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Biomedical subjects

Y Maeda

Publications and source records attributed to Y Maeda.

At least 415 records · Page 23Linked to original sources

[Clinical study of primary central nervous system lymphoma: the role of chemotherapy].

We conducted a retrospective study of 32 patients with histologically confirmed primary central nervous system lymphoma treated in our institute between 1971 and 1995 with an emphasis on the role of chemotherapy. Thirty of the 32 patients underwent tumor resection, whereas 2 patients had biopsies only. Twenty-eight patients received adjuvant therapy, 9 of whom received radiation therapy alone, 2 received chemotherapy alone, and 17 received both radiation therapy and chemotherapy. Chemotherapies performed were CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisolone). VEMP or VENP (vincristine, cyclophosphamide, mercaptopurine [or Natulan], and prednisolone), intravenous ACNU (nimustine), and intravenous or intra-arterial MCNU (ranimustine) and CBDCA (carboplatin). Survival data were available for 30 of the 32 patients. The median survival time of this study was 12.5 months. Twenty-seven patients died from one month through 79 months after the initiation of therapy, and 3 patients were alive for 13 to 69 months. Two patients who received the combination of radiation therapy and chemotherapy survived longer than 5 years. Although radiation therapy and chemotherapy were individually both effective and prolonged the survival time, their combination was more effective. The median survival time was significantly shorter (7.0 vs 16.5 months, p < 0.05) for the patients who received radiation therapy alone than for the patients who received the combination of radiation therapy and chemotherapy. We conclude from our results and review of previous studies that it is important for the chemotherapy of primary central nervous system lymphoma 1) to apply a combination of a variety of effective drugs, similar to that for systemic malignant lymphoma, and 2) to make a sufficient amount of anti-cancer drugs penetrate the whole central nervous system, thereby satisfying the adequate dose intensity for each drug.

Adolescent↗

[A case of non-smoking female with peripheral small lung squamous cell carcinoma discovered after operation of spontaneous pneumothorax].

We have experienced a lung cancer patient discovered after operation of pneumothorax by chance. The patient was 44-year-old female who had been followed up for right pneumothorax in menstruation. She got pneumothorax in menstruation recurrently complained of chest pain. Chest X-p revealed right pneumothorax. We never discovered views of catamenial pneumothorax by thoracoscopy. Partial resection of hypertrophic pleura of right S1 was performed by video assist thoracoscopic surgery. Histological diagnosis was bulla formation with a tiny focus of squamous cell carcinoma in situ. In addition, right upper lobectomy and lymph node dissection were performed. Metastasis was not recognized any lymph node. No recurrence has been observed for 17 months.

Adult↗

[Preoperative scoring and operative complications of unruptured cerebral aneurysms].

Low risk of mortality and morbidity are necessary pre-conditions for surgical treatment of unruptured cerebral aneurysms. We assessed retrospectively 132 patients with angiographically confirmed cerebral aneurysms using an unruptured aneurysm score. Among them, 84 patients were treated surgically. The score consists of the sum of scores for the following factors: associated disease (none: 0, one: 1, two or more: 2); aneurysm size (below 14 mm: 0, 15-24 mm: 1, 25 mm or more: 2); location (anterior circulation: 0, carotid cave: 1, posterior circulation: 2); and multiplicity (single: 0, two or more: 1). Eleven patients had complications and the morbidity rate including asymptomatic lesions was 13.1%. Five patients had permanent neurologic deficits (final morbidity rate 5.9%). The majority of patients with scores less than 1 underwent operations and the morbidity rate was low, whereas patients with scores between 2 and 4 had a higher morbidity rate. Preoperative scoring is useful for predicting surgical risks associated with unruptured cerebral aneurysm.

Adult↗

[The study of continuous infusion chemotherapy with low-dose cisplatin and 5-fluorouracil for patients with primary liver cancer].

Twelve patients with unresectable primary liver cancer (hepatocellular carcinoma and cholangiocarcinoma) and postoperative recurrence of primary liver cancer received continuous arterial or systemic infusion of low-dose CDDP/5-FU. This infusion chemotherapy was continued for five days, discontinued for two days, and repeated four weeks as one course basally. The partial response rate in patients with HCC or CCC treated with intra-arterial infusion was 20% and 33%, respectively. The rate in patients with HCC or CCC treated with systemic infusion was 0% and 33%, respectively. The response rate included decrease of tumor markers in all patients with HCC or CCC was 33% and 67%, respectively. These results suggest that low-dose CDDP/5-FU therapy may be effective in patients with CCC. Severe side effects such as gastro-duodenal ulcer (4 cases) and pseudomembranous colitis (1 case) were observed. The careful management of side effects should be required during this therapy.

Aged↗

[Relationship between the presence of side-holes in bone marrow aspiration needle and the number of harvested bone marrow mononuclear cells].

The aim of this study was to evaluate the yield of nucleated cells in bone marrow harvested by means of Downs' Islam aspiration needles with or without side-holes. Twenty marrow donors for HLA identical sibling transplants were studied. Bone marrow nucleated cells were harvested 50 ml in the right iliac bone with a Downs' Islam aspiration needle with or without side-holes and 50 ml in the left with another kind of needle by means of 5 ml aspirations in each donor. There were no significant difference between the number of nucleated cells by means of Downs' Islam aspiration needles with and without side-holes by cross-over analysis. All nucleated cell counts were 33.06 +/- 12.93 x 10(3)/microliter (mean +/- standard deviation) by means of the needle with side-holes and 32.90 +/- 15.25 x 10(3)/microliter by means of the needle without side-holes. The Downs' Islam aspiration needle without side-holes seems to be better in bone marrow harvest from normal volunteers than that with side-holes, because the former may be stronger than the latter.

Adolescent↗

Phosphodiester amidates of allenic nucleoside analogues: anti-HIV activity and possible mechanism of action.

Lipophilic phosphodiester amidates 2a, 2b, 4a, 4b, and 6 derived from anti-HIV agent adenallene 1a, 3a, inactive hypoxallene 1b, 3b, and 9-(4-hydroxy-2-butyn-1-yl)adenine (5) were synthesized and studied as inhibitors of HIV-1 in ATH8 cell system. All phosphodiester amidates were more biologically active than their parent nonphosphorylated compounds. Analogues 2a and 4a derived from (+/-)-adenallene 1a and (R)-enantiomer 3a are effective anti-HIV agents with EC50 approximately 0.88 and 0.21 microM, respectively. Both analogues are 16 and 28 times more effective than parent compounds 1a and 3a, respectively. Some anti-HIV activity of hypoxallene derivatives 2b and 4b was noted in the range of 0.1-10 microM but the dose-response relationship was poor. Phosphodiester amidate analogue 6 also exhibited anti-HIV activity in the range of 0.1-100 microM, but this effect was accompanied by cytotoxicity. Hydrolytic studies performed at pH 9.8 and with pig liver esterase at pH 7.4 have shown that analogue 2a gives adenallene 4'-phosphoralaninate (10a) as the major product. These results can be interpreted in terms of initial hydrolysis of phosphodiester amidates 2a, 2b, 4a, 4b, and 6 catalyzed by intracellular esterase(s) to give stable phosphomonoester amidate intermediates with a free carboxyl group. The results obtained with hypoxallene phosphoramidates 2b and 4b indicate that the aminosuccinate-fumarate enzyme system responsible for activation of AIDS drug ddIno (didanosine, Videx) can also, albeit less efficiently, activate hypoxallene 4'-phosphate (9b) and the respective (R)-enantiomer released inside the HIV-infected cells.

Adenosine Monophosphate↗

PIG-B, a membrane protein of the endoplasmic reticulum with a large lumenal domain, is involved in transferring the third mannose of the GPI anchor.

Many eukaryotic cell surface proteins are bound to the membrane via the glycosylphosphatidylinositol (GPI) anchor that is covalently linked to their carboxy-terminus. The GPI anchor precursor is synthesized in the endoplasmic reticulum (ER) and post-translationally linked to protein. We cloned a human gene termed PIG-B (phosphatidylinositol glycan of complementation class B) that is involved in transferring the third mannose. PIG-B encodes a 554 amino acid, ER transmembrane protein with an amino-terminal portion of approximately 60 amino acids on the cytoplasmic side and a large carboxy-terminal portion of 470 amino acids within the ER lumen. A mutant PIG-B lacking the cytoplasmic portion remains active, indicating that the functional site of PIG-B resides on the lumenal side of the ER membrane. The PIG-B gene was localized to chromosome 15 at q21-q22. This autosomal location would explain why PIG-B is not involved in the defective GPI anchor synthesis in paroxysmal nocturnal hemoglobinuria, which is always caused by a somatic mutation of the X-linked PIG-A gene.

Amino Acid Sequence↗

Regional cerebral blood flow in patients with schizophrenia: relevance to symptom structures.

Regional cerebral blood flow (rCBF) was measured with technetium-99m hexamethylpropyleneamine oxime single photon emission computed tomography in 38 neuroleptic-treated schizophrenic patients. To improve the validity of the evaluation of symptomatology, we applied findings previously derived in a principal component analysis (PCA) of the Positive and Negative Syndrome Scale. The PCA had disclosed five orthogonal independent symptom structures (i.e., negative, hostile/excited, thought disordered, delusional/hallucinatory, and depressive components), and obtained factor scores for 70 schizophrenic subjects, including the present sample. Stepwise regression analysis elucidated some of the cortical regions in which relative rCBF predicted the severity of symptoms--namely, lateral and orbital prefrontal, lateral temporal, inferior parietal, and medial temporal regions. Findings suggested that symptom structures derived from PCA could prove helpful in elucidating the pathophysiology of neural mechanisms.

Adult↗

RNA polymerase I associated factor 53 binds to the nucleolar transcription factor UBF and functions in specific rDNA transcription.

Mouse RNA polymerase I (Pol I) has, besides its 11 bona fide subunits, three polymerase associated factors, termed PAF53, 51 and 49 with respect to the size of each molecule. In order to analyze the function of PAFs, cDNA encoding PAF53 was isolated using an oligonucleotide probe derived from an oligopeptide sequence. The cDNA of PAF53 predicts a polypeptide of 434 amino acids with a sequence similarity to yeast Pol 1 49 kDa subunit. Anti-PAF53 antibody does not block the random transcription activity of Pol I, but blocks specific transcription from mouse ribosomal RNA promoter, demonstrating the requirement of PAF53 in the accurate initiation of Pol I transcription. Moreover, PAF53 interacted with mouse UBF in vitro, as revealed by Far-Western blotting and GST pull down assays. These results, together with the accumulation of PAF53 in the nucleolus of growing cells, suggest that PAF53 is involved in the formation of the initiation complex at the promoter by mediating the interaction between Pol I and UBF for the active rRNA synthesis.

3T3 Cells↗

Purification and characterization of a novel stress protein, the 150-kDa oxygen-regulated protein (ORP150), from cultured rat astrocytes and its expression in ischemic mouse brain.

As the most abundant cell type in the central nervous system, astrocytes are positioned to nurture and sustain neurons, especially in response to cellular stresses, which occur in ischemic cerebrovascular disease. In a previous study (Hori, O., Matsumoto, M., Kuwabara, K., Maeda, M., Ueda, H., Ohtsuki, T., Kinoshita, T., Ogawa, S., Kamada, T., and Stern, D. (1996) J. Neurochem., in press), we identified five polypeptide bands on SDS-polyacrylamide gel electrophoresis, corresponding to molecular masses of about 28, 33, 78, 94, and 150 kDa, whose expression was induced/enhanced in astrocytes exposed to hypoxia or hypoxia followed by replacement into the ambient atmosphere (reoxygenation). In the current study, the approximately 150-kDa polypeptide has been characterized. Chromatography of lysates from cultured rat astrocytes on fast protein liquid chromatography Mono Q followed by preparative SDS-polyacrylamide gel electrophoresis led to isolation of a approximately 150-kDa band only observed in hypoxic cells and which had a unique N-terminal sequence of 15 amino acids. Antisera raised to either the purified approximately 150-kDa band in polyacrylamide gels or to a synthetic peptide comprising the N-terminal sequence detected the same polypeptide in extracts of cultured rat astrocytes exposed to hypoxia; expression was not observed in normoxia but was induced by hypoxia within 24 h, augmented further during early reoxygenation, and thereafter decreased to the base line by 24 h in normoxia. ORP150 expression in hypoxic astrocytes resulted from de novo protein synthesis, as shown by inhibition in the presence of cycloheximide. In contrast to hypoxia-mediated induction of the approximately 150-kDa polypeptide, neither heat shock nor a range of other stimuli, including hydrogen peroxide, cobalt chloride, 2-deoxyglucose, or tunicamycin, led to its expression, suggesting selectivity for production of ORP150 in response to oxygen deprivation, i.e. it was an oxygen-regulated protein (ORP150). Northern and nuclear run-off analysis confirmed the apparent selectivity for ORP150 mRNA induction in hypoxia. Subcellular localization studies showed ORP150 to be present intracellularly within endoplasmic reticulum and only in hypoxic astrocytes, not cultured microglia, endothelial cells, or neurons subject to hypoxia. Consistent with these in vitro results, induction of cerebral ischemia in mice resulted in expression of ORP150 (the latter was not observed in normoxic brain). These data suggest that astroglia respond to oxygen deprivation by redirection of protein synthesis with the appearance of a novel stress protein, ORP150. This polypeptide, selectively expressed by astrocytes, may contribute to their adaptive response to ischemic stress, thereby ultimately contributing to enhanced survival of neurons.

Aerobiosis↗

Elevated levels of soluble ICAM-1 in serum of patients with acute myeloid leukemia undergoing bone marrow transplantation.

Serum soluble ICAM-1 concentrations were measured in 10 patients with or without chronic graft-vs.-host disease (GVHD) after allogeneic bone marrow transplantation. The serum soluble ICAM-1 levels in the patients with chronic GVHD were significantly higher than that in the patients without chronic GVHD. The data indicated that serum soluble ICAM-1 is a useful parameter for predicting chronic GVHD.

Acute Disease↗

Surgical stress and transient postoperative psychiatric disturbances in aged patients studied using the Yamaguchi University Mental Disorder Scale.

Psychiatric disturbances often occur in aged patients after surgery, but there is no easy or precise method of predicting their occurrence. We devised an easy mental test, the Yamaguchi University Mental Disorder Scale (YDS), based on the surgical perspective. Using both this new method and the Hasegawa mental disorder scale (HDS), we examined 106 patients who had undergone general anesthesia. HDS only was used in 70 cases, while 36 cases were examined by the newly devised YDS and were then compared with the findings obtained by HDS. On the HDS examination, factors affecting postoperative psychiatric disturbances were, in order of frequency: entering the ICU, amount of bleeding, and duration of surgery. Aged patients who experienced severe surgical stress had a higher risk of developing transient postoperative psychiatric disturbances. On the YDS examination, the relationship between surgical stress and transient postoperative psychiatric disturbances was clearly indicated, as was the case with HDS. Postoperative delirium was seen in a significant proportion of patients with low preoperative scores on YDS (P < 0.05), while no significant difference was observed between the mean preoperative scores on HDS and postoperative delirium. In the preoperative evaluation using YDS, postoperative delirium was found to be predictable, and YDS is thus considered to be a more valuable tool in managing aged patients.

Adult↗

Prevalence of hepatitis C virus infection among female prostitutes in Fukuoka, Japan.

To assess the risk of sexual transmission of hepatitis C virus (HCV), we surveyed female prostitutes to determine the prevalence of antibody to HCV (anti-HCV) and HCV RNA. Anti-HCV was examined with a second generation anti-HCV test employing a passive hemagglutination assay. HCV RNA was detected by two-stage polymerase chain reaction with primers deduced from the 5'-noncoding region of the HCV genome. All studies were performed in Fukuoka, Japan, from 1989 through 1992 and all subjects were Japanese and had no history of intravenous drug abuse. The prevalence of anti-HCV was significantly higher in the prostitutes (10.1%; 61/604) than in the controls (female blood donors; 0.8%; 52/6632) (P < 0.001). HCV RNA was found in 73.2% of the anti-HCV-positive prostitutes. The prevalence of anti-HCV among prostitutes increased with the number of years spent in prostitution (P < 0.05). Prostitutes with a history of syphilis had a higher prevalence of anti-HCV than those with no history of syphilis, irrespective of the number of years in prostitution. In a longitudinal study of 244 prostitutes, 2 of the 218 initially seronegative subjects showed anti-HCV and HCV RNA over the study period of 3 years. These two persons had no history of percutaneous exposure. Sexual transmission of HCV presents a risk for female prostitutes.

Adolescent↗

Prognostic factors for patients with advanced non-small cell lung cancer: univariate and multivariate analyses including recursive partitioning and amalgamation.

In an attempt to determine the prognostic significance of pretreatment factors for patients with advanced non-small cell lung cancer (NSCLC), 24 pretreatment clinical variables were analyzed for 185 patients with NSCLC who underwent chemotherapy and/or radiotherapy between 1985 and 1994. Following univariate analysis, we applied two multivariate statistical techniques. In a Cox regression mode, independently significant factors influencing patient survival included performance status (PS), disease stage, hemoglobin level, and serum calcium level. Recursive partitioning and amalgamation (RPA) resulted in three distinct prognostic subgroups based on PS, stage, weight loss, and hemoglobin level. The best survival was observed for patients with a good PS and Stage III disease who had a hemoglobin level > 11 g/dl. The worst survival was observed for patients with a poor PS and presence of weight loss irrespective of stage. All other patients had an intermediate prognosis. Median survival times were 95.1 weeks, 17.1 weeks and 39.3 weeks, respectively (P < 0.00005). The results of our analyses show that three important prognostic subgroups could readily be discerned using RPA.

Adult↗

Simultaneous observation of regional cerebral blood flow and event-related potential during performance of an auditory task.

Reduced amplitude of the P300 component has been reported consistently in patients with neurological and psychiatric disorders. It is unclear, however, how such patients' cognitive dysfunction is related to their P300 abnormality. Further basic knowledge regarding neural substrates for P300 generation is required for gaining an understanding of the pathological significance of the P300 amplitude reduction. To determine the brain structures involved in P300 generation, we observed the event-related potential and the regional cerebral blood flow (rCBF) in 10 normal subjects performing an oddball discrimination of pure tones. The rCBF value was assessed quantitatively with the aid of single photon emission computed tomography using technetium-99m hexamethylpropylene amine oxime. During the task performance, significant activation was observed in the posterior superior temporal and inferior parietal regions of the right hemisphere. In addition, positive correlation of the task-related increase in rCBF with the simultaneously recorded P300 amplitude was observed in the right but not the left posterior superior temporal region. These findings indicate that activation of the right non-verbal auditory area might modulate P300 generation during pure-tone discrimination.

Acoustic Stimulation↗