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Biomedical subjects

Y Sadamoto

Publications and source records attributed to Y Sadamoto.

At least 19 recordsLinked to original sources
PubMed2002

A useful approach to the differential diagnosis of small polypoid lesions of the gallbladder, utilizing an endoscopic ultrasound scoring system.

BACKGROUND AND STUDY AIMS: The purpose of this study was to assess the accuracy of endoscopic ultrasonography (EUS) in making a differential diagnosis of small (< or = 20 mm in diameter) polypoid lesions of the gallbladder, and to construct an EUS scoring system. PATIENTS AND METHODS: The EUS findings were retrospectively analyzed in 70 surgical cases of small polypoid lesions classified into two groups: neoplastic (adenocarcinoma in 11, and adenoma in 7), and non-neoplastic (cholesterol polyp in 44, inflammatory polyp in 7 and fibrous polyp in 1). The EUS variables were the maximum diameter and height/width ratio of the largest polyps, echo level, internal echo pattern, surface patterns, number and shape of polyps, presence of hyperechoic spotting, complication of gallbladder stones. The EUS data were used for the construction of an EUS scoring system to ascertain the risk of neoplasia. RESULTS: Three EUS variables, i. e. tumor maximum size, internal echo pattern, and hyperechoic spotting were statistically significant according to multivariate analysis using stepwise logistic regression models (P < 0.01, P < 0.05, and P < 0.01, respectively). The total EUS score based on the coefficient of multivariate analysis was as follows: (maximum diameter in mm) + (internal echo pattern score; where heterogeneous = 4, homogeneous = 0) + (hyperechoic spot[s] score; where presence = - 5, absence = 0). According to our EUS scoring system, the sensitivity, specificity, and accuracy for the risk of neoplastic polyps with scores of 12 or higher were 77.8 %, 82.7 % and 82.9 %, respectively. CONCLUSIONS: The EUS scoring system will be a useful means of differentiating between neoplastic and non-neoplastic polyps of the gallbladder.

Adenocarcinoma↗
PubMed2000

[A case of advanced hepatocellular carcinoma with lung and bone metastases effectively treated by orally administered UFT].

A 52-year-old male underwent hepatic subsegmentectomy for hepatocellular carcinoma (HCC). Five months later, a recurrent tumor was found in the liver and transcatheter arterial embolization (TAE) was performed. However, recurrent tumors were growing rapidly with multiple lung and bone metastases. The titer of serum AFP was elevated to 896,095 ng/ml and the titer of serum PIVKA-II was elevated to 1294.5 AU/ml. The patient was treated by oral administration of UFT (600 mg/day). Two weeks later, his general condition was improved, and several months later, the liver tumor, multiple lung metastases and multiple bone metastases had almost disappeared. The titers of serum AFP and PIVKA-II were reduced to the normal range. He has maintained a good state of health for about four years now. This case suggests the clinical usefulness of UFT for advanced HCC.

Administration, Oral↗
PubMed1999

An 18-mer peptide fragment of prosaposin ameliorates place navigation disability, cortical infarction, and retrograde thalamic degeneration in rats with focal cerebral ischemia.

It was previously reported that prosaposin possesses neurotrophic activity that is ascribed to an 18-mer peptide comprising the hydrophilic sequence of the rat saposin C domain. To evaluate the effect of the 18-mer peptide on ischemic neuronal damage, the peptide was infused in the left lateral ventricle immediately after occlusion of the left middle cerebral artery (MCA) in stroke-prone spontaneously hypertensive (SP-SH) rats. The treatment ameliorated the ischemia-induced space navigation disability and cortical infarction and prevented secondary thalamic degeneration in a dose-dependent manner. In culture experiments, treatment with the 18-mer peptide attenuated free radical-induced neuronal injury at low concentrations (0.002 to 2 pg/mL), and the peptide at higher concentrations (0.2 to 20 ng/mL) protected neurons against hypoxic insult. Furthermore, a saposin C fragment comprising the 18-mer peptide bound to synaptosomal fractions of the cerebral cortex, and this binding decreased at the 1st day after MCA occlusion and recovered to the preischemic level at the 7th day after ischemia. These findings suggest that the 18-mer peptide ameliorates neuronal damage in vivo and in vitro through binding to the functional receptor, although the cDNA encoding prosaposin receptor has not been determined yet.

Amino Acid Sequence↗
PubMed1999

Acanthosis nigricans with severe obesity, insulin resistance and hypothyroidism: improvement by diet control.

We report on a 27-year-old man with acanthosis nigricans (AN) associated with severe obesity, insulin resistance and hypothyroidism. A very low-calorie diet treatment decreased his weight and then ameliorated the insulin-resistant state. These effects were followed by remarkable improvement of the AN prior to the correction of the hypothyroidism. This confirms that AN may be mainly attributed to insulin resistance rather than hypothyroidism per se.

Acanthosis Nigricans↗
PubMed1998

Erythropoietin prevents place navigation disability and cortical infarction in rats with permanent occlusion of the middle cerebral artery.

Erythropoietin (EPO) prevents the ischemia-induced delayed neuronal death in the hippocampal CA1 field in gerbils. EPO receptor (EPOR) is also expressed in the cerebral cortex but its function is not known. To examine whether EPO has a neuroprotective action in the cortex, EPO was infused into the cerebroventricles of stroke-prone spontaneously hypertensive rats with permanent occlusion of the left middle cerebral artery. Morris water maze test indicated that EPO infusion alleviated the ischemia-induced place navigation disability. The left (ischemic)-to-right (contralateral nonischemic) (L/R) ratio of cerebrocortical area in the EPO-infused ischemic group was larger than that in the vehicle-infused ischemic group. The occlusion caused secondary thalamic degeneration but infusion of EPO prevented the decrease in the L/R ratio of thalamic area and supported neuron survival in the ventroposterior thalamic nucleus. In situ hybridization indicated that EPOR mRNA was upregulated in the periphery (ischemic penumbra) of a cerebrocortical infarct after occlusion of the middle cerebral artery, suggesting that an increased number of EPOR in neurons facilitates the EPO signal transmission, thereby preventing the damaged area from enlarging.

Animals↗
PubMed1998

Retroperitoneal Castleman's disease of the hyaline vascular type presenting arborizing calcification.

Castleman's disease (CD) usually manifests as a solitary mediastinal tumor and only rarely as an isolated retroperitoneal mass. In the latter instances it is difficult to distinguish radiographically from other retroperitoneal masses. We report a 22-year-old female patient with retroperitoneal CD of the hyaline vascular type presenting with arborizing calcification. This characteristic calcification pattern is considered unique to CD, and is useful in diagnosis when present.

Adult↗
PubMed1998

[Partial splenic embolization as a preoperative treatment for refractory idiopathic thrombocytopenic purpura].

A 53-year-old woman presented with idiopathic thrombocytopenic purpura (ITP) that was refractory to corticosteroid therapy. Her bleeding had worsened gradually due to prolonged thrombocytopenia, but her low platelet count after high-dose intravenous gamma globulin therapy contraindicated a splenectomy. We therefore decided to perform a partial splenic embolization (PSE). The patient's platelet count increased gradually thereafter, allowing us to safely perform a splenectomy. We concluded that PSE is a useful preoperative procedure, especially for patients with ITP that is refractory to high-dose intravenous gamma-globulin therapy. Moreover, it is possible to predict the effects of a splenectomy preoperatively if the PSE procedure is used.

Embolization, Therapeutic↗
PubMed1991

The effect of 1,25-dihydroxyvitamin D3 on the growth and differentiation of cultured human outer root sheath cells from normal subjects and patients with vitamin D-dependent rickets type II with alopecia.

We examined the effect of 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) on the growth and differentiation of cultured human hair outer root sheath cells (ORSC) from normal subjects and patients with vitamin D-dependent rickets type II (DDR-II) with alopecia. 1,25(OH)2D3 dose-dependently suppressed the plating efficiency, clonal growth, and DNA synthesis of normal ORSC. It enhanced the cornified envelope formation and caused morphological changes in the cells. All results indicated the existence of specific receptors for 1,25(OH)2D3 in the ORSC, and suggest that 1,25(OH)2D3 is a potent inhibitor of proliferation of ORSC as well as a stimulator of terminal differentiation. However, the cells from DDR-II patients with alopecia did not respond to 1,25(OH)2D3, suggesting a lack of the specific receptors in the cells. The differences in the cellular response to the hormone between the normal ORSC and those from the patients were apparent and easily distinguishable, therefore this experiment may be a rapid and simple diagnostic test for DDR-II patients with alopecia. Large number of hairs were difficult to obtain from patients with alopecia, and we developed a new culture method to accomplish these studies from a few plucked hair follicles. Our system may be useful in the culture of ORSC from limited number of follicles, and could be utilized to analyse the cellular characteristics of ORSC in patients with hair diseases.

Alopecia↗
PubMed1991

Culture of human outer root sheath cells from plucked hair follicles in serum-free conditions.

We succeeded in culturing human outer root sheath cells (ORSC) in serum-free conditions without a biological feeder layer. The combination of collagen type IV substrate and modified MCDB 153 medium supplemented with bovine pituitary gland extract (K-GM medium) could support the growth of ORSC. These cells can be serially cultivated for at least 4 passages and stored in liquid nitrogen with good recovery. Thus, a large series of experiments using ORSC may be run simultaneously.

Cell Division↗
PubMed1990

A new method for culturing human hair follicle cells on floating mixed collagen membranes.

A new method for culturing human hair follicle cells without a biological feeder layer has been developed. Dispersed hair follicle cells obtained from plucked hairs have been successfully grown on floating mixed collagen membranes (collagen types I and IV) and have reached a confluent state. They could be subcultured up to twice. Differentiation of the cells was maintained throughout a month in culture. Stratification of the cells and continuous epithelial pavement formation were seen, as in cultured epidermal keratinocytes.

Collagen↗
PubMed1990

Eosinophilic polymyositis induced by tranilast.

A 38-year-old man with asthma developed eosinophilic polymyositis following the administration of Tranilast, an antiasthmatic agent. Low grade fever, erythematous rashes on the entire body, dysphagia, blood eosinophilia, elevations of serum creatine phosphokinase and myoglobin levels, and inverted T waves in the electrocardiogram were noted. A muscle biopsy showed focal degeneration of muscle fibers with an infiltrate of eosinophils and lymphocytes. A rechallenge with Tranilast resulted in erythema formation, blood eosinophilia, and elevations of some serum muscle enzymes and myoglobin levels. Tranilast was considered to be the causative agent. This is the first reported case of Tranilast-induced eosinophilic polymyositis.

Asthma↗
PubMed1990

Co-culture of human hair follicles and dermal papillae in a collagen matrix.

Human hair follicles, either alone or in combination with dermal papillae, were cultured in a collagen matrix. When plucked hair follicles were cultured alone, spike-like structures composed of outer root sheath cells started growing around the follicle and then radiated into the gel. When isolated dermal papillae were embedded close to the follicles, spikes started growing earlier and grew more rapidly than without the papillae. In cultures of excised follicles from which the dermal papilla had been removed, epithelial cells (possibly hair bulb cells) started growing out from the bulbous portion and then also formed spikes. In the presence of a papilla, the spikes elongated toward the papilla, finally reaching and surrounding it. These findings suggest that dermal papilla cells produce a factor(s) that enhances growth of follicular epithelial cells and also attracts those cells. In cultures of whole excised follicles, two major characteristic patterns of cellular growth were recognized. When the dermal papilla remained inside the bulb in contact with the hair bulb matrix, the hair matrix cells proliferated and differentiated in the normal manner, resulting in elongation of the hair shaft and follicle. But when the papilla was detached from the hair bulb matrix, epithelial cells proliferated from the bulbous portion and finally formed hair follicle-like structures. Thus, attachment of the dermal papilla to the hair bulb matrix in the bulbous portion appears to be necessary for growth of the hair and follicle in the normal manner. Our model may be useful for examining the interaction between follicular epithelial cells and dermal papillae and for studying the growth of hair and follicles in vitro.

Adult↗