Prevalence of and risk factors for HIV-associated neuropathy in Melbourne, Australia 1993-2006

OBJECTIVES: The aim of the study was to describe the prevalence of and risk factors for HIV-associated sensory neuropathy (HIV-SN) in 2006 [the era of stavudine, didanosine and zalcitabine (dNRTI)-sparing highly active antiretroviral therapy (HAART)] and to compare our findings with data obtained in the same clinic in 1993 (pre-HAART) and 2001 (frequent use of dNRTI-containing HAART). METHODS: This was a cross-sectional comparative study using convenience sampling. HIV-positive adults attending a tertiary referral clinic over a 2-week period were screened for HIV-SN using the AIDS Clinical Trials Group screening tool. HIV-SN was defined as present if the patient had both neuropathic symptoms and abnormal signs. Demographic, clinical, laboratory and treatment data were considered as possible risk factors for HIV-SN, and results were compared with data obtained in the same clinic in 1993 and 2001. RESULTS: One hundred patients were screened. The prevalence of HIV-SN was 42%, which was unchanged since 2001 (44%) despite a significant reduction in the use of dNRTIs. HIV-SN remained much more common than in 1993 (42% vs 13%; P<0.0001). The only independent associations with HIV-SN in 2006 were increasing patient age and a history of exposure to either stavudine or indinavir. This compares with 1993 when neuropathy was increased in those with Mycobacterium avium complex infection, and 2001 when patient age and use of stavudine and didanosine were the independent associations with HIV-SN in this clinic. CONCLUSIONS: HIV-SN remained common among ambulatory patients in 2006 (42% prevalence) despite a significant reduction in the use of dNRTIs. In addition to patient age and stavudine exposure, indinavir use may be a risk factor for HIV-SN.     

CT findings of rupture, impending rupture, and contained rupture of abdominal aortic aneurysms

OBJECTIVE: With the increasing use of cross-sectional imaging for a variety of medical and surgical conditions affecting the abdomen and pelvis, familiarity with the imaging features of aneurysm rupture--and the findings suspicious for impending or contained aneurysm rupture--is crucial for all radiologists. This pictorial essay will review the imaging findings of rupture of abdominal aortic aneurysms and of complicated aneurysms. CONCLUSION: Prompt detection of abdominal aortic aneurysm rupture or impending rupture is critical because emergent surgery may be required and patient survival may be at stake.     

Pituitary corticotroph hyperplasia preceding adenoma in a patient with Nelson's syndrome

We report the case of a 42-year-old woman with Cushing's disease and Nelson's syndrome. When she was 17 years old, transsphenoidal surgery was performed. A detailed morphologic study demonstrated nodular hyperplasia of corticotroph cells but no adenoma. Following a long-lasting remission (14 years), Cushing's disease recurred. After an unsuccessful second transsphenoidal surgery, Cushing's disease persisted and both adrenals were removed (at the age of 34). Subsequently the patient developed Nelson's syndrome. The pituitary tumor proved to be a corticotroph adenoma; it was removed by the transsphenoidal approach (at the age of 42). Although in most patients Cushing's disease is due to an ACTH-secreting pituitary corticotroph adenoma which precedes the manifestation of Nelson's syndrome, our case indicates not only that corticotroph hyperplasia may cause Cushing's disease but that it may exist before the development of Nelson's syndrome after the removal of both adrenals. Our study supports the view that protracted stimulation of corticotrophs resulting from the elimination of the negative inhibitory feedback effect by corticosteroids plays a role in adenoma initiation.     

A case report of gadopentetate dimeglumine-induced cardiac arrest: Resuscitation using extracorporeal membrane oxygenation

Gadopentetate dimeglumine (Gd-DTPA) is commonly used for enhancement in magnetic resonance imaging, but rarely causes serious adverse reactions. The patient presented in this report had a cardiac arrest and multiple organ dysfunction syndrome within a short time after administration of Gd-DTPA. Immediately after receiving an intravenous injection of Gd-DTPA, the patient felt nausea and chest tightness, and developed systemic erythema. He was successfully treated using veno-arterial extracorporeal membrane oxygenation (ECMO) combined with continuous renal replacement therapy without any serious complications or neurological deficits. We report a patient who was successfully treated for Gd-DTPA-induced cardiac arrest with ECMO. Thus, ECMO may be an effective treatment for cardiac arrest secondary to anaphylaxis.     

Are emergency department nurse practitioners homeless?

The professional body for nurses working in emergency medicine is the College of Emergency Nursing Australasia. The professional body for doctors working in emergency medicine is the Australasian College for Emergency Medicine (ACEM). There is no professional body for nurse practitioners working in emergency medicine. The clinical role of nurse practitioners in emergency medicine more closely resembles that of doctors rather than nurses. Associate membership in ACEM would recognise their role in treating patients and would enhance their access to relevant continued professional development as has been endorsed by ACEM. It would also facilitate their further integration into the body of those who autonomously treat patients in the ED.     

An Autism-Associated Mutation Impairs Neuroligin-4 Glycosylation and Enhances Excitatory Synaptic Transmission in Human Neurons

Neuroligins (NLGNs) are a class of postsynaptic cell adhesion molecules that interact with presynaptic neurexins (NRXNs) and regulate synapse function. NLGN4 is a member of the NLGN family and consists of a unique amino acid sequence in humans that is not evolutionarily well conserved in rodents. The human-specific NLGN4 gene has been reported to be mutated in many patients with autism and other neurodevelopmental disorders. However, it remained unclear how these mutations might alter the molecular properties of NLGN4 and affect synaptic transmission in human neurons. Here, we describe a severely autistic male patient carrying a single amino acid substitution (R101Q) in the NLGN4 gene. When expressed in HEK293 cells, the R101Q mutation in NLGN4 did not affect its binding affinity for NRXNs or its capacity to form homodimers. This mutation, however, impaired the maturation of NLGN4 protein by inhibiting N-linked glycosylation at an adjacent residue (N102), which is conserved in all NLGNs. As a result, the R101Q substitution significantly decreased the surface trafficking of NLGN4 and increased its retention in the endoplasmic reticulum and Golgi apparatus. In human neurons derived from male stem cell lines, the R101Q mutation also similarly reduced the synaptic localization of NLGN4, resulting in a loss-of-function phenotype. This mutation-induced trafficking defect substantially diminished the ability of NLGN4 to form excitatory synapses and modulate their functional properties. Viewed together, our findings suggest that the R101Q mutation is pathogenic for NLGN4 and can lead to synaptic dysfunction in autism.     

Nasal Trauma: Who Nose what happens to the non-manipulated?

Background:Nasal trauma is the most common facial injury worldwide. Prompt assessment allows for recognition of injuries requiring surgical intervention in the form of nasal bone manipulation. The literature is unclear to what extent patients undergoing conservative management subsequently require surgical intervention.Methods:A retrospective chart review of all patients presenting with nasal injury between July 2017 and July 2018 who underwent conservative and surgical management was undertaken. Re-referral and subsequent surgical intervention were documented.Results:In a cohort of 390 patients with nasal injury 229 patients underwent conservative management. Average age was 29 years. Males comprised 60% of our conservative cohort and 81% of the manipulated cohort. 8.3% of patients managed conservatively and 12% of those undergoing manipulation were re-referred.Conclusion:Nasal trauma assessment is a significant workload for an ENT unit. Conservative management is appropriate following clinical assessment and does not lead to increased intervention compared with those who are surgically manipulated.