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Biomedical subjects

K Takaoka

Publications and source records attributed to K Takaoka.

At least 91 records · Page 5Linked to original sources
PubMed1997

Psychiatric manifestations accompanying interferon therapy for patients with chronic hepatitis C: an overview of cases in Japan.

Thirty case reports published in Japan that refer to psychiatric symptoms accompanying interferon (IFN) therapy were examined. These papers covered a total of 49 cases. We categorized these 49 cases into 35 cases of mood disorder, 10 of delirium and four of psychotic disorder. The key findings of our study of these cases are as follows: (i) in total, 11 patients had psychiatric past histories: five patients in the mood disorders group were susceptible to the influence of social or psychological factors; (ii) whereas the symptoms of mood disorder or delirium appeared soon after IFN was administered, the symptoms of psychotic disorders appeared later. The patients with delirium displayed many neurological abnormalities, which were reduced by suspending IFN therapy. This suggests the neurological toxicity of IFN; (iii) the outcome of most patients was good; and (iv) we suspect that IFN-induced psychiatric symptoms other than delirium are connected with psychoneuroimmunological functions.

Delirium↗
PubMed1997

Polygalacturonase isolated from the culture of the psychrophilic fungus Sclerotinia borealis.

A polygalacturonase was isolated from the culture medium of Sclerotinia borealis, a psychrophilic fungus that grows on lawn and wheat seedling under the snow in winter and induces the snow mold disease. Pectic acid was a better substrate of this enzyme than pectin when the activity was determined by measuring the reducing sugar produced. However, when the activity was measured by viscosity change, the viscosity of pectin decreased more rapidly than that of pectic acid. The results of viscosity change apparently indicate that the polygalacturonase catalyzes pectin hydrolysis as an endo-type enzyme. Highly methyl-esterified pectin was a poor substrate, as determined by measurements of reducing sugar production and viscosity change. It is suggested from the results that the methoxy group of pectin affects the polygalacturonase reaction. A reaction mechanism was proposed for the polygalacturonase reaction. Molecular mass of this enzyme was 40 kDa and its isoelectric point was pH 7.5. Optimum pH of the enzyme reaction was 4.5 and its optimum temperature was 40-50 degrees C. Thirty percent of the maximum activity was observed at 5 degrees C, but it was only slightly active above 60 degrees C. The activity was preserved for more than 2 years at 5 degrees C and pH 4.5, but it was lost when kept at room temperature overnight or heated at 50 degrees C for 30 min. The amino acid sequence of the N-terminal region of the psychrophilic polygalacturonase of Sclerotinia borealis is compared with those of polygalacturonases of mesophilic fungi. The function of this enzyme against the target plants is discussed with reference to the reaction of polygalacturonases of mesophilic fungi.

Amino Acid Sequence↗
PubMed1997

Factors affecting aseptic failure of fixation after primary Charnley total hip arthroplasty. Multivariate survival analysis.

Multivariate survival analysis with use of the Cox proportional-hazards model was applied to a consecutive series of 293 primary Charnley total hip arthroplasties performed on 246 patients. The purpose of the analysis was to identify risk factors for, and to quantitate their effects on, aseptic failure of fixation. The duration of follow-up ranged from one month to twenty-three years (average, thirteen years). The end point of survival was defined as radiographic evidence of failure of fixation or as a revision operation. Failure of fixation of the acetabular component was defined as complete demarcation or migration. Failure of the femoral component was defined as progression of at least one of five postoperative signs (subsidence, demarcation of the cement, separation of the component from the cement, fracture of the cement, and endosteal cavitation) or as the occurrence of at least two of these signs. Twenty-four specific items of data for each acetabular component and thirty specific items for each femoral component formed the sets of variables for the analysis. With use of radiographic evidence of failure as the end point, the sixteen-year rates of survival (with 95 per cent confidence interval) were 83.6 +/- 5.6 per cent for the acetabular components and 90.9 +/- 4.1 per cent for the femoral components. With use of revision as the end point, the sixteen-year rates of survival were 92.3 +/- 4.0 per cent and 95.6 +/- 3.2 per cent, respectively. The most important risk factor affecting radiographic loosening of the acetabular component was rapid wear of the polyethylene (0.2 millimeter or more annually), followed by the classification of the osteoarthrosis (as hypertrophic, normotrophic, or atrophic) according to the extent of osteophyte formation. The sockets in the hips that had hypertrophic osteoarthrosis survived longer than those in the other two groups. Survival of the acetabular component as determined on the basis of revision was affected only by rapid wear of the polyethylene. Survival of the femoral component, with either radiographic failure of fixation or revision as the end point, was affected by an unfavorable geometry of the medullary canal (a so-called stovepipe canal or a large canal). Patients who have rapid wear of the polyethylene, little osteophyte formation, or an unfavorable geometry of the canal should be followed carefully. These risk factors warrant additional evaluation.

Acetabulum↗
PubMed1997

Contralateral hip in patients with unilateral nontraumatic osteonecrosis of the femoral head.

To clarify the risk of the development of osteonecrosis of the femoral head in the contralateral hip of patients with unilateral nontraumatic osteonecrosis of the femoral head, a followup study was performed using magnetic resonance imaging. Forty-six asymptomatic contralateral hips with no evidence of osteonecrosis on magnetic resonance imaging, in patients with unilateral osteonecrosis, were subjects of this study. The period from the onset of unilateral osteonecrosis to entrance in this study ranged from 1 month to 20 years (mean, 3.1 years). There were 29 males and 17 females ranging in age from 16 to 71 years (mean, 41 years). Twenty-three patients had previous steroid therapy for various conditions: 16 had alcoholism and 7 had no etiologic factors. The followup term ranged from 3 to 8 years (average, 5.5 years). During the followup period, 1 patient (2%) had a band of low signal intensity demarcating the lesion of normal fat intensity on T1 weighted images, which progressed to collapse of the femoral head. These results suggest that in unilateral osteonecrosis cases, osteonecrosis rarely develops in the contralateral hip that has appeared normal on magnetic resonance imaging. The contralateral hip with a negative magnetic resonance imaging scan is not in Stage 0 of osteonecrosis, but is normal.

Adolescent↗
PubMed1997

[Mediastinal esophago-bronchogenic cyst presenting as a single mass].

An abnormal shadow was found on a chest X-ray film of a 42-year-old man. The mass was 17 x 12 x 11 cm, smooth, round, homogeneous, and was seen in the left upper lung field. Chest computed tomography revealed a cystic mass in contact with the left lung, the chest wall, the esophagus, and the aorta. Magnetic resonance imaging showed a wall that divided the mass into two compartments. The cystic lesion was removed and was found to contain a yellow liquid. The larger part of the mass was histologically similar to esophageal wall and the smaller part was bronchogenic. The final diagnosis was mediastinal esophago-bronchogenic cyst. In previously reported cases, two cystic masses were connected by a canal. The findings in this case support the theory by Yoshii that this type of cyst originates from the diverticulum of the foregut near the lung bud.

Adult↗
PubMed1996

A cDNA cloning of human AEBP1 from primary cultured osteoblasts and its expression in a differentiating osteoblastic cell line.

By comparing lists of 3'-directed partial cDNA sequences (gene signatures) randomly collected from various tissues, genes uniquely expressed in individual tissue can be identified. A full length cDNA clone, corresponding to one such gene signature, unique to human osteoblast and adipose tissue, was isolated. This cDNA clone encodes a 845-amino acid protein that is almost identical to the mouse adipocyte transcription factor AEBP1 except that it has additional 105 amino acids in the N terminus. A northern hybridization showed that in the differentiating murine osteoblastic cell line, AEBP1 is also expressed but that it is shut off in the final calcification phase, suggesting a transcriptional repressive effect on genes for bone formation.

3T3 Cells↗
PubMed1996

Peroneal osteocutaneous flap raised on reconstructed popliteal artery for delayed union following open tibial fractures.

Two cases of delayed union following type IIIC open tibial fracture were treated by a pedicled peroneal osteocutaneous flap raised on reconstructed popliteal vessels. Dissection of the peroneal vessels from the already traumatized extremity was tedious, but this technique provided a reliable vascularized skin and bone graft that was indispensable for the fracture healing. Peroneal osteocutaneous flaps raised on the reconstructed popliteal artery have not been reported to date; they appear to be a good alternative to free osteocutaneous flaps for non-union of the proximal tibia.

Adult↗
PubMed1996

Comparison of the primary structure of waxy proteins (granule-bound starch synthase) between polyploid wheats and related diploid species.

The waxy proteins encoded by the genomes A, B, and D in polyploid wheats and related diploid species were isolated by SDS-PAGE. The N-terminal amino acid sequences of mature proteins and V8 protease-induced fragments were determined. A total of five amino acid substitutions was detected in these sequences, which represent about 10% of the whole sequences of the waxy proteins. A comparison of these sequences in polyploid wheats with those in related diploid species revealed the following: (i) waxy proteins encoded by the A genome of polyploid wheats were identical to that of Triticum monococcum, (ii) the waxy protein encoded by the B genome of T. turgidum was identical to that of T. searsii, but differed from those of T. speltoides and T. longissimum by one amino acid substitution, (iii) the waxy protein encoded by the B genome of T. aestivum differed from that encoded by the B genome of T. turgidum by one amino acid substitution, and (iv) the waxy protein encoded by the D genome of T. aestivum was identical to that of T. tauschii.

Amino Acid Sequence↗
PubMed1996

Localization of bone morphogenetic protein-4 messenger RNA in developing mouse cochlea.

Bone morphogenetic protein-4 (BMP-4) is a cytokine that belongs to the TGF-beta superfamily. It has been implicated that it plays an important role during embryogenesis including epithelial-mesenchymal interactions and mesenchymal cells condensation. To investigate whether BMP-4 is involved in the embryogenesis of the inner ear, we performed in situ hybridization at various stages of the developing inner ear of mice. BMP-4 mRNA was detected only in the developmental stage. Its initial expression was detected in part of the otic vesicle at 9 days post-coitum (PC). As development proceeded, the hair cells of the cochlear duct were morphologically distinguishable. and BMP-4 expressing cells were found in Claudius cell region at 16 days PC. At this stage, the signal was most intense during development and the structure notably changed under the expressing cells. Mesenchymal cells were assembled and condensed underneath the BMP-4-expressing cells. The basilar membrane, with a rich extracellular matrix and elasticity, would be produced in the area between the Claudius' cells and condensed mesenchymal cells. Previous reports support the notion that BMP-4 expressed in the epithelium causes mesenchymal cell condensation and induces a structure with elasticity. In the developing cochlea. BMP-4 may be involved in the condensation and differentiation of the mesenchymal cells as well as basilar membrane formation. BMP-4 might be an essential factor for the normal development of the basilar membrane.

Animals↗
PubMed1996

Bone scintigraphy as an indicator for dome osteotomy of the pelvis: comparison between scintigraphy, radiography and outcome in 57 hips.

We performed dome pelvic osteotomy in 57 hips (54 patients) because of acetabular dysplasia. All patients had preoperative scintigraphy and were followed for more than 2 years. Excellent or good results were obtained in 49 hips, but 8 hips deteriorated. All hips which deteriorated had preoperatively a spotty isotope uptake image localized to the weight bearing area and the medial area of the joint. No hip without this image deteriorated, even when preoperative radiography showed advanced arthrosis. Our findings indicate that bone scintigraphy may be a more reliable predictor of failure for this operation than radiography.

Adolescent↗
PubMed1995

The immune reaction to heterologous serum causes osteonecrosis in rabbits.

Osteonecrosis (ON) was produced experimentally in rabbits by intravenous injection of horse serum. Eighty adult rabbits were used: 16 were injected twice with isotonic saline (Group A), 24 were injected once with saline and once with horse serum (Group B), and 40 were injected twice with horse serum (Group C). Both femurs of each rabbit were obtained from 2 h to 7 weeks after the final injection an were subjected to histological examination. No pathological changes were seen in Groups A and B. In Group C, 5 of 15 rabbits (33%) showed ON (necrosis of trabecula and bone marrow) in the femoral metaphysis. In Group C, the early major pathological findings in bone marrow are extravasation of erythrocytes in sinusoidal spaces and microthrombi in small arteries and arterioles near the lesion of extravasation. Immune complexes were demonstrated in the kidney within 24 h of the final injection of horse serum. The present study suggests that immunological reaction associated with serum sickness may play an important role in inducible ON and this model will contribute toward clarifying the pathogenesis of ON.

Animals↗
PubMed1995

Use of monoclonal antibody to detect bone morphogenetic protein-4 (BMP-4).

A monoclonal antibody that reacts with murine and human bone morphogenetic protein-4 (BMP-4) has been developed using recombinant BMP-4 as an immunogen. The antibody that bound most tightly to recombinant murine (rm)BMP-4 was selected, subcloned, and characterized. The specificity of the antibody was confirmed using Western blot analysis and enzyme-linked immunosorbent assay (ELISA). The antibody reacts with murine and human BMP-4 in both the reduced and nonreduced condition; however, this antibody shows cross-reactivity with neither human BMP-2 nor TGF-beta 1. Thus, the produced antibody could recognize the disulfide-linked dimeric structure of bioactive BMP-4, regardless of the species. Immunocytochemical study using this antibody successfully shows the cytosolic localization of BMP-4 in osteoinductive cells; i.e., BFO and Saos-2 in which the level of mRNA for BMP-4 was proved to be constitutively high by Northern blot analysis. In addition, the antibody could demonstrate the presence of BMP-4 in developmental bone formation in the alveolar bone of rat embryo by immunohistochemistry. The antibody could be used for a more sensitive approach for quantitative analysis of BMP-4.

Animals↗
PubMed1995

Psychiatric comorbidity in eating disorders: psychopathological considerations.

The psychiatric comorbidity was examined in patients who met ICD-10 criteria for eating disorders. The most frequent comorbid diagnoses were mood disorders, followed by personality disorders and neurotic disorders. Non-attendance at school was also seen. Eating disorders did not directly cause mood disorders, but rather indirectly brought them about by a devaluation of self-esteem. Features of personality disorders occurred independently of eating disorders, appearing or disappearing relative to the major object or transitional object. Neurotic disorders served as non-verbal communication, a function originally included in eating disorders. It is important to take note of the devaluation of self-esteem and the meanings of symptoms as communication within eating disorders.

Adolescent↗
PubMed1995

Polyethylene sockets and alumina ceramic heads in cemented total hip arthroplasty. A ten-year study.

From 1981 to 1983, we implanted Bioceram type-4 and type-5 prostheses in 61 hips in 54 patients with osteoarthritis secondary to acetabular dysplasia, congenital subluxation, or congenital dislocation of the hip. Fifty-seven hips in 50 patients were followed for a mean of 11.1 years (10 to 13). The mean age of the patients at operation was 53 years (31 to 70). Functional evaluation using the Merle d'Aubigné and Postel hip score showed a 77% success rate. Radiological loosening occurred in three femoral (5%) and 16 acetabular components (28%). Autologous femoral head grafts were used in 18 hips and became incorporated, giving mechanical support to the socket except for one which occupied a large weight-bearing area and eventually collapsed. The mean polyethylene wear was 1.1 mm (0 to 3.6) and the mean wear rate was 0.10 mm/year (0 to 0.31). A high rate of wear correlated with calcar resorption (p > 0.002) but not with acetabular loosening. There was no breakage of a ceramic head. Study of the ceramic heads and polyethylene sockets retrieved after ten years showed excellent surface roughness, sphericity, and bending strength for the heads but scratches and voids were seen on the sockets.

Bone Cements↗
PubMed1995

Bipolar cup design may lead to osteolysis around the uncemented femoral component.

Thirty-eight patients with a total of 45 primary uncemented bipolar hemiarthroplasties with smooth femoral components were observed for an average period of 5 years. Clinical results were excellent in 17, good in 15, fair in 10, and poor in 3 hips. Radiographs showed stem loosening and bipolar head migration in 12 and 2 hips, respectively. Endocortical femoral osteolysis developed in 26 hips (58%). Eight hips required revision surgery. All the revised hips showed circumferential wear of the polyethylene insert rims without substantial wear of the bearing surface. Histologic examination of the fibrous membrane around the stem showed many polyethylene particles that had been phagocytized by macrophages or surrounded by foreign body giant cells. No metal particles were observed at this site. The intrinsic functional mechanism of the bipolar endoprosthesis leads to persistent cyclic impingement of the stem neck on the rim of the bipolar head, producing polyethylene particles and frequent stem loosening by periprosthetic osteolysis. Unless this structural problem can be corrected and the durability of the prosthesis increased, the bipolar system should not be used for hemiarthroplastic surgery.

Adult↗
PubMed1995

Local effects of bone morphogenetic protein-4 on skeletal tissues.

To examine the local effects of bone morphogenetic protein-4 on diverse skeletal tissues in vivo, Chinese hamster ovary tumor cells transfected with the murine bone morphogenetic protein-4 gene were implanted into athymic nude mice by injection into the subcutaneous space of the skull, intra- and extraarticular spaces of the knee, paravertebral muscles, and intramedullary space in the femur, to form experimental tumors secreting bone morphogenetic protein-4. As a control, mock vector-transfected Chinese hamster ovary tumor cells were used. Three weeks after injection, the newly formed Chinese hamster ovary tumors together with the skeletal tissues adjacent to the tumor were recovered from each site and processed for histologic examination. On the periosteum of calvaria, new bone, but no cartilage, was observed, and abundant chondrogenic cell proliferation was seen in the apophysis of the spinous process and around Ranvier's groove in the knee. There were no apparent reactions to the Chinese hamster ovary tumors secreting bone morphogenetic protein-4 in the articular cartilage of the knee or the bone marrow of the femur. Control tumors did not elicit any bone or cartilage formation.

Animals↗