Value of diffusion weighted MR imaging as an early surrogate parameter for evaluation of tumor response to high-dose-rate brachytherapy of colorectal liver metastases

<p>Abstract</p> <p>Background</p> <p>To assess the value of diffusion weighted imaging (DWI) as an early surrogate parameter for treatment response of colorectal liver metastases to image-guided single-fraction ¹⁹²Ir-high-dose-rate brachytherapy (HDR-BT).</p> <p>Methods</p> <p>Thirty patients with a total of 43 metastases underwent CT- or MRI-guided HDR-BT. In 13 of these patients a total of 15 additional lesions were identified, which were not treated at the initial session and served for comparison. Magnetic resonance imaging (MRI) including breathhold echoplanar DWI sequences was performed prior to therapy (baseline MRI), 2 days after HDR-BT (early MRI) as well as after 3 months (follow-up MRI). Tumor volume (TV) and intratumoral apparent diffusion coefficient (ADC) were measured independently by two radiologists. Statistical analysis was performed using univariate comparison, ANOVA and paired t test as well as Pearson's correlation.</p> <p>Results</p> <p>At early MRI no changes of TV and ADC were found for non-treated colorectal liver metastases. In contrast, mean TV of liver lesions treated with HDR-BT increased by 8.8% (<it>p </it>= 0.054) while mean tumor ADC decreased significantly by 11.4% (<it>p </it>< 0.001). At follow-up MRI mean TV of non-treated metastases increased by 50.8% (<it>p </it>= 0.027) without significant change of mean ADC values. In contrast, mean TV of treated lesions decreased by 47.0% (<it>p </it>= 0.026) while the mean ADC increased inversely by 28.6% compared to baseline values (<it>p </it>< 0.001; Pearson's correlation coefficient of r = -0.257; p < 0.001).</p> <p>Conclusions</p> <p>DWI is a promising imaging biomarker for early prediction of tumor response in patients with colorectal liver metastases treated with HDR-BT, yet the optimal interval between therapy and early follow-up needs to be elucidated.</p

Identification and Characterization of GABAergic Projection Neurons from Ventral Hippocampus to Amygdala

GABAergic local circuit neurons are critical for the network activity and functional interaction of the amygdala and hippocampus. Previously, we obtained evidence for a GABAergic contribution to the hippocampal projection into the basolateral amygdala. Using fluorogold retrograde labeling, we now demonstrate that this projection indeed has a prominent GABAergic component comprising 17% of the GABAergic neurons in the ventral hippocampus. A majority of the identified GABAergic projection neurons are located in the stratum oriens of area CA1, but cells are also found in the stratum pyramidale and stratum radiatum. We could detect the expression of different markers of interneuron subpopulations, including parvalbumin and calbindin, somatostatin, neuropeptide Y, and cholecystokinin in such retrogradely labeled GABA neurons. Thus GABAergic projection neurons to the amygdala comprise a neurochemically heterogeneous group of cells from different interneuron populations, well situated to control network activity patterns in the amygdalo-hippocampal system

Differential Expression of SPARC in Intestinal-type Gastric Cancer Correlates with Tumor Progression and Nodal Spread

AIMS: Nodal spread is the single most important prognostic factor of survival in gastric cancer patients. In this study, genes that were upregulated in the lymph node metastases of gastric cancer were identified and may serve as putative novel therapeutic target. METHODS: Complementary DNA (cDNA) microarray analysis and quantitative real-time polymerase chain reaction of primary gastric carcinomas and matched lymph node metastasis were carried out. Immunohistochemistry with anti-SPARC antibodies was performed on large tissue sections of 40 cases with primary gastric carcinoma (20 diffuse, 20 intestinal) and the corresponding lymph node metastases, as well as on tissue microarrays of 152 gastric cancer cases. RESULTS: A cDNA microarray identified SPARC as being upregulated in primary gastric carcinoma tissue and the corresponding lymph node metastasis compared with the nonneoplastic mucosa. SPARC was expressed in fibroblasts and, occasionally, in tumor cells. However, the level of immunoreactivity was particularly strong in stromal cells surrounding the tumor. The level of expression of SPARC, determined by immunohistochemistry, correlated in intestinal-type gastric cancer with the local tumor growth, nodal spread, and tumor stage according to the International Union Against Cancer. CONCLUSIONS: Our study provides transcriptional and translational evidence for the differential expression of SPARC in gastric cancer tissue. On the basis of our observations and those made by others, we hypothesize that SPARC is a promising novel target for the treatment of gastric cancer

Visualizing the occurrence of age-dependent characteristics of T cell activation.

<p>The requirement of activation by the TCR/CD3 complex is less dependent on costimulation by CD28 in CB naive CD4⁺ T cells compared to that seen in adult cells. The intensity of Ca²⁺ influx, NFATc2 expression and IL-2 response are all age-dependent. A dramatic shift is seen in the naive T cell response at the age of 2 months. The cells’ capacity to produce high amounts of IL-2 is suddenly abrogated. Ca²⁺ influx declines to the lowest values observed in life. At 6 months of age, the IL-2 response starts to improve slowly. This “reprogramming” of T cells takes place as the passively transferred maternal Abs in the infant are beginning to decline. Limited T-cell responses likely contribute to the high risk of infants to suffer from infections and infection-related pathologies such as Sepsis and SIDS [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0166633#pone.0166633.ref043" target="_blank">43</a>,<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0166633#pone.0166633.ref044" target="_blank">44</a>] during the first months of life.</p

Key signaling pathways for IL-2 transcription are activated in TCR/CD3 stimulated naive CD4⁺ T cells of CB.

<p>(A) Protein expression by Western blot of ERK1/2 and phosphorylated ERK1/2Tyr202/ Tyr204 (pERK1/2) in naive CD4⁺ T cells of CB as well as for naive CD31⁺ adult T cells. The ratios of relative protein expression levels are indicated below the respective bands. Data are representative of two independent experiments. (B) Whole cell protein extract of NFATc2 and phosphorylated NFATc2 (pNFATc2) in CB naive CD4⁺ T cells and adult naive CD31⁺ T cells under different stimulation conditions. The densitometric analyses of the immunoblot detection for the relative protein expression level are shown as ratio of NFATc2 or pNFATc2 to αTubulin. Lysates from three different donors were pooled. Data are representative of at least three independent experiments. αTubulin was used as a loading control. (C-D). The NFATc2 protein expression in cytoplasm or nucleoplasm (separated through a dashed line) in (C) naive CD4⁺ T cells of CB or (D) CD31⁺ naive T cells of adult were detected and the phosphorylated (pNFATc2) and dephosphorylated (NFATc2) forms quantified. Cells were stimulated as indicated in the presence or absence of cyclosporin A (CsA). One representative experiment out of two comparable experiments is shown. unstim. = unstimulated.</p

Different Ca²⁺ responses of CB and adult CD31⁺ naive T cells.

<p>(A-B) Ca²⁺ mobilization in CD4⁺CD45RA⁺CD31⁺ T cells of one healthy donor (representative of at least eight healthy individuals) of PBMCs (A, adult) or CB (B) were performed in response to 0.05 μg/ml anti-CD3 Ab plus 0.5 μg/ml soluble anti-CD28 Ab (red curve) or only 0.05 μg/ml of anti-CD3 Ab alone (black curve, with anti-CD28 isotype Ab) in combination with GAMIg. The blue dotted line displays the maximum Ca²⁺ response of adult CD31⁺ naive T cells for anti-CD3 Ab stimulation alone. (C) Box plot with scatter plots representing means and SD of Ca²⁺ influx response normalized by maximal Ca²⁺ influx response to ionomycin of adult (gray circle) and CB (black circle) and their dependency on anti-CD28 Ab costimulation (anti-CD3 Ab plus anti-CD28 Ab (red box) or anti-CD3 Ab with anti-CD28 Ab isotype (blue box)). Statistical significance between groups * <i>P<</i>0.05 was determined by two-tailed ANOVA with Tukey-Kramer post-hoc test. n = number of individuals. (D) Comparison of different CD4⁺ T cell subset stimulated with anti-CD3 Ab plus anti-CD28 Ab (red box) or with anti-CD3 Ab alone (blue box). Box plot with scatter plots representing means and standard deviations of Ca²⁺ influx response normalized by maximal Ca²⁺ influx response to ionomycin. Statistical significance of differences between anti-CD3/anti-CD28 Ab or anti-CD3 Ab stimulation at concentration 0.05 μg/ml of anti-CD3 Ab CD31⁺ between groups of different T cell subsets was determined by two-tailed ANOVA <i>P</i> = 0.7745, CD45RA⁺ <i>P</i> = 0.8195, CD4⁺ <i>P</i> = 0.9926. ns = not significant. n = number of individuals. (E) CD4⁺CD45RA⁺CD31⁺ T cells of CB (filled line), and adults (dashed line) treated with 0.5 μg/ml soluble anti-CD3 Ab and anti-CD28 Ab cross-linked with GAMIg in the presence (red) or absence (black) of 2 mM EGTA. One representative experiment out of three comparable experiments is shown. (F) STIM1 protein expression in CD4⁺ T cells of CB (black) and in naive CD31⁺ T cells from adults (gray) after stimulation using anti-CD3/anti-CD28 Ab. The densitometric analyses of the ratio of STIM1/α Tubulin are shown. Results are representative of at least two experiments.</p