Climate velocities and species tracking in global mountain regions

Mountain ranges contain high concentrations of endemic species and are indispensable refugia for lowland species that are facing anthropogenic climate change1,2. Forecasting biodiversity redistribution hinges on assessing whether species can track shifting isotherms as the climate warms3,4. However, a global analysis of the velocities of isotherm shifts along elevation gradients is hindered by the scarcity of weather stations in mountainous regions5. Here we address this issue by mapping the lapse rate of temperature (LRT) across mountain regions globally, both by using satellite data (SLRT) and by using the laws of thermodynamics to account for water vapour6 (that is, the moist adiabatic lapse rate (MALRT)). By dividing the rate of surface warming from 1971 to 2020 by either the SLRT or the MALRT, we provide maps of vertical isotherm shift velocities. We identify 17 mountain regions with exceptionally high vertical isotherm shift velocities (greater than 11.67 m per year for the SLRT; greater than 8.25 m per year for the MALRT), predominantly in dry areas but also in wet regions with shallow lapse rates; for example, northern Sumatra, the Brazilian highlands and southern Africa. By linking these velocities to the velocities of species range shifts, we report instances of close tracking in mountains with lower climate velocities. However, many species lag behind, suggesting that range shift dynamics would persist even if we managed to curb climate-change trajectories. Our findings are key for devising global conservation strategies, particularly in the 17 high-velocity mountain regions that we have identified.

A global phylogeny of butterflies reveals their evolutionary history, ancestral hosts and biogeographic origins

Butterflies are a diverse and charismatic insect group that are thought to have evolved with plants and dispersed throughout the world in response to key geological events. However, these hypotheses have not been extensively tested because a comprehensive phylogenetic framework and datasets for butterfly larval hosts and global distributions are lacking. We sequenced 391 genes from nearly 2,300 butterfly species, sampled from 90 countries and 28 specimen collections, to reconstruct a new phylogenomic tree of butterflies representing 92% of all genera. Our phylogeny has strong support for nearly all nodes and demonstrates that at least 36 butterfly tribes require reclassification. Divergence time analyses imply an origin ~100 million years ago for butterflies and indicate that all but one family were present before the K/Pg extinction event. We aggregated larval host datasets and global distribution records and found that butterflies are likely to have first fed on Fabaceae and originated in what is now the Americas. Soon after the Cretaceous Thermal Maximum, butterflies crossed Beringia and diversified in the Palaeotropics. Our results also reveal that most butterfly species are specialists that feed on only one larval host plant family. However, generalist butterflies that consume two or more plant families usually feed on closely related plants.

A high-throughput multispectral imaging system for museum specimens

We present an economical imaging system with integrated hardware and software to capture multispectral images of Lepidoptera with high efficiency. This method facilitates the comparison of colors and shapes among species at fine and broad taxonomic scales and may be adapted for other insect orders with greater three-dimensionality. Our system can image both the dorsal and ventral sides of pinned specimens. Together with our processing pipeline, the descriptive data can be used to systematically investigate multispectral colors and shapes based on full-wing reconstruction and a universally applicable ground plan that objectively quantifies wing patterns for species with different wing shapes (including tails) and venation systems. Basic morphological measurements, such as body length, thorax width, and antenna size are automatically generated. This system can increase exponentially the amount and quality of trait data extracted from museum specimens.

The use of fly ashes from waste-to-energy processes as mineral CO2 sequesters and supplementary cementitious materials

This study explores the simultaneous application of fly ash (FA) generated from the thermal treatment of municipal solid waste as a CO₂ sequester through aqueous mineral carbonation and as a supplementary cementitious material (SCM) for the development of green construction materials. Two types of FAs are tested, namely an incineration fly ash (IFA) collected from electrostatic precipitator of an incineration plant and a gasification fly ash (GFA) collected from air pollution control unit of a high temperature slagging gasification waste-to-energy (WTE) plant. Ground waste glass (GWG) is used as a tertiary SCM. GFA demonstrates favorable sequestration capacity (87.5 mg/g) and high carbonation degree (74.1 %) while the IFA is found to be inactive during carbonation (3.1 mg/g, 4.6 %). Mortars blended with the wastes have shown delay in the cement hydration but eventually achieve compressive strength comparable to the control specimen. The mixing of GWG and GFA synergistically improves the performance of mortars which highlights the importance of strategic coupling of different waste streams. Most of the hazardous heavy metals, chloride and sulfate in FAs were stabilized in the mortars suggesting the potential for safe re-utilization of carbonated FAs as sustainable SCMs to concurrently close the waste loop and combat climate change.

Kinetics and modeling of trace metal leaching from bottom ashes dominated by diffusion or advection

Leaching kinetics of trace metals from incineration bottom ashes (IBA) under diffusion and advection were investigated through leaching tests of compacted granulars of IBAs and their packed columns with seawater eluent for 64 days and 26 days, respectively. Metal fluxes were distinct among species while linearily decreased at log-log scales as a function of time. Short-term environmental risks for Cu, Ni and Pb were identified under advection. The metal leaching behavior generally followed the pseudo-second order under diffusion, while the pseudo-first order kinetics under advection. Investigated metals may be further identified as diffusion- (As, Cd, Cr, Sb) and advection-dominant species (Ba, Cu, Ni, Pb, Zn) according to their fluxes, which interestingly corresponded to the low- (5.19-147.90 mg·kg^-1) and high-value (116.46-2398.44 mg·kg^-1) of their metal distribution from IBAs, respectively. Considering the general higher metal release, decay models were employed to simulate the column leaching results. Particularly, Type-II model based on two-site assumptions fit much better to the experimental data, unveiling significant yet retarded release (in 1-2 pore volumes) of certain metals from the slow-reaction sites. Further investigation on the release of bulk parameters unveiled that, there existed rebounded leaching rates primarily ascribed to the IBA heterogeneity.

Human exposure and risk assessment of recycling incineration bottom ash for land reclamation: A showcase coupling studies of leachability, transport modeling and bioaccumulation

Incineration bottom ash (IBA) faces challenges for its sustainable recycling due to the absence of scenario-specific risk assessment. Environmental risk assessment was carried out via a case study incorporating key factors to dominate human exposures during IBA utilization in land reclamation. Three research components echoing respective IBA leaching, exposures, and consequences were performed under a supportive framework to elaborate these interlinked key factors and unveil the potential environmental risks. IBA leachability was firstly investigated using various laboratory standard leaching methods while conducted a large-scale field trial experiment for mutual confirmation, suggesting that maximum leached amounts may be achieved when liquid to solid (L/S) ratio increases to 10. Dilution and transportation models were both developed to discriminate the mitigation of IBA leachate between two periods i.e. during and after land reclamation, suggesting that dilution rather than transportation may dominate the environmental impact for metal exposures. Metal bioaccumulation from a typical mollusk species was performed coupling the calculated dietary safety limits based on Singaporean diet intake for development of the threshold of toxicology concerns on human exposures. With such, IBA benign usage in land reclamation was also conferred in the form of distance and dilution factor.

Comparison and modeling of leachate transportation dominated by the field permeability with an anisotropic characteristic based on a large-scale field trial study

Permeability significantly affects leachate transportation. Yet, there often exists a gap for its measurements between laboratory and the field. To predict the fate and transport of heavy metals from IBA leaching, a large-scale field trial study was performed using a big column (d × h = 3 m × 5.5 m) packed with 1-m thickness of IBA (approx. 10.6 tons) overlaid by 4-m sand layer. The determined field permeability (k_F) was compared with that achieved from the laboratory, demonstrating a large disparity as much as 4 orders of magnitude likely due to IBA self-compaction. Indeed, back calculation using Blake-Kozeny's equation unveiled that, the "effective" diameters were significantly reduced by 21-46%. k_F also demonstrated an anisotropic characteristic associated with fingered flows, trapped bubbles and heterogeneous consolidation/cementation efficiencies. To quantify the effects by k_F, we ran a mechanistic model to simulate the transport of 11 heavy metals under advection (d_h/d_x  = 0.05 m/m), indicating dramatically prolonged breakthrough time from days to centuries. Interestingly, breakthrough time was comparable among various metal ions (0-16.6% of RSD), suggesting their synchronous movements. Metal flux under k_F was predicted in the end to address its toxicity potential, demonstrating limited environmental impacts in presence of the USEPA criterion.

Vertical distribution of heavy metals in seawater column during IBA construction in land reclamation - Re-exploration of a large-scale field trial experiment

Data from large-scale field trial experiments simulating the application of incineration bottom ash (IBA) for land reclamation were re-explored, to understand the spot-specific leaching characteristics and re-adsorption of heavy metals associated with various reclamation scenarios. Data showed that IBA leaching changed significantly as a function of seawater depth rather than time. The application of a chute had a minor effect on the total metal leached amounts; however, it would magnify the gradient of leaching concentrations across depths. Metal re-adsorption occurred within half an hour after IBA dumping, which however was significantly alleviated when a chute was applied. It may be ascribed to various degrees of contact with seawater of IBA, seawater movements and particle resuspension. Batch leaching tests from the laboratory under different L/S ratios were conducted as the references to "effective" leaching behaviors in the large-scale experiments, suggesting that the batch leaching test with the liquid to solid ratio = 10 provide a closer estimation of IBA leaching concentrations during land reclamation. As the current study took account of major field factors during land reclamation, including seawater depth (m), IBA loading (ton), IBA dropping method, particle dispersive area (m²), and settling time (min), these findings are valuable for the risk assessment of IBA utilization in land reclamation.

A large-scale field trial experiment to derive effective release of heavy metals from incineration bottom ashes during construction in land reclamation

Recycling of incineration bottom ashes (IBA) is attracting great interest as it is considered as a vital aspect for closing the waste loop to achieve sustainable development at the growing cities around the world. Various laboratory-testing methods are developed to assess the release potential of heavy metals - one of the most important concerns of using IBA, by reflecting the release conditions of heavy metals from IBA based on the targeted land reclamation application scenarios and corresponding environmental conditions. However, realistic release of the concerned elements in actual application with the presence of complex environment could possibly deviate from the outcomes produced by leaching tests carried out in the laboratory. Hence, a set of large-scale column trial experiments was performed to experimentally determine the effective release of heavy metals, when IBA is used as a filling material in land reclamation. 20 tons of IBA and 320 m³ of seawater were used in six column trial experiments. The release of 13 heavy metal elements was analyzed through multiple aspects which included kinetics of release, distribution of elements in seawater and the impacts of two different dumping methods, with and without application of a chute. After dumping of IBA into the seawater, almost instantaneous release of heavy metals with uniform horizontal dispersion was observed. Higher concentration of these elements was observed near the bottom of the column, especially when a chute was applied. Comparative analysis was then carried out to establish relationships between the results obtained from the column trial with batch leaching test carried out in the laboratory. Distinctive relationships were observed for different heavy metals which suggests the need of pursuance of further understanding on leaching of IBA in real application scenario and complex environment.

The first pilot study of expanded newborn screening for inborn errors of metabolism and survey of related knowledge and opinions of health care professionals in Hong Kong

INTRODUCTION

Newborn screening is important for early diagnosis and effective treatment of inborn errors of metabolism (IEM). In response to a 2008 coroners' report of a 14-year-old boy who died of an undiagnosed IEM, the OPathPaed service model was proposed. In the present study, we investigated the feasibility of the OPathPaed model for delivering expanded newborn screening in Hong Kong. In addition, health care professionals were surveyed on their knowledge and opinions of newborn screening for IEM.

METHODS

The present prospective study involving three regional hospitals was conducted in phases, from 1 October 2012 to 31 August 2014. The 10 steps of the OPathPaed model were evaluated: parental education, consent, sampling, sample dispatch, dried blood spot preparation and testing, reporting, recall and counselling, confirmation test, treatment and monitoring, and cost-benefit analysis. A fully automated online extraction system for dried blood spot analysis was also evaluated. A questionnaire was distributed to 430 health care professionals by convenience sampling.

RESULTS

In total, 2440 neonates were recruited for newborn screening; no true-positive cases were found. Completed questionnaires were received from 210 respondents. Health care professionals supported implementation of an expanded newborn screening for IEM. In addition, there is a substantial need of more education for health care professionals. The majority of respondents supported implementing the expanded newborn screening for IEM immediately or within 3 years.

CONCLUSION

The feasibility of OPathPaed model has been confirmed. It is significant and timely that when this pilot study was completed, a government-led initiative to study the feasibility of newborn screening for IEM in the public health care system on a larger scale was announced in the Hong Kong Special Administrative Region Chief Executive Policy Address of 2015.

Statistical comparison of leaching behavior of incineration bottom ash using seawater and deionized water: Significant findings based on several leaching methods

Bottom ashes generated from municipal solid waste incineration have gained increasing popularity as alternative construction materials, however, they contains elevated heavy metals posing a challenge for its free usage. Different leaching methods are developed to quantify leaching potential of incineration bottom ashes meanwhile guide its environmentally friendly application. Yet, there are diverse IBA applications while the in situ environment is always complicated, challenging its legislation. In this study, leaching tests were conveyed using batch and column leaching methods with seawater as opposed to deionized water, to unveil the metal leaching potential of IBA subjected to salty environment, which is commonly encountered when using IBA in land reclamation yet not well understood. Statistical analysis for different leaching methods suggested disparate performance between seawater and deionized water primarily ascribed to ionic strength. Impacts of leachant are metal-specific dependent on leaching methods and have a function of intrinsic characteristics of incineration bottom ashes. Leaching performances were further compared on additional perspectives, e.g. leaching approach and liquid to solid ratio, indicating sophisticated leaching potentials dominated by combined geochemistry. It is necessary to develop application-oriented leaching methods with corresponding leaching criteria to preclude discriminations between different applications, e.g., terrestrial applications vs. land reclamation.

Prospective assessment of the Hong Kong Hospital Authority universal Down syndrome screening programme

OBJECTIVE

To evaluate the performance of the locally developed universal Down syndrome screening programme.

DESIGN

Population-based cohort study in the period July 2010 to June 2011 inclusive.

SETTING

Four Hong Kong Hospital Authority Departments of Obstetrics and Gynaecology and a central university-based laboratory for maternal serum processing and risk determination.

PARTICIPANTS

Women were offered either a first-trimester combined test (nuchal translucency, free beta human chorionic gonadotropin, and pregnancy-associated plasma protein-A) or nuchal-translucency-only test, or a second-trimester double test (alpha-fetoprotein and total human chorionic gonadotropin) for detection of Down syndrome according to their gestational age. Those with a trisomy 21 term risk of 1:250 or higher were offered a diagnostic test.

RESULTS

A total of 16 205 pregnancies were screened of which 13 331 (82.3%) had a first-trimester combined test, 125 (0.8%) had a nuchal-translucency test only, and 2749 (17.0%) had a second-trimester double test. There were 38 pregnancies affected by Down syndrome. The first-trimester screening tests had a 91.2% (31/34) detection rate with a screen-positive rate of 5.1% (690/13 456). The second-trimester test had a 100% (4/4) detection rate with a screen-positive rate of 6.3% (172/2749). There were seven (0.9%) pregnancies that miscarried following an invasive diagnostic test. There were two Down syndrome-affected live births, both with an estimated first-trimester trisomy 21 term risk lower than 1:250.

CONCLUSION

The universal screening programme offered at the four units was effective and achieved the expected detection rates and low false-positive rates, and to maintain these, the current emphasis on training, quality control, and regular auditing must continue.

Evaluation of family-centred practices in the early intervention programmes for infants and young children in Singapore with Measure of Processes of Care for Service Providers and Measure of Beliefs about Participation in Family-Centred Service

BACKGROUND

The primary purpose of this study was to report on an evaluation of the perceptions and beliefs of service providers towards family-centred practices in 11 early intervention programmes for infants and young children in Singapore.

METHODS

The Measure of Processes of Care for Service Providers (MPOC-SP) and Measure of Beliefs about Participation in Family-Centred Service (MBP-FCS) were administered to 213 service providers made up of teachers, therapists, psychologists and social workers providing centre-based therapy to children with special needs who were below the age of 6 years.

RESULTS

Exploratory factor analyses were performed with both scales. Nineteen of the 27 MPOC-SP items were retained and supported the original four-factor structure model. The exploratory factor analyses on MBP-FCS provided a less satisfactory outcome. Fourteen of the 28 items were retained and these loaded onto four factors. The two factors relating to Beliefs about benefits of FCS and Beliefs about the absence of negative outcomes from FCS failed to emerge as separate factors. Further multiple regressions indicated that more direct work with families and positive self-efficacy in implementing FCS contributed significantly to explaining service providers' positive perception towards family-centred practice in service delivery.

CONCLUSIONS

This is the first time MPOC-SP and MBP-FCS were administered to a population in an Asian context. While MBP-FCS would benefit from further development work on its construct, MPOC-SP offered important insights into service providers' perspectives about family-centred practices that would have useful implications for professional and service development.

Brain infarction as the initial presentation of primary posterior mediastinal seminoma

A 40-year-old man was admitted with acute onset of slurred speech and right hemiparesis. Cerebral infarction was diagnosed from magnetic resonance (MR) images. Chest X-ray incidentally revealed a posterior mediastinal tumour, which proved to be seminoma on CT-guided biopsy. The patient then received chemotherapy. Five months later, right upper limb weakness and slurred speech occurred again. Brain MR images revealed two metastatic lesions in the prior infarct areas, which on histology proved to be metastatic seminoma.

Re-emergence of late presentations of fetal haemoglobin Bart's disease in Hong Kong

OBJECTIVES

To compare early and late presentations of fetal haemoglobin Bart's disease in the Kowloon West Cluster in Hong Kong, and to find reasons for the re-emergence of late presentations.

DESIGN

Case series with internal comparisons.

SETTING

Two tertiary obstetric units in Hong Kong.

PATIENTS

All cases with confirmed diagnosis of fetal haemoglobin Bart's disease from 1 January 2000 to 31 December 2009.

PRIMARY OUTCOME

antenatal care in the current pregnancy.

SECONDARY OUTCOMES

clinical presentations, ultrasound features, and pregnancy outcomes.

RESULTS

A total of 59 cases (46 early presentations and 13 late presentations) of fetal haemoglobin Bart's disease were identified during the study period. All the late presentations were identified from year 2003 onwards. Late presentations were significantly associated with non-eligible obstetric patients (69% vs 11%; P<0.001), non-booked status at our antenatal service (62% vs 0%; P<0.001), and unavailability of partner's mean corpuscular volume status (23% vs 0%; P=0.009). Mothers presenting late were more likely to have symptoms or signs (85% vs 0%; P<0.001) and to suffer from gestational hypertensive disorder (54% vs 0%; P<0.001). Ultrasound features of these pregnancies included cardiomegaly (94%), placentomegaly (98%), and hydrops fetalis (77%). All pregnancies presenting early were either legally terminated or miscarried. The perinatal mortality in late presentations was 85%.

CONCLUSION

The re-emergence of late presentations of fetal haemoglobin Bart's disease after 2003 was related to influx of non-eligible obstetric patients without proper antenatal screening and diagnosis of thalassaemia. Maternal low mean corpuscular volume and characteristic prenatal ultrasound features such as cardiomegaly, placentomegaly, and hydrops fetalis are useful for detecting affected pregnancies in this group of patients. Better education of both patients and doctors is necessary to explain the importance of early diagnosis of the disease and the seriousness of complications due to late presentations, so as to reduce undesirable maternal and perinatal outcomes.

Off-midline retroperitoneal choriocarcinoma presenting as neurologic symptoms

A 28-year-old woman suffered from frequent headaches. She had a history of a dilatation and curettage for hydatidiform moles. This admission showed markedly elevated levels of human chorionic gonadotropin (hCG) and lactate dehydrogenase. Brain MRI showed a hemorrhagic mass in the left temporal area, with rapid growth. Histology of tumors obtained from multiple areas including retroperitoneum was consistent with choriocarcinoma.

Leiomyosarcoma of ovarian vein compression as a cause of hydronephrosis

We present a case of leiomyosarcoma of the right ovarian vein with MRI findings. The patient was a 52-year-old woman who had suffered from right flank pain for one week. Abdominal ultrasound and excretory urography revealed hydronephrosis of the right kidney. Ureteroscopy showed external compression at the right upper third of the ureter. CT and MRI of the abdomen revealed a retroperitoneal mass with compression of the right ureter. The retroperitoneal mass proved on histology to be a leiomyosarcoma arising from the right ovarian vein.

Epithelioid leiomyosarcoma of the uterus: computed tomography findings

Uterine epithelioid leiomyosarcoma is a rare neoplasm. There have been no previous reports describing computed tomography (CT) findings for this tumor. A 31-year-old woman presented with a heterogeneous enhancing mass, with internal septa, in the uterus, which was shown on CT images. Histological diagnosis was compatible with epithelioid leiomyosarcoma.

Sphenoid sinus osteoma at the sella turcica associated with empty sella: CT and MR imaging findings

SUMMARY

A 50-year-old woman presented with intermittent headache for the past few years. A paranasal sinus CT scan showed a diffusely calcified lesion at the roof of the sphenoid sinus and sella turcica, with the sellar floor bony cortex involved. Empty sella was noted. MR imaging revealed a soft-tissue lesion with low signal intensity on T1-weighted images, high signal intensity on T2-weighted images, and heterogeneous enhancement on postgadolinium images. Histologic examination revealed an osteoma composed of mature lamellar bone.

Posterior epidural migration of a sequestrated lumbar disk fragment: MR imaging findings

We present a 75-year-old man who, for 2 weeks, had progressive pain in both of his thighs when standing straight. MR imaging showed a sequestrated disk fragment, which had a signal intensity similar to that of a herniated disk with a rim enhancement in the posterior epidural space and a ruptured outermost annulus of the intervertebral disk at L2-3. Awareness of these MR imaging findings can help in the diagnosis of posterior epidural disk migration.

Three-dimensional ultrasound findings of spondylocostal dysostosis in the second trimester of pregnancy

Spondylocostal dysostosis (SCD) is a rare congenital disorder that is characterized by vertebral segmentation and formation defects, and asymmetrical rib anomalies. We describe a case diagnosed during the second trimester of pregnancy with the sonographic features of abnormal alignment of the spine, hemivertebrae in the thoracic spine and kyphoscoliosis. Three-dimensional ultrasound demonstrated a 'fan-like' rib cage with fusion of the ribs. The postmortem findings confirmed the ultrasound findings and were consistent with SCD.

Intracranial epidermoid cyst with hemorrhage: MR imaging findings

We present a case of a 28-year-old woman with a cerebellopontine angle and prepontine cistern epidermoid cyst with unusual signal intensity. She presented with cranial nerve neuropathy and unsteady gait. MR imaging showed a tumor mass with central area of hemorrhage and a focal area of heterogeneous signal intensity with spotty enhancement, which correlated histologically to old blood in a cystic lumen and granulation of a cystic wall, with a large area of hemorrhage and mild vascularity.

Fully automated large-scale assessment of visceral and subcutaneous abdominal adipose tissue by magnetic resonance imaging

OBJECTIVE

To describe and evaluate a fully automated method for characterizing abdominal adipose tissue from magnetic resonance (MR) transverse body scans.

METHODS

Four MR pulse sequences were applied: SE, FLAIR, STIR, and FRFSE. On 39 subjects, each abdomen was traversed by 15 contiguous transaxial images. The total abdominal adipose tissue (TAAT) was calculated from thresholds obtained by slice histogram analysis. The same thresholds were also used in the manual volume calculation of TAAT, subcutaneous abdominal adipose tissue (SAAT) and visceral abdominal adipose tissue (VAAT). Image segmentation methods, including edge detection, mathematical morphology, and knowledge-based curve fitting, were used to automatically separate SAAT from VAAT in various 'nonstandard' cases such as those with heterogeneous magnetic fields and movement artefacts.

RESULTS

The percentage root mean squared errors of the method for SAAT and VAAT ranged from 1.0 to 2.7% for the four sequences. It took approximately 7 and 15 min to complete the 15-slice volume estimation of the three adipose tissue classes using automated and manual methods, respectively.

CONCLUSION

The results demonstrate that the proposed method is robust and accurate. Although the separation of SAAT and VAAT is not always perfect, this method could be especially helpful in dealing with large amounts of data such as in epidemiological studies.

Endometrial stromal sarcoma mimicking submucosal myoma protruding to the vagina: MRI findings

A 46-year-old woman complained of persistent abnormal vaginal bleeding over ten days. Her intrauterine device had been removed two years before. Soon after, she suffered from menorrhagia and metrorrhagia. An incidental finding of severe anemia was also noted. In this admission, our initial T2-weighted magnetic resonance imaging (MRI) revealed a well-demarcated mass predominantly in the uterine cavity. The mass was depicted by an isointense signal relative to the myometrium on T1-weighted images, high signal intensity on T2-weighted images, and slightly heterogeneous enhancement on post-contrast images. The patient refused surgery. After two years, follow-up MRI showed a pedunculated mass protruding into the upper third of the vagina with a stalk connecting to the posterior wall of the uterine cavity, simulating submucosal myoma. Histological diagnosis was compatible with low-grade endometrial stromal sarcoma.

Occupational and personal factors associated with acquired lumbar spondylolisthesis of urban taxi drivers

AIMS

To investigate the occupational and personal factors associated with lumbar spondylolisthesis in taxi drivers.

METHODS

Cross-sectional analysis of the baseline data from the Taxi Drivers' Health Study cohort. Information was retrieved from the medical records of standardised lumbosacral spine plain films, age, and anthropometric measures of 1242 subjects. Acquired spondylolisthesis (ASL) was defined as non-lytic spondylolisthesis involving lumbar spines above L5. Questionnaires were used to gather information on demographic features, health behaviours, exercise, work related physical and psychosocial factors, and driving time profiles. Multiple logistic regression was used to model the odds ratio (OR) for prevalent ASL cases associated with personal and occupational factors.

RESULTS

A total of 40 cases (3.2%) of ASL were diagnosed. Among those driving < or =5 years, 6-15 years, and >15 years, the estimated prevalence of lumbar spondylolisthesis was 1.1%, 2.4%, and 7.1% respectively. Results of multiple logistic regression suggested that taxicab driving >15 years (OR = 3.4, 95% CI 1.1 to 10.7, compared to driving < or =5 years), age (OR = 2.6, 95% CI 1.1 to 6.6 for age 46-55; and OR = 4.8, 95% CI 1.8 to 12.9 for age >55), body mass index > or =25 kg/m2 (OR = 2.2, 95% CI 1.1 to 4.6), and frequent strenuous exercise (OR = 2.2, 95% CI 1.1 to 4.5) were significantly associated with higher prevalence of spondylolisthesis. There was a consistent likely exposure-response relation between professional seniority and ASL prevalence.

CONCLUSIONS

Longitudinal studies are needed to confirm the observed association between professional driving and spondylolisthesis, and to examine further the specific occupational exposures accountable for this association.

MRI and histology of collagen template disc implantation and regeneration in rabbit temporomandibular joint: preliminary report

INTRODUCTION

We aimed to evaluate regeneration of injured temporomandibular joint (TMJ) discs following reconstituted collagen template implantation in rabbits using contrast-enhanced magnetic resonance imaging (MRI) and to correlate these findings with histology.

METHODS

Twenty-four adult rabbits were divided into five groups: group A, partial discectomy without implantation (n = 6); group B, partial discectomy with collagen template implantation (n = 6); group C, partial discectomy with subdermal graft implantation (n = 6); group D, sham operation (n = 4); and group E, control (n = 2). All rabbits received baseline MRI scans before surgery and follow-up MRI studies at 3 months after surgery. All rabbits were sacrificed for histologic analysis after the follow-up MRI.

RESULTS

In group A, follow-up MRI showed marked joint effusion in all six injured TMJs, which was accompanied by bony erosion at the tympanic fossa and mandibular condyle. In group B, MRI showed a homogenous low signal intensity in five of six discs, suggestive of regeneration. One disc showed higher signal intensity at its lateral portion than that of the original disc, indicating partial regeneration. MRI of group C depicted a low signal intensity, bandlike regenerative structure in four of the six discs. One disc with partial regeneration demonstrated relatively high signal intensity. The disc in the sixth animal of this group showed no evidence of regeneration. All of the MRI findings were in agreement with the histologic findings.

CONCLUSION

TMJ discs can regenerate following implantation of a reconstituted collagen template in discectomied rabbits. Contrast-enhanced MRI can be used to monitor and determine the degree of disc regeneration.

Evaluation of bone mineral density of the lumbar spine and proximal femur in population-based routine health examinations of healthy Asians

PURPOSE

To understand the peak bone mineral density (BMD) and annual loss of BMD of the lumbar spine (L-BMD) and the proximal femur (F-BMD) and the prevalence of osteoporosis in both sexes in Taipei City, Taiwan.

MATERIAL AND METHODS

The medical records from a recent 3-year period of annual health examinations at a single institution were reviewed. A total of 1514 men (mean age 49.08 +/- 13.62) and 1955 women (48.07 +/- 14.12), who lived in the Taipei area, had no major systemic disorders, and who had undergone both L-BMD and F-BMD examinations, were recruited.

RESULTS

In women, peak L-BMD (1.078 +/- 0.133 g/cm2) occurred in the 30 to 39-year age group, whereas peak F-BMD (0.873 +/- 0.101 g/cm2) occurred in the 17 to 29-year age group. In men, peak L-BMD (1.095 +/- 0.137 g/cm2) and F-BMD (0.989 +/- 0.140 g/cm2) both occurred in the 17 to 29-year age group. The estimated annual bone loss was 0.69% of peak L-BMD in women over 50 years; in the proximal femur this was 0.688% in women and 0.332% in men. In women over 60 years, approximately half of the population had osteoporosis in the lumbar spine.

CONCLUSION

We report descriptive BMD data of a Chinese population recruited from a Taipei urban area who underwent routine health examination. The values are similar to or higher than those of Japanese, Canadian and Greek populations. L-BMD was lower than that in the Lebanese, and F-BMD of both sexes was lower than that reported in the Greek study.

Induction of anaesthesia in the home

An intellectually impaired adult with a history of escalating violence towards hospital personnel was given an anaesthetic in his home prior to transfer to hospital for surgery. We review the implications and problems encountered, and suggest means by which such a retrieval can occur smoothly.

MRI of joint fluid in femoral head osteonecrosis

OBJECTIVE

To evaluate the relationship between joint fluid, intramedullary pressure (IMP), bone marrow edema, and stages of osteonecrosis of the femoral head (ONFH).

MATERIAL AND METHODS

We reviewed the magnetic resonance (MR) images of 28 patients with 40 documented ONFHs. IMP was measured in 16 symptomatic hips. The amount of joint fluid was graded as 0 (no fluid), 1 (fluid <5 mm in width), or 2 (fluid > or = 5 mm in width) adjacent to the entire length of the femoral neck. Associated focal and diffuse bone marrow abnormalities were evaluated. A control group of 29 recruited individuals without symptoms related to hip disease were examined. Follow-up MR images were obtained in four patients (five affected hips) 6-10 months after core decompression.

RESULTS

Of the 40 affected hips, the severity of ONFH was divided into stages 0 (n=4), I (n=28), and II (n=8 hips) on MR findings. The correlation of joint fluid to IMP and to the presence of bone marrow edema was poor. The amount of joint fluid correlated significantly with the stage of ONFH. None of the five affected hips showed decreased joint fluid on follow-up MR images.

CONCLUSION

The amount of joint fluid correlates well with the stage of ONFH. The amount of joint fluid does not correlate with IMP or bone marrow edema.

Ganglion cysts of the cruciate ligaments

PURPOSE

To evaluate the MR findings of ganglion cysts of the cruciate ligaments in correlation with clinical findings.

MATERIAL AND METHODS

We reviewed 12 patients with ganglion cysts of the cruciate ligaments obtained from a medical record of 4153 consecutive patients referred for knee MR examinations. All patients presented with chronic knee pain and 4 had restriction of knee motion. The MR imaging findings of the cysts were evaluated and correlated with clinical manifestations.

RESULTS

Seven ganglion cysts were found in the posterior cruciate ligaments and 5 in the anterior cruciate ligaments. All cysts were lobulated (n=7) or fusiform (n=5) in shape, 1.8-4.5 cm in size, along the posterior surface in the proximal or distal end of the ligaments. Ten patients had arthroscopic resection or aspiration of their cysts, became symptom free and had no recurrence on follow-up MR examinations. Two cysts reduced in size spontaneously by conservative treatment.

CONCLUSION

MR imaging can offer useful information in detection and diagnosis of patients with chronic knee pain due to ganglion cysts of the cruciate ligaments. The size and location of the ganglion cysts can attribute to the clinical manifestations.

Ganglion cysts of the cruciate ligaments

PURPOSE

To evaluate the MR findings of ganglion cysts of the cruciate ligaments in correlation with clinical findings.

MATERIAL AND METHODS

We reviewed 12 patients with ganglion cysts of the cruciate ligaments obtained from a medical record of 4153 consecutive patients referred for knee MR examinations. All patients presented with chronic knee pain and 4 had restriction of knee motion. The MR imaging findings of the cysts were evaluated and correlated with clinical manifestations.

RESULTS

Seven ganglion cysts were found in the posterior cruciate ligaments and 5 in the anterior cruciate ligaments. All cysts were lobulated (n=7) or fusiform (n=5) in shape, 1.8-4.5 cm in size, along the posterior surface in the proximal or distal end of the ligaments. Ten patients had arthroscopic resection or aspiration of their cysts, became symptom free and had no recurrence on follow-up MR examinations. Two cysts reduced in size spontaneously by conservative treatment.

CONCLUSION

MR imaging can offer useful information in detection and diagnosis of patients with chronic knee pain due to ganglion cysts of the cruciate ligaments. The size and location of the ganglion cysts can attribute to the clinical manifestations.

Determination of 8-Oxoguanine in Individual Cell Nucleus of Gamma-Irradiated Mammalian Cells

8-Oxoguanine, through its ability to mispair bases other than cytosine, is assumed to be one of the most potent premutagenic lesions in nuclear DNA damaged by reactive oxygen radicals. In this study, we examine whether the presence of residual 8-oxoguanine can be detected in mammalian cells after exposure to ionizing radiation. MOLT-4 human leukemia cells and CHO-K1 Chinese hamster cells were acutely irradiated in vitro with 0, 0.2, 0.4, 0.6 and 1.0 Gy gamma radiation at room temperature. The amounts of 8-oxoguanine and total DNA in the cell nucleus were detected by fluorescein-isothiocyanate (FITC)-labeled avidin, which binds specifically and directly to 8-oxoguanine, and propidium iodide, respectively. The intensity ratios between these two fluorescent dyes were then taken as indices to measure the content of 8-oxoguanine within individual cells. We found an apparent dose-dependent increase in the amount of 8-oxoguanine accumulated in cells of both lines. Moreover, the content of 8-oxoguanine decreased from 2 to 20 h after irradiation in CHO-K1 cells, which may reflect the time-dependent repair processes at the 8-oxoguanine lesions. This novel approach may provide a sensitive tool for in situ measurement of 8-oxoguanine in cells or even in the human body after exposure to ionizing radiation.

Dose estimation for repeated phosphorus-32 ingestion in human subjects

Dose estimation was conducted for internal phosphorus-32 exposure in one young male subject from repeated oral mis-ingestion for > 1 year. Since disclosure for previous continuous contamination, a series of urine samples were collected from this individual weekly for a period of >2 months. P-32 radioactivity in urine samples were measured by the acid precipitation method. Estimation for retrospective total effective dose equivalent received by this subject was conducted for cumulative internal dose estimation. A minimum of 9.4 mSv was estimated for an assumed single ingestion. As this was a rare case in radiation protection and internal radiation dosimetry, its implications were of considerable significance.

Regulated expression of pancreatic renin-angiotensin system in experimental pancreatitis

Our previous studies have provided evidence for the existence of an intrinsic renin-angiotensin system (RAS) in the rat pancreas, which may play a role in the regulation of pancreatic microcirculation and ductal secretion. Such a pancreatic RAS has recently shown to be activated by chronic hypoxia. The activation of a local RAS in the pancreas by chronic hypoxia and its significance of changes may be important for the physiological and pathophysiological aspects of the pancreas. In the present study, the regulation of experimentally induced acute pancreatitis on the expression of local RAS in the pancreas was investigated using Western blot, semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) and immunohistochemical approaches. Results from Western blot demonstrated that experimentally induced pancreatitis caused significantly increased expression of the pancreatic RAS component proteins. In keeping with the protein level, RT-PCR analysis also revealed the enhanced expression of pancreatic RAS genes, notably the angiotensinogen in experimental pancreatitis. Immunohistochemical results further demonstrated that increased immunoreactivity for RAS in experimental pancreatitis was predominantly localized to the endothelia and epithelia of pancreatic vasculature and ductal system respectively. The data indicate that experimental pancreatitis may elicit activation of a local RAS in the pancreas. Such an activation of pancreatic RAS and its significance of differential changes in individual RAS components could play a role in the pathophysiology of acute pancreatitis

Adhesive force of a single gecko foot-hair

Geckos are exceptional in their ability to climb rapidly up smooth vertical surfaces. Microscopy has shown that a gecko's foot has nearly five hundred thousand keratinous hairs or setae. Each 30-130 microm long seta is only one-tenth the diameter of a human hair and contains hundreds of projections terminating in 0.2-0.5 microm spatula-shaped structures. After nearly a century of anatomical description, here we report the first direct measurements of single setal force by using a two-dimensional micro-electromechanical systems force sensor and a wire as a force gauge. Measurements revealed that a seta is ten times more effective at adhesion than predicted from maximal estimates on whole animals. Adhesive force values support the hypothesis that individual seta operate by van der Waals forces. The gecko's peculiar behaviour of toe uncurling and peeling led us to discover two aspects of setal function which increase their effectiveness. A unique macroscopic orientation and preloading of the seta increased attachment force 600-fold above that of frictional measurements of the material. Suitably orientated setae reduced the forces necessary to peel the toe by simply detaching above a critical angle with the substratum.

Activation of local renin-angiotensin system by chronic hypoxia in rat pancreas

Previous studies have provided evidence that several key elements of renin-angiotensin system (RAS) are present in the rat pancreas, notably angiotensinogen, which is mandatory for intracellular generation of physiologically active angiotensin II. The data support the existence of an intrinsic RAS, which may be important for pancreatic blood flow and ductal anion secretion. In the present study, the effect of chronic hypoxia on the expression of RAS components, particularly at the levels of its precursor angiotensinogen and its receptor subtypes AT(1) and AT(2), were investigated in the rat pancreas. Results from western blot and semi-quantitative reverse-transcription polymerase chain reaction (RT-PCR) analyses unequivocally showed that chronic hypoxia caused a marked increase in angiotensinogen both at the protein and gene levels when compared with that in the normoxic pancreas. However, results from RT-PCR showed that there was a differential effect of chronic hypoxia on the expression of AT(1) and AT(2) receptor subtypes, which exhibited subtype-specific changes in gene expression. For AT(1), chronic hypoxia did not cause a significant change in mRNA expression for AT(1a) but a significant increase in mRNA expression for AT(1b). For AT(2), chronic hypoxia caused a marked increase in its mRNA expression. The increased expression of RAS component genes by chronic hypoxia and its significance of changes may be important for physiological and pathophysiological aspects of the pancreas.

Expression and localization of the renin-angiotensin system in the rat pancreas

The possibility of an intrinsic renin-angiotensin system (RAS) in the pancreas has been raised by previous studies in which immunohistochemical examination showed the presence of angiotensin II and its receptor subtypes, type 1 (AT1) and type 2 (AT2). In the present study, gene expression of several key RAS components was investigated by reverse-transcription PCR. mRNA expression for angiotensinogen, renin and angiotensin II receptor subtypes, AT1a, AT1b and AT2 was shown. The presence of angiotensinogen protein, the mandatory component for an intrinsic RAS, was demonstrated by Western blotting and localized by immunohistochemistry to the epithelia and endothelia of pancreatic ducts and blood vessels respectively. Immunoblot analysis detected a predominant protein band of about 60 kDa in the pancreas. This was consistent with the predicted value for angiotensinogen as reported in other tissues. Together with previous findings, the present study shows that the rat pancreas expresses the major RAS component genes, notably angiotensinogen and renin, required for intracellular formation of angiotensin II. The data support the notion of an intrinsic RAS in the rat pancreas which may play a role in the regulation of pancreatic functions.

Mutation of the 5' noncoding region of the BCL-6 gene in low-grade gastric lymphoma of the mucosa-associated lymphoid tissue

BCL-6 gene rearrangement and hypermutations were investigated in four Hong Kong Chinese patients with low-grade gastric lymphoma of the mucosa-associated lymphoid tissue (MALToma). The former was studied by Southern analysis and the latter by the technique of polymerase chain reaction and denaturing gradient gel electrophoresis. BCL-6 gene rearrangement was not detectable in any of the four cases. However, mutations at both the E1.11 and E1.12 segments of the 5' noncoding region of the BCL-6 gene were found in two patients. This preliminary observation suggests that the mutations of the 5' noncoding region of the BCL-6 gene rather than gene rearrangement may be playing a more important role in the tumorigenesis of low-grade gastric MALToma. Further confirmation of this finding by studying a larger number of patients will be required.

Visual input to the efferent control system of a fly's "gyroscope"

Dipterous insects (the true flies) have a sophisticated pair of equilibrium organs called halteres that evolved from hind wings. The halteres are sensitive to Coriolis forces that result from angular rotations of the body and mediate corrective reflexes during flight. Like the aerodynamically functional fore wings, the halteres beat during flight and are equipped with their own set of control muscles. It is shown that motoneurons innervating muscles of the haltere receive strong excitatory input from directionally sensitive visual interneurons. Visually guided flight maneuvers of flies may be mediated in part by efferent modulation of hard-wired equilibrium reflexes.

Case report: Spontaneous isolated mesenteric fibromatosis presenting as megaduodenum

A case of spontaneous isolated mesenteric fibromatosis presenting as megaduodenum is reported. The lesion was small, only 2 cm in its greatest diameter. However, because of its location near the ligament of Treitz and because of its characteristic infiltrative growth pattern, the tumour involved the distal duodenum and resulted in acute angulation and obstruction early in its course. We successfully resected the mass and the patient is in fair physical condition 6 months after operation.

A novel mutation of Arg306 of factor V gene in Hong Kong Chinese

We have analyzed 83 unrelated Hong Kong Chinese for the presence of genetic variants of factor V gene. Forty-three of them had a history of deep vein thrombosis. The DNA sequence variations of exons 7, 10, and 13, where the codons for Arg306, Arg506, and Arg679 are located, respectively, were studied by denaturing gradient gel electrophoresis. The G1691-->A (Arg 506-->Gln) mutation in exon 10 was not detectable in any of the 83 subjects. However, a high allelic frequency for the G1628-->A (Arg 485-->Lys) substitution was detectable in the same exon. We have also identified a novel DNA sequence mutation (A1090-->G) in exon 7 that resulted in Arg 306-->Gly substitution in 2 thrombotic patients and 1 nonthrombotic subject. Fresh blood samples were available from one of them for analysis of activated protein C resistance and the result was negative. Variation of DNA sequence was not found in exon 13 in any of our 83 subjects. The results of this study showed that, although the Arg 506-->Gln mutation was rarely found in the Hong Kong Chinese population, a different mutation site such as A 1090-->G in exon 7 of the factor V gene (Arg 306) may be of clinical importance.

Bcl-6 gene hypermutations in diffuse large B-cell lymphoma of primary gastric origin

The presence of the bcl-6 gene hypermutation was studied in 40 Hong Kong Chinese patients with diffuse large B-cell lymphoma. The primary sites of involvement were nodal in 18 cases and gastric in 22. Hypermutations at the E1.11 segment of bcl-6 gene were detectable in 16/22 (73%) primary gastric and 4/18 (22%) primary nodal lymphoma (P<0.01). Three of the 22 cases of primary gastric but none of the nodal lymphoma had mutations at E1.12. The proportion of hypermutated cases in the group with bcl-6 gene rearrangement was similar to that of the germ-line group (70% v 75%). High frequency of bcl-6 gene hypermutations was found in diffuse large B-cell lymphoma of the stomach and they were independent of rearrangement of the gene as detected by Southern analysis. Unlike gene rearrangement, hypermutations of the bcl-6 gene did not appear to carry any prognostic significance clinically.

High incidence of BCL-6 gene rearrangement in diffuse large B-cell lymphoma of primary gastric origin

The incidence of BCL-6 gene rearrangement was studied in 39 Hong Kong Chinese patients with diffuse large B-cell lymphoma. The primary site of involvement was nodal in 18 cases and gastric in 21 cases. Clonal BCL-6 gene rearrangement was found in 17% of the patients with primary nodal and 48% with primary gastric lymphoma (p = 0.05). The clinical characteristics and treatment outcome of the 21 patients with primary gastric lymphoma were analyzed according to the BCL-6 status. Significantly more patients in the germline BCL-6 gene group had advanced stage (II, III and IV) of disease. Complete remission rate following primary therapy appeared to be higher for the positive rearrangement group (70% versus 36%), but it was not statistically significant. Those with a rearranged BCL-6 gene also appeared to have better survival at 5 years (58% versus 36%) but the difference was also not statistically significant. On the other hand, patients being classified as low risk according to the International Prognostic Index had significantly better survival at 5 years (89% versus 9%, p = 0.0001). We concluded that BCL-6 gene rearrangement was more commonly found in diffuse large B-cell lymphoma of primary gastric origin than its nodal counterpart and it may be playing a more important role in the pathogenesis of gastric large B-cell lymphoma. There was a trend that the BCL-6 gene rearrangement was associated with a more favorable outcome in patients with gastric large B-cell lymphoma but the difference was not statistically significant.

In vivo length oscillations of indirect flight muscles in the fruit fly Drosophila virilis

We have used high-speed video microscopy to measure in vivo length oscillations of the indirect flight muscles of the fruit fly Drosophila virilis during tethered flight. The changes in muscle strain were measured by tracking the deformation of the thoracic exoskeleton at the origin and insertion of both the dorsal longitudinal (DLM) and the dorsal ventral (DVM) muscles. The mean peak-to-peak strain amplitudes were found to be 3.5% for the DLMs and 3.3% for the DVMs, although the strain amplitude within individual cycles ranged from 2 to 5%. These values are consistent with the small number of previous measurements of indirect flight muscle strain in other insects, but almost an order of magnitude greater than the strain amplitudes used in most biophysical studies of skinned Drosophila fibers. The results suggest that serial compliance within this sarcomere would need to relieve approximately 70% of the total strain in order for individual crossbridges to remain attached throughout a complete contraction-extension cycle.

Superoxide dismutase and catalase in protection of cardiopulmonary bypass-induced cardiac dysfunction and cellular injury

BACKGROUND

Cardiac dysfunction following cardiopulmonary bypass (CPB) is well known. Various possible sources for increased levels of oxygen free radicals (OFRs) exist during CPB and OFRs depress cardiac function. Postpump (following CPB) cardiac dysfunction may be due to increased levels of OFRs.

METHODS

This study investigated the effects of cold crystalloid cardioplegia with and without superoxide dismutase (SOD) and catalase (CAT) on cardiac function (cardiac index [CI], left ventricular work index [LVWI]), cardiac contractility (+dp/dt, +dp/dt/PAW [pulmonary arterial wedge pressure], +dp/dt/LVEDP [left ventricular end-diastolic pressure]), diastolic compliance (-dp/dt), OFR-producing activity of polymorphonuclear leukocytes (PMNL-CL); creatine kinase (CK) and MB isoenzyme of CK (MBCK), malondialdehyde (MDA), and white blood cells (WBC) and PMNLs from coronary sinus blood; and lactate levels in arterial blood in anesthetized dogs at various times (up to 90 mins) of reperfusion following 90 mins of hypothermic ischemic cardiac arrest. The dogs were divided into three groups: group I, sham bypass; group II, cold crystalloid cardioplegic cardiac arrest; group III, similar to group II but received SOD and catalase treatment.

RESULTS

Postpump decreases in cardiac function, contractility and diastolic compliance were associated with increases in PMNL-CL activity, blood MDA, plasma CK and MBCK, and plasma lactate, and decreases in WBC and PMNLs. Prevention of postpump cardiac dysfunction (function and contractility) by SOD and CAT was associated with restoration in PMNL-CL activity, plasma CK and MBCK activity, and blood MDA towards control values although not complete. The levels of plasma lactate, total WBC and PMNLs were similar in group II and group III.

CONCLUSIONS

These results suggest that postpump depression of cardiac function and contractility could be due to increased levels of OFRs and that SOD and CAT scavengers of superoxide anion and hydrogen peroxide respectively may be effective in preventing postpump cardiac dysfunction.