Biomedical subjects

Y Katoh

Publications and source records attributed to Y Katoh.

At least 91 records · Page 5Linked to original sources

PubMed1995

A case of traumatic internal carotid artery occlusion diagnosed by MRI.

The case of a 4-year-old boy with traumatic internal carotid artery occlusion is reported. This patient developed left upper limb monoparesis and convulsions 62 h after injury. Magnetic resonance imaging (MRI) showed absence of a flow void and a high signal in the C5 portion of the right internal carotid artery. The proximal side of the right carotid siphon was not demonstrated by MR angiography. Carotid angiography revealed occlusion of the right internal carotid artery about 2 cm distal from the cervical carotid bifurcation. MRI appears to be useful to diagnose traumatic internal carotid artery occlusion, especially in children.

Arterial Occlusive Diseases↗

PubMed1995

Effective treatment of drug-induced agranulocytosis using recombinant human granulocyte colony stimulating factor in pregnancy.

Drug-induced immune system mediated agranulocytosis is a rare but potentially life-threatening condition. There have been only a few reports on the drug-induced agranulocytosis during pregnancy. We present a case of agranulocytosis after prolonged intravenous infusion of ritodrine hydrochloride and additional administration of indomethacin suppositories, effectively treated using recombinant human granulocyte colony stimulating factor without any infection in a mother with twin-to-twin transfusion syndrome. Recombinant human granulocyte colony stimulating factor may have a potential use for drug-induced agranulocytosis during pregnancy.

Adult↗

PubMed1995

Correlation between volatile sulphur compounds and certain oral health measurements in the general population.

Oral malodor was measured using a portable sulphide monitor in 2,672 individuals aged 18 to 64 years. In addition, dental (DMFT) and periodontal conditions (CPITN and attachment loss), dental plaque, and tongue coating status were assessed. Before clinical examination, subjects were interviewed about their oral health habits, smoking habits, and medical history. Data on volatile sulphur compounds (VSC) were analyzed by gender, age group, and time of measurement. There were no significant differences observed in the VSC between males and females in any age group. In each age group, the measured values of oral malodor were highest in the late morning group (58.6 ppb in average), followed by the late afternoon group (52.1 ppb), while lowest values were shown in the early afternoon group (39.4 ppb). Significant correlation was observed only between the VSC value and periodontal conditions and tongue coating status. The results also suggest that oral malodor might be caused mainly by tongue coating in the younger generation and by periodontal diseases together with tongue coating in older cohorts in the general population. Age was not a risk factor for increasing VSC.

Adolescent↗

PubMed1995

[How does thermotherapy effectively work on benign prostatic hyperplasia--an experimental study].

Isometric contractile force of rabbit prostatic tissue in response to electric field stimulation (EFS), KCl, and phenylephrine were measured at incubation temperature of 37 degrees C, before and after thermal exposure to 42 degrees C, 45 degrees C, 48 degrees C and 50 degrees C for 30 minutes. The contractile force in response to EFS decreased after thermal exposure above 45 degrees C, and the contractile force in response to KCL or phenylephrine decreased after thermal exposure above 48 degrees C. All the contractile response abolished after thermal exposure to 50 degrees C. The results indicate that the nerve is more hear-sensitive than the smooth muscle in the prostate. Histological examination revealed shrinkage of cell body and dark staining of nuclear chromatin of the smooth muscle cells after thermal exposure above 48 degrees C. The same histological change of the smooth muscle as well as degenerative change of the nerve cells was observed on the prostate 3-7 months after clinical thermotherapy. From these results, it is suggested that clinical effect of thermotherapy is brought about from both neural and muscular damage of the prostate. Since the least temperature to cause an irreversible tissue damage ranges from 48 degrees C through 50 degrees C, we believe it is ideal to heat the prostate around 50 degrees C to obtain a good clinical effect of thermotherapy on benign prostatic hyperplasia as a minimum invasive treatment.

Aged↗

PubMed1995

[A case of cranial metastasis of hepatocellular carcinoma].

A case of cranial metastasis of hepatocellular carcinoma is reported. A 77-year-old woman with an elastic hard tumor in the right temporal region was referred to our department on April 30, 1992. On admission, the patient had slight weakness of the left upper limb. Plain skull X-ray and computed tomography (CT) showed bone destruction in the right temporal region. Magnetic resonance images (MRI) showed that the tumor was hypo-intense with T1-sequences and hyper-intense with T2-sequences, and included hyper-intense spots on both T1- and T2-images. Right carotid angiography showed that the tumor was fed by the middle meningeal and accessory meningeal arteries. The patient became disoriented, and the left hemiparesis worsened on May 4, 1992. CT scan revealed an irregular high-density area in the tumor because of intratumoral hemorrhage. After embolization of the arteries feeding the tumor, surgery was performed on May 8, 1992, and the tumor was totally removed. Histological examination of the tumor specimen revealed that it was a metastatic hepatocellular carcinoma. The patient died 8 months after initial diagnosis because of hepatocellular carcinoma.

Aged↗

PubMed1995

Time-lapse microcinematography of osteocytes.

We succeeded in the isolation of osteocytes from parietal bones of 16-day-old chick embryos. Isolated osteocytes showed a typical stellate morphology. More than 95% of these cells reacted with the osteocyte-specific antibody OB 7.3. In culture osteocytes formed gap junctions with each other, as could be established by ACAS. Sixteen-millimeter time-lapse microcinematography of the cells also demonstrated the formation of intercellular connections and gap junctions, and portrayed the interaction between osteocytes and osteoclasts: osteocytes seemed to inhibit osteoclast activity. This cinematography also showed the ability of osteocytes to proliferate after they had been disconnected from each other. Thereafter these cells redifferentiated into osteoblasts that became embedded in bone matrix produced by themselves. These findings suggest that osteocytes might be involved in bone formation during remodeling.

Animals↗

PubMed1995

[Influence of genetic factors on family history of upper urinary stones].

The family history between patients with upper urinary tract stones and healthy subjects was compared to evaluate the possible involvement of genetic factors in obtaining information through a questionnaire. The patients showed a significantly more marked history than the healthy subjects (p < 0.001). In particular, recurrent stone formers showed a significantly more marked history than single stone formers (p < 0.05). Compared with the healthy subjects, a more marked family history was observed in the parents, brothers and sisters, and children, but not in the spouse (p < 0.05-0.005). However, the family history was not affected by consanguineous marriage. A more marked family history was observed in patients with upper urinary tract stones, suggesting the involvement of genetic factors in the development of upper urinary tract stones. In particular, genetic factors seem to be more closely involved in recurrent stone formers.

Adult↗

PubMed1995

[A case of spasticity following spinal cord injury improved by epidural spinal cord stimulation].

Epidural spinal cord stimulation was performed in a patient complaining of spasticity with intractable pain after operation of metastatic spinal tumor. The end of the electrode was positioned along a line extending down the 11th vertebral body. Following confirmation of satisfactory effects during 10 days of trial stimulation, the electrode was permanently implanted. Excellent pain relief (80%) and significant relaxation of spasticity resulted in a medication free period with improved daily activities. Although the treatment of this case resulted in clinical success, the problem concerning the payment of the transmitter remained. We hope that the health insurance system will extend its indications to cover medical fees for the transmitter.

Carcinoma, Renal Cell↗

PubMed1995

Marked bilateral atrial dilation of unknown cause.

Four elderly women with marked bilateral atrial dilation but no evidence of significant structural or functional cardiac abnormalities other than atrial fibrillation are described. All patients demonstrated severe cardiomegaly on chest radiographs. Three patients have remained in good condition during the follow-up of 6 to 16 years except for occasional edema or pleural effusion, which was easily treated with diuretics and/or digitalis. The other patient had had only one episode of pleural effusion and leg edema at age 90 years before she died of colon cancer at age 100 years.

Aged↗

PubMed1995

[A case of meningioma associated with intracerebral hemorrhage and acute deterioration].

We report a case of convexity meningioma associated with sudden onset of intracerebral hemorrhage followed by acute deterioration. A 76-year-old previously healthy male suddenly collapsed into coma and was admitted to our department. On admission, he was deeply comatose. Computerized tomography (CT) scan revealed intracerebral hemorrhage in the right frontal lobe, together with an isodense mass lesion of about 5 cm in diameter. The density on the fronto-medial side of the mass increased after administration of contrast medium, probably due to extravasation. However, there was no enhancement of the mass lesion. Cerebral angiography revealed marked prolongation in circulation time and extravasation via the right middle internal frontal artery. The right middle meningeal artery was dilated and elongated, but no tumor stain was found. The patient died on the following day. Autopsy disclosed massive hemorrhage in the right frontal lobe together with a convexity meningioma. Histological examination showed that the tumor was a fibroblastic meningioma. We review previously reported cases of convexity meningioma associated with intracranial hemorrhage, and discuss mainly the mechanism of bleeding.

Acute Disease↗

PubMed1995

Periodontal conditions in older age cohorts aged 65 years and older in Japan, measured by CPITN and loss of attachment.

Periodontal conditions were assessed by CPITN and loss of attachment in 601 elderly people randomly selected in Kitakyushu, Japan. The percentage of edentulous persons was 21 per cent, 38 per cent and 65 per cent in the 65-74 year, 75-84 year and 85 years and older groups, respectively. In dentate persons, over 60 per cent had pocket probing depths of 4mm or more; in the majority loss of attachment did not exceed 5mm. The mean numbers of sextants with pocket probing depths of 4-5mm (CPITN 3) and probing depths of 6mm and more (CPITN 4) were similar in each age group. The mean numbers of sextants with both pockets and loss of attachment showed no clear difference among groups. Only the mean number of excluded (no, or only one tooth) sextants increased with increasing age from 1.9 to 3.1. It could therefore be suggested that in the population examined the progress of periodontal destruction with increasing age might not be shown by an increase in pocket probing depth, loss of attachment or gingival recession, but only by an increase in tooth loss. The results for the remaining teeth show that a) severe loss of periodontal attachment (6mm or more) was not frequently encountered, b) recession (attachment loss without pocketing) was present at only very low levels, c) the main periodontal problem seemed to be pocketing, which could be treated. It is therefore tempting to suggest that some of the teeth already lost, could have been saved if proper self- and professional care had been applied.

Aged↗

PubMed1995

Effect of gap dimension on wear resistance of luting agents.

PURPOSE: To examine the correlation between horizontal gap width and wear depth of luting resin cements and a glass ionomer used with resin composite inlays. MATERIALS AND METHODS: A cylindrical cavity (4 x 3 mm) was made on the occlusal surface of molars. Four specimens were prepared for each luting agent. The samples were subjected to a three-body wear test for 400,000 cycles. The wear values of both composite and luting agents were determined by profilometric tracings to the nearest 2 micrometers. The relationship between gap width and wear depth was confirmed by linear regression analysis. RESULTS: Significant relationships existed amongst gap width, cement wear and type of cement. The effects were considerably less pronounced with microfilled cements.

Analysis of Variance↗

PubMed1994

Identification of functional promoter elements in the rabbit smooth muscle myosin heavy chain gene.

Despite the importance of smooth muscle cell proliferation in vascular pathophysiological states, the mechanisms regulating smooth muscle cell growth and differentiation are poorly understood. Previous studies have shown that adult rabbit smooth muscles express two types of myosin heavy chain (MHC) isoforms, SM1 and SM2, which are generated through alternative RNA splicing from a single smooth muscle MHC (SMHC) gene. In the present study, we isolated and characterized the rabbit SMHC gene promoter. DNA sequence analysis of the upstream region of the SMHC gene revealed several putative cis-DNA regulatory elements proximal to the transcription start site. Most notably, cis-acting regulatory elements that closely resemble CC(A/T)6GG (CArG box) and myocyte enhancer binding factor 2 (MEF-2)-type sequence motifs were found in the SMHC 5'-flanking region. In addition, six E-box motifs were found in the 5'-flanking region of the SMHC gene between -374 and -2109 base pairs from the transcription start site. A series of transient transfection assays using SMHC promoter deletion constructs indicated that a promoter fragment extending to 2266 base pairs upstream of the transcription start site has the highest reporter activity in cultured rat aortic smooth muscle cells. Gel mobility shift analyses using the MEF-2-like sequence located at -1540 revealed a specific DNA protein complex, whereas the CArG-like element located at -1275 did not show protein binding. The SMHC promoter construct, p509-CAT, which included neither the CArG- nor MEF-2-type motifs, conferred 32% of chloramphenicol acetyltransferase activity in the same cells, whereas the construct p188-CAT, which contained the minimal promoter elements (TATA box), was significantly less active (7%; 2.0-fold over background). This is the first report describing the promoter elements of a gene whose expression is restricted to smooth muscle cells.

Alternative Splicing↗

PubMed1994

Effect of TFC-612, a 7-thia prostaglandin E1 derivative, on intimal thickening after endothelial injury with balloon catheter in rats.

The effect of TFC-612, methyl-6-[(1R,2S,3R)-hydroxy-2-](1E,3S,5R)-3- hydroxy-5-methyl-1-nonenyl]-5-oxocyclopentyl)thio] hexanoate, on intimal thickening of carotid artery 14 days after endothelium denudation with a balloon catheter was examined in rats. This compound significantly suppressed the neointimal area and the ratio of intimal and medial layer by 41.1% and 31.4%, respectively, at 3.2 micrograms/rat/h s.c. infusion. At this dose, this compound did not inhibit platelet aggregation induced by either collagen or ADP. It did not inhibit bromodeoxyuridine incorporation into medial smooth muscle cells at 3 days after injury. In in vitro experiments, TFC-612 did not inhibit the [3H]thymidine uptake into cultured smooth muscle cells, but it showed significant inhibition of smooth muscle cell migration induced by platelet-derived growth factor (PDGF) at more than 10(-9) M. This compound increased cyclic AMP levels dose dependently in cultured smooth muscle cells at more than 10(-8) M. These results suggest that TFC-612 inhibits intimal thickening by inhibition of smooth muscle cell migration from media to intima through cyclic AMP elevation.

Alprostadil↗

PubMed1994

Complication of silastic dural substitute 20 years after dural plasty.

A 63-year-old woman was admitted because of right hemiparesis. Both computed tomography scan and magnetic resonance imaging revealed a mass lesion in the left parieto-occipital lobe. Twenty years previously, meningioma of the left parieto-occipital region was removed at another hospital, and a dural plasty was performed using a silastic dural substitute. The patient was operated on under the diagnosis of recurrent meningioma. However, most of the mass lesion was composed of an old hematoma, which seemed to be a complication of the silastic dural substitute.

Aged↗

PubMed1994

Mutagenic effects of nitropyrenes in a soybean test system.

The mutagenic activity of 1-nitropyrene (1-NP), 1,3-dinitropyrene (1,3-DNP), 1,6-dinitropyrene (1,6-DNP) and 1,8-dinitropyrene (1,8-DNP) was assayed in heterozygous soybean plants (Y11y11), based on the appearance of mutational spots (yellow, dark green and twin) on the leaves. 1-NP, 1,3-DNP, 1,6-DNP and 1,8-DNP were direct-acting mutagens in a soybean test system, and mutagenicity was enhanced by addition of pyrene as a precursor. The mutagenicity of dinitropyrenes was enhanced by pretreatment with hepatic microsomal fractions of Aroclor 1254-treated rats. Binary and ternary isomeric mixtures of dinitropyrenes produced synergistic mutational response in the test system. The numbers of yellow and dark green spots per leaf increased by treatment with nitropyrenes. The frequency of twin spots did not change. Nitropyrenes stimulated the induction of forward and reverse mutations in soybeans. The number of light green spots (Y11y11) per leaf on homozygous soybeans (y11y11) increased markedly by treatment with 1-NP, 1,3-DNP, 1,6-DNP, and 1,8-DNP. These nitropyrenes would thus appear to cause point mutation and segmental loss as major effects.

Chi-Square Distribution↗

PubMed1994

Relationship between dental caries experience of a group of Japanese kindergarten children and the results of two caries activity tests conducted on their saliva and dental plaque.

To establish a dental caries preventive programme in 4- and 5-year-old children, caries activity tests were used to assess salivary levels of mutans streptococci (using the Mucount test, Showa Yakuhin, Japan) and the acidogenic ability of dental plaque bacteria (using the Cariostat test, Sankin, Japan) in 260 kindergarten children. The relationships between the results of these two tests and the dental caries experience (dfs) of the children was evaluated. There was a significant positive correlation between the results of the Mucount and Cariostat tests in the total group of subjects. However, 91 subjects (35%) gave conflicting results with the two tests. These subjects were divided into two groups: one group (group B) included Mucount-negative and Cariostat-positive subjects, and the other group (group C) included Mucount-positive and Cariostat-negative subjects. Group B had a significantly higher mean dfs score than a group that was negative on both tests (group A). On the other hand, no significant difference in mean dfs score was observed between group C and group A. These findings suggested that mutans streptococci levels alone are an insufficient indicator for assessing dental caries activity of children at these ages and that the role of lactobacilli and other aciduric bacteria should be considered. It was concluded that assessment of caries activity using both Mucount and Cariostat tests is useful for a dental caries preventive programme for children of these ages.

Child, Preschool↗

PubMed1994

Effects of menatetrenone on the decrease in calcium balance induced by vitamin K-deficient diet and sodium loading in rats.

The effects of menatetrenone (2-methyl-3-tetraprenyl-1,4-naphthoquinone, MK-4) on calcium balance were studied in male Sprague-Dawley rats. Experiment 1: Rats in metabolic cages that were fed a vitamin K-deficient diet and injected daily with latamoxef (100 mg/kg, i.p.) were either treated or untreated with MK-4 for 7 days. Daily food intake, urine volume and feces weight were determined, and calcium concentration in these samples was measured. Calcium balance was calculated as the difference between calcium intake and urinary and fecal calcium excretion. Cumulative calcium balance in the vitamin K-deficient group treated with latamoxef was lower than that in normal rats; this balance was significantly improved by MK-4 (1 and 10 mg/kg, s.c.) administered for 7 days. Experiment 2: Rats were fed a vitamin K-deficient diet containing 4.6% sodium chloride for 6 weeks. MK-4 was administered as a dietary supplement. Forty-eight-hour calcium balance, determined once a week, was significantly reduced compared with that of normal rats after 3 and 5 weeks; the balance was restored dose-dependently by MK-4 administration (1 and 10 mg/kg). Experiment 3: Rats were subjected to the same experimental conditions as experiment 2 for 6 weeks, and intestinal calcium transport was determined using an everted gut-sac technique. Calcium transport was reduced by the high sodium, vitamin K-deficient diet, and this reduction was restored by MK-4 administration (10 mg/kg). These results suggest that MK-4 improves the reduced calcium balance by increasing intestinal calcium absorption in these rats.

Alkaline Phosphatase↗