Search PubMed⌕ Search

Biomedical subjects

K Harada

Publications and source records attributed to K Harada.

At least 1,459 records · Page 81Linked to original sources
PubMedDate not supplied

Change of temperature in mouse tumour tissue immersed in a water bath at 44 degrees C.

We investigated the change in temperature in tumour and normal tissues of mice when immersed in a water bath at 44.0 degrees C as part of a series of studies of hyperthermia. The right hind legs of the mice bearing the experimental tumour sarcoma 180 were immersed in the water bath, and measurements were performed using the multi-thermocouple thermosensor from a radiofrequency (RF) generator every 24 sec with a precision of 0.1 degrees C. The temperature in all tumour tissues exceeded 43.0 degrees C only at 1 min 24 sec after immersion of the limbs. The rise in temperature then reached a plateau phase, and was maintained around 44.0 degrees C. However, we found that the temperature of the normal tissue was about 0.6 degrees C lower than that of the tumour tissue or the tissue around the tumour at the plateau phase.

Animals↗
PubMedDate not supplied

Usefulness of Lens culinaris agglutinin A-reactive fraction of alpha-fetoprotein (AFP-L3) as a marker of distant metastasis from hepatocellular carcinoma.

The objective of this study was to clarify the relationship between the serum level of the Lens culinaris agglutinin A-reactive fraction of alpha-fetoprotein (AFP-L3) and the clinical features including sex, age, Child's classification, virus markers, tumour size, tumour stage, distant metastasis, histopathologic findings, portal thrombus and outcome of hepatocellular carcinoma (HCC). We measured the AFP-L3 levels in 170 HCC cases at the time of diagnosis using lectin-affinity electrophoresis followed by antibody-affinity blotting. The patients were divided into two groups, those who were AFP-L3 positive (n=56; AFP-L3 >/=15% relative to the total alpha-fetoprotein (AFP) concentration) and those who were AFP-L3 negative (n=114; AFP-L3 <15%). Then we examined the association between the serum AFP-L3 level and the clinical features of HCC. No significant differences were found in age, sex, and virus markers between the AFP-L3-positive and -negative groups. However, patients in the positive group had worse liver function and larger tumours compared to the negative group. They also had more advanced cancer with poor tumour histology compared to the negative group. Distant metastasis was diagnosed significantly more often in the positive group than that in the negative group. There was no significant correlation between the AFP-L3 level and portal thrombus. Although the follow-up period was brief the prognosis for the positive group clearly was poor. These results suggest that AFP-L3 is a useful indicator of distant metastasis and a poor prognosis for HCC.

Adult↗
PubMedDate not supplied

Percutaneous injection of a low-concentration alkaline solution targeting hepatocellular carcinoma.

We developed a percutaneous low-concentration alkali injection therapy (PLAIT) targeting hepatocellular carcinoma (HCC), and compared the necrotic areas in the livers of rats that had received PLAIT [an alkaline solution of sodium hydroxide (NaOH)] with those that had received percutaneous ethanol injection therapy (PEIT) and percutaneous acetic acid injection therapy (PAIT). The necrotic area increased with increasing concentrations of NaOH solution. The survival rate of rats was 100% up to a concentration of 4 N; however, the rate dropped below 80% with concentrations over 5 N. Also, at a concentration of 2 N, the necrotic area increased with increasing quantities from 0.01 ml to 0.1 ml. PLAIT using 0.05 ml of 2 N NaOH was 1.56 times more effective than PEIT using 0.05 ml of 99.5% ethanol, and 63.33% less effective than PAIT using 0.05 ml of 50% acetic acid. However, the survival rate after PAIT was 50%, while that after PLAIT was 100%. Histopathological observation of normal rat livers after injection of 2 N NaOH at a volume of 0.05 ml showed that the tissue necrosis spread radially from the site immediately after injection by PLAIT, but necroses were not found in other organs. We conclude that PLAIT has promise as a new form of local therapy for HCC.

Animals↗
PubMedDate not supplied

Angiogenesis and vasodilation in skin warts. Association with HPV infection.

BACKGROUND: Angiogenesis is required for tumour growth. Since human papillomavirus (HPV) infection is associated with the development of neoplastic lesions, the aim of this study was to determine the possible association between HPV infection and angiogenesis in benign tumours. MATERIALS AND METHODS: Specimens of skin warts which were either negative for HPV types 1, 2, 3 and 4 (HPV-ve; n = 15), or positive for HPV2 (HPV+ve; n = 19) were compared with normal skin (NS, n = 10). Vascularity and inflammation were assessed in consecutive sections. vWF-positive blood vessels were classified as small or large using a cut-off value of 50 microns diameter. RESULTS: Vascularity values for small vessels increased significantly from NS to HPV-ve warts and from HPV-ve to HPV+ve warts. Large vessels were found only in warts and their abundance was not related to HPV status. No significant association was found between vascularity and inflammation or between vascularity values for small and large vessels. CONCLUSIONS: The development of skin warts is accompanied by angiogenesis and vasodilation and these two processes may be independently regulated. Further increased angiogenesis, but not vasodilation, is associated with the presence of HPV type 2 DNA.

Analysis of Variance↗
PubMedDate not supplied

Trace analysis of microcystins in environmental samples.

Microcystins, the cyclic heptapeptide toxins produced by cyanobacteria such as Microcystis sp., show potent hepatotoxicity and tumor-promoting activity through inhibition of protein phosphatases 1 and 2A. A toxic incident resulting in the death of 50 people in Brazil in 1996 was due to microcystins in water used for hemodialysis. Microcystins are now threatening human health and life, but many problems associated with microcystins remain unsolved. This report describes how to analyze trace amounts of microcystins in complicated matrixes such as liver tissue, lake water, and sediments.

Animals↗
PubMedDate not supplied

Dynamic MR studies of hepatocellular carcinoma with portal vein tumor thrombosis.

Gd-DTPA enhanced dynamic MR studies were evaluated in six patients with hepatocellular carcinoma associated with portal vein tumor thrombus. The portal vein tumor thrombus was clearly visualized as a low intensity lesion. The hepatic segment supplied by the portal vein showed high intensity, probably due to decreased portal blood flow and compensatory arterial blood flow. Tumors located in this segment were shown as areas of relatively low intensity compared with segmental high intensity areas. Thus dynamic MR study was found to be a useful method for differentiating the tumor from the surrounding nontumorous tissue with decreased portal blood flow.

Adult↗
PubMedDate not supplied

Magnetic susceptibility artifact in spin-echo MR imaging of the pituitary gland.

PURPOSE: To evaluate the magnetic susceptibility effect on spin-echo MR images of the pituitary gland. METHODS: Air-in-water phantom experiments and studies in normal volunteers were performed using various sampling bandwidth (8.3-33.3 kHz) spin-echo sequences with the polarity of the readout gradient normal or reversed. RESULTS: Attachment of a sphenoid septum to the sellar floor was the major factor in the appearance of the inferior surface of the pituitary gland. Patterns of distortion and/or artifactual signal intensities, related to the presence or absence of the attachment, were accentuated on the images with narrower bandwidth. A "spearhead shape" deformity of the sphenoid sinus was observed both in the air-in-water phantom experiment, and when no sphenoid septum was present. When a sphenoid septum was present, two spearhead shapes side by side were present. High-intensity artifacts were seen where the sellar floor was misplaced into the pituitary gland. CONCLUSION: Knowledge of the patterns of distortion and high-intensity artifact is important in the diagnosis of pituitary lesions.

Adult↗
PubMedDate not supplied

Tolerance to the increase in coronary blood flow induced by KRN2391.

We examined whether KRN2391, isosorbide dinitrate and nitroglycerin induced tolerance in coronary arteries. Intracoronary arterial administration of KRN2391 (1 microgram), isosorbide dinitrate (30 micrograms) or nitroglycerin (3 micrograms) produced equipotent coronary vasodilatation. Development of tolerance was determined by whether the increase in coronary blood flow, caused by intracoronary arterial administration of these drugs, was attenuated by intravenous infusion of KRN2391, isosorbide dinitrate or nitroglycerin. The increase in coronary blood flow, caused by intracoronary arterial administration of KRN2391 was not affected by intravenous infusion of KRN2391 (0.3 or 1 micrograms/kg/min), isosorbide dinitrate (30 or 100 micrograms/kg/min) or nitroglycerin (1 or 3 micrograms/kg/min). The increase in coronary blood flow, caused by intracoronary arterial administration of isosorbide dinitrate or nitroglycerin, was significantly diminished by intravenous infusion of isosorbide dinitrate and nitroglycerin, but was unaffected by intravenous infusion of KRN2391. The present results suggest that KRN2391 does not induce acute tolerance by itself or cross-tolerance between KRN2391 and other nitrates.

Animals↗
PubMedDate not supplied

Asymmetric appearance of intracranial vessels on routine spin-echo MR images: a pulse sequence-dependent phenomenon.

PURPOSE: To determine the cause of right to left signal intensity differences arising from intracranial vessels during routine spin-echo axial MR imaging of the head. METHODS AND RESULTS: Using a normal imaging sequence in which the default directions of the frequency and phase axes were horizontal and vertical, respectively, differences in signal intensity arising from the vertebral arteries were observed in a healthy subject. With the exchange of the frequency and phase axes relative to the normal sequence, no signal intensity differences between the vertebral arteries were recognized. Other pulse sequence modifications, ie, the use of motion-compensating gradients and the reversed polarity of the frequency-encoding gradient, also resulted in variable appearances of the vertebral arteries, indicating that the right-to-left signal asymmetry of the vertebral arteries observed on the normal spin-echo image results from a pulse sequence dependent phenomenon. CONCLUSIONS: Frequency-encoding and slice-selection gradients both produce motion-induced phase shifts. These phase shifts depend on the angle between the direction of flow and that of the effective vector sum of these gradients. The asymmetric appearance of the vertebral arteries during normal spin-echo imaging was found to result from the angle dependence of motion-induced phase shifts. Awareness of this artifactual phenomenon is important to avoid confusing it with conditions such as stenosis/occlusion, dissection, or slow flow.

Artifacts↗
PubMedDate not supplied

Diffusion imaging of the human brain: a new pulse sequence application for a 1.5-T standard MR system.

We developed a new pulse sequence and investigated whether the anisotropic diffusion in the human brain can be detailed with a standard whole-body MR imager. Apparent diffusion coefficient maps were produced by the proposed sequence using a 1.5-T MR unit. The sequence employed simultaneous application of three orthogonal gradients to achieve an optimal signal attenuation for imaging the brain without any increase in echo time. The orientation of the effective diffusion-encoding gradient was off-axis. On the in vivo apparent diffusion coefficient maps of four healthy volunteers, white matter tracts (the internal capsule and the corpus callosum) and the cortical and deep white matter showed anisotropic diffusion. In the gray matter, such as basal ganglia and thalami, anisotropic diffusion was not observed. A typical whole-body imager can provide in vivo human brain diffusion images of clinical quality. This technique has promising implications for the evaluation of brain development and the diagnosis of degenerative diseases.

Adult↗
PubMedDate not supplied

Tongue cancer: correlation of MR imaging and sonography with pathology.

Ten patients with tongue cancer underwent both MR imaging and sonography. In seven of these patients, pathologic findings from glossectomies were correlated with MR and sonographic results. MR images of resected specimens also were obtained in two patients, and relaxation time was calculated in one of these patients. MR images (5- to 7-mm thick slices) were obtained by using a 0.1-T resistive magnet with a 128 x 256 acquisition matrix. MR and sonography had almost the same sensitivity for detecting primary-site tongue cancer. However, in the three patients with extraorgan spread of tumor, MR was superior, showing three of three cases, compared with sonography, which showed extraorgan spread in only one of the three cases. Although MR failed in one patient to differentiate postradiation scar tissue from tumor, because of similar relaxation time of both, this imaging technique proved to be an important adjunct to the physical examination in the staging of tongue cancer.

Adult↗
PubMedDate not supplied

Transabdominal operation for carcinoma of the gastric cardia: application of pulling-up retractor and EEA stapler.

In order to ascertain the advantages of the combined use of the pulling-up retractor and EEA stapler, we reviewed 88 patients who underwent surgery for upper stomach cancer between 1978 and 1986. The length of resected esophagus was significantly longer in patients operated on using an abdominal approach with this combination, as in those using a thoracoabdominal approach, than in those who were operated on using an abdominal approach with only the retractor or without the instruments (p less than 0.05). A relatively high incidence of leakage occurred at the anastomosis of the esophagus to the stomach or jejunum following operation using a transabdominal approach without the instruments. Pulmonary complication tended to be decreased in the non-thoracotomized patients compared to the thoracotomized patients. Postoperative radiogram following the combined use showed an esophagogastrostomy at a high level in the mediastinum. Our combination technique enables lymphadenectomy in the lower mediastinum and a sufficiently long enough resection of the esophagus without fatal complications.

Anastomosis, Surgical↗
PubMedDate not supplied

Cerebrospinal fluid cytology in patients with brain tumors; a simple method using the cell culture technique.

A simplified cytologic method using the cell culture technique was employed in 71 cases with brain tumor. Neoplasitc cells were demonstrated in 17 cases (24%), that is in 11 out of 30 cases of glioma, four out of ten cases of metastatic brain tumor, and two out of 17 cases of meningioma. None of 14 other miscellaneous tumors proved positive. Identification of glioma cells could be easily made because they usually showed characteristic morphology and good proliferation in vitro. However, for other types of tumor, conventional methods were considered to be superior to the culture method because their exfoliated cells usually underwent rapid degeneration without showing characteristic morphology during the culture. Some of the illustrative cases were presented.

Adolescent↗
PubMedDate not supplied

CT of the brain in acute carbon monoxide intoxication: characteristic features and prognosis.

Of 60 patients with acute carbon monoxide (CO) intoxication caused by accidental or intentional inhalation of natural gas, smoke inhalation, or inhalation of automobile exhaust, 23 had characteristic computed tomographic findings. The most common finding, seen in 21 patients, was symmetric and diffuse low density in the cerebral white matter, which was more advanced in the centrum semiovale and varied in degree from slight to severe. In 18 patients there was a symmetric, bilateral, round low-density lesion in the globus pallidus. The size of the lesion varied from small (limited to the globus pallidus) to large (extension to the internal capsule). Of the 23 patients, six made a good recovery, four recovered with some disabilities, eight remained in a vegetative state, and five died. The prognosis depended on the severity of the cerebral white-matter changes and not on the size of the low-density lesion of the globus pallidus.

Brain↗
PubMedDate not supplied

The use of non-deparaffinized tissue sections for staining leprosy bacilli.

Reduced acid-fast staining of leprosy bacilli occurs during the dewaxing of paraffin sections by xylene and alcohols; the older and more decrepit bacilli being especially affected. By the use of non-deparaffinized sections, the leprosy bacilli which could not be stained with the usual carbol fuchsin are strongly stained. Moreover, non-deparafinized sections can be used for the periodic acid-carbol pararosanilin stain or methenamine silver stain for demonstrating mycobacteria.

Humans↗
PubMedDate not supplied

A modified allochrome procedure for demonstrating mycobacteria in tissue sections.

A modified allochrome staining procedure is presented as being the most reliable and sensitive method for demonstrating mycobacteria in tissue sections. The technic is as follows: Deparaffinize formalin fixed sections, oxidize in 10% periodic acid for 24 hours, differentiate in 1% HCl-70% ethanol, stain in Weigert's iron hematoxylin nuclear stain, and counterstain in picro-methyl glue. Mycobacteria stained brilliant red in contrast with the allochrome-stained background tissues, and apparently otherwise chromophobic bacilli are demonstrated.

Animals↗