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Biomedical subjects

Y Iwata

Publications and source records attributed to Y Iwata.

At least 127 records · Page 7Linked to original sources
PubMed1995

Effect of 2-hydroxypropyl-beta-cyclodextrin on percutaneous absorption of methyl paraben.

A potential use of 2-hydroxypropyl-beta-cyclodextrin (HP-beta-CyD) to solubilize methyl paraben and to suppress its percutaneous absorption was examined, and compared with nonionic surfactant HCO-60. HP-beta-CyD significantly increased the solubility of methyl paraben in water, where the apparent 1:1 stability constant of the soluble complex was determined to be 2150 M-1. The in-vitro cutaneous permeability of methyl paraben through an isolated skin of hairless mouse was suppressed by HP-beta-CyD, thus promoting the bioconversion of methyl paraben to the less toxic metabolite, p-hydroxybenzoic acid (p-HBA) in the epidermis. These effects of HP-beta-CyD were greater than those of HCO-60. HP-beta-CyD (2% w/v) reduced the in-vivo percutaneous absorption of methyl paraben by 66% 24 h after the topical application of a solution containing [14C]methyl paraben to hairless mouse skin. Additionally, the percutaneous absorption of [14C]HP-beta-CyD was confirmed to be extremely low. These results suggest that HP-beta-CyD is useful in liquid preparations of methyl paraben for topical application.

2-Hydroxypropyl-beta-cyclodextrin↗
PubMed1995

HLA class II genotyping by polymerase chain reaction-restriction fragment length polymorphism method (PCR-RFLP) in systemic lupus erythematosus patients.

Recently, genotyping of HLA class II alleles by digestion of polymerase chain reaction (PCR) amplified polymorphic DNA region with restriction endonucleases (PCR-RFLP) has been reported and claimed to be a simple and reliable technique. We tested the use of PCR-RFLP for genotyping of DQA 1, DQB 1, DPB 1 and DRB 1 alleles of 40 normal individuals and 19 patients with systemic lupus erythematosus (SLE). In agreement with previous reports, we observed an association of SLE with the DRB 1*1501-DQA 1*0102-DQB 1*0602 haplotype and noted an unreported association with DPB 1*0501. Although these observations must be confirmed with larger sample sizes, we believe that the PCR-RFLP is simpler and more practical than the sequence-specific oligonucleotides (PCR-SSO) for genotyping and can be invaluable to the more widespread molecular determination of HLA-class II specificities, including in non-specialized laboratories.

Genotype↗
PubMed1995

[Clinical evaluation of enzyme immuno assay systems for HCV antibody--synthetic peptide antigen and recombinant antigen].

To evaluate the frequency of the false positive results, we examined 168 patients for the presence of HCV using two HCV antibody assay systems, Synpep HCV-EIA (Synpep) and Abbott EIA II (Abbott). The results obtained by the two methods were significantly different in 22 patients. Cases in 17 of these patients, the results were positive with Abbott but negative with Synpep, and there were no clinical signs or delectable virus RNA. However, in 2 cases, the results were markedly positive with Abbott and weakly positive with Synpep. The presence of virus RNA and the increase of transaminase were observed in one case but both were noted in the other case. The serum of these two patients reacted with the C33C and C22-3 regions in RIBA II. We observed another 2 cases in which the elevation of the cut-off index with Synpep preceded that with Abbott at the early stage of acute hepatitis C. We also compared the cut-off index with the histology activity index (HAI) score determined by liver biopsy. The average cut-off index with Synpep was proportional to the HAI score in the range between 0 and 13. Based on the cut-off index/HAI score relationship, we suggest that patients with inactive chronic hepatitis show a Synpep cut-off index less than 11.

Antigens, Viral↗
PubMed1995

[Portal hemodynamic changes from TIPS--evaluation with pulse Doppler method].

Transjugular intrahepatic portosystemic shunt (TIPS) was applied in three patients with Child C liver cirrhosis. Portal venous pressure was reduced by an average of 10.7 mmHg, and results such as the disappearance of esophageal varices and reduction in ascites were obtained. The portal hemodynamics of these three patients was observed before and after TIPS using the pulse Doppler method. When portal hemodynamics in the main portal vein was examined before TIPS, it was found that the mean blood flow velocity had decreased, the blood flow volume was reduced and the cross-sectional area of the vein had increased. The congestion index was high and there was definite congestion of the portal venous system. After TIPS, the blood flow velocity and volume increased, the cross-sectional area of the vein was reduced and the congestion index was lower. Congestion of the portal venous system was improved in these three patients and the clinical efficacy of TIPS was proven by these results. If the stent can be detected sonographically, stent patency is easily confirmed with the pulse Doppler method which is usefull examination technique for follow-up of patients undergoing TIPS.

Aged↗
PubMed1995

[Detection of heterogeneous MRSA by using the PCR method and population analysis].

To assess the clinical usefulness of the PCR method for the detection of methicillin-resistant Staphylococcus aureus (MRSA) by targetting the mecA gene, we surveyed 150 clinical isolates of Staphylococcus aureus and compared the results of the PCR method with those of the standard broth microdilution method. Fifty-four isolates (36%) were positive for the mecA gene and two of them, presenting coagulase type IV, were recognized as susceptible strains by microdilution method, while all the other mecA positive strains were drug-resistant. Population analysis revealed that these two strains were heterogeneous in terms of drug-resistance and composed of two populations of cells; i.e., relatively susceptible cells and highly resistant cells. The discrepancy between the phenotypic expression (drug-resistance) and the genotype (mecA gene) seems to be due to the small percentage of highly resistant cells. Drug-resistant colonies could be induced in these strains by the contact with methicillin, indicating the selective increase of the population of resistant cells by a passage in the drug. These observations suggest that it is clinically important to detect the resistance-inducible strains (prototype MRSA) by using the PCR method and population analysis.

Bacteriological Techniques↗
PubMed1995

[A case report of acute aortic dissection with aortic regurgitation and cardiac tamponade: intimal tear just above commissure of right coronary cusp and left coronary cusp].

A 57-year-old man with acute dissecting aneurysm of the ascending aorta underwent immediate operation. Preoperative study showed aortic regurgitation and cardiac tamponade. The intimal tear originated just above commissure of right coronary cusp and left coronary cusp. The procedure was a combination of direct closure of the entry and dissecting space and resuspension of native aortic valve. It was preferential of simple intervention limited to the ascending aorta without using prosthesis. There was no complication such as aortic valve regurgitation, enlargement of the ascending aorta, or persistent of dissection during follow-up period of 12 months.

Acute Disease↗
PubMed1994

Ca(2+)-ATPase distributes differently in cardiac sarcolemma than dihydropyridine receptor alpha 1 subunit and Na+/Ca2+ exchanger.

We have investigated the distribution of the sarcolemmal Ca2+ transporters in hamster and dog ventricular myocytes by immunocytochemical and membrane fractionation techniques. The data suggest that the DHP receptor alpha 1 subunit and the Na+/Ca2+ exchanger are present in surface sarcolemma as well as T-tubule membranes located at the cardiac dyads. Compared with these Ca2+ transporters, the sarcolemmal Ca(2+)-ATPase is much less abundant in the latter fraction. Thus the sarcolemmal Ca(2+)-ATPase seems to be located predominantly in surface sarcolemma.

Animals↗
PubMed1994

Benign glandular peripheral nerve sheath tumor. A case report.

The glandular peripheral nerve sheath tumor is a rare variant of nerve sheath neoplasms in which the focally occurring glands are lined by cells showing divergent differentiation. The vast majority of the reported nerve sheath tumors harboring these glands have been malignant. We herein present a case of benign glandular peripheral nerve sheath tumor in a 43-year-old woman who had no evidence of von Recklinghausen's disease. Histologically, the tumor is composed of spindle cell component and collections of glandular component. The glandular component occupied the central two-thirds of the lesion and was lined by a single layer of nonciliated cuboidal or columnar cells. No mitotic figures were recognized in the spindle cell area. This spindle cell area had neurofibroma-like features rather than schwannoma. Many of the spindle cells had positive reaction products for S-100 protein. The glandular lining epithelium were positive for cytokeratins (CAM 5.2, AE1/AE3, PKK1) and EMA. Some epithelial cells were immunoreactive for CEA, chromogranin, somatostatin and Leu-7. These immunohistochemical findings support the neuroendocrine differentiation of the epithelial element from the schwannian component.

Adult↗
PubMed1994

Clinical applications of Lin's forceps in flexible hysteroscopy.

Eighty-one patients underwent directed biopsy with a large Lin's biopsy forceps during flexible hysteroscopy performed without cervical dilatation or anesthesia. Ninety-seven specimens were obtained, with an average size of 74.5 3(. For control study, 18 women underwent directed biopsy with a small conventional biopsy forceps. Nineteen specimens were obtained, with average size 3.4 mm3( (p <0.05). In eight women, lost intrauterine devices were retrieved with a large Lin's grasping forceps, which can easily grasp the device directly and remove it during flexible hysteroscopy.

Adult↗
PubMed1994

Removing a large submucous fibroid hysteroscopically with the two-resectoscope method.

Hysteroscopic myomectomy was performed in 25 patients using resectoscopes of two different sizes because of large submucous fibroids causing severe menorrhagia and anemia. The cervix was softened and dilated by inserting a laminaria tent the night before the operation. During the procedure a 7-mm resectoscope was first used to cut the pedicle to a size smaller than 10 mm. A sessile myoma was resected into a pedunculated myoma, and its body resected with a 9-mm resectoscope. The smaller portions were removed with a pair of forceps. Simultaneous ultrasonography was used to monitor the procedure. Specimen weights ranged from 50 to 145 g (mean 78.5 g). The operation time was 13 to 118 minutes (mean 49 min). No complications were encountered, other than a cervical laceration caused by forceps. Postoperatively, 22 patients had improvement of menorrhagia and anemia. Three women underwent the same procedure due to recurrence of the fibroid; two had full-term deliveries. Our method has proved to be safe and efficient for treatment of a sessile or large submucous fibroid.

Adult↗
PubMed1994

Increased damage to type II collagen in osteoarthritic articular cartilage detected by a new immunoassay.

A new immunoassay was developed to detect denaturation of type II collagen in osteoarthritis (OA). A peptide, alpha 1 (II)-CB11B, located in the CB11 peptide of type II collagen, was synthesized and used to produce a monoclonal antibody (COL2-3/4m) of the IgG1 (kappa) isotype. This reacts with a defined epitope in denatured but not native type II collagen and the alpha 3 chain of type XI collagen. The latter is present in very small amounts (about 1% wt/wt) in cartilage relative to the alpha 1 (II) chain. By using an enzyme-linked immunosorbent assay, type II collagen denaturation and total type II collagen content were determined. The epitope recognized by the antibody was resistant to cleavage by alpha-chymotrypsin and proteinase K which were used to extract alpha 1 (II)-CB11B from the denatured (alpha-chymotrypsin soluble) and residual native (proteinase K soluble) collagen alpha-chains, respectively, present in human femoral articular cartilage. Type II collagen content was significantly reduced from a mean (range) of 14% (9.2-20.8%) of wet weight in 8 normal cartilages to 10.3% (7.4-15.0%) in 16 OA cartilages. This decrease, which may result in part from an increased hydration, was accompanied by an increase in the percent denaturation of type II collagen in OA to 6.0% of total type II collagen compared with 1.1% in normal tissue. The percent denaturation was ordinarily greater in the more superficial zone than in the deep zone of OA cartilage.

Adult↗
PubMed1994

Acute pneumonitis presumed to be silicone embolism.

A 39-year-old housewife who underwent intramammary injections of a proprietary silicone fluid mixture showed clinical and novel transbronchial lung biopsy (TBLB) findings. She presented with complaints of progressive dyspnea, dry cough, and pleuritic chest pain 2 days after the last silicone injections. The chest X-ray and CT scan showed diffuse interstitial infiltrates. TBLB demonstrated translucent, presumably silicone globules embolized within the pulmonary capillaries. The documentation of intramammary injections, the clinical and radiographic features of acute pneumonitis, and the histopathologic evidence by TBLB, may support the causal relationship between illicit injections and the silicone embolism. We discuss the pathogenesis and urge that this potentially toxic source of pulmonary embolism be removed.

Acute Disease↗
PubMed1994

[Successful reconstruction of a skull base fracture with frontal lobe contusion by omental transplantation for recurrent posttraumatic tension pneumocephalus: a case report].

In July 1983, 26 year-old male was admitted to our neurosurgical clinic after severe head injury caused by a car accident. Recovery of consciousness was delayed for months due to bilateral frontal lobe contusions with anterior skull base fractures on both sides. He was first discharged 6 months after surgery for ventriculo-peritoneal shunting. He was readmitted to our department due to an episode of urinary incontinence with gait disturbance 11 months after the accident. CT film of the head revealed the presence of an air shadow at the left frontal base. Utilizing lyophyllized dura mater, the first cranial surgery for closure of cerebrospinal fluid leakage was carried out in July, 1984. Pneumocephalus with meningitis recurred again five years later. Repeated conventional surgery failed including a transsphenoidal and transfrontal sinus approach to treat the recurrent pneumocephalus. In order to close the defect in the skull base, and to obliterate the dead space in the left frontal lobe, vital tissue transplantation was planned. On May 23, 1990, seven years after the accident, the skull base defect was repaired by suturing fascia taken from the temporal muscle. Then the patient's vascularized omentum was utilized as an autograft by micro-surgical technique. A superficial temporal artery and vein, and superficial sylvian vein were used to vascularize the omentum. The patient has been totally free of pneumocephalus for more than three and half years following the radical surgery. Clinical omental transplantation using microsurgical technique for vascularization of cerebral circulation as well as plastic surgery has been reported.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Defective association of dystrophin with sarcolemmal glycoproteins in the cardiomyopathic hamster heart.

In ventricular muscle from 30- to 60-day-old Bio 14.6 cardiomyopathic hamsters, dystrophin-associated glycoproteins of 43, 50 and 150 kDa are markedly reduced in abundance. In particular, the 50-kDa glycoprotein is totally deficient in the sarcolemma of myopathic ventricular myocytes as revealed by immunofluorescence microscopy. The dystrophin-glycoprotein complex formation is defective in the cardiomyopathic hamster heart, because dystrophin and the glycoproteins behave independently when digitonin-solubilized ventricular homogenates are fractionated on wheat germ agglutinin beads or anti-dystrophin immunoaffinity beads.

Animals↗