Halogen- and hydrogen-bonded self-assembled fibrillar networks of substituted 1,3:2,4-dibenzylidene-D-sorbitols (DBS).

Substituting the sole primary hydroxyl group of the low molecular weight organogelator (LMOG), 1,3:2,4-dibenzylidene-D-sorbitol (DBS), with a halogen atom (Cl, Br, or I; i.e., 6-Cl-DBS, 6-Br-DBS, or 6-I-DBS) drastically alters the supramolecular self-assembled fibrillar network (SAFiN) that forms when the molecules aggregate. The SAFiN varies depending on the solvent properties, impacting the role of non-covalent hydrogen- and halogen-bonding interactions along and between fibers. The halogenated DBS derivatives have more coherent crystalline fibers than DBS, with larger length-to-width aspect ratios. High-resolution synchrotron powder X-ray diffraction of each wet-state gel in toluene and DFT optimization obtained complete structures for the three halogenated DBS derivatives in their SAFiNs. The presence of a halogen atom reduces the reliance on hydrogen bonding by enabling new halogen bonding interactions that impact the self-assembly behavior, especially in solvents of higher polarity. For 6-I-DBS and 6-Br-DBS, the primary forces driving molecular self-assembly are C-H⋯π and intermolecular halogen-to-halogen interactions, and there is one unique molecule in each unit cell. However, the Cl atoms of 6-Cl-DBS are not close, and its SAFiN structures rely more on hydrogen bonding. As a result, the enhanced hydrogen bonding, electronic differences among the halogens, and spatial factors allow its unit cell to include two independent molecules of 6-Cl-DBS.

Comparison of static and dynamic in vitro digestibility and bioaccessibility of palm-based emulsions and correlation to a human study: effects of triacylglycerol crystallinity.

The static and dynamic TIM-1 in vitro digestibility of similarly sized Span 60 o/w emulsions containing either liquid palm olein droplets (PO) or palm stearin (PS) droplets tempered to contain different levels of crystallinity (i.e., PS-SE (maximum), PS-SE-INT (intermediate), and PS-LE (undercooled)) were explored. Static in vitro digestion experiments included particle size analysis, and emulsion digestibility and bioaccessibility were compared between the static and dynamic models, respectively. ß-carotene (BC, 0.1 wt%) was also incorporated in the emulsions to determine the influence of triacylglycerol (TAG) crystallinity on BC bioaccessibility and stability during storage under accelerated lighting conditions. TAG crystallinity altered the colloidal fat crystal network properties and ultimately impacted lipid digestion, attenuating early static in vitro lipolysis for the PS emulsions compared to the PO emulsion. This correlated well with TIM-1 bioaccessibility trends and with results from our results of a previous human study wherein the rise in postprandial TAG was delayed when healthy men consumed PS-SE versus PS-LE. The presence of crystalline TAG modestly accelerated BC degradation, and did not improve preservation nor alter BC in vitro bioaccessibility.

Genetics, epidemiology, and clinical manifestations of multidrug-resistant Acinetobacter baumannii.

Acinetobacter baumannii infections have become an emerging health concern in hospitals across the world and are often associated with nosocomial infections with poorer clinical outcomes in patients with prolonged hospital stay. Management of infections involves prompt identification of the infecting strain, isolating the source of infection, and proper choice of antibiotic regimen. However, resistance to first-line antimicrobial drugs, combined with a lack of equally effective alternatives, complicates the treatment of multidrug-resistant A. baumannii. Presently, multidrug-resistant A. baumannii is a serious health concern in hospitals and long-term care facilities and requires immediate and sustained prevention efforts to control the rate of incidence. This review describes trends in epidemiology, genetic markers, and other factors that influence the incidence of multidrug-resistant A. baumannii. Current and emerging treatments as well as infection control strategies are discussed.

Functional outcomes of conservatively managed acute ruptures of the Achilles tendon.

AIMS: This prospective cohort study aims to determine if the size of the tendon gap following acute rupture of the Achilles tendon shows an association with the functional outcome following non-operative treatment. PATIENTS AND METHODS: All patients presenting within two weeks of an acute unilateral rupture of the Achilles tendon between July 2012 and July 2015 were considered for the study. In total, 38 patients (nine female, 29 male, mean age 52 years; 29 to 78) completed the study. Dynamic ultrasound examination was performed to confirm the diagnosis and measure the gap between ruptured tendon ends. Outcome was assessed using dynamometric testing of plantarflexion and the Achilles tendon Total Rupture score (ATRS) six months after the completion of a rehabilitation programme. RESULTS: Patients with a gap ≥ 10 mm with the ankle in the neutral position had significantly greater peak torque deficit than those with gaps < 10 mm (mean 23.3%; 7% to 52% vs 14.3%; 0% to 47%, p = 0.023). However, there was no difference in ATRS between the two groups (mean score 87.2; 74 to 100 vs 87.4; 68 to 97, p = 0.467). There was no significant correlation between gap size and torque deficit (τ = 0.103), suggesting a non-linear relationship. There was also no significant correlation between ATRS and peak torque deficit (τ = -0.305). CONCLUSION: This is the first study to identify an association between tendon gap and functional outcome in acute rupture of the Achilles tendon. We have identified 10 mm as a gap size at which deficits in plantarflexion strength become significantly greater, however, the precise relationship between gap size and plantarflexion strength remains unclear. Large, multicentre studies will be needed to clarify this relationship and identify population subgroups in whom deficits in peak torque are reflected in patient-reported outcome measures. Cite this article: Bone Joint J 2017;99-B:87-93.

A longitudinal analysis of methicillin-resistant and sensitive Staphylococcus aureus incidence in respect to specimen source, patient location, and temperature variation.

OBJECTIVE: Seasonal variations in temperature exert strong selective pressure on microorganism population dynamics and should be taken into account in epidemiological studies. The objective of the present study was to characterize the seasonal variation of staphylococcal infections in respect to patient location, specimen source, month of year, and temperature variation. METHODS: A retrospective longitudinal time-series analysis of methicillin-resistant and methicillin-sensitive Staphylococcus aureus (MRSA and MSSA) was conducted in northeastern Ohio over a 5-year period. Multivariable time-series analyses were performed to detect the variations in the monthly incidence based on location of patients (inpatient, outpatient, and nursing homes), source of specimen (wound, respiratory tract, and urine), time of year (January-December), and temperature variation (average monthly over 5 years). RESULTS: The results indicated a gradual increase in both MRSA and MSSA infections, with outpatient cases representing the majority of cases. If present, the seasonal nature of MRSA infections varied based on specimen source and patient location, with wound infections from outpatients more prevalent in warmer months, and respiratory infections among inpatients more prevalent during colder months. CONCLUSIONS: The current report provides a longitudinal analysis of staphylococcal epidemiology, and in the process, identifies the seasonal nature of infections to be multifactorial, depending on such variables as specimen source and patient location. The seasonal nature of staphylococcal infections appears to be the product of a complex interaction among host, pathogen, and environment.

Revision of a fractured uncemented revision stem using a custom designed punch and retrograde through-knee approach.

We report a unique case of a fractured modular cobalt chromium connection taper Revitan (Zimmer, Warsaw, IN) revision prosthesis. Macroscopic examination revealed a fracture at the diaphyseal-metaphyseal junction of this modular component. This report highlights that fractures can still occur with modern modular prostheses. We are not aware of any published failures of the Revitan revision prosthesis. We also describe a unique method of retrieval for a broken well fixed uncemented femoral stem, using a custom designed extraction instrument via a through-knee approach.

Ultrasonographic findings after Achilles tenotomy during Ponseti treatment for clubfeet: Is ultrasound a reliable tool to assess tendon healing?

INTRODUCTION: Several studies have claimed ultrasound to be useful and accurate in assessing the healing phase of Achilles tendons after tenotomy during Ponseti treatment for clubfoot deformity. The purpose of our study was to assess the healing process of Achilles tendons ultrasonographically after tenotomy as part of Ponseti clubfoot management and to assess the effects of previously not considered ultrasound properties (anisotropy, partial volume effect), and whether these practical considerations affect accurate measurements which have been claimed possible in previous studies. MATERIALS AND METHODS: We monitored the post-tenotomy healing process in 15 patients (22 tendons) using high frequency ultrasound for a minimum of six months (range 6-14 months). The scanning was discontinued once a tendon looked normal or when the appearance remained unchanged between scans. We also studied nine patients (11 tendons) who had undergone Achilles tenotomies up to seven years previously (range 34-83 months). RESULTS: In the immediate postoperative period, ultrasound showed large variations in the distance of the tenotomy from the calcaneum as well as the obliquity and completeness of the surgical division. We encountered pitfalls in the use of ultrasound to define healing stages that were not described previously. Sonography was inaccurate and subjective in assessing both completeness of the surgical division and tendon measurements. Despite ultrasonographically proven incomplete tendon division in 63 % of cases, the clinical effect of an immediate increase of passive foot dorsiflexion from the pretenotomy position with an obvious palpable tendon gap was achieved in all patients. At the end of the study, 65 % of tendons did not achieve a normal appearance. CONCLUSIONS: We do not think that routine ultrasound studies are of any value as an adjunct to clinical assessment intra- and post-operatively. It can give misleading information regarding the need to complete the tenotomy, which may increase risks associated with a further pass of the scalpel blade.

Prophylactic radiotherapy against heterotopic ossification following internal fixation of acetabular fractures: a comparative estimate of risk.

OBJECTIVE: Radiotherapy (RT) is effective in preventing heterotopic ossification (HO) around acetabular fractures requiring surgical reconstruction. We audited outcomes and estimated risks from RT prophylaxis, and alternatives of indometacin or no prophylaxis. METHODS: 34 patients underwent reconstruction of acetabular fractures through a posterior approach, followed by a 8-Gy single fraction. The mean age was 44 years. The mean time from surgery to RT was 1.1 days. The major RT risk is radiation-induced fatal cancer. The International Commission on Radiological Protection (ICRP) method was used to estimate risk, and compared with a method (Trott and Kemprad) specifically for estimating RT risk for benign disease. These were compared with risks associated with indometacin and no prophylaxis. RESULTS: 28 patients (82%) developed no HO; 6 developed Brooker Class I; and none developed Class II-IV HO. The ICRP method suggests a risk of fatal cancer in the range of 1 in 1000 to 1 in 10,000; the Trott and Kemprad method suggests 1 in 3000. For younger patients, this may rise to 1 in 2000; and for elderly patients, it may fall to 1 in 6000. The risk of death from gastric bleeding or perforation from indometacin is 1 in 180 to 1 in 900 in older patients. Without prophylaxis risk of death from reoperation to remove HO is 1 in 4000 to 1 in 30,000. CONCLUSION: These results are encouraging, consistent with much larger series and endorse our multidisciplinary management. Risk estimates can be used in discussion with patients. ADVANCES IN KNOWLEDGE: The risk from RT prophylaxis is small, it is safer than indometacin and substantially overlaps with the range for no prophylaxis.