Tohru Mori

Perioperative changes in plasma brain natriuretic peptide concentrations in patients undergoing cardiac surgery

The plasma concentrations of brain natriuretic peptide (BNP), a cardiac hormone, were measured in 30 consecutive adult patients undergoing cardiac surgery with cardiopulmonary bypass (CPB) during the perioperative period. BNP concentrations remained unchanged until 6 h after the cessation of bypass, and were elevated 12, 24, and 48 h post-bypass (P<0.0001 versus baseline). They had returned to the baseline values when measured 3 weeks postoperatively. The preoperative plasma BNP concentration correlated significantly with the left ventricular ejection fraction (r=-0.895). The peak plasma BNP concentration 24 h after bypass correlated with the cardiac index (r=-0.64), stroke volume index (r=-0.62), injection rate of dopamine hydrochloride (r=0.65), and aortic crossclamp time (r=0.57). There was also a significant correlation between the preoperative BNP concentration and the plasma BNP concentration 24 h post-CPB. These findings led us to conclude that the plasma concentrations of BNP become markedly and acutely elevated after cardiac surgery with CPB, and reflect the state of left ventricular function. Moreover, the severity of acute heart failure after cardiac surgery can be predicted by the preoperative plasma BNP concentration.

Different immune functions of peripheral blood, regional lymph node, and tumor infiltrating lymphocytes in lung cancer patients

Immune functions of peripheral blood (PBL), regional lymph node (RLNL), and tumor infiltrating lymphocytes (TIL) were evaluated in lung cancer patients. PBL had many natural killer (NK) cells and the highest NK activity, and it showed the highest augmentation of NK activity by interferon‐SgM (IFN‐γ) + recombinant interleukin‐2 (rIL‐2) among the three groups of lymphocytes. PBL had high lymphokine‐activated killer (LAK) activity of against a broad spectrum of cell lines and moderate activity against autologous tumor cells by increased effector to target (ET) ratio but the lowest ability of IL‐2 production of the three groups of lymphocytes. The RLNL not associated with tumor metastasis had a few NK cells and lower NK activity than PBL, but its LAK activity was almost the same but not greater than that of PBL. RLNL had the highest ability of IL‐2 production among the three groups of lymphocytes. All activities of RLNL associated with tumor metastasis were lower than those not associated with tumor metastasis. TIL exclusively consisted of T‐cells, especially cytotoxic/suppressor T‐Iymphocytes. NK activity and lymphocyte blastogenesis of TIL were lower than those of other groups. The LAK activity of TIL differed greatly with the case, and it was the highest against autologous tumor cells among the three groups of lymphocytes in three of eight cases. These findings showed that PBL, RLNL, and TIL had characteristic subpopulations of lymphocytes and different functions of host immune responses in lung cancer. Efficient augmentation of the characteristic immune responses will lead to a more effective total cancer therapy.

Optimal calcium concentration in the initial reperfusate for post-ischemic myocardial performance (calcium concentration during reperfusion)

The dose-response curves of calcium concentration in the initial reperfusate to mechanical recovery of ischemic myocardium was investigated with an isolated working rat heart preparation. After 20 mins of normothermic ischemic arrest, the recovery of aortic flow by reperfusion with Krebs-Henseleit buffer was 54.0 +/- 2.4% (mean +/- S.E.M.). Reduction of calcium concentration during 10 mins of initial reperfusion after 20 mins of normothermic ischemic arrest increased or decreased the recovery of aortic flow with a bell-shaped dose-response curves obtained. The maximal percent recovery of aortic flow was 75.2 +/- 1.7 at 0.5 mM calcium with normal potassium-normal magnesium solution, 74.9 +/- 3.1 at 0.1 mM with high potassium (20 mM)-normal magnesium solution, 65.4 +/- 1.5 at 1.2 mM with high potassium-high magnesium (20 mM K, 16 mM Mg) solution, and 73.4 +/- 2.7 at 1.3 mM with normal potassium-high magnesium (16 mM) solution. All of them were significantly better than that of the control group (P less than 0.01). A high concentration of potassium and magnesium affected the dose-response of calcium in the initial reperfusate. These results suggest that the control of calcium concentration in the reperfusate is important during the early stages of reperfusion, and reperfusion injury may be considerably reduced.

Delayed cardiac tamponade and hemothorax induced by an acupuncture needle

We report a 52-year-old man who presented with cardiac tamponade a few years after accidental breakage of an acupuncture needle that had not been removed. Thoracotomy showed a hemopericardium with penetration of the pulmonary artery by the very fine needle which was barely detected on the chest roentgenogram. This lesion was not suspected on the basis of roentgenography, two-dimensional echocardiography, or computed tomography, but was detected by the presence of other thick needles in the neck, chest and abdomen. This case showed a possible threat of stealthy and migrating foreign bodies, such as very fine acupuncture needles.

Characteristics of 161 Patients With Cardiac Tumors Diagnosed During 1993 and 1994 in Japan

We investigated clinical and pathologic characteristics of 161 patients with primary or secondary cardiac tumors diagnosed between 1993 and 1994 in Japan. The increased use of cardiovascular imaging, especially echocardiography, contributed to the early identification of small cardiac tumors, resulting in a reduction of the serious complications such as embolization.

Quantitative Evaluation of the Skin Circulation in Ischemic Legs by Transcutaneous Measurement of Oxygen Tension

We tried to apply transcutaneous oxygen tension (tcPo2) in evaluating the ischemic leg quantitatively from the standpoint of the skin circulation. The tcPo2 measurement was performed on the pretibial and dorsal skin at rest, on exercise loading, and during oxygen inhalation; tcPo2 on the chest wall was measured as a standard value. The subjects consisted of 47 patients with ischemic legs and 20 normal healthy males without ischemic legs. tcPo2 in the pretibial skin had a tendency to decrease with aging. There was a correlation between pretibial tcPo2 and ankle pressure (r = 0.51, p < 0.02). In the affected leg, each mean pretibial tcPo2 under 3 different conditions was much lower than that of control. Pretibial tcPo2 of patients also correlated well with the Fontaine classification of clinical severity of ischemic legs. We concluded that transcutaneous measurements of oxygen tension at the pretibial region are useful in evaluating the ischemic leg quantitatively.

Beneficial actions of acidotic initial reperfusate in stunned myocardium of rat hearts

SummaryThe effects of metabolic acidosis and alkalosis in the initial reperfusate on post-ischemic stunned myocardium were investigated in isolated rat hearts. Metabolic acidosis and alkalosis were produced by altering the doses of artificial buffer (Tris) in place of sodium bicarbonate. All hearts were subjected to global ischemia for 15 min at 37°C. The initial reperfusate under study was given during the subsequent 10 min of reperfusion, just prior to release of the aortic clamp. After that, reperfusion using normal Krebs-Henseleit buffer solution was carried out for 40 min. The acidotic initial reperfusate (pH 6.8) resulted in better protection than the alkalotic initial reperfusate (pH 7.8), as demonstrated by 1) a higher recovery of aortic flow (80.6 % ± 3.8 % vs 32.7 % ± 4.8 %, p < 0.01), 2) a smaller leakage of creatine kinase during the initial reperfusion phase (6.0 ± 0.7 vs 14.6 ± 2.1 IU/10 min/g dry weight, p < 0.05) and during the post-ischemic Langendorff perfusion phase (8.8 ± 1.7 vs 37.3 ±5.2 IU/10 min/g dry weight, p < 0.05), and 3) a lower myocardial water content at the end of reperfusion (84.8 ± 0.2 % vs 85.7 % ± 0.3 %, p < 0.05). Not only Tris buffer system, but also HEPES buffer system indicated that acidotic initial reperfusate was effective to protect against myocardial injury. These results suggest that 1) the extracellular pH during initial reperfusion profoundly influences the reversible myocardial dysfunction (stunned myocardium), and 2) the acidotic initial reperfusate improves post-ischemic myocardial performance.

Effect of magnesium and calcium on myocafdial protection by cardioplegic solutions

The cardioprotective effect of the magnesium and calcium content of hyperkalemic cardioplegic solutions was investigated using isolated rat hearts subjected to hypothermic ischemic arrest. Hearts were arrested for 180 minutes at 20 degrees C by administering a 3-minute infusion of cardioplegic solution containing various concentrations of magnesium and calcium. Treatment groups received solution with either 0, 8, or 16 mmol/L magnesium. For each of these magnesium concentrations, 0.1, 0.6, or 1.2 mmol/L calcium was also present in the solution. At each concentration of magnesium, the percentage recovery of aortic flow was dependent on the calcium concentration. The maximum percentage recovery of aortic flow was 67.9% +/- 2.3% (mean +/- standard error of the mean) in the Mg-free, 0.1 mmol/L Ca group, whereas it was 65.1% +/- 2.7% in the 8 mmol/L Mg, 0.1 mmol/L Ca group and 70.0% +/- 3.5% in the 16 mmol/L Mg, 0.6 mmol/L Ca group. No significant differences in the recovery of cardiac function and creatine kinase leakage were observed between the three groups. The findings suggested that the cardioprotective effect was dependent on the relative concentration of both magnesium and calcium, and that it is important to maintain an appropriate ionic balance in cardioplegic solutions.

Transvenous Dual Chamber Pacing via a Unilateral Left Superior Vena Cava

A 74‐year‐old woman with a unilateral left superior vena cava required dual chamber permanent pacing after a radical cardiac operation for an incomplete form of endocardial cushion defect. An active fixation ventricular lead was used to prevent the instability induced by the strange course of the electrode. For atrial pacing, a ventricular passive fixation lead was used. A transvenous dual chamber pacemaker was successfully inserted via a unilateral left superior vena cava.

Continuous measurement of transcutaneous oxygen tension on stress test in claudicants and normals.

Subjective evaluation of hemodynamics by stress tests in claudicants should be made to establish severity of functional ischemia. As an indispensable examination of vascular laboratory, non-invasive, simple methods can only satisfy methodological conditions. The aim of this study was to apply the transcutaneous oxygen tension measurement for a non-invasive, continuous detector of hemodynamic responses in skin circulation by stress tests and to elucidate the clinical usefulness of this technique. Investigated were 20 legs in patients with intermittent claudication and 9 legs in healthy persons as controls. Ten legs with ischemic pain during exercise loading revealed abnormal transcutaneous oxygen tension (tcPO2) curves in comparison with those with in normal legs. Over the continuous tcP02 curve, the minimum tcPO2 at the reverse postural change after exercise loading was the most reliable indicator for evaluating induced ischemia. We conclude that hemodynamic responses on stress tests should be analyzed both during and after exercise loading, and that the continuous tcP02 curve constitutes a useful method for evaluating and following up the claudicants.