Elevated Southern Hemisphere moisture availability during glacial periods

Late Pleistocene ice-age climates are routinely characterized as having imposed moisture stress on low- to mid-latitude ecosystems1-5. This idea is largely based on fossil pollen evidence for widespread, low-biomass glacial vegetation, interpreted as indicating climatic dryness6. However, woody plant growth is inhibited under low atmospheric CO2 (refs. 7,8), so understanding glacial environments requires the development of new palaeoclimate indicators that are independent of vegetation9. Here we show that, contrary to expectations, during the past 350 kyr, peaks in southern Australian climatic moisture availability were largely confined to glacial periods, including the Last Glacial Maximum, whereas warm interglacials were relatively dry. By measuring the timing of speleothem growth in the Southern Hemisphere subtropics, which today has a predominantly negative annual moisture balance, we developed a record of climatic moisture availability that is independent of vegetation and extends through multiple glacial-interglacial cycles. Our results demonstrate that a cool-moist response is consistent across the austral subtropics and, in part, may result from reduced evaporation under cool glacial temperatures. Insofar as cold glacial environments in the Southern Hemisphere subtropics have been portrayed as uniformly arid3,10,11, our findings suggest that their characterization as evolutionary or physiological obstacles to movement and expansion of animal, plant and, potentially, human populations10 should be reconsidered.

Creating a Digital Psychoeducation Programme for bipolar disorder in the COVID-19 pandemic

Introduction

The Covid-19 pandemic profoundly affected delivery and accessibility of mental health care services at a time when most needed. The OPTIMA Mood Disorder Service, a specialist bipolar disorder service, adapted group psychoeducation programme for delivery on-line.

Objectives

We report the feasibility of creating a digital psychoeducation programme.

Methods

The OPTIMA ten session group psychoeducation programme was converted into a ‘Digital’ intervention using video-conferencing. Sessions offered a range of key topics, derived from the initial Barcelona Group Psychoeducation Programme. At the time of writing, OPTIMA had fully completed two 10 session digital courses.

Results

A total of 12 people (6 in each group) consented to be part of a service evaluation of the digital groups. Just over half of the participants were women (7/12; 58.3%) and one identified as being non-binary (8.3); remaining participants were men. Age of participants ranged from 25 years to 65 years (Mean=42.3; SD=13.1). Data showed a high level of engagement (77%) All participants reported some improvement with a mean Bipolar Self-Efficacy scale (BPSES) post-group score of 105.6 (SD=14.8). At group level, this change was not statistically significant (F (1, 15) = 0.71, p=0.41). At an individual level, two out of five showed a reliable change index >1.96.

Conclusions

Delivering a ‘digital’ group psychoeducation programme was possible due to careful planning and programme development. There was good uptake from service users suggesting it is a feasible approach with preliminary evidence of clinical benefit.

Disclosure

No significant relationships.

Overview of HOMEChem: House Observations of Microbial and Environmental Chemistry

The House Observations of Microbial and Environmental Chemistry (HOMEChem) study is a collaborative field investigation designed to probe how everyday activities influence the emissions, chemical transformations and removal of trace gases and particles in indoor air. Sequential and layered experiments in a research house included cooking, cleaning, variable occupancy, and window-opening. This paper describes the overall design of HOMEChem and presents preliminary case studies investigating the concentrations of reactive trace gases, aerosol particles, and surface films. Cooking was a large source of VOCs, CO2, NOx, and particles. By number, cooking particles were predominantly in the ultrafine mode. Organic aerosol dominated the submicron mass, and, while variable between meals and throughout the cooking process, was dominated by components of hydrocarbon character and low oxygen content, similar to cooking oil. Air exchange in the house ensured that cooking particles were present for only short periods. During unoccupied background intervals, particle concentrations were lower indoors than outdoors. The cooling coils of the house ventilation system induced cyclic changes in water soluble gases. Even during unoccupied periods, concentrations of many organic trace gases were higher indoors than outdoors, consistent with housing materials being potential sources of these compounds to the outdoor environment. Organic material accumulated on indoor surfaces, and exhibited chemical signatures similar to indoor organic aerosol.

Storied Lessons: Learning from Anger in Childhood by Narrating

We evaluated whether narrating anger-provoking events promoted learning from those events, as compared with other responses to anger, and whether the effectiveness of narrative depended on age. In addition, we tested relations between anger-reduction and learning and in a subset of participants, between narrative quality and learning. 248 youth (8 to 17 years old) recalled an anger-provoking experience, and were randomly assigned to one of four activities: recalling the event a second time, narrating the event, and distraction (via video game play or conversation). Youth then recalled the event one last time, and rated the extent to which they had learned from that event. Younger children reported more learning when they had narrated their experience. Older youth reported more learning when they had narrated the event more frequently prior to participation. Stronger reductions in anger following regulation were associated with greater self-reported learning. Finally, more elaborative and less resolved narratives were associated with greater self-reported learning.

Dose- and time-dependent changes in gene expression in human glioma cells after low radiation doses

We have used DNA microarrays to identify changes in gene expression in cells of the radioresistant human glioma cell lines T98G and U373 after low radiation doses (0.2-2 Gy). Using Bayesian linear models, we have identified a set of genes that respond to low doses of radiation; furthermore, a hypothesis-driven approach to data analysis has allowed us to identify groups of genes with defined non-linear dose responses. Specifically, one of the cell lines we have examined (T98G) shows increased radiosensitivity at low doses (low-dose hyper-radiosensitivity, HRS); thus we have also assessed sets of genes whose dose response mirrors this survival pattern. We have also investigated a time course for induction of genes over the period when the DNA damage response is expected to occur. We have validated these data using quantitative PCR and also compared genes up-regulated in array data to genes present in the polysomal RNA fraction after irradiation. Several of the radioresponsive genes that we describe code for proteins that may have an impact on the outcome of irradiation in these cells, including RAS homologues and kinases involved in checkpoint signaling, so understanding their differential regulation may suggest new ways of altering radioresistance. From a clinical perspective these data may also suggest novel targets that are specifically up-regulated in gliomas during radiotherapy treatments.

The impact of surgically induced ischaemia on protein levels in patients undergoing rectal cancer surgery

The goal of targeted therapy has driven a search for markers of prognosis and response to adjuvant therapy. The surgical resection of a solid tumour induces tissue ischaemia and acidosis, both potent mediators of gene expression. This study investigated the impact of colorectal cancer (CRC) surgery on prognostic and predictive marker levels. Tumour expression of thymidylate synthase, thymidine phosphorylase, cyclin A, vascular endothelial growth factor (VEGF), carbonic anhydrase-9, hypoxia inducible factor-1α, and glucose transporter-1 (GLUT-1) proteins was determined before and after rectal cancer surgery. Spectral imaging of tissue sections stained by immunohistochemistry provided quantitative data. Surgery altered thymidylate synthase protein expression (P=0.02), and this correlated with the change in the proliferation marker cyclin A. The expression of hypoxia inducible factor-1α, VEGF, and GLUT-1 proteins was also different following surgery. Colorectal cancer surgery significantly impacts on intratumoral gene expression, suggesting archival specimens may not accurately reflect in situ marker levels. Although rectal cancer was the studied model, the results may be applicable to any solid tumour undergoing extirpation in which molecular markers have been proposed to guide patient therapy.

The effect of surgically induced ischaemia on gene expression in a colorectal cancer xenograft model

Delays in tissue fixation following tumour vascular clamping and extirpation may adversely affect subsequent protein and mRNA analysis. This study investigated the effect of surgically induced ischaemia in a xenograft model of a colorectal cancer on the expression of a range of prognostic, predictive, and hypoxic markers, with a particular emphasis on thymidylate synthase. Vascular occlusion of human tumour xenografts by D-shaped metal clamps permitted defined periods of tumour ischaemia. Alterations in protein expression were measured by immunohistochemistry and spectral imaging, and changes in mRNA were measured by reverse transcriptase–polymerase chain reaction. Thymidylate synthase expression decreased following vascular occlusion, and this correlated with cyclin A expression. A similar reduction in dihydropyrimidine dehydrogenase was also seen. There were significant changes in the expression of several hypoxic markers, with carbonic anhydrase-9 showing the greatest response. Gene transcriptional levels were also noted to change following tumour clamping. In this xenograft model, surgically induced tumour ischaemia considerably altered the gene expression profiles of several prognostic and hypoxic markers, suggesting that the degree of tumour ischaemia should be minimised prior to tissue fixation.

DNA damage responses at low radiation doses

Increased cell killing after exposure to low acute doses of X rays (0-0.5 Gy) has been demonstrated in cells of a number of human tumor cell lines. The mechanisms underlying this effect have been assumed to be related to a threshold dose above which DNA repair efficiency or fidelity increases. We have used cells of two radioresistant human tumor cell lines, one that shows increased sensitivity to low radiation doses (T98G) and one that does not (U373), to investigate the DNA damage response at low doses in detail and to establish whether there is a discontinuous dose response or threshold in activation of any important mediators of this response. In the two cell lines studied, we found a sensitive, linear dose response in early signaling and transduction pathways between doses of 0.1 and 2 Gy with no evidence of a threshold dose. We demonstrate that ATM-dependent signaling events to downstream targets including TP53, CHK1 and CHK2 occur after doses as low as 0.2 Gy and that these events promote an effective damage response. Using chemical inhibition of specific DNA repair enzymes, we show that inhibition of DNA-PK-dependent end joining has relatively little effect at low (<1 Gy) doses in hyper-radiosensitive cells and that at these doses the influence of RAD51-mediated repair events may increase, based on high levels of RAD51/BRCA2 repair foci. These data do not support a threshold model for activation of DNA repair in hyper-radiosensitive cells but do suggest that the balance of repair enzyme activity may change at low doses.

Osteogenic Differentiation of Mouse Embryonic Stem Cells: Differential Gene Expression Analysis by cDNA Microarray and Purification of Osteoblasts by Cadherin-11 Magnetically Activated Cell Sorting

We have previously shown osteogenic differentiation of mouse embryonic stem (ES) cells and temporal enrichment with osteoblastic cells, by stimulation with serum-containing culture medium supplemented with beta-glycerophosphate, ascorbate, and dexamethasone. In our present study we have used similar culture conditions to further investigate osteogenic differentiation of mouse ES cells. Using reverse transcription-polymerase chain reaction (RT-PCR) we demonstrated the expression of genes associated with osteoblast differentiation including the bone matrix protein osteocalcin and the transcription factor Cbfa-1/runx2. Furthermore, results of cDNA microarray analysis, and subsequent RT-PCR analysis of differentiating ES cells after exposure to osteogenic stimuli, revealed a combination of upregulation of genes involved in osteoblast differentiation including osteopontin, HSP-47, and IGF-II coupled with downregulation of genes involved in differentiation of other phenotypes such as the neuroectoderm factor Stra-13. Finally, we have applied magnetically activated cell-sorting methods to ES cell cultures treated with osteogenic stimuli and, using an antibody to cadherin-11, have purified a subpopulation of cells with osteoblastic characteristics.

Differentiation of osteoblasts and in vitro bone formation from murine embryonic stem cells

Pluripotent embryonic stem (ES) cells have the potential to differentiate to all fetal and adult cell types and might represent a useful cell source for tissue engineering and repair. Here we show that differentiation of ES cells toward the osteoblast lineage can be enhanced by supplementing serum-containing media with ascorbic acid, beta-glycerophosphate, and/or dexamethasone/retinoic acid or by co-culture with fetal murine osteoblasts. ES cell differentiation into osteoblasts was characterized by the formation of discrete mineralized bone nodules that consisted of 50-100 cells within an extracellular matrix of collagen-1 and osteocalcin. Dexamethasone in combination with ascorbic acid and beta-glycerophosphate induced the greatest number of bone nodules and was dependent on time of stimulation with a sevenfold increase when added to ES cultures after, but not before, 14 days. Co-culture with fetal osteoblasts also provided a potent stimulus for osteogenic differentiation inducing a fivefold increase in nodule number relative to ES cells cultured alone. These data demonstrate the application of a quantitative assay for the derivation of osteoblast lineage progenitors from pluripotent ES cells. This could be applied to obtain purified osteoblasts to analyze mechanisms of osteogenesis and for use of ES cells in skeletal tissue repair.

Supracostal percutaneous nephrolithotomy for upper pole caliceal calculi

The incidence of upper pole calculi is 15% of all caliceal calculi. The management of such calculi has been simplified since the advent of extracorporeal shockwave lithotripsy (SWL). In our experience, however, there is a subset of upper pole caliceal calculi wherein certain features can render SWL less than adequate treatment, namely diameter >1.5 cm, narrowing of the caliceal infundibulum, either singly or combined, and morbid obesity. In such instances, percutaneous nephrolithotomy (PCNL) is indicated. Percutaneous access to an upper pole calix can be difficult by a subcostal track. The supracostal 12th rib approach provides direct and efficient access to an upper pole calix and is ideally suited for upper pole calculi. Twenty-one patients with large or complex upper pole calculi were treated by supracostal PCNL. The maximum diameter of the calculi ranged from 7 to 40 mm. Eight were branched (staghorn). There was one horseshoe kidney, and calculi were bilaterally represented in another patient. Two patients were morbidly obese. All procedures were performed in one stage under general anesthesia. Following cystoscopy and ureteral catheterization, the upper pole calix was accessed directly with the aid of C-arm fluoroscopy and retrograde ureteral contrast injection. The percutaneous tract was dilated to a maximum of 26 F, a working sheath was inserted, and the calculi were extracted after ultrasonic or pneumatic fragmentation. One patient required secondary SWL for residual fragments. There were no intrathoracic complications, and blood loss was minimal. Large or complex upper pole caliceal calculi, particularly in the morbidly obese, can be treated effectively by PCNL using supracostal percutaneous access.

Screening for unhealthy lifestyle factors in the workplace

OBJECTIVE

To examine (1) the prevalence of four lifestyle behaviours among Australia Post employees and (2) employees' perceptions of the role of the workplace in promotion of lifestyle change.

DESIGN

A cross-sectional survey using a self-administered questionnaire involved 688 employees working in Australia Post throughout metropolitan Sydney.

MAIN OUTCOME MEASURES

Prevalence related to age and sex of alcohol consumption, cigarette smoking, inadequate exercise, perception of excessive weight.

RESULTS

36% of men and 11% of women reported drinking alcohol at levels considered hazardous or harmful; 33% of men and 25% of women reported smoking; 51% of men and 62% of women thought they were overweight; 30% of men and 39% of women did not exercise regularly. Younger respondents were more likely to report drinking hazardously or harmfully, were smokers and had multiple risk factors. A majority of respondents thought that their employer should be interested in employee's lifestyle issues, particularly excessive drinking (63%). However, few considered seeking advice from the workplace regarding smoking (16%), weight (25%) and excessive alcohol consumption (12%).

CONCLUSIONS

These results show that many of Australia Post employees have unhealthy lifestyle behaviours. While employees perceive that the workplace has an important role in promoting healthy lifestyles among staff, few are presently willing to seek advice from the workplace regarding these issues. Promotion of healthy lifestyles in Australian workplaces is a potentially important public health advance that could reduce the incidence of diseases associated with high-risk lifestyle behaviours.

Expression of alternative isoforms of the neural cell adhesion molecule (NCAM) on normal brain and a variety of brain tumours

A panel of monoclonal antibodies, including a reagent designated ERIC-1, have been characterized as binding to the human neural cell adhesion molecule (NCAM). These monoclonal antibodies bind in a relatively uniform manner to a variety of normal and neoplastic tissues arising from the neuroectoderm. However, multiple forms of the protein are known to arise from the differential splicing of exons within the NCAM gene located on chromosome 11 at q23. On human adult brain, four isoforms of 180, 170, 145 and 120 kDa have been identified. Here, we report the identification of another NCAM isoform of 95 kDa that is apparent on tissues following either N-glycanase or neuraminidase treatment to remove carbohydrate and sialic acid residues from the molecule respectively. NCAM expression is further complicated by differential post-translational modification of the molecule which is developmentally regulated. In general, fetal NCAM is more heavily polysialylated than the adult forms of the molecule. Human fetal brain has been shown to express the heavily sialylated embryonic form of NCAM, but following neuraminidase digestion, a similar pattern of NCAM expression is seen to that in adult brain. A variety of human brain tumours examined also show different patterns of NCAM expression, despite their uniform staining with monoclonal antibodies. The significance of these observations for designing new molecular and immunological approaches to the diagnosis of a variety of primary tumours is reviewed.

Perinatal bereavement

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Monoclonal antibody UJ13A recognizes the neural cell adhesion molecule (NCAM)

Monoclonal antibody (MAb) UJ13A, raised against 16-week-old human foetal brain, recognizes an antigen present on the majority of tissues of neuro-ectodermal origin. The binding profile of this antibody is similar to the known distribution of the neural cell adhesion molecule (NCAM). Although detailed immunohistological and immuno-cytochemical studies with the MAb have been published previously, we demonstrate here, through investigations of selected tissues and cell lines, that the binding profile of an anti-NCAM antiserum is similar to UJ13A. Additional indirect evidence suggesting that UJ13A recognizes NCAM comes from Northern blot analysis of cell lines either binding or not binding UJ13A as determined by indirect immunofluorescence. Only those cell lines known to bind UJ13A express high levels of NCAM mRNA. Western blot analysis of extracts of human brain show that UJ13A recognizes proteins of 180 and 140 kDa in addition to a very weak band of 120 kDa. This data corroborates the suggestion that UJ13A recognizes NCAM as these 3 isoforms of the protein are identified in human brain. Final confirmation of the specificity of UJ13A comes from the study of 3T3 fibroblasts transfected with a cDNA coding for the 125 kDa isoform of human muscle NCAM. UJ13A selectively recognizes these transfectants and binds to a 125 kDa protein isolated from the cells by Western blot analysis. Thus we conclude from these immunological, biochemical and molecular studies that the antigen recognized by the UJ13A MAb is the neural cell adhesion molecule.

Monoclonal antibodies M340 and UJ181.4 recognize antigens associated with primitive neuroectodermal tumours/tissues

Monoclonal antibodies UJ181.4 and M340 were raised from separate fusions using either human foetal brain or medulloblastoma tissue as immunogens. The antibodies are both of IgG isotype and bind to their target antigens with affinities in excess of 10(-9) M. Both monoclonal antibodies have been shown to bind to primitive neuroectodermal tumours and human foetal brain. Expression of the two antigens is developmentally regulated as no binding is detected on adult brain as determined by a variety of indirect binding assays. The two monoclonal antibodies can be clearly distinguished by their migration in a pH gradient (isoelectric focussing gels). UJ181.4 and M340 clearly recognize two different epitopes, as it is not possible to block the binding of one antibody with an excess of the other. In addition, careful study of the binding profiles of the two reagents suggest that they recognize two distinct antigens, although these have not been biochemically characterized. The reagents have proved particularly useful in both the differential diagnosis of the small round cell tumours of childhood and anaplastic brain tumours. In addition, they have formed part of a panel of reagents used for the immunomagnetic depletion of neuroblasts from bone marrow and have been used for targeting radionuclides to tumour cells in the intrathecal compartment.

Treatment of cigarette smoking with short-term high-dosage corticotrophin therapy: preliminary communication

Uncontrolled studies have indicated that the smoker's "life' can be simulated clinically by short-term, high-dosage corticotrophin therapy. Following such treatment, smokers previously prevented by the withdrawal syndrome from giving up smoking were able to do so easily. All 10 patients reported here were still not smoking after seven months.

The role of monoclonal antibodies in brain tumour diagnosis and cerebrospinal fluid (CSF) cytology

This paper reviews the diagnostic role of monoclonal antibody immunohistochemistry in a series of 189 brain tumour biopsies and 22 cases of neoplastic meningitis. The diagnostic monoclonal antibody panel, which includes markers for glial, neural, epithelial and lymphoid differentiation antigens, was used to test a wide variety of cerebral and spinal tumours by indirect immunofluorescence and immunoperoxidase techniques on unfixed frozen sections. Gliomas, meningiomas, schwannomas, medulloblastomas, choroid plexus tumours, cerebral lymphomas and metastatic carcinomas could all be reliably differentiated by means of their characteristic antigenics profiles, as defined by their patterns of reactivity with the antibody panel. Confident diagnosis was possible even in very poorly differentiated tumours and in biopsies distorted by surgical squeeze artefact, where paucity of morphological clues made diagnosis by conventional histological methods difficult or impossible. It was estimated that use of the antibody panel was responsible for, or made a significant contribution towards the final diagnosis in approximately 20% of cases. The monoclonal reagents were also found to be of great value in the detection and characterisation of neoplastic cells in CSF specimens from patients with malignant meningitis. Malignant cells were detected in 73% of cases and characterised in 16% of cases by routine cytological techniques. Employing monoclonal immunocytology however, these figures were improved to 95% and 95% respectively. Our findings suggest that patients with neoplastic meningitis can be spared prolonged investigation and inappropriate management by the early detection and characterisation of malignant cells in CSF using panels of monoclonal antibodies.