Biomedical subjects

N Hashiguchi

Publications and source records attributed to N Hashiguchi.

At least 37 records · Page 2Linked to original sources

PubMed1997

Colour Doppler sonography of breast masses: a multiparameter analysis.

OBJECTIVE: To evaluate signals from breast lesions on both colour and spectral Doppler US, and to correlate findings with angiographic and histopathological features including microvessel density. MATERIALS AND METHODS: One hundred and sixteen breast lesions in 113 patients were evaluated with colour Doppler ultrasonography. Subjective and semi-quantitative assessment of colour signals as well as spectral Doppler analysis were performed and compared. Comparison of colour Doppler features with angiographic and histopathological findings were also carried out. RESULTS: Subjective evaluation revealed that colour signals were more commonly found in malignant (89%) than benign (56%) lesions. Malignant lesions demonstrated a more elaborate vascular network (51%) compared to 12.5% in benign lesions. Spectral Doppler analysis revealed slightly higher specificity values for the pulsatility and resistivity indices, respectively, but lower sensitivity and accuracy values compared to qualitative assessment. Colour Doppler patterns corresponded well with angiograhic images, however, the correlation between colour Doppler parameters and microvessel density was not significant. CONCLUSION: Despite the increased examination time required, spectral analysis does not appear to contribute significantly to the differentiation between malignant and benign breast tumours. Features such as the density, pattern and predominant site of colour signals may be more useful for the evaluation of breast lesions on colour Doppler imaging.

Adolescent↗

PubMed1997

[Study of diarrhea-inducing strains of Escherichia coli mainly isolated in Kanto area between June and September 1996].

A total of 21,609 faecal specimens obtained from patients with diarrhea mainly in Kanto area between June and September 1996 were investigated to identify the causative pathogens for diarrhea. One-hundred fifty-seven strains of Escherichia coli of 29 different O-serotypes were isolated as the causative pathogens, which were previously recognized to induce severe abdominal cramps and diarrhea. Of these, 114 strains, in which the possibility of enterohemorrhagic E. coli due to their O-serotypes was predicted, were examined for the producibility of Vero toxins. Twenty-six (76.5%) of the 34 strains of E. coli O157 produced the Vero toxins, and other 8 strains were the non-producers. Twenty of the 26 producers produced both VT1 and VT2, whereas the other 6 strains produced VT2 only. Furthermore, 4 strains of E. coli O26, and 1 strain each of E. coli O125 and O126 produced Vero toxins. Thirty-two of the 114 strains, isolated from the patients with diarrhea and selected as the enterohemorrhagic E. coli according to the specific O-serotypes, were actually confirmed produce Vero toxins. Thirty-four strains of E. coli O157 tested were susceptible to all antibiotics such as ampicillin, doxycylin, levofloxacin, fosfomycin, chloramphenicol and polymyxin B, and no strains resistant to levofloxacin, polymyxin B and fosfomycin were found.

Bacterial Toxins↗

PubMed1996

Hemodialysis effect on serum boron level in the patients with long term hemodialysis.

Serum and dialysate boron levels in 17 patients with long term hemodialysis (HD) were determined by inductively coupled plasma emission spectrometry (ICPES). Serum boron level was compared with the value of age matched 467 healthy controls and the relationship between serum and dialysate boron level was analyzed. The results showed that serum boron level was significantly higher at the beginning of HD, and lower at the completion of HD in comparison with controls. Although the dialysate was contaminated with trace boron, HD resulted in an excessive decrease of serum boron, rather than boron exposure from the dialysate. Boron hemodialyzability was almost proportional to the gradient of the boron level at the beginning of HD and it could be controlled by the adjustment of the gradient. In conclusion, the serum boron level was very much disturbed in long term HD patients. If boron excess in serum at the beginning of HD, or deficiency at the completion of HD may contribute to the complications of HD patients, fine adjustment and close surveillance of the gradient should be taken into account.

Acute Kidney Injury↗

PubMed1996

Breast lesions: correlation of contrast medium enhancement patterns on MR images with histopathologic findings and tumor angiogenesis.

PURPOSE: To compare qualitative and quantitative magnetic resonance (MR) mammographic features of breast lesions with histopathologic findings, especially tumor angiogenesis. MATERIALS AND METHODS: Seventy-three patients (72 women, one man; aged 30-78 years; mean age, 51.0 years) with suspicious breast lesions underwent MR imaging. Noncontrast medium-enhanced localization imaging and then gadolinium-enhanced dynamic fast spoiled gradient-recalled-echo (SPGR) imaging were performed in all patients. In selected patients, subtraction fast SPGR images were obtained. The Pearson and Spearman correlation tests were used to determine the strength of the relationships between enhancement parameters and microvessel determinations. RESULTS: Time intensity curve type correlated with microvessel density grade (Spearman rank correlation test: r = .90, P < .001). The steepest slope of contrast medium uptake correlated with microvessel counts (Pearson correlation test; r = .83, P < .001). Peripheral enhancement in invasive carcinomas (n = 9) correlated with high peripheral and low central microvessel densities, which were associated with desmoplasia and/or necrosis. Internal septations (n = 2) were seen only in fibroadenomas. CONCLUSION: The density and distribution of microvessels may play major roles in the determination of the initial rate of contrast medium uptake and the heterogeneity of tumor enhancement.

Adult↗

PubMed1996

[Pulmonary arterio-venous fistula treated by embolization with steel coils].

A 63-year-old man was referred to our hospital for evaluation and treatment of severe dyspnea on exertion which had persisted for a few years. He presented with cyanosis and markedly clubbed fingers, and laboratory data disclosed hypoxemia, polycythemia, and liver dysfunction. A chest X-ray film showed increased vascular markings in both lower lung fields. Arterial blood gas analysis showed severe hypoxemia, with a PaO2 of 46 Torr and a PaCO2 of 31 Torr while the patient was breathing room air. The PaO2 increased only slightly with inhalation of 100% oxygen, which suggested the presence of a large R-L shunt. The hepatopulmonary syndrome was diagnosed. Angiography of the pulmonary artery revealed a large pulmonary arterio-venous fistula with markedly dilated arteries in both lower lobes. Transarterial embolization was done three times with a total of 62 metal coils. There were no complications. Embolization reduced the shunt from 56% to 31%, increased the PaO2, and relieved the dyspnea. Pulmonary artery embolization can be useful in treating pulmonary arterio-venous fistulas associated with the hepatopulmonary syndrome.

Arteriovenous Fistula↗

PubMed1996

Human peroxisome assembly factor-2 (PAF-2): a gene responsible for group C peroxisome biogenesis disorder in humans.

Peroxisome-biogenesis disorders (PBD) are genetically heterogeneous and can be classified into at least ten complementation groups. We recently isolated the cDNA for rat peroxisome assembly factor-2 (PAF-2) by functional complementation using the peroxisome-deficient Chinese-hamster-ovary cell mutant, ZP92. To clarify the novel pathogenic gene of PBD, we cloned the full-length human PAF-2 cDNA that morphologically and biochemically restores peroxisomes of group C Zellweger fibroblasts (the same as group 4 in the Kennedy-Krieger Institute) and identified two pathogenic mutations in the PAF-2 gene in two patients with group C Zellweger syndrome. The 2,940-bp open reading frame of the human PAF-2 cDNA encodes a 980-amino-acid protein that shows 87.1% identity with rat PAF-2 and also restored the peroxisome assembly after gene transfer to fibroblasts of group C patients. Direct sequencing of the PAF-2 gene revealed a homozygous 1-bp insertion at nucleotide 511 (511 insT) in one patient with group C Zellweger syndrome (ZS), which introduces a premature termination codon in the PAF-2 gene, and, in the second patient, revealed a splice-site mutation in intron 3 (IVS3+1G-->A), which skipped exon 3, an event that leads to peroxisome deficiency. Chromosome mapping utilizing FISH indicates that PAF-2 is located on chromosome 6p21.1. These results confirm that human PAF-2 cDNA restores peroxisome of group C cells and that defects in the PAF-2 produce peroxisome deficiency of group C PBD.

ATPases Associated with Diverse Cellular Activitie↗

PubMed1996

[Clinical usefulness of helical computed tomography in evaluating chronic obstructive pulmonary diseases].

To assess the usefulness of healical computed tomography (CT) in evaluating pathophysiological abnormalities in chronic obstructive pulmonary disease, we compared the results of helical CT with those of pulmonary-function tests in 46 subjects with pulmonary emphysema. We obtained 3-D images of emphysematous lung tissue by choosing voxels with values less than -930 HU because the mean CT score in 10 normal subjects was -869 +/- 29 HU. For each patient the total lung volume (TLV) was computed from the 3-D image of the entire lung with CT score less than -600 HU, and the volume of emphysematous lung tissue (ELV) was computed from the lung with CT score less than -930 HU. TLV measured on inspiration correlated significantly with TLC (r = 0.601, p < 0.001), and TLV measured on expiration correlated significantly with RV (r = 0.836, p < 0.0001). The difference between inspiratory TLV and expiratory TLV correlated significantly with VC (r = 0.781, p < 0.001). ELV both on inspiration and on expiration correlated significantly with FEV1/FVC (p < 0.001) and with RV (p < 0.01, p < 0.001, respectively). These results suggest that the volume data obtained by helical CT reflect functional abnormalities of the lung. In addition to volume data, the distribution of abnormal lung tissue is easily assessed by helical CT. We conclude that helical CT is useful in evaluating pathophysiological abnormalities in chronic obstructive pulmonary disease.

Humans↗

PubMed1991

An experimental study on mandibular movement and osteoporosis.

In order to clarify the relationship between mandibular movement and osteoporosis, the authors secured the temporo-mandibular joints of 8-week-old rats to immobilize their jaws; then conducted histologic studies chronologically, up to the fifth week. After three weeks, an expansion of the marrow cavity and a reduction of the trabecular were observed in the mandibular process and mandibular fossa. During the fifth week, an osteoporosis-like state was clearly observed. Further, an irregularity in the form of mandibular process was recognized, as well as a remarkable disturbance caused by cartilaginous ossification of the articular cartilage of the condyle.

Animals↗

PubMed1990

Pathohistological study on changes observed in the temporomandibular joint after experimental mutilation and shortening of the mandibular process with special reference to the changes under abnormal mandibular movement.

Abnormal mandibular movement continues to occur when fracture of the mandibular process has resulted in abnormal occlusion or abnormal mandibular movement. However, what changes might occur in the temporomandibular joint have not yet been fully clarified. In the present study, a fracture of the condylar process was experimentally induced in rats, and the resulting bone ends were wired in place. That is to say, the resulting displacement was fixed permanently. Histological studies were made on the changes of the temporomandibular joint at the postoperative third month in those rats which demonstrated abnormal occlusion and abnormal mandibular movement. Lack of uniformity of the fibrous layer and a shallowing of the mandibular fossa; proliferation of the fibrous connective tissue and reduction in size of the superior and inferior articular cavity; tylosis and irregularity in the articular disc; deformation and tylosis of the fibrous layer of the articular cartilage, tendency of the layer structure in the articular cartilage to disappear, and some effect on cartilaginous ossification in the condyle; flattening of the condyle and thinning of the layer structure in the condylar articular cartilage in the unaffected side of the mandibular joint. These changes were observed to be more marked as the displacement and occlusal abnormality of the mandible intensified, showing no morphological adaptation of the temporomandibular joint.

Animals↗

PubMed1990

An experimental study on the healing process after excision of the articular disc of the mandible--effect of short-term intermaxillary fixation.

In the present study, intermaxillary fixation for a period of 1 or 2 weeks after excision of the articular disc was administered to maturing rats. After removal of the fixation, the animals were allowed unrestricted mandibular movement. Histological observations were made at the postoperative 3rd month in those rats which demonstrated normal occlusion. As a result, it was found that the normal articular disc did not regenerate. However, in the articular cavity, both connective tissue and articular disc-like structures were found. The major changes in the mandibular fossa were tylosis of the outer fibrous layer of the fossa and an accompanying shallowing tendency. The major changes in the condyle were tylosis and morphological deformation of the fibrous layer of the parietal region. The deformation was mainly manifested by a fan-shaped hypertrophy. In the cases in which neither connective tissue nor articular disc-like structures were present in the articular cavity, changes in the mandibular fossa and condyle were remarkable. The appearance of the articular disc-like structure was more frequent in cases with 2-week intermaxillary fixation than in those with 1-week fixation.

Animals↗

PubMed1989

[Comparison of intravenous drip infusion excretory urography using ionic and non-ionic contrast media].

Ionic and non-ionic contrast media were compared for use in intravenous drip infusion excretory urography. Sixty consecutive cases were classified alternately into two groups, ionic and non-ionic, excluding cases which were known to have factors affecting contrast ability adversely, such as hydronephrosis, renal failure and so on. Each group consisted of 30 cases. A hundred ml of the ionic contrast medium (Diatrizoate--60% Urografin) or non-ionic contrast medium (Iopamidol--Iopamiron 300) was administered I.V. by drip infusion, each infusion taking less than 10 minutes, using a 18 G needle, and 0-minute, 10-minute and 20-minute films were obtained. Visibility of nephrogram, calyceal system, renal pelvis, ureters and bladder were evaluated, ranging from 0 to 3, by six radiologists who were not informed of the contrast medium used. Some detailed factors such as radiographic contrast and fullness of the collecting system and of the bladder were also analyzed. Visualization rate of the ureters was defined as the length of visualized ureters divided by the distance between the renal pelvis and the ureteral orifice of the bladder. There was no significant difference in visualization of nephrogram between the two groups. However, the non-ionic group was superior to the ionic group in visualization of the calyceal system and ureters with statistical significance, probably due to higher radiographic contrast of non-ionic medium. There was no statistical significance between the two groups, in fullness of the calyceal system and visualization rate of the ureters, whereas the ionic group was superior to the non-ionic group in fullness of the bladder.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1986

Antitumour effect of fibrinogen microspheres containing doxorubicin on Ehrlich ascites carcinoma.

The antitumour activity of fibrinogen microspheres containing doxorubicin has been evaluated against Ehrlich ascites carcinoma in mice in terms of changes in body weight and survival. Tumour cell injections were made on day 0 and microsphere injections on day 1, both intraperitoneally. The suppressive effect of the drug-containing microspheres on increase in body weight was higher than that of the free drug, and tumour-bearing mice given the microspheres lived longer than those given the free drug.

Animals↗

PubMed1986