PubMed Health⌕ Search

Biomedical subjects

T Shirota

Publications and source records attributed to T Shirota.

At least 37 records · Page 2Linked to original sources
PubMed1999

[Burkitt's lymphoma originating in gluteal muscle tissue].

We report a case of Burkitt's lymphoma originating in gluteal muscle tissue. A 61-year-old Japanese man was admitted to our hospital due to painful swelling of the left femur and gluteal region in October 1996. A laboratory examination disclosed elevated levels of serum lactate dehydrogenase and soluble interleukin 2 receptor. Gallium scintigraphy demonstrated accumulations in the left femur and gluteal region. Magnetic resonance imaging yielded intense signals and disclosed swelling of muscle tissue in the same region. Pathological examination of biopsy specimens from the left femur revealed a starry-sky pattern, and a chromosomal analysis revealed t(2;8)(p11;q24). Heightened concentrations of antibody for Epstein-Barr virus were not detected. Non-African type Burkitt's lymphoma was diagnosed on the basis of these findings. CHOP therapy and irradiation of the affected region were initially effective, but the disease eventually became resistant to treatment. The patient died of cerebral hemorrhage. As far as we know, this is the first report in Japan of Burkitt's lymphoma originating in muscle tissue.

Burkitt Lymphoma↗
PubMed1999

[Clinical effects of combination therapy with cefozopran and tobramycin for severe infections in patients with hematologic diseases].

We studied clinical effect of a combination therapy with cefozopran (CZOP) and tobramycin (TOB) for infections in 80 patients with hematologic diseases in 15 institutes. Combined doses with CZOP 2 g and TOB 60-90 mg twice a day had been given intravenously. Of the 80 patients, 61 patients (42 with acute leukemia, 10 with malignant lymphoma, 3 with aplastic anemia, 2 with chronic myeloid leukemia, 2 with multiple myeloma, and 2 with myelodysplastic syndrome) were evaluable. Those consisted of 6 patients with septicemia, 49 with suspected septicemia, 3 with pneumonia, and 3 with other infections. Clinical efficacy by the treatment was excellent in 24, good in 17, fair in 9, and poor in 11 patients, and the overall efficacy rate including excellent and good was 67.2%. Microbiologically, 5 of the 6 patients with septicemia (1 coagulase negative Staphylococcus, 2 S. pneumoniae, 1 S. oralis, and 1 E. coli) were responded. The efficacy rate in patients with severe granulocytopenia showing 100/microliter or lesser neutrophil counts during the drug administration was 57.1% (12/21). Side effects and abnormal changes of clinical laboratory findings were observed in 5 patients, and 16 patients, respectively, but most of them were mild. The findings above suggested that the combination therapy with CZOP and TOB is useful as an empiric therapy for severe infections in patients with hematologic diseases.

Adult↗
PubMed1999

[Clinical results of mitral valve surgery in children].

The clinical results of mitral valve surgery in children were evaluated. Fifty children (age ranged between 1 month and 12 years) with mitral valve regurgitation have undergone valve surgery with low operative mortality (2%). Valve plasty using several techniques including annuloplasty have been performed with quite high success rate (92%), while valve replacement was required in four patients who had the prolapse of the anterior mitral leaflet (8%). Reoperation was required in 5 patients (10%), and there were 4 late deaths. Introduction of the reconstructive technique of the chordae tendinae using artificial chordae resulted 100% success rate of mitral repair for the prolapse of the anterior mitral leaflet without death and reoperation. The reoperation free rate and the actuarial survival rate at 15 years of the patients with mitral regurgitation were 70 +/- 12% and 85 +/- 7%, respectively. In ten patients with mitral valve stenosis (age ranged between 1 month and 5 years), 5 patients required valve replacement (50%), and 2 patients died (20%). The clinical results of the surgery for the mitral stenosis were still unsatisfactory, and the reoperation free rate at 2 years was 42 +/- 30% and the actuarial survival rate at 13 years were 32 +/- 18%.

Blood Vessel Prosthesis↗
PubMed1999

[Efficacy of intravenous administration of atrial natriuretic peptide after cardiac surgery in neonates and infants].

Intravenous infusion of alpha-human atrial natriuretic polypeptide (hANP) and furosemide was performed in 12 patients (4: TGA, 3: univentricular heart, 3: HLHS, 2: VSD) after cardiopulmonary bypass. Their mean age at the operation was 68 days (6 patients in neonate), the mean body weight was 3.3 kg. All patients were treated with nitroglycerin in dose of 2 micrograms/kg/min and chlorpromazine in dose of 2.8 micrograms/kg/min and catecholamine in mean dose of 6.5 micrograms/kg/min. The criteria of indication for hANP was poor effect of furosemide alone. The hANP was given for 6-144 hours in dose of 0.1-0.2 microgram/kg/min. With the hANP and furosemide infusion, urine volume increased from 85.0 +/- 14.2 ml/kg/day to 107.9 +/- 25.3 ml/kg/day (p < 0.05), whereas the systemic arterial pressure, the central venous pressure and the renal function were unchanged. We conclude that the combination of the hANP and the furosemide is very effective in neonates and infants.

Atrial Natriuretic Factor↗
PubMed1999

Resveratrol has antagonist activity on the aryl hydrocarbon receptor: implications for prevention of dioxin toxicity.

Aryl hydrocarbon receptor (AhR) ligands such as dioxin and benzo[a]pyrene are environmental contaminants with many adverse health effects, including immunosuppression, carcinogenesis, and endothelial cell damage. We show here that a wine component, resveratrol (3,5,4'-trihydroxystilbene), is a competitive antagonist of dioxin and other AhR ligands. Resveratrol promotes AhR translocation to the nucleus and binding to DNA at dioxin-responsive elements but subsequent transactivation does not take place. Resveratrol inhibits the transactivation of several dioxin-inducible genes including cytochrome P-450 1A1 and interleukin-1beta, both ex vivo and in vivo. Resveratrol has adequate potency and nontoxicity to warrant clinical testing as a prophylactic agent against aryl hydrocarbon-induced pathology.

Anticarcinogenic Agents↗
PubMed1998

Effect of coronary bypass grafting onto the site of old myocardial infarction and the recovery of cardiac function.

This study investigated whether or not revascularization to the site of old myocardial infarction can bring beneficial effects on postoperative cardiac function. Thirty-two patients without a history of old myocardial infarction and 71 with a history of old myocardial infarction were included. The mean number of grafts bypassed were 2.7 and 2.8, and the mean duration of aortic clamping was 99 min and 105 min in non-old myocardial infarction and old myocardial infarction patients, respectively. All the patients underwent simple coronary artery bypass grafting electively. The left ventricular stroke work index in non-old myocardial infarction and old myocardial infarction were 40.8 g-m/m2 and 38.9 g-m/m2 preoperatively, and this was recovered to 41.4 g-m/m2 and 38.7 g-m/m2, respectively, at 24 hours after reperfusion (NS). Subgroups of old myocardial infarctions had high ejection fractions of more than 50% (49) and low ejection fractions of less than 50% (22). The left ventricular stroke work index in high and low ejection fractions was 39.7 g-m/m2 and 36.7 g-m/m2 preoperatively (NS). Recovery rates in both high and low ejection fractions were reduced to 74.2% and 84.3% at 3 h after reperfusion (P < 0.001 and P < 0.05 versus preoperative value), but were increased in the low ejection fraction by up to 102.7% and 108.5% at 6 and 12 h after reperfusion, while still remaining reduced in the high ejection fraction at 88.8% and 88.2%, respectively (P < 0.01). At 24 h after reperfusion, left ventricular stroke work index in the low ejection fraction was improved to 44.3 g-m/m2 or 130% of the preoperative value, and the high ejection fraction was 37.5 g-m/m2 or 100% (NS). This showed that a chief cause of reduced cardiac function in the low ejection fraction was mainly reversible myocardial damage or hibernation. Preoperative mean left ventricular ejection fractions in non-old myocardial infarctions and old myocardial infarctions were 73.1% and 55.9%, and these returned to 73.7% (NS) and 61.8% (P < 0.001) at 1 month post-coronary artery bypass grafting. A similar trend towards a significant improvement was shown in both end-diastolic volume indices and end-systolic volume indices of patients with an old myocardial infarction (P < 0.001). Regional wall motion according to AHA classification in patients with old myocardial infarctions was estimated from biplane left ventriculogram as normal, reduced, none, dyskinetic and aneurysmal, and scored as 0, 1, 2, 3 and 4, respectively. Summated scores in old myocardial infarctions was improved from 5.2 to 4.1 after coronary artery bypass grafting (P < 0.05). There was a significant improvement of summated scores from 8.17 to 6.28 in the low ejection fraction (P < 0.05); however, this was not reflected in the high ejection fraction (3.76 to 3.0; NS). The regional wall motion in the old myocardial infarctions that were heart bypassed to the left anterior ascending artery (n = 67) or to the circumflex artery (n = 40) were significantly improved at regions 2 (P < 0.05), 3 (P < 0.05) and 7 (P < 0.05), and that bypassed to right coronary artery (n = 50) was also improved at regions 3 (P < 0.05), 5 (P < 0.05) and 7 (P < 0.001). This shows that augmentation of regional blood flow by coronary artery bypass grafting will contribute to awakening the hibernated myocardium even in the old myocardial infarction.

Case-Control Studies↗
PubMed1997

Cyclic thrombocytopenia in a patient treated with cyclosporine for refractory idiopathic thrombocytopenic purpura.

Cyclic thrombocytopenia (CT) is a rare disorder with cyclic changes of the platelet counts. Though the pathogenesis of this disorder has not been clarified, recent reports suggest that periodic destruction and/or ineffective production of platelets may be important causes of the disease. We report a case of a patient with refractory idiopathic thrombocytopenic purpura (ITP) in whom CT developed after cyclosporine A (CyA) therapy. There was an inverse relation between platelet counts and the serum levels of platelet-associated immunoglobulin G (PAIgG). The ploidy of bone marrow megakaryocytes also had an inverse relation with platelet counts. When the platelet count was low, the ploidy of megakaryocytes increased (P < 0.01). The number and area of bone marrow megakaryocytes were unrelated to platelet counts. These results indicate the possibility of platelet destruction caused by immunological mechanisms in CT. Cyclosporine A could have certain but fluctuating regulatory effects against antibody production for circulating platelets, which could lead to cyclic changes of the platelet counts. This case also suggests that CyA can be effective in severe refractory ITP. Regulatory mechanisms of platelet production and destruction and appropriate doses of CyA should be further studied in autoimmune-mediated thrombocytopenias.

Adult↗
PubMed1997

Tissue reaction around miniplates used for the fixation of vascularized iliac crest bone grafts.

MATERIAL/METHOD: In six miniature pigs revascularized autologous iliac crest bone grafts were fixed with two 2.0 mm titanium miniplates to a defined defect in the angle of the mandible. Tissue reaction around the implants was examined histologically and histomorphometrically at 2, 4, and 8 weeks after surgery. RESULTS: According to the evaluation of fluorescence microradiography, the cortical and medullary circulation and healing processes of bone in the vicinity of the implanted material were not disturbed after 2 weeks. At 4 weeks after surgery osseous healing occurred at the mandibula/graft interface. The histomorphometric results for the calculated percentage of direct bone/screw contact at 2 weeks were 24% with the grafted bone and 53% with the mandible. Intensive bone formation was observed in all parts of the graft by 4 weeks. The results of direct bone/screw. contact at 4 weeks were 56% and 64% and at 8 weeks 75% and 77% for the grafted and the mandibular bone, respectively. CONCLUSION: With 2.0 mm titanium miniplates used in the animal model, stable osteosynthesis and osseous healing was evident after 8 weeks of surgery. In addition, intensive remodeling of the transplanted bone without signs of creeping substitution was noted, and the bone/screw contact of the miniplate system increased with time.

Animals↗
PubMed1997

[BUN, Bence Jones protein, and chromosomal aberrations predict survival in multiple myeloma].

The prognostic significance of of some clinical features in 41 patients with multiple myeloma (including 2 patients with plasma cell leukemia) from our institution was analyzed. Out of 14 variables isolated from the univariate analysis (P < 0.05), only three (BUN, Bence Jones protein, and chromosomal aberrations) were significant in the multivariate model (P < 0.05). Derived from these three variables, three subpopulations of patients were identified. The first group included 20 patients with a low risk of death and their median survival has not been reached. In particular, no one died during the first 60 months in this group. The second group also included 14 patients with an intermediate risk of death and a median survival of 49.2 months. The third group comprised seven patients with a high risk of death during 24 months after diagnosis and a median survival of 31.6 months (P < 0.0001). Finally, Durie & Salmon's myeloma staging system was demonstrated in the present series, and it showed prognostic validity for each stage (P < 0.0222). Compared with Durie & Salmon's staging system, our prognostic model for multiple myeloma was more useful to predict prognosis when applied to the present series.

Adult↗
PubMed1996

Trisomy 10 in acute myeloid leukemia.

We observed two patients with acute myeloid leukemia (AML) exhibiting trisomy 10 as the sole chromosome abnormality at the time of diagnosis. One patient was diagnosed with AML-MO, and the other with AML-M2. Both cases were CD7-antigen positive. However, we could not find any distinct clinico-hematologic characteristics of AML with trisomy 10 in these two patients. Trisomy 10 might be a rare recurring numerical chromosome abnormality and the incidence may be about 0.5% in de novo AML.

Aged↗
PubMed1996

Calcium movement of sarcoplasmic reticulum from hindlimb suspended muscle.

The function of the sarcoplasmic reticulum (SR) was examined in the slow soleus and fast extensor digitorum longus (EDL) muscles of rats submitted to 14 days of weightlessness produced by hindlimb suspension (HS). Ca2+ uptake, Ca2+ release and passive Ca2+ leakage through the SR membrane were investigated using a method of caffeine-induced contracture on the single mechanically skinned fibers. In the SR of suspended soleus muscles, the rate of Ca2+ uptake was higher than in the control muscles. However, there was no difference between the suspended and control muscles in the rate of Ca2+ uptake of the SR in EDL after HS. In soleus muscles, Ca2+ movements of the SR from the suspended muscle acquired the properties that were similar to those of the control fast muscle. The study of Ca2+ leakage showed that the velocity and amount of passive Ca2+ leakage from SR in soleus and EDL were apparently increased after HS. The results suggested that the functional properties of the SR membrane in slow and fast muscles were changed after HS.

Animals↗
PubMed1996

Histologic and microradiologic comparison of block and particulate cancellous bone and marrow grafts in reconstructed mandibles being considered for dental implant placement.

PURPOSE: Patterns of healing were investigated in mandibles reconstructed with three different techniques to assess their readiness for implant placement. PATIENTS AND METHODS: The subjects were 10 patients who had undergone mandibular reconstruction with either nonvascularized iliac block bone grafts (group 1; 3 patients), particulate cancellous bone and marrow (PCBM) grafts (group 2; 3 patients) for mandibular discontinuity, or PCBM grafts for mandibular marginal defects (group 3; 4 patients). Six (groups 2 and 3) or 12 months (group 1) after mandibular reconstruction, bone biopsy specimens were obtained for histologic examination with a trephine bur. As controls, bone specimens were obtained from ungrafted mandibles of patients undergoing dental implant placement. Undecalcified specimens were embedded in polyester resin and examined by routine light microscopy and microradiography. RESULTS: The morphology of the specimens from group 1 was similar to that of group 2, but not to that of the control subjects. However, the morphology of specimens from group 3 was generally similar to that of control subjects. CONCLUSION: These results suggest that mandibular reconstruction with PCBM grafts allows the placement of dental implants sooner than reconstruction with block bone grafts.

Adult↗
PubMed1996

Postoperative function after implant insertion in vascularized bone grafts in maxilla and mandible.

Between 1988 and 1992, 80 Brånemark-type implants were inserted in 18 patients during reconstruction of the mandible or maxilla with vascularized iliac crest or scapula grafts with or without additional soft tissue pedicles. In these procedures, nine vascularized bone grafts were combined with a primary insertion of 32 implants and a secondary insertion of 48 implants. Twelve patients are currently wearing the implant-borne dentures. From 32 implants inserted primarily, eight could not be used for prosthodontic rehabilitation because three were lost with a graft, three were left as sleepers, and two demonstrated a lack of osseointegration. None of the implants inserted secondarily in grafts were lost. Primary implant insertion should be performed only in close cooperation with the prosthodontist and in selected cases, for example, in free-end reconstruction of the mandible with a straight graft and where a limited number of implants is needed. Although restoration of masticatory function in patients with head and neck cancer can be achieved, compared with a healthy control group, functional impairments remain. Patients subjectively favor the nonreconstructed side of the mandible or maxilla for chewing. These findings can be correlated with a postoperative follow-up investigation using a miniature force transducer and the T-scan system.

Denture, Partial↗
PubMed1995

Hyperuricemia in patients with hyperthyroidism due to Graves' disease.

The effects of hyperthyroidism on uric acid metabolism were investigated. First, the serum uric acid level was measured in 92 patients with hyperthyroidism due to Graves' disease, eight patients with subacute thyroiditis, six patients with hypothyroidism, and 70 sex- and age-matched controls. Second, the correlation between serum thyroxine (T4) and serum uric acid was obtained in hyperthyroid Graves' disease patients before and during antithyroid drug therapy. Finally, uric acid clearance (CUA) was determined in untreated patients with hyperthyroidism due to Graves' disease. Serum uric acid was significantly elevated in patients with hyperthyroidism, and the elevation correlated well with serum T4 before treatment as a group and during treatment in each patient. A significant elevation of serum uric acid was not present in patients with a transient mild thyrotoxicosis due to subacute thyroiditis. Serum uric acid was significantly decreased in patients with hypothyroidism. Renal excretion of uric acid clearly increased in hyperthyroid patients, and CUA also increased. The increase in CUA corresponded to the increase in renal plasma flow (RPF), which was measured by p-aminohippuric acid clearance. The fractional excretion of uric acid as determined by CUA/glomerular filtration rate (GFR) was similar and within the normal range in hyperthyroid patients and normal controls. A significant inverse correlation between CUA and serum uric acid concentration was present in hyperthyroid patients as in normal controls, indicating that the renal handling of uric acid in the tubule affected uric acid excretion.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1995

Experimental reconstruction of mandibular defects with vascularized iliac bone grafts.

PURPOSE: The study evaluated the processes of incorporation and bone remodeling after microsurgical transplantation of iliac crest grafts for mandibular defect reconstruction. MATERIALS AND METHODS: A defect in the mandibular angle measuring 2 x 4 x 1 cm was reconstructed in six Göttingen minipigs with a microvascularized iliac bone graft based on the circumflex artery. The animals were killed at 14, 28, and 56 days after transplantation and the healing process was histologically examined. RESULTS: Although a constant vascular supply to the graft was restored by the microvascular reanastomosis, necrosis occurred in the major part of the bone marrow. New bone formation from the graft was markedly delayed compared with that from the mandible. Some osteocytes and marrow survived after grafting, but the volume of iliac bone tended to decrease gradually over time. In the 56-day specimens, the border between the graft and the mandible was not clear. CONCLUSION: These findings indicate that survival of the vascularized iliac bone graft in the minipig is not complete.

Animals↗
PubMed1995

Speech function following maxillectomy reconstructed by rectus abdominis myocutaneous flap.

Post-surgical maxillary defects have recently been reconstructed by microvascularized free flaps. However, few reports have evaluated the resulting speech function. This study compared the speech intelligibility of four maxillectomy patients who underwent reconstruction by rectus abdominis myocutaneous flaps (RAMCF) with that of four non-reconstructed patients who were treated with split-skin grafts and prostheses, to explore ways of achieving better speech function. Speech function was assessed by a Japanese language speech intelligibility test. Intelligibility scores ranged from 57.3% to 75.8% (mean, 70.4%) in the non-reconstructed group and from 66.2% to 77.2% (mean, 71.0%) in the reconstructed group. An analysis of articulatory manners and sites revealed that speech disorders resulted mainly from poor oronasal separation in the non-reconstructed group and from incorrect linguopalatal contact in the reconstructed group, especially for linguodentoalveolar and linguovelar sounds. Therefore, for higher speech function in the reconstructed group, dentoalveolar and palatal contours of the maxilla must be restored as closely as possible. This must also be done in patients whose maxillae are reconstructed by other types of microvascularized myocutaneous or cutaneous flaps that have similar postoperative palatal contours.

Adult↗