Herpes Simplex Virus Type 1 Infection Imposes a G1/S Block in Asynchronously Growing Cells and Prevents G1 Entry in Quiescent Cells

Herpes simplex virus type 1 (HSV-1) infection disrupted cell cycle regulation in at least two ways. First, infection of quiescent human embryonic lung cells simultaneously with readdition of serum caused inhibition of cyclin D/cyclin-dependent kinase (CDK) 4,6-specific and cyclin E/CDK2-specific phosphorylation of the retinoblastoma protein pRb. The inhibition of cyclin D/CDK4,6 kinase activity corresponded to a loss of cyclin D1 protein and a failure of CDK4 and CDK6 to translocate to the nucleus. Failure to detect cyclin E/CDK2 kinase activity was accompanied by a loss of cyclin E protein and a failure of CDK2 to translocate to the nucleus. Levels of pocket protein p130 persisted, whereas p107 did not accumulate. As a result of these effects on cyclin kinase, G0-infected cells failed to reenter the cell cycle. The second type of HSV-induced cell cycle dysregulation was observed in asynchronously dividing cell cultures. A rapid inhibition of preexisting cyclin E/CDK2 and cyclin A/CDK2 activities was observed in human embryonic lung cells, as well as two other human cell lines: C33 and U2OS. HSV-1 immediate-early gene expression was necessary for the inhibition of CDK2 kinase activity. Cyclin and CDK subunit protein levels, intracellular localization, and complex stability were unaffected by infection. In addition, levels of cyclin-dependent kinase inhibitors, p27 and p21, were not affected by HSV-1. Previous experiments demonstrated that in asynchronous infected cells, hypophosphorylated pRb and pocket protein–E2F complexes accumulated, and cellular DNA synthesis was rapidly inhibited. Coupled with the present results, this indicates that HSV-1 has evolved mechanisms for preventing cells in G1 from proceeding through the restriction point and for cells in S from completing a round of DNA replication

Conditional Random Fields and Supervised Learning in Automated Skin Lesion Diagnosis

Many subproblems in automated skin lesion diagnosis (ASLD) canbe unified under a single generalization of assigning a label, from an predefinedset, to each pixel in an image. We first formalize this generalizationand then present two probabilistic models capable of solving it. The firstmodel is based on independent pixel labeling using maximum a-posteriori(MAP) estimation. The second model is based on conditional randomfields (CRFs), where dependencies between pixels are defined using agraph structure. Furthermore, we demonstrate how supervised learningand an appropriate training set can be used to automatically determineall model parameters. We evaluate both models\u27 ability to segment achallenging dataset consisting of 116 images and compare our results to5 previously published methods

Induction by Herpes Simplex Virus of Free and Heteromeric Forms of E2F Transcription Factor

We have determined that HSV causes rapid and large increases in cell-cycle-regulated free E2F and S-phase p107/E2F DNA binding activities in asynchronous cultures of C33A cells. Induction occurred by 4 hr postinfection and coincided with the appearance of viral encoded immediate-early and delayed-early proteins, i.e., when viral DNA replication normally commences. No increase in E2F activities occurred when cells were infected with viruses expressing mutant regulatory proteins ICP4 or ICP27, or mutant replication proteins ICP8, pol or helicase, or when cells were infected with wild-type virus in the presence of inhibitors of DNA synthesis. In contrast, ICP8 mutant-infected cells contained elevated amounts of NF kappa B activity equivalent to WT virus, no induction of Sp1 relative to WT virus, and reduced ATF/CREB activity relative to WT virus. Results of transient expression assays with E2F-responsive reporters indicated that the net effect of induction of both active (free E2F) and repressive (p107/E2F) complexes was a decrease in AdE2 promoter activity and an increase in c-myc promoter activity. Taken together these results suggest that HSV can cause unscheduled changes in the amount and functional status of a cell-cycle-regulated transcription factor. These results are discussed in light of possible roles for viral-induced alterations in E2F, especially as related to imposing or overriding cell-cycle checkpoints

Inhibition of the stress-activated kinase, p38, does not affect the virus transcriptional program of herpes simplex virus type 1

To investigate the impact of stress kinase p38 activation on HSV-1 transcription, we performed a global transcript profile analysis of viral mRNA using an oligonucleotide-based DNA microarray. RNA was isolated from Vero cells infected with the KOS strain of HSV-1 in the presence or absence of SB203580, a pyridinyl imidazole inhibitor of p38. Under conditions that eliminated ATF2 activation but had no effect on c-, and reduced virus yield by 85–90%, no effect on accumulation of viral IE, DE, or L transcripts was observed by array analysis or selected Northern blot analysis at 2, 4, and 6 h post infection. Results of array data from cells infected with the ICP27 mutant d27-1 in the presence or absence of SB203580 only reflected the known restricted transcription phenotype of the ICP27 mutant. This result is consistent with a role for p38 activation on virus replication lying downstream of the essential role of ICP27 in DE and perhaps late transcription regulation. No effect of SB203580 on transcription was detected after infection with the ICP0 mutant 7134, at 0.5 or 5.0 PFU/cell, though decreases in the rate of accumulation of all kinetic classes of mRNA could be detected, relative to virus. These results indicate that inhibiting p38 activity in Vero cells, while significantly reducing virus yield, demonstrated no obvious impact on the program of viral transcription

Skin Roughness Assessment

Non

Conditional Random Fields and Supervised Learning in Automated Skin Lesion Diagnosis

Many subproblems in automated skin lesion diagnosis (ASLD) can be unified under a single generalization of assigning a label, from an predefined set, to each pixel in an image. We first formalize this generalization and then present two probabilistic models capable of solving it. The first model is based on independent pixel labeling using maximum a-posteriori (MAP) estimation. The second model is based on conditional random fields (CRFs), where dependencies between pixels are defined using a graph structure. Furthermore, we demonstrate how supervised learning and an appropriate training set can be used to automatically determine all model parameters. We evaluate both models' ability to segment a challenging dataset consisting of 116 images and compare our results to 5 previously published methods

A multicenter, randomised, double-blind, placebo-controlled, prospective crossover trial

Objective To evaluate the efficacy and safety of bupropion in the treatment of apathy in Huntington’s disease (HD). Methods In this phase 2b multicentre, double-blind, placebo-controlled crossover trial, individuals with HD and clinical signs of apathy according to the Structured Clinical Interview for Apathy—Dementia (SCIA-D), but not depression (n = 40) were randomized to receive either bupropion 150/300mg or placebo daily for 10 weeks. The primary outcome parameter was a significant change of the Apathy Evaluation Scale (AES) score after ten weeks of treatment as judged by an informant (AES-I) living in close proximity with the study participant. The secondary outcome parameters included changes of 1. AES scores determined by the patient (AES-S) or the clinical investigator (AES-C), 2. psychiatric symptoms (NPI, HADS-SIS, UHDRS-Behavior), 3. cognitive performance (SDMT, Stroop, VFT, MMSE), 4. motor symptoms (UHDRS-Motor), 5. activities of daily function (TFC, UHDRS-Function), and 6. caregiver distress (NPI-D). In addition, we investigated the effect of bupropion on brain structure as well as brain responses and functional connectivity during reward processing in a gambling task using magnetic resonance imaging (MRI). Results At baseline, there were no significant treatment group differences in the clinical primary and secondary outcome parameters. At endpoint, there was no statistically significant difference between treatment groups for all clinical primary and secondary outcome variables. Study participation, irrespective of the intervention, lessened symptoms of apathy according to the informant and the clinical investigator. Conclusion Bupropion does not alleviate apathy in HD. However, study participation/placebo effects were observed, which document the need for carefully controlled trials when investigating therapeutic interventions for the neuropsychiatric symptoms of HD. Trial registration ClinicalTrials.gov 0191496