PubMed Health⌕ Search

Biomedical subjects

T Urakami

Publications and source records attributed to T Urakami.

At least 19 recordsLinked to original sources
PubMed1998

Optical quantitation of absorbers in variously shaped turbid media based on the microscopic Beer-Lambert law. A new approach to optical computerized tomography.

To determine the concentrations of an absorber in variously shaped turbid media such as human tissue, we propose analytical expressions for diffuse re-emission in time and frequency domains, based on the microscopic Beer-Lambert law that holds true when we trace a zigzag photon path in the medium. Our expressions are implicit for the scattering properties, the volume shape, and the source-detector separation. We show that three observables are sufficient to determine the changes in the concentration and the absolute concentrations of an absorber in scattering media as long as the scattering property remains constant. The three observables are: the re-emission, the mean pathlength or group delay, and the extinction coefficient of the absorber. We also show that our equations can be extended to describe photon migration in nonuniform media. The validity of the predictions is confirmed by measuring a tissue-like phantom.

Humans↗
PubMed1998

[A case of recurrent esophageal cavernous hemangioma increasing rapidly after surgery].

A 40-year-old female was referred to our hospital for dysphagia. A hemangioma measuring 5 x 2.5 x 2.5 cm was revealed as a round defect by esophagography and was partially cystic on CT and MRI. Through a neck incision, the esophageal wall on the tumor side was initially opened. The tumor partially adhered to the esophageal wall, but was dissected from the esophageal wall and then resected easily. Microscopic examination of tumor revealed cavernous hemagioma. Thirty days after the initial surgery, the recurrent tumor was detected in the pharynx and increased rapidly. Then a second operation was performed. The tumor was completely resected by mucosectomy including normal esophageal mucosa. Recurrence was caused by residual cystic wall of the hemangioma adhering to the esophageal mucosa after the first procedure.

Adult↗
PubMed1998

Association of distal chromosome 2q with IDDM in Japanese subjects.

An insulin-dependent diabetes mellitus (IDDM)-susceptibility gene (IDDM13) has recently been mapped to a region of distal chromosome 2q, which is syntenic to the region of mouse chromosome 1 containing a murine susceptibility gene for IDDM, Idd5. To determine the contribution of this region to IDDM disease susceptibility further and to narrow the region for positional cloning of susceptibility genes, we have studied the association of distal chromosome 2q with IDDM in the genetically distinct Japanese population. A 137 mobility unit (mu) allele at D2S137 locus was significantly associated with IDDM (odds ratio 1.92, p = 0.0016). Other markers, D2S301 and D2S143, located in the same region were not associated with IDDM, indicating that IDDM13 is in linkage disequilibrium with D2S137, but not with D2S301 or D2S143. The association of D2S137 with IDDM was observed in patients lacking one of two high risk HLA alleles, DQBI*0303 and DQBI*0401, but not in patients with either of these alleles. The frequency of high risk HLA alleles was significantly lower in patients with the susceptible allele at D2S137, suggesting that IDDMI3 contributes to IDDM susceptibility in subjects without high risk genotypes at IDDM1. Demonstration of allelic association of D2S137 with IDDM localizes IDDM13 in the close vicinity (<2 centiMorgans) of D2S137, greatly facilitating fine structure mapping and positional cloning of IDDM13.

Adolescent↗
PubMed1998

Increased incidence of non-insulin dependent diabetes mellitus among Japanese schoolchildren correlates with an increased intake of animal protein and fat.

Non-insulin dependent diabetes (NIDDM) was diagnosed in 188 of more than 7 million Tokyo schoolchildren tested between 1974 and 1994 for glycosuria followed by oral glucose tolerance testing. The incidence rate of NIDDM in youth has continued to increase since 1976. While the daily energy intake has not changed significantly, the consumption of animal protein and fat by the Japanese population has greatly increased during the past two decades, and this change in diet, with low levels of physical activity, may exacerbate insulin resistance and glucose intolerance.

Adolescent↗
PubMed1997

Polycaprolactone depolymerase produced by the bacterium Alcaligenes faecalis.

Several microorganisms were isolated as bacteria degrading polycaprolactone (PCL), and one of them, a strain B273 identified as Alcaligenes faecalis, was selected. Because this strain produced only slight PCL depolymerase activity, the hyperproducing mutant, TS22, was isolated after UV irradiation. Synthesis of PCL depolymerase was derepressed, probably based on the altered regulation of metabolic pathways in strain TS22. The partially purified enzyme hydrolyzed p-nitrophenyl fatty acids and triglycerides other than PCL, but not poly(3-hydroxybutyrate), indicating that PCL depolymerase may be a kind of lipase.

Alcaligenes↗
PubMed1997

Purification and properties of poly(3-hydroxybutyrate) depolymerase from the fungus Paecilomyces lilacinus D218.

Poly(3-hydroxybutyrate) depolymerase was purified to homogeneity from the culture filtrate of Paecilomyces lilacinus D218 by column chromatography on CM-Toyopearl 650M and hydroxylapatite. The molecular weight of the enzyme was estimated to be 48,000 by SDS-PAGE. Maximal activity was observed near pH 7.0 and 45 degrees C. The Km and Vmax values for PHB were 0.13(mg/ml) and 3750 (U/mg protein), respectively. The enzyme hydrolyzed PHB and p-nitrophenyl fatty acids but not polycaprolactone and triglycerides.

Carboxylic Ester Hydrolases↗
PubMed1997

Synthesis of monoesters of pyrroloquinoline quinone and imidazopyrroloquinoline, and radical scavenging activities using electron spin resonance in vitro and pharmacological activity in vivo.

Monoesters with the ester groups at C-2 of pyrroloquinoline quinone (PQQ) and C-9 of imidazopyrroloquinoline (IPQ) were synthesized, and radical scavenging activities of coenzyme PQQ, IPQ compounds synthesized from PQQ and various amino acids, and monoesters of PQQ and IPQ were studied in vitro and in vivo. PQQ and PQQ monoesters had strong radical scavenging activity using ESR in in vitro experiments. The IC50 value for superoxide (O2-) was from 1 to 6 x 10(-8) M and that for the hydroxy radical (.OH) was from 4 to 6 x 10(-5) M. IPQ compounds and IPQ monoesters also showed radical scavenging activity. These compounds prevented injury during in vivo experiments, such as hydrocortisone-induced cataracts, endotoxin shock and CCl4-induced liver injury (isolated hepatocytes and rats). Especially, the monoesters of PQQ and IPQ prevented liver injury in rats equally by oral or intraperitoneal administration. These results suggest that PQQ functions as a radical scavenging factor in addition to being a cofactor of quinoprotein enzymes, and monoesters with the ester groups at C-2 of PQQ and C-9 of IPQ are developed as treatment or preventive medicine for disease caused by radical compounds on the basis of strong radical scavenging activities, absorbability into cells, toxicity, safety and chemical stability.

Administration, Oral↗
PubMed1997

[Evaluation of thoracoscopic surgery with mini-thoracotomy for primary lung cancer--as seen from the angle of lymph node dissection].

The extent of thoracoscopic surgery using a mini-thoracotomy for radical lung cancer surgery was investigated with regard to practical applicability. Thirteen patients with lung cancer underwent video-assisted lobectomy or segmentectomy and lymph node dissection through a 6-8 cm mini-thoracotomy. Eleven of thirteen cases were able to undergo video-assisted lobectomy and segmentectomy, but in one patient with strong adhesion and one patient who developed hemorrhage due to pulmonary arterial injury, thoracotomy was extended to 15-20 cm. Ten patients with lung cancer who underwent lobectomy under standard thoracotomy, underwent lymph node dissection under simulated 6-8 cm mini-thoracotomy. These ten cases and five cases who underwent lymph node dissection under 6-8 cm mini-thoracotomy were then switched over to standard thoracotomy to examine the possibility of residual lymph nodes. On the right-side, R2 lymph node dissection was practical, but on the left-side, #3, 3p, 4, 7 lymph node dissections were insufficient or impractical in some cases. The above results suggested that right-sided lobectomy is practical for radical thoracoscopic surgery with a mini-thoracotomy is practical for up to stage II. However, on the left side, the procedure should be confined to stage I.

Adenocarcinoma↗
PubMed1997

[Thoracoscopic surgery for benign esophageal diseases].

The thoracoscopic surgery for two benign esophageal diseases, esophageal leiomyoma and esophageal diverticulum, were successfully performed. Case 1 was a 37-year-old female with esophageal leiomyoma that was located at 30 cm from the incisor of the left anterior esophagus. The tumor was enucleated under the thoracoscopy, combined mini-thoracotomy for 3 cm in length. It was useful enough to rotate the left side to the right with two slings traction for better visualization of lesion site. After resection, the proper muscle layer of the esophagus was closed. Case 2 was a 70-year-old male, who complained of dysphagia because of esophageal diverticulum. It was 8 cm in size and located at 28 cm from the incisor of the right wall of the esophagus. It was also resected under the thoracoscopy, combined mini-thoracotomy for 3 cm in length. Intraluminal esophagoscope was useful to dissect safely and confirm the intralumen of the diverticulum. Its neck was divided parallel to the longitudinal axis of the esophagus by two endo-staplers. And then, the muscle layer was closed. It was suggested that esophageal leiomyoma and esophageal diverticulum were suitable for thoracoscopic surgery.

Adult↗
PubMed1997

[Three cases of thymic hyperplasia associated with hyperthyroidism].

We encountered three cases of thymic hyperplasia associated with hyperthyroidism. Case 1 was in a 35-year-old woman; a chest CT scan showed an anterior mediastinal mass and right-sided pleural effusion, which suggested the presence of a thymoma Case 2 was in a 21-year-old man who complained of palpebral ptosis and also had myasthenia gravis (Osserman type I). Case 3 was in a 47-year-old woman; a chest CT scan showed thymic hyperplasia and mediastinal lymphadenopathy. In all cases, anti-thyroid medication was given first, because of the associations with hyperthyroidism. Moreover, in cases 1 and 2 no tumor was found, and only hyperplasia was detected in the thymus, although both patients underwent extended thymectomy. Furthermore, surgery was not effective against the hyperthyroidism (anti-thyroid medication could not be withdrawn or reduced). In cases 2 and 3, thymic hyperplasia, as seen on chest CT scans, resolved as thyroid function was normalized by anti-thyroid medication. The pretracheal lymphadenopathy seen in case 3 also resolved. Thymic hyperplasia may have been a result, not a cause, of hyperthyroidism. When we encounter patients with thymic masses and hyperthyroidism, we should give anti-thyroid medication and observe the thymus for some time before resorting to surgery.

Adult↗
PubMed1997

[A case of pedunculated intrathoracic chest wall type lipoma].

The case was a 52-year-old female. Though the abnormal shadow on the chest X ray film was pointed out in 1990, she had been observed as a benign intrathoracic tumor for one year and four months. But she was admitted to our hospital for further evaluation because the mass shadow enlarged subsequently. The mass shadow was suspected as intrathoracic lipoma by the CT and MRI. However, because the shadow enlarged and its inner part was not single density that was equal to subcutaneous adipose tissues, left thoracotomy was performed. The tumor was pedunculated from the fatty tissue of the fifth intercostal space near the tubercle of rib. It was easily resectable, encapsulated and measured 6.0 x 3.5 x 2.5 cm in size. It was histologically diagnosed as benign lipoma. Preoperative diagnosis of the present tumor became possible to a certain extent by means of CT and MRI. However, in view of imperfect differentiation between lipoma and liposarcoma, the surgical treatment should be considered.

Female↗
PubMed1996

Synthesis and aldose reductase-inhibitory activity of imidazopyrroloquinoline esters.

Derivatives of imidazopyrroloquinoline (IPQ) and its esters were synthesized. Some of these compounds potently inhibited aldose reductases of rabbit lens and dog kidney, as well as the human recombinant enzyme, though the coenzyme pyrroloquinoline quinone (PQQ) was a relatively poor inhibitor. The IPQ esters with a methyl substituent at the C-3 carboxyl group were less potent inhibitors than the analogs without esterification at this position. An IPQ ester with the free carboxyl group at C-3 inhibited sorbitol accumulation in rat red blood cells.

Aldehyde Reductase↗
PubMed1995

Serial changes in the prevalence of islet cell antibodies and islet cell antibody titer in children with IDDM of abrupt or slow onset.

OBJECTIVE: To elucidate the significance of clinical and immunogenic heterogeneity in Japanese children with insulin-dependent diabetes mellitus (IDDM). RESEARCH DESIGN AND METHODS: Serial changes in the prevalence of islet cell antibodies (ICAs) and in ICA titer were monitored for 10 years after diagnosis in 34 IDDM children, 17 with abrupt onset and 17 with slow onset, whose durations of disease were > 5 years. RESULTS: In slow-onset IDDM children, enough beta-cell function was maintained in the early phase of the disease within 2 years after diagnosis. There was a high prevalence of ICAs in children with both forms of IDDM at the time of diagnosis (abrupt onset 94%; slow onset 82%). However, the decline in the frequency of ICAs in slow-onset IDDM seemed less marked than in abrupt-onset IDDM after a duration of > or = 1 year (47 vs. 82%, 1-3 years; 24 vs. 47%, 3-5 years; 24 vs. 47%, 5-7 years; 18 vs. 53%, 7-10 years, P < 0.05). In terms of changes in ICA titer, abrupt-onset IDDM children initially had high ICA levels of 160-320 Juvenile Diabetes Foundation units (JDF U), but these titers decreased rapidly after the 1st year. On the other hand, slow-onset IDDM children tended to continue to be ICA+ for a relatively long period with low titers of 20-40 JDF U. Among 12 children who remained ICA+ for > 5 years, slow onset was noted in 67% while abrupt onset was seen in only 33%. CONCLUSIONS: From these results, we speculated that changes in ICA titer reflect the slow autoimmune destruction of pancreatic beta-cells. It may be probable that immunogenic factors as well as environmental factors could affect the clinical features in the early phase of IDDM in children.

Age of Onset↗
PubMed1994

Association of polymorphism in the interferon gamma gene with IDDM.

Cytokines may play important roles in the pathogenesis of insulin-dependent diabetes mellitus (IDDM). We analysed a dinucleotide repeat polymorphism within the first intron of the interferon gamma (IFN-gamma) gene in Japanese diabetic patients (175 IDDM and 145 non-insulin-dependent diabetes mellitus) and 267 control subjects. A significant difference was observed in the global allele distribution of the polymorphism between the IDDM and control groups (p = 0.039). The difference from the control group was more evident in the patients whose insulin therapy started within 1 year from onset (p = 0.006) or in the young-onset (< 10 years) patients (p = 0.0006). The alleles "3" and "6" were increased in the IDDM patients, and a significant increase in the frequency of the "3/6" genotype was observed in the IDDM patient group (9.1%, RR 2.9, p = 0.010), in the patients with initial insulin therapy less than 1 year from onset (10.6%, RR 3.4, p = 0.004), or in the young-onset patients (16.7%, RR 5.7, p = 0.0003) in comparison to the control subjects (3.4%). There was a tendency towards frequent occurrence of clinical characteristics which reflect young or abrupt onset of diabetes or both, and depletion of insulin secretion capacity in the patients with "3/6" or "6/6" in comparison to the patients with other genotypes. These results suggest that the IFN-gamma gene region may contribute to the pathogenesis of IDDM and could be a genetic marker for IDDM.

Adult↗
PubMed1994

Epidemiology of type 1 (insulin-dependent) and type 2 (non-insulin-dependent) diabetes mellitus in Japanese children.

The overall annual IDDM incidence rates by area in Japan for 1985-1989 for children 0-14 years of age at diagnosis were from 1.65 to 2.07 per 100,000. The incidence in males and females did not show any temporal trends during the period between 1980 and 1989. The prevalence of IDDM was about 1 per 10,000. The clinical features at diagnosis among Japanese IDDM children identified during the 2-year period between 1979 and 1980 were as follows. Fourteen percent of the cases were in coma and 12% of the cases were asymptomatic at diagnosis. There is a suggestion that slow onset IDDM is often seen in Japan. In these children, the decline of serum CPR levels and the prevalence of ICA (islet cell antibodies) over the course of diabetes was slower than in those with an abrupt onset classical IDDM. During the period from 1975 through 1990 the incidence rates of NIDDM in school children showed as much as an approximate 1.5-fold increase along with a similar increase in the prevalence of obesity. About eighty percent of these NIDDM children were obese. A predominance of female children developing diabetes was seen in both type of diabetes, IDDM and NIDDM, in Japan. Non-obese type NIDDM in children was more common in females than in males. It is interesting to note that the mean height of Japanese children with IDDM was not different from the national average, but children with NIDDM were significantly taller than the national average.

Adolescent↗
PubMed1994

Enzyme immunoassay for erythrocyte aldose reductase.

This two-site immunoassay measures erythrocyte aldose reductase by using monoclonal and polyclonal antibodies to recombinant human enzyme. Total incubation time is 2.5 h, and the limit of detection is < 0.05 microgram/L. Analytical recovery tested with blood samples from healthy and diabetic individuals was 101-106%. Average CVs within and between assays were 3.7% and 4.8%, respectively. The enzyme content determined by this system correlated well with the activity of aldose reductase isolated from the same erythrocyte preparations. The amount of erythrocyte aldose reductase per milligram of hemoglobin was higher in women than in men (P < 0.001), but no significant correlation was observed between the amount of enzyme and the age of the individuals. This assay method should provide useful clinical information to optimize administration of aldose reductase inhibitors for effective prevention and treatment of diabetic complications.

Adult↗
PubMed1993

Recombinant human granulocyte colony-stimulating factor therapy for cyclic neutropenia associated with common variable immunodeficiency.

A 14 year old boy with common variable immunodeficiency (CVID) had regularly recurring episodes of severe infections independently of the serum gamma-globulin level. Serial blood counts revealed that this patient also had cyclic neutropenia. Recently, recombinant human granulocyte colony-stimulating factor (rhG-CSF) was reported to be an effective treatment for this disease. We tried rhG-CSF therapy for this patient and a prompt increase in the neutrophil count was noted. However, the cyclic alterations and duration of the nadir of the neutrophil count were not altered, which suggested that rhG-CSF has a variable efficacy in at least some patients with cyclic neutropenia.

Adolescent↗