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Biomedical subjects

H Nogami

Publications and source records attributed to H Nogami.

At least 55 records · Page 3Linked to original sources
PubMed1994

Bone dysplasia in a child born to parents with osteogenesis imperfecta and pseudoachondroplasia.

We report on a boy born to a mother with pseudoachondroplasia and a father with osteogenesis imperfecta (Sillence type III). At birth, the boy was found to have osteogenesis imperfecta type III. Although clinical findings of pseudoachondroplasia were not manifested at the age of 8 months, roentgenographic findings showed characteristics of pseudoachondroplasia in addition to those of osteogenesis imperfecta. He died of respiratory distress at age 15 months.

Achondroplasia↗
PubMed1994

IGF-I and IGF-binding protein gene expressions in spontaneous dwarf rat.

Effects of growth hormone (GH) and fasting on hepatic expressions of insulin-like growth factor I (IGF-I) and IGF-I-binding protein (IGFBP)-1, -2, -3, and -4 were examined in spontaneous dwarf rats (SDR), which completely and specifically lack GH among pituitary hormones. The hepatic expressions of mRNA encoding IGF-I and IGFBP-3 were reduced and IGFBP-1 mRNA was elevated in the SDR. Both chronic and acute administration of GH restored these changes, indicating the association of GH but not other pituitary hormones with hepatic expressions of these genes. In addition, the present examination revealed that mRNA level of IGFBP-2 was elevated in SDR, which could not be attenuated by exogenous GH, and that GH may not be directly relevant to the regulation of hepatic IGFBP-4 expression. Fasting for 2 days reduced IGF-I mRNA level and increased IGFBP-2 mRNA level in the SDR, as well as in the normal rat, suggesting the presence of factors other than reduced serum GH responsible for fasting-induced alteration in the expression of these mRNAs. On the other hand, fasting resulted in little change or even a reduction of IGFBP-1 mRNA level in the SDR.

Animals↗
PubMed1994

Cell function during chondrogenesis and osteogenesis induced by bone morphogenetic protein enclosed in diffusion chamber. Biochemical studies on native products derived from outside differentiating cells.

A diffusion chamber containing rabbit bone morphogenetic protein (BMP) was implanted in the abdominal muscle of a Sprague-Dawley rat. Outside of the chamber, cartilage differentiated one to two weeks after implantation, and bone replaced the cartilage three to four weeks after implantation. The interstitial fluid inside the chamber contained only biologic substances produced by cells proliferating and differentiating outside of the chamber. To investigate the cell function during chondrogenesis and osteogenesis, alkaline phosphatase activity and the amounts of S-100 alpha protein, S-100 beta protein, creatine kinase subunits M (CK-M), creatine kinase subunits B (CK-B), hyaluronic acid (HA), and chondroitin sulfate (CS) were measured in the supernatant of interstitial fluid inside the chamber. Alkaline phosphatase activity increased two to four weeks after implantation. The amount of S-100 beta protein acutely increased during the fourth week. The amount of CK-B also increased during the fourth week. The increased levels of HA and CS were also observed after two to four weeks. The examination of such native products may help not only to clarify the mechanisms of cartilage and bone development, but also to develop a sensitive bioassay for BMP.

Alkaline Phosphatase↗
PubMed1993

Light- and electron-microscopic immunocytochemistry of somatotropes in the anterior pituitary gland of European ferret, Mustela putorius furo.

Light-microscopic immunocytochemistry of ferret anterior pituitary revealed the localization of somatotropes in the pars distalis, but no immunoreactive cells were detected in the pars tuberalis. Ultrastructural studies by superimposition immunocytochemistry and immuno-electron microscopy, elucidated the morphological heterogeneity of these somatotropic cells. They were classified into 2 subtypes on the basis of size of the secretory granules. Type-I cells with small granules (mean diameter, 192 nm), were considered to be the immature somatotrop, while Type-II cells, with comparatively larger secretory granules (mean diameter, 257 nm), were considered to be the matured form of Type-I cells and the typical somatotropic cell-type, and were much more predominant than the Type-I cells. The fact that Type-II cells had a distinct Golgi zone and many mitochondria, while in Type-I cells the intracellular organelles were generally less developed, supports this suggestion. In addition to these two extreme subtypes, several intermediate forms were also encountered that may represent different transitional phases during the conversion of Type I to Type II. Protein A-gold immuno-electron microscopy illustrated the specific localization of growth hormone over the granules, with no labelling over any other cytoplasmic organelles of the 2 somatotrope subtypes.

Animals↗
PubMed1993

Increased population of nonhormone-producing cells suggests the presence of dysfunctional growth hormone cells in the anterior pituitary gland of the spontaneous dwarf rat.

Anterior pituitary gland of the spontaneous dwarf rat (SDR) with isolated growth hormone (GH) deficiency was studied using immunocytochemistry, cell count and in situ hybridization. The standard immunocytochemistry of five anterior pituitary hormones [adrenocorticotropic hormone (ACTH), luteinizing hormone, thyroid-stimulating hormone, prolactin (PRL) and GH] and S-100 protein failed to detect any cytological difference between normal rats and SDRs, except for the size of different types of cells which were smaller in SDR than in normal rats, and GH cells which were undetectable in the SDR. The cell count study again showed lack of immunoreactive GH cells in the SDR. The population of PRL cells was significantly reduced in the SDR by 40% in male and 30% in female when compared to those of the control. The population of ACTH cells was larger in the male SDR. The population of the immunonegative cells was calculated by subtracting the sum of the percentages of immunopositive cells from 100, and it was found to be remarkably increased in the SDR. The population of immunonegative cells was about 55% in both male and female SDRs, whereas it was calculated to be 18.7% (male) or 10.2% (female) in the control rats. In situ hybridization study using GH cRNA indicated the presence of a considerable number of cells which express GH mRNA in the SDR as well as in the control rats. These results taken as a whole suggest the presence of a number of dysfunctional GH cells in the SDR.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenocorticotropic Hormone↗
PubMed1993

Dexamethasone induces advanced growth hormone expression in the fetal rat pituitary gland in vivo.

The effects of dexamethasone (DEX) on the onset of GH expression in the fetal rat pituitary gland were studied. Pregnant rats received oral administration of DEX dissolved in drinking water (25 mg/liter) for 40 h before killing on days 16-19 of pregnancy. The number of immunoreactive GH cells in the control fetus on day 18 was very small, whereas it was remarkably increased by DEX to a compatible value obtained from control fetuses on day 19. The effect of DEX on the induction of immunoreactive GH cells was found to be less potent on day 17 and not evident on day 16. The population of GH cells on day 19 was doubled, and they stained more intensely by GH antiserum after DEX treatment. In situ hybridization revealed that there were many GH messenger RNA (mRNA)-positive cells in the pituitary gland of a DEX-treated fetus at day 18, whereas they were negligible in number in the age-matched control. Northern blot analysis revealed that DEX induced accumulation of small amounts of GH mRNA in the fetal pituitary gland on day 17, whereas it induced a marked elevation of GH mRNA level on day 18. Reducing the levels of endogenous glucocorticoids by the administration of metyrapone (0.5 mg/ml in drinking water) to the pregnant rats from day 17-19 resulted in the significant reduction in the number of GH cells at day 19. Short-term treatment of DEX (duplicate sc injections at 18 h and 6 h before killing) also induced immunoreactive GH cells on day-18 fetuses but not on day-17 fetuses. Immunoreactive GH cells appeared on day 17 only after quadruplicate injections of DEX during last 40 h, suggesting that there is a difference in fetal sensitivity to DEX between days 17 and 18. These results indicate that immunoreactive GH cells and GH mRNA are inducible by DEX at an earlier stage of the fetal life than they normally appear. It is suggested that glucocorticoids play an important role in the development of GH cells in the fetal pituitary gland in vivo.

Animals↗
PubMed1993

A case of bilateral dysplasia epiphysealis hemimelica associated with polydactyly and syndactyly.

Dysplasia epiphysealis hemimelica (DEH) on bilateral medial malleoli occurred in a boy who had polydactylies and syndactylies of all four limbs. Cases with both bilateral and symmetrical DEH affection as in this case seem not to have been reported previously in the literature. Dysplasia epiphysealis hemimelica complicated by congenital anomalies is extremely rare. A one-month-old boy of normal delivery had polydactylies of thumbs, small fingers, and great toes, and had symmetrical syndactylies of fingers and toes. At age eight, the patient reported swelling and tenderness on bilateral medial malleoli. Radiographs showed small blotches of radiopacity. Two years later, the radiopacities had enlarged to become typical of DEH.

Abnormalities, Multiple↗
PubMed1993

An investigation of the accuracy in measuring the body center of pressure in a standing posture with a force plate.

It has been reported that accuracy in the measured point of force application depends on the position and magnitude of load. The aim of this study is to investigate the error in measuring the body center of pressure in a standing posture with a force plate and to improve the accuracy by proposing a correction algorithm. The measurement of the point of force application with a calibrated load demonstrated its co-ordinates, which were scaled down towards the zero co-ordinate and moved parallel relative to the true co-ordinates. This trend was exaggerated with any decrease in magnitude of the load. The root mean square (r.m.s.) and maximum of errors at light load of 10 kg were 10 and 18 mm in the X axis, and 6 and 12 mm in the Y axis, respectively. The error seems to result from such causes as (i) non-linearity of the load cell, (ii) deformation of the top plate due to load application and (iii) differences in characteristics among individual load cells, including amplifiers. A mathematical representation of the measured point of force application accounting for these causes of error has been made and an algorithm for estimating the true point at any magnitude of load with only one correction equation is proposed. Actual correction of the measured point demonstrated an expected improvement in the r.m.s. error to less than 1 mm at any magnitude of load greater than 10 kg and the validity of this algorithm was confirmed.

Algorithms↗
PubMed1993

Repair of bone defect with cultured chondrocytes bound to hydroxyapatite.

Cultured chondrocytes were bound to hydroxyapatite (HA) and implanted in surgically created bone defects in the ulna of the rabbit. Chondrocytes were obtained from the iliac crest cartilage of the rabbit and were cultured on the HA block for two weeks before implantation. Scanning electron micrographs showed that pores of the HA surface and the inside of the block were filled with cultured cells. After cultivation for two weeks, the expression of chondrocyte-specific characteristics was confirmed in these cells by an implanted diffusion of chondrocyte-specific characteristics was confirmed in these cells by an implanted diffusion chamber experiment. The HA without chondrocytes served as a control. At two weeks postimplantation, proliferating chondrocytes were observed on the surface and in the inside pores of the HA-chondrocyte blocks but not the HA controls. At four and six weeks postimplantation, in the central region of the implants, there was a significant increase in the amount of bone formation in the HA with cultured chondrocytes. At 13 weeks post-implantation, the implants were partially resorbed and completely enveloped in lamellar bone, including bone marrow.

Animals↗
PubMed1993

Microvascular and cellular defects of the periosteum of osteogenesis imperfecta.

Periosteum stripped from fragments of diaphyseal long bones from osteogenesis imperfecta (OI) patients was examined both in vivo and in vitro. The OI periosteum was thickened and characteristic finding was a defective microvascular system. The vascular walls of arterioles and capillaries were thick and the lumina of many of these vessels were narrowed or occluded by hypertrophic endothelial cells and multiplication of smooth muscle cell layers. Circulatory deficiency in the OI periosteum might be regarded as one of the causes of the slender, osteopenic diaphyseal bone characteristic of the disorder. A higher proliferative activity was observed in cultured OI periosteal cells, but the cytoplasmic structure showed increased myelinoid bodies and smooth endoplasmic reticulum and decreased lysosomes and rough endoplasmic reticulum. These findings may be related to the abnormal metabolic activity of OI periosteal cells.

Adolescent↗
PubMed1992

[Prognosis of intractable asthma].

Forty-nine intractable asthma patients from January 1981 were divided into three groups. Group I consisted of patients still alive after ten years (January 1991) who were receiving decreased doses of steroids or no steroids at all. Group II patients were also alive, but the doses of steroids they were receiving were unchanged. Group III consisted of patients who had died during the ten years. Of the 49 patients, nine were in Group I, 13 in Group II and 17 in Group III. The condition of the other 10 patients was unknown. The mortality rate of the known 39 patients over 10 years was 43.6%, a very high rate. The groups of living patients (I + II) were younger than the patients in the dead group (III) and the latter patients had more obstructive ventilatory dysfunction in the stable state (FEV1.0/FVC%, and %FEV1.0 were 56.1% and 52.8%) in 1980. In the therapy carried out over the 10 years, antiallergic drugs and inhaled steroids were administered in order to decrease oral steroids in both Group I, II and III. In Group I, however, more patients had received immunotherapy (hyposensitization) or gold therapy than in Group II and III. There were more complications due to steroids during the ten years in Group II and III than in Group I. Aging and obstructive ventilatory dysfunction may be factors which worsen the prognosis of intractable asthma, and decreasing of the doses of oral steroids may be important to prevent complications.

Adolescent↗
PubMed1992

Coffin-Lowry syndrome associated with calcium pyrophosphate crystal deposition in the ligamenta flava.

Clinical and ultrastructural study of four cases of Coffin-Lowry syndrome (CLS), a heritable disorder with peculiar facies, stooped posture, vertebral changes, and mental retardation, is reported. Three of the four cases had myelopathy caused by calcification of the ligamenta flava in early adulthood. These patients demonstrated that CLS is a calcium pyrophosphate dihydrate crystal deposition disease, and it is postulated that a metabolic abnormality in collagen and in proteoglycans are responsible for some aspects of CLS.

Adolescent↗
PubMed1991

Immunohistochemistry of the pituitary pars distalis of the musk shrew, Suncus murinus.

Immunocharacteristics of the pituitary pars distalis cell types of the musk shrew, Suncus murinus, were studied by the unlabeled antibody enzyme technique, using peroxidase-antiperoxidase or avidin-biotin-peroxidase complex. The thyrotropin (TSH)-, gonadotropin (GTH)-, corticotropin (ACTH)-, prolactin (PRL)-, and growth hormone (GH)-secreting cells of the PD were identified on the basis of their immunoreactivity with different heterologous antisera. The TSH cells showed specific immunoreactivity with antisera against human (h) TSH beta and rat (r) TSH beta. Cells showing immunoreactivity with the antisera against hLH beta and ovine (o) LH beta were designated as GTH cells as no immunoreactivity was observed with antisera against hFSH beta and oFSH beta. The ACTH cells as well as the cells of the pars intermedia were revealed by anti-ACTH1-24 and anti-ACTH1-10 sera. Whereas the PRL cells were recognized by their immunoreactivity with antisera against hPRL and oPRL, the GH cells were identified with anti-hGH, anti-oGH, and anti-bovine (b) GH sera. TSH and GTH, TSH and ACTH, GTH and ACTH, ACTH and GH, ACTH and PRL, and GH and PRL cells were visualized in the same section using the dual immunoperoxidase technique. Comparison of the immunohistochemically identified cells with those described histochemically reveals several discrepancies, which expose the limitations of the latter techniques identifying adenohypophysial cells.

Adrenocorticotropic Hormone↗
PubMed1991

Zonal and age-related difference in the amounts of creatine kinase subunits in cartilage.

Energy metabolism in cartilage may affect the morphogenetic events of skeletal growth. Investigating enzymes responsible for energy metabolism in cartilage, such as creatine kinase (CK), can provide clues to an understanding of pathogenesis and treatment of osteochondrodysplasias. In this study levels of CK subunits M (muscle type) and B (brain type) were measured by a highly sensitive enzyme immunoassay system in growth and resting cartilages of the rat rib at various ages. CK-M was predominant, but there was no statistically significant difference in its quantity of CK among cartilages of various ages or between resting and growth cartilage. In contrast, although CK-B levels were low, they showed a significant decrease with advancing age and a significant increase in growth cartilage as compared with resting cartilage. The results of this study suggest that CK in cartilage, especially CK-B, may play an important role in skeletal growth.

Aging↗
PubMed1990

Allelic association of human dopamine D2 receptor gene in alcoholism.

In a blinded experiment, we report the first allelic association of the dopamine D2 receptor gene in alcoholism. From 70 brain samples of alcoholics and nonalcoholics, DNA was digested with restriction endonucleases and probed with a clone that contained the entire 3' coding exon, the polyadenylation signal, and approximately 16.4 kilobases of noncoding 3' sequence of the human dopamine D2 receptor gene (lambda hD2G1). In the present samples, the presence of A1 allele of the dopamine D2 receptor gene correctly classified 77% of alcoholics, and its absence classified 72% of nonalcoholics. The polymorphic pattern of this receptor gene suggests that a gene that confers susceptibility to at least one form of alcoholism is located on the q22-q23 region of chromosome 11.

Alcoholism↗
PubMed1990

Molecular mechanism of growth hormone (GH) deficiency in the spontaneous dwarf rat: detection of abnormal splicing of GH messenger ribonucleic acid by the polymerase chain reaction.

The spontaneous dwarf rat (SDR) is an experimental model for pituitary dwarfism with an autosomal recessive mode of inheritance. In the pituitary of the SDR, neither GH cells nor GH protein were detected by immunological methods, but SDR pituitary has a very small amount of GH mRNA. In the present study the effects of GH-releasing factor and an analog of its second messenger, (Bu)2cAMP, on the total accumulation and secretion of GH were studied in primary cultures from SDR pituitaries. GH-releasing factor and (Bu)2cAMP increased the amount of GH mRNA, but neither accumulation nor secretion of immunoreactive GH was detected. These results suggested that the mutation is not manifest during transcription, but at a later stage. The GH gene of SDR was cloned, and its sequence was determined. A point substitution was found in the consensus sequence of the 3' splice site of the third intron. Judging from this point mutation, one would predict an abnormal splicing and a 1-base deletion in the GH mRNA. Therefore, the fragment of SDR GH cDNA in which the deletion was predicted was amplified by the polymerase chain reaction. Its sequence analysis confirmed that the SDR GH mRNA had 1 base deletion which must cause a premature translational termination of GH mRNA. These results demonstrate that GH deficiency in SDR is caused by a point mutation in the GH gene producing an abnormal splicing of GH mRNA.

Animals↗