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Biomedical subjects

T Akasaka

Publications and source records attributed to T Akasaka.

At least 163 records · Page 9Linked to original sources
PubMed1995

Immunoglobulin heavy chain class switching, mu to gamma, in a human lymphoma cell line FL-318 carrying a t(14;18)(q32;q21) chromosomal translocation.

Previously, we reported the establishment of a human lymphoma cell line, FL-318, carrying a t(14;18)(q32;q21) chromosomal translocation. FL-318 cells had mu-heavy chain on the cell surface, while they expressed 'sterile' germ-line gamma transcripts, suggesting that the chromatin structure of the immunoglobulin heavy chain (IGH) locus was 'accessible' to class switch recombination. After several months of in vitro cell culture, we found a small population of FL-318 cells expressing the gamma-chain. Using a limiting dilution method, a mu-producing cell clone FL-318M, and gamma-producing FL-318G were isolated. Hybridization studies with various DNA probes from the IGH locus as well as the BCL2 gene demonstrated that the mu-constant gene was deleted on the functional IGH allele of FL-318G cells, and that the cells produced abundant productive gamma-chain messages. These studies indicated that FL-318 cells underwent spontaneous class switching during in vitro cell culture, unrelated to T cell interaction or antigenic stimulation.

Base Sequence↗
PubMed1995

[Pseudoxanthoma elasticum associated with unstable angina and Leriche syndrome: a case report].

A 64-year-old man with a history of intermittent claudication presented with chest pain. On admission, he had yellowish papules with a "plucked chicken" appearance on his neck. Histological examination of the biopsy specimen of the lesion revealed degeneration and calcification of elastic fibers in the dermis. His daughter also had similar histological changes in the skin. The diagnosis was pseudoxanthoma elasticum. Fundoscopic examination revealed angioid streaks. Electrocardiography showed inverted T waves in V2-V6, and echocardiography revealed hypokinesis in the anterior wall of the left ventricle. Emergency catheterization showed 90% stenosis in the left anterior descending coronary artery, total occlusion of the abdominal aorta, and severe stenosis in the right subclavian artery. He was treated medically and had no recurrent episodes of chest pain. A careful examination for cardiovascular diseases should be considered in patients with pseudoxanthoma elasticum.

Angina, Unstable↗
PubMed1995

[Detection of hibernating myocardium in patients with myocardial infarction by low-dose dobutamine echocardiography: comparison with thallium-201 scintigraphy with reinjection].

The identification of hibernating myocardium is important for selecting patients who will benefit from coronary revascularization. The relationship between echocardiographic and radioisotopic markers of hibernating myocardium and postrevascularization recovery of myocardial function was investigated in 21 patients who underwent successful revascularization. Each patient underwent low-dose dobutamine stress echocardiography and thallium-201 (201Tl) scintigraphy with reinjection before revascularization. The presence of contractile reserve in dobutamine stress echocardiography and Tl uptake in 201Tl scintigraphy with reinjection were defined as markers of hibernating myocardium. Follow-up echocardiograms were evaluated for improved regional wall motion in all patients at a mean of 8.6 months after revascularization. Sensitivity, specificity, and positive and negative predictive values of low-dose dobutamine stress echocardiography for indicating recovery of function after revascularization were 75.0%, 77.8%, 81.8%, and 70.0%, respectively. Sensitivity, specificity, and positive and negative predictive values of 201Tl scintigraphy with reinjection for indicating recovery of function after revascularization were 91.7%, 55.6%, 73.3%, and 83.3%, respectively. There were no statistical differences between low-dose dobutamine echocardiography and 201Tl scintigraphy in predicting postrevascularization recovery of function patients with hibernating myocardium.

Aged↗
PubMed1995

[Assessment of coronary stenosis severity using a Doppler guide wire in vivo: is the continuity equation applicable to moderate to severe coronary artery stenosis?].

The usefulness of a Doppler guide wire was evaluated in the estimation of coronary stenosis severity in patients with moderate to severe coronary stenosis using the continuity equation. The maximal coronary flow velocities (V) proximal to the stenosis (p), at the stenosis (s), and distal to the stenosis (d) were measured using a Doppler guide wire (12-MHz, 0.018-in) in 12 patients with mild coronary stenosis (less than 50% diameter stenosis: group A) and 12 patients with moderate to severe coronary stenosis (more than 50% diameter stenosis: group B). Percent diameter stenosis (%DS) was calculated from Vp/Vs by: %DS = (1 - square root of Vp/Vs) x 100 (%) (Vp = the maximal velocity proximal to the stenosis; Vs = the peak velocity at the stenotic site) Percent DS was calculated from Vd/Vs by: %DS = (1 - square root of Vd/Vs) x 100 (%) (Vd = the peak velocity distal to the stenosis) Regression of Doppler-derived %DS from Vp/Vs compared to quantitative coronary angiographic % DS were: Group A: y = 0.83x + 3.0 (r = 0.79), Group B: y = 0.63x + 9.4 (r = 0.81), Overall: y = 0.63x + 9.6 (r = 0.91) Regression of Doppler-derived %DS from Vd/Vs compared to quantitative coronary angiographic %DS were: Group A: y = 0.98x - 1.0 (r = 0.81), Group B: y = 0.67x + 14.6 (r = 0.84), Overall: y = 0.79x + 7.6 (r = 0.91) The continuity equation method using a Doppler guide wire underestimates coronary stenosis severity in patients with moderate to severe coronary stenosis, although Doppler-derived %DS is correlated with angiographic %DS.

Blood Flow Velocity↗
PubMed1995

[Adenosine triphosphate loading thallium-201 myocardial scintigraphy: optimal dose and diagnostic accuracy].

Adenosine triphosphate (ATP) is an alternative to dipyridamole or adenosine in thallium-201 myocardial scintigraphy. However, the optimal dose of ATP has not been determined. A Doppler guide wire study showed the coronary flow velocity at a dose of 0.15 mg/kg of ATP was equal or higher than that at 0.14 mg/kg of adenosine or 0.56 mg/kg of dipyridamole. ATP was given intravenously to 67 patients with coronary artery disease at 0.15 mg/kg/min for 6 min. Thallium-201 was injected at 3 min, followed by immediate and delayed (3 hrs) tomographic imaging. There was no serious side effect during examination, although chest pain (26%), dyspnea (17%), and flushing (33%) were common. The sensitivity and specificity to detect coronary artery disease were 98 and 100%, respectively. The sensitivity to detect left anterior descending artery, left circumflex artery, and right coronary artery lesions was 94, 59 and 77%, respectively. ATP loading thallium-201 scintigraphy provides an accurate diagnosis of coronary artery disease. The optimal dose of ATP is 0.15 mg/kg/min for 6 min.

Adenosine Triphosphate↗
PubMed1995

[Relationship between regional flow reserve supplied by the great saphenous vein graft and regional left ventricular wall motion: a Doppler guide wire study].

The relationship between regional flow reserve supplied by a great saphenous vein graft and myocardial infarction and anterior wall motion assessed by left ventriculography was studied in 28 patients with no stenosis in the great saphenous vein graft and the peripheral site of the recipient left anterior descending coronary arteries. The proximal segment to the anastomosis was totally or subtotally occluded. The resting graft blood flow velocity was measured using a Doppler guide wire, then 0.56 mg/kg of dipyridamole was injected for 4 minutes intravenously and the resultant increase in graft blood flow velocity was recorded. The regional flow reserve of the anterior wall supplied by great saphenous vein grafts in 11 patients with anterior myocardial infarction (MI group) was significantly lower than that in 17 patients without myocardial infarction (non-MI group) (1.5 +/- 0.3 vs 2.6 +/- 0.7, p < 0.01). The flow reserve supplied by great saphenous vein grafts in 11 patients with normal anterior wall motion was 2.8 +/- 0.7, 10 with hypokinesis 1.9 +/- 0.3, and with akinesis 1.3 +/- 0.3. Reduced anterior wall motion induced a significant decrease in the flow reserve of the anterior wall supplied by the great saphenous vein graft (p < 0.01). The anterior wall motion score of four segments assessed by left ventriculography showed a significant correlation with the flow reserve of the anterior wall supplied by the great saphenous vein graft (y = -0.24 x + 3.7, r = 0.75, p < 0.001). The results show infarcted myocardium was an important influence on coronary flow reserve.

Adult↗
PubMed1995

[Intravascular ultrasound scanning assessment of plaque distribution in the left anterior descending coronary artery just distal to the bifurcation].

Coronary plaque has a distinct spatial distribution with the peak incidence on the outer wall around the bifurcation of the left main coronary artery. Intravascular ultrasound scanning was used to evaluate the distribution of the plaque in the proximal site of the left anterior descending coronary artery in 16 patients. Coronary angiography showed the examined sites were normal in all patients. A cross-sectional coronary scan was recorded in the left anterior descending coronary artery just distal to the bifurcation using a 4.3 Fr, 30 MHz intravascular ultrasound catheter. The thickness of the plaque was measured at 0, 90, 180, and 270 degrees, where 0 degree indicates the left circumflex coronary artery branching direction. The scan was divided into four areas of 90 degrees and labeled 1 to 4 in the counterclockwise direction (site 1 was the left circumflex coronary artery branching direction). The thickness and area of the plaque were measured in each site. The percentage plaque fraction was calculated as (plaque area in each site)/(plaque area of all) x 100. In 15 (94%) of the 16 patients, images of crescent shaped plaques were obtained. The mean thicknesses of the plaque at sites 1-4 were 0.25 +/- 0.07 mm, 0.46 +/- 0.21 mm, 0.82 +/- 0.19 mm, and 0.42 +/- 0.23 mm, respectively. The mean percentage plaque fractions were 7.9 +/- 3.6% (site 1), 18.1 +/- 7.2% (site 2), 55.0 +/- 8.1% (site 3), 18.7 +/- 6.9% (site 4), respectively. In site 3, opposite to the left circumflex coronary artery branching, the thickness and percentage plaque fraction were significantly greater than the remaining three sites (p < 0.001). In vivo intravascular ultrasound scanning revealed that coronary plaque in angiographically normal left anterior descending coronary artery just distal to the bifurcation has a distinct distribution with a peak incidence opposite to the left circumflex coronary artery branching.

Aged↗
PubMed1995

Three-dimensional analysis of configuration and dynamics in patients with an annuloplasty ring by multiplane transesophageal echocardiography: comparison between flexible and rigid annuloplasty rings.

BACKGROUND AND AIM OF THE STUDY: Multiplane transesophageal echocardiography provides three-dimensional reconstruction of the mitral annulus from multiple cross-sectional views from a stable transducer position by rotating around a central axis. This study was designed to evaluate the effect of the type of annuloplasty ring on mitral annular configuration and dynamics using three-dimensional reconstruction by multiplane transesophageal echocardiography. METHODS: Ten patients who underwent mitral valve repair for pure mitral regurgitation (five patients with flexible Duran ring, five patients with rigid Carpentier ring) and five normal subjects were studied with multiplane transesophageal echocardiography. Three-dimensional configuration of the mitral annulus was obtained from multiple cross-sectional views of multiplane transesophageal echocardiography. RESULTS: In normal subjects, the mitral annulus had a non-planar configuration and reduced its area in systole. In patients with a Duran ring, the mitral annulus had a non-planar configuration and reduced its area in systole. In patients with a Carpentier ring, the mitral annulus had a planar configuration and the mitral annular area did not change during the cardiac cycle. CONCLUSION: Three dimensional reconstruction of the mitral annulus using multiplane transesophageal echocardiography revealed that mitral annular configuration and dynamics are more physiologic in patients with a flexible Duran ring that with a rigid Carpentier ring.

Echocardiography, Transesophageal↗
PubMed1994

Non-Hodgkin's lymphomas with chromosomal translocations involving 3q27 band and immunoglobulin gene loci: report of two cases.

Two cases of non-Hodgkin's lymphoma (NHL) of B-cell origin with reciprocal chromosome translocations involving the 3q27 band and loci for the immunoglobulin genes are described. In case 1, [t(3;14)(q27;q32)], the 14q32 band for the immunoglobulin heavy chain gene was involved, and in case 2, [t(3;22)(q27;q11)], the reciprocal breakpoint was the 22q11 band where the immunoglobulin lambda light chain gene is located. Although the two patients shared some clinical features, the lymphomas varied in histologic phenotypes; in case 1, the lymphoma being a diffuse large cell subtype, whereas in case 2, the lymphoma being the high grade small noncleaved cell lymphoma. Thus, the consistent association of the 3q27 translocation with a specific subtype of NHL remains to be determined. Southern blot analysis of the lymphoma cells from the two patients showed rearrangements and deletions in immunoglobulin genes with features which cannot be explained by normal immunoglobulin-generating mechanisms and which suggest that the translocations involved these loci at the molecular level. Cloning of the breakpoint using DNA probes from the immunoglobulin genes would prove a novel oncogene at the 3q27 band.

Adult↗
PubMed1994

A case of superficial epithelioma with sebaceous differentiation.

Superficial epithelioma with sebaceous differentiation developed on the left cheek of a 58-year-old man over a three-year period. Biopsy of the lesion demonstrated plate-like lobules of basophilic basaloid cells with broad attachments to the overlying epidermis. Clusters of or solitary sebaceous cells were present within the lobules. Three tumor types were considered; a subtype of sebaceoma growing in the epidermis, an acanthotic seborrheic keratosis subtype with sebaceous differentiation, or a tumor of the follicular infundibulum with sebaceous differentiation.

Aged↗
PubMed1994

Simple and efficient procedure for removing the 34 kDa allergenic soybean protein, Gly m I, from defatted soy milk.

The 34 kDa protein in the salted-out fraction of soy milk is shown to be identical to the allergenic soybean protein, Gly m I, by N-terminal amino acid sequencing and immunoblotting, using the monoclonal antibody against Gly m I. Treatment of soy milk with 1 M Na2SO4, acidifying to pH 4.5 and centrifugation removed more than 90% of the 34 kDa protein with an overall yield of 70% of total soy protein.

Allergens↗
PubMed1994

Extrathymic differentiation of a T cell bearing invariant V alpha 14J alpha 281 TCR.

We found that a homogenous CD4-/CD8- T cell bearing an invariant TCR encoded by V alpha 14J alpha 281 with a one-base N-region is highly dominant in the periphery (2-3% in spleen). Surprisingly, the high expression of this invariant V alpha 14 TCR is a general phenomenon in all laboratory strains irrespective of MHC haplotype and in some wild mouse subspecies. The majority of V alpha 14+ TCR is associated with J alpha other than J alpha 281 during the neonatal stage, after which the frequency of invariant V alpha 14J alpha 281 TCR expression increases with time reaching a maximum at around 5-8 weeks after birth. The dominant expression of V alpha 14J alpha 281 TCR is found in both euthymic and athymic mice. These results indicate that homogenous V alpha 14J alpha 281 T cells are positively selected in the periphery without thymic influence and that their VJ junction is important for positive selection. We also demonstrate that V alpha 14+ TCR gene rearrangements take place at extrathymic sites, such as bone marrow, liver, and intestine, since frequent nonproductive V alpha 14 TCR products and V alpha 14-J alpha 281 gene mediated signal sequences in circular DNA are detected as a result of TCR rearrangements in extrathymic tissues rather than in the thymus. This indicates the extrathymic development of V alpha 14J alpha 281 T cells. Furthermore, the biological roles of homogenous T cells bearing V alpha 14J alpha 281 TCR and the human counterpart of this invariant TCR are also discussed.

Amino Acid Sequence↗
PubMed1994

Sensitization to cockroach allergens of asthma patients in Japan.

To evaluate the role of allergens from Periplaneta fuliginosa, which is the most predominant cockroach species in homes in Tokyo areas, for asthma sensitization, we measured specific IgE antibodies to two cockroaches, P. fuliginosa and Blattella germanica, and to a mite, Dermatophagoides farinae, in 171 sera from children with asthma by Pharmacia's CAP system. We found that 16% of the sera had anti-P. fuliginosa IgE, whereas 9.9% had anti-B. germanica and 85% anti-D. farinae IgE. Further, we measured the levels of Per f I (Per a I equivalent) allergen in the house dust from living room, kitchen and bedding. We detected the allergen in eight of ten homes. The Per a I equivalent levels in kitchen were higher than in other sites, but they were much lower than Der I and Der II as Dermatophagoides allergens.

Allergens↗
PubMed1994

Involvement of the BCL3 gene in two patients with chronic lymphocytic leukemia.

The t(14;19)(q32;q13) is a recurring translocation found in some patients with chronic lymphocytic leukemia (CLL), and the t(14;19) juxtaposes the BCL3 gene on chromosome 19 with the immunoglobulin heavy chain gene (IGH) locus on chromosome 14. Genomic DNAs from 49 patients with chronic B-cell leukemia and the related lymphomas were examined by Southern blot hybridization using 2 separate probes, named p alpha 1.4P and p alpha .5B, from the BCL3 gene locus. None of the 18 patients with leukemic manifestations of non-Hodgkin's lymphomas had detectable BCL3 rearrangements. Of 31 patients with CLL, 2 had the BCL3 rearrangements. A comigration study using the C alpha and C epsilon constant gene probe from IGH indicated that the t(14;19) translocation occurred in these 2 patients, and they were diagnosed with CLL/prolymphocytic (PL) according to the French-American-British (FAB) classification. Probes for the IGH locus revealed that leukemia cells of the 2 patients each were clonal, indicating that both small lymphocytes and prolymphocytoid cells found in the peripheral blood of one patient had the t(14;19), as well as a major population of the small lymphocytes in the peripheral blood of a second patient. It thus appears that tumor cells carrying the t(14;19) constitute a distinct disease entity in a group of chronic B-cell leukemia, that has a converting potential to more aggressive forms.

Aged↗
PubMed1994

Non-invasive Doppler technique for detection of flow velocity in left internal mammary artery grafts.

The capability of Doppler to detect patency of left internal mammary artery grafts through the supraclavicular approach was evaluated. A total of 37 patients with a left internal mammary artery graft to the left anterior descending artery were divided into three groups, according to postoperative coronary angiographic studies. Group 1 comprised 20 patients with no significant stenosis of the left internal mammary artery and subtotal or total obstruction in the left anterior descending coronary artery proximal to the anastomotic site. There were ten patients with no significant stenosis of the left internal mammary artery and 75% stenosis of the left anterior descending coronary artery in group 2. Seven patients with significant stenosis of the left internal mammary artery formed group 3. Analysis of the flow velocity pattern in the left internal mammary artery graft included: (1) systolic peak velocity (SPV), (2) diastolic peak velocity (DPV), (3) systolic time velocity integral (SI), (4) diastolic time velocity integral (DI), (5) diastolic peak velocity/systolic peak velocity and (6) diastolic time velocity integral/diastolic time velocity integral+systolic time velocity integral. There were no significant differences in systolic peak velocity and systolic time velocity integral between the three groups. The diastolic peak velocity and diastolic time velocity integral were greater in group 1 than in groups 2 (P < 0.05, P < 0.01) and 3 (P < 0.05). The diastolic peak velocity/systolic peak velocity and diastolic time velocity integral/diastolic time velocity integral+systolic time velocity integral ratios in group 3 were significantly smaller than in groups 1 and 2 (P < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Flow Velocity↗