Biomedical subjects

Y Abe

Publications and source records attributed to Y Abe.

At least 343 records · Page 19Linked to original sources

PubMed1998

Effects of growth hormone, activin, and follistatin on the development of preantral follicle from immature female mice.

The aim of this study was to investigate whether GH and insulin-like growth factor I (IGF-I) are involved in preantral folliculogenesis and, if so, to clarify the relationship between GH/IGF-I and activin/follistatin (FS) systems in immature female mice. Ovaries were obtained from 11-day-old mice, and preantral follicles, 100-105 microm in diameter, were mechanically isolated and selected for culture. Ten preantral follicles per well were cultured with different quantities and combinations of additives as follows: no additives (control), recombinant human FSH (rhFSH), IGF-I, recombinant human GH (rhGH), activin A, and recombinant human FS (rhFS). Mean diameters of the follicles were measured daily, and estradiol and immunoreactive inhibin levels in the cultured medium were assayed by RIA on day 4. rhGH showed stimulatory effects on the follicular diameter and the secretion of estradiol and immunoreactive inhibin. These effects were augmented by the presence of IGF-I and activin A. IGF-I alone did not show any stimulatory effect. The addition of rhFSH to activin A or to rhGH and activin A promoted preantral follicular growth and hormone production. On the other hand, GH- or activin-stimulated follicular growth was suppressed by rhFS in a dose-dependent manner. These results indicate that activin A and rhGH may play an important role in controlling earlier phases of follicular development during the infantile period, which is considered to be gonadotropin independent.

Activins↗

PubMed1998

CAG repeat number correlates with the rate of brainstem and cerebellar atrophy in Machado-Joseph disease.

We compared the CAG repeat length and the severity of the brainstem and cerebellar atrophy visualized by MRI in 30 patients with Machado-Joseph disease. We found a strong correlation between the CAG repeat number and the quotient of the degree of atrophy divided by age at examination. These results suggest that the rate of disease progression is dependent on the CAG repeat size and disease progression may commence at birth.

Adult↗

PubMed1998

Separation of phospholipase A2 in Habu snake venom by glycyrrhizin (GL)-affinity column chromatography and identification of a GL-sensitive enzyme.

By means of glycyrrhizin (GL)-affinity and Mono S column chromatographies (HPLC), at least four GL-binding proteins (p25, p17, p15-1 and p15-2) in the two Superdex fractions (P-II and P-III fractions) from Habu snake venom were selectively purified. By determination of their N-terminal partial amino acid sequences, a metalloprotease (p25) and three GL-binding phospholipases A2 (gbPLA2s) [PA2Y (p17), PA21 (p15-1) and PA2B (p15-2)] were identified. PA2B (lysine-49 PLA2) was found to be the most sensitive to GL because (i) it strongly bound to a GL-affinity column; and (ii) its enzyme activity was selectively inhibited by low dose (ID50 = approx. 1.5 microM) of GL, but not by GA. Furthermore, these three gbPLA2s were phosphorylated by casein kinase II (CK-II) in vitro and GL inhibited the CK-II-mediated stimulation of their enzyme activities in vitro.

Amino Acid Sequence↗

PubMed1998

Characterization of an apoptosis-inducing factor in Habu snake venom as a glycyrrhizin (GL)-binding protein potently inhibited by GL in vitro.

By means of successive heparin-affinity and glycyrrhizin (GL)-affinity column chromatographies (HPLC), a 55 kDa GL-binding protein (gp55) was purified to apparent homogeneity from the Superdex P-I fraction of Habu snake venom. This gp55 was identified as an apoxin I-like protein, because (i) its 20 N-terminal amino acid residues (AHDRNPLEEYFRETDYEEFL) are 95% identical with the corresponding sequence of apoxin I (apoptosis-inducing factor, approx. 55 kDa) in the venom of the western diamondback rattlesnake; and (ii) L-amino acid oxidase (LAO) activity of gp55 is detected when incubated with L-leucine, but not with D-leucine. GL inhibited the LAO activity of gp55 in a dose-dependent manner, but had no effect on the activity of a 65 kDa LAO also purified from Habu snake venom. In addition, GL reduced the ability of gp55 to induce the hemolysis of sheep red blood cells. These results suggest that GL is a potent inhibitor of apoxin I-like proteins in harmful snake venoms.

Amino Acid Oxidoreductases↗

PubMed1998

[Paracrine regulation of renal hemodynamics].

There has been an intense interest in multiple interacting paracrine systems that influence renal hemodynamics. The contractile responses at different sites along the renal vascular network exhibit distinct characteristics, depending on their receptor populations or activation mechanisms. These differences in effector mechanisms have also coupled with variations in paracrine signals from adjoining endothelial and epithelial cells. In this review, we have focused on the roles of nitric oxide (NO) and adenosine in the regulation of renal microvasculature and how they interact with other vasoactive factors. Vasopressin (VP) V2 receptors as well as V1 receptors exist in renal vasculature, especially in afferent arterioles, and V2-receptor stimulation induced vasodilation. V2-receptor-mediated vasodilation was attenuated by L-NNA. In addition, Ang II did not affect the diameter of isolated rabbit afferent arterioles, but after the treatment of L-NNA, Ang II exerted a dose-dependent vasoconstriction. Thus, NO modulated the renal vascular actions of VP and Ang II. Adenosine causes vasoconstriction via the A1 receptors, which are restricted primarily to the afferent arterioles. This selective action of adenosine suggests that adenosine exerts selective control of the renal vasculature. Adenosine augmented renal vasoconstriction by NE and Ang II via the adenosine A1 receptor, and the A1 receptor antagonist significantly reduced NE- or Ang II-induced renal vasoconstriction. The plurality of these interactions indicates that while it is very important to understand the specific direct cellular actions of each individual factor, it is equally important to understand how the various interactions are orchestrated under in vivo conditions.

Adenosine↗

PubMed1998

Preoperative treatment of growth hormone-producing pituitary adenoma with continuous subcutaneous infusion of octreotide.

Preoperative therapy with octreotide, a long-acting somatostatin analog, suppresses GH hypersecretion, shrinks GH-producing tumors and leads to an improvement in subsequent surgical remission in acromegalic patients. A continuous infusion of octreotide has demonstrated more persistent suppression of GH secretion than intermittent injections, and only a few studies were reported on the effect of the tumor shrinkage with a continuous infusion of a small dose of octreotide. We therefore investigated the preoperative effects of small doses of octreotide (120-240 micrograms/day) administered continuously (with a subcutaneous infusion pump) over a short period (2 or 4 weeks) in nine untreated acromegalic patients. Octreotide therapy resulted in suppression of serum GH and IGF-1 concentrations in 8 out of 9 patients and reduction in pituitary tumor size measured by MRI in all patients (by 7.9 to 38.5%). In particular, considerable reduction in tumor size (more than 20%) occurred in 6 of 9 patients. In three patients assessed serially throughout the preoperative period, reduction in tumor size was noted within only one week after the start of octreotide therapy and reduction rate more than 20% was obtained within the first two weeks. In one patient, suprasellar tumor expansion totally disappeared after such therapy. Our results indicate that short-term continuous subcutaneous infusion of a small dose of octreotide results in not only inhibition of GH hypersecretion but also shrinkage of tumor size prior to surgery.

Adenoma↗

PubMed1998

Renal, intestinal, and adrenal responses to sodium loading in Dahl-Iwai salt-sensitive and salt-resistant rats.

This study compared renal and intestinal handling of sodium in Dahl-Iwai salt-sensitive (S) and salt-resistant (R) rats given a normal-salt diet (0.3% NaCl) and a high-salt diet (4.0% NaCl). Six-week-old female S and R rats (n = 7 each) were given a normal-salt diet for 14 days followed by a high-salt diet for 3 weeks. Systolic blood pressure was significantly higher in the S rats than in the R rats only at the end of the high-salt diet period (170 +/- 5, mean +/- SEM, vs 152 +/- 1 mmHg, p < 0.01). Daily sodium intake, water intake, urine volume, and urinary and fecal excretions did not significantly differ between the R and the S rats during the normal- and high-salt diets, except for a slight, although significant, decrease in fecal sodium excretion in the S rats as compared with the R rats in the 2nd week of the high-salt diet period. After switching from the normal-salt diet to the high-salt diet, urinary sodium excretion increased by 17- to 18-fold and fecal sodium excretion increased by about 5-fold in the 1st week of salt loading. The changes in urinary and fecal sodium excretions did not differ significantly between the groups. Cumulative sodium retention was similar in the two groups. The aldosterone/creatinine ratio in 24-hr urine, which was significantly lower in the S than in the R rats during the normal-salt diet, decreased to similar levels in both groups after salt loading, indicating a blunted response of aldosterone in the S rats. Thus, there were no discernible differences in renal and intestinal handling of sodium between the S and the R rats, except for a slight, but significant, difference in fecal sodium excretion in the 2nd week of the high-salt period. The results indicate that inappropriate suppression of aldosterone or some other mechanism induced by salt loading may be involved in blood pressure elevation in Dahl-Iwai S rats.

Adrenal Glands↗

PubMed1998

Exogenous recombinant human IL-12 augments MHC class I antigen expression on human cancer cells in vitro.

We investigated whether expressions of MHC class I and class II antigens relevant to tumor antigen presentation were changed on human tumor cells cultured with or without recombinant human IL-12(rhIL-12). We showed that the expression of MHC class I antigen on UTC-8, 28-1Cl and SBC-3 cells was augmented when these cancer cells were cultured with rhIL-12. The expression of class II antigen was slightly raised on UTC-8 and 28-1Cl cells by rhIL-12, but not enhanced on SBC-3 cells. These results suggest that rhIL-12 may provide possible enhancement of immunologic tumor recognition, and cytotoxic activity of lymphocytes against tumors through the enhanced expression of MHC class I antigen.

Carcinoma, Squamous Cell↗

PubMed1998

Periosteal ganglion of the radius: a case report.

We report a case of 43-year-old female with a periosteal ganglion arising in the right radius. Plain radiographs showed thick and sparse spicula with shallow and irregular cortical erosion, which suggested periosteal ganglion. Magnetic resonance (MR) imaging revealed a well circumscribed homogeneous lesion with low signal intensity on T1-weighted images and high signal intensity on T2-weighted images. No apparent enhancement observed after gadolinium injection suggested that the lesion was cystic. At operation, gelatinous material was removed together with the spicula, the surface of the cortex and the overlying periosteum. There was no clinical evidence of recurrence after three years of surgical treatment. MR imaging was thought to be useful to confirm the diagnosis of periosteal ganglion.

Adult↗

PubMed1998

Compensatory excretion of prostacyclin and thromboxane metabolites in obstructive sleep apnea syndrome.

Since obstructive sleep apnea syndrome (OSAS) is often linked with systemic hypertension, we sought to clarify the characteristics of prostanoid metabolism in OSAS. In 7 OSAS patients (apnea-hypopnea index, 51.0 +/- 23.4) and 7 non-snorers as control, nocturnal urine was sampled and analyzed for stable metabolites of prostacyclin (PGI2) and thromboxane A2 (TxA2), [6-keto-PGF1alpha and thromboxane B2 (TxB2)]. The ratio of 6-keto-PGF1alpha to TxB2 was significantly higher in OSAS (2.97 +/- 1.52) than in control (1.38 +/- 0.38). Successful treatment with nasal continuous positive airway pressure (8.3 +/- 1.5 cmH2O) for 3 days caused a significant decrease in mean blood pressure in OSAS. Moreover, the 6-keto-PGF1alpha to TxB2 ratio also significantly decreased to 1.74 +/- 0.58, a level which may not significantly different from control. These results suggest that the production ratio of PGI2 to TxA2 is shifted toward vasodilatation in untreated OSAS. We conclude that the production of prostanoids plays a role in compensating for the systemic hypertension in OSAS.

6-Ketoprostaglandin F1 alpha↗

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

Effect of urine component on leukocyte chemiluminescence response.

In the urine, the function of polymorphonuclear leukocytes (PMNs) is thought to be impaired because of the high osmolality and low pH along with a high concentration of inorganic salts. We investigated the effect of the properties of urine and its components on the chemiluminescence (CL) response of PMNs. This was helped by using an artificial urine. The CL response was measured by automatic luminometer following stimulation of phorbol myristate acetate. We found the CL response of PMNs to be significantly suppressed at a pH of 6 or 5, but not suppressed at a pH of 7 or 8. The CL response was significantly reduced when the osmolality was increased to 580 or 800 mOsm/kg H2O by the addition of urea as compared to the response in the standard artificial urine at an osmolality of 425 mOsm/kg H2O. A change in the osmolality by the addition of mannitol only minimally influenced the CL responses. In addition, the CL response was significantly impaired by both low and high concentrations of sodium at 12 and 300 mEq/L as compared to 77.5 mEq/L in the standard artificial urine. Potassium significantly reduced the CL response in a concentration-dependent manner in the range of from 4 to 31 mEq/L as compared to 52.3 mEq/L in the standard artificial urine. A high concentration of calcium at 8.1 or 9.9 mg/dL reduced CL response as compared to 3.9 mg/dL, whereas CL response was not reduced by the change in the concentration of magnesium. A high concentration of creatinine significantly reduced the CL response as compared to the standard artificial urine. We conclude that the function of PMNs in urine is reduced mainly by urine pH, concentration of urea, sodium, potassium, and creatinine. We suggest that reversal of these change in urine may restore functions of PMNs to clear bacteria in patients with urinary tract infections.

Bacteriuria↗

PubMed1998

Increased expression of human histocompatibility leukocyte antigen-G in colorectal cancer cells.

Human histocompatibility leukocyte antigen (HLA)-G is a nonclassical major histocompatibility complex class I molecule. HLA-G is known to provide tolerance from recognition by natural killer cells. We studied HLA-G expression in 39 human colorectal cancers and 23 extra-neoplastic colon tissue samples by RT-PCR. The expression of HLA-G mRNA was significantly more frequent in colorectal cancer (34 of 39 cases) than in the extraneoplastic tissue (10 of 23 specimens; chi2 test, p = 0.0003). HLA-G expression was also confirmed on the cancer cells immunohistochemically. These results suggested that HLA-G on colorectal cancer cells may be correlated with escape from immunological surveillance during colon cancer development.

Colon↗

PubMed1998

Expression of cell-associated isoform of vascular endothelial growth factor 189 and its prognostic relevance in non-small cell lung cancer.

Vascular endothelial growth factor (VEGF) has four isoforms (VEGF121, VEGF165, VEGF189, VEGF206). We examined the expression patterns of VEGF isoforms in non-small cell lung cancer (NSCLC) by RT-PCR. The cell-associated isoform VEGF189 was more frequently expressed in NSCLC (90.5%) than in extraneoplastic lung tissue (57.6%, p=0.00004). Immunohistochemical examination confirmed VEGF protein expression in 33 of 76 NSCLC expressing VEGF189 (V189p+ group). The V189p+ group showed significantly poorer prognosis than those without VEGF189 mRNA and protein (V189p- group, p=0.01722). These results suggest that expression of the cell-associated isoform VEGF189 is closely associated with progression of NSCLC.

Carcinoma, Non-Small-Cell Lung↗

PubMed1998

[The intrarenal distribution of prostaglandin E2 and thromboxane A2 in the rat with unilateral ureteral obstruction or unilateral nephrectomy].

BACKGROUND: We evaluated the intrarenal distribution of prostaglandin E2 (PGE2) and thromboxane B2 (TxB2) on the rats that underwent unilateral ureteral obstruction (UUO), unilateral nephrectomy (UNX) or sham operation. METHODS: Male Sprague-Dawley rats were divided into three groups; left ureteral obstruction (UUO), left nephrectomy (UNX) and sham-operation (Control). They were sacrificed at 1, 3, 6, 12, 24 hours and Day 2, Day 3, Day 5, Day 7 and Day 9 after surgery. Intrarenal distribution of eicosanoids were immunohistochemically detected on both kidneys of UUO rats, and on right kidneys of UNX and Control rats. RESULTS: PGE2: In the obstructed kidneys, immunostained PGE2 increased in medullary interstitium at one hour to 6 hours, and in glomeruli and cortical interstitium at 6 hours. An increase of immunostained PGE2 was observed again in cortical interstitium at Day 3 to 5, and in medullary interstitium at Day 2 to 5. In the intact opposite kidneys, expression of immunostained PGE2 increased in glomeruli at Day 5 to 7, and in medullary interstitium at Day 3 to 5. In UNX, immunostained PGE2 increased in the medullary interstitium of the remnant kidneys at 3 hours and Day 3 to 7. On the other hand, an increase of immunostained PGE2 observed in glomeruli and cortical interstitium of these kidneys at Day 5 to 7. TxB2: In the obstructed kidneys, immunostained TxB2 increased in glomeruli and cortical interstitium at 6 hours, and in medullary interstitium at 3 to 12 hours. Predominant expression of TxB2 was observed in medullary interstitium at 3 hours compared to PGE2. We also observed an increase of immunostained TxB2 in cortical interstitium at Day 3 to 5, and in medullary interstitium at Day 2 to 5. In the intact opposite kidneys, immunostained TxB2 increased in medullary interstitium at 3 hours and Day 3. In the remnant kidneys of UNX, an increase of immunostained TxB2 was demonstrated in glomeruli at 6 hours and Day 7, and in medullary interstitium at 3 to 6 hours and Day 3 to 7. CONCLUSION: In the obstructed kidneys, imbalance between PGE2 and TxA2 may contribute to the progression of renal injuries. The fact that expression patterns of these eicosanoids in the opposite kidneys of UUO different from that of the remnant kidneys of UNK, even though both were similarly associated with functional loss of contralateral kidneys, suggested that the opposite kidneys of UUO were affected by any additional factors different from that responsible for the remnant kidneys of UNK.

Animals↗

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↗

PubMed1998

Multidrug resistance mediated by overexpression of P-glycoprotein in human osteosarcoma in vivo.

We examined the expression levels of P-glycoprotein (P-Gp)/the human multidrug resistance gene (MDR1) and in vivo chemosensitivity in the 7 osteosarcoma xenografts. Three of seven (43%) osteosarcoma xenografts expressed MDR1 by reverse transcriptase-polymerase chain reaction (RT-PCR). The OSS-516R xenograft selected with vincristine (VCR) from the MDR1-negative xenograft OSS-516, which was sensitive to VCR and doxorubicin (DOX), acquired cross-resistance to DOX. In the OSS-516R, RT-PCR assay showed definite MDR1 expression and immunohistochemical analysis demonstrated P-Gp-positive tumor cells. These results suggest that P-Gp/MDR1 overexpression is related to multidrug resistance in human osteosarcoma in vivo.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed1998

Functional MR imaging of cortical activation of the cerebral hemispheres during motor tasks.

PURPOSE: We used functional MR imaging to evaluate cortical activation in the precentral, central, and postcentral regions of the contralateral and ipsilateral cerebral hemispheres during left- and right-handed motor tasks. METHODS: Ten healthy right-handed volunteers were studied with echo-planner MR imaging (1.5 T) while performing alternating finger apposition tasks with both hands. During the hand tasks, the areas of activated pixels were compared between subregions (precentral, central, and postcentral) of the contralateral and ipsilateral sensorimotor cortex. RESULTS: The activated area of the contralateral sensorimotor cortex was significantly larger than that of the ipsilateral cortex during tasks with either hand, whereas the ipsilateral activated area was significantly larger during the left-handed task than during the right-handed task. Ipsilateral activation was greatest in the precentral region, less in the central region, and least prominent in the postcentral region. CONCLUSIONS: Our results confirmed those of previous investigators that ipsilateral activation is more pronounced during left-sided movements than during right-sided movements. The variation in activation of the precentral, central, and postcentral subregions suggests different roles of the ipsilateral and contralateral hemispheres during motor tasks.

Adult↗