Biomedical subjects

S Murakami

Publications and source records attributed to S Murakami.

At least 235 records · Page 13Linked to original sources

PubMed1998

HL-004, the ACAT inhibitor, prevents the progression of atherosclerosis in cholesterol-fed rabbits.

HL-004, N-(2,6-diisopropylphenyl) tetradecylthioacetamide, a novel acyl-CoA:cholesterol acyltransferase (ACAT) inhibitor, was evaluated concerning the possible prevention of hyperlipidemia and atherosclerosis in 1% cholesterol-fed rabbits. HL-004 (0.2, 5 and 25 mg/kg) was orally administered once a day for 12 weeks. HL-004 inhibited the rise of total serum cholesterol at a dose of 5 mg/kg and over. In the thoracic aorta, HL-004 at the doses of 5 mg/kg and 25 mg/kg reduced the total cholesterol content by 56.3% and 84.2% compared with control, and decreased ACAT activity, dose-dependently. HL-004 also attenuated the development of aortic lesions. The area of atherosclerotic lesions was reduced by 30.3% with 5 mg/kg of HL-004 and 100% with 25 mg/kg. In this study, we suggest that the main reason for HL-004 preventing the progression of atherosclerosis is its hypocholesterolemic effect due to the inhibition of cholesterol absorption in the intestine.

Acetanilides↗

PubMed1998

Extent of mediastinal node metastasis in clinical stage I non-small-cell lung cancer: the role of systematic nodal dissection.

OBJECTIVE: To determine the extent of lymph node metastasis in clinical stage I non-small-cell lung cancer (NSCLC). METHODS: We performed a retrospective review of 524 patients with clinical stage I NSCLC who underwent lobectomy with systematic nodal dissection. RESULTS: The nodal status was N0 in 409 patients (78%), N1 in 44 (8%), N2 in 67 (13%), and N3 in four (0.8%). Thirty-six patients had single-level mediastinal nodal metastases and 35 had multi-level metastases. The incidence of N2/3 disease in patients with adenocarcinoma/squamous cell carcinoma/other histologic types according to tumor size was 0/0/0%, respectively, in tumors < or = 10 mm in diameter, 12/0/0% in tumors 11-20 mm in diameter, 14/4/23% in tumors 21-30 mm in diameter, and 26/14/20% in tumors >30 mm in diameter. Nodal metastases to the upper mediastinum from middle or lower lobe lesions were frequently observed in 51 N2 adenocarcinomas, whereas those to the lower mediastinum from upper lobe lesions were rare. Of 10 N2 squamous cell carcinomas, seven had regional and three had non-regional nodal metastases. The 5-year survival rate was 68, 43, and 30% in N0, N1, and N2, respectively (P<0.01, N0 versus N1, N0 and N2). CONCLUSIONS: Systematic mediastinal nodal dissection should be routinely performed for clinical stage I lung cancer to ensure the correct nodal status, but it might be dispensable in the patients with peripheral squamous cell carcinoma < or = 20 mm in diameter, with central squamous cell carcinoma < or = 30 mm, and with adenocarcinoma < or = 10 mm. When systematic nodal dissection cannot be performed, the incidence and extent of nodal metastases should be taken account with respect to histologic type, size, and location of the tumor.

Carcinoma, Non-Small-Cell Lung↗

PubMed1998

Diagnostic imaging in two cases of recurrent maxillary ameloblastoma: comparative evaluation of plain radiographs, CT and MR images.

We report detailed clinical and imaging findings of two patients with recurrent maxillary ameloblastoma. In one patient the recurrent tumour presented at follow-up examination 5 years after the initial operation. The other patients had a far advanced recurrent tumour with maxillary destruction extending into the adjacent normal structures including the infratemporal fossa, infraorbital fissure, masticator space and the left ethmoid sinus. The findings on conventional radiography including panoramic, posteroanterior and Waters' projection, and the findings of computed tomography (CT) and magnetic resonance (MR) imaging were evaluated using the following three variables: artefact degradation, lesion detectability, and conspicuity. The results suggested that MR imaging was the best imaging method for visualization of the tumours, followed by contrast enhanced CT. These two cases show that maxillary ameloblastoma can be difficult to control when it extends to the adjacent normal structures after destroying the maxilla. MR imaging was essential to establish the exact extent of the advanced maxillary ameloblastoma.

Adult↗

PubMed1998

The ACAT inhibitor HL-004 inhibits cholesterol absorption and lowers serum cholesterol in rats.

1. HL-004 decreased absorption of cholesteryl ester from the intestine into the lymph in a rat lymph-fistula model. 2. HL-004 reduced serum cholesterol level in acute cholesterol-fed rats. 3. HL-004 simultaneously decreased hepatic cholesteryl ester content and increased free cholesterol in cholesterol-fed rats. 4. These findings suggest that: (1) the hypocholesterolemic effect of HL-004 is principally due to inhibition of cholesterol absorption via inhibition of ACAT in the intestine; and (2) changes in hepatic cholesterol metabolism due to direct inhibition by HL-004 of hepatic ACAT may account in part for reduction of serum cholesterol level by HL-004.

Absorption↗

PubMed1998

Flow cytometric analysis of Thy-1 expression in myelodysplastic syndrome.

We analyzed the expression of Thy-1 (CD90) antigen on CD34+ bone marrow mononuclear cells (BMMNC) obtained from 25 patients with myelodysplastic syndrome (MDS) by two-color flow cytometry. Five of nine patients (55.6%) with refractory anemia with excess of blasts (RAEB) and two of 16 (12.5%) with RAEB in transformation (RAEB-t) showed more than 20% of Thy-1 expression of their CD34+ BMMNC. Regarding chromosomal abnormalities, -5/5q- or -18 might be correlated with the expression of Thy-1 on CD34+ BMMNC in MDS. Nine patients were analyzed twice, once before and once after leukemic transformation and showed no significant change in Thy-1 expression. These results show that Thy-1 was expressed on CD34+ BMMNC in certain patients with MDS before leukemic transformation and that it was maintained during the disease progression. In contrast, expression of Thy-1 did not seem essential to the leukemic transformation in MDS though the patients with high Thy-1 expression might have poorer prognosis compared with those with low Thy-1 expression.

Adolescent↗

PubMed1998

Purification and characterization of four catechol 1,2-dioxygenase isozymes from the benzamide-assimilating bacterium Arthrobacter species BA-5-17.

When Arthrobacter sp. BA-5-17 was grown on benzamide, the bacterium synthesized four different catechol 1,2-dioxygenase (CD, EC 1.13.11.1) isozymes (CD-I, II, III-1, and III-2). We purified each CD to homogeneity by a series of column chromatography. The molecular masses of the four CDs were between 68 and 72 kDa. The enzymes were made up of two identical subunits each with the molecular mass of 33 kDa. CD-I and II were indistinguishable in enzymatic properties tested. Most properties of CD-III-1 were similar to those of CD-III-2. However, CD-III-1 had a marked adsorption peak at 325 nm, which disappeared in CD-III-2 as well as in CD-I and II. CD-III-1 and III-2 were much more resistant to heating and inhibitors than CD-I and II.

Amino Acid Sequence↗

PubMed1998

Gross periostitis ossificans in mandibular osteomyelitis. Review of the English literature and radiographic variation.

OBJECTIVE: The purpose of this study was to describe a radiographic variety of gross periostitis ossificans in mandibular osteomyelitis and to determine what types of gross periostitis ossificans are related to a specific form of mandibular osteomyelitis without demonstrable causes. STUDY DESIGN: We reviewed 20 cases of gross periostitis ossificans in patients with mandibular osteomyelitis that had been reported with illustrations in the English literature, and we reviewed our own 14 cases of gross periostitis ossificans, previously reported. The radiographic features of the 34 cases of gross periostitis ossificans were classified according to the status of original contour and the appearance of gross periostitis ossificans. Histopathologic features were studied in 12 cases. RESULTS: The 34 cases of gross periostitis ossificans could be classified radiographically into 4 types. Type A, showing an "onion-skin" appearance, was caused by a carious tooth or followed extraction of a tooth. Type B and type C showed a consolidation form; in the 36.8% (7/19) of these cases in which no infectious source could be identified, it was suspected that the condition was caused by a developing unerupted tooth or a dental follicle. Type D was seen in the most chronic stage. Biopsy specimens of 12 cases commonly showed proliferation of newly formed bone, loose interstitial fibrous tissue, and a low-grade inflammatory cell infiltration. CONCLUSION: Gross periostitis ossificans of type B or type C may be a specific form of mandibular osteomyelitis without demonstrable cause.

Adolescent↗

PubMed1998

Histopathologic and radiographic findings of the simple bone cyst.

OBJECTIVE: The purpose of this study is to examine the correlation between histopathologic and radiographic findings and to discuss the cause of the simple bone cyst. STUDY DESIGN: Histopathologically, we classified 53 simple bone cysts into two types. Type A has a connective tissue membrane and type B has a partially thickened wall with dysplastic bone formation. Radiographically, we evaluated the following: margin, radiolucency, or radiopacity, relationship with tooth apices, bucco-lingual bone expansion, and displacement of the mandibular canal. RESULTS: Bone expansion and radiopacity were closely related to histopathologic findings although there was no correlation between the histopathologic findings and radiographic margin, relationship with tooth apices, and displacement of mandibular canal. Local recurrence was more likely to be observed in patients diagnosed as having type B than type A lesions. CONCLUSIONS: Type A and type B bone cysts may have different causes. Cysts determined radiographically to be radiopaque, those diagnosed as type B histopathologically, and cysts that have been treated surgically should all be followed by radiographic examinations.

Adolescent↗

PubMed1998

An analysis of the prognostic significance of p53 status for squamous cell carcinoma of the oral cavity treated by radiotherapy.

The status of the p53 gene in biopsy specimens was analyzed to determine whether it is predictive of the outcome of radiotherapy of squamous cell carcinomas of the oral cavity. Biopsy materials were obtained from 45 patients, and the p53 status of each patient was determined using a single-strand conformation polymorphism analysis. Fourteen of the patients were treated with radiation therapy alone; the other 31 patients underwent radiotherapy in combination with surgery or chemotherapy. Twenty-seven patients had tumors with wild-type p53 and 18 patients had a tumor with mutant p53. The initial tumor response was not significantly different between these two groups. Kaplan-Meier survival plots (log-rank test) showed that the probability of survival was not significantly different between two groups although the patients with mutant p53 had a tendency for longer survival (P = 0.2941). However, among the patients with stage III/IV tumors (n = 24), those with a wild-type p53 status tended to have longer survivals.

Adult↗

PubMed1998

Immunohistochemical detection for Actinomyces sp. in swine tonsillar abscess and granulomatous mastitis.

The tonsils of eleven pigs and the mammary glands of a sow were used to investigate actinomycotic lesions due to Actinomyces sp. infection. At necropsy, there was no abnormality on these tonsils, on the other hand, numerous abscesses containing sulfur granules were found in the mammary. Histopathologically, the Actinomyces sp. lesions were noted as crypt abscesses in the tonsils and as pus-forming granulomas in the mammary glands. The microorganisms in both lesions were composed of bead-like cocci, bacillary cells and short, branching filaments, those cells being positive by the Gram's and Grocott's methods. Clubs were formed around the microbial clumps in these lesions. Immunohistochemically, there were cross-reactions between antibodies of Actinomyces sp. Chiba 101 (101) and swine actinomycetes of 7 species: A. bovis, A. hyovaginalis, A. israeli, A. naeslundii, A. pyogenes, A. suis) formerly Eubacterium suits) and A. viscosus. However it was possible to differentiate Actinomyces sp. 101 from them by absorption and dilution of the antiserum, then the microorganisms in the tonsillar crypt abscesses and the granulomatous mastitis were labelled with an immunoperoxidase technique using the absorbed Actinomyces sp. 101 antiserum. Thus, these immunolabelling properties are suggestive of the presence of 'A. suis' (Grässer) Franke 1973.

Abscess↗

PubMed1998

A study of condylar movement by bilateral simultaneous videofluorography.

OBJECTIVES: To analyse the condylar movements of patients with temporomandibular disorders and investigate the mutual interaction between both temporomandibular joints (TMJs) by comparing bilateral simultaneous videofluorography with the disk position on MRI. METHODS: Fifty-two patients who had been diagnosed as having internal derangement in one or both TMJs on the base of the clinical symptoms underwent bilateral simultaneous videofluorography and MRI. The TMJs were classified from the MRI into three categories: superior disk position (SDP), reducing disk displacement (RDD) and nonreducing disk displacement (NDD). Condylar movements of the TMJs were analysed from the videofluorography and correlated with the MR diagnoses. RESULTS: The range of condylar movement of NDD joints was significantly shorter than that of SDP or RDD joints at maximum mouth opening (P < 0.001), but not at maximum protrusion and lateral protrusion. Based on the sagittal condylar path during maximum mouth opening and closing, three patterns of condylar movement were identified: normal, deflected and short. Sixty-nine per cent of the normal pattern were SDP, 55% of the deflected RDD and 77% of the short NDD. The condylar movement of a NDD or RDD joint could influence the range and pattern of movement of the contralateral joint. CONCLUSIONS: Analysis of condylar movement was helpful in assessing the state of the disk because they were closely related. The range and pattern of condylar movement of both TMJs were mutually interrelated. Patients with signs and symptoms of internal derangement should have both sides examined for an accurate and complete diagnosis.

Adolescent↗

PubMed1998

Food-dependent exercise-induced anaphylaxis: a case related to the amount of food allergen ingested.

A 24-year-old Japanese woman had suffered for 2 years from attacks of urticaria, dyspnoea and syncope associated with exercise after the ingestion of wheat. Specific IgE measurements revealed RAST class 2 for wheat and gluten (a major wheat protein), and class 3 for rye. Skin prick tests with wheat, bread, gluten and udon (a Japanese noodle made of wheat) were all positive. Food-dependent exercise-induced anaphylaxis (FDEIA) caused by wheat was suspected. Challenge tests with bread were performed. Exercise following ingestion of 64 g, but not 45 g, of bread induced generalized urticaria. Challenge tests with udon also triggered allergic reaction in a dose-dependent manner: 200 g, but not 100 g or 150 g, of udon elicited wealing and erythema with exercise. Ingestion of bread or udon alone failed to elicit any allergic reaction. This is the first case of FDEIA in which the dependence of the triggering allergic reaction on the amount of allergen ingested was clearly confirmed.

Adult↗

PubMed1998

Varicella-zoster virus distribution in Ramsay Hunt syndrome revealed by polymerase chain reaction.

The pathogenesis of facial nerve paralysis and vestibulo-cochlear dysfunction of Ramsay Hunt syndrome remains unclear as varicella-zoster virus (VZV) has not been demonstrated in the lesions. Using the polymerase chain reaction, we detected VZV genomes not only in the vesicles on the auricles or oral cavity but also in the facial nerve sheath, middle ear mucosa and cerebrospinal fluid from patients with Ramsay Hunt syndrome. The VZV genome was undetectable in the same kinds of clinical samples obtained from control patients with facial nerve paralysis of other etiologies. The results indicated that VZV spreads widely in the neural components, mucocutaneous tissue and cerebrospinal fluid. The present study will facilitate better understanding of the pathogenesis of facial nerve paralysis, vertigo, hearing impairment and other cranial nerve dysfunction of Ramsay Hunt syndrome.

Adolescent↗

PubMed1998

A case of mid-trimester intrauterine fetal death with Cushing's syndrome.

A 34-year-old woman was diagnosed with Cushing's syndrome after her first pregnancy ended in intrauterine fetal death at 25 weeks' gestation. She subsequently had a successful pregnancy after treatment of her disease. Although patients with Cushing's syndrome rarely conceive, abortion, preterm labor, and intrauterine growth retardation are common when they do.

Adrenal Cortex Neoplasms↗

PubMed1998

Expression of receptors for basic fibroblast growth factor on human periodontal ligament cells.

Basic fibroblast growth factor (FGF-2; bFGF) is a major mitogen for connective tissue cells, and participates in the healing process. It has already been reported that FGF-2 could be applicable to enhance periodontal regeneration. In the present study, we examined FGF receptor (FGFR) expression on human periodontal ligament (PDL) cells. The binding of [125I]-labeled FGF-2 to human PDL cells was studied by radioreceptor assay. The binding of [125I]-FGF-2 to PDL cells reached a plateau after 2.5 h incubation at 4 degrees C and was inhibited by the addition of unlabeled FGF-2 and acidic FGF (FGF-1; aFGF), but not insulin-like growth factor-I, platelet-derived growth factor and transforming growth factor-beta 1. Scatchard analysis revealed the presence of approximately 1.0 x 10(5) FGF-2 binding sites per cell with an apparent Kd of 1.2 x 10(-10) M. Interestingly, the binding of [125I]-FGF-2 on PDL cells reached its maximum at d 6 of the culture and then gradually decreased. Scatchard analysis also demonstrated that the number of FGFRs on a PDL cell was altered during the course of the culture, while the affinity between FGF-2 and its receptor was not. The responsiveness of PDL cells to FGF-2, which was monitored by the inhibitory effect on alkaline phosphatase activity, was reduced in proportion to the decrease in the number of FGFRs on the PDL cells. The present study suggests that PDL cells alter the responsiveness to FGF-2 during the course of the culture by changing the density of its receptor, and that the density of FGFR expression might be a marker of the cytodifferentiation of PDL cells into mineralized tissue forming cells.

Alkaline Phosphatase↗

PubMed1998

Relation between diffuse axonal injury and internal head structures on blunt impact.

Diffuse axonal injury (DAI) is a severe head injury, which exhibits symptoms of consciousness disturbance and is thought to occur through rotational angular acceleration. This paper analyzes the occurrence of DAI when direct impacts with translational accelerations are applied to two-dimensional head models. We constructed a human model reproducing the human head structure, as well as modified human models with some internal head structures removed. Blunt direct impacts were applied from a lateral direction to the bottom of the third ventricle, considered to be the center of impact, using an impactor. The analysis was done by comparing the macroscopic manifestation of DAI with the shear stress as the engineering index. In the analytical data obtained from the human model, shear stresses were concentrated on the corpus callosum and the brain stem, in the deep area. This agrees with regions of the DAI indicated by small hemorrhages in the corpus callosum and the brain stem. The analytical data obtained by the modified human models show that the high shear stress on the corpus callosum is influenced by the falx cerebri, while the high shear stress on the brain stem is influenced by the tentorium cerebelli and the shape of the brain. These results indicate that DAI, generally considered to be influenced by angular acceleration, may also occur through direct impact with translational acceleration. We deduced that the injury mechanism of DAI is related to the concentration of shear stress on the core of the brain, since the internal head structures influence the impact stress concentration.

Acceleration↗

PubMed1998

RMP, a novel RNA polymerase II subunit 5-interacting protein, counteracts transactivation by hepatitis B virus X protein.

To modulate transcription, regulatory factors communicate with basal transcription factors and/or RNA polymerases in a variety of ways. Previously, it has been reported that RNA polymerase II subunit 5 (RPB5) is one of the targets of hepatitis B virus X protein (HBx) and that both HBx and RPB5 specifically interact with general transcription factor IIB (TFIIB), implying that RPB5 is one of the communicating subunits of RNA polymerase II involved in transcriptional regulation. In this context, we screened for a host protein(s) that interacts with RPB5. By far-Western blot screening, we cloned a novel gene encoding a 508-amino-acid-residue RPB5-binding protein from a HepG2 cDNA library and designated it RPB5-mediating protein (RMP). Expression of RMP mRNA was detected ubiquitously in various tissues. Bacterially expressed recombinant RMP strongly bound RPB5 but neither HBx nor TATA-binding protein in vitro. Endogenous RMP was immunologically detected interacting with assembled RPB5 in RNA polymerase in mammalian cells. The central part of RMP is responsible for RPB5 binding, and the RMP-binding region covers both the TFIIB- and HBx-binding sites of RPB5. Overexpression of RMP, but not mutant RMP lacking the RPB5-binding region, inhibited HBx transactivation of reporters with different HBx-responsive cis elements in transiently transfected cells. The repression by RMP was counteracted by HBx in a dose-dependent manner. Furthermore, RMP has an inhibitory effect on transcriptional activation by VP16 in the absence of HBx. These results suggest that RMP negatively modulates RNA polymerase II function by binding to RPB5 and that HBx counteracts the negative role of RMP on transcription indirectly by interacting with RPB5.

Amino Acid Sequence↗

PubMed1998

Response of prostate-specific antigen after androgen withdrawal and prognosis in men with metastatic prostate cancer.

OBJECTIVE: Patients with prostate cancer generally respond to androgen withdrawal therapy, but progression to androgen independence is frequently observed. To evaluate prognostic factors in metastatic prostate cancer, patients who had been treated with endocrine therapy were investigated. METHODS: One hundred and thirty-nine patients with untreated metastatic prostate cancer (TxNxM1) who received endocrine therapy between 1986 and 1993 were included in the present study. Blood chemistry, histological grade, extent of bony metastases, clinical response to hormone therapy, and the prognosis of the patients were evaluated. RESULTS: With univariate analysis, performance status, hemoglobin concentration, serum alkaline phosphatase, lactate dehydrogenase, histological grade, extent of bony disease, and response of prostate-specific antigen (PSA) at 3 months were shown to be significant prognostic factors. With multivariate analyses, response of PSA and histological grade were significant factors predicting prognosis. CONCLUSIONS: Patients whose PSA had not normalized 3 months after the start of endocrine therapy were in the high-risk group, and should be given more aggressive treatment.

Aged↗