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Biomedical subjects

H Niimi

Publications and source records attributed to H Niimi.

At least 91 records · Page 5Linked to original sources
PubMed1996

Clinical significance and time course of antibodies to glutamic acid decarboxylase in Japanese children with type I (insulin-dependent) diabetes mellitus.

Although anti-glutamic acid decarboxylase antibodies (GADAb) have been reported to be a useful diagnostic and predictive marker of insulin-dependent diabetes mellitus (IDDM, type 1 DM) in Caucasians, a precise analysis of GADAb in Japanese children has not been reported. We examined the clinical significance and time course of GADAb in Japanese IDDM children, who have different genetic backgrounds from Caucasians. Twenty-three of 34 (67.6%) sera from recent-onset (< 6 months) IDDM, and 16 of 49 (32.7%) sera from long-standing (> or = 2 years) IDDM patients were positive for GADAb. This prevalence of GADAb in IDDM patients was significantly higher than in normal controls and the other groups including non-insulin-dependent DM, autoimmune thyroid disease and congenital hypothyroidism, and was also significantly higher in recent-onset than in long-standing IDDM. Time course analysis suggested that autoimmune response against GAD could follow different courses in individual cases after the initiation of insulin therapy. The incidence of GADAb was significantly higher in females than in males in the older age group (11-15 years). Other clinical features including residual pancreatic beta-cell function after diagnosis were demonstrated to be similar between GADAb-positive and -negative patients. In conclusion, this study using the newly established radioimmunoassay (RIA) for GADAb revealed a high prevalence of autoimmune reactivity to GAD in Japanese IDDM children. These results, using this RIA procedure, might assist in laying the groundwork for future trials of immunomodulation therapy for IDDM in Japan.

Adolescent↗
PubMed1996

[The etiology of acute lower respiratory tract infections in infants].

The etiology of acute lower respiratory tract infections (ALRI) was studied in pediatric inpatients under 2 years of age admitted to Chiba Municipal Hospital between June 1994 and March 1995. Eighty-seven patients, 99 episodes were investigated for bacterial infection with the use of blood culture and washed sputum culture, for viral infection with the use of virus isolation, antigen detection and antibody assays, for Mycoplasma pneumoniae infection with the use of antibody assay and for Chlamydia infection with the use of antigen detection. Pathogens were identified in 71 (71%) of the 99 episodes. Evidence of bacterial infection was detected in 43 episodes (43%), viral infection in 37 episodes (37%), Mycoplasma pneumoniae infection in 4 episodes (4%) and Chlamydia infection 3 episodes (3%). The major bacterial pathogens were H. influenzae, M. (B) catarrhalis and S. pneumoniae. RS virus and influenza virus epidemics occurred during the winter. A mixed bacterial and viral infection was documented in 13 episodes (13%). RS virus infection was common in infants up to 6 months old. Mixed bacterial and influenza virus infections were common in 1 or more year old children. Virus isolation was useful for the grasp of the viral epidemic. Bacterial associated infections were common in children under 2 years of age with ALRI. Washed sputum culture and sputum gram stains' were useful for the treatment of infant ALRI.

Acute Disease↗
PubMed1996

[Two cases of Listeria monocytogenes infection in Osaka Municipal Hospital].

We report two cases of sepsis and meningoencephalitis with listeriosis. They died in despite of administering sensitive antibiotics. A 2 day old girl was admitted to our hospital because of fever and cyanosis. Listeria monocytogenes type 4b was cultured from blood, CSF, throat, urine, ear. She was treated with twice exchange transfusion and sensitive antibiotics (ABPC, TOB), but died from DIC. A 48 year old man suddenly experienced an unconscious condition. A CSF culture grew L. monocytogenes type 1/2a. He was treated with sensitive antibiotics (ABPC, CEZ etc), but went bad conditions. Listeria infection of this cases developed as unfortunate infection.

Female↗
PubMed1996

Establishment and characterization of ovalbumin-specific T cell lines from patients with egg allergy.

In order to investigate T cell recognition of allergens in hen egg allergy, we have established 30 ovalbumin (OVA)-specific T cell lines (TCLs) from peripheral blood mononuclear cells of 6 patients with atopic dermatitis, who are positive for IgE antibodies to OVA and clinically allergic to hen egg, and characterized them for their cytokine production pattern. All TCLs we could study were mainly composed of CD4+ T cells. Most TCLs produced significant amounts of interleukin 4 (IL-4) and IL-5 but no or very little interferon gamma on antigen stimulation, suggesting that these TCLs belong to TH2-type T cells. Restriction elements and epitope specificities were further studied on some TCLs. Antibody blocking of the proliferative responses of the TCLs to OVA indicated that HLA-DR are acting as the dominant restriction elements for these TCLs with minor contribution of HLA-DQ. By use of 187 overlapping synthetic peptides covering the whole sequence of OVA, at least 3 different T cell epitopes were identified.

Allergens↗
PubMed1996

Spinal and femoral bone mass accumulation during normal adolescence: comparison with female patients with sexual precocity and with hypogonadism.

Since the attainment of higher bone mineral density (BMD) is a crucial strategy in preventing age-related bone loss and consequent fracture, we determined when bone mass of the lumbar spine (L2-L4) (g/cm2) and femoral neck (g/cm2) reaches its peak in healthy Japanese subjects and examined the influence of early exposure to estrogen and estrogen deficiency on BMD. We also determined the volumetric BMD, termed bone mineral apparent density (BMAD), of the lumbar spine and femoral neck. Using dual-energy x-ray absorptiometry (DXA) (Hologic QDR-1000), we measured BMD of both the lumbar spine and the femoral neck in 31 healthy children aged 2-11 yr, 269 children (138 males and 131 females) aged 13-19 yr, 12 men and 12 women aged 20-34 yr as adult controls, 11 patients with female central sexual precocity, and 3 patients with female primary hypogonadism. Because the densitometric data obtained from DXA are strongly influenced by the size of the bone in growing subjects, the volumetric BMAD (g/cm3) of the vertebral cube (L2-L4) and femoral neck were determined: BMAD (g/cm3) = BMD (g/cm2)/square root of scanned area (cm2) for the lumbar spine and by BMAD = BMD/width for the femoral neck. The BMD, both lumbar spine and femoral neck, nearly reached its peak at age 14.5-15 yr in girls and 16.5-17 yr in boys when compared with adult normal values. The difference in this age between sexes is identical to the difference in age at sexual maturation. BMD in patients with sexual precocity was high compared to age-matched controls, whereas patients with primary hypogonadism showed lower lumbar apparent BMD, and the increase in lumbar BMAD (g/cm3) was noted after the progression of puberty in healthy children, probably suggesting the importance of sex steroids in the increase of BMD and lumbar BMAD in both sexes. The girls with earlier menarche showed higher lumbar BMD at age 18 and 19 yr. For the femoral BMAD, there was no significant relationship between this value and age in girls. We conclude that peak bone mass is mainly achieved by late adolescence in Japanese as in Caucasians and that pubertal progression and probably estrogen itself play a crucial role in accumulation of bone mass in females.

Adolescent↗
PubMed1996

Early detection of infants with hypophosphatemic vitamin D resistant rickets (HDRR).

The onset of physical signs in infants with hypophosphatemic vitamin D resistant rickets (HDRR) has generally been considered to be at the age of 12 months, but the time of appearance of hypophosphatemia and rachitic signs on radiographs remains unclear. We report a prospective study in three neonates whose mothers were HDRR. At birth, despite a low maternal serum inorganic phosphorus (Pi) level, the serum Pi level was normal together with a negligible renal Pi leak in one neonate. At age 3 months, their serum Pi levels, percentages of tubular reabsorption of Pi, and renal tubular maximal rates of Pi reabsorption in relation to the glomerular filtration rate were low except for one infant. Radiographically, their rickets were not apparent at birth but at age 3 months in all. A premature born infant, born at 28 weeks' gestation weighing 1240 g, was diagnosed as HDRR based on hypophosphatemia due to low renal tubular maximal rate of phosphorus reabsorption in relation to the glomerular filtration rate (TmP/GFR) and normal urine Ca excretion at age 5 months. They were initially treated with 1 alpha-hydroxyvitamin D3 (1 alpha OHD3) and later with 1 alpha OHD3 in combination with Pi, which results in healing of the rickets and a normal increase in height. Thus, early detection and treatment of patients born from mothers with HDRR before physical signs of bow-leg and short stature is possible, but the outcome of early treatment requires further study.

Age of Onset↗
PubMed1996

[A familial case of Gorlin syndrome].

An 11-year-old girl was admitted to Chiba University Hospital because of the infection of jaw cysts. She had many pits on her palms and soles, basal cell nevus, and typical facial features to Gorlin syndrome (nevoid basal cell carcinoma syndrome). Her 14-year-old sister and 44-year-old father also had similar clinical symptoms, thus they were diagnosed as having a familial Gorlin syndrome. Recently, the father had a complication of maxillary cancer. Colony formation tests after X-ray and ultraviolet irradiation in skin fibroblasts derived from these sisters revealed no remarkable hypersensitivity to these agents. It is important to make an early diagnosis and a proper management in Gorlin syndrome, which has cancer predisposition.

Adolescent↗
PubMed1996

[Two early-childhood cases of optic neuritis].

We reported two early-childhood cases suffering from acute optic neuritis (ON). Case 1 was a 3-year-old girl, who had a preceding upper respiratory infection, headache, nausea and subsequent sudden visual disturbance. Cranial MRI revealed multiple T2-elongated lesions in the white matter. She showed two neurological relapses including ON, leading to the diagnosis of clinically probable multiple sclerosis (MS). Case 2 was a 2-year-old boy, who had an acute onset of visual disturbance without any other neurological deficits. MRI with Gd-DTPA enhancement revealed not only a disorder of optic nerves but involvement of the white matter in the acute phase. It has been suggested that there may be a broad spectrum of demyelinating disorders between ON and MS even in early-childhood. Therefore, we should bear in mind to the subsequent progression to MS in childhood ON cases with silent brain lesions.

Acute Disease↗
PubMed1995

Self-thyroid epithelial cell (TEC)-reactive CD8+ T cell lines/clones derived from autoimmune thyroiditis lesions. They recognize self-thyroid antigens directly on TEC to exhibit T helper cell 1-type lymphokine production and cytotoxicity against TEC.

Self-thyroid epithelial cell (TEC)-reactive CD8+ and CD4+ T cell lines were established by culturing T cells that infiltrate in autoimmune thyroiditis lesions. We investigated the properties of CD8+ T cell lines and clones in comparison with previously characterized CD4+ T cell lines/clones. Although the recognition of self-Ag by anti-TEC CD4+ T cell lines/clones required the cooperation of syngeneic spleen cells as APC, a representative CD8+ line (N4C) was stimulated with syngeneic TEC in the absence of APC. Precise analysis of MHC restriction using N4C-derived clones revealed that CD8+ clones recognize self-Ag on TEC in the context of class I MHC molecules. Most CD8+ clones were also found to express TCR with V beta specificities that were different from those observed for anti-TEC CD4+ clones. N4C cells produced IL-2, IFN-gamma, and TNF-alpha beta, but not IL-4 and IL-5 after stimulation with TEC, thus exhibiting the profile of lymphokine production similar to that expressed by CD4+ Th1 on one hand, but on the other, they showed the functional property that has not been observed for anti-TEC CD4+ clones. Namely, they elicited appreciable levels of cytolytic effects on syngeneic TEC in a short-term (4-h) 51Cr release assay. Thus, these results indicate that self-TEC-reactive CD8+ T cell lines/clones recognize Ag directly on TEC in a class I MHC-restricted way so as to exhibit various functions including the Th1-like profile of lymphokine production and anti-TEC cytolysis. The results are also discussed in terms of the nature of self-Ag presented with class I MHC molecules on TEC, as well as the potential roles of anti-TEC CD8+ T cells in the pathogenesis of thyroiditis.

Animals↗
PubMed1995

Optic neuritis with silent cerebral lesions: availability of FLAIR sequences.

A 10-year-old male suffering from acute optic neuritis is reported with multiple silent cerebral lesions, which remained visible only with fluid-attenuated inversion recovery sequences at 3-week intervals. Conventional sequences with magnetic resonance imaging did not visualize the lesions. Fluid-attenuated inversion recovery sequences are highly sensitive for the detection of silent lesions in acute optic neuritis.

Brain↗
PubMed1995

Antiphospholipid antibody syndrome in childhood strokes.

The significance of antiphospholipid antibodies was examined in patients with childhood strokes. Eight patients, aged 2-13 years, who presented with acute hemiplegia were studied. On the basis of magnetic resonance imaging, magnetic resonance angiography, single photon emission computed tomography, and cerebral angiographic findings, 3 children were diagnosed as having infarctions due to moyamoya disease, and the others as having idiopathic infarctions. Serologic studies revealed elevated anticardiolipin antibody (ACA) IgG in 3 of the 5 patients with idiopathic infarction; no such elevation was revealed in patients with moyamoya disease. Values for all other tests, including ACA IgM and lupus anticoagulant, were within normal limits or negative in all patients. ACA IgG, therefore, may be a more important causative agent of childhood strokes than was previously considered.

Adolescent↗
PubMed1995

Reduction of unscheduled DNA synthesis and plasminogen activator activity in Hutchinson-Gilford fibroblasts during passaging in vitro: partial correction by interferon-beta.

Two fibroblast cell lines (PG3KT and PG1NA) derived from Hutchinson-Gilford syndrome (progeria) cases were characterized, at various population doubling levels (PDL), with respect to the capacity of ultraviolet light (UV, mainly 254 nm wavelength)-induced unscheduled DNA synthesis (UDS) and plasminogen activator-like protease activity (PA). The UDS levels in PG3KT and PG1NA cells at PDL 2-3 were only slightly less than those in normal fibroblasts. With increasing PDL, both progeria cell lines exhibited reduction of the UDS levels and undetectable ones at PDL 9-11. Prompt and transient induction of PA was also detectable at less than PDL 5, whereas it was undectable at higher PDL. However, the levels of UDS and PA induction were increased about 3-7 times after pretreatment with 100 IU/ml human interferon (HuIFN)-beta preparations for more than 24 h prior to UV irradiation, although UDS and PA were undetectable at more than PDL 10. These results suggest that cytokines such as HuIFN-beta transiently compensate for the decreases in UDS and PA inducibility in progeria cells with aging.

Cell Division↗
PubMed1995

Periventricular haemosiderin deposition in patients with congenital hemiplegia.

Two patients with congenital hemiplegia without obvious prenatal, perinatal or neonatal difficulties showed linear low signal intensity lesions along the wall of the dilated lateral ventricles without any parenchymal lesions on T2- and proton density weighted MRI. Haemosiderin deposition secondary to intra-uterine subependymal haemorrhage with intraventricular haemorrhage was considered most likely from the signal intensity, distribution and clinical histories. MRI, which is the only means of detecting haemosiderin deposition, could be beneficial for evaluating the pathogenetic cause of congenital hemiplegia.

Cerebral Ventricles↗
PubMed1995

[Etiology of pediatric inpatients with pneumonia--analysis of clinical symptoms, physical examination and simple laboratory findings].

In pediatric patients with community-acquired pneumonia, most of the patients have received antibiotics before admission. In this study, we tried to determine whether we could identify the etiology of pneumonia by clinical and laboratory findings on admission. The etiology of acute pneumonia was studied in 596 pediatric inpatients. A pathogen was identified in 384 (64.4%) episodes of pneumonia. These 384 episodes were divided into six groups as follows; I: pneumonia with blood culture positive or pneumonia with bacterial antigen positive in urine, II: pneumonia with dominant bacterial pathogens in washed sputum. III: Mycoplasma pneumonia, IV: viral pneumonia, V: bacterial (I, II) + viral pneumonia, VI: bacterial (I, II) + Mycoplasma pneumonia. These groups were analyzed by clinical symptoms, physical examination and simple laboratory findings on admission. Patients with Mycoplasma pneumonia have increased blood sedimentation rate, high value of positive C-reactive protein and normal white blood cell count. It was difficult to distinguish bacterial pneumonia from viral pneumonia only based upon clinical symptoms, physical examination and simple laboratory findings.

Blood Sedimentation↗
PubMed1995

Transient pseudohypoparathyroidism of the neonate.

We report three neonates with transient hypoparathyroidism with elevated parathyroid hormone (PTH) levels to clarify further the pathogenesis of late neonatal hypocalcemia and calcium homeostasis. Clinical signs were seizures starting at age of 10 and 11 days. The biochemical features were characterized by transient hypocalcemia and hyperphosphatemia due to a high transport maximum of the phosphate/glomerular filtration rate, despite high PTH levels. All had normal magnesium and calcidiol levels (at least 5 micrograms/l) for their age, and this precludes hypoparathyroidism due to low magnesium levels and hyperparathyroidism due to overt vitamin D deficiency. To diagnose pseudohypoparathyroidism type I, intravenous human PTH (1-34) infusions were performed; however, they showed brisk responses of plasma and/or urine cyclic AMP in response to the PTH infusion, but the phosphaturic response to the PTH was sluggish compared to the controls. All three showed an increase in serum alkaline phosphatase activity, suggesting PTH stimulation of osteoblasts. They were treated initially with calcium lactate or (1 alpha)-hydroxycalciol/calcitriol. Their hypoparathyroid condition, however, was transient; they maintained normal serum calcium and PTH levels without medication before the age of 6 months. The etiology, possibly intracellular signal transduction distal to cyclic AMP and/or distinct from adenylate cyclase in the kidney, is developmental and the condition was resolved completely within 6 months of age. We have termed this condition "transient pseudohypoparathyroidism of the neonate".

Alkaline Phosphatase↗
PubMed1995

Expression of multidrug resistant gene (mdr-1/P-glycoprotein) in a megakaryoblastic cell line, CMK, and its enhancement during megakaryocytic differentiation.

Multidrug resistance is a severe clinical problem in the chemotherapy of malignant disease. Acute megakaryoblastic leukemia (AMKL) is a rare form of childhood leukemia, and is often resistant to many anti-cancer chemotherapeutic drugs. Here we report the expression of the mdr-1/P-glycoprotein in a cell line, CMK, established from a patient with AMKL. Expression of mdr-1 mRNA in CMK11-5 cells, a well differentiated subline, was higher than in CMK6 cells, a poorly differentiated subline. The level of P-glycoprotein was also higher in CMK11-5 cells. The cytokines interferon-gamma (IFN-gamma), GM-CSF and IL-3, which were shown to induce megakaryocytic differentiation of CMK cells, enhanced the expression of the mdr-1 mRNA and levels of P-glycoprotein. These results imply that differentiated megakaryocytic cells may have higher levels of the P-glycoprotein expression, suggesting a possible normal physiological function of P-glycoprotein in mature megakaryocytes.

ATP Binding Cassette Transporter, Subfamily B, Mem↗