Private healthcare sector spine surgery: patient and surgeon profiles from a large open medical scheme in South Africa

Background It is generally understood that the profile of spine surgery varies by setting, based on factors such as the age profile of the population, the economic context and access to healthcare. Relatively little is known about the profile of spine surgery in South Africa, although one previous report from the public healthcare sector suggested a high burden of trauma and infection-related surgery. To our knowledge, there has been no formal investigation in the private sector. A holistic understanding of spine surgery within our setting may be beneficial for applications such as resource allocation and informing the training needs of future specialists.   Objectives To provide insight into spinal surgery in the South African private healthcare sector by describing spine surgery characteristics within a large open medical scheme, including both patient and surgeon profiles.   Methods This retrospective review included adult inpatient spine surgeries funded by the largest open medical scheme in South Africa between 2008 and 2017. An anonymized dataset extracted from the scheme records included patient demographics, ICD-10 codes, procedure codes and surgeon specialization. Descriptive patient and surgery data were presented. Furthermore, the association between patient and surgery factors and surgeon specialization was investigated using univariate and multivariate analyses.   Results A total of 49,576 index spine surgeries were included. The largest proportion of surgeries involved members 40-59 years old (n=23,543, 48%), approximately half involved female members (n=25,293, 51%) and most were performed by neurosurgeons (n=35,439, 72%). At least 37,755 (76%) surgeries were for degenerative pathology, 2,100 (4%) for trauma and 242 (0.5%) for infection. Adjusted risk ratios (aRR) significantly associated with orthopaedic surgeon specialization included cervical spine region aRR = 0.49 (95% C.I. 0.39-0.61), trauma aRR = 1.50 (95% C.I. 1.20-1.88), deformity aRR = 1.77 (95% C.I. 1.33-2.35) and blood transfusion aRR = 1.46 (95% C.I. 1.12-1.91).   Conclusion Spine surgery in South Africa's largest open medical scheme was dominated by surgery for degenerative pathology in older adults and was performed largely by neurosurgeons. This constituted a stark contrast to a previous report from the public sector and highlighted a mismatch between exposure during public sector registrar training and private practice post-specialization. The findings support the need for private-public collaboration as well as the importance of spine fellowships for all specialists intending to practice spine surgery.

P-043 A RETROSPECTIVE OUTCOME REVIEW OF THE USE OF EGIS ACELLULAR DERMAL MATRIX DURING ABDOMINAL WALL RECONSTRUCTION

Aim

We aimed to demonstrate the relative safety profile of an established non-crosslinked porcine acellular dermal matrix (ADM) during abdominal wall reconstruction.

Material & Methods

Individual real-world safety data on specific mesh products are often lacking. With recent media scrutiny over the use of mesh, we sought to quantify outcomes and demonstrate the safety of a specific ADM (reference 1). A retrospective casenote-based outcome analysis was performed on patients who underwent mesh augmentation during abdominal wall reconstruction from two NHS institutions. Both elective and emergency patients were included from January 2018 to December 2021.

Results

Fifty-five patients were included in the study across two NHS specialist hernia centres. We identified a mean wound infection rate of 14.2% (range 2–22%) with a median follow up of 9 months (range 3–18 months). Hernia recurrence rate was 10.4% (range 5–22%). We found 7 patients (12%) developed a seroma, 1 of whom required seroma aspiration. Only 4 patients (7%) had post-operative dehiscence requiring further intervention, all of whom had Ventral Hernia Working Group (VHWG) Grade 3 or 4 wounds pre-operatively.

Conclusions

Our data supports the continued use of a widely available ADM for abdominal wall reconstruction in both elective and emergency cases, highlighting its positive relative safety profile.

Halo-external fixator frame-assisted correction to treat severe kyphotic deformity in children younger than 4 years old

BACKGROUND: Severe kyphotic deformity in young children may have devastating outcomes when neglected. Halo-pelvic traction has been shown to be very effective as part of the treatment for severe kyphosis, but little is known about application of this technique in very young individuals. The aim of this case series was to provide novel insights into the surgical technique associated with halo-external fixator frame (HEFF) treatment for severe spinal deformity in patients younger than 4 years old, along with the associated radiologic outcomes and complications METHODS: Clinical and demographic characteristics including the duration in the HEFF, HEFF-associated change in kyphosis angle (KA) and final KA following definitive surgery were extracted from medical records RESULTS: Five female patients with a mean age of 36 months (range 30-44) were included. Three patients had thoracic spinal tuberculosis (mean KA 82°), one had lumbar spinal tuberculosis (KA 42°) and one had iatrogenic post-laminectomy cervical kyphosis (type 1 neurofibromatosis)(KA 112°). The HEFF was applied for a mean of six weeks and resulted in a mean thoracic deformity correction of 29° (38%), a lumbar correction of 23° (55%) and cervical correction of 47° (42%). Definitive surgery resulted in a further mean overall deformity correction of 28, and patients had a satisfactory KA angle (23° lordosis to 31° kyphosis) at the last follow-up. HEFF-associated complications included pin-site infection, pneumonia and frame dislodgement CONCLUSION: HEFF appears to be an effective method for correcting severe kyphotic spinal deformity in very young patients where other options are limited. It allows for independent mobilisation and can provide for spinal stabilisation while awaiting bony healing after definitive surgery. However, healthcare providers should be aware of the potential dangers of HEFF hardware, such as difficulty in establishing an airway due to the fixed position of the neck Level of evidence: Level 4

Platelet reactivity and immature platelets in patients with Covid-19

Background

Coronavirus disease 2019 (Covid-19) is associated with high incidence of thromboembolic events, both venous and arterial. Currently, there are no clinical or laboratory markers to guide antithrombotic therapy in COVID-19 patients. Immature platelets represent a population of hyper-reactive platelets associated with arterial thrombotic events.

Objectives

To determine indices of immature platelets and platelet reactivity in Covid-19 patients.

Methods

This prospective study compared consecutive COVID-19 patients (n=47, median age = 56 years) to patients with acute myocardial infarction (AMI, n=100, median age = 59 years) and a group of stable patients with cardiovascular risk factors (n=64, median age=68 years). Immature platelet fraction (IPF) and immature platelet count (IPC) were determined by the Sysmex XN-3000 auto-analyzer on admission and at subsequent time-points.

Results

IPF% on admission was higher in the Covid-19 group than the stable group and similar to the AMI group (4.8% [IQR 3.4–6.9], 3.5% [2.7–5.1], 4.55% [3.0–6.75], respectively, p=0.005 for Covid-19 vs. stable). IPC on admission was also higher in the Covid-19 group than the stable group and similar to the AMI group (10.8×109/L [8.3–18.1], 7.35×109/L [5.3–10.5], 10.7×109/L [7.7–16.8], respectively, P<0.0001 for Covid-19 vs. stable). The maximal IPF% among the Covid-19 group was higher than the stable group and similar to the AMI group. The maximal IPC in the Covid-19 group was higher than the maximal IPC in both the stable and AMI groups (Covid-19: 14.4×109/L [9.4–20.9], AMI: 10.9×109/L [7.6–15.2], P=0.0035, Stable: 7.55×109/L [5.55–10.5], P<0.0001).

Conclusions

Patients with Covid-19 have increased immature platelets indices compared to stable patients with cardiovascular risk factors, and as the disease progresses also compared to AMI patients. Enhanced platelet turnover and reactivity may, therefore, have a role in the development of thrombotic events in Covid-19 patients.

Funding Acknowledgement

Type of funding sources: None. IPF in COVID-19, AMI and stable groups

Immature platelets in patients with Covid-19: association with disease severity

Background

Coronavirus disease 2019 (Covid-19) is associated with a high incidence of thromboembolic events, both venous and arterial. Currently, there are no clinical or laboratory markers to guide risk-stratification or antithrombotic therapy in Covid-19 patients. Circulating immature platelets represent a population of hyper-reactive platelets, which are associated with arterial thrombotic events.

Objectives

To assess whether the proportion of immature platelets in the circulation is associated with disease severity in patients with Covid-19

Methods

This prospective study evaluated consecutive patients with COVID-19 admitted with various degrees of disease severity, as determined by the standard Covid-19 severity Score. Disease severity was evaluated during hospitalization. Immature platelet fraction (IPF) absolute number and percentage were measured on admission and at additional time points during the hospital course using the SysmexXN-3000 auto-analyzer. The maximal values of IPF% and absolute IPF was analyzed according to disease severity.

Results

A total of 136 consecutive patients with Covid-19 were recruited. Mean age was 60±19 years for patients with mild and moderate disease and 69±14 years for patients with severe disease, 52% with mild and moderate disease and 48% with severe disease were woman, 11% with mild and moderate disease and 20% with severe disease with concurrent cardiovascular disease

The median of IPF% was higher in the severe COVID-19 group compared to patients with mild or moderate disease [4.2 (IQR 2.73–6.45) vs 5.8 (IQR 3.9–8.7), P=0.01, Figure 1)]. The median of IPF absolute number was also significantly higher in patients with severe disease comparing to patients with mild or moderate disease (4.2 (2.85–6.1) vs 5.1 (IQR 3.65–7.35), P<0.0001, Figure 2].

Conclusions

Patients with severe Covid-19 have a higher level of IPF in the circulation than patients with mild or moderate disease. IPF may serve as a reliable prognostic marker for in-hospital disease severity in patients with Covid-19

Funding Acknowledgement

Type of funding sources: None. Figure 1. IPF% (median, 95% confidence interval)Figure 2. IPF# (median, 95% confidence interval)

Effective reduction of post-inflammatory hyperpigmentation with the tyrosinase inhibitor isobutylamido-thiazolyl-resorcinol (Thiamidol)

Objective

Post‐inflammatory hyperpigmentation (PIH) is a major cosmetic concern especially in individuals with darker skin complexion. Unfortunately, treatment with anti‐inflammatory ingredients alone does not prevent the development of hyperpigmented spots. Recently, isobutylamido‐thiazolyl‐resorcinol (Thiamidol) was described as a very potent inhibitor of human tyrosinase. The objective of this research was to investigate the potential of this compound to prevent PIH induced by epidermal wounding (suction blister) and related to acne.

Methods

Suction blister‐induced PIH was treated with a formulation containing Thiamidol or a vehicle for 3 months, and the changes in hyperpigmentation were monitored by spectroscopic measurements. The effect of skin care formulations containing Thiamidol on acne‐related PIH was investigated in two studies, a vehicle‐controlled, double‐blinded, randomized clinical study and a clinical observational study. Both studies had a duration of 3 months and included assessments such as clinical photography, clinical grading and melanin index measurements.

Results

Already after 2 weeks of treatment, suction blister sites treated with Thiamidol were significantly lighter than control sites and improved throughout the treatment period. Subjects´ self‐grading demonstrated that Thiamidol significantly improved the visibility of acne‐induced hyperpigmentation compared to the vehicle treatment. A skin care regimen with Thiamidol significantly improved acne‐related PIH over 12 weeks shown by Mexameter measurements, expert grading, self‐grading and clinical photography.

Conclusion

Thiamidol represents a safe and effective ingredient for cosmetic products against post‐inflammatory hyperpigmentation.

High-energy visible light at ambient doses and intensities induces oxidative stress of skin-Protective effects of the antioxidant and Nrf2 inducer Licochalcone A in vitro and in vivo

BACKGROUND

Solar radiation causes skin damage through the generation of reactive oxygen species (ROS). While UV filters effectively reduce UV-induced ROS, they cannot prevent VIS-induced (400-760 nm) oxidative stress. Therefore, potent antioxidants are needed as additives to sunscreen products.

METHODS

We investigated VIS-induced ROS formation and the photoprotective effects of the Nrf2 inducer Licochalcone A (LicA).

RESULTS

Visible spectrum of 400-500 nm dose-dependently induced ROS in cultured human fibroblasts at doses equivalent to 1 hour of sunshine on a sunny summer day (150 J/cm² ). A pretreatment for 24 hours with 1 µmol/L LicA reduced ROS formation to the level of unirradiated cells while UV filters alone were ineffective, even at SPF50+. In vivo, topical treatment with a LicA-containing SPF50 + formulation significantly prevented the depletion of intradermal carotenoids by VIS irradiation while SPF50 + control did not protect.

CONCLUSION

LicA may be a useful additive antioxidant for sunscreens.

FMR1 premutation frequency in a large, ethnically diverse population referred for carrier testing

Fragile X syndrome (FXS) is the most common inherited cause of intellectual disability and is caused by an expansion of cytosine‐guanine‐guanine (CGG) repeats in the FMR1 gene. Female premutation allele carriers (55–200 CGG repeats) are at risk to have an affected child. Currently, specific population‐based carrier screening for FXS is not recommended. Previous studies exploring female premutation carrier frequency have been limited by size or ethnicity. This retrospective study provides a pan‐ethnic estimate of the Fragile X premutation carrier frequency in a large, ethnically diverse population of women referred for routine carrier screening during a specified time period at Progenity, Inc. Patient ethnicity was self‐reported and categorized as: African American, Ashkenazi Jewish, Asian, Caucasian, Hispanic, Native American, Other/Mixed/Unknown, or Sephardic Jewish. FXS test results were stratified by ethnicity and repeat allele category. Total premutation carrier frequency was calculated and compared against each ethnic group. A total of 134,933 samples were included. The pan‐ethnic premutation carrier frequency was 1 in 201. Only the Asian group differed significantly from this frequency. Using the carrier frequency of 1 in 201, a conservative pan‐ethnic risk estimate for a male fetus to have FXS can be calculated as 1 in 2,412. This risk is similar to the highest ethnic‐based fetal risks for cystic fibrosis and spinal muscular atrophy, for which population‐wide screening is currently recommended. This study adds to the literature and supports further evaluation into specific population‐wide screening recommendations for FXS.

Structure-Activity Relationships of Thiazolyl Resorcinols, Potent and Selective Inhibitors of Human Tyrosinase

Tyrosinase inhibitors are of great clinical interest as agents for the treatment of hyperpigmentary disorders; however, most compounds described in the literature lack clinical efficiency due to insufficient inhibitory activity against human tyrosinase (hTyr). Recently, we reported that thiazolyl resorcinols (4-resorcinylthiazol-2-amines and -amides) are both selective and efficacious inhibitors of hTyr in vitro and in vivo. Here, we measured dose-activity profiles of a large number of thiazolyl resorcinols and analogous compounds to better understand the molecular basis of their interaction with hTyr. We show that both the resorcinyl moiety and the thiazole ring must be intact to allow efficient inhibition of hTyr, while the substituents at the thiazole 2-amino group confer additional inhibitory activity, depending on their size and polarity. The results of molecular docking simulations were in excellent agreement with the experimental data, affording a rationale for the structural importance of either ring. We further propose that a special type of interaction between the thiazole sulfur and a conserved asparagine residue is partially responsible for the superior inhibitory activity of thiazolyl resorcinols against hTyr.

Inhibition of Human Tyrosinase Requires Molecular Motifs Distinctively Different from Mushroom Tyrosinase

Tyrosinase is the rate-limiting enzyme of melanin production and, accordingly, is the most prominent target for inhibiting hyperpigmentation. Numerous tyrosinase inhibitors have been identified, but most of those lack clinical efficacy because they were identified using mushroom tyrosinase as the target. Therefore, we used recombinant human tyrosinase to screen a library of 50,000 compounds and compared the active screening hits with well-known whitening ingredients. Hydroquinone and its derivative arbutin only weakly inhibited human tyrosinase with a half-maximal inhibitory concentration (IC₅₀) in the millimolar range, and kojic acid showed a weak efficacy (IC₅₀ > 500 μmol/L). The most potent inhibitors of human tyrosinase identified in this screen were resorcinyl-thiazole derivatives, especially the newly identified Thiamidol (Beiersdorf AG, Hamburg, Germany) (isobutylamido thiazolyl resorcinol), which had an IC₅₀ of 1.1 μmol/L. In contrast, Thiamidol only weakly inhibited mushroom tyrosinase (IC₅₀ = 108 μmol/L). In melanocyte cultures, Thiamidol strongly but reversibly inhibited melanin production (IC₅₀ = 0.9 μmol/L), whereas hydroquinone irreversibly inhibited melanogenesis (IC₅₀ = 16.3 μmol/L). Clinically, Thiamidol visibly reduced the appearance of age spots within 4 weeks, and after 12 weeks some age spots were indistinguishable from the normal adjacent skin. The full potential of Thiamidol to reduce hyperpigmentation of human skin needs to be explored in future studies.

Dopamine, Noradrenaline and Serotonin Receptor Densities in the Striatum of Hemiparkinsonian Rats following Botulinum Neurotoxin-A Injection

Parkinson's disease (PD) is characterized by a degeneration of dopaminergic neurons in the substantia nigra pars compacta (SNpc) that causes a dopamine (DA) deficit in the caudate-putamen (CPu) accompanied by compensatory changes in other neurotransmitter systems. These changes result in severe motor and non-motor symptoms. To disclose the role of various receptor binding sites for DA, noradrenaline, and serotonin in the hemiparkinsonian (hemi-PD) rat model induced by unilateral 6-hydroxydopamine (6-OHDA) injection, the densities of D₁, D₂/D₃, α₁, α₂, and 5HT_2A receptors were longitudinally visualized and measured in the CPu of hemi-PD rats by quantitative in vitro receptor autoradiography. We found a moderate increase in D₁ receptor density 3 weeks post lesion that decreased during longer survival times, a significant increase of D₂/D₃ receptor density, and 50% reduction in 5HT_2A receptor density. α₁ receptor density remained unaltered in hemi-PD and α₂ receptors demonstrated a slight right-left difference increasing with post lesion survival. In a second step, the possible role of receptors on the known reduction of apomorphine-induced rotations in hemi-PD rats by intrastriatally injected Botulinum neurotoxin-A (BoNT-A) was analyzed by measuring the receptor densities after BoNT-A injection. The application of this neurotoxin reduced D₂/D₃ receptor density, whereas the other receptors mainly remained unaltered. Our results provide novel data for an understanding of the postlesional plasticity of dopaminergic, noradrenergic and serotonergic receptors in the hemi-PD rat model. The results further suggest a therapeutic effect of BoNT-A on the impaired motor behavior of hemi-PD rats by reducing the interhemispheric imbalance in D₂/D₃ receptor density.

The efficacy of HI-6 DMS in a sustained infusion against percutaneous VX poisoning in the guinea-pig

Post-exposure nerve agent treatment usually includes administration of an oxime, which acts to restore function of the enzyme acetylcholinesterase (AChE). For immediate treatment of military personnel, this is usually administered with an autoinjector device, or devices containing the oxime such as pralidoxime, atropine and diazepam. In addition to the autoinjector, it is likely that personnel exposed to nerve agents, particularly by the percutaneous route, will require further treatment at medical facilities. As such, there is a need to understand the relationship between dose rate, plasma concentration, reactivation of AChE activity and efficacy, to provide supporting evidence for oxime infusions in nerve agent poisoning. Here, it has been demonstrated that intravenous infusion of HI-6, in combination with atropine, is efficacious against a percutaneous VX challenge in the conscious male Dunkin-Hartley guinea-pig. Inclusion of HI-6, in addition to atropine in the treatment, improved survival when compared to atropine alone. Additionally, erythrocyte AChE activity following poisoning was found to be dose dependent, with an increased dose rate of HI-6 (0.48mg/kg/min) resulting in increased AChE activity. As far as we are aware, this is the first study to correlate the pharmacokinetic profile of HI-6 with both its pharmacodynamic action of reactivating nerve agent inhibited AChE and with its efficacy against a persistent nerve agent exposure challenge in the same conscious animal.

Abstract LB-093: Simultaneous measurement of global methylation and copy number alterations in human colorectal cancer samples

Epigenomic changes are commonly observed in cancer. We developed a next-generation sequencing (NGS) assay which can identify subtle changes in global methylation as well as copy number alterations (CNAs). The assay measures the methylation level of some repeat elements, covering over 25% of all CpG in the genome.

Genomic DNA extracted from 18 pairs of matched colorectal tumor to normal tissue was tested (four adenocarcinomas, including one associated with inflammatory bowel disease, and fourteen adenomas, including one adenoma from a Lynch syndrome patient, one familial adenomatous polyposis (FAP) and two sessile serrated adenomas (SSA)). We also assayed organoids established from these tissues at early (2 month) and late (more than 6 months) timepoints in culture. Briefly, bisulfite conversion and enrichment of the repeats was performed. The Illumina compatible products were sequenced on a HiSEQ 2500. Analysis was performed using Bismark (Krueger F., Babraham institute) and Nexus copy number (BioDiscovery) to determine the global methylation and the CNAs, respectively. Finally, somatic and germline variants were determined by targeted sequencing of 71 genes using the QIAseq colorectal cancer panel (QIAGEN).

Our data showed that all adenocarcinoma presented hypomethylation and CNAs as well as multiple somatic variants in APC, KRAS, TP53, SMAD4 and PIK3CA. Six out of the fourteen adenomas presented CNAs and nine showed hypomethylation. The most frequently observed copy number gain affected the chromosomes 8q and 13. Eight adenomas presenting somatic mutations in APC also exhibited distinct global hypomethylation. Previous publications have reported that mutations in APC precede global hypomethylation. Interestingly, one adenoma showed significant hypomethylation but no detectable CNAs or APC mutations. The two SSA samples showed the characteristic BRAF V600E mutations and the FAP sample presented germline mutation in APC. The FAP and the SSA samples did not show hypomethylation or CNAs. Most organoids presented CNAs and somatic mutations similar to their matched tissue even after 2 years in culture. However, few organoids developed new CNAs and somatic variants. Monitoring the changes in organoid may provide important information on tumor progression.

This assay measured CNAs and methylation in colorectal cancer samples, findings which may assist in determining the status of the disease and provide guidance to the appropriate action. Our NGS assay interrogates a significant portion of the genome leading to a more accurate and sensitive evaluation of the state of these cancer cells.

Note: This abstract was not presented at the meeting.

Citation Format: Julie C. Laliberte, Michael K. Dame, Durga Attili, Bodrul Islam, Kevin Kim, Jessica Zhang, Erica L. Katz, Gina M. Newsome, Priya H. Dedhia, Adele Kruger, Tobias Mann, Tom Goodman, Jeffrey Buis, Dean E. Brenner, James Varani, Jason R. Spence, Justin A. Colacino, Jay Stoerker. Simultaneous measurement of global methylation and copy number alterations in human colorectal cancer samples [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr LB-093. doi:10.1158/1538-7445.AM2017-LB-093

Sequences of 95 human MHC haplotypes reveal extreme coding variation in genes other than highly polymorphic HLA class I and II

The most polymorphic part of the human genome, the MHC, encodes over 160 proteins of diverse function. Half of them, including the HLA class I and II genes, are directly involved in immune responses. Consequently, the MHC region strongly associates with numerous diseases and clinical therapies. Notoriously, the MHC region has been intractable to high-throughput analysis at complete sequence resolution, and current reference haplotypes are inadequate for large-scale studies. To address these challenges, we developed a method that specifically captures and sequences the 4.8-Mbp MHC region from genomic DNA. For 95 MHC homozygous cell lines we assembled, de novo, a set of high-fidelity contigs and a sequence scaffold, representing a mean 98% of the target region. Included are six alternative MHC reference sequences of the human genome that we completed and refined. Characterization of the sequence and structural diversity of the MHC region shows the approach accurately determines the sequences of the highly polymorphic HLA class I and HLA class II genes and the complex structural diversity of complement factor C4A/C4B. It has also uncovered extensive and unexpected diversity in other MHC genes; an example is MUC22, which encodes a lung mucin and exhibits more coding sequence alleles than any HLA class I or II gene studied here. More than 60% of the coding sequence alleles analyzed were previously uncharacterized. We have created a substantial database of robust reference MHC haplotype sequences that will enable future population scale studies of this complicated and clinically important region of the human genome.

Differences in the Treatment of Distal Radius Fractures by Hand Fellowship Trained Surgeons: A Study of ABOS Candidate Data

PURPOSE

The management of distal radius fractures differs based on the nature of the fracture and the experience of the surgeon. We hypothesized that patients requiring surgical intervention would undergo different procedures when in the care of a surgeon with subspecialty training in hand surgery as compared with surgeons with no subspecialty training in hand surgery.

METHODS

We queried the ABOS database for case log information submitted for part II of the ABOS examination. Queries for all codes involved with distal radius fracture management were combined with associated codes for the management of median nerve neuropathy, triangular fibrocartilage complex tears, ulnar shaft, and styloid fractures. Hand fellowship trained orthopedic surgeons were compared with those completing other fellowships and non-fellowship trained orthopedic surgeons during their board collection period.

RESULTS

During the study period, 2,317 orthopedic surgeons reported treatment of 15,433 distal radius fractures. Of these surgeons, 411 had hand fellowship training. On a per surgeon basis, fellowship trained hand surgeons operatively treated more multifragment intra-articular distal radius fractures than their non-hand fellowship trained counterparts (5.3 vs 1.2). Additional procedures associated with the management of distal radius fractures were also associated with the fellowship training of the treating surgeon.

CONCLUSIONS

Among orthopedic surgeons taking part II of the ABOS certifying examination, differences exist in the type, management, and reporting of distal radius fractures among surgeons with different areas of fellowship training.

CLINICAL RELEVANCE

This study describes the association of hand surgery fellowship training on the choice of intervention for distal radius fractures and associated conditions.

Can Radiocarpal-Spanning Fixation Be Made More Functional by Placing the Wrist in Extension? A Biomechanical Study Under Physiologic Loads

We investigate whether applying an internal radiocarpal-spanning plate with the wrist in slight extension affects the biomechanical stability of the construct. An unstable distal radius fracture was simulated in 10 cadaveric specimens and immobilized with a radiocarpal-spanning plate holding the wrist in a neutral position. This construct was then physiologically loaded through the wrist flexor and extensor tendons. The resulting motion at the fracture was captured with a displacement sensor. The plate was then extended using an in situ bending technique, placing the wrist in extension, and the experiment was repeated. No statistically significant difference in the biomechanical stability afforded by the radiocarpal-spanning plate was detected with the wrist in extension compared to that in the traditional neutral position. The radiocarpal-spanning plate fixation was more stable when loaded through the extensor tendons. We conclude that immobilizing a distal radius fracture with an internal radiocarpal-spanning plate that holds the wrist in extension does not compromise biomechanical stability.

Sporting myths: the REAL role of lactate during exercise

Background. Lactate or, as it was customarily known, ‘lactic acid’ was one of the first molecules to attract the attention of early exercise scientists, mainly because blood lactate concentration could be measured and was shown to increase with increasing exercise intensity. This connection resulted in lactate being associated with numerous other events associated with high-intensity exercise including muscle cramps, fatigue, acidosis and post-exercise muscle soreness. Nobel prize-winning research by AV Hill and Otto Meyerhof provided a rational explanation linking lactate to anaerobiosis and acidosis, which resulted in this relationship being widely accepted as fact. It was only following isotopic tracer studies of George Brooks and others that the true role of lactate during rest and exercise was revealed. Conclusions. Lactate is now acknowledged as an important intermediate of carbohydrate metabolism, taken up from the blood by tissues such as skeletal and cardiac muscle as a substrate for oxidation. Furthermore, lactate formation consumes a proton, thereby buffering against muscle acidosis. For this reason, lactate production forms an essential aid to endurance performance rather than a hindrance.

‘Mean response’ disregards the importance of individual variation

The conventional approach in the field of exercise science is to report the response to interventions as the mean (average) of the intervention group. While the mean may be a convenient measure, it fails to consider the significant individual variation present in all aspects of human biology, resulting in findings that are at best simplistic and, at worst, misleading.

Larger femoral periprosthetic bone mineral density decrease following total hip arthroplasty for femoral neck fracture than for osteoarthritis: a prospective, observational cohort study

Studies on patients with degenerative joint disease of the hip show that femoral periprosthetic bone mineral decreases following total hip arthroplasty. Scarcely any osteodensitometric data exist on femoral neck fracture (FNF) patients and periprosthetic bone remodelling. In two parallel cohorts we enrolled 87 patients (mean age, 72 ± 12 years; male:female ratio, 30:57) undergoing total hip arthroplasty for either primary osteoarthritis (OA) of the hip (n = 37) or for an acute FNF (n = 50) and followed them for a mean of 5.4 years. Outcomes were bone mineral density (BMD) changes in the periprosthetic Gruen zones 1-7, the incidence of periprosthetic fractures and clinical outcome. The bone mineral loss in the fracture group was more than twice that of the osteoarthritis group, -16.9% versus -6.8% (p = 0.004). The incidence of periprosthetic fractures was 12% (6/50) in the fracture cohort compared with none (0%) in the OA cohort (p = 0.03). Periprosthetic bone mineral loss following total hip arthroplasty is significantly greater in patients who are treated for acute FNF than in OA patients. This decrease of BMD follows a different pattern with the FNF patients losing larger proportions of bone in Gruen zones 1, 2, 6, and 7 while the OA patients tend to have larger losses only in zones 1 and 7.

Reverse total shoulder arthroplasty for the treatment of proximal humeral fractures: patterns of use among newly trained orthopedic surgeons

BACKGROUND

This study compared the use of reverse and hemishoulder arthroplasty for the treatment of proximal humeral fractures among orthopedic surgeons taking part II of the American Board of Orthopaedic Surgery board examination. We hypothesized that the use of reverse shoulder arthroplasty for fractures in the elderly is increasing amongst newly trained orthopedic surgeons.

MATERIALS AND METHODS

We queried the American Board of Orthopaedic Surgery database for the cases of proximal humeral fractures treated with arthroplasty submitted between 2005 and 2012. We evaluated the prosthesis used, patient-specific factors, complications, and the difference in use by shoulder fellowship-trained surgeons.

RESULTS

From 2005 to 2012, 5395 board-eligible orthopedic surgeons submitted cases to the database. Of these, 435 (mean, 54 per year) were proximal humeral fractures treated with arthroplasty. The overall incidence of reverse shoulder arthroplasty for fracture increased from 2% to 4% during 2005 to 2007 to 38% in 2012. Shoulder surgeons treated 5 times more proximal humeral fractures with shoulder arthroplasty and were also more than 20 times more likely to use a reverse implant (P < .0001). The difference in complication rates between reverse and hemishoulder arthroplasty was not significant (P = .49). Patients who received a hemiarthroplasty tended to be younger (mean age, 70.8 vs 75.7 years; P = .0015).

CONCLUSIONS

Overall, the use of a hemiarthroplasty for fracture is still more common (62% in 2012), although the relative proportion of reverse implants is rising. Among shoulder surgeons, more than 50% of the arthroplasties performed for fractures during the past 3 years (2010-2012) have been reverse arthroplasties.

The association between chewing and swallowing difficulties and nutritional status in older adults

BACKGROUND

The aim of this study was to investigate the associations of chewing and swallowing dysfunctions to nutritional status in older adults.

METHODS

This cross-sectional study comprised a convenience sample of 1065 community-dwelling older adults living in rural United States. Dietary assessment included the Block Full Length Food Frequency Questionnaire, 24-hour Food Intake Recall and Mini Nutritional Assessment. Classification of chewing and swallowing difficulties was determined by a criterion of outlined factors.

RESULTS

In our sample, 113 (11%) had chewing difficulties, 51 (5%) had swallowing difficulties, and 11 (1%) had both. Compared to the Dietary Reference Intakes (DRIs), the study population was deficient in calories and several nutrients. Mean daily intake in individuals reporting chewing, swallowing, or difficulties with both were 1489 ± 360, 1461 ± 374 and 1374 ± 240 calories respectively. There was no statistically significant difference between the groups. Vitamin A, vitamin E and manganese were significantly lower in those with chewing difficulties while vitamin E and magnesium were significantly lower in individuals with swallowing difficulties (p < 0.05).

CONCLUSIONS

These results emphasize the importance of chewing and swallowing difficulties in modulating nutritional outcomes in older adults. These co-morbidities should be monitored in this population and intake of nutrient dense foods should be increased in those at risk.

In vitro efficacy and release study with anti-inflammatory drugs incorporated in adhesive transdermal drug delivery systems

The topical application of two different anti-inflammatory extracts incorporated in adhesive transdermal drug delivery systems (TDDSs) was investigated. Therefore, anti-inflammatory properties and percutaneous absorption behavior of adhesive TDDSs were characterized in vitro conducting experiments with a dermatologically relevant human skin model. Anti-inflammatory efficacy against UV irradiation of both TDDSs was determined in vitro with EpiDerm™. The reduction of the release of proinflammatory cytokines by topically applied TDDSs was compared with the reduction during the presence of the specific cyclooxygenase inhibitor diclofenac in the culture medium. A similar anti-inflammatory efficacy of the topically applied TDDSs in comparison with the use of diclofenac in the culture medium should be achieved. Furthermore, percutaneous absorption in efficacy tests was compared with percutaneous absorption in diffusion studies with porcine cadaver skin. Both the topically applied TDDSs showed a significant anti-inflammatory activity. Permeation coefficients through the stratum corneum and the epidermis gained from the release studies on porcine cadaver skin (Magnolia: 2.23·10(-5) cm/h, licorice: 4.68·10(-6) cm/h) were approximately five times lower than the permeation coefficients obtained with the EpiDerm™ skin model (Magnolia: 9.48·10(-5) cm/h, licorice: 24.0·10(-6) cm/h). Therefore, an adjustment of drug doses during experiments with the EpiDerm™ skin model because of weaker skin barrier properties should be considered.

N-acetyl-L-cysteine protects against inhaled sulfur mustard poisoning in the large swine

CONTEXT

Sulfur mustard is a blister agent that can cause death by pulmonary damage. There is currently no effective treatment. N-acetyl-L-cysteine (NAC) has mucolytic and antioxidant actions and is an important pre-cursor of cellular glutathione synthesis. These actions may have potential to reduce mustard-induced lung injury.

OBJECTIVE

Evaluate the effect of nebulised NAC as a post-exposure treatment for inhaled sulfur mustard in a large animal model.

MATERIALS AND METHODS

Fourteen anesthetized, surgically prepared pigs were exposed to sulfur mustard vapor (100 μg.kg⁻¹), 10 min) and monitored, spontaneously breathing, to 12 h. Control animals had no further intervention (n = 6). Animals in the treatment group were administered multiple inhaled doses of NAC (1 ml of 200 mg.ml⁻¹ Mucomyst™ at + 30 min, 2, 4, 6, 8, and 10 h post-exposure, n = 8). Cardiovascular and respiratory parameters were recorded. Arterial blood was collected for blood gas analysis while blood and bronchoalveolar lavage fluid were collected for hematology and inflammatory cell analysis. Urine was collected to detect a sulfur mustard breakdown product. Lung tissue samples were taken for histopathological and post-experimental analyses.

RESULTS

Five of six sulfur mustard-exposed animals survived to 12 h. Arterial blood oxygenation (PaO₂) and saturation levels were significantly decreased at 12 h. Arterial blood carbon dioxide (PaCO₂) significantly increased, and arterial blood pH and bicarbonate (HCO₃⁻) significantly decreased at 12 h. Shunt fraction was significantly increased at 12 h. In the NAC-treated group all animals survived to 12 h (n = 8). There was significantly improved arterial blood oxygen saturation, HCO₃⁻ levels, and shunt fraction compared to those of the sulfur mustard controls. There were significantly fewer neutrophils and lower concentrations of protein in lavage compared to sulfur mustard controls.

DISCUSSION

NAC's mucolytic and antioxidant properties may be responsible for the beneficial effects seen, improving clinically relevant physiological indices affected by sulfur mustard exposure.

CONCLUSION

Beneficial effects of nebulized NAC were apparent following inhaled sulfur mustard exposure. Further therapeutic benefit may result from a combination therapy approach.

Maintaining replication origins in the face of genomic change

Origins of replication present a paradox to evolutionary biologists. As a collection, they are absolutely essential genomic features, but individually are highly redundant and nonessential. It is therefore difficult to predict to what extent and in what regard origins are conserved over evolutionary time. Here, through a comparative genomic analysis of replication origins and chromosomal replication patterns in the budding yeasts Saccharomyces cerevisiae and Lachancea waltii, we assess to what extent replication origins survived genomic change produced from 150 million years of evolution. We find that L. waltii origins exhibit a core consensus sequence and nucleosome occupancy pattern highly similar to those of S. cerevisiae origins. We further observe that the overall progression of chromosomal replication is similar between L. waltii and S. cerevisiae. Nevertheless, few origins show evidence of being conserved in location between the two species. Among the conserved origins are those surrounding centromeres and adjacent to histone genes, suggesting that proximity to an origin may be important for their regulation. We conclude that, over evolutionary time, origins maintain sequence, structure, and regulation, but are continually being created and destroyed, with the result that their locations are generally not conserved.

Myxoma virus induces apoptosis in cultured feline carcinoma cells

There is growing interest in utilizing replicating oncolytic viruses as cancer therapeutics agents. The effectiveness of myxoma virus-induced oncolysis was evaluated in two feline cancer cell cultures. Although myxoma virus is a rabbit-specific pathogen, protein expression driven by myxoma virus and production of infectious viral particles were detected. Cell death occurred in primary feline cancer cells within 48 h of inoculation with myxoma virus. Future studies to determine if other feline neoplasms are susceptible to myxoma virus infection are warranted.

‘Mean response’ disregards the importance of individual variation

The conventional approach in the field of exercise science is to report the response to interventions as the mean (average) of the intervention group. While the mean may be a convenient measure, it fails to consider the significant individual variation present in all aspects of human biology, resulting in findings that are at best simplistic and, at worst, misleading.

Furosemide in the treatment of phosgene induced acute lung injury

METHOD

Using previously validated methods, 16 anaesthetised large white pigs were exposed to phosgene (target inhaled dose 0.3 mg kg(-1)), established on mechanical ventilation and randomised to treatment with either nebulised furosemide (4 ml of 10 mg x ml(-1) solution) or saline control. Treatments were given at 1, 3, 5, 7, 9, 12, 16 and 20 hours post phosgene exposure; the animals were monitored to 24 hours following phosgene exposure.

RESULTS

Furosemide treatment had no effect on survival, and had a deleterious effect on PaO2: FiO2 ratio between 19 and 24 hours. All other measures investigated were unaffected by treatment.

CONCLUSION

Nebulised furosemide treatment following phosgene induced acute lung injury does not improve survival and worsens PaO2: FiO2 ratio. Nebulised furosemide should be avoided following phosgene exposure.

The fibroblast-derived paracrine factor neuregulin-1 has a novel role in regulating the constitutive color and melanocyte function in human skin

Interactions between melanocytes and neighboring cells in the skin are important in regulating skin color in humans. We recently demonstrated that the less pigmented and thicker skin on the palms and soles is regulated by underlying fibroblasts in those areas, specifically via a secreted factor (DKK1) that modulates Wnt signaling. In this study, we tested the hypothesis that dermal fibroblasts regulate the constitutive skin color of individuals ranging from very light to very dark. We used microarray analysis to compare gene expression patterns in fibroblasts derived from lighter skin types compared to darker skin types, with a focus on secreted proteins. We identified a number of genes that differ dramatically in expression and, among the expressed proteins, neuregulin-1, which is secreted by fibroblasts derived from dark skin, effectively increases the pigmentation of melanocytes in tissue culture and in an artificial skin model and regulates their growth, suggesting that it is one of the major factors determining human skin color.

A thermodynamic approach to PCR primer design

We developed a primer design method, Pythia, in which state of the art DNA binding affinity computations are directly integrated into the primer design process. We use chemical reaction equilibrium analysis to integrate multiple binding energy calculations into a conservative measure of polymerase chain reaction (PCR) efficiency, and a precomputed index on genomic sequences to evaluate primer specificity. We show that Pythia can design primers with success rates comparable with those of current methods, but yields much higher coverage in difficult genomic regions. For example, in RepeatMasked sequences in the human genome, Pythia achieved a median coverage of 89% as compared with a median coverage of 51% for Primer3. For parameter settings yielding sensitivities of 81%, our method has a recall of 97%, compared with the Primer3 recall of 48%. Because our primer design approach is based on the chemistry of DNA interactions, it has fewer and more physically meaningful parameters than current methods, and is therefore easier to adjust to specific experimental requirements. Our software is freely available at http://pythia.sourceforge.net.

Evaluation of the functional state of male accessory glands by the analysis of seminal plasma

In man, the seminal vesicles, together with the ampuls, constitutes the main source of seminal fructose. The human prostate produce citric acids, acid phosphatase and other enzymes. The exceeding high content of prostaglandins probably derives from the seminal vesicles. A combined analysis of fructose and citric acid in the ejaculate is desirable to state morphologic alterations or functional disturbances of the accessory glands. The well-known split ejaculate method enables to decide whether the ejaculatory process is normal, slight or heavily disturbed. Variations in the morphology and secretory function of the accessory glands in different mammalian species are pointed out. The influence of testosterone on the secretory function of the accessory glands is described and discussed in detail.

Sporting myths: the REAL role of lactate during exercise

Background. Lactate or, as it was customarily known, ‘lactic acid’ was one of the first molecules to attract the attention of early exercise scientists, mainly because blood lactate concentration could be measured and was shown to increase with increasing exercise intensity. This connection resulted in lactate being associated with numerous other events associated with high-intensity exercise including muscle cramps, fatigue, acidosis and post-exercise muscle soreness. Nobel prize-winning research by AV Hill and Otto Meyerhof provided a rational explanation linking lactate to anaerobiosis and acidosis, which resulted in this relationship being widely accepted as fact. It was only following isotopic tracer studies of George Brooks and others that the true role of lactate during rest and exercise was revealed. Conclusions. Lactate is now acknowledged as an important intermediate of carbohydrate metabolism, taken up from the blood by tissues such as skeletal and cardiac muscle as a substrate for oxidation. Furthermore, lactate formation consumes a proton, thereby buffering against muscle acidosis. For this reason, lactate production forms an essential aid to endurance performance rather than a hindrance.