From gut dysbiosis to altered brain function and mental illness: mechanisms and pathways

The human body hosts an enormous abundance and diversity of microbes, which perform a range of essential and beneficial functions. Our appreciation of the importance of these microbial communities to many aspects of human physiology has grown dramatically in recent years. We know, for example, that animals raised in a germ-free environment exhibit substantially altered immune and metabolic function, while the disruption of commensal microbiota in humans is associated with the development of a growing number of diseases. Evidence is now emerging that, through interactions with the gut-brain axis, the bidirectional communication system between the central nervous system and the gastrointestinal tract, the gut microbiome can also influence neural development, cognition and behaviour, with recent evidence that changes in behaviour alter gut microbiota composition, while modifications of the microbiome can induce depressive-like behaviours. Although an association between enteropathy and certain psychiatric conditions has long been recognized, it now appears that gut microbes represent direct mediators of psychopathology. Here, we examine roles of gut microbiome in shaping brain development and neurological function, and the mechanisms by which it can contribute to mental illness. Further, we discuss how the insight provided by this new and exciting field of research can inform care and provide a basis for the design of novel, microbiota-targeted, therapies.GB Rogers, DJ Keating, RL Young, M-L Wong, J Licinio, and S Wesseling

Septooptic Dysplasia with an Associated Arachnoid Cyst

A 4-week-old male infant presented with hypothermia, hypoglycemia, and hyperbilirubinemia. His medical history was remarkable for hydrocephalus secondary to an arachnoid cyst, intermittent hypoglycemia, hypothermia, and poor feeding requiring nasogastric tube for nutrition. Physical exam revealed retrognathia, mild hypotonia, micropenis, and clinodactyly. Ophthalmologic exam demonstrated bilateral optic nerve hypoplasia (ONH). Laboratory data confirmed inadequate cortisol and growth hormone response to hypoglycemia, a low thyroxine level, and direct hyperbilirubinemia. Magnetic resonance imaging of the brain confirmed the known history of arachnoid cyst with hydrocephalus but also revealed anterior pituitary hypoplasia, absence of the posterior pituitary bright spot, a thin pituitary stalk, and bilateral optic nerve hypoplasia. A diagnosis of septooptic dysplasia (SOD) was made. Hormone replacement with hydrocortisone and levothyroxine was started with improvement in the infant’s glycemic control, thermoregulation, feeding, and cholestasis. This case reinforces the importance of careful physical examination and laboratory review in a patient with known history of arachnoid cyst which has been previously described as an associated feature of optic nerve hypoplasia and hypopituitarism

Case Report Differing Tales of Two Patients after Receiving a Kidney Transplant from a Donor with Disseminated Intravascular Coagulation

In order to decrease the time on the deceased donor kidney wait list and to have more organs available, criteria for acceptable organs for transplant could be made less stringent. There are reports of successful recipient outcomes using kidney donors presenting with disseminated intravascular coagulation (DIC). We report a unique circumstance where two patients received kidneys from the same deceased donor who had DIC; one patient developed thrombotic microangiopathy (TMA) while the other did not. This difference in outcome may indicate that both donor and recipient factors contribute to the development of posttransplant TMA

Spinal cord compression due to an extra-dural intra-vascular papillary endothelial hyperplasia of the thoracic spine

We present a case of spinal cord compression in a 33-year-old male due to a T6–T7 paravertebral mass extending through the intervertebral foramen into the vertebral canal. Histopathological feature was consistent with an intra-vascular papillary endothelial hyperplasia. Differential diagnosis of the lesion and review of the literature are presented