Lazaroid (U74500A) prevents vascular and myocardial dysfunction after 24-hour heart preservation. A study based on cross-circulated blood-perfused rabbit hearts

BACKGROUND

The prevention of ventricular and vascular dysfunction has been recognized as an important factor in heart preservation. Because lipid peroxidation may cause cell membrane injury after ischemia and reperfusion, we hypothesized that the administration of a lipid peroxidation inhibitor lazaroid (U74500A) would result in an improvement of functional recovery after the 24-hour preservation period.

METHODS AND RESULTS

An isolated rabbit heart preparation perfused with support rabbit blood was used. Before preservation, 4 mg/kg of either lazaroid or solvent was given to donor rabbits. The hearts were preserved with University of Wisconsin solution for 24 hours at 0 degree C. The working model preparation (n = 7 in each group) showed a better cardiac output (74.6 +/- 25.7 versus 192.7 +/- 19.6 mL/min, P < .0001) and a lower lipid peroxide level (2.1 +/- 1.3 versus 0.6 +/- 0.3 nmol/mL. P < .05) of the coronary effluent in the heart treated with lazaroid. With a Langendorff preparation (n = 7 in each group), we evaluated the vascular dilatory function. The endothelial function assessed by the percentage increase of coronary flow in response to acetylcholine in the solvent group was significantly lower than that of the lazaroid group (69 +/- 24% versus 140 +/- 67%, P < .05), whereas no significant difference was observed between the groups regarding endothelium-independent vasodilatation as assessed by the responses to nitroglycerin and nitroprusside.

CONCLUSIONS

These results demonstrated an improved ventricular and endothelial function in the rabbit pretreated with lazaroid before preservation accompanied by a reduction of lipid peroxidation, indicating the potential benefits for long-term heart preservation.

[Bronchiolitis obliterans organizing pneumonia (BOOP) after allogeneic bone marrow transplantation]

We report a patient who underwent allogeneic bone marrow transplantation for ALL. The patient presented low grade fever, cough and dyspnea at day 3 after after bone marrow transplantation. Imaging studies showed bilateral patchy infiltrates on chest X-ray and chest CT. Though treated by antibiotics, chest auscultation recognized marked bilateral inspiratory crackles. Transbronchial lung biopsy performed on day 34 showed bronchiolitis obliterans and an organizing interstitial pneumonia. The patient was treated with methylprednisolone and follow up computed tomography findings improved.

Cytotoxic components of bardanae fructus (goboshi)

Bardanae Furctus (Goboshi) extract showed potent in vitro cytotoxicity and in vivo antitumor activity against human hepatoma HepG2 cells and mouse sarcoma 180 cells, respectively. In this study, the cytotoxicities of four fractions and three major components (arctiin, arctigenin, and chlorogenic acid) isolated from Goboshi extract were examined. Arctiin and arctigenin, which were contained in the ethylacetate fraction and n-butanol fraction, respectively, showed strong cytotoxicity against HepG2 cells, but little toxicity against Chang liver cells. Chlorogenic acid isolated from the water fraction did not affect the viability of these cells. The cytotoxicity of arctigenin against Chang liver cells was markedly potentiated by treatment with glutathione (GSH) synthesis inhibitor, L-buthionine-(S,R)-sulfoximine (BSO). On the other hand, in HepG2 cells, the cytotoxicity of arctigenin was hardly changed by BSO. The cytotoxicity of arctigenin against HepG2 cells increased in an exposure-time dependent manner. These characteristics of arctigenin were similar to those of Goboshi extract, as previously observed. We therefore conclude that the principal cytotoxic components of Goboshi extract are arctiin and its aglycone arctigenin.

Relationship between breathlessness and hypoxic and hypercapnic ventilatory response in patients with COPD

The purpose of this study is to examine the relationship between breathlessness and the ventilatory response to hypercapnia or hypoxia in patients with chronic obstructive pulmonary disease (COPD). Fifteen male patients (mean forced expiratory volume in one second (FEV1): 1.13 L) underwent tests to determine hyperoxic hypercapnic ventilatory response (HCVR) and isocapnic hypoxic ventilatory response (HVR) with simultaneous quantification of breathlessness by modified Borg scale. The ventilatory output was evaluated by the ratio of minute ventilation (V'E) divided by measured maximal voluntary ventilation (MVV). The magnitude of HCVR or HVR was assessed as the slope value of the V'E/MVV-end-tidal carbon dioxide pressure (PET,CO2) or arterial oxygen saturation (Sa,O2) regression line, respectively. The breathlessness during the tests was evaluated not only linearly in relation to V'E/MVV, but also at given levels of PET,CO2 or Sa,O2. The mean value of the breathlessness at two different levels of ventilation was greater during HVR than during HCVR, suggesting that hypoxia is dyspnogenic independently of ventilatory stimulation. The HCVR was inversely correlated with the breathlessness response to ventilation, while similar correlation was partly present for HVR. The HVR was positively correlated with the breathlessness at an Sa,O2 of 80%, whilst there was no such correlation between the HCVR and the breathlessness related to PET,CO2. Therefore, patients with a higher breathlessness related to increased ventilation had a lower HCVR and HVR, whilst those with a higher breathlessness with desaturation, which might include a direct influence of hypoxia, had a higher HVR. These findings suggest an interaction between ventilatory response and breathlessness during the test, which may partly include behavioural modulation of HCVR and HVR through the breathlessness in various ways, depending on the origin and nature of the sensation.

Production of nitric oxide (NO) in intrathoracic airways of normal humans

To gain insight into the source of exhaled nitric oxide (NO) in normal humans, we examined the effects of respiratory pattern on the concentration of NO in exhaled air while subjects were wearing a noseclip and then under endotracheal intubation, using a specially designed gas sampling system to separate exhaled air into two fractions: the initially exhaled 200 ml (Fraction 1; F1), and the remainder (Fraction 2; F2). We also examined the effect of hypoxic gas inhalation (F(I)O2 = 0.1, 3 min) on the concentration of exhaled NO. The concentration of exhaled NO measured with a chemiluminescence NO analyzer was significantly lower with intubation, by 59.2 +/- 10.6% (mean +/- SD) (F1) and 54.4 +/- 8.0% (F2), than without intubation. The concentration of NO in F1 was consistently higher than that in F2 with or without intubation. With breath holding, the concentration of NO increased markedly only in F1. In contrast, prolongation of the expiratory phase slightly but significantly increased the concentration of NO only in F2. Inhalation of hypoxic gas did not cause any significant change in NO concentration in either fraction. These data indicate that in normal humans wearing a noseclip, about 40 to 45% of NO in exhaled air originates from the lungs, particularly from intrathoracic airways. The concentration of exhaled NO collected from subjects wearing a noseclip is not affected by hypoxic gas inhalation.

[Surgical treatment of primary mediastinal tumors in children]

Twenty children with primary mediastinal tumor underwent surgical treatment. Ten patients had benign tumor and the other patients were malignant. Seven of ten patients with malignant tumor were neurogenic, and 3 patients were of germ cell tumor. In the clinical manifestation, 11 patients were asymptomatic. All of benign tumors were resected completely, but in a few patients with malignant tumors, the complete resection not possible. However, except for one patient with immature teratoma, all patients with malignant tumor have been surviving following postoperative chemotherapy and radiotherapy. Two infants with bronchogenic cyst were operated on their respiratory distress syndrome in emergency, and have been salvaged.

An in vitro system for identifying agents capable of changing serum lipoprotein(a) concentration by regulating the transcriptional activity of the apolipoprotein(a) gene promoter

A high serum concentration of lipoprotein(a) [Lp(a)] is a significant and independent risk factor for cardiovascular disease. We examined the effects of agents on the transcriptional activity of the apolipoprotein(a) [apo(a)] gene promoter and determined whether drugs identified by this assay would affect the serum concentration of Lp(a) in vivo. All-trans-retinoic acid (ATRA) and interleukin-6 increased the transcriptional activity of the apo(a) gene promoter 2.1- and 2.5-fold, respectively, whereas danazol reduced activity to 76% of the control value. Triiodothyronine had no effect on transcriptional activity. Treatment of two acute promyelocytic leukemia patients with ATRA induced maximal 2.7- and 3.2-fold increases in serum Lp(a) concentrations, respectively. Thus, the in vitro luciferase assay system is capable of identifying agents that affect the serum concentration of Lp(a) and thus may prove beneficial in the screening of new drugs for treatment of individuals with high serum Lp(a) concentrations.

Prevalence of Lyme disease spirochetes in Ixodes persulcatus and wild rodents in far eastern Russia

Borrelia spirochetes were isolated from the adult ixodid tick (Ixodes persulcatus) in three areas of far eastern Russia, namely, Khabarovsk, Vladivostok, and Yuzhno-Sakhalinsk. Borrelia infective rates of ticks in those areas were 24.5, 41.4, and 25.1%, respectively (total rate was 26.6%). Spirochetes were also isolated from the tissues of small mammals captured at Khabarovsk (infective rate was 20.8%). Samples were classified by rRNA gene restriction fragment length polymorphism (RFLP) analysis. The isolated spirochetes from ticks were classified mainly RFLP ribotype group IV (B. garinii), followed by groups II (B. garinii), III (B. afzelii), and V (B. garinii), showing that B. garinii is a dominant species among them. Both B. garinii and B. afzelii were also found in rodents, and multiple infections with those two species were observed in some rodents. B. burgdorferi sensu stricto (group I) was not isolated from either ticks or rodents.

Detection of impaired fatty acid metabolism and dyskinesis in hypertrophic cardiomyopathy with iodine-123-BMIPP

Metabolic imaging using 123I-labeled 15-(p-iodophenyl)-3-R,S-methylpentadecanoic acid (BMIPP) and Fourier phase analysis of gated blood-pool data were performed in a 60-yr-old woman with idiopathic hypertrophic cardiomyopathy. Dyskinetic wall motion was identified as a markedly delayed phase angle in the left ventricular apex, which was well perfused but highly hypertrophied like other ventricular segments. Fatty acid imaging, however, clearly demonstrated highly reduced activities in the apex, although there were no abnormalities in regional systolic function or in 201TI uptake in other hypertrophied regions. Contrast left ventriculography revealed a midventricular collapse of the left ventricle at end-systole due to markedly hypertrophied ventricular walls and dyskinesis at the apex. Thus, dyskinetic wall motion in the apex closely correlated not only with cardiac hypertrophy but also with impaired fatty acid uptake. These findings were unrelated to the myocardial perfusion state per se. Fatty acid imaging using BMIPP may contribute to the detection of myocyte degeneration not visible using conventional imaging modalities. It may also provide etiological information on regional dysfunction in hypertrophic cardiomyopathy.

Masseter muscle activity during the whole day in young adults

This study was conducted to evaluate the biting function during the entire day in young adults by measuring the masseter muscle activity with a 24-hour electromyography (EMG) system. With this system, the masseter muscle activity for 24 hours was recorded in 20 male and 10 female young adult subjects with acceptable occlusion. For the male subjects, means of the number and total duration of bursts over level 2, which is one-fourth of the maximum discharge voltage during maximum clenching, were 1938 times and 357 seconds. For the female subjects, the values were 2356 times and 419 seconds. A large percentage of such high amplitude bursts as level 3 or 4 was observed during meals in both groups. These results indicated that most of the strong bursts of the masseter muscle appeared only during meals and a number of low amplitude bursts were observed during the entire day, although masseter muscle activity during the entire day in young adults was less than expected. It is anticipated that the nature of masticatory muscle activity revealed in this study might provide valuable information about the association between the biting function and the craniofacial structure or malocclusion.

Visualization of leukocyte dynamics in the choroid with indocyanine green

PURPOSE

To report a method to evaluate leukocyte dynamics in the choroidal circulation with indocyanine green (ICG) angiography.

METHODS

Nonpigmented and pigmented rats were administered ICG solution intravenously. The fundus image was obtained with a scanning laser ophthalmoscope and recorded on magnetic tapes at a video rate (30 frames/second). The images were analyzed with a personal computer-based image analysis system.

RESULTS

On ICG angiography, hyperfluorescent dots were seen moving along the choroidal vessels and in the retinal vessels several minutes after injection. These fluorescent dots were thought to be circulating leukocytes stained with ICG. The micrographs of blood smears after ICG injection showed intense fluorescence of leukocytes. Computer-assisted image analysis allowed tracing of these fluorescent dots using a frame-by frame method.

CONCLUSIONS

Results of this study indicated that ICG can be used for vital staining of leukocytes and that it is possible to evaluate leukocyte movement in the choroidal circulation in vivo in rats.

Effects of refeeding diets on emeriamine-induced fatty liver in fasting rats

We recently reported that fatty liver and hypertriglyceridemia are easily induced by the administration of an inhibitor of fatty acid oxidation (emeriamine; (R)-3-amino-4-trimethylaminobutyric acid) to fasting rats, and that these conditions are not accompanied by the increased de novo synthesis of fatty acid [J. Nutr. Sci. Vitaminol., 42, 111-120, (1996)]. To study whether emeriamine-induced fatty liver is affected by nutrients during recovery from fatty acid oxidation inhibition, we fed rats with either a high-carbohydrate (HCHO) diet or a high-fat (HFAT) diet. Rats fed an HCHO diet following the administration of emeriamine showed a marked decrease in serum and hepatic triglycerides, and a marked increase in hepatic glycogen. The lower levels of serum and hepatic triglycerides were accompanied by decreased activities of the NADPH-generating enzymes such as malic enzyme and glucose-6-phosphate dehydrogenase. By contrast, rats fed an HFAT diet showed less significant changes in hepatic triglyceride and glycogen levels. These results suggest a reciprocal relationship between the triglyceride level and glycogen accumulation caused by HCHO diet during recovery from emeriamine.

Elastin-derived peptides and neutrophil elastase in bronchoalveolar lavage fluid

To evaluate effects of current smoking on the breakdown of lung elastin, we measured levels of elastin-derived peptides (EDP) in unconcentrated bronchoalveolar lavage (BAL) fluid from 42 community-based older asymptomatic volunteers (60 +/- 11 yr [mean +/- SD]) and examined the relationships of the concentrations of EDP with immunologically detected neutrophil elastase (NE) bound with alpha(1)-proteinase inhibitor and with esterolytic activity against the NE-sensitive synthetic substrate, methoxysuccinyl-alanyl-alanyl-prolyl-valyl paranitroanilide (MEOSAAPVNA). The measurement of EDP levels was carried out by an indirect, competitive ELISA, using a sheep IgG fraction generated against insoluble human lung elastin as a primary antibody. EDP concentrations were significantly elevated in current smokers (n = 24) compared with age-matched noncurrent smokers (n = 18) (29.9 +/- 3.5 [mean +/- SE] versus 17.0 +/- 1.8 ng/mg BAL fluid albumin, p < 0.01). We found weak but significant correlations of EDP levels with NE-alpha(1)-proteinase inhibitor complex (r = 0.38, p < 0.05) and with the esterolytic activity against the NE-sensitive synthetic substrate in BAL fluid (r = 0.65, p < 0.001). In addition, EDP levels in BAL fluid had a significant positive relationship with plasma cotinine concentrations (r = 0.53, p < 0.001), though not with pack-years of smoking (r = 0.1, NS). These data provide further evidence that the concentrations of EDP increase in BAL fluid from current smokers compared with noncurrent smokers and that enhanced breakdown of the lung elastin is associated with the increased load of NE in the lung.

Comparative pharmacokinetics of KRN8602, a new morpholino anthracycline, and adriamycin in tumor-bearing mice

It has been reported that KRN8602 shows antitumor effects similar or superior to those of Adriamycin (ADM) against several murine and human cell lines and has been found to be effective against multidrug resistant tumor cells. We investigated the pharmacokinetics of KRN8602, a new morpholino anthracycline, in comparison with ADM in mice bearing colon26 adenocarcinoma. After intravenous administration, both drugs disappeared triexponentially from the plasma and KRN8602 was eliminated faster than ADM. The rate of elimination of KRN8602 from tissues was also faster than than of ADM. The relative order of the area under the curve (AUC) of KRN8602 was spleen > tumor > small intestine > lung > kidney > heart > liver > brain > plasma, while that of ADM was spleen > kidney > lung > liver > heart > small intestine > tumor > plasma. ADM was not detectable in the brain. The AUC of KRN8602 was higher than that of ADM in the tumor and brain, but it was lower in other tissues. The tissue-to-plasma concentration ratio (KPapp) of KRN8602 was higher than that of ADM in the tumor, spleen, small intestine and brain. KRN8602 was metabolized to several metabolites. The concentrations of M1 and M2 (glycoside-type metabolites) was relatively high in the spleen. M3 (aglycone-type metabolite) showed a very high AUC ratio in the liver (34%). In tumor, M1 and M2 concentrations were low and M3 was not detected. KRN8602 had a greater activity than ADM and M2 had a cytotoxic activity similar to KRN8602 against colon26 cells in an MTT assay. These results suggest that the strong antitumor effect of KRN8602 against colon26 is due not only to its strong cytotoxic activity but also to its marked transferability into tumors. KRN8602 shows better selective toxicity than ADM, because KRN8602 is more selective for tumors than ADM and less is transferred to normal tissues.

Structure-activity relationships of (E)-3-(1,4-benzoquinonyl)-2-[(3-pyridyl)-alkyl]-2-propenoic acid derivatives that inhibit both 5-lipoxygenase and thromboxane A2 synthetase

As part of our research for the development of novel antiinflammatory drug candidates, we have designed and synthesized a series of (E)-3-(1,4-benzoquinonyl)-2-[(3-pyridyl)alkyl]-2-propenoic acid derivatives as dual inhibitors of 5-lipoxygenase (5-LO) and thromboxane (TX) A2 synthetase. In order to increase the absorption after oral administration, we introduced a carboxylic acid moiety into the 1,4-benzoquinone skeleton, which has 5-LO-inhibitory character. Introduction of a 3-pyridylalkyl group at the double bond of the 1,4-benzoquinonyl propenoic acid moiety afforded good to moderate inhibitory activities against the production of leukotriene (LT) B4 and TXA2 while not significantly inhibiting that of prostaglandin E2 by glycogen-induced peritoneal cells of rat (in vitro). The length of the methylene chain of the 3-pyridylalkyl group influenced the inhibition of LTB4 and TXB2 production. An increase of lipophilicity by introducing a more lipophilic alkoxy group did not markedly increase the inhibitory activity on LTB4 production. The position of alkoxy group on the 1,4-benzoquinone skeleton played an important role in TXA2 synthetase inhibition. Compounds such as 20c (E6700) with an appropriate alkoxy group and proper length of methylene side chain, together with a polar substituent (carboxylic acid), showed good inhibition of both 5-LO and TXA2 synthetase and possess a variety of pharmacologically beneficial effects.

Cloning and sequence analysis of a protease-encoding gene from the marine bacterium Alteromonas sp. strain O-7

The gene (aprI) encoding alkaline serine protease (AprI; subtilase) from Alteromonas sp. strain O-7 was cloned and sequenced. The nucleotide sequence of aprI has been identified. The deduced amino acid sequence indicated that aprI codes for a precursor of 715 amino acids and the precursor is composed of four regions including a signal peptide, an N-terminal pro-region, a mature protease region and a C-terminal extension region of 215 amino acids as previously described for aprII [H. Tsujibo et al., Gene, 136, 247-251 (1993)]. The amino acid sequence of the mature AprI (AprI-M) showed high sequence homology with those of other class I subtilases. The C-terminal region was characterized by a repeat of 94 amino acids residues, which showed about 50% similarity with those of the C-terminal pro-region of several known proteases from Gram-negative bacteria.

Effects of truncation of the COOH-terminal region of a Na+-independent neutral and basic amino acid transporter on amino acid transport in Xenopus oocytes

To determine the role of a neutral and basic amino acid transporter (NBAT) in amino acid transport, we microinjected several COOH-terminal deletion mutants of NBAT cRNA into Xenopus oocytes and measured transport activity for arginine, leucine, and cystine in the presence and absence of sodium. Wild-type NBAT significantly stimulated the uptake of all three amino acids 10-20-fold compared with controls. On the other hand, no mutant, except a Delta511-685 mutant, stimulated the uptake of these amino acids. The Delta511-685 mutant significantly increased the uptake of arginine. In the presence of sodium, the Delta511-685 mutant also increased the uptake of leucine. The Delta511-685 mutant did not stimulate cystine uptake in the presence or absence of sodium. The stimulation of arginine uptake by the Delta511-685 mutant was inhibited by a 100-fold excess of unlabeled leucine in the presence of sodium. Inhibition of L-arginine uptake by L-homoserine was seen only in the presence of sodium, and an increase in the inhibition of L-arginine uptake by L-histidine was seen when the extracellular pH was decreased. Furthermore, an inward current in oocytes injected with the Delta511-685 mutant was recorded electrophysiologically when basic amino acids were applied. Homoserine was also taken up, but sodium was necessary for their transport. These properties of the Delta511-685 mutant correspond to those of the y+ amino acid transporter. If NBAT is a component of the b0,+-like amino acid transport system, it is unlikely that a mutant protein (Delta511-685) is able to stimulate an endogenous y+-like transport system. These results suggest that NBAT functions as a activator of the amino acid transport system in Xenopus oocytes.

Characterization of spirochetes isolated from ticks (Ixodes tanuki, Ixodes turdus, and Ixodes columnae) and comparison of the sequences with those of Borrelia burgdorferi sensu lato strains

Ixodes persulcatus serves as a tick vector for Borrelia garinii and Borrelia afzelii in Japan; however, unidentified spirochetes have been isolated from other species of ticks. In this study, 13 isolates from ticks (6 from Ixodes tanuki, 6 from Ixodes turdus, and 1 from Ixodes columnae) and 3 isolates from voles (Clethrionomys rufocanus) were characterized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, rRNA gene restriction fragment length polymorphism, partial sequencing of the outer surface protein C (OspC) gene, whole DNA-DNA hybridization, and 16S rRNA gene sequence comparison. All of the results revealed that these Borrelia strains clearly represent at least two new species. A third is also likely, although additional strains have to be isolated and characterized before a separate species is designated. We designated all isolates of I. tanuki and C. rufocanus as group Hk501 and all isolates of I. turdus as group Ya501. Phylogenetic analysis based on 16S rRNA gene sequences distinguished these Borrelia strains from those belonging to hitherto known Borrelia species. Furthermore, the genomic groups, each with its own tick vectors with enzootic cycles, were quite different from each other and also from those of Lyme disease Borrelia species known to occur in Japan. The results of 16S rRNA gene sequence comparison suggest that the strain Am501 from I. columnae is related to group Hk501, although its level of DNA relatedness is less than 70%.

Enhanced expression of the protein kinase substrate annexin in human hepatocellular carcinoma

Annexin (AX) constitutes a new family of Ca2+-dependent membrane-binding proteins; 13 of them have been described. Among these, annexin-1 (AX-I) has displayed many biological functions in vitro. Its actual role in vivo, however, remains unknown. We already reported that AX-I was expressed in proliferating (regenerating) hepatocytes at both protein and messenger RNA (mRNA) levels. The role of AX-I in human hepatocellular carcinoma (HCC) remains obscure. In this study, the amounts of AX-I at protein and mRNA levels, as well as its localization, have been determined in the normal human liver, chronic hepatitis liver, and nontumorous and tumorous portions of HCC. AX-I was rarely found in normal and chronic liver tissues, whereas it is overexpressed at both the transcriptional and translational levels in tumorous and nontumorous regions of HCC. In addition, more AX-I was expressed in the tumorous portion than the nontumorous portion of HCC. AX-I was present in the hepatocytes and HCC cells, localized mainly in the cytoplasm. AX-I was expressed in poorly differentiated cancer cells. Furthermore, AX-I was tyrosine-phosphorylated in HCC. We also found that some of the AX-I- positive hepatocytes in the nontumorous tissues were derived from a particular subset of parenchymal cells (stem or oval cells). These results indicate that AX-I plays an important role in the malignant transformation process leading to HCC and that it is closely related to the histological grade of HCC. HCC would offer a novel tool with which to study the function of AX-I in malignant transformation.