Surgical Management of Ebstein Anomaly: The Australia and New Zealand Experience.

BACKGROUND: Ebstein anomaly is a rare congenital anomaly of the tricuspid valve which presents challenges to cardiac surgeons due to the spectrum of the disease and the technical difficulty of valve repair. The natural history of the anomaly differs between patients presenting in the neonatal period to those presenting in adulthood. METHODS: A retrospective review of all patients >15 years of age with Ebstein anomaly, undergoing surgery on the tricuspid valve at 6 centers across Australia and New Zealand was performed. Patients from 1985 to 2019 were included in the study. RESULTS: A total of 125 patients were included in the study, 76 patients (60%) undergoing tricuspid valve repair, of which 23 patients underwent a Cone repair and 49 (40%) had a tricuspid valve replacement. The mean follow-up was 7.9 ± 7.3 years. Postoperatively, early mortality was 3 patients (2%) and 10-year survival was 91.5%. A postoperative pacemaker was required in 24 patients (19%). Reoperation was required in 21 patients (17%). There was no statistically significant difference in survival or reoperation between patients who underwent repair or replacement of the tricuspid valve; however, with a small number of patients in long-term follow-up. CONCLUSION: Older children and adult patients undergoing surgery for Ebstein anomaly in Australia and New Zealand experience good medium-term postoperative survival. Repair of the valve is achieved in a significant proportion of patients with increasing use and success with the Cone repair technique.

Active Range of Motion Measurement System Using an Optical Sensor to Evaluate Hand Functions.

Impairment of hand function greatly affects the independence of a human being. Proper assessment of hand function before and after any treatment for functional restoration is important to decide better treatment strategies. Despite traditional techniques of hand function evaluation, individual joint based assessment is vital to better track the details of the hand function. Current clinical assessments with goniometers are labour intensive, cumbersome and highly depend on the skill level of the practitioner. This study introduces an active range of motion (AROM) measurement system to measure individual range of motion of finger joints using an optical sensor. The proposed method is highly efficient, and the results demonstrated that the measurements are instant, repeatable and can successfully be employed in a clinical setup for patient evaluations.Clinical Relevance-Closely working with clinician to develop rehabilitation systems, we have identified that the assessment of patient hand functions is time consuming, and accuracy can be depended on the skill level of the practitioner in measuring joint range of motions (ROM). System introduced in this study can measure the joint AROMs instantly and independent of the practitioner's skill level and hence can provide a reliable, repeatable assessment of patient's hand function.

2.5-mm articulated endoluminal forceps using a compliant mechanism.

PURPOSE: Gastrointestinal cancer can be treated using a flexible endoscope through a natural orifice. However, treatment instruments with limited degrees of freedom (DOFs) require a highly skilled operator. Articulated devices useful for endoluminal procedures, such as endoscopic submucosal dissection and biopsy, have been developed. These devices enable dexterous operation in a narrow lumen; however, they suffer from limitations such as large size and high cost. To overcome these limitations, we developed a 2.5-mm articulated forceps that can be inserted into a standard endoscope channel based on a compliant mechanism. METHODS: The compliant mechanism allows the device to be compact and affordable, which is possible due to its monolithic structure. The proposed mechanism consists of two segments, 1-DOF grasping and 2-DOF bending, that are actuated by tendon-sheath mechanisms. A prototype was designed based on finite element analysis results. RESULTS: To confirm the effectiveness of the proposed mechanism, we fabricated the prototype using a 3D printer. A series of mechanical performance tests on the prototype revealed that it achieved the following specifications: (1) DOF: 1-DOF grasping + 2-DOF bending, (2) outer diameter: 2.5 mm, (3) length of the bending segment: 30 mm, and (4) range of motion: [Formula: see text] to [Formula: see text] (grasping) and [Formula: see text] to [Formula: see text] (bending). Finally, we performed a tissue manipulation test on an excised porcine colon and found that a piece of mucous membrane tissue was successfully resected using an electric knife while being lifted with the developed forceps. CONCLUSION: The results of the evaluation experiment demonstrated a positive feasibility of the proposed mechanism, which has a simpler structure compared to those of other conventional mechanisms; furthermore, it is potentially more cost-effective and is disposable. The mechanical design, prototype implementation, and evaluations are reported in this paper.

Towards Control of a Transhumeral Prosthesis with EEG Signals.

Robotic prostheses are expected to allow amputees greater freedom and mobility. However, available options to control transhumeral prostheses are reduced with increasing amputation level. In addition, for electromyography-based control of prostheses, the residual muscles alone cannot generate sufficiently different signals for accurate distal arm function. Thus, controlling a multi-degree of freedom (DoF) transhumeral prosthesis is challenging with currently available techniques. In this paper, an electroencephalogram (EEG)-based hierarchical two-stage approach is proposed to achieve multi-DoF control of a transhumeral prosthesis. In the proposed method, the motion intention for arm reaching or hand lifting is identified using classifiers trained with motion-related EEG features. For this purpose, neural network and k-nearest neighbor classifiers are used. Then, elbow motion and hand endpoint motion is estimated using a different set of neural-network-based classifiers, which are trained with motion information recorded using healthy subjects. The predictions from the classifiers are compared with residual limb motion to generate a final prediction of motion intention. This can then be used to realize multi-DoF control of a prosthesis. The experimental results show the feasibility of the proposed method for multi-DoF control of a transhumeral prosthesis. This proof of concept study was performed with healthy subjects.

Widespread prevalence of a CREBRF variant amongst Maori and Pacific children is associated with weight and height in early childhood.

OBJECTIVE: Investigating a large and ethnically diverse cohort from the Pacific region, we aimed to replicate and extend the recently reported findings that a CREBRF genetic variant is strongly associated with body mass index in Samoans. METHODS: A birth cohort of more than six thousand children was utilised. In this study, genotyping of two markers (rs12513649 and rs373863828) was undertaken in Maori, Pacific, European and Asian individuals in the cohort. RESULTS: We report that these CREBRF genetic variants are not confined to Samoans but are prevalent in all other Pacific populations sampled, including Maori. We found that the rs373863828 variant was significantly associated with growth at 4 years of age. On average, we observed allele-specific increases in weight (P=0·004, +455 g, s.e. 0.158), height (P=0·007, +0·70 cm, s.e. 0.26) and waist circumference (P=0·004, +0·70 cm, s.e. 0.24) at 4 years of age. The rs373863828 variant was not associated with birth weight (P=0·129). CONCLUSIONS: We replicated the finding that a CREBRF variant is associated with increased body mass. We then built on the original findings by demonstrating the prevalence of the rs12513649 and rs373863828 variants in multiple Pacific population groups and by demonstrating that the rs373863828 variant is associated with growth in early childhood. Pacific population groups experience a disproportionately high burden of obesity, starting in early childhood. This new knowledge offers potential for evidence-based interventions aimed at establishing healthy growth trajectories from the earliest possible age.

Development of a multi-DoF transhumeral robotic arm prosthesis.

An anthropomorphic transhumeral robotic arm prosthesis is proposed in this study. It is capable of generating fifteen degrees-of-freedom, seven active and eight passive. In order to realize wrist motions, a parallel manipulator-based mechanism is proposed. It simulates the human anatomical structure and generates motions in two axes. The hand-of-arm prosthesis consists of under-actuated fingers with intrinsic actuation. The finger mechanism is capable of generating three degrees of freedom, and it exhibits the capability of adjusting the joint angles passively according to the geometry of the grasping object. Additionally, a parameter to evaluate finger mechanisms is introduced, and it measures the adoptability of a finger mechanism. In order to verify the mechanism's efficacy in terms of motion generation, motion simulation and kinematic analysis were carried out. Results demonstrated that the mechanisms are capable of generating the required motions.

Validity of newly-developed BMI and waist cut-off values for Sri Lankan children.

BACKGROUND: Excess body fat leads to obesity-related morbidity and population/ethnicity-specific cut-off values of anthropometric measures are useful for better diagnosis. This study assesses the suitability of newly-developed Sri Lankan anthropometric cut-off values in the diagnosis of obesity in Sri Lankan children. METHODS: A cross-sectional study was conducted at University of Colombo, Sri Lanka involving 5-15 year old children. Height, weight, waist (WC), and hip (HC) circumferences were measured. Total body fat (FM) was measured using whole body BIA. WHR and WHtR were calculated. Validity of anthropometric measures in detecting childhood obesity (Sri Lankan BMI/WC; IOTF, WHO, British and CDC BMI and British WC cut-off values) were evaluated. RESULTS: Nine hundred and twenty children were assessed. FM showed significant associations with BMI (r = 0.92, p < 0.001), WC (r = 0.90, p < 0.001) and HC (r = 0.85, p < 0.001), but poor association with WHR (r = 0.17, p < 0.001). However, WHtR had a high association with FM (r = 0.75, p < 0.001) and %FM (r = 0.78, p < 0.001). Based on %FM cut-offs, 85 (22.8%) girls and 101 (18.5%) boys were obese. All international anthropometric cut-off values under-estimated obesity. Sri Lankan WC and BMI cut-off values over-estimated obesity. International BMI based cut-off values had high specificity (>99%) but a low sensitivity (∼12-33%), while Sri Lankan BMI cut-off values had high sensitivity (>93.1) but low specificity (>79.7). CONCLUSIONS: Internationally available BMI cut-off values are poor in diagnosing obesity in Sri Lankan children. Newly developed Sri Lankan BMI cut-off values for children improved the diagnosis. WC can be used successfully as an alternative diagnostic tool of obesity.

Changes in the heme ligation during folding of a Geobacter sulfurreducens sensor GSU0935.

Ligand binding and substitution reactions are important for metalloprotein folding and function. The heme sensor of a methyl-accepting chemotaxis GSU0935 is a c-type cytochrome from the bacterium Geobacter sulfurreducens. The heme domain switches one of its axial ligands from H(2)O to a low-spin ligand, presumably Met, upon reduction. The study analyzes the stability and folding kinetics of the ferric domain. Guanidine hydrochloride denaturation yields the low-spin heme species arising from coordination of the ferric heme by non-native His residues. The population of the low-spin species further increases and then declines during protein refolding. Kinetics and mutational effects suggest that His54, from the N-terminal region of the domain, is the transient ligand to the heme. The capture and release of a non-native ligand within the compact partially-folded structures illustrates the flexibility of the heme environment in GSU0935, which may relate to the domain sensor function.

Coordination modes of tyrosinate-ligated catalase-type heme enzymes: magnetic circular dichroism studies of Plexaura homomalla allene oxide synthase, Mycobacterium avium ssp. paratuberculosis protein-2744c, and bovine liver catalase in their ferric and ferrous states.

Bovine liver catalase (BLC), catalase-related allene oxide synthase (cAOS) from Plexaura homomalla, and a recently isolated protein from the cattle pathogen Mycobacterium avium ssp. paratuberculosis (MAP-2744c (MAP)) are all tyrosinate-ligated heme enzymes whose crystal structures have been reported. cAOS and MAP have low (<20%) sequence similarity to, and significantly different catalytic functions from, BLC. cAOS transforms 8R-hydroperoxy-eicosatetraenoic acid to an allene epoxide, whereas the MAP protein is a putative organic peroxide-dependent peroxidase. To elucidate factors influencing the functions of these and related heme proteins, we have investigated the heme iron coordination properties of these tyrosinate-ligated heme enzymes in their ferric and ferrous states using magnetic circular dichroism and UV-visible absorption spectroscopy. The MAP protein shows remarkable spectral similarities to cAOS and BLC in its native Fe(III) state, but clear differences from ferric proximal heme ligand His93Tyr Mb (myoglobin) mutant, which may be attributed to the presence of an Arg(+)-N(ω)-H···¯O-Tyr (proximal heme axial ligand) hydrogen bond in the first three heme proteins. Furthermore, the spectra of Fe(III)-CN¯, Fe(III)-NO, Fe(II)-NO (except for five-coordinate MAP), Fe(II)-CO, and Fe(II)-O(2) states of cAOS and MAP, but not H93Y Mb, are also similar to the corresponding six-coordinate complexes of BLC, suggesting that a tyrosinate (Tyr-O¯) is the heme axial ligand trans to the bound ligands in these complexes. The Arg(+)-N(ω)-H to ¯O-Tyr hydrogen bond would be expected to modulate the donor properties of the proximal tyrosinate oxyanion and, combined with the subtle differences in the catalytic site structures, affect the activities of cAOS, MAP and BLC.

Oral vaccination of chickens against Newcastle disease with V4 vaccine delivered on processed rice grains.

An international effort (sponsored by the Australian Centre for International Agricultural Research) is being made to develop oral vaccines that will protect village chickens against Newcastle disease. The vaccines being used are derivatives of the avirulent Australian V4 strain that have been selected for enhanced heat resistance. The present study, undertaken in Sri Lanka, used local processed (parboiled) rice as a vehicle for the vaccine. Chickens receiving two doses of vaccine on cooked, parboiled rice were completely protected against contact challenge with the virulent SL 88/1 Sri Lankan strain of Newcastle disease virus Chickens kept in contact with these vaccinated chickens were similarly protected. Lower levels of protection were achieved with vaccine given on uncooked parboiled rice. V4 vaccine administered intranasally also gave complete protection. Serums from vaccinated chickens that survived challenge were tested for haemagglutination-inhibition antibodies, using both vaccine virus and challenge virus as antigens. Titres were higher against vaccine virus.