Citations

ABSTRACT Central nervous system infection due to herpes simplex virus (HSV) is a medical emergency and requires rapid diagnosis and initiation of therapy. In this study, we compared a routine real-time PCR assay for HSV types 1 (HSV-1) and 2 (HSV-2) to a recently FDA-approved direct PCR assay (Simplexa HSV-1/2 Direct; Focus Diagnostics, Cypress, CA) using cerebrospinal fluid samples ( n = 100). The Simplexa HSV-1/2 assays demonstrated a combined sensitivity and specificity of 96.2% (50/52) and 97.9% (47/48), respectively. In addition, the Simplexa assay does not require nucleic acid extraction, and the results are available in 60 min.

ABSTRACT Many viruses utilize cell adhesion molecules of the immunoglobulin superfamily as receptors. In particular, viruses of different classes exploit nectins. The large DNA viruses, herpes simplex and pseudorabies viruses, use ubiquitous nectins 1 and 2. The negative-strand RNA virus measles virus (MeV) uses tissue-specific nectin-4, and the positive-strand RNA virus poliovirus uses nectin-like 5 (necl-5), also known as poliovirus receptor. These viruses contact the BC, C′C″, and FG loops on the upper tip of their receptor's most membrane-distal domain. This location corresponds to the newly defined canonical adhesive interface of nectins, but how viruses utilize this interface has remained unclear. Here we show that the same key residues in the BC and FG loops of nectin-4 govern binding to the MeV attachment protein hemagglutinin (H) and cell entry, nectin-4 homodimerization, and heterodimerization with nectin-1. On the other hand, residues in the C′C″ loop necessary for homo- and heterotypic interactions are dispensable for MeV-induced fusion and cell entry. Remarkably, the C′C″ loop governs dissociation of the nectin-4 and H ectodomains. We provide formal proof that H can interfere with the formation of stable nectin-1/nectin-4 heterodimers. Finally, while developing an alternative model to study MeV spread, we observed that polarized primary pig airway epithelial sheets cannot be infected. We show that a single amino acid variant in the BC loop of pig nectin-4 fully accounts for restricted MeV entry. Thus, the three loops forming the adhesive interface of nectin-4 have different roles in supporting MeV H association and dissociation and MeV-induced fusion. IMPORTANCE Different viruses utilize nectins as receptors. Nectins are immunoglobulin superfamily glycoproteins that mediate cell-cell adhesion in vertebrate tissues. They interact through an adhesive interface located at the top of their membrane-distal domain. How viruses utilize the three loops forming this interface has remained unclear. We demonstrate that while nectin-nectin interactions require residues in all three loops, the association of nectin-4 with the measles virus hemagglutinin requires only the BC and FG loops. However, we discovered that residues in the C′C″ loop modulate the dissociation of nectin-4 from the viral hemagglutinin. Analogous mechanisms may support cell entry of other viruses that utilize nectins or other cell adhesion molecules of the immunoglobulin superfamily as receptors.

Batracylin (NSC-320846) is a dual inhibitor of DNA topoisomerases I and II. Batracylin advanced as an anticancer agent to Phase I clinical trials where dose limiting hemorrhagic cystitis (bladder inflammation and bleeding) was observed. To further investigate batracylin’s mechanism of toxicity, studies were conducted in Fischer 344 rats. Once daily oral administration of 16 or 32 mg/kg batracylin to rats for 4 days caused overt toxicity. Abnormal clinical observations and adverse effects on clinical pathology, urinalysis, and histology indicated acute renal damage and urothelial damage and bone marrow dysfunction. Scanning electron microscopy revealed sloughing of the superficial and intermediate urothelial layers. DNA damage was evident in kidney and bone marrow as indicated by histone γ-H2AX immunofluorescence. After a single oral administration of 16 or 32 mg/kg, the majority of batracylin was converted to N-acetylbatracylin (NAB) with a half-life of 4 hr to 11 hr. Mesna (Mesnex™), a drug known to reduce the incidence of hemorrhagic cystitis induced by ifosfamide or cyclophosphamide, was administered to rats prior to batracylin, but did not alleviate batracylin-induced bladder and renal toxicity. These findings suggest that batracylin results in DNA damage-based mechanisms of toxicity and not an acrolein-based mechanism of toxicity as occurs after ifosfamide or cyclophosphamide administration.

Objective (1) To characterize long‐term dizziness following observation, microsurgery, and stereotactic radiosurgery (SRS) for small to medium‐sized vestibular schwannoma (VS) using a validated self‐assessment inventory; and (2) to identify clinical variables associated with long‐term dizziness handicap. Study Design Cross‐sectional observational study. Setting Two independent tertiary academic referral centers: one located in the United States and one in Norway. Subjects and Methods All patients with sporadic VS of less than 3 cm who underwent primary microsurgery, SRS, or observation between 1998 and 2008 were identified. Subjects were surveyed via a postal questionnaire using the Dizziness Handicap Inventory (DHI) and a VS symptom questionnaire. Results The overall survey response rate was 79%. A total of 538 respondents (mean age, 64 years; 56% female) were analyzed, and the mean time interval between treatment and survey was 7.7 years. Pretreatment variables associated with greater dizziness handicap included female sex, older age, larger tumor size, preexisting diagnosis of headache or migraine, and symptoms of dizziness predating treatment. Significant posttreatment features strongly associated with poor long‐term DHI scores included frequency and severity of ongoing headache. On multivariable analysis, treatment modality did not influence long‐term dizziness handicap. Conclusion At a mean of approximately 8 years following treatment, over half of patients with VS reported ongoing dizziness. The authors have identified several baseline features that may help predict the risk of lasting dizziness. Treatment modality does not appear to influence long‐term DHI score. We found a strong association between posttreatment headache and poor dizziness handicap. Future study is needed to further define this relationship.

Abstract The lack of readily available biomarkers is a significant hindrance toward progressing to effective therapeutic and preventative strategies for Alzheimer's disease (AD). Blood‐based biomarkers have potential to overcome access and cost barriers and greatly facilitate advanced neuroimaging and cerebrospinal fluid biomarker approaches. Despite the fact that preanalytical processing is the largest source of variability in laboratory testing, there are no currently available standardized preanalytical guidelines. The current international working group provides the initial starting point for such guidelines for standardized operating procedures (SOPs). It is anticipated that these guidelines will be updated as additional research findings become available. The statement provides (1) a synopsis of selected preanalytical methods utilized in many international AD cohort studies, (2) initial draft guidelines/SOPs for preanalytical methods, and (3) a list of required methodological information and protocols to be made available for publications in the field to foster cross‐validation across cohorts and laboratories.

We describe a slowly progressive myopathy in 7 unrelated adult patients with storage of polyglucosan in muscle fibers. Genetic investigation revealed homozygous or compound heterozygous deleterious variants in the glycogenin‐1 gene (GYG1). Most patients showed depletion of glycogenin‐1 in skeletal muscle, whereas 1 showed presence of glycogenin‐1 lacking the C‐terminal that normally binds glycogen synthase. Our results indicate that either depletion of glycogenin‐1 or impaired interaction with glycogen synthase underlies this new form of glycogen storage disease that differs from a previously reported patient with GYG1 mutations who showed profound glycogen depletion in skeletal muscle and accumulation of glycogenin‐1. Ann Neurol 2014;76:891–898

Pancreatectomy is associated with significant morbidity and unpredictable outcome, with few diagnostic tools to determine, which patients gain the most benefit from this treatment, especially before the operation. This study aimed to define a preoperative signature panel of serum markers to indicate response to pancreatectomy for pancreatic cancer. Over 1000 patients with pancreatic cancer treated at two independent high‐volume institutions were included in this study and were divided into three groups, including resected, locally advanced and metastatic. Eight serum tumor markers most commonly used in gastrointestinal cancers were analyzed for patient outcome. Preoperative CA19‐9 independently indicated surgical response in pancreatic cancer. Patients with CA19‐9 ≥1000 U/mL generally had a poor surgical benefit. However, a subset of these patients still achieved a survival advantage when CA19‐9 levels decreased postoperatively. CEA and CA125 in the presence of CA19‐9 ≥1000 U/mL could independently predict the non‐decrease of CA19‐9 postoperatively. The combination of the three markers was useful for predicting a worse surgical outcome with a median survival of 5.1 months vs. 23.0 months (p < 0.001) for the training cohort and 7.0 months vs. 18.2 months (p < 0.001) for the validation cohort and also suggested a higher prevalence of early distant metastasis after surgery. Resected patients with this proposed signature showed no survival advantage over patients in the locally advanced group who did not receive pancreatectomy. Therefore, a preoperative serum signature of CEA+/CA125+/CA19‐9 ≥1000 U/mL is associated with poor surgical outcome and can be used to select appropriate patients with pancreatic cancer for pancreatectomy.

AbstractThe GM2 gangliosidoses are a group of autosomal recessive lysosomal storage disorders caused by defective β‐hexosaminidase. There are three clinical conditions in this group: Tay‐Sachs disease (TSD), Sandhoff disease (SD), and hexosaminidase activator deficiency. The three conditions are clinically indistinguishable. TSD and SD have been identified with infantile, juvenile, and adult onset forms. The activator deficiency is only known to present with infantile onset. Diagnosis of TSD and SD is based on decreased hexosaminidase activity and a change in the percentage of activity between isoforms. There are no biochemical tests currently available for activator deficiency. This unit provides a detailed procedure for identifying TSD and SD in affected individuals and carriers from leukocyte samples, the most robust sample type available. Curr. Protoc. Hum. Genet. 83:17.16.1‐17.16.8. © 2014 by John Wiley & Sons, Inc.