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Biomedical subjects

T Wada

Publications and source records attributed to T Wada.

At least 1,351 records · Page 75Linked to original sources

Elastin-lipid interaction in the arterial wall. Part 2. In vitro binding of lipoprotein-lipids to arterial elastin and the inhibitory effect of high density lipoproteins on the process.

The mechanism of lipoprotein binding to arterial elastin, and the inhibitory effect of high density lipoprotein (HDL) on the in vitro complex formation between plasma low density lipoprotein (LDL) and elastin were studied. The binding of LDL-cholesterol, phospholipids and triacylglycerols to delipidated elastin increased progressively with time over 24 h of incubation. The results of a kinetic study on lipoprotein-cholesterol concentration in the incubation medium, suggesting that the ability to bind cholesterol to elastin decreases in the following order: very low density lipoprotein (VLDL), LDL, intermediate density lipoprotein (IDL) and HDL, and that the capacities to bind to a fixed amount of elastin decrease in the order: LDL, IDL, VLDL and HDL. When a definite amount of LDL was incubated with elastin in the presence of increasing concentrations of HDL, the binding of lipids to elastin progressively decreased. On the other hand, no release of cholesterol, bound to elastin during preincubation with LDL, could be detected in additional incubations with HDL, apoHDL or apoHDL-phospholipid complex.

Aorta↗

Detection of circulating antigens in human trichinellosis.

A 'sandwich' enzyme-linked immunosorbent assay was established to detect circulating antigens of Trichinella spiralis in human sera, its sensitivity and specificity was evaluated using 4 antigens (Trichinella spiralis, Trichuris trichiura, Dirofilaria immitis and Ascaris suum), and it was found to be sensitive and specific for T. spiralis antigen. Samples of 347 individuals with suspected trichinellosis, who had eaten incompletely cooked bear meat containing larvae of T. spiralis, were examined. Among individuals showing clinical symptoms, circulating antigens were detected in 29.9%, and the prevalence of antibodies was 18.9%. Among individuals lacking clinical symptoms, antigens were detected in 21.4% and antibodies in 5.0%. It was concluded that detection of circulating antigens was more useful for making diagnoses than measurement of specific antibodies.

Animals↗

Chemotherapy administered using two-route infusion of cisplatin and sodium thiosulfate and intravenous infusion of vinblastine and peplomycin in patients with oral cancer.

The therapeutic effects of neo-adjuvant chemotherapy administered by two-route infusion of cisplatin and its antidote, sodium thiosulfate, and intravenous infusion of vinblastine and peplomycin were studied in 22 patients with previously untreated squamous cell carcinoma of the oral cavity or maxillary sinus. The overall response rate to chemotherapy was 90.9%, with a complete response in 12 patients (54.5%), a partial response in 8 patients (36.4%), and no change in 2 patients (9.1%). Histologic assessment showed a grade V response in 7 patients (31.8%), grade IV in 3 patients (13.6%), grade III in 5 patients (22.7%), grade II in 4 patients (18.2%), and grade I in 3 patients (13.6%). The cumulative 5-year survival rate, including 3 patients who died of another disease, was 72.2%. Leukocytopenia, an important side effect apparently induced by vinblastine, was seen, but no life-threatening complications occurred. Renal toxicity by cisplatin was minimal because of the use of sodium thiosulfate and fosfomycin. These data indicate that this mode of chemotherapy may be more effective for treating head and neck cancer than ordinary chemotherapy, from clinical and histologic standpoints. The high complete-response rate is especially noteworthy. No serious side effects or reductions in treatment period occurred. The results are preliminary and additional studies using a larger patient population are needed.

Adult↗

Which morphologies of synovial folds result from degeneration and/or aging of the radiohumeral joint: an anatomic study with cadavers and embryos.

The synovial folds of the radiohumeral joints in cadaveric elbows from 179 elderly subjects and 40 embryos were investigated macroscopically and histologically to determine any morphologic changes caused by aging or degeneration. The anterior and posterior folds found in the elderly population shared characteristics of folds seen in embryos, with some modifications, and were thought to originate from the primitive septum. Proportionally, the length, width, and thickness of these folds were consistent between adults and embryos. However, the embryonic folds showed a homogenous morphology. In contrast, in the adult the anterior fold was characterized by a shorter and narrower villous pattern, and the posterior fold tended to be wider. Lateral extension of the anterior or posterior folds was also observed. Moreover, the lateral fold, never seen in embryos, was present and characterized by a hard plicate pattern in the adult. These derived or specific morphologies in adults probably result from alterations in the movement of the radial head caused by aging.

Adult↗

Ferromagnetic artificial cells for artificial circulation.

It is known that deoxygenated blood is paramagnetic. A ferrofluidic actuator for an implantable artificial heart has been studied. The magnetic fluid consists of ferromagnetic magnetite particles (10 nm). If artificial cells encapsulating ferromagnetic particles are mixed in blood, the circulation is maintained by applying a magnetic field to the blood. An array of two poles of ring solenoids with a gap of 10 mm was mounted near the glass tube (7.60 mm inner diameter). The flux density was 0.236 Tesla. Two experiments were conducted using models of artificial cells: 1) the magnetic fluid and 2) the magnetic fluid and an iron cylinder (6.67 mm in diameter and 28.7 mm in length). A flow of 38 to 8 ml/min was obtained against a pressure of 12.5 to 16.3 mmHg in experiment 1, and 80 to 24 ml/min against a pressure of 53 to 240 mmHg in experiment 2. Calculation showed that magnetic fluids could move against a pressure of 100 mmHg if they had a magnetization of 113 kA/m (B = 0.236 Tesla). The magnetic fluid has a magnetization of 35.6 kA/m, whereas the magnetite is 479 kA/m, and that of iron 1398 kA/m. Artificial circulation with ferromagnetic artificial cells could be feasible if artificial cells with a magnetization of 113 kA/m are developed.

Assisted Circulation↗

Development of a membrane oxygenator for long-term respiratory support and its experimental evaluation in prolonged ECMO.

The authors developed a new membrane oxygenator (MO) for long-term respiratory support and evaluated its performance in animal experiments for as long as 336 hr. The MO, with a membrane area of 1.2 m2 and priming volume of 140 ml, is compact and designed to be interposed in a ventricular assist system (VAS) conduit. It is made with a novel hollow fiber membrane, in which micropores are blind-ended so that serum leakage can be prevented during prolonged use. The blood contacting surface of the MO is heparinized with a newly developed covalent bonding technique that ensures good thrombus resistance. In vivo evaluation with five adult goats was performed by installing the MO into a venoarterial or venovenous bypass circuit. No systemic anticoagulant therapy was used, except for a heparin-added fluid infusion to keep the pressure monitoring lines open (2-3 U/kg/hr). Throughout the experiments, no plasma leakage was observed, and gas transfer rates were maintained in a satisfactory range. Platelet counts did not decrease to less than 60% of levels before bypass, and hemolysis was negligible. The levels of coagulation parameters including fibrinogen, fibrin degradation products (FDP), antithrombin III (AT III), antiplasmin, prothrombin time (PT) and activated partial thromboplastic time (APTT) remained within physiologic ranges and relatively constant. At the end of the evaluation, no thrombus formation was noted in three of five MOs. These results suggest that this MO is a promising device for long-term respiratory support.

Animals↗

Effects of cimetidine on fluid requirement during resuscitation of third-degree burns.

Seventy percent body surface area third-degree burns were produced in four groups of six guinea pigs each, after which all were resuscitated with Ringer's lactate solution. Group 1 received 4 ml/kg/%burn. Group 2 received 1 ml/kg/%burn with cimetidine, which was begun at 0.5 hours after burn injury. Group 3 received 1 ml/kg/%burn with cimetidine, which was begun at 1 hour after burn injury. Group 4 received 1 ml/kg/%burn without cimetidine. There were no significant differences among any of the groups in blood pressures or heart rates during the study period. Group 4 showed significantly higher hematocrit values than group 2 at 4 hours after burn injury and thereafter. The cardiac outputs of group 2 were the same statistically as those of group 1. The cardiac outputs of group 3 were significantly lower than those that received cimetidine early (group 2), though still higher than those of the 1 ml control group (group 4) at 4 hours after burn injury and thereafter. At 24 hours after burn injury, the water content of the burned skin of group 2 was significantly lower than that of the other groups. We conclude that in third-degree burns, cimetidine therapy can effectively reduce burn edema and the amount of required resuscitation fluid. Early administration is better than late administration of cimetidine.

Administration, Cutaneous↗

Distinct expression of CCR1 and CCR5 in glomerular and interstitial lesions of human glomerular diseases.

We investigated the presence of CCR1- and CCR5-positive cells immunohistochemically in the kidneys of 38 patients with several renal diseases, including 13 crescentic glomerulonephritis patients. In addition, we determined cell phenotypes of CCR1- and CCR5-positive cells using a dual immunostaining technique. Urinary levels of their ligands, for CCR1 and CCR5; macrophage inflammatory protein (MIP)-1alpha, MIP-1beta and regulated upon activation in normal T cells expressed and secreted (RANTES) were evaluated by enzyme-linked immunosorbent assay. CCR1- and CCR5-positive cells were detected in both glomeruli and interstitium of the diseased kidneys. Using a dual immunostaining technique, these positive cells were CD68-positive macrophages (MPhi) and CD3-positive T cells. The number of CCR1-positive cells in glomeruli was correlated with urinary levels of MIP-1alpha. The number of CCR1-positive cells in the interstitium was correlated with both urinary MIP-1alpha and RANTES levels. CCR1-positive cells in the interstitium remained after glucocorticoid therapy, most of which were MPhi, and were correlated with the intensity of interstitial fibrosis and tubular atrophy. Glomerular CCR5-positive cells were well correlated with extracapillary lesions and urinary MIP-1alpha levels, while interstitial CCR5-positive cells, mainly CD3-positive T cells, were correlated with interstitial lesions and urinary RANTES levels. Renal CCR5-positive cells were dramatically decreased during convalescence induced by glucocorticoids. These results suggest that chemokine receptor signaling may be pivotal for human renal diseases through the recruitment and activation of MPhi and T cells; CCR5-positive cells may participate in glomerular lesions including extracapillary lesions via MIP-1alpha and in interstitial lesions via RANTES. CCR1 may be involved in interstitial lesions in resolving phase after glucocorticoid therapy.

Adolescent↗

Application of genetically engineered tubular epithelial cells in kidney disease.

We constructed an ex vivo gene transfer system to deliver cytokines into the kidney and circulation using genetically modified renal tubular epithelial cells (TEC). TEC were infected with recombinant retroviruses expressing macrophage (Mphi) growth factors using a retroviral Moloney murine leukemia virus-based MFG vector. These infected TEC have the capacity to secrete stable and sustained amounts of cytokines for prolonged periods (>4 months) in vitro and in vivo (>28 days). Implanting genetically modified TEC secreting Mphi growth factors under the kidney capsule initiates severe local renal injury in mice with a deficiency in Fas (Faslpr gene). This system offers a novel and powerful approach to probe for the impact of sustained cytokine expression in the progression of kidney destruction.

Animals↗

22-Oxacalcitriol upregulates p21(WAF1/Cip1) in human parathyroid glands. A preliminary report.

In the era of 22-oxacalcitriol (OCT), newly synthesized 1 alpha,25-dihydroxyvitamin D(3) analogue, against secondary hyperparathyroidism, the indications of parathyroidectomy (PTx) has been restricted. Recent investigations on animal models have revealed the inhibitory effects on PTH secretion after OCT treatment, whereas there has been no evidence about human parathyroid glands. A 38-year-old man with a 19-year history of hemodialysis was performed PTx after the failure of OCT treatment. Expressions of proliferative nuclear cell antigen (PCNA), calcium-sensing receptor (CaSR), vitamin D receptor (VDR), p53 and p21(WAF1/Cip1) were analyzed by Western blotting and immunohistochemistry on resected parathyroid glands. We confirmed up-regulations of CaSR and VDR, which contribute the reduction of serum PTH, by OCT treatment. Concomitant up-regulation of p21(WAF1/Cip1) but not p53, especially in nodular hyperplasia, can be considered to induce cell cycle arrest of the parathyroid cells, but not cytocidal effect of OCT.

Adult↗

Flow cytometric analysis of p53 expression during the cell cycle.

Mutant p53 expressed in many types of carcinoma lacks an inhibitory function on cell growth, but its role has been unclear. We performed two-parameter flow cytometry (FCM) to elucidate the relationship between the expression of p53 and the cell cycle in A431 cells. Fluorescence in situ hybridization proved that an A431 cell had two p53 genes whereas chromosome 17 was tetraploid. FCM showed that A431 cells expressed constantly high levels of p53 during the cell cycle. Under conditions of both serum deprivation and presence of hydroxyurea, p53 expression was decreased throughout the cell cycle, and the bivariate DNA/p53 distribution pattern during the cell cycle did not change. The expression of p53 was reduced to 60% for the first 4 h after the addition of cycloheximide, and showed no significant changes at least for 20 h. Treatment with Triton X-100 increased p53 immunoreactivity throughout the cell cycle. These results indicate that mutant p53 differs from proliferative markers such as PCNA, Ki-67 and DNA polymerase-alpha, and that there are no links between the expression of p53 and the cell cycle in A431 cells.

Cell Cycle↗

A preliminary report of neoadjuvant chemotherapy NSH-7 study in osteosarcoma: preoperative salvage chemotherapy based on clinical tumor response and the use of granulocyte colony-stimulating factor.

Eleven patients with high-grade osteosarcoma of an extremity were treated with neoadjuvant chemotherapy with NSH-7 protocol. NSH-7 is a refinement of the T-12 Rosen protocol. Preoperative chemotherapy is initiated with a doxorubicin (ADM) and high-dose methotrexate combination. If the primary tumor progresses after the first cycle, the preoperative chemotherapy is switched to a combination of cisplatin and ADM. Postoperative adjuvant chemotherapy was selected based on histological response of the primary tumor. In addition, recombinant human granulocyte colony-stimulating factor was used to prevent leukocytopenia and to increase the dose intensity of the chemotherapy. In 1 patient, preoperative chemotherapy was switched to salvage treatment. Of the 156 courses given, there were 10 delays and 4 dose reductions. Leukocytopenia accounted for only 1 delay. All 11 patients completed the chemotherapy and 5 patients were fully able to tolerate the protocol without delay or dose reduction. Nine patients remained alive and continuously free of disease at an average follow-up of 35 months. The rate of continuous disease-free survival at 3 years was 81%, which was significantly better than that of the T-12 study of our group. These observations suggest that the NSH-7 protocol is a safe and effective treatment regimen for osteosarcoma.

Adolescent↗