Ovarian sex cord stromal tumor with annular tubules in a 7-year-old child: A case report.

A seven-year-old girl who presented with precocious puberty was diagnosed with an estrogen-secreting right ovarian tumor. Right salpingo-oophorectomy with staging was performed by gynecologic oncologists. Intraoperative frozen section reported sex cord stromal tumor. Histopathological report confirmed sex cord stromal tumor with annular tubules with brisk mitotic counts (17 per 10 high-power fields). The post-operative course was uneventful. She remained asymptomatic with normalisation of serum estradiol upon six-month follow-up.

Evaluation of models predicting insignificant prostate cancer to select men for active surveillance of prostate cancer.

BACKGROUND: In an era of personalized medicine, individualized risk assessment using easily available tools on the internet and the literature are appealing. However, uninformed use by clinicians and the public raises potential problems. Herein, we assess the performance of published models to predict insignificant prostate cancer (PCa), using a multi-national low-risk population that may be considered for active surveillance (AS) based on contemporary practice. METHODS: Data on men suitable for AS but undergoing upfront radical prostatectomy were pooled from three international academic institutions in Cambridge (UK), Toronto (Canada) and Melbourne (Australia). Four predictive models identified from literature review were assessed for their ability to predict the presence of four definitions of insignificant PCa. Evaluation was performed using area under the curve (AUC) of receiver operating characteristic curves and Brier scores for discrimination, calibration curves and decision curve analysis. RESULTS: A cohort of 460 men meeting the inclusion criteria of all four nomograms was identified. The highest AUCs calculated for any of the four models ranged from 0.618 to 0.664, suggesting weak positive discrimination at best. Models had best discriminative ability for a definition of insignificant disease characterized by organ-confined Gleason score ⩽6 with a total volume ⩽0.5 ml or 1.3 ml. Calibration plots showed moderate range of predictive ability for the Kattan model though this model did not perform well at decision curve analysis. CONCLUSIONS: External assessment of models predicting insignificant PCa showed moderate performance at best. Uninformed interpretation may cause undue anxiety or false reassurance and they should be used with caution.

Learning clinical procedures through Internet visual resources: a qualitative study amongst undergraduate students.

OBJECTIVE: Acquiring competency in performing clinical procedures is central to professional education of healthcare providers. Internet visual resources (IVR), defined as visual materials openly accessible on public websites, provides a new channel to learn clinical procedures. This qualitative study aimed to profile the experience and opinions of undergraduate students (in dentistry, medicine and nursing) in learning clinical procedures through IVR. METHODS: From clinical degree programmes (Bachelor of Dental Surgery, Bachelor of Medicine, Bachelor of Surgery, and Bachelor of Nursing) of University of Hong Kong, 31 students were recruited to join six focus group discussions, which were transcribed and subjected to thematic analysis using inductive method, in which themes emerge from data. FINDINGS: Students actively looked for IVRs through various means and used them for pre-clinical preparation, post-clinical revision, learning simple and advanced procedures, exploring alternative and updated techniques, and benchmarking against international peers. IVRs were valued for their visual stimulation, inclusion of a wide variety of real-life cases, convenience in access, user-friendliness and time-saving features. Students tended to share and discuss IVRs with their peers rather than with tutors, even when contents deviated from school teaching or faculty's e-learning materials. When doubts persisted, they chose to follow faculty guidelines for examination purpose. Students were frustrated sometimes by difficulties in judging the scientific quality, lack of immediate interactive discussions and loosely structured presentations in some IVRs. Teachers' attitudes towards IVR appeared to vary greatly. CONCLUSION: Despite the wide spectrum of experience and opinions, IVR was generally viewed by undergraduates from across clinical faculties as enhancing their clinical confidence and self-perceived competency, enriching their learning experience and serving as an important supplement to formal learning in the planned curriculum.

Diagnostic prostate biopsy performed in a non-academic center increases the risk of re-classification at confirmatory biopsy for men considering active surveillance for prostate cancer.

BACKGROUND: To examine whether diagnostic biopsy (B1), for patients on active surveillance (AS) for prostate cancer, performed at an outside referral centre (external) compared with our in-house tertiary center (internal), increased the risk of re-classification on the second (confirmatory) biopsy (B2). METHODS: Patients on AS were identified from our tertiary center database (1997-2012) with PSA<10, Gleason sum (GS) ⩽6, clinical stage ⩽cT2, ⩽3 positive cores, <50% of single core involved, age ⩽75 years and having a B2. Patients who had <10 cores at B1 and delay in B2 >24 mo were excluded. Depending on center where B1 was performed, men were dichotomized to internal or external groups. All B2 were performed internally. Multivariate logistic regression examined if external B1 was a predictor of re-classification at B2. RESULTS: A total of 375 patients were divided into external (n=71, 18.9%) and internal groups (n=304, 81.1%). At B2, more men in the external group re-classified (26.8%) compared with the internal group (13.8%) (P=0.008). On multivariate analysis, external B1 predicted grade-related re-classification (odds ratio (OR) 4.14, confidence interval (CI) 2.01-8.54, P<0.001) and volume-related re-classification (OR 3.43, CI 1.87-6.25, P<0.001). Other significant predictors for grade-related re-classification were age (OR 2.13 per decade, CI 1.32-3.57, P<0.001), PSA density (OR 2.56 per unit, CI 1.44-4.73, P<0.001), maximum % core involvement (OR 1.04 per percentage point, CI 1.01-1.09, P=0.02) and time between B1 and B2 (OR 1.43 per 6 months, CI 1.21-1.71, P<0.001). CONCLUSION: At our institution, patients on AS who had their initial B1 performed externally were more likely to have adverse pathological features and re-classify on internal B2.

Accessing cancer services in North West England: the Chinese population.

Relatively few Chinese patients access tertiary cancer services in North West England. We investigated the reasons behind this using a culturally sensitive questionnaire. The questionnaire, completed by 214 Chinese people in English, Cantonese or Mandarin, evaluated the Chinese population's access and satisfaction with primary care, understanding of cancer and awareness of local cancer services. Ninety-five per cent of respondents were registered with a general practitioner (GP) and 75% had accessed primary care in the last year. Satisfaction with GP consultations was high but a third of respondents reported a lack of confidence in local National Health Service (NHS) services. Only 57% of eligible women had attended cervical screening programmes. The overall understanding of the causes and treatment of cancer and cancer services in the North West was poor. Despite registration with primary healthcare, the Chinese population under-utilise cancer prevention programmes and tertiary cancer services because of a lack of awareness and understanding of cancer services in the North West. A significant proportion of the population is dissatisfied with the perceived slow service and lack confidence in services, with 41% considering using healthcare abroad. These data highlight the critical need to engage with, educate and support the Chinese population if they are to access NHS cancer services.

Should follow-up biopsies for men on active surveillance for prostate cancer be restricted to limited templates?

OBJECTIVE: To investigate if prostate biopsy templates with fewer cores can be used during active surveillance (AS) for prostate cancer. METHODS: At present, we use an AS protocol template (ASPT) consisting of 13-17 cores. We hypothesize in the setting of known cancer, sextant (6 cores) or standard extended (10-12 cores) templates, could be used with similar effect. We identified patients in our referral institution database (1997-2009) with entry prostate-specific antigen <10 ng/mL, stage ≤cT2, Gleason sum ≤6, ≤3 cores positive for cancer, <50% of single core involved, and age ≤75 years (N = 272). Patients fulfilling standard criteria for pathologic reclassification (N = 94) at any follow-up biopsy were selected for evaluation. By mapping tumor location on the pathologic reclassification determining biopsy, hypothetical scenarios of sextant or standard extended templates (SET) were compared with our ASPT and examined for frequency of cancer detection and pathologic reclassification. RESULTS: For the 94 patients analyzed, the median number of cores taken was 9.7 (6-22) at baseline and 15 (14-17) for the reclassification biopsy. The median time between baseline and the pathologic reclassification determining biopsy was 15.4 months. Analysis of subgroupings showed that sextant template would identify 84% of cancers and 47.9% of the reclassification events, whereas SET detected 99% of cancers and 81.9% of patients who pathologically reclassified. When only considering Gleason sum ≥7 related progression events, SET found 16.2% less (n = 57) compared with ASPT (n = 68). CONCLUSION: When monitoring patients on AS, a 13-17 core template detects more pathologic reclassification than standard sextant (18.1%) or extended (52.1%) biopsy templates.

International multicentre study examining selection criteria for active surveillance in men undergoing radical prostatectomy.

BACKGROUND: The controversies concerning possible overtreatment of prostate cancer, highlighted by debate over PSA screening, have highlighted active surveillance (AS) as an alternative management option for appropriate men. Regional differences in the underlying prevalence of PSA testing may alter the pre-test probability for high-risk disease, which can potentially interfere with the performance of selection criteria for AS. In a multicentre study from three different countries, we examine men who were initially suitable for AS according to the Toronto and Prostate Cancer Research International: Active Surveillance (PRIAS) criteria, that underwent radical prostatectomy (RP) in regards to:1.the proportion of pathological reclassification(Gleason score ≥7, ≥pT3 disease),2.predictors of high-risk disease,3.create a predictive model to assist with selection of men suitable for AS. METHODS: From three centres in the United Kingdom, Canada and Australia, data on men who underwent RP were retrospectively reviewed (n=2329). Multivariable logistic regression was performed to identify predictors of high-risk disease. A nomogram was generated by logistic regression analysis, and performance characterised by receiver operating characteristic curves. RESULTS: For men suitable for AS according to the Toronto (n=800) and PRIAS (410) criteria, the rates for upgrading were 50.6, 42.7%, and upstaging 17.6, 12.4%, respectively. Significant predictors of high-risk disease were:•Toronto criteria: increasing age, cT2 disease, centre of diagnosis and number of positive cores.•PRIAS criteria: increasing PSA and cT2 disease.Cambridge had a high pT3a rate (26 vs 12%). To assist selection of men in the United Kingdom for AS, from the Cambridge data, we generated a nomogram predicting high-risk features in patients who meet the Toronto criteria (AUC of 0.72). CONCLUSION: The proportion of pathological reclassification in our cohort was higher than previously reported. Care must be used when applying the AS criteria generated from one population to another. With more stringent selection criteria, there is less reclassification but also fewer men who may benefit from AS.

Ultrafast insulator­metal phase transition in vanadium dioxide studied using optical pump­terahertz probe spectroscopy.

We studied the ultrafast dynamic behavior of the photoinduced insulator­metal phase transition in VO2 thin film using optical pump­terahertz probe spectroscopy with different excitation fluences and at different temperatures. We observed two processes in the insulator­metal phase transition in VO2: a fast process and a slow process. The fast process is a nonthermal process, which is ascribed to the nucleation of the metal phase, while the slow process is strongly affected by temperature and is ascribed to the thermally driven growth and coalescence of metal domains in VO2. The transient complex conductivity spectra at different delay times are also investigated.

Enhancement of bandgap emission of Pt-capped MgZnO films: important role of light extraction versus exciton-plasmon coupling.

We present on a systematic study of the contribution of surface plasmon (SP) coupling and light extraction toward emission enhancement of Platinum (Pt) nano-patterns capped MgZnO films. Time resolved Photoluminescence (PL) results indicate that the Pt coating can greatly reduces the non-radiative recombination rate by passivation of surface states, making the decay slow down. Temperature dependence of the integrated photoluminescence intensity reveals that the Pt nano-patterns can offer a large amount of light transfer and scattering, which enormously increase the light extraction efficiency up to 3.8-fold. These results indicate that the increased light extraction efficiency caused by surface modification via Pt coating rather than SP coupling plays a dominant role in increasing bandgap emission of MgZnO film.

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.

Prevention of nosocomial transmission of swine-origin pandemic influenza virus A/H1N1 by infection control bundle.

After the outbreak of severe acute respiratory syndrome in Hong Kong, the importance of preventing nosocomial transmission of respiratory viruses has become a top priority in infection control. During the containment and early mitigation phases of the swine-origin influenza virus (S-OIV) A H1N1 pandemic, an infection control bundle consisting of multiple coherent measures was organised by our infection control team to minimise nosocomial transmission. This included repeated open staff forum achieving high attendance; early recognition of index cases among inpatients by liberal testing; early relief of sick staff from work; directly observed hand hygiene practice during outbreaks; and monitoring of compliance with infection control practice. During the first 100 days (from 1 May to 8 August 2009) when the first 100 laboratory-confirmed patients with S-OIV and 12 infected healthcare workers (HCWs) were identified, a total of 836 asymptomatic exposed persons (184 patients and 652 HCWs) were required to undergo a seven-day medical surveillance. The infection control nurses monitored them for the onset of symptoms. Four (0.48%) exposed persons (one house officer, two non-clinical staff, and one patient) were virologically confirmed with S-OIV. Not wearing a surgical mask either by the exposed persons during contact with the index cases (4/4 vs 264/832, P=0.010) or vice versa (4/4 vs 300/832, P=0.017, Fisher's exact test) were found to be significant risk factors for nosocomial acquisition of S-OIV.

Heterostructures of germanium nanowires and germanium-silicon oxide nanotubes and growth mechanisms.

We report on a method to fabricate one-dimensional heterostructures of germanium nanowires (GeNWs) and germanium-silicon oxide nanotubes (GeSiO(x)NTs). The synthesis of the wire-tube heterostructures is carried out using a simple furnace set-up with germanium tetraiodide and germanium powders as growth precursors, gold-dotted silicon wafers as substrates and by controlling the temperature ramp rate/sequence of the growth precursors. Two types of wire-tube heterostructures resulting from distinct growth mechanisms are obtained. The type-1 heterostructure consists of a GeNW, grown via a gold-catalyzed vapour-liquid-solid process, at the lower end and a GeSiO(x)NT at the upper end. In contrast, the type-2 heterostructure is made up of a solid wire at the upper end and a hollow tube at the lower end. The solid wire portion of the type-2 heterostructure is formed through an oxide-assisted growth process.

Morphology-controlled synthesis and a comparative study of the physical properties of SnO2 nanostructures: from ultrathin nanowires to ultrawide nanobelts.

Controlled synthesis of one-dimensional materials, such as nanowires and nanobelts, is of vital importance for achieving the desired properties and fabricating functional devices. We report a systematic investigation of the vapor transport growth of one-dimensional SnO(2) nanostructures, aiming to achieve precise morphology control. SnO(2) nanowires are obtained when SnO(2) mixed with graphite is used as the source material; adding TiO(2) into the source reliably leads to the formation of nanobelts. Ti-induced modification of crystal surface energy is proposed to be the origin of the morphology change. In addition, control of the lateral dimensions of both SnO(2) nanowires (from approximately 15 to approximately 115 nm in diameter) and nanobelts (from approximately 30 nm to approximately 2 microm in width) is achieved by adjusting the growth conditions. The physical properties of SnO(2) nanowires and nanobelts are further characterized and compared using room temperature photoluminescence, resonant Raman scattering, and field emission measurements.

Massive occult haemoperitoneum following spontaneous rupture of duodenal gastrointestinal stromal tumour.

Gastrointestinal stromal tumours are an uncommon subset of mesenchymal tumour that can occur anywhere along the gastrointestinal tract. Diagnosis of gastrointestinal stromal tumours is often difficult, as presentation is variable. This case report identifies massive haemoperitoneum as an initial finding, which is an unusual mode of presentation in gastrointestinal stromal tumours.

Allele frequencies and haplotypes of 12 Y-STR loci for the local Chinese population in Hong Kong.

Haplotype frequencies were established for 12 Y-chromosome STR loci, including all loci recommended by Scientific Working Group on DNA Analysis Methods Y-STR Subcommittee (DYS391, DYS389I/II, DYS439, DYS393, DYS390, DYS385a/b, DYS438, DYS19 and DYS392) plus DYS437, in the local Chinese population in Hong Kong. In a sample of 481 unrelated males, it was possible to define 424 different haplotypes of which 388 were unique, 26 was found in two individuals, 2 were shared in three individuals, 5 were shared in four individuals and 3 were shared in five individuals. The allele diversity values for each locus ranged from 0.4273 (DYS438) to 0.9555 (DYS385a/b). The observed haplotype diversity value and discrimination capacity were 0.9992 and 0.8815, respectively. In a genetic study of these unrelated males, triple alleles were found at the DYS358 locus in six individuals. The combined Y-chromosome STR polymorphisms provide a powerful discrimination tool for routine forensic applications.

Glycerol kinase deficiency presenting with hypodipsia, osmotic diuresis and severe hypernatraemia.

A Chinese boy with glycerol kinase deficiency is reported. His presentation with severe hypernatraemia secondary to hypodipsia and glycerol-induced osmotic diuresis is unusual and not previously described in the literature.

Changes in heart rate and R-wave amplitude with posture.

BACKGROUND: Effect of gravity on heart rate and blood pressure are well documented but the effect of posture on R-wave amplitude has not been studied. AIM: To investigate the effect of posture on the heart rate (HR) and R-wave amplitude (RWA). METHODS: The electrocardiograph (ECG) was recorded in 20 young subjects on two occasions. A 5 minute recording of resting ECG was taken with the subject adopting the following postural cycle: lying, sitting, standing, sitting and lying positions. RESULTS: The standing HR was significantly higher than that in sitting and lying positions, but the RWA was significantly lower in standing compared to the sitting and lying postures. The HR significantly increased at the initial phase of postural changes, irrespective of the position. For example, the HR increased from lying to sitting (66.6+/-2.3 to 85.0+/-10.9 beat x min(-1)) but also increased when changed from sitting to lying (70.6+/-10.6 to 85.2+/-8.7 beat x min(-1)). CONCLUSION: Body posture has an effect on HR and RWA. The changes are probably related to orthostatic haemodynamic stress as well as changes in cardiac electrical axis. Whether the cause of the initial increase in the HR during postural change was attributed to skeletal muscle reflex or venous return requires further investigation.

Childhood thrombocytopenia associated with Graves disease is distinct from idiopathic thrombocytopenic purpura.

The authors report a case of thrombocytopenia in a 10-year-old Chinese girl who was also found to have Graves disease 6 months later. The clinical, hematologic, and bone marrow features were indistinguishable from chronic idiopathic thrombocytopenic purpura, but the patient's platelet counts were normalized concurrently with the control of thyrotoxicosis with carbimazole treatment. Childhood thrombocytopenia associated with autoimmune thyroid disease is a rarely reported condition and its management differs from that of idiopathic thrombocytopenic purpura.

STR data for the PowerPlex 16 loci for the Chinese population in Hong Kong.

Allele frequencies for the 15 STR loci included in the PowerPlex 16 kit were obtained from a sample of 247 unrelated Chinese in Hong Kong.

Surgical infections in patients with chronic renal failure.

Patients with chronic renal failure and uremia have impaired host defenses and wound healing that can lead to an increased risk of infection in addition to a frequent need for surgical procedures with synthetic grafts and catheters. Antibiotic therapy plus timely surgical intervention in removal of infected grafts and catheters is crucial for infection control and patient survival. Other surgical infections, such as wound problems, intraabdominal infections, fungal infections, diabetic foot ulcers, and necrotizing soft tissue infections must be attended to promptly.