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Biomedical subjects

T Hirai

Publications and source records attributed to T Hirai.

At least 235 records · Page 13Linked to original sources
PubMed1997

Zinostatin stimalamer-transcatheter arterial embolization for hepatocellular carcinoma: a comparison with lipiodol-transcatheter arterial embolization.

Twenty patients with unresectable hepatocellular carcinoma were treated by zinostatin stimalamer-transcatheter arterial embolization (SMANCS-TAE). After administration of SMANCS, a superselective catheterization technique was used to inject gelatin sponge particles into the artery or artery branch supplying the cancer-bearing segment. We compared the results of SMANCS-TAE with Lipiodol (Yamanouchi, Tokyo, Japan)-TAE performed during the same period. In 18 of 20 patients (90%), a tumor necrosis rate of 100% (grade 4) was obtained after one or two courses of SMANCS-TAE. The SMANCS group was superior to the Lipiodol-TAE group in terms of the tumor reduction rate, alpha-fetoprotein reduction rate, and cumulative 1.5-year survival rate, but not significantly. No severe side effects were noted after SMANCS-TAE. SMANCS-TAE appears to have potential as a new treatment for hepatocellularcarcinoma, and patients treated with this technique will be monitored to elucidate the long-term effects.

Aged↗
PubMed1997

[Video-assisted thoracoscopic surgery for a 89-year-old patient with primary lung cancer--report of a case].

A 89-year-old woman was referred to our hospital because of a relatively defined shadow of the right peripheral lung in chest roentgenograms. Although this case couldn't be diagnosed with transbronchial lung biopsy, adenocarcinoma of the lung (c-T1N0M0) was suspected because of radiological findings. We planned video-assisted pulmonary partial resection of the S6 in consideration of age and general status. Her postoperative courses was uneventful with no complications. Video-assisted thoracoscopic surgery is one of the treatments for elderly patients with peripheral early stage lung cancer.

Adenocarcinoma↗
PubMed1997

[Transesophageal echocardiographic findings of cortical and perforating infarctions in patients with atrial fibrillation].

The predictive value of transesophageal echocardiography was investigated for the risk stratification of atherothrombotic or embolic cerebral infarction in patients with atrial fibrillation. Left atrial spontaneous echo contrast, peak flow velocity in the left atrial appendage and generalized atherosclerosis as estimated by the intima-media wall thickness of the thoracic aorta were assessed by transesophageal echocardiography in consecutive patients with paroxysmal (n = 25) or chronic (n = 60) atrial fibrillation (mean [+/-SD] age; 63 +/- 11 years). All patients underwent brain computed tomography or magnetic resonance imaging to evaluate the presence or absence of cerebral infarction. The location of cerebral infarction was divided into two territories, the cortical branch (cortical infarction) and deep perforators (perforating infarction), to evaluate embolic and atherothrombotic cerebral infarction, respectively. Cortical and perforating infarctions were found in 42% and 16% of all patients, respectively. The grade of spontaneous echo contrast was higher in patients with cortical infarction than in those without cortical infarction. Patients with perforating infarction showed thicker aortic wall compared with patients without perforating infarction. Other parameters had no predictive value to differentiate perforating from cortical infarctions. Multiple regression analysis revealed that spontaneous echo contrast and age were independent predictors of embolic cortical infarction, whereas intima-media wall thickness of the aorta and hypertension were useful in predicting the risk of atherothrombotic perforating infarction. Transesophageal echocardiography is useful for predicting embolic cortical infarction and atherothrombotic perforating infarction.

Atrial Fibrillation↗
PubMed1997

Standardization of low attenuation area versus total lung area in chest X-ray CT as an indicator of chronic pulmonary emphysema.

We examined the methods for measuring the LAA% (100 x low attenuation area/total lung area) on thoracic X-ray CT scans in order to develop a useful indicator of chronic pulmonary emphysema (CPE). First, we modified the method for calculating the LAA% to be applicable by the programming tool installed in a commercially available CT machine in order to minimize manual procedures. This new method proved to be applicable in all CT machines produced after 1987. Second, we examined the difference in the Hounsfield Unit (HU) between different CT machines using two kinds of phantoms. One phantom was composed of Styrofoam, which has a density similar to the low attenuation areas. The other phantom was composed of Styrofoam and water, which has a density similar to the lung. We proved that the difference of LAA% with the correct value was 5% at maximum among four different CT machines. Thus, the phantom developed in the present study may play an important role in the standardization of HU. Finally, the possibility of decreasing the X-ray levels was examined. Twenty-five percent of the standard electrical current provided the same LAA% in cases where the subject was an established CPE patient, whereas the LAA% was overestimated in subjects with a normal LAA% value. However, a correction using a linear regression equation may be possible in the latter cases. It may be concluded that LAA% analysis can easily be performed in many city hospital, without much investment of manual procedures or any corrections to the HU levels between different CT machines. This method may be useful as a routine follow up for CPE patients because of the smaller irradiated dose given when using a CT machine.

Algorithms↗
PubMed1997

MR changes in the calcarine area resulting from retinal degeneration.

PURPOSE: To study MR images for atrophic changes in the calcarine area resulting from retinal degeneration. METHODS: MR images from nine patients with retinal degeneration confirmed by ophthalmologic examination and from 30 healthy volunteers were reviewed. The causes of retinal degeneration were hereditary pigmentary degeneration of the retina (four patients), high myopia (two patients), and chorioretinal atrophy (three patients); all patients had visual disturbances and visual field abnormalities. To estimate the morphological changes of the calcarine area, the widths of the right and left calcarine fissures were measured on T1-weighted sagittal images and compared with images from age-matched control subjects. RESULTS: The calcarine fissures were significantly dilated in the patients with retinal degeneration. The anterior and middle points, which represent the peripheral visual field center, were more dilated than the posterior point. CONCLUSION: The MR findings suggested calcarine atrophy related to retinal degeneration. Transneuronal degenerative changes may occur in the calcarine area after retinal degeneration.

Aged↗
PubMed1997

MR of epidermoids with a variety of pulse sequences.

PURPOSE: To assess the usefulness of fluid-attenuated inversion recovery (FLAIR) and constructive interference in steady state (CISS) sequences in depicting epidermoid tumors. METHODS: Six patients with surgically confirmed epidermoid tumors in the subarachnoid space were examined with T1-weighted MR imaging with a spin-echo sequence, and with T2- and proton density-weighted imaging with a fast spin-echo sequence, a FLAIR sequence, and a CISS sequence. In the qualitative analysis, three observers compared the five sequences for visibility of tumors and presence of artifacts. A quantitative analysis was also performed by measuring the contrast-to-noise ratio. RESULTS: On visual assessment, the FLAIR sequence depicted all tumors as hyperintense relative to cerebrospinal fluid. The CISS sequence depicted all tumors as hypointense relative to cerebrospinal fluid and was considered to show tumor extension better than the FLAIR sequence. At quantitative analysis, the mean contrast-to-noise ratios of tumor to cerebrospinal fluid on T1-, T2-, and proton density-weighted images, and on FLAIR and CISS sequences were 2.85, 3.41, 4.42, 16.13, and 20.23, respectively. The contrast-to-noise ratios for the FLAIR and CISS sequences were significantly higher than those for the T1-, T2-, and proton density-weighted sequences. The contrast-to-noise ratio was not significantly different between FLAIR and CISS sequences, although the CISS sequence was slightly superior. CONCLUSION: CISS and FLAIR sequences depicted epidermoid tumors in the subarachnoid spaces better than conventional spin-echo images did. The CISS sequence produced a relatively constant contrast between the tumors and less artifactual interference.

Adolescent↗
PubMed1997

[Primary pulmonary malignant lymphoma of mucosa-associated lymphoid tissue (MALT)--a case report with a review of Japanese literatures].

A case of non-Hodgkin malignant lymphoma of the lung was presented with a review of Japanese literatures. A 53-year-old woman was referred to our hospital because of an abnormal shadow on the roentgenogram of mass screening, with neither subjective symptoms nor abnormalities in physical examinations. Laboratory tests showed normal values. The diagnosis of pulmonary malignant lymphoma was obtained by immunohistochemical examinations. She underwent a upper lobectomy of the left lung with lymph nodes dissection of the mediastinum. The histological immunohistochemical and diagnosis of the resected tumor was primary pulmonary B-cell lymphoma of mucosa-associated lymphoid tissue (MALT) without regional lymph nodes involvement. She has been doing well without any signs of recurrence for 15 months after the operation.

Female↗
PubMed1997

Laparoscopic Hill's vagotomy by the abdominal wall lifting method.

We performed laparoscopic Hill's vagotomy by the abdominal wall lifting method in nine patients with intractable duodenal ulcer. Our original I-type lifting bar is a curved stainless-steel rod 5 mm in diameter. One I-type lifting bar is inserted intraperitoneally into each of the right and left hypochondrial regions. An incision is made in the lesser omentum near the gastroesophageal junction, and the right esophageal wall and right crus of the diaphragm are dissected and exposed. The posterior trunk of the vagus nerve is identified and divided. Then the neurovascular bundle is dissected and divided repeatedly along the lesser curvature of the stomach from the first branch of the crow's foot to the gastroesophageal junction. The mean operating time was 163 min, with little blood loss. The reduction rate of basal acid output and maximal acid output was, respectively, 73.7 +/- 0.1 and 63.7 +/- 0.1%. Four weeks after surgery, gastroduodenoscopy revealed ulcer healing to a scar.

Adult↗
PubMed1997

[A case report of Vp3 hepatocellular carcinoma responding to multidisciplinary treatment].

We report a 60-year-old man who had hepatocellular carcinoma with tumor thrombus in the main portal vein and left portal branch (VP3HCC). He was treated with transarterial chemo-embolization, surgical resection and intra-arterial infusion chemotherapy. He is now surviving without any sign of recurrence for 12 months after the initial therapy, even though the prognosis of VP3HCC is poor. This is a case in which the effect of multidisciplinary treatment was indicated.

Antibiotics, Antineoplastic↗
PubMed1996

High-Spatial-Resolution Medical-Imaging System Using a HARPICON Camera Coupled with a Fluorescent Screen.

A high-sensitivity HARPICON camera was developed for medical X-ray imaging using a fluorescent screen. It is an avalanche-multiplication-type image pick-up tube and is 32 times more sensitive than conventional tubes. The camera also has a wider dynamic range than conventional medical-imaging cameras because a maximum output signal current of 2.3 muA is obtained and, in high-illumination-intensity regions, photocurrent is not proportional to illumination intensity. The fluorescent screen is an intensifying screen of the type used for radiographic screen-film combinations in medical examination. An X-ray image on the screen is focused on the photoconductive layer of the pick-up tube using a coupling lens with f/0.65. Experiments were performed using monochromated X-rays at the Photon Factory. An image of a spatial resolution test chart was taken in a 525 scanning-line mode of the camera. The chart pattern of 5 line-pairs mm(-1 )(spatial resolution of 100 mum) was observed at an X-ray input field of 50 x 50 mm. Real-time digital images of the heart of a 12 kg dog were obtained at a frame rate of 60 images s(-1) after injection of a contrast medium into an artery. The images were stored in digital format at 512 x 480 pixels with 12 bits pixel(-1). High-spatial-resolution and high-contrast images of coronary arteries were obtained in aortography using X-rays with energy above that of the iodine K edge; the image quality was comparable with that of conventional selective coronary angiography.

Journal Article↗
PubMed1996

Nonuniform sympathetic nerve responses to intravenous hypertonic saline infusion.

Peripheral hyperosmolality produced by the intravenous infusion of hypertonic saline (HTS) increases mean arterial blood pressure (MAP) in experimental animals. The mechanisms mediating the pressor response have not been fully ascertained, but likely involve vasopressin and/or activation of the sympathetic nervous system. The primary aim of this study was to determine if HTS infusion produces regionally uniform or nonuniform changes in sympathetic nerve discharge (SND). For this purpose we recorded renal, splanchnic and lumbar SND during intravenous HTS infusion (2.5 M NaCl, 10 microliters/100 g BW per min) in chloralose-anesthetized, Sprague-Dawley rats. In rats with intact arterial baroreceptors, HTS infusion significantly increased MAP (17 +/- 2 mmHg) and lumbar SND (29 +/- 13%) but reduced splanchnic (-52 +/- 7%) and renal SND (-33 +/- 8%). After sinoaortic denervation (SAD), HTS infusion significantly increased MAP (28 +/- 6 mmHg) and lumbar SND (27 +/- 9%) and decreased renal SND (-22 +/- 8%). The increase in lumbar SND occurred significantly sooner in SAD compared with baroreceptor-intact rats. In contrast, splanchnic SND remained unchanged from control levels during HTS infusion after SAD. These results demonstrate that HTS infusion produces regionally nonuniform changes in SND, and suggest that the pressor and lumbar sympathoexcitatory responses to HTS infusion are opposed by the arterial baroreceptors.

Animals↗
PubMed1996

Gastric stump carcinoma after partial gastrectomy for benign gastric lesion: what is feasible as standard surgical treatment?

METHOD: Clinicopathological features and prognostic factors were evaluated in 26 cases of stump carcinoma, operated on in the recent 20 years, in search of the standard surgical treatment. BACKGROUND: Stump carcinoma usually emerges more than 20 years after the initial gastrectomy and is often not diagnosed in the early clinical stage, resulting in a significantly low incidence of curative resection compared with primary gastric carcinoma. RESULTS: No improvement in the survival curves for stump carcinoma was observed between the past two decades. Nodal metastases were frequently found within the first tier nodes, and no 5-year survivor was found among the patients with nodal metastasis beyond pN1. CONCLUSIONS: Subtotal gastrectomy might suffice for the treatment of stomal cancer, and most patients might not benefit from extensive lymphadenectomy.

Carcinoma↗
PubMed1996

MR signal intensity of the perirolandic cortex in the neonate and infant.

Our purpose was the study the magnetic resonance (MR) signal intensity of the perirolandic gyri perinatally and to correlate it with the histological findings in formalin-fixed brains, focusing on myelination. MRI of 20 neurologically normal neonates and infants, of 37-64 weeks postconception (PCA), were studied retrospectively. We reviewed four formalin-fixed brains of infants 37-46 weeks PCA microscopically. The posterior cortex of the precentral gyrus (P-PRE) and the anterior cortex of the postcentral gyrus (A-PST) had different signal intensity from the adjacent surrounding cortex. On T1-weighted images P-PRE and A-PST gave higher signal 41-44 weeks PCA; on T2-weighted images, they gave lower signal 37-51 weeks PCA. Histological examination revealed very little myelination of the nerve fibres within both the P-PRE and the A-PST, while considerable myelination was present in the internal capsule and central corona radiata. The changes in signal intensity in the perirolandic gyri may reflect not only the degree of myelination but also the more advanced development of the nerve cells, associated with rapid proliferation and formation of oligodendroglial cells, synapses and dendrites. They could be another important landmark for brain maturation.

Age Factors↗
PubMed1996

DNA polymerase betas from liver and testes of cherry salmon, Oncorhynchus masou: purification and characterization of DNA polymerase betas with acidic isoelectric points.

DNA polymerase betas from cherry salmon, Oncorhynchus masou, liver and testes were purified to near homogeneity, and no substantial differences between the enzymes were observed. The molecular weight of both enzymes, determined by SDS-polyacrylamide gel electrophoresis, was 39,000. The amino acid sequences of the N-terminus of the liver and testes enzymes were determined and compared with that of the rat enzyme. Of the N-terminal 30 amino acid residues of salmon liver DNA polymerase beta, 21 (70%) were identical to those of the rat enzyme sequence. However, unlike most eukaryotic DNA polymerase betas, the isoelectric points (pIs) of the DNA polymerase betas from salmon liver and testes were both estimated to be 6.2, which is significantly different from the alkaline isoelectric points (pI = 8.5-9.5) established for other highly purified vertebrate DNA polymerase betas. The cherry salmon DNA polymerase betas were still active at below 10 degrees C, compared with the rat enzyme.

Amino Acid Sequence↗
PubMed1996

Experimental study of allogeneically vascularized prefabricated flaps.

The authors fashioned vascularized island flaps using cryopreserved allogeneic vascular bundles as the vascular pedicles in rabbits. Auricular vessels of 8 cm in length were harvested and cryopreserved in liquid nitrogen for 30 days. The allovascular bundles were anastomosed into the recipients' native auricular vessels. Dorsal flaps (6 x 6 cm) in the recipient were raised on the implanted allovascular bundle. Eight days later, the flaps were elevated as vascular island flaps nourished by the allovascular bundle. Computed microangiography demonstrated the anastomoses between the vasculatures of the implanted vessels and the recipient sites 8 days after vascular implantation in the dorsal flap. Flap survival estimation, which was done 1 week after flap elevation, showed flap viability. Allogeneic vascular bundles proved their potential utility as vascular pedicles of autologous tissue transfer.

Anastomosis, Surgical↗
PubMed1996

Effects of ranolazine on the exercise capacity of rats with chronic heart failure induced by myocardial infarction.

Ranolazine was previously shown to stimulate cardiac glucose oxidation. Dichloroacetate (DCA) also does and was shown to improve exercise capacity in animals, but it has long-term toxicity problems. To test the hypothesis that ranolazine would increase exercise performance in the chronic heart failure (CHF) condition, we compared the exercise endurance capacities of rats with a surgically induced myocardial infarction (MI) with those of noninfarcted sham-operated (Sham) controls both before and after 14 and 28 days of drug administration. Chronic administration of ranolazine, 50 mg/kg twice daily (b.i.d.) oral, significantly reduced the endurance capacities of both Sham and MI rats (measured after a 12-h fast to reduce liver glycogen stores), as indicated by the reductions in run times to fatigue during a progressive treadmill test. Ranolazine produced reductions in resting plasma lactate and glucose concentrations of animals fasted for 12 h (consistent with stimulating glucose oxidation); however, tissue glycogen concentrations measured in various locomotor muscles located in the animal's hindlimb were unaffected when measured 48 h after the last treadmill test and after 12 h of fasting. Chronic administration of ranolazine did not increase the endurance capacity of rats with CHF induced by MI at the dosage and with the protocol used. To the contrary, the chronic administration of ranolazine appears to reduce the work capacity of all rats, suggesting that this drug may not be useful therapeutically in the treatment of CHF. Whether the decrements in endurance capacity produced by ranolazine are related to the high plasma concentrations of the drug produced in this study as compared with previous studies in humans remains subject to further experimentation.

Acetanilides↗
PubMed1996

Age-related changes in the olfactory system of dogs.

Age-related changes in the olfactory system were examined in 22 dogs ranging in age from 10 to 19 years old. Atrophic changes with degeneration were observed in the olfactory epithelium of dogs older than 14 years; the changes were prominent in the dogs over the age of 17 years. Immunohistochemistry using an anti-carnosine antibody, which is a marker for the olfactory cells, demonstrated a decrease in the number of olfactory cells. Electron microscopy also showed a decrease in the number of cilia of olfactory cells and microvilli of supporting cells. Atrophic changes with the features of regeneration were rarely observed in the aged animals. Lipofuscin-like granules in the olfactory epithelium became prominent with age. These age-related changes were similar to those reported in the olfactory epithelium of man and rats. Dystrophic neurites were not detected by a modified Bielschowsky stain or by neurofilament, synaptophysin and tau immunohistochemistry in the olfactory mucosa. There was no beta-amyloid- and ubiquitin-immunostaining in the olfactory mucosa. Senile brain changes, including cerebrovascular amyloidosis, age-related astrocytic gliosis and ubiquitin deposits were found in the olfactory bulb, although neurofibrillary tangles and senile plaques were not detected either by a modified Bielschowsky stain or by beta-amyloid immunohistochemistry. These results indicate that dog may be a useful animal model to study the age-related changes in the olfactory system in man.

Age Factors↗