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Local distinguishability of sets of generalized Bell states (GBSs) is investigated. We first clarify the conditions such that a set of GBSs can be locally transformed to a certain type of GBS set that is easily distinguishable within local operations and one-way classical communication. We then show that, if the space dimension $d$ is a prime, these conditions are necessary and sufficient for sets of $d$ GBSs in $\mathbb{C}^d \otimes \mathbb{C}^d$ to be locally distinguishable. Thus we obtain a simple computable criterion for local distinguishability of sets of $d$ GBSs in prime dimension $d$., 6 pages, presentation improved, final version

A broadband measurement system is developed to address the issue of temperature dependence of the complex permittivity and conductivity of low-loss substrates in the millimeter-wave bands for fifth/sixth generation wireless communication applications. The developed system can provide broadband material measurements from less than 20 GHz to over 100 GHz over variable temperatures by utilizing higher order mode resonances of a balanced-type circular disk resonator (BCDR). The broadband measurement capability of the developed system is attributed to the mode-selective behavior of the BCDR over a wideband. To demonstrate the developed system, we measure the complex permittivity of the following three substrate materials over variable temperatures from 25 °C to 100 °C: cyclo-olefin polymer (COP), ceramic-filled polytetrafluoroethylene composites, and fused silica. Furthermore, the temperature dependence of the conductivity of the surface-mounted metal is characterized for the COP substrate. The measurements indicate that the loss tangents and conductivities of the substrates increase and decrease, respectively, with the temperature and frequency in the millimeter-wave bands. The full-wave simulations using the measured complex permittivity and conductivity of the COP substrate reveal that the propagation loss of the microstrip line using the COP substrate increases with the temperature and frequency and that the increase in the loss is primarily attributed to the decrease in the conductivity.

We construct minimum-uncertainty states and a non-negative quasi probability distribution for quantum systems on a finite-dimensional space. We reexamine the theorem of Massar and Spindel for the uncertainty relationof the two unitary operators related by the discrete Fourier transformation. It is shown that some assumptions in their proof can be justified by the use of the Perron-Frobenius theorem. The minimum-uncertainty states are the ones that saturate this uncertainty inequality. The continuum limit is closely analyzed by introducing a scale factor in the limiting scheme. Using the minimum-uncertainty states, we construct a non-negative quasi probability distribution. Its marginal distributions are smeared out. However, we show that this quasi probability is optimal in the sense that there does not exist a non-negative quasi probability distribution with sharper marginal properties if the translational covariance in the phase space is assumed. Generally, it is desirable that the quasi probability is complete, i.e., it contains full information of the state. We show that the obtained quasi probability is indeed complete if the dimension of the state space is odd, whereas it is not if the dimension is even., 12 pages, 3 figures; improved presentation, final version

We investigate the performance of discrimination strategy in the comparison task of known quantum states. In the discrimination strategy, one infers whether or not two quantum systems are in the same state on the basis of the outcomes of separate discrimination measurements on each system. In some cases with more than two possible states, the optimal strategy in minimum-error comparison is that one should infer the two systems are in different states without any measurement, implying that the discrimination strategy performs worse than the trivial "no-measurement" strategy. We present a sufficient condition for this phenomenon to happen. For two pure states with equal prior probabilities, we determine the optimal comparison success probability with an error margin, which interpolates the minimum-error and unambiguous comparison. We find that the discrimination strategy is not optimal except for the minimum-error case., Comment: 8 pages, 1 figure, minor corrections made, final version

The phase point operator Δ(q,p) is the quantum mechanical counterpart of the classical phase point (q,p). The discrete form of Δ(q,p) was formulated for an odd number of lattice points by Cohendet et al. and for an even number of lattice points by Leonhardt. Both versions have symplectic covariance, which is of fundamental importance in quantum mechanics. However, an explicit form of the projective unitary representation of the symplectic group that appears in the covariance relation is not yet known. We show in this paper the existence and uniqueness of the representation, and describe a method to construct it using the Euclidean algorithm.

This paper summaries a bilateral comparison of dimensional measurements of the diameters of two precision 1.85-mm coaxial air lines and associated electrical scattering parameter measurements. The measurements were independently made by two national metrology institutes: the National Metrology Institute of Japan and the National Physical Laboratory. The laboratories also calculated the characteristic impedances and their uncertainties based on the measured diameter values and uncertainties. The difference between the characteristic impedances calculated by the two laboratories for the two lines was less than 0.2 Ω. The uncertainty of this difference at a 95% level of confidence was 0.3 Ω. The scattering parameter measurement results agreed well at almost all comparison frequencies from 5 to 65 GHz.

This paper summarizes a bilateral comparison of the measurements of the diameters of two precision coaxial air lines with a line size of 3.5 mm. These mechanical measurements were independently made by two national metrology institutes, i.e., the National Metrology Institute of Japan (NMIJ) and the National Physical Laboratory (NPL). The laboratories also calculated the characteristic impedance of each air line based on the measured diameter values. The difference between the characteristic impedances calculated by the two laboratories for both lines was less than 0.020 Omega. The uncertainty of this difference, at a 95% level of confidence for each line, was 0.084 and 0.307 Omega.

As a stochastic model for quantum mechanics we present a stationary quantum Markov process for the time evolution of the Wigner function on a lattice phase space Z_N x Z_N with N odd. By introducing a phase factor extension to the phase space, each particle can be treated independently. This is an improvement on earlier methods that require the whole distribution function to determine the evolution of a constituent particle. The process has branching and vanishing points, though a finite time interval can be maintained between the branchings. The procedure to perform a simulation using the process is presented.

We clarify the structure of the Bazhanov-Baxter model of the 3-dim N-state integrable model. There are two essential points, i) the cubic symmetries, and ii) the spherical trigonometry parametrization, to understand the structure of this model. We propose two approaches to find a candidate as a solution of the tetrahedron equation, and we find a new solution., 23 pages, Latex

We formulate the Dirac equation by a proficient method on a (1+D)-dimensional Euclidean lattice and get some new results. First, the obtained dispersion relation of the lattice fermion has no extra poles. Second, the components of the fermion is 2{sup D}, which should be compared to the 2{sup D+1} of the Kogut-Susskind (KS) fermion. Furthermore we can explicitly show that the theory has the KS discrete chiral symmetry. All the lattice fermions tend to the usual fermions on continuous spacetime. {copyright} {ital 1997} {ital The American Physical Society}

The Dirac equation is formulated on (1+{ital D})-dimensional discrete Minkowski space-time. We find that the minimum number of components of the fermion field is 2{sup D{minus}1} in the massless case, which is smaller than 2{sup D+1} of the Kogut-Susskind fermion. There exist no extra poles in the fermion propagator. The action is not Hermitian but the quantization can be performed consistently. In the (1+3)-dimensional massless case the equation describes a single species of Dirac particle in the continuous space-time limit. In the (1+1)-dimensional massless case the equation is the same as the automaton equation by {close_quote}t Hooft and describes a chiral fermion. The time evolution operator is unitary and the norm is conserved. For interacting fermions with gauge fields the evolution operator is not unitary. But in the continuum limit the unitarity will be recovered. The consequences of loosening the unitarity condition on the time evolution operator are discussed. {copyright} {ital 1997} {ital The American Physical Society}

We develop a systematic description of Weyl and Fano operators on a lattice phase space. Introducing the so-called ghost variable even on an odd lattice, odd and even lattices can be treated in a symmetric way. The Wigner function is defined using these operators on the quantum phase space, which can be interpreted as a spin phase space. If we extend the space with a dichotomic variable, a positive distribution function can be defined on the new space. It is shown that there exits a quantum Markov process on the extended space which describes the time evolution of the distribution function., Comment: Lattice2003(theory)

We propose a canonical procedure to quantize fields with interaction on discrete space-time. The time evolution operator that reproduces the field equation is represented by using canonical variables. The generator of the operator is a conserved quantity, but its existence is not obvious. It is possible to calculate the S-matrix perturbatively. Our quantization gives the same results as those given by the path integral quantization.

We have examined solutions of tetrahedron equations from the elliptic free fermion model by using Korepanov mechanism based on tetrahedral Zamolodchikov algebras. As a byproduct, we have found a new integrable 2-dim. lattice model. We have also studied the relation between tetrahedral Zamolodchikov algebras and tetrahedron equations., 10 pages, Latex

The problem whether there exist conserved quantities in the theory on discrete spacetime is studied. This problem is not obvious in the theory on discrete spacetime, because Noether's theorem is not applicable. The same problem arises even in the classical dynamics on discrete time. Some examples are shown in the classical dynamics with conserved quantities. The equation of motion is interpreted as an iterative map, which does not behave chaotically if there exists a conserved quantity. By suitable discretization the equation obtains a conserved quantity. In conclusion, an example of classical field theory with a conserved quantity is shown on four-dimensional discrete spacetime.

Periodontitis is characterized by periodontal tissue inflammation and alveolar bone loss. The intermittent administration of parathyroid hormone (PTH), a major regulator of bone remodeling, has been demonstrated to stimulate osteoblastic activity. Although the systemic administration of PTH has been reported to protect against periodontitis-associated bone loss, the effect of the topical administration of PTH is unclear. In this study, the effect of intermittent administration of PTH on osteoblastic differentiation was examined in cultured calvaria cells and then the effect of topical and intermittent administration of PTH was determined by measuring the recovery of alveolar bone loss after inducing experimental periodontitis in rats.Alkaline phosphatase activity and bone nodule formation were measured in fetal rat calvaria cells. Experimental periodontitis was induced by placing nylon ligature around rat maxillary molars for 20 d. After ligature removal (day 0), PTH was topically injected into buccal gingiva three times a week for 10 wk. Micro-computed tomography analysis and histological examination were performed on days 35 and 70.Intermittent exposure of PTH in calvaria cells increased alkaline phosphatase activity and bone nodule formation by 1.4- and 2.4-fold, respectively. Ligature procedures induced marked alveolar bone loss around the molars on day 0 and greater bone recovery was observed in the PTH-treated rats on day 70. An increase in osteoid formation on the surface of alveolar bone was detected in the PTH-treated rats.Intermittent treatment with PTH stimulated osteoblastic differentiation in fetal rat calvaria cell cultures, and topical and intermittent administration of PTH recovered alveolar bone loss in rat experimental periodontitis.

Complete solutions are given in a closed analytic form for unambiguous discrimination of three general pure states with real mutual inner products. For this purpose, we first establish some general results on unambiguous discrimination of n linearly independent pure states. The uniqueness of solution is proved. The condition under which the problem is reduced to an (n-1)-state problem is clarified. After giving the solution for three pure states with real mutual inner products, we examine some difficulties in extending our method to the case of complex inner products. There is a class of set of three pure states with complex inner products for which we obtain an analytical solution., Comment: 13 pages, 3 figures, presentation improved, reference added

We investigate a state discrimination problem which interpolates minimum-error and unambiguous discrimination by introducing a margin for the probability of error. We closely analyze discrimination of two pure states with general occurrence probabilities. The optimal measurements are classified into three types. One of the three types of measurement is optimal depending on parameters (occurrence probabilities and error margin). We determine the three domains in the parameter space and the optimal discrimination success probability in each domain in a fully analytic form. It is also shown that when the states to be discriminated are multipartite, the optimal success probability can be attained by local operations and classical communication. For discrimination of two mixed states, an upper bound of the optimal success probability is obtained., Final version, 9 pages, references added, presentation improved

We investigate a discrimination scheme between unitary processes. By introducing a margin for the probability of erroneous guess, this scheme interpolates the two standard discrimination schemes: minimum-error and unambiguous discrimination. We present solutions for two cases. One is the case of two unitary processes with general prior probabilities. The other is the case with a group symmetry: the processes comprise a projective representation of a finite group. In the latter case, we found that unambiguous discrimination is a kind of "all or nothing": the maximum success probability is either 0 or 1. We also closely analyze how entanglement with an auxiliary system improves discrimination performance., Comment: 9 pages, 3 figures, presentation improved, typos corrected, final version

There are two common settings in a quantum-state discrimination problem. One is minimum-error discrimination where a wrong guess (error) is allowed and the discrimination success probability is maximized. The other is unambiguous discrimination where errors are not allowed but the inconclusive result "I don't know" is possible. We investigate discrimination problem with a finite margin imposed on the error probability. The two common settings correspond to the error margins 1 and 0. For arbitrary error margin, we determine the optimal discrimination probability for two pure states with equal occurrence probabilities. We also consider the case where the states to be discriminated are multipartite, and show that the optimal discrimination probability can be achieved by local operations and classical communication., 7 pages, 1 figure, typos corrected, references and an appendix added, to appear in Phys. Rev. A 78

Suppose we want to identify an input state with one of two unknown reference states, where the input state is guaranteed to be equal to one of the reference states. We assume that no classical knowledge of the reference states is given, but a certain number of copies of them are available instead. Two reference states are independently and randomly chosen from the state space in a unitary invariant way. This is called the quantum state identification problem, and the task is to optimize the mean identification success probability. In this paper, we consider the case where each reference state is pure and bipartite, and generally entangled. The question is whether the maximum mean identification success probability can be attained by means of a local operations and classical communication (LOCC) measurement scheme. Two types of identification problems are considered when a single copy of each reference state is available. We show that a LOCC scheme attains the globally achievable identification probability in the minimum-error identification problem. In the unambiguous identification problem, however, the maximal success probability by means of LOCC is shown to be less than the globally achievable identification probability., 11 pages, amalgamation of arXiv:0712.2906 and arXiv:0801.0128

We study how to unambiguously identify a given quantum pure state with one of the two reference pure states when no classical knowledge on the reference states is given but a certain number of copies of each reference quantum state are presented. By the unambiguous identification, we mean that we are not allowed to make a mistake but our measurement can produce an inconclusive result. Assuming the two reference states are independently distributed over the whole pure state space in a unitary invariant way, we determine the optimal mean success probability for an arbitrary number of copies of the reference states and a general dimension of the state space. It is explicitly shown that the obtained optimal mean success probability asymptotically approaches that of the unambiguous discrimination as the number of the copies of the reference states increases., v3: 8 pages, minor corrections, journal version

We investigate the king's problem of the measurement of operators ${\stackrel{P\vec}{n}}_{k}∙\stackrel{P\vec}{\ensuremath{\sigma}}$ ($k=1$, 2, 3) instead of the three Cartesian components ${\ensuremath{\sigma}}_{x},{\ensuremath{\sigma}}_{y}$, and ${\ensuremath{\sigma}}_{z}$ of the spin operator $\stackrel{P\vec}{\ensuremath{\sigma}}$. Here, ${\stackrel{P\vec}{n}}_{k}$ are three-dimensional real unit vectors. We show the condition over three vectors ${\stackrel{P\vec}{n}}_{k}$ to ascertain the result for measurement of any one of these operators.

The mean king's problem with maximal mutually unbiased bases (MUB's) in general dimension d is investigated. It is shown that a solution of the problem exists if and only if the maximal number (d+1) of orthogonal Latin squares exists. This implies that there is no solution in d=6 or d=10 dimensions even if the maximal number of MUB's exists in these dimensions., Comment: 5 pages, 1 figure, v2: typos corrected. journal version

We address a problem of identifying a given pure state with one of two reference pure states, when no classical knowledge on the reference states is given, but a certain number of copies of them are available. We assume the input state is guaranteed to be either one of the two reference states. This problem, which we call quantum pure state identification, is a natural generalization of the standard state discrimination problem. The two reference states are assumed to be independently distributed in a unitary invariant way in the whole state space. We give a complete solution for the averaged maximal success probability of this problem for an arbitrary number of copies of the reference states in general dimension. It is explicitly shown that the obtained mean identification probability approaches the mean discrimination probability as the number of the reference copies goes to infinity., Comment: 7 pages, v2: typos corrected, journal version

A direct derivation is given for the optimal mean fidelity of quantum state estimation of a d-dimensional unknown pure state with its N copies given as input, which was first obtained by M. Hayashi in terms of an infinite set of covariant positive operator valued measures (POVM's) and by Bruss and Macchiavello establishing a connection to optimal quantum cloning. An explicit condition for POVM measurement operators for optimal estimators is obtained, by which we construct optimal estimators with finite POVM using exact quadratures on a hypersphere. These finite optimal estimators are not generally universal, where universality means the fidelity is independent of input states. However, any optimal estimator with finite POVM for M(>N) copies is universal if it is used for N copies as input., v3(journal version): title changed, presentation improved

The quantum color coding scheme proposed by Korff and Kempe (quant-ph/0405086) is easily extended so that the color coding quantum system is allowed to be entangled with an extra auxiliary quantum system. It is shown that in the extended scheme we need only $\sim 2\sqrt{N}$ quantum colors to order $N$ objects in large $N$ limit, whereas $\sim N/e$ quantum colors are required in the original non-extended version. The maximum success probability has asymptotics expressed by the Tracy-Widom distribution of the largest eigenvalue of a random GUE matrix., Comment: 10 pages

In quantum teleportation, neither Alice nor Bob acquires any classical knowledge on teleported states. The teleportation protocol is said to be oblivious to both parties. In remote state preparation (RSP) it is assumed that Alice is given complete classical knowledge on the state that is to be prepared by Bob. Recently, Leung and Shor showed that the same amount of classical information as that in teleportation needs to be transmitted in any exact and deterministic RSP protocol that is oblivious to Bob. We study similar RSP protocols, but not necessarily oblivious to Bob. First it is shown that Bob's quantum operation can be safely assumed to be a unitary transformation. We then derive an equation that is a necessary and sufficient condition for such a protocol to exist. By studying this equation, we show that one qubit RSP requires 2 cbits of classical communication, which is the same amount as in teleportation, even if the protocol is not assumed oblivious to Bob. For higher dimensions, it is still open whether the amount of classical communication can be reduced by abandoning oblivious conditions., 7 pages, 1 figure

We show that the Fano operator for one dimensional quantum system is uniquely determined by assuming the reasonable behavior under translation and parity transformation on phase space. Contrarily, for the system with lattice phase space the same procedure does not work., Comment: 13 pages

We investigate, analytically and numerically, the fermion determinant of a new action on a (1+1)-dimensional Euclidean lattice. In this formulation the discrete chiral symmetry is preserved and the number of fermion components is a half of that of Kogut-Susskind. In particular, we show that our fermion determinant is real and positive for U(1) gauge group under specific conditions, which correspond to gauge conditions on the infinite lattice. It is also shown that the determinant is real and positive for SU(N) gauge group without any condition., 12 pages, 7 figures

The mechanism by which propofol selectively attenuates the pulmonary vasodilator response to acetylcholine is unknown. The goals of this study were to identify the contributions of endogenous endothelial mediators (nitric oxide [NO], prostacyclin, and endothelium-derived hyperpolarizing factors [EDHFs]) to acetylcholine-induced pulmonary vasorelaxation, and to delineate the extent to which propofol attenuates responses to these endothelium-derived relaxing factors.Canine pulmonary arterial rings were suspended for isometric tension recording. The effects of propofol on the vasorelaxation responses to acetylcholine, bradykinin, and the guanylyl cyclase activator, SIN-1, were assessed in phenylephrine-precontracted rings. The contributions of NO, prostacyclin, and EDHFs to acetylcholine-induced vasorelaxation were assessed in control and propofol-treated rings by pretreating the rings with a NO synthase inhibitor (l-NAME), a cyclooxygenase inhibitor (indomethacin), and a cytochrome P450 inhibitor (clotrimazole or SKF 525A) alone and in combination.Propofol caused a dose-dependent rightward shift in the acetylcholine dose-response relation, whereas it had no effect on the pulmonary vasorelaxant responses to bradykinin or SIN-1. Cyclooxygenase inhibition only attenuated acetylcholine-induced relaxation at high concentrations of the agonist. NO synthase inhibition and cytochrome P450 inhibition each attenuated the response to acetylcholine, and combined inhibition abolished the response. Propofol further attenuated acetylcholine-induced relaxation after NO synthase inhibition and after cytochrome P450 inhibition.These results suggest that acetylcholine-induced pulmonary vasorelaxation is mediated by two components: NO and a cytochrome P450 metabolite likely to be an EDHF. Propofol selectively attenuates acetylcholine-induced relaxation by inhibiting both of these endothelium-derived mediators.

The Wigner functions on the one dimensional lattice are studied. Contrary to the previous claim in literature, Wigner functions exist on the lattice with any number of sites, whether it is even or odd. There are infinitely many solutions satisfying the conditions which reasonable Wigner functions should respect. After presenting a heuristic method to obtain Wigner functions, we give the general form of the solutions. Quantum mechanical expectation values in terms of Wigner functions are also discussed., Comment: 11 pages, no figures, REVTEX

Three patients with anomalous origin of the right pulmonary artery from the ascending aorta were reported. Case 1: A 33-day-old premature infant (body weight 984 g) with the right pulmonary artery arising from the ascending aorta (RAPAA) and the patent ductus arteriosus (PDA). Banding of the right pulmonary artery (RPAB) and ligation of PDA were performed as a palliative operation. AT 3-month-old (BW 2,200 g), division and direct anastomosis of the anomalous vessel to the main pulmonary trunk was done as a radical operation under hypothermic cardiopulmonary bypass (CPB). Case 2: A 16-day-old infant with RAPAA and PDA. Division and direct anastomosis of the anomalous vessel to the main pulmonary trunk and ligation of PDA were performed as a radical operation under hypothermic CPB. Case 3: A 74-day-old infant with RAPAA and Ebstein's anomaly. RPAB was performed as a first palliative operation and left Blalock-Taussig shunt as a second operation. Glenn operation is scheduled as third operation prior to Fontan type operation.

The modified Aubert procedure and left ventricular outflow tract reconstruction were performed successfully for double-outleft right ventricle with subpulmonary ventricular septal defect, which showed an unusual Shaher type 5a coronary artery pattern. This pattern was characterized by two coronary ostia arising from the right septal sinus and intramural segment in a left trunk of the coronary artery. In this case, the neo-pulmonary artery was reconstructed without prosthetic materials. However, postoperative echocardiography showed no evident supravalvar pulmonary stenosis. The modified Aubert procedure without prosthetic marerids can be used for double-outlet right ventricle and transposition of the great arteries which show dilated prelimonary artery.

We evaluated retrospectively 31 patients under hemodialysis who underwent scheduled laparotomy with a purpose to determine the optimal intra-operative water balance. The patients fell into two different periods according to the difference of the principle of anesthesia. Anesthesia method employed for the former eleven patients (1987.6-1990.12) was NLA with pancuronium for muscle relaxation and they were ventilated mechanically in ICU. More recent twenty patients (1991-1995) had epidural block plus nitrous oxide-oxygen-isoflurane with vecuronium and they were extubated early. These latter patients, compared with the preoperative values, did not show any significant changes in mean arterial pressure or systemic vascular resistance after the operation. Intra-operative water balance showed a positive correlation with PADP (r = 0.57) and a negative correlation with SVR (r = 0.36) at the end of operation. The adequate fluid infusion is necessary to maintain PADP, and the water balance of +3-5 ml x kg-1 x hr-1 is recommended during laparotomy for the patients under hemodialysis.

The usefulness of the continuous monitoring system of blood volume change (BV%), by using measured hematocrit, has been evaluated during cardiopulmonary bypass (CPB). Twelve patients for CABG were studied. The optical sensor was incorporated in the venous outlet site of CPB to measure Hct and hemoglobin oxygen saturation. The infusion of the cardioplegia caused a sharp deviation in BV%, and the use of extracorporeal ultrafiltration helped to reduce BV% rapidly. At the end of CPB, BV% was -1.4 +/- 7.7% and showed a good correlation with total water balance during CPB (r = 0.75, P0.01). However, the discrepancy between BV% and the positive water balance was observed in a case with LOS. This suggests fluid maldistribution from intra- to extra-vascular space. Continuous BV% monitoring during CPB is useful as an index of water balance and for assessing an optimum blood volume.

We report a 51-year-old male patient with tetralogy of Fallot who had an anoxic spell during pre-bypass period before intracardiac repair. Immediately after starting sternotomy, SpO2 decreased suddenly from 83% to 30% with PaO2 of 26 mmHg. Heart rate showed an increase to 120-140 bpm with little change in blood pressure. We considered that the causes of this spell were 1) light level of anesthesia, 2) hypoxemia and 3) lack of intravascular blood volume. This case warns us that we should take care to avoid an anoxic spell in an adult case for intracardiac repair.

Atrial pacing is often necessary during cardiac surgery. A total of 20 patients undergoing cardiac surgery were atrially paced with either a multipurpose pulmonary artery catheter (PAC) or an A-V paceport PAC (n = 10 each). Atrial pacing was successful in all the patients before cardiopulmonary bypass. The output threshold was 4.2 +/- 0.7 mA for a multipurpose PAC and 3.8 +/- 0.7 mA for A-V paceport PAC. Atrial pacing with both PAC's was readily performed and useful during cardiac surgery.

We presented a female patient who had complicated perioperative myocardial infarction resulting from intraoperative embolization with atheromatous debris during coronary artery bypass surgery. On separation from cardiopulmonary bypass, ventricular function was poor and she suffered from severe low cardiac output syndrome postoperatively. The intraoperative electrocardiographic monitoring showed conduction abnormalities, elevation of the ST-T segments and new Q waves. Though it is difficult to diagnosis the onset of perioperative myocardial infarction early, adequate treatment is necessary to preserve ischemic myocardium and to reduce the size of myocardial necrosis.

Twenty nine cases of type A acute aortic dissection were subjected to a retrospective study concerning perioperative management. Two keys pointed out for the management were as follow; (1) An optimal control of blood pressure is the most important measure to avoid advance of aortic dissection or rupture of dissecting aneurysm. Both pericardiac tamponade and aortic valve insufficiency should be taken care of from their onset, since they are often complicated after aortic dissections and their onset is fatal. (2) Separated brain perfusion and profound hypothermia with total circulatory arrest might involve a high risk of inducing postoperative brain damage and mortality, especially for old patients.

Post-operative respiratory management was evaluated in patients with VSD+PH. Comparison was made between Group I (6 patients under 6 months) and Group II (10 patients 6 months or above). Oxygenation after surgical operation in Gp I was poor and the patients needed longer period of mechanical ventilation (MV), while Gp II patients required shorter duration of MV. In Gp I, the duration of MV after the cardiac surgery correlated with the length of cardiopulmonary bypass. In conclusion, cardiopulmonary bypass may influence the post-operative pulmonary function and patients who require longer period of MV are younger infants or newborns whose pulmonary function is immature and PH is severe.

Four cases of anaphylactic shock are reported. In two patients who underwent A-C bypass operation, we evaluated hemodynamic changes systemically when the anaphylactic reaction occurred. At that time it was observed that arterial pressure, central venus pressure, left atrial pressure and systemic vascular resistance decreased and that cardiac index increased. In other two patients it was not possible to evaluate hemodynamic changes during reaction. But one of these two patients developed coronary spasm accompanied with anaphylactic shock and the other patient who had depressed cardiac function and had developed cardiogenic shock, died of cardiac failure after 47 days. It is suggested that hemodynamic changes in anaphylactic reaction varies depending on different general conditions of the patient.

A case of intraoperative conversion to 2nd degree from 1st degree AV block by the reversal of neuromuscular blockade was reported. A 78 year old male, who originally suffered from 1st degree AV block, underwent choledocholithotomy and T-tube drainage for choledocholithiasis. He was administered 4 mg of pancuronium at the time of intubation. The operation lasted for 160 minutes under epidural anesthesia, NLA and nitrous oxide-oxygen. The patient started spontaneous breathing and the recovery was confirmed after the operation which finished without any problem. Neuromuscular blockade was reversed with atropine 0.5 mg and neostigmine 1.0 mg that were administered simultaneously taking 3 minutes. Then he was extubated without any troublesome stimulation. Suddenly, however, he suffered from the worse condition of bradycardia with the 2nd degree AV block. It took about 45 minutes until he recovered to the original 1st degree AV block despite atropine treatment. We believe that this accident was induced by a vasovagal reflex which was triggered by extubation under the effect of neostigmine which acts longer than that of atropine. We should be careful in reversing the effect of the non-depolarizing neuromuscular blockade. A short acting neuromuscular blockade, i.e. vecuronium, is preferable so as to avoid neostigmine reversal, and extubation should be performed when the effect of neuromuscular blockade is confirmed to be exhausted.

Ten cases of intraoperative coronary artery spasm were reviewed retrospectively. Four cases were open heart surgeries, one was a surgery for aortic dissecting aneurysm, and the other five were abdominal ones. In the cases of open heart surgery under anesthesia with high dose fentanyl, coronary artery spasm occurred at weaning period from cardio-pulmonary bypass. In the cases of abdominal surgery, all under neuroleptanesthesia with continuous epidural block, coronary artery spasm occurred within one hour after the beginning or before the end of operation. In four of five abdominal surgeries, systolic blood pressure became less than 90 mmHg when coronary artery spasm occurred. Coronary artery spasm brought severe depression of myocardial contractility and life threatening arrhythmias by which weaning from cardiopulmonary bypass became difficult during open heart surgery. There was a case which required several hours before hemodynamics became stable also in abdominal surgery. It was suggested that general anesthesia with continuous epidural block could be a triggering factor of coronary artery spasm when hypotension and insufficient depth of general anesthesia are present simultaneously.