Biomedical subjects

S Kido

Publications and source records attributed to S Kido.

At least 37 records · Page 2Linked to original sources

PubMed2000

Enhanced tumorigenicity of insulinoma by X-irradiation of the gastric regions in Sprague-Dawley male rats.

BACKGROUND AND AIMS: There has been no suitable animal model for human insulinoma because incidence of pancreatic tumours induced by whole-body irradiation or chemicals has been very low. The purpose of this study was to establish an experimental model with a high incidence of insulinoma. The induction of islet cell tumour by X-irradiation was investigated. METHODS: Forty Sprague-Dawley male rats were used in this study. Twenty-eight rats were irradiated with two 10-Gy doses to the gastric region at a 3-day interval, and 12 rats not subjected to X-irradiation served as a control group. The rats were killed 16 months after the first irradiation. Expression of insulin mRNA and protein was examined by northern blot analysis and immunohistochemistry, respectively. Rat serum insulin and glucose levels were measured using enzyme-linked immunosorbent assay. RESULTS: Tumour incidence was 89.3% (25/28) in X-ray group and 8.3% (1/12) in the control group (P < 0.05). Pancreatic tumours, which appeared in all 25 rats with tumours, showed the highest incidence of all neoplasms detected. Tumour cells showed strong immunoreactivity for insulin in 20 of 25 pancreatic tumours (80%). Expression of insulin mRNA was confirmed by northern blot analysis. Furthermore, rats with pancreatic tumours had lower serum glucose levels and higher insulin levels than the control rats. CONCLUSION: X-irradiated SD rats may be considered a suitable model for insulinoma because of their high tumorigenicity.

Animals↗

PubMed2000

Comparison between computer-aided diagnosis and radiologists: assessment of pulmonary blood flow on chest radiographs.

To evaluate the performance of a computer-aided diagnosis (CAD) scheme for estimating increased pulmonary blood flow on chest radiographs, we compared computerized assessment with findings by radiologists. Our CAD scheme extracts selectively linear opacities corresponding to vessels in regions of interest (ROIs) in the right upper and lower lung zones on digitized chest radiographs, and then calculates a radiographic index as a physical measure that reflects the area of the extracted opacities in selected ROIs. As a measure of increased pulmonary blood flow, the upper/lower radiographic index ratio was calculated for each patient. Seven radiologists estimated the degree of increased pulmonary blood flow for the same images of ROI sets presented on a cathode-ray tube monitor in a randomized order. Between the normal-pulmonary capillary wedge pressure (PCWP) group and increased-PCWP groups, there was no significant difference in performance between CAD and radiologists (p = 0.105). However, when the normal and mild PCWP groups were compared, the performance of CAD was superior to that of radiologists (p = 0.001). This study indicates that our CAD scheme is promising for quantitative estimation of increased pulmonary blood flow, especially in mild cases.

Diagnosis, Computer-Assisted↗

PubMed2000

Comparison of quantitations of viral load in varicella and zoster.

The pathogenesis of varicella and zoster and the effects of antiviral treatment were investigated using real-time PCR for varicella-zoster virus (VZV) DNA in skin lesions and peripheral blood. A higher occurrence of viremic VZV DNA was observed in varicella than in zoster. Acyclovir treatment resulted in marked suppression of viremia in varicella.

Acyclovir↗

PubMed1999

Identification of regulatory sequences and binding proteins in the type II sodium/phosphate cotransporter NPT2 gene responsive to dietary phosphate.

Dietary phosphate (P(i)) is a most important regulator for renal P(i) reabsorption. The type II sodium-dependent phosphate (Na/P(i)) cotransporters (NPT2) are located at the apical membranes of renal proximal tubular cells and major functional transporters associated with renal P(i) reabsorption. The consumption of a low-P(i) diet induces the synthesis of NPT2, whereas a high P(i) diet decreases it. The molecular mechanisms of regulation by dietary P(i) are not yet known. In this report, in weaning mice fed a low-P(i) diet for 4 days, the NPT2 mRNA level was increased 1.8-fold compared with mice fed a normal P(i) diet. This increase was due to an elevation of the transcriptional activity. In the NPT2 gene promoter, the DNA footprint analysis showed that six regions were masked by the binding protein, but at the position -1010 to -985 upstream of the transcription start site, the binding clearly responded to the levels of dietary P(i). The phosphate response element (PRE) of the NPT2 gene was found to consist of the motif related to the E box, 5'-CACGTG-3'. A yeast one-hybrid system was used to clone a transcription factor that binds to the PRE sequences in the proximal promoter of the NPT2 gene. Two cDNA clones that encoded protein of the mouse transcription factor muE3 (TFE3) were isolated. This is a DNA-binding protein that activates transcription through the muE3 site of the immunoglobulin heavy chain enhancer. TFE3 antibody completely inhibited the binding to the PRE. The coexpression of TFE3 in COS-7 cells transfected with the NPT2 gene promoter markedly stimulated the transcriptional activity. The feeding of a low P(i) diet significantly increased the amount of TFE3 mRNA in the kidney. These findings suggest that TFE3 may participate in the transcriptional regulation of the NPT2 gene by dietary P(i).

Animals↗

PubMed1999

Isolation and characterization of a mouse SRY-related cDNA, mSox7.

SOX is a family of SRY-related genes, which encode transcriptional factors involved in development. In this study, we newly isolated and sequenced mouse cDNA clones for mSox7. The mSox7 gene encodes 380 amino acids containing an SRY-type HMG box. Genomic Southern analysis suggested that the mSox7 gene was a single-copy gene. Tissue specific expression of mSox7 was investigated by Northern analysis. The expression was restricted to the ovary and heart, and the size of the transcripts was estimated to be 3.6 knt. Electrophoretic mobility shift assay indicated that recombinant mSox7 polypeptide was capable of binding to a nucleotide sequence, AACAAT. Immunohistochemical study revealed that mSox7 protein was localized in oocytes in the mouse ovary.

Amino Acid Sequence↗

PubMed1999

Prognostic value of bronchiolo-alveolar carcinoma component of small lung adenocarcinoma.

BACKGROUND: Bronchiolo-alveolar carcinoma (BAC) is often observed in lung adenocarcinoma, but its clinicopathological and prognostic significance, especially in small peripheral lung adenocarcinoma, remains undetermined. METHODS: We assessed 206 consecutive cases of surgically resected small peripheral lung adenocarcinoma (less than 2 cm in diameter) recorded between 1973 and 1997. According to the component area of well differentiated BAC within maximally cut surface specimens of tumor tissue, we semiquantitatively classified the tumors into four types: those in which the BAC component comprised 0% (type I), 1% to 49% (type II), 50% to 99% (type III), and 100% (type IV) of the tumor tissue. RESULTS: Forty tumors were classified as type I, 75 as type II, 74 as type III, and 17 as type IV. The tumors with less BAC, especially type I and II, showed a significantly more aggressive nodal involvement and tumor stage, and consequently a worse prognosis, while type IV tumors had no nodal involvement and the most favorable prognosis. The patients with type III showed clinicopathological characteristics somewhere between those of type II and type IV patients. Among stage I patients, however, those with type II had the worst prognosis, while those with type I showed as good a prognosis as the other two groups. CONCLUSIONS: This novel classification based on the degree of BAC involvement in small peripheral lung adenocarcinoma may reflect clinicopathological and prognostic characteristics. This classification may prove practical for planning therapeutic strategies, in particular surgical treatment.

Adenocarcinoma↗

PubMed1999

Comparison of computed tomography and pathologic examination for evaluation of response of primary lung cancer to neoadjuvant therapy.

Twenty-four patients (nine with squamous cell carcinoma, 14 with adenocarcinoma, and one with large cell carcinoma) underwent neoadjuvant therapy followed by surgical resection. The authors studied changes in tumor size, shape, and contrast enhancement on computed tomography (CT), and compared them with results of pathologic examination of surgical specimens. The size of tumors on CT was evaluated according to the criteria of the World Health Organization. Surgical specimens were evaluated histologically on the basis of the area of viable cancer cells. Of 14 patients considered to have a partial response on the basis of World Health Organization criteria, five had pathologic changes of complete response. After therapy, the residual tumors in these five patients showed irregular shapes with concave tumor margins on CT images and no enhancement. The authors found that CT size criteria tended to underestimate the therapeutic effect demonstrated by pathologic examination. On the basis of these results, the authors propose three CT criteria for complete response: 1) more than 50% size reduction, 2) a change in tumor morphologic features from round or oval to irregular after neoadjuvant therapy, and 3) disappearance of contrast enhancement.

Adenocarcinoma↗

PubMed1999

Gastric tumor induction by 1,2-dimethylhydrazine in Wistar rats with intestinal metaplasia caused by X-irradiation.

Five-week-old male Wistar rats were X-irradiated with a total of 20 Gy in 2 equal fractions at a 3-day interval. 1,2-Dimethylhydrazine (DMH) solution was injected i.m. into the back musculature at a dose of 20 mg/kg body weight weekly for 10 weeks, beginning 20 weeks after the final irradiation. Twelve months after the initial carcinogen treatment, tumors in the fundus of the glandular stomach were observed in 5 of 23 animals receiving both X-irradiation and DMH treatment. No tumors of the glandular stomach were observed in the DMH and X-ray alone or nontreatment groups. It is concluded that the presence of intestinal metaplasia may increase sensitivity to the induction of gastric tumors by carcinogens like DMH.

1,2-Dimethylhydrazine↗

PubMed1999

Ground-glass opacity on thin-section CT: value in differentiating subtypes of adenocarcinoma of the lung.

OBJECTIVE: The purpose of this study was to determine whether thin-section CT could be used to differentiate small localized bronchioloalveolar carcinoma from peripheral adenocarcinoma having a bronchioloalveolar (replacement) growth pattern of alveolar lining cells and from adenocarcinoma not having a replacement growth pattern on the basis of the extent of ground-glass opacity revealed by thin-section CT. MATERIALS AND METHODS: One hundred twenty-four small, surgically resected, peripheral adenocarcinomas from 119 patients (67 men and 52 women; mean age, 60 years) were studied. Lesion diameters were 0.4-2.0 cm (median, 1.5 cm). The extent of ground-glass opacity within lesions on preoperative thin-section CT was reviewed retrospectively by three thoracic radiologists. On the basis of replacement growth of alveolar lining cells, small adenocarcinomas were classified histologically as localized bronchioloalveolar carcinomas (n = 42) or as adenocarcinomas with (n = 53) or without (n = 29) a replacement growth pattern of alveolar lining cells. RESULTS: The percentage of lesions that had ground-glass opacity was significantly greater in localized bronchioloalveolar carcinomas (mean, 56.7%+/-33.0%) than in adenocarcinomas with a replacement growth pattern (mean, 26.3%+/-25.3%, p < .001) or in adenocarcinomas without a replacement growth pattern (mean, 8.3%+/-4.7%, p < .001). CONCLUSION: Determination of the ground-glass opacity area in each tumor as revealed on thin-section CT was useful for differentiating small localized bronchioloalveolar carcinomas from small adenocarcinomas not having a replacement growth pattern.

Adenocarcinoma↗

PubMed1999

[Concomitant mitral valvuloplasty and fenestrated total cavopulmonary connection: a case report].

A seven-year-old boy with tricuspid atresia successfully underwent a fenestrated total cavopulmonary connection and mitral valvuloplasty. Preoperative cardiac catheterization showed a mean pulmonary artery pressure of 16 mmHg. Pulmonary arteriography showed poor development of the branches (PA index: 180). Echocardiography revealed mild to moderate mitral valve incompetence due to prolapse of anterior leaflet. Mitral valve was exposed through the trans-septal approach. The excess chorda length was tucked into a longitudinal split in the top of the posterior papillary muscle. Then wedge resection of the redundant segment of the anterior leaflet and bilateral annuloplasty were performed. Finally, a total extracardiac cavopulmonary anastomosis with a 6 mm fenestration was completed. Postoperative clinical course was uneventful, and he is doing well with no recurrence of mitral incompetence 1 year after the operation.

Child↗

PubMed1999

[Midterm results of bilateral enlargement of the aortic valve ring for valve replacement].

From 1989, 4 patients underwent bilateral enlargement of the aortic valve ring for valve replacement. Age at the operation ranged from 2 to 8 (mean 6) years; body weight ranged from 14.9 to 25.4 (mean 19.0) kg. This procedure enabled us to implant a prosthesis 3 to 4 sizes larger (19 to 23 mm) than that measured with the native aortic annulus (13 to 17 mm). There was no late death and no cardiac event over a mean follow-up period of 6.2 years. Pressure gradient across the prosthesis measured by echocardiography was 40 mmHg in 1 patient who underwent aortic valve replacement with the use of 19 mm St. Jude Medical valve at 2 years of age. There was no significant pressure gradient in other 3 patients. All patients showed normal left ventricular function. We conclude that bilateral enlargement of the aortic valve ring for valve replacement has provided good midterm results with no mortality and no cardiac event.

Aortic Valve↗

PubMed1998

The mouse Sox5 gene encodes a protein containing the leucine zipper and the Q box.

The nucleotide sequence of mouse Sox5 (mSox5) cDNA derived from the testis has been reported by Denny et al. (EMBO J. 11 (1992) 3705-3712). We newly isolated an mSox5 cDNA derived from 8.5-day mouse embryo. Our cDNA encodes a protein of 763 amino acids, which is considerably larger in size than the previous one (392 amino acids) derived from the adult mouse testis. The most significant difference between the embryo-derived and testis-derived mSox5 cDNAs is that the embryonic one encodes a leucine zipper motif and a neighboring glutamine-rich sequence stretch (named Q box), but the testis-derived one does not. The leucine zipper and the Q box are highly conserved among type-D SOX proteins including mSox5. mSox5 was suggested to be a single-copy gene by Southern analysis. With reverse transcription/polymerase chain reaction, we found that not only mouse embryo, but also the adult mouse testis, express mSox5 mRNA species encoding the leucine zipper and the Q box.

Amino Acid Sequence↗

PubMed1998

Regulation of type II renal Na+-dependent inorganic phosphate transporters by 1,25-dihydroxyvitamin D3. Identification of a vitamin D-responsive element in the human NAPi-3 gene.

Vitamin D is an important regulator of phosphate homeostasis. The effects of vitamin D on the expression of renal Na+-dependent inorganic phosphate (Pi) transporters (types I and II) were investigated. In vitamin D-deficient rats, the amounts of type II Na+-dependent Pi transporter (NaPi-2) protein and mRNA were decreased in the juxtamedullary kidney cortex, but not in the superficial cortex, compared with control rats. The administration of 1,25-dihydroxyvitamin D3 (1,25-(OH)2D3) to vitamin D-deficient rats increased the initial rate of Pi uptake as well as the amounts of NaPi-2 mRNA and protein in the juxtamedullary cortex. The transcriptional activity of a luciferase reporter plasmid containing the promoter region of the human type II Na+-dependent Pi transporter NaPi-3 gene was increased markedly by 1,25-(OH)2D3 in COS-7 cells expressing the human vitamin D receptor. A deletion and mutation analysis of the NaPi-3 gene promoter identified the vitamin D-responsive element as the sequence 5'-GGGGCAGCAAGGGCA-3' nucleotides -1977 to -1963 relative to the transcription start site. This element bound a heterodimer of the vitamin D receptor and retinoid X receptor, and it enhanced the basal transcriptional activity of the promoter of the herpes simplex virus thymidine kinase gene in an orientation-independent manner. Thus, one mechanism by which vitamin D regulates Pi homeostasis is through the modulation of the expression of type II Na+-dependent Pi transporter genes in the juxtamedullary kidney cortex.

Animals↗

PubMed1998

Cloning and characterization of mouse mSox13 cDNA.

A novel SRY-related cDNA, mSox13, was isolated from a lambda phage library derived from mouse embryo. The cDNA encodes a protein of 595 amino acids containing the SRY-type high mobility group (HMG) box and a putative leucine zipper motif. A sequence comparison of mSox13 and other type-D SOX proteins shows that the leucine zipper and a neighboring glutamine-rich sequence stretch, which was named Q box, are well conserved among known type-D SOX proteins. The expression of mSox13 is restricted to the kidney and ovary. The electrophoretic mobility shift assay indicates that the recombinant mSox13 protein is capable of binding to the AACAAT sequence.

Amino Acid Sequence↗

PubMed1998

Quantification of interstitial lung abnormalities with chest radiography: comparison of radiographic index and fractal dimension.

RATIONALE AND OBJECTIVES: The authors performed this study to evaluate two physical measures used for quantifying interstitial lung abnormalities on chest radiographs: the normalized radiographic index (RI) and the fractal dimension (FD). MATERIALS AND METHODS: The RI and FD were obtained from 50 regions of interest (ROIs) in lungs with mild interstitial abnormalities, 50 ROIs in lungs with severe interstitial abnormalities, and 50 ROIs in normal lungs. The RI was defined as the normalized percentage area of extracted opacities in selected ROIs. FD was calculated with a box-counting algorithm. To extract linear opacities selectively, the authors processed ROIs with four-directional Laplacian-Gaussian filtering and binarization, linear opacity judgment (LOJ), and linear opacity subtraction (LOS). The usefulness of the physical measures for quantifying interstitial lung abnormalities was evaluated with receiver operating characteristic analysis. RESULTS: In normal and mild abnormality groups, observer performance with the RI was worse with LOJ images (area under the receiver operating characteristic curve [Az] = .812 +/- .042) than with LOS images (Az = .912 +/- .028, P < .05), and performance with FD was better with LOJ images (Az = .867 +/- .037) than with LOS images (Az = .750 +/- .048, P < .05). In the normal and severe abnormality groups, performance with RI and FD was better with LOJ images (RI: Az = .992 +/- .007; FD: Az = .968 +/- .016) than with LOS images (RI: Az = .883 +/- .034, P < .001; FD: Az = .767 +/- .047, P < .0001). CONCLUSION: The RI is considered to reflect the sensitivity in the detection of interstitial lung abnormalities on chest radiographs. Conversely, the FD is considered to reflect specifically the linear opacities processed with LOJ.

Algorithms↗

PubMed1998

Human parvovirus B19-associated thrombocytopenic purpura.

We report two patients who presented with thrombocytopenic purpura (TP) associated with primary human parvovirus B19 (B19) infection. One patient also had transient liver dysfunction. In both cases, B19-DNA was detected in serum and bone marrow by polymerase chain reaction. Six months after the illness in patient 1 and 8 months after the illness in patient 2, B19-DNA disappeared from the serum. Serum immunoglobulin (Ig)G antibody to B19 remained positive in both cases, but B19 IgM antibody became negative 3 months after the onset in case 1 and 4 months after the onset in case 2. The mechanism of TP by B19 infection is unknown.

Adolescent↗

PubMed1998

[Significance of coronary risk factors and coronary arteriosclerosis for coronary vasospasm].

The clinical significance of coronary arteriosclerosis and coronary risk factors was investigated in patients with coronary spasm. Coronary spasm induction test with acetylcholine was performed in 140 consecutive patients (85 males and 55 females) with chest pain in our hospital. The patients were divided into positive, borderline, and negative groups according to the results of the test. The positive and borderline groups were categorized as the coronary contractive group. The coronary sclerosis index was used to evaluate the degree of coronary arteriosclerosis. Coronary risk factors were evaluated in terms of hypertension, diabetes mellitus, hyperlipidemia, obesity, history of smoking and drinking, and family history of cardiovascular events. Patients could be divided into 34.3% in the positive group and 23.6% in the borderline group, i.e. 57.9% in the coronary contractive group, and 42.1% in the negative group. There were more males than females in both positive and coronary contractive groups. The proportion of males in the coronary contractive group was higher in patients over 60 years of age than in patients under 60. In contrast, the proportion of females was higher in patients under 60 than in patients over 60. In male patients, the coronary sclerosis indices in the positive, borderline, and coronary contractive groups were higher than those in the negative group. The indices in female patients in the positive and coronary contractive groups were higher than the index in the negative group. There were no differences in terms of the presence or absence, or the degree of organic stenosis between spastic sites and nonspastic branches in the positive group. The history of smoking in male patients was significantly more common in the positive group than in the negative group. The family history was more relevant in female patients in the positive or coronary contractive group compared to the negative group. Moreover, the history of smoking in the coronary contractive group was significantly more common than that in the negative group. The development of coronary spasm may be determined, at least in part, by the degree of coronary sclerosis as well as by gender and age. Smoking habits in both sexes and family history in females are proposed as the most important risk factors for coronary spasm.

Acetylcholine↗

PubMed1998

[The usefulness of fractal geometry for the diagnosis of small peripheral lung tumors].

PURPOSE: To assess the usefulness of fractal geometry in quantitatively evaluating the convergence of peripheral vessels on peripheral lung tumors in maximum intensity projection (MIP) images. MATERIALS AND METHODS: We studied the MIP images of 34 pathologically proved small peripheral lung tumors (lung cancer in 21, hamartoma in 13) in 34 patients. To obtain MIP images, spiral CT (SOMATOM PLUS; Siemens) was performed during a single breath hold (24-second scan time, 2-mm section thickness, and 2 mm/sec table feed time, reconstructed at 1-mm increments). To evaluate the convergence of the peripheral vessels and bronchi towards the tumor, we fixed a region of interest (ROI) on the hilar side of the lung tumor, parallel to the chest wall, which consisted of 64 x 64 square pixels, in the images that divided at the center of the window width. We counted the overlapping pixels by the two-dimensional box-counting method and obtained fractal dimensional data on lung cancers and hamartomas. RESULTS: There was a statistically significant difference in the fractal dimension (D) between lung cancers (D = 1.81 +/- 0.13) and hamartomas (D = 1.67 +/- 0.10) (P = 0.0067). CONCLUSION: Fractal geometry could be useful in the diagnosis of small peripheral lung tumors.

Diagnosis, Differential↗