Very-low-density lipoprotein triglyceride and free fatty acid plasma kinetics in women with high or low brown adipose tissue volume and overweight/obesity

Although a high amount of brown adipose tissue (BAT) is associated with low plasma triglyceride concentration, the mechanism responsible for this relationship in people is not clear. Here, we evaluate the interrelationships among BAT, very-low-density lipoprotein triglyceride (VLDL-TG), and free fatty acid (FFA) plasma kinetics during thermoneutrality in women with overweight/obesity who had a low (<20 mL) or high (≥20 mL) volume of cold-activated BAT (assessed by using positron emission tomography in conjunction with 2-deoxy-2-[18F]-fluoro-glucose). We find that plasma TG and FFA concentrations are lower and VLDL-TG and FFA plasma clearance rates are faster in women with high BAT than low BAT volume, whereas VLDL-TG and FFA appearance rates in plasma are not different between the two groups. These findings demonstrate that women with high BAT volume have lower plasma TG and FFA concentrations than women with low BAT volumes because of increased VLDL-TG and FFA clearance rates. This study was registered at ClinicalTrials.gov (NCT02786251).

NeuroBlu: a natural language processing (NLP) electronic health record (EHR) data analytic tool to generate real-world evidence in mental healthcare

Introduction

EHRs contain a rich source of real-world data that can support evidence generation to better understand mental disorders and improve treatment outcomes. However, EHR datasets are complex and include unstructured free text data that are time consuming to manually review and analyse. We present NeuroBlu, a secure, cloud-based analytic tool that includes bespoke NLP software to enable users to analyse large volumes of EHR data to generate real-world evidence in mental healthcare.

Objectives

(i) To assemble a large mental health EHR dataset in a secure, cloud-based environment.

(ii) To apply NLP software to extract data on clinical features as part of the Mental State Examination (MSE).

(iii) To analyse the distribution of NLP-derived MSE features by psychiatric diagnosis.

Methods

EHR data from 25 U.S. mental healthcare providers were de-identified and transformed into a common data model. NLP models were developed to extract 241 MSE features using a deep learning, long short-term memory (LSTM) approach. The NeuroBlu tool (https://www.neuroblu.ai/) was used to analyse the associations of MSE features in 543,849 patients.

Results

The figure below illustrates the percentage of patients in each diagnostic category with at least one recorded MSE feature.

Conclusions

Delusions and hallucinations were more likely to be recorded in people with schizophrenia and schizoaffective disorder, and cognitive features were more likely to be recorded in people with dementia. However, mood symptoms were frequently recorded across all diagnoses illustrating their importance as a transdiagnostic clinical feature. NLP-derived clinical information could enhance the potential of EHR data to generate real-world evidence in mental healthcare.

Disclosure

This study was funded in full by Holmusk.

Using principal component analysis for the prediction of tumor response to transarterial chemoembolization

PURPOSE

To quantitate the tumor blush of hepatocellular carcinoma (HCC) at the time of transarterial chemoembolization (TACE) using principal component analysis (PCA), and to correlate the quantitated tumor blush to response to therapy.

MATERIALS AND METHODS

In this proof-of-concept study, 27 primary HCC tumors in 25 patients (18 men, 7 women; mean age 66 years ± 9) were analyzed. We conducted a retrospective analysis of TACE procedures that were performed during March through July of 2017. Digital subtraction angiography (DSA) was combined with PCA to condense spatial and temporal information into a single image. The tumor and liver contrast enhancements were calculated, and the ratio was used to determine the relative vascular enhancement of the tumor. Tumor response to therapy was determined at 1-month post procedure.

RESULTS

Using PCA-generated fluoroscopic imaging (PCA-FI), we quantitated the tumor blush and assigned a vascular enhancement value (VEV) to each tumor. Tumors that responded to treatment (N = 12) had statistically higher VEVs compared with the nonresponders (N = 15), with a mean value of 0.96 ± 0.455 vs. 0.57 ± 0.309, (p = 0.013).

CONCLUSIONS

We developed a method for quantitating tumor blush using routine angiographic images. The VEVs calculated using these images may allow for the prediction of tumor response to therapy. This pilot study suggests that there is a correlation between tumor blush intensity and tumor response.

Comparison of Response and Outcomes of Drug-eluting Bead Chemoembolization (DEB-TACE) Versus Radioembolization (TARE) for Patients With Colorectal Cancer Liver Metastases

BACKGROUND

To compare outcomes for patients with colorectal cancer liver metastases (CRCLM) treated by drug-eluting bead chemoembolization (DEB-TACE) or radioembolization (TARE).

PATIENTS AND METHODS

A single-center retrospective review was carried out on 202 patients with CRCLM, treated by DEB-TACE (n=47) or TARE (n=155) patients. Propensity-matching yielded 44 pairs. Paired statistical analysis was performed on matched pair demographics, treatment response, and survival.

RESULTS

Patients treated with DEB-TACE had worse extra-hepatic metastasis (68.1 vs. 47.7%, p=0.014) and ≥10 liver lesions (42.2 vs. 68.8%, p=0.001). Matched patients treated with DEB-TACE had a trend towards worse toxicity (27% vs. 9.1% (p=0.057). Index DEB-TACE treatment was not a prognostic factor for overall survival (hazard ratio=0.94, 95% confidence intervaI=0.54-1.65; p=0.83).

CONCLUSION

In the matched CRCLM cohort, there was a trend towards worse toxicity post-DEB-TACE treatment, but it was not an independent prognostic factor for survival.

Percutaneous Gastrostomy Placement for Decompression of the Excluded Gastric Remnant following Roux-en-Y Gastric Bypass Surgery

Purpose To evaluate the feasibility and safety of percutaneous gastrostomy for decompression of the excluded stomach in patients’ status post Roux-en-Y gastric bypass (RYGB).

Materials and Methods Between January 2001 and August 2017, 10 consecutive RYGB patients who underwent placement of a decompressive gastrostomy of the excluded stomach were identified in an institutional database. Technical success was defined as successful gastrostomy catheter placement in the bypassed stomach using fluoroscopy and/or ultrasound guidance. Clinical success was established if dilation of the excluded stomach improved after gastrostomy with resolution of associated symptoms. Charts were reviewed for treatment-related adverse events post-procedure.

Results The cohort was predominantly female (9/10), with an average age of 54 ± 14 years. Median follow-up was 35.2 months (range: 0.6–115). Indications for decompressive gastrostomy placement included small bowel obstruction (6/10) or afferent limb obstruction at the jejunojejunal anastomosis (4/10). The most common presenting symptoms were abdominal pain, distension, and vomiting. All patients had successful gastrostomy placement in the excluded remnant, using ultrasound and fluoroscopic guidance, with no procedural complications. The 12 to 16F Cope loop catheters was used in this cohort, and gastropexy sutures were used in two cases. All 10 patients demonstrated clinical resolution of symptoms after gastrostomy placement. Two patients developed minor complications of tube site leakage and poor tube function requiring gastrostomy exchange within 1 week of the procedure.

Conclusion Fluoroscopic and ultrasound-guided percutaneous gastrostomy catheter placement is a safe, effective, and feasible approach to treating dilation of the excluded gastric remnant in RYGB patients.

Radiofrequency Ablation vs. Cryoablation for Localized Hepatocellular Carcinoma: A Propensity-matched Population Study

BACKGROUND/AIM

To compare overall survival (OS) and liver cancer-specific survival (LCSS) of Surveillance, Epidemiology and End Results (SEER) hepatocellular carcinoma (HCC) database patients treated with cryoablation (cryo) or radiofrequency ablation (RFA).

MATERIALS AND METHODS

This was a retrospective review of Stage I or II HCC patients from the SEER database treated with cryo and RFA from 2004-2013. Kaplan-Meier and Cox regressions were performed on pooled and propensity-matched cohort.

RESULTS

Out of 3,239 patients, RFA showed a significant survival advantage over cryo in liver cancer specific survival (LCSS) (HR=1.634 p=0.0004). A total of 91 propensity-matched pairs had similar OS (HR=1.006 p=0.9768), but no difference in LCSS was observed between the groups [HR=1.412 (95%CI=0.933-2.137) p=0.1023]. Survival Cox models did not reveal treatment type as an independent prognostic factor.

CONCLUSION

Propensity-matched cohort showed no significant difference in terms of OS and LCSS was found for patients treated with either cryo or RFA for localized HCC.

Analysis of weight changes after left gastric artery embolization in a cancer-naive population

PURPOSE

We aimed to evaluate weight changes after left gastric artery (LGA) embolization in a retrospective cancer-naive cohort.

METHODS

A retrospective study was conducted to identify patients who underwent LGA embolization for gastrointestinal bleeding (GI). Patients with known cancer diagnoses at the time of LGA embolization were excluded. Pre- and postprocedure weights were assessed. Statistical analysis was performed using paired t-test and Wilcoxon signed-rank test.

RESULTS

A total of 39 patients were identified. In 21 patients who had documented pre- and postprocedural weights, a median of 16.3 kg weight loss (P = 0.045) was observed over a median time of 12 months (range, 2-72). In patients who had pre- and postprocedure endoscopies (n=6), 2 had worsening ulcers following LGA embolization and 4 had stable or no abnormal findings.

CONCLUSION

Our preliminary observation suggests that LGA embolization is well tolerated and results in unintended weight loss. Larger studies are needed to confirm these preliminary findings.

The muscle anabolic effect of protein ingestion during a hyperinsulinaemic euglycaemic clamp in middle-aged women is not caused by leucine alone

KEY POINTS

It has been suggested that leucine is primarily responsible for the increase in muscle protein synthesis after protein ingestion because leucine uniquely activates the mTOR-p70S6K signalling cascade. We compared the effects of ingesting protein or an amount of leucine equal to that in the protein during a hyperinsulinaemic-euglycaemic clamp (to eliminate potential confounding as a result of differences in the insulinogenic effect of protein and leucine ingestion) on muscle anabolic signalling and protein turnover in 28 women. We found that protein, but not leucine, ingestion increased muscle p-mTOR^Ser2448 and p-p70S6K^Thr389 , although only protein, and not leucine, ingestion decreased muscle p-eIF2α^Ser51 and increased muscle protein synthesis.

ABSTRACT

It has been suggested that leucine is primarily responsible for the increase in muscle protein synthesis (MPS) after protein ingestion because leucine uniquely activates the mTOR-p70S6K signalling cascade. We tested this hypothesis by measuring muscle p-mTOR^Ser2448 , p-p70S6K^Thr389 and p-eIF2α^Ser51 , as well as protein turnover (by stable isotope labelled amino acid tracer infusion in conjunction with leg arteriovenous blood and muscle tissue sampling), in 28 women who consumed either 0.45 g protein kg^-1 fat-free mass (containing 0.0513 g leucine kg^-1 fat-free mass) or a control drink (n = 14) or 0.0513 g leucine kg^-1 fat-free mass or a control drink (n = 14) during a hyperinsulinaemic-euglycaemic clamp procedure (HECP). Compared to basal conditions, the HECP alone (without protein or leucine ingestion) suppressed muscle protein breakdown by ∼20% and increased p-mTOR^Ser2448 and p-p70S6K^Thr389 by >50% (all P < 0.05) but had no effect on p-eIF2α^Ser51 and MPS. Both protein and leucine ingestion further increased p-mTOR^Ser2448 and p-p70S6K^Thr389 , although only protein, and not leucine, ingestion decreased (by ∼35%) p-eIF2α^Ser51 and increased (by ∼100%) MPS (all P < 0.05). Accordingly, leg net protein balance changed from negative (loss) during basal conditions to equilibrium during the HECP alone and the HECP with concomitant leucine ingestion and to positive (gain) during the HECP with concomitant protein ingestion. These results provide new insights into the regulation of MPS by demonstrating that leucine and mTOR signalling alone are not responsible for the muscle anabolic effect of protein ingestion during physiological hyperinsulinaemia, most probably because they fail to signal to eIF2α to initiate translation and/or additional amino acids are needed to sustain translation.

SEER study of ablation versus partial nephrectomy in cT1A renal cell carcinoma

Aim: Compare ablation versus partial nephrectomy (PN) in T1A renal cell carcinoma (RCC) treatment, using the SEER database. Methods: Patients with diagnosed T1A RCC from 2004 to 2013 were identified. Propensity matching paired subjects with similar background variables. Kaplan–Meier and Cox proportional hazards regression were performed before and after matching. Results: Cohort included 4592 patients (809 ablation, 3783 PN). PN compared with ablation group had significantly increased overall survival (OS; 93.6% vs 81.9% 5-year survival; p < 0.0001) and cancer-specific survival (CSS; p < 0.0001). After matching (1222 pairs), PN group had significantly increased OS (91.0% vs 86.3% 5-year survival; p = 0.0457) but similar CSS (p = 0.4023). Conclusion: Ablation offers similar CSS but lower OS as PN for T1A RCC in this SEER database.

Liver-dominant Breast Cancer Metastasis: A Comparative Outcomes Study of Chemoembolization Versus Radioembolization

AIM

To compare toxicity, response, and survival outcomes of patients with hepatic metastases from breast cancer who underwent transarterial chemoembolization (TACE) or radioembolization (TARE).

MATERIALS AND METHODS

A retrospective review was carried out of all patients who underwent TACE or TARE for liver-dominant breast cancer metastases between January 2006 and March 2016 at an academic medical center in the United States.

RESULTS

Seventeen patients in the TACE group and 30 patients in the TARE group received 32 TACE and 49 TARE treatments, respectively. Median follow-up was 9 months. Both groups had similar background variables. More all-grade adverse events were seen in the TACE group (71% vs. 44%; p=0.02). Median overall survival in the TACE group was 4.6 months compared to 12.9 months in the TARE group (p=0.2349). Treatment type was not an independent prognostic factor.

CONCLUSION

TARE is better tolerated than TACE for the treatment of liver-dominant breast cancer metastasis. There was a trend towards improved survival with TARE; however, it did not approach statistical significance. Larger studies are needed to validate these findings.

Thermal ablation versus surgical resection for localized hepatocellular carcinoma: a population study using the SEER database

AIM

To compare overall survival (OS) and liver cancer-specific survival (LCSS) in patients with localized hepatocellular carcinoma treated with surgical resection (SR) or thermal ablation (TA) using the Surveillance, Epidemiology and End Results database.

MATERIALS & METHODS

Kaplan-Meier, competing risk and Cox regression analyses were performed after identifying patients. Propensity score matching was then applied.

RESULTS

There was significantly better OS in the SR group and significantly lower probability of LCSS in the TA group. After matching, there was significantly longer OS in the SR group and a lower probability of LCSS in the TA group.

CONCLUSION

SR offered a significant survival benefit over TA for localized hepatocellular carcinoma.

Endovascular Management of SVC Syndrome due to Fibrosing Mediastinitis-A Feasibility and Safety Analysis

PURPOSE

To assess the outcomes of endovascular management for superior vena cava (SVC) syndrome secondary to fibrosing mediastinitis (FM).

METHODS

Between January 2004 and December 2016, 10 consecutive patients with endovascularly managed SVC syndrome secondary to FM were identified in an institutional database. Venograms were performed to assess the severity and location of the lesion and allow measurement for stent selection. Standard stenting and angioplasty techniques were utilized to establish luminal patency. The safety, feasibility, clinical success, and the primary and secondary patency were evaluated. Kaplan-Meier survival analysis was used to determine median duration of stent patency. A log-rank test was used to test differences in prior stent use.

RESULTS

Our cohort was predominantly female (7/10) with an average age of 42.2 years. Of the 10 patients, 3 had undergone endovascular stenting at an outside institution prior to referral to our institution due to new, recurrent, or worsening symptoms. All patients underwent venography demonstrating stenosis (8/10) or occlusion (2/10) at initial presentation. Stenting or angioplasty was technically successful in 9 (90.0%) patients. Eight of 10 patients had primary stenting, while 1 achieved vascular patency and symptom resolution with angioplasty alone. Median duration of primary patency was 31.3 months (95% confidence interval: 5.9-103). Six (54.5%) patients required secondary revision procedures. Median duration of secondary patency was 6.1 months, with 25% of revisions occurring by 4 months and 75% occurring by 20.9 months. All treated patients (9/9) reported symptomatic relief at 1-month follow-up, establishing a clinical success rate of 100%. There were no 30-day adverse effects related to the procedure.

CONCLUSION

This study demonstrates that endovascular therapy is a safe and feasible approach for managing FM-related SVC syndrome.

Data Perturbation Independent Diagnosis and Validation of Breast Cancer Subtypes Using Clustering and Patterns

Molecular stratification of disease based on expression levels of sets of genes can help guide therapeutic decisions if such classifications can be shown to be stable against variations in sample source and data perturbation. Classifications inferred from one set of samples in one lab should be able to consistently stratify a different set of samples in another lab. We present a method for assessing such stability and apply it to the breast cancer (BCA) datasets of Sorlie et al. 2003 and Ma et al. 2003. We find that within the now commonly accepted BCA categories identified by Sorlie et al. Luminal A and Basal are robust, but Luminal B and ERBB2+ are not. In particular, 36% of the samples identified as Luminal B and 55% identified as ERBB2+ cannot be assigned an accurate category because the classification is sensitive to data perturbation. We identify a “core cluster” of samples for each category, and from these we determine “patterns” of gene expression that distinguish the core clusters from each other. We find that the best markers for Luminal A and Basal are (ESR1, LIV1, GATA-3) and (CCNE1, LAD1, KRT5), respectively. Pathways enriched in the patterns regulate apoptosis, tissue remodeling and the immune response. We use a different dataset (Ma et al. 2003) to test the accuracy with which samples can be allocated to the four disease subtypes. We find, as expected, that the classification of samples identified as Luminal A and Basal is robust but classification into the other two subtypes is not.

Adhesive Characteristics of Alder-Ene Adduct of Diallyl Bisphenol a Novolac and Bisphenol a Bismaleimide

Diallyl bisphenol A–formaldehyde copolymer (ABPF) was addition cured with bisphenol A bismaleimide (BMIP) making use of the Alder-ene reaction at high temperatures. The lap shear strength (LSS) of the system was found to depend on the conditions of cure and the stoichiometry of the reactants. Moderate cross linking achieved at a 1:1 maleimide:allylphenol stoichiometry and a stepwise cure, up to a maximum of 250 °C for 2 h, was found to be the most effective in achieving the optimum LSS properties. The system exhibited greater than 100% retention of the LSS at temperatures up to 250 °C. Matrix modification using polysulfone (PS) and polycarbonate (PC) resulted in a remarkable improvement in the adhesive characteristics, although the high-temperature retention was marginally adversely affected. The performance advantage both at room temperature (RT) and at high temperature was greater in the case of PS modification, showing an optimum improvement at 20% loading as against PC modification, exhibiting maximum properties at 10% loading. Scanning electron microscopy (SEM) analysis confirmed that the fine dispersion of PS, rather than large size nodules found in PC, was conducive for the better performance of the former. Dynamic mechanical analysis (DMA) corroborated the observations made in SEM. The existence of co-continuous phases of thermoplastic, matrix and thermoplasticdissolved matrix was evidenced in the PS modification and a clear phase separation was evident in the case of the PC modified system, manifesting independent glass transitions by the individual phases.

The usefulness of diffusion-weighted imaging in the characterization of liver lesions in patients with cirrhosis

AIM

To evaluate if diffusion-weighted imaging (DWI) is useful in characterizing liver lesions in patients with cirrhosis.

MATERIALS AND METHODS

A retrospective review revealed 37 patients with cirrhosis who had 41 histologically proven hepatocellular carcinoma (HCC) lesions. Another 20 patents with cirrhosis had 29 solid nodules that remained stable for at least 12 months and were deemed to be benign hepatic nodules (BHN). Of the HCC lesions, 14 were well-differentiated (WD HCC), 20 were moderately differentiated, and seven were poorly differentiated histology. For all lesions, two reviewers analysed signal characteristics and made apparent diffusion coefficient value (ADC) measurements.

RESULTS

Visual analysis of DWI was useful in that no HCC was hypointense and no BHN was hyperintense to liver. Visual analysis of DWI was not useful in separating WD HCC from higher grades. There was substantial overlap in ADC values of the HCC and BHN. Among HCC lesions, ADC values of more than 0.99 × 10(-3) mm(2)/s had sensitivity and specificity of 85% and 86% for reviewer 1, and 63% and 64% for reviewer 2 in diagnosing WD HCC.

CONCLUSIONS

ADC measurements of BHN were higher than that of HCC, and the ADC values of WD HCC were higher than that of more aggressive grades of HCC. However, quantitative measurements may not help in determining the histological grade of individual cases of HCC.

Stochastic synchronization of interacting pathways in testosterone model

We examine the possibilities of various coupling mechanisms among a group of identical stochastic oscillators via Chemical Langevin formalism where each oscillator is modeled by stochastic model of testosterone (T) releasing pathway. Our results show that the rate of synchrony among the coupled oscillators depends on various parameters namely fluctuating factor, coupling constants [symbol; see text], and interestingly on system size. The results show that synchronization is achieved much faster in classical deterministic system rather than stochastic system. Then we do large scale simulation of such coupled pathways using stochastic simulation algorithm and the detection of synchrony is measured by various order parameters such as synchronization manifolds, phase plots etc and found that the proper synchrony of the oscillators is maintained in different coupling mechanisms and support our theoretical claims. We also found that the coupling constant follows power law behavior with the systems size (V) by [symbol; see text] ~ AV(-γ), where γ=1 and A is a constant. We also examine the phase transition like behavior in all coupling mechanisms that we have considered for simulation. The behavior of the system is also investigated at thermodynamic limit; where V → ∞, molecular population, N → ∞ but N/V → finite, to see the role of noise in information processing and found the destructive role in the rate of synchronization.

Enhancing synchrony in chaotic oscillators by dynamic relaying

In a chain of mutually coupled oscillators, the coupling threshold for synchronization between the outermost identical oscillators decreases when a type of impurity (in terms of parameter mismatch) is introduced in the inner oscillator(s). The outer oscillators interact indirectly via dynamic relaying, mediated by the inner oscillator(s). We confirm this enhancing of critical coupling in the chaotic regimes of the Lorenz system, in the Rössler system in the absence of coupling delay, and in the Mackey-Glass system with delay coupling. The enhancing effect is experimentally verified in the electronic circuit of Rössler oscillators.

Does the hepatocellular phase of gadobenate dimeglumine help to differentiate hepatocellular carcinoma in cirrhotic patients according to histological grade?

AIM

To assess the role of the hepatocellular phase on magnetic resonance imaging (MRI) following gadobenate in characterizing the grade of hepatocellular carcinoma (HCC) in cirrhotic patients.

MATERIALS AND METHODS

A retrospective review of the MRI database from October 2004 to February 2009, performed for this Institutional Review Board-approved and Health Insurance Portability and Accountability Act (HIPAA)-complaint study, revealed 237 cirrhotic patients with focal liver lesions. Patients who had both a hepatocellular phase after gadobenate and pathological confirmation of HCC were included. Forty-six patients with 73 HCC were analysed independently by two reviewers for signal characteristics. Absolute contrast-to-noise ratio (CNR) and enhancement ratio (ER) were calculated. Univariate analysis, stepwise logistic regression analysis, and receiver operating characteristic curves (ROC) were performed.

RESULTS

The mean age was 61.3 years (range 45 to 78 years). There were 11 females and 35 males, who had 22 well-differentiated (WD HCC), 35 moderately-differentiated (MD HCC), and 16 poorly-differentiated (PD HCC) hepatocellular carcinomas. On visual analysis of the hepatocellular phase, a hyperintense or isointense lesion had a sensitivity and specificity of 45% and 76%, respectively, for WD HCC. On quantitative analysis, the only significant predictor of the grade of HCC was the ER on the hepatocellular phase (p=0.019 and 0.001 for the two reviewers in logistic regression model). On ROC analysis, an ER of >13% was 47% sensitive and 89% specific in predicting WD HCC histology.

CONCLUSION

Although the hepatocellular phase of gadobenate may help to differentiate some cases of WD HCC from the more aggressive grades, there is overlap between the different grades on qualitative and quantitative analysis.

The negative association of BMI with classroom effort in elementary school children

This study was designed to evaluate the association between BMI and classroom effort in third to fifth grade, ages seven through 12. Teachers, completely blinded and unaware of the study at the time of their classroom evaluations, provided reports of academic performance and effort. Boys and girls (n = 45), which are members of an ethnically diverse community, participated. In addition to classroom measures, height, weight, and percentage body fat were evaluated. A multiple regression model controlling for ethnicity, gender, and age revealed that increasing BMI scores had little association with academic performance but effort scores decreased significantly as BMI increased. This is the first study to show that elevations in BMI in children are associated with decreasing effort in an academic setting. Thus, BMI associated reductions in effort may result in suboptimal levels of performance in the academic setting as well as in other aspects of life.

Total hip replacement in patients with multiple epiphyseal dysplasia with a mean follow-up of 15 years and survival analysis

The hip joint is commonly involved in multiple epiphyseal dysplasia and patients may require total hip replacement before the age of 30 years.

We retrospectively reviewed nine patients (16 hips) from four families. The diagnosis of multiple epiphyseal dysplasia was based on a family history, genetic counselling, clinical features and radiological findings. The mean age at surgery was 32 years (17 to 63), with a mean follow-up of 15.9 years (5.5 to 24).

Of the 16 hips, ten required revision at a mean of 12.5 years (5 to 15) consisting of complete revision of the acetabular component in three hips and isolated exchange of the liner in seven. No femoral component has loosened or required revision during the period of follow-up.

With revision for any reason, the 15-year survival was only 11.4% (95% confidence interval 1.4 to 21.4). However, when considering revision of the acetabular shell in isolation the survival at ten years was 93.7% (95% confidence interval 87.7 to 99.7), reducing to 76.7% (95% confidence interval 87.7 to 98.7) at 15 and 20 years, respectively.

Phase-flip transition in coupled electrochemical cells

Time delay is introduced in the coupling between a pair of electrochemical cells. As coupling parameters are varied, the anodic current in the two cells oscillate in synchrony in regimes of periodic as well as chaotic dynamics. When the time delay is varied a phase-flip transition is observed: the relative phase between the synchronized oscillations changes abruptly by pi . This is accompanied by an experimentally measurable discontinuous change in the frequency of the synchronized oscillators.

Total knee replacement with rotational proximal tibial osteotomy for osteoarthritis with severe external tibial torsion and patellar instability

The management of osteoarthritis of the knee associated with patellar instability secondary to external tibial torsion > 45° is challenging. Patellofemoral biomechanics in these patients cannot be achieved by intra-articular correction using standard techniques of total knee replacement.

We reviewed seven patients (eight knees) with recurrent patellar dislocation and one with bilateral irreducible lateral dislocation who had undergone simultaneous total knee replacement and internal tibial derotational osteotomy. All had osteoarthritis and severe external tibial torsion. The mean follow-up was for 47.2 months (24 to 120).

The mean objective and functional Knee Society scores improved significantly (p = 0.0001) from 29.7 and 41.5 pre-operatively to 71.4 and 73.5 post-operatively, respectively. In all patients the osteotomies healed and patellar stability was restored.

Excessive external tibial torsion should be identified and corrected in patients with osteoarthritis and patellar instability. Simultaneous internal rotation osteotomy of the tibia and total knee replacement is a technically demanding but effective treatment for such patients.