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Biomedical subjects

K Oda

Publications and source records attributed to K Oda.

At least 379 records · Page 21Linked to original sources
PubMed1992

Dying back type axonal degeneration of sensory nerve terminals in muscle spindles of the gracile axonal dystrophy (GAD) mutant mouse.

A disorder of the gracile axonal dystrophy (GAD) mutant mouse is characterized by a neuromuscular disease with sensory ataxia (detectable 30 days after birth) and paresis of the hindlimbs (detectable at 80 days). In the sensory ataxia stage, histological study of the primary sensory system shows that, in addition to the lesions in the central nervous system, peripherally projecting axons have also started to degenerate at their distal ends in muscle spindles. Although the structure of Ia fibre endings appear normal until 15 days after birth, initial changes in the annulo-spiral structure are detected around the 20th day by a degeneration of the terminal axons. Degeneration then progressed proximally and the secondary endings also start to degenerate. Neuron cell bodies located in the dorsal root ganglia are morphologically intact until the later stages. Chronological studies indicate that, although axonal degeneration progresses throughout life, it is accentuated during the rapid somatic growth period. Around 50 days of age, transient regeneration takes place at axonal endings when somatic growth has attained a plateau. Such primary sensory endings tend to be restored by fine, multiple axons which gain access to the intrafusal fibres through the original endoneurial tubes. Ultrastructural observations at the fully affected stage show intrafusal muscle fibres lying scattered within spindles due to loss of the fine network of inner capsule layers and an almost complete loss of sensory endings from the surface of intrafusal muscle fibres. These results indicate that this mutant mouse is a useful model for naturally occurring 'dying back' type axonal degeneration or 'central and peripheral distal axonopathies', and would provide significant information about the complete evolution of the pathological processes involved.

Animals↗
PubMed1992

Immunohistochemical study of transforming growth factor beta, fibronectin, and fibronectin receptor in invasive mammary carcinomas.

Thirty-one cases of mammary carcinoma were examined immunohistochemically for the expression of transforming growth factor (TGF) beta, fibronectin (FN) and fibronectin receptor (FNR) in order to clarify the reason for the reported relationship between TGF beta expression and a high incidence of lymph node metastasis. It was revealed that TGF beta expression is closely related to the expression of FN, an intercellular matrix protein, and its cellular receptor FNR, one of the integrins. The interaction between FN and FNR in a tumor is considered to form the basis of the invasive nature of carcinoma cells. Thus, it is suggested that TGF beta expression in carcinoma cells induces the interaction between FN and FNR, which may lead to carcinomatous invasion resulting in lymph nodal metastasis.

Adult↗
PubMed1992

Induction of E1A-responsive negative factors for transcription of the fibronectin gene in adenovirus E1-transformed rat cells.

The level of fibronectin (FN) gene expression is very high in resting rat 3Y1 cells but greatly decreased in adenovirus E1-transformed cells. To study the mechanism of this down-regulation, nuclear factors binding to the 5'-flanking region of the FN gene were analyzed by gel retardation assay and DNase I footprinting. Nuclear factors that were present in the transformed cells but nearly absent in resting 3Y1 cells interacted with multiple sites of the promoter region. Oligonucleotide competition with the FN promoter-chloramphenicol acetyltransferase (CAT) reporter constructs (pFCAT) for these factors in the transformed cells indicated that all of them had a negative effect on FN gene expression. Of them, a factor(s) (G10BP) binding to the G10 stretch from positions -239 to -230 and to two GC boxes consisting of the G10 stretch with one internal C residue insertion from positions -105 to -95 and -54 to -44 had the strongest repressive activity. Introduction of substitutive mutations into these G-rich sequences resulted in the increase in CAT activity of pFCAT in the transformed cells. The recognition sequences of G10BP and Sp1 overlap in two GC boxes. G10BP has stronger affinity for heparin and GC boxes than does Sp1, suggesting that G10BP may repress FN gene transcription by displacing Sp1.

Adenoviridae↗
PubMed1992

E1A-responsive elements for repression of rat fibronectin gene transcription.

The level of fibronectin (FN) gene transcription in resting rat 3Y1 cells is very high but decreases steeply after growth stimulation by serum or by the induction of E1A expression. To study the mechanism of this E1A-mediated down-regulation, the 5' flanking regions of the FN gene with various deletions and substitutions were fused to the Escherichia coli chloramphenicol acetyltransferase (CAT) gene and introduced into resting 3Y1 cells with E1A expression plasmids. The results indicate that the G10 stretch located from nucleotide position -239 to -230 and two GC boxes from position -105 to -95 and position -54 to -44 are the primary E1A-responsive elements for repression of the FN gene. Two GC boxes also contain a G10 stretch that is interrupted by the presence of an internal C residue. These sequences overlap with the Sp1 motif GGGCGG. Substitution of the sequence GGGG with ATCC or CTTA in these G-rich sequences, leaving the Sp1 motif intact, completely abolished the E1A sensitivity of the promoter. Analysis of the E1A domains by using various E1A deletion mutants indicated that the domain for binding to the retinoblastoma susceptibility gene product (RB) is essential for efficient repression. These results suggest that the gene encoding a negative factor(s) binding to the three G-rich sequences in the FN promoter is repressed by RB in resting 3Y1 cells and derepressed by expression of E1A.

Adenovirus Early Proteins↗
PubMed1992

Mitochondrial DNA of Marchantia polymorpha as a single circular form with no incorporation of foreign DNA.

A cosmid library and physical maps of mitochondrial DNA (mtDNA) from a liverwort, Marchantia polymorpha, were constructed using the cosmid clones. Electrophoresis profile and the physical maps indicated that the liverwort mtDNA was approximately 183 kb long, the smallest among plant mtDNAs, and that it consisted of a single circular molecule. Southern hybridization analysis showed that genes typical to the mitochondrial genome existed in a single copy, and also that there was no incorporation of chloroplast DNA fragments into the mitochondrial genome.

Base Sequence↗
PubMed1992

Cloning and nucleotide sequence of a frxC-ORF469 gene cluster of Synechocystis PCC6803: conservation with liverwort chloroplast frxC-ORF465 and nif operon.

A gene, frxC, which is unique to the chloroplast genome of the liverwort Marchantia polymorpha, has sequence similarity to nifH, the product of which is an iron protein of a nitrogenase. Although frxC is expressed to produce a protein in liverwort chloroplasts, its function is not known. Using a probe of liverwort chloroplast DNA, a 10.1-kb region containing a gene cluster consisting of open reading frames (ORF278-frxC-ORF469-ORF248) was isolated from the cyanobacterium Synechocystis PCC6803. In this region, frxC and ORF469 showed sequence similarities to liverwort chloroplast frxC (83%) and immediately downstream ORF465 (74%), respectively. Synechocystis frxC showed 31% amino acid sequence identity with nifH1 from Clostridium pasteurianum. Additionally, Synechocystis ORF469 showed a sequence similarity (19% identity) to C. pasteurianum nifK product, which is the beta subunit of a molybdenum-iron protein of a nitrogenase complex. Conservation of the gene arrangement between liverwort and Synechocystis suggests that the liverwort chloroplast frxC-ORF465 cluster may have evolved from an ancestor common to Synechocystis, and that these two genes may have been transferred to the nuclear genome in tobacco and rice during evolution.

Amino Acid Sequence↗
PubMed1992

Osmotic shock of fertilized mouse ova.

The effect of osmotic changes on fertilized mouse ova was studied by measuring their survival, defined as development into hatching blastocysts, after exposure to various concentrations of ethanediol (ethylene glycol). In addition, a Boyle-van't Hoff plot was derived from exposing ova to hypotonic and hypertonic solutions ranging from 0.1 to 2.8 osmol. Volume of ova was inversely proportional to osmolality over this range. Extrapolation of this relationship yielded a nonosmotic volume of the ova of 22.5%. Eighty-five per cent or more of the ova survived exposure to this wide range of concentrations and developed into blastocysts. The rate of development of ova exposed to anisotonic solutions was the same as that of controls. Ova underwent osmotic shock when abruptly diluted out of concentrated solutions of ethanediol with an isotonic solution. Their survival was highly dependent on the ethanediol concentration with which they had equilibrated before dilution, and the manner, rate and temperature of dilution. The longer the exposure to ethanediol the greater was the sensitivity of the ova to osmotic shock, reflecting permeation of ethanediol into the ova. Osmotic shock could be alleviated by dilution at a high temperature, and prevented by the use of sucrose as an osmotic buffer at 37 degrees C. Identification of the variables that influence osmotic shock of ova will be helpful in the systematic study of their cryopreservation.

Animals↗
PubMed1992

Immunohistochemical analysis of GH-producing adenomas--with special emphasis on plurihormonality of individual tumor cells by double staining.

Forty-four human growth hormone (GH)-producing adenomas were investigated immunohistochemically for the concomitant localization of GH, prolactin (PRL), and glycoprotein hormone alpha subunit. Immunoreactivity for GH, PRL, and the alpha subunit was found in 44, 37, and 36 cases, respectively. By double immunohistochemical staining, 24 of 27 cases showed colocalization of GH and alpha subunit, with the numbers of tumor cells showing double staining varying from case to case. The colocalization of GH and alpha subunit was noted in some normal pituitary cells. In adenoma cells, the colocalization of GH and PRL, and PRL and alpha subunit, was observed in 9 and 12 cases, respectively. The normal pituitary gland showed only occasional colocalization of GH and PRL, or PRL and alpha subunit. We found that GH-producing adenomas are plurihormonal at the individual tumor cell level, with coexpression of GH-alpha subunit, GH-PRL, and PRL-alpha subunit. The colocalization of GH and alpha subunit may be an expression of a subpopulation of normal anterior pituitary cells (with GH-alpha subunit coexpression), but the more frequent coexpression of GH-PRL may be pathological, accompanying tumorigenesis of the anterior pituitary cells, in which a pituitary-specific transcriptional factor, pit-1, may play a role.

Adenoma↗
PubMed1992

[Clinical studies on cefprozil granules in pediatric skin soft tissues infections].

Cefprozil (CFPZ), a newly developed cephalosporin in fine granular form, was administered to pediatric patients with skin and soft tissue infections. MICs were determined for 6 drugs including CFPZ, cephalexin (CEX), cefaclor (CCL), ampicillin (ABPC), methicillin (DMPPC), cloxacillin (MCIPC) against 53 clinical isolates of Staphylococcus aureus from these patients. An inoculum size of 10(6) CFU/ml was used in the MIC-determinations. CFPZ was given to 73 patients with ages ranging from 6 months to 10 years and 8 months and 71 cases were evaluable for clinical effects as follows; impetigo (65), Staphylococcal scalded skin syndrome (1), furuncle (1), subcutaneous abscess (3), and periproctal abscess (1). To study clinical efficacy, bacteriological effects and safety of this drug, a mean dose of 8.4 mg/kg with 3-4 daily dosages (57 cases of t.i.d. and 14 cases of q.i.d.) was administered for an average of 6 days. The results obtained are summarized as follows. 1. With regard to the 53 isolates of S. aureus, MICs of CFPZ against 52 strains (98.1%) ranged from 0.78 to 3.13 micrograms/ml. 45 strains (84.9%) were inhibited at 0.78 micrograms/ml. MIC90 of CFPZ was 1.56 micrograms/ml, but MIC against 1 strain of Methicillin-resistant S. aureus (MRSA) was 100 micrograms/ml. The MIC90 of CEX and CCL were 6.25 micrograms/ml and MIC of CEX and CCL against 1 MRSA strain were 200 and 100 micrograms/ml, respectively. The MIC90 of ABPC, DMPPC and MCIPC were 6.25, 3.13 and 0.39 micrograms/ml, respectively. CFPZ showed the second highest activity after MCIPC against S. aureus. 2. CFPZ showed very good clinical responses and clinical effects in 71 patients all of whom judged by doctors in charge as having "good" or better responses. 3. For impetigo patients, the evaluable cases by score 3, 5 and 7 days after administration of the drug were 52, 39 and 20 patients, respectively. The efficacy rates on these days were 90.4, 100 and 100%, respectively. The efficacy rate at a daily dose of 30.1-45.0 mg/kg on day 3 was 17.2% higher than that at 22.5-30.0 mg/kg, and the "excellent" response rate of 30.1-45.0 mg/kg group was 45.3% greater. Because of these results, it is expected that good clinical effects can be obtained at a daily dose of 22.5-30.0 mg/kg of CFPZ, but better responses can be expected at 30.1-45.0 mg/kg in 3-4 divided doses given for 5 days. 4. Bacteriological effects of CFPZ were determined against 60 strains of S. aureus.(ABSTRACT TRUNCATED AT 400 WORDS)

Administration, Oral↗
PubMed1992

[Pharmacokinetic and clinical studies on cefprozil granules in the pediatric field].

Cefprozil (CFPZ), a newly developed oral cephalosporin in a fine granular form for pediatric use, was administered to children with bacterial infections. MICs were determined for 6 drugs including CFPZ, cephalexin (CEX), cefaclor (CCL), ampicillin (ABPC), methicillin (DMPPC) and cloxacillin (MCIPC) against the following 84 strains isolated from cases to which CFPZ was administered; 55 strains of Gram-positive cocci (GPC) including 2 strains of Staphylococcus aureus, 49 strains of Streptococcus pyogenes, 4 strains of Streptococcus pneumoniae, and 29 strains of Gram-negative bacilli (GNB) including 10 strains of Haemophilus influenzae, 18 strains of Escherichia coli, and 1 strain of Proteus mirabilis. MIC determination of these strains was done with an inoculum size of 10(6) CFU/ml. In pharmacokinetic studies, serum concentrations, urinary concentrations and urinary recovery rates were investigated using bioassay and high-performance liquid chromatography (HPLC). CFPZ was orally administered 30 minutes before meals to 9 children with ages ranging from 7 years and 1 month to 12 years and 3 months. Three groups of 3 children were tested with doses of 4.0, 7.5 and 15.0 mg/kg, respectively. In addition to the above, clinical and bacteriological studies were performed in a total of 160 cases consisting of children with ages ranging 5 months to 12 years and 5 months. A mean dose of 8.6 mg/kg in 3-4 divided doses (130 cases of t.i.d. and 30 cases of q.i.d.) was administered for an average of 7 days. The 160 cases included 34 cases of pharyngitis, 5 cases of tonsillitis, 8 cases of acute bronchitis, 8 cases of pneumonia, 52 cases of scarlet fever, 4 cases of acute purulent otitis media, 47 cases of urinary tract infection, 1 case of purulent lymphadenitis and 1 case of posthitis. Adverse reactions and abnormal clinical laboratory test results were also examined in 166 cases, including 6 cases excluded from the evaluation of clinical efficacy. The results obtained are summarized as follows: 1. With regard to GPC, MICs of CFPZ against 2 strains of S. aureus were 0.78 or 1.56 micrograms/ml and CFPZ showed the second highest activity to MCIPC. MICs of CFPZ against 49 strains of S. pyogenes were all less than 0.025 micrograms/ml.(ABSTRACT TRUNCATED AT 400 WORDS)

Administration, Oral↗
PubMed1992

[A successful two-staged Fontan procedure for tricuspid atresia with bilateral superior venae cavae and left pulmonary arterial stenosis].

A 10-year-old boy with tricuspid atresia (type I-b), bilateral superior venae cavae and left pulmonary arterial branch stenosis was treated successfully by a two-staged Fontan procedure. At 7 years of age, left Glenn shunt was performed after creation of a communicating vessel between the right and left superior vena cava, using a GORE-TEX graft of 10 mm of diameter. Three years later, after having confirmed graft patency, Fontan procedure was achieved without any problems. We think the innominate vein creation by an artificial material was a key design for the following successful two-staged Fontan procedure in this case.

Blood Vessel Prosthesis↗
PubMed1992

[Benefit of the autoperfusion balloon catheter for emergency coronary artery grafting after failed percutaneous transluminal coronary angioplasty].

A 61-year-old man was operated on an emergent basis because of abrupt closure of left anterior descending coronary artery (LAD) following failed coronary angioplasty. At once abrupt closure occurred, Stack autoperfusion balloon catheter was placed across the coronary lesion to reestablish blood flow to the ischemic myocardial area with intraaortic balloon counterpulsation. Despite a longtime of 12 hours to cardiopulmonary bypass, the patient had been managed with excellent resolution of symptoms and ST elevation. Under a stable hemodynamic state, saphenous vein grafting to LAD was performed with minimal myocardial infarction. Stack catheter made it possible to perform the subsequent coronary bypass operation as a controlled, optimal revascularization procedure because of its passive autoperfusion effect.

Acute Disease↗
PubMed1992

[Basic and clinical study of meropenem in pediatric field].

Meropenem (MEPM), a novel parenteral carbapenem antibiotic, was examined in a cooperative study involving 12 pediatric and 1 neonatologic facilities. The results are summarized as follows. 1. Antibacterial activity Antibacterial activity of MEPM against stock organisms including 31 strains of Streptococcus agalactiae, 14 of Listeria monocytogenes, 4 of Bordetella pertussis and 3 of Neisseria meningitidis ranged from 0.025 to 0.10 micrograms/ml in MIC90's, which were equal or lower than those of control drugs such as imipenem cefazolin, cefotiam, cefotaxime, ceftazidime and latamoxef. MICs against clinical isolates were as follows: In Gram-positive bacteria, MICs were 0.20 micrograms/ml to 6.25 micrograms/ml against 3 strains of Staphylococcus aureus, and 0.025 micrograms/ml or less against 4 of Streptococcus pneumoniae. In Gram-negative bacilli, MICs were 0.10 micrograms/ml to 0.20 micrograms/ml against 3 strains of Haemophilus influenzae and 0.78, 0.10 and 0.78 micrograms/ml, respectively, against one strain each of Enterobacter cloacae, Morganella morganii and Pseudomonas aeruginosa. MIC against 1 strain of Peptococcus saccharolyticus was < or = 0.025 micrograms/ml. 2. Pharmacokinetics Maximum plasma concentrations after intravenous infusion of MEPM over 30 minutes at doses of 10, 20 and 40 mg/kg, respectively, to 3 different groups of 3 children (total 9 cases) were observed at the completion of the treatment. Mean maximum concentrations in the 3 groups were 36.3, 69.5 and 129.8 micrograms/ml, respectively, exhibiting clear dose response. Mean plasma half lives in beta phase were 0.94, 0.86 and 0.94 hours, respectively, exhibiting no difference by doses, and this trend was observed also by HPLC. Urinary excretion rates in the first 6 hours after dose in the 10, 20 and 40 mg/kg groups were 67.3, 65.6 and 68.4%, respectively. Concentrations of MEPM in cerebrospinal fluid were determined in 2 cases of pyogenic meningitis. In 1 case, 500 mg (5.9 mg/kg) of MEPM was infused intravenously over 30 minutes and concentrations on Days 6, 8 and 15 observed at 190, 60 and 100 minutes after respective doses were 0.13, 0.10 micrograms/ml and less than the detection limit. Cerebrospinal fluid-plasma concentration ratio was determinable only on Day 8 and was 2.8%. In another case to which 250 mg (38.5 mg/kg) of MEPM was infused intravenously over 30 minutes, the concentration at Days 6, 7 and 10, 1 hour after the dose were less than the detection limit on day 6, and 2.04 and 2.62 micrograms/ml, respectively on days 7 and 10. 3. Clinical efficacy Clinical efficacies were evaluated in 49 cases and the efficacy rate was 93.9%.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗
PubMed1992

[Pharmacokinetics and clinical effects of cefdinir 10% fine granules in pediatrics].

Cefdinir (CFDN), a newly developed oral cephalosporin in a 10% fine granular form, was administered to 8 children and concentrations of the drug in plasma and urine and urinary recovery rates of the drug were determined. The subjects were divided into 2 groups of 4 children each; one group received 3 mg/kg of CFDN at 1 hour before meal (in the fasting state), and the other, at 30 minutes after meal. To study clinical and bacteriological effects of this drug, a mean dose of 4.8 mg/kg t.i.d. was administered for 8 days on the average to 9 children with various infections; tonsillitis (3 cases), acute bronchitis (1), pneumonia (1), acute purulent otitis media (1), urinary tract infection (2), and impetigo (1). MICs were determined for 6 drugs including CFDN, cefaclor, cefixime (CFIX), methicillin, cloxacillin, amoxicillin (AMPC) against 4 strains freshly isolated from children receiving CFDN. An inoculum size of 10(6) cfu/ml was used in the MIC-determinations. Adverse reactions and abnormal laboratory findings attributable to this drug were also examined in these children. The results obtained are summarized as follows. 1. Mean plasma peak levels of CFDN were observed at 2 hours after administration in the before-meal group and 4 or 5 hours after administration in the after-meal group mean peak values of 0.88 and 0.50 micrograms/ml, respectively. Mean half-lives were 1.61 hours in the before-meal group and 2.54 hours in the after-meal group, and mean AUCs were 4.24 in the former and 3.59 micrograms.hr/ml in the latter. 2. Mean urinary peak concentrations of CFDN were observed during 2-4 hours after dosing in the before-meal group and during 6-8 hours in the after-meal group with values of 93.3 and 44.8 micrograms/ml, respectively, in cases for which plasma concentrations of drugs were determined. Mean urinary recovery rates during the first 8 hours after administration in the before- and after-meal groups were 16.6 and 13.4%, respectively. 3. Good clinical effects were obtained with an efficacy rate of 100% in 9 patients with 6 diseases due to bacterial infections. 4. Good bacteriological effects were also obtained against 2 strains of Streptococcus pyogenes, 2 strains of Escherichia coli and 1 strain of Haemophilus influenzae with an eradication rate of 100%. In 3 cases of these and another case (normal flora), strains present before the study were replaced by other strains.(ABSTRACT TRUNCATED AT 400 WORDS)

Amoxicillin↗
PubMed1992

[Late results of the subclavian flap repair for aortic coarctation-effects on the left upper limb].

Late results of the subclavian flap repair for the aortic coarctation and effects on the left upper limb were evaluated on 9 patients who were operated on and had been continuously followed up at Hyogo Kenritsu Amagasaki Hospital. Their mean age at operation was 2.3 years (range 9 days-5.7 years), and mean follow-up period 5.9 years (range 3.1 years-8.3 years). Reoperation for restenosis was necessary in one patient and it proved the initial aortotomy and patch angioplasty had not been extended sufficiently beyond the stenotic segment. In the remaining 8 patients, the mean values of arm-to-leg systolic pressure gradient and peak flow velocity at the descending aorta by Doppler echocardiogram were 2.5 mmHg and 1.9 m/sec respectively. Length and arm circumference of the left upper limb were all significantly shorter than those of the right side. The left systolic brachial pressure and core temperature of the hand were also significantly low comparing with those of the right side. No patients, however, complained the ischemic symptoms of the left upper limb. In conclusion, the subclavian flap repair is thought to be a safe and long effective procedure for the aortic coarctation.

Adolescent↗