Search PubMed⌕ Search

Biomedical subjects

Y Machida

Publications and source records attributed to Y Machida.

At least 37 records · Page 2Linked to original sources
PubMed1997

Chromatography of crotamiton and its application to the determination of active ingredients in ointments.

Crotamiton, which is a mixture of cis and trans isomers, was investigated by several separation techniques. One of the HPLC modes, in which crotamiton eluted as a single peak, was selected for the determination of five active ingredients (crotamiton, prednisolone, glycyrrhetinic acid, dibucaine and chlorhexidine hydrochloride) in an ointment. The simultaneous determination was performed using isocratic reversed-phase mode within 20 min by employing an octyl (C8) column and a mobile phase containing sodium dodecyl sulfate (SDS) and 2-propanol. The method was successfully applied to quality control and stability testing of the ointment.

Antipruritics↗
PubMed1997

Possible involvement of differential splicing in regulation of the activity of Arabidopsis ANP1 that is related to mitogen-activated protein kinase kinase kinases (MAPKKKs).

Three types of Arabidopsis cDNA (cANP1, cANP2 and cANP3) have been isolated that encode putative protein kinases, designated ANP1, ANP2 and ANP3. These kinases exhibit a high degree of homology to NPK1, a tobacco protein that is a member of the family of mitogen-activated protein kinase kinase kinases (MAPKKKs), which appears to function in the proliferation of tobacco cells. The predicted amino acid sequences of the kinase domains in the amino-terminal halves of the ANPs were more than 80% identical to that of NPK1, while the kinase-unrelated regions in the carboxy-terminal halves exhibited relatively low homology. Two species of cANP1 were identified, ANP1L cDNA (cANP1L) and ANP1S cDNA (cANP1S), which were derived from a single ANP1 gene: the former had an intron-like sequence in the coding region for the kinase-unrelated region, while the latter did not include such an intron-like sequence. cANP1L encoded a putative protein with both kinase and kinase-unrelated domains, resembling NPK1, whereas cANP1S encoded only the amino-terminal kinase domain because the intron-like sequence was absent, with resulting elimination of most of the kinase-unrelated region. Genetic analysis with mutant yeast cells showed that over-expression of cANP1L or of cANP1S activated the mating pheromone-responsive signal pathway which is mediated by a MAP kinase cascade. Moreover, the extent of such activation by cANP1S was greater than that by cANP1L. These results predict that differential splicing of the intron-like sequence in the ANP1 transcript might be at least one of the molecular mechanisms involved in the generation of active ANP1 protein kinase.

Alternative Splicing↗
PubMed1997

[Characteristic situation on prevention of nosocomial infection in the hospital for the severely multi-disabled--experiences in care and treatment of 4 kinds of viral hepatitis].

We experienced Hepatitis A, B, C and fulminant hepatitis due to Herpes simplex virus type 1 (HSV-1) in our hospital for the severely multi-disabled (SMD) who had both severe motor and intellectual disabilities, and some of whom might be further complicated by blindness and/or deafness. In this hospital, 100 SMDs are hospitalized. Case 1: The disabled, 25 year old male, was transmitted Hepatitis A from a nurse. Case 2: The disabled, 60 year old female carrier of Hepatitis B virus (HBV) who has been cared for more than 10 years. Case 3: The disabled, 46 year old male carrier of Hepatitis C virus (HCV) (RNA type 3), has been cared for more than 4 years. Case 4: The disabled, 39 year old male, had a fever of 39 degrees C for 9 days and suddenly died. He was diagnosed as fulminant hepatitis due to HSV-1 by necropsy. The hospitals for SMD are characteristic in prevention of nosocomial infections; 1) The disabled infected is not aware of the fact that he or she is the source of infection and that the other disabled living with him or her are in risk of infection, because of their severe mental condition. 2) All of the disabled need complete or incomplete helps for activities of daily life (ADL), so that the disabled who is the carrier of some pathogen constantly gives risk of infection to staffs, including medical staffs (doctor, nurse and therapist), psychologist and helpers by bloody secretion from wounds, saliva, urine, feces as well as menstrual blood. 3) If a carrier of some pathogen is hospitalized, the staffs should serve under risk of infection involving blood-mediated infectious disease for many years, because SMDs are permitted lifelong stay in the hospitals for SMD, which also play a role of care house or institution, by public expense in Japan. In case of an outbreak of Hepatitis A, nosocomial infection ended in the original case (a nurse), another nurse and a case of the disabled by general treatment and care against communicable diseases of the digestive organs. In care of HBV and HCV carriers, an ordinary program to prevent nosocomial infection has been practiced in our hospital more strictly than in conventional hospital. HBV vaccine is injected to staffs caring the HB carriers who are negative on HBs antibody. Thus, during more than 10 years of care of HBV carrier and more than 4 years of care of HCV carrier, nosocomial infection has never been experienced clinically as well as serologically in our hospital. However, we have often been faced by difficulty to guarantee QOL (quality of life) of the carriers, because carrier states of HBV or HCV have been long-lasting and they have been occasionally and inevitably separated physically and/or psychologically in order to prevent nosocomial infection. In case 4, it was suspected that previously latently infected HSV-1 would be activated by another viral infection which had elicited fever for 9 days before death. The patient had neither history nor sign or symptom of immunodeficiency and had never been given drugs known as to be immunosuppressive as side effect.

Adult↗
PubMed1997

Biological properties of conjugates of mitomycin C with estradiol benzoate and estradiol: their stability characteristics in biological media and their binding abilities to estrogen receptor.

Conjugates of mitomycin C (MMC) with estradiol benzoate and estradiol via glutaric acid, abbreviated to EB-glu-MMC and E-glu-MMC, respectively, were investigated in vitro to determine their stability and MMC regeneration properties in biological media and on their binding to estrogen receptor. EB-glu-MMC and E-glu-MMC were added into a mixture of 1/15 M phosphate buffer, pH 7.4 (ionic strength = 0.3), propylene glycol (PG) and rat plasma (4:5:1, v/v/v), named 10% plasma, or into a mixture of the buffer, PG and rat liver homogenate (9:10:1, v/v/w), named 5% liver homogenate, and each was incubated at 37 degrees C. The conversion characteristics of EB-glu-MMC and E-glu-MMC were compared with those in the buffer-PG (1:1, v/v) mixture previously reported. In 10% plasma, the change of EB-glu-MMC to E-glu-MMC was accelerated enzymatically to some extent, while the enzymatic degradation of E-glu-MMC was not accelerated at all. In 5% liver homogenate, EB-glu-MMC changed quickly to E-glu-MMC, whereas the degradation of E-glu-MMC was accelerated very little. E-glu-MMC was considered to be rather stable against enzyme in the biological media. Competitive binding studies using the rat uterine estrogen receptor showed that the specific binding affinity of E-glu-MMC was 0.81% to that of estradiol, while EB-glu-MMC hardly exhibited specific binding. E-glu-MMC was regarded as a hormone-drug conjugate showing a small specific binding affinity to the estrogen receptor. E-glu-MMC is considered to be an effective antitumor agent which gradually generates MMC in the body, and its receptor-mediated action to target cells such as estrogen receptor-positive tumor cells might be possible.

Animals↗
PubMed1997

[Trial for transdermal administration of sulfonylureas].

Sulfonylureas are widely used as oral hypoglycemic drugs in the treatment of non insulin dependent diabetes mellitus (NIDDM). Since sulfonylureas are usually taken for a long period, the compliance of the patients is very important. Therefore, for the improvement of the compliance of the patients, the development of a transdermal dosage form of sulfonylureas was attempted in this study. Glibenclamide (GLI) or chlorpropamide (CHL) was chosen as a principal agent and ointments were prepared by mixing 5% of GLI or CHL with a FAPG ointment base. Penetration and shearing stresses of the ointments were determined as physical characteristics of the ointments. There was no obvious difference of characteristics between the GLI ointment, or the CHL ointment and the FAPG ointment base. In drug release tests, the CHL ointment showed better release of the drug than the GLI ointment. In both ointments, comparatively rapid release of drug was observed in the initial 1 h, and continuous slow release was observed thereafter. When the ointments were applied on the back of male Wistar rats and the plasma glucose level was measured, both CHL and GLI ointments gave lower blood glucose levels than the control (FAPG base). At the all measuring points, the GLI ointment brought about significantly lower blood glucose levels than the control (p < 0.01). Thus, it was demonstrated that sulfonylureas were absorbed through the skin and lowered the blood glucose levels. The results suggest the possibility of transdermal administration of sulfonylureas for the treatment of NIDDM.

Animals↗
PubMed1997

[Sustained release double-layered progesterone suppository for luteal support therapy].

A sustained release suppository containing progesterone with a double-layered structure was prepared for the treatment of the luteal phase defect. Hydroxypropylcellulose-H (HPC) and Carbopol-934P (CP) were used as bases of the inner layer and Witepsol W35 was used as a base of the outer layer. The strength of the inner layer (stick) decreased with the increase of the rate of content of HPC component. The strength of the stick which was prepared from a mixture of HPC and CP in a ratio of 1:1, was inverse by proportional to the rate of the addition of crystalline cellulose (CC) and the amount of released drug was proportional to the rate of the addition of CC. The area under the drug release curve of the stick containing 60% of CC in the base was about 12 times of the stick containing no CC (control stick). Furthermore, the mean release time of the stick containing 60% of CC became about a half of the control stick. It was suggested that the drug release of progesterone from the stick could be controlled by changing the rate of the addition of CC. Two types of suppository which containing progesterone in both phases (suppository A) and in the stick alone (suppository B) were prepared. Both suppositories showed a sustained release property and suppository B had a lag time of two hours. When the suppositories were administered in to the vagina of rabbits, they showed a sustained release property and a rapid rise in the serum concentration was more suppressed than an ordinary Witepsol suppository. One hour after the administration of the two layered suppository, some parts of the suppository was identified macroscopically to be remained in the vagina. The usefulness of the double-layered suppository as a hospital preparation should be suggested after the attainment of the optimization of the formulation.

Acrylic Resins↗
PubMed1997

Occlusal migration of the maxillary first primary molars subsequent to the loss of antagonists.

The purpose of this study was to observe the vertical changes in unopposed maxillary first primary molars longitudinally. The subjects of this study were 17 children whose lower first primary molars had to be extracted. Space closure were prevented by crown-loop space maintainers for all these children. Plaster casts were made every 4 months for 16 to 24 months after the extraction. These series of casts were standardized, and vertical changes of the maxillary first primary molars against the occlusal plane were measured using a micro-reader. The mean changes indicated that maxillary first primary molars without intercuspidation tend to drift toward the extraction space. On the control side with antagonists, the maxillary first molars seemed to move reversed to apical throughout the observation period. Accordingly, the results of this study showed new trends after the premature loss of primary molars. The vertical changes toward extraction space varied from -0.40 mm to 1.43 mm at the 16 months after extraction. Mean changes were small, but there were some individual differences in reaction, giving negative values. However, we should always be concerned about loss of arch length and also occlusal drift of unopposed teeth, because the vertical changes were greater than 1 mm at 16 months after extraction in some cases.

Child↗
PubMed1997

Prevalence of congenital dental anomalies of the deciduous dentition in Japanese children.

We examined the prevalence of anomalies in deciduous dentition in 2,733 Japanese three-year-old children. The results showed that fused teeth occurs in 4.10%, congenital missing teeth in 2.38%, enamel hypoplasia in 1.50%, peg-shaped teeth in 0.55%, palatal cusps in upper deciduous incisors in 0.37%, supernumerary teeth in 0.07%, and color anomalies in 0.07%. Sixty-nine boys and 43 girls had fused teeth, percentages of 4.88 and 3.26, respectively. This difference was significant. All the fused teeth were located in the anterior region and were more frequent in the mandibular than in the maxillary arch. In the mandibular arch, 50 cases involved the lateral incisor and canine; the central incisor and lateral incisor were fused in 48 instances. There were 30 boys (2.12%) and 35 girls (2.65%) with congenitally missing deciduous teeth. This difference was not significant. Unilateral missing teeth were more frequently observed than bilateral missing ones. The lower lateral deciduous incisor was the most frequently missing tooth. The prevalences of fused teeth and congenital missing teeth were significantly higher in this study than in studies of American and Scandinavian children. These two anomalies are tending to increase in frequency in Japan.

Anodontia↗
PubMed1996

In vivo drug release and antitumor characteristics of water-soluble conjugates of mitomycin C with glycol-chitosan and N-succinyl-chitosan.

The water-soluble conjugates of mitomycin C (MMC) with N-succinyl-chitosan (N-Suc-chitosan) and glycol-chitosan (Gly-chitosan), named N-Suc-chitosan-glu-MMC and Gly-chitosan-glu-MMC, respectively, were characterized mainly by the plasma concentration-time profiles of MMC after intraperitoneal administration and their in vivo antitumor effect against P388 leukemia and Sarcoma 180. Before in vivo evaluation, polymer-drug binding characteristics were checked by gel-chromatography. Gel-chromatographs proposed the covalent binding of 1a-(4-carboxybutyryl)-MMC (glu-MMC) with both the polymer supports. The plasma concentration of MMC showed that each conjugate released MMC in vivo at a similar rate. Kinetic analysis suggested that the in vivo drug release should be considerably faster than the in vitro release in the buffer, pH 7.4, alone. In the treatment against P388 leukemia inoculated intraperitoneally, Gly-chitosan-glu-MMC showed the highest increase in life span (ILS) at 10 mg MMC eq/kg. It was lethally toxic at the dose of 20 mg MMC eq/kg, while N-Suc-chitosan-glu-MMC gave the highest ILS value at this dose. Each conjugate exhibited a little larger ILS value than MMC. For the Sarcoma 180 solid tumor inoculated subcutaneously, the polymer characteristics affected the antitumor effect. Namely, with the intravenous injection, Gly-chitosan-glu-MMC hardly exhibited any tumor growth inhibition, but N-Suc-chitosan-glu-MMC showed significant tumor growth suppression. As to the intratumoral administration, the tendency to suppress tumor growth was observed in MMC and both the conjugates.

Animals↗
PubMed1996

Preparation and drug release characteristics of the conjugates of mitomycin C with glycol-chitosan and N-succinyl-chitosan.

Mitomycin C (MMC) was covalently attached to glycol-chitosan (Gly-chitosan) and N-succinyl-chitosan (N-Suc-chitosan) through a spacer of the glutaryl group, and each conjugate was obtained as a water-soluble product. Stability of 1a-(4-carboxybutyryl)-MMC (Glu-MMC) in vitro was investigated by incubation in 1/15 M phosphate buffers of pH 5, 6, 7.4, 8 and 9 at 37 degrees C. The release rate of MMC from Glu-MMC was very slow at neutral pH, gradual at basic pH and relatively fast at acidic pH, but the quick decomposition of MMC proceeded simultaneously at acidic pH. Release of MMC from the conjugates in vitro was investigated by incubation in 1/15 M phosphate buffers of pH 5, 7.4 and 9 at 37 degrees C. The release rate of MMC from the conjugates was slight at acidic pH, accelerated at basic pH, and was gradual at pH 7.4. In a plasma-buffer (pH 7.4) mixture (1:1, v/v), the release rate of MMC from the conjugates was rather similar to that in only the buffer (pH 7.4).

Antibiotics, Antineoplastic↗
PubMed1996

Phylogenetic position of the Japanese river otter Lutra nippon inferred from the nucleotide sequence of 224 bp of the mitochondrial cytochrome b gene.

A 224 bp fragment of the mitochondrial cytochrome b gene has been amplified from a 30-year-old mummy-like specimen of the Japanese river otter Lutra nippon by polymerase chain reaction (PCR). The amplified products were subcloned in the Smal site of pUC 18 and sequenced. The sequence was different from those of the congeneric Eurasian otters Lutra lutra (Latvia) and Lutra lutra (China) in 7-9 nucleotides, all of which were located at the third position of a codon and identified as transitional differences A<-->G or C<-->T. The phylogenetic analysis using the 224 bp sequences of Lutra nippon, Lutra lutra (Lativa), Lutra lutra (China), Aonyx cinerea (Asian small-clawed otter), Mustela sibirica and Mustela itatsi (weasels) supports the recent morphological study that the Japanese river otter is not a subspecies of Lutra lutra, but a distinct species, Lutra nippon. We found that Lutra nippon and Lutra lutra contain the cytochrome b-like sequences, that appear to be a pseudo-form of cytochrome b gene. The sequences are characterized by the presence of deletion and termination codons by the presence of several types of sequences with minor variations, and by the faster evolutionary rate compared with that of the mitochondrial cytochrome b gene. The genes would present in the nuclear DNA rather than in the mitochondrial DNA, as in the case of the nonfunctional cytochrome b-like sequences previously reported in a rodent.

Animals↗
PubMed1996

[Functional imaging of the sensorimotor cortex using an ultra-fast MR imaging method].

UNLABELLED: The aim of this study was to assess changes in brain activity during a motor task and variable sensory stimulation using echo planar imaging, which represents the fastest clinically usefull imaging technique available. MATERIALS AND METHODS: The subjects of this study were 11 healthy-volunteers, 4 males and 11 females, with an average of 26.4 years. The subjects were instructed to tap the fingers of one hand as the motor task. Compressed air was applied 5 times a second as "simple" sensory stimulation. Simple figures were drawn on the subjects palm as "complex" sensory stimulation. In all cases, functional imaging was performed by T2*-weighted echo planar imaging (TE = 53 msec, TR = 3000 msec, flip angle = 90 degrees, matrix 64 x 64, FOV = 205 mm, slice thickness = 8 mm) alternately at rest and during the task (intervals: 30 sec). A total of 60 images was collected in 3 minutes. Images obtained by subtracting images at rest and during the task were analyzed. RESULTS AND DISCUSSION: Almost all subjects showed a transient signal increase in the contralateral paracentral region during simple sensory stimulation. Continuous signal increases in the contra- and/or ipsi-lateral para-central region were observed during complex sensory stimulation. Some exhibited signal increases in the parietal or frontal association cortex, but they disappeared when subject's attention was distracted during stimulation. All subjects displayed signal increases in the contralateral para-central region during the motor task. Some of them exhibited signal increases in the medial frontal area (supplementary motor area) and ipsilateral para-central region. These results suggest that the signal increases of functional MRI reflect not only simple reactions to stimulation but higher cerebral function as well.

Adult↗
PubMed1996

[Pharmacokinetic and clinical evaluations of azithromycin in the pediatric field].

Azithromycin (AZM), an oral macrolide antibiotic drug, was studied for its efficacy and pharmacokinetics in the treatment of pediatric patients with respiratory tract infections. The results of the study are presented. Fifteen pediatric patients in an age range between 1 and 10 years were given 8.9 to 14.7 mg/ kg body weight of AZM once daily for 3 to 4 days. Pharmacokinetics of AZM in three patients were examined. AZM concentration in plasma was 0.037 microgram/ml at 72 hours after final dosing, while urine concentration was 10.9 micrograms/ml measured during a period between 72 and 96 hours post-dosing. Fourteen patient cases were included in analysis of drug efficacy for AZM. AZM was found "markedly effective" in all seven patients with pneumonia, and "effective" in all three patients with acute bronchitis, two patients with mycoplasmal pneumonia, and one patient with tonsillitis. In one patient with mycoplasmal bronchitis, AZM was found slightly effective. The efficacy rate was 92.9% (13/14). The study found one case of side effect, moderate diarrhea. No laboratory abnormality was documented. In conclusion, an antibiotic AZM was found useful in a treatment of pediatric respiratory tract infections.

Anti-Bacterial Agents↗
PubMed1996

Clinical and histological observations of continuously formed bilateral mandibular deciduous central incisor roots after traumatic coronal destruction.

We encountered a rare case of continuously forming bilateral mandibular deciduous central incisor roots after traumatic coronal destruction. The patient, 3 year 3 month old boy, had sustained an external injury which had caused the crowns of hist bilateral deciduous central incisors to fall out when he was 12 months old. Oral examination revealed two small, hard tissues resembling tooth structures on the alveolar ridge in the area of the lost mandibular central incisors. X-ray examination revealed them to be deciduous central incisor roots. We observed the extracted roots histologically and found that the lesion of the crown fracture and pulpal exposure on these roots was completely covered by newly formed irregular dentin and cementoid tissues. In this case, the causes of the continuous root formation were considered to be that the pulp tissues of traumatized teeth were able survive, so the injured lesion was quickly healed and covered with gingival tissue. The vital pulp produced the reparative hard tissue, sealing the site of pulpal exposure and continuing root formation after the trauma.

Child, Preschool↗
PubMed1995

Visualization of site-specific recombination catalyzed by a recombinase from Zygosaccharomyces rouxii in Arabidopsis thaliana.

Excision of a DNA segment can occur in Arabidopsis thaliana by reciprocal recombination between two specific recombination sites (RSs) when the recombinase gene (R) from Zygosaccharomyces rouxii is expressed in the plant. To monitor recombination events, we generated several lines of transgenic Arabidopsis plants that carried a cryptic beta-glucuronidase (GUS) reporter gene which was designed in such a way that expression of the reporter gene could be induced by R gene-mediated recombination. We also made several transgenic lines with an R gene linked to the 35S promoter of cauliflower mosaic virus. Each transgenic line carrying the cryptic reporter gene was crossed with each line carrying the R gene. Activity of GUS in F1 and F2 progeny was examined histochemically and recombination between two RSs was analyzed by Southern blotting and the polymerase chain reaction. In seedlings and plantlets of F1 progeny and most of the F2 progeny, a variety of patterns of activity of GUS, including sectorial chimerism in leaves, was observed. A small percentage of F2 individuals exhibited GUS activity in the entire plant. This pattern of expression was ascribed to germinal recombination in the F1 generation on the basis of an analysis of DNA structure by Southern blotting. These results indicate that R gene-mediated recombination can be induced in both somatic and germ cells of A. thaliana by cross-pollination of parental transgenic lines.

Arabidopsis↗