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Biomedical subjects

M Nagashima

Publications and source records attributed to M Nagashima.

At least 163 records · Page 9Linked to original sources

[Quantitative analysis of electromyogram interference pattern in extraocular muscle].

Quantitative analysis of electromyogram (EMG) interference pattern was performed for objective evaluation. EMGs of 261 horizontal rectus muscles had been recorded in our laboratory during the past 18 years, and they were divided according to the clinical diagnosis into four categories: 56 records due to complete neuropathy, 67 due to incomplete neuropathy, 19 due to myopathy, and 119 normal. The turns and amplitude analysis program was used for EMG analysis. A turn was one wave of the interference pattern, for which we used an amplitude of more than 15 microV. Turns meant the number of turn waves per second. Turns/second and mean amplitude/turn (A/T) were plotted against each other on an X-Y diagram, and a statistical evaluation of data was done. Complete neuropathy recordings that had lower turns and lower A/T were separated from the other three categories. Incomplete neuropathy and myopathy occurred on the lower A/T area. There was a significant difference (p < 0.05) between each pair of comparisons from all four categories except for turns evaluated between myopathy and normal. Quantitative analysis proved useful for the objective evaluation of the EMG interference pattern, particularly between cases of complete and incomplete neuropathy.

Electromyography↗

Role of vascular endothelial growth factor in angiogenesis of rheumatoid arthritis.

OBJECTIVE: To examine the localization and role of vascular endothelial growth factor (VEGF), an endothelial cell specific mitogen, in rheumatoid arthritis (RA). METHODS: Immunohistochemical staining, reverse transcription polymerase chain reaction (RT-PCR) analysis and in situ hybridization for VEGF were performed on synovial tissues from 10 patients with RA, 5 patients with osteoarthritis (OA) and 3 autopsy cases. RESULTS: In RA, the proliferative ratio of synovial lining cells and vascular endothelial cells was significantly higher than that in OA and normal synovial tissues. Immunohistochemical staining demonstrated that VEGF polypeptide was strongly expressed in subsynovial macrophages, fibroblasts surrounding microvessels, vascular smooth muscle cells, and synovial lining cells, but not in vascular endothelial cells of patients with RA. On the other hand, in patients with OA and normal cases, VEGF polypeptide was slightly expressed in synovial lining cells and fibroblasts. RT-PCR showed a positive reaction for VEGF messenger RNA in RA, OA, and normal synovial tissues. A large number of subsynovial macrophages, fibroblasts, vascular smooth muscle cells, and synovial lining cells from patients with RA expressed VEGF mRNA using in situ hybridization. CONCLUSION: In RA, VEGF is synthesized and released by a large number of subsynovial macrophages, fibroblasts surrounding microvessels, vascular smooth muscle cells, and synovial lining cells and may stimulate endothelial proliferation in a paracrine manner via VEGF receptors.

Arthritis, Rheumatoid↗

Increased formation of oxidative DNA damage, 8-hydroxydeoxyguanosine, in human livers with chronic hepatitis.

8-Hydroxydeoxyguanosine (oh8dG) is a promutagenic DNA lesion produced by oxygen radicals. We examined alterations in the oh8dG level in human livers which have chronic hepatitis, liver cirrhosis, and hepatocellular carcinoma. The oh8dG content in livers with chronic hepatitis was significantly higher than the oh8dG content in normal livers (P < 0.05). There was also a significant correlation between the oh8dG content in noncancerous liver tissues with individual serum alanine aminotransferase concentration (r = 0.515; P < 0.001). Thus, chronic inflammation in the liver produces oxidative DNA damage, which may increase the risk for genomic alterations causing hepatocarcinogenesis.

Alanine Transaminase↗

Lectin binding pattern in normal human labial mucosa.

The pattern of lectin binding in normal human labial mucosa was examined by light and electron microscopy using eight different lectins (ConA, LCA, WGA, UEA-1, RCA-1, SBA, DBA and PNA) and compared with the patterns in normal human skin and oesophageal mucosa. As seen by light microscopy, ConA, LCA, and WGA stained cell membranes in all layers of the mucosae. RCA-1 stained the plasma membrane of cells in the basal and middle layers, whereas cells in the superficial layers showed little positive staining. UEA-1, SBA, and PNA stained the cells in the middle layers weakly in some cases. No positive staining for DBA was seen. By electron microscopy, reaction product indicating ConA-binding sites was observed in the plasma membrane, cisternae of the endoplasmic reticulum, nuclear envelope and the Golgi apparatus. Binding of LCA, WGA, and RCA-1 was observed in the plasma membrane. These results show that the binding pattern of PNA, SBA, and RCA-1 in labial mucosa is different from that in the normal skin or oesophageal mucosa, although the labial mucosal epithelium, epidermis, and oesophageal epithelium are all stratified squamous epithelia. These differences in the cell-surface sugar residues are likely to be related to the possible functional differences in these tissues.

Adult↗

Twelve years' experience with the St. Jude Medical valve prosthesis.

Since July 1978, 1,284 patients have received the St. Jude Medical prosthesis (425 aortic, 636 mitral, and 223 double aortic-mitral), and the results in these patients were reviewed according to guidelines of the Society of Thoracic Surgeons. Follow-up was complete in 98%. Of 80 late deaths, 29% were valve related. The actuarial survival rate, including operative deaths, at 12 years was 81.7% and 87.1%, respectively, for aortic and mitral valve replacement, and it was 82.6% at 11 years after double valve replacement. All patients were anticoagulated with warfarin to maintain the thrombotest value between 10% and 25%, which is equivalent to between 2.8 and 1.6 times the control according to the international normalized ratio of the prothrombin time. The linearized rate of complication for aortic, mitral, and double valve replacement, respectively (expressed as the percent per patient-year), was as follows: structural deterioration, 0; non-structural dysfunction, 0.16, 0.30, and 0.20; valve thrombosis, 0.05, 0.09, and 0; thromboembolism, 1.35, 1.63, and 0.79; anticoagulant-related hemorrhage, 0.10, 0.18, and 0.10; and prosthetic valve endocarditis, 0.21, 0.06, and 0.20. Reoperation was performed in 16 patients. The freedom from reoperation rate at 12 years was 99.5% and 98.0% for aortic and mitral valve replacement, respectively, and it was 99.1% at 11 years for double valve replacement. Thus, during the 12-year follow-up in patient who received the St. Jude Medical prosthesis, the valve performed satisfactorily and with an acceptable risk of late complication even though patients were anticoagulated using a lower dose of warfarin.

Actuarial Analysis↗

Postnatal development of the rat corticospinal tract, with special reference to confocal laser scanning microscopy of growing axons.

The corticospinal tract within the spinal cord of the neonatal rats, ranging from postnatal day 1 (P1) to P11, was investigated by using anterograde labeling with DiI optimized by confocal laser scanning microscopy. This method enabled us to observe a thick section containing a large population of the labeled axons and to acquire fine structure images with sufficient resolution. As advantages, novel views of diversity emerged in the developing axons and their collaterals. First, the individual parent axons showed unrestrained trajectories within the main bundle which constantly occupied the ventral part of the dorsal column. Second, there was an aberrant bundle which ran ventrally apart from the main bundle and converged into it. Third, several projection collaterals branched from the parent axons and left the main bundle in various directions, whereas the majority of them branched off at approximately a right angle. In addition, the main bundle consisted of a small number of pioneer axons and numerous follower ones. The pioneer axon tips were first found in the cervical level on P1, in the thoracic level on P2, in the lumbar level on P5 and in the sacral level on P7. The follower axon tips were observed in a wide range away from the pioneer tips to just behind them. Projection collaterals were arborized within the gray matter and their arbors entered the dorsal horn, the intermediate substance or the ventral horn in the transverse plane.

Animals↗

A multicenter, randomized, controlled trial of intravenous gamma globulin therapy in children with acute Kawasaki disease.

We studied the effect of intravenous, polyethyleneglycol-treated, human immunoglobulin, administered at 200 mg/kg per day (group A: n = 147; male 86, female 61; age < 1 year, 50) or 400 mg/kg per day (group B: n = 152; male 87, female 65; age < 1 year, 52) for five consecutive days and compared it with freeze-dried, sulfonated human immunoglobulin [group C: n = 152; male 87, female 65; age < 1 year, 51), administered at 200 mg/kg per day for five consecutive days, on the prevention of coronary artery abnormalities in Kawasaki disease. Echocardiograms were interpreted blindly and independently. Proportions of 87.1%, 95.4%, and 82.3% in groups A, B, and C, respectively, had no coronary artery abnormalities. The confidence limits of difference between the proportions of groups A and C, groups B and C, and groups B and A were -4.4% and 10.4%, 7.8% and 15.9%, and 4.0% and 10.8%, respectively. Duration of fever and serum immunoglobulin G (IgG) levels were correlated with the prevalence of coronary artery abnormalities. We concluded that intravenous, polyethyleneglycol-treated, human immunoglobulin and freeze-dried, sulfonated human immunoglobulin had clinically equivalent effects on coronary artery abnormalities, and that five daily doses of 400 mg/kg of intravenous, polyethyleneglycol-treated, human immunoglobulin is more effective than that of 200 mg/kg gamma globulin.

Acute Disease↗

Circadian rhythm of blood pressure in children with reference to normal and diseased children.

Circadian rhythms of blood pressure in children were investigated using ambulatory blood pressure monitoring (ABPM). The subjects were 58 normal children (26 boys and 32 girls), 10 children with orthostatic dysregulation (OD) consisting of (three boys and seven girls) and 13 children taking prednisolone (nine boys and four girls). Systolic pressure in the normal group increased from early morning, peaked in the afternoon and gradually dropped thereafter. Blood pressure in the 22:00-05:30 h time range was significantly lower than in other time ranges. Blood pressure in the OD group was generally lower than in the normal group, while that in the steroid group tended to be higher. Systolic mid-line estimating statistic of rhythm (MESOR) was significantly higher in boys than girls in both 10-12 year olds and 13-15 year olds according to Cosinor analysis. However, no increase in MESOR was observed in either boys or girls between the 10-12 year and 13-15 year age groups. The OD group showed lower diastolic MESOR than the normal group and the steroid group showed higher systolic MESOR. Seventy-two per cent of those in the normal group manifested significant circadian rhythm. Only 50% of 10-12 year olds manifested circadian rhythm, whereas the figure for 13-15 year olds increased to 80-90%, suggesting that a pacemaker regulating circadian rhythm comes into effect at puberty. The percentage of those who manifested circadian rhythm in the OD group and steroid group was about 60%, lower than in the normal group.

Adolescent↗

[Studies on respiratory infections in primary care clinic (V). The pattern of distribution on bacteria, Mycoplasma pneumoniae and virus isolated from patients with respiratory infections, who were seen in six private clinics, and clinical efficacy of ciprofloxacin and roxithromycin].

The pattern of distribution of bacteria, Mycoplasma pneumoniae and virus isolated from the same specimen recovered from the throat swab or the sputum of 479 patients with respiratory infections who were seen in six private clinics in Sendai City of Japan during the period from October to November in 1992 (period I) and from January to February in 1993 (period II) was documented. Of the 479 patients, 234 had acute pharyngitis, 145 had acute bronchitis, 96 had influenza, 21 had acute tonsillitis, 5 had acute pneumonia and 9 had other respiratory infections. One hundred (42.4%) strains of potential pathogen and one strain of M. pneumoniae were recovered from 236 cases in period I, and 66 (27.2%) strains of potential pathogen, one strain of M. pneumonae and 73 strains of Influenza virus (30.0%: 43 of type A Hong-Kong and 30 of type B) from 243 cases in period II. Of the 166 strains, major isolates were Staphylococcus aureus (56 strains), Streptococcus pneumoniae (12 strains), Streptococcus pyogenes (15 strains), Haemophilus influenzae (17 strains), Esherichia coli (4 strains), Klebsiella spp. (35 strains), Pseudomonas aeruginosa (4 strains) and Acinetobacter spp. (23 strains). Only one strain of S. aureus was resistant to methicillin (MIC: 50 micrograms/ml). None of S. pneumoniae was resistant to 1 microgram/ml of ampicillin. Ciprofloxacin was administered to 113 cases and roxythromycin to 220 cases by doctors in charge.(ABSTRACT TRUNCATED AT 250 WORDS)

Ciprofloxacin↗

Histamine receptors mediating a positive inotropic effect in guinea pig and rabbit ventricular myocardium: distribution of the receptors and their possible intracellular coupling processes.

The difference in histamine receptor subtypes that are involved in the positive inotropic effect of histamine in guinea pig and rabbit ventricular myocardium was analytically characterized. In guinea pig papillary muscles, the positive inotropic effect of histamine was antagonized by cimetidine but not by mepyramine. The converse was true in rabbit papillary muscles. However, histamine evoked a positive inotropic effect through H1- and H2-receptors after blockade of H2- and H1-receptors in guinea pig and rabbit papillary muscles, respectively. Adenylate cyclase was significantly activated by histamine via H2-receptors in guinea pig but not in rabbit myocardial ventricular membranes. Accumulation of [3H]inositol monophosphate in ventricular strips prelabeled with myo-[3H]inositol was increased by histamine via H1-receptors to a similar extent in rabbits and guinea pigs. Radioligand binding experiments with [3H]mepyramine and [3H]tiotidine showed an increased number of H1-receptors and a decreased number of H2-receptors in guinea pig compared with rabbit ventricular myocardium. These results suggest that the positive inotropic effects of histamine are dominated by an H1-receptor-mediated effect in rabbits and by an H2-receptor-mediated one in guinea pig ventricular myocardium, and the positive inotropic effect manifested by one subtype apparently restricts the expression of the positive inotropic effect mediated by the other subtype. This species difference is not due to a difference in densities of the receptor subtypes, but may be partly related to a difference in the extents of coupling of H2-receptors to adenylate cyclase.

Adenylyl Cyclases↗

[Effect of tumor necrosis factor and interferon-gamma on platelet-derived growth factor (PDGF) A and B gene expression in THP-1 monocytic cells].

Platelet-derived growth factor (PDGF) is a potent mitogen of mesenchymal cells. A and B chains of PDGF are transcribed in atherosclerotic plaques but details of the mechanism of the expression of either chains in vivo are not understood. It has been suggested that differentiated macrophages, which are the major origin of foam cells, but not monocytes hardly secrete PDGF in vitro. In the present study, we investigated the effect of 1) tumor necrosis factor-alpha (TNF-alpha), a macrophage derived cytokine which promote the differentiation from monocytes to macrophages, and 2) interferon-gamma (IFN-gamma), a T cell derived macrophage activating factor, on the production and mRNA expression of PDGF A and B chains in a human monocytic leukemia cell line THP-1. THP-1 cells were cultured in the presence of one of the experimental cytokines with or without the addition of phorbol 12-myristate 13-acetate (PMA). PMA is known to induce the differentiation of monocytes (including THP-1 cells) to macrophages within a period of 24 hours. Thus the treatment of THP-1 cells with a cytokine and/or PMA in vitro was expected to mimic the effect of the cytokine during the differentiation of monocytes to macrophages in vivo. Unstimulated THP-1 cells expressed no detectable amount of PDGF A or B mRNA. The treatment of THP-1 cells with PMA resulted in the strong expression of both PDGF A and B mRNAs. Stimulated with TNF-alpha (50 U/ml) on day 0, THP-1 cells expressed PDGF A mRNA significantly from 1 up to 3 days after the treatment, whereas the expression of PDGF B and mRNA was only weakly detected on day 2. The maximum signal of PDGF A mRNA was ten times stronger than that of PDGF B mRNA. Within the same period, relatively small number of TNF-alpha treated THP-1 cells had differentiated to macrophages as detected by the reduction of nitro blue tetrazolium (NBT) (35% of total cells) and by the counting of adherent cells (35% of total cells). THP-1 cells simultaneously treated with TNF-alpha and PMA strongly expressed PDGF A and B gene. Most remarkably, the expression of PDGF B mRNA was greatly enhanced with compared to the treatment with PMA alone. In addition, TNF-alpha augmented the secretion of PDGF proteins in PMA stimulated THP-1 cells. In contrast, INF gamma per se had no effect on PDGF gene expression, NBT reducing activity and cell adherence in unstimulated THP-1 cells.(ABSTRACT TRUNCATED AT 400 WORDS)

Cell Differentiation↗

An unexpected increase in circulating IFN-gamma by cyclosporin A in atopic patients: a discrepancy between in vitro and in vivo events.

Defective interferon gamma (IFN-gamma) production has been suggested to be relevant to immunologic abnormalities observed in atopic dermatitis (AD). We describe two patients with severe AD who were treated with oral cyclosporin A (Cy-A) and in whom the serum levels of IL-1 alpha, IFN-gamma and tumor necrosis factor alpha (TNF-alpha) were sequentially measured. Cy-A, known to inhibit IFN-gamma production in vitro, caused a rapid rise in serum IFN-gamma, but not Il-1 alpha and TNF alpha, levels in the patients and the IFN-gamma levels appeared to be inversely related to the therapeutic efficacy. The observed increase in serum IFN-gamma levels during Cy-A therapy may have contributed to a marked clinical improvement of the AD.

Administration, Oral↗

[Pharmacological study on functional significance of alpha 1-adrenoceptor subtypes in mammalian ventricular myocardium].

The present study was undertaken to determine alpha 1-adrenoceptor subtype involved in the inotropic, electrophysiological and phosphoinositide responses to myocardial alpha 1-adrenoceptor stimulation. Phenylephrine in the presence of the beta-adrenoceptor antagonist, propranolol, elicited a positive inotropic effect in a concentration-dependent manner in both rat and rabbit papillary muscles. In rat papillary muscle, the positive inotropic effect of phenylephrine was antagonized by the alpha 1A-selective antagonist, WB4101, but not affected by the alpha 1B-antagonist, chloroethylclonidine (CEC). On the other hand, the positive inotropic effect in rabbit papillary muscle was antagonized by both WB4101 and CEC. The inotropic response of rat papillary muscle to phenylephrine was composed of a negative inotropic phase and a positive inotropic phase, both of which were blocked only by WB4101. In both rat and rabbit papillary muscles, phenylephrine caused prolongation of action potential duration. WB4101, but not CEC, significantly suppressed the APD prolongation. Only in rat papillary muscle, phenylephrine exerted hyperpolarization of resting membrane potential, an effect which was also eliminated by WB4101. Furthermore, stimulation of phosphoinositide hydrolysis induced by phenylephrine (evaluated by [3H] inositol monophosphate accumulation) was inhibited by WB4101 in a concentration-dependent fashion, but the inhibitory effect on the response to phenylephrine was seen with CEC only at a higher concentration. From these results, it was concluded that both myocardial alpha 1A- and alpha 1B-adrenoceptor subtypes are able to mediate a positive inotropic effect, and that the alpha 1A-adrenoceptor-mediated positive inotropic effect is exclusively dependent on the prolongation of action potential duration, while the alpha 1B-adrenoceptor-mediated one appear to be due to a mechanism other than electrophysiological changes. In addition, based on the previous respects that the phosphatidyl-inositol hydrolytic products do not contribute to the alpha 1-adrenoceptor-mediated electrophysiological effects, the present data suggest that the coupling of alpha 1A-adrenoceptors to phosphatidylinositol hydrolysis may be independent of the positive inotropism.

Action Potentials↗

[A successful surgical case of supravalvular aortic stenosis with Williams syndrome: the investigations of the procedures].

We experienced a successful surgical case in which a 3-year-old boy with a characteristic elfin face, heart murmur, and mental retardation, underwent extended patch aortoplasty using equine pericardium for congenital supravalvular aortic stenosis. The aortography performed before operation, and demonstrated diffuse stenosis just above the aortic valve, which was a typical hour-glass type. The preoperative peak systolic pressure gradient between the left ventricle and ascending aorta was 120 mmHg, and was improved postoperatively. In this procedure only one cusp was incised, resulting in no deformity of the aortic valve and no obstruction of coronary arteries. In conclusion this method was excellent for the diffuse type of supravalvular aortic stenosis.

Abnormalities, Multiple↗

[Left ventricular characteristics after Jatene operation for transposition of the great arteries with intact ventricular septum--comparative study of neonatal primary and two stage repairs].

Left ventricular characteristics in late postoperative period after the arterial switch operation (ASO) was evaluated in fifty-nine patients with transposition of the great arteries and intact ventricular septum. They included 22 neonates who underwent a neonatal ASO (Group I) and 37 patients who underwent a two-stage ASO (Group II). Group II was subdivided into two groups according to the presence or absence of aortic regurgitation in the late postoperative period as group IIa (aortic regurgitation [-], 22 patients) and group IIb (aortic regurgitation [+], 15 patients). Age at ASO ranged from 4 to 27 days (average 12.7 days) in the group I, 5 to 43 months (average 12.7 months) in the group IIa, and 4 to 54 months (average 16.3 months) in the group IIb. Postoperative follow-up period ranged from 8 to 68 months (average 25.0 months) in the group I, 12 to 74 months (average 59.0 months) in the group IIa, and 19 to 66 months (average 48.5 months) in the group IIb. Left ventricular end-diastolic volume was significantly smaller in the group I (123 +/- 19% of normal) than the group IIa (146 +/- 38 of normal) and the group IIa (183 +/- 53% of normal). And left ventricular ejection fraction was significantly higher in the group I (67 +/- 5%) than the group IIa (62 +/- 11%) and the group IIb (58 +/- 8%). Left ventricular normalized mass was significantly smaller in the group I (85 +/- 11% of normal) than the group IIa (113 +/- 14% of normal) and the group IIb (130 +/- 9% of normal).(ABSTRACT TRUNCATED AT 250 WORDS)

Analysis of Variance↗

Small-cell carcinoma combined with adenocarcinoma of the gallbladder. A case report with immunohistochemical and flow cytometric studies.

A small-cell carcinoma combined with adenocarcinoma of the gallbladder was detected in a 71-year-old Japanese woman. A nodular mass measuring 4.0 x 5.0 cm was located in the fundus of the gallbladder, in which a tiny depressed lesion measuring 2 mm in diameter was macroscopically and stereomicroscopically observed. Histologically, the depressed area revealed small-cell carcinoma that consisted of atypical cells with small, round to oval nuclei and scanty cytoplasm and was surrounded by ordinary well-differentiated adenocarcinoma. Immunohistochemically, the tumor cells in an adenocarcinomatous area were diffusely positive for carcinoembryonic antigen and showed an interspersed positivity to serotonin and gastrin, while the tumor cells in the small-cell carcinoma area were negative for both antigens. The nuclear DNA content of the tumor cells of both components was aneuploid; however, the first G0/G1 peak of the small-cell carcinoma was much smaller than that of the adenocarcinoma. These results indicated that the tumor revealed a divergence in functional differentiation, and this feature suggested an initial phase of composite small-cell carcinoma and adenocarcinoma in the gallbladder.

Adenocarcinoma↗

Identification of a novel population of CD8 alpha+ beta- bone marrow-derived dendritic epidermal cells. This unique population is subsequently outnumbered by thymus-independent expansion of the CD8 alpha+ beta+ dendritic epidermal cells.

Maturation of some T cell populations has been suggested to occur in epithelial tissues. The CD8 molecule, which is expressed as heterodimers made of alpha/beta-chains on virtually all peripheral T cells, is preferentially expressed as homodimers made only of alpha-chains on a subset of CD8+ mouse gut intraepithelial lymphocytes, which arise from bone marrow (BM) precursors in a thymus-independent mechanism. This unique population of CD8 alpha+ beta- T cells, however, has not been identified in other lymphoid tissues in normal adult mice. Because our previous study demonstrated that reconstitution of thymectomized irradiated mice with T cell-depleted BM cells resulted in the appearance of CD8+, TCR-alpha beta+ dendritic epidermal cells (DEC) and suggested that a proportion of the BM-derived DEC may mature within the epidermis, we asked whether the unique phenotype of CD8 alpha+ beta- could be detected among the CD8+ BM-derived DEC. In this report for the first time we identified this unique population of CD8 alpha+ beta- cells among the DEC. Although this population comprised the predominant fraction of the BM-derived DEC in the early post-transfer period (2 to 3 mo), gradual shift from the CD8 alpha+ beta+ phenotypes occurred during the late post-transfer period (4 to 6 mo) independently of the presence of the thymus. Kinetic studies on the BM-derived DEC revealed that this phenotypic shift could be caused by the subsequent expansion of the CD8 alpha+ beta+ DEC. In contrast, the CD8 alpha+ beta- population was the major subset of the BM-derived intraepithelial lymphocytes throughout the entire observation period and the phenotypic shift with age was never observed. These results indicate that CD8 alpha+ beta- cells are preferentially detected on T cells that home to the epithelial tissues and that in the epidermis, but not in the gut epithelia, the subsequent expansion of the CD8 alpha+ beta+ DEC would dilute the high number of the CD8 alpha+ beta- cells.

Animals↗