The effect of a smaller spacer in the PASCAL Ace on residual mitral valve orifice area

BACKGROUND

Mitral transcatheter edge-to-edge repair (M-TEER) is an established treatment for functional mitral regurgitation (FMR) associated with a risk of creating iatrogenic stenosis.

OBJECTIVES

To investigate the impact of the P10 and its larger spacer compared to the narrower Ace and its smaller spacer on reduction of mitral valve orifice area (MVOA) during M-TEER.

METHODS

Consecutive patients undergoing M-TEER for treatment of severe FMR were screened retrospectively. Patients with a single PASCAL device implantation within the central segments of the MV leaflets, non-complex anatomy, and baseline MVOA ≥ 3.5cm2 were selected. Intraprocedural transesophageal echocardiography was used to compare MVOA reduction with 3D multiplanar reconstruction and direct planimetry. Device selection did not follow a prespecified MVOA threshold.

RESULTS

Seventy-two patients (81.0 years, IQR {74.3-85.0}) were included. In 32 patients, the P10 was implanted (44.4%). MR severity (p = 0.66), MR reduction (p = 0.73), and body surface area (p = 0.56) were comparable. Baseline MVOA tended to be smaller in P10 patients with the larger spacer (5.0 ± 1.1 vs. 5.4 ± 1.3cm2, p = 0.18), however, residual MVOA was larger in these patients (2.7 ± 0.7 vs. 2.3 ± 0.6cm2, p = 0.03). Accordingly, relative MVOA reduction was significantly less in P10 patients (- 45.9 ± 7.6 vs. - 56.3 ± 7.0%, p < 0.01). Indirect annuloplasty was more pronounced in Ace patients whereas mean transmitral gradients were similar.

CONCLUSION

In FMR patients with non-complex anatomy, the larger spacer of the P10 maintains greater MVOA with similar MR reduction. Hence, the use of the PASCAL Ace device in patients with small MVOAs might correlate with a risk of both clinically relevant orifice reduction and even iatrogenic stenosis.

Towards the optimization of drug delivery to the cochlear apex: Influence of polymer and drug selection in biodegradable intracochlear implants

There is growing need for new drug delivery systems for intracochlear application of drugs to effectively treat inner ear disorders. In this study, we describe the development and characterization of biodegradable, triamcinolone-loaded implants based on poly(lactic-co-glycolic acid) (PLGA) and polyethylene glycol-poly(lactic-co-glycolic acid) (PEG-PLGA) respectively, prepared by hot-melt extrusion. PEG 1500 was used as a plasticizer to improve flexibility and accelerate drug release. The sterilization process was performed by electron beam irradiation, resulting in minimal but acceptable polymer degradation for PEG-PLGA implants. The implants have been characterized by texture analysis, differential scanning calorimetry and X-ray powder diffraction. Compared to PLGA implants, PEG-PLGA implants offer similar flexibility but with improved mechanical stability, which will ease the handling and intracochlear application. A controlled release over three months was observed for dexamethasone and triamcinolone extrudates (drug load of 10%) with similar release profiles for both drugs. PEG-PLGA implants showed an initial slow release rate over several days regardless of the amount of PEG added. Mathematical simulations of the pharmacokinetics of the inner ear based on the in vitro release kinetics indicate a complete distribution of triamcinolone in the whole human scala tympani, which underlines the high potential of the developed formulation.

Severe tricuspid regurgitation worsens prognosis outcome after edge-to-edge mitral valve repair

Introduction

MitraClip has been well established for treatment of severe mitral regurgitation (MR). MR and tricuspid regurgitation (TR) often occur simultaneously and symptoms of biventricular heart failure can overlap. While it has been shown that TR grade regression can be achieved through repair of MR1, presence of moderate to severe TR can increase all-cause mortality after MitraClip2. There is currently no consensus on the management of combined MR and TR. We evaluated the impact of TR on echocardiographic and functional outcome after MitraClip.

Methods

370 patients underwent MitraClip for moderate to severe MR at our center from 2010 to 2018. Patients were dichotomized into low grade TR (grade &lt;I - I (trace - mild)) and high grade TR (grade III - V (severe - torrential)). Moderate TR (grade II) was excluded. After MitraClip for MR, patients were followed up for 12 months and their echocardiographic and functional outcome was evaluated. Use of diuretic drugs throughout 12 month follow-up was registered.

Results

Low grade TR (&lt;I - I) occurred in 225 patients (67.0%), high grade TR (III - V) was present in 111 patients (33.0%). 34 patients (9.2%) with moderate TR (II) were excluded. Patients with high grade TR had an increased morbidity (higher age, worse renal function, higher prevalence of atrial fibrillation, higher levels of natriuretic peptides, increased left atrial and right heart diameters, higher TR gradient). These patients also received significantly higher doses of torasemid (33.5±36.7 mg vs. 21.6±20.9 mg, p=0.003) and furosemid (163.4±155.5 mg vs. 75.8±72.3 mg, p=0.01). Average grade of MR at baseline was similar in both groups (2.9±0.46 vs. 2.8±0.5, p=0.66).

Procedural success of MR repair was achieved similarly in both groups (96.4% vs. 96.9%, p=0.82) and residual MR grade immediately after device implantation was comparable (p=0.61). However, recurrent MR in the high grade TR group increased during follow up, while MR further decreased in the low grade TR group (3 months: 1.24±0.7 vs. 1.16±0.7, p=0.5; 12 months: 1.46±0.93 vs. 1.12±0.61, p=0.04). Accordingly, use of diuretic drugs after 12 months rose in the high grade TR group while it did not change or even decreased in the low grade TR group (torasemid: 40.2±48.4 mg vs. 24.1±30.0 mg, p=0.04; furosemid: 197.5±251.0 mg vs. 67.1±81.8 mg, p=0.22).

Kaplan-Meier-Analysis showed significantly higher mortality (24.9 vs. 14.1%, p=0.01), higher risk for heart failure induced rehospitalisation (25,4 vs. 12,5%, p=0.005) and for major adverse cardiac and cerebrovascular events (MACCE: 42.3 vs. 29.1%, p=0.008) in the high grade TR group after 12 months.

Conclusion

MitraClip patients for MR with concomitant high grade TR (≥ III) had an increased morbidity at baseline compared to low grade TR patients. By MitraClip comparable reduction of MR was achieved. However, during 12 month follow-up in the high grade TR group recurrent MR occurred more often while use of diuretics increased.

Funding Acknowledgement

Type of funding sources: None.

Optimization of magneto-optical Kerr setup: analyzing experimental assemblies using Jones matrix formalism

We present a comparative study on an experimental and theoretical optimization of magneto-optical Kerr setups based on photoelastic modulation and phase sensitive detector methodology. The first and second harmonics, I omega,2 omega, of the reflected light intensity are measured for a CoO/Co magnetic reference film. The magnetic field dependence of the optical off-diagonal Fresnel reflection coefficients rps and rsp follows the sample magnetization. Different Kerr setups provide various dependencies of I omega,2 omega on the reflection coefficients and, hence, on the Kerr ellipticity epsilon K and rotation theta K. Jones matrix formalism has been used to analyze the impact of a systematic variation of relative analyzer and polarizer orientations with respect to each other and with respect to the retardation axis of the modulator involved in longitudinal Kerr setups for incoming s-polarized light. We find one particular setup which maximizes I(omega) as well as I2 omega and maximizes the signal-to-noise ratio. Inefficient setups are characterized by I omega,2 omega intensities involving large nonmagnetic contributions of rp and rs.

Chronic myelocytic leukemia in a juvenile rhesus macaque (Macaca mulatta)

Myeloid neoplasia has been studied extensively in human beings but has not been reported in macaques. A 2-year-old female rhesus macaque that was experimentally exposed to lead as a neonate, was noted to have immature circulating myelocytic cells, including 1% blasts, and normocytic normochromic anemia on a blood sample obtained for monthly health monitoring. The animal was treated with hydroxyurea, blood transfusion, and recombinant human erythropoietin to reduce the leukocytosis and correct the anemia. The disease had a relatively indolent course for 3 months, when it progressed to blast crisis. After the onset of blast crisis, the animal was euthanized because of bleeding problems, anemia, and a progressive decline in her health. The animal was negative by serology, polymerase chain reaction (PCR) assays, and/or culture for simian retrovirus (SRV), simian T-lymphotropic virus type I (STLV-I), and simian immunodeficiency virus (SIV). PCR assay for the bcr-ABL chromosomal translocation using primers made for the human gene was negative. Serology for Epstein-Barr virus (EBV)-like viruses was positive for IgG directed against the viral nucleocapsid antigen, but epidemiologic factors make it unlikely that the leukemia was associated with EBV-induced viral transformation. Lead exposure has been associated with neoplasia in human beings, and the possible role of neonatal lead exposure in hematologic neoplasias deserves further scrutiny.

The origin and loss of the ubiquitin activating enzyme gene on the mammalian Y chromosome

Mammalian sex chromosomes are thought to be descended from a homologous pair of autosomes: a testis-determining allele which defined the Y chromosome arose, recombination between the nascent X and Y chromosomes became restricted and the Y chromosome gradually lost its non-essential genetic functions. This model was originally inferred from the occurrence of few Y-linked genetic traits, pairing of the X and Y chromosomes during male meiosis and, more recently, the existence of X-Y homologous genes. The comparative analysis of such genes is a means by which the validity of this model can be evaluated. One well-studied example of an X-Y homologous gene is the ubiquitin activating enzyme gene ( UBE1 ), which is X-linked with a distinct Y-linked gene in many eutherian ('placental') and metatherian (marsupial) mammals. Nonetheless, no UBE1 homologue has yet been detected on the human Y chromosome. Here we describe a more extensive study of UBE1 homologues in primates and a prototherian mammal, the platypus. Our findings indicate that UBE1 lies within the X-Y pairing segment of the platypus but is absent from the human Y chromosome, having been lost from the Y chromosome during evolution of the primate lineage. Thus UBE1 illustrates the key steps of 'autosomal to X-specific' evolution of genes on the sex chromosomes.

Risk factors for endometriosis in the rhesus monkey (Macaca mulatta): a case-control study

The autopsy records between 1980 and 1995 of 399 female rhesus monkeys (Macaca mulatta) at the Wisconsin Regional Primate Research Center were examined. Spontaneous endometriosis was found in 81 (20%) of the animals. The mean (+/- SD) ages at death for animals with and without endometriosis were 20.7 +/- 5.5 (range 10-35) and 13.4 +/- 7.7 (range 4-37) years respectively. Many of the animals had been exposed to experimental procedures, including laparoscopies, hysterotomies and oestradiol implants, and these were examined as possible risk factors for endometriosis. Of the 81 affected animals, 62 were matched to unaffected controls for age at death (to within 1 year) and year of death (to within 2 years) and the effect of various factors on the development of endometriosis was determined using conditional logistic regression. Exposure to three or more oestradiol implants or one or more hysterotomies were both significant risk factors, with estimated relative risks of 9.7 (95% confidence interval 2.5-37.2) and 5.8 (95% confidence interval 1.6-20.2) respectively. Animals that had been exposed to one or more laparoscopies showed no increased risk for developing endometriosis. These findings provide insight into the aetiology of the disease in women. ?2P51 4RR00167

Serological and molecular evidence of rhesus papillomavirus type 1 infections in tissues from geographically distinct institutions

We have previously demonstrated the presence of rhesus monkey papillomavirus type 1 (RhPV-1), from molecular and pathological evidence, in a mating group within a single institution. We have now also obtained a number of fresh or archival tissues of rhesus monkeys from other geographically distinct institutions. Using PCR amplification, we observed two animals from one of these institutions and five animals from another which demonstrated RhPV-1 DNA sequences. In addition we molecularly cloned the E7, E2, E4, L2 and L1 genes of RhPV-1 into bacterial expression vectors. The fusion gene products were used to test for serological response to RhPV-1 antigens by Western blot analysis. Responses were observed in up to 52% of the animals tested. While some serologically positive animals were also RhPV-1 DNA-positive, most were not.

Mapping of the p56lck-mediated phosphorylation of GAP and analysis of its influence on p21ras-GTPase activity in vitro

The protein tyrosine kinase p56lck and other members of the src family can transduce signals from activated cell-surface receptors. As we showed earlier the GTPase-activating protein (GAP), a regulator of p21ras, is a substrate of p56lck. Here, tryptic peptides of p56lck-phosphorylated GAP were generated and analyzed by two-dimensional thin layer chromatography and mass spectroscopy. Results revealed that p56lck phosphorylates GAP specifically on Tyr-460 in vitro and in vivo. The effect of tyrosine phosphorylation of GAP on its GTPase-activating activity versus p21ras was then tested using a p21ras-dependent GTPase assay system. Our results demonstrate that p56lck-mediated tyrosine phosphorylation of GAP is not sufficient to change directly its effect on the intrinsic GTPase activity of p21ras.

Effect of radiation and age on immunoglobulin levels in rhesus monkeys (Macaca mulatta)

We report the results of a study on the immunoglobulin levels of rhesus monkeys (Macaca mulatta) in a colony consisting of the survivors of monkeys that received a single whole-body exposure to protons, electrons or X rays between 1964 and 1969. This colony has been maintained to assess the long-term effects of ionizing radiation on astronauts and high-flying pilots. Of the original 358 monkeys that were retained for lifetime studies, 129 (97 irradiated and 32 controls) were available for our study. We found no significant difference between the irradiated and control monkeys in mean levels of IgA, IgG and IgM, irrespective of the radiation treatment. The availability of these aged monkeys provided a unique opportunity to compare their immunoglobulin levels to those of other monkeys of various ages, and thus assess the effect of age on immunoglobulin levels. We found that only the IgA levels increase with age.

Linkage between two blood-group markers in rhesus monkeys (Macaca mulatta)

Using marker data on an extensive pedigreed population from the Wisconsin Regional Primate Research Center, we report the first genetic linkage in rhesus monkeys (Macaca mulatta). Five blood-group markers (G, I, J, K, and Q) and one serum protein marker (transferrin) were analyzed. Linkage analyses indicate the existence of loose linkage between G and Q (maximum lod score, Zmax = 4.84 at theta m = 0.314 +/- 0.38, theta f = 0.266 +/- 0.054). The genetic linkage described here constitutes the initial step toward the description of a genetic map in this species.

Genetic structure of three populations of rhesus macaques (Macaca mulatta): Implications for genetic management

One of the prime concerns at zoos and at primate breeding facilities is to maintain genetic variability. This can be accomplished by avoiding inbreeding. It is relatively easy to assess genetic variability and the level of inbreeding by using pedigree information and genetic markers. In this study we used genetic markers controlled by 6 independent polymorphic loci (GPI, PGD, CA2, MPI, DIA1, Tf) to ascertain genetic variation in two captive and one wild population of rhesus monkeys. Two other loci ADA and NP were also examined and found to be monomorphic in the three populations. F-statistics and contingency chi-square analyses indicated that there was significant genetic differentiation among the populations. We also found that the mean heterozygosities were very similar in the three populations, in spite of the diverse breeding strategies. These data are important because rhesus monkeys are frequently used for biomedical research; and the genetic markers provide useful information for genetic management of captive colonies of nonhuman primates. © 1992 Wiley-Liss, Inc.

[Spontaneous labor in the 38th week of pregnancy under intermittent hemodialysis treatment of the mother. Alloimmune thrombocytopenia of the newborn infant]

Uncomplicated pregnancies and spontaneous deliveries of term infants are rare if mothers are treated by haemodialysis because of terminal renal insufficiency. Pregnancies under these circumstances mostly end in abortion or stillbirth; live births are mostly delivered by Caesarean section. Independent of the mother's basic disease the infant of this case was born at 38 weeks spontaneously with a neonatal alloimmune thrombocytopenia, which is analogous to Rh-haemolytic disease of the newborn.