Hong Kong consensus recommendations on the management of pancreatic ductal adenocarcinoma

This project was undertaken to develop the first set of consensus statements regarding the management of pancreatic ductal adenocarcinoma (PDAC) in Hong Kong, with the goal of providing guidance to local clinicians. A multidisciplinary panel of experts discussed issues surrounding current PDAC management and reviewed evidence gathered in the local context to propose treatment recommendations. The experts used the Delphi approach to finalise management recommendations. Consensus was defined as ≥80% acceptance among all expert panel members. Thirty-nine consensus statements were established. These statements cover all aspects of PDAC management, including diagnosis, resectability criteria, treatment modalities according to resectability, personalised management based on molecular profiling, palliative care, and supportive care. This project fulfils the need for guidance regarding PDAC management in Hong Kong. To assist clinicians with treatment decisions based on varying levels of evidence and clinical experience, treatment options are listed in several consensus statements.

Brain-wide correspondence of neuronal epigenomics and distant projections

Single-cell analyses parse the brain's billions of neurons into thousands of 'cell-type' clusters residing in different brain structures1. Many cell types mediate their functions through targeted long-distance projections allowing interactions between specific cell types. Here we used epi-retro-seq2 to link single-cell epigenomes and cell types to long-distance projections for 33,034 neurons dissected from 32 different regions projecting to 24 different targets (225 source-to-target combinations) across the whole mouse brain. We highlight uses of these data for interrogating principles relating projection types to transcriptomics and epigenomics, and for addressing hypotheses about cell types and connections related to genetics. We provide an overall synthesis with 926 statistical comparisons of discriminability of neurons projecting to each target for every source. We integrate this dataset into the larger BRAIN Initiative Cell Census Network atlas, composed of millions of neurons, to link projection cell types to consensus clusters. Integration with spatial transcriptomics further assigns projection-enriched clusters to smaller source regions than the original dissections. We exemplify this by presenting in-depth analyses of projection neurons from the hypothalamus, thalamus, hindbrain, amygdala and midbrain to provide insights into properties of those cell types, including differentially expressed genes, their associated cis-regulatory elements and transcription-factor-binding motifs, and neurotransmitter use.

Limited liver resections in the posterosuperior segments: international multicentre propensity score-matched and coarsened exact-matched analysis comparing the laparoscopic and robotic approaches

Background

Limited liver resections (LLRs) for tumours located in the posterosuperior segments of the liver are technically demanding procedures. This study compared outcomes of robotic (R) and laparoscopic (L) LLR for tumours located in the posterosuperior liver segments (IV, VII, and VIII).

Methods

This was an international multicentre retrospective analysis of patients who underwent R-LLR or L-LLR at 24 centres between 2010 and 2019. Patient demographics, perioperative parameters, and postoperative outcomes were analysed; 1 : 3 propensity score matching (PSM) and 1 : 1 coarsened exact matching (CEM) were performed.

Results

Of 1566 patients undergoing R-LLR and L-LLR, 983 met the study inclusion criteria. Before matching, 159 R-LLRs and 824 L-LLRs were included. After 1 : 3 PSM of 127 R-LLRs and 381 L-LLRs, comparison of perioperative outcomes showed that median blood loss (100 (i.q.r. 40–200) versus 200 (100–500) ml; P = 0.003), blood loss of at least 500 ml (9 (7.4 per cent) versus 94 (27.6 per cent); P < 0.001), intraoperative blood transfusion rate (4 (3.1 per cent) versus 38 (10.0 per cent); P = 0.025), rate of conversion to open surgery (1 (0.8 per cent) versus 30 (7.9 per cent); P = 0.022), median duration of Pringle manoeuvre when applied (30 (20–46) versus 40 (25–58) min; P = 0.012), and median duration of operation (175 (130–255) versus 224 (155–300); P < 0.001) were lower in the R-LLR group compared with the L-LLR group. After 1 : 1 CEM of 104 R-LLRs with 104 L-LLRs, R-LLR was similarly associated with significantly reduced blood loss and a lower rate of conversion to open surgery.

Conclusion

Based on a matched analysis of well selected patients, both robotic and laparoscopic access could be undertaken safely with good outcomes for tumours in the posterosuperior liver segments.

A central alarm system that gates multi-sensory innate threat cues to the amygdala

Perception of threats is essential for survival. Previous findings suggest that parallel pathways independently relay innate threat signals from different sensory modalities to multiple brain areas, such as the midbrain and hypothalamus, for immediate avoidance. Yet little is known about whether and how multi-sensory innate threat cues are integrated and conveyed from each sensory modality to the amygdala, a critical brain area for threat perception and learning. Here, we report that neurons expressing calcitonin gene-related peptide (CGRP) in the parvocellular subparafascicular nucleus in the thalamus and external lateral parabrachial nucleus in the brainstem respond to multi-sensory threat cues from various sensory modalities and relay negative valence to the lateral and central amygdala, respectively. Both CGRP populations and their amygdala projections are required for multi-sensory threat perception and aversive memory formation. The identification of unified innate threat pathways may provide insights into developing therapeutic candidates for innate fear-related disorders.

Behavioral context affects social signal representations within single primate prefrontal cortex neurons

We tested whether social signal processing in more traditional, head-restrained contexts is representative of the putative natural analog-social communication-by comparing responses to vocalizations within individual neurons in marmoset prefrontal cortex (PFC) across a series of behavioral contexts ranging from traditional to naturalistic. Although vocalization-responsive neurons were evident in all contexts, cross-context consistency was notably limited. A response to these social signals when subjects were head-restrained was not predictive of a comparable neural response to the identical vocalizations during natural communication. This pattern was evident both within individual neurons and at a population level, as PFC activity could be reliably decoded for the behavioral context in which vocalizations were heard. These results suggest that neural representations of social signals in primate PFC are not static but highly flexible and likely reflect how nuances of the dynamic behavioral contexts affect the perception of these signals and what they communicate.

A multimodal cell census and atlas of the mammalian primary motor cortex

Here we report the generation of a multimodal cell census and atlas of the mammalian primary motor cortex as the initial product of the BRAIN Initiative Cell Census Network (BICCN). This was achieved by coordinated large-scale analyses of single-cell transcriptomes, chromatin accessibility, DNA methylomes, spatially resolved single-cell transcriptomes, morphological and electrophysiological properties and cellular resolution input-output mapping, integrated through cross-modal computational analysis. Our results advance the collective knowledge and understanding of brain cell-type organization1-5. First, our study reveals a unified molecular genetic landscape of cortical cell types that integrates their transcriptome, open chromatin and DNA methylation maps. Second, cross-species analysis achieves a consensus taxonomy of transcriptomic types and their hierarchical organization that is conserved from mouse to marmoset and human. Third, in situ single-cell transcriptomics provides a spatially resolved cell-type atlas of the motor cortex. Fourth, cross-modal analysis provides compelling evidence for the transcriptomic, epigenomic and gene regulatory basis of neuronal phenotypes such as their physiological and anatomical properties, demonstrating the biological validity and genomic underpinning of neuron types. We further present an extensive genetic toolset for targeting glutamatergic neuron types towards linking their molecular and developmental identity to their circuit function. Together, our results establish a unifying and mechanistic framework of neuronal cell-type organization that integrates multi-layered molecular genetic and spatial information with multi-faceted phenotypic properties.

Epigenomic diversity of cortical projection neurons in the mouse brain

Neuronal cell types are classically defined by their molecular properties, anatomy and functions. Although recent advances in single-cell genomics have led to high-resolution molecular characterization of cell type diversity in the brain1, neuronal cell types are often studied out of the context of their anatomical properties. To improve our understanding of the relationship between molecular and anatomical features that define cortical neurons, here we combined retrograde labelling with single-nucleus DNA methylation sequencing to link neural epigenomic properties to projections. We examined 11,827 single neocortical neurons from 63 cortico-cortical and cortico-subcortical long-distance projections. Our results showed unique epigenetic signatures of projection neurons that correspond to their laminar and regional location and projection patterns. On the basis of their epigenomes, intra-telencephalic cells that project to different cortical targets could be further distinguished, and some layer 5 neurons that project to extra-telencephalic targets (L5 ET) formed separate clusters that aligned with their axonal projections. Such separation varied between cortical areas, which suggests that there are area-specific differences in L5 ET subtypes, which were further validated by anatomical studies. Notably, a population of cortico-cortical projection neurons clustered with L5 ET rather than intra-telencephalic neurons, which suggests that a population of L5 ET cortical neurons projects to both targets. We verified the existence of these neurons by dual retrograde labelling and anterograde tracing of cortico-cortical projection neurons, which revealed axon terminals in extra-telencephalic targets including the thalamus, superior colliculus and pons. These findings highlight the power of single-cell epigenomic approaches to connect the molecular properties of neurons with their anatomical and projection properties.

Acute kidney injury following hepatectomy and its impact on long-term survival for patients with hepatocellular carcinoma

Background

Acute kidney injury (AKI) is increasingly being recognized after hepatectomy. This study aimed to identify factors predicting its occurrence and its impact on long-term outcome among patients with hepatocellular carcinoma (HCC).

Methods

This was a retrospective analysis of the incidence of AKI, factors predicting its occurrence, and its impact on patients undergoing hepatectomy between September 2007 and December 2018. A subgroup analysis included patients with histologically proven HCC.

Results

The incidence of AKI was 9.2 per cent in 930 patients. AKI was associated with increased mortality, morbidity, posthepatectomy liver failure (PHLF), and a longer hospital stay. On multivariable analysis, study period December 2013 to December 2018, diabetes mellitus, mean intraoperative BP below 72.1 mmHg, operative blood loss exceeding 377ml, high Model for End-Stage Liver Disease (MELD) score, and PHLF were predictive factors for AKI. Among 560 patients with HCC, hypertension, BP below 76.9 mmHg, blood loss greater than 378ml, MELD score, and PHLF were predictive factors. The 1-, 3-, and 5-year overall survival rates were 74.1, 59.2, and 51.6 per cent respectively for patients with AKI, and 91.8, 77.9, and 67.3 per cent for those without AKI. Corresponding 1-, 3-, and 5-year disease-free survival rates were 56.9, 42.3, and 35.4 per cent respectively in the AKI group, and 71.7, 54.5, and 46.2 per cent in the no-AKI group. AKI was an independent predictor of survival in multivariable analysis.

Conclusion

AKI is associated with longer hospital stay, and higher morbidity and mortality rates. It is also associated with shorter long-term survival among patients with HCC. To avoid AKI, control of blood loss and maintaining a reasonable BP (72–77 mmHg) during hepatectomy is important.

All-optical serrodyne frequency shifter

We describe and demonstrate a method to induce a single-sideband serrodyne-like optical frequency shift in an all-fiber device. The time-varying phase-shift is generated by cross-phase modulation in a nonlinear fiber. Unlike electro-optic based serrodyne methods, which require a high-fidelity and high-bandwidth analog electrical ramp modulation signal, the proposed optical method uses a simple pulsed pump and can be made simultaneously both low-loss and polarization-independent. We demonstrate the technique by shifting a 1550 nm optical signal 150 MHz in a 1.5 dB insertion-loss polarization-independent frequency shifter and show a pathway to multi-GHz shifting frequencies.

A Case of Hyperreactio Luteinalis Complicated With Biochemical Hyperandrogenism, Symptomatic Hyperthyroidism and Preeclampsia

Background: Hyperreactio luteinalis (HL) describes the development of multiple large ovarian cysts during pregnancy, which regress post-partum. We report a case of HL complicated with preeclampsia, biochemical hyperandrogenism and hyperthyroidism. Clinical Case: A 31-year-old non-obese Chinese woman presented at 14-week gestation for lower abdominal pain. USG showed a single fetus, multiple ovarian cysts with largest measured 39.5ml. She complained of hand tremor, palpitation but no vomiting. She had no goiter, orbitopathy or family history of thyroid disease. fT4 was 23.1pmol/L (normal: 9.8-19.8pmol/L) and TSH was <0.01mIU/L. Anti-TG, anti-TPO and anti-TSHR antibodies were negative. She had history of silent miscarriage at 6-week gestation in her first pregnancy 2 years ago, USG showed normal ovaries at that time. Carbimazole was started at 16-week gestation for fT4 26.6pmol/L (normal: 9.4-18.5pmol/L). The largest ovarian cyst increased to 130ml at 19-week gestation. Serum β-hCG was 251926IU/L (normal: 4060-165400IU/L). HL with hCG-mediated hyperthyroidism was suspected. Serum total testosterone was 22.9nmol/L (normal: 2.2-10.7nmol/L) and serum androstenedione was 70.5nmol/L (normal: 0.28-9.81nmol/L). Ferriham Gallwey score was 4. fT4 fell to 13.8pmol/L (normal: 8.8-17.0pmol/L) but TSH remained suppressed. Carbimazole was stopped at 22-week gestation with no rebound in fT4 level. She developed preeclampsia and GDM at 27-week gestation. IUGR was evident despite decreasing β-hCG level and ovarian cyst shrinkage. She had emergency LSCS for severe preeclampsia at 33-week gestation. A 1510g female baby with normal genitalia was delivered. Placenta pathology was normal. 2 days after delivery, β-hCG fell to 7081IU/L; fT4 was 9.9pmol/L (normal: 9-19pmol/L) and TSH was 0.25mIU/L (normal: 0.35-4.5mIU/L). Clinical Lessons: 1) hCG stimulates growth of ovarian stroma and androgen secretion, results in virilization in 30% of HL patients. However, only 5% of patients had hyperthyroidism. LH and hCG are structurally similar and bind to the same receptor. In contrast, hCG is a weak agonist of TSH receptor: a hCG level of more than 100000IU/L is required to cause clinical thyrotoxicosis. Since 30% of HL patients have normal hCG level, this may explain the lower incidence of hyperthyroidism than hyperandrogenism. 2) Degree of maternal virilization does not correlate with testosterone level. Study by Condic et al. found significant overlap of testosterone levels in women with (13.7-197.5nmol/l) and without (6.2-37.3nmol/l) virilization. Genetic polymorphism of androgen receptor may account for the different clinical manifestation. Fetal virilization is rare, due to protective role of placental aromatase. 3) Elevated hCG in apparently “normal” singleton pregnancy may be due to poor placentation in early gestation and is a risk factor for preeclampsia and IUGR in HL patients.

Robotic versus laparoscopic hepatectomy: application of the difficulty scoring system

BACKGROUND

The development of robotic system may help to relieve the difficulties encountered during laparoscopic hepatectomy. A difficulty scoring system (DSS) was developed to assess the difficulty of various laparoscopic liver resection procedures. The aim of this study is to explore if the DSS is applicable in robotic hepatectomy and to compare the outcomes of robotic hepatectomy and laparoscopic hepatectomy among different difficulty levels.

METHODS

Clinical data from all consecutive patients who underwent robotic and conventional laparoscopic hepatectomy at the Prince of Wales Hospital, Hong Kong, were prospectively collected and reviewed. The difficulty level of operations was graded using the DSS. Perioperative outcomes of robotic and conventional laparoscopic hepatectomy were compared at each difficulty level.

RESULTS

A total of 107 and 94 patients underwent robotic and laparoscopic hepatectomy during the study period, respectively. Among them, 16 and 2 patients were operated for recurrent pyogenic cholangitis, respectively, and were excluded because no mark for tumour location can be assigned. For robotic hepatectomy, a higher DSS was significantly correlated with higher minor complication rate (p = 0.001), more intraoperative blood loss (p = 0.002), longer operation time (p < 0.001) and longer post-operative hospital stay (p < 0.001). The mean DSS scores of robotic and laparoscopic hepatectomy were 4.5 and 3.6, respectively. (p = 0.004). For cases with low (DSS 1-3) and intermediate (DSS 4-6) difficulty level, there was no significant difference in operative blood loss, operation time and overall complications rate. Only 2 cases (2.2%) with high difficulty level were operated with laparoscopic approach while 20% of patients operated with robotic approach had DSS > 6.

CONCLUSIONS

DSS significantly correlated with surgical outcomes in patient who underwent robotic hepatectomy. Perioperative outcomes following robotic and conventional laparoscopic hepatectomy were similar in cases with low and intermediate difficulty. However, robotic system allowed minimally invasive approach in cases with higher difficulty level.

Enhanced recovery after surgery for liver resection

INTRODUCTION

Enhanced recovery after surgery (ERAS) reduces postoperative length of hospital stay and patient stress response to liver surgery. The aim of the present study was to evaluate the efficacy and feasibility of an ERAS programme for liver resection.

METHODS

A multidisciplinary ERAS protocol was implemented for both open and laparoscopic liver resection in a tertiary hospital in Hong Kong. The clinical outcomes of patients who underwent liver resection and underwent the ERAS perioperative programme were compared with those who received a conventional perioperative programme between September 2015 and July 2016. Propensity score matching analysis was used to minimise background differences.

RESULTS

A total of 20 patients who underwent liver resection were recruited to the ERAS programme. Their clinical outcomes were compared with another 20 patients who received hepatectomy under a conventional perioperative programme after propensity score matching. The ERAS programme was associated with a significantly shorter length of hospital stay (P=0.033) without an increase in complication rates in patients who underwent open liver resection. There was no such significant association in patients who underwent laparoscopic liver resection. No patients required readmission in this cohort.

CONCLUSIONS

The ERAS perioperative programme for liver resection is safe and feasible. It significantly shortened the hospital stay after open liver resection but not after laparoscopic liver resection.

Glial cells maintain synapses by inhibiting an activity-dependent retrograde protease signal

Glial cells regulate multiple aspects of synaptogenesis. In the absence of Schwann cells, a peripheral glial cell, motor neurons initially innervate muscle but then degenerate. Here, using a genetic approach, we show that neural activity-regulated negative factors produced by muscle drive neurodegeneration in Schwann cell-deficient mice. We find that thrombin, the hepatic serine protease central to the hemostatic coagulation cascade, is one such negative factor. Trancriptomic analysis shows that expression of the antithrombins serpin C1 and D1 is significantly reduced in Schwann cell-deficient mice. In the absence of peripheral neuromuscular activity, neurodegeneration is completely blocked, and expression of prothrombin in muscle is markedly reduced. In the absence of muscle-derived prothrombin, neurodegeneration is also markedly reduced. Together, these results suggest that Schwann cells regulate NMJs by opposing the effects of activity-regulated, muscle-derived negative factors and provide the first genetic evidence that thrombin plays a central role outside of the coagulation system.

Blocking skeletal muscle DHPRs/Ryr1 prevents neuromuscular synapse loss in mutant mice deficient in type III Neuregulin 1 (CRD-Nrg1)

Schwann cells are integral components of vertebrate neuromuscular synapses; in their absence, pre-synaptic nerve terminals withdraw from post-synaptic muscles, leading to muscle denervation and synapse loss at the developing neuromuscular junction (NMJ). Here, we report a rescue of muscle denervation and neuromuscular synapses loss in type III Neuregulin 1 mutant mice (CRD-Nrg1-/-), which lack Schwann cells. We found that muscle denervation and neuromuscular synapse loss were prevented in CRD-Nrg1-/-mice when presynaptic activity was blocked by ablating a specific gene, such as Snap25 (synaptosomal-associated 25 kDa protein) or Chat (choline acetyltransferase). Further, these effects were mediated by a pathway that requires postsynaptic acetylcholine receptors (AChRs), because ablating Chrna1 (acetylcholine receptor α1 subunit), which encodes muscle-specific AChRs in CRD-Nrg1-/-mice also rescued muscle denervation. Moreover, genetically ablating muscle dihydropyridine receptor (DHPR) β1 subunit (Cacnb1) or ryanodine receptor 1 (Ryr1) also rescued muscle denervation and neuromuscular synapse loss in CRD-Nrg1-/-mice. Thus, these genetic manipulations follow a pathway-from presynaptic to postsynaptic, and, ultimately to muscle activity mediated by DHPRs and Ryr1. Importantly, electrophysiological analyses reveal robust synaptic activity in the rescued, Schwann-cell deficient NMJs in CRD-Nrg1-/-Cacnb1-/-or CRD-Nrg1-/-Ryr1-/-mutant mice. Thus, a blockade of synaptic activity, although sufficient, is not necessary to preserve NMJs that lack Schwann cells. Instead, a blockade of muscle activity mediated by DHRPs and Ryr1 is both necessary and sufficient for preserving NMJs that lack Schwann cells. These findings suggest that muscle activity mediated by DHPRs/Ryr1 may destabilize developing NMJs and that Schwann cells play crucial roles in counteracting such a destabilizing activity to preserve neuromuscular synapses during development.

p75 Is Required for the Establishment of Postnatal Sensory Neuron Diversity by Potentiating Ret Signaling

Producing the neuronal diversity required to adequately discriminate all elements of somatosensation is a complex task during organogenesis. The mechanisms guiding this process during dorsal root ganglion (DRG) sensory neuron specification remain poorly understood. Here, we show that the p75 neurotrophin receptor interacts with Ret and its GFRα co-receptor upon stimulation with glial cell line-derived neurotrophic factor (GDNF). Furthermore, we demonstrate that p75 is required for GDNF-mediated Ret activation, survival, and cell surface localization of Ret in DRG neurons. In mice in which p75 is deleted specifically within sensory neurons beginning at E12.5, we observe that approximately 20% of neurons are lost between P14 and adulthood, and these losses selectively occur within a subpopulation of Ret⁺ nonpeptidergic nociceptors, with neurons expressing low levels of Ret impacted most heavily. These results suggest that p75 is required for the development of the nonpeptidergic nociceptor lineage by fine-tuning Ret-mediated trophic support.

Traumatic Liver Injury in Hong Kong: The Management Strategy and Outcome

Introduction

Management of liver injury is challenging and evolving. The aim of this article is to review the outcome of traumatic liver injury in Chinese people in Hong Kong.

Materials & methods

Records of 40 patients with hepatic injury who received treatment at the Prince of Wales Hospital between December 2000 and May 2005 were reviewed. Demographic data, severity of liver injury, Injury Severity Score (ISS), haemodynamic status and Glasgow Coma Scale (GCS) score on admission, investigations made, concomitant injuries, management scheme, and outcome of patients were analysed.

Results

There were 23 male and 17 female patients with a mean age of 31.3 (SD=15.4) years. Road traffic accident was the most common injury mechanism (65%). Half of the patients were treated by non-operative management (NOM). None of them required surgery during subsequent management. Patients in the operative management (OM) group had a significantly higher ISS (p=0.026), but there was no significant difference in the mortality rate between the OM and NOM groups. Patients with stable haemodynamic status and who were treated non-operatively had a significantly shorter hospital stay (p=0.006). High grade liver injury (OR=8.0, 95% CI=1.2 to 53.8, p=0.03) and ISS greater than 25 (OR=21.6, 95% CI=2.0 to 225.3, p=0.01) were independent risk factors for mortality on multivariate analysis.

Conclusions

Non-operative management of liver injury can be safely accomplished in haemodynamically stable patients, with the possible benefit of a shorter hospital stay.

Adaptor proteins NUMB and NUMBL promote cell cycle withdrawal by targeting ERBB2 for degradation

Failure of trabecular myocytes to undergo appropriate cell cycle withdrawal leads to ventricular noncompaction and heart failure. Signaling of growth factor receptor ERBB2 is critical for myocyte proliferation and trabeculation. However, the mechanisms underlying appropriate downregulation of trabecular ERBB2 signaling are little understood. Here, we have found that the endocytic adaptor proteins NUMB and NUMBL were required for downregulation of ERBB2 signaling in maturing trabeculae. Loss of NUMB and NUMBL resulted in a partial block of late endosome formation, resulting in sustained ERBB2 signaling and STAT5 activation. Unexpectedly, activated STAT5 overrode Hippo-mediated inhibition and drove YAP1 to the nucleus. Consequent aberrant cardiomyocyte proliferation resulted in ventricular noncompaction that was markedly rescued by heterozygous loss of function of either ERBB2 or YAP1. Further investigations revealed that NUMB and NUMBL interacted with small GTPase Rab7 to transition ERBB2 from early to late endosome for degradation. Our studies provide insight into mechanisms by which NUMB and NUMBL promote cardiomyocyte cell cycle withdrawal and highlight previously unsuspected connections between pathways that are important for cardiomyocyte cell cycle reentry, with relevance to ventricular noncompaction cardiomyopathy and regenerative medicine.

CT features of mediastinal lymphangiohemangioma associated with superior vena cava ectasia: A case report

We present a case of mediastinal mesenchymal tumor in a 53-year-old woman with a 1-month history of chest tightness. A histological diagnosis of lymphangiohemangioma was obtained by excisional biopsy. CT findings are reported with emphasis on its association with intratumoral superior vena cava ectasia.

Neuregulin 1 improves cognitive deficits and neuropathology in an Alzheimer's disease model

Several lines of evidence suggest that neuregulin 1 (NRG1) signaling may influence cognitive function and neuropathology in Alzheimer’s disease (AD). To test this possibility, full-length type I or type III NRG1 was overexpressed via lentiviral vectors in the hippocampus of line 41 AD mouse. Both type I and type III NRG1 improves deficits in the Morris water-maze behavioral task. Neuropathology was also significantly ameliorated. Decreased expression of the neuronal marker MAP2 and synaptic markers PSD95 and synaptophysin in AD mice was significantly reversed. Levels of Aβ peptides and plaques were markedly reduced. Furthermore, we showed that soluble ectodomains of both type I and type III NRG1 significantly increased expression of Aβ-degrading enzyme neprilysin (NEP) in primary neuronal cultures. Consistent with this finding, immunoreactivity of NEP was increased in the hippocampus of AD mice. These results suggest that NRG1 provides beneficial effects in candidate neuropathologic substrates of AD and, therefore, is a potential target for the treatment of AD.

HtrA1 Proteolysis of ApoE In Vitro Is Allele Selective

Apolipoprotein E (ApoE) belongs to a large class of proteins that solubilize lipids for physiological transport. Humans have three different APOE alleles, APOE ε2, APOE ε3, and APOE ε4, and genetic studies identified ApoE4 as the strongest genetic risk factor for Alzheimer's disease (AD). People who are homozygous for ApoE4 (i.e., ApoE4/E4) are an order of magnitude more likely to develop late-onset AD (LOAD) than ApoE3/E3 carriers. Several differences between ApoE3 and ApoE4 may contribute to AD including the observation that ApoE4 is degraded to a greater extent than ApoE3 in the human brain. Experiments with high-temperature requirement serine peptidase A1 (HtrA1), which is found in the nervous system, demonstrate that HtrA1 is an allele-selective ApoE-degrading enzyme that degrades ApoE4 more quickly than ApoE3. This activity is specific to HtrA1, as similar assays with HtrA2 showed minimal ApoE4 proteolysis and trypsin had no preference between ApoE4 and ApoE3. HtrA1 has also been reported to cleave the tau protein (Tau) and the amyloid protein precursor (APP) to hinder the formation of toxic amyloid deposits associated with AD. Competition assays with ApoE4, ApoE3, and Tau revealed that ApoE4 inhibits Tau degradation. Thus, the identification of ApoE4 as an in vitro HtrA1 substrate suggests a potential biochemical mechanism that links ApoE4 regulation of AD proteins such as Tau.

Magnetically-responsive silica-gold nanobowls for targeted delivery and SERS-based sensing

Composite colloidal structures with multi-functional properties have wide applications in targeted delivery of therapeutics and imaging contrast molecules and high-throughput molecular bio-sensing. We have constructed a multifunctional composite magnetic nanobowl using the bottom-up approach on an asymmetric silica/polystyrene Janus template consisting of a silica shell around a partially exposed polystyrene core. The nanobowl consists of a silica bowl and a gold exterior shell with iron oxide magnetic nanoparticles sandwiched between the silica and gold shells. The nanobowls were characterized by electron microscopy, atomic force microscopy, magnetometry, vis-NIR and FTIR spectroscopy. Magnetically vectored transport of these nanobowls was ascertained by time-lapsed imaging of their flow in fluid through a porous hydrogel under a defined magnetic field. These magnetically-responsive nanobowls show distinct surface enhanced Raman spectroscopy (SERS) imaging capability. The PEGylated magnetically-responsive nanobowls show size-dependent cellular uptake in vitro.

Simultaneous multi-frequency topological edge modes between one-dimensional photonic crystals

We show theoretically that, in the limit of weak dispersion, one-dimensional binary centrosymmetric photonic crystals can support topological edge modes in all photonic bandgaps. By analyzing their bulk band topology, these "harmonic" topological edge modes can be designed in a way that they exist at all photonic bandgaps opened at the center of the Brillouin zone, at all gaps opened at the zone boundaries, or both. The results may suggest a new approach to achieve robust multi-frequency coupled modes for applications in nonlinear photonics, such as frequency upconversion.

Loss of motoneuron-specific microRNA-218 causes systemic neuromuscular failure

Dysfunction of microRNA (miRNA) metabolism is thought to underlie diseases affecting motoneurons. One miRNA, miR-218, is abundantly and selectively expressed by developing and mature motoneurons. Here we show that mutant mice lacking miR-218 die neonatally and exhibit neuromuscular junction defects, motoneuron hyperexcitability, and progressive motoneuron cell loss, all of which are hallmarks of motoneuron diseases such as amyotrophic lateral sclerosis and spinal muscular atrophy. Gene profiling reveals that miR-218 modestly represses a cohort of hundreds of genes that are neuronally enriched but are not specific to a single neuron subpopulation. Thus, the set of messenger RNAs targeted by miR-218, designated TARGET(218), defines a neuronal gene network that is selectively tuned down in motoneurons to prevent neuromuscular failure and neurodegeneration.

Brains, genes, and primates

One of the great strengths of the mouse model is the wide array of genetic tools that have been developed. Striking examples include methods for directed modification of the genome, and for regulated expression or inactivation of genes. Within neuroscience, it is now routine to express reporter genes, neuronal activity indicators, and opsins in specific neuronal types in the mouse. However, there are considerable anatomical, physiological, cognitive, and behavioral differences between the mouse and the human that, in some areas of inquiry, limit the degree to which insights derived from the mouse can be applied to understanding human neurobiology. Several recent advances have now brought into reach the goal of applying these tools to understanding the primate brain. Here we describe these advances, consider their potential to advance our understanding of the human brain and brain disorders, discuss bioethical considerations, and describe what will be needed to move forward.

Antiviral therapy improves post-hepatectomy survival in patients with hepatitis B virus-related hepatocellular carcinoma: a prospective-retrospective study

BACKGROUND

The effect of antiviral therapy on the post-hepatectomy long-term survival in patients with hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC) remains uncertain.

AIM

To evaluate the effect of antiviral therapy on post-hepatectomy survival and recurrence in patients with HBV-related HCC.

METHODS

This was a prospective-retrospective study of a total of 404 patients who underwent hepatectomy for HBV-related HCC in a tertiary academic hospital. Data on patient and tumour characteristics, tumour recurrence, treatment for recurrence and survival were compared between antiviral and no antiviral groups.

RESULTS

Patient's and tumour characteristics were comparable between the two groups, except a higher proportion of patients with cirrhosis in the antiviral group. With a mean follow-up time of 52.4 months, antiviral group had a better 5-year overall survival (66.7% vs. 56.0%, P = 0.001) while there was no significant difference in the 5-year disease-free survival (44.7% vs. 38.1%, P = 0.166). Use of antiviral therapy was associated with better liver function reserve at the time of recurrence and a greater proportion of patients could receive curative treatment for recurrence (38.5% vs. 24.3%, P = 0.041). There was no significant different in the hazard ratios of patients who started antiviral therapy before or after operation (P = 0.054).

CONCLUSIONS

Use of antiviral therapy improves the long-term post-hepatectomy survival in patients with HBV-related HCC. With a better liver function reserve at the time of recurrence, a greater proportion of patients in antiviral group could receive curative treatment for recurrence.

An uncommon cause of Cushing's syndrome in a 70-year-old man

Cushing's syndrome due to exogenous steroids is common, as about 1% of the general populations use exogenous steroids for various indications. Although endogenous Cushing's syndrome due to ectopic adrenocorticotropic hormone from a pancreatic neuroendocrine tumour is rare, a correct and early diagnosis is important. The diagnosis and management require high clinical acumen and collaboration between different specialists. We report a case of ectopic adrenocorticotropic hormone Cushing's syndrome due to pancreatic neuroendocrine tumour with liver metastasis. Early recognition by endocrinologists with timely surgical resection followed by referral to oncologists led to a favourable outcome for the patient up to 12 months after initial presentation.

Heterodimerization of p45-p75 modulates p75 signaling: structural basis and mechanism of action

The formation of a p45-p75 heterodimer overrides p75’s inhibition of nerve regeneration by stopping p75 homodimers from forming and creating a complex with the Nogo receptor.

The p75 neurotrophin receptor, a member of the tumor necrosis factor receptor superfamily, is required as a co-receptor for the Nogo receptor (NgR) to mediate the activity of myelin-associated inhibitors such as Nogo, MAG, and OMgp. p45/NRH2/PLAIDD is a p75 homologue and contains a death domain (DD). Here we report that p45 markedly interferes with the function of p75 as a co-receptor for NgR. P45 forms heterodimers with p75 and thereby blocks RhoA activation and inhibition of neurite outgrowth induced by myelin-associated inhibitors. p45 binds p75 through both its transmembrane (TM) domain and DD. To understand the underlying mechanisms, we have determined the three-dimensional NMR solution structure of the intracellular domain of p45 and characterized its interaction with p75. We have identified the residues involved in such interaction by NMR and co-immunoprecipitation. The DD of p45 binds the DD of p75 by electrostatic interactions. In addition, previous reports suggested that Cys257 in the p75 TM domain is required for signaling. We found that the interaction of the cysteine 58 of p45 with the cysteine 257 of p75 within the TM domain is necessary for p45–p75 heterodimerization. These results suggest a mechanism involving both the TM domain and the DD of p45 to regulate p75-mediated signaling.

Injuries to the brain and spinal cord often result in paralysis due to the fact that the injured nerves cannot regrow to reach their normal targets and carry out their functions. At the injury sites, there are proteins released from the damaged myelin that bind the Nogo receptor (NgR) on the nerve and inhibit its regeneration. The NgR needs to form a complex with the p75 neurotrophin receptor in order to mediate this inhibitory signal. Here we found that p45, a homologue of p75, can also bind to p75 and block its inhibitory activity when overexpressed. To perform its function, p75 needs to dimerize through both its transmembrane and intracellular domains, facilitating the recruitment of several proteins. Our structural and functional studies show that p45 binds specifically to conserved regions in the p75 transmembrane and the intracellular domain and that this blocks p75 dimerization along with its downstream signaling. Thus, this study demonstrates that altering the oligomerization of p75 is a good strategy to override p75's inhibitory effects on nerve regeneration, and it opens the door for the design of specific p75 inhibitors for therapeutic applications.

Alignment dependent enhancement of the photoelectron cutoff for multiphoton ionization of molecules

The multiphoton ionization rate of molecules depends on the alignment of the molecular axis with respect to the ionizing laser polarization. By studying molecular frame photoelectron angular distributions from N(2), O(2), and benzene, we illustrate how the angle-dependent ionization rate affects the photoelectron cutoff energy. We find alignment can enhance the high energy cutoff of the photoelectron spectrum when probing along a nodal plane or when ionization is otherwise suppressed. This is supported by calculations using a tunneling model with a single ion state.

Late presentation of simple virilising 21-hydroxylase deficiency in a Chinese woman with Turner's syndrome

Classical congenital adrenal hyperplasia due to 21-hydroxylase deficiency is a well-known disorder of sexual development (previously known as ambiguous genitalia) in genotypic female neonates. We report on a 66-year-old Chinese, brought up as male, with a simple virilising form of congenital adrenal hyperplasia associated with Turner's syndrome (karyotype 45,X/47,XXX/46,XX). His late presentation was recognised due to his exceptionally short stature and persistent sexual ambiguity. His condition was only brought to medical attention as he developed a huge abdominal mass, which later turned out to be a benign ovarian mucinous cyst. It is therefore important to look out for co-existing congenital adrenal hyperplasia in patients with Turner's syndrome and virilisation, after the presence of Y chromosome material has been excluded.

P45 forms a complex with FADD and promotes neuronal cell survival following spinal cord injury

Fas-associated death domain (DD) adaptor (FADD), a member of the DD superfamily, contains both a DD and a death effector domain (DED) that are important in mediating FAS ligand-induced apoptotic signaling. P45 is a unique member of the DD superfamily in that it has a domain with sequence and structural characteristics of both DD and DED. We show that p45 forms a complex with FADD and diminishes Fas-FADD mediated death signaling. The DED of FADD is required for the complex formation with p45. Following spinal cord injury, transgenic mice over-expressing p45 exhibit increased neuronal survival, decreased retraction of corticospinal tract fibers and improved functional recovery. Understanding p45-mediated cellular and molecular mechanisms may provide insights into facilitating nerve regeneration in humans.

Mid-infrared supercontinuum generation in As2S3-silica "nano-spike" step-index waveguide

Efficient generation of a broad-band mid-infrared supercontinuum spectrum is reported in an arsenic trisulphide waveguide embedded in silica. A chalcogenide "nano-spike", designed to transform the incident light adiabatically into the fundamental mode of a 2-mm-long uniform section 1 µm in diameter, is used to achieve high launch efficiencies. The nano-spike is fully encapsulated in a fused silica cladding, protecting it from the environment. Nano-spikes provide a convenient means of launching light into sub-wavelength scale waveguides. Ultrashort (65 fs, repetition rate 100 MHz) pulses at wavelength 2 µm, delivered from a Tm-doped fiber laser, are launched with an efficiency ~12% into the sub-wavelength chalcogenide waveguide. Soliton fission and dispersive wave generation along the uniform section result in spectral broadening out to almost 4 µm for launched energies of only 18 pJ. The spectrum generated will have immediate uses in metrology and infrared spectroscopy.

ZASC1 knockout mice exhibit an early bone marrow-specific defect in murine leukemia virus replication

Background

ZASC1 is a zinc finger-containing transcription factor that was previously shown to bind to specific DNA binding sites in the Moloney murine leukemia virus (Mo-MuLV) promoter and is required for efficient viral mRNA transcription (J. Virol. 84:7473-7483, 2010).

Methods

To determine whether this cellular factor influences Mo-MuLV replication and viral disease pathogenesis in vivo, we generated a ZASC1 knockout mouse model and completed both early infection and long term disease pathogenesis studies.

Results

Mice lacking ZASC1 were born at the expected Mendelian ratio and showed no obvious physical or behavioral defects. Analysis of bone marrow samples revealed a specific increase in a common myeloid progenitor cell population in ZASC1-deficient mice, a result that is of considerable interest because osteoclasts derived from the myeloid lineage are among the first bone marrow cells infected by Mo-MuLV (J. Virol. 73: 1617-1623, 1999). Indeed, Mo-MuLV infection of neonatal mice revealed that ZASC1 is required for efficient early virus replication in the bone marrow, but not in the thymus or spleen. However, the absence of ZASC1 did not influence the timing of subsequent tumor progression or the types of tumors resulting from virus infection.

Conclusions

These studies have revealed that ZASC1 is important for myeloid cell differentiation in the bone marrow compartment and that this cellular factor is required for efficient Mo-MuLV replication in this tissue at an early time point post-infection.

Ultrasonographic findings in eyes with retinopathy of prematurity in malaysia

RetCam is an excellent screening tool for the detection of retinopathy of prematurity (ROP). However, affordability is a barrier when adopting the use of RetCam in developing countries. We aimed to describe different stages of ROP using ultrasonographic B-scan and to evaluate the association between funduscopic examinations and ultrasonographic B-scan findings in premature neonates with ROP in Malaysia. A descriptive cross sectional study was conducted in 90 eyes of 47 premature neonates with different stages of ROP in three tertiary hospitals in Malaysia. Experienced ophthalmologists performed detailed funduscopic examinations using binocular indirect ophthalmoscopy (BIO). A masked examiner performed a 10 MHz ultrasonographic B-scan evaluation with 12 meridian position images within 48 hours of clinical diagnosis. Data from the clinical examination and ultrasonographic findings were collected and analysed. We recruited 37 eyes (41.1%) with stage 1 ROP, 29 eyes (32.3%) with stage 2, 18 eyes (20.0%) with stage 3, and 3 eyes (3.3%) with stages 4 and 5 based on the clinical assessment. Ultrasonography correctly identified 3 (8.1%) stage 1 eyes, 17 (58.6%) stage 2 eyes, 13 (72.2%) stage 3 eyes, and 3 each (100%) of the stage 4 and 5 eyes. There was a significant association between the funduscopic signs and the ultrasound findings for stage 2 ROP and above (Fisher's exact test, p <0.001). In conclusion, all stages of ROP were detected and described with a 10 MHz ultrasonic B-scan system. A significant association was observed between funduscopic signs and ultrasonographic findings in premature Malaysian neonates with stage 2 ROP and above.

Loss of the oxidative stress sensor NPGPx compromises GRP78 chaperone activity and induces systemic disease

NPGPx is a member of the glutathione peroxidase (GPx) family; however, it lacks GPx enzymatic activity due to the absence of a critical selenocysteine residue, rendering its function an enigma. Here, we show that NPGPx is a newly identified stress sensor that transmits oxidative stress signals by forming the disulfide bond between its Cys57 and Cys86 residues. This oxidized form of NPGPx binds to glucose-regulated protein (GRP)78 and forms covalent bonding intermediates between Cys86 of NPGPx and Cys41/Cys420 of GRP78. Subsequently, the formation of the disulfide bond between Cys41 and Cys420 of GRP78 enhances its chaperone activity. NPGPx-deficient cells display increased reactive oxygen species, accumulated misfolded proteins, and impaired GRP78 chaperone activity. Complete loss of NPGPx in animals causes systemic oxidative stress, increases carcinogenesis, and shortens life span. These results suggest that NPGPx is essential for releasing excessive ER stress by enhancing GRP78 chaperone activity to maintain physiological homeostasis.

Inactivated HSV-2 in MPL/alum adjuvant provides nearly complete protection against genital infection and shedding following long term challenge and rechallenge

Herpes Simplex Virus Type 2 (HSV-2) infection can result in life-long recurrent genital disease, asymptomatic virus shedding, and transmission. No vaccine to date has shown significant protection clinically. Here, we used a mouse model of genital HSV-2 infection to test the efficacy of a vaccine consisting of whole, formalin-inactivated HSV-2 (FI-HSV2) formulated with monophosphoryl lipid A (MPL) and alum adjuvants. Vaccine components were administered alone or as a prime-boost immunization together with DNA vaccines encoding a truncated glycoprotein D2 (gD2t) and two conserved HSV-2 genes necessary for virus replication, UL5 (DNA helicase) and UL30 (DNA polymerase). Our results show: (1) compared with mock immunized controls, mice immunized with FI-HSV2 plus MPL/alum consistently showed protection against disease burden and total viral shedding while the mice immunized with gD2t protein with MPL/alum did not; (2) protection against genital disease and viral replication correlated with the type of boost in a prime-boost immunization with little advantage afforded by a DNA prime; (3) intramuscular (i.m.) immunization with FI-HSV2 in MPL/Alhydrogel adjuvant provided nearly complete protection against vaginal HSV-2 shedding after a lethal intravaginal (i.vag.) short-term challenge and long-term rechallenge; (4) single formulation immunization with DNA vaccines, FI-HSV2, and MPL in an aluminum phosphate (Adju-Phos) adjuvant did not increase protection relative to FI-HSV2/MPL/Adju-Phos alone; and (5) addition of MPL/alum to the FI-HSV2 was required for optimal protection against disease, viral replication, and latent virus load in the dorsal root ganglia (DRG). Most notably, an optimized vaccine formulation of FI-HSV2 MPL/Alhydrogel given i.m. completely protected against detectable vaginal HSV-2 shedding in the majority of animals and HSV-2 latent DNA in the DRG of all animals.

Randomized clinical trial of open hepatectomy with or without intermittent Pringle manoeuvre

BACKGROUND

The intermittent Pringle manoeuvre (IPM) is commonly applied during liver resection. Few randomized trials have addressed its effectiveness in reducing blood loss and the results have been conflicting. The present study investigated the hypothesis that IPM could reduce blood loss during liver resection by 50 per cent.

METHODS

Between May 2008 and April 2011, patients who underwent elective open hepatectomy were randomized into an IPM or no Pringle manoeuvre (NPM) group and stratified according to the presence or absence of cirrhosis. Data on demographics, type of hepatectomy, operative blood loss, duration of operation, mortality, morbidity and postoperative liver function were recorded and analysed. The primary endpoint was operative blood loss.

RESULTS

There were 63 patients in each group. Median (range) operative blood loss was 370 (50-3600) ml in the IPM group versus 335 (40-3160) ml in the NPM group (P = 1·000). There were no differences in blood loss in different phases of the operation, blood loss per area of liver transected or blood transfusion rate, nor in total duration of operation or liver transection time. Postoperative serum alanine aminotransferase levels were higher in the IPM group (P < 0·001). There were more postoperative complications in the IPM group (41 versus 24 per cent; P = 0·036).

CONCLUSION

The IPM did not reduce blood loss, but was associated with raised levels of postoperative liver parenchymal enzymes and more complications.

REGISTRATION NUMBER

NCT00730743 (http://www.clinicaltrials.gov).

Prevalence of undiagnosed diabetes mellitus and cardiovascular risk factors in Hong Kong professional drivers

AIMS

To investigate the prevalence of undiagnosed diabetes mellitus (DM) and cardiovascular risk factors among professional drivers in Hong Kong.

METHODS

Chinese professional drivers with no history of DM were invited to complete a questionnaire on their health status, followed by taking their body measurements, fasting blood glucose (FG) and lipids. 75g OGTT were performed when FG≥5.6 to <7.0mmol/L.

RESULTS

Of these 3376 drivers (male 92.6%, mean age 50.9±7.6 years), the prevalence of undiagnosed DM, prediabetes, and metabolic syndrome was 8.1% (272/3376, 95% CI 7.1-9.0%), 10.0% (337/3376, 95% CI 9.0-11.0%) and 26.8% (904/3376, 95% CI 25.3-28.3%) respectively, while the corresponding WHO Standard Population age-standardized prevalence was 7.8%, 9.0% and 24.7% respectively. Many of them were obese (51.2%), had hypertension (57.0%) and high cholesterol (58.7%), and a third had hypertriglyceridaemia (34.9%) and low HDL-cholesterol (29.3%). Their median working hours were 60.0 (IQR 14)h. Majority had exercise <1h/week (56.0%) and ate out ≥6times/week (54.9%).

CONCLUSIONS

Hong Kong professional drivers have higher prevalence of undiagnosed DM, cardiovascular risk factors and metabolic syndrome than the general population. Therefore, health care measures targeting against them should be taken to prevent and detect DM and cardiovascular diseases.

Surgical ablation of hepatocellular carcinoma with 2.45-GHz microwave: a critical appraisal of treatment outcomes

OBJECTIVE

To evaluate the efficacy and safety of a new generation of 2.45-GHz microwave to ablate hepatocellular carcinoma by surgical approach. DESIGN; Case series with prospective follow-up.

SETTING

A university teaching hospital in Hong Kong.

PATIENTS

From March 2009 to January 2011, 26 consecutive patients (19 men and 7 women) with a median age of 63 (range, 49-79) years with hepatocellular carcinoma were recruited. Five (19%) of the patients had recurrent hepatocellular carcinoma after previous treatment.

INTERVENTION

Microwave ablation for hepatocellular carcinomas (one tumour, n=24; two tumours, n=2) using a laparoscopic (n=16) or open approach (n=10).

MAIN OUTCOME MEASURES

Operative mortality and morbidity, rate of incomplete ablation, recurrence rate, and survival rate.

RESULTS

The median tumour diameter was 3.8 cm (range, 2.0-6.0 cm). Complications occurred in five (19%) of the patients; only one was ablation-related, and there was no operative mortality. One (4%) of the patients experienced incomplete ablation. Recurrent tumours were noted in 11 (42%) of the patients (5 were local, 2 were remote, and 4 were multifocal) after a median follow-up of 14 (range, 4-26) months. The failure rate for local disease control was 23%, and was 14% if patients with recurrent hepatocellular carcinoma were excluded. All but one patient survived until the time of censorship. The mean survival was 25 (standard deviation, 1) months.

CONCLUSION

This new-generation microwave technique is safe and effective for local ablation of hepatocellular carcinoma. It is a valuable treatment option for patients who are not candidates for hepatectomy.

Single-incision laparoscopic cholecystectomy: from four wounds to one

OBJECTIVE

To review the initial results and surgical outcomes of single-incision laparoscopic cholecystectomy.

DESIGN

Prospective case series.

SETTING

A university teaching hospital and a regional hospital in Hong Kong.

PATIENTS

All patients undergoing single-incision laparoscopic cholecystectomy from August 2009 to March 2011.

RESULTS

Fifty patients underwent single-incision laparoscopic cholecystectomy during the study period. The indications for surgery included symptomatic gallstones (n=43) and gallbladder polyps (n=7). The mean operating time was 78 (standard deviation, 24) minutes. Forty-five of the patients successfully underwent single-incision laparoscopic cholecystectomy, giving a success rate of 90%. In the remaining five patients, additional working ports were constructed to obtain better exposure and dissection around Calot's triangle. On comparing the results of the initial 25 cases to the subsequent 25 cases, in the latter group the operating time was significantly shorter (86 vs 71 minutes; P=0.02), and the success rate was higher (80% vs 100%; P=0.05). During the median follow-up period of 6.8 months, four patients had complications, which included: postoperative urinary retention (n=2), one each with a haematoma and an incisional hernia. No patient endured bile duct injury, postoperative bile leakage, or haemorrhage in our series.

CONCLUSION

Single-incision laparoscopic cholecystectomy is feasible and safe for treatment of uncomplicated gallbladder diseases. There was a reduction in the operating time and increase in success rate with accumulation of experience. Nevertheless, surgeons should be cautious about the potential risks of this new technique.

A randomized-controlled trial to investigate the effects of rivoglitazone, a novel PPAR gamma agonist on glucose-lipid control in type 2 diabetes

AIM

To examine the efficacy, safety and tolerability of rivoglitazone, a novel thiazolidinedione (TZD), and explore its effects on glucose and lipid control compared to placebo and pioglitazone in Chinese type 2 diabetic patients who are treatment naÏve or treated with a single oral blood glucose-lowering drug.

METHODS

This was a double-blind, randomized, placebo- and active-controlled study. A total of 287 Chinese type 2 diabetic patients with suboptimal glycaemic control (defined as HbA1c ≥6.5 to <10% and fasting plasma glucose ≥7 to ≤15 mmol/l) were enrolled. One hundred and seventy-four eligible patients were randomized into one of the five treatment arms for 12 weeks: placebo, pioglitazone 30 mg daily, rivoglitazone of dose 0.5, 1.0 or 1.5 mg daily. In a full set analysis, we used analysis of covariance to compare the primary endpoint defined as change in HbA1c from baseline to week 12/last observation carried forward in the rivoglitazone group at each dose level with the placebo group.

RESULTS

Changes in HbA1c were -0.11% in the 0.5-mg group; -0.22% in the 1-mg group and -0.17% in the 1.5-mg rivoglitazone group; -0.06% in the 30-mg pioglitazone group and 0.61% in the placebo group. Compared to placebo, changes were significant in all active treatment groups (all p < 0.05). Increase in high-density lipoprotein cholesterol and decrease in triglyceride were observed in the rivoglitazone 1 and 1.5 mg groups, respectively, compared to placebo from baseline to week 12 (p < 0.05). Drug-related oedema was reported in eight patients (7.7%) in all rivoglitazone groups compared to six patients (16.2%) in the pioglitazone group and one patient (3.0%) in the placebo group.

CONCLUSIONS

Rivoglitazone is an efficacious, safe and well-tolerated TZD which improved glycaemic control in Chinese type 2 diabetic patients up to 3 months.

Molecular analysis of congenital adrenal hyperplasia due to 21-hydroxylase deficiency in Hong Kong Chinese patients

BACKGROUND

Congenital adrenal hyperplasia (CAH) caused by 21-hydroxylase deficiency (21OHD) is an autosomal recessive disorder due to mutation in the CYP21A2 gene.

OBJECTIVE

To elucidate the genetic basis of 21-hydroxylase-deficient CAH in Hong Kong Chinese patients.

PATIENTS AND METHODS

Mutational analysis of the CYP21A2 gene was performed on 35 Hong Kong Chinese patients with 21OHD using direct DNA sequencing and multiplex ligation-dependent probe amplification (MLPA).

RESULTS

The genetic findings of 21 male and 14 female patients are the following: c.293-13A/C>G (intron 2 splice site; 20 alleles), p.I172N (13), p.R356W (7), p.Q318X (4). A total of 20 mutant alleles contained gross deletion/conversion of all or part of the CYP21A2 gene. A novel mutation, c.1367delA (p.D456fs), was detected in one patient. One patient had only a heterozygous mutation detected. Out of 35 patients, 16 would have been incorrectly genotyped if either DNA sequencing or MLPA alone was used for molecular analysis.

CONCLUSIONS

The frequency of various mutations in the studied patients differs from those reported in other Asian populations. Gross deletion/conversion accounts for nearly one-third of the genetic defects. Therefore, laboratories must include methods for detecting point mutations as well as gross deletions/conversions to avoid misinterpretation of genotype. Genotyping has increasingly been proven to be a useful tool for supplementing, if not replacing, hormonal profiling for the diagnosis of 21OHD.

Risk of development of diabetes mellitus in Chinese women with persistently impaired glucose tolerance after gestational diabetes

OBJECTIVES

To estimate the cumulative incidence for the development of diabetes mellitus in Chinese women with persistently impaired glucose tolerance after gestational diabetes, and evaluate putative risk factors.

DESIGN

Historical cohort study.

SETTING

A regional hospital in Hong Kong.

PATIENTS

Women with postpartum impaired glucose tolerance (as confirmed by a 75-gram oral glucose tolerance test 6 weeks after delivery) seen between January 2000 and December 2006.

RESULTS

After a mean follow-up period of 52 (standard deviation, 22; range, 12-106) months, 47 (20%) of the 238 women converted to diabetes mellitus. Concomitant postpartum impaired fasting plasma glucose levels increased the risk of future diabetes mellitus by 3.5-fold (95% confidence interval, 1.7-7.0; P=0.001) when compared to those with postpartum impaired glucose tolerance only. Based on multivariate analysis, only antepartum and postpartum fasting plasma glucose levels predicted future development of diabetes mellitus. At 1 year after delivery in 95/159 (60%) of the women, glucose tolerance regressed to normal, while in only 9/159 (6%) it progressed to diabetes mellitus. At this stage, 29% of those with impaired glucose regulation (impaired glucose tolerance, impaired fasting glucose or both) compared to 2% of those whose glucose tolerance reverted to normal developed diabetes mellitus upon subsequent follow-up (P<0.001). In all, 24/159 (15%) fulfilled the definition of metabolic syndrome and its presence was associated with 4.7-fold increased risk of future diabetes mellitus (95% confidence interval, 1.7-13.4; P=0.004).

CONCLUSIONS

Women with persistent postpartum impaired glucose tolerance after gestational diabetes have a high risk of developing diabetes mellitus. However, a significant proportion of these women regress to normal glucose tolerance 1 year after delivery, and their risk of progression to diabetes mellitus is lower than those with persistent impaired glucose regulation. Therefore, women with a history of gestational diabetes, particularly those with persistent glucose intolerance 6 weeks and 1 year after delivery, should have regular surveillance for the development of diabetes mellitus.

Testicular signaling is the potential target of perfluorooctanesulfonate-mediated subfertility in male mice

Perfluorooctanesulfonate (PFOS) was produced and used by various industries and in consumer products. Because of its persistence, it is ubiquitous in air, water, soil, wildlife, and humans. Although the adverse effects of PFOS on male fertility have been reported, the underlying mechanisms have not yet been elucidated. Here, for the first time, the effects of PFOS on testicular signaling, such as gonadotropin, growth hormone, insulin-like growth factor, and inhibins/activins were shown to be directly related to male subfertility. Sexually mature 8-wk-old CD1 male mice were administered by gavages in corn oil daily with 0, 1, 5, or 10 mg/kg PFOS for 7, 14, or 21 days. Serum concentrations of testosterone and epididymal sperm counts were significantly lower in the mice after 21 days of the exposure to the highest dose compared with the controls. The expression levels of testicular receptors for gonadotropin, growth hormone, and insulin-like growth factor 1 were considerably reduced on Day 21 in mice exposed daily to 10 or 5 mg/kg PFOS. The transcript levels of the subunits of the testicular factors (i.e., inhibins and activins), Inha, Inhba, and Inhbb, were significantly lower on Day 21 of daily exposure to 10, 5, or 1 mg/kg PFOS. The mRNA expression levels of steroidogenic enzymes (i.e., StAR, CYP11A1, CYP17A1, 3beta-HSD, and 17beta-HSD) were notably reduced. Therefore, PFOS-elicited subfertility in male mice is manifested as progressive deterioration of testicular signaling.

Amiodarone-induced thyroid dysfunction in the Hong Kong Chinese population

OBJECTIVE

To determine the frequency, risk factors, clinical features, and management of amiodarone-induced thyroid dysfunctions.

DESIGN

Retrospective study.

SETTING

A regional hospital in Hong Kong.

PATIENTS

Patients who had been prescribed amiodarone for at least 6 months from 1 October 2005 to 30 September 2007.

RESULTS

A total of 390 patients (mean age, 70 years; standard deviation, 9 years; 54% male) with a median follow-up of 43 (interquartile range, 25-69) months were studied. Hypothyroidism developed in 87 (22%) of the patients (mean age, 72 years; standard deviation, 7 years; 56% male) and thyrotoxicosis in 24 (6%) of the patients (65 years; 11 years; 54% male). Increased baseline thyrotropin (thyroid-stimulating hormone) level appeared to be predictive of amiodarone-induced hypothyroidism, in which a thyroid-stimulating hormone level of 4 mIU/L or above was associated with a 4.7-fold increase in the risk (95% confidence interval, 1.9-11.7; P<0.001). Compared with those who remained euthyroid on amiodarone, thyrotoxicosis developed in younger patients. In these patients, the classical symptoms of thyroid dysfunction were frequently absent, although worsening of underlying arrhythmias, their cardiac condition, weight loss, and over-warfarinisation were suggestive of amiodarone-induced thyrotoxicosis. In both amiodarone-induced thyrotoxicosis and hypothyroidism, the disease course was benign. Patients with the former showed a good response to anti-thyroid drugs and steroid therapy.

CONCLUSIONS

Amiodarone-induced thyroid dysfunction is common among our population. As the clinical presentations are usually vague and atypical, regular biochemical monitoring of thyroid function is warranted, particularly in patients with elevated baseline thyroid-stimulating hormone level. The disease course of amiodarone-induced thyrotoxicosis is usually benign and remits with timely administration of anti-thyroid medications, with or without corticosteroids.

The analgesic efficacy of continuous wound instillation with ropivacaine after open hepatic surgery

The analgesic efficacy of continuous local anaesthetic wound instillation after open hepatic surgery was evaluated. Forty-eight patients scheduled for elective liver surgery were assigned to receive either ropivacaine 0.25% or saline infusion at 4 ml.h(-1) for 68 h via two multi-orifice indwelling catheters placed within the musculo-fascial layer before skin closure; plasma ropivacaine concentrations were measured during the infusion. Supplemental analgesia was provided by intravenous patient-controlled analgesia morphine. Patients in the ropivacaine group had decreased mean (SD) total morphine consumption (58 (30) mg vs 86 (44) mg, p = 0.01) and less pain at rest as well as after spirometry at 4, 12, 24, 48 and 72 h postoperatively (p < 0.01). Forced vital capacity was reduced postoperatively in both groups, but the reduction was greater in the saline group at 12 and 24 h (p = 0.03). The mean plasma concentration of ropivacaine increased to 2.05 (0.78) μg.ml(-1) at the point when the infusion was terminated.