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Biomedical subjects

S Kanazawa

Publications and source records attributed to S Kanazawa.

At least 19 recordsLinked to original sources

Intra-aortic stent graft in oesophageal carcinoma invading the aorta. Prophylaxis for fatal haemorrhage.

In patients with advanced oesophageal carcinoma with aortic invasion, any therapy potentially causes fatal haemorrhage. We describe here the successful application of intra-aortic stent graft to prevent haemorrhage before radical oesophagectomy for advanced oesophageal cancer. Four patients with advanced oesophageal cancer complicated by invasion of the aorta. Under general anaesthesia, aortic invasion is evaluated by an intravascular sonography. The stent graft is passed through the right femoral artery into the descending aorta. Subsequently, the stent graft is released to expand in the thoracic aorta during an artificial cardiac arrest. Aortography is performed to check for any stent migration or endoleakage. This procedure was successful in all four patients without any complications. All patients underwent radical oesophagectomy following aortic stent-grafting. One patient survived more than 2 years after stent grafting and operation. This procedure is safe and applicable for the patient with aortic invasion before radiochemotherapy or operation.

Aged↗

Estimation of photon dose generated by a short pulse high power laser.

The authors obtain a new equation to estimate the forward component of a photon dose generated through the interaction between a target and a short pulse high power laser. As the equation is quite simple, it is useful for calculating the photon dose. The equation shows that the photon dose is proportional to the electron temperature in the range>3 MeV and proportional to the square of the electron temperature in the range<3 MeV. The dose estimated with this method is roughly consistent with the result of Monte Carlo simulation. With some assumptions and corrections, it can reproduce experimental results obtained and the dose result calculated at other laboratories.

Electrons↗

Electron acceleration by a nonlinear wakefield generated by ultrashort (23-fs) high-peak-power laser pulses in plasma.

We study experimentally the interaction of the shortest at present (23-fs) , relativistically intense (20-TW), tightly focused laser pulses with underdense plasma. MeV electrons constitute a two-temperature distribution due to different plasma wave-breaking processes at a plasma density of 10(20) cm(-3). These two groups of electrons are shown numerically to constitute bunches with very distinctive time durations.

Journal Article↗

Association of low-density lipoprotein particle size distribution and cardiovascular risk factors in children.

AIM: The objective of this study was to investigate whether the presence of small, dense lipoproteins, which are thought to be related to the metabolic syndrome caused by insulin resistance, can be predicted by routine serum lipid profiling. METHODS: The relationship between low-density lipoprotein (LDL) particle size and serum lipid levels was analysed in 284 school children (148 boys and 136 girls), aged 7 to 13 y old. LDL particle size was determined by gradient gel electrophoresis. RESULTS: The LDL particle diameter was significantly correlated with the serum levels of high-density lipoprotein cholesterol (HDL-C) (r = - 0.437, p < 0.001) and triglycerides (TG) (r = -0.432, p < 0.001), and with the atherogenic index (AI) [total cholesterol/ HDL-C] (r = -0.450, p < 0.001), while only weak correlations were observed with the serum levels of total cholesterol, apolipoprotein Al and apolipoprotein B. No significant relationship was observed between LDL particle diameter and the serum LDL-C level. CONCLUSION: The presence of small, dense LDL as a metabolic marker of lifestyle-related diseases in children seems to be reflected by a serum lipid profile characterized by an elevation in TG, a reduction in HDL-C, and a raised AI.

Adolescent↗

The expression of platelet-derived growth factor and connective tissue growth factor in different types of abdominal aortic aneurysms.

AIM: An atherosclerotic abdominal aortic aneurysms (AAAA) differ from inflammatory abdominal aortic aneurysms (IAAA), which are characterized by a non specific inflammatory reaction leading to considerable aneurysmal wall thickness from the media to adventitia and retroperitoneal fibrosis in the surrounding tissue. Platelet-derived growth factor (PDGF) and its receptor have been localized to specific cell types within atherosclerotic plaques. Human connective tissue growth factor (CTGF) is a cysteine rich polypeptide that has similar structures to PDGF and has been implicated in connective tissue formation. PDGF and CTGF may play a role in the development of aneurysmal walls in both AAAA and IAAA. METHODS: Using in situ hybridization technique with DIG-labeled RNA probes and immunostaining, we investigated CTGF gene expression, and expression of PDGF and its receptor protein, in human aneurysmal walls. RESULTS: Expression of CTGF mRNA was found on vascular smooth muscle cells (VSMC) in specimens from AAAA and IAAA. Strong CTGF expression was localized in VSMC around calcification in AAAA. In IAAA, strong expression of CTGF was observed around inflammatory cells. In the aneurysmal walls of AAAA, PDGF A and B chains were strongly stained on small vessels, and the PDGF beta receptor was also strongly stained on VSMC around calcification. In the aneurysmal wall of IAAA, weak expressions of PDGF A and B chains were observed in endothelial cells of vessel walls around the inflammatory cells, but the intensity of expression was much weaker than that on the vessel walls in AAAA. CONCLUSIONS: Such differences in fibrogenic cytokine expression may be involved in characteristic aneurysmal formation.

Adult↗

Development of a phantom compatible for MRI and hyperthermia using carrageenan gel-relationship between T1 and T2 values and NaCl concentration.

The authors developed a phantom, designated as the CAGN phantom, compatible for MRI and hyperthermia that is useful in the fundamental studies of non-invasive MR thermometry. The ingredients of this phantom are carrageenan, GdCl3 as a T1 modifier, agarose as a T2 modifier, NaCl as a conductivity modifier, NaN3 as an antiseptic and distilled water. Another phantom that was developed, the CAG phantom, has relaxation times that are adjustable to those of any human tissue. To use this phantom for electromagnetic heating, NaCl was added to change the conductivity of the phantom and clarified the relationship between the conductivity and NaCl concentration. This study examined the relationship between relaxation times and NaCl concentration of the CAGN phantom. The results showed that both T1 and T2 values were affected by NaCl and the experimental results led to the empirical formulae expressing the relationship between the relaxation rates (1/T1, 1/T2) and the concentrations of GdCl3, agarose and NaCl. The appropriate concentrations of T1 and T2 modifiers were calculated from these empirical formulae when making a specified phantom that has the required relaxation times and NaCl concentration.

Algorithms↗

Effects of efonidipine on platelet and monocyte activation markers in hypertensive patients with and without type 2 diabetes mellitus.

We compared the levels of microparticles, platelet activation markers, soluble cell adhesion molecules, and soluble selectins between hypertensive patients with and without type 2 diabetes and control subjects. Binding of anti-glycoprotein IIb/IIIa and anti-glycoprotein Ib monoclonal antibodies to platelets did not differ significantly between the hypertensive patients and controls, but platelet expression of activation markers (CD62P, CD63, PAC-1, and annexin V) was higher in the hypertensive patients. Platelet-derived microparticle (PDMP) and monocyte-derived microparticle (MDMP) levels were significantly higher in the hypertensive patients than in the controls. Soluble ICAM-1, VCAM-1, P-selectin, and E-selectin levels were also higher in the hypertensive patients, and they were significantly higher in the hypertensive patients with diabetes. After treatment with efonidipine, the levels of PDMPs, CD62P-, CD63-, PAC-1-, and annexin V-positive platelets, sICAM-1, sVCAM-1, sP-selectin, and sE-selectin all decreased significantly. The MDMP levels decreased, and the decrease was significant in the hypertensive patients with diabetes. These findings suggest that administration of efonidipine to hypertension patients with diabetes may prevent the development of cardiovascular complications caused by cell adhesion molecules or activated platelets and monocytes.

Aged↗

Bone growth oscillation: longitudinal metabolic process of bone growth in congenital adrenal hyperplasia and nonendocrine short stature.

To clarify the longitudinal metabolic process of bone growth in children, we observed the relationship between the level of serum osteocalcin (OC), a marker of bone metabolism, and growth velocity in 10 prepubertal patients with congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency and 9 prepubertal patients with nonendocrine short stature (NESS), but no major hormonal abnormalities influencing bone metabolism. Observations were made every 6 months over a 7-year period. In patients with CAH who exhibited a wide variation in growth velocity during the course of the investigation, the levels of OC fluctuated over a wide range, suggesting metabolically variable bone growth. In contrast, in patients with NESS who exhibited a relatively stable growth velocity, the OC level remained within a narrow range, suggesting metabolically stable bone growth. The meaning of such divergent metabolic processes of bone growth observed in CAH and NESS and its relationship to actual bone structure or bone intensity should be further investigated.

Adolescent↗

Detection of hepatic metastasis from medullary thyroid cancer with Tc-99m-MIBI scintigraphy in a patient with Sipple's syndrome.

We report a case of Sipple's syndrome with a hepatic tumor. A 28-year-old male with medullary thyroid cancer and bilateral pheochromocytomas was diagnosed as having Sipple's syndrome. The hepatic tumor was found to be hypervascular by means of a dynamic abdominal CT scan. An I-131-MIBG scan showed no increased accumulation in the tumor. A whole body Tc-99m-MIBI scan had shown, however, increased accumulation in the tumor by 10 minutes after i.v. Tc-99m-MIBI. The hepatic tumor was diagnosed histologically as a metastasis from the medullary thyroid cancer. To our knowledge, there have been no previous reports of increased Tc-99m-MIBI accumulation in hepatic metastases from medullary thyroid cancer.

Adrenal Gland Neoplasms↗

Intralobar pulmonary sequestration supplied by multiple anomalous arteries: report of a case.

Pulmonary sequestration is abnormal pulmonary tissue that has separated from the normal pulmonary parenchyma, is not connected to the tracheobronchial tree, and is supplied by a systemic artery. We describe herein a case of intralobar pulmonary sequestration found in a 66-year-old man who was admitted to our hospital with hemoptysis, coughing, and fever. Angiography showed that the branches of the 11th left intercostal artery and a bronchial artery had formed a hypervascular area in the lower part of the left lung. Bronchial artery embolization and subsequent embolization of the left 11th intercostal artery were performed in an attempt to control the recurrent hemoptysis. These treatments were unsuccessful, and he was transferred to our department of surgery after coughing up about 400 ml of fresh blood. A left lower lobectomy was performed. The resected lung contained a large feeding artery, some acute and partly organizing inflammatory lesions within collapsed lung parenchyma, and massive intra-alveolar hemorrhage in the peripheral area. The patient had an uneventful recovery and was discharged 22 days after his operation.

Aged↗

Expressed emotion of families and the course of mood disorders: a cohort study in Japan.

BACKGROUND: Findings on expressed emotion (EE) of the family and the course of mood disorders have not been consistent. There has also been no report on these problems from Asia. METHODS: The subjects were 32 patients diagnosed to have mood disorders on the basis of DSM-IV and ICD-10 and 36 principal members of their families. EE was evaluated using Camberwell Family Interview (CFI). A cohort study was conducted for 9 months after discharge of the patients. The patients were divided into a high-EE group and a low-EE group using a few cut-off points concerning the number of critical comments (CCs) and emotional over-involvement (EOI), the 9-month relapse risks were compared, and the relapse risk ratio and its 95% confidence interval were calculated. Also, the sensitivity, specificity, positive predictive value, and negative predictive value were calculated, and the optimal cut-off point was evaluated. Multiple logistic regression analysis was performed to control the effects of potential confounding factors. RESULTS: When the subjects with three or more CCs, or an EOI score of three or higher were regarded as a high-EE group, and the others as a low-EE group, the nine-month relapse risks were 83.3% (5/6) and 19.2% (5/26), respectively, and the relapse risk ratio (95% confidence interval) was 4.3 (1.8-12.2). The values of the validity parameters were the highest with these cut-off points. The effect of EE was also significant on multiple logistic regression analysis. LIMITATIONS: Small sample size and severity of the patients. CONCLUSIONS: Families' EE based on CFI correlated with relapse also in Japan.

Adult↗

NF-kappaB binds P-TEFb to stimulate transcriptional elongation by RNA polymerase II.

To stimulate transcriptional elongation of HIV-1 genes, the transactivator Tat recruits the positive transcription elongation factor b (P-TEFb) to the initiating RNA polymerase II (RNAPII). We found that the activation of transcription by RelA also depends on P-TEFb. Similar to Tat, RelA activated transcription when tethered to RNA. Moreover, TNF-alpha triggered the recruitment of P-TEFb to the NF-kappaB-regulated IL-8 gene. While the formation of the transcription preinitiation complex (PIC) remained unaffected, DRB, an inhibitor of P-TEFb, prevented RNAPII from elongating on the IL-8 gene. Remarkably, DRB inhibition sensitized cells to TNF-alpha-induced apoptosis. Thus, NF-kappaB requires P-TEFb to stimulate the elongation of transcription and P-TEFb plays an unexpected role in regulating apoptosis.

Apoptosis↗

Repression of MHC determinants in HIV infection.

HIV infects CD4(+) macrophages and lymphocytes. Before the development of AIDS, HIV weakens the immune system in part by blocking antigen processing and presentation via major histocompatibility complex (MHC) molecules. In this report, we discuss how HIV escapes the immune surveillance by MHC II molecules.

Antibodies, Viral↗

Systemic effects of transdermal testosterone for the treatment of microphallus in children.

OBJECTIVES: To elucidate the metabolic effects of topical testosterone for the treatment of microphallus in children. METHODS: We administered 5% testosterone ointment to 50 prepubertal boys for the treatment of microphallus, allowing us to observe its metabolic effect on plasma concentrations of testosterone as a marker of transdermally absorbed testosterone, insulin-like growth factor (IGF)-I as a marker of growth hormone secretion status, and osteocalcin as a marker of bone metabolic turnover. RESULTS: Transdermal application of testosterone for 30 days at a dose that affects penile growth increased mean (+/-SD) plasma testosterone concentrations from 7.5+/-5.1 to 31.0+/-8.2 ng/dL (pre- vs. post-treatment, respectively; P<0.01). This was associated with a slight but statistically significant elevation of IGF-I concentrations (117.2+/-76.9 vs. 154.4+/-81.5 ng/mL; P<0.05). No significant change in osteocalcin levels was found. CONCLUSIONS: When using testosterone ointment as a treatment for microphallus, it should be borne in mind that this application has systemic effects.

Administration, Cutaneous↗