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Biomedical subjects

Y Tsukamoto

Publications and source records attributed to Y Tsukamoto.

At least 145 records · Page 8Linked to original sources
PubMed1995

The coexistence of esophageal submucosal tumor and carcinoma.

The coexistence of esophageal submucosal tumor and carcinoma has been reported only in very few cases up to now, and the relationship between them is unclear. To elucidate the incidence and the pathogenesis of their coexistence, endoscopy and endoscopic ultrasonography (EUS) were sequentially performed in 95 patients who were suspected of having a submucosal tumor of the esophagus. EUS revealed 83 submucosal tumors and 12 cases of extraluminal compression. Two cases of esophageal carcinoma were observed in the series. In one patient, intraepithelial carcinoma was present on a leiomyoma originating in the muscularis mucosae, and in the other patient, multiple superficial carcinomas were presented.

Aged↗
PubMed1995

Pathophysiology and treatment of secondary hyperparathyroidism in patients with chronic renal failure.

Following four etiologies are considered as the possible reason for secondary hyperparathyroidism in the previous reports. First, a decreased serum concentration of 1,25(OH)2D3 directly stimulates PTH secretion. Second, hypocalcemia directly stimulates PTH secretion which is independent of 1,25(OH)2D3 action. Third, the presence of decreased calcemic response to PTH. Fourth, there is a strong possibility that hyperphosphatemia indirectly and/or directly may stimulate PTH secretion. The treatment of secondary hyperparathyroidism should be modified according to the stage of uremia. Excess suppression of PTH secretion could cause an adynamic bone disease. Early start of the treatment would be beneficial to prevent the bone from the development of PTH resistance.

Administration, Oral↗
PubMed1995

Endosonographic evaluation of the quality of ulcer healing induced by proton pump inhibitors.

We studied 26 gastric ulcer patients who were treated with a proton pump inhibitor to evaluate the quality of ulcer healing using endoscopic ultrasonography (EUS), and we examined the relationship between ulcer recurrence and contraction demonstrated on ulcer echoes (study I). The effect of lansoprazole versus an H2-receptor antagonist on the contraction of ulcer echoes (study II) was also investigated. In study I, gastric ulcer patients who demonstrated early healing by endoscopy often had shallow Ul-II or Ul-III ulcers and small cross-sectional areas on ulcer echoes. The early contraction on ulcer echo was associated with lower rates of ulcer relapse, and might therefore be indicative of a good quality of healing. In study II, the ulcer contraction rate after 8 weeks of treatment with lansoprazole was 71.8%, significantly higher than that achieved with H2-receptor antagonists. However, the mean cross-sectional area of gastric ulcer after 8 weeks of treatment with lansoprazole was 113.9 mm2. In conclusion, although lansoprazole was suitable for initial therapy in peptic ulcer patients, the quality of ulcer healing based on EUS findings did not appear to be adequate in patients treated for the short periods of time in this study.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed1995

Possible role of osteopontin in deposition of calcium phosphate in human pilomatricomas.

Human pilomatricomas are benign epidermal appendage tumors composed of hair matrix-like basaloid cells and keratinized remnant cells referred to as shadow cells. Deposition of calcium phosphate usually occurs in the shadow cell nests. Because osteopontin is believed to be involved in the deposition of calcium phosphate in bones, we asked whether osteopontin messenger RNA also is expressed in pilomatricomas. Using Northern blotting and in situ hybridization we detected osteopontin messenger RNA in pilomatricoma tissues but not in normal skin tissue. By the combination of in situ hybridization and immunohistochemistry, osteopontin messenger RNA-expressing cells were identified as CD68-positive macrophages surrounding the shadow cell nests. Immunohistochemistry of anti-human osteopontin antibodies revealed that the localization of osteopontin protein was consistent with that of calcium phosphate. The present results suggest that osteopontin produced by macrophages may play a significant role in the deposition of calcium phosphate in the shadow cell nests of pilomatricomas.

Amino Acid Sequence↗
PubMed1995

Two phenotypically distinct B lymphocytes (IgMhighIgDlow and IgMlowIgDhigh) in chronic gastric ulcer in the rat.

We determined the kinetics and phenotypes of infiltrating B cells in gastric ulcer in the rat induced by gastric injection of acetic acid (day 0). Few B cells were found in the lesion in the early stages of ulceration. On day 40, two kinds of B cells with phenotypes of IgMhighIgDlowOX33 (CD45)+OX19 (CD5)- and IgMlowIgDhighOX33 (CD45)+OX19 (CD5)- were scattered in the granulation tissue of open ulcers, but not in the healed scar tissue. On day 180, those two kinds of B cells formed primary follicles in the granulation tissue of open ulcers, but were absent from the healed scar tissue. The IgMhighIgDlowOX33 (CD45)+OX19 (CD5)- B cell was considered to be identical to the marginal zone B cell of rat spleen. This phenotype of B cell might be associated with inflammatory process in chronic gastric ulcer.

Acetates↗
PubMed1995

Lack of an effect of Madopar on the disposition of tolcapone and its 3-O-methylated metabolite in rats.

The effect of Madopar (benserazide and L-dopa, 1:4) on the disposition of the new selective inhibitor of catechol-O-methyltransferase, tolcapone, in rats was investigated. There was no statistically significant difference in the pharmacokinetic parameters of tolcapone in the presence or absence of Madopar except for a change in the mean residence time after oral administration. Thus, we rejected the hypothesis that the consumption of S-adenyl-L-methionine by Madopar would change the disposition of tolcapone. There were no statistically significant differences in the cumulative amount absorbed of drug and the absorption rate in the presence or absence of Madopar. We concluded that there was no interaction between tolcapone and Madopar.

Animals↗
PubMed1995

Alterations of bone matrix protein mRNA expression in rat aorta in vitro.

We examined the expression of matrix Gla protein (MGP), osteopontin (OPN), and osteonectin (ON) mRNAs in aortic rings excised from 3-month-, 10-month-, and 2-week-old rats during 72-hour incubations in serum-free media. In the aortic rings from 3-month-old rats, the expression of MGP mRNA was strong before incubation and increased during the 72-hour incubation. The expression of OPN mRNA was first detected after a 5-hour incubation and increased thereafter, and that of ON mRNA was strong before the incubation and decreased during the incubation. The expression of MGP and OPN mRNAs in 10-month- and 2-week-old rats was similar to that in 3-month-old rats. In contrast, expression of ON mRNA in 10-month-old rats and the expression of ON mRNA in 2-week-old rats was stronger than that in 3-month-old rats at every incubation period. In situ hybridization and immunohistochemistry identified the MGP, OPN, and ON mRNA-expressing cells as vascular smooth muscle cells. These results suggest that the expression of these mRNAs was regulated in incubation time-dependent and age-specific ways. We believe that this organ culture model is useful for further studies of the function of these bone matrix proteins and regulation of their expression in the vessel wall.

Animals↗
PubMed1995

Perfusion imaging of the brain by B-mode ultrasonography. An experimental study in rabbits.

BACKGROUND AND PURPOSE: The purpose of this study was to assess the ultrasonic imaging of normal rabbit brain by using echocontrast enhancer to identify the brain tissue perfusion. METHODS: A solution of SH/TA-508 (containing microbubbles of mean size 2 to 4 microns; n = 4) was used for contrast enhancement of rabbit brain tissue and was administered through the left internal carotid artery. Contrast enhancement in the ipsilateral parietal area was examined by placing a 7.5-MHz transducer on the dura after a craniectomy. Throughout the experiment, we measured parameters including arterial blood pressure, arterial blood gases, and serum glucose and hematocrit levels. We investigated whether the administration of an echocontrast enhancer would be safe for the brain tissue (n = 4). RESULTS: After injection of 100 mg/mL SH/TA-508, contrast enhancement was clearly observed within approximately 1 second in the left hemisphere (especially in the left cerebral cortex) in all animals and disappeared within 3 seconds after the end of injection. All physiological parameters remained within the normal range throughout the experiment. No focal abnormalities were observed on hematoxylin-eosin staining of the brain tissue. CONCLUSIONS: Contrast enhancement was observed in the ipsilateral hemisphere with the administration of SH/TA-508. Contrast enhancement on B-mode brain imaging would be useful for real-time identification of brain tissue perfusion and should become a promising method for bedside clinical assessment of brain tissue perfusion.

Animals↗
PubMed1995

T-614, a novel antirheumatic drug, inhibits both the activity and induction of cyclooxygenase-2 (COX-2) in cultured fibroblasts.

To elucidate the mechanism for the selective inhibition of prostaglandin E2 (PGE2) production in inflammatory tissue by T-614 (3-formylamino-7-methylsulfonylamino-6-phenoxy-4H-1-benzopyran-4-o ne), its effects on both the activity and the induction of cyclooxygenase (COX)-2 were investigated in vitro. T-614 inhibited the activity of purified COX-2 enzyme (IC50: 7.7 micrograms/ml), but was inactive against both COX-1 activities of microsomal and purified enzymes (IC50: > 300 micrograms/ml). On the other hand, when the inhibition of PGE2 production by T-614 was examined in the cultured fibroblasts stimulated with bradykinin, T-614 at 1 microgram/ml or less inhibited PGE2 release more effectively than that in the above cell-free system. Therefore, we examined which of the COX enzymes was expressed in bradykinin-stimulated fibroblasts by using both the reverse transcriptase-polymerase chain reaction (RT-PCR) and Northern blot analyses. As a result, COX-1 mRNA was constitutively expressed in the cells, whereas COX-2 mRNA was not detected without stimulation with bradykinin, but was expressed within 30 min when stimulated. Furthermore, it was found that the addition of T-614 reduced the COX-2 mRNA levels in 30 min after stimulation. These studies suggest that at least some of inhibitory effects of T-614 on prostanoids production are mediated by the synergy of the inhibition of COX-2 activity and the inhibition of induction, and such an action of T-614 may explain the pharmacological properties of this drug.

3T3 Cells↗
PubMed1995

Lungworm, Filaroides osleri, infection in a dog in Japan.

A 7-month-old male Pomeranian had severe dyspnea for 2 weeks. The lateral bronchogram showed a stenosis of the trachea. Inspite of supportive therapy including supplemental oxygen, the dog died 5 days later. Six pedunculated nodules were recognized in the mucosal surface of the trachea at necropsy. The tracheal nodules were histopathologically granuloma characterized by many coiled parasites containing a little collagen fibers, lymphocytes, plasma cells and macrophages. Female parasites had a lot of embryonated eggs in the uterus. Immature worms were observed in the dilated lymph vessels of bronchial and bronchiolar wall in the lungs. The worms were identified as Filaroides osleri based on the parasitological examinations.

Animals↗
PubMed1995

Distribution of taste buds on the epiglottis of the rat and house shrew, with special reference to air and food pathways.

We investigated the positioning of the epiglottis in the pharyngo-laryngeal region and the distribution of taste buds on the epiglottis in the rat and house shrew, animals which have different feeding habits. In the fixed samples of both species, when the mouth was closed or slightly opened, the epiglottis was found to protrude into the nasopharyngeal hiatus above the soft palate. But it retracted from its position when the mouth was widely opened. In omnivorous rats (n = 6), the mean number (mean density +/- s.d.) of taste buds was 52 (12.6 +/- 2.2/mm2) on the laryngeal surface but only 4 (1.3 +/- 1.0/mm2) on the oral surface. The three-dimensional view was reconstructed from serial sections. The taste buds were distributed most densely close to the caudal base and became fewer toward the more rostral tip. In insectivorous house shrews (n = 2), 4 taste buds on average were found only on the laryngeal surface of the epiglottis. Epiglottal taste buds may work as chemosensory detectors to initiate the reflex reaction to protect the airway from oral substances during swallowing and drinking.

Animals↗
PubMed1995

Architecture of the lateral line organ of the sea eel Conger myriaster.

The architecture of trunk canal neuromasts of the Japanese sea eel was morphologically examined. A fluid-filled canal is connected with the outside by horn-shaped tubules whose outer openings are seen as pores, which are variable in shape and very narrow as compared to the canal diameter. A projection shaped like a semilunar valve hangs over each neuromast from the opposite wall. The total number of hair cells in a canal neuromast was 500 to 600, about fivefold more numerous than that in a superficial neuromast. Two groups of hair cells, rostrally and caudally oriented, are nearly equal in number. The observed architectures are thought to favor efficient detection of the flow of water within the canal. These findings substantiate the current understanding that each canal neuromast encodes the pressure difference between two adjacent pores.

Animals↗
PubMed1995

Microbial conversion of milbemycins: oxidation of milbemycin A4 and related compounds at the C-25 ethyl group by Circinella umbellata and Absidia cylindrospora.

Microbial oxidation of milbemycin A4 at the C-25 ethyl group was performed. Milbemycin A4 was converted to 31- and 32-hydroxy derivatives by Circinella umbellata SANK 44272 along with 24- and 30-hydroxy derivatives. Related compounds, 5-ketomilbemycin A4 5-oxime and 13 beta-fluoromilbemycin A4 were similarly converted to the hydroxylated compounds by this microorganism. Absidia cylindrospora SANK 31472 converted milbemycin A4 to the corresponding 32-oic acid, 24-hydroxy derivative and a few oxygenated compounds including at the C-25 ethyl group.

Anthelmintics↗
PubMed1995

Ultrasonographic and endoscopic ultrasonographic angiography in pancreatic mass lesions.

Extracorporeal ultrasonographic (US) angiography and endoscopic ultrasonographic (EUS) angiography were performed in 40 lesions on 39 patients with various pancreatic diseases to evaluate characteristic findings. Pancreatic cancer (duct cell carcinoma) showed negative or slight enhancement. Islet cell tumor, serous cystadenoma composed of microcysts, and intraductal papillary adenoma showed strong enhancement. Solid and papillary tumor showed enhancement in the central lesion. Four of 6 cases with pseudotumorous pancreatitis had iso-enhancement which disappeared earlier than that in the pancreatic parenchyma. However, 2 cases showed slight or negative enhancement similar to pancreatic duct cell carcinoma. US angiography is useful in evaluating the vascularity of various pancreatic lesions, especially small lesions, in dynamic real-time images. EUS angiography is also useful in evaluating the vascularity in lesions that cannot be detected by US.

Carbon Dioxide↗
PubMed1995

Incidence of peptic ulcer in men is inversely correlated with blood pressure: study in an apparently healthy Japanese population.

OBJECTIVE: To study the role of autonomic nervous innervation in the etiology of peptic ulcer, we investigated the blood pressure in patients with peptic ulcer. METHODS: In 100,085 Japanese adults who were undergoing health screening examinations, including barium meal study, there were endoscopic evaluation-confirmed diagnoses of gastric ulcer in 769 cases and of duodenal ulcer in 344 cases. The blood pressure in those patients was compared with that in 57,208 normal Japanese controls with no gastrointestinal abnormalities, as confirmed by barium meal study. RESULTS: The blood pressure of younger and middle-aged men with gastric and duodenal ulcer were lower than those of normal control men. In women, except for the diastolic pressure of those in their 50s, the blood pressure in patients with peptic ulcer and normal controls did not differ significantly. The incidence of duodenal ulcer or of gastric ulcer in men was inversely related to the systolic and diastolic pressure. No definite relationship in this respect was seen in women. CONCLUSIONS: An inverse relationship was observed between the occurrence of peptic ulcer and the blood pressure level in Japanese men, but not in women. The relationship may be mediated by an inhibitory effect of the sympathetic nervous system on ulcer formation in hypertensive subjects. The reason for the sex difference in this respect is unknown.

Adult↗
PubMed1995

A progressive occlusion of the internal carotid arteries in a case of adult-onset moyamoya disease.

Progressive occlusions of the intracranial portions of ICAs are already established phenomena in childhood-onset moyamoya disease, but they have not yet been demonstrated in adult-onset patients. A patient with moyamoya disease manifested at 25 years of age was examined with cerebral angiography at 27 and 45 years of age. The angiograms taken at 27 revealed that the right ICA was completely occluded at the clinoidal portion, while the left one was patent and the occlusive/stenotic change was limited to the terminal portion. Angiograms taken 17 years later revealed that the right ICA was occluded at the origin, while the left one concentrically narrowed at the origin, then tapered off and was occluded at the clinoidal portion. The present case suggests that the ICA occlusion of moyamoya disease is not limited to the intracranial segment but progresses to the cervical segments, even in adult-onset patients. Based on these findings, two different groups of adult-onset moyamoya disease may exist; one in which the occlusive disorder has been completed by the time clinical manifestations appear and thereafter decreases, while the other group consists of occlusive disorders that steadily progress to the original portion of ICA.

Age of Onset↗
PubMed1995

[Usefulness of palliative care for the patients with recurrent gastric cancer by home-IVH].

Depending upon the type of cancer involved, the period of the end stage varies greatly, and with it decreases the quality of life (QOL). In gastric cancer, for example, the terminal stage is usually short and the QOL diminishes abruptly. Thus, it takes time keeping this decrease in QOL to minimum, despite the complications, so that the patient's last days will be even somewhat more acceptable. Improvement in QOL for the patient who cannot eat due to recurrent gastric cancer can be effectively achieved by alleviation through IVH. With this in mind, the conditions consonant with the application of home IVH are as follows: 1) The patient's pain can be kept under control at home. 2) The patient wishes to remain. 3)There is sufficient human support at home. The caretakers in the family, and especially the key person(s) must exert much effort and labor and they need rest as well. Home medical care in the terminal stage presupposes a social environment involving day care, short stay, and hospice nursing facilities of all kinds. At present, public services of this kind differ with the community, much remains uninformed to public, and clinic-hospital networking will be needed more than ever. In this difficult situation, the home-care medical services provided by the private sector are effective. These services are only for the short term, of course, and there will be a financial problem. Various measures (tax deduction, public assistance) must be considered to support the patients and caretakers.

Adult↗