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.

Phaeochromocytoma in the Hong Kong Chinese population

OBJECTIVE

To review the clinical manifestations of phaeochromocytoma in a Hong Kong Chinese population.

DESIGN

Retrospective review. SETTING. Five public hospitals in Hong Kong.

PATIENTS

Seventeen patients with operated phaeochromocytoma between 1994 and 2003 were reviewed retrospectively.

RESULTS

Six patients (35%) were men, 11 (65%) were women. The mean age at presentation was 47 (range, 17-72) years. The diagnosis post-presentation was delayed by 1 to 132 months. Over 70% of the patients had hypertension. The most frequent symptoms were headache (53%), palpitations (53%), and sweating (41%); all these symptoms were present in 24% of the patients. Four (24%) had hereditary phaeochromocytoma/paraganglioma syndrome. The sensitivity of 24-hour urinary catecholamine measurements was 82%. Mean urinary adrenaline and noradrenaline concentrations were respectively 7- and 8-fold greater than the upper reference limits. Computed tomography and metaiodobenzylguanidine scintigraphy were the most widely used means for tumour localisation (sensitivity, 100% and 87% respectively). Approximately 65% of the patients had intra-adrenal tumours; 53% were on right side, 18% were bilateral. All the patients were prescribed phenoxybenzamine (dosage range, 20-120 mg/day) preoperatively. Two thirds of the patients had improved blood pressure 1 year after the operation. No malignancy was reported after a mean follow-up period of 7 years.

CONCLUSION

Our series of patients with phaeochromocytomas commonly had a high frequency of normotension and extra-adrenal tumours. A high index of clinical suspicion and appropriate biochemical investigations are necessary to make the diagnosis, especially for patients manifesting adrenal incidentaloma and extra-adrenal lesion.

A community-acquired methicillin-resistant Staphylococcus aureus liver abscess

Liver abscesses caused by community-acquired methicillin-resistant Staphylococcus aureus are rarely reported. We report such a case in a 25-year-old man who presented with an intermittent fever. He had a history of prolonged antibiotic use for acne and skin abscesses. The liver abscess was successfully treated with percutaneous drainage and a prolonged course of linezolid. To our knowledge, this is the first reported case of a community-acquired methicillin-resistant Staphylococcus aureus liver abscess in Hong Kong, demonstrating the increasing threat posed by this multidrug-resistant organism. This case also suggests that a different epidemiology and route of infection may apply to community-acquired methicillin-resistant Staphylococcus aureus liver abscesses in contrast to the more common pyogenic liver abscesses.

Dilated common bile ducts mimicking choledochal cysts in ketamine abusers

Substance abuse is a major health and social problem among Hong Kong youth and ketamine is the drug most commonly abused. Ketamine abuse is associated with a series of side-effects that include hallucination, nausea, vomiting, elevation of blood pressure, and urinary bladder dysfunction. Here we report three cases of ketamine abuse in which the abusers presented with recurrent epigastric pain and dilated common bile ducts that mimicked choledochal cysts on imaging. The dilated biliary tree may occur more frequently than was once assumed.

p75(NTR) mediates ephrin-A reverse signaling required for axon repulsion and mapping

Reverse signaling by ephrin-As upon binding EphAs controls axon guidance and mapping. Ephrin-As are GPI-anchored to the membrane, requiring that they complex with transmembrane proteins that transduce their signals. We show that the p75 neurotrophin receptor (NTR) serves this role in retinal axons. p75(NTR) and ephrin-A colocalize within caveolae along retinal axons and form a complex required for Fyn phosphorylation upon binding EphAs, activating a signaling pathway leading to cytoskeletal changes. In vitro, retinal axon repulsion to EphAs by ephrin-A reverse signaling requires p75(NTR), but repulsion to ephrin-As by EphA forward signaling does not. Constitutive and retina-specific p75(NTR) knockout mice have aberrant anterior shifts in retinal axon terminations in superior colliculus, consistent with diminished repellent activity mediated by graded ephrin-A reverse signaling induced by graded collicular EphAs. We conclude that p75(NTR) is a signaling partner for ephrin-As and the ephrin-A- p75(NTR) complex reverse signals to mediate axon repulsion required for guidance and mapping.

Laparoscopic versus open hepatectomy for liver tumours: a case control study

OBJECTIVE

To evaluate the benefits of laparoscopic versus open resection of liver tumours.

DESIGN

Case control study.

SETTING

Tertiary teaching hospital, Hong Kong.

PATIENTS

Data from 25 patients who underwent laparoscopic resections for liver tumours from 2003 to 2006 were compared to a retrospective series of 25 patients who underwent open hepatectomy in a pair-matched design.

MAIN OUTCOME MEASURES

Duration of operation, operative morbidity and mortality, blood loss, tumour resection margin, analgesics usage, days to return to an oral diet, duration of postoperative hospital stay, and survival of patients with malignancy.

RESULTS

The demographic data and the tumour characteristics were comparable in the two patient groups, as were mortality (0% in both groups) and morbidity rates (4% in both groups). Two (8%) of the patients having laparoscopic resections were converted to open surgery. There was no statistically significant difference between the two groups in terms of operating time or resection margins. However, the laparoscopically treated patients experienced significantly less blood loss (median, 100 vs 250 mL), had shorter hospital stays (median, 4 vs 7 days), were prescribed less analgesia (median morphine dosage, 0.16 vs 0.83 mg per kg body weight), and resumed oral diet earlier (median, 1 vs 2 days). For patients with malignant tumours, there was no significant difference between the two groups in terms of actuarial and disease-free survival.

CONCLUSION

Compared to open hepatectomy, in selected patients laparoscopic liver resection delivers the benefits of decreased blood loss, shorter hospital stay, lesser requirement for analgesics, and an earlier return to an oral diet, without evidence of compromised oncological clearance.

Is regular follow-up scan for giant liver haemangioma necessary?

OBJECTIVES

To review the reliability of radiological diagnosis and need of regular scans for giant liver haemangioma, in terms of long-term outcome and management options.

DESIGN

Retrospective study.

SETTING

Division of Hepato-biliary and Pancreatic Surgery, Prince of Wales Hospital, Hong Kong.

PATIENTS

Patients with giant liver haemangioma noted on initial imaging from February 1996 to July 2006.

MAIN OUTCOME MEASURES

Patient demographics, clinical assessments, management, and outcomes.

RESULTS

There were 42 female and 22 male patients with a median age of 49 (range, 27-84) years with a suspected haemangioma. The median maximal diameter of the lesions was 5.5 cm (range, 4.0-20.3 cm). They were first detected by ultrasonography (n=45), contrast-enhanced computed tomographic scan (n=18), or magnetic resonance imaging (n=1). Besides regular follow-up scans, 22 patients were investigated further to confirm the diagnosis/exclude malignancy. Finally, 63 patients had a haemangioma and one had a hepatocellular carcinoma. Regarding the patients with haemangiomas, two were operated on for relief of pain and the rest were managed conservatively. The median duration of follow-up was 34 months. Most (54%) of the patients were asymptomatic, but in 17% the haemangioma enlarged to exceed its original size by more than 20%. There were no haemangioma-associated complications.

CONCLUSIONS

Majority of patients having giant liver haemangioma are asymptomatic and do not suffer complications. If the diagnosis is uncertain, selective further investigations may be necessary. Lesions with a confirmed diagnosis tend to remain static in size; performing regular scans for asymptomatic giant liver haemangiomas may not be necessary.

Techniques for liver resection: a review

Improvement in surgical outcomes of liver resection has been achieved in the past decade. Among other factors, a gradual change of technology platforms and refinement of surgical techniques have played significant roles. In this review, the various surgical approaches, operative techniques, operative instruments, and adjunctive measures as applied in liver resection are described, along with discussion of the pros and cons of each of these attributes. A brief description of laparoscopic liver resection is also included to address this important and emerging area in liver surgery.

Corticotropin-releasing factor receptors differentially regulate stress-induced tau phosphorylation

Hyperphosphorylation of the microtubule-associated protein tau is a key event in the development of Alzheimer's disease (AD) neuropathology. Acute stress can induce hippocampal tau phosphorylation (tau-P) in rodents, but the mechanisms and pathogenic relevance of this response are unclear. Here, we find that hippocampal tau-P elicited by an acute emotional stressor, restraint, was not affected by preventing the stress-induced rise in glucocorticoids but was blocked by genetic or pharmacologic disruption of signaling through the type 1 corticotropin-releasing factor receptor (CRFR1). Conversely, these responses were exaggerated in CRFR2-deficient mice. Parallel CRFR dependence was seen in the stress-induced activation of specific tau kinases. Repeated stress exposure elicited cumulative effects on tau-P and its sequestration in an insoluble, and potentially pathogenic, form. These findings support differential regulatory roles for CRFRs in an AD-relevant form of neuronal plasticity and may link datasets documenting alterations in the CRF signaling system in AD and implicating chronic stress as a risk factor in age-related neurological disorders.

Genetically encoding unnatural amino acids for cellular and neuronal studies

Proteins participate in various biological processes and can be harnessed to probe and control biological events selectively and reproducibly, but the genetic code limits the building block to 20 common amino acids for protein manipulation in living cells. The genetic encoding of unnatural amino acids will remove this restriction and enable new chemical and physical properties to be precisely introduced into proteins. Here we present new strategies for generating orthogonal tRNA-synthetase pairs, which made possible the genetic encoding of diverse unnatural amino acids in different mammalian cells and primary neurons. Using this new methodology, we incorporated unnatural amino acids with extended side chains into the K+ channel Kv1.4, and found that the bulkiness of residues in the inactivation peptide is essential for fast channel inactivation, a finding that had not been possible using conventional mutagenesis. This technique will stimulate and facilitate new molecular studies using tailored unnatural amino acids for cell biology and neurobiology.

Budd-Chiari-induced protein-losing enteropathy after liver transplantation

Budd-Chiari syndrome (BCS) is one of the uncommon complications of hepatic venous reconstruction in liver transplantation. Protein-losing enteropathy (PLE) secondary to this event has rarely been described. A 14-year-old girl suffering from acute hepatic failure underwent an emergency living-related liver transplantation and developed BCS 1 year later. Her condition has been managed with several sessions of hepatic venoplasty. On one occasion, she suffered septicemia and severe diarrhea, passing large amount of fibrinoid material. The diagnosis of PLE was made clinically, which resolved immediately after reestablishment of hepatic venous patency by balloon venoplasty. This observation suggested that BCS was responsible for PLE in this patient. Prompt diagnosis and early intervention for this life-threatening condition is essential.

Routine early laparoscopic cholecystectomy for acute cholecystitis after conclusion of a randomized controlled trial

Background

The aim of this retrospective review was to assess the clinical outcomes of laparoscopic cholecystectomy for acute cholecystitis since the conclusion of a randomized controlled trial in 1997.

Methods

Records of all patients admitted for acute cholecystitis in whom early laparoscopic cholecystectomy was attempted between July 1997 and December 2004 were reviewed.

Results

A total of 209 patients were recruited to this study. Forty-three surgeons performed the procedures. The conversion rate increased significantly in the early period after the trial from 21 per cent to 42 per cent (39 of 92 patients) and decreased significantly to 24 per cent (13 of 54 patients) in the later period. The proportion of operations performed by higher surgical trainees increased significantly from 17 per cent in the early period to 56 per cent in the later period. This increase was associated with a fall in conversion rate without any significant increase in duration of operation or complication rate.

Conclusion

This study has demonstrated that the results achieved in a randomized trial can be translated into clinical practice by the entire surgical unit. A structured training programme with the inclusion of an experienced surgeon assisting both trainees and specialists should minimize this learning curve.

Single nucleotide polymorphism in the promoter region of human alpha-fetoprotein (AFP) gene and its significance in hepatocellular carcinoma (HCC)

BACKGROUND

Variations of serum AFP levels in HCC patients and cell lines are likely due to the differential activity of enhancer/silencer elements that control AFP. To understand the potential mechanism underlying the differential expression of AFP, we have examined the sequence of the AFP promoter in HCC.

METHODS

Direct DNA sequencing was carried out to sequence 980 bp of AFP promoter of DNA samples isolated from 83 HCC patients.

RESULTS

Three novel SNPs in the promoter region of the AFP gene, which have not been previously reported, were found at positions -330, -401 and -692. The level of serum AFP was significantly higher in HCC patients with the CT genotype of 330 SNP or the AG genotype of the 401 SNP. The genotype of CG in 692 SNP was also associated with a significant elevated level of serum AFP, and further this genotype appeared to be associated with the high risk of HCC development. 401 SNP and 692 SNP were located at the positions of known binding sites for transcription factors that have a role in the production of AFP and the growth of tumors.

CONCLUSIONS

The novel polymorphisms identified in the promoter region of the AFP gene may be pathologically significant in HCC.

Urocortin 3 regulates glucose-stimulated insulin secretion and energy homeostasis

Urocortin 3 (Ucn 3), a member of the corticotropin-releasing factor (CRF) family of peptides, is strongly expressed in mammalian pancreatic beta cells and has been shown to stimulate insulin secretion. Here we report the investigation of the hypothesis that endogenous Ucn 3 regulates insulin secretion, particularly in the presence of nutrient excess. Secretion of Ucn 3-like immunoreactivity from cultured beta cells was stimulated by high glucose and insulin secretagogs such as GLP-1; furthermore, 5 pancreatic Ucn 3 mRNA levels in vivo were increased during the positive energy balance caused by high-fat diet and by the absence of leptin. Immunoneutralization of Ucn 3 or pharmacologic blockade of its receptor, the type 2 CRF receptor (CRFR2), attenuated high but not low glucose-induced insulin secretion from isolated islets in vitro. Cultured islets isolated from Ucn 3-null mice also secreted less insulin in response to high glucose concentrations. Consistently, peripheral injection of a selective CRFR2 antagonist before the administration of a glucose challenge significantly attenuated glucose-induced insulin secretion in vivo. Ucn 3-null mice were relatively protected from the hyperinsulinemia, hyperglycemia, glucose intolerance, hepatic steatosis, and hypertriglyceridemia induced by high-fat diet. Additionally, we found that aged Ucn 3-null mice maintained better glucose tolerance than age-matched wild-type littermates. These results suggest that endogenous Ucn 3 in the pancreas is induced under excessive caloric conditions and acts locally to augment insulin production, which in the long-term may contribute to reduced insulin sensitivity and harmful metabolic consequences.

Urocortin 2 modulates glucose utilization and insulin sensitivity in skeletal muscle

Skeletal muscle is the principal tissue responsible for insulin-stimulated glucose disposal and is a major site of peripheral insulin resistance. Urocortin 2 (Ucn 2), a member of the corticotropin-releasing factor (CRF) family, and its cognate type 2 CRF receptor (CRFR2) are highly expressed in skeletal muscle. To determine the physiological role of Ucn 2, we generated mice that are deficient in this peptide. Using glucose-tolerance tests (GTTs), insulin-tolerance tests (ITTs), and hyperinsulinemic euglycemic glucose clamp studies, we demonstrated that mice lacking Ucn 2 exhibited increased insulin sensitivity and were protected against fat-induced insulin resistance. Administration of synthetic Ucn 2 to mutant mice before the GTTs and ITTs restored blood glucose to WT levels. Administration of a CRFR2 selective antagonist to WT mice resulted in a GTT profile that mirrored that of Ucn 2-null mice. Body composition measurements of Ucn 2-null mice on a high-fat diet demonstrated decreases in fat and increases in lean tissue compared with WT mice. We propose that null mutant mice display increased glucose uptake in skeletal muscle through the removal of Ucn 2-mediated inhibition of insulin signaling. In keeping with these data, Ucn 2 inhibited insulin-induced Akt and ERK1/2 phosphorylation in cultured skeletal muscle cells and C2C12 myotubes. These data are consistent with the hypothesis that Ucn 2 functions as a local negative regulator of glucose uptake in skeletal muscle and encourage exploration of the possibility that suppression of the Ucn 2/CRFR2 pathway may provide benefits in insulin-resistant states such as type 2 diabetes.

erbB2 is required for G protein-coupled receptor signaling in the heart

erbB2/Her2, a ligandless receptor kinase, has pleiotropic effects on mammalian development and human disease. The absence of erbB2 signaling in cardiac myocytes results in dilated cardiomyopathy in mice, resembling the cardiotoxic effects observed in a subset of breast cancer patients treated with the anti-Her2 antibody herceptin. Emerging evidence suggests that erbB2 is pivotal for integrating signaling networks involving multiple classes of extracellular signals. However, its role in G protein-coupled receptor (GPCR) signaling remains undefined. Because the activation of the MAPK pathway through GPCR signaling is important for cardiac homeostasis, we investigated whether erbB2 is required for GPCR-mediated MAPK signaling in wild-type and heart-specific erbB2 mutant mice. Here we demonstrate that erbB2, but not EGF receptor, is essential for MAPK activation induced by multiple GPCR agonists in cardiac myocytes. erbB2 is immunocomplexed with a GPCR in vivo and is transactivated after ligand treatment in vitro. Coexpression of erbB2 with GPCRs in heterologous cells results in ligand-dependent complex formation and MAPK activation. Furthermore, MAPK activation and cardiac contractility are markedly impaired in heart-specific erbB2 mutants infused with a GPCR agonist. These results reveal an essential mechanism requiring erbB2 as a coreceptor for GPCR signaling in the heart. The obligatory role of erbB2 in GPCR-dependent signaling may also be important in other cellular systems.

Vascular defect beyond the endothelium in type II diabetic patients with overt nephropathy and moderate renal insufficiency

There is a paucity of data on the effects of overt nephropathy and moderate renal impairment on endothelial function in diabetic patients. A total of 26 type II diabetic (DM) patients with nephropathy (DMN+) (mean +/- s.d. age: 63.7 +/- 6.3 years), 32 diabetic patients without nephropathy (DMN-) (59.4 +/- 10.1 years), and 52 non-diabetic subjects (54.9 +/- 8.2 years) were recruited. High-resolution ultrasound scan was used to measure carotid intima media thickness (IMT) and flow-mediated dilation (FMD) of the brachial artery. Endothelium-independent dilation was determined by maximal vascular dilation after sublingual nitroglycerine (glyceryl trinitrate (GTN)-induced dilation). The mean carotid IMT increased progressively from non-DM to DMN- to DMN+ groups (0.74 +/- 0.23 vs 0.80 +/- 0.25 vs 1.03 +/- 0.38 mm; P=0.001 for trend) whereas FMD- (4.3 +/- 2.5 vs 3.9 +/- 1.7 vs 1.9 +/- 2.0%, P<0.001 for trend) and GTN-induced dilation (14.7 +/- 4.0 vs 14.5 +/- 3.9 vs 10.3 +/- 3.2%; P<0.001 for trend) declined in an opposite manner. On multivariate analysis, age (beta=0.257, P=0.009), glomerular filtration rate (beta=-0.364, P<0.001), and smoking (beta=0.25, P=0.013) were independently associated with carotid IMT (F=15.76, R(2)=0.340, P<0.001). After adjustment for baseline brachial arterial diameter, history of smoking (beta=-0.039, P<0.001), fasting plasma glucose (beta=-0.033, P=0.002), and total cholesterol (beta=-0.023, P=0.024) were independently associated with vessel diameter after FMD (F=2446.5, R(2)=0.992, P<0.001); whereas age (beta=-0.069, P=0.001) and urinary albumin excretion (beta=-0.048, P=0.018) were independently associated with vessel diameter after GTN (F=851.6, R(2)=0.967, P<0.001). Type II diabetic patients with overt nephropathy and moderate renal impairment had both structural and functional vascular abnormalities beyond the endothelium.

Biliary Cystadenoma and Other Complicated Cystic Lesions of The Liver: Diagnostic and Therapeutic Challenges

INTRODUCTION

Biliary cystadenomas are complicated cystic lesions of the liver. They are rare and pose considerable diagnostic and therapeutic challenges.

METHODS

We present our experience managing these lesions by performing a retrospective review of all patients with a preoperative diagnosis of or histologically proven biliary cystadenoma who underwent surgery between January 1995 and January 2005 at our institution. Altogether, 20 patients (16 women, 4 men) with a mean age of 58 years underwent a total of 22 operations. The diagnosis of biliary cystadenoma was based on exclusion of other pathologic entities and the presence of radiologic characteristics of biliary cystadenoma. Abdominal ultrasonography (US), computed tomography, or both were performed in all patients. US-guided fine-needle aspiration cytology was performed in seven patients and all of them were negative for malignancy. A preoperative diagnosis of biliary cystadenoma was made in 16 patients based on clinical and radiologic features and was correct in 6 of them. Diagnosis of biliary cystadenoma was not suspected in four patients.

RESULTS

The overall diagnostic accuracy was 30%. Enucleation was the most common surgical procedure and was performed in 10 patients. The mean follow-up period was 5.5+/-2.8 years. No recurrence was detected in patients with confirmed biliary cystadenoma after adequate excision.

CONCLUSIONS

The findings of this study highlight the difficulty with preoperative diagnosis of biliary cystadenoma, which has seldom been discussed in the literature. Preoperative differentiation by means of radiologic imaging is inaccurate (30%). Any therapy short of complete excision leads to local recurrence and risk of malignant transformation. Complete excision of any suspicious lesion remains the best method of diagnosis and treatment.

Urocortin 2-deficient mice exhibit gender-specific alterations in circadian hypothalamus-pituitary-adrenal axis and depressive-like behavior

Gender differences in hypothalamus-pituitary-adrenal (HPA) axis activation and the prevalence of mood disorders are well documented. Urocortin 2, a recently identified member of the corticotropin-releasing factor family, is expressed in discrete neuroendocrine and stress-related nuclei of the rodent CNS. To determine the physiological role of urocortin 2, mice null for urocortin 2 were generated and HPA axis activity, ingestive, and stress-related behaviors and alterations in expression levels of CRF-related ligands and receptors were examined. Here we report that female, but not male, mice lacking urocortin 2 exhibit a significant increase in the basal daily rhythms of ACTH and corticosterone and a significant decrease in fluid intake and depressive-like behavior. The differential phenotype of urocortin 2 deficiency in female and male mice may imply a role for urocortin 2 in these gender differences.

MicroAlbuminuria Prevalence Study (MAPS) in hypertensive type 2 diabetic patients in Hong Kong

OBJECTIVES

To assess the prevalence of macroalbuminuria and microalbuminuria, and the level of blood pressure control in patients with type 2 diabetes and hypertension in Hong Kong.

DESIGN

Cross-sectional clinic-based epidemiological study.

SETTING

Six medical centres (including two public hospital diabetes centres) in Hong Kong.

PATIENTS

Recruited from the medical centres from April to November 2002, after excluding those with bacteriuria and haematuria.

MAIN OUTCOME MEASURES

Body mass index; blood pressure; levels of blood glucose, macroalbuminuria, and microalbuminuria; treatments for hypertension and diabetes.

RESULTS

The as per-protocol recruited population of 437 hypertensive type 2 diabetic patients had a mean age of 61.7 (standard error, 0.5) years. Overall, the prevalence of diabetic nephropathy in this population was high; 18.3% had macroalbuminuria (95% confidence interval, 16.5-20.2%) and 24.9% had microalbuminuria (95% confidence interval, 22.9-27.0%). Predictive factors were advanced age, male sex, poor blood pressure control, and existing cardiovascular complications. Whilst almost all patients (96.1%) were receiving treatment for hypertension, only 25.6% had systolic/diastolic blood pressures below the 130/85 mm Hg target.

CONCLUSIONS

In Hong Kong, the prevalence of microalbuminuria and macroalbuminuria is high in type 2 diabetic patients with hypertension, particularly in males and those with poorly controlled systolic blood pressure. Tight glycaemic control, antihypertensive therapy, and use of renin-angiotensin system inhibitors/blockers are necessary to retard the progression of nephropathy to advanced renal disease.

Fatal septicaemia from Chromobacterium violaceum: case reports and review of the literature

Chromobacterium violaceum rarely causes infection in humans and its mechanism of pathogenicity is not well understood. Human infection carries a high mortality rate with a fulminating clinical progression. A high index of suspicion is required for diagnosis, and is based on recovering the organisms from blood cultures or other appropriate specimens. We present three cases of human infection managed in a tertiary referral hospital in Hong Kong with a review of the literature.

A disorganized innervation of the inner ear persists in the absence of ErbB2

ErbB2 protein is essential for the development of Schwann cells and for the normal fiber growth and myelin formation of peripheral nerves. We have investigated the fate of the otocyst-derived inner ear sensory neurons in the absence of ErbB2 using ErbB2 null mutants. Afferent innervation of the ear sensory epithelia shows numerous fibers overshooting the organ of Corti, followed by a reduction of those fibers in near term embryos. This suggests that mature Schwann cells do not play a role in targeting or maintaining the inner ear innervation. Comparable to the overshooting of nerve fibers, sensory neurons migrate beyond their normal locations into unusual positions in the modiolus. They may miss a stop signal provided by the Schwann cells that are absent as revealed with detailed histology. Reduction of overshooting afferents may be enhanced by a reduction of the neurotrophin Ntf3 transcript to about 25% of wild type. Ntf3 transcript reductions are comparable to an adult model that uses a dominant negative form of ErbB4 expressed in the supporting cells and Schwann cells of the organ of Corti. ErbB2 null mice retain afferents to inner hair cells possibly because of the prominent expression of the neurotrophin Bdnf in developing hair cells. Despite the normal presence of Bdnf transcript, afferent fibers are disoriented near the organ of Corti. Efferent fibers do not form an intraganglionic spiral bundle in the absence of spiral ganglia and appear reduced and disorganized. This suggests that either ErbB2 mediated alterations in sensory neurons or the absence of Schwann cells affects efferent fiber growth to the organ of Corti.

Emergency laparoscopic unroofing of a ruptured hepatic cyst

The use of laparoscopic techniques in the emergency treatment of liver cyst complications has not been reported in the literature. Laparoscopic surgery is a well-established treatment modality for giant hepatic cyst in the elective setting. We report a case of laparoscopic unroofing of a 15-cm ruptured hepatic cyst, which had recurred after previous percutaneous alcohol instillation therapy. Laparoscopic ultrasound was used to delineate the extent of the cyst while a Harmonic scalpel was used for dissection. The patient made an uneventful recovery and was discharged 4 days after the operation.