Low-dose anticoagulation for peripheral deep vein thrombosis of the lower extremities in cancer patients

Background

Venous thromboembolism (VTE) is a frequent complication in cancer patients and is often detected as asymptomatic peripheral deep vein thrombosis (DVT). However, guidelines for peripheral DVT have not been established in either general cardiology or onco-cardiology. Furthermore, in cancer patients, it is generally considered difficult to administer standard doses of anticoagulants due to the high risk of bleeding caused by thrombocytopenic tendency during chemotherapy, as well as bleeding lesions such as gastrointestinal and gynecological cancers.

Treatment of peripheral DVT with direct oral anticoagulants (DOACs) may minimize the worsening of bleeding and prevent the transition to proximal DVT.

Objective

The purpose of this study was to investigate the optimal treatment for peripheral DVT in cancer patients.

Methods

242 consecutive patients with peripheral DVT of the lower extremities (excluding complications of pulmonary thromboembolism or proximal DVT) were examined by venous ultrasound from April 2019 to March 2020. 190 patients could be followed up by ultrasound examination, for up to 2 years. The course of the DVT was retrospectively examined. In cases of anticoagulant therapy, standard and low dosage of DOACs were evaluated.

Results

142 patients were treated with anticoagulant (AC) therapy (group AC(+)), 48 patients were without AC therapy (group AC(−)). (4 of the 142 patients were treated with warfarin and the rest with DOACs).

DVT worsened in 8 patients (5.6%) in the AC(+) group and 23 patients (47.9%) in the AC(−) group. DVT worsening was significantly less in the AC(+) group (p<0.0001).

There were no cases of worsening to proximal type in the AC(+) group and 4 cases (17.4%) in the AC(−) group.

Of the 138 patients who used DOACs as AC therapy, 62 used half or less than the standard dose for maintenance (low-dose DOAC group), and 76 used the standard dose as maintenance (standard-dose DOAC group).

In the low-dose DOAC group, DVT worsened in 5 cases, remained unchanged in 7 cases, and improved in 50 cases. In the standard-dose DOAC group, there were 4 cases of worsening DVT, 3 cases of no change, and 69 cases of improvement. There was no significant difference in the DVT treatment effect between the two groups.

There were no thrombus-related deaths.

Conclusion

Peripheral DVT worsens in about half of cancer patients without anticoagulation, and 17% of these worsen to proximal VTE. In addition, low-dose DOACs are found to be as effective as standard-dose DOACs in treating peripheral DVT in cancer patients. Peripheral DVT treatment with low-dose DOACs can reduce the risk of bleeding complications and thrombus-related mortality in cancer patients and should be one of the supportive treatments for the completion of cancer management.

Funding Acknowledgement

Type of funding sources: None.

Modeling electrokinetic flows with the discrete ion stochastic continuum overdamped solvent algorithm

In this article we develop an algorithm for the efficient simulation of electrolytes in the presence of physical boundaries. In previous work the discrete ion stochastic continuum overdamped solvent (DISCOS) algorithm was derived for triply periodic domains, and was validated through ion-ion pair correlation functions and Debye-Hückel-Onsager theory for conductivity, including the Wien effect for strong electric fields. In extending this approach to include an accurate treatment of physical boundaries we must address several important issues. First, the modifications to the spreading and interpolation operators necessary to incorporate interactions of the ions with the boundary are described. Next we discuss the modifications to the electrostatic solver to handle the influence of charges near either a fixed potential or dielectric boundary. An additional short-ranged potential is also introduced to represent interaction of the ions with a solid wall. Finally, the dry diffusion term is modified to account for the reduced mobility of ions near a boundary, which introduces an additional stochastic drift correction. Several validation tests are presented confirming the correct equilibrium distribution of ions in a channel. Additionally, the methodology is demonstrated using electro-osmosis and induced-charge electro-osmosis, with comparison made to theory and other numerical methods. Notably, the DISCOS approach achieves greater accuracy than a continuum electrostatic simulation method. We also examine the effect of under-resolving hydrodynamic effects using a "dry diffusion" approach, and find that considerable computational speedup can be achieved with a negligible impact on accuracy.

Abstract P1-12-03: Prevalence, predictive factors, and clinical outcomes of anthracycline induced cardiac dysfunction among patients with breast cancer in Japan, where the normal body weight (BMI < 25) is dominant

Objective: Cardiac dysfunction (CD) is a major clinical problem for survivors of breast cancer. ASCO released a guideline for prevention and monitoring CD in survivors of adult cancer in 2017. Exposure to anthracycline (A) and trastuzumab are both risk factor for CD, as well as obesity is a part of multiple risk factors in the guideline. Meta-analysis shown obesity itself increases risk of A induced CD (A-CD). Prevalence of obesity and CD among non-oncology patients vary in countries, as many Western countries have obesity dominant population. Then little is known about clinical characteristics of A-CD in survivors of adult cancer among normal weight dominant countries, especially in Asia. This study was conducted to understand characteristics of A-CD among patients with breast cancer in Japan.

Method: This study used electrical charts, breast oncology database, and cardiology database to find prevalence, predictive factors, and clinical outcomes of A-CD in Hyogo Cancer Center. The definition of CD is based on diagnosis by the cardiologist. Major Cardiac Events (MACE) is defined as cardiac death or emergency admission due to CD. Obesity is defined as BMI > 30, normal body weight is defined as BMI < 25, and elderly is defined as age > 60 years old, same as in ASCO guideline. Patients gave written informed consent. IRB approved this study.

Result: From Apr. 2006, to Mar. 2017, 855 patients received A for the treatment of breast cancer. Median body weight was 55 Kg, median BMI was 23, and 93.4 % of patients are non-obese. Half of patients (46.9 %) are elderly. Almost a quarter (24 %) of patients received trastuzumab. At the median follow up 60 months, 20 patients (2.3 %) experienced CD, one patient (0.11 %) passed away due to CD, and four patients were admitted as emergency, then five patients (0.58 %) experienced MACE. Median time to onset of CD after the last dose of A is seven months. Among patients with CD, 18 patients (90 %) recovered their ejection fraction (EF), and the median time to recover of EF was two months. Predictive factors for CD include usage of trastuzumab (15 patients), elderly (eight patients), high dose anthracycline (four patients), and multiple cardiac risk factors at base line (four patients). Among patients treated without trastuzumab, only five (0.76 %) patients experienced CD, but four of them experienced MACE.

Conclusion: Prevalence of A-CD in the normal weight dominant population was lower than reported in obesity dominant population, especially in patients treated without trastuzumab. In this population, clinical outcome such as prevalence of MACE may vary depending on the usage of trastuzumab. Further study is warranted to set an optimal strategy for the prevention and monitoring of A-CD in non-obese dominant population.

Citation Format: Matsumoto K, Nonaka A, Ogata T, Ogata M, Sakai H, Nishimura M, Onoe T, Soyama M, Hashimoto K, Tane K, Hirokaga K, Takao S. Prevalence, predictive factors, and clinical outcomes of anthracycline induced cardiac dysfunction among patients with breast cancer in Japan, where the normal body weight (BMI < 25) is dominant [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P1-12-03.

Population activity in the dorsal hippocampal CA1 encoding the surrounding environment is absent during contextual fear memory expression

The hippocampus plays a critical role in contextual fear conditioning. Population activity in the hippocampal CA1 encoding the surrounding environment is thought to be responsible for retrieval of contextual fear memory. However, the characteristics of CA1 neuronal ensemble activity during retrieval of contextual fear memory remain unclear. Here, we examined CA1 ensemble activity during contextual fear memory expression in male C57Bl/6J mice, using Arc cellular compartment analysis of temporal activity by fluorescence in situ hybridization. The "Shock" group was conditioned with a footshock in two separate chambers, whereas the "No shock" group was not exposed to shocks in the chamber. Animals were then re-exposed to either the same chamber twice or two different conditioning chambers. In the No shock group, exposure to the same chamber twice activated a more significantly overlapping neuronal population than exposure to two different chambers. In the Shock group, exposure to the same conditioning chamber twice activated a similarly overlapping neuronal population as exposure to two different chambers, with overlap smaller than in nonshocked mice exposed to the same chamber twice. Thus, population activity in the hippocampal CA1 encoding the surrounding environment is detected during spatial exploration, but absent during contextual fear memory expression. Even the variable ensemble activity of CA1 may contribute to retrieval of contextual fear memory.

Clinical assessment of oral malodor intensity expressed as absolute value using an electronic nose

OBJECTIVES

In our previous study, scores determined via a multiple linear regression method (EN-MLR) involving an electronic nose provided objective halitosis-related measurements; however, this model afforded only relative expression exclusively. The objective of this investigation was to assess clinically oral malodor intensity expressed as an absolute value using an electronic nose.

SUBJECTS AND METHODS

Sixty-six subjects were evaluated based on results of an actual organoleptic test (OLT), measurements of volatile sulfur compound (VSC) concentrations, a score representing malodor intensity (EN-MI) as the absolute value and EN-MLR measured with an electronic nose system. Oral health parameters were also examined.

RESULTS

The OLT score served as a benchmark. The area under the receiver-operating characteristic (ROC) plots of EN-MI score (0.975) was significantly larger than that of log VSC (0.896) (P = 0.036); however, the area did not differ significantly from that of EN-MLR score (0.932). Percentage of teeth with pocket depth greater than or equal to 4 mm, tongue coating score and plaque control record displayed meaningful association with EN-MI score in multiple logistic regression analyses.

CONCLUSION

Oral malodor intensity expressed as an absolute value employing an electronic nose may be a suitable method for clinical evaluation of oral malodor.

Clinical assessment of oral malodor by the electronic nose system

A recently developed electronic nose has not yet been clinically applied to evaluations of oral malodor. This investigation sought to determine whether an electronic nose could clinically assess oral malodor. Twenty-nine healthy adults and 49 patients were assessed by results of an actual organoleptic test, a score representing malodor strength with an electronic nose in "top-note" mode (top-note score), and measurements of volatile sulfur compound (VSC) concentrations. The correlation coefficient between top-note and actual organoleptic scores (r = 0.71) was comparable with the log VSC and actual organoleptic scores (r = 0.63). However, the area under the receiver-operating characteristic plots for top-note score was significantly larger than that for log VSC. In logistic regression analyses with top-note score as a dependent variable, probing depth, tongue coating, and plaque control record each had independent associations. Our findings suggest that the top-note score from an electronic nose examination may be useful for the clinical evaluation of oral malodor.

Suppressive effects of selectin inhibitor SKK-60060 on the leucocyte infiltration during endotoxin induced uveitis

BACKGROUND

It is well known that selectin is involved in the development of endotoxin induced uveitis (EIU), and has a major role in leucocyte infiltration. Recently, a novel selectin inhibitor (SKK-60060) that can block P and L selectins in vitro has been developed. This study was designed to investigate the anti-inflammatory effects of SKK-60060 on the inflammatory reaction during EIU in rats by studying leucocyte-endothelium interactions.

METHODS

EIU was induced in Lewis rats by footpad injection of lipopolysaccharide (LPS). SKK-60060 was administered 15 minutes before LPS injection, and its suppressive effects on inflammatory leucocyte behaviour were evaluated in vivo with acridine orange digital fluorography; the diameters of retinal arteries and veins were also measured. After these studies, aqueous humour was collected to evaluate leucocyte infiltration and protein leakage.

RESULTS

After LPS injection, rolling leucocytes were observed in major retinal veins, followed by leucocyte infiltration into the vitreous cavity. Following treatment with SKK-60060, leucocyte rolling was significantly inhibited in the retinal veins (p <0.01), and subsequent leucocyte infiltration into the vitreous cavity was also significantly suppressed (p <0.01). Retinal vasodilation was also substantially suppressed in SKK-60060 treated rats (p <0.01). Similarly, leucocyte infiltration and protein leakage into the aqueous humour were reduced significantly by SKK-60060 (p <0.01).

CONCLUSIONS

SKK-60060 treatment significantly inhibited the inflammatory reaction induced by LPS. Its inhibitory effects on P and L-selectin resulted in suppression of leucocyte infiltration and the subsequent inflammatory reaction caused by accumulated leucocytes. The current findings suggest that SKK-60060 may be useful in the management of uveitis.

Up-regulation by clarithromycin of alpha(1)-acid glycoprotein expression in liver and primary cultured hepatocytes

alpha(1)-Acid glycoprotein (AGP) is the major transport protein for cationic drugs, endogenous ligands, and some anionic drugs in plasma. Hepatic synthesis and secretion of AGP are altered during acute inflammation as well as by a number of drugs. This alteration could influence the binding of drugs and its biological function. Macrolide antibiotics are widely used in the treatment of a variety of infectious diseases. The effects of macrolide antibiotics have been studied with respect to rat AGP expression in vivo. After the individual administration of six macrolides to rats, with the exception of oleandomycin, five increased AGP levels in serum. Of these five, clarithromycin (CAM) was the most potent inducer of AGP, which reached a maximum level between 3 to 7 days after administration. CAM increased the steady-state level of AGP mRNA in liver as well as protein level in serum in a dose-dependent manner. In addition, CAM increased AGP mRNA levels in primary cultured hepatocytes. In the luciferase promoter assay, CAM potentiated dexamethasone-increased promoter activity of the AGP gene, which contained the glucocorticoid response element, in cultured rat hepatocytes, although CAM itself had no effect on its activity. The effect of CAM and dexamethasone was diminished by glucocorticoid response element deletion or mutation or by adding the antiglucocorticoid, RU486. Further, in the mouse mammary tumor virus (MMTV) promoter containing functional glucocorticoid response element, CAM potentiated dexamethasone-increased promoter activity. In the adrenalectomized rats, CAM did not increase AGP levels in serum. These findings suggest that CAM may cause transcriptional induction of AGP, at least in part, via a glucocorticoid-mediated mechanism.

Inhibitory effect of ischemic preconditioning on leukocyte participation in retinal ischemia-reperfusion injury

PURPOSE

Recent reports have shown that ischemic preconditioning induces strong protection against retinal damage by subsequent prolonged ischemia and that this protection is mediated by mechanisms involving the adenosine A1 receptor. This study was designed to evaluate quantitatively the effects of ischemic preconditioning on leukocyte-mediated reperfusion injury after transient retinal ischemia and to define the role of the adenosine A1 receptor in these effects.

METHODS

Transient retinal ischemia was induced in male rats by temporary ligation of the optic nerve. Ischemic preconditioning (5 minutes of ischemia) was induced 24 hours before 60 minutes of ischemia. The adenosine A1 receptor antagonist 8-cyclopentyl-1,3-dipropylxanthine (DPCPX) was administered intramuscularly immediately after ischemic preconditioning. Leukocyte behavior in the retina after 60 minutes of ischemia was evaluated in vivo with acridine orange digital fluorography.

RESULTS

Ischemic preconditioning inhibited leukocyte rolling. The maximum number of rolling leukocytes was reduced to 3.0% at 12 hours after reperfusion (P < 0.01). Subsequent leukocyte accumulation was also decreased with ischemic preconditioning. The maximum number of accumulated leukocytes was reduced to 22.6% at 24 hours after reperfusion (P < 0.01). These inhibitory effects were suppressed by administration of DPCPX (P < 0.0001). The numbers of rolling leukocytes at 12 hours after reperfusion and accumulated leukocytes at 24 hours after reperfusion were 102.7% (NS) and 83.4% (P < 0.01), respectively, compared with the number without ischemic preconditioning.

CONCLUSIONS

The present study demonstrates the inhibitory effects of ischemic preconditioning on leukocyte rolling and subsequent leukocyte accumulation during retinal ischemia-reperfusion injury. Furthermore, the adenosine A1 receptor may play an important role in these inhibitory effects.

In vivo evaluation of platelet--endothelial interactions after transient retinal ischemia

PURPOSE

Accumulating evidence suggests that platelets play an important role in ischemia-reperfusion injury. To fulfill that role, platelets flowing in the bloodstream would have to interact with retinal endothelial cells and to accumulate in the postischemic retina. This study was designed to investigate quantitatively platelet-endothelial interactions in postischemic retina after transient retinal ischemia.

METHODS

Transient retinal ischemia was induced in Long-Evans rats for 60 minutes by temporal ligation of the optic nerve. Isolated platelet samples labeled with carboxyfluorescein diacetate succinimidyl ester were administered intravenously to recipient rats after various reperfusion periods. Platelet-endothelial interactions in postischemic retina were evaluated in vivo with a scanning laser ophthalmoscope. Anti-P-selectin monoclonal antibody (mAb) was administered 5 minutes before the injection of labeled platelets. P-selectin gene expression in the postischemic retina was studied by semiquantitative polymerase chain reaction.

RESULTS

Under basal conditions, infused platelets showed minimal interactions with retinal endothelial cells. In contrast, postischemic retinas showed active platelet-endothelial interactions. Many platelets were observed rolling along and adhering to the major retinal veins. The number of rolling and adhering platelets reached a peak (555 +/- 65/mm per min and 25.8 +/- 3.2/mm(2)) 12 hours after reperfusion. However, the interactions between platelets and postischemic retinal endothelial cells were substantially inhibited by neutralizing P-selectin expressed on endothelial cells. In addition, P-selectin gene expression in postischemic retina corresponded with the time course of platelet-endothelial interactions during the reperfusion period.

CONCLUSIONS

This study demonstrated that platelets actively interacted with retinal endothelial cells in the postischemic retina through P-selectin expressed on the retinal endothelial cells.

Suppressive effects of histamine H1 receptor antagonist diphenhydramine on the leukocyte infiltration during endotoxin-induced uveitis

Histamine has been shown to play an important role in the step of leukocyte rolling, the initial step to leukocyte infiltration into an inflamed region. We investigated the roles of histamine in the leukocyte recruitment during endotoxin-induced uveitis (EIU) in vivo using acridine orange digital fluorography. An injection of histamine into the vitreous cavity of a Lewis rat induced leukocyte rolling along the major retinal veins. In other experiments, EIU was induced in Lewis rats by footpad injection of lipopolysaccharide (LPS). Leukocyte rolling was also observed in the retinal veins of EIU rats. To block the histamine H1 receptor, diphenhydramine (DPH) was administered intraperitoneally 15 min before the LPS injection. DPH significantly inhibited leukocyte rolling along the major retinal veins of EIU rats, suppressing leukocyte infiltration into the vitreous cavity. The vasodilation in EIU was also significantly suppressed with DPH. Moreover, leukocyte infiltration into aqueous humor was significantly suppressed in DPH-treated rats. Although the inhibitory effects of DPH was less obvious at later time points, addition of DPH every 12 hr showed prolonged anti-inflammatory effects up to 48 hr after LPS injection. In contrast, protein leakage into the aqueous humor was not suppressed as much as leukocyte infiltration with DPH. These results suggest that histamine would play a pivotal role in leukocyte recruitment during EIU in rats. Blocking the histamine H1 receptor might help to prevent or minimize leukocyte infiltration in uveitis.

Inhibitory effects of antithrombin III against leukocyte rolling and infiltration during endotoxin-induced uveitis in rats

PURPOSE

This study was designed to investigate the suppressive effects of antithrombin (AT)III on inflammatory reactions during endotoxin-induced uveitis (EIU) in rats by studying leukocyte-endothelium interactions.

METHODS

EIU was induced in Lewis rats by footpad injection of lipopolysaccharide (LPS). ATIII was administered immediately after or at 6 hours after LPS injection. Its suppressive effects on inflammatory leukocyte behavior were evaluated in vivo with acridine orange digital fluorography. Clinical signs of inflammation were also examined, and aqueous humor (AH) was collected to evaluate leukocyte infiltration and protein leakage. In a separate experiment, P-selectin mRNA expression was studied in the iris-ciliary body (ICB) and the retina.

RESULTS

After treatment with ATIII, leukocyte rolling was substantially inhibited along the retinal veins, suppressing subsequent leukocyte infiltration into the vitreous cavity. Similarly, leukocyte infiltration and protein leakage into the AH were significantly reduced with ATIII treatment. The clinical grade of EIU was substantially lower in ATIII-treated rats. In addition, delayed administration of ATIII after EIU induction significantly attenuated these inflammatory reactions. The levels of P-selectin mRNA expression in both ICB and retina, which were upregulated after LPS injection, were substantially lower in the ATIII-treated rats.

CONCLUSIONS

ATIII treatment significantly inhibited inflammatory reactions induced with LPS. Its suppressive effects on P-selectin expression could contribute to the attenuation of leukocyte infiltration, possibly by inhibiting leukocyte rolling. The current findings suggest that ATIII may have a role in the management of patients with uveitis.

Membrane fluidity correlates with liver cancer cell proliferation and infiltration potential

We developed a method to measure membrane fluidity of living cancer cells in two- and three-dimensional cultures, and found that there was a close relationship between the membrane fluidity of cancer cells and their proliferative and infiltrative ability. Membrane fluidity is thus a promising indicator of the probability of cancer recurrence.

Atypical form of dural graft associated Creutzfeldt-Jakob disease: report of a postmortem case with review of the literature

A postmortem case of an atypical form of dural graft associated Creutzfeldt-Jakob disease (CJD) is described. A 42 year old man developed progressive spastic paresis 163 months after a cadaveric dura mater graft. He presented with no myoclonus and very late occurrence of periodic synchronous discharges on EEG. The prion protein (PrP) gene was homozygous for methionine at the polymorphic codon 129. Neuropathological examination disclosed plaque-like PrP deposits with atypical distribution of synaptic PrP accumulations in the brain. This patient represents an atypical form of dural graft associated CJD characterised by unusual clinicopathological features.

Effects of propofol on ischemia and reperfusion in the isolated rat heart compared with thiamylal

The aim of the present study was to investigate whether clinical doses of propofol and thiamylal affect oxygen free radical production and intracellular calcium concentration ([Ca2+]i) in the post-ischemic reperfused heart. Forty-eight rat hearts were perfused with a Langendorff system and loaded with Fura-2 / AM as a [Ca2+]i marker. The hearts were divided into 6 groups as follows (each group: n = 8); Group S (saline), Group TL (thiamylal 100 microM), Group TH (thiamylal 300 microM), Group I (Intralipid), Group PL (propofol 3 microM), and Group PH (propofol 10 microM). All hearts were initially perfused for 5 min as control aerobic perfusion. Afterwards, no-flow ischemia was induced for 15 min, followed by reperfusion for 20 min. The formation of hydroxyl radicals in the coronary effluent was measured with high performance liquid chromatography using salicylic acid. At the beginning of the ischemia and reperfusion periods, increases in systolic and diastolic [Ca2+]i were observed in all groups except Group TH. The high dose of thiamylal significantly suppressed this initial increase in cytosolic [Ca2+]i (Group S 1.30+/-0.15; Group TL 0.99+/-0.17; Group TH 0.70+/-0.09, at 1 min after reperfusion; systolic [Ca2+]i : p < 0.05). Total DHBAs in the coronary effluent of all groups increased significantly 1 min after reperfusion, however, there were no significant differences among the groups. Clinical doses of propofol had no significant effect on myocardial function and [Ca2+]i before and after ischemia, whereas thiamylal suppressed the increase in [Ca2+]i during ischemia and reperfusion. However, free radical formation during reperfusion was unaffected by thiamylal and propofol.

[Anesthetic management for mitral valve replacement in a patient with idiopathic hypereosinophilic syndrome]

We have experienced anesthetic management for mitral valve replacement in a 48-year-old female with idiopathic hypereosinophilic syndrome. Preoperative examination showed mild biventricular dysfunction. Anesthesia was induced and maintained with meticulous administration of fentanyl and midazolam in 66% oxygen. Administration of dopamine, dobutamine and prostaglandin E1 contributed to reducing afterload and maintaining cardiac output. The operative and postoperative courses were uneventful. Hypereosinophilic syndrome is one of the identified causes of restrictive cardiomyopathy. Anesthesia for patients with hypereosinophilic syndrome must be carried out carefully, because heart or respiratory failure is the most dangerous complication. In patients with hypereosinophilic syndrome requiring general anesthesia, perioperative steroid cover is advisable. This may reduce or prevent serious lung complications.

[Effect of pre-mixed lidocaine with propofol on propofol injection pain in elderly patients]

The purpose of this study was to compare the younger and older patients in the incidence and the severity of the pain during injection of propofol. Thirty-four, elderly patients (60-80-yr-old) and 52 patients (20-40-yr-old) scheduled to undergo elective surgery were studied. We conducted a prospective, randomized and double-blinded trial. All patients were randomly allocated to one of two groups according to the agents added to 1% propofol 20 ml; Group S, normal saline 2 ml, and Group L, 2% lidocaine 2 ml. The pain on injection was rated as none, mild, moderate, or severe. Seventy percent of patients in the S group of elderly patients experienced pain, while 22% of patients experienced pain in the L group in elderly patients. The incidence of pain on injection in the S group of older patients was comparable with S group of younger patients. The severity of pain in elderly patients was significantly decreased after premixing with lidocaine. There were no significant differences between older and younger patients in the severity of propofol injection pain in both S group and L group. In conclusion, elderly patients suffered the pain on injection of propofol with the same incidence as the younger patients did. Lidocaine premixed with propofol significantly reduces the incidence and the severity of pain associated with propofol in elderly patients.

Leukocyte-endothelial cell interactions in diabetic retina after transient retinal ischemia

Diabetes is associated with increased neural damage after transient cerebral ischemia. Recently, leukocytes, which are thought to play a central role in ischemia-reperfusion injury, have been suggested to be involved in exacerbated damage after transient ischemia in diabetic animals. The present study was designed to clarify whether the anticipated worse outcome after transient cerebral ischemia in diabetic animals was due to augmented leukocyte-mediated neural injury. Using rats with streptozotocin-induced diabetes of 4-wk duration, we investigated leukocyte-endothelial cell interactions during reperfusion after a transient 60-min period of retinal ischemia. Unexpectedly, postischemic diabetic retina showed no active leukocyte-endothelial cell interactions during reperfusion. The maximal numbers of rolling and accumulating leukocytes in diabetic retina were reduced by 73.6 and 41.2%, respectively, compared with those in nondiabetic rats. In addition, neither preischemic insulin treatment of diabetic rats nor preischemic glucose infusion of nondiabetic rats significantly influenced leukocyte-endothelial cell interactions during reperfusion. The present study demonstrated that high blood glucose concentration before induction of ischemia did not exacerbate leukocyte involvement in the postischemic retinal injury. Furthermore, diabetic retina showed suppressed leukocyte-endothelial cells interactions after transient ischemia, perhaps due to an adaptive mechanism that developed during the period of induced diabetes.

Interactions between blood cells and retinal endothelium in endotoxic sepsis

Platelets and leukocytes are thought to play a leading role in the pathogenesis of many inflammatory conditions. To recruit flowing blood cells to the inflammatory region, it would be necessary for them to interact with vascular endothelial cells. Recently, many reports have indicated the resistance of spontaneous hypertensive rats (SHR) to endotoxic sepsis. Their resistance might be derived from suppressed interaction between these blood cells and endothelial cells. Therefore, SHR and age-matched Wistar-Kyoto rats (WKY) were induced with endotoxic sepsis by intravenous injection of lipopolysaccharide (LPS). At 4, 12, 24, and 48 hours after induction, leukocyte-endothelial interactions in the retina were evaluated in vivo with acridine orange digital fluorography. Fluorescently labeled platelets were also injected to investigate platelet-endothelial interactions in the retina in endotoxic sepsis. Leukocyte rolling in SHR after LPS injection was significantly suppressed; the maximum number of rolling leukocytes was reduced by 80.1% at 12 hours after LPS injection in SHR compared with WKY. Subsequent leukocyte infiltration into the vitreous cavity was significantly inhibited in SHR. Furthermore, platelet-endothelial interactions in the retina were also suppressed in SHR treated with LPS. The maximum numbers of rolling and adherent platelets were reduced by 59.5% and 62.6%, respectively, in SHR compared with WKY. In both strains, leukocyte- and platelet-endothelial interactions were substantially inhibited by the blocking of P-selectin. These suppressed interactions could contribute to the reduction of leukocyte- and platelet-mediated tissue injury in endotoxic sepsis in SHR, resulting in their resistance to endotoxemia.

Administration of 17beta-estradiol attenuates retinal ischemia-reperfusion injury in rats

PURPOSE

Accumulating evidence has suggested that 17beta-estradiol exerts protective effects against ischemic damage in various organs. In addition, leukocytes that accumulate in postischemic tissues are thought to play a central role in ischemia-reperfusion injury. This study was designed to evaluate quantitatively the inhibitory effects of 17beta-estradiol on leukocyte accumulation during ischemia-reperfusion injury and on subsequent retinal damage after transient retinal ischemia.

METHODS

Transient (60 minutes) retinal ischemia was induced in male rats by temporary ligation of the optic nerve. Thirty minutes before induction of ischemia, 17beta-estradiol (0.1 mg/kg) was administered intraperitoneally. At 6, 12, 24, and 48 hours after reperfusion, leukocyte accumulation in the retina was evaluated in vivo by means of acridine orange digital fluorography. Histologic and electroretinographic (ERG) studies were carried out to evaluate retinal damage.

RESULTS

Treatment with 17beta-estradiol significantly inhibited postischemic leukocyte accumulation; the maximum number of accumulating leukocytes was reduced by 35.7% at 24 hours after reperfusion (P = 0.01). Histologic examination showed that administration of 17beta-estradiol significantly reduced retinal damage, which was most obvious in the inner retina, 168 hours after reperfusion (P = 0.0001). ERG studies at 12 and 168 hours after reperfusion showed that recovery of the b-wave amplitude was significantly improved with treatment of 17beta-estradiol (P = 0.023).

CONCLUSIONS

The present study demonstrated the inhibitory effects of 17beta-estradiol on leukocyte accumulation and subsequent tissue injury during retinal ischemia-reperfusion injury.

PKC-beta inhibitor (LY333531) attenuates leukocyte entrapment in retinal microcirculation of diabetic rats

PURPOSE

The activity of protein kinase C (PKC), preferentially beta isoform of PKC, has been shown to be elevated in the diabetic retina. Recently, LY333531, a specific inhibitor of PKC-beta, has been reported to improve the decrease of retinal blood flow in early diabetes. Increased leukocyte entrapment has been suggested to be involved in blood flow disturbances in the early diabetic retina. This study was designed quantitatively to evaluate leukocyte entrapment in the retinal microcirculation of diabetic rats and the effect of LY333531 on leukocyte entrapment.

METHODS

Diabetes was induced in male Long-Evans rats by intraperitoneal injection of streptozotocin (60 mg/kg). LY333531 (0.1, 1.0, or 10.0 mg/kg/d) was administered orally during a 4-week diabetic period. Leukocyte entrapment in the retinal microcirculation was quantitatively evaluated in vivo with acridine orange digital fluorography.

RESULTS

The number of leukocytes trapped in the retinal microcirculation of diabetic rats (mean +/- SEM; 14.3 +/- 1.3 cells/mm2) was significantly increased, compared with nondiabetic control rats (7.5 +/- 0.3 cells/mm2; P < 0.0001). Oral administration of LY333531 significantly decreased the number of leukocytes trapped in the retinal microcirculation of diabetic rats (10.9 +/- 0.6, 11.3 +/- 0.7, and 10.4 +/- 0.4 cells/mm2 with LY333531 0.1, 1.0, and 10.0 mg/kg/d, respectively; P < 0.05).

CONCLUSIONS

Treatment with LY333531 attenuated the increase of leukocyte entrapment in the retinal microcirculation during the period of early diabetes. This effect may contribute to the improvement of abnormal retinal blood flow in early diabetes with LY333531. LY333531 might have a therapeutic efficacy in preventing microcirculatory flow disturbances by trapped leukocytes in the early diabetic retina.

Reproducibility of scanning laser Doppler flowmetry in the rat retina and optic nervehead

PURPOSE

The purpose of this study is to confirm the reliability of scanning laser Doppler flowmetry in the rat retina and optic nervehead, and the validity of measuring changes of retinal blood flow in rats while breathing 100% oxygen.

METHODS

We used a commercially available scanning laser Doppler flowmeter. To ascertain reliability, five consecutive and separate perfusion measurements of 12 eyes of 12 anesthetized pigmented rats were performed. To evaluate the validity of the system, repeated measurements were taken in anesthetized rats breathing room air or 100% oxygen. This series of measurements was repeated three times.

RESULTS

The reliability coefficients of volume, flow, and velocity in the optic nervehead and the retina ranged from 0.80 to 0.83 and 0. 77 to 0.82, respectively. After the first exposure to oxygen, the measured values of volume, flow, and velocity were reduced by an average of 20.9-24.0%, 21.2-28.2%, and 19.5-24.5%, respectively. After the values returned to the basal condition, the second and third exposures to oxygen yielded measured values that were reduced by the same amounts as at the first exposure.

CONCLUSIONS

Scanning laser Doppler flowmetry provided relatively good reliability in measurements of blood flow in the rat retina and optic nervehead. This study has indicated the possibility of applying this system to the rat retina.

Perioperative quantitative analysis of cytokeratin 20 mRNA in peripheral venous blood of patients with colorectal adenocarcinoma

Hematogenous dissemination is a significant short-coming of colorectal carcinoma treatment. To screen patients with high risk for such blood-borne metastasis, we previously developed a highly sensitive system for the detection of cytokeratin 20 (CK-20) mRNA in blood. For a more practical application, we improved this system by making it quantitative and capable of analyzing peripheral venous blood for the detection of perioperative changes in CK-20 mRNA. CK-20 mRNA was not always detected in the preoperative blood, even in patients in an advanced stage, but it was identified without fail in intra- and post-operative blood. In addition, more copies of CK-20 mRNA were observed in the intra-operative blood than in pre- and post-operative blood. This study suggests that analysis of perioperative changes may provide important information for the precise evaluation of hematogenous dissemination and of the effect of surgical maneuvers on recurrence.

In vivo evaluation of platelet-endothelial interactions in retinal microcirculation of rats

PURPOSE

This study was designed to develop a new method to evaluate the dynamics of platelets in the retinal microcirculation in vivo and to investigate quantitatively the platelet-endothelial interactions in rat retina with the use of this system.

METHODS

Isolated platelet samples were labeled with carboxyfluorescein diacetate succinimidyl ester. After intravenous administration, platelet behavior in the retinal microcirculation was evaluated with a scanning laser ophthalmoscope. The images were recorded on S-VHS videotape and analyzed with a computer-assisted image analysis system. The platelet- endothelial interactions in the retinal microcirculation were also investigated with the use of lipopolysaccharide-stimulated endothelium or platelets activated with thrombin.

RESULTS

Fluorescent platelets were recognized as distinct dots in the retinal microcirculation and could be traced frame by frame. The velocity of platelets in the retinal arteries, capillaries, and veins was 26.1+/-6.4, 1.6+/-0.4, and 19.9+/-8.2 mm/sec, respectively. In control rats, even the activated platelets showed minimal interaction with retinal endothelial cells. In contrast, stimulated retinal endothelium showed active platelet- endothelial interactions; many platelets were observed rolling and adhering along the major retinal veins. The interactions between platelets and stimulated endothelial cells were substantially inhibited with the injection of P-selectin monoclonal antibody.

CONCLUSIONS

The present study demonstrated a new method to visualize platelet behavior in the retinal microcirculation in vivo. This method will allow quantitative evaluation of platelet dynamics and platelet- endothelial interactions in retinal pathologic conditions.

[Premixing of 5% dextrose in Ringer's acetate solution with propofol reduces incidence and severity of pain on propofol injection]

The purpose of this study was to compare the effect of premixed 5% dextrose in Ringer's acetate solution and premixed lidocaine with propofpl on the reduction of pain during injection of propofol in adult patients. We conducted a prospective, randomized, double-blinded trial. Ninety-six patients were randomly allocated to one of three groups according to the agents added to 1% propofol 20 ml; Group C, normal saline 2 ml, Group L, 2% lidocaine 2 ml, and Group A, 5% dextrose in Ringer's acetate solution 2 ml. The pain on injection was rated as none, mild, moderate, or severe. Seventy percent of patients in the C group experienced pain, while 33% and 25% of patients experienced pain in the A group and the L group, respectively. Forty-two percent of patients in the C group complained moderate to severe pain but only one patient in both A group and L group. In conclusion, 5% dextrose in Ringer's acetate solution premixed with 200 mg propofol significantly reduces incidence and severity of pain associated with propofol injection and is easier to use than premixed lidocaine.

[Hyperkalemia after irradiated blood transfusion]

A 70-yr-old woman was scheduled for hepatectomy and colectomy. We gave general anesthesia with N2O-O2-Isoflurane and continuous epidural block. About 4.5 hours after the start of the operation, 8 units of irradiated RBC-MAP were transfused. Then elevated T waves were noted and serum potassium was increased to 5.4 mmol.l-1. The transfusion of RBC-MAP was stopped and calcium gluconate was administered immediately. Then serum potassium decreased to 4.3 mmol.l-1 and ECG returned to normal. During the operation, 10 units of irradiated RBC-MAP were transfused and 8 units of them had been stored more than 1 week after the irradiation. We suspect that hyperkalemia was induced by high concentration of potassium in RBC-MAP. Irradiation of blood products is an effective way to prevent post-transfusion graft versus host disease. However, the increase in potassium is greater in the irradiated than nonirradiated RBC-MAP. We must pay attention to the high concentration of potassium in th eplasma of RBC-MAP stored after irradiation.

Influence of prior Na+ pump activity on pump and Na+/Ca2+ exchange currents in mouse ventricular myocytes

We examined the dependence of peak Na+ pump and Na+/Ca2+ exchanger currents on prior Na+ pump inhibition induced by exposure to zero extracellular K+ in voltage-clamped adult murine ventricular myocytes. Abrupt activation of the Na+ pump by reexposure of myocytes to extracellular K+ with a rapid solution switcher resulted in the development of a transient peak current at approximately 500 ms, followed by a decline over 1-2 min to a steady-state level. The magnitudes of both the peak Na+ pump current (Ip) and the peak outward Na+/Ca2+ exchange current, activated by rapidly reducing extracellular Na+ to zero with the solution switcher, were dependent on previous Na+ pump activity. [Na+] gradients (Na+-binding benzofuran isophthalate fluorescence) between the patch pipette and the bulk cytosol were relatively small and could not account for the large differences between peak and steady-state Ip and reverse Na+/Ca2+ exchanger currents. Our results are consistent with the presence of a subsarcolemmal Na+ concentration gradient, which is similar for the Na+ pump and the Na+/Ca2+ exchanger. These findings also support the hypothesis that the Na+ pump and the Na+/Ca2+ exchanger are colocalized in the sarcolemma.

Abnormal myocyte Ca2+ homeostasis in rabbits with pacing-induced heart failure

To determine whether there are abnormalities in myocyte excitation-contraction coupling and intracellular Ca2+ concentration ([Ca2+]i) homeostasis in pacing-induced heart failure (PF), we measured L-type Ca2+ current (ICa,L) and Na+/Ca2+ exchanger current (INa/Ca) with voltage clamp and measured intracellular Na+ concentration ([Na+]i) and [Ca2+]i with the use of sodium-binding benzofuran isophthalate (SBFI) and fluo 3 in ventricular myocytes isolated from control and paced rabbits. The peak systolic and diastolic levels and the amplitude of electrically stimulated [Ca2+]i transients (0.25 Hz, extracellular Ca2+ concentration = 1.08 mM) were significantly less in PF myocytes. Also, there was prolongation of the times to peak and decline of [Ca2+]i transients. ICa,L density was markedly decreased in PF myocytes. INa/Ca at -40 mV elicited by rapid exposure to 0 Na+ solution with a rapid solution switcher was significantly reduced in PF myocytes, suggesting that the function of the Na+/Ca2+ exchanger is impaired in these myocytes. In PF myocytes the decline of the [Ca2+]i transient when the Na+/Ca2+ exchanger was abruptly disabled was markedly prolonged compared with the decline in control myocytes, consistent with depressed sarcoplasmic reticulum (SR) Ca2+-ATPase function. RNase protection assay showed decreased levels of Na+/Ca2+ exchanger and SR Ca2+-ATPase mRNA in PF hearts, consistent with the function studies. We conclude that the functions of L-type Ca2+ channels, Na+/Ca2+ exchanger, and SR Ca2+-ATPase are impaired in myocytes from rabbit hearts with failure induced by rapid pacing. These abnormalities result in reduced [Ca2+]i transients and systolic and diastolic dysfunction and appear to account for the abnormal ventricular function observed.

Effect of clarithromycin on alpha1-acid glycoprotein levels in normal and diabetic rats

The elevation of alpha1-acid glycoprotein (AGP) serum level, a member of the acute phase proteins (APP) synthesized by the liver, is induced during inflammation. In this study, we show that clarithromycin (CAM), a 14-membered macrolide antibiotic, causes an increase in the serum levels of AGP in a dose-dependent manner. AGP levels peak at 48h after a single administration with CAM In order to elucidate the mechanism of AGP induction by CAM, the effects of CAM, phenobarbital (PB), ethynylestradiol (EE2) and dexamethasone (DEX) treatments on APP fluctuation patterns were examined. In addition, modulation of the AGP induction by CAM, PB, EE2 and DEX in the diabetic state was examined. In contrast to treatment by PB, CAM treatment increased alpha2-macroglobulin levels to a much lesser extent than that observed during inflammation. On the other hand, albumin levels were unaffected by CAM treatment but decreased during inflammation. In addition, AGP induction by CAM, EE2 and DEX were attenuated in streptozotocin-induced diabetic rats, whereas the PB-induced increase in AGP levels was potentiated in diabetic rats. Thus, CAM and DEX treatments appear to induce similar fluctuations in APP levels. These results suggest that CAM increases AGP levels via a mechanism which may be different from PB and typical inflammatory pathways.

Effects of overexpression of the Na+-Ca2+ exchanger on [Ca2+]i transients in murine ventricular myocytes

We measured [Ca2+]i and [Na+]i in isolated transgenic (TG) mouse myocytes overexpressing the Na+-Ca2+ exchanger and in wild-type (WT) myocytes. In TG myocytes, the peak systolic level and amplitude of electrically stimulated (ES) [Ca2+]i transients (0.25 Hz) were not significantly different from those in WT myocytes, but the time to peak [Ca2+]i was significantly prolonged. The decline of ES [Ca2+]i transients was significantly accelerated in TG myocytes. The decline of a long-duration (4-s) caffeine-induced [Ca2+]i transient was markedly faster in TG myocytes, and [Na+]i was identical in TG and WT myocytes, indicating that the overexpressed Na+-Ca2+ exchanger is functionally active. The decline of a short-duration (100-ms) caffeine-induced [Ca2+]i transient in 0 Na+/0 Ca2+ solution did not differ between the two groups, suggesting that the sarcoplasmic reticulum (SR) Ca2+-ATPase function is not altered by overexpression of the Na+-Ca2+ exchanger. There was no difference in L-type Ca2+ current density in WT and TG myocytes. However, the sensitivity of ES [Ca2+]i transients to nifedipine was reduced in TG myocytes. This maintenance of [Ca2+]i transients in nifedipine was inhibited by Ni2+ and required SR Ca2+ content, consistent with enhanced Ca2+ influx by reverse Na+-Ca2+ exchange, and the resulting Ca2+-induced Ca2+ release from SR. The rate of rise of [Ca2+]i transients in nifedipine in TG myocytes was much slower than when both the L-type Ca2+ current and the Na+-Ca2+ exchange current function together. In TG myocytes, action potential amplitude and action potential duration at 50% repolarization were reduced, and action potential duration at 90% repolarization was increased, relative to WT myocytes. These data suggest that under these conditions, overexpression of the Na+-Ca2+ exchanger in TG myocytes accelerates the decline of [Ca2+]i during relaxation, indicating enhanced forward Na+-Ca2+ exchanger function. Increased Ca2+ influx also appears to occur, consistent with enhanced reverse function. These findings provide support for the physiological importance of both these modes of Na+-Ca2+ exchange.

Mechanism of the negative inotropic effect of midazolam and diazepam in cultured foetal mouse cardiac myocytes

We have investigated the effects of midazolam and diazepam on intracellular calcium (Ca2+) handling in foetal mouse ventricular myocytes using the Ca(2+)-sensitive fluorescent indicator, indo-1. We also investigated separately whether flumazenil or the L-type Ca2+ channel agonist, Bay K8644, antagonized these myocardial depressive effects. Midazolam and diazepam decreased the Ca2+ transient and beating rate in a concentration-dependent manner, and these decreases were prevented by Bay K8644. Flumazenil did not antagonize the myocardial depressive effects. In myocytes whose sarcoplasmic reticulum was inhibited by ryanodine, midazolam and diazepam had the same potent cardiodepressive effects. Midazolam and diazepam are direct cardiac depressants, which decrease the Ca2+ transient and beating rate, and the L-type Ca2+ channel is important in the negative inotropism and chronotropism caused by these drugs.

The minimum alveolar concentration of sevoflurane in rats

There are only limited data on sevoflurane minimum alveolar concentration (MAC) in rats. This study was designed to determine the minimum alveolar concentration value for sevoflurane in younger and older rats. Minimum alveolar concentration determination was performed in spontaneously breathing animals, 9-week-old rats (younger, n = 8) and more than 13-month-old rats (older, n = 8). Rats were instrumented with a silastic catheter in the abdominal aorta via the femoral artery to allow for arterial blood gas sampling. Subsequently, minimum alveolar concentration for sevoflurane was determined in 40 younger and 38 older rats. Minimum alveolar concentration for sevoflurane in younger rats was significantly higher than in the older rats (2.68 +/- 0.19 vs. 2.29 +/- 0.19, P < 0.001). Subgroup analysis indicated that minimum alveolar concentration for sevoflurane was not affected by the presence of an arterial catheter in the abdominal aorta (younger, 2.75 +/- 0.08 vs. 2.67 +/- 0.21; older, 2.23 +/- 0.19 vs. 2.30 +/- 0.18). Minimum alveolar concentration is profoundly affected by the age of the animal, but not by limited instrumentation.

A rare case of severe acute pancreatitis complicated with pancreatic pseudocysts, obstructive jaundice and intraperitoneal hemorrhage

A 58-year-old man visited our hospital because of back pain. Blood examinations revealed the presence of acute inflammation and an increase of pancreatic enzymes. Abdominal computed tomography indicated pseudocysts in the pancreas. The patient was diagnosed as having acute pancreatitis with pseudocysts formation. During the course of the disease, a newly formed pseudocyst in the pancreatic head compressed the common bile duct, leading to the obstructive jaundice. In addition, the rupture of a pseudocyst in the pancreatic tail caused intraperitoneal hemorrhage. This is an interesting case of acute pancreatitis with pseudocysts in which two rare complications developed.

A case of coronary artery spasm during spinal anesthesia

We present a rare case of coronary artery spasm during spinal anesthesia in a patient who had neither complications nor prior history of coronary artery disease. Some factors are involved in the occurrence of perioperative coronary artery spasm. Many cases of coronary artery spasm during general anesthesia, or general plus epidural anesthesia, have been reported. Although spinal anesthesia by itself has not been reported to be a cause of coronary artery spasm, it is likely, in the current case, that the combination of the activated parasympathetic nerve system by the retraction of the peritoneum and spinal anesthesia might have caused the coronary artery spasm. Anesthesiologists need to be aware that coronary artery spasm may occur during spinal anesthesia, especially when the peritoneum is retracted.

[Effects of amrinon and prostaglandin E1 on intraoperative central and peripheral temperatures during peripheral arterial surgery]

Effects of amrinon (AM) and prostaglandin E1 (PG) on body temperatures during surgery under general anesthesia were studied. Thirty-nine elective peripheral arterial surgery patients were assigned to one of three groups. All groups received dopamine (DOA) 3 micrograms.kg-1.min-1 after intubation and ten patients receiving only DOA served as a control group. Fifteen patients who received AM 1 microgram.kg-1 followed by AM 5 micrograms.kg-1.min-1 were assigned as an AM group. Fourteen patients who received PG 0.02 micrograms.kg-1.min-1 were defined as a PG group. Rectal and fingertip temperatures were monitored continuously during surgery. Fingertip temperatures in both AM and PG groups were significantly higher than those in the control group 120 minutes after the administration of drugs. On the other hand, rectal temperatures in all groups did not differ significantly throughout the study. The rectum-fingertip temperature gradient was lower in both AM and PG group than in the control group. These results suggest that bolus injection of AM 1 microgram.kg-1 followed by AM 5 micrograms.kg-1.min-1 and PG 0.02 micrograms.kg-1.min-1 may be effective for maintaining central and peripheral temperatures during surgery under general anesthesia.

Cardiac effects of methylmethacrylate in the rat heart-lung preparation with or without volatile anesthetics

We have assessed the deleterious effects of methylmethacrylate (MMA) on cardiac function and metabolism in the isolated heart-lung preparation with or without volatile anesthetics. Wistar rats were prepared for the heart-lung model. They were randomly divided into 5 groups as follows. (1) Control (C) group. (2) Cement (M) group; they received MMA. (3) Halothane (H) group; they received MMA and 1% halothane. (4) Isoflurane (I) group; they received MMA and 1.5% isoflurane. (5) Sevoflurane (S) group; they received MMA and 2.5% sevoflurane. MMA 1000 micrograms/ml was administered 7 min after the start of perfusion except in the C group. At the end of the experimental period, the hearts were freeze-clamped and then myocardial high energy phosphates, lactate and glycogen were measured. Cardiac output in all groups but C group decreased significantly. PO2 of the perfusion blood in the M, H, I and S groups was significantly lower than that in the C group. Myocardial ATP in the M, H, I and S groups was significantly lower than that in the C group. ADP and AMP in the M, H, I and S groups were higher than those in the C group. There were no significant differences in lactate and glycogen levels between the 5 groups. MMA 1000 micrograms/ml is much higher than the blood level (0.05-31.89 micrograms/ml) which was reported in clinical patients who had femoral prosthesis. Therefore, the direct contribution of MMA itself to cardiac depression may be less than the other factors such as embolism in clinical situations. Volatile anesthetics did not influence the deleterious effects of MMA on cardiac function and metabolism.

[Anesthetic management of a neonate with primary cardiac rhabdomyoma]

We have experienced anesthetic management for cardiac rhabdomyoma in a 21-day-old male, whose pulmonary trunk was obstructed by the tumor. He was anesthetized with fentanyl 70 micrograms.kg-1 and oxygen. The operative and post-operative courses were uneventful. Cardiac tumor, especially cardiac rhabdomyoma, in infant is rare. Anesthesia for the resection of the cardiac tumor must be carried out carefully, because sudden death due to arrhythmias as well as cardiac or respiratory failure is the most dangerous complication.

Effects of artificial blood (FC-43 emulsion) on myocardial energy metabolism in the rat heart-lung preparation

We have assessed the effects of artificial blood (FC-43 emulsion) on myocardial energy metabolism in the rat heart-lung preparation. Animals were allocated to four groups (n = 8 each group) according to the ratio of perfusion blood and FC-43 as follows: group 1 = control, perfusion blood only; group 2 = 50% FC-43; group 3 = 75% FC-43; and group 4 = 100% FC-43. Hearts were perfused initially to a cardiac output of 30 ml min-1 and mean arterial pressure of 50 mm Hg. Thirty minutes after perfusion, the hearts were freeze-dried for 6 days. Myocardial high energy phosphates (ATP, ADP and AMP) were measured by high pressure liquid chromatography. Myocardial lactate and glycogen concentrations were measured by enzymatic methods. There were almost no significant differences in cardiac output, systolic pressure, right atrial pressure and heart rate among the groups. Oxygen contents of the perfusate in all FC-43 groups were significantly lower than those in the control group. Myocardial ATP concentrations in rats receiving 50%, 75% and 100% FC-43 were significantly lower than those in the control group. In addition, myocardial ADP and AMP concentrations in rats receiving 75% and 100% FC-43 were significantly higher than those in the control group. Although there is adequate oxygen-carrying capacity in FC-43 to maintain cardiac function during perfusion, the energy levels in the hearts perfused with FC-43 were lower than those in normal hearts.

Effects of intravenous anaesthetics on function and metabolism in the isolated rat heart-lung preparation

The influence of several intravenous anaesthetics on the heart was assessed using the isolated rat heart-lung preparation. Each group received 10(-3)mol litre-1 and 10(-4)mol liter-1 of ketamine, 6 micrograms ml-1 and 60 micrograms ml-1 of midazolam, 6 micrograms ml-1 and 60 micrograms ml-1 of diazepam or 0.6 micrograms ml-1 and 6 micrograms ml-1 of flunitrazepam. Systolic blood pressure in rats receiving high doses of midazolam, diazepam and ketamine were higher than that in the control group. Heart rate in rats receiving high doses of ketamine and diazepam were lower than that in the control group. However, there were no significant changes in cardiac output among the groups. Maximum rate of left ventricular tension development in rats receiving high doses of midazolam and diazepam increased significantly in comparison with that in the control group. There were no significant changes in myocardial high energy phosphates among the groups. None of the intravenous anaesthetics, even in doses which were 100 times greater than therapeutic doses, showed any depressant effects in this preparation. Moreover, it is surprising that midazolam and diazepam produced direct increases in myocardial contractility. These results suggest that the cardiodepressant effects of intravenous anaesthetics may be due to their effects on the central nervous system.

Effects of inhalation anesthetics on myocardial and hepatic energy metabolism in normotensive and spontaneously hypertensive rats subjected to hemorrhage

Forty spontaneously hypertensive rats (SHRs) and forty normotensive Wistar-ST rats (NRs) were used to assess the influence of anesthetics on myocardial and hepatic energy metabolism after hemorrhage. They were divided into five pairs of groups: a control group (pentobarbital 6 mg.100 g BW-1 ip), and four others which received 1.2% halothane, 2.2% enflurane, 1.4% isoflurane, and 3.3% sevoflurane, respectively. Following a 10 min stabilization period, blood (2 ml.100 g BW-1) was gradually withdrawn over a 5 min period from a femoral artery. Thirty min after the induction of hemorrhage, the heart and liver were removed and myocardial and hepatic metabolites (ATP, lactate, pyruvate and glycogen) were measured by enzymatic methods. There were no significant differences in myocardial metabolites among either the anesthetic groups or between SHRs and NRs. However, hepatic ATP levels in all SHR groups were significantly lower than those in NR groups. Moreover, ATP levels in the inhalation anesthetic groups of SHRs were significantly higher than that in the control group of SHRs. All inhalation anesthetics, especially isoflurane, may reduce metabolic deterioration of the liver during hemorrhage when compared to barbiturate anesthesia.

Anesthetic influences on myocardial and hepatic energy metabolism in hemorrhaged spontaneous hypertensive rats

Twenty four spontaneously hypertensive rats (SHRs) were used to assess the influence of anesthetics on myocardial and hepatic energy metabolism after hemorrhage. They were divided into four groups: a control group and three others which received pentobarbital (60 mg.kg-1 ip), 2.2% enflurane, or 1.4% isoflurane. Following a 10-min stabilisation period, blood (2 ml.100 g body weight-1) was gradually withdrawn over a 5-min period from a femoral artery. Thirty minutes after the induction of hemorrhage, the heart and liver were removed, and myocardial and hepatic metabolites (ATP, lactate, pyruvate, and glycogen) were measured by the enzymatic methods. Metabolic acidosis and decreased hematocrit were noted in all groups after hemorrhage. The mean arterial pressure in rats receiving anesthetics decreased significantly in comparison with the control group. There were significant increases of myocardial and hepatic lactate/pyruvate ratios in rats receiving enflurane when compared with controls. These results suggest that enflurane may be more detrimental than other anesthetics to the maintenance of anesthesia in hypovolemic SHRs.

Cardiac and hepatic metabolism in spontaneously hypertensive rats following acute blood loss

Seven spontaneously hypertensive rats (SHRs) and eight Wistar-St rats were used to assess the influence of hemorrhage on myocardial and hepatic energy metabolism. They received 2% halothane and pancuronium, 0.3 mg.kg(-1), during preparation. After discontinuation of halothane, blood (2 ml.100 g body weight(-1)) was gradually withdrawn over a 5 min period from a femoral artery. Thirty min after induction of hemorrhage, the heart and liver were removed and myocardial and hepatic metabolites (ATP, lactate, pyruvate and glycogen) were measured by the enzymatic methods. Acidosis and decreased hematocrit were noted in the both groups after hemorrhage. Mean arterial pressure (MAP) in SHR was significantly higher than that in Wistar rat before hemorrhage. However, there were no significant differences in MAP and heart rate between the two groups after hemorrhage. Although there were no significant differences in cardiac metabolites, a significant decrease of hepatic ATP and an increase of hepatic lactate/pyruvate ratio were found in SHR when compared with Wistar rat. These results suggest that human hypertensive disease may run a high risk in connection with acute hemorrhage.

Effect of synthetic protease inhibitors on superoxide (O2-), hydrogen peroxide (H2O2) and hydroxyl radical production by human polymorphonuclear leukocytes

The effects of clinically used protease inhibitors (aprotinin, nafamostat mesilate, gabexate mesilate) on the production of oxygen-derived free radicals (O2-, H2O2, .OH) by human polymorphonuclear leukocytes were examined. Nafamostat mesilate and gabexate mesilate markedly and dose-dependently inhibited zymosan-stimulated O2- production by human polymorphonuclear leukocytes. However, aprotinin had a slight scavenging effect on O2- produced by the xanthine-xanthine oxidase system. All the protease inhibitors inhibited H2O2 production, but had no significant scavenging effect on H2O2. Nafamostat mesilate and gabexate mesilate slightly inhibited .OH production. These results indicate that the synthetic protease inhibitors nafamostat mesilate and gabexate mesilate inhibit the production of various activated oxygen radicals by human polymorphonuclear leukocytes, and the differences in their inhibitory effects suggest that each synthetic protease inhibitor is specific for a particular oxygen-derived free radical.