Robot-assisted neck dissection via a transaxillary and retroauricular approach versus a conventional transcervical approach in papillary thyroid cancer with cervical lymph node metastases

BACKGROUND

Recently, robot-assisted neck dissection (ND) using a transaxillary approach in thyroid cancer patients with lateral neck metastases (LNM) was demonstrated to be feasible. The aim of this study was to compare the surgical outcomes of a modified transaxillary and retroauricular (TARA) versus a conventional transcervical approach in papillary thyroid carcinoma (PTC) patients with LNM.

PATIENTS AND METHODS

In total, 47 patients with PTC underwent total thyroidectomy with central compartment ND and modified radical ND except Level I. Twenty-two NDs were performed via the TARA approach, and 25 unilateral NDs were performed via the conventional transcervical approach.

RESULTS

The TARA and the open ND groups consisted of 22 and 25 patients, respectively. The operation time for ND in the TARA group was longer than that in the open ND group (209.4±38.2 minutes versus 143.1±30.5 minutes; P=.000). The mean scar satisfaction score in the TARA group was higher than in the conventional ND group (3.9±1.0 versus 2.8±1.0; P=.000). There were no differences in the mean number of retrieved lymph nodes.

CONCLUSIONS

The robot-assisted ND via the TARA approach can be an alternative option that produces excellent esthetic results for the management of LNM in PTC patients.

The natural history of arteriovenous access and risk factors associated with access thrombosis after successful kidney transplantation

INTRODUCTION

The purpose of this study was to determine the natural history of arteriovenous (AV) access after successful kidney transplantation (KT) and to identify the risk factors of spontaneous access closure in kidney transplant recipients.

METHODS

We performed a retrospective review of 115 patients who underwent KT with functioning access from June 2010 to July 2012. AV access patency was checked and recorded daily during the hospital stay and at every visit to the outpatient clinic. Patients were divided into 2 groups according to the patency of access, and risk factors of access thrombosis were assessed. Access patency was followed up until patency was lost or the study was closed.

RESULTS

At the end of follow-up, 18 (15.7%) AV accesses had spontaneously closed. Mean time to closure was 119 ± 163 days, and 12 of 18 were closed within 90 days after KT. AV access spontaneously closed in 8.5% of male patients, compared with 27.3% of female patients (P = .007), 12.2% of cases with native access compared with 35.3% of cases with artificial access (P = .016), and 11.3% of cases with wrist access compared with 25.7% of cases with elbow access (P = .049). Spontaneously closed AV accesses tended to have a lower mean access flow compared with functioning accesses (P = .019). On multivariate analysis, female sex and AV access flow volume affected spontaneous AV access closure (odds ratio 4.749, 95% confidence interval 1.919-35.383, P = .008; odds ratio 0.998, 95% confidence interval 0.996-0.999, P = .010, respectively).

CONCLUSIONS

Our results suggest that AV access thrombosis occurs more frequently during the early postoperative period, particularly in female patients or patients with low flow access, whereas it is a rare event in male patients or patients with high access flow, especially in the late postoperative period.

HNF4α contributes to glucose formation in aged rat hepatocytes

Aging-dependent physiological conditions are attributed to parenchymal structural changes to cellular functions in aged organisms. Compared to the young animals, the primary hepatocytes from old rats showed a higher glucose output and a higher expression of the key gluconeogenesis-regulating enzyme, phosphoenol pyruvate carboxykinase (PEPCK). The primary hepatocytes from old rats showed a higher glucose output and a higher expression of the key gluconeogenesis-regulating enzyme, phosphoenol pyruvate carboxykinase (PEPCK), compared with those from the young animals. The in situ hybridization study showed increased PEPCK mRNA expression in the aged liver tissues. The livers from old rats showed loosened hexagonal hepatic lobular structures, increased collagen accumulation, and high expression of the hypoxia marker hypoxia-inducible factor 1α (HIF1α). Hypoxia increased the PEPCK mRNA and protein expression levels in accordance with the HIF1α expression. PEPCK promoter luciferase reporter assay showed that hypoxia increased PEPCK through transcriptional activation. Furthermore, the hepatocyte nuclear factor α (HNF4α) protein, but not the HNF4α mRNA level, increased in parallel with the PEPCK mRNA expression under hypoxic conditions. Glucose production increased under hypoxic conditions, but this increment diminished by HNF4α siRNA in young hepatocytes. Moreover, increased glucose production from old rat hepatocytes was reversed by the down-regulation of HNF4α through a specific siRNA. This study suggests that the mild hypoxic conditions in response to aging-dependent hepatic structural changes may contribute to the induction of the gluconeogenic enzyme PEPCK through HNF4α protein stabilization.

Validation of a scoring tool to predict drug-resistant pathogens in hospitalised pneumonia patients

BACKGROUND

Health care-associated pneumonia (HCAP) affects a heterogeneous group of patients in frequent contact with health care systems. However, HCAP criteria poorly predict infection with drug-resistant (DR) pathogens.

OBJECTIVE

To validate our previously reported risk-scoring model (predictive of DR pathogen infection) in patients admitted to hospital with pneumonia.

DESIGN

We evaluated 580 patients admitted with culture-positive bacterial pneumonia. We identified risk factors, evaluated the risk-scoring model's capacity to predict infection by DR pathogens and compared the model's diagnostic accuracy with that of current HCAP criteria.

RESULTS

DR pathogens were observed in 227/580 patients (39.1%). Of 269 HCAP patients, 153 (56.9%) were infected with DR pathogens. Overtreatment was more common in HCAP than in community-acquired pneumonia (58.7% vs. 41.2%, P < 0.001). Recent hospitalisation, admission from a long-term care facility, recent antibiotic treatment and tube feeding were independently associated with DR pathogens. For pathogen prediction, the risk-scoring model showed better diagnostic accuracy than HCAP criteria (area under receiver operating-characteristic curve = 0.723 vs. 0.673, P < 0.001).

CONCLUSION

According to current HCAP criteria, half of the HCAP patients were treated unnecessarily with broad-spectrum antibiotics. Risk scoring by stratifying risk factors could improve the identification of patients likely to be infected with DR pathogens.

Robot-Assisted Selective Neck Dissection of Levels II to V via a Modified Facelift or Retroauricular Approach

Objectives

We performed robot-assisted selective neck dissection via a modified facelift or retroauricular approach without creating an apparent scar around the neck to remove neck node of levels II to V after transoral robotic surgery of a primary lesion in patients with laryngopharyngeal carcinoma. Patient data were prospectively analyzed to verify the feasibility and efficacy of robot-assisted neck dissection in the treatment of cN0 laryngopharyngeal carcinoma.

Study Design

Prospective case series.

Setting

University tertiary care facility.

Subjects and Methods

Between March 2011 and March 2012, 7 patients were enrolled in the study. Before study initiation, the Institutional Review Board of Yonsei University approved the protocol, and informed consent was obtained from all patients.

Results

Robot-assisted neck dissection was successfully performed in all patients. Five patients underwent selective neck dissection including levels II to IV, and 2 patients underwent selective neck dissection including levels II to V. The average number of lymph nodes retrieved was 25.1. Occult nodal metastasis was found in 1 (14%) neck specimen. During the follow-up period (mean of 13.5 months), all patients were alive without locoregional recurrence. All patients were extremely satisfied with their cosmetic results.

Conclusion

Robot-assisted selective neck dissection is a feasible and safe technique to manage the neck in cN0 laryngopharyngeal carcinoma patients. It may be especially helpful for patients undergoing transoral robotic surgery since no apparent scar around the neck remains. Long-term results with respect to oncologic safety and functional outcomes are required to establish the validity of robot-assisted neck dissection.

Isolation and characterization of a lytic Myoviridae bacteriophage PAS-1 with broad infectivity in Aeromonas salmonicida

To search for candidate control agents against Aeromonas salmonicida subsp. salmonicida infections in aquaculture, one bacteriophage (phage), designated as PAS-1, was isolated from the sediment samples of the rainbow trout (Oncorhynchus mykiss) culture farm in Korea. The PAS-1 was morphologically classified as Myoviridae and possessed approximately 48 kb of double-strand genomic DNA. The phage showed broad host ranges to other subspecies of A. salmonicida as well as A. salmonicida subsp. salmonicida including antibiotic-resistant strains. Its latent period and burst size were estimated to be approximately 40 min and 116.7 PFU/cell, respectively. Furthermore, genomic and structural proteomic analysis of PAS-1 revealed that the phage was closely related to other Myoviridae phages infecting enterobacteria or Aeromonas species. The bacteriolytic activity of phage PAS-1 was evaluated using three subspecies of A. salmonicida strain at different doses of multiplicity of infection, and the results proved to be efficient for the reduction of bacterial growth. Based on these results, PAS-1 could be considered as a novel Aeromonas phage and might have potentiality to reduce the impacts of A. salmonicida infections in aquaculture.

Predictors for lymph node metastasis in T1 colorectal cancer

BACKGROUND AND STUDY AIMS

It is critical that the risk of lymph node metastasis (LNM) is evaluated for determining the suitability of endoscopic resection for T1 colorectal cancer (CRC). Reported risk factors for LNM in completely resected T1 CRC are deep submucosal invasion, grade 3, angiolymphatic invasion, and budding. The aim of the present study was to identify the histopathologic factors associated with LNM in T1 CRC.

PATIENTS AND METHODS

The study involved 435 patients with T1 CRC treated by endoscopic or surgical resection between January 2001 and April 2010 at the National Cancer Center, Korea. The 435 patients were classified into two groups - those undergoing surgical resection (n = 324) and those undergoing endoscopic resection (n = 111). In the surgically resected group, details regarding depth of submucosal invasion, angiolymphatic invasion, tumor grade, budding, and background adenoma (BGA) were evaluated with respect to presence or absence of LNM. In the endoscopically resected group, the results of follow-ups and additional salvage surgeries were studied.

RESULTS

In the surgically resected group, LNM was detected in 42 patients (13.0 %). Grade 3, angiolymphatic invasion, budding, and the absence of BGA were identified as factors associated with LNM in univariate and multivariate analyses (P < 0.05). Among the 50 patients in the endoscopically resected group with high risk, three were diagnosed as being LNM-positive during the follow-up period. There was no LNM in the endoscopically resected group with low risk.

CONCLUSIONS

Grade 3, angiolymphatic invasion, budding, and the absence of BGA are the risk factors that predict LNM in patients with T1 CRC. In cases where endoscopically resected T1 CRC has no risk factor, cautious follow-up could be recommended. However, if the tumor has any risk factor, additional surgical resection should be considered.

Does donor kidney to recipient body weight ratio influence long-term outcomes of living-donor kidney transplantation?

This study evaluated the effect of the donor kidney to recipient body weight (Kw/Rw) ratio on long-term graft function and survival. We investigated retrospectively whether there was any association between Kw/Rw ratio and long-term graft survival and function after a follow-up of >10 years. We studied a consecutive series of 123 adult-to-adult living kidney transplants. According to the Kw/Rw ratio, patients were divided into 3 groups: "low" (Kw/Rw <2.85; n = 29), "medium" (2.85 ≤ Kw/Rw < 4.04; n = 63), and "high" (≥4.04; n = 31). Among the 3 groups, the mean serum creatinine levels at 1 and 6 months as well as 1 year after transplantation were significantly lower among patients with a high Kw/Rw ratio than in those with a medium or low ratio, but serum creatinine levels at 3 and 5 years did not differ significantly (P = .394 and 0.620, respectively). Graft survival rates at 5 and 10 years after transplantation were significantly lower in the "low" group. We observed a significant association between Kw/Rw ratio and graft survival (P = .018). The Kw/Rw ratio is an important factor for long-term graft survival and early graft function. However, it did not significantly affect subsequent renal function.

Lymph node ratio is an independent prognostic factor in patients with rectal cancer treated with preoperative chemoradiotherapy and curative resection

PURPOSE

To evaluate the prognostic effect of lymph node ratio (LNR) in patients with locally advanced rectal cancer who were treated with curative resection after preoperative chemoradiotherapy (CRT).

METHODS

Between October 2001 and December 2007, 519 patients who had undergone curative resection of primary rectal cancer after preoperative CRT were enrolled. Of these, 154 patients were positive for lymph node (LN) metastasis and were divided into three groups according to the LNR (≤ 0.15 [n=80], 0.16-0.3 [n=44], >0.3 [n=30]) to evaluate the prognostic effect on overall survival (OS) and disease-free survival (DFS).

RESULTS

LNR (≤ 0.15, 0.16-0.3, and >0.3) was significantly associated with 5-year OS (90.3%, 75.1%, and 45.1%; p<0.001) and DFS (66.7%, 55.8%, and 21.9%; p<0.001) rates. In a multivariate analysis, LNR (≤ 0.15, 0.16-0.3, and >0.3) was a significant independent prognostic factor for OS (hazard ratios [HRs], 1, 3.609, and 8.197; p<0.001) and DFS (HRs, 1, 1.699, and 3.960; p<0.001). LNR had a prognostic impact on OS and DFS in patients with <12 harvested LNs, as well as in those with ≥ 12 harvested LNs (p<0.05).

CONCLUSION

LNR was a significant independent prognostic predictor for OS and DFS in patients with locally advanced rectal cancer who were treated with curative resection after preoperative CRT.

Physiological antioxidative network of the bilirubin system in aging and age-related diseases

Oxidative stress is detrimental to life process and is particularly responsible for aging and age-related diseases. Thus, most organisms are well equipped with a spectrum of biological defense mechanisms against oxidative stress. The major efficient antioxidative mechanism is the glutathione system, operating a redox cycling mechanism for glutathione utilization, which consists of glutathione and its peroxidase and reductase. However, this system is mainly effective for hydrophilic oxidants, while lipophilic oxidants require another scavenging system. Since many age-related pathological conditions are related to lipid peroxidation, especially in association with the aging process, the physiological role of the scavenging system for lipophilic oxidants should be considered. In this regard, the biliverdin to bilirubin conversion pathway, via biliverdin reductase (BVR), is suggested to be another major protective mechanism that scavenges lipophilic oxidants because of the lipophilic nature of bilirubin. The efficiency of this bilirubin system might be potentiated by operation of the intertwined bicyclic systems of the suggested redox metabolic cycle of biliverdin and bilirubin and the interactive control cycle of BVR and heme oxygenase. In order to combat oxidative stress, both antioxidative systems against hydrophilic and lipophilic oxidants are required to work cooperatively. In this regard, the roles of the bilirubin system in aging and age-related diseases are reassessed in this review, and their interacting networks are evaluated.

Protective effect of 4,4'-diaminodiphenylsulfone against paraquat-induced mouse lung injury

Although 4,4'-diaminodiphenylsulfone (DDS, dapsone) has been used to treat several dermatologic conditions, including Hansen disease, for the past several decades, its mode of action has remained a topic of debate. We recently reported that DDS treatment significantly extends the lifespan of the nematode C. elegans by decreasing the generation of reactive oxygen species. Additionally, in in vitro experiments using non-phagocytic human fibroblasts, we found that DDS effectively counteracted the toxicity of paraquat (PQ). In the present study, we extended our work to test the protective effect of DDS against PQ in vivo using a mouse lung injury model. Oral administration of DDS to mice significantly attenuated the lung tissue damage caused by subsequent administration of PQ. Moreover, DDS reduced the local expression of mRNA transcripts encoding inflammation-related molecules, including endothelin-1 (ET-1), macrophage inflammatory protein-1α (MIP-1α), and transforming growth factor-β (TGF-β). In addition, DDS decreased the PQ-induced expression of NADPH oxidase mRNA and activation of protein kinase Cμ (PKCμ). DDS treatment also decreased the PQ-induced generation of superoxide anions in mouse lung fibroblasts. Taken together, these data suggest the novel efficacy of DDS as an effective protective agent against oxidative stress-induced tissue damages.

Doenjang, a fermented soybean paste, decreased visceral fat accumulation and adipocyte size in rats fed with high fat diet more effectively than nonfermented soybeans

Soybean is known to have an anti-obesity effect. We compared the anti-obesity effect of doenjang, a fermented soybean paste, with that of nonfermented soybeans in rats. Steamed soybeans and doenjang (steamed soybeans fermented and aged for 10 months) were sampled and freeze-dried. Male Sprague-Dawley rats were fed basal (BA) (5% fat), high fat (HF) (30% fat), HF+steamed soybeans (SOY), or HF+doenjang (DJ) diet ad libitum for 8 weeks. HF significantly increased body weight gain, liver weight, hepatic triglyceride (TG) and cholesterol levels, and epididymal fat pad weight compared with BA. Compared with HF, body weight gain and hepatic TG and cholesterol levels were significantly lower in SOY and DJ groups, but they were not significantly different from each other. DJ significantly reduced visceral fat weight and epididymal adipocyte size compared with HF, whereas SOY resulted in a mild reduction without significance. This was possibly because DJ showed lowered fatty acid synthase (FAS) activity and elevated carnitine palmitoyltransferase (CPT)-1 activity in liver tissue more than SOY. SOY and DJ did not affect serum total and high-density lipoprotein-cholesterol levels compared with HF; however, DJ significantly lowered the atherogenic index and serum leptin level. In conclusion, doenjang, a fermented soybean product, was more effective than soybeans for preventing diet-induced visceral fat accumulation, possibly because of its greater effects on CPT-1 activity stimulation and FAS activity suppression. These effects may be due in part to the higher content of aglycone isoflavones in doenjang.

Gene expression profiling of a cold-shocked earthworm Eisenia andrei

To identify genes that are modulated under cold-stress conditions in the earthworm Eisenia andrei, we performed a genome-wide analysis of gene expression in cold-shocked earthworms by using Serial Analysis of Gene Expression (SAGE). We identified 5,977 and 5,407 unique SAGE tags under normal and cold-stressed conditions, respectively. The majority of the SAGE tags did not match to any known expressed sequences, due to a paucity of expression data in earthworms. We converted the statistically significant SAGE tags for the cold-stressed condition into expressed sequence tags (ESTs), and the results showed that particular genes associated with energy homeostasis, cellular defense mechanisms, and ion balance were up-regulated or down-regulated. We constructed a regulatory network of some of these genes and identified rps-6 as a core gene in the cold-response regulatory-gene network. Our data provide a baseline for gene expression studies of cold shock in the Lumbricidae.

Defective nuclear translocation of stress-activated signaling in senescent diploid human fibroblasts: a possible explanation for aging-associated apoptosis resistance

In order to study the nature of aging-dependent apoptosis resistance, we compared the activation pattern of mitogen-activated protein kinases (MAPK) in response to three different stress modalities: hydrogen peroxide (H(2)O(2)), staurosporine, and thapsigargin. We observed the agonist-specific activation pattern of MAP kinases in human diploid fibroblasts (HDFs). When young HDFs were treated with PD98059, a specific inhibitor of extracellular signal-regulated kinase (ERK), H(2)O(2)-induced apoptosis was blocked, whereas staurosporine-induced apoptosis was inhibited by treatment with SB203580, a specific inhibitor of p38. In addition, the levels of anti-apoptotic protein Bcl-2 (B-cell lymphoma protein-2) were restored by PD98059 or SB239063 in cells treated with H(2)O(2) or staurosporine, respectively. We also found that inhibition of the nuclear import of p-Erk and p-p38 using wheat germ agglutinin induced apoptosis resistance in young HDF cells in response to H(2)O(2) or staurosporine. These data indicate a potential role of the nuclear translocation of apoptotic signals in the induction of apoptosis. Moreover, the nuclear translocation of activated ERK1/2 and p38 in response to H(2)O(2) or staurosporine was significantly compromised in senescent HDFs, compared with young cells. Taken together, we propose that the apoptosis resistance of senescent HDFs might be related to the defective nuclear translocation of stress-activated signals in an agonist-specific manner, which would imply the operation of an aging-dependent functional nucleo-cytoplasmic trafficking barrier.

Genomic sequence of infectious hypodermal and hematopoietic necrosis virus (IHHNV) KLV-2010-01 originating from the first Korean outbreak in cultured Litopenaeus vannamei

Due to the need to track and monitor genetic diversity, the genome of the infectious hypodermal and hematopoietic necrosis virus (IHHNV) strain KLV-2010-01 in cultured Litopenaeus vannamei shrimp that originated from the first Korean outbreak in 2010 was sequenced and analyzed. The genome, with a length of 3914 nucleotides, was sequenced from the Korean IHHNV. The genome encoded three large and overlapping open reading frames: ORF1 (NS-1) of 2001 bp, ORF2 (NS-2) of 1092 bp and ORF3 (capsid protein) of 990 bp. The overall organization, size and predicted amino acid sequence of the three ORFs in Korean IHHNV were highly similar to those of members of the infectious IHHNV group, and the most closely related strains were IHHNVs described from Ecuador and Hawaii. Additionally, phylogenetic analysis showed that the Korean IHHNV was clustered with lineage III in the infectious IHHNV group and was most similar to IHHNV isolates from Ecuador, China and Taiwan.

Prevalence and different characteristics of two serotypes of Streptococcus parauberis isolated from the farmed olive flounder, Paralichthys olivaceus (Temminck and Schlegel), in Korea

The prevalence of two serotypes of Streptococcus parauberis isolated from the olive flounder, Paralichthys olivaceus, was evaluated in a total of 29 isolates between 2003 and 2010 in Korea. Streptococcus parauberis isolates were divided into two serologically distinct types (serotype 1 and serotype 2), except for one strain (S1091), using an agglutination assay with rabbit antiserum, and serotype 1 was identified as the dominant type (24 of 29 isolates) in this study. To identify the characteristics of the two serotypes of S. parauberis, we conducted a biochemical test using the API 20 Strep kit, a transmission electron microscopy (TEM) assay, sequence analysis of 16S-23S rRNA intergenic spacer region (ISR) and a pathogenicity test. In TEM, both serotypes possessed polysaccharide capsule layers around the cell surface when bacterial cells were treated with a homologous serotype of rabbit antiserum. However, we were unable to discriminate serotype-specific biochemical characteristics and genetic characteristics of 16S-23S rRNA ISR between the two serotypes. In the pathogenicity test, the serotype 1 strains induced significantly higher mortality than the serotype 2 strains in olive flounder when experimentally inoculated via the intraperitoneal route.

Effect of dimethyl sulfoxide on cell cycle synchronization of goldfish caudal fin derived fibroblasts cells

Several studies have previously been conducted regarding cell cycle synchronization in mammalian somatic cells. However, limited work has been performed on the control of cell cycle stages in the somatic cells of fish. The aim of this study was to determine the cell cycle arresting effects of several dimethyl sulfoxide (DMSO) concentrations for different times on different cell cycle stages of goldfish caudal fin-derived fibroblasts. Results demonstrated that the cycling cells or control group (68.29%) yields significantly higher (p < 0.05) arrest in G0/G1 phase compared with the group treated for 24 h with different concentrations (0.5%, 1.0% or 1.5%) of DMSO (64.88%, 65.70%, 64.22% respectively). The cell cycle synchronization in the treatment of cells with 1.0% DMSO at 48 h (81.14%) was significantly higher than that in the groups treated for 24 h (76.82%) and the control group (77.90%). Observations showed that treatment of DMSO resulted in an increase in the proportion of cells at G0/G1 phase for 48 h of culture. However, high levels of apoptotic cells can be detected after 48 h of culture treated with 1% concentration of DMSO.

Autophagy impairment induces premature senescence in primary human fibroblasts

BACKGROUND

Recent studies have demonstrated that activation of autophagy increases the lifespan of organisms from yeast to flies. In contrast to the lifespan extension effect in lower organisms, it has been reported that overexpression of unc-51-like kinase 3 (ULK3), the mammalian homolog of autophagy-specific gene 1 (ATG1), induces premature senescence in human fibroblasts. Therefore, we assessed whether the activation of autophagy would genuinely induce premature senescence in human cells.

METHODOLOGY/PRINCIPAL FINDINGS

Depletion of ATG7, ATG12, or lysosomal-associated membrane protein 2 (Lamp2) by transfecting siRNA or infecting cells with a virus containing gene-specific shRNA resulted in a senescence-like state in two strains of primary human fibroblasts. Prematurely senescent cells induced by autophagy impairment exhibited the senescent phenotypes, similar to the replicatively senescent cells, such as increased senescence associated β-galactosidase (SA-β-gal) activity, reactive oxygen species (ROS) generation, and accumulation of lipofuscin. In addition, expression levels of ribosomal protein S6 kinase1 (S6K1), p-S6K1, p-S6, and eukaryotic translation initiation factor 4E (eIF4E) binding protein 1 (4E-BP1) in the mammalian target of rapamycin (mTOR) pathway and beclin-1, ATG7, ATG12-ATG5 conjugate, and the sequestosome 1 (SQSTM1/p62) monomer in the autophagy pathway were decreased in both the replicatively and the autophagy impairment-induced prematurely senescent cells. Furthermore, it was found that ROS scavenging by N-acetylcysteine (NAC) and inhibition of p53 activation by pifithrin-α or knockdown of p53 using siRNA, respectively, delayed autophagy impairment-induced premature senescence and restored the expression levels of components in the mTOR and autophagy pathways.

CONCLUSION

Taken together, we concluded that autophagy impairment induces premature senescence through a ROS- and p53-dependent manner in primary human fibroblasts.

Restoration of senescent human diploid fibroblasts by modulation of the extracellular matrix

Human diploid fibroblasts have the capacity to complete a finite number of cell divisions before entering a state of replicative senescence characterized by growth arrest, changes in morphology, and altered gene expression. Herein, we report that interaction with extracellular matrix (ECM) from young cells is sufficient to restore aged, senescent cells to an apparently youthful state. The identity of the restored cells as having been derived from senescent cells has been confirmed by a variety of methods, including time lapse live cell imaging and DNA finger print analysis. In addition to cell morphology, phenotypic restoration was assessed by resumption of proliferative potential, growth factor responsiveness, reduction of intracellular reactive oxygen species levels, recovery of mitochondrial membrane potential, and increased telomere length. Mechanistically, we find that both Ku and SIRT1 are induced during restoration and are required for senescent cells to return to a youthful phenotype. These observations demonstrate that human cellular senescence is profoundly influenced by cues from the ECM, and that senescent cell plasticity is much greater than that was previously believed to be the case.

Effectiveness of vision therapy for convergence dysfunctions and long-term stability after vision therapy

BACKGROUND

Symptomatic convergence insufficiency (CI) is a common binocular dysfunction. It is often associated with accommodative insufficiency (AI). Optimum therapy for this condition was recently shown to be in-clinic vision therapy (VT). More scientific studies are needed to assess the effectiveness of VT and verify these evidence-based results.

METHODS

Fifty-seven children aged 9-13 years were diagnosed with symptomatic CI (n = 27) or combined symptomatic CI and AI (n = 30). They were independently divided into a treatment and a control group, matched by age and gender. The treatment group received 12 weeks of VT while the control group received no therapy. A quality of life instrument documented the symptomatic patients and charted improvement in symptoms after therapy. Clinical aspects were also assessed to determine the treatment effects on clinical findings. Twenty children in the treatment group completed a 1 year follow-up examination.

RESULTS

Symptom scores and clinical measures of the treatment and control groups were not significantly different at baseline (p > 0.05), but showed significant differences after completion of 12 weeks of treatment (p < 0.001). No significant changes of either symptoms or signs were evident for the control group. One year follow-up examination revealed that most children maintained the improved symptom and clinical measures after VT.

CONCLUSION

This study supports the notion that VT is a successful method of treating CI and CI combined with AI.

Biliverdin reductase A in the prevention of cellular senescence against oxidative stress

Biliverdin reductase A (BLVRA), an enzyme that converts biliverdin to bilirubin, has recently emerged as a key regulator of the cellular redox cycle. However, the role of BLVRA in the aging process remains unclear. To study the role of BLVRA in the aging process, we compared the stress responses of young and senescent human diploid fibroblasts (HDFs) to the reactive oxygen species (ROS) inducer, hydrogen peroxide (H2O2). H2O2 markedly induced BLVRA activity in young HDFs, but not in senescent HDFs. Additionally, depletion of BLVRA reduced the H2O2-dependent induction of heme oxygenase-1 (HO-1) in young HDFs, but not in senescent cells, suggesting an aging-dependent differential modulation of responses to oxidative stress. The role of BLVRA in the regulation of cellular senescence was confirmed when lentiviral RNAi- transfected stable primary HDFs with reduced BLVRA expression showed upregulation of the CDK inhibitor family members p16, p53, and p21, followed by cell cycle arrest in G0-G1 phase with high expression of senescence-associated β-galactosidase. Taken together, these data support the notion that BLVRA contributes significantly to modulation of the aging process by adjusting the cellular oxidative status.