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Biomedical subjects

M Sudo

Publications and source records attributed to M Sudo.

At least 55 records · Page 3Linked to original sources
PubMed1999

Soft-wall reconstruction of posterior canal wall for surgery of noninflamed ears: a preliminary report.

OBJECTIVE: To test whether the posterior external auditory canal (EAC) wall reconstructed only by soft tissues retracts after surgery in the noninflamed ear. STUDY DESIGN: The condition of the posterior EAC wall was observed for more than 1 year after surgery in 20 noninflamed ears in which only the posterior EAC wall skin was preserved or in which the wall was reconstructed only by soft tissue during surgery. PATIENTS: Eighteen patients (20 ears) underwent ear surgery for conditions other than otitis media, including ossiculoplasty in 12 ears, cochlear implant in 3, resection of congenital cholesteatoma in 4, and resection of glomus tympanicum tumor in 1. RESULTS: Retraction of the soft posterior EAC wall was observed in only 1 of the 20 ears. In this ear, the posterior EAC wall showed only a slight retraction without any serious problems. Computed tomography revealed that mastoid aeration recovered in all 20 ears. CONCLUSIONS: In noninflamed ears, surgeons can remove the bony posterior EAC wall if necessary, and may not need to reinforce or reconstruct the wall with hard tissue. This enables surgeons to spare time and energy and obtain the same advantages as in the intact-canal-wall technique or canal wall reconstruction by a hard material.

Adolescent↗
PubMed1998

Pathophysiological and therapeutic considerations of otitis media with effusion from viewpoint of middle ear ventilation.

Using nitrous oxide, we examined the gas exchange function through the middle ear mucosa in ears with otitis media with effusion (OME) in children, and found the function to be impaired in 50% of them. The size of the mastoid was significantly smaller in ears with negative gas exchange function than those with positive function, and the presence or absence of the function was even more significantly correlated with the presence or absence of aeration in the middle ear. Furthermore, the presence or absence of aeration in ears with OME was found to be significantly correlated with their prognosis (response of OME to antibiotics treatment) and also with the presence or absence of eardrum mobility examined by a pneumatic otoscope. Finally, after myringotomy and removal of effusion, the gas exchange function recovered in most of the ears with impaired function. These results indicate that the eardrum mobility test may serve as an appropriate indicator for the surgical treatment for OME.

Child↗
PubMed1998

Intraoperative QRS-interval changes caused by hyperkalaemia in an infant with Arima syndrome.

A one-year-and-ten-months-old male infant with Arima syndrome, a very rare genetic disorder, underwent urgent insertion of a catheter for continuous ambulatory peritoneal dialysis (CAPD) under general anaesthesia. During the procedure he showed QRS-interval changes caused by hyperkalaemia which was successfully treated with calcium gluconate. The management and intraoperative complications of this syndrome are reported and available literature reviewed.

Abnormalities, Multiple↗
PubMed1998

Postnatal development of Eustachian tube: a computer-aided 3-D reconstruction and measurement study.

The postnatal development of the Eustachian tube (ET) and its surrounding structures was investigated by means of computer-aided three-dimensional (3-D) reconstruction methods in 13 normal human temporal bones, obtained from individuals 3 months to 71 years old. The cross-sectional area, width and height of the lumen in most of the cartilaginous portion of the ET were significantly smaller in children than in adults. In particular, there was a marked, age-associated difference in the shape of the lumen in the cartilaginous portion of the ET. In adults, the cross-sectional area of the lumen declined monotonically between a large opening at the pharyngeal orifice and the narrowest portion of the ET (near the border of the cartilaginous and junctional regions). In children, by contrast, the ET lumen was uniformly smaller over the first 80% of its length from the pharyngeal orifice. It is suggested that this immature morphology of the ET lumen may confer increased risk of developing otitis media during childhood.

Adolescent↗
PubMed1998

Initial recombination in a parallel-plate ionization chamber exposed to heavy ions.

For exact determination of absorbed dose in heavy-ion irradiation fields which are used in radiation therapy and biological experiments, ionization chambers have been characterized with defined heavy-ion beams and correction factors. The LET (linear energy transfer) dependence of columnar recombination in a parallel-plate ionization chamber has been examined. Using 135 MeV/u carbon and neon beams, the ion collection efficiency was measured for several gases (air, carbon dioxide, argon and tissue-equivalent gas). 95 MeV/u argon beams and 90 MeV/u iron beams were also used for measurements of columnar recombination in air. As expected by Jaffe theory, the inverse of the ratio of the ionization charge to the saturated ionization charge had a linear relationship with the inverse of the electric field strength in the region below 0.002 V(-1) cm. The gradient of the line increases as the LET of the heavy ions increases. A strong LET dependence of the gradient was observed in air and carbon dioxide. The LET dependence was not observed in tissue-equivalent gas, nitrogen or argon. The exact depth-dose distribution of the heavy-ion beam was obtained by this correction of the initial recombination effect for the collected ionization charge. The columnar recombination in air was analysed using Jaffe theory; the obtained parameter b (a track radius) should be in the range between 0.001 cm and 0.005 cm, whereas the value obtained by Jaffe is 0.00179 cm. The value of the parameter b should increase as the LET of the heavy-ion beam increases in order to reproduce the experimental values of the initial recombination.

Air↗
PubMed1998

Three-dimensional reconstruction and measurement study of human eustachian tube structures: a hypothesis of eustachian tube function.

Histologic sections from nine temporal bones with eustachian tubes (ETs) attached were analyzed with a computer-aided three-dimensional reconstruction method to determine the curvature and tilt of the ET and the anatomic relationships between the medial lamina of the ET cartilage, the levator veli palatini muscle (LVPM), and Rosenmüller's fossa. It was found that the ET is convex superomedially and is tilted medially. The LVPM is located inferolateral to the inferior margin of the medial lamina of the anterior ET cartilage. The LVPM is inferior to the medial lamina of the posterior ET cartilage. These findings suggest that the LVPM opens the anterior cartilaginous portion of the ET by rotating the medial lamina with increased dimension of the muscle body when it contracts. Rosenmüller's fossa extends along the ET with rich lymphoid tissues as far as approximately one half the total length of the ET and very close to the skull base.

Adolescent↗
PubMed1998

[Trends of asthma death among adults in Japan 1992-1994. Analysis of 313 cases reported questionnaires sent to hospitals with more than 100 beds].

The Japan Asthma Death Investigation Committee sent questionnaires to hospitals with more than 100 beds, and studied the clinical characteristics of 313 reported cases who died of asthma between 1992 and 1994. Forty percent of them were at the age between 60 and 79. Deaths of young adults in the twenties tended to increase. One third of the deaths was due to asphyxia. More than half of the patients were classified infectious or mixed type of asthma and 43.9% were graded as severe asthma. The main causes of the fatal asthma attacks were respiratory infections, fatigue and stress. Insufficient education, low compliance, delay in treatment with corticosteroids and other drugs, delay in emergency treatment, past histories of life-threatening attacks and hospitalization due to severe attacks were suggested to be risk factors of adult asthma death. Pulmonary emphysema showed relatively high frequency as a complication.

Adult↗
PubMed1997

Adenovirus-mediated expression of AMPA-type glutamate receptor channels in PC12 cells.

The alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)-type glutamate receptor channels are expressed ubiquitously in brain neurons and mediate fast excitatory neurotransmission. They are composed of four subunits, GluR1, GluR2, GluR3 and/or GluR4. We constructed recombinant adenoviruses encoding rat AMPA receptor subunit cDNAs, GluR1 (AxCAGluR1) and silently mutated GluR2 (AxCAGluR2X) with modified chicken beta-actin promoter and cytomegalovirus immediate-early enhancer. Using these adenoviral vectors, we transferred the GluR1 and GluR2 genes into PC12 cells that possess no functional AMPA receptor channels. PC12 cells infected with these viruses expressed GluR1 and GluR2 RNAs. Immunoblot analysis indicated that the expressed GluR1 and GluR2 proteins were equivalent to those of the rat brain. Functional expression of the AMPA receptor channels was examined using the whole-cell patch clamp technique. In AxCAGluR1-infected cells, the current-voltage (I-V) relationship of response to kainate, a non-desensitizing agonist of AMPA receptors, exhibited a strong inward rectification, indicating the formation of functional GluR1-homomeric channels. In cells infected with both AxCAGluR1 and AxCAGluR2X, the I-V relationship of kainate responses exhibited an outward rectification, indicating the formation of heteromeric GluR1/R2 channels. Immunocytochemical analysis revealed that the AMPA receptor subunit genes were transferred in more than 95% of the infected PC12 cells.

Adenoviridae↗
PubMed1997

Urinary nitrite/nitrate excretion in infancy: comparison between term and preterm infants.

We measured urinary nitrite/nitrate (NOx-) excretion, an index of endogenous nitric oxide formation, in term and preterm infants aged 1 week and 1, 4, 7 months. In normal term infants, urinary NOx excretion increased from 1 week to 1 month and then decreased until 4 months where it stabilized thereafter. Urinary NOx- excretion in preterm infants was significantly higher compared with term infants at 1 week of age. This finding suggests that the nitric oxide pathway in preterm infants may be activated compared with term infants in early life. With the reference values obtained in this study, this urinary marker can now be used for identifying infants with abnormal nitric oxide production.

Aging↗
PubMed1997

Use of ultrasonography in the detection of ureteric reflux in children suspected of having urinary infection.

The present study investigated whether ultrasonography was effective in detecting ureteric reflux in children suspected of having urinary infection. Seventeen children with febrile episodes and pyuria were enrolled. The ultrasound examination revealed ballooning of the renal pelvis during bladder contraction in 4 children, dilatation of the distal ureters in 6, and small kidney in 2. Cystography was performed on the 6 children with these ultrasound abnormalities and 1 child with two episodes of suspected urinary infection. Four children showed reflux. All of the 4 children had been found to have renal pelvic ballooning on ultrasound. None of the 10 children who did not undergo cystography had recurrence of urinary infection or significant bacteriuria during a median follow-up period of 12 months. Thus, scanning during bladder contraction was effective in detecting significant ureteric reflux.

Bacterial Infections↗
PubMed1997

Intermittent trimethoprim-sulfamethoxazole in children with vesicoureteral reflux.

The effectiveness of intermittent low-dose trimethoprim-sulfamethoxazole (TMP-SMZ) for the prophylaxis of recurrent urinary infection is well established in adults. The present study assessed the effectiveness and safety of intermittent low-dose TMP-SMZ in 35 children (24 boys, 11 girls, aged 1 month to 9 years, median age 5 months) with vesicoureteral reflux; 18 children had bilateral reflux. A total of 53 refluxing ureters were graded as I in 2, II in 16, III in 19, IV in 14, and V in 2 cases. The children were given 1 mg/kg body weight of trimethoprim together with 5 mg/kg of sulfamethoxazole at bedtime every other day for 6-50 months (mean +/- SD, 22.9 +/- 11.7 months). None of the boys had a recurrence of urinary infection, while 2 of the 11 girls had a total of 7 recurrences during the prophylaxis period, with a recurrence rate of 0.027 per patient month in girls. Both girls were over 3 years and had a mildly unstable bladder. Transient neutropenia (< 1,000/microliter) developed in 2 infants during the prophylaxis period, but disappeared spontaneously. Intermittent low-dose TMP-SMZ seemed very effective for the prevention of recurrent urinary infection in children with ureteral reflux even of higher grades.

Anti-Infective Agents, Urinary↗
PubMed1997

Experimentally induced acute hyperinsulinemia stimulates endogenous nitric oxide production in humans: detection using urinary NO2-/NO3-excretion.

Insulin-mediated glucose metabolism in skeletal muscle is associated with a proportional increase in muscle perfusion. The vasodilatory effect of insulin is thought to be mediated in part by endothelium-derived nitric oxide (NO). The present study was performed to determine whether acute hyperinsulinemia has any stimulatory effect on endogenous NO production in humans. Bolus intravenous injection of insulin (0.1 IU/kg body weight) caused a significant increase in urinary excretion of NO2-/NO3- together with a significant decrease in blood pressure, whereas saline infusion alone had no effect on these parameters. The increased NO response to insulin was almost comparable to that obtained with infusion of 30 g L-arginine. The acute effect of hyperinsulinemia on endogenous NO formation supports the concept that NO may mediate the vasodilatory action of insulin in humans.

Adolescent↗
PubMed1997

Elimination study of silver in a hemodialyzed burn patient treated with silver sulfadiazine cream.

Silver sulfadiazine (SSD) cream is a potent agent for the treatment of burns. In a patient with end-stage renal disease, we observed a marked elevation in serum silver concentration in the course of 2 weeks of SSD cream therapy (200 g/d). Serum concentration of silver reached a maximum of 291 ng/mL in association with a rapid deterioration of mental status. SSD therapy was discontinued, and hemodialysis, hemofiltration, or plasma exchange was continually performed. Four months later, the patient died. At autopsy, profoundly elevated levels of silver were found in brain tissues of this patient (617.3, 823.7 ng/g wet tissue weight in the cerebrum and cerebellum, respectively). To determine the most efficient therapy to remove silver from serum, we compared hemodialysis (HD), hemofiltration (HF), and plasma exchange (PE). Both plasma exchange and hemofiltration were effective in decreasing serum silver, and their effects were additive. By contrast, HD was ineffective in reducing serum silver. This case illustrates that, on SSD cream therapy, burn patients with disturbed renal function are at risk of accumulating silver in serum and tissue to the level that may cause neuralgic decompensation. Removal of serum silver can best be effected by PE, particularly when combined with HF. In contrast, HD per se does not appear efficacious. None of these blood purification modalities improves deterioration of neurological status potentially attributable to silver deposition in brain tissues.

Adult↗
PubMed1997

Congenitally small kidneys with reflux as a common cause of nephropathy in boys.

Congenital maldevelopment is sometimes found in small kidneys with ureteral reflux. However, the incidence of congenitally small kidneys and the frequency of its association with ureteral reflux remains unknown. Ultrasound scanning, performed in 4,000 apparently healthy neonates or young infants (males 2,129, females 1,871), detected 51 children suspected of having small kidneys. A careful ultrasound re-examination performed one month later in 45 of the 51 children confirmed small kidneys in eight children, one bilateral and seven unilateral. Dimercaptosuccinate (DMSA) renoscintigraphy revealed small kidneys with generally diminished uptake in six infants and no uptake unilaterally in the other two infants. One of the 12 children, who had normal findings on the initial scanning and subsequently developed urinary infection, was later diagnosed having unilateral small kidney with generally reduced DMSA uptake. All seven infants having small kidneys with reduced tracer uptake were male (incidence, 1:300 boys). All eight small kidneys in the seven boys and four of the six contralateral non-small kidneys were associated with ureteral reflux, while neither of the two infants with a non-functioning kidney had ureteral reflux. Serial ultrasounds documented the poor growth of all small kidneys. Thus, congenitally small kidneys with generally diminished DMSA uptake were highly associated with ureteral reflux and especially observed in boys.

Female↗
PubMed1997

Identification of genetic mutations in Japanese patients with fructose-1,6-bisphosphatase deficiency.

Fructose-1,6-bisphosphatase (FBPase) deficiency is an autosomal recessive inherited disorder and may cause sudden unexpected infant death. We reported the first case of molecular diagnosis of FBPase deficiency, using cultured monocytes as a source for FBPase mRNA. In the present study, we confirmed the presence of the same genetic mutation in this patient by amplifying genomic DNA. Molecular analysis was also performed to diagnose another 12 Japanese patients with FBPase deficiency. Four mutations responsible for FBPase deficiency were identified in 10 patients from 8 unrelated families among a total of 13 patients from 11 unrelated families; no mutation was found in the remaining 3 patients from 3 unrelated families. The identified mutations included the mutation reported earlier, with an insertion of one G residue at base 961 in exon 7 (960/961insG) (10 alleles, including 2 alleles in the Japanese family from our previous report [46% of the 22 mutant alleles]), and three novel mutations--a G-->A transition at base 490 in exon 4 (G164S) (3 alleles [14%]), a C-->A transversion at base 530 in exon 4 (A177D) (1 allele [4%]), and a G-->T transversion at base 88 in exon 1 (E30X) (2 alleles [9%]). FBPase proteins with G164S or A177D mutations were enzymatically inactive when purified from E. coli. Another new mutation, a T-->C transition at base 974 in exon 7 (V325A), was found in the same allele with the G164S mutation in one family (one allele) but was not responsible for FBPase deficiency. Our results indicate that the insertion of one G residue at base 961 was associated with a preferential disease-causing alternation in 13 Japanese patients. Our results also indicate accurate carrier detection in eight families (73%) of 11 Japanese patients with FBPase deficiency, in whom mutations in both alleles were identified.

Amino Acid Substitution↗
PubMed1997

Persistent hypercholesterolaemia in frequently relapsing steroid-responsive nephrotic syndrome.

OBJECTIVE: To investigate long-term changes of serum cholesterol levels in children with frequently relapsing steroid-responsive nephrotic syndrome (NS). METHODOLOGY: Serum cholesterol values just before and during or immediately after 'relapse' were reviewed and the incidence of hypercholesterolaemia (> or = 200 mg/dL) was determined in eight patients (M:F, 6:2). RESULTS: The patients with frequently relapsing NS usually showed hypercholesterolaemia (mean incidence, 81%) just before 'relapse' during clinical remission, as well as in relapse (mean incidence, 96%). A high incidence of steroid therapy was also found in each case (mean, 89%) just before relapse. CONCLUSIONS: Our results demonstrate that children with frequently relapsing NS have prolonged periods of hypercholesterolaemia, even during clinical remission. It is suggested that serum lipid profiles be monitored carefully in such patients.

Adolescent↗
PubMed1997

Early detection of prune belly syndrome in utero by ultrasonography.

A report is presented of a male infant with prune belly syndrome (PBS) in whom bladder enlargement was detected by ultrasound (US) as early as 13 weeks of gestation. Subsequent fetal US identified progressive urinary tract dilatation, ascites and oligohydramnios. At 22 weeks, the fetal bladder was drained under US guidance. A gradual resolution of oligohydramnios was detected on US performed after 26 weeks of gestation. Delivery by cesarean section was performed at 34 weeks of gestation. The newborn had typical features of PBS with a vesico-cutaneous fistula but did not show respiratory distress. Imaging studies showed hypoplastic left kidney, slightly dysplastic but functioning right kidney, megaureter, megacystis, vesicoureteral reflux and dilated prostatic urethra. The early detection of genitourinary system abnormalities and serial US suggest that a distal urethral obstruction may be the underlying mechanism of PBS. Spontaneous (or therapeutic) intra-uterine decompression of the bladder might ameliorate obstructive nephropathy and oligohydramnios, allowing adequate lung development.

Adult↗