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Summary: Necrotizing enterocolitis (NEC) is a leading cause of preterm infant morbidity and mortality. Treatment for NEC is limited and non-targeted, which makes new treatment and prevention strategies critical. Host defense peptides (HDPs) are essential components of the innate immune system and have multifactorial mechanisms in host defense. LL-37 and hBD2 are two HDPs that have been shown in prior literature to protect from neonatal sepsis-induced mortality or adult inflammatory bowel disease, respectively. Therefore, this article sought to understand if these two HDPs could influence NEC severity in murine preclinical models. NEC was induced in P14-16 C57Bl/6 mice and HDPs were provided as a pretreatment or treatment. Both LL-37 and hBD2 resulted in decreased NEC injury scores as a treatment and hBD2 as a pretreatment. Our data suggest LL-37 functions through antimicrobial properties, while hBD2 functions through decreases in inflammation and improvement of intestinal barrier integrity.

Ample evidence indicates that environmental stress impairs information processing, yet the underlying mechanisms remain partially elusive. We showed that, in several rodent models of psychopathology, the neurosteroid allopregnanolone (AP) reduces the prepulse inhibition (PPI) of the startle, a well-validated index of sensorimotor gating. Since this GABAA receptor activator is synthesized in response to acute stress, we hypothesized its participation in stress-induced PPI deficits. Systemic AP administration reduced PPI in C57BL/6J mice and Long-Evans, but not Sprague-Dawley rats. These effects were reversed by isoallopregnanolone (isoAP), an endogenous AP antagonist, and the GABAA receptor antagonist bicuculline and mimicked by AP infusions in the medial prefrontal cortex (mPFC). Building on these findings, we tested AP's implication in the PPI deficits produced by several complementary regimens of acute and short-term stress (footshock, restraint, predator exposure, and sleep deprivation). PPI was reduced by acute footshock, sleep deprivation as well as the combination of restraint and predator exposure in a time- and intensity-dependent fashion. Acute stress increased AP concentrations in the mPFC, and its detrimental effects on PPI were countered by systemic and intra-mPFC administration of isoAP. These results collectively indicate that acute stress impairs PPI by increasing AP content in the mPFC. The confirmation of these mechanisms across distinct animal models and several acute stressors strongly supports the translational value of these findings and warrants future research on the role of AP in information processing.

Persisting pain of the hip following internal fixation of fracture of the neck of the femur is often caused by capital necrosis or non-union. In a randomized trial 35 patients had 99mTc-MDP bone scintigraphy performed 6 weeks, 3, 6, and 12 months after internal fixation of their subcapital fractures with a sliding screw-plate or a sliding nail-plate. The purpose was to find out whether bone scintigraphy could predict capital necrosis or non-union before it shows up on plain radiographs, which happens later. The patients were followed up for an average of 44 months (range 12-64). Radiologically, capital necrosis occurred in five patients and non-union in six. Bone scintigraphy showed decreasing activity in the 1st year after operation in uncomplicated cases (P less than 0.03). However, it was impossible to distinguish patients with capital necrosis or non union from those with uneventful healing. There were no significant differences in the scintigraphic appearance between groups at most risk, e.g. Garden stage 3 and 4 fractures versus Garden stage 1 and 2, and fixation by sliding nail versus fixation by sliding screw-plate. In conclusion, bone scintigrams during the first 6 months after operation do not reliably predict failure of internal fixation of fractures of the neck of the femur.

One hundred and thirty fractures of the femoral neck treated with sliding screw-plate or sliding nail-plate were followed for up to 65 months postoperatively. Throughout the observation period the yearly incidence of necrosis of the femoral head was between 5 and 10 per cent, as estimated by the life table method, and after 5 years 37 per cent of the patients with united fractures had developed necrosis of the femoral head. The cases of necrosis were all characterized radiographically by one or more areas of subchondral cortical depression, generalized subchondral fragmentation or isolated patches of sclerosis. It is concluded that estimation of the frequency of femoral head necrosis after fracture of the femoral neck requires long-term follow-up and reliable, reproducible radiographical criteria for necrosis of the head. Because of the high mortality of patients sustaining these fractures, statistical methods employing censored data should be used.

A 25-year-old building worker was struck in the left hip by a 12.7-cm long bolt fired from a bolt gun. The bolt penetrated deeply into the pelvis, through the acetabulum, the joint cavity and the head of the femur leading to fixation of the hip. In spite of immediate extraction of the nail, cleansing, immobilization, antibiotics and tetanus prophylaxis, the wound became infected. The tips of the modern types of nails used in nail guns may be coated with a plastic material which can constitute a troublesome foreign body if left behind, because the nail is merely extracted without opening and exploring the track.

In a randomized trial 49 patients with fracture of the neck of the femur and an age of less than 70 years or a high level of physical activity were allocated to treatment with a sliding screw plate or a sliding nail plate fixation. The patients were followed for 2-5 years. At follow-up the union rate was found to be 86.2 per cent of the fractures in the screw plate group and 73.7 per cent in the nail plate group (P less than 0.3). Necrosis of the femoral head was encountered in respectively 10 and 21 per cent. Hip replacement was necessary in respectively 23.3 and 31.6 per cent. The nail slid out of the femoral head, resulting in recurrence of the fracture's displacement in three fractures with a sliding nail plate, and in none with a sliding screw plate (P = 0.053). Secondary loss of the femoral neck's angle was more frequently seen in the sliding nail plate group (P less than 0.01). In conclusion, the sliding screw plate gives better fixation of fractures of the neck of the femur and was followed by a lower frequency of reoperation than after an unthreaded device.