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Biomedical subjects

A Momose

Publications and source records attributed to A Momose.

At least 37 records · Page 2Linked to original sources
PubMed1996

Theoretical relationship between the post-administration time and plasma or urinary concentration of a metabolite and the unchanged drug. Administration of caffeine to horses.

In a doping test for racing horses, it is useful for the elucidation of the illegal use of drugs if one can estimate the time at which the detected drug was administered. In order to estimate the time which has elapsed after the administration of caffeine (CA) into horses, the ratios of concentration for the respective metabolites to the unchanged CA in the plasma or the urine were determined. These ratios have been known to be independent of the dose of CA. The relationship between [plasma or urinary concentration of a metabolite]/ [plasma or urinary concentration of the unchanged drug] and the post-administration time of CA was expressed in a theoretical equation using pharmacokinetic parameters. When CA was administered at 2.5 mg/kg intravenously, intramuscularly or orally, all of the experimentally observed values of plasma or urinary metabolites: theophylline, theobromine and paraxantine, agreed well with the theoretical formulas, indicating that there exists a theoretical relationship between the post-administration time and the concentration ratio of the respective metabolites to unchanged CA.

Animals↗
PubMed1995

Contrast effect of blood on phase-contrast X-ray imaging.

RATIONALE AND OBJECTIVES: As a preliminary study for application of phase-contrast X-ray imaging to medicine, we measured the X-ray refractive index of human blood and its influence on image contrast. METHODS: Using an X-ray interferometer, the X-ray phase shifts caused by human blood and its ingredients were measured from the interval of interference fringes. RESULTS: The X-ray phase shift caused by blood was 3% larger than that caused by serum. CONCLUSION: The large phase shift caused by blood is due to red blood cells, which contain hemoglobin molecules with iron atoms. It is possible that blood produces a structure in a phase-contrast X-ray image.

Blood↗
PubMed1995

Phase-contrast imaging with synchrotron X-rays for detecting cancer lesions.

RATIONALE AND OBJECTIVES: We obtained image contrast in pathologic specimens without the use of contrast material by using phase-contrast imaging with synchrotron X-rays. METHODS: An experiment was performed at the three-pole superconducting vertical wiggler beam line BL-14B at the Photon Factory in Tsukuba, Japan. The X-ray phase-contrast imaging system consisted of a double crystal monochromator, an asymmetrically cut crystal monochromator, a triple Laue-case X-ray interferometer, and film. The pathologic specimen was a sample from human liver that had metastatic carcinoma. RESULTS: The X-ray phase-contrast images of the pathologic specimen clearly depicted the cancerous lesion without the use of contrast enhancement, and the image showed good correlation with the photograph of the specimen. The X-ray absorption image did not differentiate between the normal liver tissue and the tumor. CONCLUSION: The results of this preliminary experiment reveal that for materials such as biologic specimens with a low atomic number, X-ray phase-contrast imaging better differentiates tissues than does the absorption contrast imaging commonly used in radiology.

Humans↗
PubMed1995

Phase-contrast radiographs of nonstained rat cerebellar specimen.

Phase-contrast radiography using an x-ray interferometer is presented for observing organic matter. High sensitivity of phase-contrast radiography is demonstrated with a rat cerebellar specimen without staining it with a contrast medium. The layer structure of the cerebellum can be observed in the obtained image while there is no clear structure in the corresponding absorption-contrast image. Quantitative image analysis is made possible by converting an x-ray interference pattern to an x-ray phase shift distribution. The lipid distribution in the cerebellum is discussed by evaluating x-ray phase shifts before and after lipid removal.

Animals↗
PubMed1995

Effects of exercise on plasma concentrations of caffeine and its metabolites in horses.

The effects of exercise on the metabolism of caffeine (CA) were studied 3h after administration of the drug to race horses which then underwent exercise sets (1000-m gallop). Analysis was made of pharmacokinetics of CA, changes in its plasma concentrations, its metabolites, i.e., theophylline (TP), theobromine (TB) and paraxanthine (PX), and the molar concentration ratios of CA to these metabolites. After exercise, AUC and t1/2 tended to decrease, and the concentration of CA decreased, while the concentrations of TP and TB significantly increased. The TP/CA ratio and TB/CA ratio significantly increased from 6 to 74h and from 25 to 50h after drug administration, respectively. This indicated promotion of metabolism of CA into TP and TB. The effects on PX were minimal.

Animals↗
PubMed1994

Eleven-year experience with radial keratotomy.

1,900 consecutive eyes that underwent radial keratotomy by the senior author were evaluated retrospectively. 3 months after surgery, minimum reduction in mean spherical equivalent of 0.67D was achieved with 1 incision and maximum 7.25D with 24 incisions. Uncorrected visual acuity of 20/40 or better was obtained in 99.4% of eyes with low myopia, 64.2% with moderate myopia and 32.4% with high myopia. For anisometropia, bilateral RK reduced refractive error from -12. 12D to -5. 22D in more myopic eyes and -8. 18D to -3. 4D in less myopic eyes and unilateral surgeries reduced refractive error from -9. 45D to -3. 85D. Anisometropia after surgery became clinically and physically acceptable and aniseikonia was significantly improved. No vision threatening complications occurred. Our results indicate that radial keratotomy is a relatively safe and effective surgical procedure for myopia.

Adolescent↗
PubMed1994

[The follow-up survey of results of radial keratotomy].

We reviewed 119 cases of consecutive radial keratotomies of 67 patients who were followed up for three years to evaluate the stability and safety of the surgery. The average change of overall refraction was -0.12D between one year and three years after the surgery, which was statistically insignificant. Stable refractive results were achieved in 72.3% of the eyes. 16.8% of the eyes experienced an increase from -1.00D to 2.50D, and 10.9% displayed a decrease from 1.00D to 3.50D. Eyes with preoperative high myopia were more likely to cause significant postoperative refractive change. In three years, 8.5% of the eyes gained the best corrected visual acuity of two to four lines. 2.6% of the eyes lost two lines because of macular disorders. Specular microscopy indicated that there was no significant change in corneal endothelial cell density following radial keratotomy.

Adolescent↗
PubMed1993

Response to octreotide of intestinal pseudoobstruction and pneumatosis cystoides intestinalis associated with progressive systemic sclerosis.

Intestinal pseudoobstruction and pneumatosis cystoides intestinalis are uncommon complications of progressive systemic sclerosis. We report a 26-year-old woman with this disorder who responded poorly to conventional treatment. Subcutaneous administration of octreotide, a long-acting somatostatin analogue, at a dose of 50 micrograms/day for 3 weeks, relieved symptoms such as nausea and bloating. There was also a marked decrease of intestinal gas accumulation, as documented on X-ray films.

Adult↗
PubMed1993

Histopathological study of pseudophakic bullous keratopathy developing after anterior chamber of iris-supported intraocular lens implantation.

Sixty corneal buttons excised from patients who developed pseudophakic bullous keratopathy after anterior chamber or iris-supported intraocular lens implantation were studied morphologically and statistically. The mean age of patients was 72.5 +/- 11.6 years. The mean interval between intraocular lens implantation and keratoplasty was 5.1 +/- 2.2 years. Degeneration and conversion of endothelial cells, abnormal proliferation of posterior collagenous layer, and edema of stroma and epithelium were noticed morphologically. Twenty-nine of the 60 specimens showed a surviving endothelial cell area of less than 50%. In these specimens a significant increase in the thickness of the central stroma was recognized compared with the other 31 specimens. The number of keratocytes in the 29 specimens had decreased significantly compared with the control. A linear regression study showed a significant relationship between the thickness of the stroma and the number of keratocytes. The keratocyte density decreased predominantly in the posterior part of the stroma.

Adult↗
PubMed1992

Left ventricular filling abnormalities in non-insulin-dependent diabetes mellitus and improvement by a short-term glycemic control.

To determine whether left ventricular (LV) filling abnormalities in diabetes are associated with diabetic microangiopathy, and to evaluate the effect of a short-term glycemic control on the filling abnormalities, diastolic filling dynamics were assessed by pulsed Doppler echocardiography in 246 patients with non-insulin-dependent diabetics. Isovolumic relaxation time and the ratio of peak flow velocity of atrial filling wave to peak flow velocity of early filling wave (A/E) were significantly greater in diabetic patients than in age- and sex-matched control subjects. Diabetic patients with retinopathy had significantly greater isovolumic relaxation time and A/E values than those without retinopathy. A/E was significantly decreased 1 month after insulin treatment in those without, but not with retinopathy. It is concluded that LV diastolic filling is impaired in mildly hyperglycemic patients with non-insulin-dependent diabetes mellitus without severe complications, the abnormality being more intense in patients with retinopathy. A short-term glycemic control results in a marked decrease in abnormalities in patients without, but not with retinopathy.

Adult↗
PubMed1992

Silent myocardial ischemia in patients with non-insulin-dependent diabetes mellitus as judged by treadmill exercise testing and coronary angiography.

Patients with diabetes were compared with nondiabetic control subjects, with respect to the prevalence of silent myocardial ischemia, by means of treadmill exercise testing and coronary angiography. Results of treadmill exercise testing showed ischemic ST depression in 41 of the 132 diabetic patients (mean age 61 +/- 4 years) and in 42 of the 140 nondiabetic control subjects (mean age 60 +/- 8 years) (31% vs 30%, p = NS). Coronary angiography was performed in 36 of 41 diabetic patients and 34 of 42 nondiabetic control subjects with positive results of treadmill exercise tests, who gave their consent. Among "treadmill-positive" subjects, diabetic patients had a prevalence of silent myocardial ischemia that was 2.2 times higher than that in nondiabetic control subjects (p less than 0.05). Diabetic patients who received insulin had a 2.6 times higher prevalence of silent myocardial ischemia than those who did not (p less than 0.05). Similarly diabetic patients with retinopathy has a 2.5 times higher prevalence of silent myocardial ischemia than those without it (p less than 0.05).

Aged↗
PubMed1991

Pharmacokinetics of caffeine and its metabolites in horses after intravenous, intramuscular or oral administration.

The pharmacokinetics of caffeine (CAF) and its metabolites, dimethylxanthines, were examined in horses administered 2.5 mg/kg of CAF intravenously (i.v.), intramusculary (i.m.), or orally (p.o.). The plasma samples were extracted by Extrelut and the concentrations of CAF and metabolites were determined by high performance liquid chromatography (HPLC) with a short column. The pharmacokinetics of CAF after bolus i.v. injection were described by the assumption of a two-compartment model, and those of CAF after i.m. or p.o. administration were done by the assumption of a one-compartment model. The biologic half lives of CAF were 15.5, 18.6, and 16.4 h after administering i.v., i.m. and p.o., respectively. The extent of the bioavailability of the p.o. administration was determined as 1.04 times the dose. The differences in pharmacokinetic parameters were not statistically significant among administration routes. A straight correlation existed between the logarithms of body weights of different species of animals and those of their biologic half lives of CAF. Therefore, the biologic half life of CAF in an animal might be predictable as a function of its body weight.

Administration, Oral↗
PubMed1991

[Refractive regression after intraocular lens implantation].

Study of refractive changes after IOL implantation in 147 eyes revealed that astigmatism tended to increase, and the natural regressive course followed a negative exponential function, with the steep phase within 3 weeks for spherical, and 5 weeks for cylindrical errors. One (1) week after surgery, the axis of astigmatism was predominantly with the rule, and 2 months after operation, patients with preoperative WRA changed into various astigmatic axial directions, while 76.4% of the patients with preoperative ARA reverted to ARA. Those eyes in which the astigmatic axis was not horizontal 1 week after operation ended with stronger astigmatism in 2 months.

Astigmatism↗
PubMed1991

Thirty-six month follow-up of a contemporary phakic intraocular lens for the surgical correction of myopia.

Twenty-three eyes underwent implantation of a glass anterior chamber phakic myopic intraocular lens by one of the surgeon co-authors. The follow-up was 18 to 36 months. All refractions were unchanged and stable within six weeks after surgery. Best-corrected visual acuity was achieved in all cases; in 56% of operated eyes, a one-to-three line visual improvement was noted over the preoperative status. No operative complications were encountered; no postoperative complications were noted in either the immediate or delayed phase. No intraocular lenses were removed. There was a 5.3% loss in endothelial cell count which was unchanged throughout the study. The contemporary phakic myopic intraocular lens offers a seminal approach to the surgical treatment of myopia.

Adult↗
PubMed1989

Thin-layer chromatographic screening procedure for some drugs in horse plasma.

A thin-layer chromatographic screening procedure for some basic, neutral and acidic drugs was developed using 3 ml of horse plasma. Chloroform-2-propanol (95:5, v/v) was used as the extraction solvent. The drugs were identified by a high-performance thin-layer chromatographic plate and spraying successively with some detection reagents. In this study, the extraction recovery rates and the detection limits were determined at the same time.

Animals↗
PubMed1989

[Long-term survival of a patient with pseudoaneurysm of the left ventricle following myocardial infarction].

A 76-year-old man had an extensively calcified left ventricular pseudoaneurysm which was a sequela of acute myocardial infarction suffered 22 years ago. He experienced acute anterolateral myocardial infarction in January 1964. In March 1964, the presence of a left ventricular aneurysm was suspected by chest radiography and fluoroscopy. He was, however, in good health since then. In April 1986, when he was admitted for treatment of acute bronchitis, a large calcified density was found in the left ventricular region on chest radiography. The electrocardiogram was compatible with an old anterolateral myocardial infarction. Two-dimensional echocardiography showed an immobile portion of the left ventricle which contained "moya-moya" (sluggish, smoky) echoes. A saccular aneurysm of the left ventricle was confirmed by radioisotope cardiac pool scans, reconstruction CT and left ventriculography. Due to the poor general condition of the patient, we followed his course without surgery. He died in October 1986. At autopsy, the pseudoaneurysm was markedly calcified, and its wall was adherent to the parietal pericardium. Histologically, the pseudoaneurysmal structure turned out to be a pseudoaneurysm since the saccular wall contained only scar tissue but no myocardial cells. This is a very rare case of a patient with a left ventricular pseudoaneurysm who survived for 22 years after its occurrence.

Aged↗