Differential responses between I(u) and I(w) emphasize the need to weight the EBV of different traits by the inverse of their standard deviations in index construction when the EBV vary widely in variance. The general formula developed here provides a useful genetic means of modifying the lactation curve by restricting differential genetic gains among different days of the lactation.

Animal Nutritional Physiological Phenomena↗
PubMed2005

[Tetraplegia and respiratory failure due to carcinomatous neuropathy in the early postoperative period of a lung cancer patient: report of a case].

A 63-year-old man, with atypical pulmonary mycobacteriosis and also with hepatic dysfunction due to chronic hepatitis C, underwent wedge resection of the right lower lobe for non-small cell lung cancer. On the 9th postoperative day, the patient developed acute tetraplegia and then respiratory failure. Neither computed tomography (CT) nor magnetic resonance imaging (MRI) of brain and cervical vertebrae showed any cancer metastases. The neurological symptoms were those of Guillain-Barre syndrome. Therefore, we speculate that the cause of the neuromyopathy might be autoimmune antibodies from lung cancer. Steroid pulse therapy and plasma exchange treatment were effective and the patient's symptoms disappeared in a month. We reported the extremely rare case of a lung cancer patient with acute tetraplegia in the early postoperative period.

Autoimmune Diseases↗
PubMed2005

[Ultrasound carotid artery plaque morphology and perioperative stroke risk in patients undergoing coronary artery bypass grafting].

OBJECTIVE: To determine the influence of carotid artery plaque (CAP) morphology on perioperative stroke in coronary artery bypass grafting (CABG). PATIENTS AND METHODS: Ninety-three patient undergoing CABG were studied. CAPs and other lesions including intima-media thickness (IMT) and stenosis were examined by using ultrasound imaging. CAPs were morphologically classified as either homogeneous (HmP) or heterogeneous (HtP). RESULTS: Mean and max IMT were 1.26 +/- 0.15 and 2.44 +/- 0.76 mm. Mean total plaque score was 15.75 +/- 6.82. HmP and HtP were seen in 80 (86.0%) and 54 (58.1%) patients. Stenosis greater than 50% was found in 22 (23.7%) patients. HtP was significantly associated with age (p<0.05), diabetes and severity of coronary artery disease (p<0.01) and stenosis was associated with diabetes and history of cerebrovascular events (p <0.05). Late postoperative stroke occurred in 3 (3.2%) patients during hospitalization. One of them had 90% stenosis in the carotid artery. The others had no carotid stenosis. In all of the 3, the predominant plaques were heterogeneous. CONCLUSION: CAP morphology in patients undergoing CABG was detailed. As well as stenotic lesion, plaque heterogeneity may be a risk factor for perioperative stroke. Diabetes is associated with severity of both plaque heterogeneity and stenosis.

Adult↗
PubMed2005

[Long-term prognosis after surgery for pathological stage III lung cancer].

OBJECTIVE: We studied for the purpose of revealing the long-term prognosis of the surgical treatment for pathological stage III lung cancer. METHOD: Two hundred fifty-four patients with pathological stage III disease who underwent surgical procedures in our hospital from 1981 to 2000 were investigated retrospectively. RESULTS: The 5- and 10-year survival rates of 144 patients with stage IIIA disease were 35 and 25%, while those of 110 patients with IIIB disease were 30 and 16%. The 5- and 10-year survival rates were 40 and 27% for 52 patients with T1N2 disease, 33 and 23% for 70 patients with T2N2 disease, 34 and 0% for 9 patients with T3N1 disease, and 33 and 26% for 13 patients with T3N2 disease, respectively. In the patients with IIIB disease, the 5- and 10-year survival rates of 56 patients only with pml were 47 and 26%, those of the other patients were 9 and 0%. There is significant difference among them (p < 0.0001). In 54 patients with IIIB disease in addition to pm1, the 5-year survival rates of 19 patients with exploration only and the other patients were 7 and 14%, respectively. There were no 10-year survivors in both groups. CONCLUSION: The long-term prognosis of pathological stage III disease was still not satisfactory. Therefore, we should make efforts to get a sufficient informed-consent before the surgery for the patients with stage III disease.

Humans↗
PubMed2004

Involvement of apoptosis in syncytial cell death induced by canine distemper virus.

The Yanaka strain, a field isolate of Canine distemper virus (CDV), caused extensive syncytial cytopathic effects (CPEs) followed by cell death in vitro. Syncytium formation is an important aspect of CDV pathogenicity, but the mechanism of the fusion-induced cell death is still not understood. In this study, the involvement of apoptosis in the CDV-induced CPE was investigated. We also examined apoptosis in cells infected with a persistent strain of CDV, the Yanaka-BP strain derived from the Yanaka strain, because this strain does not cause obvious CPE. DNA laddering together with Terminal transferase dUTP nick endlabeling (TUNEL) assay indicated that the Yanaka strain infection, but not the Yanaka-BP infection induced apoptosis. In addition, flow cytometric analysis similarly indicated that the Yanaka-BP strain induced apoptosis significantly less frequently than the Yanaka strain did. Thus, absence of apoptosis may be implicated in the CPE and establishment of persistent CDV infection.

Animals↗
PubMed2004

Sex differences in the relationships of abdominal fat to cardiovascular disease risk among normal-weight white subjects.

The objectives of this study are to investigate the relationships between abdominal fat and risk factors for cardiovascular disease (CVD) among normal-weight (NW) white subjects and to determine how these relationships differ by sex. NW adults (177 males and 258 females) and overweight adults (133 males and 111 females) from the Québec Family Study and the HERITAGE Family Study were retained for this study. Risk factors included systolic and diastolic blood pressures, low-density lipoprotein and high-density lipoprotein cholesterols, triglycerides, and fasting glucose. Only in NW female adults, abdominal visceral fat (AVF) area assessed by computed tomography was significantly correlated with all risk factors, except for fasting glucose, even after age, study cohort, and fat mass were taken into account. NW female subjects with at least one risk factor had a significantly higher AVF than those without risk factors, although the difference was small. Thus, only NW female adults with more AVF tended to have a more adverse CVD risk factor profile.

Abdomen↗
PubMed2004

Efficiency of different selection criteria for persistency and lactation milk yield.

A conversion formula was developed to convert the genetic covariance matrices of daily yields and of random regression coefficients between 305-d and 335-d production periods under a random regression test day model. Five selection criteria were compared in terms of genetic improvement in persistency and lactation milk: 1) lactation estimated breeding value (EBVL), 2) P6 = 279Sigma(i=65) (D280 - Di), 3) ratio of daily estimated breeding value (EBV)(r280/65 = D280/D65), 4) ratio of partial lactation EBV (P280/65 = D66 approximately 28/D5 approximately 65), and 5) differential daily EBV (d65-280 = D65 - D280), where Di refers to EBV at days in milk (DIM) i. Fundamental differences among these 5 selection criteria were interpreted conceptually with a graph. Persistency, defined as k = (delta G65 - delta G280)/215, was the average daily rate of decline in selection gain from DIM 65 to 280, which is free from the effect of lactation milk on the rate of decline. Parameter k provides an objective measure of persistency, which increases when k < 0 and decreases when k > 0. Of the 5 selection criteria compared, d65-280 and P6 achieved greater persistency at the expense of genetic gain in lactation milk, whereas selection based on EBVL achieved the highest response in lactation milk, but was coupled with greatest decline in persistency. Selection on P280/65 or r280/65 improved both lactation milk and persistency and, thus, is recommended for simultaneous improvement of these 2 economically important traits. Further study of the relative economic values of persistency and lactation milk in order to combine both traits into an index for selection decision is warranted.

Animals↗
PubMed2004

Development of an optimal index to improve lactation yield and persistency with the least selection intensity.

It is important to have improvement in both lactation milk yield and persistency. Modification of the lactation curve requires severe restrictions on selection criteria designed to simultaneously improve both milk yield and persistency. As a result, manipulating the lactation curve for improved persistency requires higher selection intensity than unrestricted selection based on 305-d estimated breeding value (EBV). Our study showed that for a given restriction imposed on both milk EBV and persistency, it is possible to derive different indexes to achieve this selection constraint with different degrees of selection intensity. Of the class of indexes that meets the same restriction, it is preferable to choose the index that requires the least selection intensity because it is easier to achieve the selection goal with the use of an index that requires a lower selection intensity than a higher selection intensity. An optimal index based on random regression (RR) coefficients was developed to achieve the prespecified stage genetic gains with the lowest selection intensity. A conversion equation was derived to convert the selection index based on RR coefficients to the selection index based on stage EBV with the lowest selection intensity. A numerical example is provided to demonstrate the procedures developed compared with conventional selection based on 305-d milk EBV.

Animals↗
PubMed2003

Modifying the lactation curve to improve lactation milk and persistency.

Daily, stage and lactation estimated breeding values (EBV) and the shape of the lactation curve for each cow are controlled by a unique set of random (genetic) regression coefficients under a test day model, thus providing a basis for genetic improvement of these characteristics. Three selection procedures were developed for simultaneous improvement of total lactation milk and persistency: 1) index selection based on daily EBV, 2) index selection based on stage EBV, and 3) index selection based on random regression (RR) coefficients. A numerical example was given to demonstrate the computation of indexes based on stage EBV and based on RR coefficients. A conversion equation was derived to convert between genetic changes in EBV and RR coefficients. Index selection based on daily EBV would require the finding of 305 weighting factors for a lactation period of 305 d, making it impractical to determine the weighting factors on a daily basis. Alternatively, a lactation period was partitioned into a few stages to facilitate the construction of index selection based on stage EBV and index selection based on RR coefficients. These selection procedures make use of the annual genetic gains routinely computed in national genetic evaluations to restrict the genetic gains between different lactation stages to achieve the desired curve. When there is no prior knowledge of annual genetic gains, the proportional restriction of genetic gains between stages may be used. In summary, this study provides a simple means of modifying the lactation curve by manipulating genetic changes in different lactation stages at a pre-specified rate.

Animals↗
PubMed2003

[Pneumothorax due to pulmonary metastasis of gingival carcinoma: report of a case].

A 72-year-old woman developed left pneumothorax 14 months after the first operation of a gingival carcinoma. The chest X-ray films and computed tomographic scans on admission revealed left pneumothorax and 2 lesions with a thin-walled cavity in the upper lung field. They seemed to be pulmonary metastasis from a carcinoma of gingiva and one of them ruptured into the pleural cavity. As airleak continued after tube thoracostomy, wedge resections of 2 lesions were performed through thoracotomy. Postoperative histological examination revealed that both of the lesions were moderately differentiated squamous cell carcinoma and they were the same histological findings as the gingival carcinoma excised previously. Pulmonary metastasis from a carcinoma of gingiva is rare, while it may be thought 1% of metastatic lung tumors. And also pulmonary metastasis is unusual cause of pneumothorax, especially without chemotherapy for it. We reported the very rare case of pneumothorax due to pulmonary metastasis from a carcinoma of gingiva.

Aged↗
PubMed2003

Flat and depressed lesions of the colon and rectum: Pathogenesis and clinical management.

INTRODUCTION: It is not clear whether flat lesions play a role in the pathogenesis of colorectal carcinoma. Flat lesions are being increasingly recognised with new colonoscopic techniques. MATERIALS AND METHODS: A total of 10,939 consecutive colonoscopies were performed over a 9-year period. After bowel preparation with polyethylene glycol electrolyte lavage solution, high-resolution video colonoscopy and indigocarmine spraying were performed to detect flat lesions. All lesions suggesting neoplastic change were removed by polypectomy or surgery. Cancers invading beyond the submucosal layer were excluded from this analysis. The gross appearance of flat-type lesions was classified as flat elevated type or flat depressed type based on the presence or absence of central depression. RESULTS: A total of 5408 neoplastic lesions were index lesions, including 5035 adenomas and 373 carcinomas (124 with submucosal invasion). The prevalence of flat depressed and flat elevated lesions were 2.8% and 18.1%, respectively. Submucosal invasion rates were 17.1% in the flat depressed, 0.8% in the flat elevated, 1.6% in the sessile, 4.0% in pedunculated lesions and 9.3% in creeping lesions. The submucosal invasion rate in the flat depressed lesions was significantly higher than in any others, except for creeping lesions (P = 0.06). The percentage of flat elevated and flat depressed carcinomas among all carcinomas invading the submucosa was 6.5% and 21.0%, respectively. CONCLUSION: Flat lesions were common during routine colonoscopy. One-quarter of colorectal cancers may be derived from flat lesions. Training in dye spray technique may result in a higher detection rate of flat colonic lesions.

Adenoma↗
PubMed2003

[Elucidation of one-lobe intrapulmonary metastasis route of primary lung cancer by means of long-term results].

OBJECTIVE: We hypothesized that the cause of one-lobe intrapulmonary metastasis of primary lung cancer is mainly lymphatic, and investigated by means of the long-term outcome. METHODS: From 1988 to 2000, 860 patients underwent complete resection of primary lung cancer patients in our hospital without neoadjuvant therapy. Patients were classified into 4 groups: group A (n 0 pm 0, n = 573), group B (n 0 pm 1, n = 37), group C (n 1 pm 0-1, n = 122), and group D (n 2 pm 0-1, n = 128). RESULTS: No significant difference was seen between groups in median age, sex ratio, histological cell type, or pathological tumor-size and p-factor. The rates of bi-lobectomy and pneumonectomy were higher in groups C and D than in groups A and B. The 5-year survival rate was 73% for group A, 57% for group B, 43% for group C, and 28% for group D. The 10-year survival rate was 57% for group A, 45% for group B, 20% for group C, and 16% for group D. There was a significant difference (p < 0.0001) between 4 groups in the 5- and 10-year survival rate. CONCLUSION: The hypothesis that the cause of one-lobe intrapulmonary metastasis may be lymphatic was not incompatible with the long-term results.

Adult↗