Integration of structural and functional data in VT ablation -- SENSE2 protocol mapping

Funding Acknowledgements

Type of funding sources: None.

Background

We have previously developed the sense protocol functional substrate mapping technique for VT ablation(1). However, functional substrate characterizaiton can involve protracted mapping time.

Purpose

We incorporated the integration of MRI data using ADAS-3D software into the mapping workflow, to integrate structural mapping information into the functional mapping substrate characterization, in order to improve procedural efficiency.

Methods

CMRs were performed in 20 patients with ischemic related VT and VT therapy in the previous 6 months. These were processed with the ADAS-3D software to characterize the extent of ventricular scars and also ADAS corridors which may correlate with VT channels. Focused substrate maps were then performed in patients, guided by the extent of ADAS scar and corridors, looking at the scar substrate in intrinsic rhythm and then functional channels using single extra pacing from the RV at 20ms above ERP (SENSE2 Protocol). Specifically healthy areas 2cm beyond the scar borderzone based on ADAS were not mapped, in order to reduce substrate mapping time and complete geometries were not created. Following delineation of functional channels pacemapping and entrainment mapping were used to confirm targets for ablation.

The ADAS 3D MRI was integrated into the into the VT substrate map on Ensite-Precision with alignment to the aorta, RV and PA (Figure 1). We compared our data with previous functional mapping data without the integration of MRI.

Results

20 patients (age 70 years; 19 male subjects) underwent ablation. Mean EF 28%. Median procedure time was 161 minutes compared with 246 minutes (in our previous study)(p=<0.001) Mean substrate mapping time was 32 mins vs 63 mins (p=<0.001). Mean ablation time was 22 mins vs 32 mins (p=0.11). 85% (17 of 20) patients were free from symptomatic VT/ anti-tachycardia pacing or implantable cardioverter defibrillator shocks at a median follow-up of 171 days. The mean VT burden was reduced from 22 events per patient in the 6 months’ pre-ablation to 1 event per patient in the median follow up period of 171 days post ablation (p=0.02). Mean shocks per-patient burden decreased from 3.5 to 0.08 in the same time period(p=0.03).

Conclusion

The SENSE2 protocol involves the integration of structural and functional data into the VT workflow for substrate characterization. It enables focused substrate maps to be performed without the need for complete geometry to be created in large ventricles. Outcomes compare favourably with our previous data but with significantly shorter procedure times. This streamlined workflow has the potential to improve care in VT ablation by shortening procedure times with similar outcomes which may reduce risks for the patient.

Figure 1: Comparison of Voltage Map with MRI scar & corridors using ADAS

[The proatherogenic effect of high salt diet combined with focal hypoperfusion on spontaneous hypertension rat]

Objective: To explore the histopathology, monocytes phenotypes and brain mRNA transcription of angiogenic and atherogenic factors preliminarily in spontaneous hypertensive rats (SHRs) fed with high salt diet and subjected to chronic focal hypoperfusion. Methods: A total of 21 SHRs were randomly assigned into SHR with normal diet (SHR-ND group, n=7), SHR fed with high salt (8%) chows (SHR-HSD group, n=14) groups. After induction of high salt diet for 20 weeks, unilateral carotid artery occlusion was applied to one half of SHR-HSD (SHR-HSD-UCAO, n=7) group for 10 weeks to mimic chronic focal cerebral hypoperfusion. The neuropathology, monocytes phenotypes and brain transcription of fibroblast growth factor (FGF-b), platelet-derived endothelial cell growth factor (PD-ECGF), angiogenin (ANG), transforming growth factor-β (TGF-β) and vascular endothelial growth factor A (VEGF-A) among three groups were compared. Results: The systolic blood pressure ((246±12) mmHg vs (220±16) mmHg, P=0.0291, 1 mmHg=0.133 kPa) and diastolic blood pressure ((189±15) mmHg vs (164±12) mmHg, P=0.0143) of SHR-HSD group were elevated significantly compared with those of SHR-ND group. Compared with normotensive Wistar-Kyoto (WKY), SHR-ND, SHR-HSD and SHR-HSD-UCAO groups demonstrated lipohyalinosis, vessel wall thickening, lumen narrowing and multiple enlarged perivascular space and diffuse disarrangement of nerve fiber and myelin vacuolation in corpus callosum pathologically. The ratio of CD11b(+) CD68(+) monocytes in peripheral blood of SHR-HSD group was higher compared with both SHR-ND and SHR-HSD-UCAO groups (P=0.000 8). The mean inflorescence index (MFI) of CD86 and CD206 showd considerable decline in SHR-HSD-UCAO group compared with those of SHR-HSD group (P=0.018 7 and 0.016 8, respectively). The CD86 MFI of CD11b+CD68+ monocytes in SHR-HSD-UCAO group was remarkably higher than that of SHR-ND and SHR-HSD groups (P=0.000 5). Compared with SHR-ND and SHR-HSD groups, the brain mRNA transcription of angiogenic factors including PD-ECGF and ANG were down-regulated (P=0.004 6 and 0.000 2, respectively), while the atherogenic factors including TGF-β and VEGF-A were up-regulated in SHR-HSD-UCAO group (P<0.000 1 and P=0.045, respectively). Conclusion: SHR-HSD-UCAO group shares the pathophysiological characteristics with advanced stage arteriosclerotic cerebral small vessel disease (aCSVD), including neuropathology, imbalanced circulating monocytes phenotypes and down-regulated angiogenic factors.

Use of peripheral blood genomic markers whose expression levels reflect that of breast tumor genomic markers to predict drug treatment and sensitivity

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Background: Tumor gene expression signatures have been used to predict drug response, and we have previously reported drug-induced signatures to be more informative than the untreated baseline signatures. However, repeated tumor sampling during treatment is not feasible for most patients. We studied peripheral mononuclear cell (PBMC) gene expression levels in association with tumor gene expression levels in an attempt to identify peripheral blood markers that may serve as more accessible surrogates to predict drug treatment and response. Methods: Chemonaive breast cancer patients were treated with an alternating sequential regimen of doxorubicin and docetaxel and randomized to start with either drug. RNA from primary tumor before and 3 weeks, and from PBMC before and 24 hours after the first cycle of each drug was hybridized on the Affymetrix HG-U133+2 array containing 54,675 probe sets. Results: Pre- and post-treatment tumors from 47 patients were studied, including 35 with paired PBMC samples. 230 pre- and 85 posttreatment PBMC probe sets showed strong correlation in expression level (Pearson correlation coefficient >0.9) with the corresponding pre- and posttreatment tumor probe set, and included genes involved in transcription regulation and binding. Of the 975 tumor probe sets whose changes distinguished doxorubicin from docetaxel treatment, 12 corresponding PBMC probe sets were identified (p < 0.001) whose changes at 24 hours distinguished the two treatments with 77% accuracy. Of the 1,081 and 1,526 tumor probe sets whose changes predicted treatment response to doxorubicin and docetaxel, 19 and 15 informative PBMC probe sets predicted response to each drug with 100% and 80% accuracy, and included TNF receptor associated protein 1 and trefoil factor 1 for doxorubicin-, and folliculin and dynein for docetaxel-response. When the PBMC probe sets were validated in an independent test set treated with docetaxel (n = 23), 87% was correctly classified as docetaxel-treated, while 89% of non-responders clustered together. Conclusions: Peripheral blood contains genomic markers whose expression levels closely reflect that of breast tumor markers, and may be promising as surrogates to predict drug treatment and sensitivity.

No significant financial relationships to disclose.

Roles for both the RAP30 and RAP74 subunits of transcription factor IIF in transcription initiation and elongation by RNA polymerase II

Mammalian transcription factor IIF (TFIIF) is a heterodimer composed of approximately 30-kDa (RAP30) and approximately 70-kDa (RAP74) subunits. TFIIF has been shown to bind RNA polymerase II and control the activity of the enzyme in both the initiation and elongation stages of transcription. Although previous studies have established a role for RAP30 in assembly of the preinitiation complex and in transcription initiation, information on the function of RAP74 in these processes has been lacking. Using a highly purified transcription system and assays that permit sensitive measurement of the contributions of both RAP30 and RAP74 to TFIIF function, we have investigated the roles of these TFIIF subunits in transcription initiation and elongation. Results of template competition experiments indicate that both RAP30 and RAP74 contribute to the formation of stable preinitiation intermediates containing RNA polymerase II. Investigation of the role of TFIIF in transcription initiation indicates that both RAP30 and RAP74 function in synthesis of the first few phosphodiester bonds of nascent transcripts and in formation of Sarkosyl-resistant pre-initiation intermediates. Finally, kinetic experiments indicate that both RAP30 and RAP74 function in TFIIF-mediated stimulation of the rate of RNA chain elongation by RNA polymerase II.

Methylation of p16 gene in hematological malignancies

OBJECTIVE

To investigate the incidence of p16 gene methylation in hematological malignancies, and the relations between p16 gene methylation and the prognosis of hematological malignancies.

METHODS

Fifty-five patients were studied by restriction enzyme polymerase chain reaction (PCR) to detect p16 gene methylation.

RESULTS

p16 gene methylation was detected in 6 of 55 patients (10.9%), who were 1 patient with M2a, 1 patient with M5a, 2 patients with chronic myelogenous leukemia (CML) in blast crisis, 1 patient with progressing multiple myeloma (MM), 1 with non-Hodgkin's lymphoma (NHL) accompanied by B-ALL, respectively. p16 gene methylation correlates with adverse prognostic features. The patients with p16 gene methylation had poor response to therapy, and died shortly after p16 gene methylation was detected.

CONCLUSION

The methylation of p16 gene plays an important role in the pathogenesis and the development of some hematological malignancies. The patients with p16 gene methylation have poor prognosis. The detection of p16 gene is a useful tool for evaluating prognosis of hematological malignancies.

Residual bone cysts after Ilizarov treatment of relapsed clubfeet

The Ilizarov technique is well established as an effective method of treating clubfoot deformities. A complication of this method is the development of cysts in the bones of the foot. The purpose of this study was to clarify the incidence, presentation, and etiology of these cysts. The radiographs of 17 feet that had undergone Ilizarov treatment for a clubfoot deformity were reviewed. In nine of the feet, discrete, well demarcated lucencies of bone were detected. They occurred in both tarsal and metatarsal bones, but most commonly in the base of the fifth metatarsal. Magnetic resonance imaging examination of two feet demonstrated a normal marrow signal. suggesting that the cysts are due to localized trabecular resorption with the space being filled with marrow fat.

186Re-etidronate. Efficacy of palliative radionuclide therapy for painful bone metastases

Pain palliation with bone-seeking radiopharmaceuticals is an effective treatment modality in patients with advanced metastatic bone cancer. Several studies have shown encouraging clinical results of palliative therapy using 186Re-HEDP, with an overall reported response rate of +/-71% for painful osseous metastasized prostate and breast cancer patients. 186Re-HEDP is a very potential isotope with numerous advantageous characteristics for this purpose. Myelosuppressive toxicity is limited and reversible, which makes repetitive treatment safe. However, individual studies are difficult to compare, and are hampered by the numerous and different methods used to assess clinical response. Standardized clinical response assessment using the objective multi-dimensional pain evaluation model should therefore be implemented.

Insulin resistance syndrome and polycystic ovary syndrome: implications for diagnosis and treatment

Both insulin resistance syndrome (IRS) and polycystic ovary syndrome (PCOS) are common endocrinopathies. IRS, usually associated with ages of 50+, type 2 diabetes mellitus (T2DM) and cardiovascular disease (CVD), is highly prevalent in young PCOS patients, exceeding the expected rate from their prevailing obesity. While it is clear that women with PCOS cluster risk factors, prospective studies to prove a higher morbidity and mortality from T2DM and CVD are not available. Nevertheless, apart from cosmetic concerns and gynecological problems, therapeutic intervention should also be designed to reduce the metabolic risk of PCOS, which may well be the main determinant of long-term health in affected women.

The impact of HLA match transfusions and presensitization on renal transplantation in the cyclosporine era

The successful engraftment of a renal transplant is dependent on multiple factors, immunological factors being of major importance. Specifically, histocompatibility, lymphocytotoxic antibodies and pretransplant blood transfusions have been shown to play a major role in determining graft outcome in renal transplant recipients receiving Azathioprine-Prednisolone immunosuppression. The impact of the immunosuppressive drug, Cyclosporine on graft outcome in relation to established risk factors were examined among 116 cadaveric and 34 living related renal allograft recipients from our center. Histoincompatibility and pretransplant blood transfusions did not significantly affect graft survival among cadaveric transplant recipients. Similarly, graft survival was not significantly different between two haplotype-matched and less well-matched living-related graft recipients (75% versus 96.5% respectively). On the other hand, lymphocytotoxic antibodies remained a major risk factor for immunologically mediated graft loss among cadaveric graft recipients (48.0% versus 92.2% four year graft survival among those with and without antibodies respectively). These results suggest that Cyclosporine has abrogated some immunological risk factors in renal transplantation.

Fluorescence light microscopy of F-actin in retinal rods and glial cells

The actin cytoskeleton of rod photoreceptors and glial cells in toad retina has been directly viewed using fluorescence microscopy of cells labeled with a potent phallotoxin that specifically binds to F-actin. The three-dimensional organization of this cytoskeletal protein consists of actin filaments, which course through the inner segment and end at the tips of the calycal processes surrounding the base of the outer segment. A transverse layer of actin staining is also observed at the base of rod outer segments in the region where new discs are formed. At the level of the external limiting membrane, evidence has been found for rings of actin within the glial cells that surround the photoreceptors. These actin rings form a structural meshwork in which photoreceptor cells are embedded.

[Effect of human recombinant gamma-interferon on proliferative activity of human laryngeal cancer cell lines]

The effect of human on PCNA expressions of HEP-2 lines was investigated using LSAB (Labelled streptacidin biotin method) with monoclonal antibody Ki-67 (anti-PCNA). The results showed that the PCNA expression which reflects the proliferative activity of cells was dependent on dose of rhu-IFN-gamma in HEP-2 cell lines. Thus, our data suggest that rhu-IFN-gamma might be useful in the treatment of laryngeal cancer because it provides effective cytostatic.