Chemical Imaging of Organic Materials by MeV SIMS Using a Continuous Collimated Ion Beam.

MeV SIMS is a type of secondary ion mass spectrometry (SIMS) technique where molecules are desorbed from the sample surface with ions of MeV energies. In this work, we present a novel system for molecular imaging of organic materials using a continuous analytical beam and a start trigger for timing based on the detection of secondary electrons. The sample is imaged by a collimated primary ion beam and scanning of the target with a lateral resolution of ∼20 μm.

Chronic High Fat Diet Intake Impairs Hepatic Metabolic Parameters in Ovariectomized Sirt3 KO Mice.

High fat diet (HFD) is an important factor in the development of metabolic diseases, with liver as metabolic center being highly exposed to its influence. However, the effect of HFD-induced metabolic stress with respect to ovary hormone depletion and sirtuin 3 (Sirt3) is not clear. Here we investigated the effect of Sirt3 in liver of ovariectomized and sham female mice upon 10 weeks of feeding with standard-fat diet (SFD) or HFD.

Combination of sirtuin 3 and hyperoxia diminishes tumorigenic properties of MDA-MB-231 cells.

Aims: Since the role of the major mitochondrial NAD-dependent deacetylase, sirtuin 3 (Sirt3), is differential in cancer, opposite to the well-known tumor-suppressing effect of hyperoxia, this study aimed to investigate the role of Sirt3 in triple-negative breast cancer (TNBC) cell line MDA-MB-231 upon hyperoxic (95% O) conditions.

Main Methods: MDA-MB-231 cells were stably transfected with Flag-tagged Sirt-3 or empty plasmid. Western blot and real-time PCR were used to monitor the expression of proteins or genes involved in mitochondrial biogenesis, metabolic regulation and antioxidant defense.

Study of the diacylglycerol composition in the liver and serum of mice with prediabetes and diabetes using MeV TOF-SIMS.

Aims: Hepatic insulin resistance, induced by fat, occurs before peripheral resistance and leads to prediabetes and diabetes. If insulin resistance is detected earlier, lifestyle changes could prevent or delay disease development. Therefore, we analysed lipids in the liver and serum of prediabetic and diabetic mice by MeV TOF-SIMS with a focus on diacylglycerols (DAGs) as the best predictor of (liver) resistance.

De novo expression of transfected sirtuin 3 enhances susceptibility of human MCF-7 breast cancer cells to hyperoxia treatment.

Sirtuin 3 (Sirt3) has a promising role in cancer tumourigenesis and treatment, but there have been controversies about its role as oncogene or tumour suppressor in different types of cancer. Changes in its expression are associated with the excessive production of reactive oxygen species (ROS), thus contributing to mitochondrial dysfunction and age-related pathologies. Hyperoxic treatment (i.

Diminished Resistance to Hyperoxia in Brains of Reproductively Senescent Female CBA/H Mice.

BACKGROUND We have explored sex differences in ability to maintain redox balance during acute oxidative stress in brains of mice. We aimed to determine if there were differences in oxidative/antioxidative status upon hyperoxia in brains of reproductively senescent CBA/H mice in order to elucidate some of the possible mechanisms of lifespan regulation. MATERIAL AND METHODS The brains of 12-month-old male and female CBA/H mice (n=9 per sex and treatment) subjected to 18-h hyperoxia were evaluated for lipid peroxidation (LPO), antioxidative enzyme expression and activity - superoxide dismutase 1 and 2 (Sod-1, Sod-2), catalase (Cat), glutathione peroxidase 1 (Gpx-1), heme-oxygenase 1 (Ho-1), nad NF-E2-related factor 2 (Nrf2), and for 2-deoxy-2-[18F] fluoro-D-glucose (18FDG) uptake.

Unsupervised segmentation of low-contrast multichannel images: discrimination of tissue components in microscopic images of unstained specimens.

Low-contrast images, such as color microscopic images of unstained histological specimens, are composed of objects with highly correlated spectral profiles. Such images are very hard to segment. Here, we present a method that nonlinearly maps low-contrast color image into an image with an increased number of non-physical channels and a decreased correlation between spectral profiles.

The role of 17β-estradiol in the regulation of antioxidant enzymes via the Nrf2-Keap1 pathway in the livers of CBA/H mice.

Aims: We aimed to explore the impact of surgical 17β-estradiol (E2) deprivation/administration on the expression of antioxidant enzymes with an emphasis on the alteration of the NF-E2-related factor 2/Kelch-like ECH-associated protein 1 (Nrf2/Keap1) pathway under physiological conditions in the livers of CBA/H mice of both sexes.

Main Methods: Hepatic oxidative stress markers were determined by measuring lipid peroxidation and DNA damage using the comet assay. The expression and activities of two isoforms of superoxide dismutase (Sod-1, Sod-2) and catalase (Cat) were studied using real-time PCR, Western blot and spectrophotometrical analyses.

Mononucleotide repeats in the SMAD4 gene promoter in colon carcinoma tissue of Croatian patients.

This study was aimed at the analysis of mononucleotide repeats -462T(15) and -4T(12) in the SMAD4 gene promoter in sporadic colon adenocarcinoma tissue of Croatian patients. The analysis has included 60 pairs of samples of colon tumor and adjacent normal tissue. The number of thymidines in the tracts -462T(15) and -4T(12) of the SMAD4 gene promoter was determined by PCR with fluorescently labeled primers followed by the analysis of obtained DNA fragments by capillary electrophoresis.

Female headstart in resistance to hyperoxia-induced oxidative stress in mice.

Increased oxygen concentration (hyperoxia) induces oxidative damage of tissues and organs. Oxygen toxicity in hyperoxia is controlled by factors such as sex, age, tissue, strain and hormones. In most species females show lower incidence of some age-related pathologies linked with oxidative stress, which has been attributed to a beneficial effect of ovarian hormones.

Alzheimer's disease and type 2 diabetes: the association study of polymorphisms in tumor necrosis factor-alpha and apolipoprotein E genes.

Type 2 diabetes (T2D) and Alzheimer's disease (AD) are two progressive disorders with high prevalence worldwide. Polymorphisms in tumor necrosis factor-alpha (TNF-α) and apolipoprotein E (ApoE) genes might be associated with both T2D and AD, representing possible genetic markers for the development of the AD in subjects with T2D. The aim was to determine ApoE and G-308A TNF-α gene polymorphisms in unrelated Croatian Caucasians: 207 patients with sporadic AD, 196 T2D patients and 456 healthy controls.

Rational variety mapping for contrast-enhanced nonlinear unsupervised segmentation of multispectral images of unstained specimen.

A methodology is proposed for nonlinear contrast-enhanced unsupervised segmentation of multispectral (color) microscopy images of principally unstained specimens. The methodology exploits spectral diversity and spatial sparseness to find anatomical differences between materials (cells, nuclei, and background) present in the image. It consists of rth-order rational variety mapping (RVM) followed by matrix/tensor factorization.

K-ras and Dpc4 mutations in chronic pancreatitis: case series.

Aim: To assess whether alterations in the K-ras, p53, and DPC4 genes are present in pancreatitis, a potential precancerous condition that can progress to pancreatic adenocarcinoma. To investigate the alterations occurring at hot spots of K-ras (exon 1), p53 (exons 5 and 7), and DPC4 (exons 8, 10 and 11).

Methods: In 10 patients with acute and 22 with chronic pancreatitis, without pancreatic intraepithelial neoplasia (PanIN), DNA was isolated from paraffin embedded tissue samples.

nm23-H1 expression and loss of heterozygosity in colon adenocarcinoma.

Background: The discovery that genetic alterations in oncogenes and tumour suppressor genes accompany tumour formation in many human tumours has encouraged the search for genes that promote or suppress tumour spread and metastasis; nm23 is a promising candidate for a metastasis suppressing gene.

Aims: To evaluate whether expression of nm23-H1 protein or loss of heterozygosity (LOH) of the nm23-H1 gene is associated with colon cancer progression.

Materials/methods: Paraffin wax embedded tissue sections were analysed immunohistochemically.

Infrequent alteration of the DPC4 tumor suppressor gene in renal cell carcinoma.

The aim of this study was to investigate the alterations in the DPC4 tumor suppressor gene in renal cell carcinoma (RCC). The study included 32 tumor specimens from Croatian patients with a diagnosis of RCC. Loss of heterozygosity (LOH) was investigated using three specific oligonucleotide primers for the three DPC4 polymorphic markers.

Status of the DPC4 tumor suppressor gene in sporadic colon adenocarcinoma of Croatian patients: identification of a novel somatic mutation.

Loss of heterozygosity (LOH) of loci on chromosome 18q occurs in a majority of colorectal cancers. The DPC4 (Smad4) tumor suppressor gene, located at 18q21.1, may be a predisposing gene for Juvenile Polyposis Syndrome.

Presence of c-Myc protein in murine myeloid leukaemia cells during growth and after irradiation.

Myeloid leukaemia (ML) is strain specific for RFM mice, which were used in these experiments. We investigated the presence of c-myc protein during the growth of ML and after irradiation of leukaemic cells. Leukaemic spleen cells were investigated 9 (nonterminal phase NTP) or 12 days (terminal phase TP) after the injection of ML cells.