Does the presence of the nerve root sedimentation sign on MRI correlate with the operative level in patients undergoing posterior lumbar decompression for lumbar stenosis?

Background contextRecent research describes the use of a nerve root sedimentation sign to diagnose lumbar spinal stenosis (LSS). The lack of sedimentation of the nerve roots (positive sedimentation sign) to the dorsal part of the dural sac is the characteristic feature of this new radiological parameter.PurposeTo demonstrate how the nerve root sedimentation sign compares with other more traditional radiological parameters in patients who have been operated for LSS.Study design/settingA retrospective chart and image review.Patient samplePreoperative magnetic resonance images (MRIs) were reviewed from 71 consecutive operative patients who presented with LSS and received spinal decompression surgery from 2006 to 2010.Outcome measuresPreoperative T2-weighted MRIs were reviewed for each patient.MethodsOne hundred thirty-four vertebral levels from L1 to L5 were measured for: sedimentation sign, cross-sectional area (CSA) and anterior/posterior (A/P) diameter of the dural sac, thickness of the ligamentum flavum, and Fujiwara grade of facet hypertrophy. Radiological measurements were made using Surgimap 1.1.2.169 software (Nemaris, Inc., New York, NY, USA). Statistical analyses were performed using the SPSS 17.0 statistical software (SPSS Inc., Chicago, IL, USA). Significance was demonstrated using unpaired t tests and chi-squared tests. Study funding was departmental. There were no study-specific conflicts of interest–associated biases.ResultsA positive sedimentation sign was determined in 120 operated levels (89.5%), whereas 14 levels (10.5%) had no sign (negative sedimentation sign). The mean CSA and A/P diameter were 140.62 mm² (standard deviation [SD]=53) and 11.76 mm (SD=3), respectively, for the no-sign group; the mean CSA and A/P diameter were 81.87 mm² (SD=35) and 8.76 mm (SD=2.2), respectively, for the sedimentation sign group (p<.001). We found that 60% of levels with Fujiwara Grade A facet hypertrophy did not have a sedimentation sign, whereas 86.3% of levels with Grade B, 93.2% of levels with Grade C, and 100.0% of levels with Grade D did have a sedimentation sign (p<.001).ConclusionsThe sedimentation sign is a new measurement tool that can enable physicians to objectively assess and quantify spinal stenosis. The sign is most often present in patients who have clinically significant lumbar stenosis and require surgery.     

Travel medicine: What’s involved? When to refer?

ObjectiveTo define the practice of travel medicine, provide the basics of a comprehensive pretravel consultation for international travelers, and assist in identifying patients who might require referral to travel medicine professionals.ConclusionA traveler’s health and safety depends on a practitioner’s level of expertise in providing pretravel counseling and vaccinations, if required. Those who advise travelers are encouraged to be aware of the extent of this responsibility and to refer all high-risk travelers to travel medicine professionals whenever possible.Rates of international travel continue to grow substantially, with an unprecedented 1 billion travelers worldwide crossing international boundaries in 2012.¹ This increasing globalization in travel increases the risk of travel-related illnesses and other health exposures; therefore, health care professionals need to accurately advise travelers about these potential risks. However, evidence suggests that the pretravel care provided to Canadian travelers, particularly immigrant travelers visiting friends and relatives (VFR), is likely suboptimal.^2,3 Only a small number of travelers seek pretravel health advice^4–6 given that there is a general lack of awareness of travel health issues and that travel health services are not insured under government health plans. Furthermore, travelers who do typically seek advice do so from practitioners who are not specifically trained to counsel patients on travel-related health risks.⁷The objective of this review is to define the practice of travel medicine, provide health care professionals with the basics of a comprehensive pretravel consultation for patients traveling internationally, and assist these clinicians in identifying patients who might require referral to travel medicine professionals.     

Efficient broadband light absorption in thin-film a-Si solar cell based on double sided hybrid bi-metallic nanogratings

Thin film solar cells (TFSCs) suffer from poor light absorption due to their small thickness, which limits most of their practical applications. Surface plasmons generated by plasmonic nanoparticles offer an opportunity for a low-cost and scalable method to optically engineer TFSCs. Here, a systematic simulation study is conducted to improve the absorption efficiency of amorphous silicon (a-Si) by incorporating double sided plasmonic bi-metallic (Al–Cu) nanogratings. The upper pair of the gratings together with an antireflection coating are responsible for minimizing the reflection losses and enhancing the absorption of low wavelength visible light spectrum in the active layer. The bottom pairs are accountable for increasing the absorption of long wavelength photons in the active layer. In this way, a-Si, which is a poor absorber in the long wavelength region, is now able to absorb broadband light from 670–1060 nm with an average simulated absorption rate of more than 70%, and improved simulated photocurrent density of 22.30 mA cm⁻², respectively. Moreover, simulation results show that the proposed structure reveals many other excellent properties such as small incident angle insensitivity, tunability, and remarkable structural parameters tolerance. Such a design concept is quite versatile and can be extended to other TFSCs.

Thin film solar cells (TFSCs) suffer from poor light absorption due to their small thickness, which limits most of their practical applications.     

Complex forefoot injuries in motorcycle couriers

We reviewed all the severe forefoot injuries admitted to two urban hospitals over a 12-month period. These included 13 tarsometatarsal injuries, of which nine occurred in motorcycle couriers. Analysis of these nine patients suggests a combination of direct trauma leading to open multifragmented metatarsal fractures, and indirect force with dorsiflexion and rotation leading to midfoot disruption. In two cases there was significant other trauma which led to delayed treatment. In six of the nine cases, inadequate footwear was noted. All the patients underwent operative reduction and stabilization, and two necessitated later plastic surgical intervention. Our review suggests that motorcycle couriers are at significant risk of severe forefoot and midfoot trauma. A high index of suspicion is necessary when such patients are admitted with multisystem injuries. Education regarding correct footwear is also warranted.     

Synthesis,In vitro and Docking Studies of New Flavone Ethers as α‐Glucosidase Inhibitors

We report herein the synthesis, α‐glucosidase inhibition and docking studies for a series of 3–15 new flavones. A simple nucleophilic substitution reaction takes place between 3′hydroxyflavone ( 2 ) with halides to afford the new flavones. Chalcone ( 1 ), 3′hydroxyflavone ( 2 ) and the newly synthesized flavones ( 3–15 ) were being evaluated for their ability to inhibit activity of α ‐glucosidase. Compounds 2 , 3 , 5 , 7 – 10 and 13 showed good inhibitory activity with IC₅₀ values ranging between 1.26 and 36.44 μ m as compared to acarbose (IC₅₀ = 38.25 ± 0.12 μ m ). Compounds 5 (5.45 ± 0.08 μ m ), 7 (1.26 ± 0.01 μ m ) and 8 (8.66 ± 0.08 μ m ) showed excellent inhibitory activity, and this may be due to trifluoromethyl substitution that is common for these compounds. Compound 7 , a 2,5‐trifluoromethyl‐substituted compound, recorded the highest inhibition activity, and it is thirty times better than the standard drug. Docking studies for compound 7 suggest that both trifluoromethyl substituents are well positioned in a binding pocket surrounded by Phe300, Phe177, Phe157, Ala278, Asp68, Tyr71 and Asp214. The ability of compound 7 to interact with Tyr71 and Phe177 is extremely significant as they are found to be important for substrates recognition by α ‐glucosidase.     

First metatarsophalangeal joint arthrodesis with two orthogonal two hole plates

Objective

First MTP joint fusion is a reliable procedure for advanced arthritis for the first MTP joint. There are many techniques described. The purpose of our study is to report clinical, radiological, functional outcomes and complications of first metatarsophalangeal joint fusion with hand preparation of the joint and fixation with two orthogonal locking plates without a compression screw.

Effects of burn with and without Escherichia coli infection in rats on intestinal vs. splenic T-cell responses.

OBJECTIVE: To evaluate the effect of burn injury with and without an Escherichia coliseptic complication on T-cell proliferation, interleukin-2 production, and Ca(2+) signaling responses in intestinal Peyer's patch and splenic T cells. DESIGN: Prospective, randomized, sham-controlled animal study. SETTING: University medical center research laboratory. SUBJECTS: Adult male Sprague-Dawley rats. INTERVENTIONS: Rats were subjected to a 30% total body surface area, full skin thickness burn. Infection in rats was induced via intraperitoneal inoculation of E. coli, 10(9) colony forming units/kg, with or without a prior burn. MEASUREMENTS AND MAIN RESULTS: Rat Peyer's patch and splenic T lymphocytes were isolated by using a nylon wool cell purification protocol. T-cell proliferation, interleukin-2 production, and Ca(2+) signaling responses were measured after stimulation of cells with the mitogen, concanavalin A. T-cell proliferation was determined by measuring incorporation of (3)H-thymidine into T-cell cultures. Interleukin-2 production by T-cell cultures was measured by using enzyme-linked immunosorbent assay. Intracellular T-cell Ca2(+ )concentration, [Ca(2+)](i), was measured by the use of Ca(2+)-specific fluorescent label, fura-2, and its fluorometric quantification. [Ca(2+)](i) was also evaluated by the use of digital video imaging of fura-2 loaded individual T cells. T-cell proliferation and interleukin-2 production were suppressed substantially in both Peyer's patch and splenic T cells 3 days after either the initial burn alone or burn followed by the E. coli inoculation at 24 hrs after the initial burn. There seemed to be no demonstrable additive effects of E. coli infection on the effects produced by burn injury alone. The T-cell proliferation and interleukin-2 production suppressions with burn or burn-plus-infection insults were correlated with attenuated Ca(2+) signaling. E. coli infection alone suppressed T-cell proliferation in Peyer's patch but not in splenic T cells at 2 days postbacterial inoculation; E. coli infection had no effect on Peyer's patch or splenic T cells at 1 day postinjury. On the other hand, burn injury alone caused a substantial T-cell proliferative suppression at 2 days postburn in both Peyer's patch and splenic cells and a significant suppression in T-cell proliferation on day 1 postburn in Peyer's patch but not in the spleen. CONCLUSION: An initial burn injury suppressed T-cell proliferation at a level that it would not be further affected by a subsequent infection even if the infection by itself has the potential of suppressing T-cell proliferation. An earlier onset of T-cell suppression in Peyer's patch cells than in the spleen with burn could be attributable to an initial hypoperfusion-related intestinal mucosal tissue injury. Overall, our study supports the concept that burn injury per se can significantly suppress T-cell mediated immunity and that the intestine is an early tissue site of such suppression.     

The kisspeptin signaling pathway and its role in human isolated GnRH deficiency

Amplification of the neurosecretory activity of the GnRH system is the defining neuroendocrine event for sexual maturation. The physiological mechanisms that drive GnRH secretion at puberty have been difficult to identify but the discovery in 2003 that the G protein coupled receptor KISS1R is a key regulator of pubertal development in mice and men has ushered in a new chapter in reproductive neuroendocrinology. KISS1R is activated by endogenous peptides derived from a precursor protein, kisspeptin. Despite kisspeptin's importance in driving the reproductive cascade, relatively few patients with GnRH deficient states and mutations in the kisspeptin pathway have been described. Yet, these cases, coupled with loss-of-function mouse models, provide unique and complementary information into the biological role of this signaling system in the control of GnRH secretion. This article will examine some of the subtleties in genotype-phenotype correlations in both mice and men carrying disabling mutations in the kisspeptin pathway.