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Biomedical subjects

M Sudo

Publications and source records attributed to M Sudo.

At least 199 records · Page 11Linked to original sources

[Development of a system for monitoring the production of leukotriene B4, C4, D4 and E4 in whole blood of pediatric asthmatic patients].

We have developed a new method using a computerized photodiode-array spectrophotometer (CPAS), to characterize the biosynthesis and the inhibition of leukotriene (LT) B4, C4, D4 and E4 in calcium ionophore (Ca-I)-stimulated whole blood. The results obtained were as follows: 1. The use of CPAS enabled us to identify and measure LTs from 2 ml volume of Ca-I stimulated whole blood as well as to check the purity of LTs, without any use of radioimmunoassay or bioassay. 2. LTC4 produced in whole blood was almost completely converted to LTE4 after 80 min incubation, and at this time both the production of LTE4 and LTB4 reached a plateau and remained constant thereafter. 3. Azelastine added in vitro caused a dose-dependent inhibition of Ca-I stimulated LTB4 and LTE4 production with an IC50 of 10 microM.

Adolescent↗

[MR imaging in infantile spasms].

CT and MRI in 13 patients with infantile spasms were analyzed. Cortical atrophy was found in 8 cases and ventricular dilatation in 9 cases. The patients with severe cortical atrophy or ventricular dilatation had poorer prognosis than the patients with normal CT findings. In addition to cortical atrophy and ventricular dilatation which were shown in CT, MRI revealed poor differentiation of gray and white matters in all cases and periventricular hyperintensity area in 9 patients. Six patients with the periventricular hyperintensity area of grade III and IV had severe developmental delay. With regard to the prognosis, MRI plays a more useful role in detecting intracranial pathology in infantile spasms.

Brain↗

Occurrence of 9-deoxy-delta 9,delta 12-13,14-dihydroprostaglandin D2 in human urine.

We have developed a highly sensitive and specific solid-phase enzyme immunoassay for 9-deoxy-delta 9,delta 12-dihydroprostaglandin D2 (delta 12-PGJ2) and studied the occurrence of this novel PGD2 metabolite in human urine. The assay detected delta 12-PGJ2 over the range of 2-200 pg, and the antiserum showed 2% cross-reaction with PGJ2 and less than 0.2% with other PGs. We used this assay and purified the delta 12-PGJ2-like immunoreactive substance from human urine. Purification consisted of chromatographies on a Sep-Pak C18 cartridge, a silicic acid column, reversed-phase high-performance liquid chromatography, and finally an affinity column of anti-delta 12-PGJ2 antibody. As a result, about 850 ng of delta 12-PGJ2-like immunoreactive substance were recovered from 60 liters of human urine. The purified material was identified as delta 12-PGJ2 by gas chromatography/high resolution-selected ion monitoring using the molecular ion m/z 448[M]+. and ions [M - 15]+, [M - 43]+, [M - 100]+., and [M - 143]+. The amounts of delta 12-PGJ2 in the urine from normal, volunteer men and women were 151.5 +/- 20.0 and 65.6 +/- 5.4 ng/24 h (mean +/- S.E., n = 5), respectively. The delta 12-PGJ2 amount in urine did not alter significantly during storage for at least 24 h or by the addition of authentic PGD2 to urine samples, suggesting that the delta 12-PGJ2 we determined was not derived from the decomposition of PGD2 in the urine during storage or purification. Moreover, when a single dose of PGD2 (1 mg/kg) was injected intravenously into cynomolgus monkeys, the urinary level of delta 12-PGJ2 increased 20- to 180-fold over the normal levels, whereas the delta 12-PGJ2 level decreased by 40-50% of the normal levels, following the administration of indomethacin at a dose of 1 mg/kg. These results indicate that delta 12-PGJ2 is formed naturally in the body and excreted as a urinary PGD2 metabolite.

Adult↗

Hypothalamic-pituitary function in growth hormone-deficient patients with pituitary stalk transection.

We compared 1.5 T magnetic resonance (MR) image findings with hypothalamic-pituitary function in 11 patients with idiopathic pituitary dwarfism, each of whom had a history of perinatal abnormalities, and 1 patient with posttraumatic pituitary dwarfism. MR imaging revealed transection of the pituitary stalk in all patients and the formation of an ectopic posterior lobe at the proximal stump in 9 patients, none of whom had polydipsia or polyuria. Three patients without an ectopic posterior lobe had diabetes insipidus. The 5 patients who had small pituitary glands (less than 2 mm in height) had hypothyroidism with low serum TSH concentrations and low serum cortisol responses to insulin-induced hypoglycemia; however, 7 patients with normal-sized pituitary glands had normal thyroid and adrenal function. The serum GH response to GHRH did not correlate with the size of the pituitary gland. The patients with small pituitary glands had delayed or prolonged serum TSH responses to TRH and impaired serum LH and FSH responses to GnRH; 4 of the patients with normal-sized pituitary glands had normal serum TSH, LH, and FSH responses. Only 2 patients had high basal serum PRL concentrations. The endocrinological data suggest that reestablishment of the hypothalamo-hypophyseal portal circulation, which cannot be seen by MR imaging, may occur. We suggest that the primary cause of idiopathic pituitary dwarfism in many patients is injury to the pituitary stalk at birth.

Adolescent↗

Eosinophilic leucocytes and arylsulfatase activity in bronchoalveolar lavage fluid of patients with bronchial asthma.

The arylsulfatase activity and histamine concentration of bronchoalveolar lavage fluid (BALF) were examined in patients with bronchial asthma in relation to the eosinophil count and asthma type (atopic and non-atopic). The BALF arylsulfatase activity and histamine concentration were significantly higher in atopic asthmatics than in non-atopic asthmatics. In atopic asthmatics, the activity of arylsulfatase was significantly increased in patients with a higher eosinophil count (10% or more). However, the BALF histamine concentration did not correlate with the eosinophil count. In non-atopic asthmatics, there was no significant correlation between arylsulfatase activity and the eosinophil count. The results show that arylsulfatase participates in IgE-mediated allergic reactions.

Adult↗

Percutaneous renal biopsy well-visualized by orthogonal ultrasound application using linear scanning.

We attempted 24 percutaneous renal biopsies under orthogonal ultrasonic guidance in 23 children with renal diseases aged 1 to 17 years old. We used a 5 MHz linear-array transducer which was positioned on the side of the abdomen and aligned parallel to the biopsy needle so that projected ultrasound reaches the needle orthogonally. Thus, we could clearly and continuously monitor the biopsy needle and transverse plane of the kidney during the biopsy. We obtained diagnostically sufficient renal specimens in all subjects and found no significant complications, including macroscopic hematuria, in any case. We found that our method simultaneously visualized the biopsy needle and kidney much more clearly and made the biopsy far easier and safer than any other method previously proposed and we recommend the procedure be widely used in adult as well as child patients.

Adolescent↗

High levels of antibodies to streptococcal cell membrane antigens specifically bound to monoclonal antibodies in acute poststreptococcal glomerulonephritis.

We produced 15 immunoglobulin G class monoclonal antibodies against antigens of the streptococcal cell membrane (SCM) of Streptococcus pyogenes (T type 12, Tanaka strain) and determined the levels in human sera of antibodies against Triton-X-extracted antigens specifically bound to each of these 15 monoclonal antibodies by enzyme-linked immunosorbent assay. Sample sera were obtained from 10 normal controls (group 1), 10 patients with streptococcal pharyngitis without sequelae (group 2), and 8 patients with acute poststreptococcal glomerulonephritis (APSGN) (group 3). Anti-streptolysin O (ASO) titers of the sera increased in the order of groups 1, 2, and 3. There was no relationship between ASO titer and the level of anti-SCM antibodies, and there was no significant difference in the level of anti-SCM antibodies determined with each of the 15 monoclonal antibodies between group 1 and group 2 sera. Group 3 sera had higher levels of antibodies to SCM antigens specifically bound to each of 14 of these 15 monoclonal antibodies than group 1 or group 2 sera did. Of these 14 monoclonal antibodies, 9 reacted with the four SCM antigens separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and electrophoretically transferred to a nitrocellulose sheet. These results suggest that high levels of antibodies to SCM antigens are related to the development of APSGN and that the systemic immune response to SCM antigens is involved in the pathogenesis of APSGN.

Acute Disease↗

[Effects of clonidine on the levels of cyclic nucleotides in rat brain regions: the change in cyclic nucleotides after clonidine alone or in combination with alpha-antagonists].

The following 4 Wistar rat groups were sacrificed by microwave irradiation after measuring blood pressure and heart rate: 1) saline control (1 ml/kg, i.v.), 2) clonidine alone (50 micrograms/kg, i.v.). 3) prazosin pretreated (0.1 mg/kg, i.v.), 4) yohimbine pretreated (1 mg/kg, i.v.). Cyclic nucleotides were analyzed in seven brain regions. Clonidine decreased blood pressure and heart rate 20 min after administration. These effects of clonidine were inhibited by yohimbine. Clonidine increased the levels of cyclic AMP in the medulla oblongata (including pons) and hypothalamus. Prazosin attenuated the cyclic AMP-increasing action of clonidine in the cerebellum. Yohimbine inhibited this action of clonidine in the cerebellum, striatum and hippocampus. Clonidine reduced cyclic GMP levels in the hypothalamus and striatum. Prazosin potentiated the cyclic GMP-reducing action of clonidine in the medulla oblongata. Yohimbine attenuated this action of clonidine in the medulla oblongata and hypothalamus. From these results, it is concluded that clonidine changes the levels of cyclic nucleotides in brain regions, especially in the part of the autonomic nervous center. In addition, it is indicated that alpha 1- or alpha 2-adrenoceptor plays a different role in the regulation of brain cyclic nucleotides, region by region.

Animals↗

Failure to induce puberty in a man with X-linked congenital adrenal hypoplasia and hypogonadotropic hypogonadism by pulsatile administration of low-dose gonadotropin-releasing hormone.

To elucidate the mechanism of hypogonadotropic hypogonadism in a patient with X-linked congenital adrenal hypoplasia, we studied the effects on serum LH and FSH of repeated iv administration of GnRH (400 micrograms, over 2 h, once a day, for 14 consecutive days), pulsatile sc administration of GnRH (5 micrograms every 90 min during days 1 approximately 56, 10 micrograms every 90 min during days 57 approximately 91) and an iv bolus injection of 10 mg of naloxone. The repeated administration of GnRH restored the hyporesponsiveness of serum FSH and increased serum testosterone level from less than 1.0 to 1.7 nmol/l, but the impaired LH response to the standard GnRH test was not improved. The pulsatile administration of GnRH for 91 consecutive days did not induce a clinical or a biochemical change of puberty. Serum testosterone remained undetectable less than 1.0 nmol/l, the hyporesponsiveness of serum LH was not improved, but basal FSH level was significantly increased and the impaired FSH response to the standard GnRH test was slightly improved. Naloxone had no effect on serum LH or FSH before or during the pulsatile administration. We conclude that hypogonadotropic hypogonadism in our patient is due to the pituitary dysfunction and that the endogenous opioid peptides may not play a role in the mechanism of inhibited gonadotropin secretions.

Adolescent↗