Search PubMed⌕ Search

Biomedical subjects

K Maeda

Publications and source records attributed to K Maeda.

At least 235 records · Page 13Linked to original sources
PubMed2000

Chinese herb nephropathy in Japan presents adult-onset Fanconi syndrome: could different components of aristolochic acids cause a different type of Chinese herb nephropathy?

BACKGROUND: We encountered two cases of Chinese herb-induced Fanconi syndrome in Japan. One component of the chinese medicine was "Kan-mokutsu" (Aristolochia manshuriensis) in which aristolochic acids (AAs) were detected. METHODS: Renal biopsy showed flattening of proximal tubular epithelial cells and paucicellular interstitial fibrosis without glomerular lesions, all of which were in accordance with Chinese herb nephropathy (CHN). To date, many cases of CHN have been reported mainly as progressive renal failure in western countries. RESULTS: However, our cases were different from those in that they presented Fanconi syndrome. The detected AAs in our cases consisted of aristolochic acid (AA)-I, II and D. In contrast, in Belgium, the incriminated agent was Aristolochia fangchi which consisted of AA-I, B, C, and aristolactum. CONCLUSION: These findings could indicate that different components of AAs could cause different clinical lesions, or that the amount of ingested AAs might reflect clinical pictures, that is to say, our patients took lower volume of Chinese herbs and might be in an early stage of CHN. Furthermore, it is likely that susceptibility to this substance may be different among races. CHN would include two clinical aspects: subacute renal failure and adult-onset Fanconi syndrome. It is important to bear in mind that CHN could present Fanconi syndrome.

Adult↗
PubMed2000

[Idiopathic plasmacytic lymphadenopathy with polyclonal hyperimmunoglobulinemia and pleural effusion].

A 56-year-old man was admitted for further evaluation of mediastinal lymphadenopathy and left pleural effusion. A blood test revealed polyclonal hypergammaglobulinemia with an elevated erythrocyte sedimentation rate and level of C-reactive protein. Chest computed tomography disclosed bilateral hilar and multiple mediastinal lymph-node swelling and bilateral pleural thickening accompanied by a moderate amount of left pleural effusion. Biopsy specimens from mediastinal lymph nodes and the right pleura were obtained under video-assisted thoracoscopy. Histology on microscopic examination demonstrated mature plasma cells and lymphocyte infiltration in the conserved lymph-node structure and the pleura, suggesting a diagnosis of idiopathic plasmacytic lymphadenopathy (IPL) with polyclonal hyperimmunoglobulinemia. Interestingly, IL-6 was elevated in the pleural effusion but normal in serum. This was a rare and instructive case of IPL accompanied by pleural effusion that was considered to be an important determinant of the clinical spectrum of the disease.

Biomarkers↗
PubMed2000

[Indications for and limitations of low anterior resection].

The indications for low anterior resection are based mainly on tumor location, penetration depth, histology, macroscopic appearance, etc. Patients with tumors located 2 cm above the puborectal muscle by digital examination can undergo low anterior resection. Distal surgical margins should be at least 1 cm from the tumor in cases of differentiated cancer and localized tumors of stage T2 or less and more than 2 cm in poorly differentiated cancer and tumors of stage T3 or greater with total mesorectal excision (TME). Longer distal surgical margins should be provided in patients with unlocalized tumors and extensive node metastasis. The final decision on whether low anterior resection is appropriate should be made after mesorectal preparation down to the levator muscles with adequate surgical margins. Low anterior resection is contraindicated in patients with poor anorectal function and high age. A rectal stump 1 to 2 cm from the dentate line should be maintained for better postoperative anorectal function if radical excision can still be performed.

Digestive System Surgical Procedures↗
PubMed2000

Pulmonary stenosis in recipient twins in twin-to-twin transfusion syndrome: report on 3 cases and review of literature.

This report describes 3 cases of pulmonary stenosis in the recipient twin in twin-twin transfusion syndrome. Fetal echocardiography showed cardiomegaly, tricuspid valve regurgitation, and increased reverse flow in the inferior vena cava, as signs of congestive heart failure in all 3 cases. We diagnosed 2 cases of pulmonary stenosis by fetal echocardiography prenatally and confirmed our findings in all 3 cases postnatally. Two cases underwent postnatal balloon valvuloplasty to release the pulmonary valvular stenosis in neonatal period. The third one died soon after delivery and autopsy showed a slightly thickened pulmonary valve. One of the cases was diagnosed in the early second trimester (20 weeks of pregnancy), the earliest detection of fetal pulmonary stenosis reported in literature. The presence of high peak velocity of the pulmonary artery at 20 weeks of pregnancy preceded the development of pulmonary stenosis in this case. This supports the hypothesis that alterations in fetal hemodynamics may result in structural cardiac abnormality.

Adult↗
PubMed2000

[Expandable metallic stent for the treatment of left-sided colonic obstruction with malignant disease].

Recently, it was reported that an EMS (expandable metallic stent) was useful for treatment of colorectal obstruction. In our department, EMSs were used for seven patients with left-sided colonic obstruction with unresectable malignant disease. After these treatments with EMS, their symptoms were improved and they were able to intake food. Stomal formation was avoided except in one patient with severe soiling. In conclusion, EMS is thought to be useful for the improvement of quality of life in the patients with unresectable malignant colonic obstruction.

Adult↗
PubMed2000

[The effect of attention on visual evoked potentials elicited by a newly designed stereogram].

PURPOSE: To investigate whether the visual evoked potentials (VEPs) obtained by a newly designed stereogram were generated by some higher function like depth perception, we examined the effect of attention on the VEPs. SUBJECTS AND METHOD: Eight subjects participated in the experiments. The VEPs were recorded according to the international 10/20 system. The stimulus consisted of circles with or without disparity presented on 4 locations around the fixation point, and they appeared in one of 3 patterns in random order when viewed through red/green spectacles 1. at the same distance as the fixation point, 2. in front of it, or 3. at the back of it. The near pattern was defined as the target. In Experiment 1, the subjects just fixated on the fixation point. In Experiments 2 and 3, they were required to respond to the target by pressing a button and counting the number (target discrimination task). RESULTS: A scalp negative potential with a latency of 170-280 msec was elicited in the lateral occipital area. For each of the 3 patterns the amplitude was greater in Experiments 2 and 3 than in Experiment 1. In Experiments 2 and 3, stimuli with disparity resulted in larger amplitude than without disparity. The target stimulus also evoked larger potentials than non-target stimuli did, although no such effect was apparent in Experiment 1. CONCLUSION: Attention, as well as disparity, increased the VEPs amplitude, which indicates that the potential could be generated by neural activity higher than V 1 including depth perception. Moreover, the potential showed characteristics similar to attention-related potentials modulated by visuo-spatial attention.

Adult↗
PubMed2000

[Development of domain specific search engines].

As cyber space exploding in a pace that nobody has ever imagined, it becomes very important to search cyber space efficiently and effectively. One solution to this problem is search engines. Already a lot of commercial search engines have been put on the market. However these search engines respond with such cumbersome results that domain specific experts can not tolerate. Using a dedicate hardware and a commercial software called OpenText, we have tried to develop several domain specific search engines. These engines are for our institute's Web contents, drugs, chemical safety, endocrine disruptors, and emergent response for chemical hazard. These engines have been on our Web site for testing.

Computers↗
PubMed1999

Total synthesis of a new cytotoxic acetogenin, jimenezin, and the revised structure.

The first total synthesis of jimenezin was achieved by using carbohydrates as chiral building blocks, thus revising the proposed structure 1 to 2. The key steps in this synthesis include an efficient construction of the THP-THF fragments 3 and 16 through a stereoselective condensation between the pyranyl aldehyde 5 and the acetylene derivative 6, and a palladium-catalyzed coupling reaction of 3 or 16 with a terminal butenolide 4.

Antineoplastic Agents, Phytogenic↗
PubMed1999

Opposite changes in phosphoinositide-specific phospholipase C immunoreactivity in the left prefrontal and superior temporal cortex of patients with chronic schizophrenia.

BACKGROUND: Abnormalities in types of neurotransmitter signaling that are coupled with phosphoinositide-specific phospholipase C (PLC) have previously been reported in brains from patients with schizophrenia. PLC, a main component of this pathway, may be affected in schizophrenia. METHODS: We immunoquantified PLC beta 1, gamma 1 and delta 1 in the left prefrontal cortex and superior temporal cortex, nucleus accumbens and amygdala, and in the right superior temporal cortex of postmortem brains obtained from a total of 19 patients with schizophrenia and a total of 27 controls. RESULTS: PLC beta 1 immunoreactivities were increased in the particulate fraction from the prefrontal cortex (by 64%), although they were decreased in the particulate fraction from the left superior temporal cortex (by 28%), as compared with the values in controls. There was no difference in PLC beta 1 immunoreactivities in the nucleus accumbens, the amygdala or the right superior temporal cortex between schizophrenic patients and controls. PLC gamma 1 and delta 1 immunoreactivities did not differ between the two groups in any of the regions studied. CONCLUSIONS: Changes in PLC beta 1 immunoreactivities in the prefrontal and superior temporal cortex of patients with schizophrenia may reflect abnormalities in neurotransmissions via receptors that are coupled with the Gq alpha-PLC beta 1 cascade.

Amygdala↗
PubMed1999

Health-related quality of life among renal-transplant recipients in Japan.

BACKGROUND: This study had four goals: (1) to evaluate an index of health-related quality of life (HQOL) among renal-transplant recipients in Japan, (2) to compare HQOL of renal-transplant recipients with that of the Japanese population as a whole, and (3,4) to study associations of HQOL with renal function and with the time since transplantation. METHODS: Questionnaires were distributed to 570 subjects. All were outpatients, were 16 years old or older, and were studied at least 1 year after they had received their latest renal transplant. HQOL was assessed with the Short Form 36-item health survey. Subjects' physicians provided data on renal function. Associations of HQOL with serum creatinine concentration and with the time since transplantation were evaluated by logistic regression. RESULTS: The response rate was 83%. Data from patients with diabetes and from those who had had at least two renal transplants were excluded; data from 395 recipients were analyzed. On the physical functioning, general health perception, vitality, and social functioning scales, the patients' scores were significantly lower than the Japanese national-norm scores. General health perception was particularly low. Serum creatinine concentrations were associated with general health perception, vitality, and social functioning. Longer times since transplantation were associated with better social functioning. CONCLUSIONS: Although social and physical functioning may improve after transplant surgery, a low self-rating of general health seemed to remain. The rarity of renal transplantation in Japan and other psychosocial factors may explain the low self-rating of general health in Japanese renal-transplant recipients.

Adolescent↗
PubMed1999

Significance of Steroid Sulfatase Expression in Human Breast Cancer.

The sulfatase pathway has been thought to be a primary means of local production of estrone in human breast cancer tissue. We measured steroid sulfatase (STS) mRNA levels in 97 breast cancers and evaluated its association with disease-free survival. High levels of STS mRNA proved to be a significant predictor of reduced relapse-free survival, both as a continuous variable (log STS mRNA; P = 0.028) and as a dichotomous variable with an optimized cutoff point (P=0.002). In multivariate analysis a high level of STS mRNA was an independent factor for predicting relapse-free survival. These results suggest a putative role of STS in breast cancer growth and metastasis, and administration of sulfatase inhibitors to breast cancer patients with high levels of STS mRNA might be an additional treatment option.

Journal Article↗
PubMed1999

Thioredoxin deficiency causes the constitutive activation of Yap1, an AP-1-like transcription factor in Saccharomyces cerevisiae.

Yap1 is a transcription factor that responds to oxidative stress in Saccharomyces cerevisiae. The activity of Yap1 is regulated at the level of its intracellular localization, and a cysteine-rich domain at the C terminus of Yap1 is involved in this regulation. We investigated the effects of redox-regulatory proteins, thioredoxin and glutaredoxin, on the regulation of Yap1, using the deficient mutants of these thiol-disulfide oxidoreductases. In the thioredoxin-deficient mutant (trx1Delta/trx2Delta), Yap1 was constitutively concentrated in the nucleus and the level of expression of the Yap1 target genes was high under normal conditions, while this was not the case for the glutaredoxin-deficient mutant (grx1Delta/grx2Delta). No distinct difference was observed in the levels of Yap1 protein between the wild type and trx1Delta/trx2Delta. The constitutive activation of Yap1 in trxDelta/trx2Delta was observed under aerobic conditions but not under anaerobic conditions. These findings suggest that thioredoxin has negative effects on this regulation via the redox states. We also show the synthetic lethality between yap1Delta and trx1Delta/trx2Delta mutation, but the yap1Delta/grx1Delta/grx2Delta triple mutant was viable, suggesting a difference of the functions between thioredoxin and glutaredoxin and a genetic interaction between Yap1 and thioredoxin in vivo.

Base Sequence↗
PubMed1999

Association study of a polymorphism of nonerythroid alpha-spectrin gene with schizophrenia.

The specificity of cytoarchitectural abnormalities in limbic structures of patients with schizophrenia and their contributions towards the etiology of schizophrenia remain unknown. We have recently reported an increased breakdown of nonerythroid alpha-spectrin (fodrin), a major component of neuronal cytoskeletal proteins, in schizophrenic left superior temporal cortices [Kitamura et al., 1998: Biol Psychiatry 43:254-262], suggesting that polymorphisms of the alpha-spectrin gene might contribute to the vulnerability to schizophrenia. We screened for genetic variations associated with schizophrenia through the C-terminus sequences of the human nonerythroid alpha-spectrin gene (SPTAN1) spanning two EF-hands and also tested a possible contribution of the polymorphism to the development of schizophrenia by an association study. We found a polymorphic region of an intron located in the second EF-hand of SPTAN1 gene. There was no significant difference between patients with schizophrenia and controls in allele frequencies or genotype distribution. There is evidence that the Psh BI SPTAN1 gene polymorphism does not play a major role in the genetic component of schizophrenia.

Adult↗
PubMed1999

Vascular endothelial growth factor expression in preoperative biopsy specimens correlates with disease recurrence in patients with early gastric carcinoma.

BACKGROUND: Recently many studies have demonstrated that the degree of tumor angiogenesis is related to the aggressiveness of the tumor and clinical outcome. Vascular endothelial growth factor (VEGF) is a well characterized inducer of angiogenesis. In this study, the authors investigated the prognostic significance of VEGF expression in patients with early gastric carcinoma together with p53 gene abnormality and tumor cell proliferation. METHODS: One hundred ninety-five endoscopically biopsied specimens obtained preoperatively from patients with early gastric carcinoma were studied immunohistochemically. RESULTS: According to conventional clinicopathologic factors, submucosal invasion, lymph node metastases, and tumor size were associated significantly with the incidence of disease recurrence. According to conventional biologic factors, VEGF expression was observed more frequently in patients with disease recurrence compared with those without disease recurrence whereas neither p53 abnormality nor tumor cell proliferation were correlated with prognosis. Moreover, multivariate analysis indicated that VEGF expression (as well as submucosal invasion and lymph node metastases) is an independent predictor of disease recurrence. CONCLUSIONS: The results of the current study show that VEGF expression may be a useful prognostic factor for patients with early gastric carcinoma.

Adult↗
PubMed1999

Mass spectrometric study on the protein chemical modification of uremic patients in advanced Maillard reaction.

The Maillard reaction, initiated by the nonenzymatic reaction of reducing sugar with protein, is proposed to play a significant role in protein aging and the complications of aging and diabetes. In this study, we detected and quantified some advanced glycation endproducts (AGEs) in human serum proteins of control and uremic patients by a highly selective and specific assay, electrospray ionization liquid chromatography-mass spectrometry-mass spectrometry (ESI-LC-MS-MS). From our results, levels of each AGEs in serum of uremic patients were significantly elevated, compared to age-matched controls. These results provide the evidence for increased modifications of proteins by Maillard reaction in uremia.

Blood Proteins↗
PubMed1999

Impaired regeneration and no amelioration with aldose reductase inhibitor in crushed unmyelinated nerve fibers of diabetic rats.

The regenerative ability of unmyelinated nerve fibers (UNFs) in diabetes and the effect of aldose reductase inhibitor (ARI) on it were ultrastructurally evaluated after sciatic nerve crush in control and untreated and tolrestat-treated streptozocin-induced diabetic rats. The density and number of UNFs were significantly increased in all groups at 5 weeks after the injury. The increase returned to the baseline level in control rats, but not in diabetic rats at 24 weeks. Although the axon size showed a marked decrease at 5 weeks and an incomplete recovery at 24 weeks in all groups, the recovery was significantly worse in diabetic than in control groups. Tolrestat did not have any effect on regeneration of UNFs in diabetes. These results suggest impaired regeneration of UNFs after nerve crush injury in diabetes and less therapeutic effect of ARI on it.

Aldehyde Reductase↗
PubMed1999

Paradoxical decrease of an adipose-specific protein, adiponectin, in obesity.

We isolated the human adipose-specific and most abundant gene transcript, apM1 (Maeda, K., et al., Biochem. Biophys. Res. Commun. 221, 286-289, 1996). The apM1 gene product was a kind of soluble matrix protein, which we named adiponectin. To quantitate the plasma adiponectin concentration, we have produced monoclonal and polyclonal antibodies for human adiponectin and developed an enzyme-linked immunosorbent assay (ELISA) system. Adiponectin was abundantly present in the plasma of healthy volunteers in the range from 1.9 to 17.0 mg/ml. Plasma concentrations of adiponectin in obese subjects were significantly lower than those in non-obese subjects, although adiponectin is secreted only from adipose tissue. The ELISA system developed in this study will be useful for elucidating the physiological and pathophysiological role of adiponectin in humans.

Adiponectin↗