Leave events among Aboriginal and Torres Strait Islander people: a systematic review.

BACKGROUND: Leave events are a public health concern resulting in poorer health outcomes. In Australia, leave events disproportionally impact Aboriginal and Torres Strait Islander people. A systematic review was conducted to explore the causes of leave events among Aboriginal and Torres Strait Islander people and strategies to reduce them. METHODS: A systematic review was conducted using Medline, Web of Science, Embase and Informit, a database with a strong focus on relevant Australian content. Additionally, we examined the references of the records included, and performed a manual search using Google, Google scholar and the Australia's National Institute for Aboriginal and Torres Strait Islander Health Research. Two independent reviewers screened the records. One author extracted the data and a second author reviewed it. To appraise the quality of the studies the Mixed Methods Appraisal Tool was used as well as the Aboriginal and Torres Strait Islander Quality Appraisal Tool. A narrative synthesis was used to report quantitative findings and an inductive thematic analysis for qualitative studies and reports. RESULTS: We located 421 records. Ten records met eligibility criteria and were included in the systematic review. From those, four were quantitative studies, three were qualitative studies and three reports. Five records studied data from the Northern Territory, two from Western Australia, two from New South Whales and one from Queensland. The quantitative studies focused on the characteristics of the patients and found associations between leave events and male gender, age younger than 45 years and town camp residency. Qualitative findings yielded more in depth causes of leave events evidencing that they are associated with health care quality gaps. There were multiple strategies suggested to reduce leave events through adapting health care service delivery. Aboriginal and Torres Strait Islander representation is needed in a variety of roles within health care provision and during decision-making. CONCLUSION: This systematic review found that multiple gaps within Australian health care delivery are associated with leave events among Aboriginal and Torres Strait Islander people. The findings suggest that reducing leave events requires better representation of Aboriginal and Torres Strait Islander people within the health workforce. In addition, partnership with Aboriginal and Torres Strait Islander people is needed during the decision-making process in providing health services that meet Aboriginal and Torres Strait Islander cultural needs.

Quantifying Argonaute 2 (Ago2) expression to stratify breast cancer.

BACKGROUND: Argonaute-2 (Ago2) is an essential component of microRNA biogenesis implicated in tumourigenesis. However Ago2 expression and localisation in breast cancer remains undetermined. The aim was to define Ago2 expression (mRNA and protein) and localisation in breast cancer, and investigate associations with clinicopathological details. METHODS: Ago2 protein was stained in breast cancer cell lines and tissue microarrays (TMAs), with intensity and localization assessed. Staining intensity was correlated with clinicopathological details. Using independent databases, Ago2 mRNA expression and gene alterations in breast cancer were investigated. RESULTS: In the breast cancer TMAs, 4 distinct staining intensities were observed (Negative, Weak, Moderate, Strong), with 64.2% of samples stained weak or negatively for Ago2 protein. An association was found between strong Ago2 staining and, the Her2 positive or basal subtypes, and between Ago2 intensity and receptor status (Estrogen or Progesterone). In tumours Ago2 mRNA expression correlated with reduced relapse free survival. Conversely, Ago2 mRNA was expressed significantly lower in SK-BR-3 (HER2 positive) and BT-20 (Basal/Triple negative) cell lines. Interestingly, high levels of Ago2 gene amplification (10-27%) were observed in breast cancer across multiple patient datasets. Importantly, knowledge of Ago2 expression improves predictions of breast cancer subtype by 20%, ER status by 15.7% and PR status by 17.5%. CONCLUSIONS: Quantification of Ago2 improves the stratification of breast cancer and suggests a differential role for Ago2 in breast cancer subtypes, based on levels and cellular localisation. Further investigation of the mechanisms affecting Ago2 dysregulation will reveal insights into the molecular differences underpinning breast cancer subtypes.

Quantifying Tip60 (Kat5) stratifies breast cancer.

Breast cancer is stratified into four distinct clinical subtypes, using three key biomarkers (Her2/Neu gene status, Estrogen and Progesterone receptor status). However, each subtype is a heterogeneous group, displaying significant variation in survival rates and treatment response. New biomarkers are required to provide more precise stratification of breast cancer cohorts to inform personalised treatment options/predict outcomes. Tip60 is a member of the MYST sub-family of histone acetyltransferases (HATs), and is directly involved in genome maintenance, gene regulation and DNA damage response/repair pathways (key chemotherapeutic influencing mechanisms). We aimed to determine if quantifying Tip60 staining patterns improved breast cancer stratification. We defined Tip60 protein in vivo, quantifying location (cytoplasmic, nuclear), percent of cells and staining intensity in a breast cancer tissue microarray (n = 337). A significant association of specific Tip60 staining patterns with breast cancer subtype, ER or PR status and Tumour grade was found. Importantly, low Tip60 mRNA expression correlated with poor overall survival and relapse free survival. We found Tip60 is a biomarker able to stratify breast cancer patients, and low Tip60 expression is a significant risk factor indicating a higher chance of disease reoccurrence. This work highlights Tip60 regulation as a key factor influencing the development of breast cancer.

Cricothyroidotomy catheters: an investigation of mechanisms of failure and the effect of a novel intracatheter stylet.

Emergency catheter cricothyroidotomy often fails. Case reports have concentrated on kinking and displacement of the catheter as the major causes. We investigated catheter tip penetration of the trachea. Using insertion angles of 90°, 75°, 60°, 45° and 30° we advanced 14 G intravenous catheters into fresh isolated sheep tracheas during high pressure oxygen insufflation. At all angles, the catheter tip became blocked by pushing into the mucosa with submucosal gas injection on one or more attempts. Full thickness rupture with extratracheal gas also occurred on insertions at 90° and 60°. We then tested a Luer-mounted prototype wire stylet which remains in situ during insufflation. Using the same methodology, the stylet was able to be placed and prevented blockage at all angles of insertion. Mucosal trauma and submucosal gas injection occurred on insertions at 90° and 75°. Our results should guide further stylet design.

MCPH1/BRIT1 limits ionizing radiation-induced centrosome amplification.

Microcephalin (MCPH1/BRIT1) is a potential tumour suppressor that localizes to the centrosome, forms ionizing radiation-induced nuclear foci (IRIF) and is involved in the DNA damage checkpoints that ensure genome stability. Here, we report the impact of Mcph1 disruption in the hyper-recombinogenic DT40 cell line. Mcph1(-/-) cells were viable and proliferated at the same rate as wild-type controls. Mcph1-deficient cells had intact G2-to-M checkpoint responses after ionizing radiation (IR) treatment, but showed moderate radiosensitivity. Light and electron microscopy indicated normal centrosome structures in Mcph1 null cells, but IR induced massive amplification of centrosome numbers in the absence of Mcph1. Mcph1 null cells formed γ-H2AX and Rad51 IRIF, but resolved them more slowly than wild-type cells. Mcph1 deficiency caused sustained Chk1 phosphorylation after IR, dysregulating Cdk2 activity. These findings show that Mcph1 controls centrosome numbers after DNA damage, which may indicate a novel tumour suppressive mechanism for microcephalin.

DNA damage induces Chk1-dependent threonine-160 phosphorylation and activation of Cdk2.

Abnormal centrosome numbers arise in tumours and can cause multipolar mitoses and genome instability. Cdk2 controls normal centrosome duplication, but Chk1-dependent centrosome amplification also occurs after DNA damage. We investigated the involvement of cyclin-dependent kinases (Cdks) in DNA damage-induced centrosome amplification using cells lacking either Cdk2, or both Cdk1 and Cdk2 activity. Cdk2(-/-) DT40 cells showed robust centrosome amplification after ionizing radiation (IR), whereas Cdk1-deficient Cdk2(-/-) cells showed no centrosome amplification, demonstrating that Cdk1 can substitute for Cdk2 in this pathway. Surprisingly, we found that Cdk2 activity was upregulated by IR in wild-type but not in Chk1(-/-) DT40 cells. Cdk2 upregulation also occurred in HeLa cells after IR treatment. Chk1-dependent Cdk2 induction was not accompanied by increased levels of Cdk1, Cdk2, cyclin A or cyclin E, but activating T160 phosphorylation of Cdk2 increased after IR. Moreover, Cdk2 overexpression restored IR-induced centrosome amplification in Cdk1-deficient Cdk2(-/-) cells, but T160A mutation blocked this rescue. Our data suggest that Chk1 signalling causes centrosome amplification after IR by upregulating Cdk2 activity through activating phosphorylation.

Mycosis fungoides--a review of the management of 28 patients and of the recent literature.

BACKGROUND: Mycosis fungoides is an uncommon cutaneous T-cell lymphoma characterized by malignant monoclonal proliferation of T-helper lymphocytes. Its course is variable with a potential for lymphatic and hematogenous involvement. We report the investigations, staging, treatment, follow-up, and outcome of 28 patients. This is the first such study reported from Ireland. METHODS: Twenty-eight patients with mycosis fungoides (14 women, 14 men; average age, 52.5 years) were reviewed over 12 years in the dermatology clinic which assesses an average of 4500 patients per year. All mycosis fungoides patients were referred from their family physicians. The diagnosis was made in all cases from a combination of clinical findings, histology, and immunohistochemistry. TNM staging revealed 11 patients at diagnosis stage IA (T1), 12 at stage IB (T2), four at stage IIB (T3), and one at stage III (T4). RESULTS: The usual male preponderance was not found. Eight patients needed multiple biopsies to establish the diagnosis. Detailed investigations were not useful in the early stages. Patients were followed up over a 12-year period. Thirteen patients died as a result of cutaneous lymphoma. Two patients with stage IA disease progressed rapidly and died, a feature reported in only 10% of patients at this stage. Five patients showed unusual features, including a long history prior to presentation, the development of the rarely reported bullous mycosis fungoides, and aggressive disease beginning at a young age. CONCLUSIONS: Mycosis fungoides is rare; we reviewed 28 patients over 12 years. The prognosis is poor at the later stages; 13 patients died. Two patients who died were unusual in that they rapidly progressed from stage IA disease; however, in the majority of patients with this stage, the prognosis is excellent. Detailed investigations were unhelpful in early stage disease. Close clinical follow-up is essential to identify disease progression.

Loss of Ikappa B-beta is associated with prolonged NF-kappa B activity in human glial cells.

Nuclear factor-kappaB (NF-kappaB) is an inducible transcription factor central in the regulation of expression of a wide variety of genes and synthesis of several proteins involved in the generation of the immune response and inflammatory processes. In resting cells, NF-kappaB is maintained in an inactive state through cytoplasmic retention by IkappaB inhibitors. Stimulation of cells with a wide variety of inducers results in proteolytic degradation of these IkappaB proteins, leading to activation of NF-kappaB. The present study shows that interleukin-1 (IL-1) causes persistent activation of NF-kappaB in glial cells. Stimulation with IL-1 also causes rapid but transient degradation of IkappaB-alpha and IkappaB-epsilon. However, NF-kappaB remains active even after these IkappaB isoforms have returned to control levels. In contrast, the IkappaB-beta isoform fails to reappear following its initial degradation by IL-1, coincident with sustained activation of NF-kappaB. In addition, in vivo overexpression of the various IkappaB isoforms revealed that IkappaB-beta is the only isoform that has the ability to inhibit IL-1-induced NF-kappaB-driven transcription. The findings also suggest that the inability of IkappaB-alpha and IkappaB-epsilon to modulate NF-kappaB activity is due to their modification in vivo. These findings indicate that IkappaB-beta is the key regulator of the activity of NF-kappaB in human glial cells.

Antiinflammatory effects of glucocorticoids in brain cells, independent of NF-kappa B.

Glucocorticoids are potent antiinflammatory drugs. They inhibit the expression of proinflammatory cytokines and adhesion molecules. It has recently been proposed that the underlying basis to such inhibition is the induction of the protein I kappa B, which inhibits the transcription factor NF-kappa B. The latter is a key activator of the genes encoding cytokines and adhesion molecules. The present study shows that the synthetic glucocorticoid, dexamethasone, inhibits the induction of the proinflammatory cytokine IL-8 and the adhesion molecules VCAM-1 and ICAM-1 in human 1321N1 astrocytoma and SK.N.SH neuroblastoma cells. However, dexamethasone failed to induce I kappa B or inhibit activation of NF-kappa B by IL-1 in the two cell types. EMSA confirmed the identity of the activated NF-kappa B by demonstrating that an oligonucleotide, containing the wild-type NF-kappa B-binding motif, inhibited formation of the NF-kappa B-DNA complexes whereas a mutated form of the NF-kappa B-binding motif was ineffective. In addition, supershift analysis showed that the protein subunits p50 and p65 were prevalent components in the activated NF-kappa B complexes. The lack of effect of dexamethasone on the capacity of IL-1 to activate NF-kappa B correlated with its inability to induce I kappa B and the ability of IL-1 to cause degradation of I kappa B, even in the presence of dexamethasone. The results presented in this paper strongly suggest that glucocorticoids may exert antiinflammatory effects in cells of neural origin by a mechanism(s) independent of NF-kappa B.

Interlaboratory study of the analysis of ampicillin by liquid chromatography.

A liquid chromatographic method for the analysis of ampicillin was examined in a collaborative study involving seven laboratories. The method included an isocratic part, which is used in the assay. The isocratic part is similar to the assay method for ampicillin of the US Pharmacopeia XXIII Revision. When the isocratic part is combined with gradient elution, the method is suitable for purity control. Six samples of ampicillin (anhydrous, trihydrate and sodium salt) with varying purity were analysed. The main component and related substances were determined. An analysis of variance proved the absence of consistent laboratory bias. The laboratory-sample interaction was significant. Estimates of the repeatability and reproducibility of the method, expressed as standard deviations of the result of the determination of ampicillin, were calculated to be about 0.9 and 1.1 respectively.

A triose-phosphate isomerase polymorphism in the Atlantic salmon Salmo salar L.

Atlantic salmon, Salmo salar L., from four European locations show allelic variation at one of three triose-phosphate isomerase (TPI) loci (TPI-3*) when separated on horizontal starch gel electrophoresis, using either eye or liver extracts. Two common alleles (*100 and *103) and one rare allele (*97) segregate at TPI-3* with unambiguous typing being possible by observing the interlocus heterodimers. Family studies demonstrate that TPI-3* 100 and *103 are of autosomal location and are inherited in a Mendelian fashion. TPI-3* variation can also be typed in adipose fin tissue, allowing nondestructive tissue sampling. Three loci are also active in brown trout, Salmo trutta, with two individuals being homozygous for TPI-3*, as are a small number of S. salar from eastern Canada. The presence of this additional variable allozyme locus in S. salar is important, since genetic studies in that species have been limited by the low level of allozyme variability detectable.

Prevention of hypokalemia caused by diuretics.

Hypokalemia induced by the use of diuretics is common. Those at risk include the elderly, women, patients with edematous states, and patients in whom higher doses and/or the more potent agents are used. Prevention should include a low-salt diet rich in potassium, magnesium, and chloride (either through foods enriched with these elements or through potassium chloride supplements) and use of low doses of short-acting diuretics in the treatment of mild to moderate hypertension. The subgroup of hypertensive patients in whom hypokalemia develops despite these recommendations may benefit from a change to the potassium-sparing diuretic spironolactone or substitution of diuretics with alternative first-line drugs.

Assessment of hypocalcemia and hypercalcemia.

Methodologic aspects including causes of factitious hypocalcemia and hypercalcemia are summarized. The differential diagnosis of hypocalcemia is reviewed under three main headings: hypoalbuminemia, hypocalcemia with decreased parathyroid hormone (PTH) action or activity, and hypocalcemia with normal PTH action and activity. The differential diagnosis of hypercalcemia is subdivided into three broad categories: hyperproteinemia, PTH-mediated hypercalcemia, and non-PTH-mediated hypercalcemia. The causes of hypocalcemia and hypercalcemia are outlined with a focus on pathophysiology and clinicochemical sequelae. A laboratory perspective is emphasized in outlining management strategies.

Assessment of hyperphosphatemia and hypophosphatemia.

Methodologic aspects including causes of factitious hyperphosphatemia and hypophosphatemia are summarized. The differential diagnosis of hyperphosphatemia is reviewed under its three broad causes: decreased glomerular filtration rate, increased exogenous or endogenous phosphate load, and increased renal tubular phosphate reabsorption. The differential diagnosis of hypophosphatemia is reviewed under its three broad causes: inadequate gastrointestinal input, excess phosphate losses, and transcellular shifts. The consequences of hyperphosphatemia and hypophosphatemia are outlined with a focus on pathophysiologic and clinicochemical sequelae. A laboratory perspective is emphasized in outlining management strategies.

The kidney in sickle cell anemia.

New insights into the physical chemistry and molecular epidemiology of sickle cell anemia have improved our understanding of the pathophysiology of the associated nephropathy, the predictors of this complication, and genetic and other factors that may modify it. In this article, we analyze the current clinicopathologic knowledge with reference to the predilection to nephropathy and the protection from hypertension, as well as the altered renal physiology of the sickle cell state that underlies both these phenomena. In the early stages of sickle cell anemia, the kidney is characterized by impaired function of the renal medulla, as evidenced by reduced capacity to concentrate, acidify, and excrete potassium into the urine. Meanwhile, the cortex functions supranormally, as evidenced by increased renal plasma flow and glomerular filtration rate, proximal tubular function, and urinary diluting capacity. In addition to the complications of hematuria and papillary necrosis, renal insufficiency supervenes in a subgroup of patients. The morphology of the glomerulopathy generally differs between children and adults; in the latter group there is a particularly poor prognosis and markedly shortened life expectancy. Renal replacement therapy has nonetheless been successful. Although hypertension may be found at this stage, it is extremely rare before the onset of significant renal impairment. The possible mechanism of this protection is discussed, with a focus on the compelling need for further investigation in light of the newly gained basic understanding of this hematorenal syndrome.

Effects of maleic acid on renal phosphorus transport: role of dietary phosphorus.

The effects of maleic acid on renal phosphate (Pi) transport were examined by clearance and brush-border membrane vesicle (BBMV) transport studies. In normal rats, maleic acid 50 mg.kg body wt-1.h-1 increased the phosphaturia (P less than 0.001). Intraperitoneal administration of a similar dose of maleic acid decreased the BBMV uptake of Pi but not glucose. In rats fed a low-phosphate diet (0.03%), the maleic acid-induced phosphaturia was blunted, but the inhibitory effect on the BBMV transport of Pi persisted. In chronic parathyroidectomized rats fed a low-phosphate diet, where the filtered load of Pi was higher than in the previous groups, the phosphaturia was abolished, but the inhibition of the BBMV transport of Pi was sustained. Both the in vitro incubation of BBMVV and in vivo administration of maleic acid were associated with a competitive inhibition of Pi transport. These studies indicate that the maleic acid-induced phosphaturia is expressed at the apical membrane entry step of Pi, and the enhanced distal tubular reabsorption accounts for the lack of phosphaturia in dietary Pi deprivation.