eScholarship@UMMS

Case report of a patient with a skin lesion.

Drug resistance occurs through a series of subtle changes that maintain substrate recognition but no longer permit inhibitor binding. In HIV-1 protease, mutations at I50 are associated with such subtle changes that confer differential resistance to specific inhibitors. Residue I50 is located at the protease flap tips, closing the active site upon ligand binding. Under selective drug pressure, I50V/L substitutions emerge in patients, compromising drug susceptibility and leading to treatment failure. The I50V substitution is often associated with amprenavir (APV) and darunavir (DRV) resistance, while the I50L substitution is observed in patients failing atazanavir (ATV) therapy. To explain how APV, DRV, and ATV susceptibility are influenced by mutations at residue 50 in HIV-1 protease, structural and binding thermodynamics studies were carried out on I50V/L-substituted protease variants in the compensatory mutation A71V background. Reduced affinity to both I50V/A71V and I50L/A71V double mutants is largely due to decreased binding entropy, which is compensated for by enhanced enthalpy for ATV binding to I50V variants and APV binding to I50L variants, leading to hypersusceptibility in these two cases. Analysis of the crystal structures showed that the substitutions at residue 50 affect how APV, DRV, and ATV bind the protease with altered van der Waals interactions and that the selection of I50V versus I50L is greatly influenced by the chemical moieties at the P1 position for APV/DRV and the P2 position for ATV. Thus, the varied inhibitor susceptibilities of I50V/L protease variants are largely a direct consequence of the interdependent changes in protease inhibitor interactions.

OBJECTIVE: To describe pancreatic function during the first year of life in infants diagnosed with cystic fibrosis (CF) using serial fecal elastase measurements.

STUDY DESIGN: This was a longitudinal study of 82 infants diagnosed with CF through newborn screening. Monthly stool samples were sent to a central laboratory for fecal elastase measurements.

RESULTS: A total of 61 infants had an initial stool sample obtained at age 9 months. Twenty-six of 29 infants with a fecal elastase value /g at study entry had a fecal elastase value /g (the accepted cutoff value for pancreatic insufficiency) on all measurements during the year; all 29 had a value /g at the end of the study. Of the 48 infants with initial fecal elastase value /g, 13 had at least 1 fecal elastase value >200 mug/g but had a final stool fecal elastase value /g; however, 4 infants with an initial fecal elastase value /g ended the year with a value >200 mug/g. Eleven of 13 infants with an initial fecal elastase value of >200 mug/g still had a value >200 mug/g at the end of the first year.

CONCLUSION: Infants with CF exhibit variability in fecal elastase values during the first year. Infants with a fecal elastase level of 50-200 mug/g at diagnosis should be treated with pancreatic enzyme replacement therapy, but fecal elastase should be remeasured at age 1 year to ensure that those with a falsely low value do not continue to receive pancreatic enzyme replacement therapy unnecessarily. Those with a fecal elastase value >200 mug/g initially can become pancreatic insufficient with time.

Polymeric microparticles have been widely investigated as platforms for delivery of drugs, vaccines, and imaging contrast agents and are increasingly used in a variety of clinical applications. Microparticles activate the inflammasome complex and induce the processing and secretion of IL-1beta, a key innate immune cytokine. Recent work suggests that although receptors are clearly important for particle phagocytosis, other physical characteristics, especially shape, play an important role in the way microparticles activate cells. We examined the role of particle surface texturing not only on uptake efficiency but also on the subsequent immune cell activation of the inflammasome. Using a method based on emulsion processing of amphiphilic block copolymers, we prepared microparticles with similar overall sizes and surface chemistries but having either smooth or highly microtextured surfaces. In vivo, textured (budding) particles induced more rapid neutrophil recruitment to the injection site. In vitro, budding particles were more readily phagocytosed than smooth particles and induced more lipid raft recruitment to the phagosome. Remarkably, budding particles also induced stronger IL-1beta secretion than smooth particles through activation of the NLRP3 inflammasome. These findings demonstrate a pronounced role of particle surface topography in immune cell activation, suggesting that shape is a major determinant of inflammasome activation.

OBJECTIVE: This study examined the effect of adjunctive intranasal insulin therapy on psychopathology and cognition in patients with schizophrenia.

METHODS: Each subject had a Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, diagnosis of schizophrenia or schizoaffective disorder and been on stable antipsychotics for at least 1 month. In an 8-week randomized, double-blind, placebo-controlled study, subjects received either intranasal insulin (40 IU 4 times per day) or placebo. Psychopathology was assessed using the Positive and Negative Syndrome Scale and the Scale for Assessment of Negative Symptoms. A neuropsychological battery was used to assess cognitive performance. The assessment for psychopathology and cognition was conducted at baseline, week 4, and week 8.

RESULTS: A total of 45 subjects were enrolled in the study (21 in the insulin group and 24 in the placebo group). The mixed model analysis showed that there were no significant differences between the 2 groups at week 8 on various psychopathology and cognitive measures (P > 0.1).

CONCLUSIONS: Adjunctive therapy with intranasal insulin did not seem to be beneficial in improving schizophrenia symptoms or cognition in the present study. The implications for future studies were discussed.

Metazoan organisms assemble two isoforms of the oligosaccharyltransferase (OST) that have different catalytic subunits (STT3A or STT3B) and partially nonoverlapping roles in asparagine-linked glycosylation. The STT3A isoform of the OST is primarily responsible for co-translational glycosylation of the nascent polypeptide as it enters the lumen of the endoplasmic reticulum. The C-terminal 65-75 residues of a glycoprotein will not contact the translocation channel-associated STT3A isoform of the OST complex before chain termination. Biosynthetic pulse labeling of five human glycoproteins showed that extreme C-terminal glycosylation sites were modified by an STT3B-dependent posttranslocational mechanism. The boundary for STT3B-dependent glycosylation of C-terminal sites was determined to fall between 50 and 55 residues from the C terminus of a protein. C-terminal NXT sites were glycosylated more rapidly and efficiently than C-terminal NXS sites. Bioinformatics analysis of glycopeptide databases from metazoan organisms revealed a lower density of C-terminal acceptor sites in glycoproteins because of reduced positive selection of NXT sites and negative selection of NXS sites.

We read the article of Hayakawa et al with great interest. The report describes the growing prevalence of vancomycin-resistant Enterococcus faecalis in Michigan, a state that also has the most reports of vancomycin-resistant Staphylococcus aureus. Similar findings were reported in the tigecycline evaluation and surveillance trial (TEST). During the 2004–2009 period, 4.6% of 3,753 E. faecalis isolates were vancomycin resistant, with the highest rates of 7.6% in the East North Central region of United States. Here we report rates and trends of vancomycin-resistant E. faecalis in the East North Central region compared with national rates from 1999 to 2010.

A few months ago, we lost Carl Woese, who revolutionized the study of evolution as a molecular science and in so doing discovered that there are three domains of life on earth. I knew Woese and think he and his work were the essence of the label “sui generis.”

Uncontrolled transposable element (TE) insertions and excisions can cause chromosome breaks and mutations with dramatic deleterious effects. The PIWI interacting RNA (piRNA) pathway functions as an adaptive TE silencing system during germline development. Several essential piRNA pathway proteins appear to be rapidly evolving, suggesting that TEs and the silencing machinery may be engaged in a classical "evolutionary arms race." Using a variety of molecular evolutionary and population genetic approaches, we find that the piRNA pathway genes rhino, krimper, and aubergine show patterns suggestive of extensive recurrent positive selection across Drosophila species. We speculate that selection on these proteins reflects crucial roles in silencing unfamiliar elements during vertical and horizontal transmission of TEs into naive populations and species, respectively.

The characterization of cells with tumour initiating potential is significant for advancing our understanding of cancer and improving therapy. Aggressive, triple-negative breast cancers (TNBCs) are enriched for tumour-initiating cells (TICs). We investigated that hypothesis that VEGF receptors expressed on TNBC cells mediate autocrine signalling that contributes to tumour initiation. We discovered the VEGF receptor neuropilin-2 (NRP2) is expressed preferentially on TICs, involved in the genesis of TNBCs and necessary for tumour initiation. The mechanism by which NRP2 signalling promotes tumour initiation involves stimulation of the alpha6beta1 integrin, focal adhesion kinase-mediated activation of Ras/MEK signalling and consequent expression of the Hedgehog effector GLI1. GLI1 also induces BMI-1, a key stem cell factor, and it enhances NRP2 expression and the function of alpha6beta1, establishing an autocrine loop. NRP2 can be targeted in vivo to retard tumour initiation. These findings reveal a novel autocrine pathway involving VEGF/NRP2, alpha6beta1 and GLI1 that contributes to the initiation of TNBC. They also support the feasibility of NRP2-based therapy for the treatment of TNBC that targets and impedes the function of TICs. of EMBO.

Vascular endothelial growth factor C (Vegfc) is a secreted protein that guides lymphatic development in vertebrate embryos. However, its role during developmental angiogenesis is not well characterized. Here, we identify a mutation in zebrafish vegfc that severely affects lymphatic development and leads to angiogenesis defects on sensitized genetic backgrounds. The um18 mutation prematurely truncated Vegfc, blocking its secretion and paracrine activity but not its ability to activate its receptor Flt4. When expressed in endothelial cells, vegfc(um18) could not rescue lymphatic defects in mutant embryos, but induced ectopic blood vessel branching. Furthermore, vegfc-deficient endothelial cells did not efficiently contribute to tip cell positions in developing sprouts. Computational modeling together with assessment of endothelial cell dynamics by time-lapse analysis suggested that an autocrine Vegfc/Flt4 loop plays an important role in migratory persistence and filopodia stability during sprouting. Our results suggest that Vegfc acts in two distinct modes during development: as a paracrine factor secreted from arteries to guide closely associated lymphatic vasculature and as an autocrine factor to drive migratory persistence during angiogenesis.

Comment on: Effects of digital tourniquet ischemia: a single center study. [Dermatol Surg. 2013]

Comment on: Essential role of Cenexin1, but not Odf2, in ciliogenesis. [Cell Cycle. 2013]

There is a lack of contemporary prospective data examining the adriamycin, bleomycin, vinblastine, dacarbazine (ABVD) and Stanford V (SV; doxorubicin, vinblastine, mechlorethamine, vincristine, bleomycin, etoposide, prednisone) regimens in older Hodgkin lymphoma (HL) patients. Forty-four advanced-stage, older HL patients (aged >/=60 years) were treated on the randomized study, E2496. Toxicities were mostly similar between chemotherapy regimens, although 24% of older patients developed bleomycin lung toxicity (BLT), which occurred mainly with ABVD (91%). Further, the BLT-related mortality rate was 18%. The overall treatment-related mortality for older HL patients was 9% vs. 0.3% for patients aged (P < 0.001). Among older patients, there were no survival differences between ABVD and SV. According to age, outcomes were significantly inferior for older versus younger patients (5-year failure-free survival: 48% vs. 74%, respectively, P = 0.002; 5-year overall survival: 58% and 90%, respectively, P < 0.0001), although time-to-progression (TTP) was not significantly different (5-year TTP: 68% vs. 78%, respectively, P = 0.37). Furthermore, considering progression and death without progression as competing risks, the risk of progression was not different between older and younger HL patients (5 years: 30% and 23%, respectively, P = 0.30); however, the incidence of death without progression was significantly increased for older HL patients (22% vs. 9%, respectively, P < 0.0001). Altogether, the marked HL age-dependent survival differences appeared attributable primarily to non-HL events.

We report a case of a very unusual combined and collision basosquamous melanocytic malignant tumor on the chest of an 84-year-old man. To our knowledge, this is the first case report describing this entity. We attempt to address the diagnostic challenge and the clinical and histological characteristics of these rare neoplasms with a review of the English literature to further categorize and summarize what has been previously reported about these extraordinary tumors.

Cutaneous manifestations associated with myelodysplastic syndromes (MDS) are uncommon and can occur as specific or nonspecific lesions. Recognizing these cutaneous manifestations is important as they can precede blood or bone marrow transformation to leukemia. Granulomatous reactions have rarely been described as nonspecific lesions of MDS. These rare cases histologically resembled granuloma annulare, sarcoid, and a generalized dermal interstitial granulomatous dermatitis (IGD) which were not associated with leukemic infiltration. The authors report an interesting case of an IGD-like eruption evolving over the course of MDS with eventual progression to systemic leukemia. IGD is an inflammatory reaction that refers to a varied spectrum of histologic patterns and is associated with a variety of systemic illnesses and hypersensitivity reactions, including lymphoma and leukemia. In patients with MDS, surveillance for leukemia is a critical component of their follow-up care. Normally, this surveillance occurs through serial peripheral blood smears and bone marrow studies. IGD-like eruptions are a cutaneous reaction pattern that may serve as an additional clinical indicator of leukemic progression in patients with MDS. Although primarily a reactive pattern, this entity can rarely harbor leukemic blasts.

BACKGROUND: Clinical studies demonstrate synergistic liver damage by alcohol and hepatitis C virus (HCV); however, the mechanisms by which alcohol promotes HCV infection remain obscure. The liver-specific microRNA-122 (miR-122) regulates HCV replication and expression of host genes, including Cyclin G1. Here, we hypothesized that alcohol regulates miR-122 expression and thereby modulates HCV RNA replication.

METHODS: The J6/JFH/Huh-7.5 model of HCV infection was used in this study. Real-time quantitative polymerase chain reaction, Western blotting, electrophoretic mobility shift assay, and confocal microscopy were used for experimental analysis.

RESULTS: We found that acute alcohol exposure (25 mM) significantly increased intracellular HCV RNA as well as miR-122 levels in Huh-7.5 and Huh-7.5/CYP2E1 expressing cells in the presence and absence of J6/JFH-HCV infection. Expression of the miR-122 target, Cyclin G1, was inhibited by alcohol both in J6/JFH-infected and uninfected Huh-7.5 cells. The use of a miR-122 inhibitor increased Cyclin G1 expression and prevented the alcohol-induced increase in HCV RNA and protein levels, suggesting a mechanistic role for alcohol-induced miR122 in HCV replication. We discovered that siRNA-mediated silencing of Cyclin G1 significantly increased intracellular HCV RNA levels compared with controls, suggesting a mechanistic role for Cyclin G1 in HCV replication. Alcohol-induced increase in miR-122 was associated with increased nuclear translocation and DNA binding of the nuclear regulatory factor-kappaB and could be prevented by NF-kappaB inhibition.

CONCLUSIONS: Our novel data indicate a miR-122-mediated mechanism for alcohol increasing HCV RNA replication. We show for the first time that Cyclin G1, a miR-122 target gene, has regulatory effects on HCV replication and that alcohol increases HCV replication by regulating miR-122 and Cyclin G1.

We performed a multicenter, International analysis of solid organ transplant (SOT)-related primary central nervous system (PCNS) posttransplant lymphoproliferative disease (PTLD). Among 84 PCNS PTLD patients, median time of SOT-to-PTLD was 54 months, 79% had kidney SOT, histology was monomorphic in 83% and tumor was EBV+ in 94%. Further, 33% had deep brain involvement, 10% had CSF involvement, while none had ocular disease. Immunosuppression was reduced in 93%; additional first-line therapy included high-dose methotrexate (48%), high-dose cytarabine (33%), brain radiation (24%) and/or rituximab (44%). The overall response rate was 60%, while treatment-related mortality was 13%. With 42-month median follow-up, three-year progression-free survival (PFS) and overall survival (OS) were 32% and 43%, respectively. There was a trend on univariable analysis for improved PFS for patients who received rituximab and/or high-dose cytarabine. On multivariable Cox regression, poor performance status predicted inferior PFS (HR 2.61, 95% CI 1.32-5.17, p = 0.006), while increased LDH portended inferior OS (HR 4.16, 95% CI 1.29-13.46, p = 0.02). Moreover, lack of response to first-line therapy was the most dominant prognostic factor on multivariable analysis (HR 8.70, 95% CI 2.56-29.57, p = 0.0005). Altogether, PCNS PTLD appears to represent a distinct clinicopathologic entity within the PTLD spectrum that is associated with renal SOT, occurs late, is monomorphic and retains EBV positivity.

The neuropeptide PDF is crucial for Drosophila circadian behavior: it keeps circadian neurons synchronized. Here, we identify GW182 as a key regulator of PDF signaling. Indeed, GW182 downregulation results in phenotypes similar to those of Pdf and Pdf-receptor (Pdfr) mutants. gw182 genetically interacts with Pdfr and cAMP signaling, which is essential for PDFR function. GW182 mediates miRNA-dependent gene silencing through its interaction with AGO1. Consistently, GW182's AGO1 interaction domain is required for GW182's circadian function. Moreover, our results indicate that GW182 modulates PDFR signaling by silencing the expression of the cAMP phosphodiesterase DUNCE. Importantly, this repression is under photic control, and GW182 activity level--which is limiting in circadian neurons--influences the responses of the circadian neural network to light. We propose that GW182's gene silencing activity functions as a rheostat for PDFR signaling and thus profoundly impacts the circadian neural network and its response to environmental inputs.

BACKGROUND: The integrity of behavioral intervention trials depends on consistent intervention delivery, and uniform, comprehensive process data collection. It can be challenging in practice due to complex human interactions involved.

OBJECTIVE: We sought to design a system to support the fidelity of intervention delivery and efficient capture of qualitative and quantitative process data for a telephone-delivered behavioral counseling intervention to increase physical activity and function after total knee replacement surgery.

METHODS: A tailored system was designed to prompt the intervention coach in the delivery of a 5 step counseling protocol to support intervention fidelity across patients. System features included structured data components, automated data exchange functions, user-friendly data capture screens, and real-time surveillance reporting. The system structured the capture of patient goals and open-ended conversation.

RESULTS: The system recorded intervention process data from each of 12 sessions held with the 92 intervention patients. During the trial, 992 telephone sessions were conducted, and more than 97% (4816/4960) of intervention process data fields were completed in the system. The coach spent 5-10 minutes preparing for each counseling call using system-generated summaries of historical data and 10-15 minutes entering intervention process data following each telephone session.

CONCLUSIONS: This intervention delivery system successfully supported the delivery of a structured behavioral counseling intervention and collection of intervention process data. It addressed the unique needs of clinical behavioral intervention trials, and had promising potential to facilitate high-fidelity translation of the intervention to broad clinical practice and Web-based multicenter clinical trials in the future.