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Biomedical subjects

R Yamamoto

Publications and source records attributed to R Yamamoto.

At least 91 records · Page 5Linked to original sources
PubMed2000

Prognostic significance of serum soluble interleukin-2 receptor level in non-Hodgkin's lymphoma: a single center study in Japan.

Interleukin 2 receptor is expressed not only on the surface of activated T or B lymphocytes, but also on certain lymphoid malignancies. The receptor is released from the cell membrane as soluble form (sIL-2R). Serum sIL-2R level is a sensitive and quantitative marker of circulating peripheral blood mononuclear cell activation or specific tumor cell growth including non-Hodgkin's lymphoma (NHL). However, the relevance of serum sIL-2R levels relating to clinical outcome in adult patients with NHL remains uncertain. Therefore, we investigated the serial serum sIL-2R levels in 28 untreated patients with NHL to evaluate its correlation with clinical characteristics. High serum sIL-2R level (>1000 U/ml) at diagnosis was associated with a high incidence of treatment failure (p=0.03) and poor overall survival (p=0.057). The serum sIL-2R levels decreased significantly after achieving complete remission (p=0.003). Further larger studies are required to evaluate whether serum sIL-2R level is an independent prognostic factor or not. However, adding this parameter to those already employed in the International Prognostic Index would perhaps provide a better prognostic index for adult patients with NHL.

Adult↗
PubMed2000

Treatment of deep vein thrombosis using temporary vena caval filters after allogeneic bone marrow transplantation.

Bone marrow transplant (BMT) recipients have risk factors for deep vein thrombosis (DVT) including venous stasis caused by immobilization in the sterile unit, vessel wall damage caused by preparative regimen or indwelling catheters, and hypercoagulability caused by decreased natural anticoagulants. We successfully treated a patient who developed massive DVT in the superior vena cava after BMT with anticoagulation and the use of temporary vena caval filters. Considering the delayed complications, permanent filter is not appropriate for BMT recipients, because the risk factors for DVT associated with BMT are transient. We considered that temporary vena caval filter is a safe and useful device to prevent pulmonary embolism after DVT in BMT recipients.

Anticoagulants↗
PubMed2000

Pyogenic granuloma of the tongue early after allogeneic bone marrow transplantation for multiple myeloma.

Oral complications occur frequently after bone marrow transplantation (BMT). Some of them are caused by regimen-related toxicity of the preparative regimen, and others by infections. In addition, oral tissues are targets of graft-versus-host disease (GVHD). Oral granulomatous lesions are not a common complication after BMT, and are especially rare on the tongue. Such rare lesions reported in the literature, developed late after BMT with oral chronic GVHD. We present here a patient who developed pyogenic granuloma of the tongue early after allogeneic BMT done for multiple myeloma. Regimen-related mucositis, oral acute GVHD, the administration of cyclosporine A, and the preexisting macroglossia might be responsible for the formation of granuloma.

Bone Marrow Transplantation↗
PubMed2000

Prognostic significance of serous and clear cell adenocarcinoma in surgically staged endometrial carcinoma.

BACKGROUND: The serous adenocarcinoma (SA) and clear cell adenocarcinoma (CCA) of endometrium have been shown to be associated with high relapse rate and poor survival. It is not clear whether prognostic significance of these specific cell types of tumor is independent of retroperitoneal lymph node metastasis and other histopathologic prognostic factors in endometrial carcinoma. METHODS: We examined 240 consecutive patients with clinical stage I to stage III endometrial carcinoma who were treated prospectively with radical surgery and/or platinum-based chemotherapy. Surgery included extended hysterectomy, bilateral salpingo-oophorectomy, and systematic pelvic and paraaortic lymph node dissection. Prognostic significance of various histopathologic factors was determined by Cox regression analysis. RESULTS: SA/CCA were more frequently associated with deep myometrial invasion, high nuclear grade (G3), lymph-vascular space invasion (LVSI), and pelvic lymph node metastasis when compared to endometrioid adenocarcinoma (EMA). Of 216 clinically staged stage I or II disease, seven of 12 cases of SA/CCA had extrauterine disease. This incidence was much higher than that for EMA (46/204) (p<0.01). A multivariate Cox regression analysis revealed that cell type, grade, LVSI, and paraaortic node metastasis (PANM) were independent prognosticators. CONCLUSIONS: Prognosis of patients with endometrial carcinoma depends on cell type, grade, LVSI, and PANM. Poor prognosis for patients with SA/CCA is independent of lymph node metastasis and other histopathologic prognostic factors. The SA/CCA should be strictly discriminated from EMA.

Adenocarcinoma, Clear Cell↗
PubMed2000

Effects of docarpamine on hemodynamics after open heart surgery in children.

Docarpamine is a dopamine prodrug which has been selected from a large number of dopamine derivatives in order to develop an orally effective dopamine. The pharmacokinetics after oral administration of docarpamine have not yet been studied in children undergoing open heart surgery. This study examined the effects of docarpamine on hemodynamics and evaluated its safety in 11 children undergoing open heart surgery for congenital heart disease. This study began when the patientOs postoperative condition was stabilized by continuous dopamine infusion into the vein at a rate of 5 micro g/kg/min. The patients were administered 40 mg/kg of docarpamine every 8 hours, and hemodynamics were measured every 4 hours for 16 hours after the initial docarpamine administration. Immediately after the initial docarpamine administration, the dose of dopamine was reduced to 3 micro g/kg/min. Infusion of dopamine was stopped 8 hours after the initial docarpamine administration. Systemic systolic and diastolic blood pressure and heart rate showed no significant changes. Mean right atrial pressure decreased 4 hours after docarpamine administration. Mixed venous oxygen saturation and mean velocity of circumferential fiber shortening increased significantly after docarpamine administration. No significant changes were observed in urine volume. All patients could be weaned from dopamine within 8 hours. No changes were observed in ECG, and no arrhythmia-inducing action was noted. Our study indicates that 40 mg/kg oral doses of docarpamine produce plasma dopamine concentration equivalent to those of a 3 to 5 micro g/kg/min dopamine infusion. Our data suggest that docarpamine is a safe and effective drug for children who have undergone open heart surgery.

Cardiac Surgical Procedures↗
PubMed2000

Computer simulation of osmotic expansion and shrinkage in okra hypocotyl segments.

Okra hypocotyl segments were incubated in solutions of 0.3 or 0.4 M sorbitol at various temperatures and their shrinkage was measured. The result yielded an apparent activation energy for shrinkage of 4.8 kcal/mol, which is close to that of the viscosity of water. This coincidence suggests that the viscosity of water, i.e., the reciprocal function of water conductivity, is a limiting factor for osmotic shrinkage. Abrasion of okra hypocotyl segments with Carborundum substantially increased the rate of their osmotic shrinkage, indicating that the cuticle is the major barrier to water uptake by segments. The apparent activation energy for osmotic shrinkage was 4.5 kcal/mol in abraded segments. By introducing water conductivity into an algorithm, osmotic shrinkage and expansion of hypocotyl segments was successfully predicted by computation with this algorithm. Hence the extent of the contribution of water conductivity in osmotic shrinkage and expansion can be evaluated. Based on this simulation, water conductivity was identified as one of the major factors in governing the elongation growth rate of cells along with the osmotic pressure of the cell sap and the mechanical properties of the cell wall.

Cell Size↗
PubMed2000

Prevention of lymphocyst formation following systematic lymphadenectomy.

BACKGROUND: The occurrence of pelvic lymphocysts is an important complication following systematic lymphadenectomy for gynecological malignancies. We employed a procedure to prevent vaginal shortening following radical hysterectomy and we examined whether this procedure could be effective in preventing pelvic lymphocyst formation. METHODS: We studied the incidence of lymphocysts in 190 patients with 84 cervical cancers, 74 endometrial cancers and 32 ovarian cancers, using computed tomographic examination at 3 and 6 months subsequent to the surgery. The surgery included radical hysterectomy and a procedure to prevent vaginal shortening (101), modified radical hysterectomy (79) and simple hysterectomy (7), with systematic lymphadenectomy. RESULTS: There was a significant difference in the incidence of pelvic lymphocysts between cervical cancer (4.8%) and ovarian cancer (18.8%). The postoperative incidence of lymphocyst formation in patients undergoing radical hysterectomy with the procedure to prevent vaginal shortening (5.9%) was significantly lower than in those who underwent modified radical hysterectomy (15.2%). CONCLUSION: Our procedure to prevent vaginal shortening could be effective in preventing not only the shortening of the vagina but also the occurrence of pelvic lymphocysts in patients undergoing radical hysterectomy with systematic lymphadenectomy for gynecological malignancies.

Adolescent↗
PubMed2000

[Thoracoscopic pleural biopsy under local anesthesia using a 2 mm laparoscope].

Thoracoscopy is indicated in patients with undiagnosed effusion after conventional methods. It has been usually performed under general anesthesia or using a thoracoscope with a thoracoscope with a diameter over 5 mm. However, it is an invasive diagnostic technique. We evaluated the feasibility of thoracoscopic pleural biopsy under local anesthesia using a 2 mm laparoscope. Six patients with a pleural effusion of unknown etiology after conventional methods, underwent thoracoscopy under local anesthesia. A 2 mm laparoscope and biopsy forceps (2 mm Minisite, United States Surgical Corp., USA) was used in all patients. Pleural fluid was removed, and the thoracic cavity was inspected. Thoracoscopic intercostal blocks were performed with 1% lidocaine, and then a biopsy was performed. The biopsy specimen was sent for histopathology. Three patients were shown to have carcinomatous pleurisy, two of them with localized lesions less than 10 mm. In the remaining three patients, non-specific diagnoses were made, but long-term follow-up revealed no malignant pleural disease. Although the pictures obtained using a 2 mm laparoscope were inferior in quality, they were adequate for the detection of malignant lesions in the pleural cavity. There were no procedure-related complications. These findings suggest that thoracoscopy using a 2 mm laparoscope is (1) a useful diagnostic tool in cases of pleural malignancy; (2) a minimally invasive method with the advantage of being easily performed under local anesthesia. Thus, thoracoscopic pleural biopsy using a 2 mm laparoscope appears to be useful for undiagnosed pleural effusion.

Anesthesia, Local↗
PubMed2000

Effect of intestinal helminthiasis on nutritional status of schoolchildren.

This study was conducted in a rural agricultural area in Siniloan, Republic of the Philippines. The subjects were the school children. The nutritional status of 58 children infected with helminthiasis (Ascaris lumbricoides and Trichuris trichiura) was compared with that of 19 uninfected controls. Prevalence of Ascaris and Trichuris was 40.3% and 71.4% respectively, and 36.4% of infected children had both Ascaris and Trichuris infections. Statistically significant evidence of an adverse effect of helminthiasis on serum albumin levels was found, but no child had inadequate levels of other nutrients. Although helminthic infections increase the level of immunoglobulin E (IgE) in children endemically exposed to these parasites, there was no significant difference in the serum IgE among Ascaris or Trichuris infected groups in this study.

Adolescent↗
PubMed1999

Telomerase activity correlates with histo-pathological factors in uterine endometrial carcinoma.

Telomerase activity has been implicated in the progression of various human tumors. Our aim was to evaluate telomerase activity and to compare it with histo-pathological factors in uterine endometrial carcinoma, to look for possible correlations. Telomerase activity was measured by dilution analysis using a PCR-based telomeric repeat amplification method and detected in 31 of 35 primary endometrial carcinoma tumor specimens. High telomerase activity, detected after 100-fold dilution of extracts, was identified in 15 specimens. There was no significant correlation between the positive telomerase activity and tumor surgical stage or histo-pathological factors. However, high telomerase activity was significantly correlated with advanced surgical stage and with pelvic lymph node metastasis. Our findings suggest that an increase in telomerase activity may be associated with tumor progression and that its level may have a prognostic value in endometrial carcinoma.

Adult↗
PubMed1999

Mutagenicity of 4-nitroquinoline 1-oxide in the MutaMouse.

As part of a collaborative study, the Mammalian Mutagenesis Study Group (MMS), a sub-organization of the Environmental Mutagen Society of Japan (JEMS) conducted mutagenicity tests in MutaMouse. Using a positive selection method, we studied the organ-specificity and time dependence of mutation induction by 4-nitroquinoline 1-oxide (4NQO). A single dose of 4NQO was administered intraperitoneally (7.5 or 15 mg/kg) or orally (200 mg/kg) to groups of male mice. On days 7, 14 and 28 after treatment, we isolated the liver, kidney, lung, spleen, bone marrow, testis and stomach in the intraperitoneal administration experiment and the liver, lung, bone marrow, testis and stomach in the oral administration experiment. In addition, we performed the peripheral blood micronucleus test to evaluate clastogenicity. In the mice treated intraperitoneally at 7.5 mg/kg, we found increased mutant frequency (MF) only in the lung, where the MF did not vary with expression time. In the mice treated at 15 mg/kg, we found increased MF in the liver, bone marrow and lung. In orally treated mice, the MF was high in the lung and liver and very high in the bone marrow and stomach while the increase in the testis was negligible. As the expression time was prolonged, the MF tended to increase in the liver, decrease in the bone marrow, and remain stable in the lung, testis and stomach. The incidence of micronucleus induction in peripheral blood cells was significantly increased (p<0.01) in the 4NQO groups when compared with the vehicle control group by intraperitoneal treatment. Thus, these assay systems appeared to be of use in detecting not only genetic mutation but also chromosomal aberration.

4-Nitroquinoline-1-oxide↗
PubMed1999

Ethylnitrosourea-induced mutation and molecular analysis of transgenic mice containing the gpt shuttle vector.

Novel transgenic mice were developed in order to study the in vivo mutagenesis. The transgenic mice carried pCGK shuttle vector, which contained the Escherichia coli gpt gene as a mutational target, the kanamycin-resistant gene (Kanr) and cos region derived from bacteriophage lambda. The shuttle vector can be recovered from the transgenic mouse genome into the gpt-deficient E. coli by an in vitro packaging method and is selectable as a Kanr phenotype. Mutations induced at the gpt gene can be easily detected with a selective agent, 6-thioguanine (6-TG). In the previous study, the pCGK shuttle vector was incorporated into Chinese hamster CHL/IU cells and the resultant transgenic cell line was shown to be a useful system to study in vitro mutagenesis at the gpt gene. Therefore, an advantage of the shuttle vector is that in vivo mutational data obtained from the transgenic mouse can be compared with those of transgenic cell line in vitro. A transgenic CD-1 mouse line, designated as #128, that carried approximately 50 copies of pCGK shuttle vectors, was selected among 4 transgenic mouse lines. To investigate the sensitivity of the #128 line, the transgenic mice were treated with a single intraperitoneal injection of 250 mg/kg of N-ethyl-N-nitrosourea (ENU) or with 50 mg kg-1 day-1 of ENU for 5 consecutive days, and bone marrow, spleen and liver were dissected to investigate their mutational responses. The background mutant frequency was between 18x10(-6) and 75x10(-6) among all tissues tested. ENU induced significant increases in the mutant frequency above the background level in all three tissues at 14 days after single or 5-day treatment with the chemical. The increases in the mutant frequencies in bone marrow, spleen and liver were 6.4- to 6.8-fold, 3.0- to 5.6-fold and 3.0- to 3.3-fold, respectively. The shuttle vector DNA was recovered from the bone marrow of both spontaneous and ENU-treated mice and the gpt gene was amplified by polymerase chain reaction. The amplified DNA was subject to DNA sequence analysis. Out of 79 spontaneous and 52 ENU-induced mutants, the gpt gene could be amplified from 28 spontaneous and 46 ENU-induced mutants. DNA sequence analysis showed that predominant mutations were identified as A:T to T:A transversions (22 out of 46 sequenced mutants) and G:C to A:T transitions (9/46) in ENU-induced mutants, whereas G:C to T:A transversions (7 out of 28 sequenced mutants) were predominant in spontaneous mutants. These results demonstrate that this transgenic mouse, in combination with the transgenic CHL/IU cell line, is a useful system to study in vivo and in vitro mutational events at the same target gene.

Amino Acid Substitution↗
PubMed1999

Incidence and distribution pattern of pelvic and paraaortic lymph node metastasis in patients with Stages IB, IIA, and IIB cervical carcinoma treated with radical hysterectomy.

BACKGROUND: The incidence and distribution pattern of retroperitoneal lymph node metastasis in patients with cervical carcinoma should be investigated based on data from systematic pelvic lymph node (PLN) and paraaortic lymph node (PAN) dissection, so that a basis can be established for determining the site of selective lymph node dissection or sampling. METHODS: A total of 208 patients with Stages IB, IIA, and IIB cervical carcinoma who underwent radical hysterectomy and systematic pelvic and PAN dissection were investigated for lymph node metastasis and histopathologic risk factors for lymph node metastasis. RESULTS: Fifty-three patients (25.5%) had lymph node metastasis. The obturator lymph nodes were most frequently involved, with a rate of 18.8% (39/208). Forty-nine of 53 node-positive patients had lymph node metastasis in the obturator, internal iliac, or common iliac lymph nodes. Of 26 solitary lymph node metastases confined to one node group, 18 were in the obturator, 3 in the internal iliac, 3 in the parametrial, and 2 in the common iliac lymph nodes. A multiple logistic regression analysis revealed that deep cervical stromal invasion and lymph-vascular space invasion were related to PLN metastasis. It was also shown that metastasis to bilateral PLNs (excluding the common iliac lymph nodes) as well as metastasis to the common iliac lymph nodes were significantly related to PAN metastasis. CONCLUSIONS: The results of this study suggest that the obturator lymph nodes can be sentinel lymph nodes of cervical carcinoma. PAN metastasis appears to occur secondarily to wide-spread PLN metastasis. These results provide a basis for determining the site of selective lymph node dissection and for estimating the existence of PAN metastasis from the pattern of metastasis in PLN in patients with cervical carcinoma.

Adult↗
PubMed1999

Combined catheter embolization and femorofemoral bypass for pseudoaneurysm of the right external iliac artery: report of a case.

Performing direct surgery for postoperative hemorrhage caused by intraperitoneal arterial injury is very difficult. We report herein the case of a 52-year-old woman who developed sudden right lower abdominal pain after numerous laparotomies and radiotherapy for advanced uterine cancer. A diagnosis of pseudoaneurysm of the right external iliac artery was made, and an emergency catheter embolization and femorofemoral bypass was successfully performed under local anesthesia. The patient was able to walk the next day. To the best of our knowledge, this is the first report of such a combined procedure in the literature.

Adenocarcinoma↗
PubMed1999

Growth and development in Arabidopsis thaliana through an entire life cycle under simulated microgravity conditions on a clinostat.

The effects of simulated microgravity conditions produced by a horizontal clinostat on the entire life cycle of Arabidopsis thaliana ecotype Columbia and Landsberg erecta were studied. Horizontal clinorotation affected little germination of seeds, growth and development of rosette leaves and roots during early vegetative growth stage, and the onset of the bolting of inflorescence axis and flower formation in reproductive growth stage, although it suppressed elongation of inflorescence axes. The clinorotation substantially reduced the numbers of siliques and seeds in Landsberg erecta, and completely inhibited seed production in Columbia. Seeds produced in Landsberg erecta on the clinostat were capable of germinating and developing rosette leaves normally on the ground. On the other hand, growth of pin formed mutant (pin/pin) of Arabidopsis ecotype Enkheim, which has a unique structure of inflorescence axis with no flower and extremely low levels of auxin polar transport activity, was inhibited and the seedlings frequently died during vegetative stage on the clinostat. Seed formation and inflorescence growth of the seedlings with normal shape (pin/+ or +/+) were also suppressed on the clinostat. These results suggest that the growth and development of Arabidopsis, especially in reproductive growth stage, is suppressed under simulated microgravity conditions on a clinostat. To complete the life cycle probably seems to be quite difficult, although it is possible in some ecotypes.

Arabidopsis↗
PubMed1999

Itai-itai disease is not associated with polymorphisms of the estrogen receptor alpha gene.

Itai-itai (or ouch-ouch) disease is a syndrome accompanied by bone mineral disorders, and which may be related to oral cadmium exposure. Itai-itai predominantly affects postmenopausal women with a history of multiple childbirths. Recently, it has been reported that polymorphisms of the estrogen receptor alpha (ERalpha) gene are associated with postmenopausal reduction of bone mineral density in Japanese women. However, estrogen receptors have never been studied in itai-itai disease. In this study, we examined the genotypic distributions of PvuII and XbaI restriction fragment length polymorphisms (RFLPs) of the ERalpha gene in patients with itai-itai disease and compared them with those of control subjects. The RFLPs are represented here as Pp (PvuII) and Xx (XbaI); the capital and small letters signify the absence and presence of restriction sites, respectively. The genotypic distributions of the patient group were: PP, 14.8%; Pp, 55.6%; pp, 29.6%; XX, 7.4%; Xx, 29.6%; and xx, 63.0%. These distributions were similar to those observed for the control groups, hence no pattern of genotypic distribution was observed that could be related to itai-itai disease. We conclude that RFLPs of the ERalpha gene may not be associated with itai-itai disease.

Adult↗
PubMed1999

Auxin polar transport in Arabidopsis under simulated microgravity conditions--relevance to growth and development.

Activity of auxin polar transport in inflorescence axes of Arabidopsis thaliana grown under simulated microgravity conditions was studied in relation to the growth and development. Seeds were germinated and allowed to grow on an agar medium in test tubes on a horizontal clinostat. Horizontal clinostat rotation substantially reduced the growth of inflorescence axes and the productivity of seeds of Arabidopsis thaliana (ecotypes Landsberg erecta and Columbia), although it little affected seed germination, development of rosette leaves and flowering. The activity of auxin polar transport in inflorescence axes decreased when Arabidopsis plants were grown on a horizontal clinostat from germination stage, being ca. 60% of 1 g control. On the other hand, the auxin polar transport in inflorescence axes of Arabidopsis grown in 1 g conditions was not affected when the segments were exposed to various gravistimuli, including 3-dimensional clinorotation, during transport experiments. Pin-formed mutant of Arabidopsis, having a unique structure of the inflorescence axis with no flower and extremely low levels of the activity of auxin polar transport in inflorescence axes and endogenous auxin, did not continue its vegetative growth under clinostat rotation. These facts suggest that the development of the system of auxin polar transport in Arabidopsis is affected by microgravity, resulting in the inhibition of growth and development, especially during reproductive growth.

Arabidopsis↗