Biomedical subjects

S Minami

Publications and source records attributed to S Minami.

At least 73 records · Page 4Linked to original sources

PubMed1999

Prolactin secretion in response to prolactin-releasing peptide and the expression of the prolactin-releasing peptide gene in the medulla oblongata are estrogen dependent in rats.

Prolactin-releasing peptide (PrRP), recently isolated from bovine hypothalamus as an endogenous ligand to a seven transmembrane-domain orphan receptor, is a candidate specific prolactin-releasing factor. The prolactin-releasing activity of the peptide and the expression of the PrRP gene were examined in vivo in relation to estrogen status. Plasma prolactin levels increased significantly with a peak at 5 min after the administration of 50 microg/kg PrRP in female rats in estrus under urethane anesthesia as compared with those in vehicle-treated control rats, but not in female rats in diestrus or proestrus or in male rats. In ovariectomized rats treated with supraphysiological concentration of estrogen, a dose-dependent increase of prolactin secretion in response to 2-50 microg/kg PrRP was observed. However, the peak values induced by 50 microg/kg PrRP were much less than those induced by 2 microg/kg thyrotropin-releasing hormone (TRH). PrRP mRNA levels in the medulla oblongata were decreased by ovariectomy and increased by estrogen treatment. The data indicate that estrogen is prerequisite to the stimulatory effect of PrRP on the secretion of prolactin and to the increase of PrRP mRNA levels in the medulla oblongata. The weak in vivo potency of PrRP on prolactin secretion relative to TRH suggests that PrRP differs from the classical hypophysiotropic hypothalamic releasing hormones.

Animals↗

PubMed1999

Effect of insulin-like growth factor-I on growth hormone-releasing factor receptor expression in primary rat anterior pituitary cell culture.

We examined the effect of insulin-like growth factor-I (IGF-I) on GH-releasing factor (GRF) receptor expression in the primary rat anterior pituitary cell culture. The levels of GRF receptor mRNA were dose-dependently reduced by IGF-I treatment for 24 h. To clarify whether altered levels of GRF receptor mRNA contribute to GRF receptor concentrations, we examined the GH response to GRF in vitro. There was no difference in basal GH secretion between control and IGF-I pretreated cells, while GRF-stimulated GH secretion in cells pretreated with IGF-I for 24 h was significantly lower than that in control cells. Moreover, specific [125I] Tyr10-human GRF binding to pituitary cells was reduced significantly by IGF-I treatment. These results suggest that IGF-I acts directly on the pituitary and participates in the regulation of GRF receptor expression.

Animals↗

PubMed1999

Massive outbreak of Escherichia coli O157:H7 infection in schoolchildren in Sakai City, Japan, associated with consumption of white radish sprouts.

In July 1996, an outbreak of Escherichia coli O157:H7 infection occurred among schoolchildren in Sakai City, Osaka, Japan. This outbreak developed in 13 North-East District and 34 Middle-South District elementary schools in the city. All children hospitalized on July 17-19 had presented on July 8 (North-East District) and July 9 (Middle-South District). School lunches served on July 1 and 8 in the North-East District and on July 1, 4, 8, and 9 in the Middle-South District were proposed by a food consumption study to be associated with infection. White radish sprouts from a single farm were the only uncooked food common to the most highly implicated meals on the involved days in two school districts (sweet and sour chicken with lettuce on July 8 in the North-East District and chilled Japanese noodles on July 9 in the Middle-South District). Two incidents of E. coli O157:H7 in neighboring areas were also related to white radish sprouts from the farm. The pulse-field gel electrophoresis patterns of isolates from patients in these two districts and the neighboring areas were identical. Thus, it was concluded that the cause of the outbreak was the white radish sprouts shipped on July 7-9 from one particular farm.

Child↗

PubMed1999

The ubiquitous transcription factor NF-Y positively regulates the transcription of human p27Kip1 through a CCAAT box located in the 5-upstream region of the p27Kip1 gene.

Abnormally low levels of the cyclin-dependent kinase inhibitor p27Kip1 are found frequently in human carcinomas, and these levels correlate directly with both histological aggressiveness and patient mortality. p27Kip1 is haplo-insufficient for tumor suppression. Thus, p27Kip1 may be a useful molecule for the development of cancer therapies. To know the possible mechanisms underlying transcriptional control, we previously cloned the promoter region of human p27Kip1 gene. We report here the characterization of the 5'-regulatory region of the human p27Kip1 gene. Promoter analysis using 5'-deletion mutants revealed that a 39-bp region between -549 and -511 was required for maximal promoter activity. Point mutation analysis revealed that a CCAAT box within this region was essential for promoter activity. Gel shift assays and cotransfection experiments using a dominant negative form of the NF-Y transcription factor showed that NF-Y directly regulates p27Kip1 transcription through this CCAAT box. This finding might provide a clue to approach the mechanism of tumorigenesis.

Base Sequence↗

PubMed1999

Prognostic implication of FLT3 and N-RAS gene mutations in acute myeloid leukemia.

Internal tandem duplication of the FLT3 gene and point mutations of the N-RAS gene are the most frequent somatic mutations causing aberrant signal-transduction in acute myeloid leukemia (AML). However, their prognostic importance is unclear. In this study, their prognostic significance was analyzed in 201 newly diagnosed patients with de novo AML except acute promyelocytic leukemia. Three patients had mutations in both genes, 43 had only the FLT3 gene mutation, 25 had only the N-RAS gene mutation, and 130 had neither. These mutations seemed to occur independently. Both mutations were related to high peripheral white blood cell counts, and the FLT3 gene mutation was infrequently observed in the French-American-British (FAB)-M2 type. AML cases with wild FLT3/mutant N-RAS had a lower complete remission (CR) rate than those with wild FLT3/wild N-RAS, whereas the presence of mutant FLT3 did not affect the CR rate. Univariate analysis showed that unfavorable prognostic factors for overall survival were age 60 years or older (P =.0002), cytogenetic data (P =.002), FAB types other than M2 (P =.002), leukocytosis over 100 +/- 10(9)/L (P =.003), and the FLT3 gene mutation (P =.004). However, the N-RAS gene mutation was only a marginal prognostic factor (P =.06). For the subjects under 60 years old, multivariate analysis showed that the FLT3 gene mutation was the strongest prognostic factor (P =.008) for overall survival. The FLT3 gene mutation, whose presence is detectable only by genomic polymerase chain reaction amplification and gel electrophoresis, might serve as an important molecular marker to predict the prognosis of patients with AML.

Acute Disease↗

PubMed1999

Cellular localization of prolactin-releasing peptide messenger RNA in the rat brain.

Prolactin-releasing peptide (PrRP), a novel peptide identified as the endogenous ligand for an orphan receptor isolated from the pituitary, is a potent stimulator of prolactin release. To get a clue of the functional roles of the peptide, we performed in situ hybridization histochemistry for PrRP mRNA to define the cellular localization of PrRP-producing cells in the brain of the cycling adult female rat during diestrus. The PrRP mRNA-containing cells were located in the caudal part of the dorsomedial nucleus of the hypothalamus. In the brainstem, the cells were found in the caudal part of the solitary tract nucleus and in the caudal ventrolateral medulla (ventrolateral intermediate reticular field). Specific signals for PrRP mRNA were not detected in other brain regions. Although PrRP is a candidate for being a hypophysiotropic specific releasing factor, the discrete distribution of PrRP in the extrahypothalamic area suggests that the peptide has other physiological functions in the central nervous system.

Animals↗

PubMed1999

Veterinary practice with chitin and chitosan.

Dramatic effects of chitin and chitosan on wound healing were demonstrated in field cases of many small animals (dogs and cats), food animals (338 cows) and 142 zoo animals. In comparison with conventional therapy with irrigation and antibiotic administration to wound, new treatment with chitin and chitosan permitted a substantial decrease in treatment frequency with minimum scar formation.

Animals↗

PubMed1999

Immunohistochemical localization of inhibin and activin subunits in human epithelial ovarian tumors.

OBJECTIVE: Our purpose was to examine the cellular localization of inhibin and activin subunits in human epithelial ovarian tumors. STUDY DESIGN: We examined the immunohistochemical localization of the alpha, betaA, and betaB subunits of inhibin in human mucinous and serous ovarian tumors including adenoma, cystic tumor with borderline malignancy, and adenocarcinoma. RESULTS: Immunostaining specific for the alpha, betaA, and betaB subunits of inhibin was observed in the tumor cells of the mucinous adenoma and the cystic tumor with borderline malignancy. We observed negative immunostaining specific for the alpha subunit and positive staining specific for the betaA and betaB subunits in the tumor cells of the mucinous adenocarcinoma. We did not observe any staining for the alpha subunit of inhibin in the serous tumors including benign adenoma, cystic tumor with borderline malignancy, and adenocarcinoma. However, positive staining results for the betaA and betaB subunits were observed in the serous tumor cells. CONCLUSION: Our results suggest that inhibins and activins might be secreted by the mucinous adenoma and the cystic tumor with borderline malignancy and that activins might be secreted by the mucinous adenocarcinoma and the serous tumors including benign adenoma, cystic tumor with borderline malignancy, and adenocarcinoma.

Activins↗

PubMed1999

Molecular structure of canine LINE-1 elements in canine transmissible venereal tumor.

We determined the 4251-bp sequence of open reading frame 2 (ORF2) of canine LINE-1 retroposon that encodes 1275 amino acids. The truncated LINE-1 inserts associated with transmissible venereal tumor (TVT) of dogs contained the 1378-bp LINE-1 insert (TVT-LINE) flanked by 10-bp direct repeats upstream to c-myc gene. The TVT-LINE elements were composed of 416 bp inverse sequences homologous to the complementary strand of the LINE-1, a 5-bp deletion and 962-bp sequences homologous to the 3' region of the LINE-1.

Animals↗

PubMed1999

A new preconditioning regimen with melphalan, busulphan and total body irradiation followed by low-dose immunosuppressant in allogeneic haemopoietic stem cell transplantation.

Twenty adult patients with high-risk leukaemia underwent allogeneic haemopoietic stem cell transplantation after melphalan, busulphan and total body irradiation followed by short-term methotrexate and low-dose cyclosporine or tacrolimus. Three patients developed veno-occlusive disease and no patient developed renal dysfunction. Seven patients experienced grade II-IV acute graft-versus-host disease (aGVHD) and five patients experienced grade III-IV. The 3-year probabilities of relapse and leukaemia-free survival were 22 +/- 11% (95% confidence interval) and 50 +/- 11%, respectively. These data suggest that this preconditioning regimen followed by a low-dose immunosuppressant provided a more anti-leukaemic effect without increased regimen-related toxicity and aGVHD.

Adult↗

PubMed1999

Restricted expression of WT1 messenger ribonucleic acid in immature ovarian follicles: uniformity in mammalian and avian species and maintenance during reproductive senescence.

WT1 is a zinc finger protein with transcriptional repressor activity on several growth factor and growth factor receptor genes. In the ovary, a potential role for WT1 in the suppression of the development of immature follicles has been demonstrated. Here, gel retardation assays further showed that recombinant WT1 protein interacted with consensus DNA sequences in the inhibin-alpha gene promoter. We investigated the pattern of WT1 expression in a wide variety of species and also over the reproductive life span in rats. In chicken ovaries, Northern blot analysis revealed the presence of WT1 transcript in small healthy white follicles (1-5 mm in diameter) and its absence in small yellow (6-12 mm in diameter) or larger follicles (F1-F5). In pig and monkey ovaries, WT1 expression was limited to granulosa cells of preantral follicles, as shown by in situ hybridization analysis. In rats, Northern blot analyses demonstrated the presence of WT1 transcript in the ovaries of young (3-mo-old) and middle-aged (9-mo-old) rats on the proestrous day, with a decrease in old (12-mo-old) rats in persistent estrus. In situ hybridization analysis further suggested that the decrease in WT1 expression in aging ovaries was associated with fewer immature follicles. Thus, WT1 expression is restricted to immature follicles in diverse avian and mammalian species and over the reproductive life span in rats. These data demonstrated that WT1 is a marker for immature follicles and suggested a potential role of this transcriptional repressor in the slow growth of early follicles.

Animals↗

PubMed1999

In vitro and in vivo antimicrobial activities of T-3811ME, a novel des-F(6)-quinolone.

The in vitro and in vivo activities of T-3811ME, a novel des-F(6)-quinolone, were evaluated in comparison with those of some fluoroquinolones, including a newly developed one, trovafloxacin. T-3811, a free base of T-3811ME, showed a wide range of antimicrobial spectra, including activities against Chlamydia trachomatis, Mycoplasma pneumoniae, and Mycobacterium tuberculosis. In particular, T-3811 exhibited potent activity against various gram-positive cocci, with MICs at which 90% of the isolates are inhibited (MIC90s) of 0.025 to 6.25 microgram/ml. T-3811 was the most active agent against methicillin-resistant Staphylococcus aureus and streptococci, including penicillin-resistant Streptococcus pneumoniae (PRSP). T-3811 also showed potent activity against quinolone-resistant gram-positive cocci with GyrA and ParC (GrlA) mutations. The activity of T-3811 against members of the family Enterobacteriaceae and nonfermentative gram-negative rods was comparable to that of trovafloxacin. In common with other fluoroquinolones, T-3811 was highly active against Haemophilus influenzae, Moraxella catarrhalis, and Legionella sp., with MIC90s of 0.0125 to 0.1 microgram/ml. T-3811 showed a potent activity against anaerobic bacteria, such as Bacteroides fragilis and Clostridium difficile. T-3811 was the most active agent against C. trachomatis (MIC, 0.008 microgram/ml) and M. pneumoniae (MIC90, 0.0313 microgram/ml). The activity of T-3811 against M. tuberculosis (MIC90, 0.0625 microgram/ml) was potent and superior to that of trovafloxacin. In experimental systemic infection with a GrlA mutant of S. aureus and experimental pneumonia with PRSP in mice, T-3811ME showed excellent therapeutic efficacy in oral and subcutaneous administrations.

Administration, Oral↗

PubMed1999

Role of permeability in the activities of beta-lactams against gram-negative bacteria which produce a group 3 beta-lactamase.

The production of a group 3 beta-lactamase permitted Escherichia coli to raise the MICs of ceftazidime, cefpirome, and meropenem greatly but those of imipenem and piperacillin only slightly. The ratios of maximum rate of hydrolysis to K(m) of ceftazidime, cefpirome, and piperacillin were lower than those of meropenem and imipenem for the group 3 beta-lactamase. The permeability coefficients for piperacillin and meropenem were higher than those for ceftazidime and cefpirome. Imipenem had the highest permeability coefficient.

Anti-Bacterial Agents↗

PubMed1999

The vascular endothelial growth factor/fms-like tyrosine kinase system in human ovary during the menstrual cycle and early pregnancy.

In human ovaries, angiogenesis is known to be associated with the development of follicles and the formation of the corpus luteum (CL). A complex vascular network is formed within the thecal cell layer during follicular growth, and rapid neovascularization occurs toward the granulosa cell layer after ovulation. Vascular endothelial growth factor (VEGF) is a multifunctional cytokine, stimulating endothelial cell growth and enhancing microvascular permeability. A specific receptor for VEGF, fms-like tyrosine kinase (Flt-1), is expressed in vascular endothelial cells that mediates the action of VEGF. We examined the localization and expression of VEGF and Flt-1, using an immunohistochemical technique and RT-PCR analysis, in human follicles and corpora lutea during the normal menstrual cycle and early pregnancy. We measured concentrations of VEGF in extracts of human CL using an enzyme-linked immunosorbent assay during the luteal phase and early pregnancy. Immunostaining for VEGF was observed in granulosa cells from small antral follicles to preovulatory follicles. The staining was detected in thecal cells from medium-sized to preovulatory follicles. The intensity of the staining was gradually increased as a follicle grew. Flt-1 was localized in granulosa and thecal cells of preovulatory follicles as well as in endothelial cells. In the human CL, the intense staining for VEGF was observed in granulosa and thecal lutein cells, especially in the midluteal phase. The immunostaining for Flt-1 was faint in endothelial cells in the CL, whereas it was distinct in granulosa and thecal lutein cells. The concentrations of VEGF in lutein extracts were high in the early and midluteal phases and tended to decrease toward the late luteal phase. During early pregnancy, a measurable amount of VEGF was detected. RT-PCR analysis demonstrated that messenger ribonucleic acids encoding VEGF121, VEGF165, and Flt-1 were expressed in the CL. These results suggest that VEGF might have an autocrine role in the ovulatory process and luteal function as well as a paracrine role in angiogenesis.

Adult↗

PubMed1999

Relationship between brain atrophy estimated by a longitudinal computed tomography study and blood pressure control in patients with essential hypertension.

To evaluate the relationship between blood pressure control and the progression of brain atrophy in the elderly, patients with essential hypertension and brain atrophy were longitudinally evaluated using computerized tomography (CT). The study evaluated 48 patients with essential hypertension aged 46-78 years, and 30 sex- and age-matched normotensive control subjects. The extent of brain atrophy as determined by caudate head index (CHI), the inverse cella media index (iCMI), and Evans' ratio (ER) was estimated twice at an interval of 5-9 years (mean, 6.9 years). The mean annual increases in CHI (deltaCHI), iCMI (delta iCMI), and ER (deltaER) were evaluated. Mean blood volume in the common carotid artery (BF) and the decrease in BF per year (deltaBF) were also determined. The deltaCHI, delta iCMI, and deltaER increased with age in the hypertensive subjects as well as the control group across all age groups evaluated. The deltaCHI, delta iCMI, and deltaER were significantly greater in the patients with essential hypertension in their 50 s as compared with the controls. In patients with essential hypertension aged 65 years or older, the deltaCHI, delta iCMI, and deltaER were significantly lower in the group in whom the blood pressure was controlled within the range of borderline hypertension than the groups in which it was controlled in the range of normal or mild hypertension. In the younger patients under the age of 65 with essential hypertension, blood pressure control did not affect the deltaCHI, delta iCMI, and deltaER. The deltaCHI, delta iCMI, and deltaER were significantly correlated with deltaBF in both groups. These findings indicate that control of systolic blood pressure within the range of borderline hypertension may delay the progression of brain atrophy in elderly patients with essential hypertension.

Aged↗

PubMed1999

Computerized digital image processing on radiographs of canine filariosis.

For objective evaluation in the lung arterial lesions, density histogram revealed by survey thoracic radiographies of fifteen canine filariosis and five normal canine were digitally analyzed, and preparation of pulmonary artery angiogram with inflated-fixed lung, the changes in the histogram and the pulmonary arterial lesion by a soft x-ray examination were compared. In the lung areas affected by filariosis, the density histogram increased the white level and decreased the black level in each part compared to a normal lung. In comparison with the normal parameters, those of the filariosis it were significantly increased in minimum grey level values (Min), maximum grey level values (Max), and the maximum frequency grey level values (Mode) and, it was significantly decreased in maximum frequency values (MaF). The pulmonary arterial lesion of the filariosis showed obvious morphological changes such as in distinction, pruning, angiectasis, and meandering. In the grade of pulmonary arterial lesion, the parameter Min, Max, Mode and MaF were changed significantly. From these results, it was clear that the methods for the lung arterial lesions analysis of x-ray images were confirmed to be highly beneficial in the lung arterial lesions for objective diagnosis.

Animals↗

PubMed1999

Asymptomatic cerebrovascular lesions detected by magnetic resonance imaging in patients with systemic lupus erythematosus lacking a history of neuropsychiatric events.

OBJECTIVE: To clarify the extent of asymptomatic cerebrovascular involvement in systemic lupus erythematosus (SLE). PATIENTS AND METHODS: Cerebral magnetic resonance imaging (MRI) findings and ultrasonography findings of 100 patients with SLE lacking present or past clinical neurologic deficits were compared with 66 age-matched volunteers to determine the combined intima-media thickness (IMT) of the common carotid artery, and tests for anti-cardiolipin antibodies (aCL). RESULTS: Thirty-eight patients, but only 2 controls, showed imaging abnormalities. Among 23 SLE patients with cerebrovascular lesions by MRI who underwent single-photon emission computed tomography (SPECT), 14 showed hypoperfusion of the lesion. The IMT value and prevalence of aCL did not differ between the 55 SLE patients tested and controls. SLE disease activity index (SLEDAI) as assessed by a quantitative clinical index was significantly greater in patients with brain lesions than in those without. CONCLUSION: The prevalence of asymptomatic brain lesions in SLE patients is highs and shows a relationship to disease activity.

Adolescent↗

PubMed1999

[Analysis of elderly patients, aged 60 years old or over, with acute lymphoblastic leukemia].

In order to obtain the realistic background information on clinical features, and the present status of treatment and outcome in elderly patients with acute lymphoblastic leukemia (ALL), we carried out random survey of patients with ALL aged 60 or over who had been admitted to 13 general hospitals in the Nagoya region from January 1990 through December 1995. Among the 20 cases collected, ages ranged from 60 to 88 (median age 68), and the male to female ratio was 11:9. Nineteen cases were L2 subtype in FAB classification. Among 17 patients, 13 had B cell series surface phenotypes (76%), 2 had T cell series (12%), one had stem cell type (6%) and one had an undetermined phenotype (6%). Ph chromosomes were detected in 4 cases among 15 analyzed (27%), whereas 5 were found to have no chromosomal abnormality. Half of the patients had some concurrent disease at diagnosis, including two with treatment-limiting complications. Common induction regimens were the combination of adriamycin (ADM) + vincristine (VCR) + cyclophosphamide (CPM) + mitoxdn trone + L-asparaginase [4 patients]. ADM + VCR + PSL [4 patients]. VCR + PSL [4 patients] and others [8 patients]. The overall remission rate was 55.0% (11/20) without any significant difference according to age. The median survival time (MST) for all cases was 205 days. (1-year survival rate:17.9%, 2-year survival rate:10.8%). There was no significant difference in survival times among patients with the Ph chromosome, those with other chromosomal abnormalities and those without them. All the patients aged 75 or over were treated with attenuated induction therapy, and they had a shorter survival than those aged less than 75, but with no statistical significance [MST:121 days versus 276 days, p = 0.307 (generalized Wilcoxon test)].

Aged↗