Nanoscale platinum printing on insulating substrates.

The deposition of noble metals on soft and/or flexible substrates is vital for several emerging applications including flexible electronics and the fabrication of soft bionic implants. In this paper, we describe a new strategy for the deposition of platinum electrodes on a range of materials, including insulators and flexible polymers. The strategy is enabled by two principle advances: (1) the introduction of a novel, low temperature strategy for reducing chloroplatinic acid to platinum using nitrogen plasma; (2) the development of a chloroplatinic acid based liquid ink formulation, utilizing ethylene glycol as both ink carrier and reducing agent, for versatile printing at nanoscale resolution using dip-pen nanolithography (DPN). The ink formulation has been printed and reduced upon Si, glass, ITO, Ge, PDMS, and Parylene C. The plasma treatment effects reduction of the precursor patterns in situ without subjecting the substrate to destructively high temperatures. Feature size is controlled via dwell time and degree of ink loading, and platinum features with 60 nm dimensions could be routinely achieved on Si. Reduction of the ink to platinum was confirmed by energy dispersive x-ray spectroscopy (EDS) elemental analysis and x-ray diffraction (XRD) measurements. Feature morphology was characterized by optical microscopy, SEM and AFM. The high electrochemical activity of individually printed Pt features was characterized using scanning electrochemical microscopy (SECM).

Interpersonal functioning and body image dissatisfaction in patients referred for NHS aesthetic surgery: A mediating role between emotion regulation and perfectionism?

BACKGROUND: Few studies have explored psychological factors associated with body image dissatisfaction in individuals seeking aesthetic surgery on the NHS. In NHS Scotland, The Adult Exceptional Aesthetic Referral Protocol (AEARP) states that individuals are only eligible for consideration for surgery where there is significant psychological distress and physical criteria associated with perceived problem of appearance. The AEARP necessitates that individuals seeking aesthetic surgery on the NHS must have a psychological assessment. It is therefore crucial to identify psychological factors associated with body image dissatisfaction that may highlight contraindications for surgery or are amenable to psychological intervention. METHOD: A total of 311 consecutive patients seeking aesthetic surgery who were referred for psychological assessment under the AEARP completed a series of psychometric measures as part of routine clinical practice. Multiple mediation analyses using bootstrapped method was used to explore the relationship between interpersonal functioning, emotion regulation, perfectionism, and body image dissatisfaction. RESULTS: Multiple mediation analysis indicated that emotion regulation partially mediates the relationship between interpersonal functioning and body image dissatisfaction in this clinical population. CONCLUSION: This study indicates that interpersonal functioning and emotion regulation significantly relate to body image dissatisfaction in this patient group. Psychological assessment of patient suitability for aesthetic surgery should include assessment of interpersonal functioning and emotion regulation which may be amenable to psychological intervention and be of significant benefit to patients either pre- or post-operatively or instead of surgery.

Sun heated surfaces are an environmental hazard for young children.

AIMS: Children commonly sustain heat contact type burn injuries from sun heated surfaces during the summer months in hot, sunny climates. The aim of this study was to review the causes and outcomes in a series of heat contact type burns sustained by children who touched hot sun heated surfaces. METHODS: A retrospective chart review was performed to identify all children who sustained burn injuries due to naturally heated surfaces and were treated between January 2012 and December 2017 at Children's Hospital Colorado. Demographics of the subjects and clinical data regarding their burn injuries were collected. RESULTS: A total of 58 children were identified over the study period, involving 118 burn wounds. The median age was 17 months (interquartile range = 14-23), and 33 were male (57%). Mean total body surface area (TBSA) was 1.4% (standard deviation = 1). A foot was the most commonly involved area, affecting 36 subjects (62%). The most common causes of these burn injuries were metal thresholds (n = 7, 12%) and metal covers or lids (n = 5, 9%) outside the home. The depth of the burn injury was partial thickness in 57 children (98%). The mean time to heal was 12 ± 6 days, and the majority of injuries occurred in June (n = 28, 48%). CONCLUSION: Heat contact type burn injuries from sun heated surfaces commonly affect children ⩽2 years of age during the summer months, and the majority of these injuries occur around the home environment. They are preventable injuries, and this information should be used for prevention and education materials for parents and healthcare providers, who reside in hot, sunny climates.

VATS management of an enlarging multicystic pneumatocele.

A multicystic pneumatocele progressively enlarged when the patient required positive pressure ventilation for an intercurrent respiratory syncytial virus infection. Video Assisted Thoracoscopic Surgery was used to visualize the pneumatocele for cannulation. One chamber of the pneumatocele was cannulated with a pigtail catheter and another large chamber ruptured, without cannulation. The multicystic pneumatocele resolved with this therapy.

Does the type of graft affect the outcome of revision anterior cruciate ligament reconstruction? a meta-analysis of 32 studies.

AIMS: Our aim was to perform a meta-analysis of the outcomes of revision anterior cruciate ligament (ACL) reconstruction, comparing the use of different types of graft. MATERIALS AND METHODS: A search was performed of Medline and Pubmed using the terms "Anterior Cruciate Ligament" and "ACL" combined with "revision", "re-operation" and "failure". Only studies that reported the outcome at a minimum follow-up of two years were included. Two authors reviewed the papers, and outcomes were subdivided into autograft and allograft. Autograft was subdivided into hamstring (HS) and bone-patellar tendon-bone (BPTB). Subjective and objective outcome measures were analysed and odds ratios with confidence intervals were calculated. RESULTS: A total of 32 studies met the inclusion criteria. Five studies used HS autografts, eight reported using BPTB autografts, two used quadriceps tendon autografts and eight used various types. Seven studies reported using allografts, while the two remaining used both BPTB autografts and allografts. Overall, 1192 patients with a mean age of 28.7 years (22.5 to 39) and a mean follow-up of 5.4 years (2.0 to 9.6) were treated with autografts, while 269 patients with a mean age of 28.4 years (25 to 34.6) and a mean follow-up of 4.0 years (2.3 to 6.0) were treated with allografts. Regarding allografts, irradiation with 2.5 mrad was used in two studies while the graft was not irradiated in the seven remaining studies. Reconstructions following the use of autografts had better outcomes than those using allograft with respect to laxity, measured by KT-1000/2000 (MEDmetric Corporation) and the rates of complications and re-operations. Those following the use of allografts had better mean Lysholm and Tegner activity scores compared with autografts. If irradiated allografts were excluded from the analysis, outcomes no longer differed between the use of autografts and allografts. Comparing the types of autograft, all outcomes were similar except for HS grafts which had better International Knee Documentation Committee scores compared with BPTB grafts. CONCLUSION: Autografts had better outcomes than allografts in revision ACL reconstruction, with lower post-operative laxity and rates of complications and re-operations. However, after excluding irradiated allografts, outcomes were similar between autografts and allografts. Overall, the choice of graft at revision ACL reconstruction should be on an individual basis considering, for instance, the preferred technique of the surgeon, whether a combined reconstruction is required, the type of graft that was previously used, whether the tunnels are enlarged and the availability of allograft. Cite this article: Bone Joint J 2017;99-B:714-23.

Patch-Augmented Rotator Cuff Repair and Superior Capsule Reconstruction.

BACKGROUND: Massive rotator cuff tears in active patients with minimal glenohumeral arthritis remain a particular challenge for the treating surgeon. METHODS: A selective literature search was performed and personal surgical experiences are reported. RESULTS: For patients with irreparable rotator cuff tears, a reverse shoulder arthroplasty or a tendon transfer are often performed. However, both procedures have rather high complication rates and debatable long-term results, particularly in younger patients. Therefore, patch-augmented rotator cuff repair or superior capsule reconstruction (SCR) have been recently developed as arthroscopically applicable treatment options, with promising biomechanical and early clinical results. CONCLUSION: For younger patients with irreparable rotator cuff tears wishing to avoid tendon transfers or reverse total shoulder arthroplasty, both patch-augmentation and SCR represent treatment options that may delay the need for more invasive surgery.

Conductive and protein resistant polypyrrole films for dexamethasone delivery.

The development of inherently conducting polymers as controllable/programmable drug delivery systems has attracted significant interest in medical bionics, and the interfacial properties of the polymers, in particular, protein adsorption characteristics, is integral to the stability of the overall performance. Herein we report a hybrid conducting system based on polypyrrole doped with an anti-inflammatory prodrug, dexamethasone phosphate (DexP), upon which post-surface modification was conducted to render the polymer more biostable. We firstly investigated the influence of the current density and DexP concentration on the physiochemical properties and surface characteristics of the resulting polymer films. Films were then surface modified with thiolated poly(ethylene glycol). The influence of surface modification on inhibition of nonspecific protein adsorption to the polymer surfaces was evaluated using electrochemistry and quartz crystal microbalance. Furthermore, studies were undertaken to examine the effect of surface coatings on the drug release behaviour triggered by electrical stimulation. Our results demonstrated that both the physiochemical and interfacial properties of conducting polymers can be modulated to enhance the performance of the materials as biocompatible drug delivery systems. This provides important insight into molecular engineering of conducting polymers to facilitate their applications in medical bionics.

The assembly of immunoglobulin-like modules in titin: implications for muscle elasticity.

Titin, a giant muscle protein, forms filaments that span half of the sarcomere and cover, along their length, quite diversified functions. The region of titin located in the sarcomere I-band is believed to play a major rôle in extensibility and passive elasticity of muscle. In the I-band, the titin sequence contains tandem immunoglobulin-like (Ig) modules intercalated by a potentially non-globular region. By a combined approach making use of small angle X-ray scattering and nuclear magnetic resonance techniques, we have addressed the questions of what are the average mutual orientation of poly-Igs and the degree of flexibility around the domain interfaces. Various recombinant fragments containing one, two and four titin I-band tandem domains were analysed. The small-angle scattering data provide a picture of the domains in a mostly extended configuration with their long axes aligned head-to-tail. There is a small degree of bending and twisting of the modules with respect to each other that results in an overall shortening in their maximum linear dimension compared with that expected for the fully extended, linear configurations. This shortening is greatest for the four module construct ( approximately 15%). 15N NMR relaxation studies of one and two-domain constructs show that the motions around the interdomain connecting regions are restricted, suggesting that titin behaves as a row of beads connected by rigid hinges. The length of the residues in the interface seems to be the major determinant of the degree of flexibility. Possible implications of our results for the structure and function of titin in muscles are discussed.

Direct measurement of octanol-water partition coefficients by high-pressure liquid chromatography.

A technique is presented for the direct measurement of octanol-water partition coefficients by HPLC. The method involves running solutes in octanol-saturated water as the mobile phase against water-saturated octanol entrained on an inert support. Log P correlates linearly with log tc for a number of standards. The measurable range in log P (so far) is -0.3 to +3.7. A critical review of chromatographic methods in Hansch analysis is given.

9-Nitrocamptothecin inhibits tumor recrosis factor-mediated activation of human immunodeficiency virus type 1 and enhances apoptosis in a latently infected T cell clone.

Transition from latency to active replication is a crucial stage for the process of human immunodeficiency virus type 1 (HIV-1) infection and life cycle. HIV-1 replication in latently infected cells can be strongly induced by the cytokine tumor necrosis factor alpha (TNF-alpha) and the proliferation-arresting chemical sodium butyrate (NaB). We have investigated the ability of the drug 9-nitrocamptothecin (9NC), a potent cellular topoisomerase I (topo I) inhibitor currently in clinical trials in cancer patients, to regulate HIV-1 replication in latently infected lymphocytic ACH-2 cells on reactivation with either TNF-alpha or NaB. Treatment of ACH-2 cells with 9NC alone resulted in increased levels of viral transcripts, while there was a slight reduction or no change in the levels of host cell transcripts. However, pretreatment of ACH-2 cells with 9NC inhibited TNF-alpha-induced extracellular HIV-1 p24 levels up to approximately 95% and nearly 80% of the cell-associated viral RNAs. The quantitative decrease in viral products was concomitant with a decrease in cellular gene expression and induction of apoptosis in the host cells. 9NC blocked the infected cells at the boundary of the S and G2 phases, resulting in an accelerated apoptosis that was further enhanced with TNF-alpha treatment. Similar results were observed following concurrent exposure to TNF-alpha and 9NC, but 9NC failed to inhibit upregulation of HIV-1 mRNA in ACH-2 cells exposed to TNF-alpha before 9NC treatment. Further, 9NC had no inhibitory effect on NaB-induced apoptosis and upregulation of HIV-1 mRNA expression regardless of whether 9NC and NaB were used concurrently or in various treatment sequences. In uninfected lymphocytic CEM cells derived from a common parental cell line, a slight downregulation of cellular gene expression was detected along with low-level apoptosis. These results demonstrate that 9NC impairs TNF-alpha-induced, but not NaB-induced, HIV-1 activation, and suggest a means of inhibiting active HIV-1 viremia arising as a result of elevated TNF-alpha levels.

Hepatic vein and retrohepatic vena caval injuries in children. Sternotomy first?

Major hepatic vein and retrohepatic vena caval injuries are often fatal because of massive uncontrollable hemorrhage. Children with these injuries can be identified by their unique and dramatic clinical presentation and the selective use of computed tomographic imaging. Volume resuscitation promotes abdominal wall tamponade and hemodynamic stability until the abdomen is opened, at which point there may be sudden exsanguination before vascular control can be obtained. An alternative approach is to open the sternum before opening the abdomen. Management in this sequence provides rapid vascular control and improves the efficiency of hepatic exclusion. To date, five children with major hepatic vascular injuries have been treated with the sternotomy-first approach and four have survived; an atriocaval shunt was used on two occasions. Although sternotomy before laparotomy improves the efficiency of hepatic exclusion and may offer improved survival, accurate preoperative case selection limits its routine use.

Aortoenteric fistula. A 7 year urban experience.

In this 7 year review of the operative records of a single city's teaching hospitals, we found 28 patients with aortoenteric fistulas. Among 25 patients with secondary aortoenteric fistulas, 80 percent presented with a herald bleed. Sepsis was rare. Most diagnostic maneuvers, with the possible exception of upper gastrointestinal tract endoscopy, computerized axial tomography, or ultrasonography, were unhelpful. As noted by others, graft excision, aortic ligature, and extraanatomic bypass is the only predictably useful operative therapy. Initial hospital survival was 60 percent, but this decreased to 36 percent because recurrent aortic complications developed in more than half the initial survivors, 75 percent of whom died. Although the pathogenesis of aortoenteric fistulas remains obscure, our study demonstrates that patients who have previously undergone complicated, repeated, or emergency aortic operations, including previous repair of an aortoenteric fistula, are at high risk for the development of another aortoenteric fistula. Serial screening by noninvasive imaging techniques, such as ultrasonography or computerized axial tomography, may be warranted in these patients.

The pediatric trauma center.

The types of facilities providing care to injured children vary greatly. Some have organized, planned, and functioning Pediatric Trauma Units with all the appropriate personnel, equipment, and facilities needed to provide whatever is needed. Other institutions have done no planning, have no trained personnel, and are, in short, ill prepared to provide any type of care. The resources needed to provide optimum care to the injured child are described for two types of facilities--the Regional Pediatric Trauma Center (RPTC), which provides the most comprehensive of pediatric trauma services, and the Trauma Center with Pediatric Commitment (TCPC), which is the type of institution at which the majority of pediatric trauma care is rendered.

Complications in tunneled CVL versus PICC lines in very low birth weight infants.

OBJECTIVE: Comparison of complications associated with tunneled central venous lines (TCVLs) versus peripherally inserted central catheters (PICCs) in infants <1500 g. STUDY DESIGN: A retrospective cohort study at a university medical center. A total of 96 catheters were placed in 60 infants between 4/94 and 3/99. A retrospective review of these infants' medical record was done to review associated complications of catheter placement. RESULTS: Both groups had similar weights and gestational ages. The duration of catheterization was 28 days in TCVLs and 11 days in PICCs (p<0.05). Total, infectious, and mechanical complications between the two groups were similar. Survival function estimates showed no difference between the two groups up to the 15th day of catheterization. CONCLUSION: There is no difference in efficacy or associated complications between the two groups. If one could anticipate needing a catheter longer than 15 days, then a TCVL might be the better choice.

Investigation of protein adsorption and electrochemical behavior at a gold electrode.

The adsorption of two model proteins, human serum albumin and immunoglobulin G, on a gold electrode surface was investigated using 125I radiolabeling and cyclic voltammetry (CV). 125I radiolabeling was used to determine the extent of protein adsorption, while CV was used to ascertain the effect of the adsorbed protein layer on the electron transfer between the gold electrode and an electroactive moiety in solution, namely, K3Fe(CN)6. The adsorbed amounts of HSA and IgG agreed well with previous results and showed approximately monolayer coverage. The amount of adsorbed protein increased when a positive potential (700 mV) was applied to the electrode, while the application of a negative potential (-800 mV) resulted in a decrease. When the solution pH was varied to alter the charge on the protein, the adsorption trends appeared to follow electrostatic interaction, namely, greater adsorption when the electrode and the protein possessed opposite charge and vice versa. The adsorbed protein layer had the effect of blocking the electron transfer. It was possible to correlate the degree of electron blocking with the amount of adsorbed protein to show that the greater the adsorption, the larger the blocking effect. Of the two proteins used, HSA proved to be more efficient at blocking the electron transfer.

Congenital microgastria in a premature infant.

The authors report the case of a 1,500-g baby boy with microgastria, vascular ring, tracheoesophageal fistula (TEF), and the VATER association. Despite repair of the TEF and placement of a gastrostomy tube, he failed to thrive and had recurrent bouts of aspiration pneumonia. Gastric augmentation at 8 months of age resolved the feeding problems, and he now has a normal diet.

Blunt bile duct injuries in children.

Three of 87 children with blunt liver injuries initially managed without operation required late intervention for bile leakage. Abdominal computed tomography scans in these patients showed liver injuries extending into the porta hepatis. Clinical courses were characterized by persistent abdominal pain, low-grade fever, and prolonged ileus. Radionucleide scan confirmed the suspicion of bile leakage. One patient had complete transection of the common bile duct, which was repaired surgically. Another had partial transection of the left hepatic duct, managed successfully with transampullary biliary decompression. The third patient with an intrahepatic injury was managed with a drain placed at celiotomy. Nonoperative management of blunt pediatric liver injuries carries a risk of persistent bile leakage. Radionucleide scan and endoscopic retrograde cholangiopancreatography are reliable modes of diagnosis and localization. Transampullary biliary decompression is a newer, effective modality for management of the proximal and/or partial bile duct injuries. Treatment must be individualized according to the site and extent of injury.

TNP-470 inhibits intraabdominal adhesion formation.

BACKGROUND/PURPOSE: Angiogenesis plays an integral role in wound healing and tissue remodeling. The authors hypothesized that inhibition of angiogenesis would reduce intraabdominal adhesion formation. METHODS: In 98 C57BL6/J mice, a 2-cm midline laparotomy was performed and a 5 mm2 SILASTIC (Dow Corning, Midland, MI) patch fixed to the right side of the peritoneum. Mice were injected with normal saline (n = 54) or TNP-470, an inhibitor of angiogenesis (n = 44; 30 mg/kg every other day over 6 days before surgery until 10 days after surgery). Animals were killed on postoperative days 10, 15, 35, and 55. Adhesions to the SILASTIC (Dow Corning) patch were scored based on their extent, type, and tenacity. Angiogenesis was quantified digitally as the area of vascularized peritoneum over the patch. RESULTS: At day 10, when TNP-470 was stopped, the percentage of vascularized peritoneum over the patch was less in treatment animals than in controls (P = .004). At day 35, the patch in treatment animals was completely covered by vascularized peritoneum, similar to controls. Adhesions in TNP-470 animals were reduced at day 10 compared with controls (P<.05) and remained reduced off treatment at day 55. CONCLUSIONS: Angiogenesis appears to play an important role in the development of intraabdominal adhesions, because the extent of early neovascularization correlates with adhesion formation. Perioperative treatment with TNP-470, a potent endothelial cell inhibitor, reduced vessel ingrowth over the patch and was associated with a sustained reduction in adhesion formation.

Carotid artery reconstruction following neonatal extracorporeal membrane oxygenation.

Although reconstruction of the right common carotid artery (RCCA) in neonatal extracorporeal membrane oxygenation (ECMO) patients is intuitively attractive, there is little known about prolonged arterial cannulation and how it may affect subsequent vascular repair. A histological study of RCCA segments from neonatal ECMO patients was performed, so that cannulation technique and catheter design could be optimized before proceeding with arterial reconstruction. Circumferential transmural necrosis (CTN) was found in 25 of 31 (80%) arteriotomy specimens in comparison with 2 of 9 (20%) more proximal carotid specimens; the remaining specimens in each group demonstrated either focal subintimal or focal transmural necrosis. CTN was more common in patients with longer ECMO runs (96 +/- 5.9 versus 75 +/- 5.6 hours, P = .009; arteriotomy site), but was independent of cannula size, birthweight, and gestational age. Eleven patients have undergone RCCA reconstruction. Doppler flow studies at 4 to 7 months of follow-up in five patients demonstrated slightly higher right-sided versus left-sided peak systolic, end-diastolic, and mean flow velocities. No neurological or developmental problems could be attributed to vascular reconstruction. In conclusion, RCCA reconstruction is technically feasible, but due to the high prevalence of CTN at the arteriotomy site, excision of this segment is recommended at the time of arterial repair.

Operative intervention for pediatric liver injuries: avoiding delay in treatment.

To identify the physiological and anatomic factors that characterize the need for operative management of blunt pediatric liver injuries, the case records of 106 pediatric trauma victims with liver injuries over a 6-year period were reviewed. Sixty-nine patients were managed without operation (nonoperative) and 37 underwent operation, 7 with penetrating and 30 with blunt liver injuries. Of these 30 patients, 21 underwent laparotomy due to blunt liver injuries (operative); the remaining 9 patients required operation due to associated intraabdominal injuries. Nine (45%) of the 21 operative patients had major hepatic vein or retrohepatic vena caval injuries, 7 of whom died. Overall mortality was 9.4% (10/106). When nonoperative and operative groups were compared, those who underwent laparotomy due to blunt liver injuries: (1) had significantly lower Champion and Pediatric Trauma Scores due to multisystem injury; (2) had 25% or greater lobar disruption with pelvic blood collections on computed tomography scan; (3) underwent early transfusion within 2 hours of admission (18/21); and (4) were frequently found to have a major hepatic vein or retrohepatic vena caval injury at the time of operation. Only one patient successfully managed without operation received greater than 30 mL/kg of blood products within 24 hours of admission. As selective nonoperative management of pediatric liver injuries gains widespread acceptance, the identification of factors that predict the need for operative intervention will limit the potential risks of delay in treatment.