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Biomedical subjects

Y Matsuda

Publications and source records attributed to Y Matsuda.

At least 631 records · Page 35Linked to original sources
PubMed1993

Rationale of surgical management for recurrent hepatocellular carcinoma.

From 1979 to 1991, 100 patients with hepatocellular carcinoma (HCC) underwent a curative hepatic resection in our institution. Five patients died within 1 month, and four patients died after longer than 1 month hospitalization. The remaining 91 patients were closely followed. Intrahepatic recurrences became obvious in 36 (40%) of these 91 patients during the follow-up period. Second operation was carried out on 22 patients, and the re-extirpation of HCCs was performed on 16 patients. Pure ethanol injection into the tumor associated with implantation of the Infuse-A-Port (Infusaid Inc., Norwood, MA) for intra-arterial infusion of anti-cancer agents was performed on the remaining six patients. Of these 22 patients, 15 are still alive, eight being free of HCC and seven with the disease, for 13 to 92 months after the first operation. The cumulative survival rate of 22 patients with repeated operations was significantly better than that of 14 patients who were treated conservatively (p < 0.05). The adequate surgical management of recurrent HCC is considered as most important in achieving better prognosis of HCC.

Adult↗
PubMed1993

Metastasis of hepatocellular carcinoma to the colon demonstrated by Tc-99m PMT scintigraphy.

A 57-year-old man was found to have a tumor in the ascending colon after hepatic segmentectomy for ruptured hepatocellular carcinoma. Colonoscopy was performed, and metastasis of the hepatocellular carcinoma to the ascending colon was suspected based on the biopsy specimens obtained from the tumor. On hepatobiliary scintigraphy using Tc-99m PMT performed to confirm this diagnosis, Tc-99m PMT was clearly observed to accumulate in the tumor. Thus, the tumor was diagnosed as metastasis of hepatocellular carcinoma.

Carcinoma, Hepatocellular↗
PubMed1993

Establishment and characterization of BALB/c retroperitoneal sarcoma with spontaneous liver metastases.

The objective of this study was to examine the identity and characteristics of a spontaneously occurring murine retroperitoneal tumor of BALB/c mouse origin that selectively metastasized to the liver. From the primary tumor, a permanent cell line, termed LMFS (liver metastasis from sarcoma) was established in vivo and in vitro. After a subcutaneous injection of more than 1 x 10(5) cells in the side back of mice, the LMFS cells proliferated at the inoculation site (100% take) and induced metastatic nodules spontaneously in the liver, but not in the lung. By the limiting dilution technique, a cloned cell line, LMFS-1, was established in vitro. The LMFS-1 cell line had similar morphological characteristics to the LMFS cells both in vitro and in vivo. The doubling time of the LMFS-1 cell line was 10 h in passage 60. The number of chromosomes ranged from 71 to 108 and 93% of metaphases showed near-tetraploidy. In microscopic examination, no specific arrangement of the LMFS tumor cells was seen; the LMFS cell had medium- to large-sized atypical nuclei and clear and large cytoplasm. Electronmicroscopy showed that the cytoplasm of the LMFS cell had a moderate amount of rough-surfaced endoplasmic reticulum but no desmosomes or microvilli. Immunohistochemically, the LMFS cells were positive for vimentin, but showed no reaction for keratin or cytokeratin. Therefore, the LMFS tumor was considered to be an undifferentiated sarcoma. The LMFS cell line should be a useful tool not only for studies of metastasis, but also for experiments on the therapy of hepatic tumors.

Aneuploidy↗
PubMed1993

The effect of nicardipine on maternal and fetal hemodynamics and uterine blood flow in chronically instrumented pregnant goats.

This study was designed to clarify the maternal and fetal hemodynamics of nicardipine (0.02 mg/kg) administered intravenously to unanesthetized, chronically instrumented pregnant goats. Nicardipine produced a significant increase in maternal heart rate and cardiac output, and a significant decrease in maternal mean arterial blood pressure and systemic vascular resistance. These changes persisted for about 30 minutes. There were no consistent changes in maternal pulmonary hemodynamics. Uterine arterial blood flow (UBF) decreased significantly (about 15%) after 5 minutes of the injection and returned to the control value within 30 minutes. A significant correlation between the decreases in UBF and maternal diastolic blood pressure was observed after 5 minutes of the injection. The fetal heart rate, blood pressure and acid-base status did not change after the injection of nicardipine. These observations of pregnant goats suggest that nicardipine might be a useful agent for the treatment of acutely hypertensive crises in pregnant patients.

Animals↗
PubMed1993

Pattern-reversal visual evoked potentials in Down's syndrome.

We examined pattern-reversal visual evoked potentials (PRVEPs) in 36 adult patients with Down's syndrome, and analyzed the effects of the ophthalmological abnormalities on results of PRVEPs. The P100 latency was significantly delayed in 24 eyes of 16 patients. The P100 latency was significantly longer and its amplitude was significantly smaller (P < 0.001) in Down's syndrome patients than in age-matched normal controls. In 9 patients without any ophthalmological abnormalities, P100 latency showed no significant difference from that in normal controls, but three of them showed a significant delay of P100. Their P100 amplitudes were significantly smaller than those in normal controls. Therefore, we considered that the ophthalmological abnormalities are one of the main factors causing PRVEPs abnormalities in Down's syndrome patients, but some unknown factors should be also responsible.

Adult↗
PubMed1993

Effects of movement-related cortical activities on pain-related somatosensory evoked potentials following CO2 laser stimulation in normal subjects.

We investigated the change in pain perception produced by the application of movement and vibration to areas adjacent to, and remote from, the painful stimulus. Pain-related somatosensory evoked potentials (pain SEPs) and the pain threshold were evaluated following CO2 laser stimulation in 17 normal subjects. The concurrent application of vibratory stimuli and the voluntary movement of the fingers of the hand to which the pain stimulus was applied significantly reduced and prolonged the pain SEPs and increased the pain threshold, consistent with the gate control theory. Pain SEPs were also significantly attenuated by voluntary (P < 0.001) and passive (P < 0.02) movement of the remote areas such as the foot, but the pain threshold was unaffected. This finding was not produced by vibration or movement imagery of the limbs without active movement. Therefore, interactions between pain perception and movement-related cortical activities must take place in some areas of the brain without relieving pain.

Adult↗
PubMed1993

Effect of environmental humidity on the transformation pathway of nitrofurantoin modifications during grinding and the physicochemical properties of ground products.

The effect of humidity on the physicochemical properties of nitrofurantoin anhydrate and monohydrate during grinding in a humidity-controlled system was investigated using X-ray diffraction analysis, IR spectroscopy, thermal analysis and scanning electron microscopy. Anhydrate and monohydrate were transformed into a noncrystalline solid and a stable monohydrate, respectively, during grinding in a closed system. During grinding in an open system, in which the humidity level of the air was controlled (5, 50 and 75% r.h.), the anhydrate absorbed moisture from the supplied air and water content was increased at 75% r.h.; thereafter the compound was transformed into monohydrate II. The anhydrate did not absorb at 5 or 50% r.h. and was transformed into a noncrystalline solid. Monohydrate I desorbed crystal water during grinding at 5% r.h. and was transformed into a noncrystalline solid. However, monohydrate I was transformed into monohydrate II at 50 and 75% r.h. without desorption of crystal water. These results suggest that the solid-state transformation of nitrofurantoin during grinding depends upon the environmental humidity.

Anhydrides↗
PubMed1993

Relative frequencies of G (VP7) and P (VP4) serotypes determined by polymerase chain reaction assays among Japanese bovine rotaviruses isolated in cell culture.

The relative frequencies of both the G (VP7) and P (VP4) serotypes of 40 bovine rotaviruses isolated in cell culture from diarrheic calves in Japan between January 1983 and February 1991 were determined by recently developed polymerase chain reaction assays. Isolates with G serotype 6 and P serotype 5 (UK-like strains) were most frequently found (42.5%) followed by isolates with G6P11 (17.5%), G6P1 (10%), or G10P5 (10%). Isolates with G10P11 (B223-like strains) were least frequently found (7.5%). The presence of various combinations of G and P serotypes suggests frequent reassortment in nature among bovine rotaviruses.

Animals↗
PubMed1993

Two-way cross-neutralization mediated by a shared P (VP4) serotype between bovine rotavirus strains with distinct G (VP7) serotypes.

Among bovine rotavirus strains, there are three G serotypes (G6, G8, and G10) and three P (VP4) serotypes (PB1, PB2, and PB3, which are defined on the basis of strains NCDV, UK, and B223, respectively). Plaque reduction neutralization assays with hyperimmune antisera disclosed two-way antigenic relationships of strain KN-4 with strain KK-3 (G10, PB3) as well as with strains NCDV (G6, PB1) and 0510 (G6, PB2). Neutralization assays with monoclonal antibodies specific for G6, G10, and PB3 revealed that KK-3 and KN-4 had the same P serotype (PB3) but that neither G6- nor G10-specific monoclonal antibody neutralized KN-4. Comparison of the VP7 gene sequence of KN-4 with those of other bovine rotavirus strains indicated that KN-4 was more similar to G6 bovine strains than to KK-3 and other G10 strains, suggesting that the G serotype of KN-4 was G6. From these results, we concluded that the two-way cross-neutralization between KN-4 and NCDV or 0510 was mediated by shared G6 serotype specificity, whereas the two-way cross-neutralization between KN-4 and KK-3 was mediated by shared P serotype specificity (PB3). Thus, KN-4 and KK-3 represent the first reported example of a two-way antigenic relationship mediated only by the P serotype. This article emphasizes the need for adopting a binary serotyping system and development of reagents which will enable classification of rotaviruses based on their G and P serotype specificities.

Amino Acid Sequence↗
PubMed1993

Hepatocellular carcinoma in adenomatous hyperplasia: detection with contrast-enhanced US with carbon dioxide microbubbles.

Adenomatous hyperplasia (AH) of the liver is considered a precancerous lesion because hepatocellular carcinoma (HCC) has been found in nodules of AH at histologic examination. Contrast material-enhanced ultrasound (US) with intraarterial infusion of carbon dioxide microbubbles was performed in four patients with HCC in AH lesions. In all four patients, a "hyperechoic focus in an area of hypoechoic change" in relation to the adjacent liver was demonstrated, compatible with the minimal vascular change associated with neoplastic transformation and carcinoma development. Because early detection of the minute cancer foci that may develop in an AH nodule is clinically important, this contrast-enhanced US technique may be a useful tool for the detection of these associated lesions.

Adenoma↗
PubMed1993

Premature rupture of the membranes--aggressive versus conservative approach: effect of tocolytic and antibiotic therapy.

The purpose of this randomized, prospective study was to evaluate the efficacy of tocolytic and antibiotic therapy in the prolongation of pregnancy and neonatal outcome in the treatment of premature rupture of the membranes without clinical labor. Delivery was delayed for 48 h, 7 days and beyond 35 weeks of gestation in 87, 39 and 18%, respectively, of patients in the treated group (n = 39) compared with 50, 12 and 17% of patients in the nontreated group (n = 42). The incidence of a low Apgar score (< 7 at 5 min), requiring artificial ventilation, and infectious morbidity was more common in the treated group than in the nontreated group (18 vs. 0, 41 vs. 17 and 39 vs. 17%, respectively). There was no significant cost difference in survivors between the treated and nontreated groups, although the mothers in the treated group were significantly more expensive. From these observations, it appears that tocolysis and antibiotics are not effective in PROM cases.

Adult↗
PubMed1993

Role of endogenous atrial natriuretic peptide in DOCA-salt hypertensive rats. Effects of a novel nonpeptide antagonist for atrial natriuretic peptide receptor.

BACKGROUND: To explore roles of endogenous atrial natriuretic peptide (ANP) in blood pressure and volume regulation, we examined the effects of a newly developed ANP antagonist, HS-142-1 (HS) in deoxycorticosterone acetate (DOCA)-salt hypertensive rats. METHODS AND RESULTS: We examined 1) the effects of HS on ANP- or brain natriuretic peptide (BNP)-induced reductions in renal vascular resistance (RVR) of rat isolated perfused kidneys, 2) the effects of HS on cyclic GMP (cGMP) production in rat cultured vascular smooth muscle cells pretreated with ANP or BNP, and 3) the renal and systemic effects of HS in DOCA-salt-treated rats and control rats. We found that 1) HS dose-dependently reversed ANP- or BNP-induced decreases in RVR; 2) ANP or BNP at 100 nM caused an eightfold increase in cGMP production. These increases in cGMP were inhibited by HS in a dose-dependent fashion, and 300 micrograms/ml HS decreased cGMP to the control level. HS alone did not influence RVR or cGMP production; and 3) DOCA-salt rats showed higher plasma concentrations of ANP (198 versus 75 pg/ml) and BNP (23.7 versus 2.7 pg/ml, each p < 0.01) than the control rats. Bolus administration of 8 mg/kg HS elevated blood pressure by 8% (p < 0.01). This rise in blood pressure was attributed to an increase in systemic vascular resistance (+14%, p < 0.05). Conversely, urinary excretion of sodium (-41%), glomerular filtration rate (-27%), and plasma (-77%) and urinary cGMP (-69%, each p < 0.01) were decreased by administration of 8 mg/kg HS. These effects were dose dependent in DOCA-salt rats but slight or negligible in the control rats. CONCLUSIONS: These results suggest that endogenous ANP and BNP may be involved in the regulation of blood pressure and body fluid volume in DOCA-salt rats in which ANP and BNP secretion is augmented.

Animals↗
PubMed1993

High density lipoprotein reverses inhibitory effect of oxidized low density lipoprotein on endothelium-dependent arterial relaxation.

We have recently reported that oxidized low density lipoprotein (ox-LDL) inhibits endothelium-dependent arterial relaxation through its increased lysophosphatidylcholine (LPC). In this study we examined whether high density lipoprotein (HDL) has any effect on the inhibition of endothelium-dependent relaxation by ox-LDL in isolated strips of rabbit thoracic aorta. Both low density lipoprotein (LDL) and HDL were isolated from normal human plasma, and LDL was oxidized by exposure to copper. Preincubation of arterial strips with ox-LDL (0.1-0.5 mg protein/ml) inhibited endothelium-dependent relaxation to acetylcholine (ACh) in a concentration-dependent manner. HDL (1 mg protein/ml) by itself had no effect on the relaxation to ACh. In the presence of HDL, the inhibition by ox-LDL was markedly reduced. Although synthetic L-alpha-palmitoyl LPC (5 micrograms/ml) completely abolished a relaxation to ACh, the preincubation of arterial strips with HDL completely prevented the LPC-induced inhibition. Moreover, a relaxation to ACh was almost completely recovered when the strips were washed with buffer containing HDL even after LPC-induced inhibition had occurred. HDL markedly reduced the incorporation of [1-14C]palmitate-labeled LPC ([14C]LPC) into cultured bovine aortic endothelial cells and promoted the release of cell-incorporated [14C]LPC into the medium, resulting in a reduction of the remaining [14C]LPC in the cells. Agarose electrophoresis after incubation of a mixture of ox-LDL labeled with [14C]LPC and unlabeled HDL demonstrated a transfer of [14C]LPC from ox-LDL to HDL. These results indicate that HDL reverses the ox-LDL-induced impairment of endothelium-dependent relaxation by removing LPC from ox-LDL and preventing LPC from acting on the endothelium.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetylcholine↗
PubMed1993

A case of tinnitus and hearing loss after cerebellar hemorrhage.

BACKGROUND: Approximately 10% of cases of hypertensive intracerebral hemorrhage are cerebellar hemorrhage. We report a case of intracerebellar hemorrhage in which the initial symptoms were hearing loss and tinnitus. SUMMARY OF REPORT: A 45-year-old man suddenly complained of hearing loss and tinnitus on the right side. Computed tomography demonstrated a high-density area 1.2 cm in diameter in the right cerebellar peduncle. Because of enlargement of the high-density area, the patient underwent surgery based on the diagnosis of hypertensive intracerebellar hemorrhage, and the hematoma was evacuated. The right-sided acoustic nerve was remarkably swollen by a subpial hematoma. CONCLUSIONS: In this case, hemorrhage of the right cerebellar peduncle extended to the eighth nerve through the subpial space, causing hearing loss and tinnitus.

Cerebral Hemorrhage↗
PubMed1993

Particle size effect of metastable calcium phosphates on crushing strength of self-setting bioactive calcium phosphate cement.

The resistance to crushing after a self-setting bioactive calcium phosphate cement, consisting of various particle sizes of tetracalcium phosphate (TECP), dicalcium phosphate dihydrate (DCPD) and hydroxyapatite (HAP), had hardened was tested after setting at 37 degrees C, 100% RH. X-ray diffraction suggested that the cement containing fine particles of DCPD and TECP was completely transformed to HAP, but that containing larger particles was not. Since particle size of both DCPD and TECP affected the dissolution rate, the crystal growth of HAP during cement formation depended on the specific surface area (Sw) of the raw materials. The crushing strength of the cement after hardening increased with an increase of its Sw.

Bone Cements↗
PubMed1993

[Synthesis of imidazo[1,2-a]pyridine derivatives and their reactions].

By the reaction of 2-benzoylmethylimidazoles (1a, b) with polarized olefins (2, 3) in the presence of K2CO3, the corresponding imidazo[1,2-a]pyridine derivatives (4, 5) were obtained. Methylsulfinylimidazopyridine derivative (7) obtained by the reaction of 5b with m-chloroperbenzoic acid (m-CPBA), easily underwent nucleophilic substitution to give the corresponding substituted compounds (8a--e). The substitution of chloroimidazopyridine derivative (11) with nucleophiles produced the corresponding substituted compounds (12a--d).

Alkenes↗
PubMed1993

[Synthesis of thiazolo[3,2-a]pyridine derivatives and their reactions].

By the reaction of 2-benzoylmethyl-4-methylthiazole (6) with polarized olefins (3, 4) in the presence of base (K2CO3 or NaH), the corresponding thiazolo[3,2-a]pyridine derivatives (7, 8) were obtained. Methylsulfinylthiazolopyridine derivative (11) obtained by the reaction of 8b with m-chloroperbenzoic acid (MCPBA), easily underwent nucleophilic substitution to give the corresponding substituted compounds (10, 12).

Pyridines↗