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Biomedical subjects

K Okubo

Publications and source records attributed to K Okubo.

At least 127 records · Page 7Linked to original sources
PubMed1998

Incidence of lymph node metastasis and its impact on long-term prognosis in clinically localized prostate cancer.

BACKGROUND: Pelvic lymph node dissection (PLND) is an important staging method for men with clinically localized prostate cancer. We report our experience with staging PLND and the impact of lymph node metastasis on long-term prognosis. METHODS: One hundred forty-eight consecutive patients who underwent staging PLND for clinically localized prostate cancer were retrospectively studied. Patients were evaluated for the presence and number of lymph node metastases, treatment (prostatectomy vs. radiotherapy), and endocrine therapy, and analyzed with respect to disease progression and survival. The mean follow-up period was 52.9 months (range, 2.3 to 165.8 months). RESULTS: Thirty-two patients (21.6%) had pelvic lymph node metastases, the incidence of which markedly decreased from 32.3% in 1982 to 1987 to 6.7% in 1994 to 1997. The intervals to disease progression and cancer death were significantly shorter in patients with positive lymph nodes (P < 0.001). In stage D1 disease, patients who underwent a radical prostatectomy tended to be free of progression longer than those receiving radiotherapy or conservative therapy (P = 0.0546). Other factors, such as early endocrine therapy, the extent of lymph node involvement and the Gleason score of the primary tumor did not predict disease progression or survival. CONCLUSION: These data suggest a decreasing trend in the incidence of lymph node metastasis in the PSA era. Although longer disease-free intervals were observed in radical prostatectomy-treated patients, the impact of an aggressive approach to stage D1 disease awaits further studies.

Adenocarcinoma↗
PubMed1998

Ultrasensitive assay of prostate-specific antigen for early detection of residual cancer after radical prostatectomy.

OBJECTIVES: Perhaps the greatest value of PSA determination in the treatment of prostate cancer is in determining persistent disease after a radical prostatectomy. We investigated the ability of an ultrasensitive PSA assay to detect residual prostate cancer in men at risk for recurrence after a radical prostatectomy. METHODS: Using the Immulite third-generation PSA assay (detection limit, less than 0.003 ng/mL), and the standard IMx PSA assay, we determined PSA levels in 205 serum samples serially obtained from 34 men after a radical prostatectomy. The average days from surgery to serum sampling was 430 (range, 63 to 1296). Patients were classified as having nonaggressive or aggressive cancers, based on clinicopathologic findings. A biochemical relapse was arbitrarily defined. RESULTS: All 17 patients with nonaggressive cancers had PSA values of less than 0.02 ng/mL throughout the sampling period. Two of these patients (12%) had 2 or more consecutive PSA increases and were considered as a biochemical relapse. In contrast, 14 (82%) of 17 patients with aggressive cancers fit criteria of a biochemical relapse. All of the relapses were identified within 2 years after surgery. The IMx assay detected only 7 biochemical relapses during the same sampling period. CONCLUSIONS: Using the Immulite PSA assay, relapse detection times may be shortened allowing for most serological recurrences to be detected within 2 years after a radical prostatectomy. Patients with aggressive cancers may require frequent postoperative PSA determinations with a highly sensitive PSA assay which would allow early intervention when treatments for relapse are effective.

Aged↗
PubMed1998

Inhibitory effects of catecholamines and maternal stress on aromatase activity in the fetal rat brain.

OBJECTIVE: Aromatization in the the fetal brain is thought to be involved both in sex differentiation during early development and in adult sexual behavior. Although recently the relationship between aromatase and catecholamine has been discussed, the effect of stress on aromatase in the fetal brain has not been clarified. Therefore, in the present study, localization of aromatase and the inhibitory effects of catecholamines and maternal stress on aromatase activity in the fetal rat brain were examined. METHODS: Localization of aromatase cytochrome P-450 using a specific polyclonal antiserum against human placenta aromatase was examined, and the inhibitory effects of dopamine and norepinephrine on aromatase activity in vitro were studied. Further, the influences of intrauterine stress on aromatase activity in the prenatal rat brain were evaluated in vivo. RESULTS: Aromatase-immunoreactive neurons are located principally in the medial amygdaloid nucleus. Aromatase activity in the fetal rat brain was competitively inhibited by dopamine and norepinephrine, with Ki values of 120 microM and 100 microM, respectively. Aromatase activity in the fetal brain was significantly lower in stressed rats given 1.5% salt water (89.2 +/- 17.5 fmol/mg/hr; n = 4) (p < 0.05) than in the control group (123.1 +/- 10.0 fmol/mg/hr; n = 4). CONCLUSION: Aromatase activity in the prenatal rat brain is influenced by catecholamine metabolism during intrauterine stress.

Amygdala↗
PubMed1998

[A case of brain abscess accompanied with sudden-onset hemiplegia as initial manifestation].

A 58-year-old male experienced a sudden stroke-like onset of right hemiplegia and numbness of his right upper limb while engaged in his desk-work on April 7, 1997. He had a past history of diabetes mellitus and hyperlipidemia. On admission, he had no fever and the blood pressure was 140/70 mmHg. General physical examination was unremarkable. Neurological examination showed 4/5 strength of his right unilateral extremities and numbness of his right upper limb. Clinical features and computed tomography (CT) without contrast medium at the onset of hemiplegia suggested a stroke. Seven days after admission, his consciousness worsened and body temperature fluctuated between 37 and 38 degrees C. Subsequent Gd-enhanced magnetic resonance (MR) which demonstrated an irregular shaped ring-enhancement lesion and lumbar puncture 9 days after admission was compatible with the diagnosis of brain abscess. Surgical drainage confirmed the presence of brain abscess due to alpha-streptococcus. It improved following surgical drainage and antibiotic therapy with PAPM.BP 2 g/day and PIPC 4 g/day. An afebrile patient of sudden stroke-like onset may be a rarity to be added to the differential diagnosis of brain abscess.

Acute Disease↗
PubMed1998

Adhesion of human red blood cells and surface charge of the membrane.

To elucidate the mechanism by which red blood cells (RBC) participate in thrombus formation, we investigated the mechanism of adhesion between human RBC. Our study showed that the morphology of RBC was changed by various cationic reagents, inducing adhesion between RBC. When RBC suspended in PBS buffer containing sodium phosphate (PBS(Na)) or potassium phosphate (PBS(K)) were treated with cationic reagents, stronger adhesion occurred between RBC treated with the latter. When concentrations of the reagents were low, adhesion was released and the RBC resumed its original morphology after washing. However, when the concentrations of reagents were high, the morphology did not normalize, although the adhesion was released. When fresh RBC were treated with cationized ferritin (CF), CF bound to the periphery of RBC membranes and induced adhesion. However, when RBC were induced to adhere strongly by a cationic reagent, no binding of CF to the membrane was not observed. When RBC were treated with CF, bindings between substances outside the membranes and bindings between the membranes and substances outside the membranes were observed. When RBC treated with neuraminidase to remove 85-90% of sialic acid were treated with the cationic reagents, both adhesion between RBC and morphological change were reduced. When RBC were pretreated with polyclonal antibody against human RBC membrane band 3 protein, treatment with the cationic reagents did not induce adhesion and morphological change of RBC. Further, when RBC induced to adhere by the cationic reagents were treated with the polyclonal antibody against band 3, in the case of weak adhesion, the adhesion was released and the RBC resumed its original morphology. However, in the case of strong adhesion, the morphology did not return to normal although the adhesion was released. These results suggest that the adhesion between RBC induced by cationic reagents was due to changes in the charge on the membrane surface, involving polysaccharide chains and membrane surface proteins.

Anion Exchange Protein 1, Erythrocyte↗
PubMed1998

Relationship between chemical structures and biological activities of triterpenoid saponins from soybean.

Saponins can be found in more than one hundred plant families and in some marine animals. However, chemical investigation of soybean (Glycine max L. Merrill) saponins has begun only as recently as the 1970s. Here we focus on the chemical structure, the content, and biological activity of soybean saponins in current studies. Especially, we focus on 2,3-dihydro-2,5-dihydroxy-6-methyl-4H-pyran-4-one (DDMP) conjugated saponins and define the chemical structure of this as a natural precursor of group B and E saponins.

Animals↗
PubMed1998

HPLC profile analysis of oleanene-glucuronides in several edible beans.

HPLC analysis and yield of oleanene-glucuronide (OG) was done on some commercially available edible beans: seeds of Glycine max, Glycine max cv. Kuromame, Phaseolus vulgaris cv. Torosuku, Phaseolus vulgaris cv. Toramame, Phaseolus vulgaris cv. Taishokintoki, Phaseolus coccineus cv. Ooshirobana, Phaseolus coccineus cv. Murasakihanamame, Vigna unguiculata cv. Chuguro, Vigna angularis cv. Dainagon, Arachis hypogaea, Pisum sativum, and Vicia faba. All the beans listed above have OG, though in varying the amounts. Furthermore the HPLC profiles of beans belonging to the same genus were very similar except for that of the Vigna genus. There was no great difference of the HPLC profiles with respect to the cultivated varieties. The structures of the major OGs in each type of beans were identified as soyasaponins I (1) and V (2), and phaseoside I (3) (Phaseolus vulgaris and P. coccineus); 1 and soyasaponin II (4) (Glycine max); 1 and 2 (Vigna unguiculata); 1 (Pisum sativum, Arachis hypogaea and Vicia faba). In contrast, those in Dainagon (Vigna angularis cv. Dainagon) were identified as azukisaponins II (5) and VI (6).

Carbohydrate Sequence↗
PubMed1998

Free-to-total prostate specific antigen ratio in clinical staging of prostate cancer.

The value of the free-to-total serum prostate-specific antigen (f/t PSA) ratio was compared with that of the total prostate specific antigen (tPSA) value for the prediction of clinical stage in patients with prostate cancer. The f/t PSA ratio was obtained from the frozen sera of 56 untreated patients with histologically proven BPH and 78 patients with prostate cancer. The clinical stage was organ-confined in 36, locally advanced in 20 and metastatic in 22 patients. Serum levels of free PSA (fPSA) and tPSA were determined using a chemiluminescent enzyme immunoassay. The f/t PSA ratio was calculated by dividing the fPSA value by the tPSA value and was compared with tPSA and fPSA in the correlation with clinical stage via the Spearman rank correlation test. Patients with prostate cancer had a significantly lower f/t PSA ratio than patients with BPH. The f/t PSA ratio did not differ between patients with clinically localized and metastatic cancer. tPSA and fPSA reflected the clinical stage and the extent of bone metastasis more accurately than the f/t PSA ratio. The extent of bone metastasis had no effect on the PSA ratio. The f/t PSA ratio had no additional value in clinical staging compared to tPSA. Our study suggests that the f/t PSA ratio does not reflect tumor load.

Aged↗
PubMed1998

Isolation and characterization of human cathepsin V: a major proteinase in corneal epithelium.

PURPOSE: To isolate and characterize a novel cathepsin gene, as part of the systematic isolation of genes uniquely active in corneal epithelium. METHODS: For the isolation of a full-length cDNA clone, a probe was selected from a set of expressed sequence tag clones classified as unique to corneal epithelium. Inserted cDNA was introduced into insect cells using a baculovirus expression system, and the secretion of recombinant protein was identified using antisera against a synthetic peptide. Proteolytic activity was determined using bovine serum albumin (BSA) as substrate. The expressions of the novel cathepsin in human cornea and other tissues were examined by reverse transcription-polymerase chain reaction (RT-PCR). RESULTS: The full-length cDNA clone encoded a peptide of 334 amino acids with 82% identity with bovine cathepsin L and 77% identity with human cathepsin L when aligned. The recombinant protein produced in the baculovirus expression system cleaves BSA, and its activity was inhibited by the cysteine proteinase inhibitors E-64 and leupeptin, but not by pepstatin A, phenylmethylsulfonyl fluoride, and EDTA. By RT-PCR, a low level of expression was observed in some other epithelial tissues of ectodermal origin, but only in cornea was it higher than cathepsin L, which is known to be a general lysosomal cathepsin. Cathepsin V protein was detected in human corneal epithelium by western blot analysis, but not in tear fluid. CONCLUSIONS: The amino acid homology and proteolytic activity of the recombinant protein indicate that the novel gene is a new member of the cathepsins that have features of cysteine proteinase. Its uniquely high expression in corneal epithelium strongly implies an important role in corneal physiology.

Amino Acid Sequence↗
PubMed1998

[PSATZ (prostate specific antigen adjusted for the transition zone volume)].

This brief review discusses the diagnostic ability of prostate specific antigen adjusted for the transition zone volume (PSATZ) for the detection of prostate cancer in patients with intermediate prostate specific antigen (PSA) levels. PSATZ was defined as the quotient of the PSA value and the calculated transition zone volume. In comparison with standard parameters including PSA and prostate specific antigen density, PSATZ could be a useful indicator for the detection of prostate cancer in patients with PSA values between 4.1 and 10.0 ng/ml, especially in those with normal digital rectal examinations. Similar observations consistent with our results have been also reported by other investigators. PSATZ has some disadvantages including volumetry and expensive cost. Further study is necessary to discuss whether PSATZ is superior to other new modalities such as free-to-total PSA ratio with regard to diagnostic cost and efficacy.

Humans↗
PubMed1997

Molecular cloning and expression of a novel human aquaporin from adipose tissue with glycerol permeability.

In a systematic analysis of genes expressed in human adipose tissue, we detected a novel gene that is expressed uniquely in adipose tissue. The sequence showed that it encodes a 342-amino-acid protein containing six putative transmembrane domains, and is a new member of the aquaporin family of water-selective membrane channels. We named this gene aquaporin 9. It features a cyclic-AMP protein kinase phosphorylation consensus site in the NH3-terminal domain. Expression of the cRNA in Xenopus oocytes yielded a 7-fold increase in osmotic water permeability blocked by 0.3 mM HgCl2, and also facilitated the uptake of glycerol. Northern blot analysis demonstrated that the mRNA is abundant in adipose tissue, but not in other tissues. Thus, this gene product may participate in glycerol transport in adipocytes.

Adipose Tissue↗
PubMed1997

Eighteen novel human genes regionally mapped on chromosome 11.

Expression sequence tags (EST) obtained by sequencing a randomly primed cDNA library and gene signatures (GS) obtained by sequencing a 3'-directed cDNA library can identify genes that are active in the source cells. Eight ESTs and ten GSs which represent novel human genes, except for one GS, and which have been assigned to human chromosome 11 were used to select cosmids from a chromosome 11-specific cosmid library. These cosmids were regionally mapped using the fluorescence in situ hybridization technique.

Animals↗
PubMed1997

Cloning of a cDNA encoding a novel sugar transporter expressed in the neonatal mouse hippocampus.

While analyzing active genes in the neonatal mouse hippocampus, we observed several novel genes that were abundantly expressed in this tissue. We report here cloning and sequencing of one of these transcripts, HiAT1 (Hippocampus Abundant Gene Transcript 1). The mRNA was 2.7 Kb in length, and the deduced amino acid sequence consisted of 490 amino acids with characteristics typical of members of the sugar transporter family. However, its overall sequence homology to known transporter cDNAs was only about 30%, suggesting strongly that it represents a novel sugar transporter gene. Northern hybridization analyses showed this transcript is detected in adult and embryonic brains, as well as in other tissues.

Amino Acid Sequence↗
PubMed1997

Isolation of a cDNA encoding a widely expressed novel zinc finger protein with the LeR and KRAB-A domains.

We have isolated a human cDNA clone representing a novel human gene. The predicted 683-amino-acid protein, designated FPM315, contains nine C2H2-type zinc finger motifs and two regions homologous to the LeR domain, a finger-associated structural domain, and the A element of the Kruppel-associated box (KRAB) domain involved in transcriptional repression. The FPM315 mRNAs were expressed in all human tissues so far examined. A cross-species genomic hybridization indicates that the FPM315 gene is highly conserved among eukaryotes. These data suggest that FPM315 might play an important role in basic cellular processes.

Amino Acid Sequence↗
PubMed1997

Analysis of an expression profile of genes in the human adipose tissue.

Increasing evidence suggests that in addition to storing excess energy as fat, adipose tissue acts as an endocrine organ secreting various factors into the blood stream. Every time a new factor is found in adipose tissue, however, its implication is discussed independently, and a systematic analyses based upon a global view of gene expression of this tissue has not been performed. To describe the function of this tissue in terms of gene expression, and to find new factors, we performed random complementary DNA (cDNA) sequencing using a 3'-directed cDNA library that faithfully represents the composition of the messenger RNA (mRNA). Various well-known but unexpected genes, including those for gelsolin, plasma glutathione peroxidase (GPX-3) and carboxypeptidase E (CPE) were shown to be very active. By comparing the expression profile of active genes in the adipose with those of other tissues and with data in dbEST, we identified seven new genes that are specifically expressed in adipose tissue. Among these, one encoded a protein with collagen-like repeats and a putative secretion signal. These data can be used as new tools for analyses of the physiology of this tissue, as well as the etiology and complications of obesity.

Adipose Tissue↗