Lanthanide ion (III) complexes of 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraaminophosphonate for dual biosensing of pH with chemical exchange saturation transfer (CEST) and biosensor imaging of redundant deviation in shifts (BIRDS)

Relaxivity-based magnetic resonance of phosphonated ligands chelated with gadolinium (Gd(3+)) shows promise for pH imaging. However instead of monitoring the paramagnetic effect of lanthanide complexes on the relaxivity of water protons, biosensor (or molecular) imaging with magnetic resonance is also possible by detecting either the nonexchangeable or the exchangeable protons on the lanthanide complexes themselves. The nonexchangeable protons (e.g. -CHx, where 3 ≥ x ≥ 1) are detected using a three-dimensional chemical shift imaging method called biosensor imaging of redundant deviation in shifts (BIRDS), whereas the exchangeable protons (e.g. -OH or -NHy , where 2 ≥ y ≥ 1) are measured with chemical exchange saturation transfer (CEST) contrast. Here we tested the feasibility of BIRDS and CEST for pH imaging of 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraaminophosphonate (DOTA-4AmP(8-)) chelated with thulium (Tm(3+) ) and ytterbium (Yb(3+)). BIRDS and CEST experiments show that both complexes are responsive to pH and temperature changes. Higher pH and temperature sensitivities are obtained with BIRDS for either complex when using the chemical shift difference between two proton resonances vs using the chemical shift of a single proton resonance, thereby eliminating the need to use water resonance as reference. While CEST contrast for both agents is linearly dependent on pH within a relatively large range (i.e. 6.3-7.9), much stronger CEST contrast is obtained with YbDOTA-4AmP(5-) than with TmDOTA-4AmP(5-). In addition, we demonstrate the prospect of using BIRDS to calibrate CEST as new platform for quantitative pH imaging.

Effect of melatonin on tumor growth and angiogenesis in xenograft model of breast cancer

As neovascularization is essential for tumor growth and metastasis, controlling angiogenesis is a promising tactic in limiting cancer progression. Melatonin has been studied for their inhibitory properties on angiogenesis in cancer. We performed an in vivo study to evaluate the effects of melatonin treatment on angiogenesis in breast cancer. Cell viability was measured by MTT assay after melatonin treatment in triple-negative breast cancer cells (MDA-MB-231). After, cells were implanted in athymic nude mice and treated with melatonin or vehicle daily, administered intraperitoneally 1 hour before turning the room light off. Volume of the tumors was measured weekly with a digital caliper and at the end of treatments animals underwent single photon emission computed tomography (SPECT) with Technetium-99m tagged vascular endothelial growth factor (VEGF) C to detect in vivo angiogenesis. In addition, expression of pro-angiogenic/growth factors in the tumor extracts was evaluated by membrane antibody array and collected tumor tissues were analyzed with histochemical staining. Melatonin in vitro treatment (1 mM) decreased cell viability (p<0.05). The breast cancer xenografts nude mice treated with melatonin showed reduced tumor size and cell proliferation (Ki-67) compared to control animals after 21 days of treatment (p<0.05). Expression of VEGF receptor 2 decreased significantly in the treated animals compared to that of control when determined by immunohistochemistry (p<0.05) but the changes were not significant on SPECT (p>0.05) images. In addition, there was a decrease of micro-vessel density (Von Willebrand Factor) in melatonin treated mice (p<0.05). However, semiquantitative densitometry analysis of membrane array indicated increased expression of epidermal growth factor receptor and insulin-like growth factor 1 in treated tumors compared to vehicle treated tumors (p<0.05). In conclusion, melatonin treatment showed effectiveness in reducing tumor growth and cell proliferation, as well as in the inhibition of angiogenesis.

Monitoring adenoviral based gene delivery in rat glioma by molecular imaging

AIM: To determine whether endothelial progenitor cells (EPCs) can be used as delivery vehicle for adenoviral vectors and imaging probes for gene therapy in glioblastoma.

METHODS: To use cord blood derived EPCs as delivery vehicle for adenoviral vectors and imaging probes for glioma gene therapy, a rat model of human glioma was made by implanting U251 cells orthotopically. EPCs were transfected with an adenovirus (AD5/carrying hNIS gene) and labeled with iron oxide and inoculated them directly into the tumor 14 d following implantation of U251 cells. Magnetic resonance imaging (MRI) was used to in vivo track the migration of EPCs in the tumor. The expression of gene products was determined by in vivo Tc-99m single photon emission computed tomography (SPECT). The findings were validated with immunohistochemistry (IHC).

RESULTS: EPCs were successfully transfected with the adenoviral vectors carrying hNIS which was proved by significantly (P < 0.05) higher uptake of Tc-99m in transfected cells. Viability of EPCs following transfection and iron labeling was not altered. In vivo imaging showed the presence of iron positive cells and the expression of transgene (hNIS) product on MRI and SPECT, respectively, all over the tumors following administration of transfected and iron labeled EPCs in the tumors. IHC confirmed the distribution of EPC around the tumor away from the injection site and also showed transgene expression in the tumor. The results indicated the EPCs’ ability to deliver adenoviral vectors into the glioma upon intratumor injection.

CONCLUSION: EPCs can be used as vehicle to deliver adenoviral vector to glioma and also act as imaging probe at the same time.

Abstract A009: Effect of melatonin on the tumor growth and angiogenesis of breast cancer

Background: Breast cancer has a high mortality rate, mainly due to tumor progression and metastatic spread. Once tumor lesion exceeds a few millimeters in diameter, hypoxia triggers a cascade of events to allow neovascularization. The major contributors to angiogenesis are the vascular endothelial growth factor (VEGF) and its receptors, which promote cell proliferation, migration, permeability and survival. Thus, controlling tumor-associated angiogenesis is a promising tactic in limiting cancer development. The melatonin administration, a hormone naturally produced and secreted in the pineal gland, appears to play an important oncostatic role in cancer and have been currently proposed different mechanisms of action. In this study we evaluated the benefits of melatonin treatment on tumor growth and angiogenesis in breast cancer.

Methods: MDA-MB-231 breast cancer cell line was cultured and cell viability was measured by MTT assay after incubation with different concentrations of melatonin (5 mM, 10 mM, 20 mM). We performed an in vivo study implanting cells in athymic nude mice. Mice were treated with 1mg of melatonin (n = 5) or vehicle (n = 8) daily, starting in the same day as tumor implantation and continued for 21 days. Tumors were measured with a digital caliper on day 7, 14 and 21 and the animals underwent SPECT scanning with Tc-99m tagged VEGF-c to detect in vivo angiogenesis (expression of VEGFR2/3). In addition, the markers of angiogenesis (VEGFR2, VEGFR3 and von Willebrand Factor (vWF)) and cell proliferation (Ki-67) were evaluated by immunohistochemistry in mammary tumor tissues.

Results: Melatonin treatment in vitro was able to significantly decrease cell viability, after 4 hours of exposure, maintaining its efficacy at higher doses after 24 hours exposure (p&lt;0.05). The animals treated with melatonin showed reduced tumor size compared to control animals after 21 days of treatment (p&lt;0.05). The mean tumor volume of control and treated animals were 282.00 ± 88.53 mm3 and 144.90 ± 38.38 mm3, respectively. The mean of tumor volume in control animals increased significantly from day 14 (118.90 ± 40.17 mm3) to day 21 (282.00 ± 88.53 mm3) (p&lt;0.05), which was not observed in the treated group. Furthermore, there was tumor regression in an animal treated with melatonin (Day 7 = 27.38 mm3; Day 14 = 8.79 mm3; Day 21 = 4.8 mm3), similar pattern was not seen in any of the control. Animals treated with melatonin showed lower activity of Tc-99-VEGF-C in the tumors compared to that of the animals that were treated with vehicle. The intensity of radioactivity in the control animals was 183.55 ± 20.92%, while the intensity of radioactivity in animals treated with melatonin was 150.46 ± 17.06%. Although there was difference in the radioactivity in the tumors between the two group, statistically significant difference was not achieved (p&gt;0.05). However, decrease of VEGFR2 in melatonin treated mice was confirmed by immunohistochemistry (p&lt;0.05). In addition, there was a decrease of micro-vessel density (vWF) and cell proliferation (Ki-67) in melatonin treated tumors (p&lt;0.05).

Conclusion: Taken together, our results showed that melatonin inhibits tumor growth, cell proliferation and blocks tumor angiogenesis in breast cancer, directing the development of a clinical study to determine its therapeutic potential for breast cancer.

Citation Format: Bruna Victorasso Jardim-Perassi, Ali S. Arbab, Lívia Carvalho Ferreira, Thaiz Ferraz Borin, Nadimpalli Ravi S. Varma, Adarsh Shankar, Asm Iskander, Meser M. Ali, Debora Aparecida Pires de Campos Zuccari. Effect of melatonin on the tumor growth and angiogenesis of breast cancer. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Breast Cancer Research: Genetics, Biology, and Clinical Applications; Oct 3-6, 2013; San Diego, CA. Philadelphia (PA): AACR; Mol Cancer Res 2013;11(10 Suppl):Abstract nr A009.

Subcurative radiation significantly increases cell proliferation, invasion, and migration of primary glioblastoma multiforme in vivo

Tumor cell proliferation, infiltration, migration, and neovascularization are known causes of treatment resistance in glioblastoma multiforme (GBM). The purpose of this study was to determine the effect of radiation on the growth characteristics of primary human GBM developed in a nude rat. Primary GBM cells grown from explanted GBM tissues were implanted orthotopically in nude rats. Tumor growth was confirmed by magnetic resonance imaging on day 77 (baseline) after implantation. The rats underwent irradiation to a dose of 50 Gy delivered subcuratively on day 84 postimplantation (n = 8), or underwent no radiation (n = 8). Brain tissues were obtained on day 112 (nonirradiated) or day 133 (irradiated). Immunohistochemistry was performed to determine tumor cell proliferation (Ki-67) and to assess the expression of infiltration marker (matrix metalloproteinase-2, MMP-2) and cell migration marker (CD44). Tumor neovascularization was assessed by microvessel density using von-Willebrand factor (vWF) staining. Magnetic resonance imaging showed well-developed, infiltrative tumors in 11 weeks postimplantation. The proportion of Ki-67-positive cells in tumors undergoing radiation was (71 +/- 15)% compared with (25 +/- 12)% in the nonirradiated group (P = 0.02). The number of MMP-2-positive areas and proportion of CD44-positive cells were also high in tumors receiving radiation, indicating great invasion and infiltration. Microvessel density analysis did not show a significant difference between nonirradiated and irradiated tumors. Taken together, we found that subcurative radiation significantly increased proliferation, invasion, and migration of primary GBM. Our study provides insights into possible mechanisms of treatment resistance following radiation therapy for GBM.

Intravenous administration of human umbilical cord blood-derived AC133+ endothelial progenitor cells in rat stroke model reduces infarct volume: magnetic resonance imaging and histological findings

Endothelial progenitor cells (EPCs) hold enormous therapeutic potential for ischemic vascular diseases. Previous studies have indicated that stem/progenitor cells derived from human umbilical cord blood (hUCB) improve functional recovery in stroke models. Here, we examined the effect of hUCB AC133+ EPCs on stroke development and resolution in a middle cerebral artery occlusion (MCAo) rat model. Since the success of cell therapies strongly depends on the ability to monitor in vivo the migration of transplanted cells, we also assessed the capacity of magnetic resonance imaging (MRI) to track in vivo the magnetically labeled cells that were administered. Animals were subjected to transient MCAo and 24 hours later injected intravenously with 10(7) hUCB AC133+ EPCs. MRI performed at days 1, 7, and 14 after the insult showed accumulation of transplanted cells in stroke-affected hemispheres and revealed that stroke volume decreased at a significantly higher rate in cell-treated animals. Immunohistochemistry analysis of brain tissues localized the administered cells in the stroke-affected hemispheres only and indicated that these cells may have significantly affected the magnitude of endogenous proliferation, angiogenesis, and neurogenesis. We conclude that transplanted cells selectively migrated to the ischemic brain parenchyma, where they exerted a therapeutic effect on the extent of tissue damage, regeneration, and time course of stroke resolution.

Direct period measurement for fiber Bragg grating using an optical imaging technique

This paper proposes an approach based on an optical imaging technique for the period measurement of fiber Bragg gratings (FBG). The simple, direct technique involves a differential interface contrast (DIC) microscope and a high-resolution CCD camera. Image processing is performed on the microscope images to obtain low-noise grating profiles and then the grating periods. Adopting a large image sample size in the image processing can reduce uncertainty. During the investigation, FBGs of different grating periods are fabricated by prestraining the photosensitive fibers during the UV-writing process. A good linearity between the measured Bragg wavelengths and grating periods is observed and the measured strain-optics coefficient was found to be in agreement with reported literature.

Effect of age on slaughterhouse by-products of indigenous cattle of Bangladesh

The present study was conducted to investigate the effect of age on slaughterhouse by-products and their chemical composition of indigenous cattle of Bangladesh. Live weight, warm carcass weight and dressing percentage of different age group (T1= 0 Tooth, T2= 2 Teeths, T3= 4 Teeths, T4= 6 Teeths and T5= 8 Teeths) of indigenous cattle were estimated. Average live weight and warm carcass weight of indigenous cattle was 167.64±79.93 kg and 84.83±47.88 kg, respectively on which age has significant effect. The average dressing percentage of indigenous cattle was 48.99±4.84. The average weight (kg) of inedible by-products eg. blood, hide, tail, scrotum, penis, cannon, horn, ear and tail was 6.35±0.69, 14.02±1.66, 0.34±0.03, 0.27±0.02, 0.28±0.03, 2.74±0.22, 0.33±0.04 and 0.17±0.02, respectively on which age has significant effect. The average weight (kg) of edible by-products eg. liver, heart, kidney, lung, brain, spleen, empty stomach, empty intestine, head and tongue was 2.40±0.22, 0.55±0.06, 0.35±0.04, 1.43±0.14, 0.33±0.01, 0.46±0.04, 6.32±0.74, 4.77±0.52, 8.21±0.78 and 0.48±0.04, respectively on which age has significant effect. The chemical composition of edible by-products was more or less similar to the main products of meat industry. DOI: http://dx.doi.org/10.3329/bjas.v42i1.15784 Bang. J. Anim. Sci. 2013. 42 (1): 62-66

PCR applications in identification of saliva samples exposed to different conditions (streptococci detection based)

Oral streptococci represent about 20% of the total oral bacteria, so if it is possible to detect the presence of oral specific bacteria from a forensic specimen by Polymerase chain reaction, this could be used to verify the presence of saliva. Aim of this study is detection of Streptococcus salivarius which is one of the most common streptococci in oral bacteria and Streptococcus mutans which is common in cases of dental caries in various body fluids and skin swabs and assessment of which one of both organisms is more reliable in saliva identification, cross sectional study on Egypt population. Negative control samples (15 samples) were taken from various body fluids (urine, semen) and skin swabs. Mock forensic samples (85 samples) included fresh saliva, saliva, cotton fabrics contaminated with saliva, cigarette butts, bitten apple and semen mixed with saliva samples). DNA extraction was done using DNeasy blood and tissue kit (Qiagen, Tokyo, Japan). Polymerase chain reaction was done for DNA amplification using Polymerase chain reaction master mix then gel electrophoresis was done for samples qualification. Control bacteria were S. salivarius and Streptococcus mutans. Streptococcus salivarius was detected in 83.5% of all saliva contained samples and S. mutans was detected in 67% of saliva contained samples. Both bacteria were not detected in other body fluids and skin swabs, so S. salivarius is more reliable in saliva identification as well as differentiating it from other body fluids. Polymerase chain reaction is valuable in detection of saliva by detecting S. salivarius.

Differential biodistribution of intravenously administered endothelial progenitor and cytotoxic T-cells in rat bearing orthotopic human glioma

BACKGROUND

A major challenge in the development of cell based therapies for glioma is to deliver optimal number of cells (therapeutic dose) to the tumor. Imaging tools such as magnetic resonance imaging (MRI), optical imaging, positron emission tomography (PET) and single-photon emission computed tomography (SPECT) has been used in cell tracking and/or biodistribution studies. In this study, we evaluate the dynamic biodistribution of systemic injected labeled cells [human cord blood derived endothelial progenitor cells (EPCs) and cytotoxic T-cells (CTLs)] in rat glioma model with in vivo SPECT imaging.

METHODS

Human cord blood EPCs, T-cells and CD14⁺ cells (monocytes/dendritic cells) were isolated using the MidiMACS system. CD14⁺ cells were converted to dendritic cells (DC) and also primed with U251 tumor cell line lysate. T-cells were co-cultured with irradiated primed DCs at 10:1 ratio to make CTLs. Both EPCs and CTLs were labeled with In-111-oxine at 37°C in serum free DMEM media. Glioma bearing animals were randomly assigned into three groups. In-111 labeled cells or In-111 oxine alone were injected through tail vein and SPECT imaging was performed on day 0, 1, and 3. In-111 oxine activity in various organs and tumor area was determined. Histochemical analysis was performed to further confirm the migration and homing of injected cells at the tumor site.

RESULTS

EPCs and CTLs showed an In-111 labeling efficiency of 87.06 ± 7.75% and 70.8 ± 12.9% respectively. Initially cell migration was observed in lung following inravenous administration of In-111 labeled cells and decreased on day 1 and 3, which indicate re-distribution of labeled cells from lung to other organs. Relatively higher In-111 oxine activity was observed in tumor areas at 24 hours in animals received In-111 labeled cells (EPCs or CTLs). Histiological analysis revealed iron positive cells in and around the tumor area in animals that received labeled cells (CTLs and EPCs).

CONCLUSION

We observed differential biodistribution of In-111-oxine labeled EPCs and CTLs in different organs and intracranial glioma. This study indicates In-111 oxine based SPECT imaging is an effective tool to study the biodistribution of therapeutically important cells.

Neural networks for shortest path computation and routing in computer networks

The application of neural networks to the optimum routing problem in packet-switched computer networks, where the goal is to minimize the network-wide average time delay, is addressed. Under appropriate assumptions, the optimum routing algorithm relies heavily on shortest path computations that have to be carried out in real time. For this purpose an efficient neural network shortest path algorithm that is an improved version of previously suggested Hopfield models is proposed. The general principles involved in the design of the proposed neural network are discussed in detail. Its computational power is demonstrated through computer simulations. One of the main features of the proposed model is that it will enable the routing algorithm to be implemented in real time and also to be adaptive to changes in link costs and network topology.

Dual-channel photoplethysmography synchronization using a Barker sequence

A Barker sequence is employed for the synchronization of two photoplethysmogram (PPG) channels. The correctness of this technique is demonstrated by recording a PPG signal, injecting a Barker sequence at the start of this trace and producing a delayed version of it. After preprocessing, cross-correlation techniques are utilized for accurate time alignment of the two traces. The algorithm can correct for any time misalignment as long as the synchronization sequence appears on both channels.

A nano-sized PARACEST-fluorescence imaging contrast agent facilitates and validates in vivo CEST MRI detection of glioma

AIM

The authors have investigated the usefulness of in vivo chemical exchange saturation transfer MRI for detecting gliomas using a dual-modality imaging contrast agent.

MATERIALS & METHODS

A paramagnetic chemical exchange saturation transfer MRI contrast agent, Eu-1,4,7,10-tetraazacclododecane-1,4,7,10-tetraacetic acid-Gly(4) and a fluorescent agent, DyLight 680, were conjugated to a generation 5 polyamidoamine dendrimer to create the dual-modality, nano-sized imaging contrast agent.

RESULTS

The agent was detected with in vivo chemical exchange saturation transfer MRI in an U87 glioma model. These results were validated using in vivo and ex vivo fluorescence imaging.

CONCLUSION

This study demonstrated the merits of using a nano-sized imaging contrast agent for detecting gliomas and using a dual-modality agent for detecting gliomas at different spatial scales.

Bioassay of Eucalyptus extracts for anticancer activity against Ehrlich ascites carcinoma (eac) cells in Swiss albino mice

OBJECTIVE

To evaluate the antineoplastic activity of Eucalyptus extract (EuE) against Ehrlich ascites carcinoma (EAC) in Swiss albino mice.

METHODS

Preliminary examination of four plant extracts (namely Eucalyptus, Costus, Azadirachta, Feronia) has been done by observing the reduction ability of number of EAC cells in previously inoculated Swiss albino mice. Among them as EuE showed maximum capability, the whole study has been conducted with EuE only. Important parameters viz. enhancement of life span, reduction of average tumor weight etc. have been studied. In addition the effects of EuE on hematological parameters in both normal and EAC inoculated mice have been measured. Effect of EuE on normal peritoneal cells has also been studied.

RESULTS

: EuE reduced tumor burden remarkably. It reduced the tumor growth rate and enhanced the life span of EAC bearing mice noticeably. It reversed back the hematological parameters towards normal, reduced the trasplantability of EAC cells and enhanced the immunomodulatory effects in mice. The host toxic effect of EuE in mice is minimum and mostly reversible with time. All such data have been compared with those obtained by running parallel experiments with bleomycin at dose 0.3 mg/kg (i.p.).

CONCLUSIONS

The Eucalyptus extract may be considered as a potent anticancer agent for advanced researches.

Endothelial progenitor cells (EPCs) as gene carrier system for rat model of human glioma

Background

Due to their unique property to migrate to pathological lesions, stem cells are used as a delivery vehicle for therapeutic genes to tumors, especially for glioma. It is critically important to track the movement, localization, engraftment efficiency and functional capability or expression of transgenes of selected cell populations following transplantation. The purposes of this study were to investigate whether 1) intravenously administered, genetically transformed cord blood derived EPCs can carry human sodium iodide symporter (hNIS) to the sites of tumors in rat orthotopic model of human glioma and express transgene products, and 2) whether accumulation of these administered EPCs can be tracked by different in vivo imaging modalities.

Methods and Results

Collected EPCs were cultured and transduced to carry hNIS. Cellular viability, differential capacity and Tc-99m uptake were determined. Five to ten million EPCs were intravenously administered and Tc-99-SPECT images were acquired on day 8, to determine the accumulation of EPCs and expression of transgenes (increase activity of Tc-99m) in the tumors. Immunohistochemistry was performed to determine endothelial cell markers and hNIS positive cells in the tumors. Transduced EPCs were also magnetically labeled and accumulation of cells was confirmed by MRI and histochemistry. SPECT analysis showed increased activity of Tc-99m in the tumors that received transduced EPCs, indicative of the expression of transgene (hNIS). Activity of Tc-99m in the tumors was also dependent on the number of administered transduced EPCs. MRI showed the accumulation of magnetically labeled EPCs. Immunohistochemical analysis showed iron and hNIS positive and, human CD31 and vWF positive cells in the tumors.

Conclusion

EPC was able to carry and express hNIS in glioma following IV administration. SPECT detected migration of EPCs and expression of the hNIS gene. EPCs can be used as gene carrier/delivery system for glioma therapy as well as imaging probes.

Treatment of phosphogypsum waste using suitable organic extractants

Phosphogypsum (PG) is a residue of the phosphate fertilizer industry that has relatively high concentrations of harmful radioactive materials. The reduction in concentration of the radionuclides from PG was investigated. The removal process is based on leaching of radionuclides using suitable organic extractants. The studied radionuclides were ²²⁶Ra, ²¹⁰Pb, ²³⁸U and ⁴⁰K. The factors affect the leaching process such as type of leaching materials, contact time, concentration of the desired solvent, liquid to solid ratio, and temperature were studied. Based on the experimental results, about 71.1, 76.4, 62.4, and 75.7% of ²²⁶Ra, ²¹⁰Pb, ²³⁸U and ⁴⁰K respectively were successfully removed from the PG. The reduction in the concentration of radionuclides was accompanied by reduction in the concentration of rare earth elements (∑REE) equals to 69.8%. Using the desired organic extractant under optimum conditions for treatment of the PG waste leads to obtain a decontaminated product that can be safely used in many industrial applications.

MRI to assess chemoprevention in transgenic adenocarcinoma of mouse prostate (TRAMP)

Background

The current method to determine the efficacy of chemoprevention in TRAMP mouse model of carcinoma of prostate (CaP) is by extracting and weighing the prostate at different time points or by immunohistochemistry analysis. Non-invasive determination of volumes of prostate glands and seminal vesicles before, during and after treatment would be valuable in investigating the efficacy of newer chemopreventive agents in CaP. The purpose of this study was to determine whether in vivo magnetic resonance imaging (MRI) using a 3 tesla clinical MRI system can be used to follow the effect of chemoprevention in TRAMP model of mouse CaP.

Methods

Mice were randomized into control and treated groups. The animals in treated group received 10 µmol/kg of CDDO, 5 days a week for 20 weeks. Animals underwent in vivo MRI of prostate gland and seminal vesicles by a clinical 3 Tesla MRI system just before (at 5 weeks), during and at the end of treatment, at 25 weeks. T1-weighted and fat saturation (FATSAT) multiecho fast spin echo T2- weighted images (T2WI) were acquired. Volume of the prostate glands and seminal vesicles was determined from MR images. T2 signal intensity changes in the seminal vesicles were determined by subtracting higher echo time (TE) from lower TE T2WI. Following treatments all animals were sacrificed, prostate and seminal vesicles collected, and the tissues prepared for histological staining. All data were expressed as mean ± 1 standard deviation. Two-way or multivariate analysis of variance followed by post-hoc test was applied to determine the significant differences. A p-value of <0.05 was considered significant.

Results

Histological analysis indicated tumor in 100% of control mice, whereas 10% of the treated mice showed tumor in prostate gland. Both MRI and measured prostate weights showed higher volume/weight in control mouse group. MRI showed significantly higher volume of seminal vesicles in control animals and T2 signal intensity changes in seminal vesicles of control mice indicating higher number of tumor foci, which was also proven by histology.

Conclusions

In vivo MRI is helpful in determining the efficacy of chemoprevention of prostate cancer in TRAMP mice.

Magnetic Resonance Imaging Estimation of Longitudinal Relaxation Rate Change (ΔR1) in Dual Gradient Echo Sequences Using an Adaptive Model

Magnetic Resonance Imaging (MRI) estimation of contrast agent concentration in fast pulse sequences such as Dual Gradient Echo (DGE) imaging is challenging. An Adaptive Neural Network (ANN) was trained with a map of contrast agent concentration estimated by Look-Locker (LL) technique (modified version of inversion recovery imaging) as a gold standard. Using a set of features extracted from DGE MRI data, an ANN was trained to create a voxel based estimator of the time trace of CA concentration. The ANN was trained and tested with the DGE and LL information of six Fisher rats using a K-Fold Cross-Validation (KFCV) method with 60 folds and 10500 samples. The Area Under the Receiver Operator Characteristic Curve (AUROC) for 60 folds was used for training, testing and optimization of the ANN. After training and optimization, the optimal ANN (4:7:5:1) produced maps of CA concentration which were highly correlated (r =0.89, P < 0.0001) with the CA concentration estimated by the LL technique. The estimation made by the ANN had an excellent overall performance (AUROC = 0.870).

Mannitol facilitates neurotrophic factor up-regulation and behavioural recovery in neonatal hypoxic-ischaemic rats with human umbilical cord blood grafts

We recently demonstrated that blood–brain barrier permeabilization using mannitol enhances the therapeutic efficacy of systemically administered human umbilical cord blood (HUCB) by facilitating the entry of neurotrophic factors from the periphery into the adult stroke brain. Here, we examined whether the same blood–brain barrier manipulation approach increases the therapeutic effects of intravenously delivered HUCB in a neonatal hypoxic-ischaemic (HI) injury model. Seven-day-old Sprague–Dawley rats were subjected to unilateral HI injury and then at day 7 after the insult, animals intravenously received vehicle alone, mannitol alone, HUCB cells (15k mononuclear fraction) alone or a combination of mannitol and HUCB cells. Behavioural tests at post-transplantation days 7 and 14 showed that HI animals that received HUCB cells alone or when combined with mannitol were significantly less impaired in motor asymmetry and motor coordination compared with those that received vehicle alone or mannitol alone. Brain tissues from a separate animal cohort from the four treatment conditions were processed for enzyme-linked immunosorbent assay at day 3 post-transplantation, and revealed elevated levels of GDNF, NGF and BDNF in those that received HUCB cells alone or when combined with mannitol compared with those that received vehicle or mannitol alone, with the combined HUCB cells and mannitol exhibiting the most robust neurotropic factor up-regulation. Histological assays revealed only sporadic detection of HUCB cells, suggesting that the trophic factor–mediated mechanism, rather than cell replacement per se, principally contributed to the behavioural improvement. These findings extend the utility of blood–brain barrier permeabilization in facilitating cell therapy for treating neonatal HI injury.

Changes in vascular permeability and expression of different angiogenic factors following anti-angiogenic treatment in rat glioma

BACKGROUND

Anti-angiogenic treatments of malignant tumors targeting vascular endothelial growth factor receptors (VEGFR) tyrosine kinase are being used in different early stages of clinical trials. Very recently, VEGFR tyrosine kinase inhibitor (Vetanalib, PTK787) was used in glioma patient in conjunction with chemotherapy and radiotherapy. However, changes in the tumor size, tumor vascular permeability, vascular density, expression of VEGFR2 and other angiogenic factors in response to PTK787 are not well documented. This study was to determine the changes in tumor size, vascular permeability, fractional plasma volume and expression of VEGFR2 in PTK787 treated U-251 glioma rat model by in vivo magnetic resonance imaging (MRI) and single photon emission computed tomography (SPECT). The findings were validated with histochemical and western blot studies.

METHODOLOGIES AND PRINCIPAL FINDINGS

Seven days after implantation of U251 glioma cells, animals were treated with either PTK787 or vehicle-only for two weeks, and then tumor size, tumor vascular permeability transfer constant (K(trans)), fractional plasma volume (fPV) and expression of VEGFR2 and other relevant angiogenic factors were assessed by in vivo MRI and SPECT (Tc-99-HYNIC-VEGF), and by immunohistochemistry and western blot analysis. Dynamic contrast-enhanced MRI (DCE-MRI) using a high molecular weight contrast agent albumin-(GdDTPA) showed significantly increased K(trans) at the rim of the treated tumors compared to that of the central part of the treated as well as the untreated (vehicle treated) tumors. Size of the tumors was also increased in the treated group. Expression of VEGFR2 detected by Tc-99m-HYNIC-VEGF SPECT also showed significantly increased activity in the treated tumors. In PTK787-treated tumors, histological staining revealed increase in microvessel density in the close proximity to the tumor border. Western blot analysis indicated increased expression of VEGF, SDF-1, HIF-1alpha, VEGFR2, VEGFR3 and EGFR at the peripheral part of the treated tumors compared to that of central part of the treated tumors. Similar expression patters were not observed in vehicle treated tumors.

CONCLUSION

These findings indicate that PTK787 treatment induced over expression of VEGF as well as the Flk-1/VEGFR2 receptor tyrosine kinase, especially at the rim of the tumor, as proven by DCE-MRI, SPECT imaging, immunohistochemistry and western blot.

Cutaneous sarcoidosis: updates in the pathogenesis

Sarcoidosis is a multiorgan granulomatous disease in which the skin is one of the frequently involved target organs. Cutaneous involvement occurs in a third of patients with sarcoidosis and has protean manifestations. More than a century has passed since the initial description of sarcoidosis, but its cause continues to be an enigma. Recent studies have introduced several new insights into the pathogenesis of this disease. The aim of this literature review was to provide a comprehensive overview on the current updates in the pathogenesis of sarcoidosis. This review has revealed that several genetic polymorphisms are associated with an increased risk of developing sarcoidosis, suggesting that genetic susceptibility to sarcoidosis is probably polygenic. Environmental factors may also modify the susceptibility to sarcoidosis. Evidence favouring an infectious aetiology has been accumulating, but the results of studies are conflicting. The current concept is that the pathogenesis of sarcoidosis involves a T-helper-1-mediated immune response to environmental antigens in a genetically susceptible host. The studies carried out on sarcoidosis have largely focused on the pulmonary aspects and have been mainly conducted by respiratory physicians. In contrast, research conducted on the cutaneous aspects of sarcoidosis is comparatively limited. Although tremendous advances have been made, there is a significant gap between the vast knowledge accumulated on sarcoidosis in recent years and the understanding of this disease.

Generalized essential telangiectasia with conjunctival involvement

Generalized essential telangiectasia (GET) is a rare skin disorder characterized by generalized development of dilated venules, which start at the lower extremities and progressively spread to the rest of the body. Mucous and conjunctival involvement is rare. The diagnosis is based on clinical examination, after excluding other primary and secondary causes of telangiectasia.