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Biomedical subjects

S Takamoto

Publications and source records attributed to S Takamoto.

At least 199 records · Page 11Linked to original sources
PubMed1994

Negative effects of wild-type p53 and s-Myc on cellular growth and tumorigenicity of glioma cells. Implication of the tumor suppressor genes for gene therapy.

Human (U251, U87, U343) and rat glioma cell lines (C6, 9L) were examined by the reverse transcriptase-polymerase chain reaction and subsequent nucleotide sequencing analysis to see whether they express wild type (wt)-p53 or mutated form (mut)-p53 messages. Results showed that U87, U343, and C6 cells expressed wt-p53 messages whereas U251 and 9L cells expressed mut-p53 messages. All these cell lines were transfected with wt-p53 cDNA or the s-myc gene linked to the mouse mammary tumor virus (MMTV) promoter. Of several G418-resistant clones obtained from each transfection, a few expressed the s-Myc or wt-p53 proteins. Independent of mutations in the intrinsic p53 gene, the cellular growth in vitro and tumorigenicity in nude mice of these clones were drastically suppressed, the extent of suppression being correlated with the expression level of the transfected gene. Flow-cytometric analysis demonstrated that both p53 and s-Myc arrested the cell cycle at the G1/S boundary. These data suggest that these genes having negative effects on tumor cell proliferation could be used in gene therapy of gliomas, which are caused by alteration of the p53 gene or by some other genetic change.

Animals↗
PubMed1994

Spontaneous non-traumatic rupture of the thoracic aorta.

Spontaneous non-traumatic rupture of the aorta is a very rare condition that requires immediate surgery. However, correct preoperative diagnosis is difficult or impossible to establish. We report a case of spontaneous aortic rupture which was successfully treated by emergency surgical exploration following a transesophageal echographic diagnosis of hemopericardium. This case, as well as other reports, suggests that hemopericardium along with symptoms which suggest aortic dissection or rupture (e.g., acute chest or back pain) should raise a strong suspicion of spontaneous aortic rupture even in the absence of intimal flap or aortic dilatation, and the emergency surgery may be life-saving.

Aorta, Thoracic↗
PubMed1994

Retrograde cerebral circulation for distal aortic arch surgery through a left thoracotomy.

We have devised a simple hypothermic retrograde cerebral circulation technique for protecting the brain during aortic arch surgery. The central venous pressure is simply elevated (15 to 18 mmHg) while the aortic arch is open and the descending aorta occluded, causing oxygen-saturated venous blood from the lower half of the body, which is undergoing deep hypothermic (15 degrees C to 18 degrees C) perfusion, to circulate in the brain in a retrograde fashion, supplying it with oxygen. Twenty-six cases of distal aortic arch aneurysm treated using this method, through a left thoracotomy with femoral vein cannulation, were evaluated. Retrograde cerebral circulation time was 59.6 +/- 13.1 minutes (40 to 93 min). Retrograde flow was 43.9 +/- 13.0 (25 to 62) mL/min. Significant oxygen and apparent lactate extraction were noted in the brain. Early death resulted in 3 of the first 14 cases (21.4%) from embolism, and in 1 of the other 12 cases (8.3%) from massive bleeding and multiple organ failure. Only one late death occurred. No death was attributed to the method itself. This method, with its simplified operative procedure using a lateral thoracotomy, supplied oxygen to the brain and protected it during interruption of the cerebral circulation. Careful management of the atherosclerotic aorta is needed.

Aged↗
PubMed1994

Endothelin-1 in cerebrospinal fluid in elderly patients with hypertension and dementia.

Endothelin-1, a potent endothelium-derived vasoconstrictive peptide, is also known to exist in the central nervous system. We determined endothelin-1-like immunoreactivity in cerebrospinal fluid by a radioimmunoassay in 32 normotensive or hypertensive elderly subjects (79 +/- 8 years old) with or without multi-infarction dementia. The mean value of endothelin-1-like immunoreactivity in cerebrospinal fluid was significantly (P < .05) elevated in subjects with essential hypertension (> or = 160/95 mm Hg, n = 5, 79 +/- 9 years old) compared with those with borderline hypertension (140-159/90-94 mm Hg, n = 4, 78 +/- 5 years old) and normotensive subjects (< 140/90 mm Hg, n = 23, 79 +/- 8 years old). The value of endothelin-1-like immunoreactivity in cerebrospinal fluid was significantly (P < .05) positively correlated with both systolic (r = .38) and diastolic (r = .42) blood pressures in all subjects. On the other hand, mean values of endothelin-1-like immunoreactivity in cerebrospinal fluid were also significantly (P < .05) elevated in the groups of patients with multi-infarction dementia that had profoundly decreased Mini-Mental State scores (< or = 10, n = 6) and moderately decreased Mini-Mental State scores (11 to 20, n = 14) compared with those values in subjects with normal cognitive function (score for Mini-Mental State > or = 21, n = 12).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1994

[Complications of marrow harvesting for transplantation].

Seventy-four responses were received from a questionnaire which had been mailed to 91 bone marrow transplantation institutes throughout Japan to assess the activity of bone marrow transplantation and complications in bone marrow donors. A total of 2329 bone marrow harvests, performed from 1688 adult donors and 641 child donors for allogeneic or syngeneic transplantation up to August 1992, were available for study. Analyses of the responses showed slight diversity regarding the marrow harvesting preparation and methods of the different bone marrow programs. The resulting perioperative complications were principally caused by anesthesia: 73 episodes of hypotension including one death 18 months later, seven of arrhythmia, one of respiratory arrest, three of mental confusion, one of asthma, one of malignant hyperthermia, one tooth injury and one broken aspiration needle. The postoperative complications were chiefly caused by marrow aspiration per se: 731 episodes of transient fever, 26 of long-lasting pain or discomfort, 10 episodes of liver dysfunction including two cases of non-A, non-B hepatitis, four cases of infection, one episode of hypotension, one of dysuria and one case of keloid formation. The study further revealed that the frequency of complications was lower in child donors than in adult donors.

Adolescent↗
PubMed1994

Treatment of pure red cell aplasia after major ABO-incompatible bone marrow transplantation resistant to erythropoietin. Bone Marrow Transplantation Team.

A case of pure red cell aplasia after major ABO-incompatible bone marrow transplantation with long duration of up to 482 days is presented. The patient exhibited resistance to treatment using intravenous gamma globulin, prednisolone and 8 week administration of erythropoietin. The patient finally responded to treatment using erythropoietin and methylprednisolone simultaneously. Because of its safety and efficacy, it might be worthwhile to try erythropoietin with methylprednisolone, if necessary, for pure red cell aplasia complicating major ABO-incompatible bone marrow transplantation.

ABO Blood-Group System↗
PubMed1993

Distal aortic arch aneurysmectomy and coronary revascularization through a left thoracotomy.

A successful single operation of a distal aortic arch aneurysm and coronary artery disease through a left lateral thoracotomy using a simple hypothermic retrograde cerebral perfusion technique for cerebral protection in a 64-year-old man is reported. During ventricular fibrillation accompanying cooling to 15 degrees C, a left internal thoracic artery was anastomosed with the left anterior descending coronary artery, and the aneurysm was replaced with a patch during hypothermic retrograde cerebral perfusion.

Aorta, Thoracic↗
PubMed1993

Reduction of reperfusion injury by recombinant human superoxide dismutase administered intravenously just prior to reperfusion.

The reduction of reperfusion injury by intravenous administration of recombinant human superoxide dismutase (r-hSOD) was evaluated in a dog model. Two hours of left anterior coronary artery clamping were followed by 30 min of partial reperfusion and 30 min of full reperfusion. In the SOD group, r-hSOD (100,000 U/kg) was given intravenously 5 min before reperfusion. Measured left ventricular (LV) segments were classified thermographically by temperature drop into central (> or = 2 degrees C) and marginal (< 2 degrees C) areas. The regional LV functions were evaluated by percentages of both segmental (%SS) and active (%AS) shortening. In the central area, the %SS values after reperfusion were -9% in the control group and -3% in the SOD group (p < 0.05). The respective %AS values were 6 and 29% (p < 0.01). In the marginal area, both groups had %SS values of -3% and respective %AS values of 34 and 22% (all not significant) after reperfusion. In the central area, there was significantly better LV function recovery in the SOD group than in the control group.

Animals↗
PubMed1993

[Two elderly cases of megacolon associated with cerebral infarction and diabetes mellitus].

The authors experienced two elderly patients of megacolon associated with cerebral infarction and diabetes mellitus. The first patient was a 66-year-old female who was admitted to our hospital for rehabilitation with a complaint of knee pain. She had suffered from diabetes mellitus since she was 30 years old and multiple cerebral infarction since age 62. Two months after admission, she had an episode of abdominal distension and obstructive symptoms. The roentgenograms of her abdomen showed diffuse dilatation of the colon. The second patient was a 78-year-old female admitted to our hospital with complaints of abdominal pain, distension of the abdomen and vomiting. Her abdomen was severely distended and plain roentgenograms of the abdomen, X-ray studies of the colon with the aid of contrast medium and CT scan of the abdomen showed striking dilatation of the colon. Megacolon may be congenital or acquired, and in acquired forms the conditions are secondary to organic diseases, smooth muscle atrophy, metabolic and neurological diseases, ulcerative colitis or psychogenic origin (idiopathic). The two patients in this series were suffered from cerebral infarction and diabetes mellitus. The mechanisms of megacolon seen in these two patients are not known, but involvement of the visceral autonomic innervation is presumed. Some elderly patients have chronic constipation, and dilatation of the colon may not be uncommon due to underlying diseases or drugs. Therefore, when examining elderly patients, careful attention should be paid to their bowel movement.

Aged↗
PubMed1992

Effect of ipriflavone on bone mineral density and calcium-related factors in elderly females.

The effects of ipriflavone (7-isopropoxy-3-phenyl-4H-1-benzopyran-4-one) on bone mineral density (BMD) of the 3rd lumbar vertebra and on calcium (Ca)-related factors, including serum calcitonin (CT) levels before and after rapid calcium infusion (4 mg/kg for 5 minutes), were studied in 11 elderly female subjects (80 +/- 2 years of age, mean +/- SE). Ipriflavone (IP) administration (600 mg/day, 7 months) resulted in inhibition of BMD loss in 7 patients (responders, mean change of BMD value 2.2 +/- 2.3%), whereas 4 patients showed a loss of BMD (nonresponders, mean change of BMD value -13.1 +/- 2.6%) compared with pretreatment values. The responder group showed a significant increase in mean pretreatment serum CT levels (from 20 +/- 2 pg/ml to 42 +/- 7 pg/ml, P < 0.05) after treatment with IP, and a significant decrease in the mean basal serum level of corrected Ca (from 9.6 +/- 0.2 mg/dl to 8.7 +/- 0.1 mg/dl, P < 0.01) after treatment with IP; nonresponders did not show these changes. For responders, both the percentage of change and the maximal value of serum CT in response to Ca infusion were maintained at rather high levels, both before and after IP treatment; nonresponders showed almost no response to a stimulation test for CT. These findings suggest that IP inhibits bone loss in elderly female subjects possibly through the mechanism of increasing CT secretion.

Aged↗
PubMed1992

Transfusion-associated graft-versus-host disease in a presumably immunocompetent patient after transfusion of stored packed red cells.

A 54-year-old woman developed transfusion-associated graft-versus-host disease (TA-GVHD) after the transfusion of stored packed red cells obtained from unrelated donors. The patient was presumed to be immunocompetent. A diagnosis of TA-GVHD was made by clinical features and postmortem pathologic findings. Sex chromatin analysis of the patient's lymphocytes demonstrated chimerism. HLA typing of the blood donors revealed one to be HLA-homozygous for one of the patient's HLA haplotypes (A33-B44-Cblank). This case illustrates the risk in the general patient population of TA-GVHD after routine blood transfusion therapy. Workers should be aware of this possibility and should continue searching for an efficient way to prevent it.

Blood Component Transfusion↗
PubMed1992

[Flow cytometric analysis of DNA aneuploidy in adrenal tumors].

Nuclear DNA content of paraffin-embedded tissue from 38 adrenal neoplasms and 9 histologically normal adrenal glands was analyzed using flow cytometry. Histological diagnosis of thirty-eight adrenal neoplasms were 3 adrenocortical carcinomas, 20 adrenocortical adenomas and 15 pheochromocytomas. In 33 cases (87%) of the 38 tumors the determination of DNA ploidy was possible. All 9 control specimens showed DNA diploid pattern in DNA histogram. In adrenocortical neoplasms the incidence of DNA aneuploidy was 0% (0 of 17) in adenomas and 100% (2 of 2) in carcinomas. All 17 adrenocortical adenomas which showed DNA diploid pattern are clinically benign. On the other hand, both 2 cases of adrenocortical carcinoma which showed DNA aneuploidy died within 1 year. These data suggest that DNA aneuploidy may be useful as a prognostic factor in adrenocortical neoplasm. With regard to pheochromocytoma, DNA aneuploidy was detected in 4 of 14 patients (29%). However, all 14 cases were clinically benign. In pheochromocytoma DNA aneuploidy was not found to be correlated with prognosis.

Adenoma↗
PubMed1992

Simple hypothermic retrograde cerebral perfusion during aortic arch replacement. A preliminary report on two successful cases.

We recently found that hypothermic retrograde cerebral perfusion can be performed by simply elevating the central venous pressure in Trendelenburg's position while the aortic arch is open. In this technique, with an occlusion balloon in the descending aorta, deep hypothermic perfusion of the lower half of the body is performed as oxygen-rich venous blood supplies the brain. Two successful cases are reported: one of dissecting aortic aneurysm, DeBakey type II, with a true aortic arch aneurysm, in a 53-year-old woman, and one of acute aortic dissection, DeBakey type I, in a 53-year-old man. With the brain under retrograde perfusion at a rectal temperature of 15 degrees C and a central venous pressure of 15 mm Hg, replacement of the ascending to the descending aorta in the former case and to the proximal aortic arch in the latter case was successful. Cerebral circulatory arrest times were 81 and 65 minutes, respectively. No neurologic deficit was found postoperatively. It is suggested that this simple technique protected the brain for a long period of cerebral circulatory arrest during the aortic arch operation by supplying it with oxygen and simplifying the operative procedure.

Aorta, Thoracic↗
PubMed1992

Outcome of Stanford type B acute aortic dissection.

BACKGROUND: The optimal timing of surgery in patients with Stanford type B aortic dissection remains controversial. This report reviews retrospectively early and long-term outcomes of patients with Stanford type B acute aortic dissections at our institute. METHODS AND RESULTS: From April 1979 through January 1991, 75 patients were diagnosed with Stanford type B aortic dissection, and 58 of them were hospitalized within 2 weeks from onset. They were treated initially as follows: emergent surgery was performed in 13 patients for rupture or impending rupture, and the remaining 45 were treated medically. In the former group, nine patients (69%) died; in the latter, eight (18%) needed surgery because of enlargement or rupture of the aneurysm in the follow-up period, and only one of these (13%) died. Of the other 37 patients treated medically, three (8%) died within 2 weeks and seven died (19%) in the chronic phase, four of them from rupture. Among 42 discharged patients initially treated medically, rupture occurred in 11.9% (five of 42). CONCLUSIONS: In acute-phase cases, surgical mortality is so high that medical treatment is preferable unless there are major complications. However, even in patients who had undergone successful initial medical treatment, expansion of the aneurysm, requiring surgery, often occurred. If careful observation reveals any sign of expansion, because elective surgery can be performed at low risk, it should be considered as soon as possible before a rupture develops.

Actuarial Analysis↗
PubMed1992

[DNA ploidy pattern as an indicator of degree of malignancy and prognosis in gastric cancer].

We used fresh materials and paraffin blocks of advanced gastric cancer to examine the relationship of DNA ploidy pattern from flow cytometry (FCM) to degree of malignancy and prognosis. No significant relationship was found between the frequency of DNA aneuploid (DA) and the clinicopathological factors (depth of invasion, degree of progression, histological type, lymph node metastasis, ly, v etc.). FCM examination using fresh materials revealed significant difference in prognosis between the non-DA and DA groups for non-curative stage III or IV cases (p < 0.05). On the other hand, in terms of the relationship between DNA ploidy patterns from paraffin blocks and prognosis for curative resection cases of ss-gastric cancer, prognosis was significantly better in the non-DA group than in the DA (p < 0.01). These results indicate that the clinicopathological prognostic factors for gastric cancer are connected in a complex way and that DNA ploidy patterns alone are not superior to the prognosis determining factors used in the past.

Aged↗
PubMed1992

[Simultaneous analysis of c-myc protein expression and cell cycle with monoclonal antibody and flow cytometry].

C-myc protein plays an important role in the regulation of cell proliferation and differentiation. In this paper, c-myc protein and DNA were doubly stained and analysed simultaneously with flow cytometry (FCM). At first, three fixatives, ethanol, methanol and paraformaldehyde, were examined using HL-60 cells, among which 50% ethanol was found to be optimal for each staining. After fixation, the cells were stained with a monoclonal antibody against c-myc protein, followed by DNA staining with PI. Simultaneous analysis demonstrated that c-myc protein was constantly expressed through the cell cycle and that the protein amount at the G2 + M phases was 1.5 times higher than that at the G1 phase. Further, the differentiation study with TPA and RA revealed that the growth, S phase and also c-myc protein expression were suppressed during the differentiation.

Cell Cycle↗
PubMed1992

Intraoperative echocardiography for diagnosis and treatment of aortic dissection. Utility of color flow mapping for surgical decision making in acute stage.

In the past eight years until July 1992, 92 patients were admitted in the acute state of aortic dissection within two weeks from the onset of symptoms. 41 were diagnosed as Stanford type A and 51 were type B by transthoracic and transesophageal echography, computer tomography, and surgery. Sensitivity of transesophageal echography to detect the intimal flap and the false lumen was 97.6% in patients with Stanford type A and 100% in patients with Stanford type B. The surgical decision making has been mostly depending on the transesophageal echographic diagnosis. When the intimal flap was detected in the ascending aorta (Stanford type A) surgery was performed in emergency regardless of any evidence of rupture, cardiac tamponade, and severe aortic regurgitation. When the aortic dissection was detected only in the descending aorta (Stanford type B) the main course of therapeutic strategy in our institute was medical treatment. Surgery was performed on 37 patients of type A and nine patients of type B with mortality of 18.9% and 55.5% respectively. Four patients of type A and 42 patients of type B were treated medically with a mortality of 75.0% and 2.2% respectively. The relatively large leakages from the anastomosis of the aortic clamp site were repaired secondarily in two patients, and fenestration of the superior mesenteric artery was performed on one patient due to ischemia of the small intestine depending on the intraoperative direct scanning of color flow mapping. Coronary artery involvement of dissection was strongly suspected in two patients by intraoperative transesophageal echography and aortocoronary bypass grafting was performed on these patients. Perfusion problems was encountered in five of 37 patients with type A aortic dissection (13.5%) during cardiopulmonary bypass. Intraoperative transesophageal echography could clearly detect the hemodynamic changes in the descending aorta resulting from inadequate perfusion which was useful for the management of perfusion control during cardiopulmonary bypass. Secondary repair of the aortic arch was required due to ischemia of the aortic arch vessels in two patients after the primary surgery. The extension of the dissection into the aortic arch vessels can be promptly diagnosed with the combination of transesophageal echography and transcutaneous echography. In conclusion, transesophageal Doppler echography is the most rapid diagnostic tool for decision making in acute aortic dissection, and intraoperative transesophageal echo can provide useful information to resolve the perfusion difficulties during cardiopulmonary bypass.(ABSTRACT TRUNCATED AT 400 WORDS)

Acute Disease↗