Predation on bacteria and accompanying mortality are important mechanisms in controlling bacterial populations and recycling of nutrients through the microbial loop. The agents most investigated and seen as responsible for bacterial mortality are viruses and protists. However, a body of evidence suggests that predatory bacteria such as the Halobacteriovorax (formerly Bacteriovorax), a Bdellovibrio-like organism, contribute substantially to bacterial death. Until now, conclusive evidence has been lacking. The goal of this study was to better understand the contributors to bacterial mortality by addressing the poorly understood role of Halobacteriovorax and how their role compares with that of viruses. The results revealed that when a concentrated suspension of Vibrio parahaemolyticus was added into microcosms of estuarine waters, the native Halobacteriovorax were the predators that responded first and most rapidly. Their numbers increased by four orders of magnitude, whereas V. parahaemolyticus prey numbers decreased by three orders of magnitude. In contrast, the extant virus population showed little increase and produced little change in the prey density. An independent experiment with stable isotope probing confirmed that Halobacteriovorax were the predators primarily responsible for the mortality of the V. parahaemolyticus. The results show that Halobacteriovorax have the potential to be significant contributors to bacterial mortality, and in such cases, predation by Halobacteriovorax may be an important mechanism of nutrient recycling. These conclusions add another dimension to bacterial mortality and the recycling of nutrients.

Object Medial pectoral nerve (MPN) to musculocutaneous nerve (MCN) neurotization for recovery of elbow flexion by biceps reinnervation is a valid option following traumatic injury to the upper brachial plexus. A major criticism of the application of this technique in infants is the smaller size of the MPN and mismatch of viable axons. We describe our institutional experience utilizing this procedure and critically examine functional outcomes. Methods Office charts and hospital records of children from over an 11-year period beginning January 1997 were reviewed. Of the 53 children of various ages undergoing brachial plexus exploration for traumatic injury of any nature, 20 underwent MPN to MCN neurotization as a part of an overall procedure in the first year of life to treat birth-related brachial plexus palsy and had at least 9 months' follow-up. Medial pectoral nerve to MCN neurotization was chosen if the results of clinical examination and intraoperative electrophysiological evidence were consistent with medial cord function. Functional recovery was defined as the ability of the child to bring their hand to their mouth. Results Sixteen patients (80%) gained functional recovery. The median age at surgery was 7 months. Median time to first clinic visit documenting recovery was 11.5 months and median overall follow up was 21.5 months. Preoperative hand function was a useful predictor of recovery of elbow flexion. Conclusions Medial pectoral nerve to MCN neurotization is a valid surgical option for the reinnervation of the biceps muscle for birth-related brachial plexus palsy when the hand is functional preoperatively. Useful elbow flexion can be expected in the majority of these children.

Object Axillary nerve palsy, isolated or as part of a more complex brachial plexus injury, can have profound effects on upper-extremity function. Radial to axillary nerve neurotization is a useful technique for regaining shoulder abduction with little compromise of other neurological function. A combined experience of this procedure used in children is reviewed. Methods A retrospective review of the authors' experience across 3 tertiary care centers with brachial plexus and peripheral nerve injury in children (younger than 18 years) revealed 7 cases involving patients with axillary nerve injury as part of an overall brachial plexus injury with persistent shoulder abduction deficits. Two surgical approaches to the region were used. Results Four infants (ages 0.6, 0.8, 0.8, and 0.6 years) and 3 older children (ages 8, 15, and 17 years) underwent surgical intervention. No patient had significant shoulder abduction past 15° preoperatively. In 3 cases, additional neurotization was performed in conjunction with the procedure of interest. Two surgical approaches were used: posterior and transaxillary. All patients displayed improvement in shoulder abduction. All were able to activate their deltoid muscle to raise their arm against gravity and 4 of 7 were able to abduct against resistance. The median duration of follow-up was 15 months (range 8 months to 5.9 years). Conclusions Radial to axillary nerve neurotization improved shoulder abduction in this series of patients treated at 3 institutions. While rarely used in children, this neurotization procedure is an excellent option to restore deltoid function in children with brachial plexus injury due to birth or accidental trauma.

Infants undergoing neurotization for Narakas grade 1 brachial plexus injury had similar long-term function to those who had improved and never required surgery. The preoperative exam findings were significantly different between the intervened and non-intervened groups, while the postoperative exam findings were not.