Jenny L. Yu

Tissue-resident natural killer (NK) cells are cell lineages distinct from thymic and conventional splenic NK cells

Natural killer (NK) cells belong to the innate immune system; they can control virus infections and developing tumors by cytotoxicity and producing inflammatory cytokines. Most studies of mouse NK cells, however, have focused on conventional NK (cNK) cells in the spleen. Recently, we described two populations of liver NK cells, tissue-resident NK (trNK) cells and those resembling splenic cNK cells. However, their lineage relationship was unclear; trNK cells could be developing cNK cells, related to thymic NK cells, or a lineage distinct from both cNK and thymic NK cells. Herein we used detailed transcriptomic, flow cytometric, and functional analysis and transcription factor-deficient mice to determine that liver trNK cells form a distinct lineage from cNK and thymic NK cells. Taken together with analysis of trNK cells in other tissues, there are at least four distinct lineages of NK cells: cNK, thymic, liver (and skin) trNK, and uterine trNK cells. DOI: http://dx.doi.org/10.7554/eLife.01659.001

Quantifying the Effect of Diabetes on Surgical Hand and Forearm Infections

PURPOSE Diabetes has long been established as a risk factor for hand and forearm infections. The purpose of this study was to review the effect of glycemic factors on outcomes among diabetic patients with surgical upper-extremity infections. We hypothesized that diabetic inpatients may benefit from stronger peri-infection glycemic control. METHODS A prospective cohort study enrolled diabetic and nondiabetic surgical hand and forearm infections over 3 years. Glycemic factors included baseline glycosylated hemoglobin, blood glucose (BG) at presentation, and inpatient BG. Poor baseline control was defined as glycosylated hemoglobin of 9.0% or greater and poor inpatient control as average BG of 180 mg/dL or greater. The main outcome of interest was the need for repeat therapeutic drainage. Multivariable logistic regression quantified the association between diabetic factors and this outcome. RESULTS The study involved 322 patients: 76 diabetic and 246 nondiabetic. Diabetic infections were more likely than nondiabetic infections to result from idiopathic mechanisms, occur in the forearm, and present as osteomyelitis, septic arthritis, and necrotizing fasciitis. Diabetic microbiology was more likely polymicrobial and fungal. After first drainage, diabetic patients were more likely to require repeat drainage and undergo eventual amputation. Among diabetic patients, poor inpatient control was associated with need for repeat drainage. CONCLUSIONS Diabetes exacerbates the burden of surgical upper-extremity infections: specifically, more proximal locations, deeper involved anatomy at presentation, broader pathogenic microbiology, increased need for repeat drainage, and higher risk for amputation. Among diabetic patients, poor inpatient glycemic control is associated with increased need for repeat drainage. TYPE OF STUDY/LEVEL OF EVIDENCE Prognostic I.

Fenestration of Solid Orbital Implants: Reducing Retrobulbar Hematoma Rate.

Purpose: Retrobulbar hematoma is an uncommon but potentially devastating complication following repair of orbital fractures. Since 2007, the senior author routinely fenestrates the solid porous polyethylene implants commonly used for orbital reconstruction. The perforated implant may facilitate drainage of postoperative bleeding and may potentially reduce the risk of retrobulbar hematoma. This study examines the rates of retrobulbar hematoma in patients who underwent orbital fracture reconstruction with placement of fenestrated or nonfenestrated implants. Methods: A retrospective chart review of patients with orbital fracture reconstruction using an implant performed by the senior author between 2006 and 2016 was conducted. Data collected included age, sex, implant type, and presence of retrobulbar hematoma. Results: One hundred four patients were included in the study. One patient who was treated with a nonperforated implant was found to have a postoperative retrobulbar hematoma. The retrobulbar hematoma did not cause visual changes or increased intraocular pressure, so the patient was observed and did not undergo any surgical intervention. The hematoma resolved spontaneously without further sequela. No patients with fenestrated implants had a retrobulbar hematoma. Conclusions: Fenestration of solid implants used in orbital floor reconstruction is simple and easy to perform, and may reduce the incidence of postoperative retrobulbar hematoma.

Comparison of Resorbable Plating Systems: Complications During Degradation

Introduction: Several bioresorbable plating systems have become standard in pediatric craniosynostosis reconstruction. A comparison of these systems is needed to aid surgeons in the preoperative planning process. The authors aim to evaluate 1 institutions experience using Resorb-X by KLS Martin and Delta Resorbable Fixation System by Stryker (Stryker Craniomaxillofacial, Kalamazoo, MI). Methods: A sample of patients with single-suture nonsyndromic craniosynostosis treated at St Louis Childrens Hospital between 2007 and 2014 using either Resorb-X or Delta bioresorbable plating systems were reviewed. Only patients with preoperative, immediate, and long-term 3-dimensional photographic images or computed tomography scans were included. A comparison of plating system outcomes was performed to determine the need for clinic and emergency room visits, imaging obtained, and incidence of subsequent surgical procedures due to complications. Results: Forty-six patients (24 Resorb-X and 22 Delta) underwent open repair with bioabsorbable plating for single suture craniosynostosis. The mean age at each imaging time point was similar between the 2 plating systems (P > 0.717). Deformity-specific measures for sagittal (cranial index), metopic (interfrontotemporale), and unicoronal (frontal asymmetry) synostosis were equivalent between the systems at all time points (0.05 < P < 0.904). A single Delta patient developed bilateral scalp cellulitis and abscesses and subsequently required operative intervention and antibiotics. Conclusion: Bioabsorbable plating for craniosynostosis in children is effective and has low morbidity. In our experience, the authors did not find a difference between the outcomes and safety profiles between Resorb-X and Delta.

Alar Pinning in Rigid External Distraction for Midfacial Hypoplasia

Background Distraction osteogenesis with a rigid external distractor is a widely accepted treatment for midfacial hypoplasia. In this study, the authors introduce the utilization of alar pinning with the external halo distractor for maxillary advancement, in place of an oral splint. Methods A retrospective chart review was conducted of 7 patients who successfully underwent distraction osteogenesis using the alar pinning technique. Midfacial hypoplasia was secondary to Crouzon syndrome (n = 4), Apert syndrome (n = 1), Pfeiffer syndrome (n = 1), or bacterial meningitis (n = 1). Three patients were managed with monobloc osteotomies, 2 with Le Fort III osteotomies, 1 with Le Fort III osteotomy and frontoorbital advancement, and 1 with Le Fort I osteotomy alone. Patient charts were analyzed for postoperative course and complications relating to the alar pins. Results Two patients had minor complications specifically related to the alar pins. One patient had concern for a mild skin infection at a pin site that resolved with oral antibiotics. The other patient had loosening of an alar pin, which did not require operative management. Retrospective chart review indicated that all patients were pleased with their results from the distraction, and no patients opted for further advancement. Discussion Utilization of alar pin sites for external distraction is a feasible and reasonable option for treatment of midfacial hypoplasia involving a Le Fort osteotomy or monobloc procedure. Fixation sites within the alar crease minimize the visibility of pin site scars and eliminate the need for a custom-made oral splint, which prevents usage of the upper dentition and frequently requires consulting a dentist or orthodontist for fabrication. Conclusions Alar pinning with an external halo distraction system for management of midfacial hypoplasia has minimal complications and is an alternative to using a custom-made oral splint.

Single Z-Plasty Versus Double-Opposing Z-Plasty: A Cadaveric Study of Palatal Lengthening.

Objective: The double-opposing Z-plasty is an effective method of repairing the cleft palate due to its reorientation of the palatal musculature and lengthening of the soft palate. A technique for lengthening the palate with a single oral Z-plasty has also been described. The authors hypothesize that these 2 techniques have equivalent effects on palate length. Methods: A cadaver study was performed. Ten fresh adult cadaver heads were used. All palates were divided in the midline. In 5 specimens, a modified double-opposing Z-plasty technique was used; 5 other specimens underwent an oral Z-plasty with a straight-line repair of the nasal mucosa. In both groups, the levator veli palatini muscles were separately dissected and reapproximated with an intravelar veloplasty. The velar length, defined in this study as the distance from the posterior nasal spine to the tip of uvula, was measured before and after the surgical procedure. Results: The double-opposing Z-plasty produced a mean increase of 1.0 ± 0.6 cm in velar length (P = 0.023). The single Z-plasty repair resulted in a mean gain of 1.1 ± 0.3 cm (P = 0.001). There was no difference in change in palate length between the 2 procedures (P = 0.941), and no difference in the percentage of soft palate lengthening (24% vs 29%, respectively; P = 0.565). Conclusions: A single oral Z -plasty provides palatal lengthening equivalent to that of a double-opposing Z-plasty procedure.

Preferences in Sleep Position Correlate With Nighttime Paresthesias in Healthy People Without Carpal Tunnel Syndrome

Background: Carpal tunnel syndrome has been associated with sleep position preferences. The aim of this study is to assess self-reported nocturnal paresthesias and sleeping position in participants with and without carpal tunnel syndrome diagnosis to further clinical knowledge for preventive and therapeutic interventions. Methods: A cross-sectional survey study of 396 participants was performed in young adults, healthy volunteers, and a patient population. Participants were surveyed on risk factors for carpal tunnel syndrome, nocturnal paresthesias, and sleep preferences. Binary logistic regression analysis was performed comparing participants with rare and frequent nocturnal paresthesias. Subanalyses for participants without carpal tunnel syndrome under and over 21 years of age were performed on all factors significantly associated with subclinical compression neuropathy in the overall population. Results: Thirty-three percent of the study population experienced nocturnal paresthesias at least weekly. Increased body mass index (P < .001) and sleeping with the wrist flexed (P = .030) were associated with a higher frequency of nocturnal paresthesias. Side sleeping was associated with less frequent nocturnal symptoms (P = .003). In participants without carpal tunnel syndrome, subgroup analysis illustrated a relationship between nocturnal paresthesias and wrist position. In participants with carpal tunnel syndrome, sleeping on the side had a significantly reduced frequency of nocturnal paresthesias. Conclusion: This study illustrates nocturnal paresthesias in people without history of carpal tunnel syndrome including people younger than previously reported. In healthy patients with upper extremity subclinical compression neuropathy, sleep position modification may be a useful intervention to reduce the frequency of nocturnal symptoms prior to developing carpal tunnel syndrome.