Search

• The approximability and the computational complexity of the Maximum Happy Set problem (MaxHS) are studied. • A (2 Δ + 1) -approximation algorithm for MaxHS on graphs with maximum degree Δ is presented. • The approximation ratio is improved to Δ if the maximum degree Δ is a constant. • The polynomial-time solvability of MaxHS on block/interval graphs is proved. • The NP-hardness of MaxHS on bipartite/cubic graphs is proved. In this paper we study the approximability of the Maximum Happy Set problem (MaxHS) and the computational complexity of MaxHS on graph classes: For an undirected graph G = (V , E) and a subset S ⊆ V of vertices, a vertex v is happy if v and all its neighbors are in S ; otherwise unhappy. Given an undirected graph G = (V , E) and an integer k , the goal of MaxHS is to find a subset S ⊆ V of k vertices such that the number of happy vertices is maximized. MaxHS is known to be NP-hard. In this paper, we design a (2 Δ + 1) -approximation algorithm for MaxHS on graphs with maximum degree Δ. Next, we show that the approximation ratio can be improved to Δ if the maximum degree Δ of the input graph is a constant. Then, we show that MaxHS can be solved in polynomial time if the input graph is restricted to block graphs, or interval graphs. We prove nevertheless that MaxHS on bipartite graphs or on cubic graphs remains NP-hard. [ABSTRACT FROM AUTHOR]

The article focuses on the impact of fucoidan, a fucose-rich polysaccharide extracted from brown seaweed, in induction of apoptosis in breast cancer cells. It highlights the role of low-molecular-weight fucoidan through calcium- and caspase-dependent mitochondrial pathways in induction of apoptosis in MDA-MB-231 breast cancer cells. Photographs depicting effect of low-molecular-weight fucoidan (LMWF) on the growth and viability of MDA-MB-231 cells are also presented.

Fucoidan, a fucose-rich polysaccharide isolated from brown alga, is currently under investigation as a new anti-cancer compound. In the present study, fucoidan extract (FE) from Cladosiphon navae-caledoniae Kylin was prepared by enzymatic digestion. We investigated whether a combination of FE with cisplatin, tamoxifen or paclitaxel had the potential to improve the therapeutic efficacy of cancer treatment. These co-treatments significantly induced cell growth inhibition, apoptosis, as well as cell cycle modifications in MDA-MB-231 and MCF-7 cells. FE enhanced apoptosis in cancer cells that responded to treatment with three chemotherapeutic drugs with downregulation of the anti-apoptotic proteins Bcl-xL and Mcl-1. The combination treatments led to an obvious decrease in the phosphorylation of ERK and Akt in MDA-MB-231 cells, but increased the phosphorylation of ERK in MCF-7 cells. In addition, we observed that combination treatments enhanced intracellular ROS levels and reduced glutathione (GSH) levels in breast cancer cells, suggesting that induction of oxidative stress was an important event in the cell death induced by the combination treatments. [ABSTRACT FROM AUTHOR]

Background: Fucoidan extract (FE), an enzymatically digested compound with a low molecular weight, is extracted from brown seaweed. As a natural compound with various actions, FE is attractive, especially in Asian countries, for improving the therapeutic efficacy and safety of cancer treatment. The present study was carried out to investigate the anti-tumor properties of FE in human carcinoma cells and further examine the underlying mechanisms of its activities. Methodology/Principal Finding: FE inhibits the growth of MCF-7, MDA-MB-231, HeLa, and HT1080 cells. FE-mediated apoptosis in MCF-7 cancer cells is accompanied by DNA fragmentation, nuclear condensation, and phosphatidylserine exposure. FE induces mitochondrial membrane permeabilization (MMP) through loss of mitochondrial membrane potential (DYm) and regulation of the expression of Bcl-2 family members. Release of apoptosis-inducing factor (AIF) and cytochrome c precedes MMP. AIF release causes DNA fragmentation, the final stage of apoptosis, via a caspase-independent mitochondrial pathway. Additionally, FE was found to induce phosphorylation of c-Jun N-terminal kinase (JNK), p38, and extracellular signal-regulated kinase (ERK) 1/2, and apoptosis was found to be attenuated by inhibition of JNK. Furthermore, FE-mediated apoptosis was found to involve the generation of reactive oxygen species (ROS), which are responsible for the decrease of DYm and phosphorylation of JNK, p38, and ERK1/2 kinases. Conclusions/Significance: These data suggest that FE activates a caspase-independent apoptotic pathway in MCF-7 cancer cells through activation of ROS-mediated MAP kinases and regulation of the Bcl-2 family protein-mediated mitochondrial pathway. They also provide evidence that FE deserves further investigation as a natural anticancer and cancer preventive agent. [ABSTRACT FROM AUTHOR]

Background: Appropriate use of anti-infective drugs is essential in clinical practice. No evidence-based guidelines or protocols have been published on the appropriate use of anti-infective drugs in patients receiving palliative care as yet. Methods: The medical records, which included the demographic data of patients, anti-infective drug use, bacteriologic findings, symptoms, and hematologic findings were reviewed retrospectively to determine the potential factors that contribute to symptom improvement of patients in terminal phase. Results: Seventy-one patients (64%) who received anti-infective drugs and had a total of 326 episodes of infection were assessed. Symptom improvement was seen in 33.1%. A total of 22.6% of episodes were started on anti-infective drugs during the last week of life and the symptom improvement in these episodes was 9.2%. Symptom improvement was hardly observed when the anti-infective drug was administered during the last week of life. The association between the decrease in the C-reactive protein (CRP) levels, the decrease of the leukocyte count, reduction of fever, and symptom improvement was determined. The decrease of CRP levels was 42.4%; leukocyte, 56.7%; and reduction of fever was 28.4%. The symptom improvement of individual treatment history was also investigated. The symptom improvement of the group who took positive treatment such as chemotherapy, radiotherapy, surgery, and catheter placement was significantly lower than that of no-treatment group. Conclusions: Active cancer treatment probably induces the symptoms related to infection and the use of anti-infective drugs. Unnecessary and excessive treatment should be avoided, and the symptoms should be managed with consideration of the patient's state of mind in order to improve the quality of life of terminally ill patients. [ABSTRACT FROM AUTHOR]

The objectives of the present study were to investigate whether buttressing sutures, which prevent the bladder neck from pulling open as the bladder fills, can promote earlier recovery from urinary incontinence after radical retropubic prostatectomy (RRP) and to identify possible risk factors associated with urinary incontinence after RRP.The present study included 72 patients who underwent non-nerve-sparing RRP without neoadjuvant therapy between January and December 2003. Among these 72 patients, intussusception of the bladder neck was performed in 24 who consented to this procedure. In the present series, continence was defined as the absence of any need to use sanitary pads or diapers. Continence was evaluated by a patient interview 1, 3 and 6 months after RRP.There were no significant differences in clinicopathological characteristics between patients with and without intussusception of the bladder neck. The percentage of continent patients 1, 3 and 6 months after RRP was 34.7%, 63.9% and 95.8%, respectively, and there were no significant differences in continence between the two groups at any time point. Among several factors examined, only bladder neck preservation was an independent predictor of recovery from urinary incontinence 1 and 3 months after RRP.These findings suggest that it would be important to preserve the bladder neck for early return to continence after non-nerve-sparing RRP; however, intussusception of the bladder neck may not offer significant improvement in earlier return of urinary control. [ABSTRACT FROM AUTHOR]

Introduction: The objective of this study was to determine whether the tumor volume in radical prostatectomy specimens of patients with prostate cancer who underwent neoadjuvant hormonal therapy (NHT) could be used as a prognostic predictor. Patients and Methods: In this study, we included 96 patients who underwent NHT followed by radical prostatectomy between January 1995 and July 2003 in our institutions. Several clinicopathological factors of these patients were analyzed, focusing on the association between tumor volume in radical prostatectomy specimens and disease recurrence. Results: The tumor volume in radical prostatectomy specimens after NHT was significantly associated with capsular penetration, seminal vesicle invasion, and lymph node metastases, among the factors examined in this study. The biochemical recurrence-free survival rates in patients with tumor volumes <1.0 cm3 were significantly higher than in those having tumor volumes ≥1.0 cm3. However, multivariate analysis showed that the tumor volume could not be used as an independent predictor for biochemical recurrence. Conclusions: In patients who received NHT prior to radical prostatectomy, the tumor volume was shown to correlate with other prognostic indicators. Furthermore, a higher probability of biochemical recurrence was noted, when there was a residual tumor volume ≥1.0 cm3 after NHT. Thus, careful follow-up and, if necessary, additional treatment should be considered in cases demonstrating tumor volumes ≥1.0 cm3 after NHT. Copyright © 2005 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]