Distributed source x-ray tube technology for tomosynthesis imaging

Tomosynthesis imaging requires projection images from different viewing angles. Conventional systems use a moving xray source to acquire the individual projections. Using a stationary distributed x-ray source with a number of sources that equals the number of required projections, this can be achieved without any mechanical motion. Advantages are a potentially faster image acquisition speed, higher spatial and temporal resolution and simple system design. We present distributed x-ray sources based on carbon nanotube (CNT) field emission cathodes. The field emission cathodes deliver the electrons required for x-ray production. CNT emitters feature a stable emission at high current density, a cold emission, excellent temporal control of the emitted electrons and good configurability. We discuss the use of stationary sources for two applications: (i) a linear tube for stationary digital breast tomosynthesis (sDBT), and (ii) a square tube for on-board tomosynthesis image-guided radiation therapy (IGRT). Results from high energy distributed sources up to 160kVp are also presented.

Superficial primary small cell carcinoma of the esophagus: clinicopathological and immunohistochemical analysis of 15 cases

Primary esophageal small cell carcinoma (PESCC) is a relatively rare and aggressive tumor with poor prognosis. Systemic spreading and metastasis often occur at diagnosis. Although 5-year survival rate of superficial squamous cell carcinoma of the esophagus can be 86.1%, 5-year survival rate of superficial PESCC is still relatively low. This study mainly retrospectively analyzed clinicopathological and immunohistochemical features of 15 cases of superficial PESCC in our hospital from 1990 to 2004, in order to find suitable diagnostic markers and applicable therapies for this disease. The records mainly included presenting symptoms, demographics, diagnostic method, histopathology, follow-up, and therapy. Immunohistochemical staining of chromogranin A (CgA), neuron-specific enolase (NSE), synaptophysin (Syn), neuronal cell adhesion molecules (CD56), thyroid transcription factor-1 (TTF-1), cytokeration 34betaE12 (CK34betaE12), cytokeratin (AE1/AE3), and cytokeratin 10/13 was performed. Incidence of superficial PESCC accounted for 4.8% of that of superficial carcinoma of the esophagus during the same period. Initial symptoms of all patients were dysphagia or accompanied with retrosternal pain and upper abdominal pain, and duration of these symptoms was 75 days averagely. Mean age of patients was 58.8 years old, and the male-to-female ratio was 2.75 : 1. Lesions were mainly located at middle thoracic esophagus. One, 2, and 5-year survival rates were 66.7, 33.3, and 6.7%, respectively. The median survival time was 19 months and mean survival time was 23.7 months after diagnosis. The percentages of PESCC samples with positive immunoreactivity were NSE 100%, Syn 100%, AE1/AE3 100%, CD56 93.3%, TTF-1 60%, CgA 53.3%, CK34betaE12 6.7%, and cytokeratin 10/13 0%, respectively. Our study suggested that PESCC was a rare and aggressive tumor with high malignancy. Superficial PESCC had rapid progression and poor prognosis compared with superficial squamous cell carcinoma of the esophagus at the same stage. The systemic therapy based on combination of postoperative chemotherapy and radiotherapy might be an effective approach for the treatment of superficial PESCC as a systemic disease. Higher proportion of positive labeling of NSE, Syn, AE1/AE3, CD56, TTF-1, and CgA in PESCC was valuably applied in diagnosis and differential diagnosis.

Induced NG2 expressing microglia in the facial motor nucleus after facial nerve axotomy

Chondroitin sulfate proteoglycan (NG2) expressing cells, ubiquitously distributed in the CNS respond to injured or diseased neurons; however, their behaviors toward injured neurons have remained to be fully explored. In the present study, along with astrocytic and microglial responses, NG2 expressing cells reacted swiftly and robustly in the facial motor nucleus (FMN) subjected to axotomy. With time, hypertrophic NG2 expressing cells gradually adhered to and enwrapped the axotomized motoneurons. Tight encapsulations around axotomized motoneurons were eventually formed at 7, 14, and 28 days after axotomy. NG2 positive processes appeared to interpose between synapsin-1 immunoreactive nerve terminals and surfaces of axotomized motoneurons. Double labeling results showed that NG2 expressing cells encapsulating axotomized facial motoneurons were mainly microglia marked by OX42 and lectin; only a few of them were positive to platelet-derived growth factor-alpha receptor and none of them positive to ED-1. No Rhodamine particle was detected in the FMN ipsilateral to axotomy after venous injection of the particles. The results suggest that activated microglia in lesioned FMN were induced to express NG2 molecules. It is concluded that axotomized FMN showed two types of NG2 expressing cells namely constitutive NG2 cells and induced-NG2 expressing microglia.

Diffusion-Weighted MRI in Predicting the Efficacy of Neoadjuvant Chemotherapy of Breast Cancer

Objective: To approach the apparent diffusion coefficient(ADC) obtained on diffusion weighted imaging (DWI) in predicting the response of breast cancer to neoadjuvant chemotherapy.Methods: 53 locally advanced breast cancer patients participated in this prospective study on neoadjuvant chemotherapy. All patients were treated with weekly neoadjuvant paclitaxel plus carboplatin for 4 cycles. DWI and ADC value were examined before chemotherapy(the first time point), after the first and the forth cycle of chemotherapy(the second and the third time point). Patients were categorized as high responders if their ADC at the second time point were higher by 2 times the standard deviation than the mean pre-chemotherapy ADC, and otherwise the patients were considered as low responders. Logistic regression was conducted to examine the independent factors predictive of clinical complete response(CR) and pathologic complete response(pCR).Results: CR was documented in 13 patients (24.5%); partial response in 36 patients (67.9%); stable disease in 4 patients (7.5%) and no patient had progressive disease. 11 patients(20.8%) have achieved pCR. There was a strong positive correlation between the percentage changes in ADC value at the third time points and the degree of the tumor reduction. A significant increase in ADC value was observed at the second time point compared with the first time point (1.104±0.117×10-3mm2/s, 1.220±0.158×10-3mm2/s, P<0.001), while the decrease of the longest diameter of the tumors measured by physical examination, ultrasound or MRI or the tumor volumn measured by MRI were not (P>0.05). Logistic regression revealed that percentage changes of ADC value at the second time point were significantly associated with CR(P=0.022, hazard ratio[HR] =1.08, 95% confidence interval[CI]: 1.01∼1.16) and pCR(P=0.022, HR =1.11, 95%CI: 1.02∼1.21). The AUC value of the receiver operating characteristic curve were 0.721(95%CI: 0.512∼0.931, P=0.017) and 0.775(95%CI: 0.598∼0.952, P=0.005) in the two diagnostic tests for CR and pCR, and the sensitivity and specificity were 76.9%, 63.6% and 77.5%, 90.5%, respectively. According to categorizing system described above, 10 patients(18.9%) were considered as high responders and 43 patients(81.1%) low responders. 7 patients(70%) of the high responders have achieved clinical CR and pCR while for the low responders there were only 6 patients(14.0%) and 4 patients (9.3%) proven to have CR and pCR. The difference have both reached statistical significance(P=0.001, P<0.001). Logistic regression confirmed that the categorizing system was independently predictive of CR(P=0.006, HR=42.26, 95%CI: 2.86∼624.08) and pCR(P=0.013, HR=25.19, 95%CI: 2.00∼318.91). Taking this categorizing system as a dignostic test, the sensitivity and specificity were 53.8% and 92.5% for CR and 63.6% and 92.9% for pCR, respectively.Conclusions: The change of ADC value obtained on DWI after the first cycle of neoadjuvant chemotherapy occured prior to the morphologic changes of the tumor and at this time ADC value could to some extent predict the efficacy of neoadjuvant chemotherapy.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 4025.

Estrogen Receptor Expression: Possible Predictor of Pathological Complete Response to Neoadjuvant Chemotherapy in Locally Advanced Breast Cancer Patients

BackgroundEstrogen receptor(ER) status has been found to correlate inversely to pathologic complete response (pCR) rates of neoadjuvant chemotherapy(NAC) of breast cancer. However, not all ER-positive breast cancer respond equally to NAC. The present study aimed to determine the relationship between different ER expression level with pCR in locally advanced breast cancer(LABC) patients who have received NAC.MethodsA retrospective study of 332 female unilateral LABC patients undergoing NAC was performed. All patients were confirmed as invasive breast cancer before treated with NAC, including VE (vinorelbine, epirubicin), CEF (cyclophosphamide, epirubicin, fluorouracil) and PCb regimen (paclitaxel, carboplatin). All patients underwent radical surgery and pCR was defined as the absence of invasive breast cancer in both breast and axillary lymph nodes. ER status were checked using the established immunohistochemical(IHC) method and defined as negative, weakly positive(1+), medium positive(2+) and strongly positive(3+). Binary logistic regression was performed to determine the independent predictors of pCR.ResultsER negativity, 1+, 2+ and 3+ were found in 156, 108, 37 and 31 patients, of which 42(26.9%), 21(19.4%), 3(8.1%) and 1 patients(3.2%) have achieved pCR. Binary logistic regression showed that different ER expression level(P=0.021) and HER2 status(P=0.007, hazard ratio[HR] =2.557, 95% confidence interval[CI]: 1.297∼5.038) were significantly associated with the pCR rates. pCR was much more likely to occur in patients with ER-negative(P=0.024, HR =13.119, 95% CI: 1.402∼122.774) or ER 1+(P=0.025, HR=12.928, 95% CI: 1.388∼120.390) tumors than those with ER 3+ tumors.ConclusionER weekly positive patients also gain considerable benefit from NAC, which is probably less effective in ER strongly positive patients in terms of pCR.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 1104.

Epidemiology of Triple Negative Breast Cancer in China

Background:The classification of tumors based on the gene expression may define intrinsic breast cancer subtypes in which the effect of risk factors could be more obvious. We sought to assess the risk factors for triple negative breast cancer on Chinese population.Methods: A retrospective study of 5761 patients was carried out from a large database of breast cancer patients undergoing surgery between January 1, 1991 and June 31, 2008 in Cancer Hospital, Fudan University, Shanghai, China. Univariate analyses were performed by chi-square test of Student's t test and multivariate analyses by logistic regression.Results: A total of 1108 women were identified as having triple negative breast cancer and were compared with the 4653 women with non-triple negative. Regardless the pathological discrepancy, women with triple negative breast cancers were significantly more likely to be younger age(P=0.001; OR=1.615, 95%CI=1.207-2.160), premenopausal (P = 0.003; OR = 1.570, 95% CI = 1.171-2.106) and parous women (P = 0.001; OR = 1.741, 95% CI = 1.269-2.387).There seems no associations with increasing risk of triple negative breast cancer for breastfeeding (P=0.126), younger age at menarche (P=0.129), first degree family history (P=0.111) and oral contraceptive usage (P=0.251).Conclusion:Based on this large population study in Chinese breast cancer patients, the risk factors for triple negative phenotype may be somewhat different from those for Western women. Therefore, a better knowledge of this issue is warranted due to it may have impact on clinical outcomes and may offer some insight into the process of carcinogenesis and therapeutic efficacy.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 2065.

Efficacy of extracorporeal shock wave lithotripsy for ureteral stones in children

PURPOSE

In this study, we retrospectively analyzed our experience with extracorporeal shock wave lithotripsy (ESWL) in children with ureteric stones.

MATERIALS AND METHODS

Between 1997 and 2008, 115 children with ureteral stones were treated by ESWL in our department. There were 67 boys and 48 girls with a mean age of 7.2 + or - 4.3 years. There were 53 (46.1%) patients with proximal ureteric stones, 16 (13.9%) with mid-ureteral stones and 46 (40.0%) with distal ureteral stones. The stone size ranged from 4 to 21 mm with a mean of 7.38 mm. Children with proximal stones were treated in the supine position, while children with mid and distal ureteric stones were treated in the prone or supine position.

RESULTS

Stone-free rate at 3 months was 94.8%, the re-treatment rate 15.7%, and overall efficacy quotient (EQ) was 83%. SWL failed in six children (5.2%). There was no significant difference in stone-free rates at 3 months between different groups classified by location and stone size. There were no serious side effects.

CONCLUSIONS

Our results indicate that ESWL with highly satisfactory stone-free rates and negligible complications can be considered as a first-line treatment for ureteric stones in the pediatric age group.

Fiber Bragg gratings with enhanced thermal stability by residual stress relaxation

Fiber Bragg gratings with greatly enhanced thermal stability have been fabricated by the use of femtosecond laser pulse irradiation on optical fibers with relaxed residual stress, through using high temperature annealing treatment. The grating reflectivity and resonant wavelength can be maintained for periods up to 20 hours using isothermal measurements and temperatures up to 1200 degrees C. No hysteresis was observed in the wavelength response when the gratings were annealed and the temperature cycled repeatedly between room temperature and 1200 degrees C.

CD3(+) and/or CD14(+) depletion from cord blood mononuclear cells before ex vivo expansion culture improves total nucleated cell and CD34(+) cell yields

Cord blood (CB) is used increasingly in transplant patients lacking sibling or unrelated donors. A major hurdle in the use of CB is its low cell dose, which is largely responsible for an elevated risk of graft failure and a significantly delayed neutrophil and platelet engraftment. As a positive correlation has been shown between the total nucleated cell (TNC) and CD34(+) cell dose transplanted and time to neutrophil and platelet engraftment, strategies to increase these measures are under development. One strategy includes the ex vivo expansion of CB mononuclear cells (MNC) with MSC in a cytokine cocktail. We show that this strategy can be further improved if CD3(+) and/or CD14(+) cells are first depleted from the CB MNC before ex vivo expansion. Ready translation of this depletion strategy to improve ex vivo CB expansion in the clinic is feasible as clinical-grade devices and reagents are available. Ultimately, the aim of improving TNC and CD34(+) transplant doses is to further improve the rate of neutrophil and platelet engraftment in CB recipients.

Phenylalanine-pyruvate aminotransferase activity in chicks subjected to phenylalanine imbalance or phenylalanine toxicity

Two experiments were done to determine the influence of Phe imbalance and excess on Phe-pyruvate aminotransferase (PAT) activity in the chick. Five replicates of 3 chicks (experiment 1) or 2 chicks (experiment 2) of a commercial brown egg layer strain were fed a semipurified diet for 1 wk and then received experimental diets for 10 d. Three diets were used in experiment 1: the basal diet contained 0.46% Phe; the imbalance diet was similar to the basal diet except that it contained a 10% mixture of indispensable amino acids lacking Phe (IAA - Phe) to create a Phe imbalance; the imbalance corrected diet was similar to the imbalance diet except that it was supplemented with 1.12% Phe to correct the imbalance. A 3 x 2 factorial arrangement of treatments in experiment 2 provided 3 dietary levels (0.46, 1.58, and 2.46%) of Phe and either no supplement or 10% supplement of IAA - Phe. Nonfasted chicks were killed and livers were sampled in experiment 1, and livers, kidneys, brains, and pectoralis major muscles were sampled in experiment 2. In experiment 1, liver PAT activity per gram of liver was 80 and 55% higher (P < 0.01) in chicks fed the imbalance and imbalance corrected diets than in chicks fed the basal diet. In experiment 2, the livers and kidneys, but not brains and muscles, of chicks that received the 10% supplement of IAA - Phe had higher activities of PAT per gram of tissue per minute and per milligram of tissue protein extract per minute than chicks that did not receive IAA - Phe (P < 0.001). No effect of dietary Phe on PAT activity was detected (P > 0.05). Phenylalanine-pyruvate aminotransferase activity appears to be regulated in response to dietary content of indispensable amino acids but not by the dietary level of Phe.

Effects of blood pressure lowering and intensive glucose control on the incidence and progression of retinopathy in patients with type 2 diabetes mellitus: a randomised controlled trial

AIMS/HYPOTHESIS

The aim of the present study was to investigate the effect of blood pressure lowering and intensive glucose control on the incidence and progression of retinopathy in type 2 diabetic patients.

METHODS

The Action in Diabetes and Vascular Disease: Preterax and Diamicron MR Controlled Evaluation (ADVANCE) Retinal Measurements study, a substudy of ADVANCE, is a randomised (using a central, computer-based procedure) controlled 2 x 2 factorial trial comprising a double-blind comparison of blood pressure lowering with perindopril-indapamide vs placebo, and an open comparison of standard vs intensive glucose control targeting a HbA(1c) of < or = 6.5% in 1,602 diabetic patients from ADVANCE centres with access to retinal cameras conducted from 2001 to 2008. At baseline and the final visit, seven-field stereoscopic retinal photographs were taken and graded by blinded readers (gradeable baseline and final photographs from 1,241 patients). Progression of > or =2 steps in the Early Treatment of Diabetic Retinopathy Study classification (using the eye with worst grading) was the primary outcome.

RESULTS

Retinopathy progressed in 59 (4.8%) patients and developed in 128 (10.3%) patients over 4.1 years. Fewer patients on blood pressure-lowering treatment (n = 623) experienced incidence or progression of retinopathy compared with patients on placebo (n = 618), but the difference was not significant (OR 0.78; 95% CI 0.57-1.06; p = 0.12). Blood pressure-lowering treatment reduced the occurrence of macular oedema (OR 0.50; 95% CI 0.29-0.88; p = 0.016) and arteriovenous nicking compared with placebo (OR 0.60; 95% CI 0.38-0.94; p = 0.025). Compared with standard glucose control (n = 611), intensive glucose control (n = 630) did not reduce (p = 0.27) the incidence and progression of retinopathy (OR 0.84; 95% CI 0.61-1.15). Lower, borderline significant risks of microaneurysms, hard exudates and macular oedema were observed with intensive glucose control, adjusted for baseline retinal haemorrhages. These effects of the two treatments were independent and additive. Adverse events in the ADVANCE study are reported elsewhere.

CONCLUSIONS/INTERPRETATION

Blood pressure lowering or intensive glucose control did not significantly reduce the incidence and progression of retinopathy, although consistent trends towards a benefit were observed, with significant reductions in some lesions observed with both interventions.

TRIAL REGISTRATION

ClinicalTrials.gov ID no. NCT00145925.

FUNDING

Grants from Servier and the National Health and Medical Research Council of Australia.