Biomedical subjects

M Ohki

Publications and source records attributed to M Ohki.

At least 109 records · Page 6Linked to original sources

PubMed1995

Trabecular texture analysis of CT images in the relationship with spinal fracture.

PURPOSE: To evaluate age-related changes in trabecular texture and bone mineral density (BMD) and to determine the usefulness of texture analysis in the assessment of the risk of fracture. MATERIALS AND METHODS: The vertebral trabecular BMD was measured in 209 women aged 18-86 years. Run length analysis was applied to computed tomographic images obtained with 2-mm section thickness. The width of the trabecula (T-texture) and the width of the intertrabecular space (I-texture) were calculated. RESULTS: I-texture significantly increased with age in women 50 years of age or older (P < .0001). Women with fracture had significantly lower BMD (P < .0001 at 60-69 years, P < .05 at 70-79 years) and significantly higher I-texture (P < .05 at 60-69 years, P < .01 at 70-79 years). For fracture risk, BMD had the highest sensitivity and I-texture had the highest specificity in women aged 60-69 years; I-texture had the highest sensitivity and specificity in women aged 70-79 years. CONCLUSION: Texture analysis was helpful in the assessment of fracture risk, especially in elderly women.

Adolescent↗

PubMed1994

An RNA-binding protein gene, TLS/FUS, is fused to ERG in human myeloid leukemia with t(16;21) chromosomal translocation.

The t(16;21)(p11;q22) translocation is a recurrent chromosomal abnormality found in several types of myeloid leukemia. We have previously demonstrated that the breakpoints of this translocation are clustered in a specific intron of the ERG gene on chromosome 21, which has recently been reported to be involved in Ewing's sarcoma. We show here that the TLS/FUS gene on chromosome 16 is fused with the ERG gene to produce the TLS/FUS-ERG chimeric transcript by this translocation. The TLS/FUS gene has been identified as a translocated gene in myxoid liposarcoma by the t(12;16)(q13;p11) translocation and encodes an RNA-binding protein that is highly homologous to the product of the EWS gene involved in Ewing's sarcoma. Thus, the TLS/FUS-ERG gene fusion in t(16;21) leukemia is predicted to produce a protein that is very similar to the EWS-ERG chimeric protein responsible for Ewing's sarcoma.

Base Sequence↗

PubMed1994

Generation of the AML1-EVI-1 fusion gene in the t(3;21)(q26;q22) causes blastic crisis in chronic myelocytic leukemia.

The t(3;21)(q26;q22) translocation, which is one of the consistent chromosomal abnormalities found in blastic crisis of chronic myelocytic leukemia (CML), is thought to play an important role in the leukemic progression of CML to an acute blastic crisis phase. The AML1 gene, which is located at the translocation breakpoint of the t(8;21)(q22;q22) translocation found in acute myelocytic leukemia, was also rearranged by the t(3;21)(q26;q22) translocation. Screening of a cDNA library of the t(3;21)-carrying leukemic cell line cells (SKH1) resulted in the isolation of two potentially complete AML1-EVI-1 chimeric cDNAs of 6 kb. Two species of AML1-EVI-1 fusion transcripts of 8.2 and 7.0 kb were detected in SKH1 cells. These cells expressed the 180 kDa AML1-EVI-1 fusion protein containing an N-terminal half of AML1 including a runt homology domain which is fused to the entire zinc finger EVI-1 protein. The AML1-EVI-1 fusion transcript was consistent in all three cases of the t(3;21)-carrying leukemia examined by RNA-based PCR. These findings strongly suggest that the t(3;21) translocation results in the formation of a new class of chimeric transcription factor which could contribute to the leukemic progression of CML through interference with cell growth and differentiation.

3T3 Cells↗

PubMed1994

Sixty new STSs (sequence-tagged sites) of human chromosome 21.

From human chromosome 21-specific libraries, 22 SfiI linking clones and 38 P1 clones were isolated and regionally mapped on the chromosome. The terminal sequences of these clones were determined and pairs of PCR primers were generated which could specifically amplify the sequenced regions. These sequence-tagged sites (STSs) should be useful for constructing a high resolution map of human chromosome 21.

Base Sequence↗

PubMed1994

Association between anthropometric measures and spinal bone mineral density.

RATIONALE AND OBJECTIVES: The relationship of vertebral bone mineral density (BMD) to various anthropometric factors, including body weight and height, vertebral volume, and muscle area was examined. The sex- and menopause-related differences in these relationships also were studied. METHODS: Both cortical and trabecular BMD were measured using quantitative computed tomography (QCT). Integral BMD was measured using dual x-ray absorptiometry (DXA) in 74 men and in 96 premenopausal and 155 postmenopausal women. The psoas muscle area was measured using CT images. Vertebral volume was determined using CT images and CT topography. RESULTS: Bone mineral density had the strongest relationship with age in postmenopausal women. Trabecular BMD was correlated with muscle area and vertebral volume in premenopausal women, but not in postmenopausal women. The correlation of trabecular BMD with various anthropometric factors in men was stronger than that in women. Dual x-ray absorptiometry-BMD was found to be more affected by bone volume than was QCT-BMD. CONCLUSIONS: The association of anthropometric factors with BMD differs in men and women, as well as in premenopausal and postmenopausal women.

Absorptiometry, Photon↗

PubMed1994

[Application of the Limulus test for practical quality control on endotoxin content in commercial human serum albumin (HSA) products. In comparison with the rabbit pyrogen test].

The bacterial endotoxin content in human serum albumin (HSA) products measured by two different Limulus amebocyte lysate (LAL) test methods, colorimetric and kinetic turbidimetric methods, were compared. So far as endotoxin-specific LAL reagents which do not show a false-positive reaction with (1-->3)-beta-D-glucan are used, a definite correlation was found between the results with the two LAL test methods. Endotoxin added to HSA products was recovered in a quantitative manner showing neither inhibition nor enhancement by HSA to the both LAL test methods. Results of the LAL tests showed a significant correlation with that of the rabbit pyrogen test. The correlation was much improved with endotoxin-added HSA. The present results indicate the practical applicability of the LAL test as an alternative method for the rabbit pyrogen test.

Animals↗

PubMed1994

Factors determining the diagnostic accuracy of digitized conventional intraoral radiographs.

A number of factors may determine the diagnostic accuracy of digitized intraoral radiographs. Conventional film radiographs were digitized with three different digitizers, a laser-scanner, a drum-scanner and a TV camera. Digital images, varying in pixel size, grey level and image processing, were displayed on three different video-monitors and assessed by 10 dentists. The detectability of incipient proximal surface caries was used as an index of the diagnostic accuracy and the effect of the different factors compared by means of receiver operating characteristic (ROC) analysis. Images digitized by the drum-scanner were found to have the best diagnostic accuracy. Sufficient diagnostic accuracy could be attained on the low-cost video monitor of a personal computer. Digital images with a pixel size of 100 microns and 32 grey levels were found to be acceptable for intraoral radiographs for diagnostic purposes. These results provide a practical guide for establishing a digital image acquiring system for any intraoral radiographs, reducing demands on data storage to a minimum.

Analysis of Variance↗

PubMed1994

Dual energy X-ray absorptiometry of the calcaneus: comparison with other techniques to assess bone density and value in predicting risk of spine fracture.

OBJECTIVE: The calcaneus has been proposed as an alternative site for assessment of bone mineral density (BMD) in women with osteoporosis. The objectives of this study were to evaluate the clinical usefulness of dual-energy X-ray absorptiometry (DXA) of the calcaneus for predicting spinal fracture and to compare the predictive value of assessment of BMD by DXA of the calcaneus, quantitative CT or DXA of the lumbar spine, and DXA of the most distal part of the radius. SUBJECTS AND METHODS: The study group consisted of 399 healthy volunteer women (aged 19-81 years) and 27 women (aged 44-85 years) who had osteoporosis. They had DXA of the calcaneus, quantitative CT and DXA of the lumbar spine, and DXA of the most distal part of the radius. T-score analyses were used to compare decreases in BMD in postmenopausal women with decreases in premenopausal women, and to compare decreases in women with and without osteoporosis. RESULTS: T-score analysis of age-related changes in BMD in the control subjects showed that densities in the calcaneus, the lumbar spine, and the most distal part of the radius decrease significantly with age in postmenopausal women. In women with osteoporosis (n = 27), BMDs in the calcaneus (DXA, p < .0002), L1-L3 (quantitative CT, p < .0001), L1-L4 (DXA, p < .0005), and the most distal part of the radius (DXA, p < .005) were significantly lower than those in healthy control subjects (n = 77). T-score analysis indicated that in women with osteoporosis, DXA of the calcaneus showed BMD losses greater than those shown by DXA of L1-L4 and the most distal part of the radius and similar to those shown by quantitative CT of L1-L3. Receiver-operating characteristic (ROC) analysis showed that findings on DXA of the calcaneus were as good a predictor of the risk of spinal fracture as findings on DXA of the lumbar spine and not as good as findings on quantitative CT of the lumbar spine. CONCLUSION: The results suggest that DXA assessment of BMD in the calcaneus is not a useful adjunct to other measurements. However, it can be used to predict the risk of fracture when better measures, such as quantitative CT, are unavailable.

Absorptiometry, Photon↗

PubMed1994

Effect of aging on smooth pursuit eye movement.

Examination of smooth pursuit eye movement is useful for detecting central nervous system disorders. It is important to take patient's age into consideration when evaluating smooth pursuit eye movement. The purpose of the present study was to clarify the effect of aging on smooth pursuit eye movement. Thirty healthy volunteers (three groups of 10 volunteers, in their fifties, sixties, and seventies and over, respectively) served as subjects, and 10 healthy young volunteers (23 to 33 years old: mean age 26) served as controls. The pursuit target was driven by sinusoidal waveform with various amplitudes and frequencies. Target peak velocities ranged from 12.6 to 94.2 degrees/s. Eye movement signals were recorded d.c. EOG and pursuit gain (ratio of eye peak velocity to target peak velocity) was measured by a computer. Pursuit gain decreased with increasing target frequency and velocity in all age groups. This tendency was more remarkable in the older groups than in the young controls; in particular, it was more frequently seen at a frequency of 0.5 Hz. On the other hand, there was no significant relationship between pursuit gain and the target amplitude. In the group in their seventies and over, pursuit gain was saturated at about 60 degrees/s.

Adult↗

PubMed1994

Ocular abnormalities in amyotrophic lateral sclerosis.

It has long been known that the oculomotor system is not involved in amyotrophic lateral sclerosis (ALS). In early stages. Some authors suggest oculomotor abnormalities in some patients. In the present study, quantitative analysis of ocular movements including smooth pursuit eye movements, optokinetic nystagmus (OKN), visual suppression of vestibular nystagmus (VS), and horizontal saccades were investigated in 9 patients with ALS. These patients were neurologically diagnosed as having ALS in the early stage. The results were as follows: The velocity of saccade was markedly reduced in 4 patients. In addition, there were abnormalities of smooth pursuit (one patient), OKN (one patient) and visual suppression (2 patients). Furthermore, these abnormalities were observed more often in patients with bulbar signs. In conclusion, the results suggest a existence of ocular abnormalities in ALS, even at early stages.

Adult↗

PubMed1994

Quantitative analysis of oblique ocular movements.

In the present study, oblique saccadic eye movements in the orthogonal and oblique directions were investigated in 10 normal subjects, and a computer program was used to accomplish quantitative assessment of oblique eye movements. Eye movements were recorded with direct-current electronystagmography (DC-ENG) and a 12-bit analog to digital converter was used to collect analog data of horizontal and vertical eye position, and stimulus signals at a sampling rate of 200 Hz. The oblique eye movement was displayed two-dimentionally on a high-resolution color graphic terminal for the evaluation of the trace of eye movements, and the peak velocity and the amplitude of the horizontal, vertical and oblique saccades were calculated. It was frequently found that the tracing line in the oblique saccadic eye movement was not completely straight, but loosely curved. The velocity of the vertical component of the oblique saccade was much lower than that of the horizontal component. This suggests that oblique saccades might be made by synchronized but independent vertical and horizontal pulse generators, and the system developed this time might be very useful for investigation of oblique eye movements in both the clinical and physiological field.

Adult↗

PubMed1994

Storage and utilization of images in otorhinolaryngology.

The amount of data in the field of otorhinolaryngology has rapidly increased, in proportion to the growing number of patients. Medical imaging has especially expanded and the percentage of image data in all information is also large. Because the space to preserve image films is increasing, it is very important to preserve them and make them easily available. Therefore, we have established a graphic filling system for storing endoscopic and radiographic images on VHS video tape and magnet-optical disk (MOD), using a personal computer. The MOD filing system is useful for storing a large amount of medical records. The user can simultaneously see the text data and the picture image on a display, and thus this system can be utilized as a database for both decision making and medical research.

Barium Sulfate↗

PubMed1994

[A randomized controlled trail of intensive and usual community-based education for blood pressure control].

A 1.5 year community-based hypertension education program was conducted and evaluated for the feasibility and effectiveness as a program for primary prevention of cardiovascular disease. The subjects were determined to be hypertensive from cardiovascular examinations and composed of 104 untreated men and women aged 35-69 whose blood pressure levels were between 140 and 179 mmHg for systolic and/or between 90 and 109 mmHg for diastolic and who had no evidence of hypertensive end organ effects in the 1990 examination. They were randomly assigned to either an intensive education (IE) group (n = 53) or a usual education (UE) group (n = 51) and invited to education classes six months later. The IE consisted of four education classes in the first six months and another 4 classes in the next 12 months. For the UE, one class in the first 6 months and another class in the next 12 months were held. Health education was focused on reduction of sodium intake, a 30 minutes of walking, and if necessary, reduction of alcohol and sugar intake. Mean (SD) values of systolic blood pressure at the start of the education program were 144.8 (11.7) mmHg in IE and 144.5 (12.2) mmHg in UE. The respective diastolic means (SD) were 80.6 (7.8) mmHg and 80.3 (8.6) mmHg. The proportion of persons who started to receive antihypertensive medication was 8-9% in both groups at six months, and 13% in IE and 29% in UE at 1.5 years. IE showed a 6 mmHg greater reduction in mean systolic blood pressure than UE at both six months and 1.5 years. No significant difference was found in diastolic blood pressure levels over time between the two groups. Dietary improvements related to reduction of salt intake were more evident in IE than in UE. There was no significant changes in means and distributions of relative weight index and alcohol intake in either group. Subgroup analysis according to antihypertensive medication use indicated that reduction of systolic blood pressure levels was significantly larger in IE than in UE for both no medication and medication subgroups at 6 months and 1.5 years. While it was difficult to evaluate an effect of the program at 1.5 years because of the difference in the proportion of medication use between IE and UE, the results at 6 months suggest that this community-based program was effective in reducing systolic blood pressure levels.

Adult↗

PubMed1994

[A case of dissecting aneurysm associated with mixed connective tissue disease].

A 41 year-old-female with mixed connective tissue disease (MCTD) associated with dissecting aneurysm (DA) of the right posterior cerebral artery is reported. This case satisfied the diagnostic criteria for MCTD, and cerebral angiography revealed the double-lumen sign and pooling of the contrast medium. Thus it was possible to make a definite diagnosis of both MCTD and DA. Fragility of the arterial wall due to the primary disease, MCTD, appeared to have played a role in the occurrence of dissection and the subarachnoid hemorrhage.

Adult↗

PubMed1993

An ets-related gene, ERG, is rearranged in human myeloid leukemia with t(16;21) chromosomal translocation.

The t(16;21)(p11;q22) translocation is a nonrandom chromosomal abnormality found in several types of myeloid leukemia, which show variable cytomorphological features. We constructed rodent-human somatic cell hybrids containing the der(16) chromosome from leukemic cells of a patient with t(16;21). Using these hybrids, we mapped the translocation breakpoint on the Not I restriction map of chromosome 21 which we had previously constructed. The result showed the proximity of the breakpoint to the ERG gene, a member of the ets oncogene superfamily. Polymerase chain reaction and Southern blot analyses of genomic DNA from the hybrids and from peripheral blood cells and bone marrow cells of patients with t(16;21) showed that the breakpoints were clustered within a single intron in the coding region of the ERG gene. This finding and the results obtained by Northern blot analysis suggested the formation of a chimeric product(s) by fusion of the ERG gene and an unknown counterpart gene on chromosome 16.

Acute Disease↗

PubMed1993

Junctions of the AML1/MTG8(ETO) fusion are constant in t(8;21) acute myeloid leukemia detected by reverse transcription polymerase chain reaction.

The chromosomal translocation, t(8;21), is found frequently in acute myeloid leukemia (AML) with maturation (FAB-M2). We have previously mapped the translocation breakpoints of t(8;21) in a specific intron of the AML1 gene on chromosome 21. In this study, we cloned cDNAs synthesized from a cell line carrying t(8;21) by reverse transcription polymerase chain reaction (RT-PCR) using an AML1-specific primer. The analysis of the cDNAs structure has led to the identification of the fusion of AML1 with a gene named MTG8 on chromosome 8, which seems to be identical to ETO. Northern analysis using MTG8 (ETO) probes detected 7.8-kb and 6.2-kb RNAs and several minor RNAs in the cell line with t(8;21), but failed to detect any transcripts in a cell line without t(8;21). A set of primers were designed to detect the AML1/MTG8(ETO) fusion by PCR. The PCR amplified identical products in all 6 patients and one cell line with t(8;21), suggesting that the AML1/MTG8(ETO) fusion is a constant feature associated with t(8;21) and the junctions of the AML1/MTG8(ETO) fusion are restricted in a unique site. Because the PCR detection of the AML1/MTG8(ETO) fusion at the RNA level is highly sensitive, it can be used as a sensitive method for diagnosis and detection of minimal residual disease in t(8;21) leukemia.

Amino Acid Sequence↗

PubMed1993

The 8;21 chromosome translocation in acute myeloid leukemia is always detectable by molecular analysis using AML1.

The AML1 gene was rearranged in leukemic cells with t(8;21)(q22;q22) or its variant, complex t(8;V;21) translocations from 33 acute myeloid leukemia (AML) patients. The AML1 rearrangement was also detected in three AML patients without t(8;21); two had a normal diploid karyotype, and one had a karyotype of 45,X, - X. The AML1 rearrangement in the t(8;21) breakpoint cluster region was not detected in leukemic cells with cytogenetic abnormalities other than t(8;21), or with normal diploidy obtained from 23 AML patients. Because leukemic cells of the five patients with complex t(8;V;21) translocations had a der(8)t(8;21) chromosome with a break in band 8q22 in common, the juxtaposition of the 5' side of AML1 to a predicted counterpart gene located in the breakpoint region of 8q22 may be an essential step in the leukemogenesis of AML with t(8;21). Our findings show that the 8;21 translocation, its variants, and the masked t(8;21) may all be detectable by the Southern hybridization method using the AML1 probes.

Adolescent↗

PubMed1993

The t(8;21) translocation in acute myeloid leukemia results in production of an AML1-MTG8 fusion transcript.

The t(8;21) translocation is one of the most frequent chromosome abnormalities in acute myeloid leukemia. It has been shown that the t(8;21) breakpoints on chromosome 21 cluster within a single specific intron of the AML1 gene, which is highly homologous to the Drosophila segmentation gene runt. Here we report that this translocation juxtaposes the AML1 gene with a novel gene, named MTG8, on chromosome 8, resulting in the synthesis of an AML1-MTG8 fusion transcript. The fusion protein predicted by the AML1-MTG8 transcript consists of the runt homology region of AML1 and the most part of MTG8, which contains putative zinc finger DNA binding motifs and proline-rich regions constituting a characteristic feature of transcription factors. The MTG8 gene is not expressed in normal hematopoietic cells, whereas AML1 is expressed at high levels. Our results indicate that the production of chimeric AML1-MTG8 protein, probably a chimeric transcription factor, may contribute to myeloid leukemogenesis.

Acute Disease↗