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Biomedical subjects

K Asano

Publications and source records attributed to K Asano.

At least 55 records · Page 3Linked to original sources
PubMed2001

Strain difference in regulation of pituitary tumor transforming gene (PTTG) in estrogen-induced pituitary tumorigenesis in rats.

Recently a novel oncogene, PTTG (pituitary tumor transforming gene) was isolated from a rat pituitary tumor cell line whose expression is apparently correlated with pituitary tumorigenesis. In the rat, estradiol (E(2)) is known to induce anterior pituitary hyperplasia. The effects of E(2), however, vary greatly among rat strains. Therefore we examined the expression of PTTG and its regulation by E(2) in F344, Wistar, Brown-Norway and Donryu rats. Four-week-old females were ovariectomized and a pellet containing 10 mg of E(2) was given s.c. Total RNA was isolated from the pituitary gland and PTTG mRNA was measured with a competitive RT-PCR technique. The F344 strain was the most susceptible to E(2) induction of pituitary tumorigenesis, followed by Wistar and Brown-Norway, while no increase in pituitary weight was noted in Donryu rats. PTTG mRNA in the gland was induced by E(2) within 48 - 72 h in F344 and Wistar, but not in Brown-Norway or Donryu strains. These data suggest that PTTG expression may at least in part be responsible for strain differences in E(2)-induced pituitary tumorigenesis.

Animals↗
PubMed2001

Genetic polymorphisms of CC chemokine receptor 3 in Japanese and British asthmatics.

Whole genome scan analyses have revealed that chromosomal region 3p21-24, which contains a gene cluster of CC chemokine receptors such as CCR3, is possibly linked to asthma. Because CCR3 ligands play a pivotal role in the selective recruitment and activation of inflammatory cells in the asthmatic airway, the authors examined whether there is any association between asthma and the CCR3 gene polymorphisms. Three polymorphisms were identified using the single stranded conformational polymorphism method in Japanese (Asian) and British (Caucasian) subjects; one silent mutation T51C and two missense mutations G824A and T971C. These polymorphisms were examined in 391 Japanese subjects (210 asthmatics and 181 nonasthmatic controls) and 234 British subjects (142 asthmatics and 92 nonasthmatic controls). Asthma diagnosis was based on episodic symptoms, documented wheeze, and the presence of reversible airflow limitation. CCR3 T51C demonstrated a significant association with the diagnosis of asthma in the British population (odds ratio 2.35, p<0.01), but not in the Japanese population. Multiple logistic regression analysis also showed that CCR3 T51C was associated with asthma (odds ratio 2.83, p < 0.02), independent of atopic phenotypes such as high levels of total or house dust mite-specific immunoglobulin-E in serum. In conclusion, a significant association between asthma and CCR3 T51C polymorphism localized on chromosome 3p21 was found.

Alleles↗
PubMed2001

DNA topology on an increase in positive writhing number of DNA: conformation changes in the time course of cis-diamminedichloroplatinum(II)-DNA adducts.

We show that the topological significance of the gel mobility of cis-diamminedichloroplatinum(II) (DDP)-closed circular DNA (ccDNA) adducts decreases with reaction time, until a point at which it joins relaxed DNA, and that the mobility of the adducts increases again. There is no relationship between the relative length of the adducts and the gel mobility. Although the significance of the decrease of gel mobility is due to the unwinding of cis-DDP-DNA (or trans-DDP-DNA) adducts, the conformational significance of the subsequent increase in mobility is unclear. To elucidate the conformational significance for unwinding of the adducts, we measured the writhing number (Wk) of the adducts using electron microscopy and analyzed the topological states of cis-DDP (or trans-DDP) adducts based on the White rule, Lk=Wk+Tk. Where, Lk and Tk represent the linking and twisting number in the ring, respectively. From the data, we found that the Wk of cis-DDP-ccDNA adducts in comparison with trans-DDP-ccDNA adducts increases from a negative to a positive number with time. This suggests that cis-DDP plays a role in the change of the topological state of ccDNA. In the abstraction of platinum from the adducts with CN- ion, the differences in both topological states may explain why Pt in trans-DDP is abstracted more easily than in cis-DDP. To explain the abstraction of Pt ion, we also discuss the findings based on the thermodynamic cycle in a intermolecular crosslink model Pt(NH3)2(guanine)2(2+)-->Pt(CN)4(2-) using the Pt parametrized PM3 method.

Algorithms↗
PubMed2001

Association between exogenous atrial natriuretic peptide and hemodynamics in dogs with congestive heart failure produced by experimental mitral regurgitation.

Association between exogenous atrial natriuretic peptide (ANP) and hemodynamic changes was ascertained in 3 dogs with overt congestive heart failure (CHF(+)) and 3 dogs without congestive heart failure (CHF(-)) caused by experimental mitral regurgitation (MR). The hemodynamic measurements were recorded in all dogs during and after 1 hr infusion of ANP at the rate of 0.1 (low dose), 0.5 (medium dose) and 1.0 (high dose) microg/kg/min, respectively. Heart rate, mean arterial pressure, pulmonary capillary wedge pressure (PCWP) and systemic vascular resistance decreased significantly during and after ANP infusion even with low dose in the CHF(+). Stroke volume, stroke volume index and cardiac output in the CHF(+) during and after ANP infusion showed an increasing trend as compared with the CHF(-). Double product, an indicator of myocardial oxygen consumption, significantly decreased during and after ANP administration at all doses in the CHF(+). These findings indicate that even at low dose, exogenous ANP improves cardiac performance and reduces myocardial oxygen consumption in the CHF(+), and suggest that ANP has beneficial effects in the treatment of dogs with overt congestive heart failure resulting from MR.

Animals↗
PubMed2001

Pneumonitis induced by ou-gon (scullcap).

A 53-year-old Japanese man with recurrent interstitial pneumonia was referred to us. The patient had taken a traditional herb medicine, otsu-ji-to, before the onset of pneumonia. A provocation test for each herbal ingredient contained in otsu-ji-to revealed that the pneumonitis had been induced by ou-gon (scullcap). Lymphocytosis with the CD8+ T-cell subset predominance was found in the bronchoalveolar lavage fluid and lymphocytic alveolitis was noted in the transbronchial lung biopsy specimen after the provocation test. Ou-gon, or scullcap, should be included in the list of drugs with definite causal association with pneumonitis.

Biopsy↗
PubMed2001

[The development of language and problems in 30 mild, moderate, and moderately severe hearing-impaired children].

Some mild, moderate, and moderately severe-hearing impaired children have poor language and educational problems despite comparatively good hearing. We studied 30 mild, moderate, and moderately severe hearing-impaired children cared for at Showa University and Jiseikai Hospitals. Their ages ranged from 3 to 14 years and average hearing from 35.0 dB HL to 68.8 dB HL. Our findings were as follows: (1) The average age of suspected hearing problem onset was 2 years 10 months. On the average, delayed diagnosis was made at 4 years 2 months and children were fitted with hearing aids at 5 years 3 months. (2) Over 25% them wore hearing aids infrequently. (3) Language delay was observed in 14 of 24 children examined using the WISC-III test. Many wore hearing aids infrequently and exhibited inadequate oral communication in Japanese due, for example, to deaf parents or children educated overseas. (4) According to a questionnaire, many mothers usually talked to the children aware of their hearing condition. But almost mothers of children with delayed development could not teach children if they couldn't hear, and only repeated same words for children's clarification, e.g., "Pardon?". It is important to detect hearing impairment in children as early as possible. Guidance by specialists and communication training are very important, especially for children who are mild, moderate, and moderately severe hearing-impaired.

Adolescent↗
PubMed2001

[A case of relapsed small cell lung cancer recognized by simple metastasis to the duodenum].

We describe a case of relapsed small cell lung cancer (SCLC) recognized by a duodenal tumor, its probable metastasis. A 69-year-old man was admitted to Keio University Hospital complaining of persistent sputum production in September, 1996. A diagnosis of SCLC of the left lung invading the mediastinum was based on a transesophageal biopsy. Chemotherapy consisting of CDDP and VP-16 followed by thoracic irradiation at a total dose of 50 Gy was performed from October 1996 to August 1997, resulting in CR (Complete Response) of the tumor. In April of 1999, a mass surrounding the duodenum was found through an abdominal CT survey for tumor relapse, but no other tumors were detected in a series of CT scans or inbone scintigraphy. Subsequent fiberscopy of the upper gastrointestinal tract revealed an ulcerative tumor extensively invading the mucosa of the duodenal bulb. Biopsy specimens obtained from the duodenal tumor showed small-cell carcinoma with features similar to those of SCLC found in 1996, suggesting that SCLC of the left lung metastasized to the duodenal wall. Chemoradiotherapy with 4 cycles of CDDP and VP-16 followed by abdominal irradiation at a dose of 30 Gy was given again from May to September 1999, producing good PR (Partial Response). Although metastasis of SCLC to the duodenum seldom occurs, this report indicates that its early detection and effective treatment may prevent serious symptoms caused by obstruction of the duodenum or the papilla Vater.

Aged↗
PubMed2001

[A case of renal cell carcinoma diagnosed by MAG3 scintigraphy because of moderate renal dysfunction].

An 84-year-old man presented at our hospital with complaints of severe gross hematuria and lower right abdominal pain. A right renal mass was detected by ultrasound sonography and plain computerized tomography (CT) scan, but an exact diagnosis was not obtained. Because the patient presented with moderate renal dysfunction and severe gross hematuria, we were unable to perform imaging studies using contrast material or ureteroscopic instruments. Finally, mercaptoacetylglycyl-glycylglycine (MAG3) scintigraphy and magnetic resonance imaging (MRI) demonstrated renal cell carcinoma, and we performed transarterial embolization (TAE) therapy using ethanol and gel foam. Based on their efficacy and noninvasiveness, we conclude that MAG3 scintigraphy and MRI are the optimal modalities for imaging in patients with renal dysfunction.

Aged↗
PubMed2001

Use of 201Tl SPECT for evaluation of biologic behavior in pituitary adenomas.

UNLABELLED: Although pituitary adenomas are regarded as benign tumors, some of them behave aggressively with malignant behavior of invasion and metastasis. Prediction of such biologic behavior in a tumor is important for therapeutic planning. The purpose of this study was to assess the usefulness of 201Tl chloride SPECT (201Tl SPECT) for evaluation of biologic behavior in pituitary adenomas. METHODS: 201Tl SPECT was performed on 22 patients with pituitary adenomas. 201Tl uptake indices were calculated, and the results were compared between invasive pituitary adenomas and noninvasive pituitary adenomas. Correlation of the 201Tl uptake index and the MIB1 monoclonal antibody labeling index (MIB1 labeling index) of the tumors was also estimated. RESULTS: In comparison with noninvasive pituitary adenomas, invasive pituitary adenomas exhibited significantly higher 201Tl uptake indices on both the early and the delayed images (P = 0.0010 and 0.0019, respectively). A significant correlation was found between the 201Tl uptake index on the delayed image and the MIB1 labeling index (P = 0.0107). CONCLUSION: 201Tl SPECT can be useful for detecting biologic aggressiveness in pituitary adenomas.

Adenoma↗
PubMed2001

[Simultaneously detected double malignancies on a duplicated kidney associated with atrophied counterpart: a case report].

A case of simultaneous double malignant tumor in the same kidney, associating renal cell carcinoma with renal pelvic transitional cell carcinoma, in a 70 year-old-male was reported. On January 6, 2000 he presented with macroscopic hematuria. There were no remarkable findings on cystoscopic examination. Drip infusion pyelography and multidetector-row computed tomography demonstrated a tumor mass on the upper pole of the left kidney and atrophic right kidney. Systemic chemotherapy with CDDP, MTX and ADR was performed preoperatively. Then, hemi-left nephrectomy underwent with the diagnosis of renal pelvic tumor and renal tumor. The surgical specimen was pathologically diagnosed as transitional cell carcinoma of the renal pelvis and renal cell carcinoma of its upper pole. This is the 32nd case of simultaneous occurrence of renal cell carcinoma and transitional cell carcinoma in the same kidney in the Japanese literature.

Aged↗
PubMed2000

Fission yeast homolog of murine Int-6 protein, encoded by mouse mammary tumor virus integration site, is associated with the conserved core subunits of eukaryotic translation initiation factor 3.

The murine int-6 locus, identified as a frequent integration site of mouse mammary tumor viruses, encodes the 48-kDa eIF3e subunit of translation initiation factor eIF3. Previous studies indicated that the catalytically active core of budding yeast eIF3 consists of five subunits, all conserved in eukaryotes, but does not contain a protein closely related to eIF3e/Int-6. Whereas the budding yeast genome does not encode a protein closely related to murine Int-6, fission yeast does encode an Int-6 ortholog, designated here Int6. We found that fission yeast Int6/eIF3e is a cytoplasmic protein associated with 40 S ribosomes. FLAG epitope-tagged Tif35, a putative core eIF3g subunit, copurified with Int6 and all five orthologs of core eIF3 subunits. An int6 deletion (int6Delta) mutant was viable but grew slowly in minimal medium. This slow growth phenotype was accompanied by a reduction in the amount of polyribosomes engaged in translation and was complemented by expression of human Int-6 protein. These findings support the idea that human and Schizosaccharomyces pombe Int-6 homologs are involved in translation. Interestingly, haploid int6Delta cells showed unequal nuclear partitioning, possibly because of a defect in tubulin function, and diploid int6Delta cells formed abnormal spores. We propose that Int6 is not an essential subunit of eIF3 but might be involved in regulating the activity of eIF3 for translation of specific mRNAs in S. pombe.

Animals↗