Anatomic ACL reconstruction: the normal central tibial footprint position and a standardised technique for measuring tibial tunnel location on 3D CT.

PURPOSE: The aim of this study was to define the normal ACL central tibial footprint position and describe a standardised technique of measuring tibial tunnel location on 3D CT for anatomic single-bundle ACL reconstruction. METHODS: The central position of the ACL tibial attachment site was determined on 76 MRI scans of young individuals. The central footprint position was referenced in the anterior-posterior (A-P) and medial-lateral (M-L) planes on a grid system over the widest portion of the proximal tibia. 3D CT images of 26 young individuals had a simulated tibial tunnel centred within the bony landmarks of the ACL footprint, and the same grid system was applied over the widest portion of the proximal tibia. The MRI central footprint position was compared to the 3D CT central footprint position to validate the technique and results. RESULTS: The median age of the 76 MRI subjects was 24 years, with 32 females and 44 males. The ACL central footprint position was at 39 (±3 %) and 48 (±2 %), in the A-P and M-L planes, respectively. There was no significant difference in this position between sexes. The median age of the 26 CT subjects was 25.5 years, with 10 females and 16 males. The central position of the bony ACL footprint was at 38 (±2 %) and 48 (±2 %), in the A-P and M-L planes, respectively. The MRI and CT central footprint positions were not significantly different in relation to the medial position, but were different in relation to the anterior position (A-P 39 % vs. 38 %, p = 0.01). The absolute difference between the central MRI and CT reference positions was 0.45 mm. CONCLUSIONS: The ACL's normal central tibial footprint reference position has been defined, and the technique of measuring tibial tunnel location with a standardised grid system is described. This study will assist surgeons in evaluating tibial tunnel position in anatomic single-bundle ACL reconstruction. LEVEL OF EVIDENCE: III.

Low-pathogenicity Mycoplasma spp. alter human monocyte and macrophage function and are highly prevalent among patients with ventilator-acquired pneumonia.

BACKGROUND: Ventilator-acquired pneumonia (VAP) remains a significant problem within intensive care units (ICUs). There is a growing recognition of the impact of critical-illness-induced immunoparesis on the pathogenesis of VAP, but the mechanisms remain incompletely understood. We hypothesised that, because of limitations in their routine detection, Mycoplasmataceae are more prevalent among patients with VAP than previously recognised, and that these organisms potentially impair immune cell function. METHODS AND SETTING: 159 patients were recruited from 12 UK ICUs. All patients had suspected VAP and underwent bronchoscopy and bronchoalveolar lavage (BAL). VAP was defined as growth of organisms at >10(4) colony forming units per ml of BAL fluid on conventional culture. Samples were tested for Mycoplasmataceae (Mycoplasma and Ureaplasma spp.) by PCR, and positive samples underwent sequencing for speciation. 36 healthy donors underwent BAL for comparison. Additionally, healthy donor monocytes and macrophages were exposed to Mycoplasma salivarium and their ability to respond to lipopolysaccharide and undertake phagocytosis was assessed. RESULTS: Mycoplasmataceae were found in 49% (95% CI 33% to 65%) of patients with VAP, compared with 14% (95% CI 9% to 25%) of patients without VAP. Patients with sterile BAL fluid had a similar prevalence to healthy donor BAL fluid (10% (95% CI 4% to 20%) vs 8% (95% CI 2% to 22%)). The most common organism identified was M. salivarium. Blood monocytes from healthy volunteers incubated with M. salivarium displayed an impaired TNF-α response to lipopolysaccharide (p=0.0003), as did monocyte-derived macrophages (MDMs) (p=0.024). MDM exposed to M. salivarium demonstrated impaired phagocytosis (p=0.005). DISCUSSION AND CONCLUSIONS: This study demonstrates a high prevalence of Mycoplasmataceae among patients with VAP, with a markedly lower prevalence among patients with suspected VAP in whom subsequent cultures refuted the diagnosis. The most common organism found, M. salivarium, is able to alter the functions of key immune cells. Mycoplasmataceae may contribute to VAP pathogenesis.

Outcome of meniscal allograft transplantation related to articular cartilage status: advanced chondral damage should not be a contraindication.

PURPOSE: Advanced chondral damage (bare bone) at presentation is considered a contraindication to meniscal allograft transplantation (MAT), yet there are few other options for young patients where arthroplasty is not appropriate. This study hypothesis is that MAT in patients with advanced chondral damage can obtain good clinical outcomes, equivalent to patients with minimal chondral damage. METHOD: A prospective longitudinal study of 99 consecutive patients who underwent MAT between May 2005 and Feb 2013, with a minimum of 1-year follow-up. Patients were categorised into two groups: 60 in Group A (Good) up to ICRS Chondral grade 3b involving <1 cm(2) and 39 in Group B (Bare) ICRS grade 3b involving >1 cm(2) or worse. Outcomes were assessed by PROMS (KOOS, IKDC, Lysholm, Tegner Activity Scale), with an endpoint of meniscal allograft failure. RESULTS: Mean follow-up was 2.9 years (range 1.1-9.1, SD 1.23), with a similar male to female and lateral to medial ratios between the groups (n.s). The age of Group B was significantly older than Group A (35 vs 29 years, p = 0.002). The status of the articular cartilage at the time of transplant was directly related to the number of years since index meniscectomy [(A) Mean 6.9 years, SD 6.3; (B) 11.9 years, SD 7.4; p = 0.001]. Pre-operatively, patients in Group B had significantly worse pain and functional outcome scores (KOOS p = 0.022, Lysholm p = 0.025, IKDC pain subset p = 0.035). The mean increase PROMs was significant in both groups at 1 year (KOOS p < 0.05, IKDC p < 0.001, Lysholm p < 0.001), and the pain and functional scores were no longer significantly different between groups (n.s.). The outcome measures continued to improve in both groups at 2 and 3 years, with slightly greater improvement in Group A. Failure of the meniscal allograft occurred in 9 patients (A:1, B:8) at a mean time of 1.1 years (SD 0.55). Kaplan-Meier survival at 2 years was 97.9% (A) and 78% (B) (p = 0.002). Logistic regression analysis demonstrated a relationship between survival and chondral grade (p = 0.001) and number of concomitant procedures (p < 0.001). CONCLUSION: Patients with advanced chondral damage should not be excluded from MAT. Though there is a higher initial failure rate, these patients obtain a similar therapeutic benefit to the traditional, ideal patient group. LEVEL OF EVIDENCE: III.

Who Can You Trust? Assessing Vulnerability to Digital Imposter Scams.

Social Security scams have become one of the most common forms of government imposter fraud. These scams cost innocent people in the USA millions of dollars each year and undercut the ability of the Social Security Administration to contact and interact with citizens about their benefits. This raises questions as to how individuals might improve their ability to discriminate between scams and real appeals from the Social Security Administration. The present study applies the techniques of inoculation theory to a nationally representative sample of over 4,000 US adults in a series of experiments. Participants are randomly assigned to one of four training programs: from general tips about scams to a targeted experiential learning program. There is strong evidence that the inoculation process successfully and significantly increases fraud detection without decreasing trust in real communications. It provides protection against both SSA and non-SSA scams, such as Amazon imposter scams. The impact, however, is specific to the mode of communication (email versus letter or SMS) and decays over time; training programs should be targeted accordingly.

Moving into the red - a near infra-red optical probe for analysis of human neutrophil elastase in activated neutrophils and neutrophil extracellular traps.

Neutrophils are the first immune cells recruited for defence against invading pathogens; however, their dysregulated activation and subsequent release of the enzyme human neutrophil elastase is associated with several, inflammation-based, diseases. Herein, we describe a FRET-based, tri-branched (one quencher, three fluorophores) near infrared probe that provides an intense OFF/ON amplified fluorescence signal for specific detection of human neutrophil elastase. The probe allowed selective detection of activated neutrophils and labelling of neutrophil extracellular traps.

The relationship between long-term blood pressure variability and cortical thickness in older adults.

High blood pressure variability (BPV) is a risk factor for cognitive decline and dementia, but its association with cortical thickness is not well understood. Here we use a topographical approach, to assess links between long-term BPV and cortical thickness in 478 (54% men at baseline) community dwelling older adults (70-88 years) from the ASPirin in Reducing Events in the Elderly NEURO sub-study. BPV was measured as average real variability, based on annual visits across three years. Higher diastolic BPV was significantly associated with reduced cortical thickness in multiple areas, including temporal (banks of the superior temporal sulcus), parietal (supramarginal gyrus, post-central gyrus), and posterior frontal areas (pre-central gyrus, caudal middle frontal gyrus), while controlling for mean BP. Higher diastolic BPV was associated with faster progression of cortical thinning across the three years. Diastolic BPV is an important predictor of cortical thickness, and trajectory of cortical thickness, independent of mean blood pressure. This finding suggests an important biological link in the relationship between BPV and cognitive decline in older age.

Collecting oral fluid samples from due-to-wean litters.

Oral fluids are a common diagnostic sample in group-housed nursery, grow-finish, and adult swine. Although oral fluids from due-to-wean litters could be a valuable tool in monitoring pathogens and predicting the health status of pig populations post-weaning, it is generally not done because of inconsistent success in sample collection. The objective of this study was to determine the optimum procedure for collecting oral fluid samples from due-to-wean litters. Successful collection of oral fluids from due-to-wean litters using "Litter Oral Fluid" (LOF) or "Family Oral Fluid" (FOF) sampling techniques were compared in 4 phases involving 920 attempts to collect oral fluids. Phase 1 testing showed that prior exposure to a rope improved the success rates of both LOF (33.4%) and FOF (16.4%) techniques. Phase 2 determined that longer access to the rope (4 h vs 30 min) did not improve the success rate for either LOF or FOF. Phase 3 evaluated the effect of attractants and found that one (Baby Pig Restart®) improved the success rate when used with the FOF technique. Phase 4 compared the success rates of "optimized LOF" (litters previously trained) vs "optimized FOF" (litter previously trained and rope treated with Baby Pig Restart®) vs standard FOF. No difference was found between the FOF-based techniques, but both were superior to the "optimized LOF" technique. Thus, FOF-based procedures provided a significantly higher probability of collecting oral fluids from due-to-wean litters (mean success rate 84.9%, range 70% to 92%) when compared to LOF-based methods (mean success rate 24.1%, range 16.5% to 32.2%).

Prospective Evaluation of Cognitive Health and Related Factors in Elderly at Risk for Developing Alzheimer's Dementia: A Longitudinal Cohort Study.

BACKGROUND: The CHARIOT PRO Main study is a prospective, non-interventional study evaluating cognitive trajectories in participants at the preclinical stage of Alzheimer's disease (AD) classified by risk levels for developing mild cognitive impairment due to AD (MCI-AD). OBJECTIVES: The study aimed to characterize factors and markers influencing cognitive and functional progression among individuals at-risk for developing MCI-AD, and examine data for more precise predictors of cognitive change, particularly in relation to APOE ε4 subgroup. DESIGN: This single-site study was conducted at the Imperial College London (ICL) in the United Kingdom. Participants 60 to 85 years of age were classified as high, medium (amnestic or non-amnestic) or low risk for developing MCI-AD based on RBANS z-scores. A series of clinical outcome assessments (COAs) on factors influencing baseline cognitive changes were collected in each of the instrument categories of cognition, lifestyle exposure, mood, and sleep. Data collection was planned to occur every 6 months for 48 months, however the median follow-up time was 18.1 months due to early termination of study by the sponsor. RESULTS: 987 participants were screened, among them 690 participants were actively followed-up post baseline, of whom 165 (23.9%) were APOE ε4 carriers; with at least one copy of the allele. The mean age was 68.73 years, 94.6% were white, 57.4% were female, and 34.8% had a Family History of Dementia with a somewhat larger percentage in the APOE ε4 carrier group (42.4%) compared to the non-carrier group (32.4%). Over half of the participants were married and 53% had a Bachelor's or higher degree. Most frequently, safety events typical for this population consisted of upper respiratory tract infection (10.4%), falls (5.2%), hypertension (3.5%) and back pain (3.0%). Conclusion (clinical relevance): AD-related measures collected during the CHARIOT PRO Main study will allow identification and evaluation of AD risk factors and markers associated with cognitive performance from the pre-clinical stage. Evaluating the psycho-biological characteristics of these pre-symptomatic individuals in relation to their natural neurocognitive trajectories will enhance current understanding on determinants of the initial signs of cognitive changes linked to AD.

The mitigating influence of time preference on the relation between smoking and BMI scores.

OBJECTIVE: Prior studies have found a strong negative relation between smoking and body mass index (BMI). Smoking and unhealthy eating both imply a preference for utility in the present at the expense of future consumption. This analysis seeks to proxy this preference through a composite index of equally weighted intertemporal behaviors to isolate the impact of smoking upon BMI independent of time discounting. DESIGN: Ordinary least squares regression is used to analyze BMI score based on a number of key independent variables. SUBJECTS: A total of 2970 individuals who provided data for the United States Department of Agriculture's (USDA) Continuing Survey of Food Intakes by Individuals (CSFII) 1994-1996, as well as the Diet and Health Knowledge Survey (DHKS). RESULTS: Adding time preference to a multivariate model inflates the magnitude of the smoking effect, consistent with discounted utility theory. CONCLUSIONS: Results suggest that full effect of the non-intertemporal aspects of smoking (e.g., the substitution of cigarettes for food) on BMI scores may be underestimated in previous studies that fail to account for the mitigating influence of time preference.

Mechanisms regulating the renal excretion of sodium during pregnancy.

Observations were made on the relation of the renin-angiotensin-aldosterone system and renal hemodynamic function to sodium balance in 43 pregnant dogs. Daily balance studies revealed that about 30-40% of ingested sodium was retained during the last half of pregnancy; during the same period, potassium balance was also positive but to a lesser extent. For groups of pregnant dogs, plasma renin activity (n = 14) and aldosterone secretion (n = 19) were significantly higher than normal; however, in some animals one or both functions were normal even though sodium retention was present. In contrast, plasma renin substrate concentration was consistently elevated during pregnancy in seven dogs. In a group of nine dogs in which both aldosterone secretion and plasma renin activity were measured, aldosterone secretion was elevated in the three dogs with the highest values for plasma renin activity; in two of the remaining six animals aldosterone secretion was elevated but plasma renin activity was normal or only slightly increased. The sequestration of sodium and water into the uterine contents was defined quantitatively in this study but evidence was lacking to support the idea that such changes led to renin release. The glomerular filtration rate (GFR) was significantly elevated throughout pregnancy but a significant decrease from the high level of mid-pregnancy occurred during the last half of pregnancy; this decrease in GFR probably contributed to the sodium retention. Administration of a large dose of deoxycorticosterone acetate (DOCA) to dogs in late pregnancy produced marked sodium retention but "escape" from the sodium-retaining steroid occurred. The data demonstrate that although increased activity of the renin-angiotensin-aldosterone system was frequently present during pregnancy, a normal rate of aldosterone secretion occurred. This finding and the observed "escape" from DOCA suggest the existence of sodium-retaining mechanisms other than the mechanism provided by a high plasma level of aldosterone.

Role of Akt2 in regulation of metastasis suppressor 1 expression and colorectal cancer metastasis.

Survival signaling is critical for the metastatic program of cancer cells. The current study investigated the role of Akt survival proteins in colorectal cancer (CRC) metastasis and explored potential mechanisms of Akt-mediated metastasis regulation. Using an orthotopic implantation model in mice, which uniquely recapitulates the entire multistep process of CRC metastasis, combined with an inducible system of short hairpin RNA-mediated Akt isoform knockdown in human CRC cells, our studies confirm a role of Akt2 in CRC cell dissemination to distant organs in vivo. Akt2 deficiency profoundly inhibited the development of liver lesions in mice, whereas Akt1 had no effect under the experimental conditions used in the study. Array analysis of human metastatic genes identified the scaffolding protein metastasis suppressor 1 (MTSS1) as a novel Akt2-regulated gene. Inducible loss of Akt2 in CRC cells robustly upregulated MTSS1 at the messenger RNA and protein level, and the accumulated protein was functionally active as shown by its ability to engage an MTSS1-Src-cortactin inhibitory axis. MTSS1 expression led to a marked reduction in levels of functional cortacin (pcortactin Y421), an actin nucleation-promoting factor that has a crucial role in cancer cell invasion and metastasis. MTSS1 was also shown to mediate suppressive effects of Akt2 deficiency on CRC cell viability, survival, migration and actin polymerization in vitro. The relevance of these findings to human CRC is supported by analysis of The Cancer Genome Atlas (TCGA) and NCBI GEO data sets, which demonstrated inverse changes in expression of Akt2 and MTSS1 during CRC progression. Taken together, the data identify MTSS1 as a new Akt2-regulated gene, and point to suppression of MTSS1 as a key step in the metastasis-promoting effects of Akt2 in CRC cells.

Key mechanisms governing resolution of lung inflammation.

Innate immunity normally provides excellent defence against invading microorganisms. Acute inflammation is a form of innate immune defence and represents one of the primary responses to injury, infection and irritation, largely mediated by granulocyte effector cells such as neutrophils and eosinophils. Failure to remove an inflammatory stimulus (often resulting in failed resolution of inflammation) can lead to chronic inflammation resulting in tissue injury caused by high numbers of infiltrating activated granulocytes. Successful resolution of inflammation is dependent upon the removal of these cells. Under normal physiological conditions, apoptosis (programmed cell death) precedes phagocytic recognition and clearance of these cells by, for example, macrophages, dendritic and epithelial cells (a process known as efferocytosis). Inflammation contributes to immune defence within the respiratory mucosa (responsible for gas exchange) because lung epithelia are continuously exposed to a multiplicity of airborne pathogens, allergens and foreign particles. Failure to resolve inflammation within the respiratory mucosa is a major contributor of numerous lung diseases. This review will summarise the major mechanisms regulating lung inflammation, including key cellular interplays such as apoptotic cell clearance by alveolar macrophages and macrophage/neutrophil/epithelial cell interactions. The different acute and chronic inflammatory disease states caused by dysregulated/impaired resolution of lung inflammation will be discussed. Furthermore, the resolution of lung inflammation during neutrophil/eosinophil-dominant lung injury or enhanced resolution driven via pharmacological manipulation will also be considered.

Identification and characterization of an in vivo regulated D15/Oma87 homologue in Shigella flexneri using differential display polymerase chain reaction.

Shigella genes expressed during infection likely contribute to adaptation and virulence in the host. Using differential display PCR (DDPCR), a cDNA fragment from Shigella flexneri serotype 5 that showed enhanced expression in a murine model was identified, cloned and sequenced. Enhanced expression was verified by RNA dot blot. The full-length gene was cloned using PCR and sequenced. The complete gene sequence was BLAST searched against GenBank, and exhibited strong homology to genes encoding Haemophilus influenzae D15 and Pasteurella multocida Oma87 protective outer membrane antigens. The S. flexneri gene putatively encodes a approximately 90-kDa protein and was termed oma90. The deduced amino acid sequence from oma90 was analyzed and compared to the D15/Oma87 antigens. Additionally, oma90 mapped to a cluster of orthologous groups, and probably contains an ancient conserved domain. The chromosomal organization of oma90 was similar to that for H. influenzae and P. multocida as well as for other known homologues. Northern blot revealed that the oma90 transcript encoded only oma90. This report represents the first description of a S. flexneri gene identified based on enhanced expression in the host. Furthermore, we report the first evidence demonstrating in vivo regulation of a member of the d15/oma87 gene family.

(Vinylaryloxy)acetic acids. A new class of diuretic agents. 4. Various ((2-substituted and 2,2-disubstituted vinyl)aryloxy)acetic acids.

A variety of [(2-substituted and 2,2-disubstituted vinyl)aryloxy]acetic acids was synthesized in which the substituents were primarily electron-withdrawing groups. These compounds were tested in dogs for their saluretic and diuretic properties. Many of the compounds exhibited significant activity; however, they were generally less potent than those reported in the three earlier papers in this series.

(Vinylaryloxy)acetic acids. A new class of diuretic agents. 2. (4-(3-Oxo-1-alkenyl)phenoxy)acetic acids.

A series of (E)-[4-(3-oxo-1-alkenyl)phenoxy]acetic acids was synthesized and tested in dogs for saluretic and diuretic properties. Several compounds exhibited noteworthy activity, e.g., (E)-[2,3-dichloro-4-(3-oxo-1-butenyl)phenoxy]acetic acid (3a). While possessing only half of the dose potency of ethacrynic acid (2), the active compounds act similarly to this diuretic in causing a prompt increase in the excretion of water and in the excretion of sodium and chloride ions in approximately equimolar amounts. Potassium ion excretion is increased but less markedly than sodium excretion.

11,12-Secoprostaglandins. 1. Acylhydroxyalkanoic acids and related compounds.

The synthesis is described of a series of acylhydroxyalkanoic acids which embody structural modifications of that class of secoprostaglandins which are formally derived from the natural substances by scission of the cyclopentane ring between carbon atoms 11 and 12. These analogues have been tested for their ability to stimulate cAMP formation in the mouse ovary, a characteristic action of the (E)-prostaglandins, and for their ability to bind to the rat lipocyte prostaglandin receptor. Certain members of the series that most closely resemble the prostaglandins in structure (e.g., 8-acetyl-12-hydroxyheptadecanoic acid) markedly stimulate cAMP formation at concentrations in the pharmacological range and show a significant affinity for the prostaglandin receptor. Conversely, these compounds are not substrates for prostaglandin 15-hydroxydehydrogenase which catalyzes a major reaction in the biological deactivation of the prostaglandins.

11,12-Secoprostaglandins. 3. 8-Alkylthio(sulfinyl and sulfonyl)-12-hydroxyalkanoic acids and related compounds.

A series of 8-alkylthio(sulfinyl and sulfonyl)-12-hydroxyalkanoic acids which embody structural features of 11,12-secoprostaglandins was synthesized and evaluated for their ability to mimic the E series prostaglandins in stimulating cAMP formation in the mouse ovary and in binding to the rat lipocyte prostaglandin receptor. A key member of the series, 8-methylsulfonyl-12-hydroxyheptadecanoic acid, markedly stimulated cAMP formation at reasonable pharmacological concentrations, shows significant affinity for a prostaglandin receptor, and effectively inhibits antigen-induced lymphocyte transformation. In contrast, this compound is not a substrate for 15-hydroxyprostaglandin dehydrogenase, the major prostaglandin-metabolizing enzyme.

11,12-Secoprostaglandins. 5. 8-Acetyl- or 8-(1-hydroxyethyl)-12-hydroxy-13-aryloxytridecanoic acids and sulfonamide isosteres as inhibitors of platelet aggregation.

The synthesis of a series of 8-acetyl- (or 1-hydroxyethyl-) 12-hydroxy-13-aryloxytridecanoic acids and their sulfonamide isosteres is described. These compounds are formally derived from members of earlier reported series of modified secoprostaglandins by replacing the omega-butyl chain termini by substituted aryloxy groups. A number of these compounds are potent inhibitors of collagen-induced blood platelet aggregation in guinea pigs on oral administration.

Structure-activity, theoretical, and X-ray studies on the intramolecular interactions in a series of novel histamine H2 receptor antagonists.

The furan ring of the histamine H2 receptor antagonist 3-amino-4-[[2-[[[5-[(dimethylamino)methyl]-2-furanyl]-methyl] thio]ethyl]amino]-1,2,5-thiadiazole 1-oxide (1a) was replaced by thiophene, pyridine, benzene, and pyrrole. The relative receptor affinities of these analogues were estimated by in vitro and in vivo techniques. A theoretical model for the stacking interaction, observed by single crystal X-ray analysis of 1a, was developed, and the ability to enter into this type of interaction was estimated. The X-ray analysis of the pyridine analogue of 1a revealed no intramolecular stacking interaction. The theoretical studies were evaluated in light of the observed receptor affinities, and the relevance of the solid-state geometry of 1a to the receptor-bound geometry was assessed. It is suggested that the stacked geometry found in the X-ray structure of 1a does not represent a conformation that is relevant to that bound at the histamine H2 receptor.