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Biomedical subjects

I Nagano

Publications and source records attributed to I Nagano.

At least 91 records · Page 5Linked to original sources
PubMed1997

Expression of tumor necrosis factor-alpha in muscles of polymyositis.

We immunohistochemically examined biopsied muscles from nine untreated patients with polymyositis (PM) and five patients with other neuromuscular diseases (ONMD), using monoclonal antibodies to tumor necrosis factor-alpha (TNF-alpha) and lymphoid surface markers. In muscles of three patients with PM, we observed many TNF-alpha positive macrophages and lymphocytes in endomysium and around vessels in the muscles. By contrast, there were few, weakly TNF-alpha stained cells in muscles of three patients with ONMD. The ratio of TNF-alpha-positive cells to the muscle fibers and the ratio of TNF-alpha-positive cells to the mononuclear cells were significantly higher in PM compared with ONMD. In addition, we observed atrophic muscle fibers more frequently in TNF-alpha-positive muscles than TNF-alpha-negative ones. We conclude that, at least, in a part of PM patients, TNF-alpha produced locally may contribute to the pathogenesis of PM.

Adult↗
PubMed1997

Implication of myocardial lactate metabolism during coronary artery bypass grafting.

Sixty-six consecutive patients with coronary artery disease were analysed in terms of myocardial lactate extraction during cardiac surgery. Sixteen patients had left main coronary heart disease and 50 were without such disease. Mean (s.d.) lactate extraction during empty beating in patients with and without left main coronary tract disease was -29.8(67)% and 12.0(15.3)%, respectively (P<0.001). No significant differences in lactate extraction were recognized during 15 min of reperfusion. Mean (s.d.) preoperative values of haemoglobin were 11.2(1.0) g/dl and these fell to 6.5(0.9) g/dl in an empty beating state during cardiopulmonary bypass (P<0.001). There was no significant difference between the two groups in preoperative and postoperative left ventricular stroke work index. An empty beating state before aortic clamping could induce unexpected ischaemia in the heart with left main coronary tract disease. A short duration of this ischaemic state does not influence functional recovery; however, exposing the left main coronary artery diseased heart to such a condition for long periods would be dangerous.

Blood Pressure↗
PubMed1997

Electron microscopic observations on the normal development of Trichinella spiralis from muscle larvae to adult worms in BALB/c mice with emphasis on the body wall, genital organs and gastrointestinal organs.

Ultrastructural changes during the development of Trichinella spiralis from muscle larvae to adult worms are described with emphasis on the body wall, genital organs and gastrointestinal organs. The cuticle of the body wall and hindgut underwent the first molting at 14 h post-infection (PI). The esophagus cuticle never molted. The hypodermal gland was formed in the lateral cords by 30 h PI. The genital primordium developed to either male or female genitals, accomplishing their sexual maturity and fertilization by 3 days PI. Glycogen disappeared during the development.

Animals↗
PubMed1997

Electron microscopic observations of the stichosome during the normal development of Trichinella spiralis from muscle larvae to adult worms in BALB/c mice.

The exocrine granules of the stichosome of Trichinella spiralis contain excretory and secretory (ES) products that may alter host cell physiology in such a way that T.spiralis can establish parasitism in the host [1,2]. The stichosome is the most intriguing but still mysterious exocrine organ. This paper describes ultrastructural changes of the stichosome during the normal development from muscle larvae to adult worms. Stichocyte granules of the muscle larva stage were excreted by 14 h post-infection (PI). Then the stichosome synthesized a new type of granules, which disappeared from the stichosome by 30 h PI. These transient granules were morphologically different from granules of muscle larva and adult stages.

Animals↗
PubMed1997

Laboratory investigation of enteroaggregative Escherichia coli O untypeable:H10 associated with a massive outbreak of gastrointestinal illness.

A massive outbreak of gastrointestinal illness occurred in Tajimi city, Gifu prefecture, in June of 1993 in which 2,697 children in elementary and junior high schools developed severe diarrhea. Stool specimens from 30 children with severe protracted diarrhea were studied. Twenty-seven strains of enteroaggregative Escherichia coli (EAggEC) isolated from 12 of 30 patients all belonged to the same serotype, O untypeable (OUT):H10, and showed the same biochemical characteristics and antibiotic susceptibility pattern. These strains were negative for the virulence factors of the four standard categories of diarrheagenic E. coli (enterotoxigenic, enteropathogenic, enteroinvasive, and enterohemorrhagic). However, the isolates showed an aggregative pattern of adherence to HEp-2 cells and had a 60-MDa plasmid and an astA gene, which encodes heat-stable enterotoxin-1 production. These data suggested that the EAggEC serotype OUT:H10 was associated with this massive outbreak of gastrointestinal illness.

Adolescent↗
PubMed1997

[A prospective study on the timing of discontinuation of aspirin before coronary artery bypass grafting].

The effects of the timing of discontinuation of aspirin before coronary artery bypass grafting (CABG) on postoperative blood loss and blood requirements were examined in 22 patients undergoing elective CABG, who were randomly assigned into two groups. In Group I (11 patients), aspirin was discontinued two days before the operation and in Group II (11 patients), aspirin was continued up to the operation. The other 40 patients, who did not take aspirin for at least seven days before the operation, served as a control Group. There were no differences in preoperative data including the platelet count and the hemoglobin concentration, nor in operative variables such as operation time, cardiopulmonary bypass duration and aortic crossclamp time among the groups. Although postoperative blood loss (six hours' loss; Group I 218 ml, Group II 183 ml and control Group 172 ml) and red blood cells transfusion requirements were not different among the groups, platelet concentrates transfusion was more frequently required in Group II (54.5%) as compared with control Group (7.5%) and Group I (9.1%). The difference between Group II and the control Group reached statistical significance (p < 0.01), but there was no significant difference between Group I and control Group. This fact suggests that preoperative two days' discontinuation of aspirin works as effectively as seven days' discontinuation.

Aged↗
PubMed1996

Melanin-laden macrophages in cerebrospinal fluid in Vogt-Koyanagi-Harada syndrome.

OBJECTIVE: To identify basophilic granules in the cytoplasm of macrophages in cerebrospinal fluid (CSF) smears from patients with Vogt-Koyanagi-Harada (VKH) syndrome as melanin pigment. DESIGN: Morphological and immunocytochemical studies were performed on CSF smears obtained from 7 patients with VKH syndrome. Specimens were stained with May-Grünwald and evaluated by a silver impregnation method (Fontana-Masson staining). For immunocyto-chemical study, the smear was reacted with mouse anti-human melanoma cell (HMB-45) monoclonal antibody. RESULTS: Basophilic granules were detected in the cytoplasm of macrophages in CSF cell smears obtained from 6 of 7 patients with VKH syndrome in the early stages (within 25 days). Using the silver impregnation method, these basophilic granules were strongly stained black. Moreover, they were identified as melanin by positive immunocytochemical staining. The total number of cells containing cytoplasmic granules ranged from 3 to 8 per 10,000 total cells in CSF. In contrast, no cells containing cytoplasmic granules were found in control CSF cell smears from patients with viral, bacterial, or noninflammatory diseases. CONCLUSION: The identification of melanin-laden macrophages in the CSF of patients with VKH syndrome suggests that these cells are responsible for pleocytosis in the immunopathologic process of VKH syndrome.

Adult↗
PubMed1996

Upregulation of Bcl-2 protein in the myasthenic thymus.

We examined the expression of Fas antigen and Bcl-2 protein in thymic tissue surgically resected from 10 patients with myasthenia gravis, using immunocytochemical techniques. Histologically, thymic tissues from 7 myasthenia gravis patients showed hyperplasia, while 3 other patients had thymomas. In hyperplastic thymic tissue, immunoreactivity for Fas antigen was observed mainly in the network of medullary epithelial cells. In contrast, expression of Fas antigen was rare in the cortex. Fas antigen was also detected to some degree in thymoma tissue from 3 patients. Bcl-2 protein was highly expressed in the medullary thymocytes in the hyperplastic thymic tissue, whereas its staining was quite low in myasthenia gravis thymomas. The number of Bcl-2-positive thymocytes in the medulla was significantly greater in the hyperplastic myasthenia gravis thymic tissue than in the control thymic tissue. These findings suggest that Bcl-2 protein may be upregulated in the myasthenia gravis thymus and that this phenomenon may be related to impaired apoptotic cell death of autoreactive thymocytes in myasthenia gravis.

Adult↗
PubMed1996

A simple method to design PCR primer to detect genomic DNA of parasites and its application to Dirofilaria immitis.

A simple method to design a polymerase chain reaction (PCR) primer for parasites of interest was developed using Dirofilaria immitis as a test sample. The method involved the cloning and sequencing of randomly amplified DNA of the parasite, and designing a primer based on the resulting DNA sequence. Using the primer, DNA fragments of the expected length were amplified by a regular PCR with genomic DNA of Dirofilaria immitis.

Animals↗
PubMed1996

Increased NADPH-diaphorase reactivity and cytokine expression in dorsal root ganglia in acquired immunodeficiency syndrome.

We studied lumbosacral dorsal root ganglia (DRGs) from 10 patients with acquired immunodeficiency syndrome (AIDS) and five controls using immunocytochemistry, in situ hybridization and NADPH-diaphorase (NADPHd) histochemistry. Human immunodeficiency virus (HIV)-1 RNA was detected in five AIDS cases, and HIV-1 p24 antigen was found in four of these patients. The densities of nodules of Nageotte (nN), macrophages and major histocompatibility complex-class II-positive cells were significantly increased in the DRGs of AIDS patients compared to controls. Cytomegalovirus antigen was observed in the DRGs of four AIDS cases and one control, but without its presence being related to neuronal degeneration. Furthermore, we detected tumor necrosis factor, interferon-gamma, interleukin (IL)-1 beta, and IL-6 in the DRGs from AIDS patients. Using NADPHd histochemistry, we showed that the number of NADPHd-positive neurons was significantly increased in the DRGs of AIDS patients compared to controls, implying upregulation of nitric-oxide (NO) production in AIDS DRGs. Generally, there were increased numbers of nN in DRGs which contained more NADPHd-positive neurons. Additionally, immunoreactivity for an inducible form of NO synthase was detected in interstitial cells in AIDS DRGs. These results suggest that reactive inflammation, including the production of cytokines, occurs in the DRGs of AIDS patients and that excessive production of NO may be related to neuronal degeneration in AIDS DRGs.

Acquired Immunodeficiency Syndrome↗
PubMed1996

Virulence in mice of Orientia tsutsugamushi isolated from patients in a new endemic area in Japan.

Four strains of Orientia tsutsugamushi (KN-1, KN-2, KN-3 and GJ-1) isolated from patients in an area of Gifu Prefecture, Japan, in which tsutsugamushi disease is newly endemic, were examined for their virulence in mice. Among these, KN-1 (identified as Kawasaki type), GJ-1 (identified as Kuroki type) and KN-2 strains were found to be non-lethal for BALB/c mice as well as CH3/HeJ mice, even with high doses (10(6) x being the 50% mouse infectious dose). On the other hand, the KN-3 strain was found to be sufficiently virulent to kill BALB/c mice. Among the prototype strains (Gilliam, Karp and Kato), the Karp and Kato strains exhibited high virulence to mice, while the Gilliam strain killed only a susceptible strain of mouse. BALB/c mice infected with KN-1 and KN-2 strains showed significant splenomegaly and moderate ascites accumulation in the first week of infection, while these symptoms became prominent during the second week of infection using KN-3, Karp and Kato strains. After infection with the GJ-1 strain, these symptoms were not observed. Antibody responses induced by infections with highly virulent strains were lower than that with low or intermediate virulent strains.

Animals↗
PubMed1996

Parvalbumin and calbindin D-28 k immunoreactivity in dorsal root ganglia in acquired immunodeficiency syndrome.

Various degrees of neuronal degeneration have been found in lumbosacral dorsal root ganglia of patients with acquired immunodeficiency syndrome (AIDS). To characterize the subpopulations of primary sensory neurons affected in AIDS, we immunostained dorsal root ganglion tissues from 11 AIDS patients and six controls using antibodies to the calcium binding proteins, parvalbumin and calbindin D-28 k. In controls, the proportion of neurons containing parvalbumin and calbindin was 18.0% and 22.4%, respectively. The majority of parvalbumin-positive neurons, which are thought to be proprioceptive neurons, were of medium to large size, while calbindin was found in both large- and small-sized neurons. The density of parvalbumin-immunoreactive neurons was reduced by 7.3% in AIDS patients, but the density of calbindin-immunoreactive neurons was preserved. Furthermore, in AIDS cases, the number of parvalbumin-positive neurons was reduced more in dorsal root ganglia in which human immunodeficiency virus (HIV) antigen was detected than in HIV-negative ganglia. These results suggest that specific subpopulations of sensory neurons positive for parvalbumin may be differentially affected over the course of AIDS, and that this could be related to peripheral neuropathy which frequently occurs in the late stages of AIDS.

Acquired Immunodeficiency Syndrome↗
PubMed1996

Apoptosis of lymphocytes in mice induced by infection with Rickettsia tsutsugamushi.

Histological examinations of mice infected with either a lethal (Karp) or a self-limitating (Gilliam) strain of Rickettsia tsutsugamushi were performed. Tingible body macrophages in the spleen and necrotizing lymphadenitis in regional lymph nodes were prominent only in the former. Apoptotic legions in the lymphocytes of these organs were clearly demonstrated by histochemical and electron microscopical examinations.

Animals↗
PubMed1996

Regulation of HIV-1 infection in astrocytes: expression of Nef, TNF-alpha and IL-6 is enhanced in coculture of astrocytes with macrophages.

'Restricted' human immunodeficiency virus type (HIV-1) infection of astrocytes is recognized in vivo in some pediatric and adult AIDS brains and in vitro in a small proportion of transfected primary fetal astrocytes. We investigated the extent of HIV-1JR-FL expression in fetal astrocytes and macrophages cultivated alone or together. Peak HIV-1 p24 antigen titres in supernatant fluids of macrophage cultures were increased with monocyte/macrophages from certain donors and were higher when macrophages were cocultivated with astrocytes. Structural HIV-1 gene (gp 41 and pol) products (protein and mRNA) were observed only in macrophages. Ten days after HIV-1JR-FL infection, astrocytes in a monoculture were stained negative or only weakly positive (1-2+) for Nef, whereas in a coculture up to 100% of astrocytes displayed Nef staining (up to 4+) in the cytoplasm. The streptavidine-biotine-peroxidase technique with certain monoclonal antibodies to Nef (Ovod et al, 1992) was specific for infected astrocytes. The intensity of Nef staining was higher in astrocytes cultivated with monocyte/macrophages from certain donors. In the coculture, tumor necrosis factor-alpha (TNF-alpha) was expressed in the astrocyte cytoplasm earlier after coinfection with HIV-1 and cytomegalovirus (CMV) compared to infection with HIV-1 alone. Interleukin-6 (IL-6) was secreted spontaneously and transiently in uninfected cocultures, but in a prolonged fashion following HIV-1 and HIV-1/CMV infections. The interactions between HIV-1- and CMV-infected macrophages and astrocytes lead to upregulation of TNF-alpha and IL-6 and enhancement of productive HIV-1 infection of macrophages and of 'restricted' HIV-1 infection of astrocytes with implications for the pathogenesis of AIDS dementia.

Astrocytes↗
PubMed1996

[A catheter-guided insertion of Pacifico's venous cannula].

Direct caval cannulation using a Pecifico's cannula has become popular in open heart surgery. However, the cannulation is often difficult especially in pediatric cases because of the right-angled, blunt and large metal tip of the catheter. To resolve this problem, we introduced a catheter-guided insertion of the cannula using an intratracheal suction catheter (IZUMO Health, Nagano, Japan) of an appropriate size as a guiding catheter. With this technique, no special skills are necessary to establish direct caval cannulation.

Cardiac Surgical Procedures↗