Update on the Hong Kong Reference Framework for Hypertension Care for Adults in Primary Care Settings-review of evidence on the definition of high blood pressure and goal of therapy.

The Hong Kong Reference Framework for Hypertension Care for Adults in Primary Care Settings is updated regularly to ensure it reflects the latest medical development and best practice. In 2017, guidelines from the United States included a major change, adopting the lower blood pressure values of 130/80 mm Hg in defining hypertension, in contrast to the prevailing international consensus of 140/90 mm Hg. After thorough review of the literature and international guidelines, the Advisory Group on Hong Kong Reference Framework for Care of Diabetes and Hypertension in Primary Care Settings (Advisory Group) recommends that the definition of hypertension adopted in the Reference Framework should remain unchanged as a blood pressure of ≥140/90 mm Hg, as there is currently inadequate evidence and lack of general consensus to support such change in Hong Kong. The Advisory Group agrees on individualised treatment goals, and recommends that the initial blood pressure goal for individuals with uncomplicated hypertension should be <140/90 mm Hg; for those who can tolerate it, the goal should be ≤130/80 mm Hg. A lower blood pressure is advisable for young or overweight/obese patients, smokers, and patients with other cardiovascular risk factors.

Tuberculosis of the spine with severe angular kyphosis: mean 34-year post-operative follow-up shows that prevention is better than salvage.

AIMS: To address the natural history of severe post-tuberculous (TB) kyphosis, with focus upon the long-term neurological outcome, occurrence of restrictive lung disease, and the effect on life expectancy. PATIENTS AND METHODS: This is a retrospective clinical review of prospectively collected imaging data based at a single institute. A total of 24 patients of Southern Chinese origin who presented with spinal TB with a mean of 113° of kyphosis (65° to 159°) who fulfilled inclusion criteria were reviewed. Plain radiographs were used to assess the degree of spinal deformity. Myelography, CT and MRI were used when available to assess the integrity of the spinal cord and canal. Patient demographics, age of onset of spinal TB and interventions, types of surgical procedure, intra- and post-operative complications, and neurological status were assessed. RESULTS: All except one of the 24 patients were treated with anti-TB chemotherapy when they were first diagnosed with spinal TB. They subsequently received surgery either for neurological deterioration, or deformity correction in later life. The mean follow-up was 34 years (11 to 59) since these surgical interventions. Some 16 patients (66.7%) suffered from late neurological deterioration at a mean of 26 years (8 to 49) after the initial drug treatment. The causes of neurological deterioration were healed disease in nine patients (56.2%), re-activation in six patients (37.5%) and adjacent level spinal stenosis in one patient (6.3%). The result of surgery was worse in healed disease. Eight patients without neurological deterioration received surgery to correct the kyphosis. The mean correction ranged from 97° to 72°. Three patients who were clinically quiescent with no neurological deterioration were found to have active TB of the spine. Solid fusion was achieved in all cases and no patient suffered from neurological deterioration after 42 years of follow-up. On final follow-up, six patients were noted to have deceased (age range: 47 years to 75 years). CONCLUSION: Our study presents one of the longest assessments of spinal TB with severe kyphosis. Severe post-TB kyphosis may lead to significant health problems many years following the initial drug treatment. Early surgical correction of the kyphosis, solid fusion and regular surveillance may avoid late complications. Paraplegia, restrictive lung disease and early onset kyphosis might relate to early death. Clinically quiescent disease does not mean cure. Cite this article: Bone Joint J 2017;99-B:1381-8.

A microfabricated low-profile wideband antenna array for terahertz communications.

While terahertz communications are considered to be the future solutions for the increasing demands on bandwidth, terahertz equivalents of radio frequency front-end components have not been realized. It remains challenging to achieve wideband, low profile antenna arrays with highly directive beams of radiation. Here, based on the complementary antenna approach, a wideband 2 × 2 cavity-backed slot antenna array with a corrugated surface is proposed. The approach is based on a unidirectional antenna with a cardiac radiation pattern and stable frequency characteristics that is achieved by integrating a series-resonant electric dipole with a parallel-resonant magnetic dipole. In this design, the slots work as magnetic dipoles while the corrugated surface radiates as an array of electric dipoles. The proposed antenna is realized at 1 THz operating frequency by stacking multiple metallized layers using the microfabrication technology. S-parameter measurements of this terahertz low-profile metallic antenna array demonstrate high efficiency at terahertz frequencies. Fractional bandwidth and gain are measured to be 26% and 14 dBi which are consistent with the simulated results. The proposed antenna can be used as the building block for larger antenna arrays with more directive beams, paving the way to develop high gain low-profile antennas for future communication needs.

The use of the distal radius and ulna classification for the prediction of growth: peak growth spurt and growth cessation.

AIMS: We report the use of the distal radius and ulna (DRU) classification for the prediction of peak growth (PG) and growth cessation (GC) in 777 patients with idiopathic scoliosis. We compare this classification with other commonly used parameters of maturity. PATIENTS AND METHODS: The following data were extracted from the patients' records and radiographs: chronological age, body height (BH), arm span (AS), date of menarche, Risser sign, DRU grade and status of the phalangeal and metacarpal physes. The mean rates of growth were recorded according to each parameter of maturity. PG was defined as the summit of the curve and GC as the plateau in deceleration of growth. The rates of growth at PG and GC were used for analysis using receiver operating characteristic (ROC) curves to determine the strength and cutoff values of the parameters of growth. RESULTS: The most specific grades for PG using the DRU classification were radial grade 6 and ulnar grade 5, and for GC were radial grade 9 and ulnar grade 7. The DRU classification spanned both PG and GC, enabling better prediction of these clinically relevant stages than other methods. The rate of PG (≥ 0.7 cm/month) and GC (≤ 0.15 cm/month) was the same for girls and boys, in BH and AS measurements. CONCLUSION: This is the first study to note that the DRU classification can predict both PG and GC, providing evidence that it may aid the management of patients with idiopathic scoliosis. Cite this article: Bone Joint J 2016;98-B:1689-96.

The dorsal skinfold chamber: A versatile tool for preclinical research in tissue engineering and regenerative medicine.

Previous human study suggested that fresh-frozen intervertebral disc allograft transplantation can relieve neurological symptoms and restore segmental kinematics. Before wide clinical application, research into the pathophysiology of the postoperative disc allograft is needed. One important question that remains to be answered in disc allografting is the healing process of the host-graft interface and the subsequent change of the endplates. With the goat model for lumbar disc allografting, histology, micro-computed tomography analysis, scanning electron microscopy and energy-dispersive X-ray spectroscopy mapping were applied to evaluate the healing of the host-graft interfaces, the remodelling of subchondral bone, and the changes of the bony and cartilaginous endplates after transplantation. It was found that healing of the host-graft interfaces started at 1.5 months and was completed at 6 months by natural remodelling. This bony remodelling was also noted in the subchondral bone area after 6 months. The bony endplate was well preserved initially, but was gradually replaced by trabecular bone afterwards; on the other hand, the cartilaginous endplate became atrophic at 6 months and nearly disappeared at the final follow-up. Collectively, after intervertebral disc allograft transplantation, bony healing and remodelling were seen which ensured the stability and mobility of the disc-transplanted segment, but the integrity of bony and cartilaginous endplates was gradually lost and nearly disappeared finally.

Lumbar intervertebral disc allograft transplantation: healing and remodelling of the bony structure.

Previous human study suggested that fresh-frozen intervertebral disc allograft transplantation can relieve neurological symptoms and restore segmental kinematics. Before wide clinical application, research into the pathophysiology of the postoperative disc allograft is needed. One important question that remains to be answered in disc allografting is the healing process of the host-graft interface and the subsequent change of the endplates. With the goat model for lumbar disc allografting, histology, micro-computed tomography analysis, scanning electron microscopy and energy-dispersive X-ray spectroscopy mapping were applied to evaluate the healing of the host-graft interfaces, the remodelling of subchondral bone, and the changes of the bony and cartilaginous endplates after transplantation. It was found that healing of the host-graft interfaces started at 1.5 months and was completed at 6 months by natural remodelling. This bony remodelling was also noted in the subchondral bone area after 6 months. The bony endplate was well preserved initially, but was gradually replaced by trabecular bone afterwards; on the other hand, the cartilaginous endplate became atrophic at 6 months and nearly disappeared at the final follow-up. Collectively, after intervertebral disc allograft transplantation, bony healing and remodelling were seen which ensured the stability and mobility of the disc-transplanted segment, but the integrity of bony and cartilaginous endplates was gradually lost and nearly disappeared finally.

Classification of Schmorl's nodes of the lumbar spine and association with disc degeneration: a large-scale population-based MRI study.

OBJECTIVE: Schmorl's nodes (SN) are highly associated with lumbar disc degeneration (DD). However, SN present with different morphologies/topographies that may be associated with varying degrees of DD. This study proposed a classification of SN to determine their morphological/topographical prevalence and association with the severity of DD. METHODS: Sagittal T2-weighted MRIs were assessed to identify SN and additional imaging findings from L1-S1 in 2,449 individuals. SN characteristics were classified by six criteria: disc level; endplate involvement; shape; size; location of endplate zone; and the presence of marrow changes. Hierarchical clustering was performed to identify distinct SN characteristics with endplate patterns. RESULTS: Good to excellent observer classification reliability was noted. SN most commonly presented at the L1 and L2 disc levels, and entailed one-third of the endplate, predominantly the middle zone. Round shape (39.2%) was the most common SN shape. Four specific SN and endplate linkage patterns were identified. 8.3% of identified SN (n = 960) were "Atypical SN". Multivariable regression showed that "Typical SN" and "Atypical SN", depending on levels, were associated with an adjusted 2- to 4-fold and a 5- to 13-fold higher risk of increased severity of DD, respectively (p < 0.05). CONCLUSIONS: This is the first large-scale magnetic resonance imaging (MRI) study to propose a novel SN classification. Specific SN-types were identified, which were associated with more severe DD. This study further broadens our understanding of the role of SN and degrees of DD, further expanding on the SN phenotyping that can be internationally adopted for utility assessment.

Systemic blood plasma CCL5 and CXCL6: Potential biomarkers for human lumbar disc degeneration.

Lumbar disc degeneration severity on magnetic resonance imaging (MRI) is associated with low back pain. Pro-inflammatory chemokines CCL5 and CXCL6 are released by induced degenerative discs, and CCL5 has been associated with discogenic back pain. A case-control study was performed, based on the Hong Kong Disc Degeneration Population-Based Cohort of Southern Chinese, to investigate if systemic levels of CCL5 and CXCL6 were elevated in subjects with disc degeneration compared to non-degenerated individuals. Eighty subjects were selected, 40 with no disc degeneration (control group; DDD score 0) and 40 with moderate/severe disc degeneration (disc degeneration group; DDD score ≥5) as noted on MRI. Subjects were matched for age, sex, body mass index and workload. Blood plasma samples were obtained from each individual, and levels of CCL5 and CXCL6 were measured. Secondary phenotypes of lumbar disc displacement and cervical disc changes were also assessed. CCL5 concentrations were significantly increased in the disc degeneration (mean: 19.8 ng/mL) compared to the control group (mean: 12.8 ng/mL) (p = 0.015). The degeneration group demonstrated higher levels of CXCL6 (mean: 56.9 pg/mL) compared to the control group (mean: 43.4 pg/mL) (p = 0.010). There was a trend towards elevated CCL5 levels with disc displacement in the degeneration group (p = 0.073). Cervical disc degeneration was not associated with elevated chemokine levels (p > 0.05). This is the first study to note that elevated systemic CCL5 and CXCL6 were associated with moderate/severe lumbar disc degeneration, further corroborating tissue studies of painful discs. These chemokines may be systemic biomarkers for the diagnosis and monitoring of disc degeneration.

Single-trial detection for intraoperative somatosensory evoked potentials monitoring.

Abnormalities of somatosensory evoked potentials (SEPs) provide effective evidence for impairment of the somatosensory system, so that SEPs have been widely used in both clinical diagnosis and intraoperative neurophysiological monitoring. However, due to their low signal-to-noise ratio (SNR), SEPs are generally measured using ensemble averaging across hundreds of trials, thus unavoidably producing a tardiness of SEPs to the potential damages caused by surgical maneuvers and a loss of dynamical information of cortical processing related to somatosensory inputs. Here, we aimed to enhance the SNR of single-trial SEPs using Kalman filtering and time-frequency multiple linear regression (TF-MLR) and measure their single-trial parameters, both in the time domain and in the time-frequency domain. We first showed that, Kalman filtering and TF-MLR can effectively capture the single-trial SEP responses and provide accurate estimates of single-trial SEP parameters in the time domain and time-frequency domain, respectively. Furthermore, we identified significant correlations between the stimulus intensity and a set of indicative single-trial SEP parameters, including the correlation coefficient (between each single-trial SEPs and their average), P37 amplitude, N45 amplitude, P37-N45 amplitude, and phase value (at the zero-crossing points between P37 and N45). Finally, based on each indicative single-trial SEP parameter, we investigated the minimum number of trials required on a single-trial basis to suggest the existence of SEP responses, thus providing important information for fast SEP extraction in intraoperative monitoring.

An alternative to a randomised control design for assessing the efficacy and effectiveness of bracing in adolescent idiopathic scoliosis.

Randomised controlled trials (RCTs) that assessed the efficacy of bracing for adolescent idiopathic scoliosis have suffered from small sample sizes, low compliance and lack of willingness to participate. The aim of this study was to assess the feasibility of a comprehensive cohort study for evaluating both the efficacy and the effectiveness of bracing in patients with adolescent idiopathic scoliosis. Patients with curves at greater risk of progression were invited to join a randomised controlled trial. Those who declined were given the option to remain in the study and to choose whether they wished to be braced or observed. Of 87 eligible patients (5 boys and 63 girls) identified over one year, 68 (78%) with mean age of 12.5 years (10 to 15) consented to participate, with a mean follow-up of 168 weeks (0 to 290). Of these, 19 (28%) accepted randomisation. Of those who declined randomisation, 18 (37%) chose a brace. Patients who were more satisfied with their image were more likely to choose bracing (Odds Ratio 4.1; 95% confidence interval 1.1 to 15.0; p = 0.035). This comprehensive cohort study design facilitates the assessment of both efficacy and effectiveness of bracing in patients with adolescent idiopathic scoliosis, which is not feasible in a conventional randomised controlled trial.

Time-frequency patterns of somatosensory evoked potentials in predicting the location of spinal cord injury.

Somatosensory evoked potentials (SEPs) were found to exhibit different time-frequency patterns after acute spinal cord injury (SCI) at different levels, which implies that changes of these patterns may be associated with the location of SCI. Based on this finding, we propose the hypothesis that there are information regarding the location of SCI contained in the time-frequency patterns of SEPs. Purpose of the present study is to verify this hypothesis by comparing the time-frequency patterns of SEPs after acute and chronic SCI at the same level. The study examined the distribution patterns of the time-frequency components (TFCs) of SEPs before and after acute and chronic injury at C5 level in the spinal cord. Experimental results of SEP recordings from 24 adult rats show that there are common areas in the time-frequency distributions of SEPs. The TFCs from both the acute injury group and the chronic injury group are located in these areas with no TFCs from the normal group. Findings suggest that these areas are likely to possess information concerning the site of neurological deficits in spinal cord while independent of the modality of injury. This study provides basis for identification of stable time-frequency patterns of SEPs after different types and locations of SCI, which will guide the development of SEP-based SCI location detection.

Morphine stimulates cancer progression and mast cell activation and impairs survival in transgenic mice with breast cancer.

BACKGROUND: Morphine stimulates angiogenesis and cancer progression in mice. We investigated whether morphine influences tumour onset, development, and animal model survival, and whether µ-opioid receptor (MOR), lymphangiogenesis, mast cell activation, and substance P (SP) are associated with the tumour-promoting effects of morphine. METHODS: Transgenic mice with a rat C3(1) simian virus 40 large tumour antigen fusion gene which demonstrate the developmental spectrum of human infiltrating ductal breast carcinoma were used. Mice were treated at different ages with clinically relevant doses of morphine or phosphate-buffered saline to determine the effect on tumour development and progression, and on mouse survival. Tumours were analysed for MOR, angiogenesis, lymphangiogenesis, SP, and mast cell activation by immunofluorescent- or laser scanning confocal-microscopy. Cytokine and SP levels were determined by enzyme-linked immunosorbent assay. RESULTS: Morphine did not influence tumour development when given before the onset of tumour appearance, but significantly promoted progression of established tumours, and reduced survival. MOR-immunoreactivity (ir) was observed in larger but not in smaller tumours. Morphine treatment resulted in increased tumour angiogenesis, peri-tumoural lymphangiogenesis, mast cell activation, and higher levels of cytokines and SP in tumours. SP-ir co-localized with mast cells and elsewhere in the tumours. CONCLUSIONS: Morphine does not affect the onset of tumour development, but it promotes growth of existing tumours, and reduces overall survival in mice. MOR may be associated with morphine-induced cancer progression, resulting in shorter survival. Mast cell activation by morphine may contribute to increased cytokine and SP levels, leading to cancer progression and refractory pain.

Detection of low HCV viraemia by repeated HCV RNA testing predicts treatment failure to triple therapy with telaprevir.

BACKGROUND: Early on-treatment virological response is one of the most important predictors for sustained virological response (SVR) to treatment of chronic hepatitis C virus (HCV) genotype 1 infection with triple therapy including HCV protease inhibitors (PI). Treatment duration (24 vs. 48 weeks) is based on HCV RNA results at weeks 4 and 12 of PI therapy when HCV RNA must be 'undetectable' to allow shorter therapy. AIM: To analyse the reliability of HCV RNA measurements at key decision time points (weeks 4 and 12) and the predictive value of concordant or discordant assay results for SVR. METHODS: Weeks 4 and 12 samples of patients receiving telaprevir-containing triple therapy were initially tested with the AmpliPrep/COBAS-TaqMan_HCV-Test-v1.0 (limit of detection; LOD = 15IU/mL) and retested with the AmpliPrep/COBAS-TaqMan_HCV-Test-v2.0 (LOD = 15IU/mL) and the High_Pure/COBAS-TaqMan_HCV-Test-v2.0 (LOD = 20IU/mL). RESULTS: Concordance among the three test results in classifying samples as HCV RNA 'undetectable' or 'detectable' was only 55% at week 4, but 85% at week 12. Retesting of 'undetectable' week 4 samples with the respective other assays revealed positive HCV RNA results in 32-50%. In 30%, HCV RNA was 'undetectable' by all three tests at week 4 and all of these patients achieved SVR. In contrast, treatment failure occurred in 62% of patients with at least one 'detectable' result, including cases with one or two other 'undetectable' tests at week 4. CONCLUSIONS: A single 'undetectable' HCV RNA result at week 4 is not always associated with achieving SVR. Repeated testing in difficult-to-treat patients may identify those at risk for treatment failure.

Intervention timing of strontium treatment on estrogen depletion-induced osteoporosis in rats: bone microstructure and mechanics.

PURPOSE: To evaluate the effect of intervention timing of Sr treatment on trabecular bone microstructure and mechanics. METHODS: Ninety female rats were randomly divided into three batches with three groups in each batch. Each group was divided according to the initiation timing of vehicle or strontium compound (SrC), which was at week 0 (early), 4 (mid-term) and 8 (late) after the ovariectomy, respectively. The treatment lasted for 12 weeks. The trabecular bone biomechanical properties, trabecular bone tissue mechanical properties, trabecular bone microstructure, and bone remodeling were analyzed with mechanical testing, nanoindentation, microCT, and histomorphometry, respectively. The osteoblast and osteoclast phenotypic genes were analyzed with real-time polymerase chain reaction (PCR). RESULTS: Early and mid-term Sr treatment significantly increased biomechanical properties of trabecular bone, which was associated with increased microarchitecture parameters, increased bone formation parameters and up-regulation of osteoblast-related gene expression. Late Sr treatment failed to exert a beneficial effect on any of those parameters. CONCLUSIONS: The beneficial effect of Sr was dependent on the intervention timing in ovariectomized rats.

The current status of bracing for patients with adolescent idiopathic scoliosis.

Adolescent idiopathic scoliosis affects about 3% of children. Non-operative measures are aimed at altering the natural history to maintain the size of the curve below 40° at skeletal maturity. The application of braces to treat spinal deformity pre-dates the era of evidence-based medicine, and there is a paucity of irrefutable prospective evidence in the literature to support their use and their effectiveness has been questioned. This review considers this evidence. The weight of the evidence is in favour of bracing over observation. The most recent literature has moved away from addressing this question, and instead focuses on developments in the design of braces and ways to improve compliance.

The effect of excision of the posterior arch of C1 on C1/C2 fusion using transarticular screws.

Transarticular screw fixation with autograft is an established procedure for the surgical treatment of atlantoaxial instability. Removal of the posterior arch of C1 may affect the rate of fusion. This study assessed the rate of atlantoaxial fusion using transarticular screws with or without removal of the posterior arch of C1. We reviewed 30 consecutive patients who underwent atlantoaxial fusion with a minimum follow-up of two years. In 25 patients (group A) the posterior arch of C1 was not excised (group A) and in five it was (group B). Fusion was assessed on static and dynamic radiographs. In selected patients CT imaging was also used to assess fusion and the position of the screws. There were 15 men and 15 women with a mean age of 51.2 years (23 to 77) and a mean follow-up of 7.7 years (2 to 11.6). Stable union with a solid fusion or a stable fibrous union was achieved in 29 patients (97%). In Group A, 20 patients (80%) achieved a solid fusion, four (16%) a stable fibrous union and one (4%) a nonunion. In Group B, stable union was achieved in all patients, three having a solid fusion and two a stable fibrous union. There was no statistically significant difference between the status of fusion in the two groups. Complications were noted in 12 patients (40%); these were mainly related to the screws, and included malpositioning and breakage. The presence of an intact or removed posterior arch of C1 did not affect the rate of fusion in patients with atlantoaxial instability undergoing C1/C2 fusion using transarticular screws and autograft.

A new mechanism of injury in ankylosing spondylitis: non-traumatic hyperextension causing atlantoaxial subluxation.

Ankylosing spondylitis (AS) is a progressive multisystem chronic inflammatory disorder. The hallmark of this pathological process is a progressive fusion of the zygapophyseal joints and disc spaces of the axial skeleton, leading to a rigid kyphotic deformity and positive sagittal balance. The ankylosed spine is unable to accommodate normal mechanical forces, rendering it brittle and susceptible to injury. Traumatic hyperextension injury of the cervical spine leading to atlantoaxial subluxation (AAS) in AS patients can often be fatal. We report a non-traumatic mechanism of injury in AS progressing to AAS attributable to persistent hyperextension, which resulted in fatal migration of C2 through the foramen magnum.

Prevalence and associated comorbidities of moderate to severe chronic renal impairment in Chinese nursing home older adults.

OBJECTIVE: To investigate the prevalence and associated comorbidities of Stage 3 (GFR 30-59 mL/min/1.73m(2)) and Stages 4 and 5 (GFR <30 mL/min/1.73m(2)) chronic kidney disease (CKD) among Chinese nursing home older adults. DESIGN: Retrospective cross-sectional study. Glomerular filtration rate (GFR) was estimated by Modification of Diet in Renal Disease Study (Chinese-adjusted) equation and The Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations. SETTING: Nine nursing homes in Hong Kong PARTICIPANTS: Participants included 812 nursing home older adults (271 men and 571 women), mean age 86.0 ± 7.6. MEASUREMENTS: Prevalence of Stage 3 (GFR 30-59 mL/min/1.73m(2)) and Stages 4 and 5 (GFR <30 mL/min/1.73m(2)) CKD. The comorbidities associated with renal impairment were also assessed. RESULTS: There were 18.4% of nursing home older adults who had elevated serum creatinine levels above the normal limits. Using Modification of Diet in Renal Disease Study and CKD-EPI equations, 26.4% and 21.2% of them had Stage 3 CKD, whereas 6.8% and 4.4% had Stage 4-5 CKD, respectively. Diabetes mellitus, hypertension, congestive heart failure, and ischemic heart disease correlated significantly with moderate to severe renal impairment in Chinese nursing home older adults. CONCLUSION: Stages 3 to 5 CKD are prevalent in Chinese nursing home older adults. Early identification of these patients facilitates drug prescription, renal management, and advance care planning.