Biomedical subjects

Y Ando

Publications and source records attributed to Y Ando.

At least 361 records · Page 20Linked to original sources

PubMed1995

Hyperosmolality rapidly reduces atrial-natriuretic-peptide-dependent cyclic guanosine monophosphate production in cultured rat inner medullary collecting duct cells.

The present study was undertaken to explore the acute effect of hyperosmolality on the response of cultured rat inner medullary collecting duct (IMCD) cells to atrial natriuretic peptide (ANP). In contrast to the stimulatory effect of chronic incubation (12 h) in hypertonic medium, it was found that short-term incubation (< 2 h) reversibly suppressed the ANP-dependent cyclic guanosine monophosphate (cGMP) production. Urea, NaCl and mannitol were equi-potent as the osmolyte in suppressing the ANP-dependent cGMP production. Receptor binding assay revealed that hyperosmolality induced a rapid and marked reduction of the maximum binding (Bmax) of ANP without a significant change of the dissociation constant (Kd). Pretreatment with protein kinase C inhibitors (calphostin-C, staurosporin) or with cytoskeleton modulators (cytochalasin-B, colchicine) did not affect the inhibitory effect of hyperosmolality. In conclusion, acute hypertonicity inhibited the ANP-induced cGMP production in contrast to chronic hypertonicity, and reduction of the number of ANP binding sites was considered to be a mechanism responsible for the inhibitory effect of hypertonicity.

Alkaloids↗

PubMed1995

PCR and immunocytochemical analyses of dystrophin-positive fibers in Duchenne muscular dystrophy.

Immunocytochemical studies on serial sections of muscles from 19 patients with Duchenne muscular dystrophy (DMD) were done using seven kinds of antidystrophin antibodies that span dystrophin. Fifteen of the patients were screened for intragenic deletions by the multiplex polymerase chain reaction (PCR); 7 were also tested, using Southern blots. Dystrophin-positive fibers were detected in 10 of the 19 patients, occurring with a frequency of 0.06-75.7%, as clusters or as single fibers in certain muscle bundles. In 7 of the 10 patients, the fibers stained with all antibodies from the N- through the C-terminal region. However, in one patient, there were dystrophin-positive fibers that stained with an N-terminal antibody (DYS-3) and an antibody specific to the rod region (DYS-1), but not with C-terminal antibody (DYS-2). In 2 patients, there were two kinds of fibers: one that did not stain with DYS-1 or DYS-2 and another that stained with all the antibodies used. Single-fiber PCR analysis in 2 patients showed that the genotype of dystrophin-positive fibers differed from that of dystrophin-negative fibers. These results suggest that the majority of dystrophin-positive fibers are of the same clonal origin, but that some are derived from plural reverse mutations, each with a different translation-frame-repairing modality and somatic mosaicism.

Adolescent↗

PubMed1995

Acquired idiopathic generalized anhidrosis: clinical manifestations and histochemical studies.

A 40-year-old male developed complete absence of sweating except for slight sweating in the axillar region. Histopathologic examination of the skin revealed lymphocytes infiltration around the sweat glands and coarse and irregular arrangement of the eccrine glands. Immunohistochemical staining using anti-CD3, CD4, and CD8 antibodies revealed that CD3 positive cells were dominant in the lesion. After intensive glucocorticoid treatment, generalized sweating was almost completely recovered.

Adult↗

PubMed1995

Lymph node metastases in gastric cancer invading the submucosal layer.

We investigated the incidence of lymph node metastasis in 80 patients with early gastric cancer invading the submucosal layer and the relation of metastasis to other clinicopathological variables. All patients underwent curative gastric resection with lymphadenectomy. Lymph node metastasis was detected histologically in 15 patients. The incidence of nodal involvement showed significant increase paralleling the depth of cancer invasion. There was no relation between nodal involvement and histological differentiation. No patients died of gastric cancer during the follow-up. We conclude that gastrectomy with R2 lymphadenectomy is an appropriate operative method for early gastric cancer in which precise diagnosis of cancer invasion cannot be confirmed preoperatively.

Adult↗

PubMed1995

Neurologic features of chronic minamata disease (organic mercury poisoning) and incidence of complications with aging.

To elucidate the neurologic features of chronic Minamata disease, and the incidence of complications with aging, we studied 80 patients with documented Minamata disease (organic mercury poisoning) from 1986 to 1994 (mean age: 63 years). Of the cardinal neurologic findings, sensory impairment was seen with highest frequency in 98.8% of patients limited to the extremities in 86.3%. Impairment of lower extremity coordination was observed in 60%, constriction of the visual field in 51.9%, and retrocochlear hearing loss in 41%. To assess age-related complications, patients were separated into three groups by age: Group I (10 to 39 years); Group II (40 to 69 years); Group III (> or = 70 years). The incidences of hypertension and cerebrovascular diseases, organic ophthalmologic disorders (including cataracts), presbyacusis, and cervical spondylosis deformans increased significantly with age. Compared with a preceding survey (1981 to 1985, 171 patients, mean age: 63.5 years), the incidences of complicated hypertension and cataracts had decreased, whereas those of cerebrovascular disease and retinitis pigmentosa remained unchanged. The incidences of abnormal brain computed tomography (CT), presbyacusis, cervical spondylosis deformans, and positive tests for urine sugar also increased. The incidences of these complications other than retinitis pigmentosa were similar to those in the general population. These results accurately reflect the recent epidemiological disease tendencies in Japan toward a decreased incidence of hypertension and an increased incidence of diabetes.

Adolescent↗

PubMed1995

Elevated serum growth hormone accelerates gastric tumorigenesis in F344 rats after treatment with N-methyl-N-nitrosourea in their drinking water.

We examined the effects of growth hormone on tumorigenesis in F344 rats treated with N-methyl-N-nitrosourea (MNU). Four-week-old male F344 rats were exposed to 100 ppm MNU in their drinking water for 15 weeks. Thereafter Group II animals received 100 microCi/100 g body weight of 131I (radiothyroidectomy, Tx) injected i.p. and Group III rats were implanted with pituitary tumors (MtT) secreting growth hormone while Group I received no further treatment after MNU. Non-carcinogen control animals received MtT, Tx or no treatment. Animals were killed at 39 weeks after starting MNU administration. Gastric tumors were present in 13 of 31 (43%), 15 of 32 (47%) and 17 of 32 (53%) rats in Groups I to III, respectively. All tumors were of well-differentiated type. Spinal cord tumors appeared in 15 of 31 (47%) in Group I, 10 of 32 (32%) in Group II and 10 of 32 (32%) in Group III, most being malignant schwannomas. Thymic lymphomas also appeared in 10 of 31 (32%), 5 of 32 (16%) and 6 of 32 (19%) animals in Groups I to III, respectively. There were no significant differences among the groups. However, tumors in Group III developed significantly earlier than in Groups I or II. This was mainly due to gastric tumors, and cumulative incidence curves for spinal cord tumors or thymic lymphomas were similar in all groups. The results indicate that gastric tumors induced by MNU in F344 male rats are influenced by elevated levels of growth hormone.

Animals↗

PubMed1995

Progesterone enhancement of stomach tumor development in SD rats treated with N-methyl-N'-nitro-N-nitrosoguanidine.

The effects of chronic progesterone treatment on gastric tumorigenesis were examined in 6-week-old male SD rats. The rats were castrated, progesterone or testosterone pellets were implanted, and, starting one week after the operation, 100 mg/liter of N-methyl-N'-nitro- N-nitrosoguanidine (MNNG) was administered in the drinking water for 16 weeks. Every 2 months the pellets were changed. Group 1 animals received castration plus MNNG while Groups 2 and 3 also received progesterone and testosterone, respectively. In the Group 4 case, progesterone and testosterone were administered alternately for 2-month periods and in Group 5 MNNG was given to intact animals. All survivors were killed one year after the start of MNNG treatment. In Group 1 the incidence of gastric tumors was significantly decreased as compared with the Group 5 value. The Group 2 incidence, in contrast, was similar to that in Group 5, and the size of the observed gastric tumors was massively increased. The area of the pyloric gland mucosa was also greater than in other groups. Testosterone treatment was associated with a less pronounced increase in tumor size and a recovery in incidence. The results indicate that progesterone may exert a promoting influence on gastric tumor development.

Animals↗

PubMed1995

Breast cancer metastatic to uterine leiomyoma: a case report.

A case is reported of a 51-year-old woman who had a hysterectomy and bilateral salpingo-oophorectomy in the same year, following a radical mastoidectomy for breast cancer with metastases to the axillary lymph nodes. Histological examination showed breast cancer metastatic to uterine leiomyoma. The literature about metastasis of extragenital cancer to a leiomyoma is reviewed, and the possible mechanism involved is discussed.

Breast Neoplasms↗

PubMed1995

The inferior vena cava diameter as a marker of dry weight in chronic hemodialyzed patients.

We have previously reported that the diameter of the inferior vena cava (IVC) reflects the amount of body fluid in hemodialyzed (HD) patients. The present study was undertaken to depict the criteria of IVC diameters for determining dry weight (DW) in anuric HD patients. In healthy subjects, the maximal diameters during quiet expiration (IVCe) and the minimal diameters during quiet inspiration (IVCi) were 16.7 +/- 3.2 and 5.7 +/- 5.4 mm, respectively (mean +/- SD). The collapsibility index (CI, 1 - IVCi/IVCe), which inversely correlates with the central venous pressure, was 0.68 +/- 0.29. In anuric HD patients, the IVCe/CI values before and after HD were 14.9 +/- 3.2/0.68 +/- 0.24 and 8.2 +/- 2.3/0.94 +/- 0.09, respectively. IVCe decreased proportionally to the amount of ultrafiltration. In HD patients with hypervolemic pulmonary edema, the IVCe and CI values were 22.4 +/- 2.9 and 0.22 +/- 0.11, respectively. We proposed that IVCe/CI after HD is 8 +/- 3 mm/0.9 +/- 0.1 as the markers of DW in anuric HD patients and that an IVCe value > or = 22 mm together with a CI < or = 0.22 implies the warning level of body fluid retention.

Analysis of Variance↗

PubMed1995

A novel V beta 2-specific endogenous mouse mammary tumor virus which is capable of producing a milk-borne exogenous virus.

We have previously reported new Mtv loci, Mtv-48 and -51, in the Japanese laboratory mouse strains CS and NC. Here we show by backcross analysis that both Mtv-48 and -51 cosegregate with very slow deletion of T cells bearing V beta 2. The nucleotide sequences of the open reading frames in the 3' long terminal repeats of Mtv-48 and -51 were very similar to those of Mtv-DDO, mouse mammary tumor virus C4 [MMTV(C4)], and MMTV(BALB/cV), which encode V beta 2-specific superantigens. Furthermore, backcross female mice carrying Mtv-48 but not Mtv-51 were found to be able to produce milk-borne MMTV(CS), which can vigorously stimulate V beta 2-expressing T cells after local injection in vivo in an I-E-dependent manner. On the other hand, mice carrying Mtv-51 but not Mtv-48 could not produce such an MMTV in milk. The nucleotide sequences of MMTV(CS) open reading frame were completely matched with those of Mtv-48. These results indicate that the provirus Mtv-48 but not Mtv-51 is capable of producing a milk-borne virus of which the superantigen stimulates V beta 2-expressing T cells.

Amino Acid Sequence↗

PubMed1995

Potassium secretion is inhibited by metabolic acidosis in rabbit cortical collecting ducts in vitro.

The role of metabolic acidosis in the regulation of transepithelial potassium transport was examined in rabbit cortical collecting ducts (CCD) using in vitro isolated tubular microperfusion and conventional microelectrode techniques. Basolateral metabolic acidosis, created by reduction of bicarbonate concentration from 25 to 5 meq/l, pH 7.40 to 6.80, depolarized the transepithelial voltage significantly (-6.5 +/- 1.0 to -2.7 +/- 1.3 mV). Basolateral acidosis also suppressed net potassium secretion (-14.3 +/- 2.1 to -9.0 +/- 1.7 pmol.min-1.mm-1). Electrophysiological study in CCD cells demonstrated that basolateral metabolic acidosis depolarized transepithelial voltage and apical and basolateral membrane voltage with an increase of transepithelial and fractional apical resistance. Basolateral acidosis did not affect the 22Na efflux nor 86Rb efflux. The inhibitory action of basolateral acidosis on net potassium secretion remained in the presence of luminal barium and in the absence of bicarbonate. Ouabain could not abolish the effect of basolateral acidosis on transepithelial voltage completely. These data lead us to conclude that basolateral acidosis affects multiple transport pathways, and it inhibits mainly apical barium-sensitive potassium transport. Additionally, it inhibits apical sodium conductance, barium-insensitive potassium transport, and stimulates a ouabain-insensitive electrogenic transport pathway to some degree.

Acidosis↗

PubMed1995

Activation of protein kinase C stimulates cAMP phosphodiesterase in rat renal collecting tubule.

The present study was undertaken to evaluate whether protein kinase C (PKC) affects adenosine 3',5'-cyclic monophosphate phosphodiesterase (cAMP-PDIE) activity in microdissected rat renal medullary collecting tubules (MCT). Phorbol 12-myristate 13-acetate (PMA, 10(-8) M), an activator of PKC, significantly stimulated cAMP-PDIE activity in intact MCT (29.5 +/- 1.5 to 38.3 +/- 3.7 fmol.min-1.mm-1, P < 0.05) but not in the proximal straight tubule [4.7 +/- 0.8 vs. 4.8 +/- 0.8, not significant (NS)] or the medullary ascending limb of Henle's loop (20.5 +/- 2.1 vs. 22.4 +/- 2.8, NS). PMA-stimulated cAMP-PDIE activity was reversed by PKC inhibitors, staurosporine (10(-8) M) and calphostin C (10(-8) M), but not by the cyclooxygenase inhibitor, indomethacin (5 x 10(-6) M). 1,2-Dioctanoyl-sn-glycerol (50 micrograms/ml), a synthetic analogue of diacylglycerol that stimulates PKC, also increased cAMP-PDIE activity in broken-cell preparations from MCT. This stimulation was also suppressed by staurosporine (10(-8) M) and calphostin C (10(-8) M). The stimulatory effect of PMA on cAMP-PDIE activity was lost with rolipram (10(-4) M), a type IV PDIE inhibitor, whereas it was preserved with N-(6-amino-hexyl)-5-chloro-1-naphthalenesulfonamide hydrochloride (W-7) (10(-4) M), a calmodulin inhibitor, or vinpocetin (10(-4) M), a direct inhibitor of type I PDIE. From these results, we suggest that activation of PKC specifically stimulates rolipram-sensitive cAMP-PDIE, but not the calmodulin-sensitive isozyme, in rat MCT.

3',5'-Cyclic-AMP Phosphodiesterases↗

PubMed1995

Luminal prostaglandin E2 modulates sodium and water transport in rabbit cortical collecting ducts.

We have previously found that arginine vasopressin (AVP) acts not only from the basolateral side but also from the luminal side of the rabbit cortical collecting duct (CCD). In the present study, we examined whether prostaglandin E2 (PGE2), another classic and potent modulator of the collecting duct functions, exerts luminal actions in the rabbit CCD perfused in vitro. Although luminal prostaglandin I2 was inert, luminal PGE2 (> 1 nM) induced transient hyperpolarization of transepithelial voltage followed by sustained depolarization in a dose-dependent manner. This action was preserved in the presence of basolateral PGE2, luminal AVP, or luminal BaCl2, but abolished by basolateral ouabain or luminal amiloride. Furthermore, unlike luminal AVP, luminal PGE2 suppressed Na transport and increased osmotic water permeability. The present study suggests that PGE2, similar to AVP but in a different fashion, modulates transepithelial transports from both luminal and basolateral sites in the CCD in vivo.

Animals↗

PubMed1995

Clinical and pharmacologic analysis of hyperfractionated daily oral etoposide.

PURPOSE: The antitumor effect of etoposide is increased by maintaining a low blood level, whereas high peak levels may cause myelotoxicity. We investigated whether a constant low blood level could be obtained by the administration of oral etoposide three times daily. PATIENTS AND METHODS: Nineteen patients with non-small-cell lung cancer were treated with oral etoposide (25 mg three times daily for 21 days) as monotherapy or in combination with cisplatin 80 mg/m2. A pharmacokinetic model that predicted the mean blood concentration (Cmean) was developed in the 10 patients on etoposide monotherapy and validated in the nine patients on combination chemotherapy. Pharmacodynamic relationships were evaluated in each group. RESULTS: Etoposide dose per body-surface area ranged from 45 to 63 mg/m2/d (median, 53), but did not correlate with plasma level. Cmean was 1.1 +/- 0.3 micrograms/mL. Peak concentrations ranged from 0.6 to 2.5 micrograms/mL. The intrapatient coefficient of variation for plasma etoposide concentrations was 22% +/- 10%. Cmean was accurately estimated as follows: Cmean = 0.098 + 0.413 x C0 + 0.458 x C2 (r = .97, P = .0001), where C0 and C2 represent concentrations before and 2 hours after administration. This model was unbiased (mean predictive error [MPE], 0.0 microgram/mL) and precise (root mean square error [RMSE], 0.1 microgram/mL). Leukopenia was the major toxicity. The surviving fraction of leukocytes (SF; nadir count/pretreatment count) was correlated to Cmean as follows: SF = 0.87 - 0.34 x Cmean (r = .67, P = .03) in the monotherapy group and SF = 0.64 - 0.33 x Cmean (R = .77, P = .03) in the combination chemotherapy group. Two and four patients treated with monotherapy and combination chemotherapy showed responses, respectively. All responders had a Cmean > or = 1.0 microgram/mL. CONCLUSION: Hyperfractionated oral etoposide achieveda stable plasma level that could be predicted by measurement at only two times.

Administration, Oral↗

PubMed1995

Involvement of the central nervous system in rheumatoid arthritis: its clinical manifestations and analysis by magnetic resonance imaging.

A rheumatoid arthritis (RA) patient showed high signal intensity in the subcortical region of the frontal and occipital lobes on T2-weighted magnetic resonance imaging (MRI). Histopathological examination in the autopsy specimen revealed severe systemic vasculitis. Additional radiological and laboratory studies revealed that transient cerebral ischemia induced by vasculitis occurred in this patient.

Arthritis, Rheumatoid↗

PubMed1995

Occult thymic carcinoma presenting as malignant cardiac tamponade.

A 66-year-old woman who presented with malignant cardiac tamponade of unknown origin was eventually found to have a tiny squamous cell carcinoma of the thymus. Thus, even a small thymic carcinoma can exhibit highly aggressive behavior. It should be included in the differential diagnosis of malignant cardiac tamponade of unknown origin.

Aged↗

PubMed1995

Change in the age of onset in patients with familial amyloidotic polyneuropathy type I.

To investigate the influence of environmental factor(s) on the pathogenesis of familial amyloidotic polyneuropathy (FAP) type I, the age of onset in 33 FAP patients in the Arao district of Kumamoto Prefecture in Japan and in 20 of their ancestors to the 3rd prior generation was carefully examined. The age of onset in FAP patients progressively became younger. This tendency was more apparent in female FAP patients than in male patients. Since the pathogenesis of amyloid formation in FAP as well as other amyloidosis diseases is not still elucidated, this phenomenon may be of interest.

Adolescent↗

PubMed1995

[Detection of Mycobacterium tuberculosis by amplification of mycobacterial DNA from pleural fluid and gastric juice: the comparison of IS6110 gene with Amplicor mycobacterium].

The polymerase chain reaction (PCR) using oligonucleotides based on the repetitive sequence (IS6110) of Mycobacterium tuberculosis and Amplicor Mycobacterium, which combines a PCR with the hybridization assay, were evaluated for detection of M. tuberculosis in pleural fluid and gastric juice. The detection limits of these two assay systems for cultured M. tuberculosis were less than 2 cells/ml, as compared with 200 cells/ml by culture. A total of 42 pleural fluid and 94 gastric juice specimens were examined. A total of 5 pleural fluid and 5 gastric juice were culture positive for M. tuberculosis. Only the PCR gave positive results in 2 pleural fluid of which laboratory findings are characteristic of tuberculous pleuritis, and in one gastric juice of the patient who was diagnosed as having pulmonary tuberculosis. Sensitivity, specificity and positive predictive value for IS6110 gene were 75%, 94% and 71.1%, respectively, in pleural fluid. Two of three positive specimens for IS6110 gene from pleural fluid were negative for Amplicor Mycobacterium. These specimens resulted in positive with Amplicor Mycobacterium when solvent extracted DNA was used. Both the PCR systems had the same sensitivity (80%), specificity (98.8%) and positive predictive value (83.3%) in gastric juice. The PCR systems would be useful for rapid detection of M. tuberculosis without long term culture and for detection of non-cultured one from pleural fluid as well as gastric juice. However, when the presence of an inhibitor of PCR is suspected in a specimen, DNA should be purified from the specimen before amplification.

Adult↗