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Biomedical subjects

M Takeda

Publications and source records attributed to M Takeda.

At least 343 records · Page 19Linked to original sources
PubMed1998

Basic and clinical studies on ApoE gene typing by line probe assay (LiPA) as a biological marker for Alzheimer's disease and related disorders: multicenter study in Japan.

The fundamental reagent capability and clinical significance of ApoE gene typing has been investigated. The result of each test shows that the reagent capability satisfied the expected standard. Four-hundred thirty-nine samples classified into three groups (Alzheimer's disease (AD), other types of dementia and nondementia) were measured to examine the clinical significance. The rate of epsilon 4 genotype of each group was 31.5%, 14.6%, 10.4%, respectively. The AD group had a higher rate than the other groups (p < 0.001). The measurement of ApoE genotype is suggested to be useful as one of the guidelines in the diagnosis of AD.

Age Factors↗
PubMed1998

Finding Genetic Network from Experiments by Weighted Network Model.

We study the problem of finding a genetic network from data obtained by multiple gene disruptions and overexpressions. We define a genetic network as a weighted graph, and analyze the computational complexity of the problem. We show that if there exists a weighted network which is consistent with given data, we can find it in polynomial time. Moreover, we also consider the optimization problem, where we try to find an optimally consistent weighted network with given data. We show that the problem is NP-hard. On the other hand, we give a polynomial-time approximation algorithm to solve it with approximation ratio 2. We report some simulation results on experiments.

Journal Article↗
PubMed1998

Learning curve and conversion to open surgery in cases of laparoscopic adrenalectomy and nephrectomy.

PURPOSE: We examine how the level of experience acquired by the laparoscopist affects the outcome of laparoscopic adrenalectomy and nephrectomy, and what is necessary to avoid complications in these surgeries. MATERIALS AND METHODS: We retrospectively evaluated the experience levels of 8 urological laparoscopists between 1991 and 1995. In addition, other cases that were converted to open surgery were collected from the institutes with which the 8 laparoscopists were affiliated. RESULTS: The rates of conversion to open surgery were 6.4% in 204 cases of adrenalectomy and 14.3% in 63 of nephrectomy. Conversion rates were related to blood loss volume but not operative time. The major causes of conversion were bleeding in 45% of cases and adhesion in 34%. There were no mortalities. Mean operative time decreased significantly, reaching that of open surgery as the number of procedures increased up to 20 adrenalectomies and 10 nephrectomies. The volume of blood lost remained low from the early experience. Blood transfusion rates were 4.4% for adrenalectomy and 11.1% for nephrectomy. CONCLUSIONS: Operative time of these procedures decreased significantly with surgeon experience and reached that of open surgery. Cases in which adhesion is anticipated should be restricted to avoid conversion. These laparoscopic procedures are acceptable as a standard operative techniques for adrenal and renal diseases.

Adrenal Gland Diseases↗
PubMed1998

Malignant lymphoma of the gingiva: MR evaluation.

PURPOSE: Our purpose was to document the MR imaging findings of malignant lymphoma of the gingiva. METHODS: Five patients with histologically proved malignant lymphoma of the gingiva were studied by MR imaging. The MR images were analyzed for tumor size, extent, and signal characteristics, bone involvement, and associated cervical lymph node enlargement. RESULTS: Clinical examination tended to underestimate the size of lymphomatous lesions. The signal intensity of the lesions was isointense to hyperintense relative to muscle on noncontrast T1-weighted images and showed variable contrast enhancement patterns. On T2-weighted images, signal intensity was isointense to hypointense relative to the oral mucosa. In one case, the mass extended to the submandibular space; in the remaining cases, the masses were limited to the gingiva and the adjacent bone. MR imaging revealed that gingival lymphomatous masses were broad-based along the mandible or maxilla and eroded through the cortex into the marrow space, but the cortex was still recognizable. No nodal involvement was noted in any of the patients with malignant lymphoma. CONCLUSION: The signal characteristics of gingival lymphoma overlap those of other tumors. The cortex separating marrow involvement from the broad-based gingival mass generally appears to be permeated with small erosions but is still recognizable.

Aged↗
PubMed1998

Basic and clinical studies on the measurement of tau protein in cerebrospinal fluid as a biological marker for Alzheimer's disease and related disorders: multicenter study in Japan.

The development of a diagnostic marker for earlier and more accurate clinical diagnosis of Alzheimer's disease (AD) is essential to identify AD patients during life unequivocally. The purpose of this study was to investigate the basic performance and clinical significance of tau level measurement in the cerebrospinal fluid (CSF) using an enzyme-linked immunosorbent assay (ELISA) developed by Innogenetics. The ELISA system showed reliable reproducibility and good linearity. For clinical studies, the CSF samples from a variety of patients (n = 332) were examined. They were classified into the four groups: Alzheimer's disease (AD); neurodegenerative disease (ND); cerebrovascular diseases (VD); and a neurological control (NC) group. The CSF-tau levels for AD, ND, VD and NC were 426 +/- 234 pg/ml, 239 +/- 157 pg/ml, 216 +/- 136 pg/ml, and 188 +/- 103 pg/ml, respectively. The CSF-tau level of the AD group was significantly higher than that of the other groups (p < 0.001). The CSF-tau levels increased during follow-up. The measurement of the tau level in CSF is shown to be a useful marker to confirm a clinical diagnosis of AD.

Aged↗
PubMed1998

[Choroidal venous dilatation in serous retinal detachment].

We studied the correlation between choroidal venous dilatation, intrachoroidal leakage of dye, and subretinal leakage from the choroid in patients with serous retinal detachment unaccompanied by choroidal neovascularization. We reviewed 13 eyes with anamnesis of serous retinal detachment, 23 eyes without anamnesis, and one eye of unknown status of a total of 37 eyes. Regarding the relationship between subretinal dye leakage from the choroid in fluorescein angiography (FAG) and choroidal venous dilatation in indocyanine green angiography (ICG), the point of subretinal leakage (31 points) was on and/or in the neighborhood of the site of choroidal venous dilatation in 87.1% of the 27 eyes, except for eyes of unknown site of leakage in FAG. The point of subretinal leakage was within and/or in the neighborhood of the intrachoroidal leakage of dye in ICG in 92% of the eyes. In serous retinal detachment without choroidal neovascular membranes, serous retinal detachment may be caused by breakdown of the outer retinal barrier due to choroidal venous congestion and intrachoroidal diffusion.

Choroid↗
PubMed1998

[Thoracoscopic decortication for chronic empyema thoracis: report of a case].

Thoracoscopic surgery for empyema thoracis treatment is still uncommon in Japan. We report a case of chronic empyema thoracis which was successfully treated with decortication through thoracoscopy. A 63-year-old man presented with respiratory distress, appetite loss and hoarseness. He had been suffering from diabetes mellitus for 13 months. His chest X-ray film revealed that he had suffered from the left chronic empyema. As the decortication procedure was feasible at the preliminary exploration, it was then performed through the thoracoscopy. The lung re-expanded well after the pleural peel was removed. His chest drainage tube was drawn out on 19th postoperative day.

Chronic Disease↗
PubMed1998

[Growth and development of colorectal cancer with subclassification on submucosa and proper muscle infiltrating cancer].

Colorectal cancer (CRC) infiltrating the submucosa (sm cancer) and the proper muscle (mp cancer) represent an early and an intermediate stage in the development of CRC, and sm and mp cancer are therefore appropriate to discuss the natural history of CRC. A total of 337 sm cancers and 291 mp cancers resected in our series were evaluated. We divided sm and mp cancers into three categories, respectively, sm 1, sm 2, sm 3, mp 1, mp 2, and mp 3, according to the depth of infiltration of the submucosa or the proper muscle. The deeper the invasion, the larger of the tumor size, and the proportion of depressed type in their configuration increases. On the contrary, the proportion of tumors with adenomatous component decreases. A larger proportion of tumors in all categories of infiltration showed PG more of ten than that of NPG in their marginal structure. In this study, 17% of sm cancer and 23% of mp cancer might develop not via the adenoma-carcinoma sequence.

Adenoma↗
PubMed1997

Plasma endothelin-1 level in patients with renovascular hypertension - does the kidney with stenosis of the renal artery upregulate production of endthelin-1?

PROBLEM: To examine the value of plasma endothelin-1 (ET-1), we measured the level of plasma ET-1 activity of peripheral venous blood and selective renal venous blood in renovascular hypertension patients, and compared that activity with corresponding renin activity and split renal function. METHODS: ET-1 level, renin activity in selective renal venous blood and peripheral venous blood, and 99mTc-dimercaptosuccinic acid renal uptake as a split renal function test were measured in 11 patients (mean 42.1 years old) with renovascular hypertension (RVH) and 6 patients with both renal cell cancer (RCC) and essential hypertension. RESULTS: 1. In patients with RVH, resting peripheral venous plasma ET-1 ranged from 0.6 to 8.1 (mean 4.07) pg/ml and was higher than the normal level (p <0.01). However, the renal vein ET-1 ratio was nor correlated with the renal vein renin ratio. 2. In patients with RCC, resting peripheral venous plasma ET-1 was not different from the normal level. There was no step-up of plasma ET-1, or renin among renal veins, or the proximal and distal parts of the interior vena cava. 3. Both renal vein renin ratio and renal vein ET-1 ratios were inversely correlated with t99mTC-dimercaptosuccinic acid renal uptake as a split renal function examination in patients with RVH. 4. The peripheral plasma ET-1 level was correlated with the degree of stenosis of the renal artery in patients with RVH of a unilateral lesion, but not bilateral lesions. CONCLUSION: These results suggest that ET-1 may take part in the hypertensive mechanisms of RVH in addition to the renin-angiotensin system, but its significance in RVH still remains to be examined.

Adolescent↗
PubMed1997

Alpha-1 adrenoceptor subtypes (high, low) in human benign prostatic hypertrophy tissue according to the affinities for prazosin.

BACKGROUND: A novel classification of alpha-1 adrenoceptor subtypes (High, Low) was applied to human benign prostatic hypertrophy (BPH) tissue. METHODS: Human BPH specimens were examined by a radioligand binding assay method using 3H-prazosin, and those data were compared with preoperative therapies. RESULTS: (1) Scatchard analysis showed a high-affinity site (Kd:27.18 +/- 6.41 pM; Bmax:9.29 +/- 0.98 fM/mg protein; mean +/- SE) as alpha 1H, and a low-affinity site (Kd: 4088.0 +/- 744.34 pM, Bmax: 140.81 +/- 19.98 fM/mg protein) as alpha 1L subtype, for prazosin. (2) The Kd and Bmax were not different in the nontreated group (n = 5), alpha 1 blocker group (n = 5), and antiandrogen group (n = 5), in either alpha 1-high affinity or alpha 1-low affinity subtype. (3) Phenoxybenzamine had different pKi values for the above two adrenoceptor subtypes. Scatchard analysis showed that alpha 1-high affinity binding site disappeared in the presence of 1 microM of phenoxybenzamine, and the Kd and Bmax values in the presence of 1 microM of phenoxybenzamine were almost identical to the alpha 1-low affinity site of the two subtypes. CONCLUSIONS: Human BPH tissue possesses both alpha 1H- and alpha 1L-adrenoceptor subtypes according to the affinities for prazosin, and only the alpha 1H subtype can be completely inhibited by some concentration of phenoxybenzamine. Treatment by alpha 1 blocker may not change the conditions of alpha 1-adrenoceptors in prostatic tissue.

Adrenergic alpha-Antagonists↗
PubMed1997

Medullary post-inspiratory neuronal and diaphragm post-inspiratory activities during spontaneous augmented breaths in anesthetized rats.

To test the hypothesis that during augmented breaths the prolonged expiratory time is correlated with the activity of medullary post-inspiratory neurons, changes in diaphragm electromyogram and post-inspiratory neuronal activities were examined in pentobarbital anesthetized rats. During augmented breaths, the mean total expiratory time significantly increased (from 0.57 +/- 0.02 to 1.20 +/- 0.07 s, P < 0.01), but the mean duration of post-inspiratory inspiratory activity (PIIA) was significantly decreased (from 0.08 +/- 0.01 to 0.02 +/- 0.003 s, P < 0.01) compared to control breaths. The mean time which the diaphragm was electrically silent was observed to be significantly prolonged during augmented breaths (from 0.48 +/- 0.02 to 1.19 +/- 0.07 s, P < 0.01). During significant prolongations of expiratory time in augmented breaths, most of the recorded neurons (9/10) in the medulla showed sustained discharges. The mean duration of discharges was longer than that of PIIA (0.02 +/- 0.003 vs. 0.50 +/- 0.10 s, P < 0.01). The mean firing frequency/breath significantly increased compared to control breaths (9.45 +/- 1.69 vs. 37.6 +/- 7.13 imp/breath, P < 0.01). These results suggested that during augmented breaths, the prolonged expiratory period may not be mediated by persisting post-inspiratory neuronal activity in the medulla.

Anesthesia↗
PubMed1997

T/G polymorphism at intron 9 of presenilin 1 gene is associated with, but not responsible for sporadic late-onset Alzheimer's disease in Japanese population.

To investigate whether presenilin 1 (PS1) gene, a major causative gene of familial early-onset Alzheimer's disease (AD), also contributes to the etiology of sporadic AD, we evaluated associations between Japanese AD and polymorphisms located at 14q24.3. While the D14S43 and FOS loci showed no association with either early- or late-onset AD, late-onset AD carrying no APOE-epsilon4 allele was associated with the G allele of the T/G polymorphism located at intron 9 of the PS1 gene (P = 0.016). Considering another study showing a positive association between AD and the T allele, this polymorphism is associated with, but not responsible for sporadic late-onset Alzheimer's disease.

Age of Onset↗
PubMed1997

Molecular heterogeneity of the cDNA encoding a 74-kDa regulatory subunit (B" or delta) of human protein phosphatase 2A.

Two cDNAs for possible splicing variants of a 74-kDa regulatory subunit (B" or delta) of human protein phosphatase 2A, were isolated. These variants were identified from human cerebral cortex by library screening and PCR, and designated delta1 and delta3 isoforms, while the previously reported isoform [Tanabe et al. (1996) FEBS Lett. 379, 107-1111 was designated delta2. Compared with the delta2 isoform, the delta1 isoform contained a 32-residue insertion beginning at residue 84, and consisted of 602 amino acids in all. The delta3 isoform lacked a 74-residue sequence corresponding to residues 1083 of the delta2 isoform, and consisted of 496 amino acids. Using isoform-specific antipeptide antisera, the 74-kDa subunit (B" or delta) originally purified from human erythrocytes was identified as the delta1 isoform.

Alternative Splicing↗
PubMed1997

Abnormal distribution of neurofilament L in neurons with Alzheimer's disease.

Abnormality of cytoskeletal proteins is closely related to the pathology of Alzheimer's disease. As neurofilament proteins are major cytoskeletal components of neurons, abnormality of neurofilaments is proposed in brain with Alzheimer's disease. Free-floating sections of the hippocampus with Alzheimer's disease were studied immunohistochemically, using a polyclonal antibody specifically bound to the tail region of neurofilament L (NF-L). In brains with early onset type of Alzheimer's disease, many neurons and dystrophic neurites were labeled by the antibody, while these observations were not seen in either brains with late onset type or control brains. Double immunohistochemical staining of NF-L and tau protein demonstrated that abnormal deposition of NF-L was not always accompanied with that of tau protein, indicating that the abnormal deposition of NF-L might not occur in parallel with that of tau protein. These observations suggest the involvement of neurofilament proteins on the pathology of Alzheimer's disease in a different way than tau protein.

Aged↗
PubMed1997

Discharge patterns of dorsal and ventral respiratory group neurons during spontaneous augmented breaths observed in pentobarbital anesthetized rats.

To clarify the difference between the firing patterns of the dorsal respiratory group (DRG) and ventral respiratory group (VRG) neurons during spontaneous augmented breaths, extracellular single unit recording of 139 respiratory-related neurons (inspiratory: 98/139, expiratory: 41/139) was performed in pentobarbital anesthetized rats. Both the I and E neurons were further classified into six groups: (1) I-augmenting, (2) I-decrementing, (3) I-other cells, (4) E-augmenting, (5) E-decrementing and (6) E-other cells. During the augmented breaths, most inspiratory neurons in the DRG (25/26) and VRG (67/72) show an increase in their discharge frequency irrespective of the cell type, but the discharges after an augmented breath were inhibited. Changes in these inspiratory neurons coincided with those of diaphragm electromyogram activity. With regard to relative changes in the mean firing rate during the inspiratory phase II of augmented breaths, there was a significant difference between the I-augmenting DRG and VRG neurons (353.5 +/- 56.9% vs. 237.5 +/- 17.1%, P < 0.01), but not in the I-decrementing and I-other neurons. On the other hand, the activities of the expiratory DRG (9/9) and VRG (27/32) neurons decreased during the augmented breath. A significant difference in the relative mean firing rate during the expiratory phase of augmented breaths was observed between the E-decrementing DRG and VRG neurons (27.3 +/- 5.2% vs. 58.0 +/- 6.3%, P < 0.05), but not between the E-augmenting and E-other neurons. These results suggested that during spontaneous augmented breaths the firing patterns of the DRG neurons were not qualitatively different from those of the VRG neurons.

Anesthesia↗