Impact of catheter ablation on functional tricuspid regurgitation in patients with atrial fibrillation

Background

Since atrial functional tricuspid regurgitation (AF-TR) is associated with increased heart failure and mortality, the management of AF-TR is clinically important. Atrial fibrillation (AF) plays the main role in AF-TR. However, the effectiveness of catheter ablation (CA) and mechanism of improvement of AF-TR haven't been fully evaluated.

Purpose

We sought to investigate the impact of CA for AF on AF-TR in patients with moderate or more TR.

Methods

We retrospectively investigated consecutive 2685 patients with AF who received CA from February 2004 to December 2019 in Japan. The current study population consisted of 102 patients with moderate or greater TR who underwent CA for AF. The echocardiographic parameters were compared between pre-ablation and post-ablation transthoracic echocardiography (TTE), and the recurrence rate of AF/ atrial tachycardia (AT) was measured.

Results

The mean age was 73.2 years, 53% were women. TR severity and TR jet area significantly improved after CA for AF (TR jet area: 5.8 [3.9–7.6] cm2 to 2.0 [1.1–3.0] cm2, p<0.001). In addition, mitral regurgitation (MR) jet area, left atrial (LA) area, mitral valve diameter, right ventricular (RV) end-diastolic area, right atrial (RA) area, tricuspid valve (TV) diameter decreased after CA (p<0.001, <0.001, <0.001, = 0.02, <0.001, and <0.001, respectively). There was no significant difference between one-year recurrence of AF/AT and TR severity at pre-ablation TTE (moderate 28.6%, moderate to severe 37.2%, and severe 31.6%, p=0.72).

Conclusions

TR severity and jet area improved after CA in patients with AF and moderate or more TR. RV size, RA size, TV diameter also decreased after CA, which may be associated with TR improvement. There was no significant difference between one-year recurrence of AF/AT and TR severity at pre-ablation TTE.

Funding Acknowledgement

Type of funding sources: None.

10-year clinical outcomes after radiofrequency catheter ablation for atrial fibrillation. A single center experience

Background

Radiofrequency catheter ablation (RFCA) for atrial fibrillation (AF) is becoming a routine procedure to treat patients with drug-refractory symptomatic AF. However, data regarding very long-term clinical outcomes is limited. The aim of the present study was to evaluate the 10-year clinical outcomes of patients who underwent RFCA for paroxysmal and persistent AF.

Methods

We retrospectively enrolled 503 consecutive patients (mean age 66,9±9,51 years; 71,6% male) who underwent RFCA for drug-refractory symptomatic AF between February 2004 and June 2011. Follow-up information was obtained using medical records and/or telephonic interviews with the patient, relatives and/or referring physicians.

Results

Among 503 patients enrolled in this study, 362 had paroxysmal atrial fibrillation (PAF) and 141 had persistent atrial fibrillation (PeAF) (72% and 28%, respectively). Mean follow-up was 8,84±3,05 years. The 10-year event-free rate for recurrent atrial tachyarrhythmia (AT) after the first procedure was 44,5% (49,4% for PAF vs 31,9% for PeAF; p=0,002 by log-rank test) and 81,9% after the last procedure (87,3% for PAF and 67,9% for PeAF; p≤0,001 by log-rank test). AT recurrence was observed most commonly during the first 12 months of the initial procedure (56%), with only 18% of them occurring after 60 months. Multivariate analysis revealed that persistent AF (hazard ratio=1,366; 95% confidence interval 1,058–1,76; p=0,017) and duration of AF >5 years (hazard ratio=1,357; 95% confidence interval 1,064–1,732; p=0,005) were independent risk factors for AT recurrence. Regarding adverse events, there were 24 (4,8%) hospitalizations for acute decompensated heart failure, 20 (4%) ischemic strokes and 14 (2,8%) bleeding complications requiring hospital admissions. Patients taking oral anticoagulation and antiarrhythmic drugs at the end of the study accounted for 32,8% and 16,7% respectively.

Conclusions

RFCA for AF provided favorable results in terms of arrhythmia event-free survival in long-term follow-up with better results in patients with paroxysmal AF. Persistent AF and long-standing AF (beyond 5 years) were associated with AT recurrence. Despite the large number of patients who discontinued oral anticoagulation, thromboembolic adverse events were rare.

Funding Acknowledgement

Type of funding sources: None.

Reduced-intensity vs myeloablative conditioning allogeneic hematopoietic SCT for patients aged over 45 years with ALL in remission: a study from the Adult ALL Working Group of the Japan Society for Hematopoietic Cell Transplantation (JSHCT)

In this study, outcomes for 575 adult ALL patients aged ≥45 years who underwent first allo-SCT in CR were analyzed according to the type of conditioning regimen (myeloablative conditioning (MAC) for 369 patients vs reduced-intensity conditioning (RIC) for 206 patients). Patients in the RIC group were older (median age, 58 vs 51 years, P<0.0001). There were no statistically significant differences in 3-year OS, disease-free survival (DFS) and non-relapse mortality (NRM): 51% vs 53%, 47% vs 39% and 38% vs 36%, respectively. Multivariate analysis showed that CR2 and HLA mismatching were associated with poor OS (P=0.002 and P=0.019, respectively). HLA mismatching was associated with lower rate of relapse (P=0.016), but was associated with higher rate of NRM (P=0.001). RIC was associated with good OS and DFS in patients who received HLA-mismatch transplantation and were aged ≥55 years compared with MAC by multivariate analysis for each event with interaction (hazard ratio (HR) and 95% confidence interval 0.35 and 0.15-0.81, P=0.014 for OS and 0.36 and 0.16-0.81, P=0.013 for DFS). Therefore, patients ≥55 years of age with HLA-mismatch transplantation should be candidates for RIC rather than MAC.

Impact of a donor source on adult Philadelphia chromosome-negative acute lymphoblastic leukemia: a retrospective analysis from the Adult Acute Lymphoblastic Leukemia Working Group of the Japan Society for Hematopoietic Cell Transplantation

BACKGROUND

We aimed to clarify the impact of the donor source of allogeneic stem cell transplantation (allo-SCT) on Philadelphia chromosome-negative acute lymphoblastic leukemia [Ph(-) ALL] with focus on cord blood (CB).

PATIENTS AND METHODS

We retrospectively analyzed data of 1726 patients who underwent myeloablative allo-SCT for adult Ph(-) ALL. The sources of the allo-SCT were related donors (RD; N = 684), unrelated donors (URD; N = 809), and CB (N = 233).

RESULTS

Overall survival (OS) in patients after CB allo-SCT in first complete remission (CR1) was comparable with that after RD or URD allo-SCT (RD: 65%, URD: 64% and CB: 57% at 4 years, P = 0.11). CB was not a significant risk factor for relapse or non-relapse mortality as well as for OS in multivariate analyses. Similarly, the donor source was not a significant risk factor for OS in subsequent CR or non-CR (RD: 47%, URD: 39% and CB: 48% in subsequent CR, P = 0.33; RD: 15%, URD: 21% and CB: 18% in non-CR, P = 0.20 at 4 years).

CONCLUSION

Allo-SCT using CB led to OS similar to those of RD or URD in any disease status. To avoid missing the appropriate timing, CB is a favorable alternative source for adult Ph(-) ALL patients without a suitable RD or URD.

Solar Cells Based on PVD Grown CuGaSe2 – Absorber and Device Properties

For solar cells based on CuGaSe2(CGS) absorber layers physical vapour deposition (PVD) was employed to deposit polycrystalline CGS thin films. Efficiencies up to 7.9% were achieved by applying a two-stage deposition process for absorber preparation. The high structural quality of the absorbers is shown. For highest cell efficiencies our standard recipe for the CdS buffer deposition had to be re-adapted. Voltage dependent spectral response measurements of the device in conjunction with absorption measurements of the absorber layers allow calculation of the minority carrier diffusion length, space charge region (SCR) width, absorber carrier concentration and the built-in voltage. The defect state density at the buffer/absorber interface is estimated. It can be shown that the benefical effect of the modified buffer deposition is mainly due to a reduced acceptor concentration at the absorber/buffer interface.

A prospective dose-finding trial using a modified continual reassessment method for optimization of fludarabine plus melphalan conditioning for marrow transplantation from unrelated donors in patients with hematopoietic malignancies

BACKGROUND

Because of the less graft-facilitating effect by bone marrow (BM), we need to assess a dosage of conditioning more accurately particularly in combination with reduced-intensity conditioning. Thus we examined that modified continual reassessment method (mCRM) is applicable for deciding appropriate conditioning of allogeneic BM transplantation.

PATIENTS AND METHODS

The conditioning regimen consisted of i.v. fludarabine (125 mg/m2) plus an examination dose of i.v. melphalan. The primary endpoint was a donor-type T-cell chimerism at day 28 with successful engraftment defined as >90% donor cells. Five patients per dose level were planned to be accrued and chimerism data were used to determine the next dose.

RESULTS

Seventeen patients were enrolled at doses between 130 and 160 mg/m2. The dose was changed from 160 to 130 mg/m(2) (second level) after five full-donor chimerisms. With one patient of 0% chimera in the second level, the dose was increased to 135 mg/m2 (third level). Following five full-donor chimerisms in the third level, the study was complete as projected.

CONCLUSIONS

mCRM was shown to be a relevant method for dose-finding of conditioning regimen. The melphalan dose of 135 mg/m2 was determined as the recommended phase II dose to induce initial full-donor chimerism.

"Transmural air leak": a computed tomographic finding following endoscopic submucosal dissection of gastric tumors

BACKGROUND AND STUDY AIMS

A small amount of free air, visible on CT but not on plain chest radiography, which appeared following endoscopic submucosal dissection (ESD) of a gastric neoplasm without endoscopically visible perforation, was defined as a "transmural air leak", and a prospective, consecutive entry study was performed to determine its incidence and clinical significance.

PATIENTS AND METHODS

Between January 2006 and September 2008, ESD was performed for 246 gastric lesions in 246 consecutive patients. Abdominal CT scan was performed 1 day after ESD. In addition, chest radiography and blood biochemistry tests were performed at different time points before and after ESD.

RESULTS

Two hundred and nineteen lesions (89 %) were curatively removed by ESD. Among the total of 246 patients, we encountered endoscopically visible perforation during ESD in 2 patients (0.8 %), and clinically suspected perforation diagnosed by the presence of free air on chest radiography but invisible during ESD in 3 patients (1 %), while transmural air leak was observed in another 33 (13 %). Air leak occurred in cases where resection size was larger, procedure time longer, and the muscularis propria on the ulcer base was exposed at the end of ESD. Patients with air leaks developed pyrexia at a higher rate than those without (36 % vs. 16 %, P = 0.018). These patients recovered with antibiotics and required no endoscopic or surgical intervention. The presence of an air leak did not affect the duration of hospital stay.

CONCLUSIONS

A transmural air leak was observed in 13 % of the patients undergoing ESD. Larger resection size, prolonged procedure time, and exposure of the muscularis propria on the ulcer base were risk factors for transmural air leak, but the outcome of patients with this complication was good.

Clinicopathological manifestations and treatment of intestinal transplant-associated microangiopathy

Intestinal transplant-associated microangiopathy (i-TAM) is an important complication after allogeneic hematopoietic SCT. From 1997 to 2006, 87 of 886 patients with diarrhea after transplantation received colonoscopic biopsy. i-TAM, GVHD and CMV colitis were diagnosed histopathologically. The median duration from transplantation to the onset of diarrhea was 32 days (range: 9-130 days) and that from the onset of diarrhea to biopsy was 12 days (range: 0-74 days). The median maximal amount of diarrhea was 2 l/day (range: 130-5600 ml/day). Histopathological diagnosis included i-TAM (n=80), GVHD (n=26), CMV colitis (n=17) and nonspecific findings (n=2) with overlapping. Among 80 patients with i-TAM, abdominal pain was a major symptom, and only 11 patients fulfilled the proposed criteria for systemic TAM. Non-relapse mortality (NRM) among patients without resolution of diarrhea was 72% and i-TAM comprised 57% of NRM. NRM was 25% among patients without intensified immunosuppression, but was 52, 79 and 100% among those with intensified immunosuppression before diarrhea, after diarrhea, and before and after diarrhea, respectively. In conclusion, i-TAM is a major complication presenting massive refractory diarrhea and abdominal pain, which causes NRM. Avoiding intensified immunosuppression that damages vascular endothelium until the resolution of i-TAM may improve transplant outcome.

Inter-ictal and post-ictal psychoses in frontal lobe epilepsy: a retrospective comparison with psychoses in temporal lobe epilepsy

There have been few studies of the psychopathology of patients with frontal lobe epilepsy (FLE). The majority of studies of both inter-ictal and post-ictal psychoses have strongly suggested the influence of temporal lobe disturbance on psychoses. Patients with organic brain damage or schizophrenia, however, sometimes show frontal lobe dysfunction. The purpose of this study was to better understand the effect, if any, of frontal lobe disturbance and seizure on psychopathology. Patients were divided into four groups based on epilepsy type and preceding seizures; 8 with FLE/inter-ictal psychosis, 3 with FLE/post-ictal psychosis, 29 with temporal lobe epilepsy (TLE)/inter-ictal psychosis, and 8 with TLE/post-ictal psychosis. Psychopathologic symptoms were retrospectively reviewed based on case notes, using a modified brief psychiatric rating scale (BPRS). Psychomotor excitement, hostility, suspiciousness, and hallucinatory behaviour were prominent features in all four groups. Six orthogonal factors were derived by factor analysis from the original data based on the 18 BPRS items. FLE patients with inter-ictal psychosis showed marked hebephrenic characteristics (i.e. emotional withdrawal and blunted effect). Our findings suggest that patients with FLE can exhibit various psychiatric symptoms. However, their psychotic symptoms, hebephrenic symptoms in particular, may often be overlooked.

Topology optimization design of flextensional actuators

Flextensional actuators can be defined as a piezoceramic (or a stack of piezoceramics) connected to a flexible mechanical structure that converts and amplifies the output displacement of the piezoceramic. Essentially, the actuator performance depends on the distribution of stiffness and flexibility in the coupling structure and, therefore, on the coupling structure topology. In this work, we propose a general method for designing flextensional actuators with large output displacement (or generative force) by applying the topology optimization method. The goal is to design a flexible structure coupled to the piezoceramic that maximizes the output displacement (or force) in some specified direction. Static and low frequency applications are considered. To illustrate the implementation of the method, 2-D topologies of flextensional actuators are presented because of the lower computational cost; however, the method can be extended to 3-D topologies. By designing other types of coupling structures connected to the piezoceramic, new designs of flextensional actuators that produce output displacements or forces in different directions can be obtained, as shown. This method can be extended for designing flextensional hydrophones and sonars.

Determinant analysis of IgE and IgG4 antibodies and T cells specific for bovine alpha(s)1-casein from the same patients allergic to cow's milk: existence of alpha(s)1-casein-specific B cells and T cells characteristic in cow's-milk allergy

In an effort to clarify the etiology of milk allergy from the standpoint of allergen-specific immune reactions, we investigated the determinants of IgE, IgG4, and T cells specific for bovine alpha(s)1-casein from the same individual patients by using its synthetic peptides and cyanogen bromide-digested fragments. Alpha(s)1-casein is a major allergen in cow's milk, and its unique conformation enabled us to investigate the determinants of antibodies without consideration about missing the reactivities because of conformational changes. Nine patients were selected as subjects from among 129 milk-sensitive infants screened by ELISA to assess the anti-alpha(s)1-casein IgE levels in their sera. By using ELISA for epitope mapping, a C-terminal region of alpha(s)1-casein was identified as a common binding site for IgE from all of these patients, whereas those for anti-alpha(s)1-casein IgG4 were located in multiple regions of alpha(s)1-casein. We determined the specificities of seven alpha(s)1-casein-specific T-cell lines established from peripheral blood mononuclear cells of two of the patients. These T cells have been shown to secrete IL-4. All of the T-cell lines had different specificities to alpha(s)1-casein. However, a common amino acid residue use was found among the determinants of various T-cell lines from each patient. The results suggest that patients allergic to cow's milk have characteristic B cells recognizing a limited region of alpha(s)1-casein and secreting alpha(s)1-casein-specific IgE. These B cells may interact particularly with T cells recognizing determinants with a common structure.

The Schizosaccharomyces pombe mei4+ gene encodes a meiosis-specific transcription factor containing a forkhead DNA-binding domain

The mei4+ gene of the fission yeast Schizosaccharomyces pombe was cloned by functional complementation. The mei4 disruptant failed to complete meiosis-I but could proliferate normally. mei4+ was transcribed only in meiosis-proficient diploid cells after premeiotic DNA replication. The mei4+ open reading frame encodes a 57-kDa serine-rich protein comprised of 517 amino acids with a forkhead/HNF3 DNA-binding domain in the amino-terminal region. Transcription of spo6+, a gene required for sporulation, was dependent on the mei4+ function. Two copies of the GTAAAYA consensus sequence, proposed as the binding site for human forkhead proteins, were found in the promoter region of spo6+. A gel mobility shift assay demonstrated the sequence-dependent binding of the GST-Mei4 forkhead domain fusion protein to DNA fragments with one of the consensus elements. Deletion of this consensus element from the spo6 promoter abolished the transcription of spo6+ and resulted in a sporulation deficiency. One-hybrid assay of Mei4 which was fused to the Gal4 DNA-binding domain localized the transcriptional activation domain in the C-terminal 140 amino acids of Mei4. These results indicate that Mei4 functions as a meiosis-specific transcription factor of S. pombe.

A chloroplast-derived sequence is utilized as a source of promoter sequences for the gene for subunit 9 of NADH dehydrogenase (nad9) in rice mitochondria

The chloroplast-derived sequence trnS-rps4/ 3'trnL-trnF-ndhJ-ndhK (4066 bases in length) is present in a region that starts 355 bases upstream of the gene for subunit 9 of NADH dehydrogenase (nad9) in the mitochondrial genome of rice. Northern blot hybridization revealed that three large transcripts of 3.05, 1.62 and 1.05 kb hybridized to strand-specific probes for both the nad9 gene and the chloroplast-derived sequence, indicating that the nad9 gene was transcribed together with the chloroplast-derived sequence. From the results of in vitro capping and ribonuclease protection experiments, as well as primer extension analysis, we identified at least seven sites for the initiation of transcription of nad9 in the chloroplast-derived sequence. All of the initiation sites for transcription of the nad9 gene were located in sequences homologous to chloroplast DNA. Two of seven initiation sites were flanked by a sequence homologous to the consensus promoter motif that includes the CRTA motif (where R is A or G) of the rice mitochondrion. However, the sequences surrounding the other five sites showed only limited similarity to the conserved sequence. It is suggested that all the promoters of the rice nad9 gene exist in a sequence that was transferred from the chloroplast during evolution. Thus, the chloroplast-derived sequence has a novel, significant function in the mitochondrial genome of this higher plant.

Limited degradation of retinoid X receptor by calpain

Recently, we have found two major physiological forms of retinoid X receptor alpha (RXR alpha): the mature 54 kDa RXR alpha and the truncated 44 kDa RXR alpha lacking a portion of N-terminal A/B domain in human and rodent livers. In this communication, we show that m-calpain was active to digest 54 kDa RXR alpha in the human hepatoma-derived cell line, HuH7, nuclei to 44 kDa fragment through 47 kDa intermediate in vitro. Although both proteolytic fragments were revealed by anti-RXR alpha antibody against its E-domain, neither fragment reacted with anti-RXR alpha antibody specific for A/B domain. The profile of the calpain-induced proteolytic fragmentation of RXR alpha was almost identical to that endogenous RXR alpha in nonmalignant human and normal mouse liver nuclei. This is the first demonstration that of RXR alpha is a substrate for m-calpain, strongly suggesting that the enzyme might also be involved in post-translational modification of the receptor in hepatocytes.

Aberrant metabolism of retinoid X receptor proteins in human hepatocellular carcinoma

A polyclonal antibody was raised against a recombinant ligand binding domain construct of the human retinoid X receptor (RXR) alpha. This antibody reacted with an endogenous 54 kDa nuclear protein from human hepatoma-derived HuH7 cells in immunoblot analyses. Immunoblotting of nuclear proteins from human hepatocellular carcinomas (HCCs) and their surrounding tissues revealed the presence of a 44 kDa RXR distinct from the 54 kDa RXR and a dramatic decrease in the relative amounts of 44 kDa RXR to 54 kDa RXR in all HCCs compared with normal tissue. In vitro shift and intracellular conversion from 54 kDa RXR to 44 kDa species were observed with the nuclear extracts of HuH7 cells. Furthermore, transfection of hRXR alpha cDNA into HuH7 cells resulted in the increase of 54 kDa RXR, whereas transfected mouse hepatocytes accumulated 44 kDa RXR. These results strongly indicated that 44 kDa RXR was a physiological proteolytic fragment of 54 kDa RXR and that post-translational metabolism of RXR was impaired in HCC and the HuH7 hepatoma-derived cell line.

Establishment and characterization of alpha s1-casein-specific T-cell lines from patients allergic to cow's milk: unexpected higher frequency of CD8+ T-cell lines

To study cow's milk allergy at the cellular level, we assessed the reactivity of peripheral blood mononuclear cells from patients allergic to cow's milk to alpha s1-casein, which is one of the major allergens in cow's milk. Proliferation of the cells to alpha s1-casein activation showed a rather weak response. Therefore to understand T-cell reactivity to alpha s1-casein in more detail, we prepared alpha s1-casein-specific T-cell lines from patients allergic to cow's milk and established 26 T-cell lines. These T-cell lines could be classified into three groups by analyzing their surface marker expression: those containing predominantly CD4+ CD8- T cells, those containing both CD4+CD8- and CD4-CD8+ T cells, and those containing predominantly CD4- CD8+ T cells. The CD8+ T cells were obtained at an unexpectedly higher frequency from the patients. These T-cell lines produced interferon-gamma and IL-4. These results suggest that CD8+ T cells specific for alpha s1-casein and CD4+ T cells were primed by the stimulation with alpha s1-casein in patients allergic to milk and that both T cells may play a key role in the onset, progression of, or recovery from cow's milk allergy.

Aberrations and convergence characteristics of a concentric-circular focusing grating coupler: analysis

The convergence characteristics of the previously proposed concentric-circular focusing grating coupler (CFGC) are analyzed, and aberration functions for such typical errors as wavelength errors, effective index errors, grating pattern distortion, and CFGC eccentricity are derived for evaluation of their allowances. The analyzed results prove that the Strehl intensity deterioration caused by a wavelength error and an effective index offset can be minimized by optimization of the annular aperture of the CFGC. In the case of Marechal's criterion, a wavelength error of ±8.6% at the annular aperture of NA = 0.440-0.607 and an effective index error of ±20.4% at NA = 0.500-0.652 are permissible, and these values are ∼100 times greater than those that are seen in a conventional focusing grating coupler that has a rotationally asymmetrical structure with respect to its optical axis.

Fabrication of a concentric-circular focusing grating coupler by a conic-wave-front interference method and light-convergence experiments using the coupler

An interference method utilizing conic-wave-front light for the fabrication of a concentric-circular and chirped grating is proposed. The design method and fabrication of an interference lens that generates conic-wave-front light are also shown. A focusing element is constructed from a concentric-circular grating coupler with a 0.4-mm diameter and a concentric-circular focusing grating coupler with an annular aperture of 2-mm focal length and 2.0-4.0-mm diameter. Light-convergence experiments using the focusing element were able to obtain a focusing spot of 0.5 µm × 0.7 µm at half-intensity widths for a wavelength of 820 nm in combination with liquid-crystal polarization elements.

Suppression by carotenoids of microcystin-induced morphological changes in mouse hepatocytes

Microcystin-LR is a liver tumor promoter in the okadaic acid class, a group of potent inhibitors of protein phosphatases 1 and 2A. Because of inhibition of protein phosphatases, microcystin-LR induces hyperphosphorylation of cellular proteins, including cytoskeletal proteins--cytokeratins 8 and 18--and causes morphological changes in mouse hepatocytes in primary culture. We studied the effects of carotenoids to antagonize microcystin-LR-induced morphological changes in hepatocytes. beta-carotene (100 nM to 100 microns) suppressed the morphological changes induced by 100 nM microcystin-LR in a dose-dependent manner. Other carotenoids tested exerted similar suppressive effects, although retinoids, such as all-trans retinol, all-trans retinoic acid, and 9-cis retinoic acid, were only weakly suppressive. The relative potency of the suppression correlated significantly with the number of conjugated double bonds in the trans configuration. beta-carotene strongly suppressed the hyperphosphorylation of cellular proteins induced by microcystin-LR without significant changes in the basal phosphorylation level. Other antioxidants, such as alpha-tocopherol, did not protect the cells against microcystin-LR. Taken together, the antagonistic effects of carotenoids against microcystin-LR are difficult to explain by their antioxidant or provitamin A activities. Suppression of the hyperphosphorylation of cellular proteins may be a novel mechanism by which carotenoids inhibit tumor promotion.

Structure of a gene subunit 9 of NADH dehydrogenase (nad9) in rice mitochondria and RNA editing of its transcript

We identified a gene for subunit 9 of NADH dehydrogenase (nad9) in rice mitochondrial DNA. Southern and Northern hybridizations demonstrated that rice nad9 is present in a unique region in mtDNA and is transcribed at a high level. The transcript of rice nad9 is edited at twelve positions.

Optical element converting linear polarization into circular-tangential polarization

A new optical element capable of converting linear polarization into circular-tangential polarization (i.e., the electric vector is along the tangential direction to a circle) is proposed and demonstrated. The conversion characteristics of the fabricated element are evaluated, and the magnitude of aberration produced by the element is shown to be insignificant.

Activation of protein kinase C by mycobacterial cord factor, trehalose 6-monomycolate, resulting in tumor necrosis factor-alpha release in mouse lung tissues

Cord factors are mycoloyl glycolipids in cell walls of bacteria belonging to Actinomycetales, such as Mycobacterium, Nocardia and Rhodococcus. They induce granuloma formation in the lung and interstitial pneumonitis, associated with production of macrophage-derived cytokines. We studied how cord factors induce biological activities in the cells. Cord factors isolated from M. tuberculosis, trehalose 6-monomycolate (mTMM) and trehalose 6,6'-dimycolate (mTDM), enhanced protein kinase C (PKC) activation in the presence of phosphatidylserine (PtdSer), diacylglycerol and Ca2+, and mTMM activated PKC alpha more strongly than PKC beta or gamma under the same assay conditions. Kinetic studies of mTMM in response to PKC activation revealed that mTMM increased the apparent affinity of PKC to Ca2+ in the presence of both PtdSer and diolein. Although this is similar to observations with unsaturated fatty acids, such as arachidonic acid, mTMM was synergistic with PtdSer for PKC activation, but arachidonic acid was not. mTMM was also different as regards PKC activation, as phorbol ester was. A single i.p. administration of mTMM to mouse induced tumor necrosis factor-alpha (TNF-alpha) in serum and in the lung, which is a unique target tissue of cord factors. Based on our recent finding that TNF-alpha is an endogenous tumor promoter, the correlation between lung cancer and pulmonary tuberculosis is discussed.

A new method for detecting beta 1,4-galactosyltransferase activity in sera of cancer patients

A new method for assaying the activity of the enzyme that catalyzes the formation of a cancer-associated glycolipid, paragloboside (nLc4Cer), from lactotriaosylceramide (Lc3Cer) and UDP-galactose has been developed that is based on a time-resolved fluoroimmunoassay (TRFIA) with a Europium (Eu)-chelate-labeled antibody. The substrate, Lc3Cer, immobilized on a microtiter plate, was incubated with UDP-galactose, MnCl2, Triton CF-54, and the enzyme. The content of the incubation product, nLc4Cer, was determined by the TRFIA with anti-nLc4Cer monoclonal antibody H-11 as the first antibody and Eu-labeled anti-mouse IgM antibody as the second one. The lower limit of detection of nLc4Cer was estimated to be 0.2 pmol. This method was used to detect the galactosyltransferase activity in sera from patients with colorectal cancer or benign colorectal adenomas and from healthy subjects of a reference sample group. The reference interval was 0-0.25 pmol/25 microliters serum/2 h. Activity was significantly greater in patients with colorectal cancer than in those with colorectal benign adenoma (P < 0.05) and the subjects of the reference sample group (P < 0.01).

Analysis of grating lens aberration

A method that approximates a diffraction formula to the Fourier integral formula by the application of a coordinate transformation is proposed, and it is proved to be a superior and more accurate approximation when it is applied to focusing systems under a nonsine condition. Based on this approximation, the condition that gives the diffraction focus position is derived by the application of two methods. The first is applicable to rotationally symmetrical aberrations such as spherical aberration, and the second is a more general method that utilizes the standard deviation of a wave aberration. These methods are actually applied to a grating lens as a way to study both chromatic aberration characteristics and oblique incidence characteristics.

Optical head employing a concentric-circular focusing grating coupler

An optical head employing a concentric-circular grating coupler (CGC) and a concentric-circular focusing grating coupler (CFGC) is proposed, and its operating principle and characteristics are reported. Satisfaction with a prerequisite for the head, i.e., the removal of aberrations caused by deviations in wavelength and the effective index, is theoretically achieved by application of the concept of optimization of an annular aperture. With CGC and CFGC fabricated by an electron-beam-writing method, we experimentally confirmed its fundamental characteristics of light input, waveguiding, output, and convergence, with an elliptical focusing spot converging at half-intensity widths of 1.8 and 4.0µm.

Inhibitory effects of (-)-epigallocatechin gallate on spontaneous hepatoma in C3H/HeNCrj mice and human hepatoma-derived PLC/PRF/5 cells

The inhibitory effect of (-)-epigallocatechin gallate (EGCG), a main constituent of Japanese green tea, on spontaneous hepatoma in C3H/HeNCrj mice was investigated. A total of 72 mice were divided into three groups; the control group without EGCG, and two experimental groups receiving 0.05% (w/w) or 0.1% EGCG in drinking water. EGCG reduced the incidence of hepatoma-bearing mice from 83.3% (control) to 56.0% (0.05% EGCG) and 52.2% (0.1% EGCG), and also reduced the average number of hepatomas per mouse from 1.83 (control) to 0.72 (0.05% EGCG) and 0.91 (0.1% EGCG) at week 65. Ridit analysis of the distribution of the number of hepatomas in each group revealed that EGCG significantly increased the rate of mice without hepatoma in the two EGCG groups as compared to the control. EGCG did not affect body weight gain, food consumption or any serum biochemical parameter. EGCG inhibited the growth and secretion of alpha-fetoprotein by human hepatoma-derived PLC/PRF/5 cells without decreasing their viability. These results indicate that EGCG may be a practical, nontoxic preventive agent against human hepatoma.

Structurally different members of the okadaic acid class selectively inhibit protein serine/threonine but not tyrosine phosphatase activity

The relative potencies of four main types of okadaic acid class compounds as inhibitors of the catalytic subunits of protein serine/threonine phosphatases 1 and 2A and the protein tyrosine phosphatase 1 were determined. These four types of compounds are okadaic acid, calyculin A, microcystin-LR, and tautomycin, which are isolated from different natural sources, a black sponge Halichondria okadai, a marine sponge Discodermia calyx, a blue-green alga Microcystis aeruginosa, and Streptomyces spirover ticillatus, respectively. While okadaic acid was a more effective inhibitor of protein phosphatase 2A (IC50, 0.07 nM) than protein phosphatase 1 (IC50, 3.4 nM), other compounds of the okadaic acid class were equally effective against the two protein serine/threonine phosphatases. The order of potency was microcystin greater than calyculin A greater than tautomycin, and the IC50S ranged from 0.1 to 0.7 nM. None of the okadaic acid class compounds inhibited protein tyrosine phosphatase 1 activity at concentrations up to 0.01 mM. These results indicate that the compounds of the okadaic acid class are selective inhibitors of protein serine/threonine but not tyrosine phosphatases.

Anticarcinogenic effects of (-)-epigallocatechin gallate

BACKGROUND

Our research objective is to develop nontoxic cancer chemopreventive agents and to apply these agents in treating humans. We are identifying agents that inhibit the process of tumor promotion in two-stage carcinogenesis experiments on mouse skin.

METHODS

We review (a) the inhibitory effect of penta-O-galloyl-beta-D-glucose (5GG) on tumor promotion by teleocidin, one of the 12-O-tetradecanoylphorbol-13-acetate (TPA)-type tumor promoters (5GG is structurally similar to (-)-epigallocatechin gallate (EGCG) and is isolated from hydrolyzed tannic acid); (b) the inhibitory effects of EGCG, the main constituent of Japanese green tea, on tumor promotion with two tumor promoters, teleocidin and okadaic acid, a non-TPA-type tumor promoter; (c) the mechanisms of action of EGCG, a single application of which reduced the specific binding of [3H]TPA and [3H]okadaic acid to a particulate fraction of mouse skin; and (d) the anticarcinogenic effects of EGCG on duodenal carcinogenesis induced by N-ethyl-N'-nitro-N-nitrosoguanidine in male C57BL/6 mice. EGCG is a nontoxic compound.

CONCLUSION

We believe that the main constituent of Japanese green tea, EGCG, is a practical cancer chemopreventive agent available in everyday life.

Liver tumor promotion by the cyanobacterial cyclic peptide toxin microcystin-LR

Certain waterblooms of toxic cyanobacteria (blue-green algae) are a health threat because of their production of toxic peptides, termed microcystins, which cause liver damage in wild and domesticated animals. The most widely studied microcystin is microcystin-LR, a heptapeptide containing the two L-amino acids, leucine and arginine. The inhibition of protein phosphatase type 1 and type 2A activities by microcystin-LR is similar to that of the known protein phosphatase inhibitor and tumor promoter okadaic acid. We show in this report that microcystin-LR, applied below the acute toxicity level, dose-dependently increases the number and percentage area of positive foci for the placental form of glutathione S-transferase in rat liver, which was initiated with diethylnitrosamine. The result was obtained independently through two animal experiments. This observation indicates that microcystin-LR is a new liver tumor promoter mediated through inhibition of protein phosphatase type 1 and type 2A activities. This provides further evidence that the okadaic acid pathway is a general mechanism of tumor promotion in various organs, such as mouse skin, rat glandular stomach and rat liver.

Elevation of 4 beta-galactosyltransferase activity for paragloboside synthesis in sera of patients with cancer

Galactosyltransferase activities in sera of cancer patients were determined by assaying the formation of paragloboside from UDP-galactose and lactotriaosylceramide immobilized on microtiter plates by means of the enzyme-linked immunosorbent assay using a monoclonal antibody, H-11, directed to paragloboside. Enzyme properties were as follows. Optimum pH was 6.8 in cacodylate buffer, and Km values were 2 microM for lactotriaosylceramide and 29 microM for UDP-galactose. The enzyme activity was inhibited by the addition of alpha-lactalbumin. Glucose (20 mM) inhibited the enzyme activity in the presence of alpha-lactalbumin (0.1 mg/ml) but not in its absence. These enzyme properties are similar to those of bovine milk galactosyltransferase, indicating that the enzyme in the sera might be lactose synthetase. The enzyme activities in sera from patients with cancer, patients with benign disease, or a reference sample group were assayed. The activity was below the limit of detection (5.5 pmol/25 microliters serum/2 h) in the reference sample group. Remarkable elevations of the enzyme activity were observed with high incidence in patients with cancer, especially those with blood cancer (100%). A high incidence was observed in the progressive stage, and the enzyme activity was detected at stage 1 in lung, esophagus, stomach, colorectal, and testis cancer. The enzyme activity in sera from patients with benign disease was elevated in 22% of the patients. After effective therapies, the enzyme activity decreased to below the limit of detection. Release of the galactosyltransferase into culture medium of cancer cells could be demonstrated. These observations suggest that the galactosyltransferase is released from cancer tissue into the circulation. The present method for the assay of galactosyltransferase may be useful for the detection of patients with cancer and for monitoring neoplastic recurrence after therapy.

Increased phosphorylation of nuclear phosphoproteins in human lung-cancer cells resistant to cis-diamminedichloroplatinum (II)

A novel non-phorbol-ester-like tumor promoter, okadaic acid (OA) has been shown to be an inhibitor of protein phosphatase I and IIA and, thus, to cause an "apparent activation" of protein kinase C (PKC). We previously showed that cis-diamminedichloroplatinum(II) (CDDP)-resistant cells, PC-9/CDDP, were cross-resistant to OA and that the cross-resistance was not due to the increased efflux of OA. We hypothesized that the phosphorylation status of some cellular proteins might be important in CDDP-resistance. No significant difference in PKC activity or total protein phosphatase activity measured in vitro was seen between PC-9 and PC-9/CDDP cells, nor in their sensitivity to inhibition by OA, nor in the amount of phosphorylation of whole cells or TCA-insoluble material. By SDS-PAGE after incubation of intact cells with 32P, we detected a marked increase, compared to PC-9 cells, in phosphorylation of the nuclear proteins of MW 32 and 20 kDa in CDDP-resistant PC-9/CDDP cells with no apparent difference in protein content. When phosphorylation of nuclear proteins observed in PC-9/CDDP cells was analyzed by 2-dimensional SDS-PAGE, the 32-kDa protein had a PI of about 4.5. The 32-kDa and 20-kDa bands were increased in a dose-dependent manner by CDDP treatment. On the other hand, no increase in phosphorylation of these proteins was observed in parental PC-9 cells. These results demonstrate a marked difference in the phosphorylation status of specific nuclear proteins between parental and CDDP-resistant cell lines, which may be related to CDDP-resistance.

Marine natural products against tumor development

This review article deals with significant effects of marine natural products in carcinogenesis, namely as chemical probes to understand the process of carcinogenesis and as possible cancer preventive agents in humans.

Purification and partial characterization of rat epididymal retinoic acid-binding protein, and its immunohistochemical localization

Two types of retinoic acid-binding proteins, designated as epididymal retinoic acid-binding protein (ERABP) types A and B, have been purified to homogeneity from rat genital organs. ERABP types A and B had molecular weights of 19,000 and 18,500 and isoelectric points of 5.72 and 5.90, respectively. The absorption spectrum of ERABP complex with retinoic acid had two peaks at 277 and 354 nm, and showed similar uncorrected fluorescence spectra to that of cellular retinoic acid-binding protein (CRABP). These ERABPs were identified as major androgen-dependent epididymal proteins by amino acid sequences analyses. Furthermore, immunohistochemical examinations revealed that the ERABPs exist in the epithelium of the proximal portion of the epididymis and in the lumen of epididymal canal and seminal tract leading from the epididymis. The existence of ERABP strongly suggests that retinoic acid might be involved in the maturation of spermatozoa.

Structure-function relationships of microcystins, liver tumor promoters, in interaction with protein phosphatase

Microcystins, isolated from toxic blue-green algae, are potent inhibitors of protein phosphatases 1 and 2A. Recently, we have reported that microcystin LR has a potent tumor-promoting activity on rat liver initiated with diethylnitrosamine. The structure of microcystins is unique in having an unusual amino acid, 3-amino-9-methoxy-10-phenyl-2,6,8-trimethyl-deca-4(E),6(E)-dienoic acid (Adda), which is thought to be significant for the activity. Geometrical isomers at C-7 in the Adda portion of microcystins, 6(Z)-Adda microcystins LR and RR, have been isolated from cyanobacteria. To estimate their tumor-promoting activities and to understand the importance of the Adda portion for activity, the maternal microcystins LR and RR and their isomers were subjected to examination of their interaction with protein phosphatases 1 and 2A and the release of glutamic pyruvic transaminase from rat liver. 6(Z)-Adda microcystins LR and RR bound to protein phosphatases 1 and 2A, inhibited their activities and released glutamic pyruvic transaminase from rat liver into serum, ten to one hundred times more weakly than the maternal microcystins LR and RR. These results indicated that the conjugated diene with 4(E),6(E) geometry in the Adda portion is important in the interaction with protein phosphatases.

Pendolmycin, a new tumor promoter of the teleocidin A class on skin of CD-1 mice

Pendolmycin, isolated from Nocardiopsis, is a compound structurally similar to teleocidin A, one of the 12-O-tetradecanoylphorbol-13-acetate (TPA)-type tumor promoters. Pendolmycin has a C5 dimethyl allyl group attached to C-7 of (-)-indolactam-V, whereas teleocidin A has a C10 linalyl group attached to the molecule. The structure-activity relationships of a hydrophobic moiety attached to (-)-indolactam-V were studied in four compounds, (-)-indolactam-V, pendolmycin, teleocidin A and newly synthesized 7-(nerolidyl)-(-)-indolactam-V in tests on inhibition of the specific [3H]TPA binding to a particulate fraction of mouse skin, activation of protein kinase C and induction of both adhesion of HL-60 cells and ornithine decarboxylase in mouse skin. The potencies of the compounds for these activities increased mainly depending on the length of the hydrophobic group. Pendolmycin had a tumor-promoting activity on mouse skin initiated with a single application of 7,12-dimethyl-benz[a]anthracene, and its potency was just between those of (-)-indolactam-V and teleocidin A. The role of the hydrophobic moiety is discussed with particular emphasis on the results obtained with 7-(nerolidyl)-(-)-indolactam-V.

Differential effects of cryptoporic acids D and E, inhibitors of superoxide anion radical release, on tumor promotion of okadaic acid in mouse skin

Cryptoporic acids D and E, isolated from the fungus Cryptoporus volvatus, are inhibitors of superoxide anion radical release. Cryptoporic acid E inhibited tumor promotion of okadaic acid in two-stage carcinogenesis experiments on mouse skin, initiated with 7,12-dimethylbenz[a]anthracene. Treatment with cryptoporic acid E using two different doses per application, 1 (1.2 mumol) and 5 mg (5.9 mumol), reduced the percentage of tumor-bearing mice from 73.3 to 53.3% and 20.0%, and the average number of tumors per mouse from 4.2 to 2.3 and 0.5 respectively in week 20 of tumor promotion. However, cryptoporic acid D slightly enhanced tumor promotion rather than inhibition of okadaic acid. Cryptoporic acid D was expected to have additional biochemical activities, such as activation of protein kinases. Cryptoporic acid D at concentrations of up to 100 microM activated protein kinase C and stimulated other protein kinase activity in vitro, whereas cryptoporic acid E did not. These two compounds provided differential effects on tumor promotion of okadaic acid on mouse skin.