The use of magnetic resonance phase-contrast cine in Chiari malformation with syringomyelia.

INTRODUCTION: Chiari malformation (CM) is a disorder of mesodermal origin and is commonly associated with syringomyelia. Foramen magnum decompression is the first-line of standard treatment in symptomatic patients with a confirmed radiographic diagnosis. Magnetic resonance (MR) cine allows accurate evaluation of cerebrospinal fluid (CSF) physiology at the craniovertebral junction but often this is under-utilised in Malaysia. METHODS: In this series, we looked into nine cases of CM with syringomyelia from clinical and radiological perspective before and after surgery. The radiological parameters were herniated tonsillar length, syrinx: cord ratio, syrinx length and diameter. Flow velocity and morphologic changes in Chiari were illustrated. RESULTS: Seven patients showed either reduction in syrinx length, syrinx: cord ratio or both postoperatively. Clinical recovery somewhat varied in motor and sensory symptoms. Four patients gained better functional grade in modified Rankin scale (MRS) while the rest remained similar. The study highlighted the advantage of CSF flow dynamics information over MR anatomical radiographic improvement in addressing the neurologic and functional recovery. We also discussed the practicality of cine sequence in preoperative patient selection, syrinx analysis and postoperative flow evaluation in anticipation of clinical outcome. CONCLUSION: Phase-contrast cine MRI is a useful tool dictated by resource availability. We recommend its routine use in preoperative analysis and subsequent observational follow-up after surgery.

Hip fractures are preventable: a proposal for osteoporosis screening and fall prevention in older people.

Osteoporosis is highly prevalent but underdiagnosed and undertreated in Hong Kong. Fragility fractures associated with osteoporosis often result in loss of independence and increased mortality for home-dwelling patients, imposing a high socio-economic burden on society. This issue requires urgent attention given the rapid growth of the elderly population in Hong Kong by approximately 4.3% each year. To address this situation, a group of experts convened to discuss practical ways to reduce the burden of fractures and formulated three recommendations: first, all men (aged ≥70 years) and women (aged ≥65 years) should receive universal dual-energy X-ray absorptiometry assessment for osteoporosis. Second, all men (aged ≥70 years) and women (aged ≥65 years) with a fracture-risk assessment-derived 10-year risk (hip fracture with bone mineral density) ≥3% should receive ≥3 years of anti-osteoporotic treatment. Third, comprehensive structured assessment (including dual-energy X-ray absorptiometry) should be conducted in older patients with a history of falling. By implementing these recommendations, we estimate that we could prevent 5234 hip fractures in 10 years, an annual incidence reduction of approximately 7%, and save HK$425 million in direct medical costs plus substantial indirect savings. Ample clinical and cost-effectiveness data support these recommendations, and studies in Hong Kong and abroad could serve as models on how to implement them. We are confident that by applying these recommendations rigorously and systematically, a significant reduction in hip fractures in Hong Kong is achievable.

Faecal microbiota transplantation for treatment of recurrent or refractory Clostridioides difficile infection in Hong Kong.

INTRODUCTION: Clostridioides difficile infection (CDI) is a leading cause of healthcare-associated infection globally, causing significant morbidity and mortality. Faecal microbiota transplantation (FMT) has emerged as a promising option for recurrent and refractory CDI. This study aimed to assess the safety, efficacy, and feasibility of FMT for CDI in Hong Kong. METHODS: We conducted a single-centre, retrospective study for all consecutive cases of recurrent or refractory CDI who underwent FMT from 2013 to 2018. Clinical demographics, outcome, and safety parameters were collected. RESULTS: A total of 24 patients with recurrent or refractory CDI (median age 70 years, interquartile range=45.0-78.3 years; 67% male) were included. Over 80% had been recently hospitalised or were long-term care facility residents. Faecal microbiota transplantation was delivered by feeding tube in 11 (45.8%), oesophagogastroduodenoscopy in eight (33.3%), and colonoscopy in six (25%) of the patients. Resolution of diarrhoea without relapse within 8 weeks was achieved in 21 out of 24 patients (87.5%) after FMT. No deaths occurred within 30 days. The FMT was well tolerated and no serious adverse events attributable to FMT were reported. CONCLUSION: Our results confirm that FMT is a safe, efficacious, and feasible intervention for patients with refractory or recurrent CDI in Hong Kong. Given the increasing disease burden and the lack of effective alternatives in Hong Kong for difficult-to-treat cases of CDI, we recommend that a territory-wide FMT service be established to address increasing demand for this treatment.

Oncogenes expand during evolution to withstand somatic amplification.

Background: Cancer-related genes are under intense evolutionary pressure. We conjectured that gene size is an important determinant of amplification propensity for oncogenes and thus cancer susceptibility and therefore could be subject to natural selection. Patients and methods: Gene information, including size and genomic locations, of all protein-coding genes were downloaded from Ensembl (release 87). Quantification of gene amplification was based on Genomic Identification of Significant Targets in Cancer scores obtained from available The Cancer Genome Atlas studies. Results: Oncogenes are larger in size as compared with non-cancer genes (mean size: 92.1 kb versus 61.4 kb; P < 0.0001) in the human genome, which is contributed by both increased total exon size (mean size: 4.6 kb versus 3.4 kb; P < 0.0001) and higher intronic content (mean %: 84.8 versus 78.0; P < 0.01). Such non-random size distribution and intronic composition are conserved in mouse and Drosophila (all P < 0.0001). Stratification by gene age indicated that young oncogenes have been subject to a stronger evolutionary pressure for gene expansion than their non-cancer counterparts. Pan-cancer analysis demonstrated that larger oncogenes were amplified to a lesser extent. Tumor-suppressor genes also moved toward small oncogenes in the course of evolution. Conclusions: Oncogenes expand in size whereas tumor-suppressor genes move closer to small oncogenes in the course of evolution to withstand oncogenic somatic amplification. Our findings have shed new light on the previously unappreciated influence of gene size on oncogene amplification and elucidated how cancers have shaped our genome to its present configuration.

Early surgery for Hong Kong Chinese elderly patients with hip fracture reduces short-term and long-term mortality.

INTRODUCTION: Studies have shown that early surgery reduces hospital and 1-year mortality in elderly patients with hip fracture, but no major study has examined such relationship in Hong Kong. This study aimed to explore the relationship of early surgery and mortality in a Chinese elderly population with hip fracture. METHODS: This observational study included patients attending public hospitals in Hong Kong. All patients who underwent surgery for geriatric hip fracture in public hospitals from January 2000 to December 2011 were studied. Data were retrieved and collected from the Clinical Data Analysis and Reporting System of the Hospital Authority. Patients were divided into three groups according to timing of surgery: early (0-2 days after admission), delayed (3-4 days after admission), and late (≥5 days after admission) groups. Based on the date of death, we analysed 30-day and 1-year mortality, regardless of cause of death. Comparison of mortality rates was also made between the period before and after implementation of Key Performance Indicator formulated by the Hospital Authority. RESULTS: The overall 1-year mortality rate was 16.8%. The relative risks of 1-year mortality were 1.21 and 1.52 when the delayed and late groups were compared with the early group, respectively. The hazard ratios of long-term mortality were 1.16 (95% confidence interval, 1.13-1.20) and 1.37 (1.33-1.41), respectively for the same comparison. CONCLUSION: Prevalence of geriatric hip fracture will continue to rise and further increase the burden on our health care system. After implementation of Key Performance Indicator, most elderly patients with hip fracture underwent surgery within 2 days provided they were medically fit. Early surgery can reduce both short-term and long-term mortality. Setting up a fragility fracture registry would be beneficial for further studies.

How well are we managing fragility hip fractures? A narrative report on the review with the attempt to setup a Fragility Fracture Registry in Hong Kong.

INTRODUCTION: In setting up a disease registry for fragility fractures in Hong Kong, we conducted a retrospective systematic study on the management of fragility hip fractures. Patient outcomes were compared with the standards from our orthopaedic working group and those from the British Orthopaedic Association that runs a mature fracture registry in the United Kingdom. METHODS: Clinical data on fragility hip fracture patients admitted to six acute major hospitals in Hong Kong in 2012 were captured. These included demographics, pre- and post-operative assessments, discharge details, complications, and 1-year follow-up information. Analysis was performed according to the local standards with reference to those from the British Orthopaedic Association. RESULTS: Overall, 91.0% of patients received orthopaedic care within 4 hours of admission and 60.5% received surgery within 48 hours. Preoperative geri-orthopaedic co-management was received by 3.5% of patients and was one of the reasons for the delayed surgery in 22% of patients. Only 22.9% were discharged with medication that would promote bone health. Institutionalisation on discharge significantly increased by 16.2% (P<0.001). Only 35.1% of patients attended out-patient follow-up 1 year following fracture, and mobility had deteriorated in 69.9% compared with the premorbid state. Death occurred in 17.3% of patients within a year of surgery compared with 1.6% mortality rate in a Hong Kong age-matched population. CONCLUSIONS: The efficiency and quality of acute care for fragility hip fracture patients was documented. Regular geri-orthopaedic co-management can enhance acute care. Much effort is needed to improve functional recovery, prescription of bone health medications, attendance for follow-up, and to decrease institutionalisation. A Fracture Liaison Service is vital to improve long-term care and prevent secondary fractures.

Hepatic cyclooxygenase-2 overexpression induced spontaneous hepatocellular carcinoma formation in mice.

Cyclooxygenase (COX)-2 is upregulated in hepatocellular carcinoma (HCC). However, the direct causative effect of COX-2 in spontaneous HCC formation remains unknown. We thus investigate the role and molecular pathogenesis of COX-2 in HCC by using liver-specific COX-2 transgenic (TG) mice. We found spontaneous HCC formation with elevated inflammatory infiltrates and neovessels in male TG mice (3/21, 14.3%), but not in any of male WT mice (0/19). Reduced representation bisulfite sequencing (RRBS) and gene expression microarrays were performed in the HCC tumor and non-HCC liver tissues to investigate the molecular mechanisms of COX-2-driven HCC. By RRBS, DNA promoter hypermethylation was identified in HCC from TG mice. Induction of promoter hypermethylation was associated with reduced tet methylcytosine dioxygenase 1 (TET1) expression by COX-2. TET1 could catalyze the conversion of 5-methylcytosine into 5-hydroxymethylcytosine (5hmC) and prevents DNA hypermethylation. In keeping with this, loss of 5hmC was demonstrated in COX-2-induced HCC. Consistently, COX-2 overexpression in human HCC cell lines could reduce both TET1 expression and 5hmc levels. Integrative analyses of DNA methylation and gene expression profiles further identified significantly downregulated genes including LTBP1, ADCY5 and PRKCZ by promoter methylation in COX-2-induced HCC. Reduced expression of LTBP1, ADCY5 and PRKCZ by promoter hypermethylation was further validated in human HCCs. Bio-functional investigation revealed that LTBP1 inhibited cell proliferation in HCC cell lines, suggesting its potential role as a tumor suppressor in HCC. Gene expression microarrays revealed that signaling cascades (AKT (protein kinase B), STK33 (Serine/Threonine kinase 33) and MTOR (mechanistic target of rapamycin) pathways) were enriched in COX-2-induced HCC. In conclusion, this study demonstrated for the first time that enhanced COX-2 expression in hepatocytes is sufficient to induce HCC through inducing promoter hypermethylation by reducing TET1, silencing tumor-suppressive genes and activating key oncogenic pathways. Inhibition of COX-2 represents a mechanism-based target for HCC prevention.

Operative outcome of Hong Kong centenarians with hip fracture.

INTRODUCTION: International clinical guidelines recommend early surgical treatment for geriatric patients with hip fracture. There are, however, few data concerning the operative outcome of centenarians. This study aimed to report the epidemiology of hip fracture and postoperative mortality rate, and to discuss whether operation is justified in centenarians in Hong Kong. METHODS: This observational study was carried out in all public hospitals of Hong Kong. All patients aged 100 years or above who underwent hip fracture surgery in any public hospital between 1 January 2010 and 31 December 2013 were included. Their postoperative mean and median survival time was recorded. RESULTS: Of 114 centenarians, 96 (84%) were female. The age of patients ranged from 100 to 109 years, with the largest number (44%) aged 100 years. The follow-up interval ranged from 5 to 1619 days (median, 412 days; interquartile range, 683 days). The 1-month, 6-month, and 1-year mortalities were 8%, 25%, and 37%, respectively. By Kaplan-Meier analysis, the postoperative mean survival was 2 years 2 months (95% confidence interval, 680-936 days) and the median survival time was 2 years (interquartile range, 1234 days). CONCLUSION: The 1-year mortality among Hong Kong centenarians with hip fracture was 37%, which is lower than the 41.1% in the general centenarian population in Japan. The median survival time after hip fracture surgery was 2 years, suggesting that surgery even at an extreme age is worthwhile to maintain quality of life. Extreme age should not be a barrier to operative treatment.

The gastrointestinal microbiota and its role in oncogenesis.

Advances in research techniques have made it possible to map the microbial communities in the gastrointestinal (GI) tract, where the majority of bacteria in the human body reside. Disturbances in these communities are referred to as dysbiosis and have been associated with GI cancers. Although dysbiosis is observed in several GI malignancies, the specific role of these changes has not been understood to the extent of Helicobacter pylori (HP) in gastric cancer (GC). This review will address the bacterial communities along the GI tract, from the oral cavity to the anal canal, particularly focusing on bacterial dysbiosis and carcinogenesis. Just as non-HP bacteria in the stomach may interact with HP in gastric carcinogenesis, the same may hold true for other GI tract malignancies, where an interplay between microbes in carcinogenesis seems conceivable, especially in colorectal cancer (CRC). In the last part of this review we will discuss the potential mechanisms of bacterial dysbiosis in GI carcinogenesis.

Systematic review with meta-analysis: faecal occult blood tests show lower colorectal cancer detection rates in the proximal colon in colonoscopy-verified diagnostic studies.

BACKGROUND: The performance of faecal occult blood tests (FOBTs) to screen proximally located colorectal cancer (CRC) has produced inconsistent results. AIM: To assess in a meta-analysis, the diagnostic accuracy of FOBTs for relative detection of CRC according to anatomical location of CRC. METHODS: Diagnostic studies including both symptomatic and asymptomatic cohorts assessing performance of FOBTs for CRC were searched from MEDINE and EMBASE. Primary outcome was accuracy of FOBTs according to the anatomical location of CRC. Bivariate random-effects model was used. Subgroup analyses were performed to evaluate test performance of guaiac-based FOBT (gFOBT) and immunochemical-based FOBT (iFOBT). RESULTS: Thirteen studies, with 17 cohorts, reporting performance of FOBT were included; a total of 26 342 patients (mean age 58.9 years; 58.1% male) underwent both colonoscopy and FOBT. Pooled sensitivity, specificity, positive likelihood ratio and negative likelihood ratio of FOBTs for CRC detection in the proximal colon were 71.2% (95% CI 61.3-79.4%), 93.6% (95% CI 90.7-95.7%), 11.1 (95% CI 7.8-15.8) and 0.3 (95% CI 0.2-0.4) respectively. Corresponding findings for CRC detection in distal colon were 80.1% (95% CI 70.9-87.0%), 93.6% (95% CI 90.7-95.7%), 12.6 (95% CI 8.8-18.1) and 0.2 (95% CI 0.1-0.3). The area-under-curve for FOBT detection for proximal and distal CRC were 90% vs. 94% (P = 0.0143). Both gFOBT and iFOBT showed significantly lower sensitivity but comparable specificity for the detection of proximally located CRC compared with distal CRC. CONCLUSION: Faecal occult blood tests, both guaiac- and immunochemical-based, show better diagnostic performance for the relative detection of colorectal cancer in the distal colon than in the proximal bowel.

Excess mortality for operated geriatric hip fracture in Hong Kong.

INTRODUCTION: Geriatric hip fracture places an increasing burden to health care systems around the world. We studied the latest epidemiology trend of geriatric hip fracture in Hong Kong, as well as the excess mortality for patients who had undergone surgery for hip fracture. METHODS: This descriptive epidemiology study was conducted in the public hospitals in Hong Kong. All patients who underwent surgery for geriatric hip fracture in public hospitals from January 2000 to December 2011 were studied. They were retrieved from the Clinical Management System of the Hospital Authority of Hong Kong. Relevant data were collected using the Clinical Data Analysis and Reporting System of the Hospital Authority. The actual and projected population size, and the age- and sex-specific mortality rates were obtained from the Census and Statistics Department of Hong Kong. The 30-day, 1-year and 5-year mortality, and excess mortality following surgery for geriatric hip fracture were calculated. RESULTS: There was a steady increase in the incidence of geriatric hip fracture in Hong Kong. The annual risk of geriatric hip fracture was decreasing in both sexes. Female patients aged 65 to 69 years had the lowest 1-year and 5-year mortality of 6.91% and 23.80%, respectively. Advancing age and male sex were associated with an increase in mortality and a higher excess mortality rate following surgery. CONCLUSION: The incidence of geriatric hip fracture is expected to increase in the future. The exact reason for a higher excess mortality rate in male patients remains unclear and should be the direction for future studies.

An 11-year retrospective experience of antibodies against the voltage-gated potassium channel (VGKC) complex from a tertiary neurological centre.

Acquired diseases classically associated with VGKC-complex antibodies include peripheral nerve hyperexcitability (PNH), Morvan's syndrome, limbic encephalitis (LE), and epilepsy. However, not all such patients have VGKC-complex antibodies and antibodies have been reported in patients without a defined immune-mediated syndrome. To analyse the clinical relevance of positive VGKC-complex antibodies requested on the basis of initial clinical suspicion. We retrospectively analysed patients with positive VGKC-complex antibodies (>100 pM) referred to our institution between 2001 and 2011. 1,614 VGKC-complex assays were performed in 1,298 patients. Titres >100 pM were detected in 57/1,298 (4 %) patients. A classic VGKC-complex channelopathy (60 %) was associated with VGKC-complex antibody titres >400 pM (p = 0.0004). LGI1 or CASPR2 antibodies were only detected in classic VGKC-complex channelopathies (LE; n = 3/4 and PNH; n = 1/5). VGKC-complex antibody titres <400 pM were seen with PNH (n = 15/22; 68 %) but also a heterogeneous range of central and/or peripheral nervous system disorders. Electromyography was supportive of PNH in 65 % of cases and symptomatic treatment was beneficial in 46 % of patients. Irrespective of titre, the rate of malignancy in patients with VGKC-complex antibodies was higher than the age-matched national incidence of malignancy (OR 19.9, 95 % CI 8.97-44.0 p<0.0001). Clinical phenotyping and antibody titres >400 pM can help determine VGKC-complex antibody relevance. Antibody titres <400 pM are associated with PNH but also a more heterogeneous clinical spectrum. The antibody association in the latter is of doubtful clinical relevance. The rate of malignancy was significantly higher than the national incidence irrespective of titre.

The Janus face of cathelicidin in tumorigenesis.

Cathelicidin is a host defense peptide with multiple innate immunity-related functions. Recent findings indicate that cathelicidin is frequently dysregulated in human cancers where it plays a paradoxical yet dominant role in the regulation of tumor malignancy. In this review, the regulation of malignant phenotypes by cathelicidin in relation to the activation of its receptors and intracellular signaling is discussed.

Review of an 11-year Experience in Retrosigmoid Approach for Treatment of Acoustic Neuromas.

This study reviews surgery on acoustic neuromas by the second author using retrosigmoid approach from January 2000 to June 2010 in the state of Sarawak. There was a total of 32 patients in this study. The commonest presenting symptom was hearing loss (81.3%), followed by headache and tinnitus (each 37.5%), ataxia (34.4%) and facial numbness (21.9%). Twenty-seven patients (84.4%) had large tumor (≥ 3cm) while 5 patients (15.6%) had medium size tumor (1.5-2.9cm). The mean tumor size was 3.6 cm. Facial nerve outcome was good to moderate in 93.7% (House and Brackmann Grade I-IV). The most common complications were CSF leak with 3 patients(9.4%) and facial numbness with 2 patients(6.3%). All either resolved with treatment or improved. There was no mortality. Excision of acoustic neuromas using retrosigmoid approach could achieve acceptable facial nerve outcome with a low incidence of morbidity without mortality.

An effective immunotherapy regimen for VGKC antibody-positive limbic encephalitis.

BACKGROUND: Voltage-gated potassium channel antibody-positive limbic encephalitis (VGKC+LE) frequently improves with immunotherapy, although the optimum regimen is unknown. The effectiveness of a combination immunomodulatory regimen was tested in consecutive VGKC+LE patients. METHODS: This was an open-label prospective study of nine VGKC+LE patients. All patients had plasma exchange (50 ml/kg), intravenous immunoglobulin (2 g/kg) and intravenous methylprednisolone (1 g×3), followed by maintenance oral prednisolone (1 mg/kg/day). Mycophenolate (2 g/day) was used in the first three patients. Assessments included serial clinical, cognitive, brain MRI and VGKC antibody testing. RESULTS: Within 1 week, seizures and hyponatraemia remitted in all affected patients. Cognitive function improved in all patients within 3 months. MRI appearances improved substantially within 9 months, with remission of inflammation in the majority of patients. All achieved immunological remission with normal VGKC antibody titres within 1-4 months. Major adverse events of therapy included one septicaemia and one thrombosis on plasma exchange and one death from sepsis after incidental bowel surgery. One patient remains in remission after 40 months of follow up, 26 months after being off all treatment. CONCLUSIONS: Our immunotherapy regimen was effective for the treatment of the clinical, cognitive and immunological features of VGKC+LE. Radiological improvement was seen in the majority. Pending randomised controlled trials, this regimen is proposed for the treatment of VGKC+LE.

Brain biopsy in the management of neurology patients.

BACKGROUND AND METHODS: To evaluate the value of brain biopsy for neurology patients in our unit, we conducted a retrospective audit of neurology patients referred for brain biopsies for non-neoplastic disease from 1993 to 2007. RESULTS: 64 patients [median (range) age 51 (16-74) years] were included. The clinical presentation was diffuse encephalopathy for 40 patients, focal for 13 and multifocal for 11. The biopsy was diagnostic in 34 patients, abnormal but non-diagnostic in 21 and normal in 9. There was a statistically significant association between clinical presentation and biopsy result (p = 0.004); diagnostic biopsies were more common in patients with focal or multifocal clinical presentations. Twenty patients (31%) had alterations of management as a result of their brain biopsy, comprising specific treatment (11 patients) or prognosis/diagnosis of untreatable conditions (9 patients). Diagnoses of treatable conditions included Whipple's disease, tuberculoma, progressive multifocal leukoencephalopathy, and neurosarcoidosis. Five patients (7.8%) had complications. CONCLUSIONS: Brain biopsy is useful and relatively safe in the management of neurology patients, with a diagnostic yield of 53% in our series; some led to significant changes in management, including treatment of infections. Patients with focal or multifocal presentation are more likely to yield a diagnostic biopsy result.

Andrographolide regulates epidermal growth factor receptor and transferrin receptor trafficking in epidermoid carcinoma (A-431) cells.

BACKGROUND AND PURPOSE: Andrographolide is the active component of Andrographis paniculata, a plant used in both Indian and Chinese traditional medicine, and it has been demonstrated to induce apoptosis in different cancer cell lines. However, not much is known about how it may affect the key receptors implicated in cancer. Knowledge of how andrographolide affects receptor trafficking will allow us to better understand new mechanisms by which andrographolide may cause death in cancer cells. EXPERIMENTAL APPROACH: We utilized the well-characterized epidermal growth factor receptor (EGFR) and transferrin receptor (TfR) expressed in epidermoid carcinoma (A-431) cells as a model to study the effect of andrographolide on receptor trafficking. Receptor distribution, the total number of receptors and surface receptors were analysed by immunofluorescence, Western blot as well as flow-cytometry respectively. KEY RESULTS: Andrographolide treatment inhibited cell growth, down-regulated EGFRs on the cell surface and affected the degradation of EGFRs and TfRs. The EGFR was internalized into the cell at an increased rate, and accumulated in a compartment that co-localizes with the lysosomal-associated membrane protein in the late endosomes. CONCLUSION AND IMPLICATIONS: This study sheds light on how andrographolide may affect receptor trafficking by inhibiting receptor movement from the late endosomes to lysosomes. The down-regulation of EGFR from the cell surface also indicates a new mechanism by which andrographolide may induce cancer cell death.