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N Yamamoto

Publications and source records attributed to N Yamamoto.

At least 325 records · Page 18Linked to original sources
PubMed1999

[Intra-arterial chemotherapy via reservoir system for advanced bladder cancer and prostate cancer].

A clinical study was performed on the efficacy of intra-arterial chemotherapy using a reservoir system for advanced urological malignancies. The reservoir system was indwelted in the femoral subcutaneous layer by Seldinger's method. Fifteen cases of inoperable complicated advanced bladder cancer and 10 cases of postoperative local recurrent bladder cancer were administered intra-arterial chemotherapy using a reservoir system. Then, 23 cases of local relapsed prostate cancer and two cases of endpocrine-resistant prostate cancer were administered the chemotherapy. The administered anti-cancerous agents were methotraxate, cis-platinum and adriamycin, then 5-FU or carboplatin was administered as maintenance therapy. The mean number of courses of chemotherapy was six for bladder cancer and four for prostate cancer. During stabilization of the local lesion, no distant deterioration was recognized. The overall clinical efficacy was a positive response (PR) and no change (NC): for 18 and 7 cases of bladder cancer, and 11 and 14 cases of prostate cancer, respectively. The median duration of stabilization was 23 months for bladder cancer and 12 months for prostate cancer. The adverse effects were fever than those with systemic chemotherapy.

Adult↗
PubMed1999

[Recurrence of hepatocellular carcinoma after liver resection].

Recurrence of hepatocellular carcinoma after liver resection is usually observed in the remnant liver, and includes metachronous multicentric occurrence and intrahepatic metastasis. In stage I and II, disease-free survival rates of clinical stage I patients are significantly better than those of clinical stage II patients, although there are no differences in the disease-free survival rates of patients with advanced disease. Disease-free survival rates in long-term survivors decreased at a constant rate due to metachronous multicentric recurrence. Therefore it is important to follow postoperative patients as long as possible. In the treatment of recurrent tumors, every effort should be made to resect the tumor in the liver. Then, other regional therapies, such as percutaneous ethanol injection therapy, microwave coagulation therapy, and transcatheter arterial chemoembolization, are indicated for patients for whom re-resection is not indicated. To prevent recurrence of hepatocellular carcinoma, it is also important to suppress the hepatic necroinflammatory process due to viral hepatitis.

Carcinoma, Hepatocellular↗
PubMed1999

[Statistics on the operations at the Department of Urology, Toyota Memorial Hospital during an 11-year period (1987-1997)].

A clinical statistic survey was carried out on the operations performed at our Hospital from 1987 through 1997. The total number of operations was 3,383 and the number of operations excluding extracorporeal shock wave lithotripsy (ESWL) was 1,672, consisting of 227 (13.6%) operations of the kidney and ureter, 194 (11.6%) operations of the bladder, 481 (28.8%) operations of the prostate and urethra, and 705 (42.2%) operations of the penis and scrotal contents. Since new endourological technology and ESWL were developed for clinical application, the mode of operation has dramatically changed during the last 11 years, trending toward minimally invasive surgery.

Humans↗
PubMed1999

[Usefulness and problems of total hepatic vascular exclusion in liver surgery].

Total hepatic vascular exclusion (THVE) is an useful method enabling safe and sure hepatic resection in patients with liver tumors adjacent to the large hepatic veins or inferior vena cava (IVC), tumor thrombi, invasion of the IVC, etc. To avoid serious hypotension during THVE, test clamping of the IVC prior to the procedure is indispensable. Hemodynamics should be carefully maintained by blood transfusion and sufficient infusion of colloidal and electrolyte solutions during THVE. The veno-venous bypass method which shunts blood from the IVC and portal vein to the superior vena cava enables prolongation of the period of THVE and is useful to avoid postoperative renal dysfunction. In situ liver perfusion with cold solution during THVE is an additional modality by which the liver is protected from warm ischemic injury and the duration of THVE can be further prolonged. However, the maximum duration of THVE is still controversial, especially in patients with chronic liver damage. The most appropriate method for THVE should be carefully chosen in each case by considering the type of lesion, liver function, and the goal of the surgery.

Constriction↗
PubMed1999

[Role of the government for development of umbilical cord blood bank system in Japan].

In Japan, development of umbilical cord blood transplantation is still on its preliminary stage. However, the nation-wide requests for dissemination of cord blood is growing. The Ministry of Health and Welfare established the "Committee on Umbilical Cord Blood Transplantation" last year and the committee has made the action plan to develop the nation-wide cord blood bank system. Our society is going to start the collaborative projects cooperated with medical professionals, politicians and community people.

Blood Banks↗
PubMed1999

[A case of mediastinal myelolipoma].

Myelolipoma is a benign tumor composed of mature adipose tissue and hematopoietic tissue. It was mainly found in the adrenal grand, but there have been reports of extra-adrenal locations. Only 7 cases of mediastinal myelolipoma have been reported ever. We have experienced a case of mediastinal myelolipoma surgically resected from a 55-year-old-man. He has visited our department because of chest pain. Chest X-ray showed typical pneumothorax, but abnormal mediastinal shadow was remarked. Chest CT showed a well circumscribed mass with fat and soft-tissue attenuation in posterior mediastinum. Lung bullectomy and mediastinal tumor resection under VATS was performed. A blue-red tumor 4 cm in diameter was resected en bloc. Pathological examination showed its composition of mature adipose tissue and hematopoietic tissue. Diagnosis was extra-adrenal myelolipoma. No recurrent nor abnormality was found in 8 months since surgery.

Endoscopy↗
PubMed1999

Survival and prognostic factors in lung cancer patients treated in phase I trials: Japanese experience.

Patients recruited for phase I trials are considered to have a poor prognosis, because the majority of them have already been heavily treated. We examined the survival of lung cancer patients admitted to phase I trials and treated with single new investigational chemotherapeutic agents or new investigational biological modifiers in the Division of Thoracic Oncology of the National Cancer Center Hospital between 1987 and 1993. Eighty-two patients had lung cancer among 121 patients registered in phase I trials. To identify prognostic factors, univariate and multivariate analyses were conducted. Median survival time (MST) from beginning of the phase I trial was 9.4 months, and the response rate was 4.2%. There were 11 (13.4%) early deaths within 3 months, and the death of 1 (1.2%) patient was treatment-related. Univariate analysis demonstrated that performance status, body weight loss, chemotherapy regimen, liver metastasis, number of metastatic sites, prior chemotherapy, and serum levels of hemoglobin, and lactate dehydrogenase were significant prognostic factors for survival. Among these factors, performance status >1, body weight loss >/=10%, and number of the metastatic sites >1 were selected as risk factors in multivariate regression analysis. The low-risk group, which included the 36 patients with no risk factors, had an MST of 13.9 months and an early death rate of 0%. The intermediate-risk group of 31 patients was characterized by patient having only one risk factor. These patients had an MST of 7.6 months and an early death rate of 13%. The high-risk group of 9 patients had two or three risk factors. These patients had an MST of only 1.5 months and a high early death rate of 78%. We conclude that the MST of lung cancer patients who participated in the phase I trials was 9.4 months. Therefore, it appears reasonable to have admitted these patients to the phase I trials. However, as the patients in the high-risk group had a poor outcome and high early death rate, they should not have been admitted to phase I trials. This prognostic model should be validated in other patient series.

Adenocarcinoma↗
PubMed1999

[The current status of molecular detection of micrometastatic prostate cancer cells].

We summarized and reviewed published reports, including our studies, on the reverse transcription-polymerase chain reaction (RT-PCR) detection of micrometastatic prostate cancer cells in lymph nodes, bone marrow and peripheral blood. Some published data preliminarily suggest that the RT-PCR assay of micrometastatic prostate cancer cells may allow a more accurate assessment of lymph node and bone metastases of prostate cancer, and offer a presurgical prediction of the pathological stage of clinically localized disease. In addition, the RT-PCR assay may have a unique prognostic value in prostate cancer. However, controversy remains over the clinical significance of the RT-PCR assay. This assay could potentially develop into a diagnostic procedure for the clinical decision making in patients with prostate cancer. To establish the clinical significance of the RT-PCR assay, further optimized and standardized RT-PCR assay studies are needed, investigating large populations and involving long-term follow-up for the determination of any association between the results of the RT-PCR assay and specific clinical outcome.

Humans↗
PubMed1999

[Bacillus Calmette-Guerin intravesical instillation treatment for carcinoma in situ of the bladder. Gifu BCG Instillation Therapy Research Group].

We performed a retrospective long-term study to evaluate the efficacy of intravesical instillation of Tokyo 172 strain Bacillus Calmette-Guerin (BCG) on carcinoma in situ (CIS) of the bladder. Between 1989 and 1998, 42 patients with CIS of bladder underwent intravesical instillation of BCG. In the follow-up period from 6 to 116 months (mean: 37.3 months), the efficacy rate of intravesical BCG instillation for CIS of the bladder was 81.0%. Two patients died from the bladder cancer. The non-recurrence rate in patients with grade 2 carcinoma (19 cases) was not significantly different from that in those with grade 3 carcinoma (23 cases). However, the recurrence rate in patients with secondary CIS (15 cases) was significantly higher than in those with primary CIS (27 cases). The recurrence of CIS was observed in 7 of 42 cases. In 6 of 7 patients, CIS recurred within one year after treatment. Total cystectomy was performed in 10 of 42 patients, and pathological findings of muscle layer invasion were detected in 8 patients. Although side effects occurred in 33 patients (77.5%), no clinically significant side effects were observed. Our results suggest that intravesical BCG therapy may be useful for the treatment of CIS of the bladder.

Adjuvants, Immunologic↗
PubMed1999

Glucocorticoid can reduce the transcriptional activation of HIV-1 promoter through the reduction of active NF-kappaB.

It is well documented that glucocorticoid (GC) can induce the transcription of the IkappaBalpha gene in several cell lines. GC treatment then increases IkappaBalpha protein levels and markedly reduces the amount of active NF-kappaB. NF-kappaB is a strong activator of HIV-1 promoter, but the mechanism by which GC influence the HIV-1 activities is not well documented. In the present study, MOLT4 and Jurkat cells were transfected with HIV-1-LTR-CAT DNA and treated with 0.2 mM H(2)O(2) or 10 ng/ml of TPA. CAT activities of the transformed MOLT4 and Jurkat cells were greatly enhanced by these treatments, but the CAT activities were markedly reduced when cells were pretreated with GC. This reduction in activity correlated well with the reduction in active NF-kappaB and the accumulation of IkappaBalpha. These findings suggest that GC can reduce the transcription of HIV-1 promoter through the reduction of active NF-kappaB.

Cell Line↗
PubMed1999

Comparison of pathologic changes in Helicobacter pylori-infected Mongolian gerbils and humans.

Helicobacter pylori has been recognized as a pathogen causing gastroduodenal disease, with adequate evidence to prove this relation in clinical research. Available animal models, however, were inadequate until 1995, when a new animal model of H. pylori infection was established using Mongolian gerbils. In this study we compared pathological changes in seven H. pylori-infected Mongolian gerbils with ulcers to five patients with gastric ulcer who underwent operation. All of the animals showed positive reactions for both H. pylori culture and serum anti-H. pylori antibody titer. All human subjects had H. pylori on the mucosal surface. Thus, inflammatory cell infiltration in the pyloric gland area was observed throughout almost all layers in the animals. In contrast, inflammation was observed in the surface layer of the mucosa in the pyloric gland area in the human subjects. Lymph follicle formation was observed more often in humans than in the animals. Inflammation of the fundic gland area in both groups was weaker than of the pyloric gland area and was observed within the mucosa. Histological changes observed in both groups were chronic active gastritis, lymph follicles, and intestinal metaplasia in the stomach. H. pylori-associated gastritis in humans is characterized by erosion, inflammation with neutrophil infiltration, lymph follicles, intestinal metaplasia, and atrophy. These findings are similar to those in this animal model. Thus, H. pylori infection might participate in the pathogenesis of gastroduodenal mucosal damage. In conclusion, the Mongolian gerbil is a good animal model for H. pylori-associated gastric diseases, and it might be useful for investigating the pathogenesis of H. pylori infection.

Adult↗
PubMed1999

[Heavy ion therapy for non-small cell lung cancer].

Carbon beam radiation has well-balanced dual actions on cancer: efficient dose localization and potent biological anticancer effect due to high RBE (Relative Biological Effectiveness). Two phase I/II clinical studies on the carbon beam radiation treatment of inoperable stage I non-small cell lung cancer (NSCLC) were carried out in our institution from October 1996 to February 1999. The dose-limiting toxicity was found to be radiation pneumonia. In the first protocol, 47 patients received 18 fractions of increasing doses from 59.4 GyE by 10% over 6 weeks. The maximum tolerated dose was found to be 95.4 GyE, while the complete tumor control dose was 85.6 GyE. In the second protocol, 34 patients received 9 fractions of in creasing doses from 68.4 GyE by 5% over 3 weeks. The maximum tolerated dose was 79.2 GyE, and the complete tumor control dose was > 68.9 GyE. The 4-year survival rate estimated by the Kaplan-Meier method was 56% for patients receiving the first protocol. Because a higher local control rate was achieved in the second protocol, the 5-year survival rate is estimated to be higher and similar to that achieved after surgery. Another phase II clinical study in patients with stage INSCLC is ongoing. Heavy-particle radiotherapy is a new modality for the treatment of lung cancer which holds promise for the 21st century.

Aged↗
PubMed1999

Evaluation of new 4 French catheters by comparison to 6 French coronary artery images.

The use of 4 Fr catheters for diagnostic coronary arteriography improves patient comfort and could potentially reduce costs by decreasing arterial complications and encouraging outpatient examination. We examined the performance of recently developed 4 Fr catheters (100 cm long, 0.042 inch internal diameter) through in vitro flow rate patterns and in vivo image quality. Flow patterns (flow rate calculated from pressure with the Hagen Poiseuille relation) were obtained by hand (10 ml volume; maximal effort, one-handed full injection) and power injection (10 ml volume; 5 ml/sec) in the 4 Fr catheters were compared to 5 Fr (0.047 inch) and 6 Fr (0.057 inch) catheters. In 20 patients, coronary arteriograms were obtained from 4 Fr hand injection (4 HI), 4 Fr power injection (4 PI), 6 Fr hand injection (6 HI ), and 6 Fr power injection (6 PI) were compared after being scored into 5 grades. Coronary diameter was assessed at two sites for all injections in the same group of patients. In power injections, peak flow rates were consistently 5.5 ml/sec in all catheters. Hand injections were much more variable; peak flow rate ranges for 5 different physicians were 3.5-6.0 ml/sec. in 6 Fr, 1.8-3.0 ml/sec. in 5 Fr and 1.4-2.0 ml/sec in 4 Fr catheters. Mean image scores of left arteriograms were significantly higher for 4 PI versus 4 HI and for 6 Fr images compared to 4 PI (p < 0.001). In right arteriograms, 4 HI scored significantly lower than other methods (4 PI, 6 HI and 6 PI; p < 0.001). In 4 HI left coronary arteriograms, the frequency of grade > 2 was 96% and > 3 was 82%. Power injection improved 4 Fr imaging to 99% greater than grade 2 and 93% greater than grade 3. There were no differences in the frequency of images above grade 3 in right coronary arteriograms. Measured coronary artery diameters at 40 normal and 17 stenotic sites by QCA analysis (Acom, Siemens AZ, Erlangen, Germany) did not influence the study data. We concluded that coronary arteriograms by hand injection with 4 Fr catheters were inferior compared to 6 Fr images. Power injection and/or larger catheters may be necessary to ensure the highest quality images are obtained.

Blood Flow Velocity↗
PubMed1999

Seroreactivity clarification and viral load quantitation in HIV-1 and HIV-2 infections in Ghana.

In Ghana, West Africa, the prevalence of dual HIV-1 and HIV-2 infections remains to be clarified, and HIV viral load measurement is yet to be established. Conventional assays for HIV-1 RNA measurements have been limited specifically to HIV-1 subtype B, preventing their utilization for Ghana where HIV-1 subtypes A, D and G are prevalent. Therefore, we set out to distinguish the types of HIV infection existing in Ghana so as to determine the extent of actual dual infections, and to measure plasma HIV-1 RNA. Blood samples were collected from 563 sick and healthy Ghanaians who visited hospitals in 1996 and 1997. After T cells were counted, HIV antibody was screened and confirmed by six different commercial assays and one in-house test. Nested PCR was then used to verify HIV-1 and HIV-2 presence by type-specific primers. Plasma HIV-1 RNA was measured by an improved commercial RT-PCR assay, sensitive to all HIV-1 group M subtypes. HIV-1 alone (89%) clearly dominated over HIV-2 alone (2%), and HIV-1 and HIV-2 dual infections were found in 9%. Valid viral load measurements were obtained on test plasma representing the main HIV-1 subtype (A) prevailing in Ghana. A high amount of HIV-1 RNA (5.9 mean log10 RNA copies/ml) was observed in the typical stages of HIV infection represented by groups of CD44 cell counts. We have clarified the seroprevalence of HIV-1 and HIV-2 amongst HIV seropositives, and the high viral load of HIV-1 reflects its influence on AIDS in Ghana.

Cross-Sectional Studies↗
PubMed1999

Marginal excision for osteosarcoma with caffeine assisted chemotherapy.

The authors report on intentional marginal excision for osteosarcoma in conjunction with caffeine assisted chemotherapy for the purpose of preservation of good limb function. Twenty-seven patients with osteosarcoma (22 patients with Stage IIB and five with Stage IIIB) preoperatively were given three-to-five courses of intraarterial cisplatin and caffeine without or with doxorubicin. For 26 (96%) responders to the chemotherapy, limb salvage surgery was conducted by means of an intentional marginal procedure, which led to the preservation of important structures such as major neurovascular bundles, tendons, ligaments, muscles, and the epiphysis. Tumors were located in the distal femur in 11 patients, the proximal tibia in eight, the proximal fibula in four, the proximal humerus in two, and the proximal femur in one patient. The histologic response of these 26 patients to the preoperative chemotherapy showed no viable cells in 19 patients with Stage IIB osteosarcoma and only scattered foci of viable cells in two patients with Stage IIB and five patients with Stage IIIB osteosarcoma. As for reconstruction, distraction osteogenesis was performed in eight patients, allograft or autoclaved bone and prosthesis composite in four, autoclaved bone in two, osteochondral allograft in two, megaprosthesis in six, and resection alone in four patients. The average functional evaluation of the 26 patients was 91% of normal. Local tumor recurrence was seen in one patient, whereas 18 patients with Stage IIB osteosarcoma remain diseasefree with a mean followup of 61 months. Two patients with Stage IIB osteosarcoma and four patients with osteosarcoma Stage IIIB died of the disease. Intentional marginal excision for osteosarcoma in conjunction with caffeine assisted chemotherapy is advantageous because it results in the preservation of healthy important structures, with joint preservation possible in selected cases. This approach should help to improve the success rate of limb salvage surgery for osteosarcoma and to preserve the function of the affected limb.

Adolescent↗