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Biomedical subjects

H Niimi

Publications and source records attributed to H Niimi.

At least 127 records · Page 7Linked to original sources
PubMed1994

[CT & MRI findings of refractory vasculitis].

We described CT and MRI findings of various refractory vasculitis. Refractory vasculitis must be divided into two categories including one group with major vascular involvement and another one with small or microvascular involvement. In cases with major vessel involvement such as Takayasu's arteritis, Kawasaki disease or vasculo-Behçet disease, CT and MRI depicted direct findings of vessels itself including stenosis, obstruction, aneurysm, and wall thickening. On the other hand, CT and MRI showed various extravascular findings in cases with small or microvascular involvement, such as CNS involvement in collagen vascular disease, pulmonary lesions in Wegener's granulomatosis and Churg-Strauss syndrome, and peritoneal lesion in SLE. Our results suggest that CT and MRI findings reflect various vascular condition of refractory vasculitis and correspond to various pathology.

Humans↗
PubMed1994

Preferential recognition of primary protein structures of alpha-casein by IgG and IgE antibodies of patients with milk allergy.

We studied the binding activities of IgE and IgG antibodies in patients with allergy to cow milk proteins, against different alpha-casein preparations: alpha-casein treated with urea, hydrochloric acid, sodium hydroxide, or sodium dodecyl sulfate (SDS); or heat-denatured alpha-casein. The binding activities of IgE and IgG antibodies to these denatured alpha-casein preparations were compared with those to native alpha-casein. The binding activities of IgE and IgG antibodies to these denatured alpha-casein preparations were similar to those to native alpha-casein although the binding activities of IgG antibodies to these denatured alpha-casein preparations were relatively heterogeneous compared with those of IgE antibodies. Since modifications of alpha-casein did not alter the ability of alpha-casein to react with these antibodies, IgE and IgG antibodies to alpha-casein in sera from patients with allergy preferentially bind to the antigenic determinants associated with primary protein structures.

Allergens↗
PubMed1994

[A female case of isolated angiitis of the central nervous system].

Isolated angiitis of the central nervous system (IACNS) is an extremely rare disorder in childhood. This report presents an 8-year-old female case of IACNS. She showed paresis at the right face and upper limb at the onset, followed by various focal neurological symptoms. Cranial T2-weighted magnetic resonance imaging revealed multiple subcortical high signal lesions, which appeared and disappeared in accordance with her clinical manifestations. The level of her plasma thrombin-antithrombin III complex (TAT) was high during the active phase of the illness and seemed to be a useful marker for the detection of vasculitis in the CNS. Complete remission was achieved by the combination therapy of prednisone and cyclophosphamide.

Angiography, Digital Subtraction↗
PubMed1993

[Acute eosinophilic pneumonia: a report of two cases].

Two cases of acute eosinophilic pneumonia (AEP) are described and the radiographic findings discussed. Two patients presented acute fever and cough, which led to acute respiratory insufficiency in 3 days. There was no past history of asthma, hypersensitivity or allergy. They became well within 5 to 12 days, with corticosteroid in one and spontaneously in another. Bronchoalveolar lavage showed more than 80% eosinophils. Plain chest roentgenogram showed air space consolidation with peripheral predominance in case 1 and ground-glass shadow with reticular pattern in case 2. On CT, dense and faint air-space opacities were noted in both entire lung fields in case 1 and faint opacities with thickened interlobular septa in case 2. Bilateral pleural effusion and mild mediastinal lymphadenopathy were noted in both. The increased lung densities showed non-segmental distribution. However, these findings are non-specific and such opacities are seen in other diffuse lung diseases such as hypersensitive pneumonitis, BOOP and pulmonary edema. Pleural effusion (44% of reported cases including ours) and mediastinal lymphadenopathy were frequently seen, and pleural effusion with or without mediastinal lymphadenopathy could represent specific findings for this disease. The authors stress that in young patients with acute respiratory insufficiency with pleural effusion and/or mediastinal lymphadenopathy on the plain chest radiograph or on CT, the possibility of AEP should be considered in the differential diagnosis.

Acute Disease↗
PubMed1993

In vivo flow visualization of induced saccular cerebral aneurysms in rats.

A surgical procedure to expose the arterial bifurcation at the base of the rat brain was developed without sacrificing the animal. Using this technique, visualization of flow in and around the induced cerebral aneurysm was achieved by detecting and following fluorescent particles in the blood stream. Cerebral aneurysms were produced by ligating one common carotid artery, inducing experimental hypertension and feeding them with beta-aminopropionitrile. Flow studies of the arterial bifurcation with an early aneurysmal formation showed that there were spiral flows proximal and distal to the bifurcation. This was the first direct visualization of the actual flow in and around cerebral aneurysms in a vital state. This technology can add further information on the development, growth and rupture of cerebral aneurysms.

Animals↗
PubMed1993

A common T-cell epitope between human thyroglobulin and human thyroid peroxidase is related to murine experimental autoimmune thyroiditis.

We have investigated functional common T-cell epitopes between human thyroglobulin (hTg) and human thyroid peroxidase (hTPO) in mice. Four hTg peptides, Tg-P1, Tg-P2, Tg-P3 and Tg-P4, in which 5 amino acid residues are identical to those of hTPO, and 1 hTPO peptide, TPO-P4 relevant to Tg-P4, were prepared. Among these peptides, only Tg-P4 (residues 2730-2743) and TPO-P4 (residues 118-131) were highly antigenic and both peptides shared the common T-cell epitope. In addition, when the spleen cells from mice immunized with mouse Tg (mTg) were restimulated in vitro by Tg-P4 or TPO-P4 as well as by mTg, these cells transferred thyroiditis to naive recipient mice. These findings indicate that this common T-cell epitope between hTg and hTPO is immunogenic and related to the development of murine experimental autoimmune thyroiditis.

Amino Acid Sequence↗
PubMed1993

[Etiology of pediatric inpatients with pneumonia].

The etiology of acute pneumonia was studied in 596 pediatric inpatients at Chiba Municipal Kaihin Hospital between January 1990 and December 1991. A pathogen was identified in 389 (64.4%) episodes of pneumonia. Evidence of bacterial infection was present in 167 (28.8%) episodes, viral infection in 178 (29.9%) and Mycoplasma pneumoniae infection in 89 (14.9%). The major bacterial pathogens were H. influenzae 117 (19.6%), S. pneumoniae 51 (8.6%), M (B). catarrhalis 24 (4.0%). RS virus was the most common respiratory virus. The peak age of the patients was 7 months to 2 years old. For bacterial pneumonia, the highest rates occurred in infants. Mycoplasma pneumonia produced the highest rates in school-age children. Mycoplasma pneumonia was prevalent at two distinct times, the first emerging in the spring of 1990 and emerging again in the autumn of 1991. RS virus and influenza virus epidemics occur during the winter. Most of the parainfluenza virus have been observed during the early summer season.

Acute Disease↗
PubMed1993

Molecular cloning and sequence analysis of the cDNA for human mitochondrial short-chain enoyl-CoA hydratase.

Short chain enoyl-CoA hydratase (SCEH) catalyzes the second step of the mitochondrial fatty acid beta-oxidation spiral. We isolated cDNA clones for human SCEH to facilitate investigation of the enzyme structure of the gene and to examine the genetic background of Reye's syndrome and sudden infant death. Oligo(dT)-primed and random primed human liver cDNA libraries in lambda gt11 were screened using the entire sequence of the rat SCEH cDNA as a probe. Three positive clones covered the full-length cDNA sequence with an open reading frame encoding a precursor polypeptide of 290 amino acid residues, and deduced relative molecular mass (31,280) with a putative N-terminal presequence of 29 residues, a 5'-untranslated sequence of 21 bp and a 3'-untranslated sequence of 391 bp. Comparison with the rat SCEH cDNA showed that the deduced amino acid sequence of the human SCEH precursor is 84% identical to that of the rat enzyme precursor. Northern blot analysis gave a single mRNA species of 1.6 kb in the human liver, fibroblast and muscle.

Amino Acid Sequence↗
PubMed1993

Comparison of the IgG subclass distribution of anti-thyroid peroxidase antibodies in healthy subjects with that in patients with chronic thyroiditis.

The IgG subclass distribution of anti-thyroid peroxidase (TPO) antibodies in patients with chronic thyroiditis and in healthy subjects has been investigated. Anti-TPO antibodies in sera of patients with chronic thyroiditis were predominantly associated with IgG1, with a lesser contribution by IgG4 and IgG3. In contrast, anti-TPO antibodies of healthy subjects were exclusively associated with IgG4. Since structural differences in IgG subclasses reflect differences in their biological roles, these findings suggest that the role of anti-TPO antibodies in patients may differ from that in healthy subjects.

Adolescent↗
PubMed1993

[Analysis of ovalbumin-specific T cell lines established from patients with hen egg allergy].

Ten ovalbumin (OVA)-specific T cell lines (TCLs) were established from peripheral blood mononuclear cells of 6 patients with hen egg allergy, and the antigen recognition of these TCLs was characterized. Two OVA epitopes were determined by use of 3 synthetic OVA peptides which have been known as murine T cell epitopes. Blocking of antigen-specific T cell proliferation by anti-HLA class II monoclonal antibodies suggest that all 3 HLA class II molecules could act as restriction elements for T cell recognition of OVA. This is the first demonstration of OVA epitopes recognized by T cells in patients with hen egg allergy, as far as we know.

Cell Line↗
PubMed1993

Characterization of a thyroiditis-inducing thyroglobulin-specific T-cell clone restricted by the H-2 molecule of a low responder mouse strain.

We established a thyroglobulin (Tg)-specific, thyroiditis-inducing T-cell clone, B12G, from B6C3F1 mice by the immunization of mouse Tg with lipopolysaccharide (LPS) from Klebsiella strain LEN (O3:K1). B12G was Thy-1.2+, CD3+, CD4+, CD18+, and CD8-, and could transfer thyroiditis to recipient mice after in vitro stimulation with mouse or bovine Tg. Histological examination showed severe thyroiditis with predominant infiltrations of polymorphonuclear cells; few mononuclear cells were observed. B12G proliferated in response to bovine, mouse, porcine, and rat Tg in the presence of irradiated spleen cells, but did not respond to chicken or human Tg. H-2b, a low-responder haplotype of experimental autoimmune thyroiditis, governed the response of the clone to Tg. B12G produced interleukin-4 (IL-4) and IL-6, but not IL-2 or interferon-gamma (IFN-gamma), on stimulation with mouse Tg. These findings were different from characteristics of previously reported Tg-specific T-cell clones from high-responder mice in terms of epitope specificity and cytokine production pattern, raising the possibility that the specificities and functions of T cells involved in the development of autoimmune thyroiditis in low-responder mice differ from those in high responders.

Animals↗
PubMed1993

[Serial MR imaging of possible Pelizaeus-Merzbacher disease].

We performed serial magnetic resonance imaging (MRI) toward 4 male children with possible Pelizaeus-Merzbacher disease (PMD). They were clinically suspected as PMD on the basis of typical neurological, electrophysiological and MRI examinations. MRI revealed that myelinated fibers were localized in brainstem, cerebellum, internal capsule, optic radiation and proximal corona radiata in case 1, while myelinated fibers were almost absent in case 2-4. On repeated MRI investigation, we found no further extension of myelination in case 1 and the absence of myelination in case 2-4. This study demonstrated that myelination in the brain is arrested immediately after birth in case 1, while no myelination developed before birth in case 2-4. It was speculated that MRI in case 1 and case 2-4 might correspond to neuropathologic findings of classical and connatal form as reported in the literature.

Child, Preschool↗
PubMed1993

[A girl with Down syndrome complicated by moyamoya disease and symptomatic atlanto-axial instability].

We reported a girl of Down syndrome with both moyamoya disease and spinal cord compression due to atlanto-axial instability. At the age of 3 years, she presented with muscle weakness of gradual onset, and could not walk without support. On admission, at the age of 6, she presented with spastic paraparesis with predominance on the right side. To explain her neurological manifestations, we performed cranial MRI first, and found multiple infarctions with predominance on the right hemisphere, the occlusive changes of internal carotid and middle cerebral arteries, and signal void flow signs in basal ganglia, which suggested moyamoya disease. Although diagnosis of moyamoya disease was confirmed by cranial angiography, discrepancy between clinical manifestations (right-side dominant spasticity) and MRI findings (right-side dominant infarctions) could not be explained. Thereafter, we performed cervical MRI, which showed severely compressed lesions with predominance on the right side, corresponding to her clinical manifestations. It is essential to perform not only cranial but also cervical MRI for a patient with Down syndrome presenting neurological complications.

Atlanto-Axial Joint↗
PubMed1992

Serum factors responsible for unusual induction of plasminogen activator activity in tuberous sclerosis.

Peripheral blood lymphocytes derived from tuberous sclerosis (TS) patients showed unusually high levels of plasminogen activator (PA) activity after treatment with N-methyl-N'-nitro-N-nitrosoguanidine (MNNG). Serum obtained from peripheral blood of TS patients also enhanced the PA activity level when normal control lymphocytes were incubated with the serum prior to MNNG treatment. Factors exhibiting the enhancing activity were eluted with a solution of about 0.70 M KCl on dye-ligand chromatography, which were inhibited on incubation with an anti-human interferon (HuIFN)-beta antibody, but not with anti-HuIFN-alpha or anti-HuIFN-gamma antibodies. Unlike in the case of HuIFN-beta, the eluted samples did not possess antiviral or anticellular activity. Thus, it seems likely that serum from TS patients contains factors which are responsible for the unusual PA induction and which have a similar epitope to HuIFN-beta.

Adolescent↗
PubMed1992

Pelizaeus-Merzbacher disease: cellular hypersensitivity to ultraviolet light.

We report two connatal cases of Pelizaeus-Merzbacher disease (PMD) with cellular ultraviolet (UV)-hypersensitivity. We studied the UV-sensitivity of cultured fibroblast cells derived from these PMD cases, as compared with UV-sensitive Cockayne syndrome (CS) and xeroderma pigmentosum (XP) cells as positive controls. The ability of the PMD cells to form colonies after UV irradiation was intermediate between those of CS cells and normal controls. There were no differences in both colony-forming ability after x-ray irradiation and unscheduled DNA synthesis (UDS) activity after UV irradiation between the PMD cells and the control cells. These cytological results suggest the possibility that a DNA defect might be involved in PMD.

Cells, Cultured↗
PubMed1992

Growth hormone-binding protein in patients with anorexia nervosa determined in two assay systems.

To learn the mechanism of low plasma insulin-like growth factor-I (IGF-I) despite high growth hormone (GH) secretion in patients with anorexia nervosa, we assessed human serum GH-binding protein (BP) (GH-BP), which has been shown to be identical to the extracellular domain of GH receptor, and therefore might reflect peripheral GH receptor expression (i.e. there is a significant linear correlation between GH-BP and IGF-I at less than 2.0 U/ml in healthy children). The serum GH-BP level was determined by gel filtration and confirmed by immunoassay using GH receptor monoclonal antibody. Furthermore, we analyzed serum IGF-binding proteins (IGFBPs) by the affinity cross-linking method to determine the GH-IGF-I axis in this condition. Measurement of GH-BP by the two assays gave identical results, suggesting that serum GH-BP corresponds to the extracellular domain of GH receptor. The low GH-BP and high IGFBP levels in patients with anorexia nervosa shown in this study, which were normalized by an improved nutritional state, would indicate resistance to GH as well as to IGFs in this condition, in which the former is in part compensated by high GH levels while the latter is not.

Adolescent↗
PubMed1992

Pulmonary arteriography with retrograde injection of contrast medium via radial artery: efficacy in neonates with ductus-dependent decreased pulmonary flow.

In an attempt to visualize the pulmonary arterial trees of neonates and infants with ductus-dependent decreased pulmonary flow, the efficacy of retrograde injection of contrast from the radial arteries of 11 consecutive patients was tested. All patients had pulmonary atresia and patent ductus arteriosus. A 22- or 24-gauge needle was inserted into the radial artery and contrast medium of 2 ml/kg was injected at flow rates of 3 to 4 ml/sec. The pulmonary arteries were filled by retrograde flow through the ductus arteriosus. This method provided clear visualization of the pulmonary arteries, especially by ductus-sided injections. Developmental anomalies of the pulmonary trunk, localized stenosis at the ductus, and aortopulmonary collateral arteries were demonstrated. No complications occurred during angiography, and all the procedures were completed within 30 minutes. This method appears to be useful in detecting anatomical abnormalities of the pulmonary arteries in neonates and infants with ductus-dependent decreased pulmonary flow.

Angiography↗