Primary splenic hodgkin lymphoma masquerading as splenic abscess.

Hodgkin lymphoma is a form of malignant lymphoid neoplasm. It can have various clinical presentations such as prolonged fever, night sweats, weight loss and asymptomatic lymphadenopathy. It has a distinct fever pattern known as Pel Ebstein fever. However, in some instances, its clinical presentation can mimic some tropical infections. Here, we present a case of primary splenic lymphoma masquerading as splenic abscess in a 53-yearold man with underlying dyslipidemia.

Montreal Cognitive Assessment - Single Cutoff Achieves Screening Purpose.

BACKGROUND AND PURPOSE: The study evaluated the performance between norm-derived age and education adjusted vs single cutoff scores of the Montreal Cognitive Assessment, Hong Kong version (HK-MoCA) in classifying cognitive impairment in Chinese older adults. METHODS: Total scores of HK-MoCA were collected from 315 subjects (128 with dementia, 122 with mild cognitive impairment (MCI) and 65 normal) attending a public district hospital-based cognition clinic from 2012 to 2017. The HK-MoCA total scores were evaluated using different cutoffs. Norm-derived age and education adjusted cutoff scores were at 16th, 7th, and 2nd percentiles. Comparison was made with the single cutoff scores validated in a local study with 21/22 for MCI and 18/19 for dementia. RESULTS: Single cutoff score of HK-MoCA differentiated MCI from normal with sensitivity of 0.861 and specificity of 0.723. To detect dementia, its sensitivity was 0.922, and specificity was 0.923. In identifying cognitive impairment, the sensitivity and specificity were 0.932 and 0.723, respectively. However, age and education adjusted cutoff scores achieved high specificities at all levels of cognitive impairment with trade-off of sensitivities. The accuracy of correctly classifying tested subjects into appropriate groups was 85.3% if single cutoff was used though the consistency between norm-derived cutoffs and expert diagnoses were only 59.0%, 54.2%, and 53.9% at 16th, 7th, and 2nd percentiles, respectively. The consistency decreased with older age and lower education level, and majority of misclassifications were false negatives. CONCLUSION: HK-MoCA is a convenient screening tool to detect cognitive impairment. Administration time is relatively short, and it has incorporated essential cognitive domains. Single cutoff scores with inherent simple education adjustment achieved screening purpose of mild cognitive impairment and dementia in Chinese older adults.

Urgent Liver Transplantation for Dietary Supplements: An Under-Recognized Problem.

BACKGROUND: The recent outbreak of acute liver failure caused by herbal/dietary supplements (HDS) in Hawaii prompted evaluation of those patients who underwent emergency liver transplantation (LT) for HDS in the United States. METHODS: We queried the Scientific Registry of Transplant Recipients (2003-2015) to identify patients who underwent urgent LT for acute hepatic necrosis (AHN) and identified those with HDS use. This group of patients was then characterized. RESULTS: Of 2408 adult cases, 625 were characterized as a drug-induced liver injury. The majority of cases (n = 300) were due to acetaminophen toxicity, but the fourth highest category was due to HDS (n = 21). Of these 21 cases caused by HDS, 13 did not list the specific agent responsible, mean age was 36 years, and all cases occurred after 2007. There probably are more cases because 25% of all LT cases in the study did not list a specific reason for liver failure and 20% of all drug-induced liver failure did not list a specific drug. CONCLUSIONS: Herbal/supplement use is the fourth most common cause of drug-induced AHN requiring LT, albeit an underestimation of the problem. Detailed questioning of patients and their support systems regarding herbal/supplement use and better reporting are imperative to further define this problem and identify products that have the potential to lead to liver failure.

Sodium-ion diffusion mechanisms in the low cost high voltage cathode material Na(2+δ)Fe(2-δ/2)(SO4)3.

Bond-valence site energy modelling, classical molecular dynamics and DFT simulations were employed to clarify Na(+) ion migration in monoclinic Na2+δFe2-δ/2(SO4)3, the recently reported first representative of a new promising class of alluaudite-type high voltage cathode materials for sodium-ion batteries. Empirical potential parameters derived from our softBV bond valence parameter set reproduce experimental unit-cell parameters. Migration energy barrier calculations based on both these empirical and on ab initio approaches consistently show a strongly anisotropic and fairly fast Na(+) ion mobility along partially occupied Na(3) channels in the c-direction. Nominally fully occupied Na(1) sites are attached to these paths with a moderate activation energy as sources of mobile ions. At elevated temperatures separate parallel Na(2) channels contribute to the ionic conductivity. As such one-dimensional pathways are highly vulnerable to blocking by structural defects, the experimentally observed favourable rate performance can only be understood as a consequence of cross-linking of the channels to a more robust higher-dimensional migration pathway network. Our static and dynamic bond valence pathway models for representative local structure models reveal that this cross-linking is achieved by the iron deficiency of the compound: iron vacancies act as low-lying interstitial sites that can be reached from both types of channels with moderate activation energies. Structural relaxations around the vacancies however reduce the sodium mobility along the channels. An analogous dual effect of blocking migration along the channels and promoting perpendicular migration would result from Na(+)/Fe(2+) antisite defects. Hence, further new alluaudite type transition metal sulphates can only be expected to yield a high rate performance, if their synthesis ensures the presence of a comparable transition metal sub-stoichiometry and/or a suitably tailored concentration of sodium/transition metal antisite defects.

A validation study of the Hong Kong version of Montreal Cognitive Assessment (HK-MoCA) in Chinese older adults in Hong Kong.

OBJECTIVE: To validate the Hong Kong version of Montreal Cognitive Assessment (HK-MoCA) in identification of mild cognitive impairment and dementia in Chinese older adults. DESIGN: Cross-sectional study. SETTING: Cognition clinic and memory clinic of a public hospital in Hong Kong. PARTICIPANTS: A total of 272 participants (dementia, n=130; mild cognitive impairment, n=93; normal controls, n=49) aged 60 years or above were assessed using HK-MoCA. The HK-MoCA scores were validated against expert diagnosis according to the Diagnostic and Statistical Manual of Mental Disorders (4th ed) criteria for dementia and Petersen's criteria for mild cognitive impairment. Statistical analysis was performed using receiver operating characteristic curve and regression analyses. Additionally, comparison was made with the Cantonese version of Mini-Mental State Examination and Global Deterioration Scale. RESULTS: The optimal cutoff score for the HK-MoCA to differentiate cognitive impaired persons (mild cognitive impairment and dementia) from normal controls was 21/22 after adjustment of education level, giving a sensitivity of 0.928, specificity of 0.735, and area under the curve of 0.920. Moreover, the cutoff to detect mild cognitive impairment was 21/22 with a sensitivity of 0.828, specificity of 0.735, and area under the curve of 0.847. Score of the Cantonese version of the Mini-Mental State Examination to detect mild cognitive impairment was 26/27 with a sensitivity of 0.785, specificity of 0.816, and area under the curve of 0.857. At the optimal cutoff of 18/19, HK-MoCA identified dementia from controls with a sensitivity of 0.923, specificity of 0.918, and area under the curve of 0.971. CONCLUSION: The HK-MoCA is a useful cognitive screening instrument for use in Chinese older adults in Hong Kong. A score of less than 22 should prompt further diagnostic assessment. It has comparable sensitivity with the Cantonese version of Mini-Mental State Examination for detection of mild cognitive impairment. It is brief and feasible to conduct in the clinical setting, and can be completed in less than 15 minutes. Thus, HK-MoCA provides an attractive alternative screening instrument to Mini-Mental State Examination which has ceiling effect (ie may fail to detect mild/moderate cognitive impairment in people with high education level or premorbid intelligence) and needs to be purchased due to copyright issues.

Pancreatic resections in renal failure patients: is it worth the risk?

Background. Chronic kidney disease affects 20 million US patients, with nearly 600,000 on dialysis. Long-term survival is limited and the risk of complex pancreatic surgery in this group is questionable. Previous studies are limited to case reports and small case series and a large database may help determine the true risk of pancreatic surgery in this population. Methods. The American College of Surgeons National Surgical Quality Improvement Program database was queried (2005-2011) for patients who underwent pancreatic resection. Renal failure was defined as the clinical condition associated with rapid, steadily increasing azotemia (rise in BUN) and increasing creatinine above 3 mg/dL. Operative trends and short-term outcomes were reviewed for those with and without renal failure (RF). Results. In 18,533 patients, 28 had RF. There was no difference in wound infections, neurologic or cardiovascular complications. Compared to non-RF patients, those with RF had more unplanned intubation (OR 4.89, 95% CI 1.85-12.89), bleeding requiring transfusion (OR 3.12, 95% CI 1.37-14.21), septic shock (OR 8.86, 95% CI 3.75-20.91), higher 30-day mortality (21.4% versus 2.3%, P < 0.001) and longer hospital stay (23 versus 12 days, P < 0.001). Conclusions. RF patients have much higher morbidity and mortality after pancreatic resections and surgeons should consider this before proceeding.

Fracture-induced subbandgap absorption as a precursor to optical damage on fused silica surfaces.

The optical damage threshold of indentation-induced flaws on fused silica surfaces was explored. Mechanical flaws were characterized by laser damage testing, as well as by optical, secondary electron, and photoluminescence microscopy. Localized polishing, chemical leaching, and the control of indentation morphology were used to isolate the structural features that limit optical damage. A thin defect layer on fracture surfaces, including those smaller than the wavelength of visible light, was found to be the dominant source of laser damage initiation during illumination with 355 nm, 3 ns laser pulses. Little evidence was found that either displaced or densified material or fluence intensification plays a significant role in optical damage at fluences >35 J/cm(2). Elimination of the defect layer was shown to increase the overall damage performance of fused silica optics.

Structural information from orientationally selective DEER spectroscopy.

Double electron-electron resonance (DEER) spectroscopy can determine, from measurement of the dipolar interaction, the distance and orientation between two paramagnetic centres in systems lacking long-range order such as powders or frozen solution samples. In spin systems with considerable anisotropy, the microwave pulses excite only a fraction of the electron paramagnetic resonance (EPR) spectrum and the resulting orientation selection needs to be explicitly taken into account if a meaningful distance and orientation is to be determined. Here, a general method is presented to analyze the dipolar interaction between two paramagnetic spin centres from a series of DEER traces recorded so that different orientations of the spin-spin vector are sampled. Delocalised spin density distributions and spin projection factors (as for example in iron-sulfur clusters), are explicitly included. Application of the analysis to a spin-labelled flavoprotein reductase/reduced iron-sulfur ferredoxin protein complex and a bi-radical with two Cu(ii) ions provides distance and orientation information between the radical centres. In the protein complex this enables the protein-protein binding geometry to be defined. Experimentally, orientationally selective DEER measurements are possible on paramagnetic systems where the resonator bandwidth allows the frequencies of pump and detection pulses to be separated sufficiently to excite enough orientations to define adequately the spin-spin vector.

Calamine lotion: mimicking intramammary calcifications.

Detection of microcalcifications is important in detecting early breast cancer. We present a case of screening mammogram in which calamine lotion mimics intramammary calcifications.

Patients' complaints in a hospital emergency department in Singapore.

INTRODUCTION: This study analysed the complaint rates, profile and trend, and complainant profile of patients' complaints received by the National University Hospital Emergency Medicine Department. An earlier ten-year study (1986-1995) was done on the complaint profile. METHODS: Records of all patients' complaints, solicited and unsolicited, from January 2002 to December 2003, were retrieved from the Medical Affairs and Quality Improvement Unit files. Complaint profile analysed was reason, validity, and outcome of complaint and staff category involved. Complainant profile analysed was relationship of complainant to patient, ethnic group, gender and residence type of the complainant; and age group and triage category of the patient. RESULTS: Complaint case rate was 1.17 per 1,000 visits, with 1.27 complaints per complaint case. The complaints were organisation/logistics (49.0 percent), communication (26.0 percent), standard of care (22.9 percent) and other issues (1.3 percent). Most standard of care (76.0 percent) and half of organisation/logistics complaints (46.8 percent) were not valid. Most communication complaints were valid (73.7 percent) and involved all staff categories equally. Most complaints (82.8 percent) were resolved with an explanation/apology. Age group specific and triage-specific complaint rates were highest among adult patients and among priority 3 patients, respectively; ethnic group and gender-specific complaint rates were highest among Chinese patients and among female patients, respectively. CONCLUSION: Staff-patient communication and organisation/logistics must be continually improved to reduce complaints, while upholding a good standard of care. These would translate into cost savings for all parties. There must also be appropriate checks and balances particularly where complaints are not valid, so that doctors can practice cost-effective medicine.

Isolation of Laribacter hongkongensis, a novel bacterium associated with gastroenteritis, from drinking water reservoirs in Hong Kong.

AIMS: Freshwater fish has been found to be the reservoir of Laribacter hongkongensis, a recently discovered bacterium associated with community-acquired gastroenteritis. However, little is known about the ecology of this bacterium in the aquatic environment. We carried out a surveillance study to investigate the presence of L. hongkongensis in water and freshwater fish from 10 drinking water reservoirs in Hong Kong. METHODS AND RESULTS: Using membrane filtration, L. hongkongensis was isolated from the waters of six reservoirs, with numbers ranging from 1 to 12 CFU l(-1). Higher recovery rates were observed in summer and during days of higher water and ambient temperatures. Of 27 freshwater fish collected from the reservoirs, L. hongkongensis was recovered from the intestines of two fish, a Goldfish and a Nile tilapia. Overall, 35 different pulsed-field gel electrophoresis patterns are found among the 59 isolates recovered from water and the two isolates from freshwater fish. CONCLUSIONS: The present report represents the first to demonstrate the presence of L. hongkongensis in natural water environments. SIGNIFICANCE AND IMPACT OF THE STUDY: Although it is unlikely that treated, drinking water is an important source of L. hongkongensis-associated gastroenteritis, one should be aware of the possibility of other contaminated water as a source of human infection.

Local recurrence of parosteal osteosarcoma adjacent to a prosthesis after 20 years: a case report.

We describe the treatment of an uncommonly late presentation of a recurrent parosteal osteosarcoma of the distal femur. The osteosarcoma had originally been detected 20 years earlier, and had been treated with wide excision and mega-prosthesis to reconstruct the femur. The tumour recurred in close proximity to the femur prosthesis and encased half the femoral stem. Because there was a large piece of metal at the site of recurrence, which might have interfered with computed tomography and magnetic resonance imaging, ultrasonography was used to locate the lesion. The tumour was successfully treated with wide local re-excision. This case emphasises the importance of the long-term follow-up of patients with parosteal osteosarcoma.

Oriented immobilization of Pseudomonas putida putidaredoxin at a gold (111)-buffer interface: a real time scanning tunnelling microscopy study.

A scanning tunnelling microscopy study of adsorption of wild-type Pseudomonas putida putidaredoxin at a gold (111)-buffer interface has been made in real time. Reversible adsorption has been observed reflecting weak interaction of the wild-type protein with a gold (111) electrode. A genetically engineered mutant, C73S-D58C, which contains a surface thiol, has been used for 'immobilization' and 'orientated adsorption' on the gold surface. The implication of such orientated immobilization in development of a bio-electrode surface has been predicted.

Engineering substrate recognition in catalysis by cytochrome P450cam.

We have a continuing interest in applying the current knowledge of cytochrome P450cam substrate recognition to engineer the enzyme for the biotransformation of unnatural substrates with the long-term aim of applications in the synthesis of fine chemicals and bioremediation of environmental contaminants. Comparisons of the structure of target substrates with that of camphor, the natural substrate, led to the design of active-site mutants with greatly enhanced activity for the oxidation of chlorinated benzenes and selectivity of (+)-alpha-pinene oxidation. The crystal structures of the F87W/Y96F/V247L mutant with 1,3,5-trichlorobenzene or (+)-alpha-pinene bound have revealed the enzyme-substrate contacts and provided insights into the activity and selectivity patterns. The structures have also provided a novel basis for further engineering of P450cam for increased activity in the oxidation of the highly inert pentachlorobenzene and hexachlorobenzene, and increased selectivity of (+)-alpha-pinene oxidation.

Are hearing and middle ear statuses at risk in Chinese patients undergoing orthognathic surgery?

Orthognathic surgery, which is performed to correct dentofacial abnormalities, has been associated with postoperative reduction in hearing sensitivity and middle ear dysfunction. In this study, the pre- and postoperative hearing status and middle ear function of 37 Chinese subjects who underwent orthognathic surgery, as well as subjective reports of aural symptoms, particularly hearing loss, tinnitus, fullness and otalgia, were investigated. There was a significant increase in the number of subjects with measured loss, perceived loss and aural fullness from pre-surgery to 1 week post surgery. However, the percentage of increase was small compared with previous findings. This difference in findings was attributed to the type of surgical techniques used, and to the fact that the Chinese population appears to be less susceptible to middle ear effusion. Subjective complaints of aural symptoms may not be accompanied by measured loss.

Refinement of facial reconstructive surgery by stereo-model planning.

The development of rapid prototyping has evolved from crude milled models to laser polymerized stereolithographic models of excellent accuracy. The technology was advanced further with the recent introduction of fused deposition modelling and a three-dimensional ink-jet printing technique in stereo-model fabrication. The concept of using a three-dimensional model in planning the operation has amazed maxillofacial surgeons since its first application in grafting a skull defect in 1995. It was followed by many bright ideas for applications in the field of facial reconstructive surgery. Stereo-models may assist in diagnosis of facial fractures, joint ankylosis and even impacted teeth. The surgery can be simulated prior the operation of complex craniofacial syndromes, facial asymmetry and distraction osteogenesis. The stereo-model can be used for preparation of reconstructive plate or joint prostheses. It is of enormous value for educational teaching and as a patient information tool when obtaining the consent for surgery.

Engineering the CYP101 system for in vivo oxidation of unnatural substrates.

The protein engineering of CYP enzymes for structure-activity studies and the oxidation of unnatural substrates for biotechnological applications will be greatly facilitated by the availability of functional, whole-cell systems for substrate oxidation. We report the construction of a tricistronic plasmid that expresses the CYP101 monooxygenase from Pseudomonas putida, and its physiological electron transfer co-factor proteins putidaredoxin reductase and putidaredoxin in Escherichia coli, giving a functional in vivo catalytic system. Wild-type CYP101 expressed in this system efficiently transforms camphor to 5-exo-hydroxycamphor without further oxidation to 5-oxo-camphor until >95% of camphor has been consumed. CYP101 mutants with increased activity for the oxidation of diphenylmethane (the Y96F-I395G mutant), styrene and ethylbenzene (the Y96F-V247L mutant) have been engineered. In particular, the Y96F-V247L mutant shows coupling efficiency of approximately 60% for styrene and ethylbenzene oxidation, with substrate oxidation rates of approximately 100/min. Escherichia coli cells transformed with tricistronic plasmids expressing these mutants readily gave 100-mg quantities of 4-hydroxydiphenylmethane and 1-phenylethanol in 24-72 h. This new in vivo system can be used for preparative scale reactions for product characterization, and will greatly facilitate directed evolution of the CYP101 enzyme for enhanced activity and selectivity of substrate oxidation.