Displacement of the lumpectomy cavity defined by surgical clips and seroma based on 4D-CT scan for external-beam partial breast irradiation after breast-conserving surgery: a comparative study

OBJECTIVE

To compare the displacements of the lumpectomy cavity delineated by the surgical clips and the seroma based on four-dimensional CT (4D-CT) for external-beam partial breast irradiation (EB-PBI) after breast-conserving surgery (BCS).

METHODS

14 breast cancer patients after BCS were recruited for EB-PBI and undertook 4D-CT simulation. On the 10 sets of the 4D-CT images, all the surgical clips in the cavity were delineated. The gross tumour volume (GTV) formed by the clips, the seroma, and both the clips and the seroma were defined as GTVc, GTVs and GTVc+s, respectively. The displacements of the centre of mass (COM) of the clips, GTVc, GTVs, GTVc+s and the selected clips in the three-dimensional (3D) directions were recorded and compared.

RESULTS

In the left-right, anterior-posterior and superior-inferior directions, the displacements were 2.20, 1.80 and 2.70 mm for the clip COM; 0.90, 1.05 and 1.20 mm for GTVc; 0.80, 1.05 and 0.80 mm for GTVs; and 0.90, 1.20 and 1.40 mm for GTVc+s, respectively. In the 3D directions, the displacements of the clip COM were greater than the GTVc, GTVs, GTVc+s, and the displacements of the clip COM, GTVc+s, GTVc and GTVs were significantly greater than the displacements of the selected clips (p<0.05).

CONCLUSION

The displacements of the clip COM were greater than that of the GTVc, GTVs, GTVc+s and the four selected clips. The optimal internal target volume should be defined based on the boundary displacements.

ADVANCES IN KNOWLEDGE

When the GTV was delineated using the clips and/or the seroma, there was displacement difference between the lumpectomy cavity centre and the boundary for the EB-PBI. The optimal internal target volume should be defined based on the boundary displacements of the lumpectomy cavity.

Comparison of patient-specific internal gross tumor volume for radiation treatment of primary esophageal cancer based separately on three-dimensional and four-dimensional computed tomography images

To compare the target volume, position and matching index of the patient-specific internal gross tumor volume (IGTV) based on three-dimensional (3D) and four-dimensional (4D) computed tomography (CT) images for primary esophageal cancer. Twenty-nine patients with primary thoracic esophageal cancer underwent 3DCT and 4DCT scans during free breathing. IGTVs were constructed using three approaches: combining the gross target volumes from the 10 respiratory phases of the 4DCT dataset to produce IGTV10 ; IGTV2 was acquired by combining the two extreme phases; and IGTV3D was created from the 3DCT-based gross target volume by enlarging the 95th percentile of motion in each direction measured by the 4DCT. 0.16 cm lateral (LR), 0.14 cm anteroposterior (AP) and 0.29 cm superoinferior (SI) in the upper; 0.18 cm LR, 0.10 cm AP and 0.63 cm SI in the middle; and 0.40 cm LR, 0.58 cm AP and 0.82 cm in the lower thoracic esophagus could account for 95% of respiratory-induced tumor motion. The centroid position shift between IGTV10 and IGTV2 was all below 0.10 cm, and less than 0.20 cm between IGTV10 and IGTV3D . IGTV10 was bigger than IGTV2 ; the mean value of matching index for IGTV2 to IGTV10 was 0.87 ± 0.05, 0.85 ± 0.06 and 0.83 ± 0.05 for upper, middle and distal thoracic esophageal tumors, respectively, and just 0.57 ± 0.11, 0.56 ± 0.13 and 0.40 ± 0.03 between IGTV3D and IGTV10 . 4DCT-based IGTV10 is a reasonable patient-specific IGTV for primary thoracic esophageal cancer, and IGTV2 is considered as an acceptable alternative to IGTV10 . However, it seems unreasonable to use IGTV3D substitute IGTV10 .

Improved glycaemic control with vildagliptin added to insulin, with or without metformin, in patients with type 2 diabetes mellitus

AIM

The aim of this study is to assess the efficacy and safety of vildagliptin 50 mg bid as add-on therapy to insulin in type 2 diabetes mellitus (T2DM).

METHODS

This is a multicentre, double-blind, placebo-controlled, parallel group, clinical trial in T2DM patients inadequately controlled by stable insulin therapy, with or without metformin. Patients received treatment with vildagliptin 50 mg bid or placebo for 24 weeks.

RESULTS

In all, 449 patients were randomized to vildagliptin (n = 228) or placebo (n = 221). After 24 weeks, the difference in adjusted mean change in haemoglobin A1c (HbA1c) between vildagliptin and placebo was -0.7 ± 0.1% (p < 0.001) in the overall study population, -0.6 ± 0.1% (p < 0.001) in the subgroup also receiving metformin and -0.8 ± 0.2% (p < 0.001) in the subgroup without metformin. Vildagliptin therapy was well tolerated and had a similarly low incidence of hypoglycaemia compared with placebo (8.4 vs. 7.2%, p = 0.66) in spite of improved glycaemic control, and was not associated with weight gain. (+0.1 vs. -0.4 kg).

CONCLUSIONS

Vildagliptin 50 mg bid added to insulin significantly reduced HbA1c in patients with T2DM inadequately controlled by insulin, with or without metformin. Vildagliptin was well tolerated, with a safety profile similar to placebo. These results were achieved without weight gain or an increase in hypoglycaemia incidence or severity in spite of improved glycaemic control.

HMGB1 promotes the differentiation of Th17 via up-regulating TLR2 and IL-23 of CD14+ monocytes from patients with rheumatoid arthritis

High-mobility group box 1 (HMGB1) is a non-histone nuclear protein that is released extracellulary and has been implicated in autoimmune disease. Toll-like receptor 2 (TLR2) signalling is thought to be essential for the inflammatory response and for immune disorders. In recent studies, enhanced HMGB1 and TLR2 expressions have been found in rheumatoid arthritis (RA), respectively. The aim of this study is to explore whether HMGB1 stimulation can up-regulate the expression of TLR2 on CD14(+) monocytes from patients with RA and to clarify the subsequent events involving Th17 cells and Th17 cell-associated cytokine changes. Our results showed that the frequency of CD14(+) cells in peripheral blood mononuclear cell (PBMC) was obviously increased, and enhanced expression of TLR2 on CD14(+) monocytes was also found in patients with RA, compared with healthy controls with statistical significance (P < 0.001). In addition, the levels of IL-17, IL-23 and IL-6 in supernatants from cultured monocytes from patients and in patient's plasma were increased, and NF-κB, the downstream target of TLR2, also showed a marked elevation after monocytes were stimulated by HMGB1. This implies that the enhanced TLR2 pathway and Th17 cell polarization may be due to HMGB1 stimulation in rheumatoid arthritis.

One-year safety, tolerability and efficacy of vildagliptin in patients with type 2 diabetes and moderate or severe renal impairment

AIM

Assess long-term safety and efficacy of the dipeptidlyl peptidase-4 (DPP-4) inhibitor vildagliptin in 369 patients with type 2 diabetes mellitus (T2DM) and moderate or severe renal impairment (RI).

METHODS

Double-blind, randomized, parallel-group, 52-week clinical trial comparing safety and efficacy of vildagliptin (50 mg qd, n = 216) and placebo (n = 153) added to ongoing stable antihyperglycaemic treatment, in patients with T2DM and moderate or severe (glomerular filtration rate [GFR] ≥ 30 to <50 ml/min/1.73 m(2) and < 30 ml/min/1.73 m(2) ) RI.

RESULTS

The study population comprised 122 and 89 patients with moderate RI and 94 and 64 patients with severe RI randomized to vildagliptin and placebo, respectively, with the majority of patients receiving background insulin therapy (72% and 82% for moderate and severe RI, respectively). After 1 year, the between-treatment difference in adjusted mean change in A1C was -0.4 ± 0.2% (p = 0.005) in moderate RI (baseline = 7.8%) and -0.7 ± 0.2% (p < 0.0001) in severe RI (baseline = 7.6%). In patients with moderate RI, similar proportions of patients experienced any adverse event (AE) (84 vs. 85%), any serious adverse event (SAE) (21 vs. 19%), any AE leading to discontinuation (5% vs. 6%) and death (1% vs. 0%) with vildagliptin and placebo, respectively. This was also true for patients with severe RI: AEs (85% vs. 88%), SAEs (25% vs. 25%), AEs leading to discontinuation (10% vs. 6%) and death (3% vs. 2%).

CONCLUSIONS

In patients with T2DM and moderate or severe RI, vildagliptin added to ongoing antidiabetic therapy had a safety profile similar to placebo during 1-year observation. Furthermore, relative to placebo, a clinically significant decrease in A1C was maintained throughout 1-year treatment with vildagliptin.

Chronic treatment with a glucokinase activator delays the onset of hyperglycaemia and preserves beta cell mass in the Zucker diabetic fatty rat

AIMS/HYPOTHESIS

Glucokinase activators (GKAs) are currently being developed as new therapies for type 2 diabetes and have been shown to enhance beta cell survival and proliferation in vitro. Here, we report the effects of chronic GKA treatment on the development of hyperglycaemia and beta cell loss in the male Zucker diabetic fatty (ZDF) rat, a model of type 2 diabetes with severe obesity.

METHODS

Cell protection by GKA was studied in MIN6 and INS-1 cells exposed to hydrogen peroxide. Glucose homeostasis and beta cell mass were evaluated in ZDF rats dosed for 41 days with Cpd-C (a GKA) or glipizide (a sulfonylurea) as food admixtures at doses of approximately 3 and 10 mg kg(-1) day(-1).

RESULTS

Incubation of MIN6 and INS-1 832/3 insulinoma cell cultures with GKA significantly reduced cell death and impairment of intracellular NADH production caused by exposure to hydrogen peroxide. Progression from prediabetes (normoglycaemia and hyperinsulinaemia) to overt diabetes (hyperglycaemia and hypoinsulinaemia) was significantly delayed in male ZDF rats by in-feed treatment with Cpd-C, but not glipizide. Glucose tolerance, tested in the fifth week of treatment, was also significantly improved by Cpd-C, as was pancreatic insulin content and beta cell area. In a limited immunohistochemical analysis, Cpd-C modestly and significantly enhanced the rate of beta cell proliferation, but not rates of beta cell apoptosis relative to untreated ZDF rats.

CONCLUSIONS/INTERPRETATION

These findings suggest that chronic activation of glucokinase preserves beta cell mass and delays disease in the ZDF rat, a model of insulin resistance and progressive beta cell failure.

Safety and efficacy of vildagliptin versus placebo in patients with type 2 diabetes and moderate or severe renal impairment: a prospective 24-week randomized placebo-controlled trial

AIM

Assess safety/tolerability and efficacy of the DPP-4 inhibitor vildagliptin in 515 patients with type 2 diabetes mellitus (T2DM) and moderate or severe renal impairment (RI).

METHODS

Double-blind, randomized, parallel-group, placebo-controlled, 24-week clinical trial assessing safety and efficacy of vildagliptin (50 mg qd) added to current antidiabetic therapy, in patients with T2DM and moderate or severe RI (GFR ≥ 30 to <50 or <30 ml/min/1.73 m(2) ).

RESULTS

The study population comprised of 165 and 129 patients with moderate RI and 124 and 97 patients with severe RI randomized to vildagliptin and placebo, respectively, with most patients receiving background insulin therapy (68 and 81% for moderate and severe RI, respectively). After 24 weeks, the between-treatment difference in the adjusted mean change in A1C was -0.5 ± 0.1% (p < 0.0001) in moderate RI (baseline A1C = 7.9%) and -0.6 ± 0.1% (p < 0.0001) in severe RI (baseline A1C = 7.7%). In patients with moderate RI, similar proportions of those receiving vildagliptin or placebo experienced any AE (68 vs. 73%), any SAE (9 vs. 9%), any AE leading to discontinuation (3 vs. 5%) or death (1 vs. 1%). This was also true for patients with severe RI: AEs (73 vs. 74%), SAEs (19 vs. 21%), AEs leading to discontinuation (9 vs. 6%) and death (2 vs. 4%).

CONCLUSIONS

In this 24-week study of 515 patients with T2DM and moderate or severe RI, vildagliptin added to ongoing antidiabetic therapy had a safety profile similar to placebo. Further, relative to placebo, vildagliptin elicited a statistically and clinically significant decrease in A1C in patients with moderate or severe RI.

The design and delivery of a thermally responsive peptide to inhibit S100B-mediated neurodegeneration

S100B, a glial-secreted protein, is believed to play a major role in neurodegeneration in Alzheimer's disease, Down syndrome, traumatic brain injury, and spinocerebellar ataxia type 1 (SCA1). SCA1 is a trinucleotide repeat disorder in which the expanded polyglutamine mutation in the protein ataxin-1 primarily targets Purkinje cells of the cerebellum. Currently, the exact mechanism of S100B-mediated Purkinje cell damage in SCA1 is not clear. However, here we show that S100B may act via the activation of the receptor for advanced glycation end product (RAGE) signaling pathway, resulting in oxidative stress-mediated injury to mutant ataxin-1-expressing neurons. To combat S100B-mediated neurodegeneration, we have designed a selective thermally responsive S100B inhibitory peptide, Synb1-ELP-TRTK. Our therapeutic polypeptide was developed using three key elements: (1) the elastin-like polypeptide (ELP), a thermally responsive polypeptide, (2) the TRTK12 peptide, a known S100B inhibitory peptide, and (3) a cell-penetrating peptide, Synb1, to enhance intracellular delivery. Binding studies revealed that our peptide, Synb1-ELP-TRTK, interacts with its molecular target S100B and maintains a high S100B binding affinity as comparable with the TRTK12 peptide alone. In addition, in vitro studies revealed that Synb1-ELP-TRTK treatment reduces S100B uptake in SHSY5Y cells. Furthermore, the Synb1-ELP-TRTK peptide decreased S100B-induced oxidative damage to mutant ataxin-1-expressing neurons. To test the delivery capabilities of ELP-based therapeutic peptides to the cerebellum, we treated mice with fluorescently labeled Synb1-ELP and observed that thermal targeting enhanced peptide delivery to the cerebellum. Here, we have laid the framework for thermal-based therapeutic targeting to regions of the brain, particularly the cerebellum. Overall, our data suggest that thermal targeting of ELP-based therapeutic peptides to the cerebellum is a novel treatment strategy for cerebellar neurodegenerative disorders.

Clinical experience with vildagliptin in the management of type 2 diabetes in a patient population ≥75 years: a pooled analysis from a database of clinical trials

AIM

To report the experience with vildagliptin in a patient population with type 2 diabetes mellitus (T2DM) ≥75 years.

METHODS

Efficacy data from seven monotherapy and three add-on therapy to metformin studies, respectively, of ≥24 weeks duration were pooled; effects of 24 weeks of treatment with vildagliptin (50 mg bid) in patients ≥75 years were assessed in these two pooled datasets. Safety data were pooled from 38 studies of ≥12 to ≥104 weeks duration; adverse events (AEs) profiles of vildagliptin (50 mg bid) were evaluated relative to a pool of comparators; 301 patients ≥75 years were analysed. Data in patients <75 years are provided as a reference.

RESULTS

Mean age of the elderly population was 77 years. Changes in haemoglobin A1c (HbA1c) with vildagliptin in the patient group ≥75 years were -0.9% from a baseline of 8.3% in monotherapy (p < 0.0001) and -1.1% from a baseline of 8.5% in add-on therapy to metformin (p = 0.0004), and these reductions were similar to those seen in the younger patients. The corresponding weight changes in the elderly patients were -0.9 kg (p = 0.0277) and -0.2 kg [not significant (NS)], respectively, and no confirmed hypoglycaemic events, including no severe events, were reported. AEs, drug-related AEs, serious adverse events (SAEs) and deaths were reported with a lower frequency in older patients receiving vildagliptin than comparators [133.9 vs. 200.6, 14.5 vs. 21.8, 8.8 vs. 16.5 and 0.0 vs. 1.7 events per 100 subject year exposure (SYE), respectively], and the incidence of discontinuations due to AEs was similar in the two groups (7.2 vs. 7.5 events per 100 SYE, respectively). The safety profile of vildagliptin was overall similar in younger and older patients.

CONCLUSIONS

Vildagliptin was effective and well-tolerated in type 2 diabetic patients ≥75 years (mean age 77 years).

Dopamine D2 receptor signaling modulates mutant ataxin-1 S776 phosphorylation and aggregation

Spinocerebellar ataxia 1 (SCA1) is a dominantly inherited neurodegenerative disease associated with progressive ataxia resulting from the loss of cerebellar Purkinje cells (PCs) and neurons in the brainstem. In PCs of SCA1 transgenic mice, the disease causing ataxin-1 protein mediates the formation of S100B containing cytoplasmic vacuoles and further self-aggregates to form intranuclear inclusions. The exact function of the ataxin-1 protein is not fully understood. However, the aggregation and neurotoxicity of the mutant ataxin-1 protein is dependent on the phosphorylation at serine 776 (S776). Although protein kinase A (PKA) has been implicated as the S776 kinase, the mechanism of PKA/ataxin-1 regulation in SCA1 is still not clear. We propose that a dopamine D(2) receptor (D2R)/S100B pathway may be involved in modulating PKA activity in PCs. Using a D2R/S100B HEK stable cell line transiently transfected with GFP-ataxin-1[82Q], we demonstrate that stimulation of the D2R/S100B pathway caused a reduction in mutant ataxin-1 S776 phosphorylation and ataxin-1 aggregation. Activation of PKA by forskolin resulted in an enhanced S776 phosphorylation and increased ataxin-1 nuclear aggregation, which was suppressed by treatment with D2R agonist bromocriptine and PKA inhibitor H89. Furthermore, treating SCA1 transgenic PC slice cultures with forskolin induced neurodegenerative morphological abnormalities in PC dendrites consistent with those observed in vivo. Taken together our data support a mechanism where PKA dependent mutant ataxin-1 phosphorylation and aggregation can be regulated by D2R/S100B signaling.