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Biomedical subjects

K Seo

Publications and source records attributed to K Seo.

At least 91 records · Page 5Linked to original sources
PubMed1991

Interleukin 4-mediated induction of CD4+/CD8+ T cells during infancy.

Neonatal human CD4+ T cells will co-express CD8 on their surface following short-term culture with interleukin 4 (IL-4). Adult T cells do not respond in this manner. In this study we examine this phenomenon as a function of age and determine that IL-4 responsiveness decreases with time to approach adult levels at about 2 years. This phenomenon may be relevant to the documented ability of neonatal CD4+ T cells to function as suppressors.

Adolescent↗
PubMed1991

[Pharmacokinetic and clinical evaluation of cefpirome in the pediatric field].

We conducted a pharmacokinetic and clinical study on cefpirome (HR 810, CPR), an aminothiazolylmethoxyiminoacetamido cephalosporin (ATOIC), and obtained the following results. 1. Concentrations in blood/excretion in urine. We studied pharmacokinetic in children upon intravenous bolus injections and 30-minute and 1-hour intravenous drip infusions in single dosages of 10, 20, and 40 mg/kg, and obtained virtually the same results as those found in adult subjects. Upon intravenous bolus injections, mean blood concentrations 30 minutes after administration of 10, 20, and 40 mg/kg were 26.1, 47.8, and 82.8 micrograms/ml, respectively, and half-lives were 1.13, 1.43, and 1.26 hours, respectively. Upon 30-minute intravenous drip infusion, mean blood concentrations on completion of the drip infusions of 10, 20, and 40 mg/kg were 43.2, 106.9, and 163.0 micrograms/ml, respectively, and half-lives were 1.15, 1.09, and 1.15 hours, respectively. In addition, upon 1-hour intravenous drip infusion, mean blood concentrations on completion of infusion were 27.1 micrograms/ml for 10 mg/kg and 47.5 micrograms/ml for 20 mg/kg, and half-lives were 1.09 and 1.40 hours, respectively. A clear dose response was observed at all dosages for either administration method. Mean excretion rates in urine in the first 8 hours after administration were 60.6-71.1% upon intravenous bolus injections of 10-40 mg/kg, and upon intravenous drip infusion, the values were 50.2-83.8% for administration of 10-40 mg/kg 6 or 7 hours after completion of drip infusion. 2. Concentrations in the cerebrospinal fluid Penetration into the cerebrospinal fluid was studied in 2 subjects, and a concentration of 0.28-5.19 micrograms/ml was observed upon administration of 50 mg/kg, a moderate degree of penetration compared to the penetration of cephalosporins of group 5 studied up to now. 3. Clinical results Evaluation of clinical effects of CPR on various types of bacterial infections was conducted in 56 subjects, excluding 3 subjects who had diseases which were excluded from the study. The breakdown was as follows: 3 cases of meningitis, 1 case of septicemia, 25 cases of bronchial pneumonia, 1 case each of tonsillitis and infection of the external acoustic meatus, 2 cases each of scarlet fever and phlegmon, 8 cases each of lymphadenitis and urinary tract infections, and 5 cases of staphylococcal scalded skin syndrome. Results of excellent or good were obtained in 54 subjects for an efficacy rate of 96.4%.(ABSTRACT TRUNCATED AT 400 WORDS)

Absorption↗
PubMed1990

Cervicovaginal microflora and pregnancy outcome: results of a double-blind, placebo-controlled trial of erythromycin treatment.

Available information suggests that some instances of preterm birth or premature rupture of membranes are associated with clinically unrecognized infection and inflammation of the lower uterine segment, decidua, and fetal membranes. Various cervicovaginal microorganisms have been recovered from these sites. Many of these microorganisms produce factors that may lead to weakening of the fetal membranes, release of prostaglandins, or both. This study evaluated the presence of various lower genital tract microflora and bacterial conditions in 229 women enrolled in a double-blind, placebo-controlled trial of short-course erythromycin treatment at 26 to 30 weeks' gestation to prevent preterm birth. Demographic, obstetric, and microbiologic parameters were prospectively evaluated. Premature rupture of membranes occurred less frequently (p less than 0.01) among women who received erythromycin (6%) versus placebo (16%). Preterm premature rupture of membranes also occurred less frequently, although not significantly (p = 0.3) in patients who received erythromycin (2%) versus placebo (5%). Erythromycin treatment significantly decreased the occurrence of premature rupture of membranes among women who were initially positive for Chlamydia trachomatis infection. Logistic regression analysis demonstrated that C. trachomatis (p = 0.05; odds ratio, 9), vaginal wash phospholipase C (p = 0.08; odds ratio, 6) and prior preterm birth (p = 0.007; odds ratio 17) were associated with increased risk of preterm birth. Bacterial vaginosis, Mycoplasma hominis, Ureaplasma urealyticum were not significantly associated with increased risk of preterm birth or preterm rupture of membranes. These findings support a role for selected lower genital tract microflora in preterm birth and premature rupture. Large controlled treatment trials of specific infections or conditions associated with preterm birth and premature rupture of membranes are required to confirm the value of antimicrobial treatments in prevention of microbial-associated preterm birth.

Adolescent↗
PubMed1990

Cross-reactive polysaccharide antigens (types a, d, and h) of the mutans group of streptococci: different molecular forms of the type as distinguishable by monoclonal antibodies.

As compared to the previous precipitin inhibition tests differences were found in the reactivities of monoclonal antibodies (MAbs), a-4 and a-84 with Streptococcus cricetus (serotype a) in an enzyme immunoassay using whole cells, purified cell wall antigen and haptenic sugars coated onto microtitre wells. Investigation into the differences led to the finding that the purified antigen from S. cricetus cells consisted mainly of three forms with different molecular weights and sugar contents. MAb a-4 reacted with a high molecular weight form (AgI, molecular weight of 46,000) and low molecular weight forms (AgII and AgIII, molecular weights of 9,800 and 20,000, respectively) whereas MAb a-84 reacted only with the high-molecular form. Gas chromatographic analysis revealed that all antigens contained rhamnose, galactose and glucose but in different ratios of the sugars. Although the binding site of AgII/AgIII with MAb a-4 seemed to be slightly different from that of AgI with MAb a-84, the predominant immunodeterminant of the antigens was considered to be the same. On the basis of these results, the chemical structures of the antigenic determinants are suggested. The nature of the antigen-antibody reactions is discussed.

Antibodies, Monoclonal↗
PubMed1990

A side reaction in solid phase synthesis. Insertion of glycine residues into peptide chains via Nim----N alpha transfer.

In solid-phase peptide synthesis using N alpha-Boc-Nim-tosyl-histidine (Boc-His(Tos)), byproducts having extra Gly residues in the peptide chain were observed at a high rate. When a Boc-amino acid such as Asn was incorporated after assembly of Boc-His(Tos), the Nim-tosyl group was partially or fully cleaved by an activating agent, 1-hydroxybenzotriazole. In the successive coupling reactions, Boc-Gly was incorporated into the free Nim ring as well as the alpha-amino function, and the Nim-Gly was then transferred to the alpha-amino group of Gly of the peptide chain after removal of these Boc groups to give extra Gly residues at the position of Gly. This was observed in only the coupling reaction with Boc-Gly and could be circumvented using a more stable Nim protecting group for His, such as a dinitrophenyl group.

Amino Acid Sequence↗
PubMed1990

Ureteral action potential and histological changes in the upper urinary tract receiving the formalin.

The present study investigates the ureteral action potential and histological changes of pelvi-ureteral system after injection of the formalin into the obstracted ureters or the renal pelvis. In the first experiment, formalin was injected into the obstructed ureters of 18 dogs for 30 minutes. In the second, formalin was injected into the obstracted renal pelvis of 13 dogs for 30 minutes using ureteral balloon catheters, and then renal pelvis were released from obstraction and catheters were removed. In these experiments, ureteral electromyogram were recorded and histological changes of pelvi-ureteral system were also observed microscopically. Results 1. After injection of formalin into the ureters, ureteral action potential disappeared and had not restored. Histologically, damage was observed in the ureteral smooth muscle as well as in the mucosa. 2. After injection of formalin into the renal pelvis, ureteral action potential disappeared in 46% of the ureters. In 54% of the ureters, action potential had not disappeared, however discharge interval became irregular. Histological changes of the renal pelvis was not related to the presence or absence of ureteral action potential. The results of the present study show that ureteral smooth muscle play part in the conduction of the ureteral excitation, and have an irregular autonomic discharge.

Action Potentials↗
PubMed1990

[Studies on function of the upper urinary tract. XXIX. Canine ureteral electromyogram isolated from "so-called Pacemaker"].

Many workers have reported that ureteral peristaltic movement is controlled by the "so-called Pacemaker". But, in our recent studies, it was revealed that the existence of pacemaker is not always necessary for the peristaltic movement. In this study, we made isolated and non-isolated prototype models, using 18 mongrel dogs, to explore the influential factors on ureteral peristaltic discharge. Bilateral kidney and ureter were exposed transperitoneally. Unilateral upper urinary tract was prepared to preserve the pacemaker without renal blood supply, and contralateral one was prepared not to preserve the pacemaker by cutting at the proximal portion of the ureter. Vesico-ureteral reflux (VUR) was caused on these two models. A luminal pressure and ureteral electromyogram was recorded. In the result, there is spontaneous peristaltic discharges of the ureter which had the tendency to increase peristaltic frequency according to the increase of the luminal pressure. It was suggested that adequate expanding stimulation is the factor of peristaltic discharge to increase, and the peristaltic discharge under this condition propagates from upper to lower portion of the ureter.

Action Potentials↗
PubMed1990

Removal of adherent bacteria from catheter materials in vitro by N-acylated amino acids.

Indwelling urinary catheters may act as a reservoir of bacteria and cause urinary tract infections. Removal of the bacteria adherent to a urinary catheter should reduce the incidence of catheter-associated urinary tract infections. Using several N-acylated amino acids with combinations of four different acyl residues, we investigated their efficacy in removing adherent bacteria from catheter materials in vitro. Among them, acyl phenylalanine and acyl glycine (with acyl lengths of eight or ten) exhibited the highest ability to remove adherent bacteria.

Amino Acids↗
PubMed1990

[Pharmacokinetic and clinical evaluation of aztreonam in neonates and premature infants].

In order to study serum concentration and urinary concentration (urinary recovery rate) of aztreonam (AZT), AZT was administered via intravenous bolus injection at dose levels of 10 mg/kg, 20 mg/kg and 50 mg/kg to 7 cases of 4 to 26 days old mature or premature infants nearing cure-stage of various bacterial infections upon the treatment with AZT. Clinical evaluation was made in 19 cases with therapy with AZT alone and 13 cases with combination therapy with AZT + ampicillin (ABPC), with a total of 32 cases. The former group included 10 males and 9 females of 0 to 43 days of age and the latter group included 7 males and 6 females of 6 to 41 days of age. All the cases treated with AZT alone including 5 cases for prophylaxis were evaluable. In the 13 combination therapy cases, however, the effect of AZT was evaluable only in 3 cases excluding the cases in which ABPC-susceptible bacteria were the culprits. 1. Changes in serum concentrations and urinary recovery of AZT. Pharmacokinetics of AZT in serum was examined in 5 matured infants at dose levels of 10 mg/kg in 2 cases and 20 mg/kg in 3 cases. Highest levels were observed with the first sampling at 30 minutes after administration in all the cases with values of 29.1 micrograms/ml with 10 mg/kg dose, and 37.8 micrograms/ml and 55.5 micrograms/ml with 20 mg/kg dose in in cases with ages between 4 and 7 days and 1 case with age above 8 days, respectively. Half-life (T 1/2) values were 3.42, 3.05 and 1.58 hours, respectively for the above three groups of patients. As is described here, the T 1/2 value in the infant with age above 8 days was considerably shorter than the T 1/2 values in infants of younger day-ages. Urinary recovery rates of administered AZT were between 10.4 and 52.6%, showing a large individual diversity. In addition to the above cases, one premature infant was administered with AZT (the dose level: 50 mg/kg) and examined for pharmacokinetic parameters at day-ages of 11 days and 19 days. Serum levels of AZT examined were the highest at 30 minutes after dosage (the first sampling) and were 106.8 micrograms/ml at 11 days of age, and 90.4 micrograms/ml at 19 days of age. Serum levels decreased to 16.2 and 9.6 micrograms/ml, respectively, in 8 hours after dosage, at ages of 11 and 19 days. T 1/2 values were 2.62 and 2.35 hours, respectively.(ABSTRACT TRUNCATED AT 400 WORDS)

Ampicillin↗
PubMed1990

Quantitative analysis of experimental peritumoral edema in cats.

Cat brain tumors were produced by stereotactical xenotransplantation of rat glioma clone F98 into the internal capsule of the left hemisphere. Two to four weeks after implantation, the tissue content of water, sodium, potassium, calcium, magnesium, serum albumin, serum immunoglobulin, and hemoglobin was measured in samples taken from the tumor, from peritumoral white and gray matter, and from homotopic regions of the opposite hemisphere. Extravasated serum protein content was determined by subtracting intravascular from total tissue protein, using the hemoglobin content as a marker of blood volume. The development of brain tumors was accompanied by severe vasogenic brain edema, which was clearly confined to the ipsilateral white matter. The increase of water was paralleled by an increase of sodium, calcium, and serum proteins. Potassium and magnesium content remained constant. The calculated sodium and calcium content of edema fluid approximated that of blood serum. The content of blood proteins was about 50% lower, but the ratio of albumin/immunoglobulin was the same as in blood. It is concluded that peritumoral edema is a combination of plasma ultrafiltrate and whole plasma extravasation with different modes of formation. Implications for the pathophysiology and therapy of peritumoral edema are discussed.

Animals↗
PubMed1989

Directional immobilization of sodium- and potassium-activated ATPase to expose its cytoplasmic part to the liquid phase on microtiter plates by wheat germ agglutinin.

A convenient method for highly efficient and directional immobilization of intact sodium- and potassium-activated ATPase (Na,K-ATPase) using wheat germ agglutinin linked on microtiter plates was developed. Wheat germ agglutinin, which bound tightly to the beta-subunit of Na,K-ATPase and had no effect on the Na,K-ATPase activity, the potassium-activated p-nitrophenylphosphatase activity, or the inhibitory action of ouabain, was covalently linked to microtiter plates and used as an immobilizer of the enzyme. The amount of Na,K-ATPase coupled to microtiter plates in this immobilizing system was more than 10-fold greater than that used in the direct immobilizing system (O. Urayama, M. Nakao, H. Nagamune, and H. Sugiyama, (1984) Anal. Biochem. 141, 194-198). Also in this system, the cytoplasmic domain of Na,K-ATPase was exposed to the liquid phase. This technique was useful for investigating the reactivities of monoclonal antibody specific for the cytoplasmic domain of the enzyme. Moreover, because this technique was used successfully in the immobilization of periodic acid--Schiff positive staining glycoprotein 1 prepared from human erythrocytes and human alpha 2-macroglobulin, the technique should also be useful for other membrane or secreted proteins that possess N-linked sugar chains containing bisecting N-acetylglucosamine or a high amount of sialic acid.

Animals↗
PubMed1989

Experimental transplantation gliomas in the adult cat brain. 2. Pathophysiology and magnetic resonance imaging.

In adult cats experimental brain tumours were produced by stereotactical xenotransplantation of the rat glioma clone F 98 into the internal capsule of the left hemisphere. Two to four weeks after transplantation tumours and peritumoural oedema were investigated by magnetic resonance imaging (MRI), electrophysiological recording and analysis of tissue content of water, electrolytes and extravasated serum proteins. Spherical tumours with a diameter of about 10 mm developed at the injection site and were surrounded by massive white matter oedema. Water content in peritumoural white matter increased from 2.63 +/- 0.17 to 3.65 +/- 0.19 ml/g d.w. (means +/- SD), sodium from 187 +/- 11 to 351 +/- 55 mueq/g d.w. and calcium from 7.4 +/- 1.1 to 13.3 +/- 1.3 +/- 1.3 mueq/g d.w. Potassium and magnesium did not change. Oedema development was associated with the extravasation of 18.0 +/- 16.8 mg/g d.w. albumin and 15.8 +/- 12.2 mg/g d.w. immunoglobulin. The calculated electrolyte content of oedema fluid approximated that of plasma but the serum protein content was about 40% lower. The ratio of low (albumin) to high (immunoglobulin) molecular weight proteins was the same in blood and oedema fluid. It is, therefore, concluded that peritumoural oedema consist of two components, a whole plasma extravasate and a protein-free ultrafiltrate. Peritumoural oedema could be clearly detected by MRI but differentiation between tumour and oedema was only possible after contrast enhancement with gadolinium-DTPA. The ratios of the intensities of the MR signal correlated linearly with the water content within white matter. MRI, in consequence, allows quantification of oedema provided a reference area with normal water content is present.

Animals↗
PubMed1989

Experimental transplantation gliomas in the adult cat brain. 3. Regional biochemistry.

Experimental brain tumours were produced in adult cats by stereotactic xenotransplantation of the rat glioma clone F98. Regional ATP, glucose and lactate were measured after 2-4 weeks on coronal cryostat sections by substrate-induced bioluminescence, potassium content was imaged by the histochemical sodium cobaltinitrite method, and regional pH by incubating cryostat sections with the fluorescent pH-indicator umbelliferone. The regional biochemical alterations were correlated with magnetic resonance imaging and tissue water content. Biochemical changes were heterogeneous in tumours but exhibited a rather uniform pattern in peritumoural oedema. ATP was consistently reduced, glucose and lactate were increased and pH was more alkaline than in normal white matter. The decrease of ATP matched the increase of water, indicating that ATP decline represents fractional dilution in the oedematous tissue rather than break-down of energy metabolism. The increased lactate levels, therefore, may originate from the tumour and not from a metabolic disturbance in the peritumoural oedematous tissue. The implications of this interpretation for the pathogenesis of peritumoural oedema are discussed.

Adenosine Triphosphate↗
PubMed1989

Effect of barbiturate treatment on post-ischemic protein biosynthesis in gerbil brain.

The effect of barbiturate treatment on post-ischemic cerebral protein biosynthesis was studied in gerbils subjected to 5 min transient occlusion of carotid arteries followed by 2 h or 48 h recirculation. Ischemia induced a remarkable decline of amino acid incorporation into brain proteins in most forebrain structures. The initial inhibition recovered to near normal after 2 days recirculation in all regions except the vulnerable CA1 sector. Barbiturate treatment, which previously has been shown to prevent delayed neuronal death in CA1 sector, did not ameliorate the initial inhibition of protein synthesis but it significantly improved subsequent recovery, especially in the vulnerable CA1 sector of hippocampus. These observations indicate that delayed neuronal death in CA1 sector of hippocampus results from selective failure of post-ischemic recovery and not from selective ischemic injury of the protein synthesizing machinery. This explains that delayed neuronal death can be prevented by therapeutic interventions which are initiated during the post-ischemic recirculation phase.

Animals↗
PubMed1989

[A case of congenital absence of the right coronary aortic cusp].

A 12-year-old boy with absence of the right coronary cusp underwent aortic valve replacement with a 21 mm St. Jude Medical prosthetic valve. He was known to have noncyanotic congenital heart disease at the age of 2 months. The diagnosis of aortic insufficiency was first made when he was 1 1/4 years old. Intensive medical treatment was continued while he was growing up. Cardiac catheterization was performed repeatedly at ages 3 1/2 and 7. The findings on the fourth cardiac catheterization at 12 years of age were pulmonary arterial pressure of 90/60 mmHg, left ventricular end-diastolic pressure of 25 mmHg and poor contraction of the left ventricle. Although IABP support was necessary for treatment of severe low cardiac output state in the early postoperative period, he was discharged at 1 month after operation, Now, he goes to school under anticoagulant therapy. Intensive medical care followed by elective aortic valve replacement may be a useful treatment for isolated congenital absence of the aortic valve cusp.

Aortic Valve↗