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Biomedical subjects

K Iinuma

Publications and source records attributed to K Iinuma.

At least 55 records · Page 3Linked to original sources

Gonadal suppression by a GnRH analogue does not alter somatic growth in rats with complete GH deficiency.

Sexual dimorphism of somatic growth in rats appears to reflect differing actions of sex steroids. However, mechanisms of gonadal steroid effects on the somatotropic axis are incompletely understood. To evaluate whether GH is involved in the effects of long-term gonadal suppression on somatic growth in rats, a GnRH agonistic analogue (GnRHa) was administered to normal Sprague-Dawley rats (controls) and to a strain of rats with complete growth hormone deficiency (GHD; n=4-6 in each group). Subcutaneous injection of GnRHa (2 mg/kg) or saline were given within 48 h after birth and repeated every 3 weeks. GnRHa treatment significantly reduced serum gonadal steroid levels in rats of both sexes with small testes in males and impaired development of internal genitalia in females. GnRHa-treated control females became significantly heavier (P<0.01 ANOVA for repeated measures) than saline-treated rats beginning at 8 weeks. However, female GHD rats with GnRHa treatment did not differ in body weight from rats receiving saline. In male rats, GnRHa treatment did not change body weight in either control or GHD rats. Serum IGF-I concentrations did not differ between treatment groups in GHD and control rats of either sex. Hepatic GH binding was reduced significantly by GnRHa treatment in female control rats (P<0.01), but not in female GHD rats. These data suggest that sexual dimorphism in body size and its modulation by estrogens are independent of circulating IGF-I levels suggesting non-endocrine IGF-I-mediated mechanisms, and that GH-induced somatic growth is modulated by estrogens, but not androgens, in rats.

Analysis of Variance↗

Genotypic analysis of hepatitis C virus in blood donors in Indonesia.

A study was conducted to describe the genetic diversity of hepatitis C virus (HCV) in a population of positive blood donors from throughout Indonesia. Repeat analysis by reverse transcription-polymerase chain reaction (RT-PCR) of 102 anti-HCV positive samples showed that 67 gave HCV-specific positive signals by the PCR for the 5'-untranslated genomic region of HCV. Further genotypic analysis on 64 HCV RNA-positive samples indicated that 57 belonged to the following individual genotypes: 1a, 1b, 2a, 2b, and 3b. The predominant HCV genotypes in this donor population were 1b (57.8%), 2a (17.2%), and 3b (10.9%). The core sequences of the 4 indeterminate samples when aligned with published sequences of various HCV genotypes showed a range of homology from 16.16% to 78.67%. Comparative analysis of genotypic representation from other anti-HCV-positive study populations, including polytransfused pediatric and adult renal dialysis groups, is now being carried out to determine the potential genotypic association with mechanistic HCV spread.

5' Untranslated Regions↗

Use of cultured tubular cells isolated from human urine for investigation of renal transporter.

AIM: To facilitate the understanding of the transporter function of human renal tubular cells, we have developed a simple method using primary cultured proximal tubule (PT) cells isolated from voided urine. METHODS: PT cells grown to confluence on glass coverslips could be identified by parallel arrays of spindle cells and hemicyst formation. Brush-border gamma-glutamyl transpeptidase (gammaGTP) activity was histochemically identified. Apical membrane Na+/H+ exchanger (NHE) activity was measured by monitoring changes in intracellular pH (pHi) after an acid load in a single cell level using the pH-sensitive dye 2'7'-bis-(2-carboxyethyl)-5.6'carboxyfluorescein (BCECF). RESULTS: Amiloride and 5-(N-ethyl-N-isopropyl) amiloride (EIPA) inhibited the NHE activity with half-maximal inhibition values (IC50) of 15.3 and 4.0 microM, respectively. NHE-3 mRNA was detected by the RT-PCR technique in clonally proliferated PT cells. CONCLUSION: These results suggest that cultured PT cells isolated from human urine express amiloride-resistant NHE-3 activity on the apical membranes, which can be compared to functional properties of PT in vivo. Our experimental strategy offers a useful experimental approach to investigating human renal tubular transport function in vitro.

Adult↗

[Nation-wide survey on hemimegalencephaly in Japan].

We report here 38 Japanese patients with hemimegalencephaly collected by a national survey study. All the patients were sporadic. There was no familial occurrence or sex difference. Some patients had basic diseases: hypomelanosis of Ito in 3 cases and organic nevus syndromes in 8. Most patients had hemiparesis, and 11 were bed-ridden. All except for 3 patients had mental retardation, being profound in half of them. There was no correlation between the side of hemimegalencephaly and clinical symptoms. All patients had epileptic seizures, which first appeared within 24 hours after birth in 4 cases, within 7 days in 7, within a month in 2, within 6 months in 10, and within a year in 4. Antiepileptic drugs were not very effective for controlling seizures. In 7 patients, however, functional hemispherectomy resulted in seizure control and improved development. The patients whose epileptic symptom occurred earlier tended to be more severe in clinical symptoms.

Adolescent↗

[A case with mild subdural hematoma presenting with a transient cluster of convulsions--problems concerning differentiation from benign infantile convulsion and benign complex partial epilepsies in infancy].

A 1-month-old girl showed frequent partial seizures of sudden onset. Continuous spikes were observed in left central area during the ictal period, although interictal EEG showed neither epileptiform discharges nor focal signs. Optimal seizures control was obtained with intravenous administration of diazepam and subsequent oral administration of phenobarbital. She showed neither abnormal physical and neurological signs after seizures nor sequelae. CT examination on two days after the onset of seizures showed no obvious abnormal high density area. However, MRI examination on 10 days after the onset showed subdural hematoma in the left front-temporal area and right occipital area. Except for MRI findings, this case may be diagnosed as benign infantile convulsion or benign complex partial epilepsies in infancy. This case suggested that serial neuroradiological examinations were recommended for prospective studies about benign infantile convulsion and benign complex partial epilepsies in infancy.

Acute Disease↗

Mitogenic action of lysophosphatidic acid in proximal tubular epithelial cells obtained from voided human urine.

Focal tubular cell multiplication at sites on an injured nephron is a critical event in the recovery phase following acute tubular necrosis. During this process, numerous viable tubular cells exfoliate and are shed into the urine. Lysophosphatidic acid (LPA) is generated in the plasma membrane of injured cells and acts as an intercellular mediator of various biological processes, including inflammation, proliferation and repair. In the present study, exfoliated proximal tubule (PT) cells were isolated from human urine and the mitogenic effects of LPA were investigated as a model of repair and proliferation following renal injury. LPA stimulated a 23. 5% increase in DNA synthesis, a 29.4% increase in cell number and an 86.6% decrease in cAMP content. All of these responses were pertussis toxin sensitive, indicating the involvement of G(i)-type G-proteins in LPA signalling. Conversely, the LPA-induced DNA synthesis and the decrease in intracellular cAMP content were insensitive to wortmannin, an inhibitor of phosphatidylinositol 3-kinase (PI3K), suggesting a mitogenic response via PI3K-independent mechanisms. Furthermore, we detected specific mRNA transcripts for the recently cloned human LPA-receptors, endothelial differentiation gene (Edg)-2 and Edg-4 (Edg-2>>Edg-4) by reverse transcription-PCR in PT cells. Our data suggest that LPA may behave as a local growth factor in PT cells following tubular injury.

Cell Division↗

Oral-facial-digital syndrome with hypothalamic hamartoma, postaxial ray hypoplasia of the limbs, and vagino-cystic communication: a new variant?

We report on a 20-month-old girl with hypothalamic hamartoma, left cerebral atrophy, tongue nodules, oral frenula, micrognathia, hypoplasia of the left ulna, the fibulae, and right tibia, polysyndactyly of the hands and feet, vagino-cystic drainage with hydrometrocolpos, megaloureters, and hydronephrosis, agenesis of urethra, complex partial seizures, and central precocious puberty. The differential diagnosis is discussed. We conclude that the malformation complex in this girl is an oral-facial-digital syndrome, but is different from any of the 11 known subtypes.

Female↗

Effects of mean and swing pressures on piston-type high-frequency oscillatory ventilation in rabbits with and without acute lung injury.

To determine whether low mean airway pressure (MAP) and/or stroke volume (SV) settings cause lung injury during piston-type high-frequency oscillatory ventilation (HFOV), we investigated the influence of various combinations of MAP and SV on the amplitude of the pressure swing at four different sites in the normal lung of rabbits. We also examined the effects of these factors on progression of lung injury in lavaged surfactant-deficient lungs. We measured changes in the mean pressure (MP) and swing pressure (SP) during HFOV at MAPs ranging between 5-30 cm H2O in combination with SVs ranging from 5-30 mL in 13 rabbits at four different sites: 1) the proximal airway, 2) the distal end of the endotracheal tube, 3) the bronchi, and 4) the pleural space. Lung lavage was performed in 8 rabbits and differences in MP and SP between normal and surfactant-deficient rabbits were investigated. In the remaining 5 rabbits, lungs were lavaged and subjected to two trials of sustained inflation to 30 cm H2O for 15 s to reverse atelectasis, and the resulting SP was measured. In normal lungs, SP increased at the bronchial and pleural sites as MAP was increased. Alterations in SV did not affect MP in normal or lavaged lungs. In the lavages, surfactant-deficient lungs at MAPs < or = 15 cm H2O, there were significant increases in SP at the distal end of the endotracheal tube and the bronchial sites. SP decreased to the prelavaged level following sustained inflation to 30 cm H2O for 15 s. We conclude that low MAP settings are insufficient to open alveoli in the low-compliance lung and allow for development of atelectasis rather than air trapping. SP was markedly increased in the presence of atelectasis, possibly leading to excessive expansion of the airway. In the clinical setting, such overexpansion of the distal airways may contribute to lung injury. Our findings suggest that physicians should use caution in reducing MAP during piston-type HFOV until lung compliance has normalized, especially in infants with respiratory distress syndrome.

Air Pressure↗

Molecular analysis of Japanese patients with steroid 21-hydroxylase deficiency.

We have designed a rapid and convenient strategy to determine nine of the most common mutations in the 21-hydroxylase gene (CYP21). The frequency of the mutations was investigated in 34 Japanese patients affected with congenital adrenal hyperplasia (CAH) caused by 21-hydroxylase deficiency. We characterized 82% of the CAH chromosomes. The most frequent mutations were a C/A to G substitution in intron 2 in the salt-wasting form of the disease and an I172N in the simple virilizing form. Three de novo mutations were found. Two homozygous mutations (S268T and N493S) were detected by direct sequencing of all exons of CYP21 in two siblings, who had a normal genotype at all positions screened. We successfully applied these methods for prenatal diagnosis in one family. These procedures proved to be sensitive and rapid for the detection of the most common known mutations in the CYP21 gene and may be useful for genetic screening.

Adrenal Hyperplasia, Congenital↗

Detection of apoptosis in acute promyelocytic leukemia cells in vivo during differentiation-induction with all-trans retinoic acid in combination with chemotherapy.

In two patients with acute promyelocytic leukemia (APL) treated with all-trans retinoic acid (ATRA) in combination with chemotherapy, we demonstrated that cells with apoptotic morphology were recognized in a small fraction of whole blood cells (0.2-0.4%) at the regression phase of leukocytosis with mostly maturing aberrant granulocytes of APL clone origin. Moreover, in a light-density cell fraction ( < 1.077) of peripheral blood or marrow cells obtained from three patients, DNA fragmentation was detected by agarose gel electrophoresis temporarily. These findings may suggest that, during the treatment with ATRA, a small fraction of APL cells maturing toward the stage of terminal differentiation underwent apoptosis in vivo, which might be enriched by the combination of chemotherapy to ATRA administration.

Adolescent↗

The origin of hypsarrhythmia and tonic spasms in West syndrome: evidence from a case of porencephaly and hydrocephalus with focal hypsarrhythmia.

We report on a 3-year-old girl with West syndrome and with focal hypsarrhythmia. The left hemisphere of the patient was virtually completely defective and continuous hypsarrhythmia was only seen in the residual right frontal cortex, where an interictal single photon emission computed tomography (SPECT) showed hyperperfusion. Despite a focal epileptic pattern, the tonic spasms were quite symmetrical. In our patient, spasms might not require the sensorimotor cortex, but the brainstem containing the descending pathways that control spinal reflexes and other infratentorial structures seem to be essential for the occurrence of spasms. This is in accordance with the result of an ictal SPECT that showed hyperperfusion of the brainstem and cerebellum. These findings suggest that hypsarrhythmia originates from cortical lesions, while subcortical structures may be primarily responsible for the tonic spasms in this patient.

Brain↗

Pilot study of screening for Wilson disease using dried blood spots obtained from children seen at outpatient clinics.

Wilson disease (WD) is an autosomal recessive disorder of copper accumulation leading to liver and/or brain damage. In this paper, we describe the results of a pilot study of screening for WD using ceruloplasmin determinations in dried blood samples. Specimens were collected from children aged 1 to 6 years who were seen at local paediatric outpatient clinics in the Miyagi Prefecture. We measured ceruloplasmin (CP) concentrations in 2789 children using an enzyme-linked immunosorbent assay. The mean value was 12.4 +/- 3.95 mg/dl blood. Among these children, we identified two (case 1, male, 2 years old; case 2, female, 3 years old) with markedly reduced CP concentrations. Apart from low serum copper concentrations, their biochemical findings were almost normal, as were growth and development. To confirm the diagnosis, we analysed the WD gene and detected A803T/2871delC mutations in case 1 and R778L/G1035V mutations in case 2. We conclude that these children were presymptomatic WD patients. The CP level in dried blood samples from children aged 1 to 6 years appears to be a reliable marker for early detection of WD.

Ceruloplasmin↗

Urinary bile alcohol profile in infants with intrahepatic cholestasis: identification of 5beta-cholestane-3alpha,7alpha,24,25-tetrol.

Urinary bile acids and bile alcohols were examined in six infants aged between 1 and 6 mo who had intrahepatic cholestasis. Following extraction, hydrolysis and solvolysis, cholanoids were analysed by gas-liquid chromatography and gas-liquid chromatography-mass spectrometry. The relative ratio of the urinary excretion of bile alcohols to bile acids was very low (0.07-0.22) in three patients with mild to severe cholestasis, whereas the urinary excretion of bile alcohols was 2-4 times greater than that of the total bile acids in three patients with slight cholestasis. The urinary bile alcohol spectrum in infants appears to be quite different from that in adults. Although the major bile alcohol was 27-nor-5beta-cholestane-3alpha,7alpha,12alpha,24 ,25-pentol, comprising more than 50% of total urinary bile alcohols in healthy adults, it accounted for only 35% of total urinary bile alcohols in our patients. In addition, bile alcohols carrying chenodeoxycholic acid type nucleus were detected in our patients by comparison of the retention times and mass spectra with those of authentic standards. The presence of 5beta-cholestane-3alpha,7alpha,24,25-tetrol confirmed for the first time in this study may represent an alternative pathway for chenodeoxycholic acid biosynthesis via a "25-hydroxylation pathway" in early life.

Adult↗