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Biomedical subjects

K Okada

Publications and source records attributed to K Okada.

At least 433 records · Page 24Linked to original sources
PubMed1998

Comparison of variant expression of estrogen receptor mRNA in normal breast tissue and breast cancer.

To investigate whether estrogen receptor abnormalities are associated with resistance of breast cancer to endocrine therapy, we compared estrogen receptor mRNA between normal breast tissue and carcinoma. Using the RT-PCR, paired cancer and normal breast tissue specimens from 15 patients were analyzed. Exon-deleted variants were found in both tumor and normal tissue, with differences of variant expression between normal and tumor tissue being observed. One patient showed multiple deletions in the hormone-binding domain. Alterations in the amount and/or kind of variant ER expression may be important in determining the response of breast cancer to endocrine therapy.

Base Sequence↗
PubMed1998

Expression of c-MET/HGF receptor mRNA and protein in human non-malignant and malignant prostate tissues.

We previously reported the expression of hepatocyte growth factor (HGF), a ligand for c-MET, at the level of mRNA and protein in human prostate tissues. The present study was carried out to evaluate the relationship between c-MET expression and cancer cell proliferation or effect of cancer therapy. The expression both in mRNA and protein levels of c-MET proto-oncogene was determined semi-quantitatively by reverse transcription-competitive polymerase chain reaction (RT-competitive PCR) and Western blot analysis for prostate tissues from 32 Japanese male subjects. In addition, tissue localization of c-MET translation product was examined by immunohistochemistry for corresponding specimens. Although there was significantly higher c-MET protein expression in malignant (prostate cancer treated with/without neoadjuvant endocrine therapy) than in non-malignant prostate tissues (normal prostate and benign prostate hyperplasia; BPH), unexpectedly, c-MET mRNA showed high expression in the non-malignant group. Thus, there was no parallelism between mRNA and protein expressions of c-MET. Endocrine therapy did not alter c-MET mRNA and protein expressions in human prostate cancer. Immunohistochemical localization and expression of c-MET protein was found to be intense in cancer cells and weak in epithelia of normal and hyperplastic prostates. Unconcerted expression of mRNA and protein of c-MET, the reason of which is uninterpretable, is supposed to be one of characteristics of human prostate cancer.

Aged↗
PubMed1998

[Examination of relation among the generation effect, the level-of-processing effect, and the modality effect in explicit memory tasks].

The main purpose of the present study was to examine the relationship among generation effect, level-of-processing effect, and modality effect in explicit memory. In Experiment 1, the results in the category-name cued recall task showed generation effect. The results in the word-fragment cued recall task showed equal performance level in both read condition and generate condition. In Experiment 2, level-of-processing effect and modality effect were investigated in the word-fragment cued recall task. The results showed the level-of-processing effect, but did not show the modality effect. In Experiment 3, construction of materials and the way of presentation of study list were manipulated in the word-fragment cued recall task. The results showed generation effect, and suggested that the blocked presentation of a study list enhanced conceptually-driven processing. The results of these three experiments were discussed from the following four points: relationship among generation effect, level-of-processing effect, and modality effect in explicit memory tasks; classification of memory task; comparison between word-fragment cued recall task and category-name cued recall task; and conceptually driven processing in explicit memory tasks.

Acoustic Stimulation↗
PubMed1998

[Tumor volume and percent of gland involvement with tumor as predictors of pathological stage in prostate cancer].

BACKGROUND: It is well recognized that tumor volume correlates with pathological stage, histological grade and progression in prostate cancer. We analyzed the tumor volume and the percent of gland involvement with tumor (%TV/PV) to determine if either or both of these morphometric factors would be good predictors of pathological stage. METHODS: The pathological reviews were retrospectively performed on the basis of the 22 step sectioned prostate specimens removed by radical retropublic prostatectomy for clinical T1c-T2-T3 prostate cancer. The percent of gland involvement with tumor was calculated using the following formula [100 x (tumor volume cc/prostate volume cc)]. When the patients had organ confined disease (OCD) or specimen confined disease (SCD) they were defined as surgically cured patients, whereas the patients with positive surgical margin, seminal vesicle involvement or positive lymph node were defined as not surgically cured patients. RESULTS: The likelihood of OCD was 25% in patients with clinical T1c-T2 disease. No patients with clinical T3 had OCD. Patients with SCD was not observed. The mean tumor volume was 1.3 cc in the surgically cured patients and 6.2 cc in the not surgically cured patients. The tumor volume correlated with pathological stage (r = 0.607, p = 0.0054). The mean %TV/PV was 3.23% in the surgically cured patients and 18.2% in the not surgically cured patients. The %TV/PV also correlated with pathological stage (r = 0.543, p = 0.0129). Both the tumor volume and the %TV/PV in surgically cured patients were less than those in the not surgically cured patients. A correlation between tumor grade and both the tumor volume and the %TV/PV were not observed. CONCLUSION: The tumor volume and the %TV/PV correlated well with the final pathological stage. Multiple regression analysis showed that the tumor volume was the best predictor of pthological stage.

Disease Progression↗
PubMed1998

[A case of segmental sunset glow fundus following a choroidal tumor-like lesion].

This paper presents a very rare case of segmental sunset glow fundus following a choroidal tumor-like lesion in a 59-year-old woman. She complained of metamorphopsia in her left eye. Funduscopic examination disclosed a pale yellowish choroidal tumefaction, superotemporal to the macula. She was initially thought to have a choroidal tumor. However, in spite of systemic investigation, a diagnosis could not be made. Gradually the lesion became flattened but spread to the periphery. Iridocyclitis with Koeppe's nodule occurred but regressed after treatment with a topical steroid. Three months after the initial onset of the lesion, funduscopy showed a red area, the "sunset glow", in the superior temporal quadrant. This case resembles Harada disease because of the red coloration in the fundus, iridocyclitis with Koeppe's nodule, and human leukocyte antigen (HLA)-DR4 positivity. But other findings were not compatible with the criteria of Harada disease. It seems that the present lesion has not been reported in the past.

Choroid↗
PubMed1998

[Effect of epidural pressure gradient on buprenorphine flux through the dural hole after combined spinal-epidural anesthesia--comparison between bolus injection and continuous infusion].

Combined spinal-epidural anesthesia is a useful technique. However, there has been no attempt to investigate the risk of epidural opioid, especially buprenorphine, flux through the dural hole. The purpose of this study was to compare the effect of epidural buprenorphine administered across the dura into subarachnoid space, between two different methods of administration; bolus injection (Group I) and continuous infusion (Group II). Sixty patients for transvaginal hysterectomy were divided into two groups. Group I received buprenorphine 0.1-0.2 mg with 0.25% bupivacaine, and Group II 0.4 mg with 0.25% bupivacaine 40 ml continuously (infusion rate was 1.7 ml.h-1). Pain relief was similar in both groups, but the total buprenorphine requirement was lower in Group I than in Group II. The incidence of nausea and vomiting was significantly higher in Group I than that in Group II, 73% and 16%, respectively. It indicates that the increase of nausea and vomiting is predominantly determined by a high rate of flux into subarachnoid space and only partly determined by blood concentrations. In contrast to continuous infusion, the drug movement through the dural hole may increase by bolus injection due to its higher pressure. We recommend careful injection of epidural buprenorphine such as by continuous infusion with low pressure after combined spinal-epidural anesthesia.

Adult↗
PubMed1998

Simple right atrial procedure for chronic atrial fibrillation with atrial septal defect and aortic valvular regurgitation in an elderly patient.

A right atrial separation procedure was performed to eliminate atrial fibrillation (AF) during concomitant repair of an atrial septal defect and aortic valve regurgitation in an elderly patient. This procedure consisted of a Y-shaped incision in the right atrium, followed by cryoablation of the tricuspid annulus and the atrial septum. Only excision of the left atrial auricular appendage was performed in the left atrium. Although this procedure was devised to eliminate chronic AF associated with a solitary atrial septal defect, it was effective to eliminate chronic AF associated with atrial septal defect and aortic valve regurgitation in an elderly patient.

Aged↗
PubMed1998

[HELLP syndrome in triplet pregnancy complicated by DIC and transient diabetes insipidus].

A 29-year-old woman with a triplet pregnancy received emergency caesarean section in the 33rd week of pregnancy. She lost 2 babies, one of whom was a fetal death and the other a neonatal death. Three weeks before delivery, she was admitted to hospital suffering from vomiting, diarrhea and polyuria. There were no laboratory abnormalities such as a slightly elevated levels of liver enzymes, nor any clinical symptoms of preeclampsia. At the end of the operation, disseminated intravascular coagulation (DIC) occurred and HELLP syndrome was diagnosed. However, the hemoglobin level was in the normal range at this point. On the 2nd postoperative day, hemolytic anemia developed in spite of the resolution of other problems. We suggested that the hemolysis, which may have been caused by a latent hemoconcentration and a membrane disorder of the red cells, was an osmotic hemolysis. This case was unique for the following reasons; 1) a lack of symptoms of hypertension, proteinuria and edema, 2) complications due to diabetes insipidus, 3) postpartum severe hemolysis following latent hemoconcentration, and 4) slow progress of the condition after onset. Early detection of HELLP syndrome is difficult. It should be considered in the management of patients with unrecognizable hemoconcentration and nonspecific complications.

Adult↗
PubMed1998

Stereoselective metabolism of benoxaprofen in rats. Biliary excretion of benoxaprofen taurine conjugate and glucuronide.

Benoxaprofen (BOP) was administered iv to bile duct-cannulated rats at a dose of 10 mg/kg. BOP and its metabolites in plasma, urine, and bile were quantified using HPLC. A previously unidentified BOP metabolite was found in HPLC chromatograms of rat bile, and the metabolite was isolated chromatographically. Positive-ion fast-atom bombardment (FAB) MS analysis of the compound showed [M+H]+ at m/z 409, i.e. 108 mass units greater than the molecular weight of BOP (301 mass units). In the 1H NMR spectrum of the compound, two signals assigned to two methylene groups appeared at 2.53 ppm and 3. 30 ppm, in addition to BOP signals. Analysis of FAB mass spectra and 1H-1H and 1H-13C correlated NMR spectra of the isolated metabolite suggested that the new metabolite was a BOP taurine conjugate (BOP-T). A BOP-T standard was chemically synthesized, and physicochemical data were compared with those for the isolated metabolite. Identical results, i.e. RF values from TLC, RT values from HPLC, and FAB MS and 1H-13C correlated NMR findings, were obtained, establishing that the new metabolite found in rat bile was BOP-T. In five rats, mean values for per cent excretion of the dose in bile over 12 hr for BOP glucuronide (BOP-G), BOP-T, and unchanged BOP were 13.2 +/- 2.3, 2.54 +/- 0.80, and 0.33 +/- 0.09%, respectively. Furthermore, the optical isomers of BOP and its metabolites in plasma and bile were analyzed using a chiral HPLC column. (R)-BOP showed rapid plasma elimination, whereas the plasma elimination of (S)-BOP was very slow. The amounts of BOP, BOP-G, and BOP-T enantiomers excreted into the bile were as follows: (S)-BOP-G and (R)-BOP-G, 12.5 +/- 1.8 and 2.1 +/- 0.6% of the dose; (R)-BOP-T and (S)-BOP-T, 2.0 +/- 0.6 and 0.3 +/- 0.05% of the dose; (R)-BOP and (S)-BOP, 0.02 +/- 0.03 and 0.2 +/- 0.1% of the dose, respectively. (S)-BOP was metabolized mainly to BOP-G, and BOP-T excreted into the bile was produced mainly from (R)-BOP.

Animals↗
PubMed1998

[Infective endocarditis--a review of 21 cases in last 10 years].

Twenty one cases of infective endocarditis in last 10 years were re-evaluated by Duke's criteria. Fourteen strains of Streptococcus viridans, 4 of Enterococcus faecalis, 1 of Haemophilus parainfluenzae were isolated from blood culture. As to the minimum inhibitory concentration (MIC) of 8 strains of Streptococci, imipenem revealed the lowest MIC value, following penicillin G, ceftriaxon not equal to ampicillin, vancomycin and gentamicin. One strain of them was penicillin-resistant (0.8 micrograms/ml). Serum inhibitory test (SIT) and serum bactericidal test (SBT) were undergone for 6 cases. The assay was efficient to determine penicillin-tolerance of causative bacterium. Vegetations were observed in 18 cases of 21 by the echo-cardiography, especially transesophageal echocardiography had better diagnostic sensitivity compared to transthoracic echocardiography. However, it took 12 weeks from the first febrile episode to achieve definite diagnosis. One of reasons to take such a long time to reach diagnosis was that major causative organism was S. sanguis, whose inflammatory reaction to the host was said to be strikingly weak.

Adolescent↗
PubMed1998

[A collision tumor between squamous cell carcinoma and malignant lymphoma of urinary bladder: a case report].

A 68-year-old-male was admitted to our hospital with the chief complaint of macrohematuria. He was diagnosed with malignant lymphoma at 63 years old. Cystoscopy and computerized tomography revealed a non-papillary and broad based tumor at the anterior wall of the urinary bladder and partial cystectomy was done. Pathological diagnosis was collision tumor between squamous cell carcinoma and malignant lymphoma. To our knowledge, this is the 13th case of collision tumor associated with genitourinary organs in the literature.

Aged↗
PubMed1998

Human tumor antigen-specific T lymphocytes and interleukin-2-activated natural killer cells: comparisons of antitumor effects in vitro and in vivo.

Human antitumor effector cells include class I major histocompatibility complex (MHC)-restricted T cells and non-MHC-restricted natural killer (NK) cells. These two types of effector cells have not been directly compared for the ability to eliminate tumor cell targets. Here, we compare in vitro and in vivo antitumor functions of two human T-cell lines specific for a shared tumor antigen to the antitumor functions of A-NK cells, a subset of IL-2-activated NK cells. Human squamous cell carcinoma of the head and neck cell lines cultured in suspensions or as spheroids or tumor xenografts established in nude mice were used to evaluate antitumor functions of IL-2-activated and expanded T and NK effector cells in various assays, both in vitro and in vivo. Both tumor cell targets, PCI-13 and OSC-19, expressed class I and II MHC antigens after IFN-gamma pretreatment, gave rise to tumors upon injection into immunosuppressed nude mice, and were resistant to lysis by resting NK cells but sensitive to lysis mediated by A-NK cells or HLA-A2-restricted T-cell lines specific for a shared squamous cell carcinoma of the head and neck antigen. No significant differences were observed in the ability of A-NK cells or tumor-specific T cells to bind to tumor cell monolayers or to enter into spheroids. However, A-NK cells mediated significantly higher killing than tumor-specific CD8+ T cells in 4-h 51Cr-release assays (a measure of cell membrane damage and necrosis), 1-h [3H]thymidine-release assays (a measure of DNA fragmentation and apoptosis), and in terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assays (a measure of apoptosis). In contrast, CD8+ T cells were consistently more effective than A-NK cells in inducing growth inhibition of tumor cells in 24-h MTT assays. In the presence of tumor-specific antibodies, A-NK cell binding, entry into spheroids, and infiltration into tumor in vivo were significantly increased. In vivo perilesional delivery of effector cells to mice with established tumors indicated that human A-NK cells exert antitumor effects as potent as those of tumor-specific T cells. However, in contrast to tumor-specific T cells, A-NK cells are readily available for cancer therapy, expand rapidly in culture without prior sensitization, and can be armed with antitumor antibodies to increase localization of effector cells to the tumor.

Animals↗
PubMed1998

[Prostatectomy for prostate cancers].

Radical prostatectomy may afford cure in men in whom the malignancy is completely extirpable. Historical experiences as well as ours agreed that long term survival after radical prostatectomy was excellent if the disease was confined to the organ. Cure may also be expected in some selected patients with minimal extra-organ invasion. Furthermore, preoperative hormonal therapy may improve the cure rate in these invasive diseases. However, if cure means affording the patient the best chance of dying of some causes other than cancer, some of those extirpable diseases may be cured without surgery. This idea was supported by epidemiologic data on the natural history of the disease, and retrospective observations of conservatively treated patients. Challenging issues toward the 21st century are to expand the range of surgically curative diseases, and to identify diseases extirpable but predestined never to kill the host during the natural course of his life.

Aged↗
PubMed1998

Enhanced hepatocyte growth factor level in human prostate cancer treated with endocrine therapy.

Hepatocyte growth factor (HGF) has been revealed to have various functions such as regeneration, cancer invasion and tumor suppression in normal and cancer cells of different organs. To compare HGF expression in non-malignant prostate tissues and prostate cancers pretreated with or without neoadjuvant endocrine therapy (pretreated PC and non-treated PC), the amounts of HGF protein and mRNA were quantitated by Western blot analysis and reverse transcription-competitive polymerase chain reaction. The biologically active HGF (baHGF), which was converted by an HGF activator protein from secretory type proHGF, showed significantly higher expression in pretreated PC than in non-treated PC. The amounts of baHGF in pretreated PC were similar to those in non-malignant prostate tissues. There was no difference in the expression level of full-length HGF mRNA encoding secretory type HGF among the three groups. No variance of tissue content of short variant HGF mRNA encoding a competitive HGF antagonist among the three groups indicated that short variant HGF protein in prostate cancer seemed not to function similarly to a competitive HGF antagonist in benign prostate tissues. These results suggest that the tissue level of baHGF in non-treated and pretreated PC depends on activation of proHGF supplied from distal organs rather than de novo HGF mRNA synthesis in prostate glands. Increased baHGF in pretreated PC is expected to relate to tumor suppression in vivo.

Antineoplastic Agents, Hormonal↗
PubMed1998

[Primary clear cell carcinoma of the lung: report of an operative case].

The patient was a 75-year-old man complaining of cough in July 1996. Chest X-ray demonstrated a tumor in the left S6. Percutaneous lung biopsy specimen revealed lung cancer. On September 4, 1996, left lobectomy (R 2 a) was performed. The tumor was 3.8 x 3.2 x 2.1 cm in size and showed a white yellow solid mass (pT2N0M0, pStage I, p1d0e0pm0). The pathological examination was confirmed no differentiation in adenocarcinoma and squamous cell carcinoma. More than 90% of the tumor cells were characterized as having large clear cytoplasm. On immunohistochemical study, the tumor cells expressed positive with EMA, CEA, cytokeratin and negative with vimentin. The postoperative findings showed no presence of renal cell carcinoma. As the result, a diagnosis of primary clear cell carcinoma of the lung was made. The postoperative course is uneventful.

Adenocarcinoma, Clear Cell↗
PubMed1998

[Treatment of prostate cancer in patients aged 75 or older].

In view of the increasing incidence and mortality rate of prostate cancer in Japan, the management of elderly patients with prostate cancer is an important issue now. We therefore analyzed the clinicopathological features and long-term outcomes of 182 patients with prostate cancer, aged 75 or older, in order to establish the treatment strategy for this age group of patients. There were more patients with advanced disease (stage C-D) than those with localized disease (stage A2-B), and the patients with moderate to poorly differentiated tumors were more numerous than those with well-differentiated tumors. The overall survival curve of the patients with localized prostate cancer was in line with the age-matched expected survival curve, while that with advanced prostate cancer was far below the expected survival curve. These results demonstrated that advanced prostate cancer in elderly patients is as harmful as in younger patients, indicating the necessity for early detection and treatment of prostate cancer among the younger generation. On the other hand, localized prostate cancer in elderly patients should be treated less invasively to maintain their quality of life.

Aged↗