Upper Respiratory Tract Infection Trends in a Psychiatric Institute in Singapore.

OBJECTIVES: To compare the incidence of upper respiratory tract infection (URTI) between inpatients at the Institute of Mental Health in Singapore and the general population over 8 years to determine the effectiveness of our infection control strategies. METHODS: Data for cases of influenza and URTI at our institute between January 2012 and December 2019 were collected. National data were derived from weekly infectious disease bulletins that report daily averages of people attending polyclinics/surgeries with influenza and URTI. Interrupted time series analyses were used to determine the impact of infection prevention and control strategies on incidence. RESULTS: Over the 8 years, there were 1607 cases of URTI involving 182 clusters, equal to 3.16 cases per 10 000 patient-bed-days. 965 (60%) cases and 95 (52%) clusters occurred in long-stay wards, whereas 642 (40%) cases and 87 (48%) clusters occurred in acute wards. The median cluster size was 12 in the long-stay wards and 7 in the acute wards (p < 0.0001). The spikes in cases in June and December may be attributed to the increased staff and visitor mobility during school vacations in June and December. Strategies implemented during the study period did not significantly reduce the incidence of URTI. Previous strategies implemented in 2005 to meet accreditation standards are more likely to be contributors. CONCLUSION: Infection control strategies of our institute appear to be effective, because the incidence of URTI was lower in our institute than in the community. The similar incidence of URTI in acute and long-stay wards indicates that service-user turnover is not a contributor. Rather, staff and visitors are more likely to be the vector. The larger clusters in long-stay wards indicates a greater risk of transmission in such settings. Increased activity in our institute during school vacations may be associated with an increase in cases in June and December. It is difficult to determine if strategies implemented during the study period successfully reduce the incidence of URTI.

Pitfalls of International Classification of Diseases - Perinatal mortality in analysing stillbirths.

OBJECTIVES: This study aimed to evaluate the trend of stillbirth from 2009 to 2018. The causes of stillbirth were classified using the International Classification of Diseases - Perinatal Mortality (ICD-PM). STUDY DESIGN AND METHODS: A retrospective chart review was performed on 135 stillbirths from 2009 to 2018 in a tertiary university teaching hospital. The annual stillbirth rate was calculated, and the trend was evaluated. The cause of death was reclassified using ICD-PM. RESULTS: The stillbirth rate was 3.70 per 1000 total births, and it remained stable over the studied period (P = 0.238). Most of the stillbirth (97.8%) were antepartum deaths. The proportion of unexplained stillbirth was reduced from 57% to 18.5% after reclassified by ICD-PM coding. Another major cause of antepartum stillbirths was disorders related to fetal growth, which consisted of mothers with medical and surgical conditions (11%, n = 15, ICD-PM code A5, M4) or mothers with complications of placenta, cord and membranes (8.9%, n = 12, ICD-PM code A5, M1). CONCLUSION: The use of ICD-PM was useful in reducing the proportion of unexplained stillbirths. ICD-PM has the advantages of coding related to the timing of stillbirth and associated maternal conditions. Pitfalls including the unclear use of the code A3-'antepartum hypoxia,' guidance on coding of well-controlled maternal medical conditions and placental pathology and the importance of subcategorisation need to be addressed.

MHD simulation of supersonic FRC merging corrected by non-invasive magnetic measurements.

In this study, a newly developed correction method with external magnetic measurements for the magnetohydrodynamics (MHD) simulation of the collisional merging formation of a field-reversed configuration (FRC) realized the estimation of the internal structure of the FRCs without invasive internal measurements. In the collisional merging formation of FRCs, an FRC is formed via merging of two initial FRC-like plasmoids at supersonic/Alfvénic velocity. An invasive diagnostic may also interfere with the collisional merging formation process. A two-dimensional resistive MHD simulation was conducted to evaluate the global behavior and internal structure of FRCs in the collisional merging formation process without invasive measurements. This code simulated the initial formation and collisional merging processes of FRCs including discharge circuits. However, the translation velocity and the pressure of initial FRCs did not simultaneously agree with the experimental values because the magnetic pressure gradient in each formation region could not be reproduced without the artificial adjustment of the initial condition. The experimentally measured current distribution was given as the initial condition of the circuit calculation in the developed correction method. The initial FRCs were successfully translated at the translation velocity and plasma pressure in the corrected simulation, both of which were equivalent to the experiments. The properties of the merged FRCs in the experiments such as volume, total temperature, and average electron density were reproduced in the corrected simulation. The detailed radial profile of the internal magnetic field of the FRC was also measured and found to agree very well with the simulation results.

Diabetes mellitus and tuberculosis in Korean adults: impact on tuberculosis incidence, recurrence and mortality.

The prevalence of diabetes mellitus (DM) worldwide is increasing markedly, and many countries with rising rates also have a high incidence rate of tuberculosis (TB). To investigate the relationships of fasting serum glucose (FSG) and DM with TB incidence, recurrence and mortality risk in a prospective cohort study in South Korea. Our study comprised 1 267 564 Koreans who received health insurance from the National Health Insurance System, had an initial medical evaluation between 1997 and 2000 and were prospectively followed biennially. Participants with DM had a higher risk for incident TB (hazard ratio [HR] 1.81, 95%CI 1.71-1.91 in males, HR 1.33; 95%CI 1.20-1.47 in females) than those without DM. There was a strong positive trend for TB risk with rising FSG among males. The risk for recurrent TB among those with previous TB was significantly higher in males (HR 1.58, 95%CI 1.43-1.75) and in females with DM (HR 1.38, 95%CI 1.08-1.76). The increased risk of death from TB during follow-up was also significant in men (HR 1.91, 95%CI 1.87-1.95) and in women (HR 1.71, 95%CI 1.65-1.77). A diagnosis of DM is a risk factor for TB, TB recurrence and death from TB. Screening for TB should be considered among people living with DM in Korea, particularly those with severe DM. .

Internal magnetic field measurements of translated and merged field-reversed configuration plasmas in the FAT-CM device.

Field-reversed configuration (FRC) Amplification via Translation-Collisional Merging (FAT-CM) experiments have recently commenced to study physics phenomena of colliding and merged FRC plasma states. Two independently formed FRCs are translated into the confinement region of the FAT-CM device, collided near the mid-plane of the device with a relative speed of up to ∼400 km/s, and a final merged FRC plasma state is achieved. To measure internal magnetic field profiles of the translated and merged FRC plasmas as well as to understand its collisional-merging process, an internal magnetic probe array, developed by TAE Technologies, has been installed in the mid-plane of the FAT-CM device. Initial magnetic field measurements indicate that both the translated and the merged FRC plasma states exhibit a clear field-reversed structure, which is qualitatively in good agreement with 2D MHD simulation. It is found and verified that a sufficient mirror field in the confinement region is required for colliding FRCs to be fully merged into a single FRC plasma state.

Inference of field reversed configuration topology and dynamics during Alfvenic transients.

Active control of field reversed configuration (FRC) devices requires a method to determine the flux surface geometry and dynamic properties of the plasma during both transient and steady-state conditions. The current tomography (CT) method uses Bayesian inference to determine the plasma current density distribution using both the information from magnetic measurements and a physics model in the prior. Here we show that, from the inferred current sources, the FRC topology and its axial stability properties are readily obtained. When Gaussian process priors are used and the forward model is linear, the CT solution involves non-iterative matrix operations and is then ideally suited for deterministic real-time applications. Because no equilibrium assumptions are used in this case, inference of plasma topology and dynamics up to Alfvenic frequencies then becomes possible. Inference results for the C-2U device exhibit self-consistency of motions and forces during Alfvenic transients, as well as good agreement with plasma imaging diagnostics.

CT features in surgically proven cases of ovarian torsion-a pictorial review.

Ovarian torsion is a surgical emergency characterized by a partial or complete rotation of the ovarian vascular pedicle, causing obstruction to venous outflow followed by arterial inflow. Clinically, ovarian torsion frequently mimics other causes of acute pelvic pain such as appendicitis, diverticulitis, renal colic etc. Ultrasonography is the first-line imaging modality of choice for evaluation of ovarian torsion. MRI is useful as a problem-solving tool in patients with equivocal or non-diagnostic ultrasonography studies. CT is ordinarily not utilized in a young female with suspected ovarian torsion due to the radiation dose. However, the significant expansion in use of CT imaging in emergency departments for female patients presenting with acute abdominal pain has increased the likelihood that ovarian torsion may be first seen on CT. In addition, a non-specific clinical presentation may lead to an initial imaging with CT rather than ultrasonography. Ultrasound features of the ovarian torsion are well known and sufficiently described across literature as compared with the CT scan findings. In view of the increasing usage of CT as the modality of choice in emergency settings, it is imperative for the radiologist to familiarize with the CT features of ovarian torsion. An early correct diagnosis by the radiologist in clinically unsuspected cases, facilitating a prompt surgery to restore the ovarian blood flow can prevent permanent irreversible damage. There is limited published data available on the CT features of ovarian torsion. This pictorial essay illustrates CT findings with histological correlation of surgically proven ovarian torsion in our institution. These patients were primarily investigated with CT scan for acute pelvic pain ascribed to non-gynaecological causes such as bowel or urinary tract lesions.

Cytomorphological changes induced by intraperitoneal chemotherapy present important diagnostic pitfalls in peritoneal fluid cytology.

OBJECTIVE: Intraperitoneal chemotherapy (IP ChT) is an emerging modality in the treatment of advanced gastric adenocarcinoma with peritoneal disease. Cytological evaluation of peritoneal fluid specimens from patients undergoing IP ChT is important in clinical management. However, direct intraperitoneal exposure to chemotherapeutic agents induces cytomorphological changes in benign constituents of peritoneal fluid, presenting particular challenges to accurate cytological interpretation. These morphological changes have not been well characterised in the literature. We systematically reviewed the cytomorphological features in immunocytochemically-confirmed positive and negative IP ChT peritoneal fluid samples to elucidate the degree of morphological overlap between malignant and reactive cells. METHODS: We reviewed 39 peritoneal fluid samples of patients treated with IP ChT, and scored specific cytomorphological parameters of both benign and malignant cells with the aid of relevant immunocytochemical interrogation. RESULTS: The present findings show a significant degree of morphological overlap between reactive and malignant cells. Abnormal, "exploding" mitotic figures, nuclear membrane irregularities, multi-nucleation and cytoplasmic vacuolation were commonly observed in negative fluid specimens. The most helpful feature that favoured malignant cells was the increased nuclear-to-cytoplasmic ratio. A background inflammatory milieu of eosinophils and/or neutrophils was seen in 45-58% of post IP ChT peritoneal fluid specimens. The presence of pseudoparakeratotic cells, a novel observation in post IP ChT fluid specimens is also described. CONCLUSIONS: The extent of reactive cytomorphological anomalies arising from treatment with IP ChT poses unique diagnostic challenges and may prompt a malignant or 'atypical' diagnosis in benign reactive samples.

Papular angiolymphoid hyperplasia and lymphoplasmacytic plaque: a clinical and histological spectrum.

Acral pseudolymphomatous angiokeratoma of children (APACHE) is a rare form of cutaneous pseudolymphoma characterized byangiomatous papules with a predilection for the acral regions of children. Classically, a dense dermal lymphocytic infiltrate composed of both T and B cells is seen in histological specimens, together with prominent vessels lined by plump endothelial cells. Increasing evidence suggests that this condition is neither necessarily acral, pseudolymphomatous, nor angiokeratomatous. It may not always be a pediatric disease. Therefore, the correctness of its nomenclature has been questioned. Herein, we report threecases whose clinical and histological features were consistent with the diagnosis of APACHE. To our knowledge, this is the first report of APACHE from Southeast Asia. We also discuss why we believe "APACHE" to be a misnomer and support "papular angiolymphoid hyperplasia" as a more accurate and encompassing term. In addition, we illustrate a case with significant overlapping features with lymphoplasmacytic plaque in children, suggesting that both entities may exist on a clinical andhistological spectrum.

Do we need transbronchial lung biopsy if we have bronchoalveolar lavage Xpert® MTB/RIF?

BACKGROUND: Studies evaluating the role of transbronchial lung biopsy (TBLB) in diagnosing pulmonary tuberculosis (PTB) date back decades and have shaped current practice. However, with the recent advent of bronchoalveolar lavage (BAL) Xpert® MTB/RIF, it is time to re-evaluate the role of TBLB. OBJECTIVE: To assess the impact of BAL and TBLB with the addition of BAL Xpert on diagnostic PTB yields and time to treatment initiation in sputum-scarce or acid-fast bacilli (AFB) smear-negative PTB patients. METHODS: We retrospectively reviewed all sputum-scarce or AFB smear-negative patients who underwent both BAL and TBLB for suspected PTB between March 2011 and October 2013. Xpert was performed on all BAL specimens. RESULTS: Of 158 patients included in our analysis, 44 were culture-proven PTB. Ninety-four per cent of the patients had AFB smear-negative BAL samples. The sensitivity and specificity of Xpert in AFB smear-negative BAL samples were respectively 60% and 98%. The addition of BAL Xpert expedited the institution of PTB treatment while having diagnostic yields comparable to those of conventional BAL with TBLB. CONCLUSIONS: The use of BAL Xpert may obviate the need for TBLB in increasing the diagnostic yield of PTB in sputum-scarce or AFB smear-negative patients.

Safety of transorally-inserted anvil for esophagojejunostomy in laparoscopic total gastrectomy.

BACKGROUND: To assess the safety of transorally-inserted anvil (TOA) for use during esophagojejunostomy (EJ) reconstruction during laparoscopic total gastrectomy (LTG). METHODS: Between March 2009 and December 2011, 39 consecutive open total gastrectomies (OTGs) and 36 LTGs using TOA for gastric cancer were comparatively evaluated. We investigated postoperative complications, using the Clavien-Dindo classification. To evaluate the effect of a learning period in using TOA for LTG, we also investigated shifts in the patterns of complications and changes in total operation time over the course of the study. RESULTS: The patient characteristics at baseline were not different between both groups, except for the extent of lymphadenectomy (P < 0.001) and depth of tumor invasion (P = 0.003). Multivariate analysis revealed that TOA usage elevated the occurrence of infectious complications significantly (OR = 3.32, P = 0.042), but was not associated with EJ-related complications. TOA usage did not need a learning period for the length of time required to complete the operation, or the likelihood of developing an EJ-related or infectious complication. CONCLUSIONS: TOA use for EJ during LTG is relatively simple and easy enough not to require a learning period for surgeons. This procedure did not elevated the occurrence of EJ-related complications compared to circular stapling in open surgery, but it does require special prevention efforts to avoid infectious complications.

Field reversed configuration confinement enhancement through edge biasing and neutral beam injection.

Field reversed configurations (FRCs) with high confinement are obtained in the C-2 device by combining plasma gun edge biasing and neutral beam injection. The plasma gun creates an inward radial electric field that counters the usual FRC spin-up. The n = 2 rotational instability is stabilized without applying quadrupole magnetic fields. The FRCs are nearly axisymmetric, which enables fast ion confinement. The plasma gun also produces E × B shear in the FRC edge layer, which may explain the observed improved particle transport. The FRC confinement times are improved by factors 2 to 4, and the plasma lifetimes are extended from 1 to up to 4 ms.

Decomposition of trifluoromethane in a dielectric barrier discharge non-thermal plasma reactor.

The decomposition of trifluoromethane (CHF3) was carried out using non-thermal plasma generated in a dielectric barrier discharge (DBD) reactor. The effects of reactor temperature, electric power, initial concentration and oxygen content were examined. The DBD reactor was able to completely destroy CHF3 with alumina beads as a packing material. The decomposition efficiency increased with increasing electric power and reactor temperature. The destruction of CHF3 gradually increased with the addition of O2 up to 2%, but further increase in the oxygen content led to a decrease in the decomposition efficiency. The degradation pathways were explained with the identified by-products. The main by-products from CHF3 were found to be COF2, CF4, CO2 and CO although the COF2 and CF4 disappeared when the plasma were combined with alumina catalyst.

Ministry of Health clinical practice guidelines: bipolar disorder.

The Ministry of Health (MOH) has published clinical practice guidelines on Bipolar Disorder to provide doctors and patients in Singapore with evidence-based guidance on the management of bipolar disorders. This article reproduces the introduction and executive summary (with recommendations from the guidelines) from the MOH clinical practice guidelines on Bipolar Disorder, for the information of readers of the Singapore Medical Journal. Chapters and page numbers mentioned in the reproduced extract refer to the full text of the guidelines, which are available from the Ministry of Health website: http: //www.moh.gov.sg/content/moh_web/home/Publications/guidelines/clinical_practiceguidelines/2011/bipolar_disorder.html. The recommendations should be used with reference to the full text of the guidelines. Following this article are multiple choice questions based on the full text of the guidelines.

Dynamic formation of a hot field reversed configuration with improved confinement by supersonic merging of two colliding high-ß compact toroids.

A hot stable field-reversed configuration (FRC) has been produced in the C-2 experiment by colliding and merging two high-ß plasmoids preformed by the dynamic version of field-reversed θ-pinch technology. The merging process exhibits the highest poloidal flux amplification obtained in a magnetic confinement system (over tenfold increase). Most of the kinetic energy is converted into thermal energy with total temperature (T{i}+T{e}) exceeding 0.5 keV. The final FRC state exhibits a record FRC lifetime with flux confinement approaching classical values. These findings should have significant implications for fusion research and the physics of magnetic reconnection.

Hydrogen sulphide is pro-inflammatory in haemorrhagic shock.

OBJECTIVE: H(2)S is pro-inflammatory in inflammatory models, thus we investigated whether H(2)S plays a role in haemorrhagic shock (HS)-associated inflammation. METHODS: Male, Sprague-Dawley rats were given an inhibitor of H(2)S biosynthesis, DL-propargylglycine (PAG, 50 mg/kg, i. v.) or saline (1 ml/kg) 30 min before blood withdrawal and subjected to HS (mean arterial pressure (MAP) of 40 mM Hg for 90 min) followed by reinfusion of shed blood. Animals were killed at 5, 90, 270 and 630 min after reinfusion. RESULTS: Pre-treatment of animals with PAG 1) increased the HR recovery rate (n = 6 - 12, P < 0.05); 2) attenuated the increase in plasma levels of TNF-alpha and IL-6 and reduced lung iNOS expression levels (n =5 P, < 0.05); and 3) attenuated the increase in plasma levels of ALT and reduced HS-induced increase in liver and lung myeloperoxidase (MPO) activity (n = 5, P < 0.05). CONCLUSIONS: H(2)S is pro-inflammatory in HS and inhibition of H(2)S biosynthesis may reduce some HS-induced inflammatory responses and organ injury.

Decomposition of hydrofluorocarbons in a dielectric-packed plasma reactor.

This study investigated the decomposition of hydrofluorocarbons (HFCs) having high global warming potentials by using a dielectric-packed-bed nonthermal plasma reactor with barium titanate beads as the packing material. The target HFCs were 1,1,1,2-tetrafluoroethane (HFC-134a) and 1,1-difluoroethene (HFC-132a). The effects of several parameters such as reaction temperature, oxygen content, and initial concentration on the HFC decomposition efficiency were evaluated. There was essentially no temperature dependence of the HFC decomposition efficiency in the range 150-250 degrees C. The optimum oxygen content for HFC decomposition was found to be about 0.5 vol %. Variations in the initial concentration did not affect the decomposition efficiency. The decomposition products were analyzed, and some decomposition pathways were elucidated. The energy requirements for the decomposition of HFC-134a and HFC-132a were found to be 0.038 and 0.062 mol MJ-1, respectively, based on the initial concentrations of 200 and 120 ppm (parts per million, volumetric).

Transabdominal ultrasound assessment of the fetal head and the accuracy of vacuum cup application.

OBJECTIVE: To investigate whether the accuracy of vacuum cup placement can be improved by intrapartum ultrasound assessment of the fetal head position during the second stage of labor prior to vacuum extraction for prolonged second stage. METHODS: 50 women undergoing vacuum extraction for prolonged second stage were randomly allocated to either digital examination (n=25) or digital examination together with transabdominal intrapartum ultrasound (n=25) prior to vacuum extraction by the attending obstetrician. The distance between the centre of the chignon and the flexion point was then measured by a midwife immediately after delivery. The flexion point was defined as 6 cm posterior to the anterior fontanelle or 3 cm anterior to the posterior fontanelle. RESULTS: There were no statistically significant differences in the demographic data, duration of labor, incidence of induction/augmentation, and intrapartum complications between the two groups. The mean distance between the centre of the chignon and the flexion point was 2.1+/-1.3 cm in the group with digital examination and ultrasound assessment and 2.8+/-1.0 cm in the group with digital examination alone. The difference in the mean distance between the two groups was statistically significant (p=0.039). CONCLUSION: Intrapartum transabdominal ultrasound assessment of the fetal head position during the second stage of labor improves the accuracy of vacuum cup placement during vacuum extraction for prolonged second stage.