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Biomedical subjects

N Tanaka

Publications and source records attributed to N Tanaka.

At least 523 records · Page 29Linked to original sources
PubMed1999

Anterior arthroscopic synovectomy plus capsuloplasty with a pedicle graft for the treatment of rheumatoid popliteal cysts.

OBJECTIVE: To assess the value of arthroscopic synovectomy plus capsuloplasty with a pedicle graft in patients with rheumatoid cysts of the knee. METHODS: We examined 31 rheumatoid knees in 9 men and 22 women with an average age of 52.5 years at time of operation. Postoperative clinical symptoms were investigated in comparison with each factor examined before the operation. RESULTS: Postoperative results showed that 74% of the patients were grade 0 (no swelling or pain), 23% were grade 1 (swelling and slight discomfort after strenuous work or sports), and 3% were grade 2 (swelling and tenderness after normal activities). The improvement rate of the patients with arthroscopic synovectomy plus pedicle graft capsuloplasty was significantly higher than that of the untreated controls or patients with arthroscopic synovectomy or pedicle graft capsuloplasty. The preoperative degree of joint effusion, acceleration in the erythrocyte sedimentation rate, radiographic grades, and histological activity in the knee joint at the time of operation were correlated with the final clinical symptoms. CONCLUSION: Our method may be useful for preventing recurrence of rheumatoid popliteal cysts.

Arthritis, Rheumatoid↗
PubMed1999

[Analysis of the long-term prognosis for conjunctival malignant melanomas in Japan].

PURPOSE: To investigate the long-term prognosis for primary conjunctival malignant melanomas in Japan. MATERIALS & METHODS: We conducted a survey of 61 cases which had been reported in a 38-year period (1959 to 1996). We gathered information regarding the survival of patients, the post-operative follow-up period, the causes of death, and recurrences. Answers were obtained segarding 51 cases (84%). Detailed progress was identified in 23 of these cases. The survival rates were calculated using the Kaplan-Meier method. RESULTS: The survival rates were 95.1% after 1 year, 72.9% after 3 years, and 53.4% after 5 years. These values are relatively low compared with those reported in Europe and the United States.

Adolescent↗
PubMed1999

Bile acid synthesis in the Smith-Lemli-Opitz syndrome: effects of dehydrocholesterols on cholesterol 7alpha-hydroxylase and 27-hydroxylase activities in rat liver.

The Smith-Lemli-Opitz syndrome (SLOS) is a congenital birth defect syndrome caused by a deficiency of 3beta-hydroxysterol Delta(7)-reductase, the final enzyme in the cholesterol biosynthetic pathway. The patients have reduced plasma and tissue cholesterol concentrations with the accumulation of 7-dehydrocholesterol and 8-dehydrocholesterol. Bile acid synthesis is reduced and unnatural cholenoic and cholestenoic acids have been identified in some SLOS patients. To explore the mechanism of the abnormal bile acid production, the activities of key enzymes in classic and alternative bile acid biosynthetic pathways (microsomal cholesterol 7alpha-hydroxylase and mitochondrial sterol 27-hydroxylase) were measured in liver biopsy specimens from two mildly affected SLOS patients. The effects of 7- and 8-dehydrocholesterols on these two enzyme activities were studied by using liver from SLOS model rats that were treated with the Delta(7)-reductase inhibitor (BM15.766) for 4 months and were comparable with more severe SLOS phenotype in plasma and hepatic sterol compositions. In the SLOS patients, cholesterol 7alpha-hydroxylase and sterol 27-hydroxylase were not defective. In BM15.766-treated rats, both enzyme activities were lower than those in control rats and they were competitively inhibited by 7- and 8-dehydrocholesterols. Rat microsomal cholesterol 7alpha-hydroxylase did not transform 7-dehydrocholesterol or 8-dehydrocholesterol into 7alpha-hydroxylated sterols. In contrast, rat mitochondrial sterol 27-hydroxylase catalyzed 27-hydroxylation of 7- and 8-dehydrocholesterols, which were partially converted to 3beta-hydroxycholestadienoic acids. Addition of microsomes to the mitochondrial 27-hydroxylase assay mixture reduced 27-hydroxydehydrocholesterol concentrations, which suggested that 27-hydroxydehydrocholesterols were further metabolized by microsomal enzymes. These results suggest that reduced normal bile acid production is characteristic of severe SLOS phenotype and is caused not only by depletion of hepatic cholesterol but also by competitive inhibition of cholesterol 7alpha-hydroxylase and sterol 27-hydroxylase activities by accumulated 7- and 8-dehydrocholesterols. Unnatural bile acids are synthesized mainly by the alternative pathway via mitochondrial sterol 27-hydroxylase in SLOS.

Animals↗
PubMed1999

[Vascular trauma].

Vascular trauma is essentially acute arterial obstruction, often combined with hemorrhage, fracture, and infection. It can be both life-threatening and limb-threatening and needs an emergency operation. In vascular trauma patient, multiple fracture and organ injury, such as brain, lung, liver, spleen, kidney, or gastrointestinal tract should be evaluated to decide treatment priority. When the pulse distal from the injured site is absent or diminished, vascular trauma is most likely and reconstruction should be accomplished within "the golden time (6-8 hours)". Intimal damage followed by platelet aggregation and thrombus formation will necessitate resection and repair of the site instead of simple thrombectomy. Although autogenous vein is the first choice, artificial graft can be implanted for short segment in non-infected field.

Blood Vessels↗
PubMed1999

[A case of local recurrence of rectal cancer responding to local intraarterial infusion therapy].

A 42-year-old male developed pain in the right gluteal region due to local recurrence after curative resection of advanced lower rectal cancer. Radiotherapy (60 Gy) was performed, but satisfactory results were not obtained. Therefore, a reservoir was placed lowing cannulation of the internal iliac artery. The chemotherapy, in addition to intravenous administration of low dose CDDP (20 mg), included local intraarterial infusion therapy with 5-FU (1,500 mg/5 hour) once per week. After 10 courses of this chemotherapy (total dose: CDDP, 200 mg; 5-FU, 15,000 mg), the pain decreased, and the tumor size was reduced without side effects, improving the patient's QOL. At present, multidisciplinary treatments including such chemotherapy and radiotherapy is performed for local recurrence of rectal cancer, but adequate results are often not obtained. Local intraarterial infusion chemotherapy via the internal iliac artery accompanied by changes in blood flow can be safely performed on an outpatient basis, and appears to be effective for local recurrence of rectal cancer.

Adenocarcinoma↗
PubMed1999

[Bacteria isolated from surgical infections and their susceptibilities to antimicrobial agents: special references to bacteria isolated between July 1996 and June 1997].

The annual multicenter studies on isolated bacteria from infections in general surgery and their antimicrobial susceptibility have been conducted in 20 facilities in Japan since July 1982. This paper describes the results obtained during period from July 1996 to June 1997. The number of cases investigated as objectives was 217 for one year. A total of 406 strains were isolated from 177 cases (81.6% of total cases). From primary infections 162 strains were isolated, and from postoperative infections 244 strains were isolated, respectively. From primary infections, anaerobic bacteria were predominant, while from postoperative infections, aerobic Gram-positive bacteria were predominant. Among aerobic Gram-positive bacteria, the isolation rate of Enterococcus spp. was the highest. In postoperative infections, the majority of them were Enterococcus faecalis, while in primary infections, many of them were Enterococcus avium. The isolation rate of Staphylococcus spp., especially from postoperative infections, followed that of Enterococcus spp. Among anaerobic Gram-positive bacteria, Peptostreptococcus spp. and Streptococcus spp. were commonly isolated from both types of infections. Among aerobic Gram-negative bacteria, Escherichia coli was the most predominantly isolated from primary infections, followed by Klebsiella pneumoniae and Pseudomonas aeruginosa in this order, and from postoperative infections, P. aeruginosa was the most predominantly isolated, followed by E. coli and Enterobacter cloacae. Among anaerobic Gram-negative bacteria, Bacteroides fragilis group was the majority of isolates from both types of infections. The isolation rate of aerobic Gram-negative bacillus has decreased with time, while those of anaerobes like B. fragilis group and of aerobic Gram-positive bacteria have gradually increased in both types of infections. We found vancomycin-resistant strains of neither Staphylacoccus aureus nor Enterococcus spp.; however, the MIC of arbekacin for one of strains of S. aureus was 100 micrograms/ml. Both the MIC90's of meropenem and imipenem/cilastatin against P. aeruginosa isolated in this term were 25 micrograms/ml, which were higher than those against the strains isolated in the previous years. Compared with the isolated strains in the year 1995, progress of resistance against carbapenem antibiotics was confirmed.

Anti-Bacterial Agents↗
PubMed1999

Circulating levels of soluble CD30 and other markers in colorectal cancer patients.

In a search for new biologic serum tumor markers with prognostic value we evaluated the soluble form of the CD30 (sCD30), a marker of cells producing T helper 2 (Th2)-type cytokines, interleukin-1 receptor antagonist (IL-1ra), soluble interleukin-2 receptor (sIL-2R), soluble tumor necrosis factor -type I, -type II (sTNF-R55, -75) and immunosuppressive acidic protein (IAP) in patients, with advanced colorectal cancer. The data showed that abnormal levels of sCD30 were detected in eight (80.0%) out of ten patients. In contrast, sCD30 levels were not detected in healthy volunteers. The relationship between sCD30, sIL-2R and IAP were positively correlated. In contrast, sCD30 and IL-1ra were negatively correlated. These results suggested that IL-1ra may play a role, at least in part, to inhibit CD30 release, and sCD30 appears to be a new biologic serum tumor marker of possible use in the clinical setting of cancer patients.

Adult↗
PubMed1999

The role of previous infection of hepatitis B virus in Hbs antigen negative and anti-HCV negative Japanese patients with hepatocellular carcinoma: etiological and molecular biological study.

The aim of this study is to elucidate the important role of the previous infection of HBV, and the relations among HBV genome integration and p53 gene mutation, telomerase activity and genetic instability in liver tissue with HBsAg-negative (NB) and anti-HCV negative (NC) hepatocellular carcinoma (HCC). We examined the backgrounds of 34 NB and NC (NBNC) Japanese patients with chronic liver disease (CLD) patients not associated with HCC and 26 NBNC CLD patients with HCC. HBV genome integration into host cell genome, p53 gene mutation telomerase activity and genetic instability were examined in 6 with NBNC HCC (NBNC-HCC) tumorous tissue (T) and non-tumorous tissues (NT). In the NBNC group, HBV-related antibody positive patients with HCC are significantly more than the patients without HCC. Moreover, concerning the stage of the coexisted liver diseases, in NBNC CLD, LC patients with HCC is 19 of 26 (73.1%) , on the other hand, LC patients without HCC is 16 of 34 (47.1%). LC patients with HCC group is significantly more than that without HCC. Three (50%) of 6 in T and 3 cases (50% ) in NT were found to integrated genome of HBV. p53 gene mutation was observed in 3 (50%) of T. Concerning the telomerase activity, 3 of 6 cases (50%) in T and 1 case in NT was recognized. There was no genetic instability (LOH or RER) of D2S123, D3S1067 and TP 53 in T and NT. Finally in T of NBNC HCC cases, TTVDNA was detected in 3 of 5. Even in the HBsAg-negative and anti-HCV negative HCC cases, CLD coexisting with LC, previous HBV infection and HBVDNA integration were observed. There were a few cases with HBVDNA integration, p53 gene mutation, telomerase activity and genetic instability, simultaneously in HCC tissue, and in some cases, the coexistence with TTVDNA were concurrently confirmed. It is speculated that the important role of the previous infection of HBV may have also been proposed for HCC oncogentic progression in NBNC CLD [corrected].

Adolescent↗
PubMed1999

[A phase I trial of adenoviral p53 gene therapy for non-small cell lung cancer].

Lung cancer is one of the leading causes of cancer deaths worldwide. The high mortality rate for lung cancer results from the absence of standard therapeutic strategies, suggesting that lung cancer may be a suitable target disease for a novel gene-based therapy. Restoration of the function of a single pivotal gene product appears sufficient to mediate antitumor effects that are potentially clinically significant. Preclinical studies in animal models have demonstrated tumor regression following intratumoral administration of an adenovirus vector containing The wild-type tumor suppressor p53 gene. The efficacy and safety of the p53 gene therapy protocol for non-small cell lung cancer are now being evaluated in clinical trials. Although much research needs to be done following trials in the earliest stages, the treatment may offer a unique mechanism of action with a potentially high therapeutic index. This article reviews recent highlights in this rapidly evolving field.

Adenoviridae↗
PubMed1999

Induction of differentiation-dependent apoptosis in human esophageal squamous cell carcinoma by adenovirus-mediated p21sdi1 gene transfer.

When keratinocytes withdraw from the cell cycle, they migrate from the basal to the superficial layers of the epidermis and undergo morphological and biochemical changes during the process of terminal differentiation. These differentiation features of keratinocytes are known to be altered or reduced in esophageal cancer cells. Therefore, we examined the effects of transferring the cyclin-dependent kinase inhibitor p21sdi1 gene into human esophageal cancer cell lines as well as normal keratinocytes using an adenovirus vector system. Ectopic expression of p21sdi1 protein resulted in cell cycle arrest at the G1 phase and produced morphological changes, such as enlarged nuclei and a flattened cellular shape, changes specific to the differentiated phenotype. The human involucrin protein is a specific product of keratinocyte differentiation, which is selectively expressed in the suprabasal epidermal layers. Western blot analysis and immunohistochemical staining demonstrated that involucrin expression was 3- to 5-fold enhanced by the forced expression of p21sdi1 in esophageal cancer cells, whereas only a mild up-regulation up to 1.2-fold occurred in normal keratinocytes. We also found that exogenous introduction of the p2sdi1 gene transcriptionally activated the upstream promoter function of the involucrin gene. These stimulatory effects on involucrin expression were not observed when another cyclin-dependent kinase inhibitor gene, p16(INK4a), was transduced. Moreover, p21sdi1 expression in esophageal cancer cells transduced with p21sdi1 led to a rapid apoptotic cell death after a transient dormant phase, although keratinocytes transduced with p21sdi1 survived longer by terminally withdrawing from the cell cycle. These results may have an important implication for understanding the biology of differentiation-dependent apoptosis in human esophageal squamous cell carcinoma.

Adenoviruses, Human↗
PubMed1999

Involvement of apoptosis in activation-induced cell death of bacteria-reactive human CD45RO+ T cells.

Although the identity of the T cells that protect against bacteria in humans remains unknown, it is clear that patients with bacterial infection have reduced numbers of T cells in their blood. Here we have determined whether this T cell loss is a consequence of bacterial antigen-mediated activation-induced cell death (AICD). By flowcytometric analysis, less than 0.3% of freshly isolated T cells from healthy volunteers and patients with severe pneumonia were identified as apoptotic. However, during culture the rate of apoptosis in peripheral blood T cells from patients was 3.0 +/- 0.9%; and increased further in the presence of anti-CD3 (7.4 +/- 2.1%) and decreased when IL-2 was added (4.4 +/- 1.3%). In contrast, no changes were observed in healthy volunteers on addition of anti-CD3. Further, anti-CD3 significantly increased the susceptibility to apoptosis of CD45RO+ T cells, but not CD45RA+ T cells from patients, and the percentage of CD45RO+ T cells in patients was significantly higher than that in healthy volunteers. Flowcytometric analysis revealed the expression level of Fas to be higher in the patients than healthy volunteers. Collectively, these findings demonstrated that bacteria-reactive T cells were more susceptible to AICD and that Fas-FasL pathways of apoptosis were involved. AICD of CD45RO+ T cells, therefore, provides an explanation for the loss of bacteria-reactive T cells during bacterial infection.

Adult↗
PubMed1999

Fas-mediated cytotoxicity by gammadelta T cells during acute rejection in xenotransplantation of spheroidal aggregate-cultured hepatocytes.

Xenogeneic transplantation has recently become a subject of interest for the transplantation community due to the current organ shortage, which could be partially or even totally solved by the development of this strategy. However, xenogenetic rejection remains a formidable barrier preventing such use in a clinical setting. The spheroidal aggregate-cultured hepatocytes of WKA rats were injected into the spleen of C3H mice, and quantitative assessment of transplanted xenogeneic hepatocytes using 99mTc-GSA demonstrated that hepatocytes decreased dramatically 2 days after transplantation (day 2) and few viable hepatocytes in spheroids were detected on day 3. The NK activity significantly increased on day 1, and gammadelta receptor/FasL-expressing T cells appeared on day 2. These results suggested that xenogeneic cytotoxicity consisted of gammadelta T cells through the Fas/Fas ligand system, as well as non-T-cell-mediated cellular response, in the MHC-unrestricted pathway in this intrasplenically transplanted xenogeneic hepatocyte model.

Animals↗
PubMed1999

Hyperammonemia induced by administration of glucose and insulin after hepatopancreatectomy in rats.

Massive resection of both the liver and pancreas is performed as a radical procedure in some cases of advanced biliary cancer, but it has been reported that this disease is frequently complicated by hyperbilirubinemia or hepatic insufficiency postoperatively, which is a serious hindrance to performing such extended surgery (Nimura et al., 1991; Nakamura et al., 1992). To investigate the pathogenesis of hepatic dysfunction after hepatopancreatectomy, we performed 4 surgical procedures consisting of 68% hepatectomy, 90% pancreatectomy, 68% hepatectomy plus 90% pancreatectomy (hepatopancreatectomy) and sham-surgery in rats. Then, rats were continuously infused with 5% or 20% glucose solution at a constant speed (50 mL/day) for 24 hours in the fasting state, thus creating a total of 8 groups. During infusion of 20% glucose solution into rats with pancreatectomy or hepatopancreatectomy, insulin (1 U/5 g glucose) was added to the solution to adjust the blood glucose. In rats infused with 20% glucose solution with added insulin after hepatopancreatectomy, the blood glucose level did not differ, but adenosine 5'-triphosphate (ATP) and energy charge levels in the liver tissue were significantly lower, while the blood ammonia level was significantly higher than those in the other 7 groups. These results demonstrate that continuous infusion of high concentrations of glucose solution with added insulin after hepatopancreatectomy in rats reduces hepatic mitochondrial function, resulting in hyperammonemia due to reduced urea synthesis.

Alanine↗