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Biomedical subjects

R Aoyama

Publications and source records attributed to R Aoyama.

At least 19 recordsLinked to original sources
PubMed2006

Ischemia-induced disturbance of neuronal network function in the rat spinal cord analyzed by voltage-imaging.

Using a voltage-imaging technique, we analyzed the acute effect of ischemia, hypoxia and hypoglycemia on the neuronal network function of the rat spinal cord. Ischemic, hypoxic, or hypoglycemic stress was loaded to spinal cord slices with an oxygen- and glucose-free, oxygen-free, or glucose-free mock cerebrospinal fluid, respectively. Depolarizing signals in the dorsal horn, induced by dorsal root stimulation, consisted of fast (pre-synaptic) and slow (post-synaptic) components. The slow component was attenuated much more than the fast component under an ischemic condition (P<0.0002). Post-synaptic neuronal activities in lamina III-IV were suppressed earlier than those in lamina I-II. The nerve fiber was relatively resistant to ischemia. As long as the fast component was preserved in the dorsal horn, the suppression of the fast and slow components was reversible. There was a significant difference (P<0.05) in the recovered slow component sizes between the group in which the fast component was suppressed by more than 20% by ischemia and the group in which the suppression was less than 20%. Further prolonged stress irreversibly eliminated most of the slow component, and attenuated the fast component (to 59+/-8%) accompanied by cellular damage in histology. Suppression of neural activity by hypoxic or hypoglycemic stress was less prominent than that by ischemia. Prolonged ischemic stress suddenly and irreversibly eliminated depolarizing signals in the ventral horn accompanied by morphological damage of motoneurons. Immunohistochemical staining was negative for apoptosis. We have, for the first time, analyzed the processes of spinal cord disturbance induced by ischemia, hypoxia and hypoglycemia at the neuronal network level by directly observing the regional neuronal network activities within the spinal cord. We conclude that synaptic transmission in the dorsal horn, especially in deep regions, is vulnerable and first affected by these stresses. Severe ischemic stress induces irreversible dysfunction of neurons accompanied by eventual cell death in both dorsal and ventral horns.

Animals↗
PubMed2000

A refined 3-dimensional QSAR of cytochrome P450 2C9: computational predictions of drug interactions.

A ligand-based model is reported that predicts the Ki values for cytochrome P450 2C9 (CYP2C9) inhibitors. This CoMFA model was used to predict the affinity of 14 structurally diverse compounds not in the training set and appears to be robust. The mean error of the predictions is 6 microM. The experimentally measured Ki values of the 14 compounds range from 0.1 to 48 microM. Leave-one-out cross-validated partial least-squares gives a q2 value of between 0.6 and 0.8 for the various models which indicates internal consistency. Random assignment of biological data to structure leads to negative q2 values. These models are useful in that they establish a pharmacophore for binding to CYP2C9 that can be tested with site-directed mutagenesis. These models can also be used to screen for potential drug interactions and to design compounds that will not bind to this enzyme with high affinity.

Aryl Hydrocarbon Hydroxylases↗
PubMed1993

Comparative study of reverse flow island flaps in the lower extremities--peroneal, anterior tibial, and posterior tibial island flaps in 25 patients.

The reverse flow island flap is one of the most versatile reconstructive procedures in the lower extremity. There are three major arteries, the peroneal, the anterior tibial, and the posterior tibial artery, and a reverse flow island flap pedicled by each vessel and its intermuscular cutaneous perforators is available. Twenty-five reverse flow island flaps were clinically applied for soft tissue defects in the lower leg (10 peroneal, 8 anterior tibial, and 7 posterior tibial flaps). We report a comparative study of the characteristics and indications of the peroneal, anterior tibial, and posterior tibial reverse flow flaps. We conclude that the anterior tibial reverse flow flaps are more likely, without venous anastomosis, to become congested and necrose than the peroneal and posterior tibial flaps.

Adult↗
PubMed1991

Operations for microforms of cleft lip.

Microform cleft lip is a mild expression of cleft lip and may be difficult to repair. Its severity may be defined by the degree of downward depression of the nostril rim, skin striae of the upper lip, notching of Cupid's bow, and deformity of the vermilion border. Variation in surgical repair is reported for each type of microform cleft lip.

Cleft Lip↗
PubMed1990

Cleft lip-nose repair technique: sequential repair.

The results of repairing cleft lip by aesthetic plastic surgery are now excellent. However, the cleft lip-nose deformity is still very difficult to repair with the present techniques. A technique that can repair the cleft lip-nose deformity with good results is presented. The technique is divided into three parts: Part I consists of nasal repair of the primary cleft lip. Part II is nasal reconstruction as a secondary operation with or without lip repair. For example, nasal reconstruction may be secondary to repair of deformities of the sill, rim, limen nasi, septum, or nasal bones. Part III is an aesthetic nasal operation such as rhinoplasty, mentoplasty, or zygomaplasty.

Cleft Lip↗
PubMed1990

[A case of malignant mesenchymoma of the maxilla].

The case of a 48-year-old male with a malignant mesenchymoma of the maxilla is reported. The patient had complained of bloody rhinorrhea and cheek pain, and a total maxillectomy was performed. The tumor consisted of a rhabdomyosarcoma, an osteosarcoma and a chondrosarcoma, which were relatively differentiated. Later, recurrence of a tumor and a lung metastasis occurred, however the tumor revealed undifferentiated mesenchymal cells. This led us to suspect the origin of the malignant mesenchymoma had been a primitive mesenchymal cell. To our a knowledge, the present case is the first reported case of a malignant mesenchymoma with a maxillary origin in the world.

Chondrosarcoma↗
PubMed1990

[Morphological study on the intraocular proliferative membrane of proliferative diabetic retinopathy and proliferative vitreoretinopathy].

The membranes from 42 eyes with PDR and 8 eyes with PVR were removed during vitreous surgery. In 12 of those with PDR and 3 of the cases with PVR, the reproliferated membranes formed beneath silicone oil (SO) were removed and were histologically and immunohistochemically examined, using morphometrical quantitative analysis. In each case, area coefficient, fibrous content and the number of new vessels, and thick basement membranes, increased wall cells and multilayer basement membranes of new vessels were studied. In both PDR and PVR, the number of cells per unit area tended to be increased with the period of time after SO was injected, while the percentage of fibrous components did not change. The Percentage of occurrence of each type of new vessels was almost the same in both primary and reproliferative PDR membranes. In the primary proliferative PDR membranes, endothelial cell proliferation was found predominantly, while glial hyperplasia was predominant in the primary proliferated PVR membranes and the reproliferated membranes under SO of PDR and PVR.

Basement Membrane↗
PubMed1989

[Clinical studies of cefpodoxime proxetil in pediatric field].

Clinical studies of cefpodoxime proxetil (CPDX-PR), a new cephem antibiotic, were carried out in 60 patients in the pediatric field. The overall efficacy rate on 54 patients with various infections was 98.1%, and few side effects, all of them very mild, were developed in 6 of 60 patients (10%). It was concluded that CPDX-PR was one of the most useful antibiotics in the pediatric field because of the high efficacy rate and the safety.

Acute Disease↗
PubMed1989

[Clinical studies on cefteram pivoxil in pediatrics].

Cefteram pivoxil (CFTM-PI), a newly developed oral cephem antibiotic was administered to treat 16 children with various infections. The results were summarized as follows. 1. The clinical responses were "excellent" in 7, "good" in 5, "fair" in 3 and "poor" in 1, with 75.0% efficacy rate. 2. No side effects and no abnormal laboratory findings were observed.

Bacterial Infections↗
PubMed1986

Aesthetic considerations of the cleft lip operation.

The results of a cleft lip operation are checked from the anterior, the profile, and the caudal views and even if the deformities are minimal, for aesthetic reasons they should be repaired. Philtrum length, philtrum shape, philtrum depth, nasolabial triangular area, vermilion thickness, Cupid's bow peak, horizontal upper lip groove, vermilion border, alar size, depth of alar groove, nasal deviation, nostril shape, nasal tip, columella height, sill shape, columella width, and facial balance of the anterior, profile, and caudal views are used as aesthetic checkpoints for the results of a cleft lip operation. If deformities are found, the aesthetic plastic surgeon should repair them to achieve a more satisfactory result. In addition, augmentation rhinoplasty, augmentation mentoplasty, or other craniofacial surgery may be performed.

Chin↗
PubMed1984

[Clinical studies on sulbactam/cefoperazone in pediatric field].

Clinical studies on sulbactam/cefoperazone (SBT/CPZ) were carried out and the results were as follows: Eleven patients (pneumonia 8, acute purulent arthritis of the knee joint 1, urinary tract infection 2) were treated with SBT/CPZ, in doses of 30-67 mg/kg divided 3 times per day for 3-61/3 days intravenously. The overall efficacy rate was 100%. As to adverse reaction, diarrhea was observed in 1 case. Abnormal laboratory data were noted in 2 cases (GPT elevation in 1, and eosinophilia and GPT elevation in 1).

Age Factors↗
PubMed1984

[Clinical studies on ceftriaxone in the pediatric field].

Clinical studies on ceftriaxone (Ro 13-9904, CTRX) were carried out and the results were as follows: Twelve patients (acute purulent tonsillitis 1, pneumonia 6, urinary tract infection 5) were treated with CTRX, in doses of 21-48 mg/kg divided 2 times per day for 3.5-8 days intravenously. The overall efficacy rate was 100%. No adverse reactions were observed. No abnormal laboratory data were noted.

Adolescent↗
PubMed1984

[Clinical studies on ceftazidime in the pediatric field].

Ceftazidime ( CAZ ) is a newly developed cephalosporin. Clinical studies on this drug was carried out and the results were as follows. Twenty-nine patients (acute purulent tonsillitis 2, acute bronchitis 1, pneumonia 15, acute purulent lymphadenitis 2, pyoderma 1, skin abscess 2 and urinary tract infection 6) were treated with CAZ in doses of 42-1 mg/kg (mean 59 mg/kg) divided 2-3 times per day for 3-10 days (mean 5.7 days) intravenously. The overall efficacy rate was 96.6%. As to adverse reaction, drug fever was observed in 1 patient. Abnormal laboratory data were noted in 4 cases (elevation of serum GOT, GPT and BUN in 1, elevation of serum GOT and GPT in 1, elevation of BUN in 1 and leukopenia in 1).

Adolescent↗
PubMed1983

Monocyte function in idiopathic nephrotic syndrome in childhood.

The monocyte function of 112 specimens from 42 children with idiopathic nephrotic syndrome (INS) aged from 2 to 17 years was studied by the methods of nitroblue tetrazolium (NBT) reduction, phagocytosis of immunobeads (IB) and yeast cells, chemotaxis and acid alpha-naphthyl acetate esterase (ANAE) staining. The dissociation between phagocytosis and chemotaxis was observed in the fresh cases of steroid sensitive INS and in the cases of steroid non-sensitive INS. In the fresh cases of steroid sensitive INS, NBT reduction and phagocytosis were increased, but chemotaxis was decreased. In the cases of steroid non-sensitive INS, the phagocytosis of IB was decreased, but chemotaxis was increased. These findings suggest a different pathogenesis between steroid sensitive and steroid non-sensitive INS. The dissociation between phagocytosis and chemotaxis may be explained by the alteration of the surface receptors of monocyte and by lymphokines.

Adolescent↗
PubMed1983

[Comprehensive evaluation of cefotetan in pediatrics].

Fundamental and clinical studies on cefotetan (CTT), a new cephamycin antibiotic, were carried out under a joint study programme in pediatric field, and the following results were obtained. Pharmacokinetic study In 20 pediatric patients with normal renal function, weighing 15 to 48 kg, CTT was injected intravenously at 20 mg/kg in 3 to 5 minutes. The mean blood concentration of CTT was 215.6 micrograms/ml at 15 minutes after the end of injection, 90.7 micrograms/ml at 1 hour, 57.2 micrograms/ml at 2 hours, 33.9 micrograms/ml at 4 hours and 10.2 micrograms/ml at 8 hours. The half-life of the drug in the beta-phase, computed from the mean blood concentrations up to 8 hours postdosing, was 2.61 hours. The peak of the mean urinary excretion of cefotetan appeared in 0 to 2 hours after the injection and 36.5% of the dose was recovered in the urine. The mean excretion at 0 to 8 hours was 68.1%. Clinical study Clinical effects of CTT was evaluated in 285 patients with 287 diseases, since 1 patient had both pneumonia and erysipelas, and another both pneumonia and acute otitis media. Daily dosage of CTT ranged from 15 to 123 mg/kg, and 266 patients (93.3%) received the drug either 2 or 3 times daily. The clinical response was seen in 83.3% of the 6 cases with sepsis, 89.3% of the 122 cases with pneumonia with or without pyothorax, 96.2% of the 52 cases with either acute bronchitis or tonsillitis, 92.5% of the 67 cases with urinary tract infection and 92.5% of the 40 cases with other infections. The causative organisms were detected in 160 patients and the rate of complete disappearance was 80.6%. Out of 310 patients, side effects were seen in 9 cases, diarrhea in 8 (2.6%) and rash in 1 (0.3%). Abnormal clinical laboratory findings were seen in 24 cases, elevation of serum transaminases in 19 (7.8%), elevation of TTT and LDH in 1 (0.4%) and eosinophilia in 4 (1.6%). None of these cases showed serious side effects or abnormal clinical laboratory findings. From the above results, it is concluded that CTT is one of the useful drug for treatment of infections in pediatric field.

Adolescent↗
PubMed1983

[Experimental and clinical evaluation of cefotetan in pediatrics].

Basic and clinical studies on cefotetan (CTT) were carried out and the results were as follows: Absorption and excretion Two patients were given 10 mg/kg of CTT by one shot intravenous injection. At 30 minutes after injection, mean serum level was 76.5 micrograms/ml and the half-life time was 2.3 hours. Mean 6-hour urinary recovery in same patients was 57.5%. Clinical evaluation Forty-two patients were treated with CTT, in doses of 19.2-102.9 mg/kg divided 2-4 times per day for 3-10 days intravenously. Responses were excellent in 14, good in 23, fair in 1, poor in 4, and the overall efficacy rate was 88.1%. As to adverse reaction, urticaria was observed in 1 patient. Abnormal laboratory data noted were elevation of GOT in 1, GOT and GPT in 2, creatinine in 1, and eosinophilia in 3 patients.

Adolescent↗
PubMed1983

[Clinical evaluation of cefpiramide in pediatrics].

Cefpiramide (CPM) is a newly developed cephalosporin. Clinical studies on this drug were carried out and the results were as follows; Forty-three patients (purulent lymphadenitis 2, cellulitis 2, purulent otitis media 1, purulent tonsillitis 3, acute bronchitis 2, pneumonia 22, bronchiectasis 1, urinary tract infection 10) were treated with CPM, in doses of 20 approximately 82 mg/kg divided 2 approximately 4 times per day for 3 approximately 11 days intravenously. The overall efficacy rate was 83.7%. As to adverse reaction, 4 cases, which includes 3 cases of diarrhea and 1 case of exanthema, were observed. Abnormal laboratory data noted were liver dysfunction in 3 cases (6.8%), and eosinophilia in 2 cases (4.5%).

Adolescent↗