Additive Schwarz Preconditioners with Minimal Overlap for Triangular Spectral Elements

The additive Schwarz preconditioner with minimal overlap is extended to triangular spectral elements (TSEM). The method is a generalization of the corresponding method in tensorial quadrilateral spectral elements (QSEM). The proposed preconditioners are based on partitioning the domain into overlapping subdomains, solving local problems on these subdomains and solving an additional coarse problem associated with the subdomain mesh. The results of numerical experiments show that the proposed preconditioner are robust with respect to the number of elements and are more efficient than the preconditioners with generous overlaps.     

Purine anti-metabolite attenuates nuclear factor κB and related pro-inflammatory cytokines in experimental vasospasm

Background

Increased nuclear factor κB (NF-κB) bioexpression, as well as TNF-α, IL-1β and IL-6 levels, were observed after aneurysmal subarachnoid hemorrhage (SAH). It is of interest to investigate the effect of 6-mercaptopurine (6-mp) on cytokines/NF-κB in this SAH model.

Materials and methods

A rodent double-hemorrhage SAH model was employed. Serum and cerebrospinal fluid (CSF) samples were collected to examine IL-1, IL-6 and TNF-α levels. NF-κB subunit p65 and its inhibitor of nuclear factor κB (IκB) were examined (by Western blot). TNF-α was used to induce the phosphorylation of IκB in the presence or absence of 6-mp.

Results

Nuclear NF-κB subunit p65/IκB kinase in the basilar artery was over-expressed, and cytokines was notably increased in the SAH groups, compared with the controls (P?P?Conclusions Through inhibiting IκB bioexpression, 6-mp decreases NF-κB-related IL-1β, IL-6, and TNF-α in the presence of SAH. The study suggests 6-mp exerts vascular anti-inflammatory properties through inhibiting IκB kinase and subsequently blocks bio-activation of NF-κB and related cytokines, which may contribute to its antivasospastic effect in animals subjected to SAH.     

Early Data from the First Population-Wide Breast Cancer-Specific Registry in Hong Kong

Background

Current measures for breast cancer prevention and options for treatment adopted in Hong Kong are mainly based on research data and clinical evidence from overseas. It is essential to establish a cancer-specific registry to monitor the status of breast cancer in Hong Kong.

Objectives

We summarized the current status of breast cancer in Hong Kong based on the data collected from Hong Kong Breast Cancer Registry (HKBCR).

Methods

Prevalent and newly diagnosed breast cancers (including in situ and invasive breast cancers) were registered in the HKBCR. Information on patient demographics, risk factors, medical information, and survival were analyzed and reported in this study.

Results

Data of 2,330 breast cancer patients were analyzed. We observed an earlier median age at diagnosis in Hong Kong than those reported in other countries. Distribution of cancer stage was: stage 0 (11.4%), stage I (31.4%), stage II (41%), stage III (12.5%), stage IV (0.8%), and unclassified (2.9%). The percentages of patients who received surgery, chemotherapy, radiation therapy, and endocrine therapy were 98.7, 67.9, 64.8, and 64.1%, respectively. At a median follow-up of 1.2?years, locoregional recurrence was recorded at 2%, distant recurrence at 2.8%, and breast-cancer–related mortality at 0.3%.

Conclusions

The HKBCR serves as a surveillance program to monitor disease and treatment patterns. It is pivotal to support research for more effective breast cancer prevention and treatment strategies in Hong Kong.     

The impact of social networks and partnership status on treatment choice in men with localized prostate cancer

Study Type – Decision analysis (cohort) Level of Evidence 2b What's known on the subject? and What does the study add? Very little is known about prostate cancer decision‐making. Hence, marital status is often assumed a proxy for the amount of social support. While marital status is often used as a proxy for social support, we found that the quality of support may impact treatment type more than the extent of the social matrix.

OBJECTIVES

• ? To determine whether martial status and social support impact treatment choice.
• ? The decision to pursue radical prostatectomy for prostate cancer is often influenced by factors outside the realm of tumour risk, such as a man's support system at home.

PATIENTS AND METHODS

• ? We performed a retrospective cohort study of 418 low‐income men who were diagnosed with non‐metastatic prostate cancer and underwent definitive treatment with either radical prostatectomy or radiotherapy.
• ? We performed univariate and multivariate mixed‐effects logistic regression analysis, with the dependent variable being treatment type.
• ? Confidence intervals (CIs) for the predicted probabilities and relative risks were derived using bias‐corrected bootstrapping with 1000 repetitions.

RESULTS

• ? Men with two or more members in their support system were more likely to be older, Hispanic, have less than a high school education, earn more than US $1500 monthly, have high‐risk disease and be in a significant relationship.
• ? In multivariate analysis, partnered men with fewer than two social support members (relative risk, RR, 1.23; 95% CI, 1.02–1.63) were more likely to undergo surgery, whereas men who were morbidly obese (RR, 0.46; 95% CI, 0.09–0.88), high school graduates (RR, 0.80; 95% CI, 0.64–0.99) or had high‐risk disease (RR, 0.58; 95% CI, 0.44–0.85) were less likely to undergo surgery than their respective referent groups.
• ? Partnered men with two or more social support members were no more likely to undergo surgery than unpartnered men who lacked any social support.

CONCLUSIONS

• ? In the present study cohort, married men with fewer than two members in their social network were more likely to have undergone surgery.
• ? Although marital status is often used as a proxy for social support, we find that the quality of support and partner may impact treatment type more than the extent of the social matrix.

     

Imaging predictors of the response to transarterial chemoembolization in patients with hepatocellular carcinoma: a radiological-pathological correlation

Transarterial chemoembolization (TACE) is one of the standard therapies for bridging patients with hepatocellular carcinoma (HCC) to transplantation. This study was designed to determine which features on pre- and post-TACE imaging are associated with tumor necrosis in pathological specimens. Records of 105 patients with 132 HCC lesions who underwent liver transplantation after TACE were retrospectively reviewed. In 70% of the nodules, >90% necrosis was achieved. The development of >90% lesion necrosis upon pathological analysis was associated with avid lesion enhancement (P = 0.03) and the presence of a feeding vessel larger than 0.9 mm in diameter on the pre-TACE visceral angiogram (P = 0.01). Near-complete lesion necrosis was also associated with an extensive accumulation of ethiodized oil within a lesion during TACE administration (P = 0.04). On post-TACE computed tomography imaging, a lack of residual contrast enhancement (P < 0.0001), a decrease in the lesion size (P = 0.04), a high lesion density due to an accumulation of ethiodized oil (P = 0.03), and a diffuse distribution of ethiodized oil throughout the lesion (P = 0.0001) were also correlated with near-complete lesion necrosis upon pathological analysis. In conclusion, this study found multiple pre- and post-TACE imaging characteristics of HCC that were associated with near-complete tumor necrosis upon histopathological analysis after TACE. These findings may help to guide the selection of an optimal treatment strategy for bridging patients with HCC to liver transplantation.     

Cross sectional survey on the concerns and anxiety of patients waiting for organ transplants

Aim: We aimed to gain an understanding of patient concerns while on a transplantation waiting list in areas with long transplant waiting time. Methods: The study population comprised patients with organ failure on the transplant waiting list in Hong Kong. They were invited to complete a questionnaire survey. Demographic data and waiting time were collected. Respondents rated their chance of getting transplanted, their subjective concerns and feelings, level of happiness and support received. Results: A total of 442 patients on the waiting list for kidney, liver, lung and heart‐lung transplants completed the questionnaire survey. The majority of patients (93.0%) were waiting for kidney transplantation. More than half of the respondents (63.3%) had been waiting for more than 3 years. Patients with longer transplant waiting times had lower self‐estimated chance of receiving a transplant (P = 0.004). Self‐estimated chance of getting transplanted was positively associated with the happiness score (P < 0.0001). Issues of most concerns to the patients waiting for organ transplants were: inconvenience of therapy (48.2%), disease progression (47.9%), burden to family (59.5%) and financial difficulties (52.3%). More female patients on the waiting list (50.0% vs 25.7% in male) reported concerns about suffering associated with the illnesses. 21.7% of patients considered the level of support received inadequate. Conclusions: Our patients had long waiting time for transplantation, which is associated with a lower perceived chance of getting a transplant. Attention to more psychosocial support to these patients waiting for organ transplant is important. Promoting and improving organ donation would be the ultimate way to help these patients.     

Wilms' tumor in a horseshoe kidney

The incidence of horseshoe kidney is about 1 in 400 cases. The presence of Wilms' tumor with a horseshoe kidney is unusual, and the occurrence of Wilms' tumor in a horseshoe kidney is estimated at 0.4 to 0.9% of all Wilms' tumors. We report the case of a 5-year-old boy who presented with a stage IV Wilms' tumor in a horseshoe kidney. The patient was treated with preoperative chemotherapy followed by surgical resection and adjuvant chemotherapy. This case illustrates the role of preoperative chemotherapy for preserving renal function and aims to highlight the multimodality treatment of Wilms' tumor.