The clinical outcome of fractional flow reserve based coronary revascularization strategy of the patients on hemodialysis

Background

The optimal coronary revascularization strategy for the patients on hemodialysis is yet to be determined. In the real-world practice, we sometimes encounter the rapid deterioration after percutaneous coronary intervention (PCI) to angiographically intermediate but functionally significant stenosis. According to the fractional flow reserve (FFR) based revascularization strategy, the clinical outcome of the deferred lesions is reported to be almost equivalent to that of the lesions received PCI. However, whether the relationship also applies to hemodialysis patients is unclear.

Purpose

To assess the clinical outcome of the lesions for which revascularization strategy was determined by FFR in patients with hemodialysis.

Methods

Consecutive 147 vessels in 120 patients with hemodialysis whose revascularization strategy was decided according to the FFR were enrolled in this study. We compared the clinical outcomes of the deferred group (FFR ≥0.80, 87 vessels, 78 patients) with the PCI group (FFR<0.80, 60 vessels, 42 patients). The primary endpoint of this study was target vessel failure (TVF) defined as a composite of TV revascularization and myocardial infarction evaluated by per-vessel analysis. The secondary endpoint was major adverse cardiovascular events (MACE) defined as all cause death, myocardial infarction, urgent revascularization evaluated by per-patient analysis.

Results

The median follow-up period was 2.3 years (interquartile range, 1.5–4.0 years). The beseline characteristics of the lesions and patients were well balanced between the 2 treatment groups except for the distribution of target vessels and FFR value. The cumulative TVF rate was not significantly different between the deferred group and PCI group (2-year event rate 26.7% vs. 17.7%; Log-rank p=0.23). The risk of MACE was also not significantly different between two groups (2-year event rate 35% vs. 30%; Log-rank p=0.48).

Conclusion

The clinical outcome of the lesions/patients for which received revascularization based on FFR was equivalent to the deferred lesions/patients even in the patients on hemodialysis (2,129/3,000).

Funding Acknowledgement

Type of funding sources: None. Table 1Figure 1

Aggressive lipid lowering therapy with pitavastatin and ezetimibe improve cardiovascular outcomes in patients with ST segment elevation myocardial infarction: insights from the HIJ-PROPER Study

Aims

The purpose of this study was to evaluate the effect of aggressive lipid-lowering therapy with pitavastatin and ezetimibe in patients with ST-segment elevation myocardial infarction (STEMI) as compared with those with other classification of an acute coronary syndrome (ACS) including non-STEMI (NSTEMI) and unstable angina pectoris (UA).

Methods

This is a post hoc sub-analysis of the HIJ-PROPER study. In the original study, ACS patients with dyslipidemia were randomized to either pitavastatin + ezetimibe therapy or pitavastatin monotherapy. In the present analysis, we divided HIJ-PROPER participants into the STEMI group (n=880) and NSTEMI + UA group (n=841). Cardiovascular events were analyzed between the two groups. The primary endpoint was a composite of major advanced cardiovascular events (MACE; all-cause death, non-fatal myocardial infarction, non-fatal stroke, unstable angina pectoris, and ischemia-driven revascularization)

Result

During median follow-up period of 3.4 years, the cumulative incidence of the primary endpoint in STEMI group was 31.9% in the pitavastatin+ezetimibe therapy, compared with 39.7% in the pitavastatin-monotherapy (HR, 0.77; 95% CI, 0.62–0.97; p=0.02). However, there was no effect of pitavastatin+ezetimibe therapy on the primary endpoint in the NSTEMI + UA group. Concerning the individual components of the primary endpoint in STEMI group, the percentage of occurrence of all-cause death was significantly lower in the pitavastatin+ezetimibe therapy compared to pitavastatin mono-therapy (14 patients (3.2%) vs. 31 patients (6.9%), respectively; HR, 0.45; 95% CI, 0.23–1.84, p=0.01). Multivariate analysis revealed that use of ezetimibe and prevalence of diabetes mellitus at baseline were independent predictors of primary endpoints in STEMI group (HR, 0.79; 95% CI, 0.63–0.99; p=0.04 for use of ezetimibe, HR 1.54; 95% CI, 1.22–1.94, p=0.0003 for diabetes mellitus).

Conclusion

Patients with pitavastatin+ezetimibe therapy as compared with pitavastatin-monotherapy had lower cardiovascular event in patients with ST-segment elevation myocardial infarction.

Kaplan-Meier curves for primary endpoint

Funding Acknowledgement

Type of funding source: None

Lower levels of high-density lipoprotein cholesterol are associated with increased cardiovascular events in patients with acute coronary syndrome receiving contemporary lipid-lowering therapy

Background

This study aimed to elucidate whether high-density lipoprotein cholesterol (HDL-C) at 3-month follow-up for patients receiving contemporary lipid-lowering therapy after acute coronary syndrome (ACS) could predict cardiac events.

Methods

The HIJ-PROPER study was a multicenter, prospective, randomized trial comparing intensive lipid-lowering therapy (pitavastatin + ezetimibe) and conventional lipid-lowering therapy (pitavastatin monotherapy) after ACS. For the present analysis, the entire cohort was divided into three groups according to HDL-C levels at 3-month follow-up (Group 1, HDL-C ≤43 mg/dL; Group 2, 43–53.6 mg/dL; Group 3; HDL-C ≥53.6 mg/dL). Baseline characteristics and the incidence of the primary endpoint (a composite of all-cause death, non-fatal myocardial infarction, non-fatal stroke, unstable angina pectoris, or ischemia-driven revascularization) were compared among the three groups.

Results

The primary endpoint was reported in 34.8%, 30.1%, and 24.6% of patients in Groups 1, 2, and 3, respectively. The incidence of the primary endpoint was significantly higher in Group 1 than in Group 3 (hazard ratio [HR], 1.5; 95% confidence interval [CI], 1.19–1.9; p=0.001). Irrespective of the treatment regimen, Group 1 had a significantly higher rate of the primary endpoint than Group 3 (pitavastatin + ezetimibe therapy: HR, 1.6; 95% CI, 1.12–2.22; p=0.01 and pitavastatin monotherapy: HR, 1.4; 95% CI, 1.05–1.98; p=0.02). These trends remained even after adjustment for baseline characteristics and lipid profiles.

Conclusions

Lower levels of HDL-C at 3-month follow-up are associated with higher incidence of the cardiovascular events in patients with acute coronary syndrome receiving contemporary lipid-lowering therapy.

HDL-C levels and Cardiovascular events

Funding Acknowledgement

Type of funding source: None

Distinct MCM10 Proteasomal Degradation Profiles by Primate Lentiviruses Vpr Proteins

Viral protein R (Vpr) is an accessory protein found in various primate lentiviruses, including human immunodeficiency viruses type 1 and 2 (HIV-1 and HIV-2) as well as simian immunodeficiency viruses (SIVs). Vpr modulates many processes during viral lifecycle via interaction with several of cellular targets. Previous studies showed that HIV-1 Vpr strengthened degradation of Mini-chromosome Maintenance Protein10 (MCM10) by manipulating DCAF1-Cul4-E3 ligase in proteasome-dependent pathway. However, whether Vpr from other primate lentiviruses are also associated with MCM10 degradation and the ensuing impact remain unknown. Based on phylogenetic analyses, a panel of primate lentiviruses Vpr/x covering main virus lineages was prepared. Distinct MCM10 degradation profiles were mapped and HIV-1, SIVmus and SIVrcm Vprs induced MCM10 degradation in proteasome-dependent pathway. Colocalization and interaction between MCM10 with these Vprs were also observed. Moreover, MCM10 2-7 interaction region was identified as a determinant region susceptible to degradation. However, MCM10 degradation did not alleviate DNA damage response induced by these Vpr proteins. MCM10 degradation by HIV-1 Vpr proteins was correlated with G₂/M arrest, while induction of apoptosis and oligomerization formation of Vpr failed to alter MCM10 proteolysis. The current study demonstrated a distinct interplay pattern between primate lentiviruses Vpr proteins and MCM10.

Three YXXL Sequences of a Bovine Leukemia Virus Transmembrane Protein are Independently Required for Fusion Activity by Controlling Expression on the Cell Membrane

Bovine leukemia virus (BLV), which is closely related to human T-cell leukemia viruses, is the causative agent of enzootic bovine leukosis, the most common neoplastic disease of cattle. The transmembrane subunit of the BLV envelope glycoprotein, gp30, contains three completely conserved YXXL sequences that fit an endocytic sorting motif. The two N-terminal YXXL sequences are reportedly critical for viral infection. However, their actual function in the viral life cycle remains undetermined. Here, we identified the novel roles of each YXXL sequence. Syncytia formation ability was upregulated by a single mutation of the tyrosine (Tyr) residue in any of the three YXXL sequences, indicating that each YXXL sequence is independently able to regulate the fusion event. The alteration resulted from significantly high expression of gp51 on the cell surface, thereby decreasing the amount of gp51 in early endosomes and further revealing that the three YXXL sequences are independently required for internalization of the envelope (Env) protein, following transport to the cell surface. Moreover, the 2nd and 3rd YXXL sequences contributed to Env protein incorporation into the virion by functionally distinct mechanisms. Our findings provide new insights regarding the three YXXL sequences toward the BLV viral life cycle and for developing new anti-BLV drugs.

P5577Preoperative transaortic pressure gradient predicts renal functional improvement after transcatheter aortic valve implantation in patients with chronic kidney disease

Introduction

Transcatheter aortic valve implantation (TAVI) theoretically increases renal blood flow through increasing cardiac output by relieving aortic valvular obstruction of blood flow from left ventricle, resulting in a renal functional recovery in patients with severe aortic valve stenosis (AS). However, procedural steps of TAVI including contrast use potentially damages renal medulla and may deteriorate renal function.

Purpose

The aim of this study was to investigate renal functional change and clarify preoperative predictors for renal functional improvement after TAVI in chronic kidney disease (CKD) patients with severe AS.

Methods

A total of 88 consecutive severe AS patients with CKD (grade >3) who underwent TAVI from 2015 to 2018 was enrolled in this observational study. They were divided into two groups depending on their renal functional improvement after TAVI that was defined as more than 10% increase in estimated glomerular filtration rate (eGFR) at discharge from their preoperative level.

Results

Among the whole candidates, 49 patients (55.7%) were improved their renal function. Patients with the lowest preoperative eGFR achieved the highest increase in eGFR after TAVI (CKD grade >4: +22.7±23.7%, Figure). Patients in the Improved group had lower hemoglobin level, higher mean transaortic pressure gradient (TAPG), and higher aortic valve gradient before TAVI, compared to those in the Non-improved group. However, contrast volume during the procedure was not significantly different between the groups. Multivariate logistic regression analysis revealed that high mean TAPG and low left ventricular ejection fraction (LVEF) before TAVI were independent predictors for the improvement of renal function (odds ratio (OR): 1.04, 95% confidence interval (CI): 1.00–1.08; OR: 0.94, 95% CI: 0.89–0.99, respectively), even after the adjustment of baseline eGFR level and hemoglobin level that were statistically significant on univariate logistic regression analysis. Receiver Operating Characteristic (ROC) curve showed the cut-off level of preoperative mean TAPG in renal functional improvement after TAVI as 47.0 mmHg (Sensitivity: 47.9%, Specificity: 79.5%, area under the curve: 0.62).

Correlation between CKDgrade and ΔeGFR

Conclusions

Preoperative high mean TAPG may predict renal functional improvement after TAVI in patients with deteriorated renal function. This non-invasive predictor may help clinicians to consider to perform TAVI in a challenging case with severe CKD.

Blood-Separating Device Without Energy Source for Implantable Medical Devices

Coagulation of blood inside the implanted medical device is quite a critical problem to limit the lifetime. In this paper, we propose a microfluidic blood separating device using curved and branched channels. It utilizes centrifugal force on curved flow and separates blood flow into blood cell rich and blood cell poor ones at the bifurcation. Though it cannot separate the plasma from blood cells completely, the blood with small concentrations of blood cells will have low coagulatibity and extend the lifetime of the implant medical device. The device does not require any external pumps or valves, i.e., the system does not need any power sources but the blood pressure. We conducted experiments with a titanium foil which contacted to human whole blood with different hematocrit values for 7 days. The device was experimentally characterized with respect to the channel design. The former experiments suggested that lower concentration of blood cells helps avoiding blood coagulations, and the latter showed that the separation by our device is mainly affected by the flow rate and channel curvature.

Generation of a neutralization-resistant CCR5 tropic simian/human immunodeficiency virus (SHIV-MK38) molecular clone, a derivative of SHIV-89.6

Previously, we reported that a new genetically diverse CCR5 (R5) tropic simian/human immunodeficiency virus (SHIV-MK38) adapted to rhesus monkeys became more neutralization resistant to SHIV-infected plasma than did the parental SHIV-KS661 clone. Here, to clarify the significance of the neutralization-resistant phenotype of SHIV in a macaque model, we initially investigated the precise neutralization phenotype of the SHIVs, including SHIV-MK38 molecular clones, using SHIV-MK38-infected plasma, a pooled plasma of human immunodeficiency virus (HIV)-infected individuals, soluble CD4 and anti-HIV-1 neutralizing mAbs, the epitopes of which were known. The results show that SHIV-KS661 had tier 1 neutralization sensitivity, but monkey-adapted R5 tropic SHIV-MK38 acquired neutralization resistance similar to that of tier 2 or 3 as a clone virus. Sequence analysis of the env gene suggested that the neutralization-resistant phenotype of SHIV-MK38 was acquired by conformational changes in Env associated with the net charge and potential N-linked glycosylation sites. To examine the relationship between neutralization phenotype and stably persistent infection in monkeys, we performed in vivo rectal inoculation experiments using a SHIV-MK38 molecular clone. The results showed that one of three rhesus monkeys exhibited durable infection with a plasma viral load of 105 copies ml- 1 despite the high antibody responses that occurred in the host. Whilst further improvements are required in the development of a challenge virus, it will be useful to generate a neutralization-resistant R5 tropic molecular clone of the SHIV-89.6 lineage commonly used for vaccine development - a result that can be used to explore the foundation of AIDS pathogenesis.

Identification and characterization of common B cell epitope in bovine leukemia virus via high-throughput peptide screening system in infected cattle

Background

Bovine leukemia virus (BLV) is the causative agent of enzootic bovine leukosis, the most common neoplastic disease of cattle. BLV is closely related to human T cell leukemia virus. B cell epitopes are important for the use of antibodies as therapeutic agents, the epitope-driven vaccine design, and immunological assays. A common B cell epitope for BLV has not yet been found due to individual differences in disease susceptibility.

Results

We used a peptide microarray with 156 synthetic 15-mer peptides covering the envelope glycoprotein gp51 and the Gag proteins p15, p24, and p12 to map B cell epitope and one B cell epitope, gp51p16, was recognized by all four cattle experimentally infected with BLV. A newly developed high-throughput peptide ELISA system revealed 590 (91.2 %) of 647 cattle naturally infected with BLV, carrying 25 different bovine leukocyte antigen class II DRB3 (BoLA-DRB3) alleles, responded to a 20-mer gp51p16-C peptide containing a C-terminal cysteine and gp51p16. Alanine mutation and comparison of the sequences at 17 amino acid positions within gp51p16-C revealed that R7, R9, F10, V16, and Y18 were the common binding sites to BLV antibodies, and two of these sites were found to be highly conserved. Transient expression in the cells of five infectious molecular clones of BLV with a single alanine mutation at five common antibody binding sites had no effect syncytia formation of the gp51 protein. In addition, the mutant proteins, R7A and R9A had no effect on the expression of gp51 protein; the gp51 protein expressions of F10A, V16A and Y18A were lower than that of the wild type protein.

Conclusions

This is the first report to identify a common B cell epitope in BLV by comprehensive screening of BLV-infected cattle with varied genetic backgrounds in BoLA-DRB3. Our results have important implications for disease control and diagnosis.

Generation of a monkey-tropic human immunodeficiency virus type 1 carrying env from a CCR5-tropic subtype C clinical isolate

Several derivatives of human immunodeficiency virus type 1 (HIV-1) that evade macaque restriction factors and establish infection in pig-tailed macaques (PtMs) have been described. These monkey-tropic HIV-1s utilize CXCR4 as a co-receptor that differs from CCR5 used by most currently circulating HIV-1 strains. We generated a new monkey-tropic HIV-1 carrying env from a CCR5-tropic subtype C HIV-1 clinical isolate. Using intracellular homologous recombination, we generated an uncloned chimeric virus consisting of at least seven types of recombination breakpoints in the region between vpr and env. The virus increased its replication capacity while maintaining CCR5 tropism after in vitro passage in PtM primary lymphocytes. PtM infection with the adapted virus exhibited high peak viremia levels in plasma while the virus was undetectable at 12-16 weeks. This virus serves as starting point for generating a pathogenic monkey-tropic HIV-1 with CCR5-tropic subtype C env, perhaps through serial passage in macaques.

Generation of a replication-competent simian-human immunodeficiency virus, the neutralization sensitivity of which can be enhanced in the presence of a small-molecule CD4 mimic

Simian-human immunodeficiency virus (SHIV) carrying the envelope from the clade B clinical human immunodeficiency virus type 1 (HIV-1) isolate MNA, designated SHIV MNA, was generated through intracellular homologous recombination. SHIV MNA inherited biological properties from the parental HIV-1, including CCR5 co-receptor preference, resistance to neutralization by the anti-V3 loop mAb KD-247 and loss of resistance in the presence of the CD4-mimic small-molecule YYA-021. SHIV MNA showed productive replication in rhesus macaque PBMCs. Experimental infection of a rhesus macaque with SHIV MNA caused a transient but high titre of plasma viral RNA and a moderate antibody response. Immunoglobulin in the plasma at 24 weeks post-infection was capable of neutralizing SHIV MNA in the presence but not in the absence of YYA-021. SHIV MNA could serve a model for development of novel therapeutic interventions based on CD4-mimic-mediated conversion of envelope protein susceptible to antibody neutralization.

Generation of a replication-competent chimeric simian-human immunodeficiency virus carrying env from subtype C clinical isolate through intracellular homologous recombination

A new simian-human immunodeficiency virus (SHIV), carrying env from an uncloned HIV-1 subtype C clinical isolate (97ZA012), was generated through intracellular homologous recombination, a DNA repair mechanism of the host cell. PCR fragments amplified from an existing SHIV plasmid (a 7-kb fragment from the 5' end and a 1.5-kb fragment from the 3' end) and a 4-kb fragment amplified from 97ZA012 cDNA containing env were co-transfected to human lymphoid cells. The resulting recombinant was subjected to serial passage in rhesus peripheral blood mononuclear cells (RhPBMCs). The resulting SHIV 97ZA012 was replication competent in RhPBMCs and monkey alveolar macrophages, and possessed CCR5 preference as an entry co-receptor. Experimental infection of rhesus macaques with SHIV 97ZA012 caused high titers of plasma viremia and a transient but profound depletion of CD4(+) T lymphocytes in the lung. Animal-to-animal passage was shown to be a promising measure for further adaptation of the virus in monkeys.

Intraoperative ultrasound arteriography with the "Coded Harmonic Angio" technique. Report of three cases

The result of combining the ultrasound Coded Excitation method and an ultrasound contrast agent (UCA), the Coded Harmonic Angio (CHA) technique provides arterial images with exceptional spatial, temporal, and contrast resolution that are comparable to those produced by conventional digital subtraction angiography. The authors report on their experience with intraoperative ultrasound arteriography performed using the transdural CHA technique in three patients: one harboring a meningioma, another with a middle cerebral artery aneurysm, and a third with an arteriovenous malformation. The present study demonstrates how intraoperative cerebral ultrasound arteriography can be applied to assess the adequacy of neurovascular procedures without the presence of an experienced operator.

Restenosis following carotid endarterectomy--clinical profiles and pathological findings

Restenosis following carotid endarterectomy is not a rare condition. Among 122 endarterectomies we experienced, five restenoses (4.1%) were encountered and treated by the second surgery. The present report clarifies the clinical profiles and pathological findings of restenosis following carotid endarterectomy. Mean age of restenosis group (59 years old) was not significantly different from the group without restenosis (62 years old). Average duration between the first endarterectomy and the second surgery was 17 months (8-30 months). Initial symptoms were transient ischemic attack in three sides, minor stroke in one side, and asymptomatic in one. Degree of stenosis was tight (> or = 90%) in two and moderate (70-89%) in three. It is interesting to note that no ulcer was noted in the first endarterectomy specimen. At surgery for restenosis, two cases had symptoms and another two cases were asymptomatic, though all had neck bruits. Four of five lesions were treated by short venous graft from common carotid artery to distal internal carotid artery and another lesion was treated by second endarterectomy and Dacron patch graft. Pathology was studied in four and all showed myointimal hyperplasia. Three of four restenosis tissues showed mutant form p53 by immunohistochemistry. The present study indicates that restenosis following carotid endarterectomy is not a rare status. Short venous bypass across the stenotic portion is the treatment of choice. Monoclonal growth of smooth muscle with mutant form p53 might be related to the restenosis.

A 13-bp cis-regulatory element in the LTR promoter of the tobacco retrotransposon Tto1 is involved in responsiveness to tissue culture, wounding, methyl jasmonate and fungal elicitors

The tobacco Tto1 is one of the few active LTR-retrotransposons of plants, and its transposition is activated by tissue culture and is primarily regulated at the transcriptional level. The expression of Tto1 RNA can also be activated by various stresses, including viral infection, wounding, and treatment with jasmonate, a signal molecule of plant defence responses. It is shown here that the Tto1 LTR promoter is responsible for a high level of expression in cultured tissues of transgenic tobacco plants. We demonstrate that a 13-bp repeated motif (TGGTAGGTGAGAT) in the LTR functions as a cis-regulatory element, which confers the responsiveness to tissue culture, wounding and methyl jasmonate. Fungal elicitors also activate the promoter containing multiple copies of the 13-bp motif. Expression mediated by the 13-bp motif is activated markedly by okadaic acid and moderately by K252a, so that both phosphorylation and dephosphorylation of proteins are possibly involved in the signalling pathways. Interestingly, the 13-bp motif contains a conserved motif, Box L (also called AC-I or H-box like sequence) which has been shown to be involved in the expression of phenylpropanoid synthetic genes. Moreover, extended homologies are found between promoters of Tto1 and an asparagus defence gene, AoPR1, suggesting a possibility that the ancient insertion of an ancestral Tto1-related retrotransposon has provided some of the promoter/regulatory sequences, including the 13-bp motif-related sequence, of the AoPR1 gene. Based on the structural and functional similarity between the two promoters, a possible evolutionary role of the regulatory sequences of LTR-retrotransposons is discussed.

Transcriptional activation of the tobacco retrotransposon Tto1 by wounding and methyl jasmonate

The tobacco retrotransposon Tto1, one of a few active retrotransposons of plants, has been shown to be activated by tissue culture. Its transposition is regulated mainly at the transcriptional level. It is shown here that expression of Tto1 can be induced in leaves of tobacco by wounding stress. Exogenous supply of methyl jasmonate, which is known to be a potent inducer of certain wound-responsive genes in plants, also induces Tto1 RNA expression. Tto1 RNA was detected within 2 to 4 h after wounding/cutting treatment, and increased levels of Tto1 RNA were observed during subsequent incubation periods for 48 h. Expression of Tto1 RNA after cutting treatment was induced more significantly in young expanding leaves rather than in older mature leaves, suggesting that developmental or physiological factors may be required for the strong response to Tto1 transcription to wounding stimuli. Experiments with transgenic tobacco plants carrying the Tto1-LTR: beta-glucuronidase fusion gene (LTR:GUS) revealed that Tto1 actually contains cis-regulatory regions in response to wounding and methyl jasmonate. These findings are discussed in relation to the mechanism of transcriptional activation and the evolutionary role played by retrotransposons.

Expression of tPA mRNA in the facial nucleus following facial nerve transection in the rat

Plasminogen activators (PAs) have been suggested to play a role in neuronal migration and glial cell proliferation in the developing CNS. Less is known, however, about the role of PAs in the mature nervous system. To elucidate the role of tissue type plasminogen activator (tPA) in the nervous system we used in situ hybridization to study the expression of tPA mRNA within the rat facial nucleus after facial nerve transection. We also studied the effect of MK-801 on tPA mRNA expression in order to investigate whether the previously reported N-methyl-D-aspartate (NMDA) receptor activation is involved in this model. tPA mRNA was expressed in the ipsilateral facial motoneurones from 6 h after injury. This expression continued for at least 2 weeks after facial nerve transection. Administration of MK-801 before axonal injury did not affect the expression of tPA mRNA in the facial nucleus. These data suggest that tPA might be involved in the regenerative process without NMDA receptor activation in mature facial neurones.

Autonomous transposition of the tobacco retrotransposon Tto1 in rice

The complete nucleotide sequence of the tobacco retrotransposon Tto1, one of the few active retrotransposons of plants, was determined. The sequence analysis suggests that Tto1 carries all functions required for autonomous transposition through reverse transcription. Gene organization and the nature of the transcription product suggest that Tto1 uses a gene expression mechanism different from those employed by retroviruses and most retrotransposons to regulate Gag and Pol stoichiometry. Tto1 was introduced into rice to study its autonomous transposition in heterologous hosts. Transcription and transposition of Tto1 were observed in rice cells. To probe the autonomous transposition through reverse transcription, a modified Tto1 retrotransposon in which part of a reverse transcriptase gene was replaced with an intron-containing hygromycin resistance gene was constructed and introduced into rice cells. Loss of the intron was observed only when intact Tto1 was cotransfected. These results indicate that Tto1 can transpose autonomously through reverse transcription and that the host factors required for transposition are conserved among monocots (class Magnoliopsida; rice) and dicots (class Liliopsida; tobacco), which diverged approximately 200 million years ago. These findings are discussed in relation to the regulation and evolution of retrotransposons and the possible use of Tto1 as a molecular genetic tool.

Extrachromosomal circular forms of the tobacco retrotransposon Tto1

Extrachromosomal DNA forms of Drosophila retrotransposons (RTn) and retroviruses have been extensively analyzed. However, no such analysis with plant RTn has been reported. Here, we report the analysis of extrachromosomal forms of the tobacco RTn Tto1. Tto1 is one of a few active RTn of plants and has been shown to be activated in tissue culture. Extrachromosomal circular DNA forms of Tto1, with one or two long terminal repeats (LTR), were found in cultured cells. Sequence analysis of the sites of circularization through joining two LTR showed that the junction between the LTR contains small deletions and/or insertions. The insertions are heterogeneous and do not show any homology to the Tto1 sequence. Similar insertions have been detected in the extrachromosomal circular forms of the copia element of Drosophila and suggested to be the result of excision of genomic copia. The structural features of the junctions found in Tto1 suggest that the insertions are produced by a mechanism other than excision. The potential mechanism of production of the extrachromosomal circular forms of Tto1 is discussed.

Expression of PDGF in relation to cell division in atherosclerotic intima of human carotid arteries

The platelet derived growth factor (PDGF) plays an important role for development of atherosclerosis. We therefore immunostained carotid atheroma specimens for PDGF. We also detected dividing cell species of the atheroma with in vitro labeling of bromodeoxyuridine (BUdR). Thirty specimens of carotid atheroma were obtained by endarterectomy and they were incubated for 3 hours with Dulbecco's modified Eagle medium/20% fetal calf serum culture medium containing BUdR/fluorodeoxyuridine (FUdR). They were ethanol-fixed, thin-sliced, and immunostained for BUdR, PDGF, smooth muscle actin and macrophage. The PDGF immunoreactivity was mainly detected in the macrophages of the subendothelial area, where BUdR-positive cells were present. Percentage of BUdR-positive cells in the atheroma specimens ranged from 3% to 15%. The BUdR-labeled small cells were mainly located in the subendothelial area, and they were identified as non-foamy macrophages by double immunostaining with anti-macrophage antibody. The results indicate that nonfoamy macrophages have potentials for cell division and they might play an important role for the development and growth of atheroma by secreting PDGF.

Brief exposure to hypoxia induces bFGF mRNA and protein and protects rat cortical neurons from prolonged hypoxic stress

We examined the hypoxic tolerance phenomenon in vitro. Brief exposure to hypoxia induced the production of basic fibroblast growth factor (bFGF) mRNA and protein in rat cortical neurons and protected them from hypoxic injury. Cortical neurons were cultured from 18th-day rat embryos in a serum-free medium and subjected to brief (4 h) and/or prolonged (24 h) hypoxia. Neuronal damage was assessed by quantifying lactate dehydrogenase (LDH) activity in the medium. After brief hypoxia, LDH release was identical to that of the controls, whereas prolonged hypoxia caused a significant increase in LDH release, indicating neuronal death. However, if brief hypoxia was applied 2 days prior to the prolonged hypoxia, no increase in LDH release was observed. The bFGF mRNA expression was assessed with Northern blot and protein immunoreactivity with Western blot analysis. The brief period of hypoxia caused a 2.5-fold increase in bFGF mRNA and considerable bFGF protein expression 1 day later, but prolonged hypoxia caused increase in the expression of bFGF mRNA at 2 days and no protein expression until 3 days after the start of the hypoxia. When cells were subjected to prolonged hypoxia 2 days after brief hypoxia, however, no increase in bFGF mRNA was observed, while bFGF protein was expressed continuously. We also observed that exogenously applied bFGF reduced neuronal injury produced by prolonged hypoxia. The results obtained with this model suggest that brief hypoxia induces bFGF protein and thus tolerance to subsequent lethal hypoxia. Basic FGF might play a role as a tolerance-associated factor in this process. Thus, an in vitro model is useful for assessing the response of cortical neurons to hypoxic stress and for researching new factors related to ischemic tolerance.

Expression of growth inhibitory factor mRNA following cortical injury in rat

Growth inhibitory factor (GIF) inhibits survival and neurite formation of cortical neurons in vitro and is found abundantly in the normal human brain. The role of GIF is still obscure, although it is reported to decrease in the brain in Alzheimer's disease. We examined changes in GIF mRNA expression in a rat cortical-ablation model with the aid of an in situ hybridization technique. In sham-operated animals, the GIF mRNA was expressed consistently in the cerebral cortex, hippocampus, and thalamus. One day after cortical ablation of the left somatosensory cortex, the expression tended to decrease in the cortex ipsilateral to the injury. Four days after surgery, it increased markedly in the affected cortex and thereafter returned to the level of the control animals except for the area surrounding the injury, where GIF mRNA again increased 2 to 3 weeks after ablation. The transient increase in GIF mRNA expression may reflect efforts to inhibit excessive sprouting of neurites. We also studied the effect of topically applied basic fibroblast growth factor (bFGF), which has a range of neurotrophic effects, on GIF mRNA expression. Topically applied bFGF enhanced the suppression of GIF at 1 day after surgery, though it did not affect the subsequent response. GIF can therefore be assumed to affect the outgrowth of injured neurites and might play a major role in maintenance of the neuronal network in cooperation with other trophic factors. Modification of these factors may be the key to improve neuronal damage after injury.

Changes in growth inhibitory factor mRNA expression compared with those in c-jun mRNA expression following facial nerve transection

We investigated growth inhibitory factor (GIF) mRNA expression within the rat facial nucleus with the aid of in situ hybridization. We found that GIF mRNA was expressed abundantly in the facial motoneurons of sham operated animals, and that this gene expression decreased after transection of the facial nerve. This decrease of GIF mRNA was first detected on the third day and was maintained for at least five weeks after transection of the nerve. Changes in c-jun, an immediate early gene, were also investigated with this model, and it was found that c-jun mRNA started to increase in the facial nucleus on the first day and that this increase was maintained for at least 5 weeks. These results suggest that the facial motoneurons, when their axons are transected, continuously respond to the injury and that GIF mRNA is actively suppressed to reduce the inhibition of neurite outgrowth in order to regenerate the axons.

Messenger RNA and protein expression of basic fibroblast growth factor receptor after cortical ablation

In a previous report we demonstrated that basic fibroblast growth factor (bFGF), as a multipotent neurotrophic factor, could prevent retrograde degeneration of the thalamic neurons after ablation of the somatosensory cortex. To elucidate the mechanism of this bFGF action, we examined changes in FGF receptor (FGFR) mRNA (flg) expression with in situ hybridization. The FGF receptor protein was detected with the immunoblotting method. The FGFR mRNA expression was found to be diffusely increased in the affected cortex. Microscopic observation indicated that FGFR mRNA was expressed in several types of cortical cells including neurons and non-neuronal cells. This increase could be observed as early as 6 hours after surgery and lasted for 48 hours. In the thalamus, however no change in FGFR mRNA signals was observed. Western blotting detected a protein immunoreactive to anti-FGFR antibody. Samples from the periablated cortex showed an increase in FGFR protein. Samples from the thalamus, however, showed no difference in FGFR protein level between the lesion side and the contralateral side. Application of exogenous bFGF in Gelfoam to the cortical ablation cavity did not show any effect on the gene expression or protein level of FGFR. These results suggest that FGFR is diffusely induced throughout the injured cortex in the early phase after injury and that bFGF may play an important role after injury. Topically applied bFGF might thus modulate cellular responses in the cortex and have a neurotrophic effect on the affected thalamic neurons.

Prostaglandin E1 induces c-Fos and Myc proteins and protects rat hippocampal cells against hypoxic injury

We investigated the effects of prostaglandin (PG) E1 on the hypoxic injury of fetal rat hippocampal cells. Primary hippocampal cell cultures (embryonic day 18) were established and maintained. After 72 h in culture, PGE1 was added to the serum-free medium at a final concentration of 10(-5)-10(-9) M. Cultures were divided into two groups: The normoxia group was in culture for another 48 h, and the hypoxia group was exposed to 24 h of hypoxia followed by continuation of culture for another 24 h. As a quantitative measure of cell death, lactate dehydrogenase (LDH) activity was estimated in the culture medium. The LDH activity, released by the hypoxic insult, was significantly smaller with PGE1 treatment at 10(-6), 10(-7), and 10(-8) M (p < 0.01) and 10(-9) M (p < 0.05) compared with the control. No differences in the LDH activities were observed in the normoxia group. Glial culture was not affected by the hypoxia. Western blot analysis showed an increased induction of 62-kDa c-Fos and 58, 60, and 66 kDa Myc proteins in rat hippocampal cells with 10(-7) M PGE1 treatment. We conclude that PGE1 at concentrations of 10(-6)-10(-9) M protects rat hippocampal neurons against hypoxic insult.

Blood-borne macromolecule induces FGF receptor gene expression after focal ischemia

We have detected fibroblast growth factor receptor (FGFR) gene expression in the focal ischemia model. The FGFR gene expression in neurons can be explained by neuronal network disturbances, but the mechanism of astroglial gene expression remains uncertain. We speculated that blood-borne edema fluid may activate gene expression of astroglias. To prove this hypothesis, we compared the pattern's of gene expression of FGFR and distribution of edema fluid by using serial tissue sections of the middle cerebral artery (MCA) ischemia. The left MCA of twenty-four male Wistar rats were occluded, and sacrificed 1, 3, 4, 7 and 14 days later by transcardiac perfusion and fixation. The tissues were sliced thinly to 14 microns sections. Part of the tissue sections was used for in situ hybridization for rat FGFR with [35S]labeled RNA probes. The other part of the sections was used for immunostaining for albumin, immunoglobulin G (IgG) and IgM. The FGFR mRNA expression was evident in the lesion-side hemisphere. In the cortex, neurons mainly expressed FGFR gene in the cortex, whereas astroglias and capillary endothelium expressed FGFR in the corpus callosum and internal capsule. The albumin distributed cortex and white matter of the lesion-side and it extended to the contralateral side. The IgG distributed mainly in the lesion-side white matter, and in part extended to the contralateral side. The IgM only distribute to the infarcted area. When we compared topographical distribution of FGFR in the white matter and pattern of albumin, IgG and IgM distribution, pattern of IgG distribution correlated well to the area of FGFR expression.(ABSTRACT TRUNCATED AT 250 WORDS)

Kinetic analysis of transport and opioid receptor binding of [3H](-)-cyclofoxy in rat brain in vivo: implications for human studies

[3H]Cyclofoxy (CF: 17-cyclopropylmethyl-3,14-dihydroxy-4,5-alpha-epoxy-6-beta-fluoromorp hinan) is an opioid antagonist with affinity to both mu and kappa subtypes that was synthesized for quantitative evaluation of opioid receptor binding in vivo. Two sets of experiments in rats were analyzed. The first involved determining the metabolite-corrected blood concentration and tissue distribution of CF in brain 1 to 60 min after i.v. bolus injection. The second involved measuring brain washout for 15 to 120 s following intracarotid artery injection of CF. A physiologically based model (Sawada et al., 1990a) and a classical compartmental pharmacokinetic model (Wong et al., 1986a) were compared. The models included different assumptions for transport across the blood-brain barrier (BBB); estimates of nonspecific tissue binding and specific binding to a single opiate receptor site were found to be essentially the same with both models. The nonspecific binding equilibrium constant varied modestly in different brain structures (Keq = 3-9), whereas the binding potential (BP) varied over a much broader range (BP = 0.6-32). In vivo estimates of the opioid receptor dissociation constant were similar for different brain structures (KD = 2.1-5.2 nM), whereas the apparent receptor density (Bmax) varied between 1 (cerebellum) and 78 (thalamus) pmol/g of brain. The receptor dissociation rate constants in cerebrum (k4 = 0.08-0.16 min-1; koff = 0.16-0.23 min-1) and brain vascular permeability (PS = 1.3-3.4 ml/min/g) are sufficiently high to achieve equilibrium conditions within a reasonable period of time. Graphical analysis (Patlak and Blasberg, 1985) of the data is inappropriate due to the high tissue-loss rate constant (kb = 0.03-0.07 min-1) for CF in brain. From these findings, CF should be a very useful opioid receptor ligand for the estimation of the receptor binding parameters in human subjects using [18F]CF and positron emission tomography.

Angiographic demonstration of acute phase of intracranial arterial spasm following aneurysm rupture. Case report

A case documenting the acute phase of intracranial arterial spasm following rupture of an aneurysm arising from the left internal carotid artery is reported. The patient deteriorated due to recurrent hemorrhage while undergoing angiography 12 hours after the initial aneurysm rupture. The acute deterioration was accompanied by dilatation of the ipsilateral pupil and occurred during injection of contrast material. There was delayed filling of the middle cerebral artery complex along with this narrowing. The arterial narrowing was confirmed to have completely disappeared on an angiographic series performed 14 minutes after the first series of films. The etiology of the acute vasospasm is discussed.

[An in vitro study on combination effect of isepamicin and beta-lactam antibiotics]

A study was done on the combined actions of an aminoglycoside, isepamicin (ISP), and 3 beta-lactam antibiotics (cefoperazone (CPZ), latamoxef (LMOX) and imipenem/cilastatin sodium (IPM/CS] against clinical isolates of Pseudomonas aeruginosa, Serratia marcescens and Klebsiella pneumoniae. Minimal inhibitory concentrations of individual antibiotics were compared first. ISP and IPM/CS had strong antibacterial activities against all 3 bacterial species while the antibacterial activities of CPZ against P. aeruginosa and S. marcescens, and that of LMOX against P. aeruginosa were much weaker than those of IPM/CS or ISP. Fractional inhibitory concentration indices determined by the checker-board dilution method were compared next. ISP, when used in combination with beta-lactam antibiotics (CPZ, LMOX, or IPM/CS), showed synergistic or additive effect on most strains of the all 3 species, the combination of ISP and CPZ being most effective. Although less effective, synergistic or additive effects were also observed with the combinations of 2 beta-lactam antibiotics (CPZ and IPM/CS, LMOX and IPM/CS). Time course experiments demonstrated that ISP combined with CPZ had bactericidal activities against all 3 bacterial species at concentrations at which the respective drug alone showed only bacteriostatic activity.

Comparison of iron-59, indium-111, and gallium-69 transferrin as a macromolecular tracer of vascular permeability and the transferrin receptor

Tracer amounts of [59Fe++]citrate, [111In+++]chloride, and [68Ga+++]chloride were complexed with autologous plasma transferrin. Each of these complexes were co-administered with [125I]albumin by i.v. injection and their biodistribution was studied in Wistar rats. The plasma clearance of 59Fe and [125I]albumin was monoexponential with half-times of 49-70 and 277 min, respectively. The plasma clearance of 68Ga and 111In was biexponential with second component half-times of 157 and 232 min, respectively. Indium-111 tissue distribution was similar to that of [125I]albumin in heart, lung, muscle, brain and Walker-256 allograft. Iron-59 distribution spaces were generally the highest of the metal complexes in all tissues except muscle, where the 68Ga space was highest. The effects of transferrin-specific receptor-mediated endocytosis can be avoided in many organs and Walker-256 allografts by using the indium-transferrin complex, and the radiolabeled complex may be a convenient macromolecular tracer to estimate vascular permeability and vessel pore size in tumor and systemic tissue. In contrast, the iron-transferrin complex may be useful for measuring and imaging transferrin-specific receptors in brain and tumor tissue.

Extent of thermal penetration of Nd-YAG laser--histological considerations

The extent of thermal penetration of Nd-YAG laser was studied histologically. The material was obtained from seven cases of various types of intracranial and extracranial tumours and normal temporal muscle obtained at operation. After irradiation of the tumour surface with the laser, the tumours were removed and depth and width of pathological changes caused by heat were studied. Histologically, materials consisted of a vaporized surface, carbonized, vesicular, necrotic, oedematous layer and surrounding intact brain tumour tissue. There was a direct relationship between the thermal effect and the irradiated thermal energy (watt x exposure time x pulse number). The results showed that the thermal effect was limited to a depth of 6 to 10 mm from the irradiated surface when irradiated 4 times at the power of 90 watts for 2 seconds.

Catecholamine-secreting malignant schwannoma in a patient with multiple intracranial aneurysms. Case report

A case is reported of malignant schwannomatosis (malignant transformation of von Recklinghausen's disease) with catecholamine production in a patient with multiple intracranial aneurysms. The patient had a history of episodic hypertension and elevated levels of catecholamines in the serum and 24-hour urinary excretion. Postmortem examination revealed diffuse central nervous system (CNS) dissemination of the tumor from the thoracolumbar spinal malignant schwannoma. A high concentration of catecholamines was demonstrated in the tumor tissue, and histochemical and electron microscopy studies suggested the presence of catecholamines in the cytoplasm of some of the tumor cells. This patient's clinical and radiological features, including severe headache, vomiting, stiff neck, ptosis of the eye ipsilateral to the internal carotid-posterior communicating artery aneurysms, and local arterial narrowing, mimicked those of subarachnoid hemorrhage from a ruptured aneurysm. However, the clinical picture was caused by diffuse CNS dissemination of the tumor, another primary malignant schwannoma of the oculomotor nerve, and intimal fibrous thickening of the arterial wall.

[Sellar fibrosarcoma following radiotherapy for prolactinoma]

A 51-year-old house woman visited the Department of Neurosurgery, Osaka University Hospital for examination of the head injury on Oct. 7, 1975. Neurological examination was normal. Endocrinological examination showed galactorrhea. The patient had a past history of premature menopause. Plain skull films revealed enlargement of sella turcica and CT scan showed sellar tumor with suprasellar expansion which was enhanced by contrast medium. The serum prolactin (PRL) level was 3,290 ng/ml. Diagnosis of PRL secreting pituitary adenoma (prolactinoma) was made. Though surgical removal of the tumor was recommended, it was refused by the patient. Therefore, careful observation was continued as an out-patient until May 1979 when she noticed a temporal hemianopsia of her left eye. She was admitted and had partial removal of the tumor via frontal route and subsequent irradiation (total dose of 5,000 rad by Lineac). The tumor was verified to be a prolactinoma by the immunohistochemical staining. Postoperative course was uneventful and she lead a normal life. In Oct. 1981, severe faceache began and she was readmitted. Sella was destructed extensively and CT scan revealed a hugh sellar tumor with multi-directional extrasellar extension which was less enhanced than that of the first study. The serum PRL level was 588 ng/ml and the regrowth of prolactinoma was suspected. High dose bromocriptine (40 mg/day) therapy was started. The serum PRL level rapidly fell to the negligible value, however, shrinkage of the tumor was not observed. On Jan. 20, 1982, suddenly she developed a left hemiparesis and her level of consciousness gradually deteriorated. On Mar. 11, 1982, the second operation was performed and a solid firm tumor in the base of the skull was partially removed. The tumor was histologically verified to be a fibrosarcoma. After the second operation bromocriptine therapy was discontinued, however expected elevation of the serum PRL level was not recognized. She died on Apr. 4, 1982.