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Biomedical subjects

Y Shimada

Publications and source records attributed to Y Shimada.

At least 307 records · Page 17Linked to original sources
PubMed1997

[The effect of low-dose prostaglandin E1 on intra- and post-operative renal function].

We investigated the effects of low-dose prostaglandin E1 (PGE1) on intra- and post-operative renal function in 109 adult patients undergoing upper abdominal surgery. Anesthesia was maintained with a combination of thoracic epidural combined with inhalational anesthesia. Sixty-seven patients received PGE1 at a rate of 0.2 microgram.kg-1.min-1 throughout surgery. Forty-two patients, who did not receive PGE1, served as control. Pre- and post-operative renal function was evaluated with serum levels of BUN and creatinine (Cr), while intra-operative renal function was evaluated mainly with urine output and urine flow rate during anesthesia. Urinary Na excretion and creatinine clearance (Ccr) were determined during surgery in limited cases. Urine output and urine flow rate during anesthesia were greater in PGE1 group than in control group, whereas infusion volumes and infusion rates were not different between the groups. In PGE1 group, urine flow rate was greater during surgery than before surgery, while in control group, it was unchanged. Na excretion during anesthesia was also greater in PGE1 group than in control group. In control group, Na excretion and Ccr were smaller during surgery than before surgery, while in PGE1 group, they were unchanged. Postoperative serum BUN and creatinine levels were not different between the groups. Decreased Na excretion and decreased Ccr in control group indicated that renal function was depressed during surgery, whereas unchanged Ccr, unchanged Na excretion and increased urine flow rate in PGE1 group indicated that renal function was well-maintained during surgery with PGE1. Low-dose PGE1 thus prevented depression of renal function during surgical anesthesia.

Abdomen↗
PubMed1997

[The effect of low-dose prostaglandin E1 on intra- and post-operative liver function].

We investigated the effects of low-dose prostaglandin E1 (PGE1) on intra- and post-operative liver function in 109 adult patients undergoing upper abdominal surgery. Patients were divided into 2 groups; Control group (n = 42) and PGE1 group (n = 67). In PGE1 group, PGE1 was infused throughout surgery at a rate of 0.02 microgram kg-1 min-1. In both groups, anesthesia was maintained with a combination of inhalational and thoracic epidural anesthesia. Epidural anesthesia was maintained with 1.5% lidocaine infused epidurally at a constant rate (8 +/- 2 ml.hr-1). The continuous epidural infusion of lidocaine was initiated before surgery and discontinued at the end of surgery. Preoperative and postoperative liver function was evaluated with blood chemistry examination. Intraoperative liver function was evaluated in 84 patients (33 in control group and 51 in PGE1 group) by measuring plasma lidocaine concentration. Plasma lidocaine concentration was determined 1 and 3 hours after the initiation of lidocaine infusion and 0 and 2 hours after its termination. There were no differences between the groups in doses and infusion rates of lidocaine. In both groups, lidocaine concentration increased progressively as infusion was continued. Lidocaine concentration was significantly lower in PGE1 group than in control group at the end of the infusion. In 22 patients in control group and 35 in PGE1 group who received high-dose lidocaine (> 8 mg.kg-1), lidocaine concentration remained significantly lower in PGE1 group than in control group throughout the infusion period. The difference in lidocaine concentrations between the groups increased progressively as infusion was continued, though the doses and the infusion rates of lidocaine were not different between the groups. Postoperative liver function did not differ between the groups. Because removal of lidocaine from blood to liver parallels hepatic blood flow, the lower plasma lidocaine concentration in PGE1 group indicated that hepatic blood flow was higher and liver function was better-maintained with PGE1 during anesthesia and surgery. Low dose PGE1 thus improved intraoperative liver function during upper abdominal surgery.

Abdomen↗
PubMed1997

[The effect of low-dose prostaglandin E1 on serum and urinary fluoride concentrations in patients anesthetized with sevoflurane].

We investigated the effects of low-dose prostaglandin E1 (PGE1) on serum and urinary concentrations of inorganic fluoride in 39 adult patients undergoing upper abdominal surgery. Anesthesia was maintained with a combination of N2O-O2-sevoflurane and thoracic epidural anesthesia. Twenty-two patients received infusion of PGE1 at a rate of 0.02 micrograms.kg-1.min-1 throughout surgery. Seventeen patients served as control by not receiving PGE1. Serum inorganic fluoride concentrations (FB) were determined before the induction of anesthesia and 0, 2 and 24 hours after the end of anesthesia. Urinary inorganic fluoride concentrations (FU) were determined before the induction of anesthesia, and 0, 24 and 48 hours after the end of anesthesia. These was no difference between PGE1 group and control group in anesthetic dose (MAC hours) of sevoflurane. In both groups, FB peaked at the end of anesthesia. In PGE1 group, UB peaked at the end of anesthesia, while in control group, it peaked 24 hours after anesthesia. There were differences between groups neither in FB nor in FU throughout the study period. The relationships between anesthetic dose and fluoride concentrations, however, differed significantly between the groups. In control group FB values of 0, 2 and 24 hours after anesthesia correlated positively with MAC hours, respectively, while in PGE1 group they did not. Similarly in control group, FU values of 24 and 48 hours after anesthesia correlated positively with MAC hours, respectively, while in PGE1 group, they did not. Thus in patients receiving high-dose sevoflurane, FB and FU tended to be lower in PGE1 group than in control group. In contrast, in PGE1 group, urinary excretion of fluoride during surgery correlated positively with MAC hours, while in control group, it did not. Urinary fluoride excretion during surgery was significantly greater in PGE1 group than in control group. These results suggested that PGE1 might prevent elevation of serum and urinary fluoride concentrations in patients receiving high-dose sevoflurane. This effect might result from enhanced urinary excretion of fluoride with PGE1.

Abdomen↗
PubMed1997

[Continuous epidural morphine for postoperative pain relief after spinal surgery--use of an epidural catheter placed at the time of surgery].

Postoperative analgesia by continuous epidural morphine infusion after spinal surgery was investigated in a retrospective study. An epidural catheter was placed by surgeons at the time of surgery. Postoperative pain was less intense and use of analgesics and sedative was less frequent in patients with continuous epidural morphine (n = 41) as compared with patients without continuous epidural morphine (n = 41). Among the patients with continuous epidural morphine, postoperative pain in patients (n = 16) with the dura opened or dural rent during surgery was less intense and the uses of analgesics and sedative was less frequent as compared with patients (n = 25) without the dural rent. There were no severe complications except for respiratory depression in a patient with chronic obstructive pulmonary disease. Our study demonstrated the ease of insertion of an epidural catheter at the time of surgery and the good quality of epidural analgesia after spinal surgery.

Adult↗
PubMed1997

Contribution of tumor necrosis factor alpha and interleukin-1 alpha on the production of macrophage inflammatory protein-2 in response to respiratory syncytial virus infection in a murine macrophage cell line, RAW264.7.

The production of several inflammatory cytokines, such as murine macrophage inflammatory protein-2 (MIP-2), tumor necrosis factor (TNF), and interleukin (IL)-1, was investigated in response to respiratory syncytial virus (RSV) infection in a murine macrophage cell line, RAW264.7, with special reference to mutual relation of their productions. The kinetics of MIP-2 production showed a trend for a biphasic pattern, that is, MIP-2 levels became detectable from 2 h postinfection (p.i.) and increased markedly until 8 h p.i. Thereafter, this level fell to the same level until 16 h p.i. and then increased again. TNF alpha was also detectable at 2 h p.i. and then increased sharply until 8 h p.i., when the peak level attained. Compared with the levels of MIP-2 and TNF alpha, that of IL-1 alpha/beta, especially IL-1 beta, was lower (ng versus pg/ml order). The presence of anti-TNF alpha or anti-IL-1 alpha antibody did not influence the early phase of MIP-2 production but significantly inhibited the late phase, suggesting that MIP-2 is induced by the combined effects of RSV infection via direct induction and indirectly after initial induction of TNF alpha and IL-1 alpha productions. Although RSV-infected RAW264.7 cells had no alteration in viability compared with mock-infected control, these data demonstrate that RSV is a potent inducer of inflammatory cytokines by direct induction and indirectly via the initial production of other cytokines.

Animals↗
PubMed1997

[The temperature dependency of the protective properties of the St. Thomas' Hospital cardioplegic solution, the University of Wisconsin solution, and Bretschneider buffered solution].

We studied three preservation solutions such as St. Thomas' hospital cardioplegic solution No. 2 (ST), the University of Wisconsin solution (UW) and Bretschneider's solution (BR) for protective properties, especially in terms of temperature dependence during the preservation. Rat hearts were studied and divided into three groups; ST. UW and BR. In each group, six hearts were carried out perfusion, cardioplegic infusion, ischemia and reperfusion for four different conditions. Using an isolated working rat heart model, the hearts were subjected to 5 minutes Langendorff perfusion followed by 20 minutes working perfusion. During this working period, cardiac functions such as aortic and coronary flow, aortic pressure, and heart rates were measured every 5 minutes. After working perfusion, 3 minutes of cardioplegic infusion was carried out either with UW, ST, and BR at 37, 20, 4, 1 degree C. The hearts were subjected to either 35 min at 37 degrees C, 120 min at 20 degrees C, 300 min at 4 degrees C, or 450 min at 1 degree C. The hearts were immersed in the same solution during ischemia. The hearts were reperfused at 37 degrees C, initially in the Langendorff mode for 15 min. Coronary effluent was collected for the measurement of CK leakage during reperfusion. The heart were then converted to the working mode for 20 minutes. During working reperfusion period, the variables of cardiac function were again measured and expressed as a percentage of their individual preischemic control values. Under conditions of 37 degrees C ischemia, % recovery of cardiac output (%CO) in ST group is 62.8 +/- 2.8%, although the hearts preserved with UW and BR were not recovered. Under conditions of 20 degrees C ischemia, %CO in UW, ST and BR were 46.8 +/- 2.7, 82.0 +/- 3.1 and 41.4 +/- 2.6%, respectively. Under conditions of 4 degrees C ischemia, %CO in UW, ST and BR were 66.2 +/- 8.0, 68.6 +/- 2.3 and 47.2 +/- 2.9%, respectively. Under conditions of 1 degrees C ischemia, %CO in UW, ST and BR were 70.6 +/- 3.3, 56.5 +/- 1.6 and 43.0 +/- 2.5%, respectively. In conclusions, ST revealed the best protective properties for the heart preservation between 37 degrees C and 20 degrees C ischemia. The properties of ST was similar to that of UW under conditions of 4 degrees C, although UW showed most excellent protective properties under conditions of 1 degrees C ischemia. These results suggested that, protective ability of preservation solution might be changed by the temperature during preservation period.

Adenosine↗
PubMed1996

Optimal size criteria of malignant lymph nodes in the treatment planning of radiotherapy for esophageal cancer: evaluation by computed tomography and magnetic resonance imaging.

PURPOSE: To determine the optimal size criterion for detection of lymph node metastases from esophageal cancer for radiotherapy by computed tomography (CT) and magnetic resonance (MR) imaging. METHODS AMD MATERIALS: In 58 patients with esophageal cancer treated with subtotal esophagectomy and radical lymph node dissection the preoperative MR (n = 58) images and CT scans (n = 41) were reviewed. The relationship of the CT and MR findings for the neck and mediastinum to the surgical and histopathological results was examined. Five size criteria on malignant lymph nodes were used to construct receiver operating characteristic (ROC) curves for CT and MR, and their detectabilities were evaluated. RESULTS: The specificities of both modalities at the cutoff of 3 mm short-axis diameter were lower than those at the cutoff of 5 mm or more. In contrast, the sensitivities apparently decreased at the cutoff of 10 mm or more. The analysis of the ROC curves showed that the optimal size criterion for malignant lymph nodes was 5 mm for both CT and MR. When the criterion of 5 mm was used, the sensitivity, specificity, and accuracy for CT was 68, 92, and 87%, respectively, and the respective values for MR were 70, 93, and 89%. Although there was no significant difference between the two ROC curves, MR was useful in distinguishing lymph nodes from vascular structures because of the flow void. CONCLUSIONS: There was no significant difference between CT and MR in the detection of malignant lymph nodes from esophageal cancer. The optimal size criterion for both CT and MR in the detection of cervical and mediastinal lymph node metastases is 5 mm for short-axis diameter. These results suggest that all regional lymph nodes of 5 mm or more on CT or MR should be regarded as part of the gross tumor volume in the treatment planning of radiotherapy for esophageal cancer.

Adult↗
PubMed1996

Integrin-specific tissue-type plasminogen activator engineered by introduction of the Arg-Gly-Asp sequence.

To tailor tissue-type plasminogen activator (tPA) to possess an affinity for the integrins, several mutants were constructed by introducing the Arg-Gly-Asp (RGD) sequene into the tPA molecule. These mutants were expressed in COS-1 cells and partially purified by lysine-Sepharose chromatography. The RGD-dependent binding of the mutants to platelet integrin, integrin alpha IIb beta 3, was evaluated by subtracting the nonspecific binding in the presence of 10 mM EDTA (or 1 mg/ml GRGDSP). The binding assay showed that two tPA mutants possess high affinity for the integrin in an RGD-dependent manner. One mutant is 148RGD-tPA with RGDS in place of DRDS (residues 148 to 151) in the loop region of the kringle 1 domain of tPA, and the other is 270RGD-tPA with RGDS in place of SQPQ (residues 270 to 273) in the linker region between the kringle 2 and protease domains. Using the chromogenic substrate Spectrozyme tPA, the 148RGD-tPA mutant was shown to possess amidolytic activity comparable with that of native tPA, while the 270RGD-tPA mutant exhibited several-fold lower activity. In addition, the 148RGD-tPA exhibited full tPA activity even when interacting with the integrin alpha IIb beta 3. These results suggest that the bifunctional 148RGD-tPA molecule might be useful as an improved thrombolytic agent specific for the platelet integrin, the integrin alpha IIb beta 3.

Amino Acid Sequence↗
PubMed1996

The responses of skin blood flow, mean arterial pressure and R-R interval induced by cold stimulation with cold wind and ice water.

This study was designed to evaluate the peripheral circulation response to cold wind stimulation. Skin blood flow (SBF), ECG R-R intervals (RRs) and mean arterial pressure (MAP) were measured in ten healthy men under strictly controlled conditions. Cold wind flow and ice water bath were prepared as cold stimulations. The subjects were exposed to each cold stimulation and the values of the responses were simultaneously recorded. The cold wind stimulation reduced SBF (maximally 40.4 +/- 3.2%) and increased MAP (maximally 106.9 +/- 1.3%), but did not affect RRs. On the other hand, all parameters were affected by the ice water stimulation, which reduced SBF to 16.4 +/- 1.2% and RRs to 85.1 +/- 3.0%, and increased MAP to 130.6 +/- 2.4% compared with the control state. All subjects suffered from intense pain during the ice water but not the cold wind stimulation, and two of them were eliminated from this study because of vagotonia. After phentolamine iontophoresis was used to block the receptor of peripheral alpha-adrenergic nerve terminals, the cold wind stimulation did not affect SBF. These results suggest that cold wind stimulation is a useful test for evaluating peripheral alpha-adrenergic nerve function in relation to cold sensation, without increase of RRs and noxious pain.

Adolescent↗
PubMed1996

Heterogeneous aging of macrophage-lineage cells in the capacity for TNF production and self renewal in C57BL/6 mice.

We examined age-related changes in both tumor necrosis factor-alpha (TNF) producing ability and the replicative capacity of macrophage-lineage cells from different anatomical tissues concomitantly in mice. We have previously demonstrated that alveolar macrophages of aged mice secreted decreased amounts of TNF activity compared with that of younger counterpart. In this study, it is demonstrated that peritoneal macrophages exhibited increased TNF activity with aging, while the bone marrow-derived adherent cells secreted less TNF activity. In addition, we showed that the numbers of their progenitor cells (GM-CFUs) in the bone marrow increased with age, whereas those in the spleen did not change with aging. We conclude that age associated changes in functions and proliferative capacities of macrophage-lineage cells are tissue dependent.

Animals↗
PubMed1996

Effects of water ingestion on gastric electrical activity and heart-rate variability in healthy human subjects.

Electrogastrography (EGG) is a method to record electrical activity of the stomach using cutaneous electrodes. Power ratio (PR) is one of the parameters and means the relative change of EGG power of gastric activity from before to after certain stimulations (e.g., meals, water or drugs). Autonomic nervous function is an important modulator of gastric activity, but its relation with the EGG parameters has not been well clarified. We recorded EGG and the R-R interval simultaneously both before and after drinking 150 ml water for 400 s, and spectrally analyzed them using the maximum entropy method in 12 healthy volunteers. We calculated PR from before to after water ingestion, and the power of the high-frequency component of R-R interval variability before (pre-HF) and after water ingestion (post-HF), and their ratio (rHF = post-HF/pre-HF). PR was positively correlated with rHR (r = 0.727; P < 0.05) and negatively correlated with pre-HF (r = 0.706; P < 0.05), and rHF was negatively correlated with pre-HF (r = 0.776; P < 0.05). These results suggest that simultaneous recording of EGG and ECG for frequency domain analysis is necessary to estimate the vagal nervous activity.

Adult↗
PubMed1996

Origin of nerves supplying the posterior portion of lumbar intervertebral discs in rats.

STUDY DESIGN: The authors studied the origin of nerves supplying the posterior portion of lumbar intervertebral discs in rats by resection of the sympathetic trunks. OBJECTIVE: To understand discogenic low back pain from the innervation of the lumbar intervertebral discs. SUMMARY OF BACKGROUND DATA: The afferent pathways of discogenic low back pain have not been studied thoroughly. It has been reported that stimulation of an inflamed lower spinal nerve root elicits leg pain but not low back pain and that stimulation of the posterior portion of lumbar intervertebral discs evokes only low back pain. These facts suggest that pain sensation from the posterior portion of lumbar discs is not transmitted via the lower spinal nerve roots. METHODS: Forty-five Wistar rats were used. Seven days after the resection of sympathetic trunks with ganglia at different levels, the whole lumbar spine was stained by an acetylcholinesterase histochemical method. The posterior portions of lumbar intervertebral discs were observed. RESULTS: The dense nerve network on the posterior portion of lumbar intervertebral discs had disappeared almost completely after total resection of bilateral sympathetic trunks at L2-L6. However, there was a slight decrease in the network after bilateral single-level resection or unilateral multisegmental resection. CONCLUSIONS: The results showed that the posterior portion of lumbar intervertebral discs was innervated by the sympathetic nerves multisegmentally and bilaterally.

Afferent Pathways↗
PubMed1996

Role of neuropeptide Y and its receptor subtypes in neurogenic pulmonary edema.

The effect of neuropeptide Y on the number of perivascular carbon deposits, assessed as a measure of lung vascular permeability, was examined in isolated perfused lung preparations of rats. The number of carbon particle deposits after bronchial application of neuropeptide Y was increased in a dose-dependent manner. In the presence of a beta-adrenoceptor antagonist, norepinephrine augmented the effects of neuropeptide Y. Peptide YY, an analog of neuropeptide Y, demonstrated a much lower potency for increasing the number of carbon deposits, and neuropeptide Y-(18-36), which elicits a weak antagonist action on the neuropeptide Y Y3 receptor, significantly decreased the neuropeptide Y-induced increase. Furthermore, examination of the influence of neuropeptide Y-(18-36) pretreatment on fibrin-induced neurogenic pulmonary edema, in rats, revealed a reduction of the protein concentration ratio of tracheal fluid to serum. Therefore, we conclude that neuropeptide Y may elevate vascular permeability in the pulmonary circulation, conceivably through the neuropeptide Y Y3 receptor, and that neuropeptide Y may in fact play a physiological role even in the in-situ pulmonary circulation.

Animals↗
PubMed1996

Characterization of p53 gene mutations in esophageal squamous cell carcinoma cell lines: increased frequency and different spectrum of mutations from primary tumors.

We screened 29 human esophageal squamous cell carcinoma (ESC) cell lines for mutations of the p53 gene through all coding exons and exon-intron junctions. Mutations were found in 22 cell lines (76%), consisting of 20 single-base substitutions, 2 small deletions and 1 single-base insertion. Out of 20 single-base substitution, 5 were located at the exon-intron junctions and mRNAs with abnormal splicing were detected by RT-PCR in 4 of them. A G:C to T:A transversion, which occurred rather frequently in resected tumors of ESC, was observed in only 1 cell line, and, instead, frequent transitions at CpG sites were detected. We also examined 65 fresh tumor materials, from all of which we tried to establish cell lines, and detected mutations in 26 samples (40%). Compared with the results in these fresh tumor materials, the mutation incidence in cell lines was significantly high and the mutation spectrum was also different. From these 65 tumors, 10 cell lines were established, including 3 cell lines from 26 tumors with p53 mutations and 7 cell lines from 39 without mutations, which indicates that there was no significant correlation between the status of the p53 gene in each fresh tumor and its establishment as a cell line. In 7 cell lines established from mutation-free tumors, newly acquired mutations were detected in 5, which suggests that mutations might occur during the process of establishing cell lines.

Base Sequence↗
PubMed1996

Prognostic value of monolayer culture patterning in primary cell culture of oesophageal cancer.

The growth of primary cell cultures of oesophageal cancer was compared with the clinical outcome of patients from whom the cancers were taken. Ninety-three patients underwent curative resection, with no operative deaths, and were divided into three groups according to the monolayer culture pattern of the primary cell culture: culture from 43 patients (46 per cent) grew no malignant cells (group 1), 21 (23 per cent) produced monolayer epithelial growth (group 2) and the rest (from 29 patients) established cell lines (group 3). The 5-year survival rate of patients in group 2 (29 per cent) and group 3 (23 per cent) was significantly lower (P < 0.005) than that of those in group 1 (51 per cent). Monolayer epithelial growth potential is a significant prognostic factor in patients with oesophageal cancer.

Adult↗