Search PubMed⌕ Search

Biomedical subjects

M Sudo

Publications and source records attributed to M Sudo.

At least 73 records · Page 4Linked to original sources
PubMed1997

Age-related changes of urinary nitrite/nitrate excretion in normal children.

We measured the urinary excretion of nitrite/nitrate, stable metabolites of nitric oxide, using the brucine method in 90 healthy normal children (47 boys and 43 girls), aged from 1.0 to 17.1 years, to establish the age-related normal range in children. The urinary nitrite/nitrate excretion was highest in the youngest children and decreased in an age-dependent manner to reach constant levels at about 12 years of age in both sexes. The data may be useful in identifying sick children with abnormal nitric oxide production.

Adolescent↗
PubMed1997

Assessment of endogenous nitric oxide formation in newborns: measurement of urinary nitrite and nitrate concentrations.

We measured the urinary nitrite and nitrate (NOx-) excretion, an index of endogenous nitric oxide formation, in term and preterm newborns on the 1st and 4th days of age. In the infants of both groups, the urinary NOx- excretion significantly increased from the 1st to the 4th day. The urinary NOx- excretion in preterm infants was significantly higher as compared with term babies on both days. Furthermore, the urinary NOx- excretion was significantly elevated in preterm infants with respiratory distress syndrome as compared with those without cardiopulmonary complications on the 4th day. These changes of urinary NOx- excretion in newborns strongly suggest the presence of an active physiological role for nitric oxide in the circulatory adaptation to extrauterine life.

Female↗
PubMed1997

Postnatal change in angle between the tympanic annulus and surrounding structures. Computer-aided three-dimensional reconstruction study.

Postnatal developmental relationships in human ears were studied by a computer-aided three-dimensional reconstruction and measurement method. We measured the angle, in reference to the horizontal plane, between the tympanic annulus, the oval window, and the internal auditory canal (IAC) in 20 normal temporal bones obtained from individuals between 1 day old and 76 years old. The horizontal plane was defined as the plane sloped 30 degrees infero-anteriorly from the plane of the horizontal canal in each specimen. The plane of the tympanic annulus changed from a nearly horizontal orientation (34.2 degrees from the horizontal plane) in neonates to a more vertical orientation (63.3 degrees from the horizontal plane) in adults. The tympanic annulus and oval window planes remained at the same angle to each other (11.9 degrees +/- 5.1 degrees) throughout postnatal development, as did the plane of the tympanic annulus and the IAC (68.6 degrees +/- 5.3 degrees). These findings have implications for ear surgeons, especially those operating on young children.

Adolescent↗
PubMed1997

Narrowest (isthmus) portion of eustachian tube: a computer-aided three-dimensional reconstruction and measurement study.

Nine normal human temporal bones from persons 16 to 88 years old were studied by computer aided three-dimensional reconstruction and measurement. The length of the eustachian tube (ET) lumen in three portions (from pharyngeal orifice to tympanic orifice: cartilaginous, junctional, and bony) averaged 23.6 +/- 4.3 mm, 3.0 +/- 1.9 mm, and 6.4 +/- 2.6 mm. The narrowest portion of the ET lumen was in the cartilaginous portion in all cases: 20.5 +/- 4.2 mm from the pharyngeal orifice and 3.1 +/- 1.6 mm from the pharyngeal margin of the junctional portion. The cross-sectional area of the narrowest portion was 0.65 +/- 0.2 mm2. The tendon of the tensor veli palatini muscle (TVPM) inserted into the lateral lamina in the narrowest portion of the ET lumen in five of nine cases. These results suggest that contraction of the TVPM opens the narrowest portion of the ET lumen to ventilate the middle ear and that this portion also plays a role in protecting the middle ear.

Adolescent↗
PubMed1997

Immunohistochemistry of lymphocytes and macrophages in human celloidin-embedded temporal bone sections with acute otitis media.

Immunohistochemical analyses were used to investigate the distribution of lymphocytes and macrophages in routine human temporal bone sections obtained from a subject with acute suppurative otitis media. Primary antibodies specific for human CD3 and CD43 (T-lymphocytes), CD20 (B-lymphocytes), CD45 (leukocyte common antigen), and CD68 (macrophages) were used. As a pretreatment, the sections were soaked in antigen retrieval solution (saturated sodium hydroxide-methanol solution in methanol at a ratio of 1:3). A second antigen retrieval procedure (microwave treatment in 1% zinc sulfate) was also employed for identifying CD3-positive cells. Then the avidin-biotin-peroxidase complex technique was performed. Positive reactions to all antibodies but anti-CD68 were observed in the mucosa of the eustachian tube, tympanic cavity, and mastoid air cells. Particularly, cells positive to anti-CD3 or anti-CD43 were making a diffuse invasion upon the lamina propria. CD68-positive cells were scattered only in the effusion of mastoid air cells. These results suggest that the retrospective immunohistochemical study of archival temporal bone sections is a promising approach to investigate the pathogenesis of otitis media.

Acute Disease↗
PubMed1997

Endogenous nitric oxide production in Kawasaki disease.

To evaluate in vivo nitric oxide production in Kawasaki disease (KD), urinary nitrite/nitrate (NOx) excretion was measured in 8 children with KD (age 1.1-2.7 years). Urinary NOx excretion was 0.66 +/- 0.22 mmol mmol-1 creatinine (mean +/- SD) in the 8 children with KD in the initial stages. The levels were significantly increased compared with those of 12 age-matched healthy control subjects (0.35 +/- 0.08 mmol mmol-1 creatinine). Urinary Nox excretion was serially determined in four patients. For each patient, there was a further rise in urinary NOx excretion from baseline levels coincident with the administration of intact-type gammaglobulin and aspirin. With clinical and laboratory improvement, however, urinary NOx excretion declined to the normal range. These findings suggest that endogenous nitric oxide production is enhanced in children with acute KD. Further studies are needed to clarify the role of nitric oxide in the pathogenesis and clinical course of KD.

Child, Preschool↗
PubMed1997

Chronic erythropoietin treatment enhances endogenous nitric oxide production in rats.

To examine the effect of chronic administration of recombinant human erythropoietin (rHuEPO) on endogenous nitric oxide (NO) activity, we treated Sprague-Dawley rats with rHuEPO (100 IU kg-1 or 300 IU kg-1) or a corresponding vehicle for 2 weeks, administered subcutaneously on alternate days. Treatment elicited increases in haematocrit and systolic blood pressure in a dose-dependent fashion. Simultaneous administration of NG-nitro-L-arginine methyl ester (L-NAME, 20 mg dl-1 of drinking water), but not aminoguanidine (400 mg dl-1), induced a further significant rise in blood pressure. The effect of L-NAME was inhibited by a large dose of L-arginine (2.0 g dl-1). Polycythaemia and hypertension induced by chronic rHuEPO therapy were associated with increased urinary NO2- and NO3- (NOx-) excretion, while co-administration of L-NAME, but not aminoguanidine, reduced NOx- excretion. Our results indicate that chronic rHuEPO treatment has a significant pressor effect, but induces a compensatory increase in the steady-state release of NO by constitutive NO synthase in normal rats. Such enhanced NO synthesis may act as a protective mechanism against the hypertensive effect of rHuEPO.

Animals↗
PubMed1997

[Angiotensin I-converting enzyme gene polymorphism and renal disease].

ACE inhibitor is known to have a therapeutic efficacy in renal diseases by reducing proteinuria and maintaining renal function. However, the relationship between ACE gene polymorphism and renal disease has not been fully elucidated. In this study, a 287 base pair(bp) I/D polymorphism of the ACE gene was examined with polymerase chain reaction(PCR) in 100 healthy subjects, 34 patients with chronic glomerulonephritis(CGN), 29 with chronic renal failure(CRF) and 25 with diabetes mellitus(DM) with(13) and without(12) nephropathy. We also measured serum ACE activity of these patients. ACE genotype and derived allele frequencies in each disease group did not differ significantly from those in healthy subjects. In all disease groups, values of serum ACE activity were higher in genotype DD than in genotype II. These findings suggest no significant association between I/D polymorphism of the ACE gene and renal disease. Further studies are needed to clarify these findings, considering renal function and type of renal disease.

Adult↗
PubMed1996

Chronic nicotine treatment delays the developmental increase in brain muscarinic receptors in rat neonate.

Developmental increase in the muscarinic receptors ([3H]quinuclidinyl benzylate binding sites) of rat neonate brain (cerebral cortex and cerebellum) was significantly inhibited by chronic nicotine treatment of the dams during pregnancy and lactation. However, development of the nicotinic receptors ([3H]cytisine binding sites) was not inhibited and rather was up-regulated in the cerebral cortex and brainstem by the nicotine treatment. Such inhibition and up-regulation were not seen in nicotine-withdrawn rats after birth. These results suggest that nicotine treatment during lactation may cause a remarkable delay in development of muscarinic neurotransmission in rat neonates.

Aging↗
PubMed1996

Stimulatory and inhibitory effects of sodium nitroprusside on soluble guanylate cyclase.

We investigated, using rat brain cortex supernatant as a source of guanylate cyclase (GC), whether sodium nitroprusside (SNP) can not only activate but also inhibit GC. SNP (I and 10 microM) activated the rat brain GC; however, at higher concentrations GC activation was reduced, resulting in a bell-shaped concentration-activation curve. Preincubation of GC with 10 microM SNP attenuated GC activation by SNP, S-nitroso-N-acetylpenicillamine (SNAP) or 3-morpholinosydnonimine-N-ethyl-carbamine (SIN). Such inhibitory effects of SNP were partially supressed by a nitric oxide (NO) scavenger oxyhemoglobin. The preincubation of GC with K4Fe(CN)6 (a carrier molecule for SNP but devoid of NO) had no inhibitory effects on GC activation. These results indicate that SNP, probably through NO, has dual effects on GC activity, stimulation and inhibition.

Animals↗
PubMed1996

Development of primary hypothyroidism with antithyroglobulin, antiperoxidase, and blocking-type thyrotropin receptor antibodies after radiation therapy for neuroblastoma.

We describe a girl with hypothyroidism and blocking-type thyrotropin receptor antibodies that developed after chemotherapy and irradiation of the neck region for neuroblastoma. Results of thyroid studies before treatment were normal. Twenty months after completion of treatment, the girl had hypothyroidism with high titers of blocking-type thyrotropin receptor antibodies, antithyroglobulin, and antiperoxidase antibodies.

Antibodies↗
PubMed1996

Urinary excretion of pyridinium cross-links of collagen in infancy.

This cross-sectional study evaluated urinary excretion of pyridinium cross-links of collagen, specific markers of ongoing bone resorption, in infants aged 1 week to 7 months and examined the relationship between urinary cross-links and individual renal function. Spot urines from a total of 100 infants were analyzed. The collagen cross-links, pyridinoline (Pyd) and deoxypyridinoline (D-Pyd), were assayed by fluorescence detection after high-performance liquid chromatography (HPLC). Beta2-Microglobulin (beta2M), an index of renal tubular function, was determined by radioimmunoassay. In healthy term infants, urinary collagen cross-links were several times higher than the reported data for older children, with peak values seen at 1 month of age. Excretion of Pyd and D-Pyd was also markedly elevated in 1-month-old preterm infants, despite poor somatic growth. Such high excretion of collagen cross-links probably reflects the state of accelerated bone turnover in infancy. The postnatal change in the cross-links was different from that in urinary beta2M, and the values obtained did not correlate with beta2M in either term or preterm infants. These results indicate that cross-link excretion is not influenced directly by individual renal function.

Amino Acids↗
PubMed1996

Urinary uric acid excretion in term and premature infants.

OBJECTIVE: To clarify postnatal changes in urinary uric acid (UA) excretion in normal term infants and to examine the effects of prematurity or illness on the UA excretion. METHODOLOGY: Measurements of urinary UA were performed in term and premature infants at the ages of 1 and 7 days and at 1 and 4 months, as well as 7 months in term infants. RESULTS: Urinary UA levels were lowest on day 7 in term infants. The levels were highest on day 1 in premature infants and remained significantly higher compared to term babies during the first month of life. Respiratory failure requiring ventilation and oxygen supply resulted in further significant elevation of urinary UA in premature infants. CONCLUSIONS: With the reference values obtained in the study reported here, urinary UA can now be used for the diagnosis and monitoring of inherited disorders of purine metabolism and for the assessment of oxygen radical insult to sick infants.

Age Factors↗