The effect of β-alanine and NaHCO3 co-ingestion on buffering capacity and exercise performance with high-intensity exercise in healthy males

Introduction

β-alanine (BAl) and NaHCO₃ (SB) ingestion may provide performance benefits by enhancing concentrations of their respective physiochemical buffer counterparts, muscle carnosine and blood bicarbonate, counteracting acidosis during intense exercise. This study examined the effect of BAl and SB co-supplementation as an ergogenic strategy during high-intensity exercise.

Methods

Eight healthy males ingested either BAl (4.8 g day^?1 for 4 weeks, increased to 6.4 g day^?1 for 2 weeks) or placebo (Pl) (CaCO₃) for 6 weeks, in a crossover design (6-week washout between supplements). After each chronic supplementation period participants performed two trials, each consisting of two intense exercise tests performed over consecutive days. Trials were separated by 1 week and consisted of a repeated sprint ability (RSA) test and cycling capacity test at 110 % Wmax (CCT_110 %). Placebo (Pl) or SB (300 mg kgbw^?1) was ingested prior to exercise in a crossover design to creating four supplement conditions (BAl-Pl, BAl-SB, Pl–Pl, Pl-SB).

Results

Carnosine increased in the gastrocnemius (n = 5) (p = 0.03) and soleus (n = 5) (p = 0.02) following BAl supplementation, and Pl-SB and BAl-SB ingestion elevated blood HCO₃ ^? concentrations (p < 0.01). Although buffering capacity was elevated following both BAl and SB ingestion, performance improvement was only observed with BAl-Pl and BAl-SB increasing time to exhaustion of the CCT_110 % test 14 and 16 %, respectively, compared to Pl–Pl (p < 0.01).

Conclusion

Supplementation of BAl and SB elevated buffering potential by increasing muscle carnosine and blood bicarbonate levels, respectively. BAl ingestion improved performance during the CCT_110 %, with no aggregating effect of SB supplementation (p > 0.05). Performance was not different between treatments during the RSA test.     

BCG-induced trained immunity in NK cells: Role for non-specific protection to infection

Adaptive features of innate immunity, also termed ‘trained immunity’, have recently been shown to characterize monocytes of BCG vaccinated healthy volunteers. Trained immunity leads to increased cytokine production in response to non-related pathogens via epigenetic reprogramming of monocytes. Recently, memory-like properties were also observed in NK cells during viral infections, but it is unknown if memory properties of NK cells contribute to trained immunity due to BCG vaccination.     

Lung function of preterm infants before and after viral infections

Our aim was to determine whether viral lower respiratory tract infections (LRTIs) adversely affect prematurely born infants’ lung function at follow up. Seventy infants, median gestational age 34 (range, 24–35)?weeks were prospectively followed; 32 had an RSV (n?=?14) or another respiratory viral (n?=?18) LRTI (viral LRTI group) and 38 had no LRTI (no LRTI group). Six of the viral LRTI and five of the no LRTI group had been hospitalised. Nasopharyngeal aspirates (NPAs) obtained whenever the infants had an LRTI. Lung function (functional residual capacity [FRC_He], compliance [Crs] and resistance [Rrs] of the respiratory system) was measured at 36 weeks postmenstrual age (PMA) and 1 year corrected. At 1 year, lung volume (FRCpleth) and airways resistance (Raw) were also assessed. There were no significant differences in the lung function of the two groups at 36 weeks PMA but at 1 year, the viral LRTI compared to the no LRTI group had a higher mean Raw (23 versus 17 cm H₂O/l/s, p?=?0.0068), the differences remained significant after adjustment. Conclusion: These results suggest viral LRTIs, regardless of whether hospitalisation is required, adversely affect prematurely born infants’ airway resistance at follow up.     

Bedside upper gastrointestinal series in critically ill low birth weight infants

Background

The upper gastrointestinal (UGI) series is the preferred method for the diagnosis of malrotation. A bedside UGI technique was developed at our institution for use in low birth weight, critically ill neonates to minimize the risks of transportation from the neonatal intensive care unit (NICU) such as hypothermia and dislodgement of support lines and tubes.

Objective

To determine the ability of a bedside UGI technique to identify the position of the duodenojejunal junction (DJJ) in low birth weight, critically ill infants in the NICU.

Materials and methods

We retrospectively reviewed bedside UGI examinations performed in premature infants weighing less than 1,500 g from 2008 to 2013 and correlated the findings with clinical data, imaging studies and surgical findings.

Results

Of 27 patients identified (weight range: 633–1,495 g), 21 (78%) bedside UGI series were diagnostic. Twenty of 27 cases (74%) demonstrated normal intestinal rotation. One case demonstrated malrotation with midgut volvulus, which was confirmed at surgery. In six cases (22%), the position of the DJJ could not be accurately determined. No cases of malrotation with midgut volvulus were missed. None of the patients with normal bedside UGI studies was found to have malrotation based on clinical follow-up (mean: 20 months), surgical findings or further imaging.

Conclusion

The bedside UGI is a useful technique to exclude malrotation in critically ill neonates and minimizes potential risks of transportation to the radiology suite. Pitfalls that may preclude a diagnostic examination include incorrect timing of radiographs, patient rotation, suboptimal enteric tube position and bowel distention. In cases of diagnostic uncertainty, a follow-up study should be performed.     

Kidney and liver transplantation in children with fibrocystic liver–kidney disease: Data from the US Scientific Registry of Transplant Recipients: 1990–2010

The natural history and survival of children with fibrocystic liver–kidney disease undergoing solid organ transplantation have infrequently been described. We report outcomes in a cohort of US children with fibrocystic liver–kidney disease receiving solid organ transplants over 20 yr. Retrospective cohort study of pediatric transplant recipients with diagnoses of fibrocystic liver–kidney disease from 1/1990 to 3/2010, using data from the SRTR. Subjects were categorized by the first transplanted organ: LT, KT, or SLK. Primary outcomes were death, re‐transplant, transplant of the alternate organ, or initiation of dialysis. Seven hundred and sixteen subjects were transplanted in this period. Median age at first transplant was 9.7 yr. Of the LT, 14 (19%) required a second liver transplant at median of 0.2 yr, and five (7%) required kidney transplant or dialysis at a median of 9.0 yr. Of the KT, 188 (31%) required a second kidney transplant or dialysis at a median of 5.9 yr. Twenty‐nine (5%) subsequently received liver transplant at a median of 6.0 yr. Among patients in this registry, far more children underwent kidney than liver transplants. The risk of subsequently needing transplantation of an alternate organ was low.