Michael R. Wilson

Actionable Diagnosis of Neuroleptospirosis by Next-Generation Sequencing

A 14-year-old boy with severe combined immunodeficiency presented three times to a medical facility over a period of 4 months with fever and headache that progressed to hydrocephalus and status epilepticus necessitating a medically induced coma. Diagnostic workup including brain biopsy was unrevealing. Unbiased next-generation sequencing of the cerebrospinal fluid identified 475 of 3,063,784 sequence reads (0.016%) corresponding to leptospira infection. Clinical assays for leptospirosis were negative. Targeted antimicrobial agents were administered, and the patient was discharged home 32 days later with a status close to his premorbid condition. Polymerase-chain-reaction (PCR) and serologic testing at the Centers for Disease Control and Prevention (CDC) subsequently confirmed evidence of Leptospira santarosai infection.

Case Definitions, Diagnostic Algorithms, and Priorities in Encephalitis: Consensus Statement of the International Encephalitis Consortium

BACKGROUND Encephalitis continues to result in substantial morbidity and mortality worldwide. Advances in diagnosis and management have been limited, in part, by a lack of consensus on case definitions, standardized diagnostic approaches, and priorities for research. METHODS In March 2012, the International Encephalitis Consortium, a committee begun in 2010 with members worldwide, held a meeting in Atlanta to discuss recent advances in encephalitis and to set priorities for future study. RESULTS We present a consensus document that proposes a standardized case definition and diagnostic guidelines for evaluation of adults and children with suspected encephalitis. In addition, areas of research priority, including host genetics and selected emerging infections, are discussed. CONCLUSIONS We anticipate that this document, representing a synthesis of our discussions and supported by literature, will serve as a practical aid to clinicians evaluating patients with suspected encephalitis and will identify key areas and approaches to advance our knowledge of encephalitis.

Neuroanatomical correlates of impaired recognition of emotion in dementia

Neurodegenerative diseases frequently affect brain regions important for emotional processing, offering a valuable opportunity to study the effects of brain injury on emotion. The current study examined the neuroanatomical correlates of impaired recognition of emotions in patients with neurodegenerative disease. Performance on recognition of facial expressions, as measured by the Florida Affect Battery, was correlated with regional changes in gray matter tissue content in 50 patients with neurodegenerative disease using voxel-based morphometry. Recognition accuracy in the group was poor for negative emotions (fear, anger and sadness) and good for happiness, consistent with previous studies. For negative emotions, a region in the right lateral inferior temporal gyrus (Brodmans area (BA) 20) extending into the right middle temporal gyrus (BA 21) was correlated with accuracy. This effect appeared to be strongest for sadness, which was also independently correlated with atrophy in the superior temporal gyrus. These data suggest that regions in the right lateral and inferolateral temporal lobe are important for visual processing of negative emotions from faces and that functioning of this right temporal network is most critical for recognition of sad faces.

Diagnosing Balamuthia mandrillaris Encephalitis With Metagenomic Deep Sequencing

Identification of a particular cause of meningoencephalitis can be challenging owing to the myriad bacteria, viruses, fungi, and parasites that can produce overlapping clinical phenotypes, frequently delaying diagnosis and therapy. Metagenomic deep sequencing (MDS) approaches to infectious disease diagnostics are known for their ability to identify unusual or novel viruses and thus are well suited for investigating possible etiologies of meningoencephalitis.

Depletion of Abundant Sequences by Hybridization (DASH): using Cas9 to remove unwanted high-abundance species in sequencing libraries and molecular counting applications.

Next-generation sequencing has generated a need for a broadly applicable method to remove unwanted high-abundance species prior to sequencing. We introduce DASH (Depletion of Abundant Sequences by Hybridization). Sequencing libraries are ‘DASHed’ with recombinant Cas9 protein complexed with a library of guide RNAs targeting unwanted species for cleavage, thus preventing them from consuming sequencing space. We demonstrate a more than 99 % reduction of mitochondrial rRNA in HeLa cells, and enrichment of pathogen sequences in patient samples. We also demonstrate an application of DASH in cancer. This simple method can be adapted for any sample type and increases sequencing yield without additional cost.

Scattering of Ne from the liquid–vapor interface of glycerol: A molecular dynamics study

A model potential for the scattering of Ne off liquid glycerol is developed. The model is based on a nine‐site description of glycerol which takes into account torsional flexibility and hydrogen bonding. This model is used to carry out molecular dynamics calculations of the scattering as a function of collision energy. The results for the sticking probability and energy transfer are in good agreement with experiments. The model predicts a wide angular distribution of the scattered atoms with a mild decrease in the energy transfer as a function of exit angle for a fixed incident angle. The model also provides insight into the importance of the corrugated nature of the surface and the types of liquid modes that play a major role in the energy transfer process.

Tendon shift in hallux valgus : observations at MR imaging

Abstract Objective. This study was undertaken to demonstrate a shift in tendon alignment at the first metatarsophalangeal joint in patients with hallux valgus by means of magnetic resonance imaging. Design. Ten normal feet and 20 feet with the hallux valgus deformity conforming to conventional clinical and radiographic criteria were prospectively studied using magnetic resonance imaging. Correlation was made between tendon position at the first metatarsophalangeal joint and the severity of the hallux valgus deformity. Results. There is a significant shift in tendon position at the first metatarsophalangeal joint of patients with hallux valgus. The insertion of the abductor hallucis tendon is markedly plantarward and the flexor and extensor tendons bowstring at the first metatarsophalangeal joint compared with patients without the deformity. The severity of the tendon shift correlates with the hallux valgus angle and clinical severity of the hallux valgus deformity in each case. Conclusion. Patients with hallux valgus have a significant tendon shift at the first metatarsophalangeal joint which appears to contribute to development of the deformity.

A Novel Cause of Chronic Viral Meningoencephalitis: Cache Valley Virus

Immunodeficient patients are particularly vulnerable to neuroinvasive infections that can be challenging to diagnose. Metagenomic next generation sequencing can identify unusual or novel microbes and is therefore well suited for investigating the etiology of chronic meningoencephalitis in immunodeficient patients.

Achilles tendon ruptures: functional outcome of surgical repair with a "pull-out" wire.

This is a retrospective review of 30 consecutive patients with acute Achilles tendon ruptures treated surgically by a single surgeon between 1992 and 1999. Repair was effected with a 26-gauge “pull-out” wire technique. A compressive dressing reinforced with plaster was employed to immobilize the ankle in neutral for 6 weeks. The hardware was removed 6 weeks postoperatively under local anesthesia. Intensive physical therapy was employed until ankle motion was symmetric and single heel raise was possible. Average follow-up was 4 years (range, 1–8 years). Nearly all patients (29/30) report satisfaction with their outcome. Most patients (29/30) had AOFAS Ankle-Hindfoot Scores greater than 90. Twenty-three (77%) returned to preoperative levels of athletic activities. Isometric testing documented 81% plantarflexion strength compared to the normal ankle at a mean of 32 months postoperatively. Five of eight women reported shoe wear difficulties related to the incision. There were no reruptures or deep infections. The “pull-out” wire technique is recommended for patients who wish to return to an active lifestyle. This method provides rigid approximation of tendon length, minimizes strangulation of tissue, repairs large gaps, and avoids late foreign-body reactions.

A tale of two approaches: how metagenomics and proteomics are shaping the future of encephalitis diagnostics.

PURPOSE OF REVIEW We highlight how metagenomics and proteomics-based approaches are being applied to the problem of diagnosis in idiopathic encephalitis. RECENT FINDINGS Low cost, high-throughput next-generation sequencing platforms have enabled unbiased sequencing of biological samples. Rapid sequence-based computational algorithms then determine the source of all the nonhost (e.g., pathogen-derived) nucleic acids in a sample. This approach recently identified a case of neuroleptospirosis, resulting in a patients dramatic clinical improvement with intravenous penicillin. Metagenomics also enabled the discovery of a neuroinvasive astrovirus in several patients. With regard to autoimmune encephalitis, advances in high throughput and efficient phage display of human peptides resulted in the discovery of autoantibodies against tripartite motif family members in a patient with paraneoplastic encephalitis. A complementary assay using ribosomes to display full-length human proteins identified additional autoantibody targets. SUMMARY Metagenomics and proteomics represent promising avenues of research to improve upon the diagnostic yield of current assays for infectious and autoimmune encephalitis, respectively.