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Biomedical subjects

H Niimi

Publications and source records attributed to H Niimi.

At least 19 recordsLinked to original sources
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↗
PubMed1992

Detection of house dust mite (HDM)-specific IgE antibodies on nasal mast cells from asthmatic patients whose skin prick test and RAST are negative for HDM.

Mast cells are found in nasal smears of pediatric patients with perennial bronchial asthma whose skin prick test and radioallergosorbent test (RAST) are negative for inhalant allergens. IgE antibodies were demonstrated on these mast cells by monoclonal anti-human IgE antibodies, whereas IgG antibodies were not detected by monoclonal anti-IgG antibodies. In order to pursue the causative allergen for asthma in these patients, binding potential between IgE antibodies on nasal mast cells and house dust mite (HDM), the most prevalent aeroallergen, was examined by an immunochemical technique. Out of 9 patients whose skin prick test and RAST were negative for HDM, 7 were found to have HDM-specific IgE antibodies on their nasal smear mast cells. None of these 7 patients had IgE antibodies to cedar pollen, a negative control aero-allergen, on their mast cells. Specific binding of HDM on the mast cells was further confirmed by the fact that nasal mast cells from patients with egg allergy bound egg white but not HDM on their surface. Preincubation of mast cells with anti-IgE antibodies inhibited binding of HDM on the mast cells, indicating that HDM was bound to surface IgE antibodies on the mast cells. These experiments enabled us to expeditiously identify sensitization to an inhalant allergen, such as HDM, in young asthmatic patients whose allergen cannot be found by conventional laboratory diagnostic procedures.

Allergens↗
PubMed1992

Serum intact parathyroid hormone concentration measured by a two-site immunoradiometric assay in normal subjects and patients with various parathyroid disorders.

Serum intact parathyroid hormone (PTH) concentration was measured by a two-site immunoradiometric assay (IRMA) in normal subjects and patients with various parathyroid disorders. Serum intact PTH levels were all within the detection limit of the IRMA in normal subjects, and there was a significant negative correlation between serum calcium (Ca) and intact PTH levels. Although 3 out of 26 patients (11.5%) with primary hyperparathyroidism had a normal serum intact PTH concentration, these patients could be readily discriminated from normal subjects by plotting serum intact PTH against the serum Ca concentration. In contrast, serum intact PTH was undetectable in 16 out of 17 patients (94.1%) with idiopathic hypoparathyroidism. Patients with pseudohypoparathyroidism (PHP) type I, mostly under treatment with active vitamin D, exhibited wide distribution of serum intact PTH concentration, and appeared to belong to two distinct subgroups. One group of patients demonstrated a similar relationship between serum intact PTH and Ca levels to normal subjects. The other exhibited much higher serum intact PTH levels despite a normal serum Ca concentration, and no obvious relationship could be observed between the two parameters. These results demonstrate that an inverse relationship between serum Ca and intact PTH can be demonstrated in normal subjects with normocalcemia, that most of the parathyroid disorders can be diagnosed by measuring serum Ca and the intact PTH concentrations simultaneously, and that patients with PHP can be divided into two subgroups: one with a normal relationship between serum Ca and intact PTH, and the other with a high serum PTH level in the face of normocalcemia.

Adolescent↗
PubMed1992

[Neonatal tuberous sclerosis: report of a case studied by cranial MRI].

We reported longitudinal cranial MRI studies of a neonate with tuberous sclerosis who presented convulsive seizures on the first day after birth. Cortical tubers were not detected on MRI performed at the age of 1 month, but became evident at 18 months after birth. This finding might reflect the pathological difference between the amount of myelin around the cortical tuber and other white matter lesions, which increased with age. A heterotopic islet was shown as partially stratiform appearance on MRI. This result suggests that the structure of the heterotopic islet might be heterogeneous.

Brain↗
PubMed1992

[Diagnosis of food allergy based on rectal mucosal cytology].

We performed rectal and/or oral challenge tests on 8 patients with suspected but unproven diagnosis of food allergy based on detailed medical history and findings from radioallergosorbent tests (RAST). The cells appearing in the rectal mucosal smear serially for 48 hours after allergen challenge were examined. The following results were obtained: 1) Significant numbers of not only eosinophils but also mast cells appeared in the rectal smears after challenges with suspected-food allergens, but not with unrelated foods. This confirmed the antigen-specificity of the method. 2) In some cases, the appearance of mast cells and eosinophils was bimodal, suggesting the existence of a later allergic response in addition to an immediate-type reaction. 3) The food-specific appearance of mast cells and eosinophils was observed in association with clinical symptoms after challenge, even in patients whose IgE antibodies to the allergen were negative or commercially unavailable. In conclusion, we propose that rectal mucosal cytology in conjunction with rectal and/or oral challenge tests is a reliable and objective method to diagnose unproven or suspected food allergy.

Child↗
PubMed1992

[Allergy to casein hydrolysate formula. A study of sensitizing allergen].

A six-month old baby, who had been fed for 2 months with casein hydrolysate formula (MA-1) for treatment of milk allergy, developed diarrhea. The baby's RAST score for milk was negative. IgE antibodies to MA-1 but not to MA-1 depleted of lipid (fat-free MA-1), were demonstrated by enzyme-linked immunosorbent assay (ELISA). It was confirmed by the appearance of numerous mast cells and eosinophils in a rectal smear taken after challenge with MA-1 (but not detected after challenge with fat-free MA-1) that some component in the lipid of MA-1 must be an allergen in this patient.

Caseins↗
PubMed1992

Red cell velocity and microvessel diameter measurement by a two fluorescent tracer method under epifluorescence microscopy: application to cerebral microvessels of cats.

Fluorescein isothiocyanate (FITC)-labeled red blood cells (RBCs) and rhodamine-B isothiocyanate (RITC)-labeled dextran were used as two fluorescent tracers under intravital fluorescence microscopy. RBC velocity in cerebral microvessels of cats was measured with a dual window technique using FITC-labeled RBCs as a flow tracer. Measurement of the vessel diameter was performed using a digital image processor system by staining plasma with RITC-labeled dextran. The RBC velocity, obtained directly with digital cross-correlation of videodensitometric signals derived from the two windows, coincided with those obtained with the frame-by-frame analysis. The obtained RBC velocity ranged between 12.9 and 0.45 mm/sec in arterioles (< 60 microns) in diameter, 4.2 and 0.18 mm/sec in venules (< 60 microns in diameter), and 1.1 and 0.26 mm/sec in capillaries. The use of the labeled RBCs as the flow tracer enabled us to measure a wide range of RBC velocity (up to about 7 mm/sec) by setting the distance between the two windows beyond about 200 microns.

Animals↗
PubMed1992

[Clinical evaluation of a new carbapenem, meropenem, in infants and children].

A new carbapenem antibiotic, meropenem (MEPM), was evaluated for its safety and efficacy in 33 infants and children. MEPM was effective in all the 32 evaluable cases including 4 cases of bacterial meningitis and 5 cases of Pseudomonas aeruginosa infections. The mean half life of plasma concentrations of MEPM was 0.84 +/- 0.09 hours after 30 minutes intravenous drip infusion. Mild diarrhea (2 cases), transient elevation of transaminases (8 cases), and transient eosinophilia (2 cases) were associated with the MEPM therapy, but none of them was problematic. These data suggest that MEPM is safe in infants and children and could be one of the therapeutic agents for severe infections or infections in compromised hosts.

Adolescent↗
PubMed1992

[Autoimmune response to thyroglobulin. Proliferative response to thyroglobulin fragments in low responder mice].

Thyroglobulin (Tg) is one of the major thyroid autoantigens involved in autoimmune thyroiditis. The immune response of mice to Tg is genetically controlled by H-2-linked genes. To elucidate the regulation mechanism of autoimmune response to Tg in low responder mice, we studied the proliferative response of lymph node cells (LNC) to mouse Tg (MTg) and enzyme-digested MTg fragments. MTg was treated with Staphylococcus aureus V8 protease followed by separation of the fragments into 6 fractions (Fr1-Fr6: 264,000-17,000) by high performance liquid chromatography (HPLC), LNC from MTg immunized CBA/N (H-2k) mice, a high responder strain, proliferated in response to MTg and all fractions (Fr1-Fr6) of MTg fragments in vitro. In contrast, LNC from MTg immunized BALB/c (H-2d) and B10 (H-2b) mice, low responder strains, did not respond to native Tg but responded well to some smaller Tg fractions (Fr3, 4, 5). In addition, when BALB/c mice were immunized with MTg Fr4 with a molecular weight of 63,000, LNC from BALB/c mice proliferated in response to MTg as well as MTg Fr4. These findings suggest that T cells which are capable of responding to Tg do exist even in low responder mice and that the activation of these autoreactive T cells is suppressed by a regulatory cell subpopulation in low responder mice.

Animals↗
PubMed1991

Magnetic resonance imaging of the brain in congenital rubella virus and cytomegalovirus infections.

Two children with congenital rubella virus and six with cytomegalovirus (CMV) infections, were examined by magnetic resonance (MR) and CT. Cranial MR imaging (MRI) with T2-weighted spin-echo (SE) and inversion recovery (IR) sequences demonstrated the following: periventricular hyperintensity (4), subcortical hyperintensity (5), delayed myelination (4), oligo/pachygyria (2), cerebellar hypoplasia (2). This study showed that the more-disabled children had more marked abnormal MRI findings. MRI was more effective in the detection of parenchymal lesion than was CT, although intraventricular calcification was better visualized with CT.

Brain↗
PubMed1991

Magnetic resonance imaging in a case of mumps postinfectious encephalitis with asymptomatic optic neuritis.

A 5-year-old male patient with asymptomatic optic neuritis and mumps postinfectious encephalitis or acute disseminated encephalomyelitis is reported. Magnetic resonance imaging (MRI) with a short inversion time inversion recovery sequence was valuable in detecting clinically silent lesions of the unilateral right optic nerve in addition to visual evoked potentials. Evidence of concurrent optic neuritis was useful for detecting more extensive neurological involvement, leading to the diagnosis of mumps postinfectious encephalitis. A systematic MRI study should be performed in children with mumps encephalitis, regardless of appreciable clinical deficits.

Child, Preschool↗
PubMed1991

Insusceptibility of Cockayne syndrome-derived lymphocytes to plasminogen activator-like protease induction by ultraviolet rays and its abolition by interferon.

Protease induced by ultraviolet rays (UV) has been extensively investigated in human cells. Plasminogen activator-like protease (PA) activity was induced soon after UV irradiation in peripheral lymphocytes derived from healthy donors. In contrast, UV-irradiated lymphocytes derived from Cockayne syndrome (CS) cases did not show marked protease inducibility. Epstein-Barr (EB) virus-transformed CS lymphoblastoid cells were also characterized by insusceptibility to UV-induction of PA. However, when CS-derived cells were treated with a human interferon (HuIFN) preparation prior to irradiation, induction of PA activity was detected, irrespective of the kind of HuIFN (alpha or gamma). The results indicate the possibility of abnormal PA metabolism in CS-derived cells.

Cell Survival↗
PubMed1991

Nasal administration of salmon calcitonin for prevention of glucocorticoid-induced osteoporosis in children with nephrosis.

To determine the effect of intranasal administration of salmon calcitonin on glucocorticoid-induced osteoporosis in children with nephrosis, we gave 100 U of calcitonin intranasally on alternate days with 1 alpha-hydroxyvitamin D3 to five children, 8 to 12 years of age, with frequently relapsing nephrosis. Four patients with osteoporosis, 10 to 14 years of age, were treated only with 1 alpha-hydroxyvitamin D3 and served as control subjects. Both groups were treated with an almost equal amount of glucocorticoids previously and during this study period. Bone mineral content of the spine was measured by a quantitative computed tomographic technique. The bone mineral content was preserved in both cortical and spongeous areas of the vertebrae during the 16-month period in the calcitonin-treated group but was decreased significantly in the control group. Urinary hydroxyproline and calcium excretion decreased significantly in the calcitonin-treated group. The serum calcium and phosphorus concentrations and the parathyroid function did not change significantly in either group. We conclude that calcitonin suppressed bone resorption and might be useful for the long-term treatment of osteoporosis, in combination with 1 alpha-hydroxyvitamin D3, in children with nephrosis requiring long-term glucocorticoid therapy.

Administration, Intranasal↗
PubMed1991

Comparison of cellular sensitivity to UV killing with neuropsychological impairment in Cockayne syndrome patients.

We studied the neuropsychological function including mental status and motor development, and cellular susceptibility to UV killing in four Cockayne syndrome (CS), of whom three were classic form (type I) and one was congenital form (type II). The results showed that there was no correlation between the age at symptomatic onset of CS neurological disorders and the levels of cellular UV-hypersensitivity and that neuropsychological impairment did not parallel cellular hypersensitivity to UV killing. It was suggested that the cellular UV-hypersensitivity might not be the essential cause of neurodegeneration in CS.

Adolescent↗