Identifying the emergence of the superficial peroneal nerve through deep fascia on ultrasound and by dissection: Implications for regional anesthesia in foot and ankle surgery

Regional anesthesia relies on a sound understanding of anatomy and the utility of ultrasound in identifying relevant structures. We assessed the ability to identify the point at which the superficial peroneal nerve (SPN) emerges through the deep fascia by ultrasound on 26 volunteers (mean age 27.85 years ± 13.186; equal male: female). This point was identified, characterized in relation to surrounding bony landmarks (lateral malleolus and head of the fibula), and compared to data from 16 formalin‐fixed human cadavers (mean age 82.88 years ± 6.964; equal male: female). The SPN was identified bilaterally in all subjects. On ultrasound it was found to pierce the deep fascia of the leg at a point 0.31 (±0.066) of the way along a straight line from the lateral malleolus to the head of the fibula (LM‐HF line). This occurred on or anterior to the line in all cases. Dissection of cadavers found this point to be 0.30 (±0.062) along the LM‐HF line, with no statistically significant difference between the two groups (U = 764.000; exact two‐tailed P = 0.534). It was always on or anterior to the LM‐HF line, anterior by 0.74 cm (±0.624) on ultrasound and by 1.51 cm (±0.509) during dissection. This point was significantly further anterior to the LM‐HF line in cadavers (U = 257.700, exact two‐tailed P < 0.001). Dissection revealed the nerve to divide prior to emergence in 46.88% (n = 15) limbs, which was not identified on ultrasound (although not specifically assessed). Such information can guide clinicians when patient factors (e.g., obesity and peripheral edema) make ultrasound‐guided nerve localization more technically challenging. Clin. Anat. 32:390–395, 2019. © 2019 Wiley Periodicals, Inc.     

Vocalizations of infants with hearing loss compared with infants with normal hearing: Part I--phonetic development

OBJECTIVE: Infants with hearing loss are known to be slower to develop spoken vocabulary than peers with normal hearing. Previous research demonstrates that they differ from normal-hearing children in several aspects of prelinguistic vocal development. Less is known about the vocalizations of early-identified infants with access to current hearing technologies. This longitudinal study documents changes in prelinguistic vocalizations in early-identified infants with varying degrees of hearing loss, compared with a group of infants with normal hearing. It was hypothesized that infants with hearing loss would demonstrate phonetic delays and that selected aspects of phonetic learning may be differentially affected by restricted auditory access. DESIGN: The vocalizations and early verbalizations of 21 infants with normal hearing and 12 early-identified infants with hearing loss were compared over a period of 14 mo (from 10 to 24 mo of age). Thirty-minute mother-child interaction sessions were video recorded at 6- to 8-wk intervals in a laboratory playroom setting. Syllable complexity changes and consonantal development were quantified from vocalizations and early verbalizations. Early behaviors were related to speech production measures at 36 mo of age. Participants with hearing loss were recruited from local audiology clinics and early intervention programs. Participants with normal hearing were recruited through day care centers and pediatrician offices. RESULTS: Relative to age-matched, normal-hearing peers, children with hearing loss were delayed in the onset of consistent canonical babble. However, certain children with moderately-severe losses babbled on time, and infants with cochlear implants babbled within 2 to 6 mo of implantation. The infants with hearing loss had smaller consonantal inventories and were slower to increase syllable shape complexity than age-matched normal-hearing peers. The overall pattern of results suggested that consonant development in infants with hearing loss was delayed but not qualitatively different from children with normal hearing. Delays appeared to be less pronounced than suggested by previous research. However, fricative/affricate development progressed slowly in infants with hearing loss and divergence from the patterns of normal-hearing children was observed. Six children (2 with normal hearing; 4 with hearing loss) were identified as atypical, based on their rates of development. At 24 mo of age, these children persisted in producing a high proportion (0.59) of vocalizations lacking consonants, which was negatively correlated with Goldman-Fristoe scores at 36 mo (r = -0.60). CONCLUSIONS: Results suggest that early-identified children are delayed in consonant and syllable structure development, which may influence early word learning rates. Fricative/affricate development appears to be challenging for some infants with hearing loss. This may be related to the effects of sensorineural hearing loss on high-frequency information, restricted bandwidth provided by amplification, and reduced audibility in contexts of noise and reverberation. Delayed fricative use may have implications for morphological development. Atypically slow rates of change in syllable development may indicate that a child is at risk for delayed speech development.     

Epidemiology of Sexual Health in the Virtual Environment: A Multinational Online Survey of Spanish- and Portuguese-Speaking Men who use an Internet Sexual Networking Site

There is limited data on the sexual health of users of sexual networking websites for men who have sex with men (MSM) in Latin America. Members of a MSM-targeted social/sexual networking website in Latin America, Spain, and Portugal participated in an online sexual health survey. Among 36,063 respondents, nearly 90 % reported having anal or vaginal intercourse in the past 3 months. Among sexually active men, 53.2 % used condoms inconsistently. In the past year, 54 % of respondents reported undergoing sexually transmitted infections (STI) testing and 67 % reported testing yearly or more often for HIV. Self-reported HIV prevalence was 9.1 %. Differences were seen by geographic region. Unprotected intercourse with partners of different or unknown HIV status was associated with recent STI diagnosis (OR = 1.83, t = 13.15, d.f. = 21, p < .001) and HIV diagnosis (OR = 2.20, t = 14.00, d.f. = 21, p < .001). Online surveys are a promising tool for HIV/STI surveillance and prevention internationally to reach an important subset of MSM.     

The Syndemic Condition of Psychosocial Problems and HIV Risk Among Male Sex Workers in Ho Chi Minh City,Vietnam

In Vietnam, the co-occurrence (i.e., “syndemic”) of psychosocial factors (e.g., depression and substance use) may disproportionately burden male sex workers and increase their HIV risk. A comprehensive survey was conducted among 300 male sex workers in Ho Chi Minh City, Vietnam in 2010. We performed logistic regression to examine the association between the syndemic variable—a count score of the number of five psychosocial conditions endorsed—and unprotected anal sex (UAS) in the past. One-third of participants reported any UAS, and 42 % reported ≥2 psychosocial health problems. In multivariable models, experiencing ≥4 psychosocial health problems was significantly associated with UAS. Every unit increase in number of psychosocial health problems was associated with a 25–30 % increase in odds of UAS. Understanding the syndemic condition and its association with HIV risk among male sex workers in Vietnam may lead to the development of more effective, comprehensive interventions.     

Detecting grain rotation at the nanoscale

It is well-believed that below a certain particle size, grain boundary-mediated plastic deformation (e.g., grain rotation, grain boundary sliding and diffusion) substitutes for conventional dislocation nucleation and motion as the dominant deformation mechanism. However, in situ probing of grain boundary processes of ultrafine nanocrystals during plastic deformation has not been feasible, precluding the direct exploration of the nanomechanics. Here we present the in situ texturing observation of bulk-sized platinum in a nickel pressure medium of various particle sizes from 500 nm down to 3 nm. Surprisingly, the texture strength of the same-sized platinum drops rapidly with decreasing grain size of the nickel medium, indicating that more active grain rotation occurs in the smaller nickel nanocrystals. Insight into these processes provides a better understanding of the plastic deformation of nanomaterials in a few-nanometer length scale.The plastic deformation of conventional polycrystalline metals has been well-studied. The plastic behavior of coarse-grained metals (with particle size larger than 100 nm) is mainly controlled by the nucleation and motion of lattice dislocations. Plastic deformation by dislocation glide results in crystallite rotations, generating lattice preferred orientation or texture. The anisotropic physical properties of a polycrystalline material are strongly related to the preferred alignment of its crystallites. Texture studies are of interest in many fields. In material science and engineering, texture control is essential in improving the strength and lifetime of structural materials (1). In Earth science, understanding texture development of minerals is important for interpreting seismic anisotropy in the Earth’s interior (2–5).The plastic deformation of nanomaterials has attracted much interest in recent years (6–12), but many controversies still exist (6–17). Various mechanisms have been reported (8, 11–18). It has been proposed that below a critical length scale the strength of nanometals would exhibit an inverse Hall–Petch size dependence because in the plastic deformation of fine nanocrystals, dislocation activity gives way to grain boundary (GB) sliding, diffusion, and grain rotation (7). If GB-mediated mechanisms dominate plastic deformation, it would yield a d⁻⁴ dependence on grain rotation rate, where d is the grain size (9), i.e., grain rotation activity would be greatly enhanced in fine nanocrystals. Grain-rotation-induced crystallographic alignment has been observed in 2–3-nm ferrihydrite nanocrystals (15–17). In contrast, computer simulations suggest that GB mobility drops with decreasing grain size (19, 20). Although the observation of grain rotation during deformation of micrometer-sized crystals is feasible (21, 22), in situ probing of grain rotation of ultrafine nanocrystals is difficult, precluding the direct exploration of mechanics at nanometer scales. Whether grain rotation becomes more active and dominant in finer nanocrystals is not yet experimentally verified. In this work, radial diamond-anvil cell (rDAC) X-ray diffraction (XRD) experiments (2) are used to make in situ observation of the texturing of stressed polycrystalline platinum in nickel media of various mean particle sizes, from 500 nm down to 3 nm. The texturing change of platinum is expected to reflect some activity at the GBs of the nickel medium.     

Does switching anti-TNFα biologic agents represent an effective option in childhood chronic uveitis: The evidence from a systematic review and meta-analysis approach

Objective

To summarize the evidence regarding the effectiveness of switching to a second anti-TNFα treatment in children with autoimmune chronic uveitis (ACU), refractory to the first course of anti-TNFα treatment.

Methods

We conducted a systematic literature review between January 2000 and May 2013 to investigate the efficacy of a second anti-TNFα agent in the treatment of ACU in children (≤16 years) refractory to a first course of a single anti-TNFα treatment, topical and/or systemic steroid therapy and at least one DMARD. The primary outcome measure was the improvement of intraocular inflammation, as defined by the SUN working group criteria, at 6 (±2) months of treatment.

Results

Among 1086 identified articles, 128 were scrutinized: 10 observational studies, 6 on adalimumab (ADA), 3 on infliximab (INF), and 1 on both, were deemed eligible. Study cohort included 40 children (ADA = 34 and INF = 6), median age 8 years (range 3–16). Nine were males, 28 females (gender not reported in 3), 39/40 were affected by JIA. Seventeen children received etanercept: 11 were switched to ADA, the remaining 6 to INF. All 23 children who previously received INF were switched to ADA. Altogether, 30 children (24 on ADA, 6 on INF) of 40 responded to treatment: 0.75 (95% CI: 0.51–100) was the combined estimate of the proportion of subjects improving.

Conclusions

Despite the fact that no RCT is available and the number of cases is small, this review provides evidence that switching to a second anti-TNFα agent results in improvement of ocular activity for the 75% treated children     

Pathophysiology of eosinophilic esophagitis: recent advances and their clinical implications

Introduction: Diagnostic and therapeutic strategies in eosinophilic esophagitis (EoE) are evolving. New knowledge regarding the pathophysiology of EoE has been the foundation for updated diagnostic recommendations and new therapeutic trials.

Areas covered: We performed structured literature searches in Medline and PubMed, Cochrane meta-analyses, and abstracts of international congresses to review therapeutic approaches for EoE in July 2018. Additional articles were obtained by perusing the references of articles identified in the original PubMed search. Articles were excluded if they did not focus on the mechanism of disease, diagnosis, or treatment of humans with EoE.

Expert commentary: Recent advances in the understanding of mechanisms underlying the pathology of EoE have resulted in significant change in the diagnostic algorithm for EoE, and are identifying promising potential targets for personalized medicine. There is a clinical need for improved targeted therapy for EoE, and better understanding the underlying pathophysiology of EoE will help to determine therapeutic targets. In this review, we highlight key mechanisms in the pathophysiology of EoE and how they are being utilized to change therapy in EoE.