Phylogenetic relationships of Trypanosoma chelodina and Trypanosoma binneyi from Australian tortoises and platypuses inferred from small subunit rRNA analyses

Trypanosome infections are often difficult to detect by conventional microscopy and their pleomorphy often confounds differential diagnosis. Molecular techniques are now being used to diagnose infections and to determine phylogenetic relationships between species. Complete small subunit rRNA gene sequences were determined for isolates of Trypanosoma chelodina from the Brisbane River tortoise (Emydura signata), the saw-shelled tortoise (Elseya latisternum), and the eastern snake-necked tortoise (Chelodina longicollis) from southeast Queensland, Australia. Partial sequence data were also obtained for T. binneyi from a platypus (Ornithorhynchus anatinus) from Tasmania. Phylogenetic relationships between T. chelodina, T. binneyi and other species were examined by maximum parsimony and likelihood methods. The Australian tortoise and platypus trypanosomes did not exhibit any close phylogenetic relationships with those of mammals, reptiles or amphibians, but were closely related to each other, and to fish trypanosomes. This contra-indicates their co-evolution with their vertebrate hosts but does not exclude co-evolution with different groups of invertebrate vectors, notably insects and leeches.

Acetazolamide poisoning in a toddler

Acetazolamide ingestion and its sequelae have not been previously reported in children. A 12-month-old girl, weighing 10 kg, developed metabolic acidosis following ingestion of between 500 and 1250 mg of acetazolamide. The maximum base deficit recorded was 11.6. She was treated with sodium bicarbonate and recovered completely. Accidental poisoning should be included in the differential diagnosis of a child presenting with metabolic acidosis.

Granulomatous meningoencephalomyelitis in dogs

Granulomatous meningoencephalomyelitis (GME) is a morphological description of an inflammatory disorder of the canine central nervous system (CNS). It has been reported in many areas of the world. including Australia, and is one of the more common nervous disorders of dogs. Most breeds of dogs of both sexes and all ages can be affected but young to middle-aged small and terrier breeds have been stated as being more susceptible. There are variable anatomical forms and distribution of the lesions in the CNS; the presenting clinical signs can reflect singly or collectively cerebellar, cerebral, and brain stem dysfunction. Meningeal and spinal cord involvement are also common. There is no specific diagnostic test but a combination of clinical signs, history and cerebro-spinal fluid cytology are useful indicators. However differential diagnosis from other inflammatory disorders of the brain is difficult. No infectious agent aetiology has been established for GME and therefore no satisfactory therapeutic approach is available. The role of the immune system in terms of either initiating or potentiating the lesions in the CNS appears to be the most likely direction for further investigation into the nature of this disorder.

Primary aldosteronism

Approaching the fiftieth year since its original description, primary aldosteronism is now thought to be the commonest potentially curable and specifically treatable form of hypertension. Correct identification of patients with primary aldosteronism requires that the effects of time of day, posture, dietary sodium intake, potassium levels and medications on levels of aldosterone and renin be carefully considered. Accurate elucidation of the subtype is essential for optimal treatment, and adrenal venous sampling is the only reliable means of differentiating aldosterone-producing adenoma from bilateral adrenal hyperplasia. With genetic testing already available for one inherited form, making more cumbersome biochemical testing for that subtype virtually obsolete and bringing about improvements in treatment approach, an intense search is underway for genetic mutations causing other, more common familial varieties of primary aldosteronism.

A peritoneal dialysis patient with fatal culture-negative peritonitis

Culture-negative peritoneal inflammation accounts for between 5 and 20% of cases of peritonitis in peritoneal dialysis patients. Diagnostic yields may be enhanced considerably by reculturing dialysate effluents using appropriate collection methods and optimal laboratory techniques (including prolonged low-temperature and anaerobic incubations). In patients with persistent culture-negative peritonitis, consideration should be given to the possibilities of unusual or fastidious microorganisms (especially fungi and mycobacteria) and non-infective causes (especially drug reactions, malignancy, visceral inflammation and retroperitoneal inflammation). In this paper, an illustrative case of persistent culture-negative peritonitis is presented followed by a discussion of the investigative approach to such patients, with particular emphasis on differential diagnosis and the limitations of currently available tests.

A simplified endogenous erythroid colony assay for the investigation of polycythaemia

The in vitro growth of erythroid colonies in the absence of erythropoietin, known as endogenous erythroid colonies (EEC) forms part of the diagnostic criteria for polycythaemia vera (PV). The availability of EEC culture in routine laboratory setting is limited as culture methods are technically demanding, difficult to standardize, expensive and laborious. In this study, we assessed the performance characteristics of a simplified method using ammonium chloride red cell lysis followed by culture on commercially available, batch-tested, methylcellulose media. Seventy-six patients were included; four were secondarily excluded on the basis of culture failure. Of the 14 patients with PV, 13 (93%) were positive for EEC on at least one occasion: 90% (nine of 10) of bone marrow and 67% (six of nine) of peripheral blood specimens were positive. All 30 patients with secondary polycythaemia (n = 12) or apparent polycythaemia (n = 18) were negative for EEC. The incidence of EEC in idiopathic erythrocytosis was 40% (eight of 28); 50% (five of 10) in those who met one of the minor criteria for PV and 17% (three of 18) in those who did not. We conclude that our EEC assay yield results comparable with that of more elaborate methods.

Gene-expression profiling reveals distinct expression patterns for classic versus variant Merkel cell phenotypes and new classifier genes to distinguish Merkel cell from small-cell lung carcinoma

Merkel cell carcinoma (MCC) is a rare aggressive skin tumor which shares histopathological and genetic features with small-cell lung carcinoma (SCLC), both are of neuroendocrine origin. Comparable to SCLC, MCC cell lines are classified into two different biochemical subgroups designated as 'Classic' and 'Variant'. With the aim to identify typical gene-expression signatures associated with these phenotypically different MCC cell lines subgroups and to search for differentially expressed genes between MCC and SCLC, we used cDNA arrays to pro. le 10 MCC cell lines and four SCLC cell lines. Using significance analysis of microarrays, we defined a set of 76 differentially expressed genes that allowed unequivocal identification of Classic and Variant MCC subgroups. We assume that the differential expression levels of some of these genes reflect, analogous to SCLC, the different biological and clinical properties of Classic and Variant MCC phenotypes. Therefore, they may serve as useful prognostic markers and potential targets for the development of new therapeutic interventions specific for each subgroup. Moreover, our analysis identified 17 powerful classifier genes capable of discriminating MCC from SCLC. Real-time quantitative RT-PCR analysis of these genes on 26 additional MCC and SCLC samples confirmed their diagnostic classification potential, opening opportunities for new investigations into these aggressive cancers.

Characterization of acute whiplash-associated disorders

Study Design. An experimental study of motor and sensory function and psychological distress in subjects with acute whiplash injury. Objectives. To characterize acute whiplash injury in terms of motor and sensory systems dysfunction and psychological distress and to compare subjects with higher and lesser levels of pain and disability. Summary of Background Data. Motor system dysfunction, sensory hypersensitivity, and psychological distress are present in chronic whiplash associated disorders ( WAD), but little is known of such factors in the acute stage of injury. As higher levels of pain and disability in acute WAD are accepted as signs of poor outcome, further characterization of this group from those with lesser symptoms is important. Materials and Methods. Motor function ( cervical range of movement [ ROM], joint position error [JPE]; activity of the superficial neck flexors [EMG] during a test of craniocervical flexion), quantitative sensory testing ( pressure, thermal pain thresholds, and responses to the brachial plexus provocation test), and psychological distress (GHQ-28, TAMPA, IES) were measured in 80 whiplash subjects ( WAD II or III) within 1 month of injury, as were 20 control subjects. Results. Three subgroups were identified in the cohort using cluster analysis based on the Neck Disability Index: those with mild, moderate, or severe pain and disability. All whiplash groups demonstrated decreased ROM and increased EMG compared with the controls ( all P < 0.01). Only the moderate and severe groups demonstrated greater JPE and generalized hypersensitivity to all sensory tests ( all P < 0.01). The three whiplash subgroups demonstrated evidence of psychological distress, although this was greater in the moderate and severe groups. Measures of psychological distress did not impact on between group differences in motor or sensory tests. Conclusions. Acute whiplash subjects with higher levels of pain and disability were distinguished by sensory hypersensitivity to a variety of stimuli, suggestive of central nervous system sensitization occurring soon after injury. These responses occurred independently of psychological distress. These findings may be important for the differential diagnosis of acute whiplash injury and could be one reason why those with higher initial pain and disability demonstrate a poorer outcome.

Histoplasmosis in Australia: A report of a case with a review of the literature

Histoplasmosis is a rare but serious fungal infection commonly presenting as mucosal ulceration of the oral cavity. It is increasingly recognized in Australia but the source of infection remains obscure and it is likely to be under-diagnosed. We report a case of chronic mucosal ulceration which failed to fully respond to periodontal therapy. Histology and culture of a gingival biopsy was consistent with histoplasmosis, and the patient responded favourably to treatment with oral itraconazole. Histoplasmosis may present to general dental practitioners as chronic mucosal ulceration and should be considered in the differential diagnosis of such lesions. Diagnosis is best made by culture and histology of biopsy specimens.

Primary aldosteronism - careful investigation is essential and rewarding

Once considered rare, primary aldosteronism (PAL) is now regarded as the commonest potentially curable and specifically treatable form of hypertension. At Greenslopes Hospital Hypertension Unit (GHHU), the decision in 1991 to screen all (and not just hypokalemic or resistant) hypertensives by aldosterone/renin ratio (ARR) testing led to a 10-fold increase in detection rate of PAL and four-fold increase in removal rate of aldosterone-producing adenomas (APAs). The GHHU/Princess Alexandra Hospital Hypertension Unit PAL series stands at 977 patients and 250 APAs removed with hypertension cured in 50-60% (remainder improved). Reliable detection requires that interfering medications are withdrawn (or their effects considered) before ARR measurement, and reliable methods (such as fludrocortisone suppression testing) to confirm PAL. Adrenal venous sampling is the only dependable way to differentiate APA from bilateral adrenal hyperplasia. Genetic testing has facilitated detection of alucocorticoid-remediable, familial PAL. Identification of mutations causing the more common familial variety described by GHHU in 1991 should further aid in detection of PAL. (C) 2003 Elsevier Ireland Ltd. All rights reserved.

Hereditary pancreatitis in a family of Aboriginal descent

Hereditary pancreatitis is an autosomal dominant condition characterized by recurrent episodes of acute pancreatitis, usually starting in childhood. We present a family who was ascertained when an 11-year-old girl presented with an episode of acute pancreatitis. Her father and other family members had also had recurrent bouts of acute pancreatitis. Genetic testing revealed a pathogenic mutation in the cationic trypsinogen gene in the proband, her father and her paternal grandmother. As far as we are aware, this is the first Aboriginal kindred with mutation-proven hereditary pancreatitis. Hereditary pancreatitis is an important differential diagnosis to consider in a patient with recurrent episodes of acute pancreatitis with no obvious precipitating cause. This family is of Aboriginal descent and the implications of the family's background are also discussed when considering the aetiology of the condition. We emphasize the need to ascertain a full family history from patients with a history of repeated episodes of acute pancreatitis and also emphasize the need to avoid ethnic stereotypes when assessing patients.

Syringomatous adenoma of the nipple

Infiltrating syringomatous adenoma (SA) of the nipple is a rare but distinct benign clinical entity affecting the breast. It needs to be included in the differential diagnosis of patients who present with a lump in the nipple/areola complex. It is similar histologically to a syringoma, a benign tumour originating in the ducts of the dermal sweat glands, and importantly needs to be distinguished from a tubular carcinoma. SA of the nipple is locally infiltrating but is not known to metastasise. It often presents as a subareolar lesion with clinical, mammographic and ultrasound findings suspicious for malignancy. Whilst it may be possible to suspect the diagnosis on fine needle cytology, core biopsy or excisional biopsy is usually required to establish the diagnosis. There is a tendency to recurrence if excision is incomplete. The following is a case report, literature review and discussion of the surgical management options available in this unusual condition. (C) 2004 Elsevier Ltd. All rights reserved.

Polioviruses and other enteroviruses isolated from faecal samples of patients with acute flaccid paralysis in Australia, 1996-2004

Background: Acute flaccid paralysis (AFP) is the most common clinical presentation of acute poliovirus infection, occurring in 0.1-1% of infected cases. AFP surveillance has been used world-wide to monitor the control and eradication of circulating wild poliovirus. This study aims to review the significance of all enteroviruses, including polioviruses, isolated from patients with AFP in Australia between 1996 and 2004. Methods: We undertook a retrospective review of all notified cases of AFP, aged 0-15 years and resident in Australia at the time of notification. We reviewed all available clinical and virological data for these cases and all records of the Polio Expert Committee, which determined the final classification for all cases. Results: There were 335 notified cases that satisfied the case definition for AFP, 162 (48%) of whom had at least one faecal sample tested. Enteroviruses isolated from the faeces of 26 (16%) of the 162 cases were Coxsackie A24, Coxsackie B5, enterovirus 71, enterovirus 75, echovirus 9, echovirus 11 and echovirus 18. In addition, one or more polioviruses were isolated from the faeces of seven patients. Six of seven polioviruses were characterised as Sabin-like, one was not characterised, but all were considered to be incidental isolates. Five of these cases were classified as infant botulism, one case as transverse myelitis and one as a focal mononeuropathy. Conclusion: With the eradication of circulating wild polioviruses, other enteroviruses are being more commonly identified as the cause of polio-like illnesses. In the polio end game, when there is increased testing for polioviruses, it is important to consider infant botulism as a differential diagnosis in cases presenting with AFP.