B. infantis EVC001 Is Well-Tolerated and Improves Human Milk Oligosaccharide Utilization in Preterm Infants in the Neonatal Intensive Care Unit

Not all infants carry specialized gut microbes, meaning they cannot digest human milk oligosaccharides and therefore do not receive complete benefits from human milk. B. infantis EVC001 is equipped to convert the full array of complex oligosaccharides into compounds usable by the infant, making it an ideal candidate to stabilize gut function and improve nutrition in preterm infants. A prospective, open-label study design was used to evaluate the tolerability of B. infantis EVC001 and its effects on the fecal microbiota in preterm infants in a Neonatal Intensive Care Unit. Thirty preterm infants <1,500 g and/or <33 weeks gestation at birth were divided into two matched groups, and control infants were enrolled and discharged prior to enrolling EVC001 infants to prevent cross-colonization of B. infantis: (1) fifteen control infants received no EVC001, and (2) fifteen infants received once-daily feedings of B. infantis EVC001 (8.0 x 10⁹ CFU) in MCT oil. Clinical information regarding medications, growth, nutrition, gastrointestinal events, diagnoses, and procedures was collected throughout admission. Infant stool samples were collected at baseline, Study Days 14 and 28, and 34-, 36-, and 38-weeks of gestation. Taxonomic composition of the fecal microbiota, functional microbiota analysis, B. infantis, and human milk oligosaccharides (HMOs) in the stool were determined or quantified using 16S rRNA gene sequencing, metagenomic sequencing, qPCR, and mass spectrometry, respectively. No adverse events or tolerability issues related to EVC001 were reported. Control infants had no detectable levels of B. infantis. EVC001 infants achieved high levels of B. infantis (mean = 9.7 Log10 CFU/μg fecal DNA) by Study Day 14, correlating with less fecal HMOs (ρ = -0.83, P < 0.0001), indicating better HMO utilization in the gut. In this study, B. infantis EVC001 was shown to be safe, well-tolerated, and efficient in colonizing the preterm infant gut and able to increase the abundance of bifidobacteria capable of metabolizing HMOs, resulting in significantly improved utilization of human milk. Clinical Trial Registration: https://clinicaltrials.gov/ct2/show/NCT03939546, identifier: NCT03939546.

Relationship between episodes of unsustained VTs detected early after an ICD implant and subsequent monomorphic VTs causing appropriate therapy

Introduction

Non-sustained ventricular tachycardias (NSVT) are observed frequently among ICD patients with left ventricular dysfunction (LVD).

Purpose

To analyze the relationship between episodes of NSVTs and monomorphic VTs (MVTs) that subsequently cause appropriate therapies.

Methods

416 ICD patients with LVD (LVEF &lt;45%) followed for 41±27 months. ICD programming (detection and therapies) was standardized. NSVT was defined as any VT of ≥5 beats which did not met the detection criteria occurring within the first 6 months after ICD implant. We analyzed 2201 NSVTs (10+7 beats), which occurred in 250 of the 416 patients (Median=2; IQR=0–7). The mean cycle length (CL) of NSVT was 323±32 ms (adjusted per multiple episodes/patient, generalized estimating equation method (GEEM)).

Results

During the follow-up, 1441 MVT occurred in 183 patients. After showing a significant correlation between burden of NSVT and the occurrence of appropriate therapies due to MVT (C coefficient=0.68; p&lt;0.001), we observed that subjects with &gt;5 NSVT presented an excess of adjusted risk: HR=1.97 (95% CI=1.45–2.72); p&lt;0.001. However, the adjusted mean CL of NSVTs was similar in patients with (322±34) vs. without MVT (324±26 ms); p=0.3.

Among patients who presented NSVTs and MVTs (n=145 subjects), we analyzed the relationship between the adjusted mean CL of the NSVTs (n=1288 episodes) and the CL of the first appropriate therapy due to MVT occurring subsequently. We found a significant and positive correlation between the two (r=0.88; p&lt;0.001); the strongest correlation was observed in subjects with &gt;5 NSVTs (r=0.97, n=52)). The robustness of such correlation was similar in individuals with ischemic (r=0.86; n=91) versus non-ischemic cardiomyopathy (r=0.90; n=54), and in primary (r=0.86; n=75) versus secondary prevention (r=0.90; n=70). The agreement between the CL of first MVT and the adjusted mean CL of NSVT episodes (GEEM) was determined according to the Bland-Altman Method. The difference between the two values was 2±8.3 ms, with only 7.6% (11/145) of patients in whom the difference between the two CL was outside the concordance limits. The agreement was greater, again, in individuals with &gt;5 NSVTs. As shown in the Figure, in more than 95% of patients both values were within the interval of agreement (0.32±4 ms).

Conclusions

1-The burden of NSVTs occurring early after an ICD implant, but not their CL, is associated with a higher incidence of appropriate therapies due to MVT at follow-up.

2-The CL of the NSVTs and that of the first and subsequent MVTs is virtually the same in patients with higher NSVT burden. Therefore, it could be the same tachycardia, but with different duration.

Figure 1

Funding Acknowledgement

Type of funding source: None

An incoherent HIFU transducer for treatment of the medial branch nerve: Numerical study and in vivo validation

BACKGROUND

Chronic back pain due to facet related degenerative changes affects 4-6 million patients a year in the United States. Patients refractory to conservative therapy may warrant targeted injections of steroids into the joint or percutaneous medial branch nerve denervation with radiofrequency ablation. We numerically tested a novel noninvasive high intensity focused ultrasound transducer to optimize nerve ablation near a bone-soft tissue interface.

METHODS

A transducer with 4 elements operating in an incoherent mode was modeled numerically and tested pre-clinically under fluoroscopic guidance. After 6 lumbar medial branch nerve ablations were performed in 2 pigs, they were followed clinically for 1 week and then sacrificed for pathological evaluation.

RESULTS

Simulations show that the acoustic spot size in water at 6 dB was 14mm axial x 1.6mm lateral and 52mm axial x 1.6mm lateral for coherent and incoherent modes, respectively. We measured the size of N = 6 lesions induced in vivo in a pig model and compared them to the size of the simulated thermal dose. The best match between the simulated and measured lesion size was found with a maximum absorption coefficient in the cortical bone adjusted to 30 dB/cm/MHz. This absorption was used to simulate clinical scenarios in humans to generate lesions with no potential side effects at 1000 and 1500 J.

CONCLUSION

The elongated spot obtained with the incoherent mode facilitates the targeting during fluoroscopic-guided medial branch nerve ablation.

Depreciación del caballo Pura Raza Española con la deformación del borde dorsal del cuello

Se plantea como objetivo estimar la depreciación de un caballo Pura Raza Española con la deformación del borde dorsal del cuello. Se estudió a una población de 500 caballos de Pura Raza Española clasificados en 4 edades: Potros (6 meses-4 años), en doma 4-8 años, adultos 8-12 años y maduros (12-20 años), pertenecientes a 65 propietarios, 10 centros de cría Pura Raza Española y un matadero en Andalucía y Extremadura, España. Se realizó la estimación de la depreciación para un año una vez detectada la deformación del borde dorsal de cuello, de manera separada por 3 grupos etarios: caballos en doma 4-8 años, caballos adultos 8-12 años y caballos maduros (12-20 años), mediante tres métodos, el método de línea recta, el método de la reducción de saldo (5%) y el método de la suma de los dígitos de los años. En relación a la depreciación del caballo de Pura Raza Española con deformación del borde dorsal del cuello, estimada para un año, es bastante alta y proporcional al costo del caballo. En conclusión, la depreciación del caballo de Pura Raza Española con la deformación del borde dorsal del cuello, se puede presentar en promedio a partir de los 6 años de edad (aproximadamente entre 4-8 años), la depreciación calculada por los tres métodos línea recta, reducción del saldo al 5% y suma de los dígitos fue similar, solo presento variación por el grupo etario 4-8 años 95%, 8-12 años 99% y 12-20 años 98% de depreciación respetivamente.

P2879Effectiveness of first versus subsequentes ATP attemps: predictors and clinical consequences

Introduction

Antitachycardia pacing (ATP) terminates the majority (but not all) of slow VTs (S-VT) with a cycle length (CL) >320 ms.

Purpose

To analyze the efficacy, safety and predictors of ATP, comparing the first (ATP-1) to the second (ATP-2) and third (ATP-3) attempts.

Methods

We studied 556 S-VT (CL=354±18 ms; range: 321–415 ms; 1.6% syncopes) occurring in 67 patients. ATP programming was standardized, including three consecutive bursts of 15 pulses at 91% of VT CL.

Results

ATP effectiveness declined significantly from ATP-1 (436/556: 78%) compared to ATP-2 (24/103: 23%) and ATP-3 (10/79: 13%), p<0.01 for all comparisons. The percentage of variation of RR intervals (P-RR, %) was significantly higher prior to effective ATP-1 (2.73±1.45 vs 1.23±0.9; p<0.001). After an ineffective ATP-1, the P-RR decreased dramatically, with no differences between episodes terminated or not at ATP-2 (0.6±0.14 vs 0.44±0.16; p=0.6) or ATP-3 (0.54±0.15 vs. 0.52±0.14; p=0.7). The postpacing interval – CL difference (PPI-CLd) after an unsuccessful ATP-1 was shorter in episodes terminating at ATP-2 or ATP-3 (180±24 vs 211±15 ms; p<0.001) being 200 ms the cut-off point with the best sensitivity and specificity for non-effective ATP-2 and ATP-3 (93% and 74%, respectively). By multivariate analysis, the duration of native QRS complex (dQRS) (ms) was found the only independent predictor of a PPI-CLd ≥200 ms (OR=1.04; p=0.003). The best cutoff point of dQRS for PP-CLd ≥200 ms was 120 ms (sensitivity and specificity of 66% and 79%, respectively).

Several predictors of ATP efficacy were found by logistic regression: a) ATP-1: P-RR (OR=7.3; p<0.001), beta-blockers (OR=4.1; p<0.001) and dQRS (OR=0.95; p<0.001); b) ATP-2: PPI-CLd (OR=0.94; p=0.001) and dQRS (OR=0.96; p=0.04); c) ATP-3: PPI-CLd (OR=0.93; p=0.009).

Patients with a dQRS≥120 ms had a lower adjusted effectiveness of ATP and a higher proportion of S-VT causing syncope. Table.

Table 1 Patients with QRS <120 ms Patients with QRS ≥120 ms p value Adjusted effectiveness of ATP-1 89% (82–96) 70% (59–80) 0.008 Adjusted effectiveness of ATP-2 47% (32–63) 23% (11–35) 0.036 Adjusted effectiveness of ATP-3 18% (3–33) 3% (0–6) 0.003 Adjusted incidence of syncope due to S-VT 0.18% (0–0.6) 4.1% (2.1–6.1) 0.025 Values are expressed as mean (95% CI). Generalized Estimating Equations Method.

Conclusions

The efficacy of ATP in terminating S-VT is mainly due to the ATP-1. The regularization of RR intervals after ineffective ATP-1 underlies the lower efficacy of ATP-2 and ATP-3. Since the dQRS correlated significantly with the PPI-CLd, patients with a dQRS≥120 ms had a lower ATP-1, ATP-2 and ATP-3 effectiveness, leading to a higher incidence of syncope.

Biochemical changes in knee articular cartilage of novice half-marathon runners

Objective

To evaluate changes in knee articular cartilage of novice half-marathon runners using magnetic resonance imaging T2 relaxation time mapping.

Methods

Healthy subjects were recruited from local running clubs who met the following inclusion criteria: (i) age 18–45 years; (ii) body mass index less than 30 kg/m²; (iii) had participated in one half-marathon or less (none within the previous 6 months); (iv) run less than 20 km/week; (v) no previous knee injury or surgery; (vi) no knee pain. T2 signals were measured pre- and post-race to evaluate the biochemical changes in articular cartilage after the subjects run a half-marathon.

Results

A significant increase in the mean ± SD T2 relaxation time was seen in the outer region of the medial tibial plateau (50.1 ± 2.4 versus 54.7 ± 2.6) and there was a significant decrease in T2 relaxation time in the lateral femoral condyle central region (50.2 ± 4.5 versus 45.4 ± 2.9). There were no significant changes in the patella, medial femoral condyle and lateral tibia articular surfaces.

Conclusion

An increase in T2 relaxation time occurs in the medial tibial plateau of novice half-marathon runners. This limited region of increased T2 values, when compared with complete medial compartment involvement seen in studies of marathon runners, may represent an association between distance run and changes seen in articular cartilage T2 values.

3325Incidence, outcomes and microbiology in patients with infective endocarditis

Introduction

Despite recent improvements in management, infective endocarditis remains associated with high morbidity and mortality. Over the last few decades, several factors have impacted on both the incidence and outcomes following infective endocarditis.

Purpose

Using a national linkage approach, we describe the changing age- and sex-stratified incidence and outcomes of infective endocarditis in Scotland over the last 25 years.

Methods

We conducted a consecutive retrospective individual patient linkage study across multiple national databases. Using data extracted from the Scottish hospital discharge dataset held by the Information Services Division of NHS National Services Scotland, we extracted episodes for all patients aged 20 years or older who were admitted with infective endocarditis between January 1, 1990, and December 31, 2014 in Scotland, UK. Patient episodes with infective endocarditis were linked to national prescribing and microbiology databases. The primary outcome was 1-year mortality following the index presentation. Generalised additive models were constructed to estimate the crude and age- and sex-stratified incidence rates (using a poison distribution) as well as trends in mortality (using a binomial distribution) adjusted for age, sex and comorbidity.

Results

Across 12,446 individual patients, there were a total of 12,667 hospitalisations (mean age 68±17 years, 55% females) with infective endocarditis using a 5-year look back period. The estimated crude rate of hospitalisation increased from 7.38 per 100,000 (95% CI 6.58 to 8.28) in 1990 to 15.09 per 100,000 (95% CI 13.90 to 16.39) in 2014 (p<0.001). Over the period of the study, 31% (3,877/12,667) of people admitted to hospital with infective endocarditis died within one year of admission. Case fatality fell markedly in both men and women from 1990 to 2014 (Figure). Microbiology was status was available for 34% of all hospitalisations with staphylococcus cultures associated with worse outcomes.

Conclusions

Despite the crude incidence of infective endocarditis doubling over the last 25 years and case fatality remaining high, the risk of death has markedly fallen over the last two decades. Staphylococcus cultures remain an independent marker of poor prognosis in this cohort.

Acknowledgement/Funding

British Heart Foundation

Scale Thickness Predicts Skin Puncture-Force Resistance in Three Pleuronectiform Fishes

In fishes, the skin and scales provide a physical barrier to the external environment and must withstand direct physical insult from biotic and abiotic features of the habitat. Flatfishes likely rely heavily on their scales for physical defense because they rest directly on the substrate. Using a flatfish model, we asked: what are the effects of scale type and scale morphology on puncture force resistance? We also asked: are there morphological and functional differences between the eyed and blind sides in flatfishes and do the morphological and functional properties of scales vary with organism size? Using a large size range of three species of Pleuronectid flatfish (Isopsetta isolepis, n = 10; Parophrys vetulus, n = 10; and Platichthys stellatus, n = 12), we measured the force required to puncture the integument using a sample of skin+scales taken from the eyed and blind side of each individual. We also measured the diameter, area, and thickness of the scales of each individual. Scaling relationships (body length vs. variable of interest) were derived for each species and compared with a priori expectations of geometric similarity. We found no relationship between scale type and puncture resistance and no differences in morphological parameters or puncture resistance between the eyed and blind side within a given species. These flatfish species do vary in their ability to withstand puncture forces; however, once scale thickness is taken into account, species differences disappear. Thus, the ability of a flatfish to withstand mechanical insult from puncture-forces varies depending on the thickness of the scale.

Tree root dynamics in montane and sub-alpine mixed forest patches

BACKGROUND AND AIMS

The structure of heterogeneous forests has consequences for their biophysical environment. Variations in the local climate significantly affect tree physiological processes. We hypothesize that forest structure also alters tree root elongation and longevity through temporal and spatial variations in soil temperature and water potential.

METHODS

We installed rhizotrons in paired vegetation communities of closed forest (tree islands) and open patches (canopy gaps), along a soil temperature gradient (elevations of 1400, 1700 and 2000 m) in a heterogeneous mixed forest. We measured the number of growing tree roots, elongation and mortality every month over 4 years.

KEY RESULTS

The results showed that the mean daily root elongation rate (RER) was not correlated with soil water potential but was significantly and positively correlated with soil temperature between 0 and 8 °C only. The RER peaked in spring, and a smaller peak was usually observed in the autumn. Root longevity was dependent on altitude and the season in which roots were initiated, and root diameter was a significant factor explaining much of the variability observed. The finest roots usually grew faster and had a higher risk of mortality in gaps than in closed forest. At 2000 m, the finest roots had a higher risk of mortality compared with the lower altitudes.

CONCLUSIONS

The RER was largely driven by soil temperature and was lower in cold soils. At the treeline, ephemeral fine roots were more numerous, probably in order to compensate for the shorter growing season. Differences in soil climate and root dynamics between gaps and closed forest were marked at 1400 and 1700 m, but not at 2000 m, where canopy cover was more sparse. Therefore, heterogeneous forest structure and situation play a significant role in determining root demography in temperate, montane forests, mostly through impacts on soil temperature.