Establishment and characterization of synovial cell clones with integrated human T-cell leukemia virus type-I

Human T cell leukemia virus type-I (HTLV-I)-integrated synovial cell clones (SCCs) were established from four HTLV-I-infected patients with chronic proliferative arthropathy. Extracted DNAs of these SCCs were examined for the existence of HTLV-I proviral DNA. Electron microscopic analysis and immunohistochemical staining were also performed to examine the nature of the HTLV-I integrated SCCs. SCCs derived from all four patients consisted of either HTLV-I integrated or nonintegrated cells. HTLV-I integrated SCCs also produced viral messenger RNA which was detected by reverse transcriptase-polymerase chain reaction as well as viral protein which was detected by immunohistochemical staining. Phenotypically, these SCCs containing HTLV-I proviral DNA were shown to be all cell types as observed by electron microscopic analysis and immunohistochemical analysis. Moreover, expression of HTLV-I glycoprotein was greater in SCCs with a monocyte marker. These findings suggest that SCCs harboring HTLV-I have an important role in synovial hyperplasia.

The involvement of the stimulatory G protein in sexual dimorphism of beta-adrenergic receptor-mediated functions in rat liver

In rat hepatocytes, beta-adrenergic receptor (beta-AR)-mediated cAMP generation was found to be higher in the female than in the male. As compared to the male, the number of beta-AR, detected by [125I]iodocyanopindolol, was elevated in the female. In agonist competition experiments, the proportion of beta-AR in the high-affinity state was promoted in the female than in the male. The alpha subunit of the stimulatory G protein (Gs alpha) was quantified using ADP-ribosylation catalyzed by cholera toxin. The amount of Gs alpha, both small, 42 kDa (Gs alpha S), and large, 47 kDa (Gs alpha L), forms increased in parallel with enhancement of catecholamine-sensitive adenylate cyclase activity in the female. The female showed a disproportionate increase in Gs alpha L, which is preferentially coupled to beta-AR, compared with Gs alpha S. In addition, 17 beta-estradiol facilitated isoproterenol-induced cAMP generation in both male and female rats, whereas castration or testosterone had no effect on this response. It is proposed that the cellular sites for sexual dimorphism in hepatic beta-adrenergic functions are the coupling state of beta-AR to Gs and the amount of Gs alpha as well as the level of beta-AR.

Better grading systems for evaluating the degree of lymph node invasion in cancer of the thoracic esophagus

To evaluate the quality of various grading systems for lymph node invasion in cancer of the thoracic esophagus, the surgical results of 142 patients who underwent systematic lymph node dissection with curative intent were analyzed. The survival probability of patients in the same grade was modeled using a Weibull distribution and the parameters were estimated by the maximum likelihood principle. The quality of each grading system was measured by the Akaike Information Criterion (AIC) of the estimated statistical model, by which the smaller the AIC of a grading system, the smaller the loss of information for predicting outcomes. The AIC of the TNM grading of the International Union Against Cancer, the grading of the Japanese Society for Esophageal Diseases, and the grading designed according to the total number of positive lymph nodes became substantially smaller in that order. The AIC of grading systems variously designed on rather simple criteria were examined with the aim of creating a better grading system. It was concluded that a grading system based on the total number of positive nodes and the state of the paratracheal and/or middle mediastinal node groups was better than the other systems examined.

Inhibition of neovascularization in vivo by gold compounds

As mononuclear cell infiltration and growth of pannus critically depend on synovial neovascularization in rheumatoid arthritis (RA), inhibition of the synovial blood vessels would have the potential to reduce rheumatoid inflammation. In this investigation, we studied the effect of gold sodium thiomalate (GST) and auranofin (AUR) on neovascularization in vivo by using a micropocket technique. Both GST and AUR suppressed rabbit corneal neovascularization in a dose-dependent fashion. Significant inhibition was observed by 3 mg/kg GST and 1 mg/kg AUR injected intravenously every other day. These injections maintained serum gold concentrations at the level of 2-5 micrograms/ml and less than 2 micrograms/ml in GST- and AUR-injected rabbits, respectively. These are concentrations attained in the serum or synovium of rheumatoid patients treated by gold compounds. Similar inhibition was observed by both intramuscular administration of GST and oral administration of AUR. In contrast, no inhibition was observed when non-steroidal anti-inflammatory drugs (NSAIDs; 20 mg/kg acetylsalicylic acid, 10 mg/kg ibuprofen and 10 mg/kg indomethacin) were injected intravenously on a daily basis. These results suggested that gold compounds have an antiangiogenic effect in vivo. The inhibition of neovascularization by gold compounds suggested that they may suppress rheumatoid synovitis by reducing the number of small blood vessels required for mononuclear cell infiltration and synovial tissue proliferation.

Surgical treatment of ossification of the posterior longitudinal ligament in the thoracic spine

Thoracic ossification of the posterior longitudinal ligament (OPLL) is a rare entity causing thoracic myelopathy. Its surgical decompression is still challenging. Three patients admitted with progressive myelopathy due to thoracic OPLL are described. A transthoracic anterolateral approach was used in the first and second cases, in which OPLL was located at the T3-T4 and T5-T6 and at the T7-T8 levels, respectively. In the third case, a transsternal approach was adopted for OPLL at the T1-T2 level. The OPLL, including dural ossification, was removed by microsurgical techniques as extensively as possible. Myelopathy in all three cases became relieved or stable postoperatively. Operative procedures are described in detail. From the viewpoint of surgical anatomy, the selection of operative approach depends on the level of the OPLL. The authors emphasize that a transthoracic anterolateral approach is the treatment of choice for extensive anterior pathology such as OPLL involving more than two thoracic bodies below the T4. A transsternal approach can provide excellent access to a lesion at the upper three thoracic bodies.

Heart rate variability before the occurrence of silent myocardial ischemia during ambulatory monitoring

Thirty-three ischemic episodes in 19 patients with stable coronary artery disease were studied to clarify changing autonomic nervous system activity during daily life before the occurrence of myocardial ischemia. Nonischemic points were studied for comparison of control data with ischemic episodes. These were defined as (1) patient showing no ischemic ST-T change while having the same heart rate with onset of ischemic episodes, and (2) presence within 1 to 2 hours before or after onset of ischemic episodes in the same patient. We analyzed heart rate (HR) variability during the 30-minute period before the onset and after the end of ischemic episodes during 24-hour monitoring. The period of 30 to 40 minutes before ischemia was regarded as the baseline, and HR variability was analyzed at 10-minute intervals before each ischemic episode and nonischemic point. HR variability was quantified on the band of 2 components: low frequency (0.04 to 0.15 Hz; LF) and high frequency (0.15 to 0.40 Hz; HF). Of the 33 episodes, 24 (73%) had a greater LF/HF value during the 30-minute period before ischemia than that before the nonischemic points. Distribution of the number of the 24 episodes demonstrated circadian rhythm with a peak from 8 to 10 A.M. HF power began to decrease from the last 10 minutes before ischemia, compared with baseline. A significant decrease in HF power with a background of greater value of LF/HF may explain the reduced ischemic threshold for ischemia during daily life.

Microsurgical anatomy of the lower cervical spine and cord

The authors dissected the cervical spine and its surrounding structures from 40 adult cadavers under a surgical microscope. The anterior part of the spine and spinal cord was examined after vertebrectomy. The posterior longitudinal ligament (PLL) consists of two layers; the anterior one is termed the deep layer, and the posterior one is termed the superficial layer. These two layers adhered together loosely. In the lateral portion of the spinal canal, the superficial layer joined the periradicular sheath at the level of the intervertebral disc spaces and joined the dura mater at the level of the vertebral bodies. After the removal of the deep layer, the anterior internal vertebral venous plexus was seen on top of the lateral part of the superficial layer. The venous plexus was embedded between the double-layered PLLs, was not located in the epidural space, and was not seen in the medial part of the PLL. The PLL without venous channels on top of it was about 10 mm in width at the levels of the intervertebral disc and about 5 mm at the levels of the vertebral body. The anterior root exit zone (AREZ) was an elliptical shape; the transverse length of the AREZ was about 2 mm, and the longitudinal length was 10 to 15 mm. The average number of anterior rootlets on the AREZ was 17 to 25 and tended to decrease in the lower cervical spinal cord. The posterior structures were examined after en bloc laminectomy.(ABSTRACT TRUNCATED AT 250 WORDS)

Serum levels of p60 soluble tumor necrosis factor receptor during acute Kawasaki disease

To evaluate the role of tumor necrosis factor alpha (TNF-alpha) during acute Kawasaki disease, we measured p60 soluble tumor necrosis factor receptor (sT-NF-R) shedding into the circulation in 48 patients with acute Kawasaki disease, all of whom received intravenous infusions of gamma-globulin. Of the 48 patients, 5 had coronary artery lesions. Serum concentrations of p60 sTNF-R and TNF-alpha were measured by a sandwich enzyme immunoassay. Patients with Kawasaki disease had increased serum levels of p60 sTNF-R. We found a positive correlation between serum levels of p60 sTNF-R and levels of TNF alpha during acute Kawasaki disease. Moreover, patients with coronary artery lesions had higher levels of sTNF-R than did those without coronary artery lesions. Our findings indicate that p60 sTNF-R levels in serum may be useful for determining the severity of vascular damage during acute Kawasaki disease, and that patients with Kawasaki disease and high sTNF-R levels seem to be susceptible to coronary artery lesions even if they receive therapy with intravenous infusions of gamma-globulin.

Frequent loss of heterozygosity in the region including BRCA1 on chromosome 17q in squamous cell carcinomas of the esophagus

Ninety-four esophageal squamous cell carcinomas were examined for loss of heterozygosity at several loci on the long arm of chromosome 17 (17q), using restriction fragment length polymorphism markers. Loss of heterozygosity was observed in 56 (62%) of 91 tumors that were informative with at least one marker. Comparison of these results with clinicopathological data indicated that the losses on chromosome 17q had occurred at an early stage of carcinogenesis. Detailed deletion mapping in these tumors revealed that the region commonly deleted was within the segment between loci defined by two markers at chromosomal band 17q21.3.

How extensive should lymph node dissection be for cancer of the thoracic esophagus?

From 1985 to 1992, 171 patients with cancer of the thoracic esophagus underwent esophagectomy with systematic dissection of regional lymph nodes including cervical nodes. The hospital mortality rate was 5.3%. The dissected nodes were classified into four groups: the deep cervical (C), upper mediastinal and cervical paratracheal (U), middle and lower mediastinal (L), and upper perigastric (G) groups. The U group mainly consisted of nodes beside the recurrent laryngeal nerves. The phase of cancer infiltration of lymph nodes was evaluated by the total number and the distribution of involved nodes. Of cases with nodal involvement, only 37% were in the late phase, in which more than seven nodes or in which the U, L, and G groups were all involved. Of cases in the earliest phase in which only one node was involved, 93% had either the U or G group involved. The C group of nodes was infrequently involved until the late phase. Cancer had metastasized to the U and G groups across a considerable anatomic distance even in earlier phases. Outcomes of the cases with nodal involvement not in the late phase were satisfactory; the cumulative survival was 60% at 3 years and 54% at 5 years. Systematic nodal dissection would benefit even cases with nodal involvement, unless the disease is in the late phase. Nodes beside the recurrent nerves and upper perigastric nodes should be dissected with higher priority, though they are located anatomically distant.

[Sympathetic ophthalmia in an elderly man]

A 78-years-old man suffered from sympathetic ophthalmia. He had been treated with 5-fluorouracil (5-FU) for metastasis of colon cancer in the liver. He received a perforating eye injury in the left eye thereafter the eye became phthisic. Two months after the injury, he noticed visual disturbance in the right eye. He was treated with large doses of systemic corticosteroid after a diagnosis of uveitis of the right eye, but the visual acuity of the right eye became worse. The eye showed non-specific diffuse uveitis. A diagnosis of sympathetic ophthalmia was made from previous history and ocular findings. We enucleated the injured eye and continued the systemic corticosteroid. Then the right eye improved. Histopathological examination of the enucleated eye revealed the choroid was infiltrated with a granulomatous lesion of lymphocytes and epithelioid cells. HLA typing showed DR4, DR8, DR52, DR53, and DQ1, and we made a final diagnosis of sympathetic ophthalmia. It is probable that the clinical findings were modified by the 5-FU treatment and the patient's advanced age.

Myocardial metabolic markers of total ischemia in vitro

The influence of total ischemia on the formation of products of anaerobic metabolism was investigated in canine hearts in vitro. Contents of organic acids were quantitatively analyzed by gas chromatography-mass spectrometry, and high energy phosphate compounds were determined using the luciferin-luciferase enzyme system. During a 10-min period of total ischemia, myocardial creatine phosphate significantly decreased, while ATP remained unchanged as compared with preischemic values. Both 10 min and 60 min of ischemia induced significant increase in tissue succinic acid levels. In contrast, a significant increase in myocardial lactic acid content was only induced with 60 min of ischemia. The data obtained indicate that the accumulation of succinic acid may be regarded as a potential metabolic marker of myocardial total ischemia.

Beneficial effects of iloprost on acute myocardial ischemia in dogs

The effects of intravenous administration of iloprost, a prostacyclin analogue, on myocardial energy metabolism and myocardial blood flow (MBF) were examined in anesthetized open-chest dogs subjected to 60 min of myocardial ischemia by coronary ligation. Iloprost administration at levels of 0.1 or 0.2 micrograms/kg/min was started 30 min before the commencement of ischemia and continued throughout the 90 min observation period. Since systolic aortic pressure in the iloprost 0.2 micrograms/kg/min group showed significantly lower values than that in the control group, whereas no clear effect was observed with the lower concentration (0.1 micrograms/kg/min), this latter group was further investigated. This 0.1 microgram/kg/min dose of iloprost lacked influence on MBF in both ischemic and nonischemic areas but did result in a significantly higher value for high energy phosphate contents in the ischemic myocardium. Moreover, myocardial mitochondrial respiratory function in the ischemic area was significantly improved. These results indicate that iloprost brought about preservation of myocardial energy metabolism without alteration of coronary perfusion, suggesting that it may exert a direct cardioprotective effect.

Correlation between myocardial blood flow and tissue succinate during acute ischemia

This study was performed to clarify the relationship between degree plus duration of myocardial ischemia and tissue succinate or lactate contents, and to assess whether their accumulation might be a metabolic marker of ischemic myocardium. Regional myocardial blood flow (MBF) was measured using the hydrogen gas clearance method in anesthetized open-chest dogs subjected to 10 min or 60 min of myocardial ischemia by coronary ligation. The contents of succinic acid and lactic acid in myocardium corresponding to locations of MBF measurement were quantitatively analyzed by gas chromatography-mass spectrometry. In severely ischemic areas with MBF less than 20 ml/min/100g, significant increases in both succinic and lactic acids were observed 10 min after coronary occlusion. Sixty min of ischemia induced significant increase in the myocardial succinic acid content not only in severely but also in moderately ischemic areas. In contrast, lactic acid was significantly increased only in the severely ischemic area 60 min after coronary occlusion. These results indicate a good correlation between degree plus duration of myocardial ischemia and tissue succinic acid content, suggesting that its accumulation in myocardium may be a reliable and sensitive metabolic marker of coronary ligation ischemia.

Developmental change in activity of red cell porphobilinogen deaminase and its electrophoretic variant in the Japanese population

The activity of porphobilinogen deaminase (PBGD), an enzyme whose partial deficiency is associated with acute intermittent porphyria (AIP), changes during development. Little is known about the postnatal change of PBGD activity and the prevalence of its electrophoretic variant in the Japanese population. The activity of PBGD was measured fluorometrically in 194 infants aged 0-12 months, while isoelectric focusing of PBGD was performed in 400 healthy Japanese adults aged 20-45 years and 30 children with various hematological disorders aged 1-15 years. The PBGD level was 1.9 times higher in the neonates than in the adults, decreased abruptly during the first month of life, and reached the adult level at the age of 9 months. None of the 400 healthy Japanese adults and the 30 children with hematological disorders showed any electrophoretic variant. These results suggest that there is no need to consider any polymorphism in the gene dose study of PBGD and that the biochemical screening of AIP is applicable to since the late infancy.

The utility of Nitroderm TTS in angina pectoris: long-term treatment after switching from long-acting oral isosorbide dinitrate

Long-acting oral isosorbide dinitrate (ISDN) was replaced by Nitroderm TTS, and the utility of this drug in long-term treatment was assessed in 69 patients with angina pectoris. The frequency of attacks (p < 0.001) and the consumption of sublingual nitrate tablets (p < 0.01) were found to be significantly lower at 2 weeks to 6 months than in the observation period in patients who experienced attacks or received sublingual tablets during the observation period. On the other hand, no significant time-lapse changes from the observation period were noted in patients who experienced no attacks or received no sublingual tablets during the observation period. The symptoms of adverse effects were mild. The improvement rates (improved) of subjective symptoms and electrocardiogram (ECG) in Group A were about 50% after 6 months. On the other hand, the improvement rates (not aggravated) of subjective symptoms and ECG in Group B were more than 90%. Nitroderm TTS is considered a useful plaster preparation which can be used for sufficiently extended periods of time because its efficacy was as high as, or higher than, that of oral ISDN when this drug was administered over a long period of time after a switch from long-acting oral ISDN in angina pectoris patients.

Malignant lymphoma presenting as a cardiac tumor

We report a case of malignant lymphoma whose initial symptoms were heart failure. An echocardiogram showed a large tumor in the right ventricle, and a definitive diagnosis was obtained at autopsy. Of particular interest in our case, the lymphoma was confined to the heart and a mediastinal lymph node, with its greatest bulk being intracardiac. This case is a rare manifestation of malignant lymphoma.

Inhibition of mitogen-induced response of human peripheral blood mononuclear cells by bucillamine, a new antirheumatic sulfhydryl drug

The mechanism of action of bucillamine, [N-(2-mercapto-2-methylpropionyl)-L-cysteine] (BC), a novel antirheumatic drug that is used in patients with rheumatoid arthritis (RA), was compared with that of D-penicillamine (DP). BC inhibited phytohemagglutinin (PHA)-induced DNA synthesis of peripheral blood mononuclear cells (PBMCs) in a dose-dependent manner, and this inhibition occurred both in the presence and absence of copper, whereas DP-induced inhibition required the presence of cupric ions. Significant inhibition of DNA synthesis was observed at a BC concentration of 10 micrograms/ml. The disulfide form of BC, but not DP disulfide, suppressed the proliferation of PBMCs. After preincubation of human peripheral blood T lymphocytes or Møs with BC or DP, these cells were combined and the overall PHA response was estimated. Inhibition of the PHA response was observed following pretreatment of either T lymphocytes or Møs with BC, whereas inhibition was attained only when T lymphocytes were pretreated with DP and copper. As sulfhydryl agents produce hydrogen peroxide in the presence of cupric ions, the effect of catalase on DP- and BC-induced inhibition of PBMC DNA synthesis was examined. Catalase partially reversed the BC-induced inhibition of DNA synthesis of PBMCs, and it restored the inhibition by DP and copper almost to the control level. These results suggest that BC suppresses the function of both T lymphocytes and Møs in the mitogen response of PBMCs, whereas the action of DP is targeted at T lymphocytes.

cDNA cloning and characterization of a novel member of steroid-induced cytochrome P450 3A in rats

A unique cDNA clone, termed cDEX, coding for dexamethasone-inducible novel rat cytochrome P450 was isolated and characterized. The restriction enzyme map of the cDEX was slightly different from the reported two CYP3A1 sequences, and several nucleotide substitutions were found. Compared to the CYP3A1 sequence reported as P450pcn1 by F. Gonzalez et al. (J. Biol. Chem. 1985, 260, 7435-7441), there were 26 substitutions of nucleotides leading to 11 amino acid changes and a six-base (two amino acid)-long deletion in the open reading frame. Comparison with the sequence of pP450IGC2 reported by V. Ribeiro and M. C. Lechner (Arch. Biochem. Biophys., 1992, 293, 147-152) showed 18 nucleotide changes resulting in eight amino acid substitutions and the six-base-long deletion in the coding region. cDEX and these clones shared 97.8 and 98.4% similarity in deduced amino acid sequences, respectively, while only 86.3% similarity with P450pcn2 (CYP3A2). RNA blot hybridization analysis indicated that the mRNA corresponding to cDEX was mainly induced in rat liver by the administration of steroidal agents.

Neurosteroids in cerebrospinal fluid in neurologic disorders

In order to investigate the role of "neurosteroids" in the central nervous system (CNS), cerebrospinal fluid (CSF) levels of dehydroepiandrosterone (DHEA) and dehydroepiandrosterone sulfate (DHEAS) were determined by radioimmunoassay in 57 patients with various neurologic disorders and 26 patients with non-neurologic disorders. The content of CSF DHEA and DHEAS in patients with Guillain-Barré syndrome (GBS), and the content of CSF DHEAS in patients with carcinomatous meningitis were significantly higher as compared to non-neurological control patients. These changes may be explained by the breakdown of blood-nerve barrier in these disorders. A significant positive correlation was observed between DHEAS and total protein in CSF. In males but not females, a negative correlation was observed between CSF DHEAS and aging. The level of CSF DHEAS, but not DHEA, was significantly higher in males than in females.

Effects of diabetes on cardiac glycogen metabolism in rats

The effects of diabetes on myocardial glycogen metabolism in rats were examined and compared with those of fasting. Male Wistar rats were divided into three groups: controls, streptozotocin-induced diabetics, and one-week fasted. Isolated rat hearts were subjected to substrate-free 30-min Langendorff perfusion followed by 60-min working heart perfusion with glucose alone or in combination with insulin or insulin plus beta-hydroxybutyrate (BHB). Myocardial glycogen contents were determined before or 30 min after Langendorff perfusion, or 60 min after working heart perfusion. Before Langendorff perfusion, tissue glycogen concentrations in control, diabetic, and fasted hearts were 3.3 +/- 0.2, 10.0 +/- 0.9, and 5.7 +/- 0.5 (mg/g wet weight), respectively. In diabetic rats, the myocardial glycogen concentration was markedly decreased after working heart perfusion of any of the substrate combinations, even those with insulin and BHB. In contrast, myocardial glycogen in control or fasted rats was not reduced after the addition of glucose with insulin, and/or glucose with insulin and BHB. These results suggest that degradation of tissue glycogen occurs in isolated perfused hearts from diabetic rats, while a clearly different response is shown by fasted hearts.

Increased CYP1A2 content and capacity to activate Glu-P-1 and Trp-P-2 in liver microsomes of scorbutic ODS rats

Osteogenic Disorder Shionogi (ODS) rats, which cannot synthesize ascorbic acid due to a deficiency of L-gulonolactone oxidase, become scorbutic when not supplied with dietary ascorbic acid. We used the deficient rats to study the effects of ascorbic acid on the amount of cytochrome P450 enzymes in liver microsomes. The total amount of hepatic cytochrome P450 in ODS rats deprived of ascorbic acid was lower by approximately 40%, whereas ODS rats fed with ascorbic acid and the wild strain had the same level of total hepatic cytochrome P450. Western blot analysis for various forms of cytochrome P450 in liver microsomes indicated that the amount of CYP1A2 was significantly higher in ascorbic acid deficient rats. On the other hand, amounts of CYP2B2 and 3A were lower, and those of CYP2E1 and CYP2C6/11 were unaffected. In accordance with the higher amount of CYP1A2, Northern blot analysis showed increased expression of CYP1A2 mRNA. The capacity of microsomes to produce mutagens from 2-amino-6-methyl-dipyrido[1,2-a:3',2'-d]imidazole acetate (Glu-P-1) and 3-amino-1-methyl-5H-pyrido[4,3-b]indole acetate (Trp-P-2) was higher in scorbutic ODS rats by the Ames test. These results indicate that the effects of ascorbic acid deficiency on the expression of cytochrome P450 in ODS rat livers are form-specific and that the increased CYP1A2 is associated with increased metabolic activation of promutagens in the scorbutic state.

Assessment of area at risk and efficacy of treatment in patients with acute coronary syndrome using 99mTc tetrofosmin imaging in humans

The determination of the myocardium at risk before intervention and the change in that region after intervention constitute a promising measurement tool for the assessment of acute therapy. A new 99mTc labeled myocardial blood flow tracer, 99mTc tetrofosmin, is expected to enable the evaluation of myocardium at risk because of the absence of redistribution. This preliminary study was performed in 9 patients with acute coronary syndrome (4 unstable angina and 5 acute myocardial infarction) to investigate whether recovery of perfusion by tetrofosmin imaging parallels mechanical improvement. Tetrofosmin imaging was performed acutely and 3-30 days later. Visual analysis of defect severity was assessed in both studies. Segments with improvement in perfusion were accompanied by significant wall motion recovery compared with normal and unimproved segments (delta WMI: normal segments 0.40 +/- 0.67, improved segments 1.79 +/- 0.68, unimproved segments -0.15 +/- 0.16, p < 0.01 for improved segments compared with other groups), suggesting the efficacy of this tracer for the assessment of the acute therapy. These data suggest that 99mTc tetrofosmin imaging is a useful method for the assessment of the myocardial area at risk and the efficacy of acute therapy in acute myocardial infarction and unstable angina.

Cypridina luciferin analog reduces the incidence of ischemia/reperfusion-induced ventricular fibrillation

A Cypridina luciferin analog (CLA), considered to be a sensitive and specific agent for the assay of superoxide, was assessed in isolated hearts for its effects on ischemia/reperfusion injury. Hearts of anesthetized male Wistar rats were isolated and perfused with a modified Krebs-Henseleit bicarbonate buffer to serve as non-recirculating working heart preparations. After 15 min of perfusion to achieve stability, they underwent 20 min of global ischemia and were then reperfused for 30 min with or without 250 microM of CLA, dissolved in the perfusate. The incidence of ventricular fibrillation was only 13% in the CLA group, whereas it was 88% in the controls. The CLA treatment was further associated with significantly increased left ventricular developed pressure and cardiac output; and in contrast, the left ventricular end-diastolic pressure was significantly reduced, as compared with the control group. Thiobarbiturate reacting substance content in the hearts of the CLA group was significantly decreased (27.5 +/- 2.4 versus 36.9 +/- 9.7 mumol/g dry weight). This study thus indicates that CLA may be useful for alleviating ischemia/reperfusion injury (reperfusion-induced arrhythmia and damage to heart function) involving free radicals.